Science.gov

Sample records for qiu ping li

  1. Ping-pong auto-zero amplifier with glitch reduction

    DOEpatents

    Larson, Mark R.

    2008-01-22

    A ping-pong amplifier with reduced glitching is described. The ping-pong amplifier includes a nulling amplifier coupled to a switching network. The switching network is used to auto-zero a ping amplifier within a ping-pong amplifier. The nulling amplifier drives the output of a ping amplifier to a proper output voltage level during auto-zeroing of the ping amplifier. By being at a proper output voltage level, glitches associated with transitioning between a ping amplifier and a pong amplifier are reduced or eliminated.

  2. Complete Subsurface Elemental Composition Measurements with PING

    NASA Astrophysics Data System (ADS)

    Parsons, A. M.

    2012-06-01

    The Probing In situ with Neutrons and Gamma rays (PING) instrument will measure the complete bulk elemental composition of the subsurface of Mars down to ~ 1 m depth without the need for contacting the surface or extracting samples.

  3. Complete Subsurface Elemental Composition Measurements With PING

    NASA Technical Reports Server (NTRS)

    Parsons, A. M.

    2012-01-01

    The Probing In situ with Neutrons and Gamma rays (PING) instrument will measure the complete bulk elemental composition of the subsurface of Mars as well as any other solid planetary body. PING can thus be a highly effective tool for both detailed local geochemistry science investigations and precision measurements of Mars subsurface reSOurces in preparation for future human exploration. As such, PING is thus fully capable of meeting a majority of both ncar and far term elements in Challenge #1 presented for this conference. Measuring the ncar subsurface composition of Mars will enable many of the MEPAG science goals and will be key to filling an important Strategic Knowledge Gap with regard to In situ Resources Utilization (ISRU) needs for human exploration. [1, 2] PING will thus fill an important niche in the Mars Exploration Program.

  4. mPing: The bursting transposon

    PubMed Central

    Naito, Ken; Monden, Yuki; Yasuda, Kanako; Saito, Hiroki; Okumoto, Yutaka

    2014-01-01

    Though transposable elements (TEs) have been considered as an efficient source of evolution, it has never been possible to test this hypothesis because most of TE insertions had occurred millions of years ago, or because currently active TEs have very few copies in a host genome. However, mPing, the first active DNA transposon in rice, was revealed to hold a key to answer this question. mPing has attained high copy numbers and still retained very high activity in a traditional rice strain, which enabled direct observation of behavior and impact of a bursting TE. A comprehensive analysis of mPing insertion sites has revealed it avoids exons but prefers promoter regions and thus moderately affects transcription of neighboring genes. Some of the mPing insertions have introduced possibly useful expression profile to adjacent genes that indicated TE’s potential in de novo formation of gene regulatory network. PMID:25053919

  5. Multiple ping sonar accuracy improvement using robust motion estimation and ping fusion.

    PubMed

    Yu, Lian; Neretti, Nicola; Intrator, Nathan

    2006-04-01

    Noise degrades the accuracy of sonar systems. We demonstrate a practical method for increasing the effective signal-to-noise ratio (SNR) by fusing time delay information from a burst of multiple sonar pings. This approach can be useful when there is no relative motion between the sonar and the target during the burst of sonar pinging. Otherwise, the relative motion degrades the fusion and therefore, has to be addressed before fusion can be used. In this paper, we present a robust motion estimation algorithm which uses information from multiple receivers to estimate the relative motion between pings in the burst. We then compensate for motion, and show that the fusion of information from the burst of motion compensated pings improves both the resilience to noise and sonar accuracy, consequently increasing the operating range of the sonar system.

  6. PingER History and Methodology

    SciTech Connect

    Cottrell, L

    2003-10-01

    This paper describes the methodology of the PingER toolkit/project. It provides some examples of how the results have been used to identify evolutionary changes in WAN response times and connectivity quality over the past 10 years, as well as some of the challenges faced in maintaining and deploying the system.

  7. [Development idea and practice of Qiu Mao-liang's acupuncture diagnosis and treatment].

    PubMed

    Zhao, Jing-sheng

    2014-11-01

    Professor Qiu Mao-liang is considered as one of the representatives in the renaissance and development of acupuncture and moxibustion in the 20th century, whose academic characteristics could be summarized as "sticking to tradition and absorbing new knowledge". The practice ideas, methods and influence factors that were presented in acupuncture clinical practice are analyzed in this paper, from which development tendency and practice pattern of modern acupuncture clinical practice are discussed.

  8. Early Embryogenesis-Specific Expression of the Rice Transposon Ping Enhances Amplification of the MITE mPing

    PubMed Central

    Teramoto, Shota; Tsukiyama, Takuji; Okumoto, Yutaka; Tanisaka, Takatoshi

    2014-01-01

    Miniature inverted-repeat transposable elements (MITEs) are numerically predominant transposable elements in the rice genome, and their activities have influenced the evolution of genes. Very little is known about how MITEs can rapidly amplify to thousands in the genome. The rice MITE mPing is quiescent in most cultivars under natural growth conditions, although it is activated by various stresses, such as tissue culture, gamma-ray irradiation, and high hydrostatic pressure. Exceptionally in the temperate japonica rice strain EG4 (cultivar Gimbozu), mPing has reached over 1000 copies in the genome, and is amplifying owing to its active transposition even under natural growth conditions. Being the only active MITE, mPing in EG4 is an appropriate material to study how MITEs amplify in the genome. Here, we provide important findings regarding the transposition and amplification of mPing in EG4. Transposon display of mPing using various tissues of a single EG4 plant revealed that most de novo mPing insertions arise in embryogenesis during the period from 3 to 5 days after pollination (DAP), and a large majority of these insertions are transmissible to the next generation. Locus-specific PCR showed that mPing excisions and insertions arose at the same time (3 to 5 DAP). Moreover, expression analysis and in situ hybridization analysis revealed that Ping, an autonomous partner for mPing, was markedly up-regulated in the 3 DAP embryo of EG4, whereas such up-regulation of Ping was not observed in the mPing-inactive cultivar Nipponbare. These results demonstrate that the early embryogenesis-specific expression of Ping is responsible for the successful amplification of mPing in EG4. This study helps not only to elucidate the whole mechanism of mPing amplification but also to further understand the contribution of MITEs to genome evolution. PMID:24921928

  9. Launch Creativity with Ping-Pong Ball Challenge

    ERIC Educational Resources Information Center

    Kornoelje, Joanne; Roman, Harry T.

    2011-01-01

    Educators at Thomas A. Edison Middle School have worked together to bring invention information and activities to life. One activity in particular, Ping-Pong Ball Invention Challenge, has proven a great success. The Ping-Pong Ball Invention Challenge was inspired by the basic rules for PBS's "Design Squad"'s "Pop Fly" activity. In this article,…

  10. Solution of nonlinear Gribov-Levin-Ryskin-Mueller-Qiu evolution equation for gluon distribution function

    NASA Astrophysics Data System (ADS)

    Devee, Mayuri; Sarma, J. K.

    2014-03-01

    In this paper we have determined the behavior of gluon distribution function by solving the Gribov-Levin-Reskin-Mueller-Qiu (GLR-MQ) evolution equation,which is nonlinear in gluon density. The moderate Q2 behavior of G(x, t), where t = ln(Q2/Λ2), is obtained by employing the Regge like behaviour of gluon distribution function at small-x. Here Q2 behavior of nonlinear gluon distribution function is investigated for small values x = 10-2, 10-3, 10-4 and 10-5 rexpectively. Our predictions are compared with different parametrisations and are found in good agreement. It is observed from our results that with the nonlinear corrections incorporated, the strong growth of G(x,t) that corresponds to the linear QCD evolution equation is slowed down. Moreover essential taming of gluon distribution function is observed for R = 2 GeV-1 as expected.

  11. High Sensitivity Subsurface Elemental Composition Measurements with PING

    NASA Astrophysics Data System (ADS)

    Parsons, A. M.; Bodnarik, J. G.; Evans, L. G.; McClanahan, T. P.; Namkung, M.; Nowicki, S. F.; Schweitzer, J. S.; Starr, R. D.; Trombka, J. I.

    2012-10-01

    The Probing In situ with Neutrons and Gamma rays (PING) instrument, with its PNG and gamma and neutron spectrometers, is a promising technology for measuring the bulk elemental composition of the subsurface of any rocky body in the solar system.

  12. Measuring the Digital Divide with PingER

    SciTech Connect

    Cottrell, L.

    2003-10-01

    We introduce the PingER project/toolkit and show its relevance to monitoring sites in developing countries. We then show results from PingER that illustrate the extent of the Digital Divide in terms of Internet performance between developed and developing regions, which developing regions are catching up, keeping up, or falling behind and the magnitude of the differences in performance between developed regions and developing regions.

  13. GenePING: secure, scalable management of personal genomic data

    PubMed Central

    Adida, Ben; Kohane, Isaac S

    2006-01-01

    Background Patient genomic data are rapidly becoming part of clinical decision making. Within a few years, full genome expression profiling and genotyping will be affordable enough to perform on every individual. The management of such sizeable, yet fine-grained, data in compliance with privacy laws and best practices presents significant security and scalability challenges. Results We present the design and implementation of GenePING, an extension to the PING personal health record system that supports secure storage of large, genome-sized datasets, as well as efficient sharing and retrieval of individual datapoints (e.g. SNPs, rare mutations, gene expression levels). Even with full access to the raw GenePING storage, an attacker cannot discover any stored genomic datapoint on any single patient. Given a large-enough number of patient records, an attacker cannot discover which data corresponds to which patient, or even the size of a given patient's record. The computational overhead of GenePING's security features is a small constant, making the system usable, even in emergency care, on today's hardware. Conclusion GenePING is the first personal health record management system to support the efficient and secure storage and sharing of large genomic datasets. GenePING is available online at , licensed under the LGPL. PMID:16638151

  14. Calculation of weighted averages approach for the estimation of ping tolerance values

    USGS Publications Warehouse

    Silalom, S.; Carter, J.L.; Chantaramongkol, P.

    2010-01-01

    A biotic index was created and proposed as a tool to assess water quality in the Upper Mae Ping sub-watersheds. The Ping biotic index was calculated by utilizing Ping tolerance values. This paper presents the calculation of Ping tolerance values of the collected macroinvertebrates. Ping tolerance values were estimated by a weighted averages approach based on the abundance of macroinvertebrates and six chemical constituents that include conductivity, dissolved oxygen, biochemical oxygen demand, ammonia nitrogen, nitrate nitrogen and orthophosphate. Ping tolerance values range from 0 to 10. Macroinvertebrates assigned a 0 are very sensitive to organic pollution while macroinvertebrates assigned 10 are highly tolerant to pollution.

  15. [Chinese medicine discovered in "Jing Ping Mei"].

    PubMed

    Yoshimoto, S

    1992-01-01

    Using a novel written in the Ming dynasty and dealing with the time of Zong dynasty, I tried to assess the common medical services available in those days. The name of the novel is "Jing Ping Mei". The book contains many descriptions of sexual acts and had long been listed as an erotic novel, but by studying its contents closely we came to see that the life of the people in olden times is vividly and concisely illustrated. When a person became critically ill, first a doctor was called in, and then the so-called "three nuns and six old women" gave herb drugs or moxa treatments. They sometimes worked as midwives, said prayers, or acted as a shaman. They lived closely with the family of Xi Men Qing. If these women were unsuccessful, taoists came to pray and perform rituals. Finally the diviner or fortune-teller (yin-yang master) made preparations to allow free passage to the other world. Then the date of the funeral, position of the tomb, and the fate of the person were told. These steps are all described in the book. The doctor deals with many departments, such Ren, He, Liu. Bogus doctors such as Hu, and Zhao also appear in the stories. They are generally called bell doctors or wandering doctors. They are regarded as second-class doctors, but they were more popular with the common people and were engaged in medical services. In fact, it seems that they were respected by the townspeople. In some ways, they were associated with taoism. ...

  16. Subsurface In situ elemental composition measurements with PING

    NASA Astrophysics Data System (ADS)

    Parsons, A.; McClanahan, T.; Bodnarik, J.; Evans, L.; Nowicki, S.; Schweitzer, J.; Starr, R.

    This paper describes the Probing In situ with Neutron and Gamma rays (PING) instrument, that can measure the subsurface elemental composition in situ for any rocky body in the solar system without the need for digging into the surface. PING consists of a Pulsed Neutron Generator (PNG), a gamma ray spectrometer and neutron detectors. Subsurface elements are stimulated by high-energy neutrons to emit gamma rays at characteristic energies. This paper will show how the detection of these gamma rays results in a measurement of elemental composition. Examples of the basalt to granite ratios for aluminum and silicon abundance are provided.

  17. Subsurface In Situ Elemental Composition Measurements with PING

    NASA Technical Reports Server (NTRS)

    Parsons, Ann; McClanahan, Timothy; Bodnarik, Julia; Evans, Larry; Nowicki, Suzanne; Schweitzer, Jeffrey; Starr, Richard

    2013-01-01

    This paper describes the Probing In situ with Neutron and Gamma rays (PING) instrument, that can measure the subsurface elemental composition in situ for any rocky body in the solar system without the need for digging into the surface. PING consists of a Pulsed Neutron Generator (PNG), a gamma ray spectrometer and neutron detectors. Subsurface elements are stimulated by high-energy neutrons to emit gamma rays at characteristic energies. This paper will show how the detection of these gamma rays results in a measurement of elemental composition. Examples of the basalt to granite ratios for aluminum and silicon abundance are provided.

  18. Riffs on the Infinite Ping-Pong Ball Conundrum

    ERIC Educational Resources Information Center

    Mamolo, Ami; Bogart, Tristram

    2011-01-01

    This article presents a novel re-conceptualisation to a well-known problem--The Ping-Pong Ball Conundrum. We introduce a variant of this super-task by considering it through the lens of "measuring infinity"--a conceptualisation of infinity that extrapolates measuring properties of numbers, rather than cardinal properties. This approach is…

  19. Moment of Inertia of a Ping-Pong Ball

    ERIC Educational Resources Information Center

    Cao, Xian-Sheng

    2012-01-01

    This note describes how to theoretically calculate and experimentally measure the moment of inertia of a Ping-Pong[R] ball. The theoretical calculation results are in good agreement with the experimental measurements that can be reproduced in an introductory physics laboratory.

  20. Washington Commentary: Endless Ping-Pong over Math Education

    ERIC Educational Resources Information Center

    Lewis, Anne C.

    2005-01-01

    Ever since the charter school movement became big news, Anne C. Lewis has refrained from writing about it very much because it seemed more like covering each hit in a Ping-Pong game. As study and counter-study rolled off the presses and into the press releases, the substance became less and less relevant. Each new study was always sure to be…

  1. Intelligent Management of Intelligence Agencies: Beyond Accountability Ping-Pong

    ERIC Educational Resources Information Center

    Tetlock, Philip E.; Mellers, Barbara A.

    2011-01-01

    The intelligence community (IC) is asked to predict outcomes that may often be inherently unpredictable--and is blamed for the inevitable forecasting failures, be they false positives or false negatives. To move beyond blame games of accountability ping-pong that incentivize bureaucratic symbolism over substantive reform, it is necessary to reach…

  2. Single-ping ADCP measurements in the Strait of Gibraltar

    NASA Astrophysics Data System (ADS)

    Sammartino, Simone; García Lafuente, Jesús; Naranjo, Cristina; Sánchez Garrido, José Carlos; Sánchez Leal, Ricardo

    2016-04-01

    In most Acoustic Doppler Current Profiler (ADCP) user manuals, it is widely recommended to apply ensemble averaging of the single-pings measurements, in order to obtain reliable observations of the current speed. The random error related to the single-ping measurement is typically too high to be used directly, while the averaging operation reduces the ensemble error of a factor of approximately √N, with N the number of averaged pings. A 75 kHz ADCP moored in the western exit of the Strait of Gibraltar, included in the long-term monitoring of the Mediterranean outflow, has recently served as test setup for a different approach to current measurements. The ensemble averaging has been disabled, while maintaining the internal coordinate conversion made by the instrument, and a series of single-ping measurements has been collected every 36 seconds during a period of approximately 5 months. The huge amount of data has been fluently handled by the instrument, and no abnormal battery consumption has been recorded. On the other hand a long and unique series of very high frequency current measurements has been collected. Results of this novel approach have been exploited in a dual way: from a statistical point of view, the availability of single-ping measurements allows a real estimate of the (a posteriori) ensemble average error of both current and ancillary variables. While the theoretical random error for horizontal velocity is estimated a priori as ˜2 cm s‑1 for a 50 pings ensemble, the value obtained by the a posteriori averaging is ˜15 cm s‑1, with an asymptotical behavior starting from an averaging size of 10 pings per ensemble. This result suggests the presence of external sources of random error (e.g.: turbulence), of higher magnitude than the internal sources (ADCP intrinsic precision), which cannot be reduced by the ensemble averaging. On the other hand, although the instrumental configuration is clearly not suitable for a precise estimation of turbulent

  3. [Doctor HUANG Shi-ping's acupuncture with golden needles].

    PubMed

    Chen, Teng-Fei; Ma, Zeng-Bin; Xin, Si-Yuan; Zhu, Jiang

    2013-08-01

    Taking Doctor HUANG Shi-ping as the representative, the school of Huang's golden needle is based on Chinese martial art. Golden needles are adopted as main tool. Attaching great importance on the combination of acupuncture and moxibustioin, it is also characterized with penetrating needling with long needles. Through the development of three generations, it once outshone other schools in the field of acupuncture, and became famous all over the world. It made great contribution to the development of the course of acupuncture. However, with the development of the history, the form of acupuncture education as well as apparatus were all undergone an unified reform. Therefore, Doctor HUANG Shi-ping's acupuncture school be lost gradually.

  4. The Pediatric Imaging, Neurocognition, and Genetics (PING) Data Repository.

    PubMed

    Jernigan, Terry L; Brown, Timothy T; Hagler, Donald J; Akshoomoff, Natacha; Bartsch, Hauke; Newman, Erik; Thompson, Wesley K; Bloss, Cinnamon S; Murray, Sarah S; Schork, Nicholas; Kennedy, David N; Kuperman, Joshua M; McCabe, Connor; Chung, Yoonho; Libiger, Ondrej; Maddox, Melanie; Casey, B J; Chang, Linda; Ernst, Thomas M; Frazier, Jean A; Gruen, Jeffrey R; Sowell, Elizabeth R; Kenet, Tal; Kaufmann, Walter E; Mostofsky, Stewart; Amaral, David G; Dale, Anders M

    2016-01-01

    The main objective of the multi-site Pediatric Imaging, Neurocognition, and Genetics (PING) study was to create a large repository of standardized measurements of behavioral and imaging phenotypes accompanied by whole genome genotyping acquired from typically-developing children varying widely in age (3 to 20 years). This cross-sectional study produced sharable data from 1493 children, and these data have been described in several publications focusing on brain and cognitive development. Researchers may gain access to these data by applying for an account on the PING portal and filing a data use agreement. Here we describe the recruiting and screening of the children and give a brief overview of the assessments performed, the imaging methods applied, the genetic data produced, and the numbers of cases for whom different data types are available. We also cite sources of more detailed information about the methods and data. Finally we describe the procedures for accessing the data and for using the PING data exploration portal.

  5. Distorted genetic segregation of the transposon mPing at the long arm of chromosome 12 in rice

    PubMed Central

    Horibata, Akira; Kakikubo, Yoshihiro; Kato, Tsuneo

    2015-01-01

    A class II transposable element, mPing exists in the rice genome ubiquitously and can transpose even in ordinary cultivation conditions. A copy of mPing was identified at the long arm of chromosome 12. In reciprocal backcrossed F1s between a heterozygote and a homozygote without mPing, the male gametes with this mPing from heterozygotes were transmitted to the next generation at a lower frequency than those without mPing, resulting in distorted genetic segregation in self-fertilized progenies, as well as in F1s after backcrossing. Pollens with mPing tended to germinate on stigma less than those without mPing. These results, however, could not explain the lower transmission of male gametes with mPing. In addition, no excision of mPing was observed in a homozygote. Thus, it was suggested that male gametes with mPing were eliminated partly from pollination to fertilization by negative competition against male gametes without mPing. Less formation of microspores with mPing in meiosis could also be a cause for the distorted segregation, although this could not be examined. At least two ORFs, whose functions have not been identified, are located near this mPing. It is plausible that either of these ORFs or both are necessary for the normal functioning of male gametes. PMID:26366117

  6. Ping-pong polymerization by allylation and hydroformylation for alternating vinyl alcohol-vinyl monomer copolymers.

    PubMed

    Ito, Shingo; Noguchi, Masaki; Nozaki, Kyoko

    2012-11-01

    Inspired by the enzymatic ping-pong mechanism, we designed a novel "ping-pong polymerization", which employs allylation and hydroformylation in an iterative and alternating manner. Thus, alternating and regioregular vinyl alcohol-vinyl monomer copolymers possessing multiple hydroxy groups in a periodical manner were successfully synthesized.

  7. Intelligent management of intelligence agencies: beyond accountability ping-pong.

    PubMed

    Tetlock, Philip E; Mellers, Barbara A

    2011-09-01

    The intelligence community (IC) is asked to predict outcomes that may often be inherently unpredictable-and is blamed for the inevitable forecasting failures, be they false positives or false negatives. To move beyond blame games of accountability ping-pong that incentivize bureaucratic symbolism over substantive reform, it is necessary to reach bipartisan agreements on performance indicators that are transparent enough to reassure clashing elites (to whom the IC must answer) that estimates have not been politicized. Establishing such transideological credibility requires (a) developing accuracy metrics for decoupling probability and value judgments; (b) using the resulting metrics as criterion variables in validity tests of the IC's selection, training, and incentive systems; and (c) institutionalizing adversarial collaborations that conduct level-playing-field tests of clashing perspectives.

  8. Instability in Fermi-Ulam `ping-pong' problem

    NASA Astrophysics Data System (ADS)

    Zharnitsky, Vadim

    1998-11-01

    The motion of a classical particle bouncing elastically between two parallel walls, with one of the walls undergoing a periodic motion is considered. This problem, called Fermi-Ulam `ping-pong', is known to possess only bounded solutions if the motion of the wall is sufficiently smooth 0951-7715/11/6/003/img1, where p(t) is the position of the wall. It is shown that the stability result does not hold if p(t) is just a continuous function by providing two examples of instability. The second example also answers the question posed in Levi M and Zehnder E (1995 Boundedness of solutions for quasiperiodic potentials SIAM J. Math. Anal. 26 1233-56) about instability in the `squash player's' problem. Both examples are constructed for an equivalent system with motionless walls. The reduced system is obtained using the transformation, developed in the heat equation theory to solve the moving boundary problem.

  9. Planetary Geochemistry Techniques: Probing In-Situ with Neutron and Gamma Rays (PING) Instrument

    NASA Astrophysics Data System (ADS)

    Parsons, A.; Bodnarik, J.; Burger, D.; Evans, L.; Floyd, S.; Lim, L.; McClanahan, T.; Namkung, M.; Nowicki, S.; Schweitzer, J.; Starr, R.; Trombka, J.

    2011-03-01

    The Probing in situ with Neutrons and Gamma rays (PING) instrument uses a pulsed neutron generator and neutron and gamma-ray detectors to measure the surface and subsurface elemental composition of planetary bodies without the need for drilling.

  10. PING Gamma Ray and Neutron Measurements of a Meter-Scale Carbonaceous Asteroid Analog Material

    NASA Astrophysics Data System (ADS)

    Bodnarik, J. G.; Schweitzer, J. S.; Parsons, A. M.; Evans, L. G.; Starr, R. D.

    2012-03-01

    We compare PING experimental data from the asteroid stimulant, basalt, and granite structures with computer simulations for a homogenous carbonaceous asteroid to show that the asteroid simulant's response closely approximates a carbonaceous asteroid.

  11. Bitz, Ginoux, Jacobson, Nizkorodov, and Yang Receive 2013 Atmospheric Sciences Ascent Awards: Citation for Ping Yang

    NASA Astrophysics Data System (ADS)

    Webster, Peter J.

    2014-07-01

    The Atmospheric Sciences section of AGU awards one of the five Ascent Awards to Professor Ping Yang of the Department of Atmospheric Sciences at Texas A&M University for significant contributions to atmospheric scattering, radiative transfer, and remote sensing.

  12. Tissue culture-induced transpositional activity of mPing is correlated with cytosine methylation in rice

    PubMed Central

    Ngezahayo, Frédéric; Xu, Chunming; Wang, Hongyan; Jiang, Lily; Pang, Jinsong; Liu, Bao

    2009-01-01

    Background mPing is an endogenous MITE in the rice genome, which is quiescent under normal conditions but can be induced towards mobilization under various stresses. The cellular mechanism responsible for modulating the activity of mPing remains unknown. Cytosine methylation is a major epigenetic modification in most eukaryotes, and the primary function of which is to serve as a genome defense system including taming activity of transposable elements (TEs). Given that tissue-culture is capable of inducing both methylation alteration and mPing transposition in certain rice genotypes, it provides a tractable system to investigate the possible relationship between the two phenomena. Results mPing transposition and cytosine methylation alteration were measured in callus and regenerated plants in three rice (ssp. indica) genotypes, V14, V27 and R09. All three genotypes showed transposition of mPing, though at various frequencies. Cytosine methylation alteration occurred both at the mPing-flanks and at random loci sampled globally in callus and regenerated plants of all three genotypes. However, a sharp difference in the changing patterns was noted between the mPing-flanks and random genomic loci, with a particular type of methylation modification, i.e., CNG hypermethylation, occurred predominantly at the mPing-flanks. Pearson's test on pairwise correlations indicated that mPing activity is positively correlated with specific patterns of methylation alteration at random genomic loci, while the element's immobility is positively correlated with methylation levels of the mPing's 5'-flanks. Bisulfite sequencing of two mPing-containing loci showed that whereas for the immobile locus loss of CG methylation in the 5'-flank was accompanied by an increase in CHG methylation, together with an overall increase in methylation of all three types (CG, CHG and CHH) in the mPing-body region, for the active locus erasure of CG methylation in the 5'-flank was not followed by such a

  13. PI-ping - Benchmark Tool for Testing Latencies and Throughput in Operating Systems

    NASA Astrophysics Data System (ADS)

    Abaffy, J.; Krajčovič, T.

    In this paper we present a benchmark tool called PI-ping that can be used to compare real-time performance of operating systems. It uses two types of processes that are common in operating systems - interactive tasks demanding low latencies and also processes demanding high CPU utilization. Most operating systems have to perform well in both conditions and the goal is to achieve the highest throughput when keeping the latencies within a reasonable interval. PI-ping measures the latencies of an interactive process when the system is under heavy computational load. Using PI-ping benchmark tool we are able to compare different operating systems and we attest the functionality of it using two very common operating systems - Linux and FreeBSD.

  14. [An exploration of the training of medical talents in China for Ryukyu islands based on the Liu qiu bai wen (One Hundred Question of Ryukyu)].

    PubMed

    He, Lanping

    2014-09-01

    Ryukyu sent more than 20 batches of returned students to China for studying during the Ming and Qing Dynasties, many of whom were studying medicine. Liu qiu bai wen (One Hundred Question of Ryukyu) was the record of discussion between Cao Cunxin, a famous doctor of the Qing Dynasty, and the oversea disciples of Lü Fengyi from Ryukyu. However, it was not only a medical book, but also served as an important witness on overseas dissemination of TCM, and the fresh case of Chinese training medical talented persons for Ryukyu. Training Ryukyu medical students in the Qing Dynasty was good for the expansion of Chinese medicine in the Ryukyu, and promoted the development and social progress of the Ryukyu medicine and health, made a significant contribution to maintain the friendly relationship between the two countries. PMID:25579213

  15. Creating Accessible Science Museums with User-Activated Environmental Audio Beacons (Ping!)

    ERIC Educational Resources Information Center

    Landau, Steven; Wiener, William; Naghshineh, Koorosh; Giusti, Ellen

    2005-01-01

    In 2003, Touch Graphics Company carried out research on a new invention that promises to improve accessibility to science museums for visitors who are visually impaired. The system, nicknamed Ping!, allows users to navigate an exhibit area, listen to audio descriptions, and interact with exhibits using a cell phone-based interface. The system…

  16. The Probing In-Situ With Neutron and Gamma Rays (PING) Instrument for Planetary Composition Measurements

    NASA Technical Reports Server (NTRS)

    Parsons, A.; Bodnarik, J.; Evans, L.; McClanahan, T.; Namkung, M.; Nowicki, S.; Schweitzer, J.; Starr, R.

    2012-01-01

    The Probing In situ with Neutrons and Gamma rays (PING) instrument (formerly named PNG-GRAND) [I] experiment is an innovative application of the active neutron-gamma ray technology successfully used in oil field well logging and mineral exploration on Earth over many decades. The objective of our active neutron-gamma ray technology program at NASA Goddard Space Flight Center (NASA/GSFC) is to bring PING to the point where it can be flown on a variety of surface lander or rover missions to the Moon, Mars, Venus, asteroids, comets and the satellites of the outer planets and measure their bulk surface and subsurface elemental composition without the need to drill into the surface. Gamma-Ray Spectrometers (GRS) have been incorporated into numerous orbital planetary science missions. While orbital measurements can map a planet, they have low spatial and elemental sensitivity due to the low surface gamma ray emission rates reSUlting from using cosmic rays as an excitation source, PING overcomes this limitation in situ by incorporating a powerful neutron excitation source that permits significantly higher elemental sensitivity elemental composition measurements. PING combines a 14 MeV deuterium-tritium Pulsed Neutron Generator (PNG) with a gamma ray spectrometer and two neutron detectors to produce a landed instrument that can determine the elemental composition of a planet down to 30 - 50 cm below the planet's surface, The penetrating nature of .5 - 10 MeV gamma rays and 14 MeV neutrons allows such sub-surface composition measurements to be made without the need to drill into or otherwise disturb the planetary surface, thus greatly simplifying the lander design, We are cun'ently testing a PING prototype at a unique outdoor neutron instrumentation test facility at NASA/GSFC that provides two large (1.8 m x 1.8 m x ,9 m) granite and basalt test formations placed outdoors in an empty field, Since an independent trace elemental analysis has been performed on both these

  17. Loss of l(3)mbt leads to acquisition of the ping-pong cycle in Drosophila ovarian somatic cells

    PubMed Central

    Sumiyoshi, Tetsutaro; Sato, Kaoru; Yamamoto, Hitomi; Iwasaki, Yuka W.; Siomi, Haruhiko; Siomi, Mikiko C.

    2016-01-01

    In Drosophila germ cells, PIWI-interacting RNAs (piRNAs) are amplified through a PIWI slicer-dependent feed-forward loop termed the ping-pong cycle, yielding secondary piRNAs. However, the detailed mechanism remains poorly understood, largely because an ex vivo model system amenable to biochemical analyses has not been available. Here, we show that CRISPR-mediated loss of function of lethal (3) malignant brain tumor [l(3)mbt] leads to ectopic activation of the germ-specific ping-pong cycle in ovarian somatic cells. Perinuclear foci resembling nuage, the ping-pong center, appeared following l(3)mbt mutation. This activation of the ping-pong machinery in cultured cells will greatly facilitate elucidation of the mechanism underlying secondary piRNA biogenesis in Drosophila. PMID:27474440

  18. Ping-pong gaze” secondary to monoamine oxidase inhibitor overdose

    PubMed Central

    Attaway, Amy; Sroujieh, Laila; Mersfelder, Tracey L.; Butler, Christopher; Ouellette, Daniel

    2016-01-01

    An infrequent manifestation of monoamine oxidase inhibitor (MAOI) toxicity is “ping-pong gaze” (PPG). We describe the case of a 26-year-old female who was found unresponsive after taking 40 tablets of phenelzine. On presentation to the hospital, her eyes were moving in characteristic “ping pong” fashion. After 6 hours her gaze terminated. The following day her neurologic exam was benign and she had no long-term sequelae. While the etiology of PPG is unknown, it is most often seen with irreversible structural brain damage. However, a detailed literature review revealed that previous cases of MAOI toxicity where the patient survived have all had complete neurologic recovery. PMID:27127395

  19. Planetary Geochemistry Techniques: Probing In-Situ with Neutron and Gamma Rays (PING) Instrument

    NASA Technical Reports Server (NTRS)

    Parsons, A.; Bodnarik, J.; Burger, D.; Evans, L.; Floyd, S.; Lin, L.; McClanahan, T.; Nankung, M.; Nowicki, S.; Schweitzer, J.; Starr, R.; Trombka, J.

    2011-01-01

    The Probing In situ with Neutrons and Gamma rays (PING) instrument is a promising planetary science application of the active neutron-gamma ray technology so successfully used in oil field well logging and mineral exploration on Earth. The objective of our technology development program at NASA Goddard Space Flight Center's (NASA/GSFC) Astrochemistry Laboratory is to extend the application of neutron interrogation techniques to landed in situ planetary composition measurements by using a 14 MeV Pulsed Neutron Generator (PNG) combined with neutron and gamma ray detectors, to probe the surface and subsurface of planetary bodies without the need to drill. We are thus working to bring the PING instrument to the point where it can be flown on a variety of surface lander or rover missions to the Moon, Mars, Venus, asteroids, comets and the satellites of the outer planets.

  20. Arbovirus-Derived piRNAs Exhibit a Ping-Pong Signature in Mosquito Cells

    PubMed Central

    Vodovar, Nicolas; Bronkhorst, Alfred W.; van Cleef, Koen W. R.; Miesen, Pascal; Blanc, Hervé; van Rij, Ronald P.; Saleh, Maria-Carla

    2012-01-01

    The siRNA pathway is an essential antiviral mechanism in insects. Whether other RNA interference pathways are involved in antiviral defense remains unclear. Here, we report in cells derived from the two main vectors for arboviruses, Aedes albopictus and Aedes aegypti, the production of viral small RNAs that exhibit the hallmarks of ping-pong derived piwi-associated RNAs (piRNAs) after infection with positive or negative sense RNA viruses. Furthermore, these cells produce endogenous piRNAs that mapped to transposable elements. Our results show that these mosquito cells can initiate de novo piRNA production and recapitulate the ping-pong dependent piRNA pathway upon viral infection. The mechanism of viral-piRNA production is discussed. PMID:22292064

  1. Predictive analysis of landslide susceptibility in the Kao-Ping watershed, Taiwan under climate change conditions

    NASA Astrophysics Data System (ADS)

    Shou, K. J.; Wu, C. C.; Lin, J. F.

    2015-01-01

    Among the most critical issues, climatic abnormalities caused by global warming also affect Taiwan significantly for the past decade. The increasing frequency of extreme rainfall events, in which concentrated and intensive rainfalls generally cause geohazards including landslides and debris flows. The extraordinary Typhoon Morakot hit Southern Taiwan on 8 August 2009 and induced serious flooding and landslides. In this study, the Kao-Ping River watershed was adopted as the study area, and the typical events 2007 Krosa Typhoon and 2009 Morakot Typhoon were adopted to train the susceptibility model. This study employs rainfall frequency analysis together with the atmospheric general circulation model (AGCM) downscaling estimation to understand the temporal rainfall trends, distributions, and intensities in the Kao-Ping River watershed. The rainfall estimates were introduced in the landslide susceptibility model to produce the predictive landslide susceptibility for various rainfall scenarios, including abnormal climate conditions. These results can be used for hazard remediation, mitigation, and prevention plans for the Kao-Ping River watershed.

  2. PING Gamma Ray and Neutron Measurements of a Meter-Sized Carbonaceous Asteroid Analog

    NASA Technical Reports Server (NTRS)

    Bodnarik, J.; Burger, D.; Evans, L.; Floyd, S.; Lim, L.; McClanahan, T.; Namkung, M.; Nowicki, S.; Parsons, A.; Schweitzer, J.; Starr, R.; Trombka, J.

    2011-01-01

    Determining the elemental composition of carbonaceous (spectral type C) asteroids is still one of the basic problems when studying these objects. The only main source of elemental composition information for asteroids is from their optical, NIR and IR properties, which include their spectral reflectance characteristics, albedo, polarization, and the comparison of optical spectroscopy with meteorite groups corresponding to asteroids of every spectral type. Unfortunately, these sources reflect observations from widely contrasting spatial scales that presently yield a void in the continuum of microscopic and macroscopic evidence, a lack of in situ measurement confirmation, and require deeper sensing techniques to discern the nature of these asteroids. The Probing In situ with Neutrons and Gamma rays (PING) instrument is ideally suited to address this problem because it can be used to determine the bulk elemental composition, H and C content, the average atomic weight and density of the surface and subsurface layers of C-type asteroids, and can provide measurements used to determine the difference between and distinguish between different types of asteroids. We are currently developing the PING instrument that combines gamma ray and neutron detectors with a 14 Me V pulsed neutron generator to determine the in-situ bulk elemental abundances and geochemistry of C-type asteroids with a spatial resolution of 1 m down to depths of tens of cm to 1 m. One aspect of the current work includes experimentally testing and optimizing PING on a known meter-sized Columbia River basalt C-type asteroid analog sample that has a similar composition and the same neutron response as that of a C-type asteroid. An important part of this effort focuses on utilizing timing measurements to isolate gamma rays produced by neutron inelastic scattering, neutron capture and delayed activation processes. Separating the gamma ray spectra by nuclear processes results in higher precision and sensitivity

  3. New constraints on the Mae Ping core-complex NW-Thailand: Is the Mae-Ping an Indosinian (Triassic) relict?

    NASA Astrophysics Data System (ADS)

    Palzer, Markus; Oesterle, Juergen; Kloetzli, Urs

    2013-04-01

    The Mae Ping fault zone is seen as one of the major strike-slip shear zones in SE-Asia and is trending NW-SE over 500 km across Thailand. Within this fault zone, a 150 km long and 5 km wide core-complex of ductile deformed amphibolite-facies rocks containing lenses of an older high-grade px-amph-pl paragenesis occurs. These so called Lan Sang Gneisses are named after the outcrops situated in the Lan Sang National Park. Despite several former investigations (Lacassin et al., 1997; Morley et al., 2012) some aspects concerning the time, regime and cause of exhumation remain unclear. Further on, the old relictic granulite-facies paragenesis has never been studied in detail. Older models constitute a restraining bend within a left-lateral regime as the origin of the exhumation of the Lan Sang Gneisses. New detailed structural, petrographical and geochronological investigations of the Lan Sang Gneisses were undertaken to develop different PTt-paths for different rock types within the Lan Sang Gneisses with special emphasis on the lenses of old high grade rocks which probably represent an older lower crust. We use detailed field investigations on a NE-SW profile following a river outcrop in Lan Sang National Park, zircon and monazite ages of three different rock types, structural and petrographical investigations on more than 100 thin sections and electron microprobe analyses and techniques such as geothermometers and -barometers. On the basis of our observations and measurements, we are able to reconstruct and quantify the different prograde and retrograde histories. First results now strongly question the model of a restraining bend and lead us to the conclusion that the origin of the amphibolite-facies deformation may lie in the late Triassic Indosinian orogeny. If this is the case, the importance of the whole Mae-Ping for the lateral Extrusion of SE-Asia during the Himalayan orogeny must be questioned.

  4. Solar X-Ray Spectroscopy And Polarimetry By Instrument Ping-M Onboard Interhelioprobe

    NASA Astrophysics Data System (ADS)

    Kotov, Yury; Dergachev, Valentin; Kochemasov, Alexey; Yurov, Vitaly; Tyshkevich, V.; Glyanenko, Alexander; Savchenko, Mikhail; Lazutkov, Vadim; Skorodumov, Dmitry; Trofimov, Yury; Zakharov, Mikhail; Rubtsov, Igor; Kruglov, Evgeniy

    The instrument PING-M for X-ray spectroscopy and polarimetry of solar full disk radiation is described. It will be the part of scientific instrument set for the InterHelioProbe space mission. Instrument consists of three detectors: the Soft X-ray detector (SXRD), the Hard X-ray detector (HXRD) and Hard X-ray polarimeter (PING-P). Spectrometer SXRD is based on a relatively novel type of semiconductor detector SDD (Silicon Drift Detector) that will operate in the energy range 1.5-25 keV, which is similar to GOES X-Ray Sensor (XRS) region. Unlike GOES the SXRD is capable to measure the energy of each photon with high resolution (better 200 eV at 5.9 keV) and operate with high count rate. The X-ray spectra of solar flares obtained by the SXRD should show evidence of Fe and Fe/Ni line emission and multi-thermal plasma. HXRD operates in energy range 15-150 keV. Fast nonorganic scintillator (is based on LaBr3(Ce)) with good energy resolution (≤12% at 60keV and ≤3.5% at 662keV) is used. Apart from measurement of spectra the value of the break energy point that separates the thermal and non-thermal processes in flare would be revealed. In the talk the results of testing of laboratory models are presented. PING-P Hard X-ray polarimeter consists of active scatterer made of three organic p-terphenyl scintillators and six peripheral scattered radiation detectors made of CsI(Tl) scintillators. Effective area of polarimeter is about 5 cm2 in its energy range. Minimal measurable degree of polarization is 0.9 % for 100 sec exposition and X1 solar flare.

  5. Solar X-ray polarimetry and spectrometry instrument PING-M for the Interhelioprobe mission

    NASA Astrophysics Data System (ADS)

    Kotov, Yu. D.; Yurov, V. N.; Glyanenko, A. S.; Lupar, E. E.; Kochemasov, A. V.; Trofimov, Yu. A.; Zakharov, M. S.; Faradzhaev, R. M.; Tyshkevich, V. G.; Rubtsov, I. V.; Dergachev, V. A.; Kruglov, E. M.; Lazutkov, V. P.; Savchenko, M. I.; Skorodumov, D. V.

    2016-08-01

    The PING-M experiment is designed to investigate solar X-ray activity. The instrument includes a hard X-ray polarimeter (PING-P), a hard X-ray spectrometer (HXRS) and a soft X-ray spectrometer (SXRS). PING-P has the energy range of 20-150 keV and an effective area of about 2.5 cm2. It uses three organic scintillation detectors as active scatterers, which work in coincidence with six absorber detectors, based on CsI(Tl) scintillator. This technique allows us to considerably improve the polarimeter sensitivity. HXRS has the energy range of 20-600 keV and an effective area of about 15 cm2. It is based on a fast inorganic scintillator (LaBr3(Ce) or CeBr3) with a relatively high energy resolution of 3.5-4.5% at 662 keV. The SXRS energy range is 1.5-25 keV, and its aperture is ø0.1 mm, which provides the registration of solar flares in the range from C1 to X20 class of GOES scale. It is based on a SDD semiconductor detector with an energy resolution better than 200 eV at 5.9 keV line. The experiment will be performed onboard the Russian interplanetary mission Interhelioprobe which is planned for launch after 2025. The instrument will allow us to investigate angular and energy distributions of accelerated electrons, plasma heating processes, etc. Stereoscopic polarimetry and spectrometric observations will be possible if a similar instrument is installed onboard a near Earth satellite, or the second probe of the Interhelioprobe mission.

  6. It all started in Falköping, Sweden: Safe Communities - global thinking and local action for safety.

    PubMed

    Svanström, Leif

    2012-01-01

    After constructing the Safe Community model and applying it in Falköping Municipality, Sweden, a first step was taken to establish a Swedish network for knowledge exchange between Safe Communities. Falköping was the first to be involved, and was then joined by Lidköping and Motala. Later, there followed Harstad in Norway, and some communities in Australia. Criteria were developed to define the concept operationally. In 1986, collaboration was embarked upon with the World Health Organization, and since 1991 there have been annual conferences on Safe Communities. Many academic centres around the world are now involved. Certification of communities started in 1989, and 272 communities have now been designated as a Safe Community (20 February 2011). The regional organisations, especially the Asian and European networks, embrace more than half of the designated communities. A global organisation has been considered, but the strength of the movement lies in local engagement and regional networking.

  7. Development of the Probing In-Situ with Neutron and Gamma Rays (PING) Instrument for Planetary Science Applications

    NASA Technical Reports Server (NTRS)

    Parsons, A.; Bodnarik, J.; Burger, D.; Evans, L.; Floyd, S; Lim, L.; McClanahan, T.; Namkung, M.; Nowicki, S.; Schweitzer, J.; Starr, R.; Trombka, J.

    2011-01-01

    The Probing In situ with Neutrons and Gamma rays (PING) instrument is a promising planetary science application of the active neutron-gamma ray technology that has been used successfully in oil field well logging and mineral exploration on Earth for decades. Similar techniques can be very powerful for non-invasive in situ measurements of the subsurface elemental composition on other planets. The objective of our active neutron-gamma ray technology program at NASA Goddard Space Flight Center (NASA/GSFC) is to bring instruments using this technology to the point where they can be flown on a variety of surface lander or rover missions to the Moon, Mars, Venus, asteroids, comets and the satellites of the outer planets. PING combines a 14 MeV deuterium-tritium pulsed neutron generator with a gamma ray spectrometer and two neutron detectors to produce a landed instrument that can determine the elemental composition of a planet down to 30 - 50 cm below the planet's surface. The penetrating nature of.5 - 10 MeV gamma rays and 14 MeV neutrons allows such sub-surface composition measurements to be made without the need to drill into or otherwise disturb the planetary surface, thus greatly simplifying the lander design. We are currently testing a PING prototype at a unique outdoor neutron instrumentation test facility at NASA/GSFC that provides two large (1.8 m x 1.8 m x.9 m) granite and basalt test formations placed outdoors in an empty field. Since an independent trace elemental analysis has been performed on both the Columbia River basalt and Concord Gray granite materials, these samples present two known standards with which to compare PING's experimentally measured elemental composition results. We will present experimental results from PING measurements of both the granite and basalt test formations and show how and why the optimum PING instrument operating parameters differ for studying the two materials.

  8. PingER: Internet performance monitoring -- How do collisions make better physics

    SciTech Connect

    Matthews, W.

    2000-02-17

    Internet connectivity is critical infrastructure for modern high energy nuclear and particle physics experiments at laboratories around the world. Achieving the ambitious computing goals is dependent on reliable and fast connections between collaborators in geographically separate regions. The ambitious computing goals of experiments such as BaBar, RHIC and the LHC place internet connectivity in a highly critical position. More over the ability to monitor performance and identify weak points for upgrades has become pivotal to recruiting collaborators not only overseas from the location of the experiment but in locations previously considered remote. The methodology of the Internet End-to-End Performance Monitoring (IEPM) project and long-term trends in regional and trans-oceanic performance measured by the PingER tools has previously been described. The project has grown significantly and now 593 nodes at 424 sites in 72 countries are monitored by 28 monitoring sites in 15 countries. A total of 2,138 end-to-end pairs are monitored, making PingER probably the largest performance monitoring project in the world. Recently particular effort has been made to extend the monitoring of locations in East Europe and the former USSR and to Central and South America and the Middle East, reflecting the increasing reach of high energy nuclear and particle physics research.

  9. The second-phase development of the China JinPing underground laboratory

    DOE PAGES

    Li, Jianmin; Ji, Xiangdong; Haxton, Wick; Wang, Joseph S.Y.

    2015-03-24

    During 2013-2015 an expansion of the China JinPing underground Laboratory (CJPL) will be undertaken along a main branch of a bypass tunnel in the JinPing tunnel complex. This second phase of CJPL will increase laboratory space to approximately 96,000 m³, which can be compared to the existing CJPL-I volume of ~ 4,000 m³. One design configuration has eight additional hall spaces, each over 60 m long and approximately 12 m in width, with overburdens of about 2.4 km of rock, oriented parallel to and away from the main water transport and auto traffic tunnels. There are additional possibilities for furthermore » expansions at a nearby second bypass tunnel and along the entrance and exit branches of both bypass tunnels, potentially leading to an expanded CJPL comparable in size to Gran Sasso. Concurrent with the excavation activities, planning is underway for dark matter and other rare-event detectors, as well as for geophysics/engineering and other coupled multi-disciplinary sensors. In the town meeting on 8 September, 2013 at Asilomar, CA, associated with the 13th International Conference on Topics in Astroparticle and Underground Physics (TAUP), presentations and panel discussions addressed plans for one-ton expansions of the current CJPL germanium detector array of the China Darkmatter EXperiment (CDEX) collaboration and of the duel-phase xenon detector of the Panda-X collaboration, as well as possible new detector initiatives for dark matter studies, low-energy solar neutrino detection, neutrinoless double beta searches, and geoneutrinos. JinPing was also discussed as a site for a low-energy nuclear astrophysics accelerator. Geophysics/engineering opportunities include acoustic and micro-seismic monitoring of rock bursts during and after excavation, coupled-process in situ measurements, local, regional, and global monitoring of seismically induced radon emission, and electromagnetic signals. Additional ideas and projects will likely be developed in the next few

  10. The Second-phase Development of the China JinPing Underground Laboratory

    NASA Astrophysics Data System (ADS)

    Li, Jianmin; Ji, Xiangdong; Haxton, Wick; Wang, Joseph S. Y.

    During 2013-2015 an expansion of the China JinPing underground Laboratory (CJPL) will be undertaken along a main branch of a bypass tunnel in the JinPing tunnel complex. This second phase of CJPL will increase laboratory space to approximately 96,000 m3, which can be compared to the existing CJPL-I volume of ∼ 4,000 m3. One design configuration has eight additional hall spaces, each over 60 m long and approximately12 m in width, with overburdens of about 2.4 km of rock, oriented parallel to and away from the main water transport and auto traffic tunnels. There are additional possibilities for further expansions at a nearby second bypass tunnel and along the entrance and exit branches of both bypass tunnels, potentially leading to an expanded CJPL comparable in size to Gran Sasso. Concurrent with the excavation activities, planning is underway for dark matter and other rare-event detectors, as well as for geophysics/engineering and other coupled multi-disciplinary sensors. In the town meeting on 8 September, 2013 at Asilomar, CA, associated with the 13th International Conference on Topics in Astroparticle and Underground Physics (TAUP), presentations and panel discussions addressed plans for one-ton expansions of the current CJPL germanium detector array of the China Darkmatter EXperiment (CDEX) collaboration and of the duel-phase xenon detector of the Panda-X collaboration, as well as possible new detector initiatives for dark matter studies, low-energy solar neutrino detection, neutrinoless double beta searches, and geoneutrinos. JinPing was also discussed as a site for a low-energy nuclear astrophysics accelerator. Geophysics/engineering opportunities include acoustic and micro-seismic monitoring of rock bursts during and after excavation, coupled-process in situ measurements, local, regional, and global monitoring of seismically induced radon emission, and electromagnetic signals. Additional ideas and projects will likely be developed in the next few years

  11. The second-phase development of the China JinPing underground laboratory

    SciTech Connect

    Li, Jianmin; Ji, Xiangdong; Haxton, Wick; Wang, Joseph S.Y.

    2015-03-24

    During 2013-2015 an expansion of the China JinPing underground Laboratory (CJPL) will be undertaken along a main branch of a bypass tunnel in the JinPing tunnel complex. This second phase of CJPL will increase laboratory space to approximately 96,000 m³, which can be compared to the existing CJPL-I volume of ~ 4,000 m³. One design configuration has eight additional hall spaces, each over 60 m long and approximately 12 m in width, with overburdens of about 2.4 km of rock, oriented parallel to and away from the main water transport and auto traffic tunnels. There are additional possibilities for further expansions at a nearby second bypass tunnel and along the entrance and exit branches of both bypass tunnels, potentially leading to an expanded CJPL comparable in size to Gran Sasso. Concurrent with the excavation activities, planning is underway for dark matter and other rare-event detectors, as well as for geophysics/engineering and other coupled multi-disciplinary sensors. In the town meeting on 8 September, 2013 at Asilomar, CA, associated with the 13th International Conference on Topics in Astroparticle and Underground Physics (TAUP), presentations and panel discussions addressed plans for one-ton expansions of the current CJPL germanium detector array of the China Darkmatter EXperiment (CDEX) collaboration and of the duel-phase xenon detector of the Panda-X collaboration, as well as possible new detector initiatives for dark matter studies, low-energy solar neutrino detection, neutrinoless double beta searches, and geoneutrinos. JinPing was also discussed as a site for a low-energy nuclear astrophysics accelerator. Geophysics/engineering opportunities include acoustic and micro-seismic monitoring of rock bursts during and after excavation, coupled-process in situ measurements, local, regional, and global monitoring of seismically induced radon emission, and electromagnetic signals. Additional ideas and projects will likely be developed in the

  12. Security of modified Ping-Pong protocol in noisy and lossy channel

    PubMed Central

    Han, Yun-Guang; Yin, Zhen-Qiang; Li, Hong-Wei; Chen, Wei; Wang, Shuang; Guo, Guang-Can; Han, Zheng-Fu

    2014-01-01

    The “Ping-Pong” (PP) protocol is a two-way quantum key protocol based on entanglement. In this protocol, Bob prepares one maximally entangled pair of qubits, and sends one qubit to Alice. Then, Alice performs some necessary operations on this qubit and sends it back to Bob. Although this protocol was proposed in 2002, its security in the noisy and lossy channel has not been proven. In this report, we add a simple and experimentally feasible modification to the original PP protocol, and prove the security of this modified PP protocol against collective attacks when the noisy and lossy channel is taken into account. Simulation results show that our protocol is practical. PMID:24816899

  13. Beam pinging, sweeping, shaking, and electron/ion collecting, at the Proton Storage Ring

    SciTech Connect

    Hardek, T.W.; Macek, R.J.; Plum, M.A.; Wang, T.S.F.

    1993-01-01

    We have built, installed and tested a pinger for use as a general diagnostic at the Los Alamos Proton Storage Ring (PSR). Two 4-m-long parallel-plate electrodes with a plate spacing of 10.2 cm provide kicks of up to 1.1 mrad. A pair of solid-state pulsers may be operated in a single-pulse mode for beam pinging (tune measurements) or in a burst mode at up to 700 kHz pulse rates for beam sweeping. During our 1992 operating period we used the pinger for beam sweeping, for beam shaking, for measuring the tune shift, and we have used it as an ion chamber. Using the pinger as an ion chamber during production conditions has yielded some surprising results.

  14. Beam pinging, sweeping, shaking, and electron/ion collecting, at the Proton Storage Ring

    SciTech Connect

    Hardek, T.W.; Macek, R.J.; Plum, M.A.; Wang, T.S.F.

    1993-06-01

    We have built, installed and tested a pinger for use as a general diagnostic at the Los Alamos Proton Storage Ring (PSR). Two 4-m-long parallel-plate electrodes with a plate spacing of 10.2 cm provide kicks of up to 1.1 mrad. A pair of solid-state pulsers may be operated in a single-pulse mode for beam pinging (tune measurements) or in a burst mode at up to 700 kHz pulse rates for beam sweeping. During our 1992 operating period we used the pinger for beam sweeping, for beam shaking, for measuring the tune shift, and we have used it as an ion chamber. Using the pinger as an ion chamber during production conditions has yielded some surprising results.

  15. Dolphin-inspired combined maneuvering and pinging for short-distance echolocation.

    PubMed

    Forsythe, Stephen E; Leinhos, Henry A; Bandyopadhyay, Promode R

    2008-10-01

    The biorobotic emulation of swimming and flying animals carrying out short-distance echolocation while maneuvering is considered. A simple and lightweight sonar for use on a small, maneuverable underwater vehicle for short-distance echolocation is explored. This sonar has four sensors and uses broadband, high-frequency signals to echolocate. The frequency-time characteristics of these signals are compared to those of bats and dolphins. The biosonar is paired with a biologically inspired, maneuverable, underwater vehicle, the combined use of sensors and maneuverability being analogous to animal behavior. Homing experiments have been carried out in an acoustic test facility where identification and localization of multiple targets is based on fusion of acoustic returns from multiple pings.

  16. Creating accessible science museums with user-activated environmental audio beacons (ping!).

    PubMed

    Landau, Steven; Wiener, William; Naghshineh, Koorosh; Giusti, Ellen

    2005-01-01

    In 2003, Touch Graphics Company carried out research on a new invention that promises to improve accessibility to science museums for visitors who are visually impaired. The system, nicknamed Ping!, allows users to navigate an exhibit area, listen to audio descriptions, and interact with exhibits using a cell phone-based interface. The system relies on computer telephony, and it incorporates a network of wireless environmental audio beacons that can be triggered by users wishing to travel to destinations they choose. User testing indicates that the system is effective, both as a way-finding tool and as a means of providing accessible information on museum content. Follow-up development projects will determine if this approach can be successfully implemented in other settings and for other user populations.

  17. A student's analysis of the Moi University-Linköping University exchange programme.

    PubMed

    Mwenda, A S

    2012-11-01

    Introduction : Moi University College of Health Sciences was established in 1989. It is comprised of the schools of medicine, nursing, public health and dentistry. Since its inception, the college has been in collaboration with Linköping University in Sweden. This collaboration has taken the form of student and staff exchanges, as well as infrastructure and library improvements. This study was carried out to analyse the exchange programme and highlight some of the strengths that the exchange programme brings to the students' academic experience. Methods : A qualitative cross-sectional survey was conducted among the students who participated in the elective/exchange programme in the years 2009, 2010 and 2011. Self-administered questionnaires were completed by the participants. Additional data were obtained from the recommendations and conclusions from the reports that the students wrote after their participation in the exchange programme. Focus group discussions and key informant interviews were also carried out. Results : A total of 46 students participated in the exchange programme: 27 from Moi University and 19 from Linköping University. The disciplines of students reflected the undergraduate courses offered by these universities. The exchange programme's strengths were exposing students to new cultural settings, different healthcare system organisation and influencing future academic and personal lives, as well as making education global. The main challenge facing the exchange programme was language. Discussion : This study shows the exchange programme as a strong pillar of the medical education curriculum, enabling students to get a global perspective on their education, while exposing them to significant cultural and healthcare organisation diversity. There is a need to expand the collaboration so that more students have the opportunity to experience the overseas exchange programme. PMID:23823594

  18. Xiao-Ai-Ping, a TCM Injection, Enhances the Antigrowth Effects of Cisplatin on Lewis Lung Cancer Cells through Promoting the Infiltration and Function of CD8(+) T Lymphocytes.

    PubMed

    Li, Wanshuai; Yang, Yang; Ouyang, Zijun; Zhang, Qi; Wang, Lu; Tao, Feifei; Shu, Yongqian; Gu, Yanhong; Xu, Qiang; Sun, Yang

    2013-01-01

    Objectives. To investigate how Xiao-Ai-Ping injection, a traditional Chinese medicine and an ancillary drug in tumor treatment, enhances the antitumor effects of cisplatin on Lewis lung cancer (LLC) cells. Methods. LLC-bearing mice were daily intraperitoneally injected with various doses of cisplatin, Xiao-Ai-Ping, or cisplatin plus Xiao-Ai-Ping, respectively. Body weight and tumor volumes were measured every three days. Results. Combination of Xiao-Ai-Ping and cisplatin yielded significantly better antigrowth and proapoptotic effects on LLC xenografts than sole drug treatment did. In addition, we found that Xiao-Ai-Ping triggered the infiltration of CD8(+) T cells, a group of cytotoxic T cells, to LLC xenografts. Furthermore, the mRNA levels of interferon- γ (ifn- γ ), perforin-1 (prf-1), and granzyme B (gzmb) in CD8(+) T cells were significantly increased after combination treatment of Xiao-Ai-Ping and cisplatin. In vitro studies showed that Xiao-Ai-Ping markedly upregulated the mRNA levels of ifn- γ , prf-1, and gzmb in CD8(+) T cells in a concentration-dependent manner, suggesting that Xiao-Ai-Ping augments the function of CD8(+) T cells. Conclusions. Xiao-Ai-Ping promotes the infiltration and function of CD8(+) T cells and thus enhances the antigrowth effects of cisplatin on LLC xenografts, which provides new evidence for the combination of Xiao-Ai-Ping and cisplatin in clinic in China.

  19. Kinetics of Spanish broom peroxidase obeys a Ping-Pong Bi-Bi mechanism with competitive inhibition by substrates.

    PubMed

    Pérez Galende, Patricia; Hidalgo Cuadrado, Nazaret; Kostetsky, Eduard Ya; Roig, Manuel G; Villar, Enrique; Shnyrov, Valery L; Kennedy, John F

    2015-11-01

    In plants, adverse conditions often induce an increase in reactive oxygen species (ROS) such as hydrogen peroxide (H2O2). H2O2 is reduced to water, and thus becomes detoxified by enzymes such as Cytisus multiflorus peroxidase (CMP). Here, the steady-state kinetics of the H2O2-supported oxidation of different organic substrates by CMP was investigated. Analysis of the initial rates vs. H2O2 and reducing substrate concentrations proved to be consistent with a substrate-inhibited Ping-Pong Bi-Bi reaction mechanism. The phenomenological approach expresses the peroxidase Ping-Pong mechanism in the form of the Michaelis-Menten equation and affords an interpretation of the effects in terms of the kinetic parameters [Formula: see text] , [Formula: see text] , kcat, [Formula: see text] , [Formula: see text] and of the microscopic rate constants, k1 and k3, of the shared three-step catalytic cycle of peroxidases.

  20. Kinetics of Spanish broom peroxidase obeys a Ping-Pong Bi-Bi mechanism with competitive inhibition by substrates.

    PubMed

    Pérez Galende, Patricia; Hidalgo Cuadrado, Nazaret; Kostetsky, Eduard Ya; Roig, Manuel G; Villar, Enrique; Shnyrov, Valery L; Kennedy, John F

    2015-11-01

    In plants, adverse conditions often induce an increase in reactive oxygen species (ROS) such as hydrogen peroxide (H2O2). H2O2 is reduced to water, and thus becomes detoxified by enzymes such as Cytisus multiflorus peroxidase (CMP). Here, the steady-state kinetics of the H2O2-supported oxidation of different organic substrates by CMP was investigated. Analysis of the initial rates vs. H2O2 and reducing substrate concentrations proved to be consistent with a substrate-inhibited Ping-Pong Bi-Bi reaction mechanism. The phenomenological approach expresses the peroxidase Ping-Pong mechanism in the form of the Michaelis-Menten equation and affords an interpretation of the effects in terms of the kinetic parameters [Formula: see text] , [Formula: see text] , kcat, [Formula: see text] , [Formula: see text] and of the microscopic rate constants, k1 and k3, of the shared three-step catalytic cycle of peroxidases. PMID:26416239

  1. Synergistic "ping-pong" energy transfer for efficient light activation in a chromophore-catalyst dyad.

    PubMed

    Quaranta, Annamaria; Charalambidis, Georgios; Herrero, Christian; Margiola, Sofia; Leibl, Winfried; Coutsolelos, Athanassios; Aukauloo, Ally

    2015-10-01

    The synthesis of a porphyrin-Ru(II) polypyridine complex where the porphyrin acts as a photoactive unit and the Ru(II) polypyridine as a catalytic precursor is described. Comparatively, the free base porphyrin was found to outperform the ruthenium based chromophore in the yield of light induced electron transfer. Mechanistic insights indicate the occurrence of a ping-pong energy transfer from the (1)LC excited state of the porphyrin chromophore to the (3)MCLT state of the catalyst and back to the (3)LC excited state of the porphyrin unit. The latter, triplet-triplet energy transfer back to the chromophore, efficiently competes with fast radiationless deactivation of the excited state at the catalyst site. The energy thus recovered by the chromophore allows improved yield of formation of the oxidized form of the chromophore and concomitantly of the oxidation of the catalytic unit by intramolecular charge transfer. The presented results are among the rare examples where a porphyrin chromophore is successfully used to drive an oxidative activation process where reductive processes prevail in the literature.

  2. Estimation of typhoon rainfall in GaoPing River: A Multivariate Maximum Entropy Method

    NASA Astrophysics Data System (ADS)

    Pei-Jui, Wu; Hwa-Lung, Yu

    2016-04-01

    The heavy rainfall from typhoons is the main factor of the natural disaster in Taiwan, which causes the significant loss of human lives and properties. Statistically average 3.5 typhoons invade Taiwan every year, and the serious typhoon, Morakot in 2009, impacted Taiwan in recorded history. Because the duration, path and intensity of typhoon, also affect the temporal and spatial rainfall type in specific region , finding the characteristics of the typhoon rainfall type is advantageous when we try to estimate the quantity of rainfall. This study developed a rainfall prediction model and can be divided three parts. First, using the EEOF(extended empirical orthogonal function) to classify the typhoon events, and decompose the standard rainfall type of all stations of each typhoon event into the EOF and PC(principal component). So we can classify the typhoon events which vary similarly in temporally and spatially as the similar typhoon types. Next, according to the classification above, we construct the PDF(probability density function) in different space and time by means of using the multivariate maximum entropy from the first to forth moment statistically. Therefore, we can get the probability of each stations of each time. Final we use the BME(Bayesian Maximum Entropy method) to construct the typhoon rainfall prediction model , and to estimate the rainfall for the case of GaoPing river which located in south of Taiwan.This study could be useful for typhoon rainfall predictions in future and suitable to government for the typhoon disaster prevention .

  3. Determining the Technical Standards of Ping Pong Table by Using Close Range Photogrammetry

    NASA Astrophysics Data System (ADS)

    Acar, U.; Bayram, B.; Cetin, H. I.; Sanlı, F. B.

    2012-07-01

    In the presented study, quality measurements were made regarding three different ping pong tables that were produced with three different materials. Measurements were made on the purpose of confirming whether the tables can be used as a match table that is in the standard of International Table Tennis Federation or not. For this confirmation, bouncing height of the table tennis ball is measured which is approved by ITTF. Average bouncing height that is required by federation standards is minimum 23 cm for free falling table tennis ball from 30 cm. In order to locate the bounce on the tables, the table tennis ball is released from 30cm in free fall with equipment was. In the meantime, 24 video frames videos were shot with a Full HD (1920 × 1080) camera. Each frame of videos that were taken is separated from each other. Each frame is analyzed and highest bounce is measured. As a result of the study, the bouncing heights of the three tables were measured as 23.04 cm, 23.33 cm, 22.91 cm for table1, for table2 and for table3 respectively.

  4. Transpositional activation of mPing in an asymmetric nuclear somatic cell hybrid of rice and Zizania latifolia was accompanied by massive element loss.

    PubMed

    Shan, X H; Ou, X F; Liu, Z L; Dong, Y Z; Lin, X Y; Li, X W; Liu, B

    2009-11-01

    We have reported previously that the most active miniature inverted terminal repeat transposable element (MITE) of rice, mPing, was transpositionally mobilized in several rice recombinant inbred lines (RILs) derived from an introgressive hybridization between rice and wild rice (Zizania latifolia Griseb.). To further study the phenomenon of hybridization-induced mPing activity, we undertook the present study to investigate the element's behavior in a highly asymmetric somatic nuclear hybrid (SH6) of rice and Z. latifolia, which is similar in genomic composition to that of the RILs, though probably contains more introgressed alien chromatins from the donor species than the RILs. We found that mPing, together with its transposase-donor, Pong, underwent rampant transpositional activation in the somatic hybrid (SH6). Because possible effects of protoplast isolation and cell culture can be ruled out, we attribute the transpositional activation of mPing and Pong in SH6 to the process of asymmetric somatic hybridization, namely, one-step introgression of multiple chromatin segments of the donor species Z. latifolia into the recipient rice genome. A salient feature of mPing transposition in the somatic hybrid is that the element's activation was accompanied by massive loss of its original copies, i.e., abortive transpositions, which was not observed in previously reported cases of mPing activity. These data not only corroborated our earlier finding that wide hybridization and introgression may trigger transpositional activation of otherwise quiescent transposable elements, but also suggest that transpositional mobilization of a MITE like mPing can be accompanied by dramatic reduction of its original copy numbers under certain conditions, thus provide novel insights into the dynamics of MITEs in the course of genome evolution. PMID:19711051

  5. The NIH Toolbox Cognition Battery: Results from a Large Normative Developmental Sample (PING)

    PubMed Central

    Akshoomoff, Natacha; Newman, Erik; Thompson, Wesley K.; McCabe, Connor; Bloss, Cinnamon S.; Chang, Linda; Amaral, David G.; Casey, B. J.; Ernst, Thomas M.; Frazier, Jean A.; Gruen, Jeffrey R.; Kaufmann, Walter E.; Kenet, Tal; Kennedy, David N.; Libiger, Ondrej; Mostofsky, Stewart; Murray, Sarah S.; Sowell, Elizabeth R.; Schork, Nicholas; Dale, Anders M.; Jernigan, Terry L.

    2014-01-01

    Objective The NIH Toolbox Cognition Battery (NTCB) was designed to provide a brief, efficient computerized test of key neuropsychological functions appropriate for use in children as young as 3 years of age. This report describes the performance of a large group of typically developing children and adolescents and examines the impact of age and sociocultural variables on test performance. Method The NTCB was administered to a sample of 1020 typically developing males and females ranging in age from 3 to 20 years, diverse in terms of socioeconomic status (SES) and race/ethnicity, as part of the new publicly accessible Pediatric Imaging, Neurocognition, and Genetics (PING) data resource, at 9 sites across the United States. Results General additive models of nonlinear age-functions were estimated from age-differences in test performance on the 8 NTCB subtests while controlling for family SES and genetic ancestry factors (GAFs). Age accounted for the majority of the variance across all NTCB scores, with additional significant contributions of gender on some measures, and of SES and race/ethnicity (GAFs) on all. After adjusting for age and gender, SES and GAFs explained a substantial proportion of the remaining unexplained variance in Picture Vocabulary scores. Conclusions The results highlight the sensitivity to developmental effects and efficiency of this new computerized assessment battery for neurodevelopmental research. Limitations are observed in the form of some ceiling effects in older children, some floor effects, particularly on executive function tests in the youngest participants, and evidence for variable measurement sensitivity to cultural/socioeconomic factors. PMID:24219608

  6. Quality control of waste to incineration--waste composition analysis in Lidköping, Sweden.

    PubMed

    Petersen, Cecilia Mattsson; Berg, Per E O; Rönnegård, Lars

    2005-12-01

    In order to decrease environmental impacts in waste management the choice of treatment method must be based on the characteristics of the waste. Present sampling procedures do not provide statistically representative samples of solid waste and this provides difficulties in characterization. The objective of this study was to develop a procedure for waste component analysis and sampling of waste after collection and at plant level. A further objective was to characterize the waste delivered to an incineration plant for physical and chemical properties and to determine the amounts of delivered waste that could be classified as biofuels and fossil fuels. The proportions of recyclables and hazardous waste were also examined. Samples were taken randomly from waste trucks and divided by square implementation. Statistical analysis of the results showed that the number of sub-samples could be decreased with only a moderate increase in the confidence interval. This means that future waste composition analyses could be made more efficient and thereby less expensive. The analysis of the waste delivered to the Lidköping incineration plant (Central Sweden) showed that 66.4% of the household waste was composed of biofuels and 21.3% of non-renewable combustibles, of which 40.3% were recyclables. In addition, 11.6% of the household waste was non-combustible and 0.6% hazardous waste. The heat value for the biofuels was 18.0-19.7 MJ kg(-1) dry mass (DM) and for the fossil fuels 28.2-33.9 MJ kg(-1) DM. The industrial waste consisted of 35.9% biofuels, 62.0% fossil fuels, 1.6% non-combustible and 0.5% hazardous waste. The heat value was 19.5 MJ kg(-1) DM for the biofuels and 31.4 MJ kg(-1) DM for the fossil fuels. PMID:16379121

  7. Characterization and distribution of polycyclic aromatic hydrocarbon contaminations in surface sediment and water from Gao-ping River, Taiwan.

    PubMed

    Doong, Ruey-An; Lin, Yu-Tin

    2004-04-01

    The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) in water and sediment samples collected from 12 locations in Gao-ping River, Taiwan were analyzed. Molecular ratios and principal component analysis (PCA) were used to characterize the possible pollution sources. Concentrations of total 16 PAHs (SigmaPAHs) in water samples ranged from below method detection limits (ping River. The petrogenic PAHs may be mainly from the leakage of crude oil and the refined products from urban vehicle traffic, while the pyrolytic PAH input is located in the proximity near the mouth of estuary of the River. The PCA analysis confirmed that petrochemical industrial parks located in the vicinity of estuary of Gao-ping River might be the possible source for the PAH input.

  8. The characteristics of a low background germanium gamma ray spectrometer at China JinPing Underground Laboratory.

    PubMed

    Zeng, Zhi; Mi, Yuhao; Ma, Hao; Cheng, Jianping; Su, Jian; Yue, Qian

    2014-09-01

    A low background germanium gamma ray spectrometer, GeTHU, has been installed at China JinPing Underground Laboratory (CJPL). The integral background count rate of the spectrometer was 0.629 cpm between 40 and 2700 keV, the origins of which were studied by Monte Carlo simulation. Detection limits and efficiencies were calculated for selected gamma peaks. Some samples of rare event experiments were measured and (137)Cs contamination was found in boric acid. GeTHU will be mainly used to measure environmental samples and screen materials in dark matter and double beta decay experiments. PMID:24950199

  9. Li(+) solvation in glyme-Li salt solvate ionic liquids.

    PubMed

    Ueno, Kazuhide; Tatara, Ryoichi; Tsuzuki, Seiji; Saito, Soshi; Doi, Hiroyuki; Yoshida, Kazuki; Mandai, Toshihiko; Matsugami, Masaru; Umebayashi, Yasuhiro; Dokko, Kaoru; Watanabe, Masayoshi

    2015-03-28

    Certain molten complexes of Li salts and solvents can be regarded as ionic liquids. In this study, the local structure of Li(+) ions in equimolar mixtures ([Li(glyme)]X) of glymes (G3: triglyme and G4: tetraglyme) and Li salts (LiX: lithium bis(trifluoromethanesulfonyl)amide (Li[TFSA]), lithium bis(pentafluoroethanesulfonyl)amide (Li[BETI]), lithium trifluoromethanesulfonate (Li[OTf]), LiBF4, LiClO4, LiNO3, and lithium trifluoroacetate (Li[TFA])) was investigated to discriminate between solvate ionic liquids and concentrated solutions. Raman spectra and ab initio molecular orbital calculations have shown that the glyme molecules adopt a crown-ether like conformation to form a monomeric [Li(glyme)](+) in the molten state. Further, Raman spectroscopic analysis allowed us to estimate the fraction of the free glyme in [Li(glyme)]X. The amount of free glyme was estimated to be a few percent in [Li(glyme)]X with perfluorosulfonylamide type anions, and thereby could be regarded as solvate ionic liquids. Other equimolar mixtures of [Li(glyme)]X were found to contain a considerable amount of free glyme, and they were categorized as traditional concentrated solutions. The activity of Li(+) in the glyme-Li salt mixtures was also evaluated by measuring the electrode potential of Li/Li(+) as a function of concentration, by using concentration cells against a reference electrode. At a higher concentration of Li salt, the amount of free glyme diminishes and affects the electrode reaction, leading to a drastic increase in the electrode potential. Unlike conventional electrolytes (dilute and concentrated solutions), the significantly high electrode potential found in the solvate ILs indicates that the solvation of Li(+) by the glyme forms stable and discrete solvate ions ([Li(glyme)](+)) in the molten state. This anomalous Li(+) solvation may have a great impact on the electrode reactions in Li batteries. PMID:25733406

  10. Librarians as Advocates of Social Media for Researchers: A Social Media Project Initiated by Linköping University Library, Sweden

    ERIC Educational Resources Information Center

    Persson, Sassa; Svenningsson, Maria

    2016-01-01

    Librarians at Linköping University help researchers keep abreast of developments in their fields and to increase the visibility of their work. Strategic, professional use of social media ought to be an essential part of a researcher's communication strategy. This article investigates the level of awareness of the professional use of social media…

  11. Exploring a Conceptual Model-Based Approach to Teaching Situated Word Problems: A Response to Yan Ping Xin and Dake Zhang

    ERIC Educational Resources Information Center

    Jitendra, Asha K.

    2011-01-01

    This article presents the author's response to Yan Ping Xin and Dake Zhang's recent critical evaluation of her and colleagues' work in "Exploring a Conceptual Model-Based Approach to Teaching Situated Word Problems," published in "The Journal of Educational Research" in 2009 (Vol. 102, No. 6). Most critiques of prior research are written in a fair…

  12. Assessing Lexicon: Validation and Developmental Data of the Picture Naming Game (PiNG), a New Picture Naming Task for Toddlers

    ERIC Educational Resources Information Center

    Bello, A.; Giannantoni, P.; Pettenati, P.; Stefanini, S.; Caselli, M. C.

    2012-01-01

    Background: Understanding lexical abilities in infants and toddlers is important, yet no single tool can be used. Aims: To perform a validation of a new tool (known as the Picture Naming Game, or "PiNG") for assessing lexical comprehension and production in toddlers and to obtain developmental trends for Italian children. Methods & Procedures:…

  13. Mobilization of the active MITE transposons mPing and Pong in rice by introgression from wild rice (Zizania latifolia Griseb.).

    PubMed

    Shan, Xiaohui; Liu, Zhenlan; Dong, Zhenying; Wang, Yongming; Chen, Yu; Lin, Xiuyun; Long, Likun; Han, Fangpu; Dong, Yingshan; Liu, Bao

    2005-04-01

    Hybridization between different species plays an important role in plant genome evolution, as well as is a widely used approach for crop improvement. McClintock has predicted that plant wide hybridization constitutes a "genomic shock" whereby cryptic transposable elements may be activated. However, direct experimental evidence showing a causal relationship between plant wide hybridization and transposon mobilization has not yet been reported. The miniature-Ping (mPing) is a recently isolated active miniature inverted-repeat transposable element transposon from rice, which is mobilized by tissue culture and gamma-ray irradiation. We show herein that mPing, together with its putative transposase-encoding partner, Pong, is mobilized in three homologous recombinant inbred lines (RILs), derived from hybridization between rice (cultivar Matsumae) and wild rice (Zizania latifolia Griseb.), harboring introgressed genomic DNA from wild rice. In contrast, both elements remain immobile in two lines sharing the same parentage to the RILs but possessing no introgressed DNA. Thus, we have presented direct evidence that is consistent with McClintock's insight by demonstrating a causal link between wide hybridization and transposon mobilization in rice. In addition, we report an atypical behavior of mPing/Pong mobilization in these lines, i.e., the exclusive absence of footprints after excision. PMID:15647520

  14. Li diffusion in zircon

    NASA Astrophysics Data System (ADS)

    Cherniak, D. J.; Watson, E. B.

    2010-09-01

    Diffusion of Li under anhydrous conditions at 1 atm and under fluid-present elevated pressure (1.0-1.2 GPa) conditions has been measured in natural zircon. The source of diffusant for 1-atm experiments was ground natural spodumene, which was sealed under vacuum in silica glass capsules with polished slabs of zircon. An experiment using a Dy-bearing source was also conducted to evaluate possible rate-limiting effects on Li diffusion of slow-diffusing REE+3 that might provide charge balance. Diffusion experiments performed in the presence of H2O-CO2 fluid were run in a piston-cylinder apparatus, using a source consisting of a powdered mixture of spodumene, quartz and zircon with oxalic acid added to produce H2O-CO2 fluid. Nuclear reaction analysis (NRA) with the resonant nuclear reaction 7Li(p,γ)8Be was used to measure diffusion profiles for the experiments. The following Arrhenius parameters were obtained for Li diffusion normal to the c-axis over the temperature range 703-1.151°C at 1 atm for experiments run with the spodumene source: D_{text{Li}} = 7.17 × 10^{ - 7} { exp }( - 275 ± 11 {text{kJmol}}^{ - 1} /{text{RT}}){text{m}}2 {text{s}}^{ - 1}. Diffusivities are similar for transport parallel to the c-axis, indicating little anisotropy for Li diffusion in zircon. Similar Li diffusivities were also found for experiments run under fluid-present conditions and for the experiment run with the Dy-bearing source. Li diffusion is considerably faster than diffusion of other cations in zircon, with a smaller activation energy for diffusion. Although Li diffusion in zircon is comparatively rapid, zircons will be moderately retentive of Li signatures at mid-crustal metamorphic temperatures, but they are unlikely to retain this information for geologically significant times under high-grade metamorphism.

  15. Presence of Li clusters in molten LiCl-Li

    DOE PAGES

    Merwin, Augustus; Phillips, William C.; Williamson, Mark A.; Willit, James L.; Motsegood, Perry N.; Chidambaram, Dev

    2016-05-05

    Molten mixtures of lithium chloride and metallic lithium are of significant interest in various metal oxide reduction processes. These solutions have been reported to exhibit seemingly anomalous physical characteristics that lack a comprehensive explanation. ln the current work, the physical chemistry of molten solutions of lithium chloride and metallic lithium, with and without lithium oxide, was investigated using in situ Raman spectroscopy. The Raman spectra obtained from these solutions were in agreement with the previously reported spectrum of the lithium cluster, Li8. Furthermore, this observation is indicative of a nanofluid type colloidal suspension of Li8, in a molten salt matrix.more » It is suggested that the formation and suspension of lithium clusters in lithium chloride is the cause of various phenomena exhibited by these solutions that were previously unexplainable.« less

  16. Presence of Li Clusters in Molten LiCl-Li

    NASA Astrophysics Data System (ADS)

    Merwin, Augustus; Phillips, William C.; Williamson, Mark A.; Willit, James L.; Motsegood, Perry N.; Chidambaram, Dev

    2016-05-01

    Molten mixtures of lithium chloride and metallic lithium are of significant interest in various metal oxide reduction processes. These solutions have been reported to exhibit seemingly anomalous physical characteristics that lack a comprehensive explanation. In the current work, the physical chemistry of molten solutions of lithium chloride and metallic lithium, with and without lithium oxide, was investigated using in situ Raman spectroscopy. The Raman spectra obtained from these solutions were in agreement with the previously reported spectrum of the lithium cluster, Li8. This observation is indicative of a nanofluid type colloidal suspension of Li8 in a molten salt matrix. It is suggested that the formation and suspension of lithium clusters in lithium chloride is the cause of various phenomena exhibited by these solutions that were previously unexplainable.

  17. Presence of Li Clusters in Molten LiCl-Li

    PubMed Central

    Merwin, Augustus; Phillips, William C.; Williamson, Mark A.; Willit, James L.; Motsegood, Perry N.; Chidambaram, Dev

    2016-01-01

    Molten mixtures of lithium chloride and metallic lithium are of significant interest in various metal oxide reduction processes. These solutions have been reported to exhibit seemingly anomalous physical characteristics that lack a comprehensive explanation. In the current work, the physical chemistry of molten solutions of lithium chloride and metallic lithium, with and without lithium oxide, was investigated using in situ Raman spectroscopy. The Raman spectra obtained from these solutions were in agreement with the previously reported spectrum of the lithium cluster, Li8. This observation is indicative of a nanofluid type colloidal suspension of Li8 in a molten salt matrix. It is suggested that the formation and suspension of lithium clusters in lithium chloride is the cause of various phenomena exhibited by these solutions that were previously unexplainable. PMID:27145895

  18. Presence of Li Clusters in Molten LiCl-Li.

    PubMed

    Merwin, Augustus; Phillips, William C; Williamson, Mark A; Willit, James L; Motsegood, Perry N; Chidambaram, Dev

    2016-01-01

    Molten mixtures of lithium chloride and metallic lithium are of significant interest in various metal oxide reduction processes. These solutions have been reported to exhibit seemingly anomalous physical characteristics that lack a comprehensive explanation. In the current work, the physical chemistry of molten solutions of lithium chloride and metallic lithium, with and without lithium oxide, was investigated using in situ Raman spectroscopy. The Raman spectra obtained from these solutions were in agreement with the previously reported spectrum of the lithium cluster, Li8. This observation is indicative of a nanofluid type colloidal suspension of Li8 in a molten salt matrix. It is suggested that the formation and suspension of lithium clusters in lithium chloride is the cause of various phenomena exhibited by these solutions that were previously unexplainable. PMID:27145895

  19. Madame Li Li: Communist Revolutionary, Adult Educator, Lifelong Learner

    ERIC Educational Resources Information Center

    Boshier, Roger; Huang, Yan

    2009-01-01

    Prior to 1949 the Chinese Communist Party orchestrated innovative and participatory forms of adult education. This article concerns Madame Li Li, a leading Chinese Communist woman adult educator. Western delegates at the International Council for Adult Education 1984 Shanghai symposium on adult education were fascinated by Madame Li Li because,…

  20. Structure of 10,11Li and the reaction 11Li (p , d)10Li

    NASA Astrophysics Data System (ADS)

    Fortune, H. T.

    2016-09-01

    I examine the properties of 11Li and the low-lying resonances in 10Li, as they relate to neutron removal from 11Li. Comparison with results from a recent 11Li (p , d) reaction strongly suggests that that experiment observed only the 2+ resonance, and not the 1+.

  1. A novel method to differentiate between ping-pong and simultaneous exchange kinetics and its application to the anion exchanger of the HL60 cell

    PubMed Central

    1992-01-01

    We have developed a new test to differentiate between ping-pong and simultaneous mechanisms for tightly coupled anion exchange. This test requires the use of a dead-end reversible noncompetitive inhibitor. As an example, we have applied the test to the anion exchanger of the HL60 cell using the salicylic acid derivative 3,5-diiodosalicylic acid (DIS), which reversibly inhibits HL60 cell Cl/Cl exchange. The concentration of DIS that causes 50% inhibition (ID50) increased only slightly as either intra- or extracellular chloride was increased, indicating that DIS inhibits HL60 anion exchange in a noncompetitive manner. In agreement with this observation, plots of the slope of the Dixon plot as a function of 1/[Clo] or 1/[Cli] were fit with straight lines with nonzero intercepts, indicating that DIS does not compete with either of the substrates ([Clo] and [Cli]). The secondary Dixon slope test is based on the fact that, for a dead-end inhibitor such as DIS, the slope of the Dixon plot slope vs. 1/[Cli] (secondary Dixon slope or SDS) is independent of extracellular Cl when the exchange mechanism follows ping-pong kinetics. Similarly, the SDS calculated from a plot as a function of 1/[Clo] is also independent of intracellular Cl for a ping-pong exchanger. In contrast to this prediction, we found that for DIS inhibition of Cl/Cl exchange in HL60 cells the slope of the Dixon plot slope vs. 1/[Cli] decreased by a factor of 2.5-fold when [Clo] was increased from 1 to 11 mM (P < 0.0001). This change in the SDS rules out ping-pong kinetics, but is consistent with a simultaneous model of Cl/Cl exchange in which there are extra- and intracellular anion binding sites, both of which must be occupied by suitable anions in order to allow simultaneous exchange of the ions. PMID:1474373

  2. [An exploration of sexual knowledge, attitudes and behavior in aboriginal elementary school students in the Ping-Tung area].

    PubMed

    Hsu, H Y; Liu, C A; Lin, Y C

    1997-04-01

    The purpose of this study was to investigate sexual knowledge, attitudes and behavior of fifth and sixth grade students in aboriginal elementary schools in the Ping-Tung area. A structured questionnaire was administered to 1091 students who were selected by cluster sampling. The results showed: (1) The sexual knowledge score was low but sexual attitudes showed a positive trend. (2) 64.7% and 67.4% of students had at some time seen pictures of male or female sexual organs. (3) About 61% of students had seen sexual magazines or videotapes. (4) 66.2% of male and 88.1% of female students had heard about wet dreams or menstruation before their first experience; more than half of the students thought that wet dreams need treatment. (5) 17.8% of students had masturbation experience, and after that 59.3% of students had fear or guilt feeling. (6) Female students had significantly higher knowledge and attitude scores than male students, Demographic variables produced no significant difference in the above scores. (7) 42.4% of students most desired to know what phenomena indicate sexual maturity. (8) Sex knowledge had significantly positive correlation with sex attitude. PMID:9355399

  3. [Tai ping sheng hui fang (Taiping Holy Prescriptions for Universal Relief) and the compilation during the early Song Dynasty].

    PubMed

    Han, Yi

    2010-07-01

    Tai ping sheng hui fang, the first medical formulary of the Song Dynasty, compiled from the 3(rd) year of Taiping-xingguo reign to the 3(rd) year of Chunhua reign (978 ∼ 992), under the edict of the Taizong Emperor, was popularly applied and extensively circulated and called "the first formulary of the Dynasty". It is extremely significant in the medical history of the Song Dynasty due to its theory of prescription art, practical prescriptions and clinical practice. During the process of its circulation, different versions appeared, including the Guozijian Orthodox Version, Guozijian Small-character Version, Chongwen Hall Abridged Version, Newly Carved Version of Zhuanyunsi, and the Local Abridged Version, thus adapting to the demands of various walks of life in the society. Its unique role in the development of the Song society was founded by its introduction, application and popularization by the emperors, local officials, medical scholars, diplomatic envoys, and intellectuals. The "kind administration" of the authority and the government was further greatly facilitated by the involvement of the government and the introduction of printing. Its practical prescriptions became forceful tools to prevent and treat diseases, to conquer witchcraft, to protect local social security, and to pronounce the merits of officials and physicians at all levels. PMID:21122337

  4. Integrated control of the dengue vector Aedes aegypti in Liu-Chiu village, Ping-Tung County, Taiwan.

    PubMed

    Wang, C H; Chang, N T; Wu, H H; Ho, C M

    2000-06-01

    Because of an inadequate supply of potable water, villagers of Small Liu-Chiu Isle, Ping-Tung County, Taiwan, store water in containers supporting a large population of Aedes aegypti. In 1989-96, integrated control measures against Ae. aegypti were implemented on the basis of community participation. These measures included release of mosquito larvivorous fish in the drinking water storage facilities, application of larvicides to the water storage facilities in vegetable gardens, removal of discarded and unused containers and tires, improvement of household water storage facilities, and increase of potable water supply. Before implementation of the integrated control measures in 1988, 74% of the water-containing vessels were water storage facilities, and 24% of those were infested by Ae. aegypti. In 1989, the Breteau index for the entire island, indicating the average distribution density for larval Ae. aegypti, was 53.9, as compared to an index of 1.2 in 1996. In 4 villages located at the southwest and middle of the island, Ae. aegypti nearly became extinct because of the enthusiastic participation of the community. Before the implementation of integrated control, Ae. aegypti was the dominant species in containers both inside and outside the household, but after the integrated control, Aedes albopictus became predominant outside. PMID:10901632

  5. [Tai ping sheng hui fang (Taiping Holy Prescriptions for Universal Relief) and the compilation during the early Song Dynasty].

    PubMed

    Han, Yi

    2010-07-01

    Tai ping sheng hui fang, the first medical formulary of the Song Dynasty, compiled from the 3(rd) year of Taiping-xingguo reign to the 3(rd) year of Chunhua reign (978 ∼ 992), under the edict of the Taizong Emperor, was popularly applied and extensively circulated and called "the first formulary of the Dynasty". It is extremely significant in the medical history of the Song Dynasty due to its theory of prescription art, practical prescriptions and clinical practice. During the process of its circulation, different versions appeared, including the Guozijian Orthodox Version, Guozijian Small-character Version, Chongwen Hall Abridged Version, Newly Carved Version of Zhuanyunsi, and the Local Abridged Version, thus adapting to the demands of various walks of life in the society. Its unique role in the development of the Song society was founded by its introduction, application and popularization by the emperors, local officials, medical scholars, diplomatic envoys, and intellectuals. The "kind administration" of the authority and the government was further greatly facilitated by the involvement of the government and the introduction of printing. Its practical prescriptions became forceful tools to prevent and treat diseases, to conquer witchcraft, to protect local social security, and to pronounce the merits of officials and physicians at all levels.

  6. Protective effects of Ping-Lv-Mixture (PLM), a medicinal formula on arrhythmias induced by myocardial ischemia-reperfusion.

    PubMed

    An, Wei; Yang, Jing

    2006-11-01

    Ping-Lv-Mixture (PLM) is a Chinese medicinal formula. The present study aimed to determine the effects of PLM on myocardial ischemia-reperfusion (MI/R) induced arrhythmias in rats. Arrhythmia model was established by occlusion of the left arterial descending coronary artery and thereafter reperfusion. A lead II electrocardiogram was monitored throughout the experiment. The results showed that pretreatment of PLM to MI/R rats significantly reduced the incidence and duration of ventricular tachycardia and ventricular fibrillation. On induction of MI/R, the activities of creatine kinase and lactate dehydrogenase were increased in vehicle group. PLM (0.04-1.00 g/kg) administration prevented the increase of these enzymes. Moreover, a significant increase of myocardium superoxide dismutase and decrease of malondialdehyde contents were observed in rats of PLM groups. On the other hand, the expressions of platelet activating factor (PAF) receptor mRNA was down-regulated in a dose-dependent manner in the PLM-treated groups by RT-PCR. Thus, it can be concluded that pretreatment with PLM inhibited lipid peroxidation in rats through suppressing the expression of PAF receptor, which may contribute to its preventive effect on myocardial ischemia-reperfusion induced arrhythmias.

  7. Persistence of pro-arrhythmic spatio-temporal calcium patterns in atrial myocytes: a computational study of ping waves.

    PubMed

    Thul, Rüdiger; Coombes, Stephen; Bootman, Martin D

    2012-01-01

    Clusters of ryanodine receptors within atrial myocytes are confined to spatially separated layers. In many species, these layers are not juxtaposed by invaginations of the plasma membrane (transverse tubules; 'T-tubules'), so that calcium-induced-calcium signals rely on centripetal propagation rather than voltage-synchronized channel openings to invade the interior of the cell and trigger contraction. The combination of this specific cellular geometry and dynamics of calcium release can lead to novel autonomous spatio-temporal calcium waves, and in particular ping waves. These are waves of calcium release activity that spread as counter-rotating sectors of elevated calcium within a single layer of ryanodine receptors, and can seed further longitudinal calcium waves. Here we show, using a computational model, that these calcium waves can dominate the response of a cell to electrical pacing and hence are pro-arrhythmic. This highlights the importance of modeling internal cellular structures when investigating mechanisms of cardiac dysfunction such as atrial arrhythmia.

  8. Removal of pharmaceutical residues using ozonation as intermediate process step at Linköping WWTP, Sweden.

    PubMed

    Baresel, Christian; Malmborg, Jonas; Ek, Mats; Sehlén, Robert

    2016-01-01

    Pilot tests as basis for the design, implementation and operation of a future full-scale oxidation plant completing the existing sewage treatment in Linköping, Sweden, were performed. Using an ozonation step between bio-sedimentation and post-denitrification processes, the primary goal was the removal of the highest priority substances to effluent water levels that will not cause adverse effects in the recipient considering the natural dilution. The study included initial emission screenings, dose control trials, treatment performance studies and eco-toxicity studies. At an ozone dose of 5 mg O3/L, most substances could be removed. Ecotoxicological tests showed no negative effect for the tested ozone doses. High levels of oxygen into the denitrification could be rapidly reduced in the biology. The number of bacteria in the treated water could be significantly reduced even at relatively low ozone doses. Based on these results, the planning for the full-scale implementation of the treatment system was initiated in 2015. PMID:27120656

  9. Li-Fraumeni syndrome.

    PubMed

    Ossa, Carlos Andrés; Molina, Gustavo; Cock-Rada, Alicia María

    2016-06-03

    The Li-Fraumeni syndrome is characterized clinically by the appearance of tumors in multiple organs generally at an early age. This hereditary condition is caused by germinal mutations in the TP53 gene, which codifies for the tumoural suppressor gene p53. We present the case of a patient aged 31 with clinical and molecular diagnosis of Li-Fraumeni syndrome who presented two synchronous tumors: a leiomyosarcoma on the forearm and a phyllodes breast tumour. She had a family history of cancer, including a son diagnosed with a cortical adrenal carcinoma when he was three years old, who died at five from the disease. Furthermore, her maternal grandmother and great-grandmother died of stomach cancer at 56 and 60 years old, respectively, while her other great-grandmother and a great aunt presented with breast cancer at the ages of 60 and 40, respectively. After genetic counseling, complete sequencing and analysis of duplications and deletions in the TP53 gene were ordered prior to diagnosis. The molecular analysis of a DNA sample taken from peripheral blood lymphocytes revealed the germinal mutation c.527G>T (p.Cys176Phe) on exon 5 of the TP53 gene, a deleterious mutation described previously in tumoural tissues. To our knowledge, this is the first published case in Colombia of Li-Fraumeni syndrome with confirmed molecular diagnosis. The diagnosis and management of Li-Fraumeni syndrome should be performed by a multidisciplinary team, and genetic counselling should be offered to patients and their relatives.

  10. Li-Fraumeni syndrome.

    PubMed

    Ossa, Carlos Andrés; Molina, Gustavo; Cock-Rada, Alicia María

    2016-01-01

    The Li-Fraumeni syndrome is characterized clinically by the appearance of tumors in multiple organs generally at an early age. This hereditary condition is caused by germinal mutations in the TP53 gene, which codifies for the tumoural suppressor gene p53. We present the case of a patient aged 31 with clinical and molecular diagnosis of Li-Fraumeni syndrome who presented two synchronous tumors: a leiomyosarcoma on the forearm and a phyllodes breast tumour. She had a family history of cancer, including a son diagnosed with a cortical adrenal carcinoma when he was three years old, who died at five from the disease. Furthermore, her maternal grandmother and great-grandmother died of stomach cancer at 56 and 60 years old, respectively, while her other great-grandmother and a great aunt presented with breast cancer at the ages of 60 and 40, respectively. After genetic counseling, complete sequencing and analysis of duplications and deletions in the TP53 gene were ordered prior to diagnosis. The molecular analysis of a DNA sample taken from peripheral blood lymphocytes revealed the germinal mutation c.527G>T (p.Cys176Phe) on exon 5 of the TP53 gene, a deleterious mutation described previously in tumoural tissues. To our knowledge, this is the first published case in Colombia of Li-Fraumeni syndrome with confirmed molecular diagnosis. The diagnosis and management of Li-Fraumeni syndrome should be performed by a multidisciplinary team, and genetic counselling should be offered to patients and their relatives. PMID:27622479

  11. Geoscience, Engineering, and Physics Opportunities at the China JinPing Underground Laboratory, its Extension, and at Other Sites > 2000 m

    NASA Astrophysics Data System (ADS)

    Wang, J. S.; Li, S.; Feng, X.

    2013-12-01

    The expansion of the China JinPing Laboratory (CJPL) is planned along a main branch of a bypass tunnel in the JinPing tunnel complex during 2013 -2015. This second phase of CJPL (CJPL-2) will have laboratory space increased from existing volume of nearly 2,000 m3 to approximately 80,000m3. In this presentation, we first review the geophysical and engineering findings during the originally tunnel excavations of the JingPing tunnel complexes which are substantially under overburdens from 2,000 to 2,500 m. Acoustic emissions associated with excavation disturbed zones and fracture openings in the excavation damaged zones were monitored before some sudden rock bust events were observed. The CJPL-2 offers opportunities to validate the rock burst modeling and prediction capabilities for other deep excavation studies. We also discuss the possibilities of other local, regional, and global monitoring of seismic-induced radon emission and electromagnetic monitoring studies, coupled process in situ measurements, and other experiments from the prospective of geoscience studies at depths over 2000 m. Geophysical and engineering opportunities were evaluated together with the physics experiments requirements in a 2015 town meeting associated with the 13th International Conference on Topics in Astroparticle and Underground Physics (TAUP). The main objective of CJPL-2 is to provide amber spaces needed worldwide for physics rare event detections that can be benefited to locate at CJPL-2, the currently deepest physics laboratory. Discussions the TAUP town meeting included one-ton expansions of current CJPL setups of Germanium detector in the China Darkmatter EXperiment (CDEX), two-phase Xenon detector of the PandiX experiment, other cryogenic dark matter detectors, superheated liquid detectors, scintillation solar neutrino detectors, neutrino-less double beta decay detectors, nuclear astrophysics synthesis accelerators, and other experimental and detector ideas.

  12. Electronic Properties of LiFePO4 and Li doped LiFePO4

    SciTech Connect

    Zhuang, G.V.; Allen, J.L.; Ross, P.N.; Guo, J.-H.; Jow, T.R.

    2005-06-28

    The potential use of different iron phosphates as cathodematerials in lithium-ion batteries has recently been investigated.1 Oneof the promising candidates is LiFePO4. This compound has severaladvantages in comparison to the state-of-the-art cathode material incommercial rechargeable lithium batteries. Firstly, it has a hightheoretical capacity (170 mAh/g). Secondly, it occurs as mineraltriphylite in nature and is inexpensive, thermally stable, non-toxic andnon-hygroscopic. However, its low electronic conductivity (~;10-9 S/cm)results in low power capability. There has been intense worldwideresearch activity to find methods to increase the electronic conductivityof LiFePO4, including supervalent ion doping,2 introducingnon-carbonaceous network conduction3 and carbon coating, and theoptimization of the carbon coating on LiFePO4 particle surfaces.4Recently, the Li doped LiFePO4 (Li1+xFe1-xPO4) synthesized at ARL hasyield electronic conductivity increase up to 106.5 We studied electronicstructure of LiFePO4 and Li doped LiFePO4 by synchrotron based soft X-rayemission (XES) and X-ray absorption (XAS) spectroscopies. XAS probes theunoccupied partial density of states, while XES the occupied partialdensity of states. By combining XAS and XES measurements, we obtainedinformation on band gap and orbital character of both LiFePO4 and Lidoped LiFePO4. The occupied and unoccupied oxygen partial density ofstates (DOS) of LiFePO4 and 5 percent Li doped LiFePO4 are presented inFig. 1. Our experimental results clearly indicate that LiFePO4 has wideband gap (~; 4 eV). This value is much larger than what is predicted byDFT calculation. For 5 percent Li doped LiFePO4, a new doping state wascreated closer to the Fermi level, imparting p-type conductivity,consistent with thermopower measurement. Such observation substantiatesthe suggestion that high electronic conductivity in Li1.05Fe0.95 PO4 isdue to available number of charge carriers in the material. Furthermore,Hall effect

  13. Developing an Activity and Absorption-based Quality Control Platform for Chinese Traditional Medicine: Application to Zeng-Sheng-Ping

    PubMed Central

    Yin, Taijun; Yang, Guanyi; Ma, Yong; Xu, Beibei; Hu, Ming; You, Ming; Gao, Song

    2015-01-01

    Ethnopharmacological relevance Zeng-Sheng-Ping (ZSP) is a marketed Chinese traditional medicine used for cancer prevention. Aim of the study Currently, for the quality control of Chinese traditional medicines, marker compounds are not selected based on bioactivities and pharmaceutical behaviors in most of the cases. Therefore, even if the “quality” of the medicine is controlled, the pharmacological effect could still be inconsistent. The aim of this study is to establish an activity and absorption-based platform to select marker compound(s) for the quality control of Chinese traditional medicines. Materials and methods We used ZSP as a reference Chinese traditional medicine to establish the platform. Activity guided fractionation approach was used to purify the major components from ZSP. NMR and MS spectra were used to elucidate the structure of the isolated compounds. MTT assay against oral carcinoma cell line (SCC2095) was performed to evaluate the activities. UPLC-MS/MS was used to quantify the pure compounds in ZSP and the active fraction. The permeabilities of the identified compounds were evaluated in the Caco-2 cell culture model. The intracellular accumulation of the isolated compounds was evaluated in the SCC2095 cells. Results The major compounds were identified from ZSP. The contents, anti-proliferation activities, permeabilities, and intracellular accumulations of these compounds were also evaluated. The structure of these purified compounds were identified by comparing the NMR and MS data with those of references as rutaevine (1), limonin (2) , evodol (3), obacunone (4), fraxinellone (5), dictamnine (6), maackiain (7), trifolirhizin (8), and matrine (9). The IC50 of compounds 5, 6, and 7 against SCC2095 cells were significantly lower than that of ZSP. The uptake permeability of compounds 5, 6, and 7 were 2.58 ± 0. 3 × 10−5, 4.33 ± 0.5 × 10−5, and 4.27 ± 0.8 × 10−5 respectively in the Caco-2 cell culture model. The intracellular

  14. Corrosion of type 316 stainless steel in molten LiF-LiCl-LiBr

    SciTech Connect

    Tortorelli, P.F.; DeVan, J.H.; Keiser, J.R.

    1981-01-01

    The properties of LiF-LiCl-LiBr salt make it attractive as a solvent for extracting tritium from a fusion reactor lithium blanket. Consequently, the corrosion of type 316 stainless steel by flowing (about 15 mm/s) LiF-LiCl-LiBr at a maximum temperature of 535/sup 0/C was studied to determine whether compatibility with the structural material would be limiting in such a system. The corrosion rate was found to be low (<2 ..mu..m/year) except immediately after the addition of a small amount of lithium metal to the salt. The lithium addition increased the corrosion rate to approx. 13.5 ..mu..m/year at 535/sup 0/C (approximately that of type 316 stainless steel exposed to lithium flowing at a similar velocity). At the proposed operating temperature (less than or equal to approx. 535/sup 0/C), however, it appears that type 316 stainless steel has acceptable compatibility with the tritium-processing salt LiF-LiCl-LiBr for use with a lithium blanket.

  15. Calorimetric studies of Cu-Li, Li-Sn, and Cu-Li-Sn.

    PubMed

    Fürtauer, S; Tserenjav, E; Yakymovych, A; Flandorfer, H

    2013-06-01

    Integral molar enthalpies of mixing were determined by drop calorimetry for Cu-Li-Sn at 1073 K along five sections xCu/xSn ≈ 1:1, xCu/xSn ≈ 2:3, xCu/xSn ≈ 1:4, xLi/xSn ≈ 1:1, and xLi/xSn ≈ 1:4. The integral and partial molar mixing enthalpies of Cu-Li and Li-Sn were measured at the same temperature, for Li-Sn in addition at 773 K. All binary data could be described by Redlich-Kister-polynomials. Cu-Li shows an endothermic mixing effect with a maximum in the integral molar mixing enthalpy of ∼5300 J · mol(-1) at xCu = 0.5, Li-Sn an exothermic minimum of ∼ -37,000 J · mol(-1) at xSn ∼ 0.2. For Li-Sn no significant temperature dependence between 773 K and 1073 K could be deduced. Our measured ternary data were fitted on the basis of an extended Redlich-Kister-Muggianu model for substitutional solutions. Additionally, a comparison of these results to the extrapolation model of Chou is given.

  16. Kinetic modeling of lipase-catalyzed esterification reaction between oleic acid and trimethylolpropane: a simplified model for multi-substrate multi-product ping-pong mechanisms.

    PubMed

    Bornadel, Amin; Akerman, Cecilia Orellana; Adlercreutz, Patrick; Hatti-Kaul, Rajni; Borg, Niklas

    2013-01-01

    Kinetic models are among the tools that can be used for optimization of biocatalytic reactions as well as for facilitating process design and upscaling in order to improve productivity and economy of these processes. Mechanism pathways for multi-substrate multi-product enzyme-catalyzed reactions can become very complex and lead to kinetic models comprising several tens of terms. Hence the models comprise too many parameters, which are in general highly correlated and their estimations are often prone to huge errors. In this study, Novozym(®) 435 catalyzed esterification reaction between oleic acid (OA) and trimethylolpropane (TMP) with continuous removal of side-product (water) was carried out as an example for reactions that follow multi-substrate multi-product ping-pong mechanisms. A kinetic model was developed based on a simplified ping-pong mechanism proposed for the reaction. The model considered both enzymatic and spontaneous reactions involved and also the effect of product removal during the reaction. The kinetic model parameters were estimated using nonlinear curve fitting through unconstrained optimization methodology and the model was verified by using empirical data from different experiments and showed good predictability of the reaction under different conditions. This approach can be applied to similar biocatalytic processes to facilitate their optimization and design.

  17. Phone-based Intervention under Nurse Guidance after Stroke (PINGS): Concept for Lowering Blood Pressure after Stroke in Sub-Saharan Africa

    PubMed Central

    Ovbiagele, Bruce

    2014-01-01

    Over the last four decades, rates of stroke occurrence in low-and middle-income countries (LMIC) have roughly doubled, whereas they have substantively decreased in high income countries (HIC). The majority of these LMIC are in Sub-Saharan Africa (SSA) where the burden of stroke will probably continue to rise over the next few decades due to an ongoing epidemiological transition. Moreover, SSA is circumstantially distinct: socioeconomic obstacles, cultural barriers, under-diagnosis, uncoordinated care, and shortage of physicians impede the ability of SSA countries to implement CVD prevention among people with DM in a timely and sustainable manner. Reducing the burden of stroke in SSA may necessitate an initial emphasis on high-risk individuals motivated to improve their health, multidisciplinary care coordination initiatives with clinical decision support, evidence-based interventions tailored for cultural relevance, task shifting from physicians to nurses and other health providers, use of novel patient-accessible tools, and a multi-level approach that incorporates individual- and system- level components. This article proposes a theory-based integrated blood pressure self-management intervention called Phone-based Intervention under Nurse Guidance after Stroke (PINGS) that could be tested among hospitalized stroke patients with poorly controlled HTN encountered in SSA. PINGS would comprise the implementation of nurse-run BP control clinics and administration of health technology (personalized phone text messaging and home telemonitoring), aimed at boosting patient self-efficacy and intrinsic motivation for sustained adherence to antihypertensive medications. PMID:25440360

  18. Lithium salts for advanced lithium batteries: Li-metal, Li-O2, and Li-S

    SciTech Connect

    Younesi, Reza; Veith, Gabriel M.; Johansson, Patrik; Edstrom, Kristina; Vegge, Tejs

    2015-06-01

    Presently lithium hexafluorophosphate (LiPF6) is the dominant Li-salt used in commercial rechargeable lithium-ion batteries (LIBs) based on a graphite anode and a 3-4 V cathode material. While LiPF6 is not the ideal Li-salt for every important electrolyte property, it has a uniquely suitable combination of properties (temperature range, passivation, conductivity, etc.) rendering it the overall best Li-salt for LIBs. However, this may not necessarily be true for other types of Li-based batteries. Indeed, next generation batteries, for example lithium-metal (Li-metal), lithium-oxygen (Li-O2), and lithium sulphur (Li-S), require a re-evaluation of Li-salts due to the different electrochemical and chemical reactions and conditions within such cells. Furthermore, this review explores the critical role Li-salts play in ensuring in these batteries viability.

  19. Lithium salts for advanced lithium batteries: Li-metal, Li-O2, and Li-S

    DOE PAGES

    Younesi, Reza; Veith, Gabriel M.; Johansson, Patrik; Edstrom, Kristina; Vegge, Tejs

    2015-06-01

    Presently lithium hexafluorophosphate (LiPF6) is the dominant Li-salt used in commercial rechargeable lithium-ion batteries (LIBs) based on a graphite anode and a 3-4 V cathode material. While LiPF6 is not the ideal Li-salt for every important electrolyte property, it has a uniquely suitable combination of properties (temperature range, passivation, conductivity, etc.) rendering it the overall best Li-salt for LIBs. However, this may not necessarily be true for other types of Li-based batteries. Indeed, next generation batteries, for example lithium-metal (Li-metal), lithium-oxygen (Li-O2), and lithium sulphur (Li-S), require a re-evaluation of Li-salts due to the different electrochemical and chemical reactions andmore » conditions within such cells. Furthermore, this review explores the critical role Li-salts play in ensuring in these batteries viability.« less

  20. Electronic Properties of LiFePO4 and Li doped LiFePO4

    SciTech Connect

    Allen, J.L.; Zhuang, G.V.; Ross, P.N.; Guo, J.-H.; Jow, T.R.

    2006-05-31

    LiFePO{sub 4} has several potential advantages in comparison to the transition metal oxide cathode materials used in commercial lithium-ion batteries. However, its low intrinsic electronic conductivity ({approx} 10{sup -9} S/cm) is problematic. We report here a study by soft x-ray absorption/emission spectroscopy of the electronic properties of undoped LiFePO{sub 4} and Li-doped LiFePO{sub 4} in which Li{sup +} ions are substituted for Fe{sup 2+} ions in an attempt to increase the intrinsic electronic conductivity. The conductivities of the Li{sub 1+x}Fe{sub 1-x}PO{sub 4} samples were, however, essentially unchanged from that of the undoped LiFePO{sub 4}. Nonetheless, evidence for changing the electronic properties of LiFePO{sub 4} by doping with excess Li+ was observed by the XAS/XES spectroscopy. New pre-edge features the O-1s XAS spectrum of Li{sub 1.05}Fe{sub 0.95}PO4 is a direct indication that the charge compensation for substitution of Fe{sup 2+} by Li{sup +} resides in the unoccupied O-2p orbitals. A charge transfer (CT) excitation was also observed in the doped material implying that the unoccupied O-2p orbitals created by doping are strongly hybridized with unoccupied Fe-3d orbitals of neighboring sites. However, the strong covalent bonding within the (PO{sub 4}){sup 3-} anions and the large separation of the Fe cations means that the charge created by doping is not delocalized in the manner of electrons or holes in a semiconductor.

  1. 6Li from Solar Flares.

    PubMed

    Ramaty; Tatischeff; Thibaud; Kozlovsky; Mandzhavidze

    2000-05-10

    By introducing a hitherto ignored 6Li producing process, due to accelerated 3He reactions with 4He, we show that accelerated particle interactions in solar flares produce much more 6Li than 7Li. By normalizing our calculations to gamma-ray data, we demonstrate that the 6Li produced in solar flares, combined with photospheric 7Li, can account for the recently determined solar wind lithium isotopic ratio, obtained from measurements in lunar soil, provided that the bulk of the flare-produced lithium is evacuated by the solar wind. Further research in this area could provide unique information on a variety of problems, including solar atmospheric transport and mixing, solar convection and the lithium depletion issue, and solar wind and solar particle acceleration.

  2. Recovery of Li from alloys of Al- Li and Li- Al using engineered scavenger compounds

    DOEpatents

    Riley, W. D.; Jong, B. W.; Collins, W. K.; Gerdemann, S. J.

    1994-01-01

    A method of producing lithium of high purity from lithium aluminum alloys using an engineered scavenger compound, comprising: I) preparing an engineered scavenger compound by: a) mixing and heating compounds of TiO2 and Li2CO3 at a temperature sufficient to dry the compounds and convert Li.sub.2 CO.sub.3 to Li.sub.2 O; and b) mixing and heating the compounds at a temperature sufficient to produce a scavenger Li.sub.2 O.3TiO.sub.2 compound; II) loading the scavenger into one of two electrode baskets in a three electrode cell reactor and placing an Al-Li alloy in a second electrode basket of the three electrode cell reactor; III) heating the cell to a temperature sufficient to enable a mixture of KCl-LiCl contained in a crucible in the cell to reach its melting point and become a molten bath; IV) immersing the baskets in the bath until an electrical connection is made between the baskets to charge the scavenger compound with Li until there is an initial current and voltage followed by a fall off ending current and voltage; and V) making a connection between the basket electrode containing engineered scavenger compound and a steel rod electrode disposed between the basket electrodes and applying a current to cause Li to leave the scavenger compound and become electrodeposited on the steel rod electrode.

  3. Ab initio and kinetic Monte Carlo study of lithium diffusion in LiSi, Li12Si7, Li13Si5 and Li15Si4

    NASA Astrophysics Data System (ADS)

    Moon, Janghyuk; Lee, Byeongchan; Cho, Maenghyo; Cho, Kyeongjae

    2016-10-01

    The kinetics of lithium atoms in various Li-Si binary compounds are investigated using density functional theory calculations and kinetic Monte Carlo calculations. The values of the Li migration energy barriers are identified by NEB calculations with vacancy-mediated, interstitial and exchange migration mechanisms in crystalline LiSi, Li12Si7, Li13Si4, and Li15Si4. A comparison of these NEB results shows that the vacancy-mediated Li migration is identified as the dominant diffusion mechanisms in Li-Si compounds. The diffusion coefficients of Li in Li-Si compounds at room temperature are determined by KMC simulation. From the KMC results, the recalculated migration energy barriers in LiSi, Li12Si7, Li13Si4, and Li15Si4 correspond to 0.306, 0.301, 0.367 and 0.320 eV, respectively. Compared to the Li migration energy barrier of 0.6 eV in crystalline Si, the drastic reduction in the Li migration energy barriers in the lithiated silicon indicates that the initial lithiation of the Si anode is the rate-limiting step. Furthermore, it is also found that Si migration is possible in Li-rich configurations. On the basis of these findings, the underlying mechanisms of kinetics on the atomic scale details are elucidated.

  4. Li-Fraumeni Syndrome.

    PubMed

    Correa, Hernán

    2016-06-01

    Li-Fraumeni syndrome (LFS) is a cancer predisposition syndrome caused by a germline mutation of the TP53 gene on chromosome 17p13.1. It has an autosomal dominant pattern of inheritance with high penetrance. These patients have a very high lifetime cumulative risk of developing multiple malignancies and have a strong family history of early-onset malignancies. The protein p53, encoded by TP53, has a complex set of genome-preserving functions initiated during episodes of cellular stress and DNA damage. In LFS, TP53 gene mutations cause the loss of function of p53, leading to downstream events permissive for development of various malignancies throughout life. The LFS component tumors include soft tissue sarcomas, osteosarcoma, premenopausal breast cancer, brain tumors, and adrenal cortical carcinomas. Multiple types of sarcomas have been reported in association with LFS; this review article will focus on the most frequently encountered pediatric sarcomas associated with TP53 mutations. PMID:27617148

  5. Electron-impact Ionization Of Li2 And Li+2

    SciTech Connect

    Colgan, James P

    2008-01-01

    Electron-impact ionization cross sections for Li{sub 2} and Li{sup +}{sub 2} are calculated using a configuration-average distorted-wave method. Bound orbitals for the molecule and its ions are calculated using a single configuration self-consistent field method based on a linear combination of Slater-type orbitals. The bound orbitals are transformed onto a two-dimensional lattice ({tau}, {theta}), which is variable in the radial coordinate and constant in the angular coordinate, from which Hartree with local exchange potentials are constructed. The single particle Schrodinger equation is then solved for continuum distorted-waves with S-matrix boundary conditions. Total ionization cross sections for Li{sub 2} at an equilibrium internuclear separation of R = 5.0 and for Li{sup +}{sub 2} at an equilibrium internuclear separation of R = 5.9 are presented.

  6. Outgassing in the LiD/LiOH System

    SciTech Connect

    Schildbach, M; Siekhaus, W; Dinh, L; McLean II, W

    2003-10-17

    Temperature programmed decomposition (TPD), scanning electron microscopy (SEM) and x-ray diffraction (XRD) were performed on lithium hydroxide (LiOH) polycrystallites and LiD/LiOH composite nanocrystals. Our studies revealed that LiOH grains are thermally decomposed into Li{sub 2}O, releasing water, following a three dimensional phase boundary movement from the surface inward. The rate of H{sub 2}O released is controlled by a rate constant that is expressed as: d{alpha}/dt ={upsilon}.e {sup -E/RT}.f({alpha}) where t is time; {alpha} is the reacted fraction (0 to 1); {upsilon} is the pre-exponential factor which includes many constants describing the initial state of the sample such as three dimensional shape factors of initial particles, molecular mass, density, stoichiometric factors of chemical reaction, active surface and number of lattice imperfections, and so forth; E is the activation energy for the rate controlling process, R is the gas molar constant, and f({alpha}) is an analytical function which is determined by the rate-limiting reaction mechanism (random nucleation, diffusion, phase boundary motion, etc.). Due to fewer neighboring bonds at the surface, surface lithium hydroxide decomposes at low activation energies of {approx} 86-92 kJ/mol with corresponding pre-exponential factors of {approx} 2.7 x 10{sup 6}-1.2 x 10{sup 7} s{sup -1}. Near-surface hydroxide, having bonding much like bulk hydroxide but experiencing more stress/strain, decomposes at activation energies of {approx} 89-108 kJ/mol with corresponding pre-exponential factors of {approx} 9.5 x 10{sup 5}-9.3 x 10{sup 7}s{sup -1}. Bulk lithium hydroxide, however, decomposes at higher activation energies of {approx} 115-142 kJ/mol with corresponding pre-exponential factors of {approx} 4.8 x 10{sup 6}-1.2 x 10{sup 9} s{sup -1}. Bulk lithium hydroxide is very stable if stored at room temperature. However, lithium hydroxide molecules at or near the surface of the grains slowly decompose, in a vacuum

  7. Insights into Li(+) Migration Pathways in α-Li3VF6: A First-Principles Investigation.

    PubMed

    Islam, Mazharul M; Wilkening, Martin; Heitjans, Paul; Bredow, Thomas

    2012-11-01

    Magnetic, structural, and defect properties of lithium vanadium hexafluoride (α-Li3VF6) are investigated theoretically with periodic quantum chemical methods. It is found that the ferromagnetic phase is more stable than the antiferromagnetic phase. The crystal structure contains three inequivalent Li sites (Li(1), Li(2), and Li(3)), where Li(1) occupies the middle position of the triplet Li(2)-Li(1)-Li(3). The calculated Li vacancy formation energies show that vacancy formation is preferred for the Li(1) and Li(3) sites compared to the Li(2) position. The Li exchange processes between Li(1) ↔ Li(3), Li(1) ↔ Li(2), and Li(2) ↔ Li(3) are studied by calculating the Li(+) migration between these sites using the climbing-image nudged elastic band approach. It is observed that Li exchange in α-Li3VF6 may take place in the following order: Li(1) ↔ Li(3) > (Li(1) ↔ Li(2) > Li(2) ↔ Li(3). This is in agreement with recently published results obtained from 1D and 2D (6)Li exchange nuclear magnetic resonance spectroscopy.

  8. Anion Coordination Interactions in Solvates with the Lithium Salts LiDCTA and LiTDI

    SciTech Connect

    McOwen, Dennis W.; Delp, Samuel A.; Paillard, Elie; Herriot, Cristelle; Han, Sang D.; Boyle, Paul D.; Sommer, Roger D.; Henderson, Wesley A.

    2014-04-17

    Lithium 4,5-dicyano-1,2,3-triazolate (LiDCTA) and lithium 2-trifluoromethyl-4,5-dicyanoimidazole (LiTDI) are two salts proposed for lithium battery electrolyte applications, but little is known about the manner in which the DCTA- and TDI- anions coordinate Li+ cations. To explore this in-depth, crystal structures are reported here for two solvates with LiDCTA: (G2)1:LiDCTA and (G1)1:LiDCTA with diglyme and monoglyme, respectively, and seven solvates with LiTDI: (G1)2:LiTDI, (G2)2:LiTDI, (G3)1:LiTDI, (THF)1:LiTDI, (EC)1:LiTDI, (PC)1:LiTDI and (DMC)1/2:LiTDI with monoglyme, diglyme, triglyme, tetrahydrofuran, ethylene carbonate, propylene carbonate and dimethyl carbonate, respectively. These latter solvate structures are compared with the previously reported acetonitrile (AN)2:LiTDI structure. The solvates indicate that the LiTDI salt is much less associated than the LiDCTA salt and that the ions in LiTDI, when aggregated in solvates, have a very similar TDI-...Li+ cation mode of coordination through both the anion ring and cyano nitrogen atoms. Such coordination facilitates the formation of polymeric ion aggregates, instead of dimers. Insight into such ion speciation is instrumental for understanding the electrolyte properties of aprotic solvent mixtures with these salts.

  9. Electrolytic LiCl precipitation from LiCl-KCl melt in porous Li-Al anodes

    SciTech Connect

    Vallet, C.E.; Heatherly, D.E.; Heatherly, L. Jr.; Braunstein, J.

    1983-12-01

    Composition gradients such as those predicted to occur during discharge of porous Li-Al negative electrodes of Li/S batteries with LiCl-KCl eutectic electrolyte were generated and measured in the LiCl-KCl anolyte of an electrolysis cell with Li-Al electrodes. Precipitation of lithium chloride during electrolysis was observed by two-dimensional scanning of electrolyte composition in the front part of quenched porous Li-Al anode sections using SEM/EDX. The distribution of sites of increased or decreased LiCl concentration, LiCl saturation and precipitation was mapped. Cathodic regions were observed near the cell walls. Preliminary results of analysis by Auger spectroscopy confirm LiCl precipitation in the porous anode. 16 references, 7 figures, 1 table.

  10. Electrolytic LiCl precipitation from LiCl-KCl melt in porous Li-Al anodes

    NASA Astrophysics Data System (ADS)

    Vallet, C. E.; Heatherly, D. E.; Heatherly, L., Jr.; Braunstein, J.

    1983-12-01

    Composition gradients such as those predicted to occur during discharge of porous Li-Al negative electrodes of Li/S batteries with LiCl-KCl eutectic electrolyte were generated and measured in the LiCl-KCl anolyte of an electrolysis cell with Li-Al electrodes. Precipitation of lithium chloride during electrolysis was observed by two-dimensional scanning of electrolyte composition in the front part of quenched porous Li-Al anode sections using SEM/EDX. The distribution of sites of increased or decreased LiCl concentration, LiCl saturation and precipitation was mapped. Cathodic regions were observed near the cell walls. Preliminary results of analysis by Auger spectroscopy confirm LiCl precipitation in the porous anode.

  11. Metallic Li colloids studied by Li-7 MAS NMR in electron-irradiated LiF

    NASA Astrophysics Data System (ADS)

    Zogal, O. J.; Beuneu, F.; Vajda, P.; Florian, P.; Massiot, D.

    Li-7 MAS NMR spectra of 2.5 MeV electron-irradiated LiF crystals have been measured in a field of 9.4 T. Besides the resonance line of the ionic compound, a second well-separated spectrum is observed in the region of the Knight shift value for metallic lithium. At room temperature, the latter can be decomposed into two components with different Knight shift and linewidth values. When the temperature is increased, line narrowing takes place at first, indicating shortening of correlation times for self-diffusion, independently in both components. Above 370 K, both lines broaden and approach each other before collapsing into a single line. The high ppm component disappears after crossing the melting temperature of metallic lithium (454 K). The two lines are attributed to different types of metallic Li: one to bulk-like metal, the other to Li present initially under pressure and relaxing to the former under thermal treatment.

  12. Transport properties derived from ion-atom collisions: 6Li-6Li+ and 6Li-7Li+ Cases

    NASA Astrophysics Data System (ADS)

    Bouledroua, Moncef; Bouchelaghem, Fouzia; LPR Team

    2014-10-01

    This investigation treats quantum-mechanically the ion- atom collisions and computes the transport coefficients, such as the coefficients of mobility and diffusion. For the case of lithium, the calculations start by determining the gerade and ungerade potential curves through which ionic lithium approaches ground lithium. Then, by considering the isotopic effects and nuclear spins, the elastic and charge-transfer cross sections are calculated for the case of 6Li+and7Li+ colliding with 6Li. Finally, the temperature-dependent diffusion and mobility coefficients are analyzed, and the results are contrasted with those obtained from literature. The main results of this work have been recently published in. This work has been realized within the frames of the CNEPRU Project D01120110036 of the Algerian Ministry of Higher Education.

  13. Li2S Film Formation on Lithium Anode Surface of Li-S batteries.

    PubMed

    Liu, Zhixiao; Bertolini, Samuel; Balbuena, Perla B; Mukherjee, Partha P

    2016-02-01

    The precipitation of lithium sulfide (Li2S) on the Li metal anode surface adversely impacts the performance of lithium-sulfur (Li-S) batteries. In this study, a first-principles approach including density functional theory (DFT) and ab initio molecular dynamics (AIMD) simulations is employed to theoretically elucidate the Li2S/Li metal surface interactions and the nucleation and growth of a Li2S film on the anode surface due to long-chain polysulfide decomposition during battery operation. DFT analyses of the energetic properties and electronic structures demonstrate that a single molecule adsorption on Li surface releases energy forming chemical bonds between the S atoms and Li atoms from the anode surface. Reaction pathways of the Li2S film formation on Li metal surfaces are investigated based on DFT calculations. It is found that a distorted Li2S (111) plane forms on a Li(110) surface and a perfect Li2S (111) plane forms on a Li(111) surface. The total energy of the system decreases along the reaction pathway; hence Li2S film formation on the Li anode surface is thermodynamically favorable. The calculated difference charge density of the Li2S film/Li surface suggests that the precipitated film would interact with the Li anode via strong chemical bonds. AIMD simulations reveal the role of the anode surface structure and the origin of the Li2S formation via decomposition of Li2S8 polysulfide species formed at the cathode side and dissolved in the electrolyte medium in which they travel to the anode side during battery cycling. PMID:26836249

  14. Li2S Film Formation on Lithium Anode Surface of Li-S batteries.

    PubMed

    Liu, Zhixiao; Bertolini, Samuel; Balbuena, Perla B; Mukherjee, Partha P

    2016-02-01

    The precipitation of lithium sulfide (Li2S) on the Li metal anode surface adversely impacts the performance of lithium-sulfur (Li-S) batteries. In this study, a first-principles approach including density functional theory (DFT) and ab initio molecular dynamics (AIMD) simulations is employed to theoretically elucidate the Li2S/Li metal surface interactions and the nucleation and growth of a Li2S film on the anode surface due to long-chain polysulfide decomposition during battery operation. DFT analyses of the energetic properties and electronic structures demonstrate that a single molecule adsorption on Li surface releases energy forming chemical bonds between the S atoms and Li atoms from the anode surface. Reaction pathways of the Li2S film formation on Li metal surfaces are investigated based on DFT calculations. It is found that a distorted Li2S (111) plane forms on a Li(110) surface and a perfect Li2S (111) plane forms on a Li(111) surface. The total energy of the system decreases along the reaction pathway; hence Li2S film formation on the Li anode surface is thermodynamically favorable. The calculated difference charge density of the Li2S film/Li surface suggests that the precipitated film would interact with the Li anode via strong chemical bonds. AIMD simulations reveal the role of the anode surface structure and the origin of the Li2S formation via decomposition of Li2S8 polysulfide species formed at the cathode side and dissolved in the electrolyte medium in which they travel to the anode side during battery cycling.

  15. Reactions of metallic Li or LiC6 with organic solvents for lithium ion battery

    NASA Astrophysics Data System (ADS)

    Nakajima, Tsuyoshi; Hirobayashi, Yuki; Takayanagi, Yuki; Ohzawa, Yoshimi

    2013-12-01

    DSC (Differential Scanning Calorimetry) study has been made on the reactions of metallic Li or LiC6 with organic solvents for lithium ion battery. Ethylene carbonate (EC) more easily reacts with metallic Li and LiC6 than propylene carbonate (PC). This may be because formation of lithium alkyl carbonate is more difficult for PC than EC. On the other hand, diethyl carbonate (DEC), ethyl methyl carbonate (EMC) and dimethyl carbonate (DMC) react with Li in the same manner. Reactions of Li and LiC6 with organic solvents have been discussed based on the results of quantum calculation.

  16. The Electrochemistry of Li-LiCl-Li2O Molten Salt Systems and the Role of Moisture

    NASA Astrophysics Data System (ADS)

    Gese, Natalie J.

    Uranium can be recovered from uranium-oxide (UO2) spent fuel through the combination of oxide reduction and electrorefining processes. During oxide reduction, the spent fuel is introduced to molten LiCl-Li 2O salt at 650°C, and the UO2 is reduced to uranium metal via two routes: (1) electrochemically, and (2) chemically by lithium metal (Li°) that is produced electrochemically. However, the hygroscopic nature of both LiCl and Li2O leads to the formation of LiOH, contributing hydroxyl anions (OH-), the reduction of which interferes with the Li° generation required for the chemical reduction of UO 2. In order for the oxide reduction process to be an effective method for the treatment of uranium-oxide fuel, the role of moisture in the LiCl-Li 2O system must be understood. The behavior of moisture in the LiCl-Li 2O molten-salt system was studied using cyclic voltammetry, chronopotentiometry, and chronoamperometry while reduction to hydrogen was confirmed with gas chromatography.

  17. Domain II loop 3 of Bacillus thuringiensis Cry1Ab toxin is involved in a "ping pong" binding mechanism with Manduca sexta aminopeptidase-N and cadherin receptors.

    PubMed

    Pacheco, Sabino; Gómez, Isabel; Arenas, Ivan; Saab-Rincon, Gloria; Rodríguez-Almazán, Claudia; Gill, Sarjeet S; Bravo, Alejandra; Soberón, Mario

    2009-11-20

    Bacillus thuringiensis Cry toxins are used worldwide as insecticides in agriculture, in forestry, and in the control of disease transmission vectors. In the lepidopteran Manduca sexta, cadherin (Bt-R(1)) and aminopeptidase-N (APN) function as Cry1A toxin receptors. The interaction with Bt-R(1) promotes cleavage of the amino-terminal end, including helix alpha-1 and formation of prepore oligomer that binds to APN, leading to membrane insertion and pore formation. Loops of domain II of Cry1Ab toxin are involved in receptor interaction. Here we show that Cry1Ab mutants located in domain II loop 3 are affected in binding to both receptors and toxicity against Manduca sexta larvae. Interaction with both receptors depends on the oligomeric state of the toxin. Monomers of loop 3 mutants were affected in binding to APN and to a cadherin fragment corresponding to cadherin repeat 12 but not with a fragment comprising cadherin repeats 7-12. In contrast, the oligomers of loop 3 mutants were affected in binding to both Bt-R(1) fragments but not to APN. Toxicity assays showed that either monomeric or oligomeric structures of Cry1Ab loop 3 mutations were severely affected in insecticidal activity. These data suggest that loop 3 is differentially involved in the binding with both receptor molecules, depending on the oligomeric state of the toxin and also that possibly a "ping pong" binding mechanism with both receptors is involved in toxin action.

  18. Yu Ping Feng San reverses cisplatin-induced multi-drug resistance in lung cancer cells via regulating drug transporters and p62/TRAF6 signalling

    PubMed Central

    Lou, Jian-Shu; Yan, Lu; Bi, Cathy W. C.; Chan, Gallant K. L.; Wu, Qi-Yun; Liu, Yun-Le; Huang, Yun; Yao, Ping; Du, Crystal Y. Q.; Dong, Tina T. X.; Tsim, Karl W. K.

    2016-01-01

    Yu Ping Feng San (YPFS), an ancient Chinese herbal decoction composed of Astragali Radix, Atractylodis Macrocephalae Rhizoma and Saposhnikoviae Radix, has been used in the clinic for treating immune deficiency. In cancer therapy, YPFS is being combined with chemotherapy drugs to achieve improved efficacy; however, scientific evidence to illustrate this combination effect is lacking. The present study aims to demonstrate the anti-drug resistance of YPFS in cisplatin (DDP)-resistant non-small cell lung cancer cells (A549/DDP). The application of YPFS exhibited a synergistic enhancement of DDP-induced cytotoxicity as well as of the apoptotic signalling molecules. DDP-induced expression of the multi-drug-resistance efflux transporters was markedly reduced in the presence of YPFS, resulting in a higher intracellular concentration of DDP. In addition, the application of YPFS increased DDP-induced ROS accumulation and MMP depletion, decreased p62/TRAF6 signalling in DDP-treated A549/DDP cells. The co-treatment of DDP and YPFS in tumour-bearing mice reduced the tumour size robustly (by more than 80%), which was much better than the effect of DDP alone. These results indicate that YPFS can notably improve the DDP-suppressed cancer effect, which may be a consequence of the elevation of intracellular DDP via the drug transporters as well as the down regulation of p62/TRAF6 signalling. PMID:27558312

  19. Yu Ping Feng San, an Ancient Chinese Herbal Decoction Containing Astragali Radix, Atractylodis Macrocephalae Rhizoma and Saposhnikoviae Radix, Regulates the Release of Cytokines in Murine Macrophages

    PubMed Central

    Du, Crystal Y. Q.; Choi, Roy C. Y.; Zheng, Ken Y. Z.; Dong, Tina T. X.; Lau, David T. W.; Tsim, Karl W. K.

    2013-01-01

    Yu Ping Feng San (YPFS), a Chinese herbal decoction, is composed of Astragali Radix (AR; Huangqi), Atractylodis Macrocephalae Rhizoma (AMR; Baizhu) and Saposhnikoviae Radix (SR; Fangfeng) in a weight ratio of 1∶2∶1. Clinically, YPFS has been widely used to regulate immune functions; however, the action mechanism of it is not known. Here, we addressed this issue by providing detail analyses of chemical and biological properties of YPFS. By using rapid resolution liquid chromatography coupled with mass spectrometry, fifteen chemicals deriving from different herbs of YPFS were determined, and which served as a control for the standardization of the herbal extract of YPFS. In general, the amounts of chosen chemical markers were higher in a preparation of YPFS as compared to that of single herb or two-herb compositions. In order to reveal the immune functions of YPFS, the standardized extract was applied onto cultured murine macrophages. The treatment of YPFS stimulated the mRNA and protein expressions of pro-inflammatory cytokines via activation of NF-κB by enhancing IκBα degradation. In contrast, the application of YPFS suppressed the expressions of pro-inflammatory cytokines significantly in the lipopolysaccharide (LPS)-induced chronic inflammation model. In addition, YPFS could up regulate the phagocytic activity in cultured macrophages. These results therefore supported the bi-directional immune-modulatory roles of YPFS in regulating the releases of cytokines from macrophages. PMID:24244327

  20. Comparative investigation of concentrations of major and trace elements in organic and conventional Danish agricultural crops. 1. Onions (Allium cepa Hysam) and peas (Pisum sativum ping pong).

    PubMed

    Gundersen, V; Bechmann, I E; Behrens, A; Stürup, S

    2000-12-01

    210 samples of onions (Allium cepa Hysam) from 11 conventionally and 10 organically cultivated sites and 190 samples of peas (Pisum sativum Ping Pong) from 10 conventionally and 9 organically cultivated sites in Denmark were collected and analyzed for 63 and 55 major and trace elements, respectively, by high-resolution inductively coupled plasma mass spectrometry. Sampling, sample preparation, and analysis of the samples were performed under carefully controlled contamination-free conditions. Comparative statistical tests of the element concentration mean values for each site show significantly (p < 0.05) different levels of Ca, Mg, B, Bi, Dy, Eu, Gd, Lu, Rb, Sb, Se, Sr, Ti, U, and Y between the organically and conventionally grown onions and significantly (p < 0.05) different levels of P, Gd, and Ti between the organically and conventionally grown peas. Principal component analysis (PCA) applied to the 63 elements measured in the individual onion samples from the 21 sites split up the sites into two groups according to the cultivation method when the scores of the first and third principal components were plotted against each other. Correspondingly, for peas, a PCA applied to the 55 elements measured as mean values for each site split up the 19 sites into two groups according to the cultivation method when the scores of the third and fourth principal component were plotted against each other. The methodology may be used as authenticity control for organic cultivation after further method development. PMID:11312781

  1. High accuracy ab initio studies of Li6+, Li6-, and three isomers of Li6

    NASA Astrophysics Data System (ADS)

    Temelso, Berhane; Sherrill, C. David

    2005-02-01

    The structures and energetics of Li6+, Li6- and three isomers of Li6 are investigated using the coupled-cluster singles, doubles and perturbative triples [CCSD(T)] method with valence and core-valence correlation consistent basis sets of double- to quadruple-ζ quality (cc-pVXZ and cc-pCVXZ, where X =D-Q). These results are compared with qualitatively different predictions by less reliable methods. Our results conclusively show that the D4h isomer is the global minimum structure for Li6. It is energetically favored over the C5v and D3h structures by about 5.1 and 7.1kcalmol-1, respectively, after the inclusion of the zero-point vibrational energy (ZPVE) correction. Our most accurate total atomization energies are 123.2, 117.6, and 115.7kcalmol-1 for the D4h, C5v, and D3h isomers, respectively. Comparison of experimental optical absorption spectra with our computed electronic spectra also indicate that the D4h isomer is indeed the most stable structure. The cation, anion, and some higher spin states are investigated using the less expensive cc-pCVDZ basis set. Adiabatic ionization energies and electron affinities are reported and compared with experimental values. Predictions of molecular properties are found to be sensitive to the basis set used and to the treatment of electron correlation.

  2. Evaluation of LiCl-LiBr-KBr electrolyte for Li-alloy/metal disulfide cells

    SciTech Connect

    Kaun, T.D.

    1987-01-01

    The physical properties of a new molten salt electrolyte for lithium-alloy/metal disulfide cells, 25 mol % LiCl-37 mol % LiBr-38 mol % KBr, were investigated. Cyclic voltammetry of FeS/sub 2/ in the new molten salt at 375 to 425/sup 0/C indicated improved electrochemistry and stability of the reaction on the upper voltage plateau (1.75 V vs. LiAl). The new electrolyte provides an opportunity to operate an upper-plateau (UP) FeS/sub 2/ electrode at a lower temperature, 400/sup 0/C, and with a higher activity of lithium ion in the electrolyte. The broad liquidus of this molten salt at 400/sup 0/C also supports operation at high current density. Testing of 24- to 48-Ah cells indicated greater than 50% improved energy and power density over the conventional two-plateau FeS/sub 2/ cell with LiCl-KCl electrolyte. The conventional FeS/sub 2/ cells would lose 50% of their upper-plateau capacity within 200 cycles. The elimination of this capacity decline problem was demonstrated by 400 cycles and 5400 h of stable operation with a dense UP FeS/sub 2/ electrode cell, which maintained 89% utilization of theoretical capacity throughout the test.

  3. Reactive transport modeling of Li isotope fractionation

    NASA Astrophysics Data System (ADS)

    Wanner, C.; Sonnenthal, E. L.

    2013-12-01

    The fractionation of Li isotopes has been used as a proxy for interaction processes between silicate rocks and any kind of fluids. In particular, Li isotope measurements are powerful because Li is almost exclusively found in silicate minerals. Moreover, the two stable Li isotopes, 6Li and 7Li, differ by 17% in mass introducing a large mass dependent isotope fractionation even at high temperature. Typical applications include Li isotope measurements along soil profiles and of river waters to track silicate weathering patterns and Li isotope measurements of geothermal wells and springs to assess water-rock interaction processes in geothermal systems. For this contribution we present a novel reactive transport modeling approach for the simulation of Li isotope fractionation using the code TOUGHREACT [1]. It is based on a 6Li-7Li solid solution approach similar to the one recently described for simulating Cr isotope fractionation [2]. Model applications include the simulation of granite weathering along a 1D flow path as well as the simulation of a column experiment related to an enhanced geothermal system. Results show that measured δ7Li values are mainly controlled by (i) the degree of interaction between Li bearing primary silicate mineral phases (e.g., micas, feldspars) and the corresponding fluid, (ii) the Li isotope fractionation factor during precipitation of secondary mineral phases (e.g., clays), (iii) the Li concentration in primary and secondary Li bearing mineral phases and (iv) the proportion of dissolved Li that adsorbs to negatively charged surfaces (e.g., clays, Fe/Al-hydroxides). To date, most of these parameters are not very well constrained. Reactive transport modeling thus currently has to rely on many assumptions. Nevertheless, such models are powerful because they are the only viable option if individual contributions of all potential processes on the resulting (i.e., measured) Li isotopic ratio have to be quantitatively assessed. Accordingly, we

  4. Nanoscale spinel LiFeTiO4 for intercalation pseudocapacitive Li(+) storage.

    PubMed

    Chen, Ruiyong; Knapp, Michael; Yavuz, Murat; Ren, Shuhua; Witte, Ralf; Heinzmann, Ralf; Hahn, Horst; Ehrenberg, Helmut; Indris, Sylvio

    2015-01-14

    Intercalation pseudocapacitive Li(+) storage has been recognized recently in metal oxide materials, wherein Li(+) intercalation into the lattice is not solid-state diffusion-limited. This may bridge the performance gap between electrochemical capacitors and battery materials. To date, only a few materials with desired crystal structure and with well-defined nanoarchitectures have been found to exhibit such attractive behaviour. Herein, we report for the first time that nanoscale spinel LiFeTiO4 as a cathode material for Li-ion batteries exhibits intercalation pseudocapacitive Li(+) storage behaviour. Nanoscale LiFeTiO4 nanoparticles with native carbon coating were synthesized by a sol-gel route. A fast and large-amount of Li(+) storage (up to 1.6 Li(+) per formula unit over cycling) in the nanoscale LiFeTiO4 host has been achieved without compromising kinetics.

  5. Observations of 6Li in Galactic Stars

    NASA Astrophysics Data System (ADS)

    Hobbs, L. M.

    2000-05-01

    Several important goals have motivated observationally challenging attempts to measure 6Li/7Li isotopic ratios and, hence, 6Li abundances in stars. In particular, a general understanding, based on cosmic-ray spallation reactions, of the nucleosynthetic origins of the very low Galactic abundances of 6Li, Be, and B has followed from measurements of both the relative and the absolute abundances of these various, related isotopes. In the cases of Be and B, such data are currently available for 20 or more stars that span a wide range of metallicity, i.e. age. In contrast, nuclear burning of the very fragile 6Li nuclei during stellar contraction to the main sequence generally reduces the surface abundance of this lighter isotope below the observable limit. A few relatively nearby stars of low metallicity which are found close to the Population II main-sequence turnoff during later hydrogen burning seem to constitute the observable exceptions. Spectra of very high quality, typically with R > 100,000 and S/N > 400 at V > 9.0, are needed to reveal the small extra asymmetry and the small extra width that are introduced into the profile of the isotopically blended Li I 6707 A line by the small fractions of 6Li detected so far. Precise measurements of (or, in all but a few cases, uppper limits on) the 6Li/7Li ratio are now available for almost 30 stars. At a ratio 6Li/7Li = 0.06, the first positive detection of stellar 6Li was achieved in 1993 for the turnoff halo star HD 84937, by Smith, Lambert, & Nissen. Probable detections of the lighter isotope at generally similar isotopic ratios have since been reported for four additional metal-poor stars. The imminent availability of more telescopes in the 8m to 10m class promises a rewarding extension of this effort to a relatively large number of excellent, fainter 6Li candidates.

  6. Li 2TiO 3 pebbles reprocessing, recovery of 6Li as Li 2CO 3

    NASA Astrophysics Data System (ADS)

    Alvani, C.; Casadio, S.; Contini, V.; Di Bartolomeo, A.; Lulewicz, J. D.; Roux, N.

    2002-12-01

    A process for obtaining Li 2CO 3 from Li 2TiO 3 powder by wet chemistry was developed. This is considered useful in view of the recovery of the 6Li isotope from lithium titanate breeder burned to its end of life in a fusion reactor. The process was optimized with respect to the chemical attack of titanate and the precipitation of carbonate from aqueous solutions to get a powder with chemical and morphological characteristics suitable for its reexploitation in the fabrication of Li 2TiO 3 pebbles. Reprocessing was also planned to adjust the 6Li concentration to the desired value and to obtain a homogeneous distribution in the powder batch. Further development concerning reprocessing of sintered Li 2TiO 3 pebbles is in progress exploiting the results obtained with lithium titanate powders.

  7. Diffusion and possible freezing phases of Li-ions in LiFePO4

    NASA Astrophysics Data System (ADS)

    Yiu, Yuen; Toft-Petersen, Rasmus; Ehlers, Georg; Vaknin, David

    Elastic and inelastic neutron scattering studies of LiFePO4 single crystal reveal new Li-ion diffusion properties relevant to its function as Li-battery materials. In the past decade there has been broad interest in LiFePO4 and its related compounds, largely due to the applications of these materials as cathodes in Li- batteries. This is owing to these materials' high charge-discharge ability and conductivity, both of which are by virtue of the Li-ions' high mobility. In this talk, we present our findings on the temperature and directional dependence of Li-ions' diffusion in LiFePO4. LiFePO4 adopts the olivine structure at room temperature (Space group: Pnma), which contains channels along principal crystalline directions that allow Li-ion motion. Elastic neutron scattering reveals lowering of symmetry from the Pnma structure below room temperature, which can be interpreted as the freezing of Li-ions, and can be subsequently linked to the reported decrease in Li-ion conductivity. Inelastic neutron scattering, in the 35K to 720K temperature range, shows temperature dependence, as well as anisotropy (i.e. along 0K0 versus 00L) of Li-ion diffusion. Ames Laboratory is supported by U.S. DOE, BES, DMSE, under Contract #DE-AC02-07CH11358. Spallation Neutron Source of Oak Ridge National Laboratory is sponsored by U.S. DOE, BES, SUFD.

  8. Thermal stability of LiPF 6 salt and Li-ion battery electrolytes containing LiPF 6

    NASA Astrophysics Data System (ADS)

    Yang, Hui; Zhuang, Guorong V.; Ross, Philip N.

    The thermal stability of the neat lithium hexafluorophosphate (LiPF 6) salt and of 1 molal (m) solutions of LiPF 6 in prototypical Li-ion battery solvents was studied with thermogravimetric analysis (TGA) and on-line Fourier transform infrared (FTIR). Pure LiPF 6 salt is thermally stable up to 107 °C in a dry inert atmosphere, and its decomposition path is a simple dissociation producing lithium fluoride (LiF) as solid and PF 5 as gaseous products. In the presence of water (300 ppm) in the carrier gas, its decomposition onset temperature is lowered as a result of direct thermal reaction between LiPF 6 and water vapor to form phosphorous oxyfluoride (POF 3) and hydrofluoric acid (HF). No new products were observed in 1 m solutions of LiPF 6 in ethylene carbonate (EC), dimethyl carbonate (DMC) and ethyl methyl carbonate (EMC) by on-line TGA-FTIR analysis. The storage of the same solutions in sealed containers at 85 °C for 300-420 h did not produce any significant quantity of new products as well. In particular, no alkylflurophosphates were found in the solutions after storage at elevated temperature. In the absence of either an impurity like alcohol or cathode active material that may (or may not) act as a catalyst, there is no evidence of thermally induced reaction between LiPF 6 and the prototypical Li-ion battery solvents EC, PC, DMC or EMC.

  9. Chemoprevention of oral cancer in animal models, and effect on leukoplakias in human patients with ZengShengPing, a mixture of medicinal herbs.

    PubMed

    Sun, Zheng; Guan, Xiaobing; Li, Ning; Liu, Xiaoyong; Chen, Xiaoxin

    2010-02-01

    ZengShengPing (ZSP), a mixture of six medicinal herbs, has been reported to prevent esophageal squamous cell carcinoma (SCC) in human patients with dysplasia. This study was designed to investigate the chemopreventive effects of ZSP on oral cancer in animal models and human patients. In the 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster cheek pouch model, ZSP (6g/kgBW/day by gavage for 10 weeks) significantly reduced the number of visible tumor, the tumor volume, and the incidence of SCC (P<0.01). Two biomarkers associated with cell proliferation, silver stained nucleolar organizer region (AgNOR) and proliferating cell nuclear antigen (PCNA)-labeling index, were also significantly suppressed by ZSP treatment (P<0.01). In the 4-nitroquinoline 1-oxide (4NQO)-induced oro-esophageal cancer model in mice, ZSP (10% in diet) also significantly reduced the incidence of tongue SCC from 55.2% (16/29) to 22.2% (6/27) (P<0.05), and slightly reduced the incidence of esophageal SCC from 34.5% (10/29) to 22.2% (6/27). Furthermore, in a randomized clinical trial on patients with oral leukoplakia, ZSP (4 tablets, 3 times per day for 8-12months) reduced the size of oral lesion in 67.8% (40/59) patients, whereas the placebo was effective in 17% (9/53) patients (P<0.01). Such an effect was associated with significant decrease of AgNOR and PCNA-labeling index. In summary, our studies have demonstrated the chemopreventive effects of ZSP on two animal models of oral cancer, and human patients with oral leukoplakia. PMID:20022553

  10. [Effects of saline-alkali stress on electrical impedance spectroscopy parameters and ion contents in shoots of Ping'ou hybrid hazelnut].

    PubMed

    Zhang, Li; Jia, Zhi-Guo; Ma, Qing-Hua; Zhang, Gang; Wang, Gui-Xi

    2014-11-01

    To study the adaptability to salt-alkaline stress of Ping'ou hybrid hazelnut, 'Liaozhen 3' shoots which were treated with three types of stress neutral NaCl, alkaline Na2CO3, and mixed salt-alkali, and the changes in electrical impedance spectroscopy (EIS) parameters and mineral ion contents were subsequently determined. The correlations between the EIS parameters and mineral ion contents were analyzed. The results showed that with the increasing level of NaCl, specific high- frequency resistance (r), specific low-frequency resistance ( r(l)), specific intracellular resistance (r(i)) and specific extracellular resistance (r(e)) of shoots decreased firstly, then increased, and finally decreased again. However, these parameters increased gradually with the increasing level of Na2CO3, while r(l) and r(e) decreased slowly in the mixed salt-alkali treatments. The Na+ contents of shoots increased significantly under the three salt-alkali stresses with the order of NaCl stress > mixed salt-alkali stress > Na2CO3 stress. Furthermore, Na2CO3 stress resulted in the decreases in the contents of three elements Zn, B and Ca. The significant negative correlation was found between the sum of five cations and four EIS parameters r(l), r(e), relaxation time (τ) , and distribution coefficient of relaxation time (ψ). The shoots of 'Liaozhen 3' might be tolerant of Na2CO3 stress of 200 mmol · L(-1), while they could be resistant to NaCl stress of 100-150 mmol · L(-1). PMID:25898608

  11. Measurement of Solubility of Metallic Lithium Dissolved in Molten LiCl-Li2O

    NASA Astrophysics Data System (ADS)

    Burak, Adam J.; Simpson, Michael F.

    2016-07-01

    The solubility of lithium metal in molten LiCl-Li2O mixtures has been measured at various concentrations of Li2O ranging from 0 wt.% to 2.7 wt.% at a temperature of approximately 670-680°C. After contacting molten lithium with molten LiCl-Li2O for several hours to achieve equilibrium saturation, samples were taken by freezing the salt onto a room-temperature steel rod and dissolving in water for analysis. Both volume of hydrogen gas generated and volume of titrated HCl were measured to investigate two different approaches to calculating the lithium concentration. There appeared to be no effect of Li2O concentration on the Li solubility in the salt. But the results vary between different methods of deducing the amount of dissolved Li. The H2 collection method is recommended, but care must be taken to ensure all of the H2 has been included.

  12. Measurement of Solubility of Metallic Lithium Dissolved in Molten LiCl-Li2O

    NASA Astrophysics Data System (ADS)

    Burak, Adam J.; Simpson, Michael F.

    2016-10-01

    The solubility of lithium metal in molten LiCl-Li2O mixtures has been measured at various concentrations of Li2O ranging from 0 wt.% to 2.7 wt.% at a temperature of approximately 670-680°C. After contacting molten lithium with molten LiCl-Li2O for several hours to achieve equilibrium saturation, samples were taken by freezing the salt onto a room-temperature steel rod and dissolving in water for analysis. Both volume of hydrogen gas generated and volume of titrated HCl were measured to investigate two different approaches to calculating the lithium concentration. There appeared to be no effect of Li2O concentration on the Li solubility in the salt. But the results vary between different methods of deducing the amount of dissolved Li. The H2 collection method is recommended, but care must be taken to ensure all of the H2 has been included.

  13. Metalization of Li2S particle surfaces in Li-S batteries

    NASA Astrophysics Data System (ADS)

    Chen, Yan-Xin; Kaghazchi, Payam

    2014-10-01

    The Li-S battery is the most promising candidate for future electric vehicles. The study of stabilities and conductivities of Li2S nanoparticles, which are used as pre-lithiated cathode materials, is crucial for the development of Li-S batteries. Here, we investigate the atomic and electronic structures as well as stabilities of Li2S surfaces and nanoparticles using density functional theory (DFT) and classical electrostatic models. We show that Li2S nanoparticles have octahedral shape and consist of only (111) facets. At low concentrations of Li, the surfaces of nanoparticles are metalized non-polar Li2S(111) surfaces. The metalization is found to be due to the depletion of valence bands of surface states. However, for higher concentrations of Li, the nanoparticle faces are insulator non-polar Li2S(111) surfaces. This study suggests that Li2S nanoparticles with (111) surfaces are very promising cathode materials for Li-S batteries.The Li-S battery is the most promising candidate for future electric vehicles. The study of stabilities and conductivities of Li2S nanoparticles, which are used as pre-lithiated cathode materials, is crucial for the development of Li-S batteries. Here, we investigate the atomic and electronic structures as well as stabilities of Li2S surfaces and nanoparticles using density functional theory (DFT) and classical electrostatic models. We show that Li2S nanoparticles have octahedral shape and consist of only (111) facets. At low concentrations of Li, the surfaces of nanoparticles are metalized non-polar Li2S(111) surfaces. The metalization is found to be due to the depletion of valence bands of surface states. However, for higher concentrations of Li, the nanoparticle faces are insulator non-polar Li2S(111) surfaces. This study suggests that Li2S nanoparticles with (111) surfaces are very promising cathode materials for Li-S batteries. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr03428g

  14. Li-rich anti-perovskite Li3OCl films with enhanced ionic conductivity

    SciTech Connect

    Lu, XJ; Wu, G; Howard, JW; Chen, AP; Zhao, YS; Daemen, LL; Jia, QX

    2014-08-13

    Anti-perovskite solid electrolyte films were prepared by pulsed laser deposition, and their room-temperature ionic conductivity can be improved by more than an order of magnitude in comparison with its bulk counterpart. The cyclability of Li3OCl films in contact with lithium was evaluated using a Li/Li3OCl/Li symmetric cell, showing self-stabilization during cycling test.

  15. (6)Li, (7)Li Nuclear Magnetic Resonance Investigation of Lithium Coordination in Binary Phosphate Glasses

    SciTech Connect

    Alam, T.M.; Boyle, T.J.; Brow, R.K.; Conzone, S.

    1999-02-08

    {sup 6}Li and {sup 7}Li solid state magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy has been used to investigate the local coordination environment of lithium in a series of xLi{sub 2}O {center_dot} (1-x)P{sub 2}O{sub 5} glasses, where 0.05 {le} x {le} 0.55. Both the {sup 6}Li and {sup 7}Li show chemical shift variations with changes in the Li{sub 2}O concentration, but the observed {sup 6}Li NMR chemical shifts closely approximate the true isotropic chemical shift and can provide a measure of the lithium bonding environment. The {sup 6}Li NMR results indicate that in this series of lithium phosphate glasses the Li atoms have an average coordination between four and five. The results for the metaphosphate glass agree with the coordination number and range of chemical shifts observed for crystalline LiPO{sub 3}. An increase in the {sup 6}Li NMR chemical shift with increasing Li{sub 2}O content was observed for the entire concentration range investigated, correlating with increased cross-linking of the phosphate tetrahedral network by O-Li-O bridges. The {sup 6}Li chemical shifts were also observed to vary monotonically through the anomalous glass transition temperature (T{sub g}) minimum. This continuous chemical shift variation shows that abrupt changes in the Li coordination environment do not occur as the Li{sub 2}O concentration is increased, and such abrupt changes can not be used to explain the T{sub g} minimum.

  16. Photoemission study of Li@C60

    NASA Astrophysics Data System (ADS)

    Yagi, Hajime; Ogasawara, Naoko; Zenki, Masashi; Miyazaki, Takafumi; Hino, Shojun

    2016-05-01

    Ultraviolet and X-ray photoelectron spectra (UPS and XPS) of thin films prepared by either depositing or applying [Li@C60]+(PF6)- on the substrates are presented. The UPS and XPS of [Li@C60]+(PF6)- applied films suggest that PF6- anions come out from the surface by annealing at 250 °C. The UPS and XPS of the deposited thin films indicate that the film does not contain PF6- anion but is composed of only Li@C60. Changing the sublimation temperature reveals that encapsulated Li cations begin to escape from the C60 cage when heated above 550 °C.

  17. Downscaling tropical cyclone activity using regional models: Impact of air-sea coupling on the frequency and intensity of Atlantic hurricanes Authors: Jen-shan Hsieh, Mingkui Li, R. Saravanan, and Ping Chang Texas A & M University, College Station, TX

    NASA Astrophysics Data System (ADS)

    Hsieh, J.; Li, M.; Saravanan, R.; Chang, P.

    2009-12-01

    Tropical cyclones are an important component of climate variability in the tropics and the subtropics. Unfortunately, these cyclones are poorly represented in coarse-resolution global general circulation models. Fine-resolution regional atmospheric models can be used to better simulate the properties of tropical cyclones, typically using specified sea surface temperature as the lower boundary condition. Such a boundary condition cannot simulate the cold wake associated with a tropical cyclone, which arises due to the enhanced vertical mixing and entrainment below the oceanic mixed layer. This cold wake has potential implications for the intensity of the tropical cyclone itself, because it can act as a negative air-sea feedback and lead to a weakening of the storm. Therefore, proper representation of this air-sea feedback is important when assessing the sensitivity of tropical cyclone frequency and intensity to climate change. We address this issue using a coupled regional climate model, where a regional atmospheric model is coupled to a regional ocean model. The model domain encompasses the Atlantic Ocean and adjoining continental regions. The atmospheric component is the NCAR WRF model running at 30 km horizontal resolution. The oceanic component is the Regional Ocean Modeling System (ROMS) running at 0.25 degree resolution. The atmospheric and oceanic models exchange fluxes of momentum, heat, and freshwater. The control coupled integration using this model simulates fairly realistic tropical variability, including a number of hurricane-like tropical vortices. To assess the sensitivity of tropical cyclone activity to air-sea coupling, we have also carried out a companion uncoupled integration, where the time-evolving sea surface temperature from the control coupled integration is used as the lower boundary condition for the uncoupled atmospheric model. We analyze the frequency and intensity of the tropical cyclones, as well as the associated precipitation, in both the coupled and the uncoupled integrations. Preliminary results indicate that air-sea feedbacks can have a significant impact on tropical cyclone activity.

  18. Nanoscale LiFePO4 and Li4Ti5O12 for High Rate Li-ion Batteries

    SciTech Connect

    Jaiswal, A.; Horne, C.R.; Chang, O.; Zhang, W.; Kong, W.; Wang, E.; Chern, T.; Doeff, M. M.

    2009-08-04

    The electrochemical performances of nanoscale LiFePO4 and Li4Ti5O12 materials are described in this communication. The nanomaterials were synthesized by pyrolysis of an aerosol precursor. Both compositions required moderate heat-treatment to become electrochemically active. LiFePO4 nanoparticles were coated with a uniform, 2-4 nm thick carbon-coating using an organic precursor in the heat treatment step and showed high tap density of 1.24 g/cm3, in spite of 50-100 nm particle size and 2.9 wtpercent carbon content. Li4Ti5O12 nanoparticles were between 50-200 nm in size and showed tap density of 0.8 g/cm3. The nanomaterials were tested both in half cell configurations against Li-metal and also in LiFePO4/Li4Ti5O12 full cells. Nano-LiFePO4 showed high discharge rate capability with values of 150 and 138 mAh/g at C/25 and 5C, respectively, after constant C/25 charges. Nano-Li4Ti5O12 also showed high charge capability with values of 148 and 138 mAh/g at C/25 and 5C, respectively, after constant C/25 discharges; the discharge (lithiation) capability was comparatively slower. LiFePO4/Li4Ti5O12 full cells deliver charge/discharge capacity values of 150 and 122 mAh/g at C/5 and 5C, respectively.

  19. Li+ ionic diffusion and vacancy ordering in beta-LiGa.

    PubMed

    Nakamura, Koichi; Motoki, Keisuke; Michihiro, Yoshitaka; Kanashiro, Tatsuo; Yahagi, Masahito; Hamanaka, Hiromi; Kuriyama, Kazuo

    2007-01-01

    7Li and 71Ga NMR measurements have been performed to study the Li+ ionic motion and vacancy ordering in the lithium semimetal beta-LiGa. The temperature dependence of the spin-lattice relaxation rate, T1(-1) of the 7Li nuclei in the 50 atom% Li sample shows an asymmetric broad peak around 175 K and is interpreted in terms of fast Li ionic diffusion. The activation energy of hopping is estimated as 0.11 eV using a non-Debye type relaxation model. In the temperature dependence of T1(-1) of the 7Li nuclei in 44 and 47 atom% Li samples, steep peaks are observed at 225 and 195 K, respectively. The origin of these anomalous peaks is attributed to the order-disorder transformation of Li+ vacancies. The temperature dependence of T1(-1) of the 71Ga nuclei measured above 200 K is interpreted in terms of the relaxation originating from the fluctuation of the electric field gradient at the 71Ga nuclei due to mobile Li+ ions. The activation energy for the Li+ ionic diffusion estimated from T1(-1) of the 71Ga nuclei is comparable with that obtained from T1(-1) of the 7Li nuclei.

  20. Pros and cons of vertical integration between clinical medicine and basic science within a problem-based undergraduate medical curriculum: examples and experiences from Linköping, Sweden.

    PubMed

    Dahle, L O; Brynhildsen, J; Behrbohm Fallsberg, M; Rundquist, I; Hammar, M

    2002-05-01

    Problem-based learning (PBL), combined with early patient contact, multiprofessional education and emphasis on development of communications skills, has become the basis for the medical curriculum at the Faculty of Health Sciences in Linköping (FHS), Sweden, which was started in 1986. Important elements in the curriculum are vertical integration, i.e. integration between the clinical and basic science parts of the curriculum and horizontal integration between different subject areas. This article discusses the importance of vertical integration in an undergraduate medical curriculum, according to experiences from the Faculty of Health Sciences in Linköping, and also give examples on how it has been implemented during the latest 15 years. Results and views put forward in published articles concerning vertical integration within undergraduate medical education are discussed in relation to the experiences in Linköping. Vertical integration between basic sciences and clinical medicine in a PBL setting has been found to stimulate profound rather than superficial learning, and thereby stimulates better understanding of important biomedical principles. Integration probably leads to better retention of knowledge and the ability to apply basic science principles in the appropriate clinical context. Integration throughout the whole curriculum entails a lot of time and work in respect of planning, organization and execution. The teachers have to be deeply involved and enthusiastic and have to cooperate over departmental borders, which may produce positive spin-off effects in teaching and research but also conflicts that have to be resolved. The authors believe vertical integration supports PBL and stimulates deep and lifelong learning.

  1. Modification of LiCl-LiBr-KBr electrolyte for LiAl/FeS{sub 2} batteries

    SciTech Connect

    Kaun, T.D.; Jansen, A.N.; Henriksen, G.L.; Vissers, D.R.

    1996-06-01

    The bipolar LiAl/FeS{sub 2} battery is being developed to achieve the high performance and long cycle life needed for electric vehicle application. The molten-salt (400 to 440 C operation) electrolyte composition for this battery has evolved to support these objectives. An earlier change to LiCl-LiBr-KBr electrolyte is responsible for significantly increased cycle life (up to 1,000 cycles). Recent electrolyte modification has significantly improved cell performance; approximately 50% increased power, with increased high rate capacity utilization. Results are based on power-demanding EV driving profile test at 600 W/kg. The effects of adding small amounts (1--5 mol%) of LiF and LiI to LiCl-LiBr-KBr electrolyte are discussed. By cyclic voltammetry, the modified electrolytes exhibit improved FeS{sub 2} electrochemistry. Electrolyte conductivity is little changed, but high current density (200 mA/cm{sup 2}) performance improved by approximately 50%. A specific feature of the LiI addition is an enhanced cell overcharge tolerance rate from 2.5 to 5 mA/cm{sup 2}. The rate of overcharge tolerance is related to electrolyte properties and negative electrode lithium activity. As a result, the charge balancing of a bipolar battery configuration with molten-salt electrolyte is improved to accept greater cell-to-cell deviations.

  2. [Comparative study of theoretical literature on cold pathogenic disease in Wai tai mi yao fang (Arcane Essentials from the Imperial Library) and Tai ping sheng hui fang (Taiping Holy Prescriptions for Universal Relief)].

    PubMed

    Zhang, Huirui; Liang, Yongxuan

    2014-09-01

    In the Wai tai mi yao fang (Arcane Essentials from the Imperial Library) compiled in 752, its portion on cold pathogenic disorders embodies the achievements before the mid Tang Dynasty, whereas that in the Tai ping sheng hui fang (Taiping Holy Prescriptions for Universal Relief), compiled in 992 embodies those before the early Song Dynasty. Comparison on the theory of cold disorders in both books reveal that, during the 2 centuries period from mid Tang to early Song Dynasties, the texts as a carrier for the transmission of such theory in both show no distinct changes, but only with minor revisions and improvements.

  3. Solvation of the Li+-Cl--Li+ triple ion in the gas phase

    NASA Astrophysics Data System (ADS)

    Jarek, Russell L.; Denson, Stephen C.; Shin, Seung Koo

    1998-09-01

    Fourier-transform ion cyclotron resonance (FT-ICR) spectrometry was employed to study solvations of the Li+-Cl--Li+ triple ion with oxygen-donor Lewis bases in the gas phase. The LiClLi+ triple ions were produced in an ICR cell by laser desorption ionization of a lithium chloride/dibenzo-18-crown-6-ether matrix pasted on a Teflon substrate. O-donor Lewis bases include 1,4-dioxane, 1,3-dioxane, tetrahydrofuran (THF), acetone and diethyl ether. All O-donors associate directly with LiClLi+ with the maximum solvation numbers of 3 for 1,4-dioxane, 1,3-dioxane and diethyl ether, and 4 for THF and acetone at room temperature. The rate constants for the stepwise solvations were measured, and the solvent binding energies were determined from van't Hoff plots. The structures and energetics of LiClLi+ and the 1:1 complexes of Li+ and LiClLi+ with the dioxanes, THF, and acetone were calculated at the Hartree-Fock (HF) level with a 6-311G(d,p) basis set, and those of more highly coordinated LiClLi+ complexes were calculated with a 6-31G(d) basis set. Solvation enthalpies and free energies were calculated, and solvent binding energies were compared with experiments. The mechanisms of stepwise solvations of the LiClLi+ triple ion with dioxanes, THF, and acetone are discussed in light of experimental kinetics and binding energies and theoretical structures and solvation energies.

  4. Kinetic measurement and prediction of the hydrogen outgassing from the polycrystalline LiH/Li2O/LiOH system

    SciTech Connect

    Dinh, L N; Grant, D M; Schildbach, M A; Smith, R A; Siekhaus, W J; Balazs, B; Leckey, J H; Kirkpatrick, J; McLean II, W

    2005-04-06

    Due to the exothermic reaction of lithium hydride (LiH) salt with water during transportation and handling, there is always a thin film of lithium hydroxide (LiOH) present on the LiH surface. In dry or vacuum storage, this thin LiOH film slowly decomposes. We have used temperature-programmed reaction/decomposition (TPR) in combination with the isoconversion method of thermal analysis to determine the outgassing kinetics of H{sub 2}O from pure LiOH and H{sub 2} and H{sub 2}O from this thin LiOH film. H{sub 2} production via the reaction of LiH with LiOH, forming a lithium oxide (Li{sub 2}O) interlayer, is thermodynamically favored, with the rate of further reaction limited by diffusion through the Li{sub 2}O and the stability of the decomposing LiOH. Lithium hydroxide at the LiOH/vacuum interface also decomposes easily to Li{sub 2}O, releasing H{sub 2}O which subsequently reacts with LiH in a closed system to form H{sub 2}. At the onset of dry decomposition, where H{sub 2} is the predominant product, the activation energy for outgassing from a thin LiOH film is lower than that for bulk LiOH. However, as the reactions at the LiH/Li{sub 2}O/LiOH and at the LiOH/vacuum interfaces proceed, the overall activation energy barrier for the outgassing approaches that of bulk LiOH decomposition. The kinetics developed here predicts a hydrogen evolution profile in good agreement with hydrogen release observed during long term isothermal storage.

  5. Stability of the Solid Electrolyte Interface on the Li Electrode in Li-S Batteries.

    PubMed

    Zheng, Dong; Yang, Xiao-Qing; Qu, Deyang

    2016-04-27

    By means of high performance liquid chromatography-mass spectroscopy, the concentration of sulfur and polysulfides was determined in nonaqueous electrolytes. The stability of sulfur and Li in eight electrolytes was studied quantitatively. It was found that sulfur reacted with Li in most of the commonly used electrolytes for lithium-sulfur batteries. The reaction products between sulfur and Li were qualitatively identified. In some cases, the solid electrolyte interface on the Li can successfully prevent the interaction between S and Li; however, it was found that the solid electrolyte interface was damaged by polysulfide ions. PMID:27045986

  6. Effect of Li diffusion on the composition of LiNbO 3 at high temperature

    NASA Astrophysics Data System (ADS)

    Chen, Y. L.; Wen, J. P.; Kong, Y. F.; Chen, S. L.; Zhang, W. L.; Xu, J. J.; Zhang, G. Y.

    2002-07-01

    LiNbO 3 crystals with a variety of compositions were prepared by the vapor transport equilibration (VTE) technique. Crystals were characterized through the measurements of fundamental absorption edge, lattice parameters and the electric field required for ferroelectric domain switching. The techniques employed for characterization served as tools for the determination of the composition and homogeneity of the crystals. We discussed the Li diffusion mechanisms in LiNbO 3 crystals at high temperature and found that the Li vacancy model is consistent with the experimental results for the VTE-grown LiNbO 3 crystal.

  7. Li ion diffusion in LiAlO2 investigated by Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Hu, Qiwei; Lei, Li; Jiang, Xiaodong; Feng, Zhe Chuan; Tang, Mingjun; He, Duanwei

    2014-11-01

    The temperature dependence of Li ions behavior of γ-LiAlO2 has been studied from 78 to 873 K. On heating, the Li ions underwent positional disordering along the structural channels, with the Li ions related modes at 220, 366 and 400 cm-1 broadening and weakening dramatically. An anomalous maximum in the bandwidths of the Li ions related modes is observed. It should be apparent that there are at least two distinct thermally activated processes. A model suggested by Andrade and Porto is used to describe the linewidth of a phonon.

  8. The Impact of Li Grain Size on Coulombic Efficiency in Li Batteries

    PubMed Central

    Mehdi, B. Layla; Stevens, Andrew; Qian, Jiangfeng; Park, Chiwoo; Xu, Wu; Henderson, Wesley A.; Zhang, Ji-Guang; Mueller, Karl T.; Browning, Nigel D.

    2016-01-01

    One of the most promising means to increase the energy density of state-of-the-art lithium Li-ion batteries is to replace the graphite anode with a Li metal anode. While the direct use of Li metal may be highly advantageous, at present its practical application is limited by issues related to dendrite growth and low Coulombic efficiency, CE. Here operando electrochemical scanning transmission electron microscopy (STEM) is used to directly image the deposition/stripping of Li at the anode-electrolyte interface in a Li-based battery. A non-aqueous electrolyte containing small amounts of H2O as an additive results in remarkably different deposition/stripping properties as compared to the “dry” electrolyte when operated under identical electrochemical conditions. The electrolyte with the additive deposits more Li during the first cycle, with the grain sizes of the Li deposits being significantly larger and more variable. The stripping of the Li upon discharge is also more complete, i.e., there is a higher cycling CE. This suggests that larger grain sizes are indicative of better performance by leading to more uniform Li deposition and an overall decrease in the formation of Li dendrites and side reactions with electrolyte components, thus potentially paving the way for the direct use of Li metal in battery technologies. PMID:27703188

  9. The Impact of Li Grain Size on Coulombic Efficiency in Li Batteries

    NASA Astrophysics Data System (ADS)

    Mehdi, B. Layla; Stevens, Andrew; Qian, Jiangfeng; Park, Chiwoo; Xu, Wu; Henderson, Wesley A.; Zhang, Ji-Guang; Mueller, Karl T.; Browning, Nigel D.

    2016-10-01

    One of the most promising means to increase the energy density of state-of-the-art lithium Li-ion batteries is to replace the graphite anode with a Li metal anode. While the direct use of Li metal may be highly advantageous, at present its practical application is limited by issues related to dendrite growth and low Coulombic efficiency, CE. Here operando electrochemical scanning transmission electron microscopy (STEM) is used to directly image the deposition/stripping of Li at the anode-electrolyte interface in a Li-based battery. A non-aqueous electrolyte containing small amounts of H2O as an additive results in remarkably different deposition/stripping properties as compared to the “dry” electrolyte when operated under identical electrochemical conditions. The electrolyte with the additive deposits more Li during the first cycle, with the grain sizes of the Li deposits being significantly larger and more variable. The stripping of the Li upon discharge is also more complete, i.e., there is a higher cycling CE. This suggests that larger grain sizes are indicative of better performance by leading to more uniform Li deposition and an overall decrease in the formation of Li dendrites and side reactions with electrolyte components, thus potentially paving the way for the direct use of Li metal in battery technologies.

  10. Electrochemistry of LiCl-Li2O-H2O Molten Salt Systems

    SciTech Connect

    Natalie J. Gese; Batric Pesic

    2013-03-01

    Uranium can be recovered from uranium oxide (UO2) spent fuel through the combination of the oxide reduction and electrorefining processes. During oxide reduction, the spent fuel is introduced to molten LiCl-Li2O salt at 650 degrees C and the UO2 is reduced to uranium metal via two routes: (1) electrochemically, and (2) chemically by lithium metal (Li0) that is produced electrochemically. However, the hygroscopic nature of both LiCl and Li2O leads to the formation of LiOH, contributing hydroxyl anions (OH-), the reduction of which interferes with the Li0 generation required for the chemical reduction of UO2. In order for the oxide reduction process to be an effective method for the treatment of uranium oxide fuel, the role of moisture in the LiCl-Li2O system must be understood. The behavior of moisture in the LiCl-Li2O molten salt system was studied using cyclic voltammetry, chronopotentiometry and chronoamperometry, while reduction to hydrogen was confirmed with gas chromatography.

  11. Direct observation of Li diffusion in Li-doped ZnO nanowires

    NASA Astrophysics Data System (ADS)

    Li, Guohua; Yu, Lei; Hudak, Bethany M.; Chang, Yao-Jen; Baek, Hyeonjun; Sundararajan, Abhishek; Strachan, Douglas R.; Yi, Gyu-Chul; Guiton, Beth S.

    2016-05-01

    The direct observation of Li diffusion in Li-doped zinc oxide nanowires (NWs) was realized by using in situ heating in the scanning transmission electron microscope (STEM). A continuous increase of low atomic mass regions within a single NW was observed between 200 °C and 600 °C when heated in vacuum, which was explained by the conversion of interstitial to substitutional Li in the ZnO NW host lattice. A kick-out mechanism is introduced to explain the migration and conversion of the interstitial Li (Lii) to Zn-site substitutional Li (LiZn), and this mechanism is verified with low-temperature (11 K) photoluminescence measurements on as-grown and annealed Li-doped zinc oxide NWs, as well as the observation of an increase of NW surface roughing with applied bias.

  12. Response to Comment on "Cycling Li-O₂ batteries via LiOH formation and decomposition".

    PubMed

    Liu, Tao; Kim, Gunwoo; Carretero-González, Javier; Castillo-Martínez, Elizabeth; Bayley, Paul M; Liu, Zigeng; Grey, Clare P

    2016-05-01

    Lithium-oxygen (Li-O2) batteries cycle reversibly with lithium iodide (LiI) additives in dimethoxyethane (DME) to form lithium hydroxide (LiOH). Viswanathan et al. argue that because the standard redox potential of the four-electron (e(-)) reaction, 4OH(-) ↔ 2H2O + O2 + 4e(-), is at 3.34 V versus Li(+)/Li, LiOH cannot be removed by the triiodide ion (I3(-)). However, under nonaqueous conditions, this reaction will occur at a different potential. LiOH also reacts chemically with I3(-) to form IO3(-), further studies being required to determine the relative rates of the two reactions on electrochemical charge.

  13. Cycling Li-O₂ batteries via LiOH formation and decomposition.

    PubMed

    Liu, Tao; Leskes, Michal; Yu, Wanjing; Moore, Amy J; Zhou, Lina; Bayley, Paul M; Kim, Gunwoo; Grey, Clare P

    2015-10-30

    The rechargeable aprotic lithium-air (Li-O2) battery is a promising potential technology for next-generation energy storage, but its practical realization still faces many challenges. In contrast to the standard Li-O2 cells, which cycle via the formation of Li2O2, we used a reduced graphene oxide electrode, the additive LiI, and the solvent dimethoxyethane to reversibly form and remove crystalline LiOH with particle sizes larger than 15 micrometers during discharge and charge. This leads to high specific capacities, excellent energy efficiency (93.2%) with a voltage gap of only 0.2 volt, and impressive rechargeability. The cells tolerate high concentrations of water, water being the dominant proton source for the LiOH; together with LiI, it has a decisive impact on the chemical nature of the discharge product and on battery performance. PMID:26516278

  14. Mixed salts of LiTFSI and LiBOB for stable LiFePO4-based batteries at elevated temperatures

    SciTech Connect

    Chen, Xilin; Xu, Wu; Engelhard, Mark H.; Zheng, Jianming; Zhang, Yaohui; Ding, Fei; Qian, Jiangfeng; Zhang, Ji-Guang

    2014-01-01

    To achieve stable long-term cycling stability at elevated temperatures, mixed salts of LiTFSI and LiBOB are used to replace LiPF6 salt in non-aqueous electrolytes for LiFePO4-based batteries. It is found that adding LiBOB in LiTFSI-based electrolytes effectively prevents the severe corrosion to Al current collectors that often is observed in LiTFSI-based electrolytes, which have high thermal stability. The cells using LiTFSI-LiBOB-based electrolytes demonstrate superior high temperature (60 °C) stability and very similar room temperature performance (i.e., cycling stability and rate capability) when compared to cells using the LiPF6-based electrolyte.

  15. Investigation of the role of 10Li resonances in the halo structure of 11Li through the 11Li (p , d)10Li transfer reaction

    NASA Astrophysics Data System (ADS)

    Sanetullaev, A.; Kanungo, R.; Tanaka, J.; Alcorta, M.; Andreoiu, C.; Bender, P.; Chen, A. A.; Christian, G.; Davids, B.; Fallis, J.; Fortin, J. P.; Galinski, N.; Gallant, A. T.; Garrett, P. E.; Hackman, G.; Hadinia, B.; Ishimoto, S.; Keefe, M.; Krücken, R.; Lighthall, J.; McNeice, E.; Miller, D.; Purcell, J.; Randhawa, J. S.; Roger, T.; Rojas, A.; Savajols, H.; Shotter, A.; Tanihata, I.; Thompson, I. J.; Unsworth, C.; Voss, P.; Wang, Z.

    2016-04-01

    The first measurement of the one-neutron transfer reaction 11Li(p,d)10Li performed using the IRIS facility at TRIUMF with a 5.7 A MeV11Li beam interacting with a solid H2 target is reported. The 10Li residue was populated strongly as a resonance peak with energy Er = 0.62 ± 0.04 MeV having a total width Γ = 0.33 ± 0.07 MeV. The angular distribution of this resonance is characterized by neutron occupying the 1p1/2 orbital. A DWBA analysis yields a spectroscopic factor of 0.67 ± 0.12 for p1/2 removal strength from the ground state of 11Li to the region of the peak.

  16. Changes in DNA methylation and transgenerational mobilization of a transposable element (mPing) by the Topoisomerase II inhibitor, Etoposide, in rice

    PubMed Central

    2012-01-01

    Background Etoposide (epipodophyllotoxin) is a chemical commonly used as an anti-cancer drug which inhibits DNA synthesis by blocking topoisomerase II activity. Previous studies in animal cells have demonstrated that etoposide constitutes a genotoxic stress which may induce genomic instability including mobilization of normally quiescent transposable elements (TEs). However, it remained unknown whether similar genetically mutagenic effects could be imposed by etoposide in plant cells. Also, no information is available with regard to whether the drug may cause a perturbation of epigenetic stability in any organism. Results To investigate whether etoposide could generate genetic and/or epigenetic instability in plant cells, we applied etoposide to germinating seeds of six cultivated rice (Oryza sativa L.) genotypes including both subspecies, japonica and indica. Based on the methylation-sensitive gel-blotting results, epigenetic changes in DNA methylation of three TEs (Tos17, Osr23 and Osr36) and two protein-encoding genes (Homeobox and CDPK-related genes) were detected in the etoposide-treated plants (S0 generation) in four of the six studied japonica cultivars, Nipponbare, RZ1, RZ2, and RZ35, but not in the rest japonica cultivar (Matsumae) and the indica cultivar (93-11). DNA methylation changes in the etoposide-treated S0 rice plants were validated by bisulfite sequencing at both of two analyzed loci (Tos17 and Osr36). Transpositional activity was tested for eight TEs endogenous to the rice genome in both the S0 plants and their selfed progenies (S1 and S2) of one of the cultivars, RZ1, which manifested heritable phenotypic variations. Results indicated that no transposition occurred in the etoposide-treated S0 plants for any of the TEs. Nonetheless, a MITE transposon, mPing, showed rampant mobilization in the S1 and S2 progenies descended from the drug-treated S0 plants. Conclusions Our results demonstrate that etoposide imposes a similar genotoxic stress on

  17. Anti-inflammatory effect of Yu-Ping-Feng-San via TGF-β1 signaling suppression in rat model of COPD

    PubMed Central

    Yang, Zhong-Shan; Yan, Jin-Yuan; Han, Ni-Ping; Zhou, Wei; Cheng, Yu; Zhang, Xiao-Mei; Li, Ning; Yuan, Jia-Li

    2016-01-01

    Objective(s): Yu-Ping-Feng-San (YPFS) is a classical traditional Chinese medicine that is widely used for treatment of the diseases in respiratory systems, including chronic obstructive pulmonary disease (COPD) recognized as chronic inflammatory disease. However, the molecular mechanism remains unclear. Here we detected the factors involved in transforming growth factor beta 1 (TGF-β1)/Smad2 signaling pathway and inflammatory cytokines, to clarify whether YPFS could attenuate inflammatory response dependent on TGF-β1/Smad2 signaling in COPD rats or cigarette smoke extract (CSE)-treated human bronchial epithelial (Beas-2B) cells. Materials and Methods: The COPD rat model was established by exposure to cigarette smoke and intratracheal instillation of lipopolysaccharide, YPFS was administered to the animals. The efficacy of YPFS was evaluated by comparing the severity of pulmonary pathological damage, pro-inflammation cytokines, collagen related genes and the activation of TGF-β1/Smad2 signaling pathway. Furthermore, CSE-treated cells were employed to confirm whether the effect of YPFS was dependent on the TGF-β1/Smad2 signaling via knockdown Smad2 (Si-RNA), or pretreatment with the inhibitor of TGF-β1. Results: Administration of YPFS effectively alleviated injury of lung, suppressed releasing of pro-inflammatory cytokines and collagen deposition in COPD animals (P<0.05), whereas exogenous TGF-β1 promoted releasing of IL-1β, IL-6, TNFα (P<0.05). Administration YPFS reduced inflammatory response significantly, also down-regulated TGF-β1/Smad2 signaling in vivo and in vitro. Unexpectedly, knockdown Smad2 or inhibition of TGF-β1 abolished anti-inflammatory effect of YPFS in CSE-treated cells. Conclusion: YPFS accomplished anti-inflammatory effects mainly by suppressing phosphorylation of Smad2, TGF-β1/Smad2 signaling pathway was required for YPFS-mediated anti-inflammation in COPD rats or CSE-treated Beas-2B cells. PMID:27803787

  18. Utility of Li and Li Isotopes as Tracers of Continental Weathering

    NASA Astrophysics Data System (ADS)

    James, R. H.; Wimpenny, J. B.; Pogge von Strandmann, P.; Kisakurek, B.; Hathorne, E. C.; Anand, P.; Burton, K. W.

    2008-12-01

    Lithium is potentially an attractive tracer of continental weathering because its two isotopes have a large relative mass difference, it is unaffected by biological activity and it is only slightly incompatible during magmatic processes so tends to be relatively uniformly distributed in the Earth's crust. Moreover, Li is conservative in the oceans, with a residence time of ca. 1 million years, and it is isotopically uniform on a global scale (δ7Li ~+31‰). Seminal work by Lui Chan and her co-workers has shown that the Li and Li isotope balance of the oceans is maintained by inputs of high-temperature hydrothermal fluids at oceanic ridges (with δ7Li ~+6.7‰) and dissolved Li from rivers (average δ7Li = +23‰), and low-temperature removal of Li into oceanic basalts and marine sediments. Despite this potential, relatively little is known about the behaviour of Li during continental weathering. In this study, we will present an overview of the work that we have conducted on Li and Li isotopes in rivers, soils and estuaries from catchments in Greenland, Iceland and the Himalaya, as well as laboratory studies of mineral dissolution and precipitation. Each of these case studies illustrates the effects of weathering processes on the riverine isotope signal, and the estuarine data illustrate how this signal is transferred to the oceans. Our data suggest that variations in rock type have little effect on riverine δ7Li; the principal control is preferential removal of 6Li into secondary minerals formed during weathering, leaving the residual waters enriched in 7Li. In subglacial environments, where weathering rates are very low, uptake of Li by ferric oxyhydroxides formed during sulphide oxidation is important. Our results clearly demonstrate that weathering processes can exert a significant effect on the Li isotope composition of natural waters. In order to understand whether changes in such processes with time are preserved, we have also generated records of the past

  19. Attainable gravimetric and volumetric energy density of Li-S and li ion battery cells with solid separator-protected Li metal anodes.

    PubMed

    McCloskey, Bryan D

    2015-11-19

    As a result of sulfur's high electrochemical capacity (1675 mA h/gs), lithium-sulfur batteries have received significant attention as a potential high-specific-energy alternative to current state-of-the-art rechargeable Li ion batteries. For Li-S batteries to compete with commercially available Li ion batteries, high-capacity anodes, such as those that use Li metal, will need to be enabled to fully exploit sulfur's high capacity. The development of Li metal anodes has focused on eliminating Coulombically inefficient and dendritic Li cycling, and to this end, an interesting direction of research is to protect Li metal by employing mechanically stiff solid-state Li(+) conductors, such as garnet phase Li7La3Zr2O12 (LLZO), NASICON-type Li1+xAlxTi2-x(PO4)3 (LATP), and Li2S-P2S5 glasses (LPS), as electrode separators. Basic calculations are used to quantify useful targets for solid Li metal protective separator thickness and cost to enable Li metal batteries in general and Li-S batteries specifically. Furthermore, maximum electrolyte-to-sulfur ratios that allow Li-S batteries to compete with Li ion batteries are calculated. The results presented here suggest that controlling the complex polysulfide speciation chemistry in Li-S cells with realistic, minimal electrolyte loading presents a meaningful opportunity to develop Li-S batteries that are competitive on a specific energy basis with current state-of-the-art Li ion batteries. PMID:26722800

  20. Attainable gravimetric and volumetric energy density of Li-S and li ion battery cells with solid separator-protected Li metal anodes.

    PubMed

    McCloskey, Bryan D

    2015-11-19

    As a result of sulfur's high electrochemical capacity (1675 mA h/gs), lithium-sulfur batteries have received significant attention as a potential high-specific-energy alternative to current state-of-the-art rechargeable Li ion batteries. For Li-S batteries to compete with commercially available Li ion batteries, high-capacity anodes, such as those that use Li metal, will need to be enabled to fully exploit sulfur's high capacity. The development of Li metal anodes has focused on eliminating Coulombically inefficient and dendritic Li cycling, and to this end, an interesting direction of research is to protect Li metal by employing mechanically stiff solid-state Li(+) conductors, such as garnet phase Li7La3Zr2O12 (LLZO), NASICON-type Li1+xAlxTi2-x(PO4)3 (LATP), and Li2S-P2S5 glasses (LPS), as electrode separators. Basic calculations are used to quantify useful targets for solid Li metal protective separator thickness and cost to enable Li metal batteries in general and Li-S batteries specifically. Furthermore, maximum electrolyte-to-sulfur ratios that allow Li-S batteries to compete with Li ion batteries are calculated. The results presented here suggest that controlling the complex polysulfide speciation chemistry in Li-S cells with realistic, minimal electrolyte loading presents a meaningful opportunity to develop Li-S batteries that are competitive on a specific energy basis with current state-of-the-art Li ion batteries.

  1. Li-Ion Battery with LiFePO4 Cathode and Li4Ti5O12 Anode for Stationary Energy Storage

    NASA Astrophysics Data System (ADS)

    Wang, Wei; Choi, Daiwon; Yang, Zhenguo

    2013-01-01

    Li-ion batteries based on commercially available LiFePO4 cathode and Li4Ti5O12 anode were investigated for potential stationary energy storage applications. The full cell that operated at flat 1.85 V demonstrated stable cycling up to 200 cycles followed by a rapid fade. A Li-ion full cell with Ketjen black modified LiFePO4 cathode and an unmodified Li4Ti5O12 anode exhibited negligible fade after more than 1200 cycles with a capacity of ~130 mAh/g at C/2. The improved stability, along with its cost-effectiveness, environmental benignity, and safety, make the LiFePO4/Li4Ti5O12 combination Li-ion battery a promising option for storing renewable energy.

  2. Effect of a pyrrolidinium zwitterion on charge/discharge cycle properties of Li/LiCoO2 and graphite/Li cells containing an ionic liquid electrolyte

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Seitaro; Yoshizawa-Fujita, Masahiro; Takeoka, Yuko; Rikukawa, Masahiro

    2016-11-01

    Ionic liquids (ILs) containing zwitterions have been studied as electrolytes for lithium-ion batteries (LIBs). The effects of addition of a pyrrolidinium zwitterion in an IL electrolyte on the thermal and electrochemical stability and charge/discharge properties of Li/LiCoO2 and graphite/Li cells were investigated. The thermal decomposition temperature of the IL electrolyte composed of N-methyl-N-propylpyrrolidinium bis(fluorosulfonyl)amide ([P13][FSA])/lithium bis(trifluoromethylsulfonyl)amide (LiTFSA) with 3-(1-butylpyrrolidinium)propane-1-sulfonate (Bpyps) as the zwitterionic additive, the thermal decomposition temperature was about 300 °C. The electrochemical window of [P13][FSA]/LiTFSA/Bpyps was 0-+5.4 V vs. Li/Li+, which was almost identical to that of [P13][FSA]/LiTFSA. Li|electrolyte|LiCoO2 cells containing the IL/Bpyps electrolyte system exhibited high capacities in the cut-off voltage range of 3.0-4.6 V, even after 50 cycles. The increase in the interfacial resistance between the electrolyte and cathode with cycling was suppressed. In the cyclic voltammograms of cells employing a graphite electrode, the intercalation/deintercalation of lithium ions were observed in the range of 0 and + 0.4 V vs. Li/Li+. Further, graphite|electrolyte|Li cells containing [P13][FSA]/LiTFSA/Bpyps exhibited stable charge/discharge cycle behaviour over 50 cycles.

  3. Nanomaterials Meet Li-ion Batteries.

    PubMed

    Kwon, Nam Hee; Brog, Jean-Pierre; Maharajan, Sivarajakumar; Crochet, Aurélien; Fromm, Katharina M

    2015-01-01

    Li-ion batteries are used in many applications in everyday life: cell phones, laser pointers, laptops, cordless drillers or saws, bikes and even cars. Yet, there is room for improvement in order to make the batteries smaller and last longer. The Fromm group contributes to this research focusing mainly on nanoscale lithium ion cathode materials. This contribution gives an overview over our current activities in the field of batteries. After an introduction on the nano-materials of LiCoO(2) and LiMnPO(4), the studies of our cathode composition and preparation will be presented.

  4. A martyr for modernity: Qiu Jin -- feminist warrior, and revolutionary.

    PubMed

    Fan, H; Mangan, J A

    2001-01-01

    Qui Jin, at one level, was an oriental twentieth-century Judith, the mythical Jewish widow from Bethulia who cut off the head of Holofernes, the Assyrian general besieging the city, thus saving the Israelites from destruction. Qui Jin was, as Judith was, a self-reliant heroine who when others seemed 'helpless and demoralized undertook to save them single-handedly', or in her case virtually single-handedly. This, of course, was both her making and her unmaking. In Chinese terms the story of Qui Jin, like the story of Judith if less famous, less publicised, more recent, is the story of an icon at once central and at the same time marginal to tradition. She contradicted the most cherished customs on Confucian Chinese culture. She was a radical force who thrust her way to the centre of the concentric circles of customs surrounding this culture and was pushed back to the margins by conservatism. Nevertheless Qui Jin was not without success. She challenged a long-established mythology of exclusively masterful patriarchy - and created a counter myth of purposeful patriotic feminism. She was a counter-cultural icon who changed perceptions of Chinese femininity. She gave courage, confidence and purpose to those women who came after her and absorbed her ambitions for modern Chinese womanhood. For them she was a modern national heroine and a personification of a modern nation of equal men and women. For Qui Jin the body was an instrument of female revolution to be trained, strengthened and prepared for confrontation. As a revolutionary militant she was a failure; as a revolutionary talisman she was a success. For the Chinese women of the 1911 Revolution hers was an exemplary emancipatory story: subscribe, struggle, sacrifice. Patriotism through feminism is the purpose. Her heroism was firmly outside the historic patriarchal order. Her adulation is thus all the more remarkable because of the profound traditions she rejected, the controversial mannerisms she adopted, the uncompromising attitudes she embraced. She eschewed motherhood, abandoned marriage, dismissed femininity, and yet won acclaim in the most traditional of cultures. Qui Jin was hardly a cynosure of universal acclaim but she was admired, respected and emulated by radical Chinese women and men seeking a new society accommodating women. Her modern feminism struggled to overcome an ancient patriarchy. Here was her appeal. She exuded no moral ambiguity. Consequently, if she was demonized by the conventional; she was deified by the radical - and inspired them as the contemplated and attempted to construct the future. There is a point, of course, that should not be overlooked. Qui Jin, in fact, is not divorced from occidental culture and political iconography. Qui Jin is closely associated with the attitudes, aspirations and fantasies of modern Western feminism. As Margarita Stocker observes, a 'romantic heroine, angry feminist, radical, activist is one example of a pervasive figure', in modern Western cultural mythology 'a figure we may sum up as the Woman with a Gun'. Force, that potent means to power, is available to the gun user irrespective of age of sex, with a resulting 'crucial alteration in the sexual politics of violence'. The Woman with a Gun can now be emphatically heroic - without duplicity, without deceitfulness, without subterfuge. Moral ambiguity in action has been abandoned. She becomes an unambiguous potent force - an armed woman faces an armed man on equal terms - physically, psychologically, morally. Equality offers the legal right and responsibility to kill in the name of patriotism. Modern culture has just caught up with Qui Jin. PMID:18464347

  5. A martyr for modernity: Qiu Jin -- feminist warrior, and revolutionary.

    PubMed

    Fan, H; Mangan, J A

    2001-01-01

    Qui Jin, at one level, was an oriental twentieth-century Judith, the mythical Jewish widow from Bethulia who cut off the head of Holofernes, the Assyrian general besieging the city, thus saving the Israelites from destruction. Qui Jin was, as Judith was, a self-reliant heroine who when others seemed 'helpless and demoralized undertook to save them single-handedly', or in her case virtually single-handedly. This, of course, was both her making and her unmaking. In Chinese terms the story of Qui Jin, like the story of Judith if less famous, less publicised, more recent, is the story of an icon at once central and at the same time marginal to tradition. She contradicted the most cherished customs on Confucian Chinese culture. She was a radical force who thrust her way to the centre of the concentric circles of customs surrounding this culture and was pushed back to the margins by conservatism. Nevertheless Qui Jin was not without success. She challenged a long-established mythology of exclusively masterful patriarchy - and created a counter myth of purposeful patriotic feminism. She was a counter-cultural icon who changed perceptions of Chinese femininity. She gave courage, confidence and purpose to those women who came after her and absorbed her ambitions for modern Chinese womanhood. For them she was a modern national heroine and a personification of a modern nation of equal men and women. For Qui Jin the body was an instrument of female revolution to be trained, strengthened and prepared for confrontation. As a revolutionary militant she was a failure; as a revolutionary talisman she was a success. For the Chinese women of the 1911 Revolution hers was an exemplary emancipatory story: subscribe, struggle, sacrifice. Patriotism through feminism is the purpose. Her heroism was firmly outside the historic patriarchal order. Her adulation is thus all the more remarkable because of the profound traditions she rejected, the controversial mannerisms she adopted, the uncompromising attitudes she embraced. She eschewed motherhood, abandoned marriage, dismissed femininity, and yet won acclaim in the most traditional of cultures. Qui Jin was hardly a cynosure of universal acclaim but she was admired, respected and emulated by radical Chinese women and men seeking a new society accommodating women. Her modern feminism struggled to overcome an ancient patriarchy. Here was her appeal. She exuded no moral ambiguity. Consequently, if she was demonized by the conventional; she was deified by the radical - and inspired them as the contemplated and attempted to construct the future. There is a point, of course, that should not be overlooked. Qui Jin, in fact, is not divorced from occidental culture and political iconography. Qui Jin is closely associated with the attitudes, aspirations and fantasies of modern Western feminism. As Margarita Stocker observes, a 'romantic heroine, angry feminist, radical, activist is one example of a pervasive figure', in modern Western cultural mythology 'a figure we may sum up as the Woman with a Gun'. Force, that potent means to power, is available to the gun user irrespective of age of sex, with a resulting 'crucial alteration in the sexual politics of violence'. The Woman with a Gun can now be emphatically heroic - without duplicity, without deceitfulness, without subterfuge. Moral ambiguity in action has been abandoned. She becomes an unambiguous potent force - an armed woman faces an armed man on equal terms - physically, psychologically, morally. Equality offers the legal right and responsibility to kill in the name of patriotism. Modern culture has just caught up with Qui Jin.

  6. Structural transformation of Li 2CoPO 4F upon Li-deintercalation

    NASA Astrophysics Data System (ADS)

    Khasanova, Nellie R.; Gavrilov, Alexey N.; Antipov, Evgeny V.; Bramnik, Kirill G.; Hibst, Hartmut

    Electrochemical performance and structural properties of the high-voltage cathode material Li 2CoPO 4F have been investigated. The cyclic voltammetry and coulometry under potential step mode in the voltage range 3.0-5.1 V vs. Li revealed a structural transformation at potentials above 4.8 V. This transformation occurring upon Li-extraction appears to be irreversible: the subsequent Li-insertion does not result in restoration of the initial structure, but takes place within a new "modified" framework. According to the structure refinement this modification involves the mutual rotations of (CoO 4F 2) octahedra and (PO 4) tetrahedra accompanied by the considerable unit cell expansion which is expected to enhance the Li-transport upon subsequent cycling. The new framework demonstrates a reversible Li-insertion/extraction in a solid-solution regime with stabilized discharge capacity at around 60 mAh g -1.

  7. Preparation and some properties of Cu-Li alloys containing up to 20 at. % Li

    SciTech Connect

    Mendelsohn, M.; Krauss, A.R.; Gruen, D.M.

    1985-01-01

    Lithium strongly segregates to the surface of Cu-Li alloys, thus substantially lowering the Cu sputtering yield relative to pure Cu. Use of Cu-Li limiters or divertors in tokamaks can therefore be expected to be beneficial in limiting high-Z plasma impurity influx. A large scale (100-200g) method for the preparation of Cu-Li alloys is described. Analysis reveals that on solidification from the melt stratification occurs which leads to compositional inhomogeneity. The results are discussed in the light of the Cu-Li binary phase diagram and rationalized on the basis of large density differences between Cu and Cu-Li solid solutions. It is concluded that obtaining homogeneous Cu-Li solid solutions is a nontrivial task.

  8. Layered Li-Mn-M-oxides as cathodes for Li-ion batteries:. Recent trends

    NASA Astrophysics Data System (ADS)

    Shaju, K. M.; Subba Rao, G. V.; Chowdari, B. V. R.

    2002-12-01

    There is an increasing demand for manganese (Mn) based mixed oxides which can effectively replace the presently used LiCoO2 as cathode in Li-ion batteries (LIB). The well-studied spinel, LiMn2O4 and its doped derivatives give a capacity of 100-120 mAh/g, but show capacity-fading on cycling especially above 55°C. The layered LiMnO2, isostructural to LiCoO2 (so called O3-structure) can be a viable cathode. However, studies have shown that it undergoes conversion to spinel structure on cycling and thus gives capacity-fading. Other alternative systems recently studied are: O2-structured layered Li-M-Mn-oxides with the general formula Li(2/3)+x(MyMn1-y)O2, M = Li, Ni, Co; x ≤ 0.33 and y = 0.1-0.67, O3-Li(Ni1/2Mn1/2)O2, Li(NixCo1-2xMnx)O2, and M'-substituted Li2MnO3 (M' = Ni, Co, Cr). Some of them are shown to have stable cycling performance, good rate-capability and structural stability over charge-discharge cycling in the 2.5-4.6 V region. Further, the electrochemical processes in the above mixed oxides have been shown to involve Ni2+/4+ or Cr3+/6+ redox couple, thus invoking novel ideas to develop new cathode materials. A brief review of the work done on the above O2- and O3-layered Li-Mn-M-oxides (M = metal) as cathodes for LIB is presented.

  9. Antiperovskite Li 3 OCl superionic conductor films for solid-state Li-ion batteries

    DOE PAGES

    Lü, Xujie; Howard, John W.; Chen, Aiping; Zhu, Jinlong; Li, Shuai; Wu, Gang; Dowden, Paul; Xu, Hongwu; Zhao, Yusheng; Jia, Quanxi

    2016-02-02

    We prepared antiperovskite Li3OCl superionic conductor films via pulsed laser deposition using a composite target. A significantly enhanced ionic conductivity of 2.0 × 10-4 S cm-1 at room temperature is achieved, and this value is more than two orders of magnitude higher than that of its bulk counterpart. Moreover, the applicability of Li3OCl as a solid electrolyte for Li-ion batteries is demonstrated.

  10. Effect of the composition of Al-Li alloys on the quantitative relation between the δ'(Al3Li), S1(Al2MgLi), and T1(Al2CuLi) phases

    NASA Astrophysics Data System (ADS)

    Betsofen, S. Ya.; Antipov, V. V.; Grushin, I. A.; Knyazev, M. I.; Khokhlatova, L. B.; Alekseev, A. A.

    2015-01-01

    Al-Li alloys are considered. A quantitative approach to the determination of the ratio of the fractions of the binary and ternary intermetallic phases in Al-Mg(Cu)-Li alloys is developed on the basis of chemical and phase composition balance equations and the experimentally measured lattice parameter of the α solid solution. The ratio of the fractions of the δ'(Al3Li) and S1(T1) phases in Al-Mg(Cu)-Li alloys is shown to be determined by the ratio of the mole fractions of Li and Mg(Cu). Equations are proposed for calculating the weight fractions of the S1(Al2MgLi), T1(Al2CuLi) and δ'(Al3Li) phases in domestic and foreign Al-Mg-Li alloys 1420, 1424, 5090 and Al-Cu-Li alloys 1440, 1460, 1461, 1441, 1469, 2090, 2095, 8090, and Weldalite 049.

  11. Power capability improvement of LiBOB/PC electrolyte for Li-ion batteries

    NASA Astrophysics Data System (ADS)

    Kaneko, Hiroaki; Sekine, Kyoichi; Takamura, Tsutomu

    Lithium bis(oxalto)borate (LiBOB) is quite effective to prevent vigorous decomposition of propylene carbonate (PC) at the graphite anode of a Li-ion battery during Li insertion. PC is a very good solvent that is inexpensive, has high conductivity and a low melting point; however, the power capability of PC electrolyte containing LiBOB is unsatisfactory. In an attempt to improve the power capability of the LiBOB/PC electrolyte, mixed electrolytes containing both LiBOB and LiClO 4 were examined. An integrated fiber felt of highly graphitized carbon was used as the working electrode and the performance was evaluated by cyclic voltammetry (CV), constant current followed by constant voltage charge (CCCV) and constant current discharge. The CV produced a stable peak for Li extraction, but the peak height was as low as half that obtained in a conventional electrolyte such as a 1:1 mixture of ethylene carbonate (EC) and dimethyl carbonate (DMC) containing 1 M LiClO 4. However, the peak height in PC, containing 1/49 M LiBOB and 1 M LiClO 4, became 1.5 times higher than that in PC containing 1 M LiBOB. The peak height was increased further using a 1:1 mixture of PC and acetonitrile (AN) containing 1/49 M LiBOB and 1 M LiClO 4, although the cycleability was poor. A similar tendency was observed with the CCCV test. The CV peak height was plotted against the ionic conductivity of several solvents and showed no linear relationship, implying that the reaction activity was influenced by the solid electrolyte interphase (SEI) formed. The charge transfer resistance was evaluated by impedance spectroscopy. The results revealed that not only the surface film resistance but also the charge transfer resistance was markedly increased in the electrolyte containing LiBOB; however, they were reduced by the addition of LiClO 4.

  12. Ferromagnetism in chemically reduced LiNbO3 and LiTaO3 crystals

    NASA Astrophysics Data System (ADS)

    Yan, Tao; Ye, Ning; Xu, Liuwei; Sang, Yuanhua; Chen, Yanxue; Song, Wei; Long, Xifa; Wang, Jiyang; Liu, Hong

    2016-05-01

    The ferromagnetism of bulk LiNbO3 and LiTaO3 at room temperature was investigated for the first time in the present work. The stoichiometric LiNbO3 is non-magnetic, while congruent LiNbO3 and LiTaO3 show very weak ferromagnetism. After chemical reduction in a mixture of zinc and lithium carbonate powders under flowing nitrogen, the ferromagnetic behavior of each sample became clear, with an increased value of magnetization. The saturation magnetization, the magnetic remanence and the coercive field of reduced congruent LiNbO3 are 7.0  ×  10‑3 emu g‑1, 0.65  ×  10‑3 emu g‑1 and 0.050 kOe, respectively. The ferromagnetism of chemically reduced LiNbO3 and LiTaO3 can be explained by considering the intrinsic Li vacancies, the appearance of Nb4+ (or Ta4+) on the surface with non-zero net spin and the oxygen vacancies at the surface.

  13. Strain imaging of a LiCoO2 cathode in a Li-ion battery

    NASA Astrophysics Data System (ADS)

    Matsushita, Yuki; Osaka, Ryuma; Butsugan, Kenta; Takata, Keiji

    2016-09-01

    Li-ion batteries have been recognized as promising devices for a sustainable society. Layered LiCoO2 and graphite are commonly used as electrode materials for Li-ion batteries. When charging and discharging, Li-ions are extracted or inserted into the interlayers, which causes changes in volume. Scanning probe microscopy (SPM) can allow high resolution imaging of these volume changes, which enables us to investigate Li-ion migration without destruction. We observed volume changes in the LiCoO2 cathode using SPM and successfully imaged the distribution of the volume changes corresponding to the LiCoO2 particles. Volume changes in the interspace were significantly larger than those in the particles. The large volume changes are caused by electrolyte flux induced by changes in concentration of Li ions. The volume changes were greatly reduced when the electrolyte dried out. The dry-out and infiltration of electrolyte between the LiCoO2 particles and the current collector spread out with the procedure of degradation of the batteries. The boundaries between the dry-out and infiltration regions acted as barriers of electrolyte flux.

  14. Uniform second Li ion intercalation in solid state ɛ-LiVOPO4

    NASA Astrophysics Data System (ADS)

    Wangoh, Linda W.; Sallis, Shawn; Wiaderek, Kamila M.; Lin, Yuh-Chieh; Wen, Bohua; Quackenbush, Nicholas F.; Chernova, Natasha A.; Guo, Jinghua; Ma, Lu; Wu, Tianpin; Lee, Tien-Lin; Schlueter, Christoph; Ong, Shyue Ping; Chapman, Karena W.; Whittingham, M. Stanley; Piper, Louis F. J.

    2016-08-01

    Full, reversible intercalation of two Li+ has not yet been achieved in promising VOPO4 electrodes. A pronounced Li+ gradient has been reported in the low voltage window (i.e., second lithium reaction) that is thought to originate from disrupted kinetics in the high voltage regime (i.e., first lithium reaction). Here, we employ a combination of hard and soft x-ray photoelectron and absorption spectroscopy techniques to depth profile solid state synthesized LiVOPO4 cycled within the low voltage window only. Analysis of the vanadium environment revealed no evidence of a Li+ gradient, which combined with almost full theoretical capacity confirms that disrupted kinetics in the high voltage window are responsible for hindering full two lithium insertion. Furthermore, we argue that the uniform Li+ intercalation is a prerequisite for the formation of intermediate phases Li1.50VOPO4 and Li1.75VOPO4. The evolution from LiVOPO4 to Li2VOPO4 via the intermediate phases is confirmed by direct comparison between O K-edge absorption spectroscopy and density functional theory.

  15. Nuclear Charge Radii of Li-8,Li-9 Determined by Laser Spectroscopy

    SciTech Connect

    Ewald, G; Nortershauser, W.; Dax, A ..; Gotte, S; Kirchner, Rolf; Kluge, H J.; Kuhl, T H.; Sanchez, R J.; Wojtasek, Alesia S.; Bushaw, Bruce A.; Drake, Gordon W. F.; Yan, Z C.; Zimmerman, Colin H.

    2004-09-09

    The 2S ' 3S transition of 6,7,8,9 Li was studied by high-resolution laser spectroscopy using two-photon Doppler-free excitation and resonance-ionization detection. The hyperfine structure splitting and the isotope shift were determined with precision at the 100 kHz level. Combined with recent theoretical work, the changes in nuclear charge radii of 8,9Li were determined. These are now the lightest short-lived isotopes for which the charge radii have been measured. It is found that the charge radii monotonically decrease with increasing neutron number from 6Li to 9Li.

  16. Nanotechnology in Li-ion Batteries

    SciTech Connect

    Mukaibo, Hitomi

    2010-06-04

    This is the second of three talks on nanostructures for li-ion batteries. The talks provide an up-to-date review of the issues and challenges facing Li-ion battery research with special focus on how nanostructures/ nanotechnology are being applied to this field. Novel materials reported as prospective candidates for anode, cathode and electrolyte will be summarized. The expected role of nanostructures in improving the performance of Li-ion batteries and the actual pros and cons of using such structures in this device will be addressed. Electrochemical experiments used to study Li-ion batteries will also be discussed. This includes the introduction to the standard experimental set-up and how experimental data (from charge-discharge experiments, cyclic voltammetry, impedance spectroscopy, etc) are interpreted.

  17. Comment on Li pellet Conditioning in TFTR

    SciTech Connect

    R.V. Budny

    2011-05-23

    Li pellet conditioning in TFTR results in a reduction of the edge electron density which allows increased neutral beam penetration, central heating, and fueling. Consequently the temperature profiles became more peaked with higher central Ti, Te, and neutron emission rates.

  18. Specification For ST-5 Li Ion Battery

    NASA Technical Reports Server (NTRS)

    Castell, Karen D.; Day, John H. (Technical Monitor)

    2000-01-01

    This Specification defines the general requirements for rechargeable Space Flight batteries intended for use in the ST-5 program. The battery chemistry chosen for this mission is lithium ion (Li-Ion).

  19. Unravelling Li-Ion Transport from Picoseconds to Seconds: Bulk versus Interfaces in an Argyrodite Li6PS5Cl-Li2S All-Solid-State Li-Ion Battery.

    PubMed

    Yu, Chuang; Ganapathy, Swapna; de Klerk, Niek J J; Roslon, Irek; van Eck, Ernst R H; Kentgens, Arno P M; Wagemaker, Marnix

    2016-09-01

    One of the main challenges of all-solid-state Li-ion batteries is the restricted power density due to the poor Li-ion transport between the electrodes via the electrolyte. However, to establish what diffusional process is the bottleneck for Li-ion transport requires the ability to distinguish the various processes. The present work investigates the Li-ion diffusion in argyrodite Li6PS5Cl, a promising electrolyte based on its high Li-ion conductivity, using a combination of (7)Li NMR experiments and DFT based molecular dynamics simulations. This allows us to distinguish the local Li-ion mobility from the long-range Li-ion motional process, quantifying both and giving a coherent and consistent picture of the bulk diffusion in Li6PS5Cl. NMR exchange experiments are used to unambiguously characterize Li-ion transport over the solid electrolyte-electrode interface for the electrolyte-electrode combination Li6PS5Cl-Li2S, giving unprecedented and direct quantitative insight into the impact of the interface on Li-ion charge transport in all-solid-state batteries. The limited Li-ion transport over the Li6PS5Cl-Li2S interface, orders of magnitude smaller compared with that in the bulk Li6PS5Cl, appears to be the bottleneck for the performance of the Li6PS5Cl-Li2S battery, quantifying one of the major challenges toward improved performance of all-solid-state batteries. PMID:27511442

  20. Unravelling Li-Ion Transport from Picoseconds to Seconds: Bulk versus Interfaces in an Argyrodite Li6PS5Cl-Li2S All-Solid-State Li-Ion Battery.

    PubMed

    Yu, Chuang; Ganapathy, Swapna; de Klerk, Niek J J; Roslon, Irek; van Eck, Ernst R H; Kentgens, Arno P M; Wagemaker, Marnix

    2016-09-01

    One of the main challenges of all-solid-state Li-ion batteries is the restricted power density due to the poor Li-ion transport between the electrodes via the electrolyte. However, to establish what diffusional process is the bottleneck for Li-ion transport requires the ability to distinguish the various processes. The present work investigates the Li-ion diffusion in argyrodite Li6PS5Cl, a promising electrolyte based on its high Li-ion conductivity, using a combination of (7)Li NMR experiments and DFT based molecular dynamics simulations. This allows us to distinguish the local Li-ion mobility from the long-range Li-ion motional process, quantifying both and giving a coherent and consistent picture of the bulk diffusion in Li6PS5Cl. NMR exchange experiments are used to unambiguously characterize Li-ion transport over the solid electrolyte-electrode interface for the electrolyte-electrode combination Li6PS5Cl-Li2S, giving unprecedented and direct quantitative insight into the impact of the interface on Li-ion charge transport in all-solid-state batteries. The limited Li-ion transport over the Li6PS5Cl-Li2S interface, orders of magnitude smaller compared with that in the bulk Li6PS5Cl, appears to be the bottleneck for the performance of the Li6PS5Cl-Li2S battery, quantifying one of the major challenges toward improved performance of all-solid-state batteries.

  1. Negative Electrodes for Li-Ion Batteries

    SciTech Connect

    Kinoshita, Kim; Zaghib, Karim

    2001-10-01

    Graphitized carbons have played a key role in the successful commercialization of Li-ion batteries. The physicochemical properties of carbon cover a wide range; therefore identifying the optimum active electrode material can be time consuming. The significant physical properties of negative electrodes for Li-ion batteries are summarized, and the relationship of these properties to their electrochemical performance in nonaqueous electrolytes, are discussed in this paper.

  2. Lost in Translation (LiT)

    PubMed Central

    Dollery, Colin T

    2014-01-01

    Translational medicine is a roller coaster with occasional brilliant successes and a large majority of failures. Lost in Translation 1 (‘LiT1’), beginning in the 1950s, was a golden era built upon earlier advances in experimental physiology, biochemistry and pharmacology, with a dash of serendipity, that led to the discovery of many new drugs for serious illnesses. LiT2 saw the large-scale industrialization of drug discovery using high-throughput screens and assays based on affinity for the target molecule. The links between drug development and university sciences and medicine weakened, but there were still some brilliant successes. In LiT3, the coverage of translational medicine expanded from molecular biology to drug budgets, with much greater emphasis on safety and official regulation. Compared with R&D expenditure, the number of breakthrough discoveries in LiT3 was disappointing, but monoclonal antibodies for immunity and inflammation brought in a new golden era and kinase inhibitors such as imatinib were breakthroughs in cancer. The pharmaceutical industry is trying to revive the LiT1 approach by using phenotypic assays and closer links with academia. LiT4 faces a data explosion generated by the genome project, GWAS, ENCODE and the ‘omics’ that is in danger of leaving LiT4 in a computerized cloud. Industrial laboratories are filled with masses of automated machinery while the scientists sit in a separate room viewing the results on their computers. Big Data will need Big Thinking in LiT4 but with so many unmet medical needs and so many new opportunities being revealed there are high hopes that the roller coaster will ride high again. PMID:24428732

  3. LiNbO3 Cylinder Fiber

    NASA Technical Reports Server (NTRS)

    Kornreich, Philip

    2004-01-01

    We have successfully fabricate optical fiber with a thin layer of LiNbO3 at the boundary of the glass core and clear glass cladding. The construction of this fiber is based on our successful Semiconductor Cylinder Fibers (SCF). A schematic representation of a LiN bo, Cylinder Fiber. These fibers can be used as light modulators, sonar detectors and in other applications. The core diameter of the fiber is sufficiently small compared to the light wavelength and the indices of refraction of the core and cladding glasses are sufficiently close in value so that there is sufficient light at the core cladding boundary to interact with the LiNbO3 layer. This fiber functions best when just a single light mode propagates through the fiber. The idea for a LiNbO3 Cylinder Fiber came from Dr. Tracee Jamison of NASA. The optical properties of LiNbO3 can be changed with strain or the application of an electric field. Thus these fibers can be used as acoustic sensors as for example in a sonar. They can also be used as electric field operated light modulators. However, for this application the fibers would be made with a cross section in the form of a "D". The core with its surrounding LiNbO, layer would be close to the flat portion of the "D" shaped fiber. Two metal contacts would be deposited on the flat portion of the fiber on either side of the core. A voltage applied across these contacts will result in an electric field in the core region that can be used for modulating the optical properties of the LiNbO3 layer. To our knowledge this is the first ever LiNbO3 Cylinder Fiber made.

  4. LiNbO3 Cylinder Fiber

    NASA Technical Reports Server (NTRS)

    2004-01-01

    We have successfully fabricate optical fiber with a thin layer of LiNbO3 at the boundary of the glass core and dear glass cladding. The construction of this fiber is based on our successful Semiconductor Cylinder Fibers (SCF). A schematic representation of a LiNbO3 Cylinder Fiber is shown. These fibers can be used as light modulators, sonar detectors and in other applications. The core diameter of the fiber is sufficiently small compared to the light wavelength and the indices of refraction of the core and cladding glasses are sufficiently close in value so that there is sufficient light at the core cladding boundary to interact with the LiNbO3 layer. This fiber functions best when just a single light mode propagates through the fiber. The idea for a LiNbO3 Cylinder Fiber came from Dr. Tracee Jamison of NASA. The optical properties of LiNbO3 can be changed with strain or the application of an electric field. Thus these fibers can be used as acoustic sensors as for example in a sonar. They can also be used as electric field operated light modulators. However, for this application the fibers would be made with a cross section in the form of a 'D'. The core with its surrounding LiNbO, layer would be close to the flat portion of the 'D' shaped fiber. Two metal contacts would be deposited on the flat portion of the fiber on either side of the core. A voltage applied across these contacts will result in an electric field in the core region that can be used for modulating the optical properties of the LiNbO, layer. To our knowledge this is the first ever LiNbO, Cylinder Fiber made.

  5. An experimental study for Li recycling in an electrolytic reduction process for UO2 with a Li2O-LiCl molten salt

    NASA Astrophysics Data System (ADS)

    Park, Wooshin; Hur, Jin-Mok; Hong, Sun-Seok; Choi, Eun-Young; Im, Hun Suk; Oh, Seung-Chul; Lee, Jae-Won

    2013-10-01

    If Li is excessively produced in an electrolytic reduction process for UO2 with a Li2O-LiCl molten salt, a part of Li2O will be lost in the form of Li as deposited on the cathode, and the Li can cause negative effects on a post process. To solve these problems, a method for Li recycling was investigated in this study. A series of experiments were carried out consisting of four runs. In the first run, UO2 fragments were electrochemically reduced at 3.2 V of cell voltage. The excess Li was then recovered by transferring to another electrode at 0.3 V of cell voltage. The recovered Li was then utilized as the source for the reduction of fresh UO2 fragments. Finally, the remaining UO2 was electrochemically reduced at 3.2 V of cell voltage. The concentration of Li2O was reasonably maintained as a result of the Li recycling without a significant loss. Consequently, the potential problems by Li could be disregarded using the recycling method. The electrolytic reduction process for UO2 will be more efficient and sustainable by combining the technology for Li recycling and the conventional electrolytic reduction process.

  6. Tracing Waste Water with Li isotopes

    NASA Astrophysics Data System (ADS)

    Millot, R.; Desaulty, A. M.

    2015-12-01

    The contribution of human activities such as industries, agriculture and various domestic inputs, becomes more and more significant in the chemical composition of the dissolved load of rivers. Human factors act as a supplementary key process. Therefore the mass-balance for the budget of catchments and river basins include anthropogenic disturbances. In the present study, we investigate waste water tracing by the use of Li isotopes in a small river basin near Orléans in France (l'Egoutier, 15 km² and 5 km long). It is well known that Li has strategic importance for numerous industrial applications including its use in the production of batteries for both mobile devices (computers, tablets, smartphones, etc.) and electric vehicles, but also in pharmaceutical formulations. In the present work, we collected river waters samples before and after the release from a waste water treatment plant connected to an hospital. Lithium isotopic compositions are rather homogeneous in river waters with δ7Li values around -0.5‰ ± 1 along the main course of the stream (n=7). The waste water sample is very different from the natural background of the river basin with Li concentration being twice of the values without pollution and significant heavy lithium contribution (δ7Li = +4‰). These preliminary results will be discussed in relation with factors controlling the distribution of Li and its isotopes in this specific system and compared with the release of other metals such as Pb or Zn.

  7. Material Compatibility with Isothermal Pb-Li

    SciTech Connect

    Pint, Bruce A; Walker, Larry R; Unocic, Kinga A

    2012-01-01

    Eutectic Pb-Li is a leading candidate for current fusion blanket concepts as a coolant. However, there is very little data about the compatibility of most materials with Pb-Li above 500 C where the dissolution rate of many conventional alloys increases rapidly. Current work is beginning to assess Pb-Li compatibility from 500 to 800 C using isothermal capsule experiments. Aluminide coatings hold some promise in protecting conventional Fe-base alloys at 600-700 C. However, there is a significant initial Al loss that has not been clearly explained. Furthermore, the reaction product with coated materials is LiAlO{sub 2} rather than Al{sub 2}O{sub 3} at 600 and 700 C. Even when pre-oxidized to form {alpha}-Al{sub 2}O{sub 3}, an alumina layer on FeCrAl transformed to LiAlO{sub 2} at 700 and 800 C. At 500 C, the preformed oxide partially transformed from alumina and some Li was detected in the oxide layer.

  8. LiGa(OTf)(sub 4) as an Electrolyte Salt for Li-Ion Cells

    NASA Technical Reports Server (NTRS)

    Reddy, V. Prakash; Prakash, G. K. Syria; Hu, Jinbo; Yan, Ping; Smart, Marshall; Bugga, ratnakumar; Chin, Keith; Surampudi, Subarao

    2008-01-01

    Lithium tetrakis(trifluoromethane sulfo - nato)gallate [abbreviated "LiGa(OTf)4" (wherein "OTf" signifies trifluoro - methanesulfonate)] has been found to be promising as an electrolyte salt for incorporation into both liquid and polymer electrolytes in both rechargeable and non-rechargeable lithium-ion electrochemical cells. This and other ingredients have been investigated in continuing research oriented toward im proving the performances of rechargeable lithium-ion electrochemical cells, especially at low temperatures. This research at earlier stages, and the underlying physical and chemical principles, were reported in numerous previous NASA Tech Briefs articles. As described in more detail in those articles, lithiumion cells most commonly contain nonaqueous electrolyte solutions consisting of lithium hexafluorophosphate (LiPF6) dissolved in mixtures of cyclic and linear alkyl carbonates, including ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), diethyl carbonate (DEC), and ethyl methyl carbonate (EMC). Although such LiPF6-based electrolyte solutions are generally highly ionically conductive and electrochemically stable, as needed for good cell performance, there is interest in identifying alternate lithium electrolyte salts that, relative to LiPF6, are more resilient at high temperature and are less expensive. Experiments have been performed on LiGa(OTf)4 as well as on several other candidate lithium salts in pursuit of this interest. As part of these experiments, LiGa(OTf)4 was synthesized by the reaction of Ga(OTf)3 with an equimolar portion of LiOTf in a solvent consisting of anhydrous acetonitrile. Evaporation of the solvent yielded LiGa(OTf)4 as a colorless crystalline solid. The LiGa(OTf)4 and the other salts were incorporated into solutions with PC and DMC. The resulting electrolyte solutions exhibited reasonably high ionic conductivities over a relatively wide temperature range down to 40 C (see figure). In cyclic

  9. Simulation of Ti diffusion into LiNbO3 in Li-rich atmosphere

    NASA Astrophysics Data System (ADS)

    Zhang, De-Long; Zhuang, Yu-Ran; Hua, Ping-Rang; Pun, E. Y. B.

    2007-01-01

    A model is proposed for describing two-dimensional diffusion of Ti into an initially congruent LiNbO3 crystal under a Li-enriched atmosphere created by a mixed two-phase (Li3NbO4 and LiNbO3) powder at elevated temperature [vapor transport equilibration (VTE)]. The influence of VTE treatment on Ti diffusivity is considered in the model. To solve the model, four key input parameters including Li-concentration-dependent Li and Ti diffusivities and two switching times t1 and t2 were determined. Prior to solve the Ti-diffusion model, a one-dimensional VTE model is solved at first to obtain the dynamic Li2O concentration depth profile. Both the Li-diffusion and Ti-diffusion models were solved by using finite difference method. Based on secondary-ion-mass spectrometry analysis, the validity of the VTE and Ti-diffusion models as well as the numerical method employed are confirmed. After that, diffusion at 1100°C of an 8-μm-wide, 100-nm-thick Ti strip defined on the surface of a Z-cut or an X-cut substrate was simulated for the VTE duration up to 130h. Based on the numerical results, the Ti-(Li-)diffusion characteristics are discussed in the aspects of (1) the relation of depth and width profile function of Ti concentration to the VTE duration, (2) the substrate cut effect on both the Ti and Li diffusions, (3) the relation of the 1/e Ti-concentration depth and half-width to the VTE duration, and (4) the VTE duration dependence of the mean [Li ]/[Nb] ratio within the Ti-diffused layer.

  10. Simulation of Ti diffusion into LiNbO{sub 3} in Li-rich atmosphere

    SciTech Connect

    Zhang Delong; Zhuang Yuran; Hua Pingrang; Pun, E. Y. B.

    2007-01-01

    A model is proposed for describing two-dimensional diffusion of Ti into an initially congruent LiNbO{sub 3} crystal under a Li-enriched atmosphere created by a mixed two-phase (Li{sub 3}NbO{sub 4} and LiNbO{sub 3}) powder at elevated temperature [vapor transport equilibration (VTE)]. The influence of VTE treatment on Ti diffusivity is considered in the model. To solve the model, four key input parameters including Li-concentration-dependent Li and Ti diffusivities and two switching times t{sub 1} and t{sub 2} were determined. Prior to solve the Ti-diffusion model, a one-dimensional VTE model is solved at first to obtain the dynamic Li{sub 2}O concentration depth profile. Both the Li-diffusion and Ti-diffusion models were solved by using finite difference method. Based on secondary-ion-mass spectrometry analysis, the validity of the VTE and Ti-diffusion models as well as the numerical method employed are confirmed. After that, diffusion at 1100 deg. C of an 8-{mu}m-wide, 100-nm-thick Ti strip defined on the surface of a Z-cut or an X-cut substrate was simulated for the VTE duration up to 130 h. Based on the numerical results, the Ti-(Li-)diffusion characteristics are discussed in the aspects of (1) the relation of depth and width profile function of Ti concentration to the VTE duration, (2) the substrate cut effect on both the Ti and Li diffusions, (3) the relation of the 1/e Ti-concentration depth and half-width to the VTE duration, and (4) the VTE duration dependence of the mean [Li]/[Nb] ratio within the Ti-diffused layer.

  11. Li-7 abundances in halo stars: Testing stellar evolution models and the primordial Li-7 abundance

    NASA Technical Reports Server (NTRS)

    Chaboyer, Brian; Demarque, P.

    1994-01-01

    A large number of stellar evolution models with (Fe/H) = -2.3 and -3.3 have been calculated in order to determine the primordial Li-7 abundance and to test current stellar evolution models by a comparison to the extensive database of accurate Li abundances in extremely metal-poor halo stars observed by Thorburn (1994). Standard models with gray atmospheres do a very good job of fitting the observed Li abundances in stars hotter than approximately 5600 K. They predict a primordial. Li-7 abundance of log N(Li) = 2.24 +/- 0.03. Models which include microscopic diffusion predict a downward curvature in the Li-7 destruction isochrones at hot temperatures which is not present in the observations. Thus, the observations clearly rule out models which include uninhibited microscopic diffusion of Li-7 from the surface of the star. Rotational mixing inhibits the microscopic diffusion and the (Fe/H) = -2.28 stellar models which include both diffusion and rotational mixing provide an excellent match to the mean trend in T(sub eff) which is present in the observations. Both the plateau stars and the heavily depleted cool stars are well fit by these models. The rotational mixing leads to considerable Li-7 depletion in these models and the primordial Li-7 abundance inferred from these models is log N(Li) = 3.08 +/- 0.1. However, the (Fe/H) = -3.28 isochrones reveal problems with the combined models. These isochrones predict a trend of decreasing log N(Li) with increasing T(sub eff) which is not present in the observations. Possible causes for this discrepancy are discussed.

  12. Li-Ion Battery with LiFePO4 Cathode and Li4Ti5O12 Anode for Stationary Energy Storage

    SciTech Connect

    Wang, Wei; Choi, Daiwon; Yang, Zhenguo

    2013-01-01

    i-ion batteries based on commercially available LiFePO4 cathode and Li4Ti5O12 anode were investigated for potential stationary energy storage applications. The full cell that operated at flat 1.85V demonstrated stable cycling for 200 cycles followed by a rapid fade. A significant improvement in cycling stability was achieved via Ketjen black coating of the cathode. A Li-ion full cell with Ketjen black modified LiFePO4 cathode and an unmodified Li4Ti5O12 anode exhibited negligible fade after more than 1200 cycles with a capacity of ~130mAh/g. The improved stability, along with its cost-effectiveness, environmentally benignity and safety, make the LiFePO4/ Li4Ti5O12 Li-ion battery a promising option of storing renewable energy.

  13. Structural and electrochemical stability of Li-rich layer structured Li2MoO3 in air

    NASA Astrophysics Data System (ADS)

    Ma, Jun; Gao, Yurui; Wang, Zhaoxiang; Chen, Liquan

    2014-07-01

    Li2MnO3 is an important component of the Li-rich Mn-based high-capacity cathode material for lithium ion batteries, xLi2MnO3·(1 - x)LiM‧O2 composites. Replacing Li2MnO3 with iso-structured Li2MoO3 is expected to improve the rate performance and suppress the oxygen release of the composites at high potentials due to the higher electric conductivity of Li2MoO3 and its more facile charge compensation (by Mo4+/Mo6+ redox) upon Li removal than that of Li2MnO3. As part of our series work on the Li2MoO3-based Li-rich layer structured cathode materials, this article is to study the structural and performance stability of Li2MoO3 in air. The obtained information will shed light on the development and application of xLi2MoO3·(1 - x)LiM‧O2 composite cathode materials though Li2MoO3 will not be applied as an independent cathode material.

  14. Association and Diffusion of Li(+) in Carboxymethylcellulose Solutions for Environmentally Friendly Li-ion Batteries.

    PubMed

    Casalegno, Mosè; Castiglione, Franca; Passarello, Marco; Mele, Andrea; Passerini, Stefano; Raos, Guido

    2016-07-21

    Carboxymethylcellulose (CMC) has been proposed as a polymeric binder for electrodes in environmentally friendly Li-ion batteries. Its physical properties and interaction with Li(+) ions in water are interesting not only from the point of view of electrode preparation-processability in water is one of the main reasons for its environmental friendliness-but also for its possible application in aqueous Li-ion batteries. We combine molecular dynamics simulations and variable-time pulsed field gradient spin-echo (PFGSE) NMR spectroscopy to investigate Li(+) transport in CMC-based solutions. Both the simulations and experimental results show that, at concentrations at which Li-CMC has a gel-like consistency, the Li(+) diffusion coefficient is still very close to that in water. These Li(+) ions interact preferentially with the carboxylate groups of CMC, giving rise to a rich variety of coordination patterns. However, the diffusion of Li(+) in these systems is essentially unrestricted, with a fast, nanosecond-scale exchange of the ions between CMC and the aqueous environment. PMID:27253620

  15. Simulated electrolyte-metal interfaces -- Li3PO4 and Li

    NASA Astrophysics Data System (ADS)

    Xu, Xiao; Du, Yaojun A.; Holzwarth, N. A. W.

    2007-03-01

    There has recently been a lot of interest in solid electrolyte materials such as LiPON developed at Oak Ridge National Laboratory for use in Li-ion batteries and other technologies. We report on the results of our model calculations on idealized interfaces between Li3PO4 and Li metal, studying the structural stability and the ion mobility, using first-principles density functional techniques with the PWscf and pwpaw codes. Starting with a supercell constructed from Li3PO4 in its crystalline γ-phase structure and several layers of Li metal, we used optimization and molecular dynamics techniques to find several meta-stable configurations. The qualitative features of the results are consistent with experimental evidence that the electrolyte is quite stable with respect to Li metal. In addition to stability analyses, we plan to study Li-ion diffusion across the interface. J. B. Bates, N. J. Dudney, and co-workers, Solid State Ionics, 53-56, 647-654 (1992). http://www.pwscf.org and http://pwpaw.wfu.edu. N. J. Dudney in Gholam-Abbas Nazri and Gianfranco Pistoia, Eds., Lithium Batteries: Science and Technology, Chapt. 20, pp. 623-642, Kluwer Academic Publishers, 2004. ISBN 1-4020-7628-2.

  16. Association and Diffusion of Li(+) in Carboxymethylcellulose Solutions for Environmentally Friendly Li-ion Batteries.

    PubMed

    Casalegno, Mosè; Castiglione, Franca; Passarello, Marco; Mele, Andrea; Passerini, Stefano; Raos, Guido

    2016-07-21

    Carboxymethylcellulose (CMC) has been proposed as a polymeric binder for electrodes in environmentally friendly Li-ion batteries. Its physical properties and interaction with Li(+) ions in water are interesting not only from the point of view of electrode preparation-processability in water is one of the main reasons for its environmental friendliness-but also for its possible application in aqueous Li-ion batteries. We combine molecular dynamics simulations and variable-time pulsed field gradient spin-echo (PFGSE) NMR spectroscopy to investigate Li(+) transport in CMC-based solutions. Both the simulations and experimental results show that, at concentrations at which Li-CMC has a gel-like consistency, the Li(+) diffusion coefficient is still very close to that in water. These Li(+) ions interact preferentially with the carboxylate groups of CMC, giving rise to a rich variety of coordination patterns. However, the diffusion of Li(+) in these systems is essentially unrestricted, with a fast, nanosecond-scale exchange of the ions between CMC and the aqueous environment.

  17. Interaction of water with LiCl, LiBr, and LiI in the deeply supercooled region

    NASA Astrophysics Data System (ADS)

    Souda, Ryutaro

    2007-12-01

    The hydration mechanism of lithium halides was studied using time-of-flight secondary ion mass spectrometry as a function of temperature. The lithium halides embedded in thin films of amorphous solid water segregate to the surface at temperatures higher than 135-140K, with efficiency increasing in the order of LiCl, LiBr, and LiI. A monolayer of LiCl and LiI adsorbed on the surface of amorphous solid water tends to diffuse into the bulk at 160K. The infrared absorption band revealed that the aqueous lithium-halide solutions and crystals are formed simultaneously at 160K; these phenomena are explicable as a consequence of the evolution of supercooled liquid water. The strong surfactant effect is inferred to arise from hydration of a contact ion pair having hydrophilic (lithium) and hydrophobic (halide) moieties. Furthermore, bulk diffusion of lithium halides might result from the formation of a solvent-separated ion pair in supercooled liquid water. The presence of two liquid phases of water with different local structures is probably responsible for the formation of these two hydrates, consistent with the calculated result reported by Jungwirth and Tobias[J. Phys. Chem. B 106, 6361 (2002)].

  18. High-performance LiCoO 2 by molten salt (LiNO 3:LiCl) synthesis for Li-ion batteries

    NASA Astrophysics Data System (ADS)

    Tan, K. S.; Reddy, M. V.; Rao, G. V. Subba; Chowdari, B. V. R.

    In an effort to increase and sustain the reversible capacity of LiCoO 2 on cycling, LiCoO 2 is prepared by using the molten-salt of the eutectic LiNO 3-LiCl at temperatures 650-850 °C with or without KOH as an oxidizing flux. The compounds are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), chemical analysis, surface area and density techniques. Cathodic behaviour was examined by cyclic voltammetry (CV) and charge-discharge cycling. The 850 °C-synthesized LiCoO 2, which has excess lithium incorporated in to it, shows a reversible capacity, with ˜98% coulombic efficiency, of 167 (±2) mAh g -1 at a specific current of 30 mAg -1 in the range 2.5-4.4 V up to 80 cycles with no capacity-fading. When cycled to a higher cut-off voltage (4.5 V), a capacity of 192 (±2) mAh g -1 versus Li is obtained at the fifth cycle, but capacity-fading is observed, viz., ˜ 6% after 60 cycles. On the basis of the CV and capacity-voltage profiles, this is attributed to the non-suppression of the hexagonal (H1) ↔ (H1-3) structural transition. A similar capacity-fading, i.e., ˜5-6%, during 5-40 cycles, is also observed in the LiCoO 2 prepared at 650 and 750 °C when cycled up to only 4.3 V and this is ascribed to the non-suppression of the H1 ↔ M ↔ H1 phase transitions (M = monoclinic).

  19. The 9Be(8Li,9Be)8Li elastic-transfer reaction

    NASA Astrophysics Data System (ADS)

    Camargo, O.; Guimarães, V.; Lichtenthäler, R.; Scarduelli, V.; Kolata, J. J.; Bertulani, C. A.; Amro, H.; Becchetti, F. D.; Jiang, Hao; Aguilera, E. F.; Lizcano, D.; Martinez-Quiroz, E.; Garcia, H.

    2008-09-01

    Angular distributions for the 9Be(8Li,9Be)8Li elastic-transfer reaction have been measured with a 27-MeV Li8 radioactive nuclear beam. Spectroscopic factors for the <9Be|8Li+p> bound system were obtained from the comparison between the experimental differential cross sections and finite-range distorted-wave Born approximation calculations made with the code FRESCO. The spectroscopic factors so obtained are compared with shell-model calculations and other experimental values. Using the present value for the spectroscopic factors, cross sections and reaction rates for the 8Li(p,γ)9Be direct proton-capture reaction of astrophysical interest were calculated in the framework of the potential model.

  20. Recombination gamma-luminescence at the nanometal Li - dielectric LiF interfaces

    NASA Astrophysics Data System (ADS)

    Ibragimova, E. M.; Mussaeva, M. A.; Buzrikov, Sh. N.

    2015-06-01

    Recombination 60Co-gamma-luminescence (GL) was studied experimentally in LiF:K,Cu crystals at the dose rate 406 R/s in the temperature range 273-473 K, when localized charge carriers are released from the hole/electron color center traps and Li vacancies are highly mobile. The crystals were preliminary irradiated in the 60Co gamma-source at 300-320 K to doses 107, 108, 109 R to generate F-aggregate centers and nano-colloids of Li. The intensity of GL bands at 570 nm (F4 centers) and 670 nm (F2+ centers) was shown to increase after 106 R above 370 K due to dominant contribution from radiative recombination of the released carries at the interface of nanometal-Li-dielectric-LiF. These bands can be used for gamma-dose measurements at 107-108 R.

  1. Modeling Li-ion conductivity in LiLa(PO3)4 powder

    NASA Astrophysics Data System (ADS)

    Mounir, Ferhi; Karima, Horchani-Naifer; Khaled, Ben Saad; Mokhtar, Férid

    2012-07-01

    Polycrystalline powder and single-crystal of LiLa(PO3)4 are synthesized by solid state reaction and flux technique, respectively. A morphological description of the obtained product was made based on scanning electron microscopy micrographs. The obtained powder was characterized by X-ray powder diffraction, FTIR and Raman spectroscopies. Ionic conductivity of the LiLa(PO3)4 powder was measured and evaluated over a temperature range from 553 to 913 K. Single crystals of LiLa(PO3)4 are characterized by single-crystal X-ray diffraction. The LiLa(PO3)4 structure was found to be isotypic with LiNd(PO3)4. It crystallizes in the monoclinic system with space group C2/c and cell parameters: a=16.635(6) Å, b=7.130(3) Å, c=9.913(3) Å, β=126.37(4)°, V=946.72(6) Å3 and Z=4. The LiLa(PO3)4 structure was described as an alternation between spiraling chains (PO3)n and (La3+, Li+) cations along the b direction. The small Li+ ions, coordinated to four oxygen atoms, were located in the large connected cavities created between the LaO8 polyhedra and the polyphosphate chains. The jumping of Li+ through tunnels of the crystalline network was investigated using complex impedance spectroscopy. The close value of the activation energies calculated through the analysis of conductivity data and loss spectra indicate that the transport in the investigated system is through hopping mechanism. The correlation between ionic conductivity of LiLa(PO3)4 and its crystallographic structure was investigated and the most probably transport pathway model was determined.

  2. Thermodynamic optimization of the Li-Pb system aided by first-principles calculations

    NASA Astrophysics Data System (ADS)

    Zhou, Chenyang; Guo, Cuiping; Li, Changrong; Du, Zhenmin

    2016-08-01

    The Li-Pb system was optimized using CALPHAD (CALculation of PHAse Diagram) method. The enthalpies of formation of eight intermetallic compounds Li4Pb (Li22Pb5), Li7Pb2, Li10Pb3, Li3Pb, Li8Pb3, Li5Pb2, αLiPb and βLiPb at 0 K were calculated from first-principles calculations with DFT + GGA approximations. The liquid phase was treated as (Li,Li0.8Pb0.2,Pb) using an associated solution model because a short-range-order phenomenon was proven to exist in liquid. The solution phases fcc and bcc were described as (Li,Pb) with a simple substitutional model. The intermetallic compounds Li4Pb, Li3Pb and Li5Pb2 were treated as stoichiometric compounds. With certain solubility ranges, the intermetallic compounds Li7Pb2, αLiPb and βLiPb were modeled as Li7(Li,Pb)2, (Li,Pb)(Li,Pb) and (Li,Pb)(Li,Pb) using the two-sublattice model. A set of self-consistent thermodynamic parameters in the Li-Pb system was obtained in the present work.

  3. Composition gradients in electrolyzed LiCl-KCl eutectic melts

    NASA Astrophysics Data System (ADS)

    Vallet, C. E.; Heatherly, D. E.; Braunstein, J.

    1983-12-01

    Analysis of transport in a mixed electrolyte has previously predicted significant composition gradients in the LiCl-KCl electrolyte of high temperature LiS/ batteries. Composition gradients in quenched electrolyzed LiCl-KCl eutectic contained in yttria felt are measured with high distance resolution by scanning electron microscopy with energy dispersive X-ray spectroscopy. The reported results include composition profiles of LiCl-KCl coontained in porous Y2O3 and electrolyzed in three cells, two with solid Li-Al electrodes and one with a porous Li-Al anode.

  4. Suppressing The Growth Of Dendrites In Secondary Li Cells

    NASA Technical Reports Server (NTRS)

    Davies, Evan D.; Perrone, David E.; Shen, David H.

    1996-01-01

    Proposed technique for suppressing growth of lithium dendrites in rechargeable lithium electrochemical power cells involves periodic interruption of steady charging current with short, high-current discharge pulses. Technique applicable to lithium cells of several different types, including Li/TiS(2), Li/NbSe(3), Li/CoO(2), Li/MoS(2), Li/Vo(x), and Li/MnO(2). Cells candidates for use in spacecraft, military, communications, automotive, and other applications in which high-energy-density rechargeable batteries needed.

  5. Formation and reduction behaviors of zirconium oxide compounds in LiCl-Li2O melt at 923 K

    NASA Astrophysics Data System (ADS)

    Sakamura, Yoshiharu; Iizuka, Masatoshi; Kitawaki, Shinichi; Nakayoshi, Akira; Kofuji, Hirohide

    2015-11-01

    The reduction behaviors of ZrO2, Li2ZrO3 and (U,Pu,Zr)O2 in a LiCl-Li2O salt bath at 923 K were investigated. This study was conducted as part of a feasibility study on the pyrochemical treatment of damaged fuel debris generated by severe accidents at light water reactors. It was demonstrated in electrolytic reduction tests that the uranium in synthetic corium specimens of (U,Pu,Zr)O2 with various ZrO2 contents could be reduced to the metallic form and that part of the zirconium was converted to Li2ZrO3. Zirconium metal and Li2ZrO3 were obtained by the reduction of ZrO2. The reduction of Li2ZrO3 did not proceed even in LiCl containing no Li2O. Moreover, the stable chemical forms of the ZrO2-Li2O complex oxide were investigated as a function of the Li2O concentration in LiCl. ZrO2 was converted to Li2ZrO3 at a Li2O concentration of 0.018 wt%. As the Li2O concentration was increased, Li2ZrO3 was converted to Li6Zr2O7 and then to Li8ZrO6. It is suggested that the removal of Li2ZrO3 from the reduction product is a key point in the pyrochemical treatment of corium.

  6. Enhanced electrochemical performance of Li-rich cathode Li[Li0.2Mn0.54Ni0.13Co0.13]O2 by surface modification with lithium ion conductor Li3PO4

    NASA Astrophysics Data System (ADS)

    Wang, Zhiyuan; Luo, Shaohua; Ren, Jie; Wang, Dan; Qi, Xiwei

    2016-05-01

    Li-rich layered cathode Li[Li0.2Mn0.54Ni0.13Co0.13]O2 is prepared via a co-precipitation followed with high-temperature calcination, and then successfully modified with nano-Li3PO4 by ball milling and annealing. The TEM and EDS reveal that Li3PO4 is homogeneously coated on the particle surface of Li[Li0.2Mn0.54Ni0.13Co0.13]O2. And the electrochemical performance of Li[Li0.2Mn0.54Ni0.13Co0.13]O2 is significantly improved by coating with lithium ion conductor Li3PO4. The Li3PO4-coated sample delivers a high initial discharge capacity of 284.7 mAhg-1 at 0.05 C, and retains 192.6 mAhg-1 after 100 cycles at 0.5 C, which is higher than that of the pristine sample (244 mAhg-1 at 0.05 C and 168.2 mAhg-1 after 100 cycles at 0.5 C). The electrochemical impedance spectroscopy (EIS) demonstrates that the resistance for Li/Li3PO4-coated Li[Li0.2Mn0.54Ni0.13Co0.13]O2 cell was reduced compared to Li/Li[Li0.2Mn0.54Ni0.13Co0.13]O2, which indicates the Li3PO4 coating layer with high ionic conductivity (6.6 × 10-8 S cm-1) facilitates the diffusion of lithium ions through the interface between electrode and electrolyte and accelerates the charge transfer process. What is more, the Li3PO4 coating layer can also act as a protection layer to protect the cathode material from encroachment of electrolyte. The two aspects account for the enhanced electrochemical performance of Li3PO4-coated Li[Li0.2Mn0.54Ni0.13Co0.13]O2.

  7. Surface characterization of the carbon cathode and the lithium anode of Li-O₂ batteries using LiClO₄ or LiBOB salts.

    PubMed

    Younesi, Reza; Hahlin, Maria; Edström, Kristina

    2013-02-01

    The surface compositions of a MnO₂ catalyst containing carbon cathode and a Li anode in a Li-O₂ battery were investigated using synchrotron-based photoelectron spectroscopy (PES). Electrolytes comprising LiClO₄ or LiBOB salts in PC or EC:DEC (1:1) solvents were used for this study. Decomposition products from LiClO₄ or LiBOB were observed on the cathode surface when using PC. However, no degradation of LiClO₄ was detected when using EC/DEC. We have demonstrated that both PC and EC/DEC solvents decompose during the cell cycling to form carbonate and ether containing compounds on the surface of the carbon cathode. However, EC/DEC decomposed to a lesser degree compared to PC. PES revealed that a surface layer with a thickness of at least 1-2 nm remained on the MnO₂ catalyst at the end of the charged state. It was shown that the detachment of Kynar binder influences the surface composition of both the carbon cathode and the Li anode of Li-O₂ cells. The PES results indicated that in the charged state the SEI on the Li anode is composed of PEO, carboxylates, carbonates, and LiClO₄ salt. PMID:23336349

  8. Lattice dynamics in Bosonic 7 Li

    NASA Astrophysics Data System (ADS)

    Chen, Huiyao Y.; Jung, Minwoo; Rabinowitz, Jacob; Madjarov, Ivaylo S.; Cheung, Hil F. H.; Patil, Yogesh Sharad; Vengalattore, Mukund

    2016-05-01

    The light mass and strong spin-dependent interactions in 7 Li make it an attractive candidate to study Bosonic quantum magnetism and lattice dynamics in regimes where rapid dynamics is favored, e.g. percolative transport and entropy segregation. Such studies require large ensembles of quantum degenerate 7 Li atoms which has proved to be a technical challenge. We describe our ongoing efforts to overcome this challenge using Raman sideband cooling (RSC). In addition to enabling the rapid production of large degenerate gases, RSC is also a very powerful means of local control of lattice gas dynamics. Extending this to a spinful 7 Li Bose gas will also enable studies of transport and defect dynamics in F=1 lattice gases. This work is supported by the ARO MURI on non-equilibrium dynamics.

  9. Long-lived states of antiprotonic lithium pLi {sup +} produced in p+ Li collisions

    SciTech Connect

    Sakimoto, Kazuhiro

    2011-09-15

    Antiproton capture by lithium atoms (p+Li{yields}pLi{sup +}+e) is investigated at collision energies from 0.01 to 10 eV by using a semiclassical (also know as quantum-classical hybrid) method, in which the radial distance between the antiproton and the Li{sup +} ion is treated as a classical variable, and the other degrees of freedom are described by quantum mechanics. Analyzing the wave packet of the emitted electrons and making use of the energy conservation rule enable us to calculate the state distribution of the produced antiprotonic lithium pLi{sup +} atoms and also to distinguish between the capture and ionization ({yields}p+Li{sup +}+e) channels at collisional energies above the ionization threshold. This method is tested for the capture of negative muons by hydrogen atoms, which was rigorously investigated in previous quantum mechanical studies. Most of the pLi{sup +} atoms produced in p+Li are found to be sufficiently stable against Auger decays and are experimentally observable as long-lived states. The present system bears close similarities to the system of p+He(2S). It is therefore expected that long-lived antiprotonic helium pHe{sup +} atoms can be efficiently produced in the p capture by metastable He(2 {sup 3}S) atoms.

  10. Re-evaluation of the eutectic region of the LiBr-KBr-LiF system

    SciTech Connect

    Redey, L.; Guidotti, R.A.

    1996-05-01

    The separator pellet in a thermal battery consists of electrolyte immobilized by a binder (typically, MgO powder). The melting point of the electrolyte determines the effective operating window for its use in a thermal battery. The development of a two-hour thermal battery required the use of a molten salt that had a lower melting point and larger liquidus range than the LiCl-KCl eutectic which melts at 352 C. Several candidate eutectic electrolyte systems were evaluated for their suitability for this application. One was the LiCl-LiBr-KBr eutectic used at Argonne National Laboratories for high-temperature rechargeable batteries for electric-vehicle applications. Using a custom-designed high-temperature conductivity cell, the authors were able to readily determine the liquidus region for the various compositions studied around the original eutectic for the LiBr-KBr-LiF system. The actual eutectic composition was found to be 60.0 m/o LiBr-37.5 m/o KBr-2.5 m/o LiF with a melting point of 324 {+-} 0.5 C.

  11. Electrochemical behaviors of wax-coated Li powder/Li 4Ti 5O 12 cells

    NASA Astrophysics Data System (ADS)

    Park, Han Eol; Seong, Il Won; Yoon, Woo Young

    The wax-coated Li powder specimen was effectively synthesized using the drop emulsion technique (DET). The wax layer on the powder was verified by SEM, Focused Ion Beam (FIB), EDX and XPS. The porosity of a sintered wax-coated Li electrode was measured by linear sweep voltammetry (LSV) and compared with that of a bare, i.e., un-coated Li electrode. The electrochemical behavior of the wax-coated Li powder anode cell was examined by the impedance analysis and cyclic testing methods. The cyclic behavior of the wax-coated Li powder anode with the Li 4Ti 5O 12 (LTO) cathode cell was examined at a constant current density of 0.35 mA cm -2 with the cut-off voltages of 1.2-2.0 V at 25 °C. Over 90% of the initial capacity of the cell remained even after the 300th cycle. The wax-coated Li powder was confirmed to be a stable anode material.

  12. Asymptotic and near-target direct breakup of 6Li and 7Li

    NASA Astrophysics Data System (ADS)

    Kalkal, Sunil; Simpson, E. C.; Luong, D. H.; Cook, K. J.; Dasgupta, M.; Hinde, D. J.; Carter, I. P.; Jeung, D. Y.; Mohanto, G.; Palshetkar, C. S.; Prasad, E.; Rafferty, D. C.; Simenel, C.; Vo-Phuoc, K.; Williams, E.; Gasques, L. R.; Gomes, P. R. S.; Linares, R.

    2016-04-01

    Background: Li,76 and 9Be are weakly bound against breakup into their cluster constituents. Breakup location is important for determining the role of breakup in above-barrier complete fusion suppression. Recent works have pointed out that experimental observables can be used to separate near-target and asymptotic breakup. Purpose: Our purpose is to distinguish near-target and asymptotic direct breakup of Li,76 in reactions with nuclei in different mass regions. Method: Charged particle coincidence measurements are carried out with pulsed Li,76 beams on 58Ni and 64Zn targets at sub-barrier energies and compared with previous measurements using 208Pb and 209Bi targets. A detector array providing a large angular coverage is used, along with time-of-flight information to give definitive particle identification of the direct breakup fragments. Results: In interactions of 6Li with 58Ni and 64Zn, direct breakup occurs only asymptotically far away from the target. However, in interactions with 208Pb and 209Bi, near-target breakup occurs in addition to asymptotic breakup. Direct breakup of 7Li into α -t is not observed in interactions with 58Ni and 64Zn. However, near-target dominated direct breakup was observed in measurements with 208Pb and 209Bi. A modified version of the Monte Carlo classical trajectory model code platypus, which explicitly takes into account lifetimes associated with unbound states, is used to simulate sub-barrier breakup reactions. Conclusions: Near-target breakup in interactions with Li,76 is an important mechanism only for the heavy targets 208Pb and 209Bi. There is insignificant near-target direct breakup of 6Li and no direct breakup of 7Li in reactions with 58Ni and 64Zn. Therefore, direct breakup is unlikely to suppress the above-barrier fusion cross section in reactions of Li,76 with 58Ni and 64Zn nuclei.

  13. NASA Goddards LiDAR, Hyperspectral and Thermal (G-LiHT) Airborne Imager

    NASA Technical Reports Server (NTRS)

    Cook, Bruce D.; Corp, Lawrence A.; Nelson, Ross F.; Middleton, Elizabeth M.; Morton, Douglas C.; McCorkel, Joel T.; Masek, Jeffrey G.; Ranson, Kenneth J.; Ly, Vuong; Montesano, Paul M.

    2013-01-01

    The combination of LiDAR and optical remotely sensed data provides unique information about ecosystem structure and function. Here, we describe the development, validation and application of a new airborne system that integrates commercial off the shelf LiDAR hyperspectral and thermal components in a compact, lightweight and portable system. Goddard's LiDAR, Hyperspectral and Thermal (G-LiHT) airborne imager is a unique system that permits simultaneous measurements of vegetation structure, foliar spectra and surface temperatures at very high spatial resolution (approximately 1 m) on a wide range of airborne platforms. The complementary nature of LiDAR, optical and thermal data provide an analytical framework for the development of new algorithms to map plant species composition, plant functional types, biodiversity, biomass and carbon stocks, and plant growth. In addition, G-LiHT data enhance our ability to validate data from existing satellite missions and support NASA Earth Science research. G-LiHT's data processing and distribution system is designed to give scientists open access to both low- and high-level data products (http://gliht.gsfc.nasa.gov), which will stimulate the community development of synergistic data fusion algorithms. G-LiHT has been used to collect more than 6,500 km2 of data for NASA-sponsored studies across a broad range of ecoregions in the USA and Mexico. In this paper, we document G-LiHT design considerations, physical specifications, instrument performance and calibration and acquisition parameters. In addition, we describe the data processing system and higher-level data products that are freely distributed under NASA's Data and Information policy.

  14. Role of dopants in LiF:Mg,Cu, LiF:Mg,P and LiF:Mg,Cu,P detectors

    SciTech Connect

    Mohammadi, Kh. Moussavi Zarandi, A.; Afarideh, H.; Shahmaleki, S.

    2013-06-15

    In this study, electronic structure of LiF crystal doped with Mg,Cu,P impurities was studied with WIEN2k code on the basis of FPLAPW+lo method. Results show that in Mg-doped LiF composition, an electronic trap was created with impurity concentration of 1.56% and 3.125%. In this condition, the electronic trap with increasing the percentage of the impurities up to 4.687% is annihilated. It was found, that by doping of Mg and Cu or P simultaneously, a hole-trap is created in valence band. It was realized that in LiF:Mg,Cu, LiF:Mg,P and LiF:Mg,Cu,P, Cu impurity and Li atom, have a key role in creation of levels which lead to create electronic and hole traps. Mg impurity and F atom, only have a role in creation of electronic traps. In addition, P impurity has a main role in creation of the electronic and hole traps in LiF:Mg,Cu,P. The activation energy of electronic and hole trap in LiF:Mg,Cu, LiF:Mg,P and LiF:Mg,Cu,P crystalline lattice were obtained as 0.3 and 5.5 eV, 0.92 and 3.4 eV and 0.75 and 3.1 eV, respectively. - Graphical abstract: Figure (a) and (b) shows changes in electronic structure and band gap energy of LiF crystal due to presence of Mg and Cu, Mg and P ions respectively. - Highlights: • Electronic structure of LiF, LiF:Mg,Cu, LiF:Mg,P and LiF:Mg,Cu,P materials were studied with WIEN2K code. • In LiF:Mg,Cu and LiF:Mg,Cu,P, Li atom and Cu impurity have a key role in creation of levels. • F atom and Mg impurity only have a role in creation of electronic traps. • In LiF:Mg,Cu,P, P impurity has a main role in creation of electronic and hole traps.

  15. A novel dual-salts of LiTFSI and LiODFB in LiFePO4-based batteries for suppressing aluminum corrosion and improving cycling stability

    NASA Astrophysics Data System (ADS)

    Li, Faqiang; Gong, Yan; Jia, Guofeng; Wang, Qinglei; Peng, Zhengjun; Fan, Wei; Bai, Bing

    2015-11-01

    The strong corrosion behavior at the Al current collector restricts the application range of lithium bis (trifluoromethanesulfonylimide) (LiTFSI), despite its high stability against water and thermal. SEM, LSV and Tafel curves proved that adding LiODFB into LiTFSI-based electrolytes could suppress aluminum corrosion caused by LiTFSI-based electrolytes. The cycling stability and rate capability of LiFePO4-based batteries using LiTFSI0.6-LiODFB0.4-based electrolytes is excellent as compared to LiFePO4-based batteries using LiPF6-based electrolytes.

  16. Achromatic Cooling Channel with Li Lenses

    SciTech Connect

    Balbekov, V.

    2002-04-29

    A linear cooling channel with Li lenses, solenoids, and 201 MHz RF cavities is considered. A special lattice design is used to minimize chromatic aberrations by suppression of several betatron resonances. Transverse emittance of muon beam decreases from 2 mm to 0.5 mm at the channel of about 110 m length. Longitudinal heating is modest, therefore transmission of the channel is rather high: 96% without decay and 90% with decay. Minimal beam emittance achievable by similar channel estimated as about 0.25 mm at surface field of Li lenses 10 T.

  17. Liénard-type chemical oscillator

    NASA Astrophysics Data System (ADS)

    Ghosh, Shyamolina; Ray, Deb Shankar

    2014-03-01

    We show that a class of arbitrary, autonomous kinetic equations in two variables describing chemical and biochemical oscillations can be reduced to the form of a Liénard oscillator. The basis of this reduction scheme is a set of linear transformations of the original variables into a new set of variables which can be found by direct inspection of the kinetic equations. Our study reveals that despite their diverse origin, these kinetic equations when cast as a Liénard system form a universality class, make it possible to identify the forcing term as well as the nonlinear damping coefficient responsible for dynamical control of the underlying limit cycle behavior.

  18. Li Isotope Studies of Olivine in Mantle Xenoliths by SIMS

    NASA Technical Reports Server (NTRS)

    Bell, D. R.; Hervig, R. L.; Buseck, P. R.

    2005-01-01

    Variations in the ratio of the stable isotopes of Li are a potentially powerful tracer of processes in planetary and nebular environments [1]. Large differences in the 7Li/6Li ratio between the terrestrial upper mantle and various crustal materials make Li isotope composition a potentially powerful tracer of crustal recycling processes on Earth [2]. Recent SIMS studies of terrestrial mantle and Martian meteorite samples report intra-mineral Li isotope zoning [3-5]. Substantial Li isotope heterogeneity also exists within and between the components of chondritic meteorites [6,7]. Experimental studies of Li diffusion suggest the potential for rapid isotope exchange at elevated temperatures [8]. Large variations in 7Li, exceeding the range of unaltered basalts, occur in terrestrial mantle-derived xenoliths from individual localities [9]. The origins of these variations are not fully understood.

  19. Performance of new 10 kW class MCFC using Li/K and Li/Na electrolyte

    SciTech Connect

    Mugikura, Yoshihiro; Yoshiba, Fumihiko; Izaki, Yoshiyuki; Watanabe, Takao

    1996-12-31

    The molten carbonate fuel cell (MCFC) uses generally mixture of lithium carbonate and potassium carbonate (Li/K) as the electrolyte. NiO cathode dissolution is one of serious problems for MCFC life. The NiO cathode has been found to dissolve into the electrolyte as Ni{sup 2+} ion which is reduced to metallic Ni by H{sub 2} in the fuel gas and bridges the anode and the cathode. The bridges short circuit and degrade cell performance and shorten cell life. Since solubility of NiO in mixture of lithium carbonate and sodium carbonate (Li/Na) is lower than in Li/K, it takes longer time to take place slowing by NiO cathode dissolution in Li/Na compared with in Li/K. The ionic conductivity of Li/Na is higher than of Li/K, however, oxygen solubility in Li/Na is lower 9 than in Li/K. A new 10 kW class MCFC stack composed of Li/K cells and Li/Na cells, was tested. Basic performance of the Li/K cells and Li/Na cells of the stack was reported.

  20. Synthesis and characterization of LiZnP and LiZnAs semiconductor material

    NASA Astrophysics Data System (ADS)

    Montag, Benjamin W.; Reichenberger, Michael A.; Arpin, Kevin R.; Sunder, Madhana; Nelson, Kyle A.; Ugorowski, Philip B.; McGregor, Douglas S.

    2015-02-01

    Research for a reliable solid-state semiconductor neutron detector continues because such a device has not been developed, and would have greater efficiency, than present-day gas-filled 3He and 10BF3 neutron detectors. Further, a semiconductor neutron detector would be more compact and rugged than most gas-filled or scintillator neutron detectors. The 6Li(n,t)4He reaction yields a total Q value of 4.78 MeV, a larger yield than the 10B(n,α)7Li, and is easily identified above background radiation interactions. Hence, devices composed of either natural Li (naturally 7.5% 6Li) or enriched 6Li (approximately 95% 6Li) may provide a semiconductor material for compact high-efficiency neutron detectors. A sub-branch of the III-V semiconductors, the filled tetrahedral compounds, known as Nowotny-Juza compounds (AIBIICV), are desirable for their cubic crystal structure and semiconducting electrical properties. These compounds were originally studied for photonic applications. In the present work, Equimolar portions of Li, Zn, and P or As were sealed under vacuum (10-6 Torr) in quartz ampoules with a boron nitride lining, and loaded into a compounding furnace. The ampoule was heated to 200 °C to form the Li-Zn alloy, subsequently heated to 560 °C to form the ternary compound, LiZnP or LiZnAs, and finally annealed to promote crystallization. The chemical composition of the synthesized starting material was confirmed at Galbraith Laboratories, Inc. by Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES), which showed the compounds can be reacted in equal ratios, 1-1-1, to form ternary compounds. Recent additions to the procedure have produced higher yields, and greater synthesis reliability. Synthesized powders were also characterized by x-ray diffraction, where lattice constants of 5.751±.001 Å and 5.939±.002 Å for LiZnP and LiZnAs, respectively, were determined.

  1. Comment on "Cycling Li-O₂ batteries via LiOH formation and decomposition".

    PubMed

    Viswanathan, Venkatasubramanian; Pande, Vikram; Abraham, K M; Luntz, Alan C; McCloskey, Bryan D; Addison, Dan

    2016-05-01

    Based on a simple thermodynamic analysis, we show that iodide-mediated electrochemical decomposition of lithium hydroxide (LiOH) likely occurs through a different mechanism than that proposed by Liu et al (Research Article, 30 October 2015, p. 530). The mismatch in thermodynamic potentials for iodide/triiodide (I(-)/I3 (-)) redox and O2 evolution from LiOH implies a different active iodine/oxygen electrochemistry on battery charge. It is therefore possible that the system described in Liu et al may not form the basis for a rechargeable lithium-oxygen (Li-O2) battery.

  2. Single step transformation of sulphur to Li2S2/Li2S in Li-S batteries

    NASA Astrophysics Data System (ADS)

    Helen, M.; Reddy, M. Anji; Diemant, Thomas; Golla-Schindler, Ute; Behm, R. Jürgen; Kaiser, Ute; Fichtner, Maximilian

    2015-07-01

    Lithium-sulphur batteries have generated tremendous research interest due to their high theoretical energy density and potential cost-effectiveness. The commercial realization of Li-S batteries is still hampered by reduced cycle life associated with the formation of electrolyte soluble higher-order polysulphide (Li2Sx, x = 4-8) intermediates, leading to capacity fading, self-discharge, and a multistep voltage profile. Herein, we have realized a practical approach towards a direct transformation of sulphur to Li2S2/Li2S in lithium-sulphur batteries by alteration of the reaction pathway. A coconut shell derived ultramicroporous carbon-sulphur composite cathode has been used as reaction directing template for the sulphur. The lithiation/delithiation and capacity fading mechanism of microporous carbon confined sulphur composite was revealed by analyzing the subsurface using X-ray photoelectron spectroscopy. No higher-order polysulphides were detected in the electrolyte, on the surface, and in the subsurface of the cathode composite. The altered reaction pathway is reflected by a single-step profile in the discharge/charge of a lithium-sulphur cell.

  3. Single step transformation of sulphur to Li2S2/Li2S in Li-S batteries

    PubMed Central

    Helen, M.; Reddy, M. Anji; Diemant, Thomas; Golla-Schindler, Ute; Behm, R. Jürgen; Kaiser, Ute; Fichtner, Maximilian

    2015-01-01

    Lithium-sulphur batteries have generated tremendous research interest due to their high theoretical energy density and potential cost-effectiveness. The commercial realization of Li-S batteries is still hampered by reduced cycle life associated with the formation of electrolyte soluble higher-order polysulphide (Li2Sx, x = 4–8) intermediates, leading to capacity fading, self-discharge, and a multistep voltage profile. Herein, we have realized a practical approach towards a direct transformation of sulphur to Li2S2/Li2S in lithium-sulphur batteries by alteration of the reaction pathway. A coconut shell derived ultramicroporous carbon-sulphur composite cathode has been used as reaction directing template for the sulphur. The lithiation/delithiation and capacity fading mechanism of microporous carbon confined sulphur composite was revealed by analyzing the subsurface using X-ray photoelectron spectroscopy. No higher-order polysulphides were detected in the electrolyte, on the surface, and in the subsurface of the cathode composite. The altered reaction pathway is reflected by a single-step profile in the discharge/charge of a lithium-sulphur cell. PMID:26173723

  4. Chemical stability enhancement of lithium conducting solid electrolyte plates using sputtered LiPON thin film

    NASA Technical Reports Server (NTRS)

    West, W. C.; Whitacre, J. F.; Lim, J. R.

    2004-01-01

    Sputter deposition of LiPON films directly onto high Li+ conductivity solid electrolyte plates has been investigated as a means to minimize the reactivity of the plates to metallic Li. The LiPON films were shown to effectively passivate the plates in contact with metallic Li, in contrast to unpassivated plates that reacted immediately in contact with Li metal.

  5. Structural transformations of Li2C2 at high pressures

    NASA Astrophysics Data System (ADS)

    Efthimiopoulos, Ilias; Benson, Daryn E.; Konar, Sumit; Nylén, Johanna; Svensson, Gunnar; Häussermann, Ulrich; Liebig, Stefan; Ruschewitz, Uwe; Vazhenin, Grigory V.; Loa, Ingo; Hanfland, Michael; Syassen, Karl

    2015-08-01

    Structural changes of Li2C2 under pressure were studied by synchrotron x-ray diffraction in a diamond anvil cell under hydrostatic conditions and by using evolutionary search methodology for crystal structure prediction. We show that the high-pressure polymorph of Li2C2 , which forms from the I m m m ground-state structure (Z =2 ) at around 15 GPa, adopts an orthorhombic P n m a structure with Z =4 . Acetylide C2 dumbbells characteristic of I m m m Li2C2 are retained in P n m a Li2C2 . The structure of P n m a Li2C2 relates closely to the anticotunnite-type structure. C2 dumbbell units are coordinated by nine Li atoms, as compared to eight in the antifluorite structure of I m m m Li2C2 . First-principles calculations predict a transition of P n m a Li2C2 at 32 GPa to a topologically identical phase with a higher C m c m symmetry. The coordination of C2 dumbbell units by Li atoms is increased to 11. The structure of C m c m Li2C2 relates closely to the Ni2 In-type structure. It is calculated that C m c m Li2C2 becomes metallic at pressures above 40 GPa. In experiments, however, P n m a Li2C2 is susceptible to irreversible amorphization.

  6. Li-ion diffusion in Li4Ti5O12 and LiTi2O4 battery materials detected by muon spin spectroscopy

    NASA Astrophysics Data System (ADS)

    Sugiyama, Jun; Nozaki, Hiroshi; Umegaki, Izumi; Mukai, Kazuhiko; Miwa, Kazutoshi; Shiraki, Susumu; Hitosugi, Taro; Suter, Andreas; Prokscha, Thomas; Salman, Zaher; Lord, James S.; Mânsson, Martin

    2015-07-01

    Lithium diffusion in spinel Li4Ti5O12 and LiTi2O4 compounds for future battery applications has been studied with muon spin relaxation (μ+SR ) . Measurements were performed on both thin-film and powder samples in the temperature range between 25 and 500 K. For Li4Ti5O12 and above about ˜200 K , the field distribution width (Δ ) is found to decrease gradually, while the field fluctuation rate (ν ) increases exponentially with temperature. For LiTi2O4 , on the contrary, the Δ (T ) curve shows a steplike decrease at ˜350 K , around which the ν (T ) curve exhibits a local maximum. These behaviors suggest that Li+ starts to diffuse above around 200 K for both spinels. Assuming a jump diffusion of Li+ at the tetrahedral 8 a site to the vacant octahedral 16 c site, diffusion coefficients of Li+ at 300 K in the film samples are estimated as (3.2 ±0.8 ) ×10-11 cm2/s for Li4Ti5O12 and (3.6 ±1.1 ) ×10-11 cm2/s for LiTi2O4 . Further, some small differences are found in both thermal activation energies and Li-ion diffusion coefficients between the powder and thin-film samples.

  7. Soft X-Ray Irradiation Effects of Li2O2, Li2CO3 and Li2O Revealed by Absorption Spectroscopy

    PubMed Central

    Qiao, Ruimin; Chuang, Yi-De; Yan, Shishen; Yang, Wanli

    2012-01-01

    Li2O2, Li2CO3, and Li2O are three critical compounds in lithium-air and lithium-ion energy storage systems. Extensive measurements have been carried out to study the chemical species and their evolutions at difference stages of the device operation. While x-ray spectroscopy has been demonstrated to be one of the most powerful tools for such purpose, no systematic study on the irradiation effects have been reported. Here we carry out extensive time, position, and irradiation dependent Li K-edge soft x-ray absorption spectroscopy on these compounds with so far the best energy resolution. The ultra-high resolution in the current study allows the features in the absorption spectra to be well-resolved. The spectral lineshape thus serves as the fingerprints of these compounds, enabling the tracking of their evolution under x-ray irradiation. We found that both Li2O2 and Li2CO3 evidently evolve towards Li2O under the soft x-ray irradiation with Li2CO3 exhibiting a surprisingly higher sensitivity to x-rays than Li2O2. On the other hand, Li2O remains the most stable compound despite experiencing substantial irradiation dose. We thus conclude that high resolution soft x-ray spectroscopy could unambiguously fingerprint different chemical species, but special cautions on irradiation effects would be needed in performing the experiments and interpreting the data properly. PMID:23145116

  8. Probing the failure mechanism of nanoscale LiFePO₄ for Li-ion batteries

    SciTech Connect

    Gu, Meng; Shi, Wei; Zheng, Jianming; Yan, Pengfei; Zhang, Ji-guang; Wang, Chongmin

    2015-05-18

    LiFePO4 is a high power rate cathode material for lithium ion battery and shows remarkable capacity retention, featuring a 91% capacity retention after 3300 cycles. In this work, we use high-resolution transmission electron microscopy (HRTEM), energy dispersive x-ray spectroscopy (EDS), and electron energy loss spectroscopy (EELS) to study the gradual capacity fading mechanism of LiFePO4 materials. We found that upon prolonged electrochemical cycling of the battery, the LiFePO4 cathode shows surface amorphization and loss of oxygen species, which directly contribute to the gradual capacity fading of the battery. The finding is of great importance for the design and improvement of new LiFePO4 cathode for high-energy and high-power rechargeable battery for electric transportation.

  9. Bulk and Surface Properties of Liquid Al-Li and Li-Zn Alloys

    NASA Astrophysics Data System (ADS)

    Trybula, Marcela; Gancarz, Tomasz; Gasior, Wladyslaw; Pasturel, Alain

    2014-11-01

    Physicochemical properties like density, surface tension, and viscosity of liquid binary Al-Li and Li-Zn alloys have been measured using draining crucible method. The experimentally measured surface-tension values have been compared to theoretical results based either on the Butler model or the compound formation model assuming the existence of the most favored A 1 B 2 and A 2 B 3 clusters. Several models for viscosity calculation have been also applied and discussed in confrontation with measured data. Finally, the clustering effects in the liquid Al-Li and Li-Zn alloys have been examined using two microscopic functions, i.e., the concentration fluctuation function in the long-wavelength limit and the Warren-Cowley short-range order parameter.

  10. Bulk and Surface Properties of Liquid Al-Li and Li-Zn Alloys

    NASA Astrophysics Data System (ADS)

    Trybula, Marcela; Gancarz, Tomasz; Gasior, Wladyslaw; Pasturel, Alain

    2014-08-01

    Physicochemical properties like density, surface tension, and viscosity of liquid binary Al-Li and Li-Zn alloys have been measured using draining crucible method. The experimentally measured surface-tension values have been compared to theoretical results based either on the Butler model or the compound formation model assuming the existence of the most favored A 1 B 2 and A 2 B 3 clusters. Several models for viscosity calculation have been also applied and discussed in confrontation with measured data. Finally, the clustering effects in the liquid Al-Li and Li-Zn alloys have been examined using two microscopic functions, i.e., the concentration fluctuation function in the long-wavelength limit and the Warren-Cowley short-range order parameter.

  11. Corrosion behavior of Fe-Ni-Cr alloys in the molten salt of LiCl-Li 2O at high temperature

    NASA Astrophysics Data System (ADS)

    Cho, S. H.; Zhang, J. S.; Shin, Y. J.; Park, S. W.; Park, H. S.

    2004-02-01

    At Korea Atomic Energy Research Institute (KAERI), we investigated the corrosion behavior of a series of Fe-Cr-Ni alloys with different chromium contents in molten LiCl and molten LiCl-25wt%Li 2O mixture at temperatures ranging from 923 to 1123 K. In molten LiCl, dense protective scale of LiCrO 2 grows outwardly while corrosion is accelerated by addition of Li 2O to LiCl. The basic fluxing of Cr 2O 3 by Li 2O would be the cause of accelerated corrosion. Because of low oxygen solubility and very high Li 2O activity in the molten LiCl-Li 2O mixture, Cr is preferentially corroded while Ni remains stable and thus, corrosion rate of the alloys in molten LiCl-Li 2O mixture increases with an increase in Cr content.

  12. Multi-spin-state at a Li3PO4/LiCoO2 (104) interface.

    PubMed

    Sumita, Masato; Ohno, Takahisa

    2016-02-14

    We have found the disproportion between the intermediate spin (IS) and low spin (LS) configurations of Co atoms at a Li3PO4/LiCoO2 (104) interface through density functional molecular dynamics (DF-MD). The manifold of the spin state at the interface, however, does not affect the band alignment between the Li3PO4 and LiCoO2 regions. PMID:26812388

  13. Pt and Pd catalyzed oxidation of Li2O2 and DMSO during Li-O2 battery charging.

    PubMed

    Gittleson, Forrest S; Ryu, Won-Hee; Schwab, Mark; Tong, Xiao; Taylor, André D

    2016-05-01

    Rechargeable Li-O2 and Li-air batteries require electrode and electrolyte materials that synergistically promote long-term cell operation. In this study, we investigate the role of noble metals Pt and Pd as catalysts in the Li-O2 oxidation process and their compatibility with dimethyl sulfoxide (DMSO) based electrolytes. We identify a basis for low potential Li2O2 evolution followed by oxidative decomposition of the electrolyte to form carbonate side products. PMID:27111589

  14. 6Li foil thermal neutron detector

    SciTech Connect

    Ianakiev, Kiril D; Swinhoe, Martyn T; Favalli, Andrea; Chung, Kiwhan; Macarthur, Duncan W

    2010-01-01

    In this paper we report on the design of a multilayer thermal neutron detector based on {sup 6}Li reactive foil and thin film plastic scintillators. The {sup 6}Li foils have about twice the intrinsic efficiency of {sup 10}B films and about four times higher light output due to a unique combination of high energy of reaction particles, low self absorption, and low ionization density of tritons. The design configuration provides for double sided readout of the lithium foil resulting in a doubling of the efficiency relative to a classical reactive film detector and generating a pulse height distribution with a valley between neutron and gamma signals similar to {sup 3}He tubes. The tens of microns thickness of plastic scintillator limits the energy deposited by gamma rays, which provides the necessary neutron/gamma discrimination. We used MCNPX to model a multilayer Li foil detector design and compared it with the standard HLNCC-II (18 {sup 3}He tubes operated at 4 atm). The preliminary results of the {sup 6}Li configuration show higher efficiency and one third of the die-away time. These properties, combined with the very short dead time of the plastic scintillator, offer the potential of a very high performance detector.

  15. Clay nanocomposites for use in Li batteries

    NASA Astrophysics Data System (ADS)

    Moore, Gregory John

    1999-11-01

    Nanocomposites, materials made of more than one component and combined in an ordered manner on the nanometer scale, were synthesized using clay mineral hosts with various types of guests. The guests include polymers such as polyethylene oxide (PEO) and polyaniline (PANI), large molecules such as ethylmethyl sulfone, tetramethylene sulfone, and various length alkylamines. Vanadyl groups (VO 2+) were also incorporated with the clays. The otherwise non-swellable mica clay, synthetic Na-fluorophlogopite, was expanded by intercalation of acidic ions such as Cu2+ and Fe3+. As aqueous solutions, these ions caused the stable fluoromica to go from its dehydrated interlayer spacing of 9.8 A to over 14 A. This clay became a host for many other reactions including swelling with alkylamines to over 25 A. However, despite hydrated Cu2+ ions swelling fluorophlogopite, polymeric species such as PEO or PANI could not be inserted. Another clay that was used for formation of nanocomposites came from a procedure for the synthesis of Li-taeniolite, Li(Mg2Li)Si 4O10F2. The clay was synthesized following a high temperature method that led to a non-reactive product. Instead, a novel precursor route was employed that gave a clay product with a single hydration layer. Various chemical analyses gave a formula of Li0.8(Mg 2.2Li0.8)Si4O10(F1.6O 0.4)·H2O. For the purpose of forming nanocomposite electrolytes, ethylmethyl sulfone was synthesized and incorporated into the clay. For comparison of different shaped sulfones, tetramethylene sulfone also was inserted into the layers for electrolytic studies. To make a polymer-clay electrolyte, polyethylene oxide was intercalated into the Li-taeniolite. All of these new electrolyte materials were characterized using impedance spectroscopy for measurement of their conductivity. Syntheses and analyses are thoroughly discussed for all of these materials. Special attention is placed on powder x-ray diffraction and thermogravimetric techniques to

  16. Al-Cu-Li and Al-Mg-Li alloys: Phase composition, texture, and anisotropy of mechanical properties (Review)

    NASA Astrophysics Data System (ADS)

    Betsofen, S. Ya.; Antipov, V. V.; Knyazev, M. I.

    2016-04-01

    The results of studying the phase transformations, the texture formation, and the anisotropy of the mechanical properties in Al-Cu-Li and Al-Mg-Li alloys are generalized. A technique and equations are developed to calculate the amounts of the S1 (Al2MgLi), T1 (Al2CuLi), and δ' (Al3Li) phases. The fraction of the δ' phase in Al-Cu-Li alloys is shown to be significantly higher than in Al-Mg-Li alloys. Therefore, the role of the T1 phase in the hardening of Al-Cu-Li alloys is thought to be overestimated, especially in alloys with more than 1.5% Li. A new model is proposed to describe the hardening of Al-Cu-Li alloys upon aging, and the results obtained with this model agree well with the experimental data. A texture, which is analogous to that in aluminum alloys, is shown to form in sheets semiproducts made of Al-Cu-Li and Al-Mg-Li alloys. The more pronounced anisotropy of the properties of lithium-containing aluminum alloys is caused by a significant fraction of the ordered coherent δ' phase, the deformation mechanism in which differs radically from that in the solid solution.

  17. Phase relationships in positive electrodes of high temperature Li-Al/LiCl-KCl/FeS2 cells

    NASA Astrophysics Data System (ADS)

    Tomczuk, Z.; Tani, B.; Otto, N. C.; Roche, M. F.; Vissers, D. R.

    1982-05-01

    The phases present in FeS2 electrodes operated in LiCl-KCl eutectic electrolyte are determined by X-ray diffraction and metallographic examination. The phases are FeS2, KFeS2, Li3Fe2S4, Li2.33Fe0.67S2, Fe/1-x/S, Li2FeS2, LiK6Fe24S26Cl, Li2S, and Fe. The metallographic and crystallographic characteristics of these phases are given. The sequence of Li-Fe-S phases in the FeS2 electrode is found to be in accord with the sequence predicted from the equilibrium LiFe-S phase diagram. It is noted that two of the Li-Fe-S phases found at room temperature (Li2.33Fe0.67S2 and Li2FeS2) result from decomposition on cooling of a solid solution phase: Li/2+x/Fe/1-x/S2, x ranging from 0 to 0.33.

  18. Li diffusion and substitution in chemically diverse synthetic zircon

    NASA Astrophysics Data System (ADS)

    Trail, D.

    2015-12-01

    Li concentrations and 7Li/6Li ratios in zircon may potentially trace crustal recycling because continental and mantle-derived zircons yield distinct values (Ushikubo et al. 2008; Bouvier et al. 2012). To some extent, the usefulness of these differences may depend upon the retentively of Li in zircon. Cherniak and Watson (2010) measured relatively high diffusivities for Li; here we sought to discover the scenarios under which Li mobility might be inhibited by charge compensating cations. We conducted "in" diffusion experiments in synthetic Lu-doped (~5000 ppm), P-doped (~250 ppm), and nearly pure zircon following the procedure in Cherniak and Watson (2010). In separate experiments, Li was ion implanted at depth within polished Mud Tank zircon slabs to form a Gaussian Li concentration profile; the relaxed concentration profile was measured after heating the zircon slabs. In all experiments, which ranged from 920 to 650 oC, calculated diffusivities were in agreement with a previously established Arrhenius relationship calibrated on trace element poor Mud Tank zircon (Cherniak and Watson, 2010). We also conducted complementary LA-ICP-MS mapping on the surfaces of P- and Lu-doped synthetic zircon crystals after the Li diffusion results were obtained. This revealed heterogeneous though patterned correlation between Li+Lu in the near surface of the crystal (no strong patterns emerged for P+Li). And finally, we observed that synthetic sector-zoned zircon exhibits near step function Li concentration profiles - correlating with changes in the rare earth element concentrations across these sectors - which allowed us to examine Li diffusion in yet another manner. Re-heating these grains followed by LA-ICP-MS analysis revealed significant Li migration, with no detectable migration of the rare earth elements. While our experiments cannot be considered exhaustive, we have yet to find a scenario where Li mobility in synthetic zircon depends on charge compensating cations.

  19. Epitaxial thin film growth of LiH using a liquid-Li atomic template

    SciTech Connect

    Oguchi, Hiroyuki; Ikeshoji, Tamio; Orimo, Shin-ichi; Ohsawa, Takeo; Shiraki, Susumu; Hitosugi, Taro; Kuwano, Hiroki

    2014-11-24

    We report on the synthesis of lithium hydride (LiH) epitaxial thin films through the hydrogenation of a Li melt, forming abrupt LiH/MgO interface. Experimental and first-principles molecular dynamics studies reveal a comprehensive microscopic picture of the crystallization processes, which sheds light on the fundamental atomistic growth processes that have remained unknown in the vapor-liquid-solid method. We found that the periodic structure that formed, because of the liquid-Li atoms at the film/MgO-substrate interface, serves as an atomic template for the epitaxial growth of LiH crystals. In contrast, films grown on the Al{sub 2}O{sub 3} substrates indicated polycrystalline films with a LiAlO{sub 2} secondary phase. These results and the proposed growth process provide insights into the preparation of other alkaline metal hydride thin films on oxides. Further, our investigations open the way to explore fundamental physics and chemistry of metal hydrides including possible phenomena that emerge at the heterointerfaces of metal hydrides.

  20. Long-Range Forces in the Li + Li2 and Na + Na2 Systems

    NASA Astrophysics Data System (ADS)

    Bent, Gary D.; Michels, H. Harvey

    2003-05-01

    The interaction potentials for the approach of a lithium atom to the lithium molecule and a sodium atom to the sodium molecule were calculated from 15 Ådown to the equilibrium geometry of the trimers. The emphasis of the calculations was to find the minimum energy paths and examine the asymptotic behavior of the approaches in order to obtain an accurate representation of the long-range forces. The CBS method of Petersson, et al was used in order to determine the intermolecular forces to a high degree of accuracy. The long-range behavior of Li + Li2 -> Li3 was compared to the three-body dispersion coefficient calculated for Li3 by Marinescu and Starace and the Li + Li2 dispersion terms of Varandas and Pais. The agreement of the ab initio calculations with the work of Varandas and Pais was excellent. The agreement with the work of Marinescu and Starace was satisfactory until 10 Åwhere their results began to diverge from our calculations. This is attributed to the observation that they considered only the C6 dispersion term.

  1. Li-rich layer-structured cathode materials for high energy Li-ion batteries

    NASA Astrophysics Data System (ADS)

    Li, Liu; Lee, Kim Seng; Lu, Li

    2014-08-01

    Li-rich layer-structured xLi2MnO3 ṡ (1 - x)LiMO2 (M = Mn, Ni, Co, etc.) materials have attracted much attention due to their extraordinarily high reversible capacity as the cathode material in Li-ion batteries. To better understand the nature of this type of materials, this paper reviews history of development of the Li-rich cathode materials, and provides in-depth study on complicated crystal structures and reaction mechanisms during electrochemical charge/discharge cycling. Despite the fabulous capability at low rate, several drawbacks still gap this type of high-capacity cathode materials from practical applications, for instance the large irreversible capacity loss at first cycle, poor rate capability, severe voltage decay and capacity fade during electrochemical charge/discharge cycling. This review will also address mechanisms for these inferior properties and propose various possible solutions to solve above issues for future utilization of these cathode materials in commercial Li-ion batteries.

  2. Capturing and Processing Soil GHG Fluxes Using the LI-COR LI-8100A

    NASA Astrophysics Data System (ADS)

    Xu, Liukang; McDermitt, Dayle; Hupp, Jason; Johnson, Mark; Madsen, Rod

    2015-04-01

    The LI-COR LI-8100A Automated Soil CO2 Flux System is designed to measure soil CO2 efflux using automated chambers and a non-steady state measurement protocol. While CO2 is an important gas in many contexts, it is not the only gas of interest for many research applications. With some simple plumbing modifications, many third party analyzers capable of measuring other trace gases, e.g. N2O, CH4, or 13CO2 etc., can be interfaced with the LI-8100A System, and LI-COR's data processing software (SoilFluxPro™) can be used to compute fluxes for these additional gases. In this paper we describe considerations for selecting an appropriate third party analyzer to interface with the system, how to integrate data into the system, and the procedure used to compute fluxes of additional gases in SoilFluxPro™. A case study is presented to demonstrate methane flux measurements using an Ultra-Portable Greenhouse Gas Analyzer (Ultra-Portable GGA, model 915-0011), manufactured by Los Gatos Research and integrated into the LI-8100A System. Laboratory and field test results show that the soil CO2 efflux based on the time series of CO2 data measured either with the LI-8100A System or with the Ultra-Portable GGA are essentially the same. This suggests that soil GHG fluxes measured with both systems are reliable.

  3. In-house fabrication and testing capabilities for Li and Li-ion 18650 cells

    NASA Astrophysics Data System (ADS)

    Nagasubramanian, G.

    2010-04-01

    For over 10 years Sandia Labs have been involved in an US DOE-funded program aimed at developing electric vehicle batteries for transportation applications. Currently this program is called "Advanced Battery Research (ABR)." In this effort we were preparing 18650 cells with electrodes supplied by or purchased from private companies for thermal abuse and electrical characterization studies. Lately, we are coating our own electrodes, building cells and evaluating performance. This paper describes our extensive in-house facilities for slurry making, electrode coating, cell winding etc. In addition, facilities for electrical testing and thermal abuse will be described. This facility allows us to readjust our focus quickly to the changing demands of the still evolving ABR program. Additionally, we continue to make cells for our internal use. We made several 18650 cells both primary (Li-CFx) and secondary (Li-ion) and evaluated performance. For example Li-CFx cells gave ~2.9Ahr capacity at room temperature. Our high voltage Li-ion cells consisting of carbon anode and cathode based on LiNi 0.4Mn 0.3Co 0.3O2 in organic electrolytes exhibited reproducible behavior and gave capacity on the order of 1Ahr. Performance of Li-ion cells at different temperatures and thermal abuse characteristics will be presented.

  4. Correlation of anisotropy and directional conduction in β-Li3PS4 fast Li+ conductor

    DOE PAGES

    Chen, Yan; Cai, Lu; Liu, Zengcai; dela Cruz, Clarina R.; Liang, Chengdu; An, Ke

    2015-07-06

    Our letter reports the correlation of anisotropy and directional conduction in the fast Li+ conductor β-Li3PS4, one of the low-symmetry crystalline electrolyte candidates. The material has both high conductivity and good stability that serves well for the large-scale energy storage applications of all-solid-state lithium ion batteries. The anisotropic physical properties, demonstrated here by the thermal expansion coefficients, are crucial for compatibility in the solid-state system and battery performance. Neutron and X-ray powder diffraction measurements were done to determine the crystal structure and thermal stability. Moreover, the crystallographic b-axis was revealed as a fast expansion direction, while negligible thermal expansion wasmore » observed along the a-axis around the battery operating temperatures. The anisotropic behavior has its structural origin from the Li+ conduction channels with incomplete Li occupancy and a flexible connection of LiS4 and PS4 tetrahedra within the framework. This indicates a strong correlation in the direction of the ionic transport in the low-symmetry Li+ conductor.« less

  5. Making Li-air batteries rechargeable: material challenges

    SciTech Connect

    Shao, Yuyan; Ding, Fei; Xiao, Jie; Zhang, Jian; Xu, Wu; Park, Seh Kyu; Zhang, Jiguang; Wang, Yong; Liu, Jun

    2013-02-25

    A Li-air battery could potentially provide three to five times higher energy density/specific energy than conventional batteries, thus enable the driving range of an electric vehicle comparable to a gasoline vehicle. However, making Li-air batteries rechargeable presents significant challenges, mostly related with materials. Herein, we discuss the key factors that influence the rechargeability of Li-air batteries with a focus on nonaqueous system. The status and materials challenges for nonaqueous rechargeable Li-air batteries are reviewed. These include electrolytes, cathode (electocatalysts), lithium metal anodes, and oxygen-selective membranes (oxygen supply from air). The perspective of rechargeable Li-air batteries is provided.

  6. The carbon electrode in nonaqueous Li-O2 cells.

    PubMed

    Ottakam Thotiyl, Muhammed M; Freunberger, Stefan A; Peng, Zhangquan; Bruce, Peter G

    2013-01-01

    Carbon has been used widely as the basis of porous cathodes for nonaqueous Li-O(2) cells. However, the stability of carbon and the effect of carbon on electrolyte decomposition in such cells are complex and depend on the hydrophobicity/hydrophilicity of the carbon surface. Analyzing carbon cathodes, cycled in Li-O(2) cells between 2 and 4 V, using acid treatment and Fenton's reagent, and combined with differential electrochemical mass spectrometry and FTIR, demonstrates the following: Carbon is relatively stable below 3.5 V (vs Li/Li(+)) on discharge or charge, especially so for hydrophobic carbon, but is unstable on charging above 3.5 V (in the presence of Li(2)O(2)), oxidatively decomposing to form Li(2)CO(3). Direct chemical reaction with Li(2)O(2) accounts for only a small proportion of the total carbon decomposition on cycling. Carbon promotes electrolyte decomposition during discharge and charge in a Li-O(2) cell, giving rise to Li(2)CO(3) and Li carboxylates (DMSO and tetraglyme electrolytes). The Li(2)CO(3) and Li carboxylates present at the end of discharge and those that form on charge result in polarization on the subsequent charge. Li(2)CO(3) (derived from carbon and from the electrolyte) as well as the Li carboxylates (derived from the electrolyte) decompose and form on charging. Oxidation of Li(2)CO(3) on charging to ∼4 V is incomplete; Li(2)CO(3) accumulates on cycling resulting in electrode passivation and capacity fading. Hydrophilic carbon is less stable and more catalytically active toward electrolyte decomposition than carbon with a hydrophobic surface. If the Li-O(2) cell could be charged at or below 3.5 V, then carbon may be relatively stable, however, its ability to promote electrolyte decomposition, presenting problems for its use in a practical Li-O(2) battery. The results emphasize that stable cycling of Li(2)O(2) at the cathode in a Li-O(2) cell depends on the synergy between electrolyte and electrode; the stability of the electrode and

  7. Mechanism of Li-doping into Li 4Ti 5O 12 negative active material for Li-ion cells by new chemical method

    NASA Astrophysics Data System (ADS)

    Tabuchi, Toru; Yasuda, Hideo; Yamachi, Masanori

    Li 4+ XTi 5O 12 (X > 0) negative active material has been successfully synthesized by a new chemical method for Li-doping with the catalytic function of naphthalene in Li-organic complex solution of butylmethylether (BME) or dimethoxyethane (DME) solvent. The Li-doping reaction rate constant in BME was found to be greater than that of the case of DME and its value was 5.10 and 2.78 × 10 -4 S -1/2, respectively, by the calculation from the slope of distinct straight line in the relationship between ln(1/1 - Y) and √{ t } , where Y is molar fraction of Li-doping materials of Li 7Ti 5O 12.

  8. Amorphous Li2 O2 : Chemical Synthesis and Electrochemical Properties.

    PubMed

    Zhang, Yelong; Cui, Qinghua; Zhang, Xinmin; McKee, William C; Xu, Ye; Ling, Shigang; Li, Hong; Zhong, Guiming; Yang, Yong; Peng, Zhangquan

    2016-08-26

    When aprotic Li-O2 batteries discharge, the product phase formed in the cathode often contains two different morphologies, that is, crystalline and amorphous Li2 O2 . The morphology of Li2 O2 impacts strongly on the electrochemical performance of Li-O2 cells in terms of energy efficiency and rate capability. Crystalline Li2 O2 is readily available and its properties have been studied in depth for Li-O2 batteries. However, little is known about the amorphous Li2 O2 because of its rarity in high purity. Herein, amorphous Li2 O2 has been synthesized by a rapid reaction of tetramethylammonium superoxide and LiClO4 in solution, and its amorphous nature has been confirmed by a range of techniques. Compared with its crystalline siblings, amorphous Li2 O2 demonstrates enhanced charge-transport properties and increased electro-oxidation kinetics, manifesting itself a desirable discharge phase for high-performance Li-O2 batteries. PMID:27486085

  9. Thermodynamics and kinetics of defects in Li2S

    NASA Astrophysics Data System (ADS)

    Moradabadi, Ashkan; Kaghazchi, Payam

    2016-05-01

    Li2S is the final product of lithiation of sulfur cathodes in lithium-sulfur (Li-S) batteries. In this work, we study formation and diffusion of defects in Li2S. It is found that for a wide range of voltages (referenced to metal Li) between 0.17 V and 2.01 V, positively charged interstitial Li (Li+) is the most favorable defect type with a fixed formation energy of 1.02 eV. The formation energy of negatively charged Li vacancy ( VL i - ) is also constant, and it is only 0.13 eV higher than that of Li+. For a narrow range of voltages between 0.00 V and 0.17 V, the formation energy of neutral S vacancy is the lowest and it decreases with decreasing the cell voltage. The energy barrier for Li+ diffusion (0.45 eV), which takes place via an exchange mechanism, is 0.18 eV higher than that for VL i - (0.27 eV), which takes place via a single vacancy hopping. Considering formation energies and diffusion barriers, we find that ionic conductivity in Li2S is due to both Li+ and VL i - , but the latter mechanism being slightly more favorable.

  10. Concentration dependence of Li+/Na+ diffusion in manganese hexacyanoferrates

    NASA Astrophysics Data System (ADS)

    Takachi, Masamitsu; Fukuzumi, Yuya; Moritomo, Yutaka

    2016-06-01

    Manganese hexacyanoferrates (Mn-HCFs) with a jungle-gym-type structure are promising cathode materials for Li+/Na+ secondary batteries (LIBs/SIBs). Here, we investigated the diffusion constants D Li/D Na of Li+/Na+ against the Li+/Na+ concentration x Na/x Li and temperature (T) of A 1.32Mn[Fe(CN)6]0.833.6H2O (A = Li and Na). We evaluated the activation energy E\\text{a}\\text{Li}/E\\text{a}\\text{Na} of D Li/D Na against x Na/x Li. We found that E\\text{a}\\text{Na} steeply increases with x Na from 0.41 eV at x Na = 0.69 to 0.7 eV at 1.1. The increase in E\\text{a}\\text{Na} is ascribed to the occupancy effect of the Na+ site. The increase in E\\text{a}\\text{Li} is suppressed, probably because the number of Li+ sites is three times that of Na+ sites.

  11. Structures of NADH and CH[subscript 3]-H[subscript 4] Folate Complexes of Escherichia coli Methylenetetrahydrofolate Reductase Reveal a Spartan Strategy for a Ping-Pong Reaction

    SciTech Connect

    Pejchal, Robert; Sargeant, Ryan; Ludwig, Martha L.

    2010-03-08

    Methylenetetrahydrofolate reductases (MTHFRs; EC 1.7.99.5) catalyze the NAD(P)H-dependent reduction of 5,10-methylenetetrahydrofolate (CH{sub 2}-H{sub 4}folate) to 5-methyltetrahydrofolate (CH{sub 3}-H{sub 4}folate) using flavin adenine dinucleotide (FAD) as a cofactor. The initial X-ray structure of Escherichia coli MTHFR revealed that this 33-kDa polypeptide is a ({beta}{alpha}){sub 8} barrel that aggregates to form an unusual tetramer with only 2-fold symmetry. Structures of reduced enzyme complexed with NADH and of oxidized Glu28Gln enzyme complexed with CH{sub 3}-H{sub 4}folate have now been determined at resolutions of 1.95 and 1.85 {angstrom}, respectively. The NADH complex reveals a rare mode of dinucleotide binding; NADH adopts a hairpin conformation and is sandwiched between a conserved phenylalanine, Phe223, and the isoalloxazine ring of FAD. The nicotinamide of the bound pyridine nucleotide is stacked against the si face of the flavin ring with C4 adjoining the N5 of FAD, implying that this structure models a complex that is competent for hydride transfer. In the complex with CH{sub 3}-H{sub 4}folate, the pterin ring is also stacked against FAD in an orientation that is favorable for hydride transfer. Thus, the binding sites for the two substrates overlap, as expected for many enzymes that catalyze ping-pong reactions, and several invariant residues interact with both folate and pyridine nucleotide substrates. Comparisons of liganded and substrate-free structures reveal multiple conformations for the loops {beta}2-{alpha}2 (L2), {beta}3-{alpha}3 (L3), and {beta}4-{alpha}4 (L4) and suggest that motions of these loops facilitate the ping-pong reaction. In particular, the L4 loop adopts a 'closed' conformation that allows Asp120 to hydrogen bond to the pterin ring in the folate complex but must move to an 'open' conformation to allow NADH to bind.

  12. Synthesis and optical characterization of LiKB4O7, Li2B6O10, and LiCsB6O10 glasses.

    PubMed

    Adamiv, V; Teslyuk, I; Dyachok, Ya; Romanyuk, G; Krupych, O; Mys, O; Martynyuk-Lototska, I; Burak, Ya; Vlokh, R

    2010-10-01

    In the current work we report on the synthesis of LiKB(4)O(7), Li(2)B(6)O(10), and LiCsB(6)O(10) borate glasses. The results for their piezo-optic, acousto-optic, acoustic, elastic, refractive, optical transmission, and optical resistance properties are also presented. It is shown that some of these glasses represent efficient acousto-optic materials that are transparent down to the vacuum ultraviolet range and highly resistant to laser radiation.

  13. Synthesis and optical characterization of LiKB4O7, Li2B6O10, and LiCsB6O10 glasses

    SciTech Connect

    Adamiv, V.; Teslyuk, I.; Dyachok, Ya.; Romanyuk, G.; Krupych, O.; Mys, O.; Martynyuk-Lototska, I.; Burak, Ya.; Vlokh, R.

    2010-10-01

    In the current work we report on the synthesis of LiKB4O7, Li2B6O10, and LiCsB6O10 borate glasses. The results for their piezo-optic, acousto-optic, acoustic, elastic, refractive, optical transmission, and optical resistance properties are also presented. It is shown that some of these glasses represent efficient acousto-optic materials that are transparent down to the vacuum ultraviolet range and highly resistant to laser radiation.

  14. Neutron irradiation and compatibility testing of Li 2O

    NASA Astrophysics Data System (ADS)

    Porter, D. L.; Krsul, J. R.; Laug, M. T.; Walters, L. C.; Tetenbaum, M.

    1984-05-01

    A study was made of the neutron irradiation behavior of 6Li-enriched Li 2O in EBR-II. In addition, a stress corrosion study was performed ex-reactor to test the compatibility of Li 2O with a variety of stainless steels. The irradiation tests showed that tritium and helium retention in the Li 2O (˜ 89% dense) lessened with neutron exposure, and the retentions appear to approach a steady-state after ˜ 1% 6Li burnup. The stress corrosion studies, using 316 stainless steel (Ti-modified) and a 35% Ni alloy, showed that stress does not enhance the corrosion, and that dry Li 2O is not significantly corrosive, the LiOH content producing the corrosive effects. Corrosion, in general, was not severe because a passivation in sealed capsules seemed to occur after a time which greatly reduced corrosion rates.

  15. Defect complexes in Li-doped MgO

    NASA Astrophysics Data System (ADS)

    Richter, N. A.; Stavale, F.; Levchenko, S. V.; Nilius, N.; Freund, H.-J.; Scheffler, M.

    2015-05-01

    Magnesium oxide (MgO) is used in a variety of industrial applications due to its low cost and structural stability. In heterogeneous catalysis, MgO and Li-doped MgO have been studied as catalysts for the oxidative coupling of methane. In this work, we analyze the structure and stability of defect complexes comprising Li dopants and oxygen vacancies in MgO, combining scanning tunneling microscopy, photon-emission experiments, and density-functional theory computations. The experimental results strongly indicate that after annealing Li-doped MgO to temperatures of 600 K and higher, Li evaporates from the surface, but Li defects, such as substitutional defects, interstitials, or defect complexes comprising Li remain in the bulk. Our calculations show that bulk defect complexes containing F2 + color centers, that have donated their two electrons to two adjacent Li defects, are the most stable configurations at realistic pressure and temperature conditions.

  16. Electrolyte effects in Li(Si)/FeS{sub 2} thermal batteries

    SciTech Connect

    Guidotti, R.A.; Reinhardt, F.W.

    1994-10-01

    The most common electrochemical couple for thermally activated (``thermal``) batteries is the Li-alloy/FeS{sub 2} system. The most common Li-alloys used for anodes are 20% Li-80% Al and 44% Li-56% Si (by weight); liquid Li immobilized with iron powder has also been used. The standard electrolyte that has been used in thermal batteries over the years is the LiCl-KCl eutectic that melts at 352{degrees}C. The LiCl-LiBr-LiF eutectic had the best rate and power characteristics. This electrolyte melts at 436{degrees}C and shows very low polarization because of the absence of Li+ gradients common with the LiCl-KCl eutectic. The low-melting electrolytes examined included a KBr-LiBr-LiCl eutectic (melting at 321{degrees}C), a LiBr-KBr-LiF eutectic (melting at 313{degrees}C), and a CsBr-LiBr-KBr eutectic (melting at 238{degrees}C). The CsBr-based salt had poor conductivity and was not studied further. The LiBr-KBr-LiF eutectic outperformed the KBr-LiBr-LiCl eutectic and was selected for more extensive testing. Because of their lower melting points and larger liquidi relative to the LiCl-KCl eutectic, the low-melting electrolytes are prime candidates for long-life applications (i.e., for activated lives of one hour or more). This paper will detail the relative performance of the Li(Si)/FeS{sub 2} couple using primarily the LiCl-KCl (standard) eutectic, the LiCl-LiBr-LiF (all-Li) eutectic, and the LiBr-KBr-LiF (low-melting) eutectic electrolytes. Most of the tests were conducted with 5-cell batteries; validation tests were also carried out with appropriate full-sized batteries.

  17. Electrolyte effects in Li(Si)/FeS2 thermal batteries

    NASA Astrophysics Data System (ADS)

    Guidotti, Ronald A.; Reinhardt, Frederick W.

    The most common electrochemical couple for thermally activated ('thermal') batteries is the Li-alloy/FeS2 system. The most common Li-alloys used for anodes are 20% Li-80% Al and 44% Li-56% Si (by weight); liquid Li immobilized with iron powder has also been used. The standard electrolyte that has been used in thermal batteries over the years is the LiCl-KCl eutectic that melts at 352 C. The LiCl-LiBr-LiF eutectic had the best rate and power characteristics. This electrolyte melts at 436(degrees)C and shows very low polarization because of the absence of Li(+) gradients common with the LiCl-KCl eutectic. The low-melting electrolytes examined included a KBr-LiBr-LiCl eutectic (melting at 321 C), a LiBr-KBr-LiF eutectic (melting at 313 C), and a CsBr-LiBr-KBr eutectic (melting at 238 C). The CsBr-based salt had poor conductivity and was not studied further. The LiBr-KBr-LiF eutectic outperformed the KBr-LiBr-LiCl eutectic and was selected for more extensive testing. Because of their lower melting points and larger liquidi relative to the LiCl-KCl eutectic, the low-melting electrolytes are prime candidates for long-life applications (i.e., for activated lives of one hour or more). This paper will detail the relative performance of the Li(Si)/FeS2 couple using primarily the LiCl-KCl (standard) eutectic, the LiCl-LiBr-LiF (all-Li) eutectic, and the LiBr-KBr-LiF (low-melting) eutectic electrolytes. Most of the tests were conducted with 5-cell batteries; validation tests were also carried out with appropriate full-sized batteries.

  18. Li(+) Local Structure in Li-Tetraglyme Solvate Ionic Liquid Revealed by Neutron Total Scattering Experiments with the (6/7)Li Isotopic Substitution Technique.

    PubMed

    Saito, Soshi; Watanabe, Hikari; Hayashi, Yutaka; Matsugami, Masaru; Tsuzuki, Seiji; Seki, Shiro; Canongia Lopes, José N; Atkin, Rob; Ueno, Kazuhide; Dokko, Kaoru; Watanabe, Masayoshi; Kameda, Yasuo; Umebayashi, Yasuhiro

    2016-07-21

    Equimolar mixtures of lithium bis(trifluoromethanesulfonyl)amide (LiTFSA) and tetraglyme (G4: CH3O-(CH2CH2O)4-CH3) yield the solvate (or chelate) ionic liquid [Li(G4)][TFSA], which is a homogeneous transparent solution at room temperature. Solvate ionic liquids (SILs) are currently attracting increasing research interest, especially as new electrolytes for Li-sulfur batteries. Here, we performed neutron total scattering experiments with (6/7)Li isotopic substitution to reveal the Li(+) solvation/local structure in [Li(G4)][TFSA] SILs. The experimental interference function and radial distribution function around Li(+) agree well with predictions from ab initio calculations and MD simulations. The model solvation/local structure was optimized with nonlinear least-squares analysis to yield structural parameters. The refined Li(+) solvation/local structure in the [Li(G4)][TFSA] SIL shows that lithium cations are not coordinated to all five oxygen atoms of the G4 molecule (deficient five-coordination) but only to four of them (actual four-coordination). The solvate cation is thus considerably distorted, which can be ascribed to the limited phase space of the ethylene oxide chain and competition for coordination sites from the TFSA anion. PMID:27388117

  19. Solution-processable glass LiI-Li4SnS4 superionic conductors for all-solid-state Li-ion batteries

    DOE PAGES

    Kern Ho Park; Oh, Dae Yang; Choi, Young Eun; Nam, Young Jin; Han, Lili; Kim, Ju -Young; Xin, Huolin; Lin, Feng; Oh, Seung M.; Jung, Yoon Seok

    2015-12-22

    The new, highly conductive (4.1 × 10–4 S cm–1 at 30 °C), highly deformable, and dry-air-stable glass 0.4LiI-0.6Li4SnS4 is prepared using a homogeneous methanol solution. Furthermore, the solution process enables the wetting of any exposed surface of the active materials with highly conductive solidified electrolytes (0.4LiI-0.6Li4SnS4), resulting in considerable improvements in electrochemical performances of these electrodes over conventional mixture electrodes.

  20. Thermal Stability of LiPF6 Salt and Li-ion Battery Electrolytes Containing LiPF6

    SciTech Connect

    Yang, Hui; Zhuang, Guorong V; Ross, Jr, Philip N

    2006-03-08

    The thermal stability of the neat LiPF6 salt and of 1 molal solutions of LiPF6 in prototypical Li-ion battery solvents was studied with thermogravimetric analysis (TGA) and on-line FTIR. Pure LiPF6 salt is thermally stable up to 380 K in a dry inert atmosphere, and its decomposition path is a simple dissociation producing LiF as solid and PF5 as gaseous products. In the presence of water (300 ppm) in the carrier gas, its decomposition onset temperature is lowered as a result of direct thermal reaction between LiPF6 and water vapor to form POF3 and HF. No new products were observed in 1 molal solutions of LiPF6 in EC, DMC and EMC by on-line TGA-FTIR analysis. The storage of the same solutions in sealed containers at 358 K for 300 420 hrs. did not produce any significant quantity of new products as well. In particular, noalkylflurophosphates were found in the solutions after storage at elevated temperature. In the absence of either an impurity like alcohol or cathode active material that may (or may not) act as a catalyst, there is no evidence of thermally induced reaction between LiPF6 and the prototypical Li-ion battery solvents EC, PC, DMC or EMC.

  1. Analyzing Powers of the ^58Ni(^6 Li,d)^62Zn Reaction at E(^6Li)=34 MeV and the D State of ^6Li.

    NASA Astrophysics Data System (ADS)

    Veal, K. D.; Brune, C. R.; Geist, W. H.; Karwowski, H. J.; Ludwig, E. J.; Mendez, A. J.; Kozlowska, B.; Bartosz, E. E.; Cathers, P. D.; Drummer, T. L.; Kemper, K. W.; Eiró, A. M.

    1996-10-01

    We continue our studies of the D states of light nuclei with ^6Li, where the magnitude and sign of the ratio of the asymptotic normalization constants, η(^6Li), have not yet been determined.(A. M. Eiró et al.), Few Body Systems, Suppl. 8, 369 (1995). Calculations have shown that tensor analyzing powers of transfer reactions induced by polarized ^6Li ions show considerable sensitivity to the ^6Li D state.^2 Using the FSU polarized ^6Li beam and Si ΔE-E detector telescopes, we have measured cross section and vector and tensor analyzing powers (VAP and TAP) of the ^58Ni(^6 Li,d)^62Zn (0^+ g.s.) reaction at E(^6Li)=34 MeV for 10^circ<=θ_lab<= 40^circ. A DWBA analysis of cross section and VAP strongly suggests that the reaction proceeds via direct α transfer. In addition, an analysis including coupling to the 3^+ state in ^6Li is underway. Comparisons of these data with preliminary calculations and implications for η(^6Li) will be presented.

  2. Hyperfine fields at the Li site in LiFePO(4)-type olivine materials for lithium rechargeable batteries: a (7)Li MAS NMR and SQUID study.

    PubMed

    Tucker, Michael C; Doeff, Marca M; Richardson, Thomas J; Fiñones, Rita; Cairns, Elton J; Reimer, Jeffrey A

    2002-04-17

    The (7)Li NMR isotropic shift for olivine LiMPO(4) (M = Fe, Mn, Co, Ni) is assigned to hyperfine coupling between the (7)Li nucleus and the transition metal unpaired electrons on the basis of the Curie-Weiss temperature dependence of the shift. The hyperfine shift arises from a linear combination of Li-O-M through-bond interactions wherein the unpaired A' electrons contribute a negative shift and the unpaired A' ' electrons contribute a positive shift. The hyperfine coupling constant is determined for each composition.

  3. Solution-Processable Glass LiI-Li4 SnS4 Superionic Conductors for All-Solid-State Li-Ion Batteries.

    PubMed

    Park, Kern Ho; Oh, Dae Yang; Choi, Young Eun; Nam, Young Jin; Han, Lili; Kim, Ju-Young; Xin, Huolin; Lin, Feng; Oh, Seung M; Jung, Yoon Seok

    2016-03-01

    A new, highly conductive (4.1 × 10(-4) S cm(-1) at 30 °C), highly deformable, and dry-air-stable glass 0.4LiI-0.6Li4 SnS4 is prepared using a homogeneous methanol solution. The solution process enables the wetting of any exposed surface of the active materials with highly conductive solidified electrolytes (0.4LiI-0.6Li4 SnS4), resulting in considerable improvements in the electrochemical performance of these electrodes over conventional mixture electrodes. PMID:26690558

  4. Investigation of structural, mechanical, electronic, optical, and dynamical properties of cubic BaLiF3, BaLiH3, and SrLiH3

    NASA Astrophysics Data System (ADS)

    Yalcin, Battal G.; Salmankurt, Bahadır; Duman, Sıtkı

    2016-03-01

    The structural, mechanical, electronic, optical, and dynamical properties of BaLiF3, BaLiH3, and SrLiH3 cubic perovskite materials are theoretically investigated by using first principles calculations. Obtained results are in reasonable agreement with other available theoretical and experimental studies. The considered materials are found to be mechanically stable in the cubic structure. We found that all materials are brittle. The modified Becke-Johnson (mBJ) exchange potential has been used here to obtain an accurate band order. The calculated band-gap energy value of BaLiF3 (8.26 eV) within the mBJ potential agrees very well with the experimentally reported value of 8.41 eV. In order to have a deeper understanding of the bonding mechanism and the effect of atomic relaxation on the electronic band structure, the total and partial density of states have also been calculated. We have investigated the fundamental optical properties, such as the real ɛ 1(ω) and imaginary ɛ 2(ω) parts of the dielectric function, absorption coefficient α(ω), reflectivity R(ω), and refractive index n(ω) in the energy range from 0 to 40 eV within the mBJ potential. The band-gap energy obtained from the absorption spectrum is around 8.76, 3.99, and 3.31 eV for BaLiF3, BaLiH3, and SrLiH3 crystals, respectively. It should be noted that BaLiF3 could be a strong potential candidate as a laser material for the development of a vacuum-ultraviolet light emitting diode once direct transition is confirmed by experimental studies. Finally, we have calculated the lattice dynamical properties of BaLiF3, BaLiH3, SrLiH3, and SrLiF3 crystals. The full phonon dispersion curves of these materials are reported for the first time. Our results clearly indicate that the materials are dynamically stable, except for SrLiF3, in the cubic structure. The obtained zone-center phonon frequencies of BaLiF3, BaLiH3, and SrLiH3 accord very well with previous experimental measurements.

  5. G-LiHT: Goddard's LiDAR, Hyperspectral and Thermal Airborne Imager

    NASA Technical Reports Server (NTRS)

    Cook, Bruce; Corp, Lawrence; Nelson, Ross; Morton, Douglas; Ranson, Kenneth J.; Masek, Jeffrey; Middleton, Elizabeth

    2012-01-01

    Scientists at NASA's Goddard Space Flight Center have developed an ultra-portable, low-cost, multi-sensor remote sensing system for studying the form and function of terrestrial ecosystems. G-LiHT integrates two LIDARs, a 905 nanometer single beam profiler and 1550 nm scanner, with a narrowband (1.5 nanometers) VNIR imaging spectrometer and a broadband (8-14 micrometers) thermal imager. The small footprint (approximately 12 centimeters) LIDAR data and approximately 1 meter ground resolution imagery are advantageous for high resolution applications such as the delineation of canopy crowns, characterization of canopy gaps, and the identification of sparse, low-stature vegetation, which is difficult to detect from space-based instruments and large-footprint LiDAR. The hyperspectral and thermal imagery can be used to characterize species composition, variations in biophysical variables (e.g., photosynthetic pigments), surface temperature, and responses to environmental stressors (e.g., heat, moisture loss). Additionally, the combination of LIDAR optical, and thermal data from G-LiHT is being used to assess forest health by sensing differences in foliage density, photosynthetic pigments, and transpiration. Low operating costs (approximately $1 ha) have allowed us to evaluate seasonal differences in LiDAR, passive optical and thermal data, which provides insight into year-round observations from space. Canopy characteristics and tree allometry (e.g., crown height:width, canopy:ground reflectance) derived from G-LiHT data are being used to generate realistic scenes for radiative transfer models, which in turn are being used to improve instrument design and ensure continuity between LiDAR instruments. G-LiHT has been installed and tested in aircraft with fuselage viewports and in a custom wing-mounted pod that allows G-LiHT to be flown on any Cessna 206, a common aircraft in use throughout the world. G-LiHT is currently being used for forest biomass and growth estimation

  6. Li-Ge-H system: Hydrogenation and structural properties of LiGeHx (0

    NASA Astrophysics Data System (ADS)

    Pavlyuk, V.; Ciesielski, W.; Kulawik, D.; Prochwicz, W.; Rożdżyńska-Kiełbik, B.

    2016-11-01

    The synthesis, isothermal section at 450 °C of the Li-Ge-H system in the concentration region from 40 at.% Li to 70 at.% Li and structural characterizations of the observed phases are reported. The hydrogenation and structural properties of the LiGeHx (0 < x < 0.25) phase were studied by volumetric analysis and X-ray diffraction. The absorption of hydrogen by LiGe binary compound produce the ternary hydride phase LiGeHx (0 < x < 0.25), thus the volume tetragonal unit cell increases on 1.8 Å3. The LiGeHx solid solution is formed by means of the insertion of hydrogen atoms into tetrahedral voids of parent LiGe structure. The extension of homogeneity range of LiGeHx (0 < x < 0.25) phase and its crystal structure were more precisely refined using X-ray diffraction data. Electronic structure calculations reveal an increased occupation of electronic states at the Fermi level for LiGeHx in comparison to LiGe.

  7. Evolution of Li2O2 growth and its effect on kinetics of Li-O2 batteries.

    PubMed

    Xia, Chun; Waletzko, Michael; Chen, Limei; Peppler, Klaus; Klar, Peter J; Janek, Jürgen

    2014-08-13

    Lithium peroxide (Li2O2), the solid and intrinsically electronic insulating discharge product of Li-O2 batteries strongly influences the discharge and charge kinetics. In a series of experiments, we investigated the growth of Li2O2 upon discharge and the corresponding reduction and oxidation processes by varying the depth of discharge. The results indicate that insulating Li2O2 particles with a disc-like shape were formed during the initial discharge stage. Afterward, the nucleation and growth of Li2O2 resulted in the formation of conducting Li2O2 shells. When the discharge voltage dropped below 2.65 V, the Li2O2 discs evolved to toroid-shaped particles and defective superoxide-like phase presumably with high conductivity was formed on the rims of Li2O2 toroids. Both Li2O2 and the superoxide-like phase are unstable in ether-based electrolytes resulting in the degradation of the corresponding cells. Nevertheless, by controlling the growth of Li2O2, the chemical reactivity of the discharge product can be suppressed to improve the reversibility of Li-O2 batteries.

  8. Enhanced performance of Li|LiFePO4 cells using CsPF6 as an electrolyte additive

    NASA Astrophysics Data System (ADS)

    Xiao, Liang; Chen, Xilin; Cao, Ruiguo; Qian, Jiangfeng; Xiang, Hongfa; Zheng, Jianming; Zhang, Ji-Guang; Xu, Wu

    2015-10-01

    The practical application of lithium (Li) metal anode in rechargeable Li batteries is hindered by both the growth of Li dendrites and the low Coulombic efficiency (CE) during repeated charge/discharge cycles. Recently, we have discovered that CsPF6 as an electrolyte additive can significantly suppress Li dendrite growth and lead to highly compacted and well aligned Li nanorod structures during Li deposition on copper substrates. In this paper, the effect of CsPF6 additive on the performance of rechargeable Li metal batteries with lithium iron phosphate (LFP) cathode is further studied. Li|LFP coin cells with CsPF6 additive in electrolytes show well protected Li anode surface, decreased resistance, enhanced rate capability and extended cycling stability. In Li|LFP cells, the electrolyte with CsPF6 additive shows excellent long-term cycling stability (at least 500 cycles) at a charge current density of 0.5 mA cm-2 without internal short circuit. At high charge current densities, the effect of CsPF6 additive becomes less significant. Future work needs to be done to protect Li metal anode, especially at high charge current densities and for long cycle life.

  9. Evolution of Li2O2 growth and its effect on kinetics of Li-O2 batteries.

    PubMed

    Xia, Chun; Waletzko, Michael; Chen, Limei; Peppler, Klaus; Klar, Peter J; Janek, Jürgen

    2014-08-13

    Lithium peroxide (Li2O2), the solid and intrinsically electronic insulating discharge product of Li-O2 batteries strongly influences the discharge and charge kinetics. In a series of experiments, we investigated the growth of Li2O2 upon discharge and the corresponding reduction and oxidation processes by varying the depth of discharge. The results indicate that insulating Li2O2 particles with a disc-like shape were formed during the initial discharge stage. Afterward, the nucleation and growth of Li2O2 resulted in the formation of conducting Li2O2 shells. When the discharge voltage dropped below 2.65 V, the Li2O2 discs evolved to toroid-shaped particles and defective superoxide-like phase presumably with high conductivity was formed on the rims of Li2O2 toroids. Both Li2O2 and the superoxide-like phase are unstable in ether-based electrolytes resulting in the degradation of the corresponding cells. Nevertheless, by controlling the growth of Li2O2, the chemical reactivity of the discharge product can be suppressed to improve the reversibility of Li-O2 batteries. PMID:25006701

  10. Enhanced Performance of Li|LiFePO4 Cells Using CsPF6 as an Electrolyte Additive

    SciTech Connect

    Xiao, Liang; Chen, Xilin; Cao, Ruiguo; Qian, Jiangfeng; Xiang, Hongfa; Zheng, Jianming; Zhang, Jiguang; Xu, Wu

    2015-10-20

    The practical application of lithium (Li) metal anode in rechargeable Li batteries is hindered by both the growth of Li dendrites and the low Coulombic efficiency (CE) during repeated charge/discharge cycles. Recently, we have discovered that CsPF6 as an electrolyte additive can significantly suppress Li dendrite growth and lead to highly compacted and well aligned Li nanorod structure during Li deposition on copper substrates. In this paper, the effect of CsPF6 additive on the performance of rechargeable Li metal batteries with lithium iron phosphate (LFP) cathode was further studied. Li|LFP coin cells with CsPF6 additive in electrolytes show well protected Li anode surface, decreased resistance, enhanced rate capability and extended cycling stability. In Li|LFP cells, the electrolyte with CsPF6 additive shows excellent long-term cycling stability (at least 500 cycles) at a charge current density of 0.5 mA cm-2 without internal short circuit. At high charge current densities, the effect of CsPF6 additive becomes less significant. Future work needs to be done to protect Li metal anode, especially at high charge current densities and for long cycle life.

  11. Thermophysical properties of LiCoO₂-LiMn₂O₄ blended electrode materials for Li-ion batteries.

    PubMed

    Gotcu, Petronela; Seifert, Hans J

    2016-04-21

    Thermophysical properties of two cathode types for lithium-ion batteries were measured by dependence on temperature. The cathode materials are commercial composite thick films containing LiCoO2 and LiMn2O4 blended active materials, mixed with additives (binder and carbon black) deposited on aluminium current collector foils. The thermal diffusivities of the cathode samples were measured by laser flash analysis up to 673 K. The specific heat data was determined based on measured composite specific heat, aluminium specific heat data and their corresponding measured mass fractions. The composite specific heat data was measured using two differential scanning calorimeters over the temperature range from 298 to 573 K. For a comprehensive understanding of the blended composite thermal behaviour, measurements of the heat capacity of an additional LiMn2O4 sample were performed, and are the first experimental data up to 700 K. Thermal conductivity of each cathode type and their corresponding blended composite layers were estimated from the measured thermal diffusivity, the specific heat capacity and the estimated density based on metallographic methods and structural investigations. Such data are highly relevant for simulation studies of thermal management and thermal runaway in lithium-ion batteries, in which the bulk properties are assumed, as a common approach, to be temperature independent. PMID:27031918

  12. Composite Solid Electrolyte Containing Li+- Conducting Fibers

    NASA Technical Reports Server (NTRS)

    Appleby, A. John; Wang, Chunsheng; Zhang, Xiangwu

    2006-01-01

    Improved composite solid polymer electrolytes (CSPEs) are being developed for use in lithium-ion power cells. The matrix components of these composites, like those of some prior CSPEs, are high-molecular-weight dielectric polymers [generally based on polyethylene oxide (PEO)]. The filler components of these composites are continuous, highly-Li(+)-conductive, inorganic fibers. PEO-based polymers alone would be suitable for use as solid electrolytes, were it not for the fact that their room-temperature Li(+)-ion conductivities lie in the range between 10(exp -6) and 10(exp -8) S/cm, too low for practical applications. In a prior approach to formulating a CSPE, one utilizes nonconductive nanoscale inorganic filler particles to increase the interfacial stability of the conductive phase. The filler particles also trap some electrolyte impurities. The achievable increase in conductivity is limited by the nonconductive nature of the filler particles.

  13. High current LiSOCl2 batteries

    NASA Astrophysics Data System (ADS)

    Debiccari, Daniel J.

    The paper describes cell construction, performance, and safety aspects of two high-rate active Li/SOCl2 batteries designed to operate at current densities as high as 26 mA/sq cm in pulse modes of 20 millisec to several minutes. Both cell designs employ a flat-plate arrangement of electrodes, a cyanoacrylate-coated anode, a bonded carbon/copper cathode, and a 1.6 M electrolyte. The major differences of the two designs are the size of the cell and the method of anode attachment. The two batteries were shown to provide over 10 times the mission life of the Ni-Cd batteries; thus, they will eliminate the logistic problems associated with the recharge requirements of the latter. In addition, a replacement of the Ni-Cd battery types with lighter Li-thionyl chloride batteries will significantly reduce battery weight and increase its capacity.

  14. Li, B and N in ancient materials

    NASA Astrophysics Data System (ADS)

    Fink, D.

    1983-12-01

    The content of B and Li is examined in several ancient and, for comparison, in modern objects for techological and household use (glasses, coins, nails, needles, bells, shells, bones, pitch, minerals). For most samples the B content is proportional to the Li content, the proportionality factor ranging from 1 to 6. The data scatteringroups of examined species are given. It is known that the N content of bones decreases with age due to decomposition of organic materials. This is confirmed, and simultaneously an enrichment of B was observed for ancient bones, probably due to salt transport from the surrounding soil into the bones. Coins frequently show a nitrogen enriched layer on their surfaces due to corrosion. B surface contaminations are sometimes observed for glasses and mother-of-pearl.

  15. Metastable structure of Li13Si4

    NASA Astrophysics Data System (ADS)

    Gruber, Thomas; Bahmann, Silvia; Kortus, Jens

    2016-04-01

    The Li13Si4 phase is one out of several crystalline lithium silicide phases, which is a potential electrode material for lithium ion batteries and contains a high theoretical specific capacity. By means of ab initio methods like density functional theory (DFT) many properties such as heat capacity or heat of formation can be calculated. These properties are based on the calculation of phonon frequencies, which contain information about the thermodynamical stability. The current unit cell of "Li13Si4" given in the ICSD database is unstable with respect to DFT calculations. We propose a modified unit cell that is stable in the calculations. The evolutionary algorithm EVO found a structure very similar to the ICSD one with both of them containing metastable lithium positions. Molecular dynamic simulations show a phase transition between both structures where these metastable lithium atoms move. This phase transition is achieved by a very fast one-dimensional lithium diffusion and stabilizes this phase.

  16. Li + ion diffusion in nanoscale alumina coatings

    NASA Astrophysics Data System (ADS)

    Johannes, Michelle; Bernstein, Noam

    Nanoscale coatings of alumina are used to stabilize surfaces for a variety of technologies. Diffusion of ions through these coatings is of primary importance: in some cases, diffusion is unwanted (e.g. corrosion) and in others (e.g. electrode materials), it is necessary. In this work DFT and AIMD calculations are used to investigate Li+ ion diffusion through a nano-layer of alumina, examining the phase (alpha, gamma, and amorphous), ion concentration, and electron count dependence. We look at the role of the surface itself in promoting diffusion. One of our main findings is that as the number of ions or charge increases, the diffusivity rises. We show how our data can explain electrochemical data from coated LiCoO2 cathodes and may point toward better and more efficient coatings for stabilizing electrodes.

  17. Li7La3Zr2O12 Interface Modification for Li Dendrite Prevention.

    PubMed

    Tsai, Chih-Long; Roddatis, Vladimir; Chandran, C Vinod; Ma, Qianli; Uhlenbruck, Sven; Bram, Martin; Heitjans, Paul; Guillon, Olivier

    2016-04-27

    Al-contaminated Ta-substituted Li7La3Zr2O12 (LLZ:Ta), synthesized via solid-state reaction, and Al-free Ta-substituted Li7La3Zr2O12, fabricated by hot-press sintering (HP-LLZ:Ta), have relative densities of 92.7% and 99.0%, respectively. Impedance spectra show the total conductivity of LLZ:Ta to be 0.71 mS cm(-1) at 30 °C and that of HP-LLZ:Ta to be 1.18 mS cm(-1). The lower total conductivity for LLZ:Ta than HP-LLZ:Ta was attributed to the higher grain boundary resistance and lower relative density of LLZ:Ta, as confirmed by their microstructures. Constant direct current measurements of HP-LLZ:Ta with a current density of 0.5 mA cm(-2) suggest that the short circuit formation was neither due to the low relative density of the samples nor the reduction of Li-Al glassy phase at grain boundaries. TEM, EELS, and MAS NMR were used to prove that the short circuit was from Li dendrite formation inside HP-LLZ:Ta, which took place along the grain boundaries. The Li dendrite formation was found to be mostly due to the inhomogeneous contact between LLZ solid electrolyte and Li electrodes. By flatting the surface of the LLZ:Ta pellets and using thin layers of Au buffer to improve the contact between LLZ:Ta and Li electrodes, the interface resistance could be dramatically reduced, which results in short-circuit-free cells when running a current density of 0.5 mA cm(-2) through the pellets. Temperature-dependent stepped current density galvanostatic cyclings were also carried out to determine the critical current densities for the short circuit formation. The short circuit that still occurred at higher current density is due to the inhomogeneous dissolution and deposition of metallic Li at the interfaces of Li electrodes and LLZ solid electrolyte when cycling the cell at large current densities.

  18. Yu Ping Feng San, an Ancient Chinese Herbal Decoction, Regulates the Expression of Inducible Nitric Oxide Synthase and Cyclooxygenase-2 and the Activity of Intestinal Alkaline Phosphatase in Cultures

    PubMed Central

    Du, Crystal Y. Q.; Choi, Roy C. Y.; Dong, Tina T. X.; Lau, David T. W.; Tsim, Karl W. K.

    2014-01-01

    Yu Ping Feng San (YPFS), a Chinese herbal decoction comprising Astragali Radix (AR; Huangqi), Atractylodis Macrocephalae Rhizoma (AMR; Baizhu), and Saposhnikoviae Radix (SR; Fangfeng), has been used clinically to treat inflammatory bowel diseases (IBD). Previously, we demonstrated a dual role of YPFS in regulating cytokine release in cultured macrophages. In this study, we elucidated the anti-inflammatory effect of YPFS that is mediated through modulating the expression of three key enzymes involved in IBD: inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and intestinal alkaline phosphatase (IALP). In a lipopolysaccharide (LPS)-induced chronic-inflammation model of cultured murine macrophages, YPFS treatment suppressed the activation of iNOS and COX-2 expression in a dose-dependent manner. Conversely, application of YPFS in cultured small intestinal enterocytes markedly induced the expression of IALP in a time-dependent manner, which might strengthen the intestinal detoxification system. A duality of YPFS in modulating the expression of iNOS and COX-2 was determined here. The expression of iNOS and COX-2 in macrophages was induced by YPFS, and this activation was partially blocked by the NF-κB-specific inhibitor BAY 11-7082, indicating a role of NF-κB signaling. These YPFS-induced changes in gene regulation strongly suggest that the anti-inflammatory effects of YPFS are mediated through the regulation of inflammatory enzymes. PMID:24967898

  19. Thermal and Cycle-Life Behavior of Commercial Li-ion and Li-Polymer Cells

    NASA Technical Reports Server (NTRS)

    Zimmerman, Albert H.; Quinzio, M. V.

    2001-01-01

    Accelerated and real-time LEO cycle-life test data will be presented for a range of commercial Li-ion and Li-polymer (gel type) cells indicating the ranges of performance that can be obtained, and the performance screening tests that must be done to assure long life. The data show large performance variability between cells, as well as a highly variable degradation signature during non-cycling periods within the life tests. High-resolution Dynamic Calorimetry data will be presented showing the complex series of reactions occurring within these Li cells as they are cycled. Data will also be presented for cells being tested using an Adaptive Charge Control Algorithm (ACCA) that continuously adapts itself to changes in cell performance, operation, or environment to both find and maintain the optimum recharge over life. The ACCA has been used to prevent all unneeded overcharge for Li cells, NiCd cells and NiH2 cells. While this is important for all these cell types, it is most critical for Li-ion cells, which are not designed with electrochemical tolerance for overcharge.

  20. A new active Li-Mn-O compound for high energy density Li-ion batteries

    NASA Astrophysics Data System (ADS)

    Freire, M.; Kosova, N. V.; Jordy, C.; Chateigner, D.; Lebedev, O. I.; Maignan, A.; Pralong, V.

    2016-02-01

    The search for new materials that could improve the energy density of Li-ion batteries is one of today’s most challenging issues. Many families of transition metal oxides as well as transition metal polyanionic frameworks have been proposed during the past twenty years. Among them, manganese oxides, such as the LiMn2O4 spinel or the overlithiated oxide Li[Li1/3Mn2/3]O2, have been intensively studied owing to the low toxicity of manganese-based materials and the high redox potential of the Mn3+/Mn4+ couple. In this work, we report on a new electrochemically active compound with the `Li4Mn2O5’ composition, prepared by direct mechanochemical synthesis at room temperature. This rock-salt-type nanostructured material shows a discharge capacity of 355 mAh g-1, which is the highest yet reported among the known lithium manganese oxide electrode materials. According to the magnetic measurements, this exceptional capacity results from the electrochemical activity of the Mn3+/Mn4+ and O2-/O- redox couples, and, importantly, of the Mn4+/Mn5+ couple also.

  1. A new active Li-Mn-O compound for high energy density Li-ion batteries.

    PubMed

    Freire, M; Kosova, N V; Jordy, C; Chateigner, D; Lebedev, O I; Maignan, A; Pralong, V

    2016-02-01

    The search for new materials that could improve the energy density of Li-ion batteries is one of today's most challenging issues. Many families of transition metal oxides as well as transition metal polyanionic frameworks have been proposed during the past twenty years. Among them, manganese oxides, such as the LiMn2O4 spinel or the overlithiated oxide Li[Li1/3Mn2/3]O2, have been intensively studied owing to the low toxicity of manganese-based materials and the high redox potential of the Mn(3+)/Mn(4+) couple. In this work, we report on a new electrochemically active compound with the 'Li4Mn2O5' composition, prepared by direct mechanochemical synthesis at room temperature. This rock-salt-type nanostructured material shows a discharge capacity of 355 mAh g(-1), which is the highest yet reported among the known lithium manganese oxide electrode materials. According to the magnetic measurements, this exceptional capacity results from the electrochemical activity of the Mn(3+)/Mn(4+) and O(2-)/O(-) redox couples, and, importantly, of the Mn(4+)/Mn(5+) couple also.

  2. Potential energy surfaces of the electronic states of Li2F and Li2F-

    NASA Astrophysics Data System (ADS)

    Bhowmick, Somnath; Hagebaum-Reignier, Denis; Jeung, Gwang-Hi

    2016-07-01

    The potential energy surfaces of the ground and low-lying excited states for the insertion reaction of atomic fluorine (F) and fluoride (F-) into the dilithium (Li2) molecule have been investigated. We have carried out explicitly correlated multi-reference configuration interaction (MRCI-F12) calculations using Dunning's augmented correlation-consistent basis sets. For the neutral system, the insertion of F into Li2 proceeds via a harpoon-type mechanism on the ground state surface, involving a covalent state and an ionic state which avoid each other at long distance. A detailed analysis of the changes in the dipole moment along the reaction coordinate reveals multiple avoided crossings among the excited states and shows that the charge-transfer processes play a pivotal role for the stabilization of the low-lying electronic states of Li2F. For the anionic system, which is studied for the first time, the insertion of F- is barrierless for many states and there is a gradual charge transfer from F- to Li2 along the reaction path. We also report the optimized parameters and the spectroscopic properties of the five lowest states of the neutral and seven lowest states of the anionic systems, which are strongly stabilized with respect to their respective Li2 + F/F- asymptotes. The observed barrierless insertion mechanisms for both systems make them good candidates for investigation under the ultracold regime.

  3. A Thermally Conductive Separator for Stable Li Metal Anodes.

    PubMed

    Luo, Wei; Zhou, Lihui; Fu, Kun; Yang, Zhi; Wan, Jiayu; Manno, Michael; Yao, Yonggang; Zhu, Hongli; Yang, Bao; Hu, Liangbing

    2015-09-01

    Li metal anodes have attracted considerable research interest due to their low redox potential (-3.04 V vs standard hydrogen electrode) and high theoretical gravimetric capacity of 3861 mAh/g. Battery technologies using Li metal anodes have shown much higher energy density than current Li-ion batteries (LIBs) such as Li-O2 and Li-S systems. However, issues related to dendritic Li formation and low Coulombic efficiency have prevented the use of Li metal anode technology in many practical applications. In this paper, a thermally conductive separator coated with boron-nitride (BN) nanosheets has been developed to improve the stability of the Li metal anodes. It is found that using the BN-coated separator in a conventional organic carbonate-based electrolyte results in the Coulombic efficiency stabilizing at 92% over 100 cycles at a current rate of 0.5 mA/cm(2) and 88% at 1.0 mA/cm(2). The improved Coulombic efficiency and reliability of the Li metal anodes is due to the more homogeneous thermal distribution resulting from the thermally conductive BN coating and to the smaller surface area of initial Li deposition. PMID:26237519

  4. A Thermally Conductive Separator for Stable Li Metal Anodes.

    PubMed

    Luo, Wei; Zhou, Lihui; Fu, Kun; Yang, Zhi; Wan, Jiayu; Manno, Michael; Yao, Yonggang; Zhu, Hongli; Yang, Bao; Hu, Liangbing

    2015-09-01

    Li metal anodes have attracted considerable research interest due to their low redox potential (-3.04 V vs standard hydrogen electrode) and high theoretical gravimetric capacity of 3861 mAh/g. Battery technologies using Li metal anodes have shown much higher energy density than current Li-ion batteries (LIBs) such as Li-O2 and Li-S systems. However, issues related to dendritic Li formation and low Coulombic efficiency have prevented the use of Li metal anode technology in many practical applications. In this paper, a thermally conductive separator coated with boron-nitride (BN) nanosheets has been developed to improve the stability of the Li metal anodes. It is found that using the BN-coated separator in a conventional organic carbonate-based electrolyte results in the Coulombic efficiency stabilizing at 92% over 100 cycles at a current rate of 0.5 mA/cm(2) and 88% at 1.0 mA/cm(2). The improved Coulombic efficiency and reliability of the Li metal anodes is due to the more homogeneous thermal distribution resulting from the thermally conductive BN coating and to the smaller surface area of initial Li deposition.

  5. High performance MCFC using Li/Na electrolyte

    SciTech Connect

    Donado, R.A.; Ong, E.T.; Sishtla, C.I.

    1995-08-01

    The substitution of a lithium/ sodium carbonate (Li/Na) mixture for the lithium/potassium carbonate (Li/K) electrolyte used in MCFCs holds the promise of higher ionic conductivity, higher exchange current density at both electrodes, lower vapor pressure, and lower cathode dissolution rates. However, when the substitution is made in cells optimized for use with the Li/K electrolyte, the promised increase in performance is not realized. As a consequence the literature contains conflicting data with regard to the performance, compositional stability, and chemical reactivity of the Li/Na electrolyte. Experiments conducted at the Institute of Gas Technology (IGT) concluded that the source of the problem is the different wetting characteristics of the two electrolytes. Electrode pore structures optimized for use with Li/K do not work well with Li/Na. Using proprietary methods and materials, IGT was able to optimize a set of electrodes for the Li/Na electrolyte. Experiments conducted in bench-scale cells have confirmed the superior performance of the Li/Na electrolyte compared to the Li/K electrolyte. The Li/Na cells exhibited a 5 to 8 percent improvement in overall performance, a substantial decrease in the rate of cathode dissolution, and a decreased decay rate. The longest running cell has logged over 13,000 hours of operation with a decay rate of less than 2 mV/1000 hours.

  6. Conjugated dicarboxylate anodes for Li-ion batteries

    NASA Astrophysics Data System (ADS)

    Armand, M.; Grugeon, S.; Vezin, H.; Laruelle, S.; Ribière, P.; Poizot, P.; Tarascon, J.-M.

    2009-02-01

    Present Li-ion batteries for portable electronics are based on inorganic electrodes. For upcoming large-scale applications the notion of materials sustainability produced by materials made through eco-efficient processes, such as renewable organic electrodes, is crucial. We here report on two organic salts, Li2C8H4O4 (Li terephthalate) and Li2C6H4O4(Li trans-trans-muconate), with carboxylate groups conjugated within the molecular core, which are respectively capable of reacting with two and one extra Li per formula unit at potentials of 0.8 and 1.4V, giving reversible capacities of 300 and 150mAhg-1. The activity is maintained at 80∘C with polyethyleneoxide-based electrolytes. A noteworthy advantage of the Li2C8H4O4 and Li2C6H4O4 negative electrodes is their enhanced thermal stability over carbon electrodes in 1M LiPF6 ethylene carbonate-dimethyl carbonate electrolytes, which should result in safer Li-ion cells. Moreover, as bio-inspired materials, both compounds are the metabolites of aromatic hydrocarbon oxidation, and terephthalic acid is available in abundance from the recycling of polyethylene terephthalate.

  7. Er3+ diffusion in LiTaO3 crystal

    NASA Astrophysics Data System (ADS)

    Zhang, De-Long; Zhang, Qun; Wong, Wing-Han; Pun, Edwin Yue-Bun

    2015-12-01

    Some Er3+-doped LiTaO3 plates were prepared by in-diffusion of Er-metal film locally coated onto congruent Z-cut substrate in air at a wide temperature range from 1000 to 1500 °C. After diffusion, Er3+-doping effect on LiTaO3 refractive index and Li2O out-diffusion arising from Er3+ in-diffusion were studied at first. Refractive indices at the doped and undoped surface parts were measured by prism coupling technique and the surface composition was estimated. The results show that Er3+ dopant has small contribution to the LiTaO3 index. Li2O out-diffusion is slight (Li2O content loss <0.3 mol%) for the temperature below 1300 °C while is moderate (Li2O content loss <0.6 mol%) for the temperature above 1400 °C. The Er3+ profile was studied by secondary ion mass spectrometry. The study shows that the diffused Er3+ ions follow either a complementary error function or a Gaussian profile. Characteristic parameters including diffusivity, diffusion constant, activation energy, solubility, solubility constant and heat of solution were obtained and compared with the LiNbO3 case. The comparison shows that the diffusivity and solubility in LiTaO3 are considerably smaller than in LiNbO3 because of the difference of Ta and Nb in atomic weight.

  8. Li2OHCl crystalline electrolyte for stable metallic lithium anodes

    DOE PAGES

    Hood, Zachary D.; Wang, Hui; Samuthira Pandian, Amaresh; Keum, Jong Kahk; Liang, Chengdu

    2016-01-22

    In a classic example of stability from instability, we show that Li2OHCl solid electrolyte forms a stable solid electrolyte interface (SEI) with metallic lithium anode. The Li2OHCl solid electrolyte can be readily achieved through simple mixing of air-stable LiOH and LiCl precursors with a mild processing temperature under 400 °C. Additionally, we show that continuous, dense Li2OHCl membranes can be fabricated at temperatures less than 400 °C, standing in great contrast to current processing temperatures of over 1600 °C for most oxide-based solid electrolytes. The ionic conductivity and Arrhenius activation energy were explored for the LiOH-LiCl system of crystalline solidmore » electrolytes where Li2OHCl with increased crystal defects was found to have the highest ionic conductivity and reasonable Arrhenius activation energy. The Li2OHCl solid electrolyte displays stability against metallic lithium, even in extreme conditions past the melting point of lithium metal. Furthermore, to understand this excellent stability, we show that SEI formation is critical in stabilizing the interface between metallic lithium and the Li2OHCl solid electrolyte.« less

  9. Generation of Li combustion aerosols for animal inhalation studies.

    PubMed

    Allen, M D; Greenspan, B J; Briant, J K; Hoover, M D

    1986-07-01

    A system was developed for generating Li aerosols to determine the potential health hazards of postulated accidents associated with the use of Li as a fusion reactor blanket or coolant. The aerosol was generated by sweeping Ar through a stainless steel chamber filled with Li metal that was heated inductively to temperatures up to 1300 degrees C. Argon carried the Li vapor into a burning chamber where it was mixed with air. The reaction of Li vapor with air formed an intense white flame that produced typical branched-chain condensation aerosol particles. This system generated well-controlled concentrations up to 2500 mg/m3 for periods of 4 h. The mass median aeordynamic diameter of the aerosol was approximately 0.66 micron with a geometric standard deviation of 1.5. Aerosols could be generated that were greater than 96% Li2O and LiOH, LiOH.H2O, or Li2CO3 by controlling the CO2 and H2O concentrations in the supply air. The system is currently being used to investigate the acute toxicity of Li combustion aerosols in laboratory animals.

  10. Composite Solid Electrolyte for Li Battery Applications

    NASA Technical Reports Server (NTRS)

    Nagasubramanian, G.; Attia, A. I.; Halpert, G.; Peled, E.

    1993-01-01

    The electrochemical, bulk and interfacial properties of the polyethylene oxide (PEO) based composite solid electrolyte (CSE) comprising LiI, PEO, and Al2O3 have been evaluated for Li battery applications. The bulk interfacial and transport properties of the CSEs seem to strongly depend on the alumina particle size. For the CSE films with 0.05 micron alumina while the bulk conductivity is around 10(exp -4) (mho/cm) at 103 C, the Li ion transport number seems to be close to unity at the same temperature. Compared to the PEO electrolyte this polymer composite electrolyte seems to exhibit robust mechanical and interfacial properties. We have studied three different films with three different alumina sizes in the range 0.01-0.3 micron. Effects of Al2O3 particle size on the electrochemical performance of polymer composite electrolyte is discussed. With TiS2 as cathode a 10 mAh small capacity cell was charged and discharged at C/40 and C/20 rates respectively.

  11. Endurance testing with Li/Na electrolyte

    SciTech Connect

    Ong, E.T.; Remick, R.J.; Sishtla, C.I.

    1996-12-31

    The Institute of Gas Technology (IGT), under subcontract to M-C Power Corporation under DOE funding, has been operating bench-scale fuel cells to investigate the performance and endurance issues of the Li/Na electrolyte because it offers higher ionic conductivity, higher exchange current densities, lower vapor pressures, and lower cathode dissolution rates than the Li/K electrolyte. These cells have continued to show higher performance and lower decay rates than the Li/K cells since the publication of our two previous papers in 1994. In this paper, test results of two long-term 100-cm{sup 2} bench scale cells are discussed. One cell operated continuously at 160 mA/cm{sup 2} for 17,000 hours with reference gases (60H{sub 2}/20CO{sub 2}/20H{sub 2}O fuel at 75% utilization and 30CO{sub 2}/70 air oxidant humidified at room temperature at 50% utilization). The other cell operated at 160 mA/cm{sup 2} for 6900 hours at 3 atm with system gases (64H{sub 2}/16CO{sub 2}/20H{sub 2}O at 75% utilization and an M-C Power system-defined oxidant at 40% utilization). Both cells have shown the highest performance and longest endurance among IGT cells operated to date.

  12. CuLi2Sn and Cu2LiSn: Characterization by single crystal XRD and structural discussion towards new anode materials for Li-ion batteries

    PubMed Central

    Fürtauer, Siegfried; Effenberger, Herta S.; Flandorfer, Hans

    2014-01-01

    The stannides CuLi2Sn (CSD-427095) and Cu2LiSn (CSD-427096) were synthesized by induction melting of the pure elements and annealing at 400 °C. The phases were reinvestigated by X-ray powder and single-crystal X-ray diffractometry. Within both crystal structures the ordered CuSn and Cu2Sn lattices form channels which host Cu and Li atoms at partly mixed occupied positions exhibiting extensive vacancies. For CuLi2Sn, the space group F-43m. was verified (structure type CuHg2Ti; a=6.295(2) Å; wR2(F²)=0.0355 for 78 unique reflections). The 4(c) and 4(d) positions are occupied by Cu atoms and Cu+Li atoms, respectively. For Cu2LiSn, the space group P63/mmc was confirmed (structure type InPt2Gd; a=4.3022(15) Å, c=7.618(3) Å; wR2(F²)=0.060 for 199 unique reflections). The Cu and Li atoms exhibit extensive disorder; they are distributed over the partly occupied positions 2(a), 2(b) and 4(e). Both phases seem to be interesting in terms of application of Cu–Sn alloys as anode materials for Li-ion batteries. PMID:25473128

  13. Characterizing Lava Flows With LiDAR

    NASA Astrophysics Data System (ADS)

    Deligne, N. I.; Cashman, K. V.; Deardorff, N.; Dietterich, H. R.; House, P. K.; Soule, S.

    2009-12-01

    Digital elevation models (DEMs) have been used in volcanology in predictive modeling of lava flow paths, both for assessment of potential hazards and specific predictions of lava flow paths. Topographic analysis of a lava flow is potentially useful for mapping and quantifying flow surface morphologies, which in turn can be used to determine flow emplacement conditions, such as effusion rate, steadiness of flow, and interactions with pre-existing topography and surface water. However, this has been limited in application because of the coarse resolution of most DEMs. In recent years, use of Light Detection and Ranging (LiDAR) airborne laser altimetry, capable of producing high resolution (≤ 1 meter) DEMs, has become increasingly common in the geomorphic and mapping community. However, volcanologists have made little use of airborne LiDAR. Here we compare information obtained using field observations and standard (10 meter) DEMs against LiDAR high resolution DEMs to assess the usefulness, capabilities, and limitations of LiDAR as applicable to lava flows. We compare morphologic characteristics of five lava flows of different compositions, tectonic settings, flow extents, slopes, and eruption duration: (1) 1984 Mauna Loa lava flow, Hawaii; (2) December 1974 Kilauea lava flow, Hawaii; (3) c. 1600 ybp Collier Cone lava flow, central Oregon Cascades; (4) Holocene lava flows from the Sand Mountain volcanic chain, central Oregon Cascades; and (5) Pleistocene lava flows along the Owyhee River, eastern Oregon basin and range. These lava flows range in composition from basalt to andesite, and have eruption durations ranging from 6 hours (observed) to years (inferred). We measure channel width, levee and flow front heights, compression ridge amplitude, wavelength and tumuli dimensions, and surface roughness. For all but the smallest scale features, LiDAR is easily used to quantify these features, which often is impossible or technically challenging to do in the field, while

  14. Coincidence in the two-photon spectra of Li and Li2 at 735 nm

    NASA Astrophysics Data System (ADS)

    DeGraffenreid, W.; Sansonetti, Craig J.

    2005-02-01

    A coincidence between the 22S1/2-32S1/2 two-photon transition in the atomic spectrum of 6Li and the X 1Σ+g→ E 1Σ+g two-photon ro-vibrational series of 7Li2 was observed near 735 nm in a heat pipe oven using a tunable laser and thermionic diode detection scheme. The molecular transition obscures one component of the 6Li atomic transition. Selective detection of the atomic transition was obtained by adding an intensity-modulated laser that drives atoms from the 3S to 16P state. The coincident molecular transition and four nearby molecular lines were identified using previously determined Dunham coefficients.

  15. Spectroscopic information of 6Li from elastic scattering of deuterons, 3He and 4He by 6Li

    NASA Astrophysics Data System (ADS)

    Amar, A.

    2014-07-01

    The elastic scattering of deuterons, 3He and 4He on 6Li at different incident energies have been analyzed in the framework of the optical model (OM) using ECIS88 as well as SPI GENOA codes. The optical potential parameters were extracted in the phenomenological treatment. A good agreement between theoretical and experimental differential cross-sections was obtained in whole angular range. Parameters for real part of potential have been also calculated microscopically with double-folding model for the d, 3He and 4He scattering, respectively, using DFPOT code. The elastic transfer mechanism has been studied by coupled reaction channel (CRC) method using FRESCO code. Spectroscopic amplitudes of 6Li ≡ t + 3He and 6Li ≡ α + d configurations have been extracted from d, 3He and 4He scattering on 6Li at wide energy range. A comparison between spectroscopic amplitudes obtained from deuteron and α elastically scattering from 6Li has been made. The extracted spectroscopic amplitudes of 6Li ≡ 4He + d(SF = SA2) from 6Li(d, 6Li)d and 6Li(α, 6Li)α are not the same as expected theoretically.

  16. 7Li Spin-Lattice Relaxation at Low Temperatures in a Superionic Conductor β-LiGa

    NASA Astrophysics Data System (ADS)

    Endou, Shigeki; Ohno, Takashi; Kishimoto, Yutaka; Nishioka, Daisuke; Michihiro, Yoshitaka; Kawasaki, Yu; Ideta, Yukiichi; Kuriyama, Kazuo; Hamanaka, Hiromi; Yahagi, Masahito

    2009-10-01

    In order to investigate the Li+ ionic diffusion and the electronic states in a mixed conductor β-LiGa with high Li+ ionic diffusibility and electron/hole conductivity, 7Li NMR linewidth and spin-lattice relaxation measurements have been performed in 44.0, 47.0, and 50.0 at. % Li β-LiGa samples at 10.03 MHz in the temperature range between 10 and 320 K. The onset temperature TMN=70 K of the motional narrowing in 50.0 at. % sample has been determined from the temperature dependence of the linewidth. The Li+ ionic diffusion is found to contribute to the spin-lattice relaxation rate 1/T1 down to ˜0.5 TMN even below TMN where the motional narrowing does not occur. The high diffusibility of Li+ ions has been proved from a microscopic point of view. At low temperatures, the relations 1/T1T=3.5× 10-4, 3.8× 10-4, and 5.1× 10-4 s-1 K-1 are observed in 44.0, 47.0, and 50.0 at. % Li samples, respectively. The density of states of conduction electrons at the Fermi level in these compounds becomes higher with increasing Li content, which is consistent with the predictions by band calculations.

  17. Transport properties of LiCoPO4 and Fe-substituted LiCoPO4

    NASA Astrophysics Data System (ADS)

    Allen, Jan L.; Thompson, Travis; Sakamoto, Jeff; Becker, Collin R.; Jow, T. Richard; Wolfenstine, Jeff

    2014-05-01

    LiCoPO4 is a promising cathode material to enable high energy, abuse tolerant Li-ion batteries. However, LiCoPO4 has relatively poor electronic conductivity which may be improved by chemical substitution. In this work, the ionic and electronic conductivities of dense, polycrystalline LiCoPO4 and Fe2+/Fe3+-substituted LiCoPO4 (Li1-xCo0.9Fe0.1PO4) are measured and compared. Both materials are predominantly ionic conductors with relatively good bulk ionic and relatively poor electronic conductivities. Li1-xCo0.9Fe0.1PO4 exhibits both higher bulk ionic and electronic conductivity. The increased bulk ionic conductivity of Li1-xCo0.9Fe0.1PO4 is believed to originate mainly from extra Li vacancies and the increased electronic conductivity is believed to originate mainly from creating more mobile hole polarons compared to LiCoPO4 as a result of Fe2+/Fe3+ substitution.

  18. Interface-enhanced Li ion conduction in a LiBH4-SiO2 solid electrolyte.

    PubMed

    Choi, Yong Seok; Lee, Young-Su; Oh, Kyu Hwan; Cho, Young Whan

    2016-08-10

    We have developed a fast solid state Li ion conductor composed of LiBH4 and SiO2 by means of interface engineering. A composite of LiBH4-SiO2 was simply synthesized by high energy ball-milling, and two types of SiO2 (MCM-41 and fumed silica) having different specific surface areas were used to evaluate the effect of the LiBH4/SiO2 interface on the ionic conductivity enhancement. The ionic conductivity of the ball-milled LiBH4-MCM-41 and LiBH4-fumed silica mixture is as high as 10(-5) S cm(-1) and 10(-4) S cm(-1) at room temperature, respectively. In particular, the conductivity of the latter is comparable to the LiBH4 melt-infiltrated into MCM-41. The conductivities of the LiBH4-fumed silica mixtures at different mixing ratios were analyzed employing a continuum percolation model, and the conductivity of the LiBH4/SiO2 interface layer is estimated to be 10(5) times higher than that of pure bulk LiBH4. The result highlights the importance of the interface and indicates that significant enhancement in ionic conductivity can be achieved via interface engineering. PMID:27468702

  19. Scenarios analysis of sediment variation after catastrophe in slopeland area: Case study of Typhoon Morakot in GaoPing river watershed, Taiwan

    NASA Astrophysics Data System (ADS)

    Zeng, Yi-Chao; Wang, Ji-Shang; Jan, Chyan-Deng; Fu, Kuei-Lin

    2014-05-01

    Typhoon Morakot formed in August 3, 2009, and struck Taiwan during August 7 to 10. The storm produced copious amounts of rainfall, peaking approached 3,000 mm, surpassing the previous record of 1,987 mm caused by Typhoon Herb in 1996 (Lin et al., 2011). A total of 127 debris flows, enormous mudslides and severe flooding were triggered by the extreme amount of rain (SWCB, 2010), which resulted in the heaviest casualties and significant property loss in southern Taiwan, especially in the slopeland area of Gaoping River watershed. Because of the large sediments caused by Typhoon Morakot would impact the public safety and stability of environment in next decade. Therefore, the sediment variation is what we concerned in the future. This study used a sediment budget model (SBM) to analyse the sediment change for different scenarios of rainfall. The SBM was developed by Water Resources Agency (WRA, 2000) which mainly composed of hydrological, sediment yielding, and transport modules. The heavy rainfall events are regarded as most active condition to cause sediment erosion and deposition, Therefore, there are three rainfall scenarios proposed by statistical analysis results of historical rainfall events as hydrological module input data which are Normal Type (returned period for 48-hour rainfall below 50-year), Extreme Type I (returned period for 48-hour rainfall less than 100-year) and Extreme Type II rainfall scenarios (returned period for 48-hour rainfall approached 200-year), respectively. The parameters of sediment yielding and transport modules were collected from the airborne LiDAR scanning, field survey and multi-period digital terrain that included before and after catastrophe data. The regression equations of rainfall with vegetation recovery rate and increased landslide ratio were also established from analyzing the relationship between typhoon-triggered landslides area and historical accumulative rainfall, and used to predict the sediment volume of slope

  20. Li-Ion Cell Development for Low Temperature Applications

    NASA Technical Reports Server (NTRS)

    Huang, C.-K.; Sakamoto, J. S.; Surampudi, S.; Wolfenstine, J.

    2000-01-01

    JPL is involved in the development of rechargeable Li-ion cells for future Mars Exploration Missions. The specific objectives are to improve the Li-ion cell cycle life performance and rate capability at low temperature (<<-20 C) in order to enhance survivability of the Mars lander and rover batteries. Poor Li-ion rate capability at low temperature has been attributed to: (1) the electrolytes becoming viscous or freezing and/or (2) reduced electrode capacity that results from decreased Li diffusivity. Our efforts focus on increasing the rate capability at low temperature for Li-ion cells. In order to improve the rate capability we evaluated the following: (1) cathode performance at low temperatures, (2) electrode active material particle size on low temperature performance and (3) Li diffusivity at room temperature and low temperatures. In this paper, we will discuss the results of our study.

  1. Mobilities of Li(+)-attached butanol isomers in He gas.

    PubMed

    Takahashi, K; Saito, K; Koizumi, T; Matoba, S; Kojima, T M; Tanuma, H; Shiromaru, H

    2013-08-28

    Mobilities of Li(+)-attached butanol isomers, (n-BuOH)Li(+), (s-BuOH)Li(+), (i-BuOH)Li(+), and (t-BuOH)Li(+), in helium gas were measured over a range of reduced electric fields (E/N = 25-96 Td) at room temperature. Arrival time measurements accurately identified small differences in the measured mobilities of the isomer ions. At low E/N (≤30 Td, corresponding to a mean collision energy ε≤0.05 eV), (n-BuOH)Li(+) showed a mobility about 1.5% greater than that of the other ions, but at high E/N (≥75 Td, ε≥0.1 eV) its mobility was about 1.1% less.

  2. Direct three-photon triple ionization of Li and double ionization of Li+

    NASA Astrophysics Data System (ADS)

    Emmanouilidou, A.; Hakobyan, V.; Lambropoulos, P.

    2013-06-01

    We explore the three-photon triple ionization from the ground state of Li with short wavelength free electron lasers. We calculate and discuss the cross sections used in the relevant rate equations and the dependence of the ion yields on laser intensity and pulse duration. In addition to the three-photon 3e ejection we also discuss two- and three-photon 2e ejection in Li+, which occurs as a by-product in the sequence of the channels active in the overall interaction. We conclude by assessing the requirements for the observability of the above-mentioned direct three-photon multielectron processes.

  3. Li overlayer formation, oxidation and sputtering characteristics of Al-Li alloys and W/Al-Li composites for fusion applications

    SciTech Connect

    Krauss, A.R. ); DeWald, A.B.; Scott, P.; Savage, H. )

    1990-01-01

    The next generation of long pulse fusion devices will impose severe requirements on the properties of plasma-facing materials. In devices such as ITER, a divertor design is being considered, using a divertor plate which would be either tungsten or a low-Z material such as graphite or beryllium. Strongly segregating lithium alloys have been proposed as a means of producing a self-sustaining low-Z overlayer which lowers plasma Z{sub eff} and resists self-sputtering. Aluminum-lithium alloys are among the better-characterized lithium-bearing alloys, and it has been demonstrated that lithium segregates strongly in aluminum. However, aluminum has a relatively low melting point, and for low lithium concentrations, the lithium diffusion rate is too slow to replenish lithium at the rate at which it is eroded by the incoming plasma. It has been suggested previously that the superionic {beta} phase Al-Li alloy (48--54 at. % Li) should have high enough diffusivity to be able to replenish surface lithium, and that incorporation of the {beta}-phase AlLi in a composite with tungsten would provide high temperature strength and melt layer stability, along with significantly better thermal conductivity than pure tungsten. Such a composite has been fabricated, as well as a variation containing titanium as a means of controlling oxidation at grain boundaries. The Li overlayer formation, erosion, and replenishment are characterized for the {beta}-phase LiAl alloy, and W-AlLi and W-Ti-AlLi composites. It is found that if there is no oxide layer to inhibit the Li segregation, Li diffusion is extremely rapid, and an oxygen-free Li overlayer is formed which is stable under continuous ion beam sputtering. 21 refs., 7 figs.

  4. Physical chemistry of molten-salt batteries. Final report, October 1, 1981-September 30, 1982. LiCl precipitation from LiCl-KCl anolyte in porous Li-Al electrodes

    SciTech Connect

    Vallet, C.E.; Heatherly, D.E.; Heatherly, L. Jr.; Braunstein, J.

    1983-05-01

    Composition gradients such as those predicted to occur during discharge of porous Li-Al negative electrodes of Li/S batteries with LiCl-KCl eutectic electrolyte were generated and measured in the LiCl-KCl anolyte of an electrolysis cell with Li-Al electrodes. LiCl precipitation during electrolysis was observed by two-dimensional scanning of electrolyte composition in the front part of quenched porous Li-Al anode sections using SEM/EDX. The distribution of sites of increased or decreased LiCl concentration, LiCl saturation and precipitation was mapped. Cathodic regions were observed near the cell walls. Preliminary results of analysis by Auger spectroscopy confirm LiCl precipitation in the porous anode.

  5. Prediction of superconductivity in Li-intercalated bilayer phosphorene

    SciTech Connect

    Huang, G. Q.; Xing, Z. W.; Xing, D. Y.

    2015-03-16

    It is shown that bilayer phosphorene can be transformed from a direct-gap semiconductor to a BCS superconductor by intercalating Li atoms. For the Li-intercalated bilayer phosphorene, we find that the electron occupation of Li-derived band is small and superconductivity is intrinsic. With increasing the intercalation of Li atoms, both increased metallicity and strong electron-phonon coupling are favorable for the enhancement of superconductivity. The obtained electron-phonon coupling λ can be larger than 1 and the superconducting temperature T{sub c} can be increased up to 16.5 K, suggesting that phosphorene may be a good candidate for a nanoscale superconductor.

  6. Electrical conduction of LiF interlayers in organic diodes

    SciTech Connect

    Bory, Benjamin F.; Janssen, René A. J.; Meskers, Stefan C. J.; Gomes, Henrique L.; Leeuw, Dago M. de

    2015-04-21

    An interlayer of LiF in between a metal and an organic semiconductor is commonly used to improve the electron injection. Here, we investigate the effect of moderate bias voltages on the electrical properties of Al/LiF/poly(spirofluorene)/Ba/Al diodes by systematically varying the thickness of the LiF layer (2-50 nm). Application of forward bias V below the bandgap of LiF (V < E{sub g} ∼ 14 V) results in reversible formation of an electrical double layer at the LiF/poly(spirofluorene) hetero-junction. Electrons are trapped on the poly(spirofluorene) side of the junction, while positively charged defects accumulate in the LiF with number densities as high as 10{sup 25}/m{sup 3}. Optoelectronic measurements confirm the built-up of aggregated, ionized F centres in the LiF as the positive trapped charges. The charged defects result in efficient transport of electrons from the polymer across the LiF, with current densities that are practically independent of the thickness of the LiF layer.

  7. Superconductivity in Li-doped {alpha}-rhombohedral boron

    SciTech Connect

    Nagatochi, T.; Sumiyoshi, A.; Kimura, K.; Hyodo, H.; Soga, K.; Sato, Y.; Terauchi, M.; Esaka, F.

    2011-05-01

    Metal transition and superconductivity were observed in Li-doped {alpha}-rhombohedral boron ({alpha}-B{sub 12}). The authors have established a purification method and obtained a large amount of high-purity {alpha}-B{sub 12} powder. Li doping into purified {alpha}-B{sub 12} was attempted by vapor diffusion processing (VDP) in a Mo or Ta tube. Li-doped {alpha}-B{sub 12} contained metallic glittering particles. Meissner effects were observed in such a compound with the nominal composition Li{sub x}B{sub 12} (x = 1.0, 1.4, 1.5, 1.7, or 2.5) (T{sub c} = 3.2-7 K). As for Li{sub 2.5}B{sub 12}, the temperature dependence of its electrical conductivity indicates a metallic character and its electrical resistivity drop is detected near the Meissner temperature. The existence of Li and Fermi edges in Li-doped {alpha}-B{sub 12} crystals was verified by transmission electron microscopy-electron energy loss spectroscopy (TEM-EELS). Lattice expansion, which is a well-known indicator of metal doping into a crystal, was also observed. Thus, Li doping into {alpha}-B{sub 12} was successfully achieved. Our work also suggests that it is possible to dope a larger amount of Li into {alpha}-B{sub 12} and to increase its T{sub c}.

  8. Study of lithium borosilicotitanate glasses with LiCl

    SciTech Connect

    Deshpande, A. V.; Paighan, N. S.

    2012-06-05

    The effect of LiCl addition on the properties of Li{sub 2}O: B{sub 2}O{sub 3}: SiO{sub 2}: TiO{sub 2} glasses has been studied. It has been observed that the ionic conductivity increases by about half an order with LiCl addition. The decrease in glass transition temperature T{sub g} and increase in the molar volume with LiCl addition have good correlation with conductivity results. The observed increase in density of glasses has been explained on the basis of heavier Cl{sup -} ion which is accommodated in the interstices in the glass network.

  9. Probing anode degradation in automotive Li-ion batteries

    NASA Astrophysics Data System (ADS)

    Kwon, Ou Jung

    The lithium-ion battery is drawing attention as a power source for future clean and fuel-efficient vehicles. Although the Li-ion battery presently shows best performance for energy density and power density compared to other rechargeable batteries, some degradation problems still remain as key challenges for long-term durability in automotive applications. Among those problems, Li deposition is well known for causing permanent capacity loss. Fundamental mechanisms of Li deposition in the carbon anode are, however, not fully understood, especially at subzero temperature and/or under high rate charge. This dissertation introduces comprehensive study of Li deposition using automotive 18650 Li-ion cells. The mechanism and relevant diagnostic methods as well as preventive charging protocol are discussed. In part one, a new diagnostic tool is introduced utilizing 3-electrode cell system, which measures thermodynamic and kinetic parameters of cathode and anode, respectively, as a function of temperature and SOC (state of charge): open circuit potential (OCP); Li diffusion coefficient in active particles; and internal resistance. These data are employed to understand electrochemical reaction and its thermal interaction under charging conditions that result in Li deposition. Part two provides a threshold parameter for the onset of Li deposition, which is not commonly used anode potential but charge capacity, or more specifically the amount of Li+ ions participating in intercalation reaction without Li deposition at given charging circumstances. This is called the critical charge capacity in this thesis, beyond which capacity loss at normal operating condition is observed, which becomes more serious as temperature is lowered and/or charge C-rate increases. Based on these experimental results, the mechanism of Li deposition is proposed as the concept of anode particle surface saturation, meaning that once the anode particle surface is saturated with Li in any charging

  10. Nucleosynthesis of Li-7 in flares on UV Ceti stars

    NASA Technical Reports Server (NTRS)

    Karpen, J. T.; Worden, S. P.

    1979-01-01

    The possible production of Li-7 by nuclear reactions in UV Ceti flares has been considered. By utilizing solar observations and theory, a relationship is derived between flare energy and production rates for Li-7; approximately 100 erg of total flare energy is found to denote the formation of a Li-7 atom. Based on this value and best estimates of UV Ceti-type flare rates, it is concluded that less than 10% of the Li-7 observed in the intestellar medium may have been produced by this mechanism. Formation of significant amounts of interstellar deuterium by this method is ruled out.

  11. Li partitioning in the benthic foraminifera Amphistegina lessonii

    NASA Astrophysics Data System (ADS)

    Langer, Gerald; Sadekov, Aleksey; Thoms, Silke; Mewes, Antje; Nehrke, Gernot; Greaves, Mervyn; Misra, Sambuddha; Bijma, Jelle; Elderfield, Henry

    2015-12-01

    The shallow water benthic foraminifer Amphistegina lessonii was grown in seawater of variable Li and Ca concentration and shell Li/Ca was determined by means of LA-ICPMS. Shell Li/Ca is positively correlated to seawater Li/Ca only when the Li concentration of seawater is changed. If the seawater Ca concentration is changed, shell Li/Ca remains constant. This indicates that Li does not compete with Ca for incorporation in the shell of A. lessonii. A recently proposed calcification model can be applied to divalent cations (e.g., Mg and Sr), which compete for binding sites of ion transporters and positions in the calcite lattice. By contrast, the transport pathway of monovalent cations such as Li is probably diffusion based (e.g., ion-channels), and monovalent cations do not compete with Ca for a position in the calcite lattice. Here we present a new model for Li partitioning into foraminiferal calcite which predicts our experimental results and should also be applicable to other alkali metals.

  12. Eutectic melting of LiBH4-KBH4.

    PubMed

    Ley, Morten B; Roedern, Elsa; Jensen, Torben R

    2014-11-28

    Eutectic melting in mixtures of alkali and alkali earth metal borohydrides can pave the way for new applications as fast ionic conductors, and facilitate hydrogen release by low temperature chemical reactions and convenient nanoconfinement. Here, we determine the eutectic composition for the lithium potassium borohydride system, 0.725LiBH4-0.275KBH4, with the lowest melting point, Tmelt ∼105 °C, of all known alkali and alkali earth metal borohydride mixtures. Mechanochemistry and manual mixing of LiBH4-KBH4 mixtures facilitate the formation of LiK(BH4)2. However, the melting or heat treatments used in this work do not produce LiK(BH4)2. The bimetallic borohydride dissociates into the monometallic borohydrides at ∼95 °C and partial melting occurs at ∼105 °C. Analysis of the unit cell volumes of LiBH4, KBH4 and LiK(BH4)2 in the temperature range 25 to 90 °C indicates that the formation of the bimetallic borohydride is facilitated by a more dense packing as compared to the reactants. Thus, LiK(BH4)2 is considered metastable and the formation is pressure induced. A phase diagram for the LiBH4-KBH4 system is established, which illustrates the low eutectic melting point and the stability range for the bimetallic borohydride, LiK(BH4)2.

  13. Properties of (Ga,Mn)As codoped with Li

    SciTech Connect

    Miyakozawa, Shohei; Chen, Lin; Matsukura, Fumihiro; Ohno, Hideo

    2014-06-02

    We grow Li codoped (Ga,Mn)As layers with nominal Mn composition up to 0.15 by molecular beam epitaxy. The layers before and after annealing are characterized by x-ray diffraction, transport, magnetization, and ferromagnetic resonance measurements. The codoping with Li reduces the lattice constant and electrical resistivity of (Ga,Mn)As after annealing. We find that (Ga,Mn)As:Li takes similar Curie temperature to that of (Ga,Mn)As, but with pronounced magnetic moments and in-plane magnetic anisotropy, indicating that the Li codoping has nontrivial effects on the magnetic properties of (Ga,Mn)As.

  14. Properties of (Ga,Mn)As codoped with Li

    NASA Astrophysics Data System (ADS)

    Miyakozawa, Shohei; Chen, Lin; Matsukura, Fumihiro; Ohno, Hideo

    2014-06-01

    We grow Li codoped (Ga,Mn)As layers with nominal Mn composition up to 0.15 by molecular beam epitaxy. The layers before and after annealing are characterized by x-ray diffraction, transport, magnetization, and ferromagnetic resonance measurements. The codoping with Li reduces the lattice constant and electrical resistivity of (Ga,Mn)As after annealing. We find that (Ga,Mn)As:Li takes similar Curie temperature to that of (Ga,Mn)As, but with pronounced magnetic moments and in-plane magnetic anisotropy, indicating that the Li codoping has nontrivial effects on the magnetic properties of (Ga,Mn)As.

  15. The Heusler phases LiRh{sub 2}Si and LiRh{sub 2}Ge: Synthesis, structure and properties

    SciTech Connect

    Bailey, Mark S.; Li Qingan; Lobkovsky, Emil B.; Hinks, D.G.; Mitchell, J.F.

    2008-01-15

    The isostructural Heusler phases LiRh{sub 2}Si and LiRh{sub 2}Ge have been synthesized from the elements and an excess of lithium at 1000 deg. C. Both materials adopt the CuMn{sub 2}Al crystal structure, space group Fm-3m (No. 225) with the room temperature lattice parameter a=5.747(1) A [Vol=189.866(1) A{sup 3}] and a=5.847(1) A [Vol=199.88(6) A{sup 3}] for LiRh{sub 2}Si and LiRh{sub 2}Ge, respectively. X-ray analyses suggest mixed site occupancy of the form Li{sub 1-x}Rh{sub 2}Si{sub 1+x} (x<0.4), but not for LiRh{sub 2}Ge. Both materials are diamagnetic, {chi}{sub mol}(LiRh{sub 2}Si)=-6x10{sup -5} cm{sup 3}(mole){sup -1} and {chi}{sub mol}(LiRh{sub 2}Ge)=-10x10{sup -5} cm{sup 3}(mole){sup -1} and metallic with room temperature resistivities of approximately 19 and 32 {mu}{omega} cm, respectively. These properties are consistent with the calculated electronic structure. - Graphical abstract: Rh, Li and either Si or Ge form an ordered coloring pattern of the bcc lattice in the Heusler phases LiRh{sub 2}Si and LiRh{sub 2}Ge. Crystals grown from a reactive Li flux are diamagnetic metals that exhibit a T-linear resistivity above 60 K.

  16. First-cycle irreversibility of layered Li-Ni-Co-Mn oxide cathode in Li-ion batteries.

    SciTech Connect

    Kang, S.-H.; Abraham, D. P.; Yoon, W.-S.; Nam, K.-W.; Yang, X.-Q.; Chemical Sciences and Engineering Division; BNL

    2008-07-01

    The first-cycle irreversibility of Li{sub 1.048}(Ni{sub 1/3}Co{sub 1/3}Mn{sub 1/3}){sub 0.952}O{sub 2} (LiMO{sub 2}) cathode material in lithium and lithium-ion cells has been studied using galvanostatic cycling and in situ synchrotron X-ray diffraction. The so-called 'lost capacity' of a Li/LiMO{sub 2} cell observed during initial cycle in conventional voltage ranges (e.g., 3.0-4.3 V) could be completely recovered by discharging the cell to low voltages (<2 V). During the deep discharge, the lithium cell exhibited an additional voltage plateau, which is believed to result from the formation of Li{sub 2}MO{sub 2}-like phase on the oxide particle surface due to very sluggish lithium diffusion in Li{sub 1-{Delta}}MO{sub 2} with {Delta} {yields} 0 (i.e., near the end of discharge). Voltage relaxation curve and in situ X-ray diffraction patterns, measured during relaxation of the lithium cell after deep discharge to obtain 100% cycle efficiency, suggested that the oxide cathode returned to its original state after the following two-step relaxation processes: relatively quick disappearance of the Li{sub 2}MO{sub 2}-like phase on the particle surface, followed by slow lithium diffusion in the layered structure. Experiments conducted in Li{sub 4}Ti{sub 5}O{sub 12}/LiMO{sub 2} lithium-ion cells confirmed that the physical loss of lithium (via surface film formation or parasitic electrochemical reactions, etc.) from LiMO{sub 2} was negligible up to an oxide voltage of 4.3 V vs. Li{sup +}/Li.

  17. First principle study of LiXS2 (X = Ga, In) as cathode materials for Li ion batteries

    NASA Astrophysics Data System (ADS)

    Feng-Ya, Rao; Fang-Hua, Ning; Li-Wei, Jiang; Xiang-Ming, Zeng; Mu-Sheng, Wu; Bo, Xu; Chu-Ying, Ouyang

    2016-02-01

    From first principle calculations, we demonstrate that LiXS2 (X = Ga, In) compounds have potential applications as cathode materials for Li ion batteries. It is shown that Li can be extracted from the LiXS2 lattice with relatively small volume change and the XS4 tetrahedron structure framework remains stable upon delithiation. The theoretical capacity and average intercalation potential of the LiGaS2 (LiInS2) cathode are 190.4 (144.2) mAh/g and 3.50 V (3.53 V). The electronic structures of the LiXS2 are insulating with band gaps of 2.88 eV and 1.99 eV for X = Ga and In, respectively. However, Li vacancies, which are formed through delithiation, change the electronic structure substantially from insulating to metallic structure, indicating that the electrical conductivities of the LiXS2 compounds should be good during cycling. Li ion migration energy barriers are also calculated, and the results show that Li ion diffusions in the LiXS2 compounds can be as good as those in the currently widely used electrode materials. Project supported by the National High Technology and Development Key Program, China (Grant No. 2015AA034201), the National Natural Science Foundation of China (Grant Nos. 11234013 and 11264014), the Natural Science Foundation of Jiangxi Province, China (Grant Nos. 20133ACB21010, 20142BAB212002, and 20132BAB212005), and the Foundation of Jiangxi Provincial Education Committee, China (Grant Nos. GJJ14254 and KJLD14024).

  18. Measuring Li+ inventory losses in LiCoO2/graphite cells using Raman microscopy

    DOE PAGES

    Snyder, Chelsea Marie; Apblett, Christopher A.; Grillet, Anne; Thomas Edwin Beechem; Duquette, David

    2016-03-25

    Here, the contribution from loss of Li+ inventory to capacity fade is described for slow rates (C/10) and long-term cycling (up to 80 cycles). It was found through electrochemical testing and ex-situ Raman analysis that at these slow rates, the entirety of capacity loss up to 80 cycles can be explained by loss of Li+ inventory in the cell. The Raman spectrum of LiCoO2 is sensitive to the state of lithiation and can therefore be leveraged to quantify the state of lithiation for individual particles. With these Raman derived estimates, the lithiation state of the cathode in the discharged statemore » is compared to electrochemical data as a function of cycle number. High correlation is found between Raman quantifications of cycleable lithium and the capacity fade. Additionally, the linear relationship between discharge capacity and cell overpotential suggests that the loss of capacity stems from an impedance rise of the electrodes, which based on Li inventory losses, is caused by SEI formation and repair.« less

  19. Predicted Structure, Thermo-Mechanical Properties and Li Ion Transport in LiAlF4 Glass

    SciTech Connect

    Stechert, T. R.; Rushton, M. J. D.; Grimes, R. W.; Dillon, A. C.

    2012-08-15

    Materials with the LiAlF{sub 4} composition are of interest as protective electrode coatings in Li ion battery applications due to their high cationic conductivity. Here classical molecular dynamics calculations are used to produce amorphous model structures by simulating a quench from the molten state. These are analysed in terms of their individual pair correlation functions and atomic coordination environments. This indicates that amorphous LiAlF{sub 4} is formed of a network of corner sharing AlF{sub 6} octahedra. Li ions are distributed within this network, primarily associated with non-bridging fluorine atoms. The nature of the octahedral network is further analysed through intra- and interpolyhedral bond angle distributions and the relative populations of bridging and non-bridging fluorine ions are calculated. Network topology is considered through the use of ring statistics, which indicates that, although topologically well connected, LiAlF{sub 4} contains an appreciable number of corner-linked branch-like AlF{sub 6} chains. Thermal expansion values are determined above and below the predicted glass transition temperature of 1340 K. Finally, movement of Li ions within the network is examined with predictions of the mean squared displacements, diffusion coefficients and Li ion activation energy. Different regimes for lithium ion movement are identified, with both diffusive and sessile Li ions observed. For migrating ions, a typical trajectory is illustrated and discussed in terms of a hopping mechanism for Li transport.

  20. Reversible superconductor-insulator transition in LiTi2O4 induced by Li-ion electrochemical reaction

    PubMed Central

    Yoshimatsu, K.; Niwa, M.; Mashiko, H.; Oshima, T.; Ohtomo, A.

    2015-01-01

    Transition metal oxides display various electronic and magnetic phases such as high-temperature superconductivity. Controlling such exotic properties by applying an external field is one of the biggest continuous challenges in condensed matter physics. Here, we demonstrate clear superconductor-insulator transition of LiTi2O4 films induced by Li-ion electrochemical reaction. A compact electrochemical cell of pseudo-Li-ion battery structure is formed with a superconducting LiTi2O4 film as an anode. Li content in the film is controlled by applying a constant redox voltage. An insulating state is achieved by Li-ion intercalation to the superconducting film by applying reduction potential. In contrast, the superconducting state is reproduced by applying oxidation potential to the Li-ion intercalated film. Moreover, superconducting transition temperature is also recovered after a number of cycles of Li-ion electrochemical reactions. This complete reversible transition originates in difference in potentials required for deintercalation of initially contained and electrochemically intercalated Li+ ions. PMID:26541508

  1. Li3-O-Li3 molecule: a metal-nonmetal-metal sandwichlike compound with a distending electron cloud.

    PubMed

    Chen, Wei; Li, Zhi-Ru; Wu, Di; Li, Ying; Sun, Chia-Chung

    2005-10-22

    The D3d and D2d isomers of the Li3-O-Li3 molecule are metal-nonmetal-metal sandwichlike structures that contain two Li3 superalkali atoms. Their geometries and the real frequencies are obtained at the CCSD(T)/aug-cc-pVDZ level. They are different from the traditional types of the nonmetal-metal-nonmetal sandwich compounds. The natural bond orbital calculation and the topological property nabla2rho(r) calculation indicate that they are typical ionic compounds. In two isomers, the O2- anion is sandwiched in between two Li3+ cation rings. However, the different orientations of two Li3+ planes give the D3d isomer its own special characteristics. Under the action of the O2- anion in the center, the valence electrons of the D3d isomer are pushed out from two Li3+ triangle rings. This special interaction causes three phenomena. First, the valence electron clouds are distended. Second, the vertical ionization energy of the D3d isomer is considerably low, 4.39 eV, so that it may also be viewed as a superalkali atom. Third, we find that the D3d isomer owns the out-of-plane aromaticity and the largest negative nucleus-independent chemical shift value (-10.8 ppm) exists at 2.5 A above the center of the Li3+ ring, not at the center of the Li3+ ring like the isolated aromatic Li3+ cation.

  2. Li2CuVO4: A high capacity positive electrode material for Li-ion batteries

    NASA Astrophysics Data System (ADS)

    Ben Yahia, Hamdi; Shikano, Masahiro; Yamaguchi, Yoichi

    2016-07-01

    The new compound Li2CuVO4 was synthesized by a solid state reaction route, and its crystal structure was determined from single crystal X-ray diffraction data. Li2CuVO4 was characterized by galvanometric cycling, cycle voltammetry, and electrochemical impedance spectroscopy. The structure of Li2CuVO4 is isotypic to Pmn21-Li3VO4. It can be described as a disordered wurtzite structure with rows of Li1/Cu1 atoms alternating with rows of (Li2/Cu2)-V-(Li2/Cu2) atoms along [100]. All cations are tetrahedrally coordinated. The lithium and copper atoms are statistically disordered over two crystallographic sites. The electrochemical cycling between 2.0 and 4.7 V indicates that almost two lithium atoms could be extracted and re-intercalated. This delivers a maximum discharge capacity of 257 mA h g-1 at a C/50 rate (theoretical capacity = 139 mA h g-1 for one lithium). Li2CuVO4 shows also high rate capability with a capacity of 175 mA h g-1 at 1C rate. This demonstrates that Cu-based compounds can be very interesting as electrodes for Li-ion batteries if Cu-dissolution is avoided.

  3. An atomic beam of 6Li — 7Li for high resolution spectroscopy from matrix isolation sublimation

    NASA Astrophysics Data System (ADS)

    Oliveira, A. N.; Sacramento, R. L.; Silva, B. A.; Uhlmann, F. O.; Wolff, W.; Cesar, C. L.

    2016-07-01

    We propose the Matrix Isolation Sublimation (MlSu) technique for generating cold lithium atoms for the measurement of the 6Li - 7Li isotope shift in D1 and D2 transitions. The technique is capable of generating cold 6Li and 7Li beams at 4 K with forward velocity of 125 m/s. Using this beam we offer a distinguished source of lithium atoms for transitions measurements, adding a new possibility to make high resolution spectroscopy towards improving the experimental checks of the theory.

  4. Characterization of low-melting electrolytes for potential geothermal borehole power supplies: The LiBr-KBr-LiF eutectic

    SciTech Connect

    Guidotti, R.A.; Reinhardt, F.W.

    1998-05-01

    The suitability of modified thermal-battery technology for use as a potential power source for geothermal borehole applications is under investigation. As a first step, the discharge processes that take place in LiSi/LiBr-KBr-LiF/FeS{sub 2} thermal cells were studied at temperatures of 350 C and 400 C using pelletized cells with immobilized electrolyte. Incorporation of a reference electrode allowed the relative contribution of each electrode to the overall cell polarization to be determined. The results of single-cell tests are presented, along with preliminary data for cells based on a lower-melting CsBr-LiBr-KBr eutectic salt.

  5. Reversible superconductor-insulator transition in LiTi2O4 induced by Li-ion electrochemical reaction.

    PubMed

    Yoshimatsu, K; Niwa, M; Mashiko, H; Oshima, T; Ohtomo, A

    2015-01-01

    Transition metal oxides display various electronic and magnetic phases such as high-temperature superconductivity. Controlling such exotic properties by applying an external field is one of the biggest continuous challenges in condensed matter physics. Here, we demonstrate clear superconductor-insulator transition of LiTi2O4 films induced by Li-ion electrochemical reaction. A compact electrochemical cell of pseudo-Li-ion battery structure is formed with a superconducting LiTi2O4 film as an anode. Li content in the film is controlled by applying a constant redox voltage. An insulating state is achieved by Li-ion intercalation to the superconducting film by applying reduction potential. In contrast, the superconducting state is reproduced by applying oxidation potential to the Li-ion intercalated film. Moreover, superconducting transition temperature is also recovered after a number of cycles of Li-ion electrochemical reactions. This complete reversible transition originates in difference in potentials required for deintercalation of initially contained and electrochemically intercalated Li(+) ions.

  6. Defect Structure of Li-Doped BPO 4: A Nanostructured Ceramic Electrolyte for Li-Ion Batteries

    NASA Astrophysics Data System (ADS)

    Jak, M. J. G.; Kelder, E. M.; Schoonman, J.

    1999-01-01

    In this paper the defect chemistry of Li-doped BPO4(BPO4-xLi2O, 0≤x≤0.1) is studied. This nanostructured ceramic electrolyte is used in all-solid-state Li-ion batteries. By changing the Li-doping level the influence on the crystal structure is studied and related to t he properties of the material. X-ray diffraction, Fourier-transformed infra-red spectroscopy (FT-IR),31P,11B, and7Li magic-angle-spinning solid state nuclear magnetic resonance, neutron diffraction, and inductively coupled plasma optical-emission spectroscopy measurements are used in order to study the structure. The electrical properties are studied with AC-impedance spectroscopy (AC-IS). The experimental data show that the defect structure of Li-doped BPO4can be described with two defect models, Li″B+2Li·iand V‴B+3Li·i, suggesting that the ionic conductivity takes place via interstitial Li ions.

  7. Primordial Li abundance and massive particles

    SciTech Connect

    Latin-Capital-Letter-Eth apo, H.

    2012-10-20

    The problem of the observed lithium abundance coming from the Big Bang Nucleosynthesis is as of yet unsolved. One of the proposed solutions is including relic massive particles into the Big Bang Nucleosynthesis. We investigated the effects of such particles on {sup 4}HeX{sup -}+{sup 2}H{yields}{sup 6}Li+X{sup -}, where the X{sup -} is the negatively charged massive particle. We demonstrate the dominance of long-range part of the potential on the cross-section.

  8. Searching for “LiCrIIPO4”

    NASA Astrophysics Data System (ADS)

    Mosymow, E.; Glaum, R.; Kremer, R. K.

    2014-10-01

    The two new phosphates LiCrII4(PO4)3 and Li5CrII2CrIII(PO4)4 are discovered as equilibrium phases (ϑ=800 °C) in the quarternary system Li/Cr/P/O. Their crystal structures have been determined from single-crystal X-ray diffraction data {LiCrII4(PO4)3: violet-blue, Pnma (no. 62), Z=4, a=6.175(1) Å, b=14.316(3) Å, c=10.277(2) Å, 100 parameters, R1=0.028, wR2=0.08, 2060 unique reflections with Fo>4σ(Fo); Li5CrII2CrIII(PO4)4: greyish-green, P1bar (no. 2), Z=1, a=4.9379(7) Å, b=7.917(2) Å, c=8.426(2) Å, α=109.98(2)°, β=90.71(1)°, γ=104.91(1)°, 131 parameters, R1=0.022, wR2=0.067, 1594 unique reflections with Fo>4σ(Fo)}. Li5CrII2CrIII(PO4)4 adopts an hitherto unknown structure type. The crystal structure of LiCrII4(PO4)3 is isotypic to that of NaCdII4(PO4)3 and related to that of the mineral silicocarnotite Ca5(PO4)2(SiO4). Significant disorder between Li+ and Cr2+ is observed for both crystal structures. The oxidation states assigned to chromium in these two phosphates are in agreement with UV/vis/NIR absorption spectra and magnetic susceptibility data recorded for both compounds. Instead of “LiCrIIPO4” mixtures of LiCrII4(PO4)3, Li5CrII2CrIII(PO4)4, Cr2O3, and CrP are observed at equilibrium. Instead of “Li2CrIIP2O7” four-phase mixtures consisting of Li9CrIII3(P2O7)3(PO4)2, Li3CrIII2(PO4)3, LiCrP2O7, and CrP were obtained.

  9. Selected test results from the LiFeBatt iron phosphate Li-ion battery.

    SciTech Connect

    Ingersoll, David T.; Hund, Thomas D.

    2008-09-01

    In this paper the performance of the LiFeBatt Li-ion cell was measured using a number of tests including capacity measurements, capacity as a function of temperature, ohmic resistance, spectral impedance, high power partial state of charge (PSOC) pulsed cycling, pulse power measurements, and an over-charge/voltage abuse test. The goal of this work was to evaluate the performance of the iron phosphate Li-ion battery technology for utility applications requiring frequent charges and discharges, such as voltage support, frequency regulation, and wind farm energy smoothing. Test results have indicated that the LiFeBatt battery technology can function up to a 10C{sub 1} discharge rate with minimal energy loss compared to the 1 h discharge rate (1C). The utility PSOC cycle test at up to the 4C{sub 1} pulse rate completed 8,394 PSOC pulsed cycles with a gradual loss in capacity of 10 to 15% depending on how the capacity loss is calculated. The majority of the capacity loss occurred during the initial 2,000 cycles, so it is projected that the LiFeBatt should PSOC cycle well beyond 8,394 cycles with less than 20% capacity loss. The DC ohmic resistance and AC spectral impedance measurements also indicate that there were only very small changes after cycling. Finally, at a 1C charge rate, the over charge/voltage abuse test resulted in the cell venting electrolyte at 110 C after 30 minutes and then open-circuiting at 120 C with no sparks, fire, or voltage across the cell.

  10. Fast neutron measurements with 7Li and 6Li enriched CLYC scintillators

    NASA Astrophysics Data System (ADS)

    Giaz, A.; Blasi, N.; Boiano, C.; Brambilla, S.; Camera, F.; Cattadori, C.; Ceruti, S.; Gramegna, F.; Marchi, T.; Mattei, I.; Mentana, A.; Million, B.; Pellegri, L.; Rebai, M.; Riboldi, S.; Salamida, F.; Tardocchi, M.

    2016-07-01

    The recently developed Cs2LiYCl6:Ce (CLYC) crystals are interesting scintillation detectors not only for their gamma energy resolution (<5% at 662 keV) but also for their capability to identify and measure the energy of both gamma rays and fast/thermal neutrons. The thermal neutrons were detected by the 6Li(n,α)t reaction while for the fast neutrons the 35Cl(n,p)35S and 35Cl(n,α)32P neutron-capture reactions were exploited. The energy of the outgoing proton or α particle scales linearly with the incident neutron energy. The kinetic energy of the fast neutrons can be measured using both the Time Of Flight (TOF) technique and using the CLYC energy signal. In this work, the response to monochromatic fast neutrons (1.9-3.8 MeV) of two CLYC 1″×1″ crystals was measured using both the TOF and the energy signal. The observables were combined to identify fast neutrons, to subtract the thermal neutron background and to identify different fast neutron-capture reactions on 35Cl, in other words to understand if the detected particle is an α or a proton. We performed a dedicated measurement at the CN accelerator facility of the INFN Legnaro National Laboratories (Italy), where the fast neutrons were produced by impinging a proton beam (4.5, 5.0 and 5.5 MeV) on a 7LiF target. We tested a CLYC detector 6Li-enriched at about 95%, which is ideal for thermal neutron measurements, in parallel with another CLYC detector 7Li-enriched at more than 99%, which is suitable for fast neutron measurements.

  11. Li-doping process for Li xSiO-negative active material synthesized by chemical method for lithium-ion cells

    NASA Astrophysics Data System (ADS)

    Tabuchi, Toru; Yasuda, Hideo; Yamachi, Masanori

    Li-doped SiO-negative active material (Li xSiO) has been successfully synthesized by chemical method with immersion in Li-organic complex solution obtained by dissolving naphthalene and metallic Li into butyl methyl ether (BME) solvent. The rest potential of resultant Li xSiO electrode drastically shifts to less noble value at the beginning of immersion and tends to be stable at around 0.21 V versus Li/Li +, which means the progress of Li-doping into SiO-negative active material. Furthermore, this chemical Li-doping process proceeds by the catalysis function of naphthalene and leads to reduce the irreversible capacity of SiO-negative electrode caused by consumption of Li sources provided from positive electrode.

  12. Thermal characterization of Li/sulfur, Li/ S-LiFePO4 and Li/S-LiV3O8 cells using Isothermal Micro-Calorimetry and Accelerating Rate Calorimetry

    NASA Astrophysics Data System (ADS)

    Seo, Jeongwook; Sankarasubramanian, Shrihari; Kim, Chi-Su; Hovington, Pierre; Prakash, Jai; Zaghib, Karim

    2015-09-01

    The thermal behavior of three cathode materials for the lithium/sulfur (Li/S) cell, namely - sulfur, sulfur-LiFePO4 (S-LFP) composite and sulfur-LiV3O8 (S-LVO) composite was studied using Isothermal Micro-Calorimetry (IMC) at various discharge rates. A continuum model was used to calculate the reversible entropic heat and irreversible resistive heat generated over the discharge process and the model data was compared to the experimental data to elucidate contributions of reversible and irreversible heats to the overall heat generated during discharge. The reaction enthalpy (ΔHRx) was measured using IMC for each elementary reaction step and in combination with the calculated reversible entropic heat and irreversible resistive heat was fitted against the experimental total heat measurement. The model showed an excellent fit against the experimental data. Further, Accelerating Rate Calorimetry (ARC) was used to study the thermal safety of these three cells. The cell with the S-LVO composite cathode was found to have the highest onset temperature for thermal runaway and also the lowest maximum self-heat rate. Results of this study suggest that S-LVO composite is a promising electrode for Li/S cells.

  13. Electrocatalysis in Li-S batteries

    NASA Astrophysics Data System (ADS)

    Al salem, Hesham I. A.

    Stabilizing polysulfide-shuttle process while ensuring high sulfur loading holds the key to realize high theoretical energy density (2500 Wh/kg) of lithium-sulfur (Li-S) batteries. Though several carbon based porous materials have been used as host structures for sulfur and its intermediate polysulfides, the week adsorption of polysulfides on carbon surface and its poor reaction kinetics limits them from practical application. Here, we preset a novel electcatalysis approach to stabilize polysulfide shuttle process and also enhance its red-ox kinetics. As a proof of concept, we have studied in-detail using conventional electrocatalyst (Pt/graphene composite), further the same extended to cost-effective electrocatalysts such as WS2 nanosheets and Metal carbides for viable practical applications. Nature of electrocatalyst, concentration of polysulfides and temperature of the cell on electrochemical properties will be discussed. We reveal substantial improvement in electrochemical properties such as specific capacity, rate capability, and coulombic efficiency and corroborate our findings with systematic experimental studies. Interaction between electrocatalyst and polysulfides has been evaluated by conducting X-ray photoelectron spectroscopy and electron microscopy studies at various electrochemical conditions. As a conclusion, introducing a catalyst in the Li-S system will open a new avenue for improving electrochemical performance.

  14. Computational modeling of Li-ion batteries

    NASA Astrophysics Data System (ADS)

    Grazioli, D.; Magri, M.; Salvadori, A.

    2016-08-01

    This review focuses on energy storage materials modeling, with particular emphasis on Li-ion batteries. Theoretical and computational analyses not only provide a better understanding of the intimate behavior of actual batteries under operational and extreme conditions, but they may tailor new materials and shape new architectures in a complementary way to experimental approaches. Modeling can therefore play a very valuable role in the design and lifetime prediction of energy storage materials and devices. Batteries are inherently multi-scale, in space and time. The macro-structural characteristic lengths (the thickness of a single cell, for instance) are order of magnitudes larger than the particles that form the microstructure of the porous electrodes, which in turn are scale-separated from interface layers at which atomistic intercalations occur. Multi-physics modeling concepts, methodologies, and simulations at different scales, as well as scale transition strategies proposed in the recent literature are here revised. Finally, computational challenges toward the next generation of Li-ion batteries are discussed.

  15. First-principles simulations of the porous layered calcogenides Li2 +xSnO3 and Li2 +xSnS3

    NASA Astrophysics Data System (ADS)

    Howard, Jason; Holzwarth, N. A. W.

    2016-08-01

    First-principles simulations of the porous layered calcogenide materials Li2SnO3 and Li2SnS3 are used to study their structures, Li ion mobilities, and their interactions with excess Li. The pristine materials are characterized by a regular pattern of voids within the calcogenide layers which are occupied by intralayer Li ions. The energetically most favorable Li ion migration processes for both materials result in a net motion perpendicular to the layers and involve intralayer Li ions and nearby interstitial sites. The ideal lattice has eight symmetry related stable interstitial sites within the conventional unit cell which, in addition to participating in the Li ion migration processes, are also important for accommodating excess Li during lithiation processes. Consistent with experimental findings, the simulations find that the addition of Li atoms to Li2SnO3 results in a disruption of the calcogen lattice with the breaking of Sn-O bonds. The estimated voltage versus bcc Li for this system is in qualitative agreement with experiment provided that Sn/Li disorder is taken into account. By contrast, the simulations predict that the addition of Li atoms to Li2SnS3 results in a stable metallic material up to a stoichiometry of Li3SnS3 . This prediction has not yet been studied experimentally. Simulations of surfaces of these materials find that it is energetically favorable to add a small amount of excess surface Li. However, interfaces of these materials with Li metal are found to be reactive. Some of the findings may be relevant to other materials having the same crystal structure such as Li2MnO3 and Li2TiO3 .

  16. The influence of temperature and salinity on the Li/Ca and d7Li of inorganic and biogenic carbonates

    NASA Astrophysics Data System (ADS)

    Marriott, C.; Staubwasser, M.; Crompton, R.; Henderson, G.

    2003-04-01

    Lithium is the sixth most abundant metal in the ocean. It is conservative with a residence time of around 1Ma and has two stable isotopes ^7Li and ^6Li that are not actively involved in biological processes. Isotopic fractionation is observed during incorporation into calcium carbonate but no previous work has systematically examined the controls on this fractionation. We have investigated Li incorporation and isotopic fraction in both inorganically precipitated calcite and coralline aragonite (1). In both cases there is an inverse correlation of Li concentration with temperature and no significant variation in isotopic fractionation. A decrease in D Li/Ca from 0.0092 to 0.0030 is seen over a temperature range of 5--30^oC, whilst an offset of approximately -8.5 ppm is seen in the δ^7Li ratio relative to the growth solution. The temperature dependence of Li/Ca has an increased sensitivity at low temperatures and might therefore be useful in examining changes in bottom water temperature. We are now investigating Li/Ca and δ^7Li of foraminifera. Previous work (2) has suggested little variability in Li/Ca with temperature, although this was for samples from warmer water where Li/Ca is not sensitive. In this study, Uvigerina are examined in a series of core top samples from the Arabian Sea with a depth range of 95--1800m and corresponding temperature range of 5--20^oC. A series of inorganic calcite samples have also been precipitated in order to examine the effect of salinity on Li/Ca, δ^7Li and δ44Ca over a salinity range of 10--50 psu. The distribution coefficient of Li shows a positive correlation with salinity over this range. δ^7Li and δ44Ca measurements for these samples are presently being analysed. (1) Marriott et al., 2002, GCA, 66, A485 (2) Delaney et al., 1985, GCA, 49, 1327

  17. Continuous flame aerosol synthesis of carbon-coated nano-LiFePO(4) for Li-ion batteries.

    PubMed

    Waser, Oliver; Büchel, Robert; Hintennach, Andreas; Novák, Petr; Pratsinis, Sotiris E

    2011-10-01

    Core-shell, nano-sized LiFePO(4)-carbon particles were made in one step by scalable flame aerosol technology at 7 g/h. Core LiFePO(4) particles were made in an enclosed flame spray pyrolysis (FSP) unit and were coated in-situ downstream by auto thermal carbonization (pyrolysis) of swirl-fed C(2)H(2) in an O(2)-controlled atmosphere. The formation of acetylene carbon black (ACB) shell was investigated as a function of the process fuel-oxidant equivalence ratio (EQR). The core-shell morphology was obtained at slightly fuel-rich conditions (1.0LiFePO(4) particles were formed at fuel-lean conditions (0.8LiFePO(4) with a crystal size of 65 nm and 30 wt% ACB content. Uncoated LiFePO(4) or segregated LiFePO(4)-ACB grew to 250 nm at these conditions. Annealing at 800 °C induced carbothermal reduction of LiFePO(4) to Fe(2)P by ACB shell consumption that resulted in cavities between carbon shell and core LiFePO(4) and even slight LiFePO(4) crystal growth but better electrochemical performance. The present carbon-coated LiFePO(4) showed superior cycle stability and higher rate capability than the benchmark, commercially available LiFePO(4). PMID:23407817

  18. Continuous flame aerosol synthesis of carbon-coated nano-LiFePO4 for Li-ion batteries

    PubMed Central

    Waser, Oliver; Büchel, Robert; Hintennach, Andreas; Novák, Petr; Pratsinis, Sotiris E.

    2013-01-01

    Core-shell, nanosized LiFePO4-carbon particles were made in one step by scalable flame aerosol technology at 7 g/h. Core LiFePO4 particles were made in an enclosed flame spray pyrolysis (FSP) unit and were coated in-situ downstream by auto thermal carbonization (pyrolysis) of swirl-fed C2H2 in an O2-controlled atmosphere. The formation of acetylene carbon black (ACB) shell was investigated as a function of the process fuel-oxidant equivalence ratio (EQR). The core-shell morphology was obtained at slightly fuel-rich conditions (1.0 < EQR < 1.07) whereas segregated ACB and LiFePO4 particles were formed at fuel-lean conditions (0.8 < EQR < 1). Post-annealing of core-shell particles in reducing environment (5 vol% H2 in argon) at 700 °C for up to 4 hours established phase pure, monocrystalline LiFePO4 with a crystal size of 65 nm and 30 wt% ACB content. Uncoated LiFePO4 or segregated LiFePO4-ACB grew to 250 nm at these conditions. Annealing at 800 °C induced carbothermal reduction of LiFePO4 to Fe2P by ACB shell consumption that resulted in cavities between carbon shell and core LiFePO4 and even slight LiFePO4 crystal growth but better electrochemical performance. The present carbon-coated LiFePO4 showed superior cycle stability and higher rate capability than the benchmark, commercially available LiFePO4. PMID:23407817

  19. An Update on C458 AI-Li for Cryotanks

    NASA Technical Reports Server (NTRS)

    Babel, Henry W.; Rioja, Roberto; Jata, Kumar

    2003-01-01

    This viewgraph representation provides an overview of ongoing research being conducted on C458 Al-Li composite cryotanks. Topics covered include: structural design of C458 Al-Li cryotanks, C458 ingot casting capability, C458 plate properties, summary of attained properties, design database capabilities, fatigue tests and testing, and ongoing research projects.

  20. Understanding oxygen reactions in aprotic Li-O2 batteries

    NASA Astrophysics Data System (ADS)

    Shunchao, Ma; Yelong, Zhang; Qinghua, Cui; Jing, Zhao; Zhangquan, Peng

    2016-01-01

    Although significant progress has been made in many aspects of the emerging aprotic Li-O2 battery system, an in-depth understanding of the oxygen reactions is still underway. The oxygen reactions occurring in the positive electrode distinguish Li-O2 batteries from the conventional Li-ion cells and play a crucial role in the Li-O2 cell’s performance (capacity, rate capability, and cycle life). Recent advances in fundamental studies of oxygen reactions in aprotic Li-O2 batteries are reviewed, including the reaction route, kinetics, morphological evolution of Li2O2, and charge transport within Li2O2. Prospects are also provided for future fundamental investigations of Li-O2 chemistry. Project supported by the Recruitment Program of Global Youth Experts of China, the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA09010401), the Science and Technology Development Program of Jilin Province, China (Grant No. 20150623002TC), and the Natural Science Foundation of Jiangsu Province, China (Grant No. BK20131139).

  1. Ethylmethylcarbonate, a promising solvent for Li-ion rechargeable batteries

    SciTech Connect

    Ein-Eli, Y.; Thomas, S.R.; Koch, V.; Aurbach, D.; Markovsky, B.; Schechter, A.

    1996-12-01

    Ethylmethylcarbonate (EMC) has been found to be a promising solvent for rechargeable Li-ion batteries. Graphite electrodes, which are usually sensitive to the composition of the electrolyte solution, can be successfully cycled at high reversible capacities in several Li salt solutions in this solvent (LiAsF{sub 6}, LiPF{sub 6}, etc.). These results are interesting because lithium ions cannot intercalate into graphite in diethyl carbonate solutions and cycle poorly in dimethyl carbonate solutions. To understand the high compatibility of EMC for Li-ion battery systems as compared with the other two open-chain alkyl carbonates mentioned above, the surface chemistry developed in both Li and carbon electrodes in EMC solution was studied and compared with that developed on these electrodes in other alkyl carbonate solutions. Basically, the major surface species formed on both electrodes in EMC include ROLi, ROCO{sub 2}Li, and Li{sub 2}CO{sub 3} species. The uniqueness of EMC as a battery solvent is discussed in light of these studies.

  2. Using LiDAR to characterize logjams in lowland rivers

    NASA Astrophysics Data System (ADS)

    Abalharth, Mahdi; Hassan, Marwan A.; Klinkenberg, Brian; Leung, Vivian; McCleary, Richard

    2015-10-01

    Logjams significantly influence watershed hydrology, flow regime, channel morphology and stability, and processes in lowland rivers. Consequently, logjams play a major role in the existence and conservation of the riparian and aquatic ecosystems along major waterways. In this paper, we attempt to detect and quantify logjams in river channels using LiDAR technology in conjunction with traditional fieldwork. To the best of our knowledge, LiDAR-based analysis has not been used to characterize logjams in streams. Overall, when applied in a lowland river environment, LiDAR-based analysis demonstrates a comprehensive solution for detecting logjams in relation to the fieldwork, with a low rate of omission. A filtered approach predicted the presence of 95% of fieldwork-reported logjams (a 5% rate of omission), but also identified six logjams not identified in the field (a 10% rate of commission). A nonfiltered approach identified 87% of field-reported logjams, producing a 13% rate of omission and a 6.7% rate of commission. Dimension measurements were more consistent in the filtered LiDAR approach, showing 53%, 34%, and 90% of R2 improvements for the length, width, and height, respectively, over the unfiltered LiDAR values. As vegetation cover hindered accurate delineation of logjam boundaries by LiDAR, field and LiDAR measurements of nonvegetation-obstructed logjams were more highly correlated than the field and LiDAR measurements of partially and completely vegetation-obstructed logjams.

  3. Si(Li) X-ray astronomical spectroscopy

    NASA Technical Reports Server (NTRS)

    Holt, S. S.

    1975-01-01

    The general considerations involved in the choice of Si(Li) as a non-dispersive spectrometer for X-ray astronomy are discussed. In particular, its adaptation to HEAO-B is described as an example of the space-borne application of Si(Li) technology.

  4. Rigorous LiDAR Strip Adjustment with Triangulated Aerial Imagery

    NASA Astrophysics Data System (ADS)

    Zhang, Y. J.; Xiong, X. D.; Hu, X. Y.

    2013-10-01

    This paper proposes a POS aided LiDAR strip adjustment method. Firstly, aero-triangulation of the simultaneously obtained aerial images is conducted with a few photogrammetry-specific ground control points. Secondly, LiDAR intensity images are generated from the reflectance signals of laser foot points, and conjugate points are automatically matched between the LiDAR intensity image and the aero-triangulated aerial image. Control points used in LiDAR strip adjustment are derived from these conjugate points. Finally, LiDAR strip adjustment of real data is conducted with the POS aided LiDAR strip adjustment method proposed in this paper, and comparison experiment using three-dimensional similarity transformation method is also performed. The results indicate that the POS aided LiDAR strip adjustment method can significantly correct the planimetric and vertical errors of LiDAR strips. The planimetric correction accuracy is higher than average point distance while the vertical correction accuracy is comparable to that of the result of aero-triangulation. Moreover, the proposed method is obliviously superior to the traditional three-dimensional similarity transformation method.

  5. Localization of vacancies and mobility of lithium ions in Li{sub 2}ZrO{sub 3} as obtained by {sup 6,7}Li NMR

    SciTech Connect

    Baklanova, Ya. V.; Arapova, I. Yu.; Buzlukov, A.L.; Gerashenko, A.P.; Verkhovskii, S.V.; Mikhalev, K.N.; Denisova, T.A.; Shein, I.R.; Maksimova, L.G.

    2013-12-15

    The {sup 6,7}Li NMR spectra and the {sup 7}Li spin–lattice relaxation rate were measured on polycrystalline samples of Li{sub 2}ZrO{sub 3}, synthesized at 1050 K and 1300 K. The {sup 7}Li NMR lines were attributed to corresponding structural positions of lithium Li1 and Li2 by comparing the EFG components with those obtained in the first-principles calculations of the charge density in Li{sub 2}ZrO{sub 3}. For both samples the line width of the central {sup 7}Li transition and the spin–lattice relaxation time decrease abruptly at the temperature increasing above ∼500 K, whereas the EFG parameters are averaged (〈ν{sub Q}〉=42 (5) kHz) owing to thermally activated diffusion of lithium ions. - Graphical abstract: Path of lithium ion hopping in lithium zirconate Li{sub 2}ZrO{sub 3}. - Highlights: • Polycrystalline samples Li{sub 2}ZrO{sub 3} with monoclinic crystal structure synthesized at different temperatures were investigated by {sup 6,7}Li NMR spectroscopy. • Two {sup 6,7}Li NMR lines were attributed to the specific structural positions Li1 and Li2. • The distribution of vacancies was clarified for both lithium sites. • The activation energy and pathways of lithium diffusion in Li{sub 2}ZrO{sub 3} were defined.

  6. H2 adsorption in Li-decorated porous graphene

    NASA Astrophysics Data System (ADS)

    Seenithurai, S.; Pandyan, R. Kodi; Kumar, S. Vinodh; Munieswaran, P.; Saranya, C.; Mahendran, M.

    2015-06-01

    Porous graphene (PG) has been decorated with Li atoms and subsequently studied the hydrogen (H2) adsorption characteristics, by using Density Functional Theory (DFT)-based calculations. A 2×2 PG has been decorated with eight Li atoms. Upto four H2 molecules get adsorbed on each Li atom. The maximum H2 storage capacity that could be achieved in 2×2PG-8Li is 8.95 wt% which is higher than the U.S. DOE's revised target for the on-board vehicles. The average H2 adsorption binding energy is 0.535 eV/H2, which lies between 0.2-0.6 eV/H2 that is required for achieving adsorption and desorption at near ambient conditions. Thus, Li-decorated PG could be a viable option for on-board automobile applications.

  7. Hollow Li20B60 Cage: Stability and Hydrogen Storage

    PubMed Central

    Wang, Jing; Wei, Zhi-Jing; Zhao, Hui-Yan; Liu, Ying

    2016-01-01

    A stable hollow Li20B60 cage with D2 symmetry has been identified using first-principles density functional theory studies. The results of vibrational frequency analysis and molecular dynamics simulations demonstrate that this Li20B60 cage is exceptionally stable. The feasibility of functionalizing Li20B60 cage for hydrogen storage was explored theoretically. Our calculated results show that the Li20B60 molecule can adsorb a maximum of 28 hydrogen molecules. With a hydrogen uptake of 8.190 wt% and an average binding energy of 0.336 eV/H2, Li20B60 is a remarkable high-capacity storage medium. PMID:27076264

  8. Hollow Li20B60 Cage: Stability and Hydrogen Storage.

    PubMed

    Wang, Jing; Wei, Zhi-Jing; Zhao, Hui-Yan; Liu, Ying

    2016-04-14

    A stable hollow Li20B60 cage with D2 symmetry has been identified using first-principles density functional theory studies. The results of vibrational frequency analysis and molecular dynamics simulations demonstrate that this Li20B60 cage is exceptionally stable. The feasibility of functionalizing Li20B60 cage for hydrogen storage was explored theoretically. Our calculated results show that the Li20B60 molecule can adsorb a maximum of 28 hydrogen molecules. With a hydrogen uptake of 8.190 wt% and an average binding energy of 0.336 eV/H2, Li20B60 is a remarkable high-capacity storage medium.

  9. Polymer electrolytes for a rechargeable li-Ion battery

    SciTech Connect

    Argade, S.D.; Saraswat, A.K.; Rao, B.M.L.; Lee, H.S.; Xiang, C.L.; McBreen, J.

    1996-10-01

    Lithium-ion polymer electrolyte battery technology is attractive for many consumer and military applications. A Li{sub x}C/Li{sub y}Mn{sub 2}O{sub 4} battery system incorporating a polymer electrolyte separator base on novel Li-imide salts is being developed under sponsorship of US Army Research Laboratory (Fort Monmouth NJ). This paper reports on work currently in progress on synthesis of Li-imide salts, polymer electrolyte films incorporating these salts, and development of electrodes and cells. A number of Li salts have been synthesized and characterized. These salts appear to have good voltaic stability. PVDF polymer gel electrolytes based on these salts have exhibited conductivities in the range 10{sup -4} to 10{sub -3} S/cm.

  10. Recombination luminescence from electron-irradiated Li-diffused Si

    NASA Technical Reports Server (NTRS)

    Johnson, E. S.; Compton, W. D.; Noonan, J. R.; Streetman, B. G.

    1973-01-01

    Lithium doping has a dramatic effect on the low-temperature photoluminescence of electron-irradiated Si. In oxigen-lean Si with Li doping, a new irradiation-dependent luminescence band between 0.75 and 1.05 eV is observed, which is dominated by a zero-phonon peak at 1.045 eV. This band is believed to be due to radiative transitions involving a Li-modified divacancy. This band is present also in oxygen-rich, Li-diffused Si and is accompanied by bands previously related to the Si-G15(K) center and the divacancy. The intensities of the Li-modified divacancy and Si-G15(K) center bands are relatively weak in the oxygen-rich material, apparently due to the formation of lithium-oxygen complexes which reduce the concentration of unassociated interstitial Li and O.

  11. Solution-processable glass LiI-Li4SnS4 superionic conductors for all-solid-state Li-ion batteries

    SciTech Connect

    Kern Ho Park; Oh, Dae Yang; Choi, Young Eun; Nam, Young Jin; Han, Lili; Kim, Ju -Young; Xin, Huolin; Lin, Feng; Oh, Seung M.; Jung, Yoon Seok

    2015-12-22

    The new, highly conductive (4.1 × 10–4 S cm–1 at 30 °C), highly deformable, and dry-air-stable glass 0.4LiI-0.6Li4SnS4 is prepared using a homogeneous methanol solution. Furthermore, the solution process enables the wetting of any exposed surface of the active materials with highly conductive solidified electrolytes (0.4LiI-0.6Li4SnS4), resulting in considerable improvements in electrochemical performances of these electrodes over conventional mixture electrodes.

  12. Er3+ diffusion in congruent LiNbO3 crystal in Li-enriched atmosphere

    NASA Astrophysics Data System (ADS)

    Zhang, De-Long; Jia, Qi-Shen; Hua, Ping-Rang; Pei-Zhang, Zhang, Wen-Jun; Yang, Qing-Zhong; Liu, Hong-Li; Cui, Yu-Ming; Pun, E. Y. B.

    2007-10-01

    The thermal diffusion of Er3+ into X- and Z-cut congruent LiNbO3 crystal in Li-enriched atmosphere [i.e., vapor transport equilibration (VTE)], created by Li3NbO4-LiNbO3 two-phase powder at the temperature around 1130°C, was attempted. Single-crystal x-ray diffraction, micro-Raman, photoluminescence spectroscopy, and secondary ion mass spectrometry (SIMS) were used to study the crystalline phase with respect to Er3+ ion and the Er3+ diffusivity. The results show that the thickness of the Er film coated should not be thicker than 10nm for an X-cut plate and 15nm for a Z-cut plate. In this case, the diffusion is complete if the duration is long enough (>150h ) and the Er3+ ions in the diffused layer still retain the LiNbO3 phase. On the other hand, if the initial thickness of the Er metal film is thicker than 10nm for the X-cut plate and 15nm for the Z-cut plate, the diffusion will be incomplete no matter how long the duration is. This is because the residual Er3+ ions form irremovable ErNbO4 grains on the surface of the crystal. SIMS analysis on an X-cut VTE (1130°C/192h) and a Z-cut VTE (1129°C/158h) crystal coated, respectively, with 10 and 15nm thick Er film reveals that the Er diffusion shows obvious anisotropy with the mean diffusion coefficients of 0.0155 and 0.0957μm2/h, respectively. The surface concentrations are 1.5×1020 and 1.0×1020at./cm3, respectively. The diffused Er3+ ions follow the stretched-exponential decay profile with a stretching factor of 1.85 and 3.5, respectively. The Li /Nb ratio in the Er-diffused layer is similar to 99.4% for the X-cut sample coated with 10nm thick Er film and 99.3% for the Z-cut crystal coated with 15nm thick Er film. The rms roughness of the diffused surface is better than 6 and 4nm for the X-cut and Z-cut samples, respectively.

  13. Fast Li ion dynamics in the solid electrolyte Li7 P3 S11 as probed by (6,7) Li NMR spin-lattice relaxation.

    PubMed

    Wohlmuth, Dominik; Epp, Viktor; Wilkening, Martin

    2015-08-24

    The development of safe and long-lasting all-solid-state batteries with high energy density requires a thorough characterization of ion dynamics in solid electrolytes. Commonly, conductivity spectroscopy is used to study ion transport; much less frequently, however, atomic-scale methods such as nuclear magnetic resonance (NMR) are employed. Here, we studied long-range as well as short-range Li ion dynamics in the glass-ceramic Li7 P3 S11 . Li(+) diffusivity was probed by using a combination of different NMR techniques; the results are compared with those obtained from electrical conductivity measurements. Our NMR relaxometry data clearly reveal a very high Li(+) diffusivity, which is reflected in a so-called diffusion-induced (6) Li NMR spin-lattice relaxation peak showing up at temperatures as low as 313 K. At this temperature, the mean residence time between two successful Li jumps is in the order of 3×10(8) s(-1) , which corresponds to a Li(+) ion conductivity in the order of 10(-4) to 10(-3) S cm(-1) . Such a value is in perfect agreement with expectations for the crystalline but metastable glass ceramic Li7 P3 S11 . In contrast to conductivity measurements, NMR analysis reveals a range of activation energies with values ranging from 0.17 to 0.26 eV, characterizing Li diffusivity in the bulk. In our case, through-going Li ion transport, when probed by using macroscopic conductivity spectroscopy, however, seems to be influenced by blocking grain boundaries including, for example, amorphous regions surrounding the Li7 P3 S11 crystallites. As a result of this, long-range ion transport as seen by impedance spectroscopy is governed by an activation energy of approximately 0.38 eV. The findings emphasize how surface and grain boundary effects can drastically affect long-range ionic conduction. If we are to succeed in solid-state battery technology, such effects have to be brought under control by, for example, sophisticated densification or through the preparation

  14. Mössbauer spectra as a “fingerprint” in tin lithium compounds: Applications to Li-ion batteries

    NASA Astrophysics Data System (ADS)

    Robert, F.; Lippens, P. E.; Olivier-Fourcade, J.; Jumas, J.-C.; Gillot, F.; Morcrette, M.; Tarascon, J.-M.

    2007-01-01

    Several Li-Sn crystalline phases, i.e. Li 2Sn 5, LiSn, Li 7Sn 3, Li 5Sn 2, Li 13Sn 5, Li 7Sn 2 and Li 22Sn 5 were prepared by ball-milling and characterized by X-ray powder diffraction and 119Sn Mössbauer spectroscopy. The analysis of the Mössbauer hyperfine parameters, i.e. isomer shift ( δ) and quadrupole splitting ( Δ), made it possible to define two types of Li-Sn compounds: the Sn-richest compounds (Li 2Sn 5, LiSn) and the Li-richest compounds (Li 7Sn 3, Li 5Sn 2, Li 13Sn 5, Li 7Sn 2, Li 22Sn 5). The isomer shift values ranged from 2.56 to 2.38 mm s -1 for Li 2Sn 5, LiSn and from 2.07 to 1.83 mm s -1 for Li 7Sn 3, Li 5Sn 2, Li 13Sn 5, Li 7Sn 2 and Li 22Sn 5, respectively. A Δ- δ correlation diagram is introduced in order to identify the different phases observed during the electrochemical process of new Sn-based materials. This approach is illustrated by the identification of the phases obtained at the end of the first discharge of η-Cu 6Sn 5 and SnB 0.6P 0.4O 2.9.

  15. Dynamic studies of {sup 11}Li and its core {sup 9}Li on {sup 208}Pb near the Coulomb barrier

    SciTech Connect

    Cubero, M.; Borge, M. J. G.; Alcorta, M.; Madurga, M.; Tengblad, O.; Acosta, L.; Martel, I.; Sanchez-Benitez, A. M.; Alvarez, M. A. G.; Gomez-Camacho, J.; Diget, C.; Galaviz, D.; Fernandez-Garcia, J. P.; Lay, J. A.; Moro, A. M.; Mukha, I.; Shotter, A.; Walden, P.

    2010-04-26

    We measured the scattering of the halo nucleus {sup 11}Li and its core {sup 9}Li on the lead target at TRIUMF at energies below and around to the Coulomb barrier. We report here on our preliminary analysis of the inclusive breakup reaction.

  16. Enhanced ionic conductivity with Li7O2Br3 phase in Li3OBr anti-perovskite solid electrolyte

    NASA Astrophysics Data System (ADS)

    Zhu, Jinlong; Li, Shuai; Zhang, Yi; Howard, John W.; Lü, Xujie; Li, Yutao; Wang, Yonggang; Kumar, Ravhi S.; Wang, Liping; Zhao, Yusheng

    2016-09-01

    Cubic anti-perovskites with general formula Li3OX (X = Cl, Br, I) were recently reported as superionic conductors with the potential for use as solid electrolytes in all-solid-state lithium ion batteries. These electrolytes are nonflammable, low-cost, and suitable for thermoplastic processing. However, the primary obstacle of its practical implementation is the relatively low ionic conductivity at room temperature. In this work, we synthesized a composite material consisting of two anti-perovskite phases, namely, cubic Li3OBr and layered Li7O2Br3, by solid state reaction routes. The results indicate that with the phase fraction of Li7O2Br3 increasing to 44 wt. %, the ionic conductivity increased by more than one order of magnitude compared with pure phase Li3OBr. Formation energy calculations revealed the meta-stable nature of Li7O2Br3, which supports the great difficulty in producing phase-pure Li7O2Br3 at ambient pressure. Methods of obtaining phase-pure Li7O2Br3 will continue to be explored, including both high pressure and metathesis techniques.

  17. An attempt to study LiH and Li{sub 2} molecules by high resolution pulsed laser spectroscopy

    SciTech Connect

    Bouloufa, Nadia; Cabaret, Louis; Cacciani, Patrice; Camus, Pierre; Pitcheev, Boris; Vetter, Raymond

    1998-12-16

    As we start a program to study alkali hydrides and dimers, we have developed a two-step photoionisation experiment on Li{sub 2} molecules based on the use of an atomic beam and two pulsed dye lasers. The first resonant step which excites the A {sup 1}{sigma}{sub u}{sup +}-X {sup 1}{sigma}{sub g}{sup +}Li{sub 2} dimer systems is a home-made cw-seeded DCM dye laser with a laser linewidth of 55 MHz (FWHM) and near the Fourier transform limit. The second step is a larger width fixed frequency UV laser which allows the photoionisation of the selectively excited molecules. The three {sup 6}Li{sub 2}, {sup 6}Li {sup 7}Li and {sup 7}Li{sub 2} spectra are recorded simultaneously by the use of a doubly-accelerating time-of-flight ion analyser. Comparison between recorded and calculated absorption spectra using Dunham parameters found in the literature is satisfactory. To develop similar pulsed high-resolution investigations in LiH, we have characterized our molecular beam by using the laser induced fluorescence (LIF) technique with a cw blue dye laser. Two Franck-Condon LiH Doppler-free resonances have been observed.

  18. The properties of and analytical methods for detection of LiOH and Li2CO3

    NASA Technical Reports Server (NTRS)

    Selvaduray, Guna

    1991-01-01

    Lithium hydroxide (LiOH) is used as a CO2 absorbent in the Shuttle Extravehicular Mobility Unit (EMU) Portable Life Support System (PLSS). The first objective was to survey parameters that may be used to indicate conversion of LiOH to Li2CO3, and compile a list of all possible properties, including physical, chemical, structural, and electrical, that may serve to indicate the occurrence of reaction. These properties were compiled for the reactant (LiOH), the intermediate monohydrate compound (LiOH.H2O), and the final product (Li2CO3). The second objective was to survey measurement and analytical techniques which may be used in conjunction with each of the properties identified above, to determine the extent of conversion of LiOH to Li2CO3. Both real-time and post-run techniques were of interest. The techniques were also evaluated in terms of complexity, technology readiness, materials/equipment availability, and cost, where possible.

  19. Kinetic measurement and prediction of the hydrogen outgassing from the polycrystalline LiH/LiOH system

    SciTech Connect

    Dinh, L N; Grant, D M; Schildbach, M A; Smith, R A; Leckey, J H; Siekhaus, W J; Balazs, B; McLean II, W

    2005-03-09

    In this report, we present the use of temperature programmed reaction/decomposition (TPR) in the isoconversion mode to measure outgassing kinetics and to make kinetic prediction concerning hydrogen release from the polycrystalline LiH/LiOH system in the absence of any external H{sub 2}O source.

  20. ERD measurement of depth profiles of H and Li in Pt-coated LiCoO2 thin films

    NASA Astrophysics Data System (ADS)

    Tsuchiya, B.; Morita, K.; Iriyama, Y.; Majima, T.; Tsuchida, H.

    2013-11-01

    By combining elastic recoil detection (ERD) analysis with Rutherford backscattering spectrometry (RBS) using 9.0-MeV oxygen-ion (O4+) probe beams from a tandem accelerator, we simultaneously investigated the distributions of lithium (Li), hydrogen (H), cobalt (Co), and platinum (Pt) in 20 nm Pt/260 nm LiCoO2 multi-layer thin films acting as the positive electrode in a solid-state Li+ ion battery and, deposited on Li1.4Ti2Si0.4P2.6O12-AlPO4 (LATP) substrates by using pulsed laser deposition. Measurement of the ERD and RBS spectra revealed the effects of Pt deposition on the hydrogen absorption characteristics of the LiCoO2 thin films, with segregation of Co to the surface as a catalyst. We speculate from the results that the presence of H in the LiCoO2 thin films has a marked influence on Li+ ion conduction in Li-battery systems.

  1. Novel Phase Transitions in the Breathing Pyrochlore Lattice: Li7-NMR on LiInCr4O8 and LiGaCr4O8

    NASA Astrophysics Data System (ADS)

    Tanaka, Yu; Yoshida, Makoto; Takigawa, Masashi; Okamoto, Yoshihiko; Hiroi, Zenji

    2014-11-01

    We report Li7-NMR studies on LiInCr4O8 and LiGaCr4O8, in which Cr3 + ions with spin 3 /2 form a breathing pyrochlore lattice, a network of tetrahedra with alternating sizes. In LiInCr4O8 with large alternation, the nuclear relaxation rate 1 /T1 shows an activated temperature (T ) dependence down to 18 K, indicating a singlet ground state with a spin gap. This behavior, however, is disrupted by an antiferromagnetic transition at 13 K, which is preceded by another, most likely structural, transition at 16 K. In contrast, LiGaCr4O8 with a small alternation shows no spin gap but exhibits a first-order antiferromagnetic transition over a distributed T range 13-20 K. Nevertheless, 1 /T1 of the paramagnetic phase diverges toward 13 K, indicating proximity to a second-order transition. The results indicate that LiGaCr4O8 is located in the vicinity of a tricritical point in the phase diagram.

  2. A detailed reactive cross section study of X + Li2 → Li + LiX, with X = H, D, T, and Mu.

    PubMed

    da Cunha, Wiliam F; Leal, Luciano A; da Cunha, Thiago F; e Silva, Geraldo M; Martins, João B L; Gargano, Ricardo

    2014-07-01

    In this work we apply quasiclassical trajectory theory to the X + Li2 → Li + LiX reactions, with X standing for H, D, T, and Mu, in order to determine dynamical properties such as state-to-state reactive cross-section, rotational, vibrational, and translational product distributions. By using the literature benchmark potential energy surface, we were able to predict the aforementioned dynamical property in remarkable qualitative agreement with data in the literature for the H + Li2 → Li + LiH channel. Particularly, our results points toward the well known cross section independence with ro-vibrational excitations for high excitation regimes. Since the methodology is known to be well suited for the other species, as we considered the same PES, our results are expected to be similarly accurate for D, T, and Mu. The present work consists on a significant progress in this area of research, since previous theoretical calculations-based on known potential energy surface-deviated from the experimental results.

  3. The {sup 9}Be({sup 8}Li,{sup 9}Be){sup 8}Li elastic-transfer reaction

    SciTech Connect

    Camargo, O.; Guimaraes, V.; Lichtenthaeler, R.; Scarduelli, V.; Kolata, J. J.; Bertulani, C. A.; Amro, H.; Becchetti, F. D.; Jiang Hao; Aguilera, E. F.; Lizcano, D.; Martinez-Quiroz, E.; Garcia, H.

    2008-09-15

    Angular distributions for the {sup 9}Be({sup 8}Li,{sup 9}Be){sup 8}Li elastic-transfer reaction have been measured with a 27-MeV {sup 8}Li radioactive nuclear beam. Spectroscopic factors for the <{sup 9}Be|{sup 8}Li+p> bound system were obtained from the comparison between the experimental differential cross sections and finite-range distorted-wave Born approximation calculations made with the code FRESCO. The spectroscopic factors so obtained are compared with shell-model calculations and other experimental values. Using the present value for the spectroscopic factors, cross sections and reaction rates for the {sup 8}Li(p,{gamma}){sup 9}Be direct proton-capture reaction of astrophysical interest were calculated in the framework of the potential model.

  4. Facile molten salt synthesis of Li2NiTiO4 cathode material for Li-ion batteries.

    PubMed

    Wang, Yanming; Wang, Yajing; Wang, Fei

    2014-01-01

    Well-crystallized Li2NiTiO4 nanoparticles are rapidly synthesized by a molten salt method using a mixture of NaCl and KCl salts. X-ray diffraction pattern and scanning electron microscopic image show that Li2NiTiO4 has a cubic rock salt structure with an average particle size of ca. 50 nm. Conductive carbon-coated Li2NiTiO4 is obtained by a facile ball milling method. As a novel 4 V positive cathode material for Li-ion batteries, the Li2NiTiO4/C delivers high discharge capacities of 115 mAh g(-1) at room temperature and 138 mAh g(-1) and 50°C, along with a superior cyclability. PMID:24855459

  5. Effect of Li diffusion on the domain inversion of LiNbO3 prepared by vapor transport equilibration

    NASA Astrophysics Data System (ADS)

    Chen, Yunlin; Xu, Jingjun; Kong, Yongfa; Chen, Shaolin; Zhang, Guangyin; Wen, Jianping

    2002-07-01

    LiNbO3 crystals with a composition close to stoichiometry were prepared by using a vapor transport equilibration (VTE) technique. The influence of the intrinsic defect density in the electric field periodic poling LiNbO3 crystal is studied. The switching field is found to decrease with the intrinsic defects. The reduction of intrinsic defects is mainly due to a change in the Li/Nb ratio in the LiNbO3 crystal, as a result of lithium diffusion during the VTE process. The switching field of approx2 kV/mm in stoichiometric LiNbO3 is about one fourth of the previously published results obtained with near-stoichiometric crystals, and is approximately one tenth of the conventional congruent field. Periodic poling of thicker stoichiometric substrates was successfully performed by means of an electric field poling process at room temperature.

  6. Determination of the Li/Nb ratio in LiNbO 3 crystals prepared by vapor transport equilibration method

    NASA Astrophysics Data System (ADS)

    Chen, Yunlin; Zhang, Wanlin; Shu, Yongchun; Lou, Cibo; Kong, Yongfa; Huang, Ziheng; Xu, Jingjun; Zhang, Guangyin

    2003-07-01

    Off-congruent lithium niobate (LiNbO 3) single crystal was prepared by vapor transport equilibration (VTE). The Li/Nb ratio was determined by means of indirect methods such as the lattice parameters, the fundamental absorption edge position and the IR vibrational spectrum. Comparison of the results of the VTE LiNbO 3 with those of the congruent crystal and congruent composition melt added 6 wt% K 2O. In all cases the Li 2O content was found to be closer to 50% than that of the congruent composition melt added 6 wt% K 2O. The homogeneity of the composition in the crystal was also investigated. The data presented in this work show that the VTE method can be effectively applied to produce LiNbO 3 stoichiometric crystal.

  7. Facile molten salt synthesis of Li2NiTiO4 cathode material for Li-ion batteries.

    PubMed

    Wang, Yanming; Wang, Yajing; Wang, Fei

    2014-01-01

    Well-crystallized Li2NiTiO4 nanoparticles are rapidly synthesized by a molten salt method using a mixture of NaCl and KCl salts. X-ray diffraction pattern and scanning electron microscopic image show that Li2NiTiO4 has a cubic rock salt structure with an average particle size of ca. 50 nm. Conductive carbon-coated Li2NiTiO4 is obtained by a facile ball milling method. As a novel 4 V positive cathode material for Li-ion batteries, the Li2NiTiO4/C delivers high discharge capacities of 115 mAh g(-1) at room temperature and 138 mAh g(-1) and 50°C, along with a superior cyclability.

  8. LiCl Dehumidifier LiBr absorption chiller hybrid air conditioning system with energy recovery

    DOEpatents

    Ko, Suk M.

    1980-01-01

    This invention relates to a hybrid air conditioning system that combines a solar powered LiCl dehumidifier with a LiBr absorption chiller. The desiccant dehumidifier removes the latent load by absorbing moisture from the air, and the sensible load is removed by the absorption chiller. The desiccant dehumidifier is coupled to a regenerator and the desiccant in the regenerator is heated by solar heated hot water to drive the moisture therefrom before being fed back to the dehumidifier. The heat of vaporization expended in the desiccant regenerator is recovered and used to partially preheat the driving fluid of the absorption chiller, thus substantially improving the overall COP of the hybrid system.

  9. Low Temperature Milling of the LiNH2 + LiH Hydrogen Storage System

    SciTech Connect

    Osborn, William; Markmaitree, Tippawan; Shaw, Leonard D.; Hu, Jian Z.; Kwak, Ja Hun; Yang, Zhenguo

    2009-05-01

    Ball milling of the LiNH2 + LiH storage system was performed at 20°C, -40°C, and -196°C, and the resulting powders were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), nuclear magnetic resonance (NMR), specific surface area (SSA) analysis, and kinetics cycling measurements. Ball milling at -40°C showed no appreciable deviations from the 20°C sample, but the -196°C powder exhibited a significant increase in the hydrogen desorption kinetics. NMR analysis indicates that a possible explanation for the kinetics increase is the retention of internal defects generated during the milling process that are annealed at the collision site at higher milling temperatures.

  10. Orbitally driven trimerization in LiVO2 and LiVS2: a ``partial Mott transition''

    NASA Astrophysics Data System (ADS)

    Wu, Hua; Khomskii, D. I.

    2011-03-01

    Layered triangular-lattice transition-metal compounds often display interesting magnetic and electronic properties. Here we studied the formation of the trimerized spin-singlet state of the V3+ (S = 1) in vanadates Li VO2 and Li VS2 and their electronic structure with a special orbital order, using constrained LSDA+ U calculations combined with lattice optimization. The obtained results show that the trimerization distortion in Li VO2 increases as the effective U decreases, and the calculated distortion of ~ 0.3 AA at the small U = 1 eV agrees well with the experiments, indicating that Li VO2 is close to a metal-insulator transition. The corresponding distortion in Li VS2 is even stronger, being ~ 0.4 AA at the U = 1 eV, which is due to enhanced electron delocalization via increased V-S covalency, in spite of a lattice expansion. This agrees with the experimental finding that Li VS2 has a metal-insulator transition. The calculated energy gain associated with the trimerization well accounts for the observed structural phase transition temperature in Li VO2 and Li VS2 . We conclude that the trimerization in Li VO2 and Li VS2 is due to a partial delocalization of the orbitally ordered electrons---a ``partial Mott transition,'' occurring not in the whole system but in small clusters (here in trimers). This situation is contrasted with that in Na VO2 , which is further away from the localized-itinerant crossover and thus remains insulating with different orbital ordering.

  11. Dependence of LiNO3 decomposition on cathode binders in Li-S batteries

    NASA Astrophysics Data System (ADS)

    Godoi, Fernanda Condi de; Wang, Da-Wei; Zeng, Qingcong; Wu, Kuang-Hsu; Gentle, Ian R.

    2015-08-01

    This study brings a new insight into the interfacial compatibility of cathode binders with modified electrolytes in lithium-sulfur batteries. We compared the oxygen-containing binders sodium alginate (NaAlg) and sodium carboxymethyl cellulose (NaCMC) with the conventional oxygen-free polyvinylidene difluoride. The results revealed that the NaAlg and NaCMC binders strongly facilitated the decomposition of the electrolyte additive LiNO3 at potentials lower than 1.8 V. This is primarily attributed to the influence of oxygen-containing functional groups. However, when LiNO3 was absent from the electrolyte, the sulfur cathode with the NaAlg binder showed the most stable performance. To prevent LiNO3 decomposition and acquire stable cycling, the discharge voltage was limited to 1.8 V. At the conclusion of testing (100 cycles, voltage cutoff = 1.8 V), the NaAlg-based cathode maintained 608 mAh g-1 of capacity (52% of the initial capacity). This represented a 35% increase in the specific capacity obtained at the 100th discharge cycle with the cutoff voltage at 1.5 V. Our results suggest a rational choice of the binders used in sulfur composite cathodes.

  12. Li NMR study of heavy-fermion LiV2O4 containing magnetic defects

    SciTech Connect

    Zong, X.; Das, S.; Borsa, F.; Vannette, M.; Prozorov, R.; Schmalian, J.; Johnston, D.

    2008-04-21

    We present a systematic study of the variations of the {sup 7}Li NMR properties versus magnetic defect concentration up to 0.83 mol% within the spinel structure of polycrystalline powder samples and a collection of small single crystals of LiV2O4 in the temperature range from 0.5 to 4.2 K. We also report static magnetization measurements and ac magnetic susceptibility measurements at 14 MHz on the samples at low temperatures. Both the NMR spectrum and nuclear spin-lattice relaxation rate are inhomogeneous in the presence of the magnetic defects. The NMR data for the powders are well explained by assuming that (i) there is a random distribution of magnetic point defects, (ii) the same heavy Fermi liquid is present in the samples containing the magnetic defects as in magnetically pure LiV2O4, and (iii) the influences of the magnetic defects and of the Fermi liquid on the magnetization and NMR properties are separable. In the single crystals, somewhat different behaviors are observed. Remarkably, the magnetic defects in the powder samples show evidence of spin freezing below T {approx} 1.0 K, whereas in the single crystals with similar magnetic defect concentration no spin freezing was found down to 0.5 K. Thus different types of magnetic defects and/or interactions between them appear to arise in the powders versus the crystals, possibly due to the substantially different synthesis conditions of the powders and crystals.

  13. Extraction of Li and Co from Li-ion Batteries by Chemical Methods

    NASA Astrophysics Data System (ADS)

    Guzolu, Jafar Sharrivar; Gharabaghi, Mahdi; Mobin, Mohammad; Alilo, Hojat

    2016-05-01

    In this work a process involving ultrasonic washing and leaching and precipitation was used to recover Li and Co from spent Li-ion batteries. Ultrasonic washing was used to reduce energy consumption and pollution whereas hydrochloric acid was used as leaching reagent. 98 % of Li and nearly 99 % of Co were obtained under optimum condition of 5 M hydrochloric acid solution, temperature of 95 °C, reaction time of 70 min, and solid-liquid ratio of 10 g/L. In this process at first nickel, copper, iron, aluminum, cobalt, and manganese were precipitated from leaching solution using sodium hydroxide at pH f 12.5 and reaction time of 1 h and temperature was 55 °C and all metal recoveries were more than 99 %. In the precipitation experiments, lithium loss was only 18.34 %. In the next stage, white lithium carbonate was precipitated by addition of saturated sodium carbonate solution to the left filtrate from first precipitation step. The purity of the recovered powder of lithium was 95 %.

  14. Target electron ionization in Li2+-Li collisions: A multi-electron perspective

    NASA Astrophysics Data System (ADS)

    Śpiewanowski, M. D.; Gulyás, L.; Horbatsch, M.; Kirchner, T.

    2015-05-01

    The recent development of the magneto-optical trap reaction-microscope has opened a new chapter for detailed investigations of charged-particle collisions from alkali atoms. It was shown that energy-differential cross sections for ionization from the outer-shell in O8+-Li collisions at 1500 keV/amu can be readily explained with the single-active-electron approximation. Understanding of K-shell ionization, however, requires incorporating many-electron effects. An ionization-excitation process was found to play an important role. We present a theoretical study of target electron removal in Li2+-Li collisions at 2290 keV/amu. The results indicate that in outer-shell ionization a single-electron process plays the dominant part. However, the K-shell ionization results are more difficult to interpret. On one hand, we find only weak contributions from multi-electron processes. On the other hand, a large discrepancy between experimental and single-particle theoretical results indicate that multi-electron processes involving ionization from the outer shell may be important for a complete understanding of the process. Work supported by NSERC, Canada and the Hungarian Scientific Research Fund.

  15. Mass-spectrometric study of vaporization and thermodynamic properties of Li 2ZrO 3(s)

    NASA Astrophysics Data System (ADS)

    Kato, Yoshinari; Asano, Mitsuru; Harada, Toshio; Mizutani, Yasuo

    1993-07-01

    Partial pressures of Li(g), LiO(g), Li 2O(g) and O 2(g) over Li 2ZrO 3(s) have been determined by a mass-spectrometric Knudsen effusion method. Over various lithium-containing oxides, the partial pressures of Li 2O(g) decrease in the following order: Li 2 O > Li 5AlO 4 ⋍ Li 4TiO 4 ⋍ Li 8PbO 6 > Li 2SnO 3 > Li 4SiO 4 > Li 2TiO 3 ⋍ Li 2ZrO 3 > LiAlO 2 ⋍ Li 2SiO 3 > LiNbO 3. From the gas-solid equilibria, enthalpies of formation for Li 2ZrO 3(s) from elements and from constituent oxides have been calculated to be ΔfHo298( Li2ZrO3, s) = -(1742.3 ± 8.8) kJmol-1 and ΔfoxHo298( Li2ZrO3, s) = -(46.1 ± 92) KJmol-, respectively. Enthalpies of the reaction for adding 1 mole of Li 2O(s) to various oxides decrease with increasing the Li 2O molar content. The results show that the oxides with less Li 2O molar content have more ability to stabilize the pseudo-Li 2O component for lithium aluminates, silicates, titanates, molybdates, ferrates and zirconates.

  16. Lava flow texture LiDAR signatures

    NASA Astrophysics Data System (ADS)

    Whelley, P.; Garry, W. B.; Scheidt, S. P.; Irwin, R. P., III; Fox, J.; Bleacher, J. E.; Hamilton, C. W.

    2014-12-01

    High-resolution point clouds and digital elevation models (DEMs) are used to investigate lava textures on the Big Island of Hawaii. An experienced geologist can distinguish fresh or degraded lava textures (e.g., blocky, a'a and pahoehoe) visually in the field. Lava texture depends significantly on eruption conditions, and it is therefore instructive, if accurately determined. In places where field investigations are prohibitive (e.g., Mercury, Venus, the Moon, Mars, Io and remote regions on Earth) lava texture must be assessed from remote sensing data. A reliable method for differentiating lava textures in remote sensing data remains elusive. We present preliminary results comparing properties of lava textures observed in airborne and terrestrial Light Detection and Ranging (LiDAR) data. Airborne data, in this study, were collected in 2011 by Airborne 1 Corporation and have a ~1m point spacing. The authors collected the terrestrial data during a May 2014 field season. The terrestrial scans have a heterogeneous point density. Points close to the scanner are 1 mm apart while 200 m in the distance points are 10 cm apart. Both platforms offer advantages and disadvantages beyond the differences in scale. Terrestrial scans are a quantitative representation of what a geologist sees "on the ground". Airborne scans are a point of view routinely imaged by other remote sensing tools, and can therefore be quickly compared to complimentary data sets (e.g., spectral scans or image data). Preliminary results indicate that LiDAR-derived surface roughness, from both platforms, is useful for differentiating lava textures, but at different spatial scales. As all lava types are quite rough, it is not simply roughness that is the most advantageous parameter; rather patterns in surface roughness can be used to differentiate lava surfaces of varied textures. This work will lead to faster and more reliable volcanic mapping efforts for planetary exploration as well as terrestrial

  17. Relevance of LiPF6 as Etching Agent of LiMnPO4 Colloidal Nanocrystals for High Rate Performing Li-ion Battery Cathodes

    PubMed Central

    2016-01-01

    LiMnPO4 is an attractive cathode material for the next-generation high power Li-ion batteries, due to its high theoretical specific capacity (170 mA h g–1) and working voltage (4.1 V vs Li+/Li). However, two main drawbacks prevent the practical use of LiMnPO4: its low electronic conductivity and the limited lithium diffusion rate, which are responsible for the poor rate capability of the cathode. The electronic resistance is usually lowered by coating the particles with carbon, while the use of nanosize particles can alleviate the issues associated with poor ionic conductivity. It is therefore of primary importance to develop a synthetic route to LiMnPO4 nanocrystals (NCs) with controlled size and coated with a highly conductive carbon layer. We report here an effective surface etching process (using LiPF6) on colloidally synthesized LiMnPO4 NCs that makes the NCs dispersible in the aqueous glucose solution used as carbon source for the carbon coating step. Also, it is likely that the improved exposure of the NC surface to glucose facilitates the formation of a conductive carbon layer that is in intimate contact with the inorganic core, resulting in a high electronic conductivity of the electrode, as observed by us. The carbon coated etched LiMnPO4-based electrode exhibited a specific capacity of 118 mA h g–1 at 1C, with a stable cycling performance and a capacity retention of 92% after 120 cycles at different C-rates. The delivered capacities were higher than those of electrodes based on not etched carbon coated NCs, which never exceeded 30 mA h g–1. The rate capability here reported for the carbon coated etched LiMnPO4 nanocrystals represents an important result, taking into account that in the electrode formulation 80% wt is made of the active material and the adopted charge protocol is based on reasonable fast charge times. PMID:26799094

  18. Relevance of LiPF6 as Etching Agent of LiMnPO4 Colloidal Nanocrystals for High Rate Performing Li-ion Battery Cathodes.

    PubMed

    Chen, Lin; Dilena, Enrico; Paolella, Andrea; Bertoni, Giovanni; Ansaldo, Alberto; Colombo, Massimo; Marras, Sergio; Scrosati, Bruno; Manna, Liberato; Monaco, Simone

    2016-02-17

    LiMnPO4 is an attractive cathode material for the next-generation high power Li-ion batteries, due to its high theoretical specific capacity (170 mA h g(-1)) and working voltage (4.1 V vs Li(+)/Li). However, two main drawbacks prevent the practical use of LiMnPO4: its low electronic conductivity and the limited lithium diffusion rate, which are responsible for the poor rate capability of the cathode. The electronic resistance is usually lowered by coating the particles with carbon, while the use of nanosize particles can alleviate the issues associated with poor ionic conductivity. It is therefore of primary importance to develop a synthetic route to LiMnPO4 nanocrystals (NCs) with controlled size and coated with a highly conductive carbon layer. We report here an effective surface etching process (using LiPF6) on colloidally synthesized LiMnPO4 NCs that makes the NCs dispersible in the aqueous glucose solution used as carbon source for the carbon coating step. Also, it is likely that the improved exposure of the NC surface to glucose facilitates the formation of a conductive carbon layer that is in intimate contact with the inorganic core, resulting in a high electronic conductivity of the electrode, as observed by us. The carbon coated etched LiMnPO4-based electrode exhibited a specific capacity of 118 mA h g(-1) at 1C, with a stable cycling performance and a capacity retention of 92% after 120 cycles at different C-rates. The delivered capacities were higher than those of electrodes based on not etched carbon coated NCs, which never exceeded 30 mA h g(-1). The rate capability here reported for the carbon coated etched LiMnPO4 nanocrystals represents an important result, taking into account that in the electrode formulation 80% wt is made of the active material and the adopted charge protocol is based on reasonable fast charge times.

  19. Developing New Electrolytes for Advanced Li-ion Batteries

    NASA Astrophysics Data System (ADS)

    McOwen, Dennis Wayne

    The use of renewable energy sources is on the rise, as new energy generating technologies continue to become more efficient and economical. Furthermore, the advantages of an energy infrastructure which relies more on sustainable and renewable energy sources are becoming increasingly apparent. The most readily available of these renewable energy sources, wind and solar energy in particular, are naturally intermittent. Thus, to enable the continued expansion and widespread adoption of renewable energy generating technology, a cost-effective energy storage system is essential. Additionally, the market for electric/hybrid electric vehicles, which both require efficient energy storage, continues to grow as more consumers seek to reduce their consumption of gasoline. These vehicles, however, remain quite expensive, due primarily to costs associated with storing the electrical energy. High-voltage and thermally stable Li-ion battery technology is a promising solution for both grid-level and electric vehicle energy storage. Current limitations in materials, however, limit the energy density and safe operating temperature window of the battery. Specifically, the state-of-the-art electrolyte used in Li-ion batteries is not compatible with recently developed high-voltage positive electrodes, which are one of the most effectual ways of increasing the energy density. The electrolyte is also thermally unstable above 50 °C, and prone to thermal runaway reaction if exposed to prolonged heating. The lithium salt used in such electrolytes, LiPF6, is a primary contributor to both of these issues. Unfortunately, an improved lithium salt which meets the myriad property requirements for Li-ion battery electrolytes has eluded researchers for decades. In this study, a renewed effort to find such a lithium salt was begun, using a recently developed methodology to rapidly screen for desirable properties. Four new lithium salts and one relatively new but uncharacterized lithium salt were

  20. Theoretical study of Si20Li20 cage cluster

    NASA Astrophysics Data System (ADS)

    Zdetsis, Aristides D.; Koukaras, Emmanuel N.

    2012-12-01

    The stabilization effects of Li on Si20Li20 cage clusters, as a special example of SinLin clusters, are studied by high accuracy all electron density functional theory calculations. This allows to assess the capability of Li to play a role similar to hydrogen in stabilizing silicon cages similar to SinHn (and CnHn), in view of its capacity to stabilize planar Si6Li6 rings similar to benzene. It is shown that indeed Si20Li20 is a very stable cage of high D5d symmetry with large HOMO-LUMO gap and real frequencies. Based on the binding energy, its stability is the highest among all Si20Li20 clusters examined here, including almost all conceivable best and worst bonding and stability cases. This is highly suggestive that this highly symmetric "icosahedral" cage should be the global, or at least a very low-lying local minimum of the energy hyper-surface. It is therefore illustrated that the "rule of thumb" for building stable SinLin structures homologous to the corresponding aromatic CnHn molecules suggested earlier by Zdetsis [J. Chem. Phys. 127, 214306 (2007)], is also valid for "Fulleranes" and cages, including also the geometry and symmetry of the ideal structure(s). Preliminary results on Si60Li60 cages confirm this assertion.

  1. Processing LiDAR Data to Predict Natural Hazards

    NASA Technical Reports Server (NTRS)

    Fairweather, Ian; Crabtree, Robert; Hager, Stacey

    2008-01-01

    ELF-Base and ELF-Hazards (wherein 'ELF' signifies 'Extract LiDAR Features' and 'LiDAR' signifies 'light detection and ranging') are developmental software modules for processing remote-sensing LiDAR data to identify past natural hazards (principally, landslides) and predict future ones. ELF-Base processes raw LiDAR data, including LiDAR intensity data that are often ignored in other software, to create digital terrain models (DTMs) and digital feature models (DFMs) with sub-meter accuracy. ELF-Hazards fuses raw LiDAR data, data from multispectral and hyperspectral optical images, and DTMs and DFMs generated by ELF-Base to generate hazard risk maps. Advanced algorithms in these software modules include line-enhancement and edge-detection algorithms, surface-characterization algorithms, and algorithms that implement innovative data-fusion techniques. The line-extraction and edge-detection algorithms enable users to locate such features as faults and landslide headwall scarps. Also implemented in this software are improved methodologies for identification and mapping of past landslide events by use of (1) accurate, ELF-derived surface characterizations and (2) three LiDAR/optical-data-fusion techniques: post-classification data fusion, maximum-likelihood estimation modeling, and hierarchical within-class discrimination. This software is expected to enable faster, more accurate forecasting of natural hazards than has previously been possible.

  2. Li intercalation at graphene/hexagonal boron nitride interfaces

    NASA Astrophysics Data System (ADS)

    Shirodkar, Sharmila N.; Kaxiras, Efthimios

    2016-06-01

    Intercalation of Li in graphite and other layered structures is of interest for highly efficient energy storage devices. In this paper, we determine the extent to which Li intercalates at the different interfaces formed between graphene (G) and hexagonal boron nitride (hBN) heterostructures. We use ab initio calculations to explore in detail the position of the dispersed Li atoms, changes in the structure at the interfaces, energetic stability of the configurations, and the corresponding electronic structure with varying concentrations of the intercalant. We trace the origin of the energetic stability and maximum concentration of Li that intercalates into various layered structures to the ability of the interface to accept electrons. Our calculations indicate that Li intercalates easiest at G/G interfaces, followed by interfaces between G/hBN, whereas Li cannot intercalate in hBN/hBN interfaces. Our results provide a framework for the design of experimental setups with optimal Li intercalation and reveal the implications of intercalation on the dielectric properties of these materials and their possible application in plasmonics.

  3. Exploring tree species signature using waveform LiDAR data

    NASA Astrophysics Data System (ADS)

    Zhou, T.; Popescu, S. C.; Krause, K.

    2015-12-01

    Successful classification of tree species with waveform LiDAR data would be of considerable value to estimate the biomass stocks and changes in forests. Current approaches emphasize converting the full waveform data into discrete points to get larger amount of parameters and identify tree species using several discrete-points variables. However, ignores intensity values and waveform shapes which convey important structural characteristics. The overall goal of this study was to employ the intensity and waveform shape of individual tree as the waveform signature to detect tree species. The data was acquired by the National Ecological Observatory Network (NEON) within 250*250 m study area located in San Joaquin Experimental Range. Specific objectives were to: (1) segment individual trees using the smoothed canopy height model (CHM) derived from discrete LiDAR points; (2) link waveform LiDAR with above individual tree boundaries to derive sample signatures of three tree species and use these signatures to discriminate tree species in a large area; and (3) compare tree species detection results from discrete LiDAR data and waveform LiDAR data. An overall accuracy of the segmented individual tree of more than 80% was obtained. The preliminary results show that compared with the discrete LiDAR data, the waveform LiDAR signature has a higher potential for accurate tree species classification.

  4. The diffusive overshooting approach to Li abundance in clusters

    NASA Astrophysics Data System (ADS)

    Zhang, Q. S.

    2012-12-01

    Helioseimic investigation shows that convective overshooting can penetrate 0.37HP to the location where the temperature is 2.5 × 106 K, which is the typical temperature of the reaction Li7(p, α)He4. This indicates that overshooting mixing should be involved in investigating the solar Li abundance problem. Observations of the Li abundance of solar twins show that the Sun is not very peculiar. Overshooting mixing should also be involved in investigating Li abundance in clusters. However, fully overshooting mixing with a length of 0.37HP results in too much Li depletion to fit the observations in the solar case. Therefore, using the diffusive process to describe the overshooting is more suitable. The diffusive overshooting approach requires the turbulent root-mean-square velocity in the overshooting region in order to calculate the diffusion coefficient. Turbulent convection models (TCMs), which are suggested by helioseimic investigation, can provide the turbulent properties in the overshooting region. However, TCMs are often too complex to be applied in calculations of stellar evolution. There is an easier way to use the asymptotic solution of TCMs. In this paper the asymptotic solution of Li & Yang's TCM, which results in agreement in both solar sound speed and solar Li abundance, is used to investigate the Li abundance in clusters (Hyades, Praesepe, NGC 6633, NGC 752, NGC 3680 and M67). It is found that overshooting mixing leads to significant Li depletion in old clusters (t > 1 Gyr) and has little effect in young clusters (t < 1 Gyr).

  5. Expectation values of the e{sup +}Li system

    SciTech Connect

    Mitroy, J.

    2004-08-01

    Close to converged energies and expectation values for e{sup +}Li are computed using a ground state wave function consisting of 1200 explicitly correlated Gaussians. The best estimate of the e{sup +}Li energy was -7.532 895 5 hartree which has a binding energy of 0.002 482 hartree against dissociation into Ps+Li{sup +}. The 2{gamma} annihilation rate for the spin singlet state was 6.996x10{sup 9} s{sup -1}. The annihilation rate for the triplet state, taking into account core annihilation and the 3{gamma} decay, was 9.36x10{sup 6} s{sup -1}.

  6. Tensor Modeling Based for Airborne LiDAR Data Classification

    NASA Astrophysics Data System (ADS)

    Li, N.; Liu, C.; Pfeifer, N.; Yin, J. F.; Liao, Z. Y.; Zhou, Y.

    2016-06-01

    Feature selection and description is a key factor in classification of Earth observation data. In this paper a classification method based on tensor decomposition is proposed. First, multiple features are extracted from raw LiDAR point cloud, and raster LiDAR images are derived by accumulating features or the "raw" data attributes. Then, the feature rasters of LiDAR data are stored as a tensor, and tensor decomposition is used to select component features. This tensor representation could keep the initial spatial structure and insure the consideration of the neighborhood. Based on a small number of component features a k nearest neighborhood classification is applied.

  7. Fatigue crack growth behaviour of Al-Li alloys

    NASA Astrophysics Data System (ADS)

    Saravanakumar, R.; Ramakrishna, K. S.; Kanna, B. Avinash

    2013-06-01

    Al-Li alloys are being used in aircraft structures due to its low density and inherent mechanical properties. Fatigue Crack Growth (FCG) resistance is usually high compared to conventional Al-alloys attributed to increased modulus and crack closure. Extensive investigations concern about the FCG resistance and crack closure in Al-Li alloys. The present work reviews the FCG resistance in Al-Li alloys and the mechanisms associated with it. The alloy 8090 is taken for the consideration and sometimes compared with 2024.

  8. Dynamic dipole polarizability of Li{sup +} embedded in plasmas

    SciTech Connect

    Kar, S.; Kamali, M. Z. M.; Ratnavelu, K.

    2014-03-05

    Dynamic dipole polarizabilities of the system Li{sup +} embedded in weakly coupled plasmas are investigated using highly correlated exponential wave functions in the framework of the pseudostate summation technique. The Debye-Hückel shielding approach of plasma modeling is used to represent weakly coupled plasma environment. In free-atomic cases, results obtained from the present study are in agreement with the available calculations. Frequency-dependent polarizability of Li{sup +} as function of screening parameter is presented for the first time. Resonance frequencies for Li{sup +} are also presented in terms of screening parameter.

  9. Li metal for x-ray refractive optics

    SciTech Connect

    Pereira, Nino R.; Arms, Dohn A.; Clarke, Roy; Dierker, Steve B.; Dufresne, Eric; Foster, D.

    2004-01-27

    Lithium metal is the best material for refractive lenses that must focus x-rays with energies below 15 keV, but to date no lens from Li has been reported. This letter demonstrates focusing of 10 keV x-rays with a one-dimensional sawtooth lens made from Li. The lens theoretical gain is 4.5, with manufacturing imperfections likely responsible for the threefold gain that is observed. Despite the Li reactivity the lens is stable over months of operation if kept under vacuum.

  10. Electronic properties of Li-doped zigzag graphene nanoribbons

    NASA Astrophysics Data System (ADS)

    Narin, P.; Kutlu, E.; Sarikavak-Lisesivdin, B.; Lisesivdin, S. B.; Özbay, E.

    2016-10-01

    Zigzag graphene nanoribbons (ZGNRs) are known to exhibit metallic behavior. Depending on structural properties such as edge status, doping and width of nanoribbons, the electronic properties of these structures may vary. In this study, changes in electronic properties of crystal by doping Lithium (Li) atom to ZGNR structure are analyzed. In spin polarized calculations are made using Density Functional Theory (DFT) with generalized gradient approximation (GGA) as exchange correlation. As a result of calculations, it has been determined that Li atom affects electronic properties of ZGNR structure significantly. It is observed that ZGNR structure exhibiting metallic behavior in pure state shows half-metal and semiconductor behavior with Li atom.

  11. Probing the Reaction Pathway of Dehydrogenation of the LiNH2 + LiH Mixture Using In Situ 1H NMR Spectroscopy

    SciTech Connect

    Hu, Jian Zhi; Kwak, Ja Hun; Yang, Zhenguo; osborn, william; Markmaitree, Tippawan; Shaw, Leonard D.

    2008-06-15

    Using variable temperature in situ 1H NMR spectroscopy on a mixture of LiNH2 + LiH that was mechanically activated using high energy ball milling, the dehydrogenation of the LiNH2 + LiH to Li2NH + H2 was investigated. The analysis indicates NH3 release at a temperature as low as 300C and rapid reaction between NH3 and LiH at ~ 1500C. The transition from NH3 release to H2 appearance accompanied by disappearance of NH3 confirms unambiguously the two-step elementary reaction pathway proposed by other workers.

  12. Exploration of LiO2 by the method of electrochemical quartz crystal microbalance in TEGDME based Li-O2 battery

    NASA Astrophysics Data System (ADS)

    Lu, Yong; Tong, Shengfu; Qiu, Feilong; Jiang, Jie; Feng, Ningning; Zhang, Xueping; He, Ping; Zhou, Haoshen

    2016-10-01

    We confirmed the existence of LiO2 by electrochemical quartz crystal microbalance (EQCM) in TEGDME based Li-O2 batteries. Our results indicated that Li2O2 is generated through stepwise electrochemical reactions rather than disproportionation. We report for the first time that the formed Li2O2 oxidizes to LiO2 at relative negative potential and O2 at positive potential respectively. Our conclusions were based on both experimental observations and quantitative analysis. This may enlighten us to reconsider the Li-O2 batteries mechanisms in a quantitative way.

  13. Effects of electrolyte salts on the performance of Li-O2 batteries

    SciTech Connect

    Nasybulin, Eduard N.; Xu, Wu; Engelhard, Mark H.; Nie, Zimin; Burton, Sarah D.; Cosimbescu, Lelia; Gross, Mark E.; Zhang, Jiguang

    2013-02-05

    It is well known that the stability of nonaqueous electrolyte is critical for the rechargeable Li-O2 batteries. Although stability of many solvents used in the electrolytes has been investigated, considerably less attention has been paid to the stability of electrolyte salt which is the second major component. Herein, we report the systematic investigation of the stability of seven common lithium salts in tetraglyme used as electrolytes for Li-O2 batteries. The discharge products of Li-O2 reaction were analyzed by X-ray diffraction, X-ray photoelectron spectroscopy and nuclear magnetic resonance spectroscopy. The performance of Li-O2 batteries was strongly affected by the salt used in the electrolyte. Lithium tetrafluoroborate (LiBF4) and lithium bis(oxalato)borate (LiBOB) decompose and form LiF and lithium borates, respectively during the discharge of Li-O2 batteries. Several other salts, including lithium bis(trifluoromethane)sulfonamide (LiTFSI), lithium trifluoromethanesulfonate (LiTf), lithium hexafluorophosphate (LiPF6), lithium perchlorate (LiClO4) , and lithium bromide (LiBr) led to the discharge products which mainly consisted of Li2O2 and only minor signs of decomposition of LiTFSI, LiTf, LPF6 and LiClO4 were detected. LiBr showed the best stability during the discharge process. As for the cycling performance, LiTf and LiTFSI were the best among the studied salts. In addition to the instability of lithium salts, decomposition of tetraglyme solvent was a more significant factor contributing to the limited cycling stability. Thus a more stable nonaqueous electrolyte including organic solvent and lithium salt still need to be further developed to reach a fully reversible Li-O2 battery.

  14. Vaporization and thermochemical properties of Li 8Zr0 6 and comparison with other lithium-containing complex oxides

    NASA Astrophysics Data System (ADS)

    Asano, Mitsuru; Kato, Yoshinari; Harada, Toshio; Mizutani, Yasuo

    1996-06-01

    A mass-spectrometric Knudsen effusion method is used for the determination of partial pressures of Li (g), LiO (g), Li 2O (g), Li 2O 2 (g), Li 3O (g) and O 2 (g) over Li 8ZrO 6 (s/1) in the temperature range 1181-1429 K. From the gas-solid equilibria, enthalpies of formation for Li 8ZrO 6 (s) are calculated to be ΔfH298o (Li 8ZrO 6, s) = -(3558.5 ± 16.5) kJ mol -1 from the elements and ΔfoxH298o (Li 8ZrO 6, (s)= - (66.1 ± 18.6) kJ mol -1 from the constituent oxides, Li 2O(s) and ZrO 2 (s). Over various lithium-containing complex oxides, the partial pressures of Li 2O (g) decrease in the following order: Li 2O (s) > Li 5AlO 4(1) ≈ Li 2PbO 6 (s) ≈ Li 8ZrO 6 (s/1) ≈ Li 4TiO 4 (s/1) > Li 6Zr 2O 7 (s) > Li 2SnO 3 (s) > Li 4SiO 4 (s/1) > Li 2Ti 3 (s) ≈ Li 2ZrO 3 (s) > LiAlO 2 (s) ≈ Li 2SiO 3 (1) > LiNbO 3 (1). Thermodynamic activities and activity coefficients of the pseudo Li 2O component in the complex oxides are evaluated from the partial pressures of Li 2O (g). The results show that the complex oxides with less Li 20 molar content have more ability to stabilize the pseudo Li 2O component in binary Li 2OMO x, system (M  Al, Si, Ti and Zr).

  15. Studies on preventing Li dendrite formation in Li-S batteries by using pre-lithiated Si microwire anodes

    NASA Astrophysics Data System (ADS)

    Hagen, M.; Quiroga-González, E.; Dörfler, S.; Fahrer, G.; Tübke, J.; Hoffmann, M. J.; Althues, H.; Speck, R.; Krampfert, M.; Kaskel, S.; Föll, H.

    2014-02-01

    In this work, detailed studies on Li dendrite formation in Li-S Batteries are reported. Li dendrites can grow rapidly, may pierce through or can easily grow around the separator. Dendrites can even lead to short circuits when cathode and/or anode are wrapped with the separator. By replacing the Li metal anode with a pre-lithiated Si anode, these dendrite problems could be successfully prevented and were not observed for more than 200 cycles. The here used Si microwire array anodes are examined with ether and carbonate based electrolytes and different charging conditions vs. a Li metal counter electrode and demonstrate very high capacities matching the theoretical values. Electrochemical pre-lithiated Si microwire array anodes are examined in full cells with binder free, sulfur infiltrated carbon nanotube cathodes (CNT-S) and various polysulfide or Li2S containing electrolytes. The average polysulfide chain length and the presence of LiNO3 in the electrolyte have a great impact on the cycle stability of the cell, next to the charging conditions.

  16. Lithium motion in the anode material LiC6 as seen via time-domain 7Li NMR

    NASA Astrophysics Data System (ADS)

    Langer, J.; Epp, V.; Heitjans, P.; Mautner, F. A.; Wilkening, M.

    2013-09-01

    Since the commercialization of rechargeable lithium-ion energy storage systems in the early 1990s, graphite intercalation compounds (GICs) have served as the number one negative electrode material in most of today's batteries. During charging the performance of a battery is closely tied with facile Li insertion into the graphite host structure. So far, only occasionally time-domain nuclear magnetic resonance (NMR) measurements have been reported to study Li self-diffusion parameters in GICs. Here, we used several NMR techniques to enlighten Li hopping motions from an atomic-scale point of view. Li self-diffusion in the stage-1 GIC LiC6 has been studied comparatively by temperature-variable spin-spin relaxation NMR as well as (rotating frame) spin-lattice relaxation NMR. The data collected yield information on both the relevant activation energies and jump rates, which can directly be transformed into Li self-diffusion coefficients. At room temperature the Li self-diffusion coefficient turns out to be 10-15m2s-1, thus, slightly lower than that for layer-structured cathode materials such as Lix≈0.7TiS2.

  17. THE NEW DETECTIONS OF {sup 7}Li/{sup 6}Li ISOTOPIC RATIO IN THE INTERSTELLAR MEDIA

    SciTech Connect

    Kawanomoto, S.; Kajino, T.; Aoki, W.; Ando, H.; Noguchi, K.; Tanaka, W.; Bessell, M.; Suzuki, T. K.; Honda, S.; Izumiura, H.; Kambe, E.; Okita, K.; Watanabe, E.; Yoshida, M.; Sadakane, K.; Sato, B.; Tajitsu, A.; Takada-Hidai, M.

    2009-08-20

    We have determined the isotopic abundance ratio of {sup 7}Li/{sup 6}Li in the interstellar media (ISMs) along lines of sight to HD169454 and HD250290 using the High-Dispersion Spectrograph on the Subaru Telescope. We also observed {zeta} Oph for comparison with previous data. The observed abundance ratios were {sup 7}Li/{sup 6}Li = 8.1{sup +3.6} {sub -1.8} and 6.3{sup +3.0} {sub -1.7} for HD169454 and HD250290, respectively. These values are in reasonable agreement with those observed previously in the solar neighborhood ISMs within {+-}2{sigma} error bars and are also consistent with our measurement of {sup 7}Li/{sup 6}Li = 7.1{sup +2.9} {sub -1.6} for a cloud along the line of sight to {zeta} Oph. This is good evidence for homogeneous mixing and instantaneous recycling of the gas component in the Galactic disk. We also discuss several source compositions of {sup 7}Li, Galactic cosmic-ray interactions, stellar nucleosynthesis, and big bang nucleosynthesis.

  18. Adsorption of insoluble polysulfides Li2S(x) (x = 1, 2) on Li2S surfaces.

    PubMed

    Liu, Zhixiao; Hubble, Dion; Balbuena, Perla B; Mukherjee, Partha P

    2015-04-14

    In lithium-sulfur batteries, the growth of insulating discharge product Li2S film affects the cathode microstructure and the related electron as well as lithium ion transport properties. In this study, chemical reactions of insoluble lithium polysulfides Li2Sx (x = 1, 2) on crystal Li2S substrate are investigated by a first-principles approach. First-principles atomistic thermodynamics predicts that the stoichiometric (111) and (110) surfaces are stable around the operating cell voltage. Li2Sx adsorption is an exothermic reaction with the (110) surface being more active to react with the polysulfides than the stoichiometric (111) surface. There is no obvious charge transfer between the adsorbed molecule and the crystal Li2S substrate. Analysis of the charge density difference suggests that the adsorbate interacts with the substrate via a strong covalent bond. The growth mechanism of thermodynamically stable surfaces is investigated in the present study. It is found that direct Li2S deposition is energetically favored over Li2S2 deposition and reduction process. PMID:25752296

  19. Optically pumped cerium-doped LiSrAlF.sub.6 and LiCaAlF.sub.6

    DOEpatents

    Marshall, Christopher D.; Payne, Stephen A.; Krupke, William F.

    1996-01-01

    Ce.sup.3+ -doped LiSrAlF.sub.6 crystals are pumped by ultraviolet light which is polarized along the c axis of the crystals to effectively energize the laser system. In one embodiment, the polarized fourth harmonic light output from a conventional Nd:YAG laser operating at 266 nm is arranged to pump Ce:LiSrAlF.sub.6 with the pump light polarized along the c axis of the crystal. The Ce:LiSrAlF.sub.6 crystal may be placed in a laser cavity for generating tunable coherent ultraviolet radiation in the range of 280-320 nm. Additionally, Ce-doped crystals possessing the LiSrAlF.sub.6 type of chemical formula, e.g. Ce-doped LiCaAlF.sub.6 and LiSrGaF.sub.6, can be used. Alternative pump sources include an ultraviolet-capable krypton or argon laser, or ultraviolet emitting flashlamps. The polarization of the pump light will impact operation. The laser system will operate efficiently when light in the 280-320 nm gain region is injected or recirculated in the system such that the beam is also polarized along the c axis of the crystal. The Ce:LiSrAlF.sub.6 laser system can be configured to generate ultrashort pulses, and it may be used to pump other devices, such as an optical parametric oscillator.

  20. Optically pumped cerium-doped LiSrAlF{sub 6} and LiCaAlF{sub 6}

    DOEpatents

    Marshall, C.D.; Payne, S.A.; Krupke, W.F.

    1996-05-14

    Ce{sup 3+}-doped LiSrAlF{sub 6} crystals are pumped by ultraviolet light which is polarized along the c axis of the crystals to effectively energize the laser system. In one embodiment, the polarized fourth harmonic light output from a conventional Nd:YAG laser operating at 266 nm is arranged to pump Ce:LiSrAlF{sub 6} with the pump light polarized along the c axis of the crystal. The Ce:LiSrAlF{sub 6} crystal may be placed in a laser cavity for generating tunable coherent ultraviolet radiation in the range of 280-320 nm. Additionally, Ce-doped crystals possessing the LiSrAlF{sub 6} type of chemical formula, e.g. Ce-doped LiCaAlF{sub 6} and LiSrGaF{sub 6}, can be used. Alternative pump sources include an ultraviolet-capable krypton or argon laser, or ultraviolet emitting flashlamps. The polarization of the pump light will impact operation. The laser system will operate efficiently when light in the 280-320 nm gain region is injected or recirculated in the system such that the beam is also polarized along the c axis of the crystal. The Ce:LiSrAlF{sub 6} laser system can be configured to generate ultrashort pulses, and it may be used to pump other devices, such as an optical parametric oscillator. 10 figs.

  1. On the hyperfine structures of the ground state(s) in the 6Li and 7Li atoms

    NASA Astrophysics Data System (ADS)

    Frolov, A. M.

    2016-06-01

    The hyperfine structure of the ground 22 S-states of the three-electron atoms and ions is investigated. By using our recent numerical values for the doublet electron density at the atomic nucleus, we determine the hyperfine structure of the ground (doublet) 22 S-state(s) in the 6Li and 7Li atoms. Our predicted values (228.2058 and 803.5581 MHz, respectively) agree well with the experimental values 228.20528(8) MHz (6Li) and 803.50404(48) MHz (7Li [R.G. Schlecht and D.W. McColm, Phys. Rev. 142, 11 (1966)]). The hyperfine structures of a number of lithium isotopes with short lifetimes, including 8Li, 9Li, and 11Li atoms are also predicted. The same method is used to obtain the hyperfine structures of the three-electron 7Be+ and 9Be+ ions in their ground 22 S-states. Finally, we conclude that our approach can be generalized to describe the hyperfine structure in the triplet n 3 S-states of the four-electron atoms and ions.

  2. Y-doped Li8ZrO6: A Li-Ion Battery Cathode Material with High Capacity.

    PubMed

    Huang, Shuping; Wilson, Benjamin E; Wang, Bo; Fang, Yuan; Buffington, Keegan; Stein, Andreas; Truhlar, Donald G

    2015-09-01

    We study--experimentally and theoretically--the energetics, structural changes, and charge flows during the charging and discharging processes for a new high-capacity cathode material, Li8ZrO6 (LZO), which we study both pure and yttrium-doped. We quantum mechanically calculated the stable delithiated configurations, the delithiation energy, the charge flow during delithiation, and the stability of the delithiated materials. We find that Li atoms are easier to extract from tetrahedral sites than octahedral ones. We calculate a large average voltage of 4.04 eV vs Li/Li(+) for delithiation of the first Li atom in a primitive cell, which is confirmed by galvanostatic charge/discharge cycling data. Energy calculations indicate that topotactic delithiation is kinetically favored over decomposition into Li, ZrO2, and O2 during the charging process, although the thermodynamic energy of the topotactic reaction is less favorable. When one or two lithium atoms are extracted from a primitive cell of LZO, its volume and structure change little, whereas extraction of the third lithium greatly distorts the layered structure. The Li6ZrO6 and Li5ZrO6 delithiation products can be thermodynamically metastable to release of O2. Experimentally, materials with sufficiently small particle size for efficient delithiation and relithiation were achieved within an yttrium-doped LZO/carbon composite cathode that exhibited an initial discharge capacity of at least 200 mAh/g over the first 10 cycles, with 142 mAh/g maintained after 60 cycles. Computations predict that during the charging process, the oxygen ion near the Li vacancy is oxidized for both pure LZO and yttrium-doped LZO, which leads to a small-polaron hole. PMID:26264394

  3. OH - absorption in off-congruent LiNbO 3 crystals prepared by Li-poor vapor transport equilibration

    NASA Astrophysics Data System (ADS)

    Zhang, De-Long; Hua, Ping-Rang; Pun, Edwin Yue-Bun

    2009-06-01

    An X-cut and a Z-cut Li-deficient, non-congruent LiNbO 3 crystal were prepared by carrying out Li-poor vapor transport equilibration (VTE) treatment on one mm thick congruent plates at 1100 °C for 170 h. From the measured optical absorption edges (OAE), the Li 2O content is evaluated to be 47.74 ± 0.13 mol% in the X-cut plate and 47.61 ± 0.13 mol% in the Z-cut VTE crystal. The composition homogeneity is verified by measuring the OAE as a function of the crystal thickness. The visible optical absorption and powder X-ray diffraction studies allow to conclude that both VTE crystals retain still the LiNbO 3 phase. OH - absorption characteristics of the two VTE crystals were investigated in comparison with those of the as-grown crystals. The results show that the Li-poor VTE treatment only slightly modifies the area, spectral width, spectral shape and background absorption of the OH - band. Comparison shows that the Li-poor VTE effects on the OH - absorption have large differences from the Li-rich VTE effects in bandwidth and areas of three component peaks at 3466, 3481 and 3488 cm -1. These spectral differences are explained on the basis of the H + site occupation and crystal defect models taking into account the VTE effect on crystal defect concentration. The Li-poor VTE effects are attributed to the VTE inducing the redistribution of OH - ions in different sites.

  4. Lithium and Isotopic Ratio Li6/Li7 in Magnetic roAp Stars as an Indicator of Active Processes

    NASA Astrophysics Data System (ADS)

    Polosukhina, N.; Shavrina, A.; Lyashko, D.; Nesvacil, N.; Drake, N.; Smirnova, M.

    2015-04-01

    The lines of lithium at 6708 Å and 6103 Å are analyzed in high resolution spectra of some sharp-lined and slowly rotating roAp stars. Three spectral synthesis codes— STARSP, ZEEMAN2, and SYNTHM—were used. New lines of rare earth elements (REE) from the DREAM database and the lines calculated on the basis of the NIST energy levels were included. Magnetic splitting and other line broadening processes were taken into account. For both lithium lines, the enhanced abundances of lithium in the atmospheres of the stars studied are obtained. The lithium abundance determined from the Li 6103 Å line is higher than that from the Li 6708 Å for all the stars. This may be evidence of vertical lithium stratification, abnormal temperature distribution, or unidentified blending of the 6103 Å line. Our work on two roAp stars, HD 83368 and HD 60435 (Shavrina et al. 2001) provides evidence of an enhanced lithium abundance near the magnetic-field poles. We can expect similar effects in the sharp-lined roAp stars. High lithium abundance for all the stars and the estimates of the 6Li/7Li ratio (0.2-0.5) can be explained by production of Li in the cosmic ray spallation reactions in the interstellar medium where the stars were born, and by preservation of the original 6Li and 7Li by strong magnetic fields of these stars. The values of the 6Li/7Li ratio expected from production by cosmic rays are about 0.5-0.8 (Knauth et al. 2003; Webber et al. 2002). New laboratory and theoretical gf-values for REE lines are necessary in order to refine our estimates of lithium abundances and the isotopic ratio.

  5. The effect of the carbon nanotube buffer layer on the performance of a Li metal battery

    NASA Astrophysics Data System (ADS)

    Zhang, Ding; Zhou, Yi; Liu, Changhong; Fan, Shoushan

    2016-05-01

    Lithium (Li) metal is one of the most promising candidates as an anode for the next-generation energy storage systems because of its high specific capacity and lowest negative electrochemical potential. But the growth of Li dendrites limits the application of the Li metal battery. In this work, a type of modified Li metal battery with a carbon nanotube (CNT) buffer layer inserted between the separator and the Li metal electrode was reported. The electrochemical results show that the modified batteries have a much better rate capability and cycling performance than the conventional Li metal batteries. The mechanism study by electrochemical impedance spectroscopy reveals that the modified battery has a smaller charge transfer resistance and larger Li ion diffusion coefficient during the deposition process on the Li electrode than the conventional Li metal batteries. Symmetric battery tests show that the interfacial behavior of the Li metal electrode with the buffer layer is more stable than the naked Li metal electrode. The morphological characterization of the CNT buffer layer and Li metal lamina reveals that the CNT buffer layer has restrained the growth of Li dendrites. The CNT buffer layer has great potential to solve the safety problem of the Li metal battery.Lithium (Li) metal is one of the most promising candidates as an anode for the next-generation energy storage systems because of its high specific capacity and lowest negative electrochemical potential. But the growth of Li dendrites limits the application of the Li metal battery. In this work, a type of modified Li metal battery with a carbon nanotube (CNT) buffer layer inserted between the separator and the Li metal electrode was reported. The electrochemical results show that the modified batteries have a much better rate capability and cycling performance than the conventional Li metal batteries. The mechanism study by electrochemical impedance spectroscopy reveals that the modified battery has a

  6. An iodide-based Li7P2S8I superionic conductor.

    PubMed

    Rangasamy, Ezhiylmurugan; Liu, Zengcai; Gobet, Mallory; Pilar, Kartik; Sahu, Gayatri; Zhou, Wei; Wu, Hui; Greenbaum, Steve; Liang, Chengdu

    2015-02-01

    In an example of stability from instability, a Li(7)P(2)S(8)I solid-state Li-ion conductor derived from β-Li(3)PS(4) and LiI demonstrates electrochemical stability up to 10 V vs Li/Li(+). The oxidation instability of I is subverted via its incorporation into the coordinated structure. The inclusion of I also creates stability with the metallic Li anode while simultaneously enhancing the interfacial kinetics and ionic conductivity. Low-temperature membrane processability enables facile fabrication of dense membranes, making this conductor suitable for industrial adoption.

  7. Deposition studies of lithium and bismuth at tungsten microelectrodes in LiCl:KCl eutectic

    NASA Astrophysics Data System (ADS)

    Carlin, Richard T.; Osteryoung, Robert A.

    1989-05-01

    Tungsten microelectrodes (diam = 25 microns) have been used to study the deposition and stripping behavior of Li/Li(+) and Bi/Bi(3+) in the LiCl:KCl eutectic at 400 C. The Li deposition current can be simulated assuming the growth of a single hemisphere of liquid metal on the microelectrode. High stripping current densities were observed and quantitated using standard electrochemical equipment. An inverted microscope assembly was employed for in situ observation of the Li/Li(+) deposition and stripping processes at the microelectrode. A precipitate appears to form in the melt surrounding the electrode during Li deposition.

  8. Li3PO4-doped Li7P3S11 glass-ceramic electrolytes with enhanced lithium ion conductivities and application in all-solid-state batteries

    NASA Astrophysics Data System (ADS)

    Huang, Bingxin; Yao, Xiayin; Huang, Zhen; Guan, Yibiao; Jin, Yi; Xu, Xiaoxiong

    2015-06-01

    70Li2S·(30-x)P2S5·xLi3PO4 (mol%) amorphous powders are prepared by a high-energy ball milling technique, and the glass-ceramics are obtained by the crystallization of as-prepared amorphous samples. The XRD patterns show that a crystalline phase with a Li7P3S11 structure is obtained for x ≤ 3, while a structure change is observed for x = 5. The Li+-ion conductivity is enhanced by the substitution of Li3PO4 for P2S5, and the 70Li2S·29P2S5·1Li3PO4 glass-ceramics exhibit the highest total conductivity of 1.87 × 10-3 S cm-1 at 25 °C and the lowest activation energy of 18 kJ mol-1. The LiCoO2 in the all-solid-state cell of In-Li/70Li2S·29P2S5·1Li3PO4/LiCoO2 exhibits a discharge capacity of 108 mAh g-1, which is 20% higher than that in the In-Li/70Li2S·30P2S5/LiCoO2 cell. The higher discharge capacity of the LiCoO2 electrode is attributed to the higher Li+-ion conductivity of the solid electrolyte and lower interface resistance of electrode-electrolyte.

  9. Reversible lithium intercalation in a lithium-rich layered rocksalt Li2RuO3 cathode through a Li3PO4 solid electrolyte

    NASA Astrophysics Data System (ADS)

    Zheng, Yueming; Hirayama, Masaaki; Taminato, Sou; Lee, Soyeon; Oshima, Yoshifumi; Takayanagi, Kunio; Suzuki, Kota; Kanno, Ryoji

    2015-12-01

    Li2RuO3 (001) films with a lithium-rich layered rocksalt structure are epitaxially grown on a Al2O3(0001) substrate through pulsed laser deposition, followed by stacking of an amorphous Li3PO4 solid electrolyte. A half solid-state battery with a Li3PO4/Li2RuO3 cathode, liquid electrolyte, and lithium anode exhibits two redox peak pairs at 3.4 and 3.6 V, demonstrating lithium intercalation in the Li2RuO3 through the Li3PO4 solid electrolyte. All-solid-state batteries are fabricated by Li or In metal anode deposition on the Li3PO4/Li2RuO3. The Li/Li3PO4/Li2RuO3 cell delivers an initial discharge capacity of 101 mAh g-1, which does not fade significantly over 30 cycles. Furthermore, the Li2RuO3 rate capability is comparable to that of a liquid-type battery. Lithium-rich layered materials are available for use as cathodes in all-solid-state batteries.

  10. Growth of lanthanide-doped LiGdF4 nanoparticles induced by LiLuF4 core as tri-modal imaging bioprobes.

    PubMed

    Zhai, Xuesong; Lei, Pengpeng; Zhang, Peng; Wang, Zhuo; Song, Shuyan; Xu, Xia; Liu, Xiuling; Feng, Jing; Zhang, Hongjie

    2015-10-01

    Multimodal imaging can compensate for the deficiencies and incorporate the advantages of individual imaging modalities. In this paper, we demonstrated the synthesis of core-shell nanocomposites LiLuF4@LiGdF4:Yb,Er/Tm constituted of tetragonal LiLuF4 nanoparticles as core and Yb,Er/Tm-codoped LiGdF4 as shell. LiLuF4@LiGdF4:Yb,Er/Tm nanoparticles display brighter upconversion luminescence (UCL) than NaGdF4:Yb,Er/Tm nanoparticles with the same size under continuous-wave excitation at 980 nm. The active shell layer of LiGdF4:Yb,Er/Tm not only provide the UCL center, but also serve as magnetic resonance (MR) imaging contrast agent. To further improve the UCL intensity, the inert LiGdF4 shell was coated on the LiLuF4@LiGdF4:Yb,Er/Tm nanoparticles. Furthermore, LiLuF4@LiGdF4:Yb,Tm@LiGdF4 nanoparticles have been successfully applied to UCL/X-ray computed tomography (CT)/MR tri-modal imaging on the modal of tumor-bearing mice. PMID:26148475

  11. Electrochemical Investigation of Al–Li/LixFePO4 Cells in Oligo(ethylene glycol) Dimethyl Ether/LiPF6

    SciTech Connect

    Wang, X.J.; Zhou, Y.N.; Lee, H.S.; Nam, K.W.; Yang, X.Q.; Haas, O.

    2011-02-01

    1 M LiPF{sub 6} dissolved in oligo(ethylene glycol) dimethyl ether with a molecular weight, 500 g mol{sup -1} (OEGDME500, 1 M LiPF{sub 6}), was investigated as an electrolyte in experimental Al-Li/LiFePO{sub 4} cells. More than 60 cycles were achieved using this electrolyte in a Li-ion cell with an Al-Li alloy as an anode sandwiched between two Li x FePO{sub 4} electrodes (cathodes). Charging efficiencies of 96-100% and energy efficiencies of 86-89% were maintained during 60 cycles at low current densities. A theoretical investigation revealed that the specific energy can be increased up to 15% if conventional LiC{sub 6} anodes are replaced by Al-Li alloy electrodes. The specific energy and the energy density were calculated as a function of the active mass per electrode surface (charge density). The results reveal that for a charge density of 4 mAh cm{sup -2} about 160 mWh g{sup -1} can be reached with Al-Li/LiFePO{sub 4} batteries. Power limiting diffusion processes are discussed, and the power capability of Al-Li/LiFePO{sub 4} cells was experimentally evaluated using conventional electrolytes.

  12. Electrochemical performance of LiCoO2/SrLi2Ti6O14 batteries for high-power applications

    NASA Astrophysics Data System (ADS)

    Liu, Jianhong; Sun, Xiaoman; Li, Yanan; Wang, Xingqin; Gao, Yun; Wu, Ke; Wu, Ningning; Wu, Borong

    2014-01-01

    LiCoO2/SrLi2Ti6O14 Li-ion rechargeable batteries with ∼6 Ah capacities are designed and assembled for use in hybrid electric vehicle (HEV) applications. For comparison, LiCoO2/Li4Ti5O12 batteries are also constructed using similar processing parameters. Power tests are carried out using the hybrid pulse power characterization (HPPC) method. Experimental results show that the LiCoO2/SrLi2Ti6O14 batteries have better power performance and more stable charge/discharge direct current (DC) resistances compared with the LiCoO2/Li4Ti5O12 batteries. At a 50% depth of discharge (DOD), LiCoO2/SrLi2Ti6O14 batteries have an excellent specific charge power density of 3973 W kg-1, which can be attributed to the high Li diffusion capability and high electronic conductivity of the SrLi2Ti6O14 material.

  13. Measurement of the absolute and differential cross sections for 7Li(γ, n0)6Li

    SciTech Connect

    W.A. Wurtz, R.E. Pywell, B.E. Norum, S. Kucuker, B.D. Sawatzky, H.R. Weller, M.W. Ahmed, S. Stave

    2011-10-01

    We have measured the cross section of the photoneutron reaction channel {sup 7}Li+{gamma}{yields}{sup 6}Li(g.s.)+n where the progeny nucleus is the ground state of {sup 6}Li. We obtained the absolute cross section at photon energies 10, 11, 12, 13, 15, 20, 25, 30, and 35 MeV and also the dependence of the cross section on polar angle for all but the highest photon energy. For the energies 10 to 15 MeV we were able to use linearly polarized photons to obtain the dependence of the cross section on the photon polarization.

  14. Viscosity and carbon dioxide solubility for LiPF6, LiTFSI, and LiFAP in alkyl carbonates: lithium salt nature and concentration effect.

    PubMed

    Dougassa, Yvon Rodrigue; Jacquemin, Johan; El Ouatani, Loubna; Tessier, Cécile; Anouti, Mérièm

    2014-04-10

    In this paper, we have reported the CO2 solubility in different pure alkyl carbonate solvents (EC, DMC, EMC, DEC) and their binary mixtures as EC/DMC, EC/EMC, and EC/DEC and for electrolytes [solvent + lithium salt] LiX (X = LiPF6, LiTFSI, or LiFAP) as a function of the temperature and salt concentration. To understand the parameters that influence the structure of the solvents and their ability to dissolve CO2, through the addition of a salt, we first analyzed the viscosities of EC/DMC + LiX mixtures by means of a modified Jones-Dole equation. The results were discussed considering the order or disorder introduced by the salt into the solvent organization and ion solvation sphere by calculating the effective solute ion radius, rs. On the basis of these results, the analysis of the CO2 solubility variations with the salt addition was then evaluated and discussed by determining specific ion parameters Hi by using the Setchenov coefficients in solution. This study showed that the CO2 solubility has been affected by the shape, charge density, and size of the ions, which influence the structuring of the solvents through the addition of a salt and the type of solvation of the ions.

  15. Ion hopping in crystalline and glassy spodumene LiAl Si2 O6 : 7Li spin-lattice relaxation and 7Li echo NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Qi, F.; Rier, C.; Böhmer, R.; Franke, W.; Heitjans, P.

    2005-09-01

    Nuclear magnetic resonance spectroscopy was used to study polycrystalline β -spodumene (β-LiAlSi2O6) as well as glassy specimens with the same chemical composition. Li7 spin-lattice relaxation measurements were carried out in a broad temperature range and for several Larmor frequencies. In addition to a pronounced rate maximum at high temperatures, stemming from the long-range Li motion in these aluminosilicates, we found a weak maximum in the crystalline modification near 120K . The latter result confirms the existence of a local double-well structure in which the Li ions reside. The ionic motion was also monitored by solid- and stimulated-echo spectra as well as by the decay of the Jeener-Broekaert echo. Under conditions which are discussed in detail, the latter is a direct measure of the hopping correlation function. For the glass this function was found to decay faster and more stretched than that of the crystal at a given temperature. Furthermore, the relevant barriers against the high-temperature long-range Li motion are larger in the crystal as compared to the glass.

  16. LiCaAl/sub 6/:Cr/sup 3+/

    SciTech Connect

    Payne, S.A.; Chase, L.L.; Newkirk, H.W.; Smith, L.K.; Krupke, W.F. )

    1988-11-01

    The authors report the discovery of a new laser, LiCaAIF/sub 6/:Cr/sup 3/ (Cr/sup 3+/ :LiCAF). The intrinsic (extrapolated maximum) slope efficiency was found to be 67 percent. For comparison, they also measured the intrinsic slope efficiencies of BeAl/sub 2/O/sub 4/:Cr/sup 3+/ (alexandrite), Na/sub 3/Ga/sub 2/Li/sub 3/F/sub 12/:Cr/sup 3+/, and ScBO/sub 3/:Cr/sup 3+/, and obtained values of 65,28, and 26 percent, respectively. The tuning range of LiCaAIF/sub 6/:Cr/sup 3+/ was determined to be at least 720-840 nm. The conventional spectroscopic properties, such as the absorption, emission, and emission lifetimes as a function of temperature, are reported as well.

  17. 20-Gbps optical LiFi transport system.

    PubMed

    Ying, Cheng-Ling; Lu, Hai-Han; Li, Chung-Yi; Cheng, Chun-Jen; Peng, Peng-Chun; Ho, Wen-Jeng

    2015-07-15

    A 20-Gbps optical light-based WiFi (LiFi) transport system employing vertical-cavity surface-emitting laser (VCSEL) and external light injection technique with 16-quadrature amplitude modulation (QAM)-orthogonal frequency-division multiplexing (OFDM) modulating signal is proposed. Good bit error rate (BER) performance and clear constellation map are achieved in our proposed optical LiFi transport systems. An optical LiFi transport system, delivering 16-QAM-OFDM signal over a 6-m free-space link, with a data rate of 20 Gbps, is successfully demonstrated. Such a 20-Gbps optical LiFi transport system provides the advantage of a free-space communication link for high data rates, which can accelerate the visible laser light communication (VLLC) deployment. PMID:26176448

  18. Stability of polymer binders in Li-O2 batteries

    SciTech Connect

    Nasybulin, Eduard N.; Xu, Wu; Engelhard, Mark H.; Nie, Zimin; Li, Xiaohong S.; Zhang, Jiguang

    2013-06-24

    A number of polymers with various chemical structures were studied as binders for air electrodes in Li-O2 batteries. The nature of the polymer significantly affects the binding properties in the carbon electrodes thus altering the discharge performance of Li-O2 batteries. Stability of polymers to the aggressive reduced oxygen species generated during discharge was tested by ball milling them with KO2 and Li2O2, respectively. Most of the polymers decomposed under these conditions and mechanisms of the decompositions are proposed for some of the polymers. Polyethylene was found to have excellent stability and is suggested as robust binder for air electrodes in Li-O2 batteries.

  19. LiBr passivation effect of porous nanocrystalline hydrogenated silicon

    NASA Astrophysics Data System (ADS)

    Amor, Sana Ben; Haddadi, Ikbel; Seif, El Whibi; Daik, Ridha; Bousbih, Rabaa; Dimassi, Wissem; Ezzaouia, Hatem

    2015-12-01

    Nanocrystalline hydrogenated silicon (nc-Si:H) films were deposited on a p-type silicon substrate by plasma enhanced chemical vapor deposition (PECVD), using SiH4 and H2 as reactive gases. Porous (nc-Si:H) layers were afterward obtained and immersed in a lithium bromide (LiBr) aqueous solution in order to enhance their optical and electrical properties for a potential solar cells application. A decrease in the reflectivity to about 9% for Li/porous nc-Si:H layer deposited at 75 sccm against an increase in the minority carrier lifetime were obtained. We correlate these results to the change in crystalline characteristics and chemical composition of the layers in order to understand the effect of LiBr coating on nc-Si:H Through optical and electrical characterization we have demonstrated the possibility of using such LiBr treatment to improve the properties of porous nc-Si:H.

  20. Observation of interspecies 6Li-133Cs Feshbach resonances

    NASA Astrophysics Data System (ADS)

    Repp, M.; Pires, R.; Ulmanis, J.; Heck, R.; Kuhnle, E. D.; Weidemüller, M.; Tiemann, E.

    2013-01-01

    We report on the observation of 19 interspecies Feshbach resonances in an optically trapped ultracold Bose-Fermi mixture of 133Cs and 6Li in the two energetically lowest spin states. We assign the resonances to s- and p-wave molecular channels by a coupled-channels calculation, resulting in an accurate determination of LiCs ground-state potentials. Fits of the resonance position based on the undressed asymptotic bound state model do not provide the same level of accuracy as the coupled-channels calculation. Several broad s-wave resonances provide prospects to create fermionic LiCs molecules with a large dipole moment via Feshbach association followed by stimulated Raman passage. Two of the s-wave resonances overlap with a zero crossing of the Cs scattering length, which offers prospects for the investigation of polarons in an ultracold Li-Cs mixture.

  1. Methods and preliminary measurement results of liquid Li wettability

    SciTech Connect

    Zuo, G. Z. Hu, J. S.; Ren, J.; Sun, Z.; Yang, Q. X.; Li, J. G.; Zakharov, L. E.; Mansfield, D. K.

    2014-02-15

    A test of lithium wettability was performed in high vacuum (< 3 × 10{sup −4} Pa). High magnification images of Li droplets on stainless steel substrates were produced and processed using the MATLAB{sup ®} program to obtain clear image edge points. In contrast to the more standard “θ/2” or polynomial fitting methods, ellipse fitting of the complete Li droplet shape resulted in reliable contact angle measurements over a wide range of contact angles. Using the ellipse fitting method, it was observed that the contact angle of a liquid Li droplet on a stainless steel substrate gradually decreased with increasing substrate temperature. The critical wetting temperature of liquid Li on stainless steel was observed to be about 290 °C.

  2. Oxygen Selective Membranes for Li-Air (O2) Batteries

    PubMed Central

    Crowther, Owen; Salomon, Mark

    2012-01-01

    Lithium-air (Li-air) batteries have a much higher theoretical energy density than conventional lithium batteries and other metal air batteries, so they are being developed for applications that require long life. Water vapor from air must be prevented from corroding the lithium (Li) metal negative electrode during discharge under ambient conditions, i.e., in humid air. One method of protecting the Li metal from corrosion is to use an oxygen selective membrane (OSM) that allows oxygen into the cell while stopping or slowing the ingress of water vapor. The desired properties and some potential materials for OSMs for Li-air batteries are discussed and the literature is reviewed. PMID:24958173

  3. Automatic registration method for mobile LiDAR data

    NASA Astrophysics Data System (ADS)

    Wang, Ruisheng; Ferrie, Frank P.

    2015-01-01

    We present an automatic mutual information (MI) registration method for mobile LiDAR and panoramas collected from a driving vehicle. The suitability of MI for registration of aerial LiDAR and aerial oblique images has been demonstrated under an assumption that minimization of joint entropy (JE) is a sufficient approximation of maximization of MI. We show that this assumption is invalid for the ground-level data. The entropy of a LiDAR image cannot be regarded as approximately constant for small perturbations. Instead of minimizing the JE, we directly maximize MI to estimate corrections of camera poses. Our method automatically registers mobile LiDAR with spherical panoramas over an approximate 4-km drive, and is the first example we are aware of that tests MI registration in a large-scale context.

  4. Characteristics of Li diffusion on silicene and zigzag nanoribbon

    NASA Astrophysics Data System (ADS)

    Yan-Hua, Guo; Jue-Xian, Cao; Bo, Xu

    2016-01-01

    We perform a density functional study on the adsorption and diffusion of Li atoms on silicene sheet and zigzag nanoribbons. Our results show that the diffusion energy barrier of Li adatoms on silicene sheet is 0.25 eV, which is much lower than on graphene and Si bulk. The diffusion barriers along the axis of zigzag silicene nanoribbon range from 0.1 to 0.25 eV due to an edge effect, while the diffusion energy barrier is about 0.5 eV for a Li adatom to enter into a silicene nanoribbon. Our calculations indicate that using silicene nanoribbons as anodes is favorable for a Li-ion battery. Project supported by the National Natural Science Foundation of China (Grant Nos. 11074212 and 11204123) and the Natural Science Foundation of Jiangsu province, China (Grant No. BK20130945).

  5. An Iodide-Based Li 7 P 2 S 8 I Superionic Conductor

    DOE PAGES

    Rangasamy, Ezhiylmurugan; Liu, Zengcai; Gobet, Mallory; Pilar, Kartik; Sahu, Gayatri; Zhou, Wei; Wu, Hui; Greenbaum, Steve; Liang, Chengdu

    2015-01-20

    Stability from Instability: A Li7P2S8I solid state Li-ion conductor derived from -Li3PS4 and LiI demonstrates exceptional electrochemical stability. The oxidation instability of I is subverted nullified via its incorporation into the coordinated structure. The inclusion of I also creates stability with metallic Li anode while simultaneously improving the interfacial kinetics. Low temperature membrane processability enables facile fabrication of dense membranes, making it suitable for industrial adoption.

  6. The Li isotope composition of modern biogenic carbonates

    NASA Astrophysics Data System (ADS)

    Dellinger, M.; West, A. J.; Adkins, J. F.; Paris, G.; Eagle, R.; Freitas, P. S.; Bagard, M. L.; Ries, J. B.; Corsetti, F. A.; Pogge von Strandmann, P.; Ullmann, C. V.

    2015-12-01

    The lithium stable isotope composition (δ7Li) of sedimentary carbonates has great potential to unravel weathering rates and intensity in the past, with implications for understanding the carbon cycle over geologic time. However, so far very little is known about the potential influence of fractionation of the stable Li isotope composition of biogenic carbonates. Here, we investigate the δ7Li of various organisms (particularly mollusks, echinoderms and brachiopods) abundant in the Phanerozoic record, in order to understand which geologic archives might provide the best targets for reconstructing past seawater composition. The range of measured samples includes (i) modern calcite and aragonite shells from variable natural environments, (ii) shells from organisms grown under controlled conditions (temperature, salinity, pCO2), and (iii) fossil shells from a range of species collected from Miocene deposits. When possible, both the inner and outer layers of bivalves were micro-sampled to assess the intra-shell heterogeneity. For calcitic shells, the measured δ7Li of bivalve species range from +32 to +41‰ and is systematically enriched in the heavy isotope relative to seawater (31 ‰) and to inorganic calcite, which is characterized by Δ7Licalcite-seawater = -2 to -5‰ [1]. The Li isotope composition of aragonitic bivalves, ranging from +16 to +22‰, is slightly fractionated to both high and low δ7Li relative to inorganic aragonite. The largest intra-shell Li isotope variability is observed for mixed calcite-aragonite shells (more than 20‰) whereas in single mineralogy shells, intra-shell δ7Li variability is generally less than 3‰. Overall, these results suggest a strong influence of vital effects on Li isotopes during bio-calcification of bivalve shells. On the contrary, measured brachiopods systematically exhibit fractionation that is very similar to inorganic calcite, with a mean δ7Li of 27.0±1.5‰, suggesting that brachiopods may provide good

  7. New Anode Material for Rechargeable Li-ION Cells

    NASA Technical Reports Server (NTRS)

    Huang, C. -K.; Smart, M.; Halpert, G.; Surampudi, S.; Wolfenstine, J.

    1995-01-01

    Carbon materials, such as graphite, cokes, pitch and PAN fibers, are being evaluated in lithium batteries as alternate anode materials with some degree of success. There is an effort to look for other non-carbon anode materials which have larger Li capacity, higher rate capability, smaller first charge capacity loss and better mechanical stability during cycling. A Li-Mg-Si material is evaluated.

  8. Lost in Translation (LiT): IUPHAR Review 6.

    PubMed

    Dollery, Colin T

    2014-05-01

    Translational medicine is a roller coaster with occasional brilliant successes and a large majority of failures. Lost in Translation 1 ('LiT1'), beginning in the 1950s, was a golden era built upon earlier advances in experimental physiology, biochemistry and pharmacology, with a dash of serendipity, that led to the discovery of many new drugs for serious illnesses. LiT2 saw the large-scale industrialization of drug discovery using high-throughput screens and assays based on affinity for the target molecule. The links between drug development and university sciences and medicine weakened, but there were still some brilliant successes. In LiT3, the coverage of translational medicine expanded from molecular biology to drug budgets, with much greater emphasis on safety and official regulation. Compared with R&D expenditure, the number of breakthrough discoveries in LiT3 was disappointing, but monoclonal antibodies for immunity and inflammation brought in a new golden era and kinase inhibitors such as imatinib were breakthroughs in cancer. The pharmaceutical industry is trying to revive the LiT1 approach by using phenotypic assays and closer links with academia. LiT4 faces a data explosion generated by the genome project, GWAS, ENCODE and the 'omics' that is in danger of leaving LiT4 in a computerized cloud. Industrial laboratories are filled with masses of automated machinery while the scientists sit in a separate room viewing the results on their computers. Big Data will need Big Thinking in LiT4 but with so many unmet medical needs and so many new opportunities being revealed there are high hopes that the roller coaster will ride high again. PMID:24428732

  9. Modelling rating curves using remotely sensed LiDAR data

    USGS Publications Warehouse

    Nathanson, Marcus; Kean, Jason W.; Grabs, Thomas J.; Seibert, Jan; Laudon, Hjalmar; Lyon, Steve W.

    2012-01-01

    Accurate stream discharge measurements are important for many hydrological studies. In remote locations, however, it is often difficult to obtain stream flow information because of the difficulty in making the discharge measurements necessary to define stage-discharge relationships (rating curves). This study investigates the feasibility of defining rating curves by using a fluid mechanics-based model constrained with topographic data from an airborne LiDAR scanning. The study was carried out for an 8m-wide channel in the boreal landscape of northern Sweden. LiDAR data were used to define channel geometry above a low flow water surface along the 90-m surveyed reach. The channel topography below the water surface was estimated using the simple assumption of a flat streambed. The roughness for the modelled reach was back calculated from a single measurment of discharge. The topographic and roughness information was then used to model a rating curve. To isolate the potential influence of the flat bed assumption, a 'hybrid model' rating curve was developed on the basis of data combined from the LiDAR scan and a detailed ground survey. Whereas this hybrid model rating curve was in agreement with the direct measurements of discharge, the LiDAR model rating curve was equally in agreement with the medium and high flow measurements based on confidence intervals calculated from the direct measurements. The discrepancy between the LiDAR model rating curve and the low flow measurements was likely due to reduced roughness associated with unresolved submerged bed topography. Scanning during periods of low flow can help minimize this deficiency. These results suggest that combined ground surveys and LiDAR scans or multifrequency LiDAR scans that see 'below' the water surface (bathymetric LiDAR) could be useful in generating data needed to run such a fluid mechanics-based model. This opens a realm of possibility to remotely sense and monitor stream flows in channels in remote

  10. Shipborne LiDAR system for coastal change monitoring

    NASA Astrophysics Data System (ADS)

    Kim, chang hwan; Park, chang hong; Kim, hyun wook; hyuck Kim, won; Lee, myoung hoon; Park, hyeon yeong

    2016-04-01

    Coastal areas, used as human utilization areas like leisure space, medical care, ports and power plants, etc., are regions that are continuously changing and interconnected with oceans and land and the sea level has risen by about 8cm (1.9mm / yr) due to global warming from 1964 year to 2006 year in Korea. Coastal erosion due to sea-level rise has caused the problem of marine ecosystems and loss of tourism resources, etc. Regular monitoring of coastal erosion is essential at key locations with such volatility. But the survey method of land mobile LiDAR (light detection and ranging) system has much time consuming and many restrictions. For effective monitoring beach erosion, KIOST (Korea Institute of Ocean Science & Technology) has constructed a shipborne mobile LiDAR system. The shipborne mobile LiDAR system comprised a land mobile LiDAR (RIEGL LMS-420i), an INS (inertial navigation system, MAGUS Inertial+), a RTKGPS (LEICA GS15 GS25), and a fixed platform. The shipborne mobile LiDAR system is much more effective than a land mobile LiDAR system in the measuring of fore shore areas without shadow zone. Because the vessel with the shipborne mobile LiDAR system is continuously moved along the shoreline, it is possible to efficiently survey a large area in a relatively short time. Effective monitoring of the changes using the constructed shipborne mobile LiDAR system for seriously eroded coastal areas will be able to contribute to coastal erosion management and response.

  11. Luminescence in Li2BaP2O7.

    PubMed

    Hatwar, L R; Wankhede, S P; Moharil, S V; Muthal, P L; Dhopte, S M

    2015-09-01

    The photo-, thermo- and optically stimulated luminescence in Li2BaP2O7 activated with Eu(2+) /Cu(+) are reported. Strong thermoluminescence, which is about two times greater than LiF-TLD 100 was observed in the Eu(2+) -activated sample. It also exhibited optically stimulated luminescence sensitivity of ~20% that of commercial Al2O3:C phosphor. PMID:25351563

  12. Repetitively pulsed Cr:LiSAF laser for lidar applications

    SciTech Connect

    Shimada, Tsutomu; Early, J.W.; Lester, C.S.; Cockroft, N.J.

    1994-03-01

    A Cr:LiSAF laser has been successfully operated at time averaged powers up to 11 W and at pulse repetition rates to 12 Hz. During Q-switch operation, output energy as high as 450 mJ (32 ns FWHM) was obtained. Finally, line narrowed Q-switched pulses (< 0.1 nm) from the Cr:LiSAF laser were successfully used as a tunable light source for lidar to measure atmospheric water content.

  13. Double and triple photoionization of Li and Be

    SciTech Connect

    Colgan, J.; Pindzola, M.S.; Robicheaux, F.

    2005-08-15

    We present calculations for the double photoionization (with excitation) and the triple photoionization of Li and Be. We extend and more fully discuss the previous calculations made for Li by Colgan et al. [Phys. Rev. Lett. 93, 053201 (2004)] and present calculations for Be. The Be triple photoionization cross sections are compared with previous double shake-off model calculations of Kheifets and Bray [J. Phys. B 36, L211 (2003)], and our calculations are found to be significantly lower.

  14. Investigation of interfacial resistance between LiCoO 2 cathode and LiPON electrolyte in the thin film battery

    NASA Astrophysics Data System (ADS)

    Jeong, Eunkyung; Hong, Chan; Tak, Yongsug; Nam, Sang Cheol; Cho, Sungbaek

    All solid-state thin film battery was prepared with conventional sputtering technologies. Low conductivity of lithium phosphorus oxynitride (LiPON) electrolyte and higher resistance at the interface of LiCoO 2/LiPON was crucial for the development of thin film battery. Presence of thermally treated Al 2O 3 thin film at the interface of LiCoO 2/LiPON decreased the interfacial resistance and increased the discharge capacity with the better cycling behaviors. Surface analysis and electrochemical impedance measurement indicate the formation of solid solution LiCo 1- yAl yO 2 at the interface of LiCoO 2/LiPON.

  15. Recognizing Excellence: Pinging--Sound at Work

    ERIC Educational Resources Information Center

    Lindquist, William; Forsberg, Britt

    2014-01-01

    One author shares the unique opportunity to be immersed in the science of "sound at work" through participation in NOAA's (National Oceanic and Atmospheric Administration) Teacher at Sea Program. A third- through fifth-grade learning outcome within the Nature of Science section of the "Next Generation Science Standards"…

  16. An Atmospheric Pressure Ping-Pong "Ballometer"

    ERIC Educational Resources Information Center

    Kazachkov, Alexander; Kryuchkov, Dmitriy; Willis, Courtney; Moore, John C.

    2006-01-01

    Classroom experiments on atmospheric pressure focus largely on demonstrating its existence, often in a most impressive way. A series of amusing physics demonstrations is widely known and practiced by educators teaching the topic. However, measuring the value of atmospheric pressure(P[subscript atm]) is generally done in a rather mundane way,…

  17. Te/C nanocomposites for Li-Te Secondary Batteries

    PubMed Central

    Seo, Jeong-Uk; Seong, Gun-Kyu; Park, Cheol-Min

    2015-01-01

    New battery systems having high energy density are actively being researched in order to satisfy the rapidly developing market for longer-lasting mobile electronics and hybrid electric vehicles. Here, we report a new Li-Te secondary battery system with a redox potential of ~1.7 V (vs. Li+/Li) adapted on a Li metal anode and an advanced Te/C nanocomposite cathode. Using a simple concept of transforming TeO2 into nanocrystalline Te by mechanical reduction, we designed an advanced, mechanically reduced Te/C nanocomposite electrode material with high energy density (initial discharge/charge: 1088/740 mA h cm−3), excellent cyclability (ca. 705 mA h cm−3 over 100 cycles), and fast rate capability (ca. 550 mA h cm−3 at 5C rate). The mechanically reduced Te/C nanocomposite electrodes were found to be suitable for use as either the cathode in Li-Te secondary batteries or a high-potential anode in rechargeable Li-ion batteries. We firmly believe that the mechanically reduced Te/C nanocomposite constitutes a breakthrough for the realization and mass production of excellent energy storage systems. PMID:25609035

  18. Georeferenced LiDAR 3D Vine Plantation Map Generation

    PubMed Central

    Llorens, Jordi; Gil, Emilio; Llop, Jordi; Queraltó, Meritxell

    2011-01-01

    The use of electronic devices for canopy characterization has recently been widely discussed. Among such devices, LiDAR sensors appear to be the most accurate and precise. Information obtained with LiDAR sensors during reading while driving a tractor along a crop row can be managed and transformed into canopy density maps by evaluating the frequency of LiDAR returns. This paper describes a proposed methodology to obtain a georeferenced canopy map by combining the information obtained with LiDAR with that generated using a GPS receiver installed on top of a tractor. Data regarding the velocity of LiDAR measurements and UTM coordinates of each measured point on the canopy were obtained by applying the proposed transformation process. The process allows overlap of the canopy density map generated with the image of the intended measured area using Google Earth®, providing accurate information about the canopy distribution and/or location of damage along the rows. This methodology was applied and tested on different vine varieties and crop stages in two important vine production areas in Spain. The results indicate that the georeferenced information obtained with LiDAR sensors appears to be an interesting tool with the potential to improve crop management processes. PMID:22163952

  19. Li and Be depletion in metal-poor subgiants

    NASA Astrophysics Data System (ADS)

    García Pérez, A. E.; Primas, F.

    2006-02-01

    A sample of metal-poor subgiants has been observed with the UVES spectrograph at the Very Large Telescope and abundances of Li and Be have been determined. Typical signal-to-noise per spectral bin values for the co-added spectra are of the order of 500 for the ion{Li}{i} line (670.78 nm) and 100 for the ion{Be}{ii} doublet lines (313.04 nm). The spectral analysis of the observations was carried out using the Uppsala suite of codes and marcs (1D-LTE) model atmospheres with stellar parameters from photometry, parallaxes, isochrones and Fe ii lines. Abundance estimates of the light elements were corrected for departures from local thermodynamic equilibrium in the line formation. Effective temperatures and Li abundances seem to be correlated and Be abundances correlate with [O/H]. Standard models predict Li and Be abundances approximately one order of magnitude lower than main-sequence values which is in general agreement with the observations. On average, our observed depletions seem to be 0.1 dex smaller and between 0.2 and 0.4 dex larger (depending on which reference is taken) than those predicted for Li and Be, respectively. This is not surprising since the initial Li abundance, as derived from main-sequence stars on the Spite plateau, may be systematically in error by 0.1 dex or more, and uncertainties in the spectrum normalisation and continuum drawing may affect our Be abundances systematically.

  20. Georeferenced LiDAR 3D vine plantation map generation.

    PubMed

    Llorens, Jordi; Gil, Emilio; Llop, Jordi; Queraltó, Meritxell

    2011-01-01

    The use of electronic devices for canopy characterization has recently been widely discussed. Among such devices, LiDAR sensors appear to be the most accurate and precise. Information obtained with LiDAR sensors during reading while driving a tractor along a crop row can be managed and transformed into canopy density maps by evaluating the frequency of LiDAR returns. This paper describes a proposed methodology to obtain a georeferenced canopy map by combining the information obtained with LiDAR with that generated using a GPS receiver installed on top of a tractor. Data regarding the velocity of LiDAR measurements and UTM coordinates of each measured point on the canopy were obtained by applying the proposed transformation process. The process allows overlap of the canopy density map generated with the image of the intended measured area using Google Earth(®), providing accurate information about the canopy distribution and/or location of damage along the rows. This methodology was applied and tested on different vine varieties and crop stages in two important vine production areas in Spain. The results indicate that the georeferenced information obtained with LiDAR sensors appears to be an interesting tool with the potential to improve crop management processes.

  1. Anion-redox nanolithia cathodes for Li-ion batteries

    NASA Astrophysics Data System (ADS)

    Zhu, Zhi; Kushima, Akihiro; Yin, Zongyou; Qi, Lu; Amine, Khalil; Lu, Jun; Li, Ju

    2016-08-01

    The development of lithium-air batteries is plagued by a high potential gap (>1.2 V) between charge and discharge, and poor cyclability due to the drastic phase change of O2 (gas) and Ox- (condensed phase) at the cathode during battery operations. Here we report a cathode consisting of nanoscale amorphous lithia (nanolithia) confined in a cobalt oxide, enabling charge/discharge between solid Li2O/Li2O2/LiO2 without any gas evolution. The cathode has a theoretical capacity of 1,341 Ah kg-1, a mass density exceeding 2.2 g cm-3, and a practical discharge capacity of 587 Ah kg-1 at 2.55 V versus Li/Li+. It also displays stable cycling performance (only 1.8% loss after 130 cycles in lithium-matched full-cell tests against Li4Ti5O12 anode), as well as a round-trip overpotential of only 0.24 V. Interestingly, the cathode is automatically protected from O2 gas release and overcharging through the shuttling of self-generated radical species soluble in the carbonate electrolyte.

  2. Te/C nanocomposites for Li-Te Secondary Batteries.

    PubMed

    Seo, Jeong-Uk; Seong, Gun-Kyu; Park, Cheol-Min

    2015-01-01

    New battery systems having high energy density are actively being researched in order to satisfy the rapidly developing market for longer-lasting mobile electronics and hybrid electric vehicles. Here, we report a new Li-Te secondary battery system with a redox potential of ~1.7 V (vs. Li(+)/Li) adapted on a Li metal anode and an advanced Te/C nanocomposite cathode. Using a simple concept of transforming TeO2 into nanocrystalline Te by mechanical reduction, we designed an advanced, mechanically reduced Te/C nanocomposite electrode material with high energy density (initial discharge/charge: 1088/740 mA h cm(-3)), excellent cyclability (ca. 705 mA h cm(-3) over 100 cycles), and fast rate capability (ca. 550 mA h cm(-3) at 5C rate). The mechanically reduced Te/C nanocomposite electrodes were found to be suitable for use as either the cathode in Li-Te secondary batteries or a high-potential anode in rechargeable Li-ion batteries. We firmly believe that the mechanically reduced Te/C nanocomposite constitutes a breakthrough for the realization and mass production of excellent energy storage systems.

  3. Te/C nanocomposites for Li-Te Secondary Batteries

    NASA Astrophysics Data System (ADS)

    Seo, Jeong-Uk; Seong, Gun-Kyu; Park, Cheol-Min

    2015-01-01

    New battery systems having high energy density are actively being researched in order to satisfy the rapidly developing market for longer-lasting mobile electronics and hybrid electric vehicles. Here, we report a new Li-Te secondary battery system with a redox potential of ~1.7 V (vs. Li+/Li) adapted on a Li metal anode and an advanced Te/C nanocomposite cathode. Using a simple concept of transforming TeO2 into nanocrystalline Te by mechanical reduction, we designed an advanced, mechanically reduced Te/C nanocomposite electrode material with high energy density (initial discharge/charge: 1088/740 mA h cm-3), excellent cyclability (ca. 705 mA h cm-3 over 100 cycles), and fast rate capability (ca. 550 mA h cm-3 at 5C rate). The mechanically reduced Te/C nanocomposite electrodes were found to be suitable for use as either the cathode in Li-Te secondary batteries or a high-potential anode in rechargeable Li-ion batteries. We firmly believe that the mechanically reduced Te/C nanocomposite constitutes a breakthrough for the realization and mass production of excellent energy storage systems.

  4. Synthesis and characterisation of copper doped Ca-Li hydroxyapatite

    NASA Astrophysics Data System (ADS)

    Pogosova, M. A.; Kazin, P. E.; Tretyakov, Y. D.

    2012-08-01

    Hydroxyapapites M10(PO4)6(OH)2 (MHAP), where M is an alkaline earth metal, colored by incorporation of copper ions substituting protons, were discovered recently [1]. Now this kind of apatite-type materials can be used as inorganic pigments. Until now blue (BaHAP), violet (SrHAP) and wine-red (CaHAP) colors were achieved by the copper ions introduction [2]. The task of the present work was to study possibility of further M-ion substitution to affect the color and shift it toward the red-orange tint. Polycrystalline hydroxyapatites Ca10-xLix+yCuz(PO4)6O2H2-y-z-σ (Ca-LiHAP) were synthesized by solid state reaction at 1150 °C (ceramic method) and studied by X-ray powder diffraction (XRD), infrared absorption and diffuse-reflectance spectroscopy. Refinement of the X-ray diffraction patterns by the Rietveld method shows that CaHAP unit cell parameters are a little bigger, than Ca-LiHAP ones. Small difference between unit cell parameters could be caused by two ways of the Li+ ions introduction: (1) at the Ca2+ sites (Ca-Li substitution); (2) into hexagonal channels (H-Li substitution). The Li ions doping changes the color of the copper doped CaHAP from wine-red to pink and red.

  5. Georeferenced LiDAR 3D vine plantation map generation.

    PubMed

    Llorens, Jordi; Gil, Emilio; Llop, Jordi; Queraltó, Meritxell

    2011-01-01

    The use of electronic devices for canopy characterization has recently been widely discussed. Among such devices, LiDAR sensors appear to be the most accurate and precise. Information obtained with LiDAR sensors during reading while driving a tractor along a crop row can be managed and transformed into canopy density maps by evaluating the frequency of LiDAR returns. This paper describes a proposed methodology to obtain a georeferenced canopy map by combining the information obtained with LiDAR with that generated using a GPS receiver installed on top of a tractor. Data regarding the velocity of LiDAR measurements and UTM coordinates of each measured point on the canopy were obtained by applying the proposed transformation process. The process allows overlap of the canopy density map generated with the image of the intended measured area using Google Earth(®), providing accurate information about the canopy distribution and/or location of damage along the rows. This methodology was applied and tested on different vine varieties and crop stages in two important vine production areas in Spain. The results indicate that the georeferenced information obtained with LiDAR sensors appears to be an interesting tool with the potential to improve crop management processes. PMID:22163952

  6. Anion-redox nanolithia cathodes for Li-ion batteries

    NASA Astrophysics Data System (ADS)

    Zhu, Zhi; Kushima, Akihiro; Yin, Zongyou; Qi, Lu; Amine, Khalil; Lu, Jun; Li, Ju

    2016-08-01

    The development of lithium–air batteries is plagued by a high potential gap (>1.2 V) between charge and discharge, and poor cyclability due to the drastic phase change of O2 (gas) and Ox‑ (condensed phase) at the cathode during battery operations. Here we report a cathode consisting of nanoscale amorphous lithia (nanolithia) confined in a cobalt oxide, enabling charge/discharge between solid Li2O/Li2O2/LiO2 without any gas evolution. The cathode has a theoretical capacity of 1,341 Ah kg‑1, a mass density exceeding 2.2 g cm‑3, and a practical discharge capacity of 587 Ah kg‑1 at 2.55 V versus Li/Li+. It also displays stable cycling performance (only 1.8% loss after 130 cycles in lithium-matched full-cell tests against Li4Ti5O12 anode), as well as a round-trip overpotential of only 0.24 V. Interestingly, the cathode is automatically protected from O2 gas release and overcharging through the shuttling of self-generated radical species soluble in the carbonate electrolyte.

  7. Neutron detection with LiInSe2

    NASA Astrophysics Data System (ADS)

    Bell, Zane W.; Burger, A.; Matei, Liviu; Groza, Michael; Stowe, Ashley; Tower, Joshua; Kargar, Alireza; Hong, Huicong

    2015-08-01

    The detection of thermal neutrons has traditionally been accomplished with 3He-tubes, but with the recent shortage of 3He, much research has gone into finding suitable replacements. Both relatively inefficient 10B- and 6LiF-coated silicon diodes and HgI2 have been known for many years, and engineered structures in Si that have been filled with 10B and 6LiF have shown promise. These devices are intended to realize an optimal juxtaposition of neutron-sensitive material and semiconductor and thereby simulate a semiconductor containing B or Li. Such material has been realized for the first time in the form of 6LiInSe2 in which collectable charge from the 6Li(n,t) reaction indicates a neutron event. In this paper we report neutron and gamma responses of 6LiInSe2, we show pulse height spectra from pure gamma sources and from a thermal neutron source, and we derive the μτ product from the position of spectral features as a function of bias voltage. In addition, we demonstrate the observation of the beta decay of 116mIn in samples exposed to thermal neutrons. This feature of the response serves as an additional confirmation of exposure to neutrons.

  8. Investigations of the safety of Li/SOCl2 batteries

    NASA Astrophysics Data System (ADS)

    Abraham, K. M.; Mank, R. M.; Holleck, G. L.

    1980-02-01

    Forced overdischarge behavior of Li/SOCl2 cells was studied using spirally wound C-size and small prismatic cells. Cathode and anode limited cells were tested. Cathode limited cells could be forcibly overdischarged for long periods of time without explosions. Anode limited cells, on the other hand, were found to be potentially hazardous. Our data suggest that anode limited cells are likely to explode during forced overdischarge. The behavior of Li/SOCl2 cells during application of a (charge) current was investigated using C-size cells. It was possible to subject either new or partially discharged cells to a (charging) current without apparent hazard. The charging reactions involve a sequence of regenerative processes so that only small amounts of chemicals accumulate in the cells. On the basis of materials characterized from IR spectral and cyclic voltammetry data, a mechanism is proposed for the oxidation reactions in SOCl2/LiAlCl4 solutions. Preliminary studies indicated that Li2S/AlCl3 based electrolytes may be useful as alternatives to LiAlCl4 in Li/SOCl2 batteries.

  9. Towards a Li barometer for bimineralic eclogites: experiments in CMAS

    NASA Astrophysics Data System (ADS)

    Hanrahan, Margaret; Brey, Gerhard; Woodland, Alan; Altherr, Rainer; Seitz, Hans-Micheal

    2009-08-01

    An eclogite barometer has profound importance in the study of upper mantle processes and potential application to diamond prospecting. Studies on the partitioning of Li between clinopyroxene (cpx) and garnet (grt) in natural samples have shown that this particular element is very sensitive to changes in pressure and could be calibrated as the barometer demanded for bimineralic eclogites. Experiments were performed from 4 to 13 GPa and 1,100-1,400°C in the CMAS (CaO, MgO, Al2O3, SiO2) system with Li added as Li3PO4 to quantify this pressure dependence into a barometer expressed in the following equation: P = (0.00255 T - ln K d)/0.2351 where P is in GPa, T is in °C and K d is defined as the partition coefficient of Li (in ppm) between clinopyroxene and garnet. The experimental pressures are reproduced to ±0.38 GPa (1σ) by this equation. This barometer is strictly applicable only to CMAS. Experiments at 1,300°C, 8-12 GPa showed that Henry’s Law is fulfilled for Li partitioning between cpx and grt in the concentration range of approximately 0.01-1 wt% Li. Direct application of the equation to experiments in natural systems performed at 1,300°C from 4 to 13 GPa consistently overestimates pressures by approximately 2 GPa.

  10. Lithium hydroxide, LiOH, at elevated densities

    SciTech Connect

    Hermann, Andreas; Ashcroft, N. W.; Hoffmann, Roald

    2014-07-14

    We discuss the high-pressure phases of crystalline lithium hydroxide, LiOH. Using first-principles calculations, and assisted by evolutionary structure searches, we reproduce the experimentally known phase transition under pressure, but we suggest that the high-pressure phase LiOH-III be assigned to a new hydrogen-bonded tetragonal structure type that is unique amongst alkali hydroxides. LiOH is at the intersection of both ionic and hydrogen bonding, and we examine the various ensuing structural features and their energetic driving mechanisms. At P = 17 GPa, we predict another phase transition to a new phase, Pbcm-LiOH-IV, which we find to be stable over a wide pressure range. Eventually, at extremely high pressures of 1100 GPa, the ground state of LiOH is predicted to become a polymeric structure with an unusual graphitic oxygen-hydrogen net. However, because of its ionic character, the anticipated metallization of LiOH is much delayed; in fact, its electronic band gap increases monotonically into the TPa pressure range.

  11. Fluoro-Carbonate Solvents for Li-Ion Cells

    SciTech Connect

    NAGASUBRAMANIAN,GANESAN

    1999-09-17

    A number of fluoro-carbonate solvents were evaluated as electrolytes for Li-ion cells. These solvents are fluorine analogs of the conventional electrolyte solvents such as dimethyl carbonate, ethylene carbonate, diethyl carbonate in Li-ion cells. Conductivity of single and mixed fluoro carbonate electrolytes containing 1 M LiPF{sub 6} was measured at different temperatures. These electrolytes did not freeze at -40 C. We are evaluating currently, the irreversible 1st cycle capacity loss in carbon anode in these electrolytes and the capacity loss will be compared to that in the conventional electrolytes. Voltage stability windows of the electrolytes were measured at room temperature and compared with that of the conventional electrolytes. The fluoro-carbon electrolytes appear to be more stable than the conventional electrolytes near Li voltage. Few preliminary electrochemical data of the fluoro-carbonate solvents in full cells are reported in the literature. For example, some of the fluorocarbonate solvents appear to have a wider voltage window than the conventional electrolyte solvents. For example, methyl 2,2,2 trifluoro ethyl carbonate containing 1 M LiPF{sub 6} electrolyte has a decomposition voltage exceeding 6 V vs. Li compared to <5 V for conventional electrolytes. The solvent also appears to be stable in contact with lithium at room temperature.

  12. Li+ ion transport studies in Li2O-Li2SO4-ZnO-B2O3 glass system

    NASA Astrophysics Data System (ADS)

    Kolavekar, Sangeeta B.; Lakshmikantha, R.; Ayachit, N. H.; Anavekar, R. V.

    2013-06-01

    Li+ ion transport studies have been carried in Li2O-Li2SO4-ZnO-B2O3 glass system. Electrical conductivity has been measured out over a wide range of temperature (450K-500K) and frequencies (40 Hz - 10 MHz). The dc conductivities show Arrhenius behavior and show compositional dependence. The ac conductivity behavior has been analyzed using Almond-West power law using a single exponent. The exponent `s' obtained from the power law fits is found to have values ranging from 0.36 - 0.45 in these glasses and shows temperature dependence, which is attributed to high degree of modification in the glass network.

  13. Mg2Si As Li-Intercalation Host For Li Cells

    NASA Technical Reports Server (NTRS)

    Huang, Chen-Kuo; Surampudi, Subbarao; Attia, Alan; Halpert, Gerald

    1993-01-01

    Compound Mg2Si shows promise as lithium-intercalation host for ambient-temperature rechargeable lithium electrochemical cells. As anode reactant material, LiXMg2Si chemically stable in presence of organic electrolyte used in such cells and stores large amounts of lithium. Intercalation reactions highly reversible at room temperature. Also retains sufficient mechanical strength during charge/discharge cycling. Lithium cells containing LixMg2Si anodes prove useful in spacecraft, military, communications, automotive, and other applications in which high energy-storage densities of lithium cells in general and rechargeability of cells needed.

  14. Single-crystalline LiFePO4 nanosheets for high-rate Li-ion batteries.

    PubMed

    Zhao, Yu; Peng, Lele; Liu, Borui; Yu, Guihua

    2014-05-14

    The lithiation/delithiation in LiFePO4 is highly anisotropic with lithium-ion diffusion being mainly confined to channels along the b-axis. Controlling the orientation of LiFePO4 crystals therefore plays an important role for efficient mass transport within this material. We report here the preparation of single crystalline LiFePO4 nanosheets with a large percentage of highly oriented {010} facets, which provide the highest pore density for lithium-ion insertion/extraction. The LiFePO4 nanosheets show a high specific capacity at low charge/discharge rates and retain significant capacities at high C-rates, which may benefit the development of lithium batteries with both favorable energy and power density.

  15. Identity of Passive Film Formed on Aluminum in Li-ion BatteryElectrolytes with LiPF6

    SciTech Connect

    Zhang, Xueyuan; Devine, T.M.

    2006-09-01

    The passive film that forms on aluminum in 1:1 ethylene carbonate + ethylmethyl carbonate with 1.2M LiPF{sub 6} and 1:1 ethylene carbonate + dimethyl carbonate with 1.0M LiPF{sub 6} was investigated by a combination of electrochemical quartz crystal microbalance measurements (EQCM), electrochemical impedance spectroscopy (EIS), and x-ray photoelectron spectroscopy. During anodic polarization of aluminum a film of AlF{sub 3} forms on top of the air-formed oxide, creating a duplex, or two-layered film. The thickness of the AlF{sub 3} increases with the applied potential. Independent measurements of film thickness by EQCM and EIS indicate that at a potential of 5.5V vs. Li/Li{sup +}, the thickness of the AlF{sub 3} is approximately 1 nm.

  16. Laser performance of in-band pumped Er : LiYF4 and Er : LiLuF4 crystals

    NASA Astrophysics Data System (ADS)

    Gorbachenya, K. N.; Kurilchik, S. V.; Kisel, V. E.; Yasukevich, A. S.; Kuleshov, N. V.; Nizamutdinov, A. S.; Korableva, S. L.; Semashko, V. V.

    2016-02-01

    Spectroscopic properties of Er : LiLuF4 and Er : LiYF4 crystals in the spectral region near 1.5 μm and the lasing characteristics of these crystals under in-band pumping at a wavelength of 1522 nm are studied. With the Er : LiLuF4 crystal, the maximum slope efficiency with respect to the absorbed pump power was 44% at a wavelength of 1609 nm. Continuous-wave operation of an inband pumped Er : LiYF4 laser is obtained for the first time. The output power at a wavelength of 1606 nm was 58 mW with a slope efficiency of 21%.

  17. Probing the failure mechanism of nanoscale LiFePO{sub 4} for Li-ion batteries

    SciTech Connect

    Gu, Meng; Yan, Pengfei; Wang, Chongmin; Shi, Wei; Zheng, Jianming; Zhang, Ji-guang

    2015-05-18

    LiFePO{sub 4} is a high power rate cathode material for lithium ion battery and shows remarkable capacity retention, featuring a 91% capacity retention after 3300 cycles. In this work, we use high-resolution transmission electron microscopy and electron energy loss spectroscopy to study the gradual capacity fading mechanism of LiFePO{sub 4} materials. We found that upon prolonged electrochemical cycling of the battery, the LiFePO{sub 4} cathode shows surface amorphization and loss of oxygen species, which directly contribute to the gradual capacity fading of the battery. The finding can guide the design and improvement of LiFePO{sub 4} cathode for high-energy and high-power rechargeable battery for electric transportation.

  18. Are lithium niobate (LiNbO3) and lithium tantalate (LiTaO3) ferroelectrics bioactive?

    PubMed

    Vilarinho, Paula Maria; Barroca, Nathalie; Zlotnik, Sebastian; Félix, Pedro; Fernandes, Maria Helena

    2014-06-01

    The use of functional materials, such as ferroelectrics, as platforms for tissue growth in situ or ex situ, is new and holds great promise. But the usage of materials in any bioapplication requires information on biocompatibility and desirably on bioactive behavior when bone tissue engineering is envisaged. Both requirements are currently unknown for many ferroelectrics. Herein the bioactivity of LiNbO3 and LiTaO3 is reported. The formation of apatite-like structures on the surface of LiNbO3 and LiTaO3 powders after immersion in simulated body fluid (SBF) for different soaking periods indicates their bioactive potential. The mechanism of apatite formation is suggested. In addition, the significant release of lithium ions from the ferroelectric powders in the very first minutes of soaking in SBF is examined and ways to overcome this likely hurdle addressed.

  19. Structural Evolution and Li Dynamics in Nanophase Li3PS4 by Solid-State and Pulsed Field Gradient NMR

    SciTech Connect

    Gobet, Mallory; Greenbaum, Steve; Sahu, Gayatri; Liang, Chengdu

    2014-01-01

    The ceramic lithium ion conductor -Li3PS4 has a disordered and nanoporous structure that leads to an enhancement in ionic conductivity by some three orders of magnitude compared to the crystalline phase. The phase is prepared by thermal treatment of an inorganic-organic complex based on Li3PS4 and THF. Multinuclear (1H, 6,7Li, 31P) solid state NMR spectroscopy is used to characterize the structural phase evolution of the starting material at various steps in the thermal treatment. The phase formed after high temperature treatment is recognized as spectroscopically distinct from the bulk -Li3PS4 compound. Also formed is an amorphous lithium thiophosphate phase that is metastable as verified by annealing over an extended period. Lithium ion self-diffusion coefficients are measurable by standard pulsed gradient NMR methods at 100oC and with values consistent with the high ionic conductivity previously reported for this material.

  20. THE HIGH TEMPERATURE CHEMICAL REACTIVITY OF LI2O

    SciTech Connect

    Kessinger, G.; Missimer, D.

    2009-11-13

    The ultimate purpose of this study was to investigate the use of a Li-Ca mixture for direct reduction of actinide oxides to actinide metals at temperatures below 1500 C. For such a process to be successful, the products of the reduction reaction, actinide metals, Li{sub 2}O, and CaO, must all be liquid at the reaction temperature so the resulting actinide metal can coalesce and be recovered as a monolith. Since the established melting temperature of Li{sub 2}O is in the range 1427-1700 C and the melting temperature of CaO is 2654 C, the Li{sub 2}O-CaO (lithium oxidecalcium oxide) pseudo-binary system was investigated in an attempt to identify the presence of low-melting eutectic compositions. The results of our investigation indicate that there is no evidence of ternary Li-Ca-O phases or solutions melting below 1200 C. In the 1200-1500 C range utilizing MgO crucibles, there is some evidence for the formation of a ternary phase; however, it was not possible to determine the phase composition. The results of experiments performed with ZrO{sub 2} crucibles in the same temperature range did not show the formation of the possible ternary phase seen in the earlier experiment involving MgO crucibles, so it was not possible to confirm the possibility that a ternary Li-Ca-O or Li-Mg-O phase was formed. It appears that the Li{sub 2}O-CaO materials reacted, to some extent, with all of the container materials, alumina (Al{sub 2}O{sub 3}), magnesia (MgO), zirconia (ZrO{sub 2}), and 95% Pt-5% Au; however, to clarify the situation additional experiments are required. In addition to the primary purpose of this study, the results of this investigation led to the conclusions that: (1) The melting temperature of Li{sub 2}O may be as low as 1250 C, which is considerably lower than the previously published values in the range 1427-1700 C; (2) Lithium oxide (Li{sub 2}O) vaporizes congruently; (3) Lithium carbonate and Li2O react with 95% Pt-5% Au, and also reacts with pure Pt; and (4

  1. Thermochemical properties of Li 6Zr 2O 7(s) by a mass-spectrometric Knudsen effusion method

    NASA Astrophysics Data System (ADS)

    Kato, Yoshinari; Asano, Mitsuru; Harada, Toshio; Mizutani, Yasuo

    1993-12-01

    Partial pressures of Li(g), LiO(g), Li 2O(g), Li 2O 2(g), Li 3O(g) and O 2(g) over Li 6Zr 2O 7(s) are studied by a mass-spectrometric Knudsen effusion method. From enthalpies of reaction for gas-solid equilibria, the enthalpies of formation for Li 6Zr 2O 7(s) are determined to be ΔfH°298( Li6Zr2O7, s) = -(4092.5 ± 14.2) kJmol-1 from the elements and ΔfoxH°298( Li6Zr2O7, s) = -(101.4 ± 15.9) kJmol-1 from the constituent oxides, Li 2O(s) and ZrO 2(s). Over various lithiumcontaining complex oxides, the partial pressures of Li 2O(g) decrease as follows: Li 2O > Li 5AlO 4 ⋍ Li 4TiO 4 ⋍ Li 8PbO 6 > Li 6Zr 2O 7 > Li 2SnO 3 > Li 4SiO 4 > Li 2TiO 3 ⋍ Li 2ZrO 3 > LiAlO 2 = Li 2SiO 3 > LiNbO 3. From the results of the partial pressures of Li 2O(g), thermodynamic activities and activity coefficients of the pseudo Li 2O component are discussed in relation to the molar fraction of Li 2O in each binary Li2O- MOx system (M = Al, Si, Ti and Zr).

  2. Measuring the ratio of aqueous diffusion coefficients between 6Li +Cl - and 7Li +Cr - by osmometry

    NASA Astrophysics Data System (ADS)

    Fritz, Steven J.

    1992-10-01

    Osmotic equilibrium is a singular occurrence in the evolution of an osmotic cell because at this event the net solution flux is zero such that -J w · V¯w = J s · V¯s. At this juncture, the diffusion coefficient of the solute through the membrane (ω) equals the solute flux ( Js) divided by the osmotic pressure (ΔΠ). Because the solute permeability coefficient (ω) is related to the Fickian diffusion coefficient ( D) through the gas constant, temperature, and the membrane's thickness and tortuosity, the ratio of ω values for individual isotopic species equals the ratio of D values for the same isotopic components. A 0.9450 molal LiCl solution was placed within sealed dialysis tubing and osmoted against a kilogram of deionized water at 22°C. Osmotic equilibrium occurred at 164 ± 10 min. The ratio of ω6Li +Cl -/ω7Li +Cl - was measured to be 1.011 ± 0.003 - a value close to the square root of the mass ratio between 7LiCl and 6LiCl (= 1.012) as calculated by Graham's Law. The measured diffusion coefficient ratio was used to predict the degree of hyperfiltration-induced fractionation of Li isotopes as a function of membrane ideality. When a membrane's σ exceeds 0.95 (as is likely for low-porosity shales) the 6Li /7Li ratio on the high-pressure side of the membrane can theoretically vary by more than 0.0017.

  3. The Origin of Capacity Fade in the Li2MnO3·LiMO2 (M = Li, Ni, Co, Mn) Microsphere Positive Electrode: An Operando Neutron Diffraction and Transmission X-ray Microscopy Study.

    PubMed

    Chen, Chih-Jung; Pang, Wei Kong; Mori, Tatsuhiro; Peterson, Vanessa K; Sharma, Neeraj; Lee, Po-Han; Wu, She-Huang; Wang, Chun-Chieh; Song, Yen-Fang; Liu, Ru-Shi

    2016-07-20

    The mechanism of capacity fade of the Li2MnO3·LiMO2 (M = Li, Ni, Co, Mn) composite positive electrode within a full cell was investigated using a combination of operando neutron powder diffraction and transmission X-ray microscopy methods, enabling the phase, crystallographic, and morphological evolution of the material during electrochemical cycling to be understood. The electrode was shown to initially consist of 73(1) wt % R3̅m LiMO2 with the remaining 27(1) wt % C2/m Li2MnO3 likely existing as an intergrowth. Cracking in the Li2MnO3·LiMO2 electrode particle under operando microscopy observation was revealed to be initiated by the solid-solution reaction of the LiMO2 phase on charge to 4.55 V vs Li(+)/Li and intensified during further charge to 4.7 V vs Li(+)/Li during the concurrent two-phase reaction of the LiMO2 phase, involving the largest lattice change of any phase, and oxygen evolution from the Li2MnO3 phase. Notably, significant healing of the generated cracks in the Li2MnO3·LiMO2 electrode particle occurred during subsequent lithiation on discharge, with this rehealing being principally associated with the solid-solution reaction of the LiMO2 phase. This work reveals that while it is the reduction of lattice size of electrode phases during charge that results in cracking of the Li2MnO3·LiMO2 electrode particle, with the extent of cracking correlated to the magnitude of the size change, crack healing is possible in the reverse solid-solution reaction occurring during discharge. Importantly, it is the phase separation during the two-phase reaction of the LiMO2 phase that prevents the complete healing of the electrode particle, leading to pulverization over extended cycling. This work points to the minimization of behavior leading to phase separation, such as two-phase and oxygen evolution, as a key strategy in preventing capacity fade of the electrode.

  4. The Origin of Capacity Fade in the Li2MnO3·LiMO2 (M = Li, Ni, Co, Mn) Microsphere Positive Electrode: An Operando Neutron Diffraction and Transmission X-ray Microscopy Study.

    PubMed

    Chen, Chih-Jung; Pang, Wei Kong; Mori, Tatsuhiro; Peterson, Vanessa K; Sharma, Neeraj; Lee, Po-Han; Wu, She-Huang; Wang, Chun-Chieh; Song, Yen-Fang; Liu, Ru-Shi

    2016-07-20

    The mechanism of capacity fade of the Li2MnO3·LiMO2 (M = Li, Ni, Co, Mn) composite positive electrode within a full cell was investigated using a combination of operando neutron powder diffraction and transmission X-ray microscopy methods, enabling the phase, crystallographic, and morphological evolution of the material during electrochemical cycling to be understood. The electrode was shown to initially consist of 73(1) wt % R3̅m LiMO2 with the remaining 27(1) wt % C2/m Li2MnO3 likely existing as an intergrowth. Cracking in the Li2MnO3·LiMO2 electrode particle under operando microscopy observation was revealed to be initiated by the solid-solution reaction of the LiMO2 phase on charge to 4.55 V vs Li(+)/Li and intensified during further charge to 4.7 V vs Li(+)/Li during the concurrent two-phase reaction of the LiMO2 phase, involving the largest lattice change of any phase, and oxygen evolution from the Li2MnO3 phase. Notably, significant healing of the generated cracks in the Li2MnO3·LiMO2 electrode particle occurred during subsequent lithiation on discharge, with this rehealing being principally associated with the solid-solution reaction of the LiMO2 phase. This work reveals that while it is the reduction of lattice size of electrode phases during charge that results in cracking of the Li2MnO3·LiMO2 electrode particle, with the extent of cracking correlated to the magnitude of the size change, crack healing is possible in the reverse solid-solution reaction occurring during discharge. Importantly, it is the phase separation during the two-phase reaction of the LiMO2 phase that prevents the complete healing of the electrode particle, leading to pulverization over extended cycling. This work points to the minimization of behavior leading to phase separation, such as two-phase and oxygen evolution, as a key strategy in preventing capacity fade of the electrode. PMID:27314640

  5. Electrochemical performances of co-substituted (La and Li) LiLa{sub x−y}Li{sub y}Ni{sub 1−x}O{sub 2} cathode materials for rechargeable lithium-ion batteries

    SciTech Connect

    Mohan, P.; Paruthimal Kalaignan, G.

    2013-09-01

    Graphical abstract: - Highlights: • LiLa{sub x−y}Li{sub x}Ni{sub 1−x}O{sub 2} powders were prepared by a sol–gel method at 600 °C for 10 h. • LiLa{sub x−y}Li{sub x}Ni{sub 1−x}O{sub 2} powder materials had well defined layer structure, and no impurities. • LiLa{sub 0.10}Li{sub 0.10}Ni{sub 0.80}O{sub 2} crystallite size was reduced compared with those of LiNiO{sub 2}. • Li/LiPF{sub 6}/LiLa{sub x−y}Li{sub x}Ni{sub 1−x}O{sub 2} cells were of high charge/discharge capacity, with columbic efficiency at 25 °C and 45 °C. • LiLa{sub 0.10}Li{sub 0.10}Ni{sub 0.80}O{sub 2} good cyclic stability, rate capability and better 45 °C. - Abstract: Co-substituted LiLa{sub x−y}Li{sub y}Ni{sub 1−x}O{sub 2} cathode materials were synthesized by sol–gel method using aqueous solutions of metal nitrates and tartaric acid as chelating agent at 600 °C for 10 h. The structure and electrochemical properties of the synthesized materials were characterized by using XRD, SEM, EDAX, TEM, cyclic voltammetry, charge/discharge and electrochemical impedance spectroscopy. XRD studies revealed a well defined layer structure and a linear variation of lattice parameters with the addition of lanthanum and lithium confirmed phase pure compounds in a rhombohedral structure. TEM and SEM analysis shows that LiLa{sub 0.10}Li{sub 0.10}Ni{sub 0.80}O{sub 2} has smaller particle size and regular morphological structure with narrow size distribution than those of LiNiO{sub 2}. Variations of dual mixing and hexagonal ordering with the substituted elements have enhanced the charge/discharge capacities at both room (25 °C) and elevated temperatures (45 °C), respectively. LiLa{sub 0.10}Li{sub 0.10}Ni{sub 0.80}O{sub 2} had high charge/discharge capacity, low irreversible capacity and better elevated temperature performance.

  6. Preparation, structure, and electrochemistry of layered polyanionic hydroxysulfates: LiMSO4OH (M = Fe, Co, Mn) electrodes for Li-ion batteries.

    PubMed

    Subban, Chinmayee V; Ati, Mohamed; Rousse, Gwenaëlle; Abakumov, Artem M; Van Tendeloo, Gustaaf; Janot, Raphaël; Tarascon, Jean-Marie

    2013-03-01

    The Li-ion rechargeable battery, due to its high energy density, has driven remarkable advances in portable electronics. Moving toward more sustainable electrodes could make this technology even more attractive to large-volume applications. We present here a new family of 3d-metal hydroxysulfates of general formula LiMSO4OH (M = Fe, Co, and Mn) among which (i) LiFeSO4OH reversibly releases 0.7 Li(+) at an average potential of 3.6 V vs Li(+)/Li(0), slightly higher than the potential of currently lauded LiFePO4 (3.45 V) electrode material, and (ii) LiCoSO4OH shows a redox activity at 4.7 V vs Li(+)/Li(0). Besides, these compounds can be easily made at temperatures near 200 °C via a synthesis process that enlists a new intermediate phase of composition M3(SO4)2(OH)2 (M = Fe, Co, Mn, and Ni), related to the mineral caminite. Structurally, we found that LiFeSO4OH is a layered phase unlike the previously reported 3.2 V tavorite LiFeSO4OH. This work should provide an impetus to experimentalists for designing better electrolytes to fully tap the capacity of high-voltage Co-based hydroxysulfates, and to theorists for providing a means to predict the electrochemical redox activity of two polymorphs.

  7. Li-Rich Li-Si Alloy As A Lithium-Containing Negative Electrode Material Towards High Energy Lithium-Ion Batteries

    PubMed Central

    Iwamura, Shinichiroh; Nishihara, Hirotomo; Ono, Yoshitaka; Morito, Haruhiko; Yamane, Hisanori; Nara, Hiroki; Osaka, Tetsuya; Kyotani, Takashi

    2015-01-01

    Lithium-ion batteries (LIBs) are generally constructed by lithium-including positive electrode materials, such as LiCoO2, and lithium-free negative electrode materials, such as graphite. Recently, lithium-free positive electrode materials, such as sulfur, are gathering great attention from their very high capacities, thereby significantly increasing the energy density of LIBs. Though the lithium-free materials need to be combined with lithium-containing negative electrode materials, the latter has not been well developed yet. In this work, the feasibility of Li-rich Li-Si alloy is examined as a lithium-containing negative electrode material. Li-rich Li-Si alloy is prepared by the melt-solidification of Li and Si metals with the composition of Li21Si5. By repeating delithiation/lithiation cycles, Li-Si particles turn into porous structure, whereas the original particle size remains unchanged. Since Li-Si is free from severe constriction/expansion upon delithiation/lithiation, it shows much better cyclability than Si. The feasibility of the Li-Si alloy is further examined by constructing a full-cell together with a lithium-free positive electrode. Though Li-Si alloy is too active to be mixed with binder polymers, the coating with carbon-black powder by physical mixing is found to prevent the undesirable reactions of Li-Si alloy with binder polymers, and thus enables the construction of a more practical electrochemical cell. PMID:25626879

  8. Structural and Electrochemical Characterization of Pure LiFePO 4 and Nanocomposite C- LiFePO 4 Cathodes for Lithium Ion Rechargeable Batteries

    DOE PAGES

    Kumar, Arun; Thomas, R.; Karan, N. K.; Saavedra-Arias, J. J.; Singh, M. K.; Majumder, S. B.; Tomar, M. S.; Katiyar, R. S.

    2009-01-01

    Pure limore » thium iron phosphate ( LiFePO 4 ) and carbon-coated LiFePO 4 (C- LiFePO 4 ) cathode materials were synthesized for Li-ion batteries. Structural and electrochemical properties of these materials were compared. X-ray diffraction revealed orthorhombic olivine structure. Micro-Raman scattering analysis indicates amorphous carbon, and TEM micrographs show carbon coating on LiFePO 4 particles. Ex situ Raman spectrum of C- LiFePO 4 at various stages of charging and discharging showed reversibility upon electrochemical cycling. The cyclic voltammograms of LiFePO 4 and C- LiFePO 4 showed only a pair of peaks corresponding to the anodic and cathodic reactions. The first discharge capacities were 63, 43, and 13 mAh/g for C/5, C/3, and C/2, respectively for LiFePO 4 where as in case of C- LiFePO 4 that were 163, 144, 118, and 70 mAh/g for C/5, C/3, C/2, and 1C, respectively. The capacity retention of pure LiFePO 4 was 69% after 25 cycles where as that of C- LiFePO 4 was around 97% after 50 cycles. These results indicate that the capacity and the rate capability improved significantly upon carbon coating.« less

  9. Understanding abnormal potential behaviors at the 1st charge in Li2S cathode material for rechargeable Li-S batteries.

    PubMed

    Jung, Yongjo; Kang, Byoungwoo

    2016-08-01

    In this study, electrochemical behaviors of Li2S such as a large potential barrier at the beginning of the 1st charging process and a continuous increase in potential to ∼4 V during the rest of this process were understood through X-ray photoelectron spectroscopy measurements and electrochemical evaluations for a full utilization of Li2S. The large potential barrier to the 1st charge in Li2S can be caused by the presence of insulating oxidized products (Li2SO3 or Li2SO4-like structures) on the surface; simple surface etching can remove them and thereby reduce the potential barrier. Even though the potential barrier was substantially reduced, the electrochemical activity of Li2S might not be improved due to the continuous increase in potential. This increase in potential was related to the polarization caused by the Li2S-conversion reaction; the polarization can affect the utilization of Li2S in subsequent cycles. We speculate that the increase in potential is related to the decomposition of oxidized products such as Li2CO3-like or Li2O-like structures on the surface of the Li2S particles. These findings indicate that the full utilization of Li2S can be achieved by controlling their surface characteristics, especially the surface oxidation products. PMID:27426215

  10. A New 6Li Detection in a Halo Subgiant, and Constraints for the Depletion of the Big Bang 7Li Abundance

    NASA Astrophysics Data System (ADS)

    Deliyannis, C. P.; Ryan, S. G.

    2000-05-01

    We present measurements of the 6Li/7Li isotope ratio in ten metal-poor stars derived from very high resolution (100,000) and S/N (300-800/pixel) McDonald 2.7-meter coude spectra, including two possible 6Li detections. We present specific new evidence that we have indeed detected the 6Li absorption feature, and not a convective asymmetry of the 7Li feature. One of our detections argues in favor of a protostellar (and not a surface-spallated) origin for this 6Li. We find that 6Li has either not evolved strongly with metallicity, in contrast to what is observed for Be and B, or else concurrent 6Li production is matched by stellar depletion. While such fine-tuning seems unlikely, no models can explain the origin of 6Li without such depletion. In the context of the observed 9Be/7Li depletion correlation and its slow-mixing explanation, taking our data at face value implies that the Big Bang 7Li abundance is no more than 0.2-0.3 dex higher than the values observed in the halo Li plateau.

  11. Temperature dependence of δ7Li, δ44Ca and Li/Ca during growth of calcium carbonate

    NASA Astrophysics Data System (ADS)

    Marriott, Caedmon S.; Henderson, Gideon M.; Belshaw, Nick S.; Tudhope, Alexander W.

    2004-05-01

    Lithium and calcium isotope ratios, together with the Li/Ca element ratio, have been measured in calcites precipitated inorganically at temperatures ranging from 5 to 30 °C, and on seasonal growth bands from a coral. These measurements indicate the potential uses of these three environmental proxies. Carbonate Li isotopes are lighter than the solution from which they grow, probably due to equilibrium fractionation. This fractionation is not significantly influenced by temperature and, because Li is not involved in any known biological process, this suggests that carbonates will provide a recorder for the past Li-isotope composition of natural waters and hence for past weathering conditions. As has been observed previously for inorganic aragonite, the Ca-isotopes in inorganic calcite are lighter than the growth solution, and are only weakly dependent on temperature. This confirms that the temperature dependence observed in some species of foraminifera [Geochem. Geophys. Geosyst. 1 (2001)] reflects additional isotope fractionation due to biological processes during mineralization. Ca isotopes may therefore provide a powerful tool with which to investigate the processes of biomineralization. Finally, Li/Ca ratios in inorganic and biogenic carbonates increase as temperatures decrease with a sensitivity of ≈4% per °C. This temperature dependence of Li/Ca may prove useful to assess past temperatures in cold environments such as the deep ocean.

  12. First principles lattice thermal conductivity of Li2Se, Li2Te and alloys: phase space guidelines for thermal transport

    NASA Astrophysics Data System (ADS)

    Lindsay, Lucas; Mukhopadhyay, Saikat; Parker, David

    The lattice thermal conductivities (k) of Li2Se, Li2Te and alloys are examined using a first-principles Peierls-Boltzmann transport methodology. The dominant resistance to heat-carrying acoustic phonons in Li2Se and Li2Te comes from the interactions of these modes with two optic phonons, aoo scattering. In typical cubic and hexagonal materials (e . g . , Si, GaAs, AlN) aoo scattering does not play a considerable role in determining k, as it requires significant bandwidth and dispersion of the optic phonon branches, both present in Li2Se and Li2Te. We discuss how these properties and other features of the phonon dispersion (e . g . , bunching of the acoustic branches and an acoustic-optic frequency gap) combine to determine the overall conductivity of a material. Thus, microscopic scattering phase space arguments are generalized to give a more comprehensive view of intrinsic thermal transport in crystalline solids. We note that these general considerations are important for the discovery and design of new `high k' and `low k' materials for thermal management applications. L. L., S. M. and D. S. P. acknowledge support from the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division.

  13. Relating the 3D electrode morphology to Li-ion battery performance; a case for LiFePO4

    NASA Astrophysics Data System (ADS)

    Liu, Zhao; Verhallen, Tomas W.; Singh, Deepak P.; Wang, Hongqian; Wagemaker, Marnix; Barnett, Scott

    2016-08-01

    One of the main goals in lithium ion battery electrode design is to increase the power density. This requires insight in the relation between the complex heterogeneous microstructure existing of active material, conductive additive and electrolyte providing the required electronic and Li-ion transport. FIB-SEM is used to determine the three phase 3D morphology, and Li-ion concentration profiles obtained with Neutron Depth Profiling (NDP) are compared for two cases, conventional LiFePO4 electrodes and better performing carbonate templated LiFePO4 electrodes. This provides detailed understanding of the impact of key parameters such as the tortuosity for electron and Li-ion transport though the electrodes. The created hierarchical pore network of the templated electrodes, containing micron sized pores, appears to be effective only at high rate charge where electrolyte depletion is hindering fast discharge. Surprisingly the carbonate templating method results in a better electronic conductive CB network, enhancing the activity of LiFePO4 near the electrolyte-electrode interface as directly observed with NDP, which in a large part is responsible for the improved rate performance both during charge and discharge. The results demonstrate that standard electrodes have a far from optimal charge transport network and that significantly improved electrode performance should be possible by engineering the microstructure.

  14. ON INFRARED EXCESSES ASSOCIATED WITH Li-RICH K GIANTS

    SciTech Connect

    Rebull, Luisa M.; Carlberg, Joleen K.; Gibbs, John C.; Cashen, Sarah; Datta, Ashwin; Hodgson, Emily; Lince, Megan; Deeb, J. Elin; Larsen, Estefania; Altepeter, Shailyn; Bucksbee, Ethan; Clarke, Matthew; Black, David V.

    2015-10-15

    Infrared (IR) excesses around K-type red giants (RGs) have previously been discovered using Infrared Astronomy Satellite (IRAS) data, and past studies have suggested a link between RGs with overabundant Li and IR excesses, implying the ejection of circumstellar shells or disks. We revisit the question of IR excesses around RGs using higher spatial resolution IR data, primarily from the Wide-field Infrared Survey Explorer. Our goal was to elucidate the link between three unusual RG properties: fast rotation, enriched Li, and IR excess. Our sample of RGs includes those with previous IR detections, a sample with well-defined rotation and Li abundance measurements with no previous IR measurements, and a large sample of RGs asserted to be Li-rich in the literature; we have 316 targets thought to be K giants, about 40% of which we take to be Li-rich. In 24 cases with previous detections of IR excess at low spatial resolution, we believe that source confusion is playing a role, in that either (a) the source that is bright in the optical is not responsible for the IR flux, or (b) there is more than one source responsible for the IR flux as measured in IRAS. We looked for IR excesses in the remaining sources, identifying 28 that have significant IR excesses by ∼20 μm (with possible excesses for 2 additional sources). There appears to be an intriguing correlation in that the largest IR excesses are all in Li-rich K giants, though very few Li-rich K giants have IR excesses (large or small). These largest IR excesses also tend to be found in the fastest rotators. There is no correlation of IR excess with the carbon isotopic ratio, {sup 12}C/{sup 13}C. IR excesses by 20 μm, though relatively rare, are at least twice as common among our sample of Li-rich K giants. If dust shell production is a common by-product of Li enrichment mechanisms, these observations suggest that the IR excess stage is very short-lived, which is supported by theoretical calculations. Conversely, the

  15. On Infrared Excesses Associated with Li-rich K Giants

    NASA Astrophysics Data System (ADS)

    Rebull, Luisa M.; Carlberg, Joleen K.; Gibbs, John C.; Deeb, J. Elin; Larsen, Estefania; Black, David V.; Altepeter, Shailyn; Bucksbee, Ethan; Cashen, Sarah; Clarke, Matthew; Datta, Ashwin; Hodgson, Emily; Lince, Megan

    2015-10-01

    Infrared (IR) excesses around K-type red giants (RGs) have previously been discovered using Infrared Astronomy Satellite (IRAS) data, and past studies have suggested a link between RGs with overabundant Li and IR excesses, implying the ejection of circumstellar shells or disks. We revisit the question of IR excesses around RGs using higher spatial resolution IR data, primarily from the Wide-field Infrared Survey Explorer. Our goal was to elucidate the link between three unusual RG properties: fast rotation, enriched Li, and IR excess. Our sample of RGs includes those with previous IR detections, a sample with well-defined rotation and Li abundance measurements with no previous IR measurements, and a large sample of RGs asserted to be Li-rich in the literature; we have 316 targets thought to be K giants, about 40% of which we take to be Li-rich. In 24 cases with previous detections of IR excess at low spatial resolution, we believe that source confusion is playing a role, in that either (a) the source that is bright in the optical is not responsible for the IR flux, or (b) there is more than one source responsible for the IR flux as measured in IRAS. We looked for IR excesses in the remaining sources, identifying 28 that have significant IR excesses by ∼20 μm (with possible excesses for 2 additional sources). There appears to be an intriguing correlation in that the largest IR excesses are all in Li-rich K giants, though very few Li-rich K giants have IR excesses (large or small). These largest IR excesses also tend to be found in the fastest rotators. There is no correlation of IR excess with the carbon isotopic ratio, 12C/13C. IR excesses by 20 μm, though relatively rare, are at least twice as common among our sample of Li-rich K giants. If dust shell production is a common by-product of Li enrichment mechanisms, these observations suggest that the IR excess stage is very short-lived, which is supported by theoretical calculations. Conversely, the Li

  16. Electrochemical Li Topotactic Reaction in Layered SnP3 for Superior Li-Ion Batteries

    PubMed Central

    Park, Jae-Wan; Park, Cheol-Min

    2016-01-01

    The development of new anode materials having high electrochemical performances and interesting reaction mechanisms is highly required to satisfy the need for long-lasting mobile electronic devices and electric vehicles. Here, we report a layer crystalline structured SnP3 and its unique electrochemical behaviors with Li. The SnP3 was simply synthesized through modification of Sn crystallography by combination with P and its potential as an anode material for LIBs was investigated. During Li insertion reaction, the SnP3 anode showed an interesting two-step electrochemical reaction mechanism comprised of a topotactic transition (0.7–2.0 V) and a conversion (0.0–2.0 V) reaction. When the SnP3-based composite electrode was tested within the topotactic reaction region (0.7–2.0 V) between SnP3 and LixSnP3 (x ≤ 4), it showed excellent electrochemical properties, such as a high volumetric capacity (1st discharge/charge capacity was 840/663 mA h cm−3) with a high initial coulombic efficiency, stable cycle behavior (636 mA h cm−3 over 100 cycles), and fast rate capability (550 mA h cm−3 at 3C). This layered SnP3 anode will be applicable to a new anode material for rechargeable LIBs. PMID:27775090

  17. Photoionization of Li and radiative recombination of Li{sup +} in Debye plasmas

    SciTech Connect

    Qi, Y. Y.; Wu, Y.; Wang, J. G.

    2009-03-15

    The photoionization cross sections in the photoelectron energy below 2 Ry are calculated for the ground and n{<=}4 excited states of Li embedded in plasma environments and the radiative-recombination (RR) rate coefficients for Li{sup +} were presented for temperature T=100-32 000 K in a wide range of plasma parameters. The plasma screening interaction is described by the Debye-Hueckel model and the energy levels and wave functions including both the bound and continuum states are calculated by solving the Schroedinger equation numerically in a symplectic integration scheme. The screening of Coulomb interactions remarkably changes the photoionization cross sections near the ionization threshold, and especially for the ns states, the Cooper minimum is uncovered and shifted to the higher energy as the screening interaction increases. The RR rate coefficients at low temperature have a complex variation on the Debye lengths; whereas at higher temperature the RR rate coefficients decrease with the increasing of screening effects. Comparison of present results with those of other authors when available is made.

  18. Degradation diagnosis of aged Li4Ti5O12/LiFePO4 batteries

    NASA Astrophysics Data System (ADS)

    Castaing, Rémi; Reynier, Yvan; Dupré, Nicolas; Schleich, Donald; Jouanneau Si Larbi, Séverine; Guyomard, Dominique; Moreau, Philippe

    2014-12-01

    Li4Ti5O12/LiFePO4 cells are cycled under 4 different conditions of discharge profile (galvanostatic or driving-based) and cycling rates (C/8 or 1C) during 4-5 months. All the cells exhibit capacity fade whose extent is not correlated with the aging condition. In order to understand aging phenomena, cells are disassembled at the end of cycle life and the recovered electrodes are analyzed using electrochemistry, electron microscopy, XRD and MAS-NMR. Positive and negative electrodes show no loss in active material and no change in electrochemical activity, active material structure and composite electrode structure. This rules out any irreversible electrode degradation. Lithium stoichiometry estimated by both XRD and electrochemistry is unexpectedly low in the positive electrode when the aging is stopped at full discharge. That indicates a loss of cyclable lithium or electrons leading to cell balancing evolution. That loss may have been caused by parasitic reactions occurring at both electrodes, in accordance with their rich surface chemistry as evidenced by MAS-NMR.

  19. Growth and characterization of nanocrystalline PbS:Li thin films

    NASA Astrophysics Data System (ADS)

    Portillo, M. Chávez; Mathew, X.; Juárez Santiesteban, H.; Pacio Castillo, M.; Portillo Moreno, O.

    2016-10-01

    The structural, electrical and opto-electronic properties of PbS thin films doped with Li+ ion were investigated. The crystallite size showed a strong dependence on Li doping, the crystal size changed from 36 nm to 12 nm due to Li incorporation in PbS. Optical band gap showed a shift in the range ∼1.5-2.3 eV with Li incorporation. Urbach tailing in the band gap was observed and the Urbach energy has a dependence on the amount of incorporated Li. SEM images showed a notable change in grain size with Li doping, however the morphology changes from large grains to agglomerations of smaller grains when doped with Li. The electric conductivity of the films showed a dependence on Li doping, reached a maximum value and later decreased for higher Li containing films. The doped samples showed better photosensitivity.

  20. Interstitial lithium diffusion pathways in γ-LiAlO2: a computational study.

    PubMed

    Islam, Mazharul M; Bredow, Thomas

    2015-11-19

    Although the Li diffusion in single crystalline γ-LiAlO2 was studied with temperature-dependent Li-7 NMR spectroscopy and conductivity measurements recently, the exact diffusion pathways are not yet clearly identified. Therefore, the present study aims at elucidating the diffusion pathways in γ-LiAlO2 theoretically from first principles. Competing pathways for Li diffusion are investigated using the climbing-image nudged-elastic-band approach with periodic quantum-chemical density functional theory (DFT) method. Li can migrate between two regular LiO4 tetrahedral sites via Li point defect (VLi) and via a Li Frenkel defect (VLi + Lii). On the basis of calculated activation energies for Li diffusion pathways, it is concluded that Li conductivity is strongly dependent on the distribution of Li vacancies and interstitial Li in the lattice. For Frenkel defects where Lii is far away from the migrating Li atom, the calculated activation energies for jumps to nearest-neighbor vacant sites agree with experimental values.

  1. Neutron transfer reactions induced by {sup 8}Li on {sup 9}Be

    SciTech Connect

    Guimaraes, V.; Lichtenthaeler, R.; Camargo, O.; Barioni, A.; Assuncao, M.; Kolata, J. J.; Amro, H.; Becchetti, F. D.; Jiang, Hao; Aguilera, E. F.; Lizcano, D.; Martines-Quiroz, E.; Garcia, H.

    2007-05-15

    Angular distributions for the elastic scattering of {sup 8}Li on {sup 9}Be and the neutron transfer reactions {sup 9}Be({sup 8}Li,{sup 7}Li){sup 10}Be and {sup 9}Be({sup 8}Li,{sup 9}Li){sup 8}Be were measured with a 27 MeV {sup 8}Li radioactive nuclear beam. Spectr- oscopic factors for {sup 8}Li (multiply-in-circle sign)n{sup 9}Li and {sup 7}Li (multiply-in-circle sign)n{sup 8}Li bound systems were obtained from the comparison between the experimental differential cross section and finite-range distorted-wave Born approximation calculations with the code FRESCO. The spectroscopic factors obtained were compared to shell model calculations and to other experimental values from (d,p) reactions. Using the present values for the spectroscopic factor, cross sections for the direct neutron-capture reactions {sup 7}Li(n,{gamma}){sup 8}Li and {sup 8}Li(n,{gamma}){sup 9}Li were calculated in the framework of a potential model.

  2. The effect of the carbon nanotube buffer layer on the performance of a Li metal battery.

    PubMed

    Zhang, Ding; Zhou, Yi; Liu, Changhong; Fan, Shoushan

    2016-06-01

    Lithium (Li) metal is one of the most promising candidates as an anode for the next-generation energy storage systems because of its high specific capacity and lowest negative electrochemical potential. But the growth of Li dendrites limits the application of the Li metal battery. In this work, a type of modified Li metal battery with a carbon nanotube (CNT) buffer layer inserted between the separator and the Li metal electrode was reported. The electrochemical results show that the modified batteries have a much better rate capability and cycling performance than the conventional Li metal batteries. The mechanism study by electrochemical impedance spectroscopy reveals that the modified battery has a smaller charge transfer resistance and larger Li ion diffusion coefficient during the deposition process on the Li electrode than the conventional Li metal batteries. Symmetric battery tests show that the interfacial behavior of the Li metal electrode with the buffer layer is more stable than the naked Li metal electrode. The morphological characterization of the CNT buffer layer and Li metal lamina reveals that the CNT buffer layer has restrained the growth of Li dendrites. The CNT buffer layer has great potential to solve the safety problem of the Li metal battery. PMID:27181758

  3. The effect of the carbon nanotube buffer layer on the performance of a Li metal battery.

    PubMed

    Zhang, Ding; Zhou, Yi; Liu, Changhong; Fan, Shoushan

    2016-06-01

    Lithium (Li) metal is one of the most promising candidates as an anode for the next-generation energy storage systems because of its high specific capacity and lowest negative electrochemical potential. But the growth of Li dendrites limits the application of the Li metal battery. In this work, a type of modified Li metal battery with a carbon nanotube (CNT) buffer layer inserted between the separator and the Li metal electrode was reported. The electrochemical results show that the modified batteries have a much better rate capability and cycling performance than the conventional Li metal batteries. The mechanism study by electrochemical impedance spectroscopy reveals that the modified battery has a smaller charge transfer resistance and larger Li ion diffusion coefficient during the deposition process on the Li electrode than the conventional Li metal batteries. Symmetric battery tests show that the interfacial behavior of the Li metal electrode with the buffer layer is more stable than the naked Li metal electrode. The morphological characterization of the CNT buffer layer and Li metal lamina reveals that the CNT buffer layer has restrained the growth of Li dendrites. The CNT buffer layer has great potential to solve the safety problem of the Li metal battery.

  4. DISCOVERY OF SUPER-Li-RICH RED GIANTS IN DWARF SPHEROIDAL GALAXIES

    SciTech Connect

    Kirby, Evan N.; Fu, Xiaoting; Deng, Licai; Guhathakurta, Puragra

    2012-06-10

    Stars destroy lithium (Li) in their normal evolution. The convective envelopes of evolved red giants reach temperatures of millions of kelvin, hot enough for the {sup 7}Li(p, {alpha}){sup 4}He reaction to burn Li efficiently. Only about 1% of first-ascent red giants more luminous than the luminosity function bump in the red giant branch exhibit A(Li) > 1.5. Nonetheless, Li-rich red giants do exist. We present 15 Li-rich red giants-14 of which are new discoveries-among a sample of 2054 red giants in Milky Way dwarf satellite galaxies. Our sample more than doubles the number of low-mass, metal-poor ([Fe/H] {approx}< -0.7) Li-rich red giants, and it includes the most-metal-poor Li-enhanced star known ([Fe/H] = -2.82, A(Li){sub NLTE} = 3.15). Because most of the stars have Li abundances larger than the universe's primordial value, the Li in these stars must have been created rather than saved from destruction. These Li-rich stars appear like other stars in the same galaxies in every measurable regard other than Li abundance. We consider the possibility that Li enrichment is a universal phase of evolution that affects all stars, and it seems rare only because it is brief.

  5. Influence of post-grown Li-rich and Li-poor vapor transport equilibration on composition, OH- absorption and optical-damage threshold of Mg (5 mol%) : LiNbO3 crystals

    NASA Astrophysics Data System (ADS)

    Zhang, De-Long; Wang, Zhen; Hua, Ping-Rang; Pun, Edwin Yue-Bun

    2010-09-01

    Li-rich (Li-poor) vapor transport equilibration (VTE) treatments on a number of Z-cut 0.47 mm thick congruent MgO (5 mol% in melt) : LiNbO3 crystals were carried out at 1100°C over different durations ranging in 1-172 (40-395) h. Neutron activation analysis shows that neither Li-rich nor Li-poor VTE-induced Mg and Nb loss from the crystal occurred. The Li2O content in the crystal was measured as a function of VTE duration by the gravimetric method. The Li-rich/Li-poor VTE effects on OH- absorption were studied in comparison with the as-grown crystal. The study shows that the Li-rich VTE results in OH- absorption band annihilation. After further oxidation treatment the band reemerges and peaks at the same wavenumber as that of the as-grown crystal (˜3535.6 cm-1), showing that the MgO concentration in the Li-rich VTE crystal is still above the optical-damage threshold. The Li-poor VTE causes OH- band shift to 3486.3-3491.6 cm-1, indicating that the MgO concentration in all Li-poor VTE crystals is all below the optical-damage threshold. Further successive Li-rich VTE and oxidation treatments on the Li-poor VTE-treated crystal lead the band to shift back to 3535.6 cm-1, showing that the post Li-rich VTE brought the Li-poor VTE-treated crystal above the optical-damage threshold again. It is found that the peaking position, band width, peaking absorption and band area of the absorption at ˜3486 cm-1 all increase monotonously with the decrease of the Li2O content arising from prolonged Li-poor VTE, and quantitative relationships to the Li2O content are established for the latter two parameters. The VTE effects on the OH- absorption are conducted with the VTE-induced OH- content alteration and charge redistribution.

  6. Synthesis and characterization of lithium oxonitrate (LiNO)

    PubMed Central

    Switzer, Christopher H.; Miller, Thomas W.; Farmer, Patrick J.; Fukuto, Jon M.

    2012-01-01

    The oxonitrate (1−) anion (NO−), the one-electron reduction product of nitric oxide and conjugate base of HNO, has not been synthesized and isolated due to the inherent reactivity of this anion. The large scale synthesis and characterization of a stable NO− salt is described here. The lithium salt of oxonitrate (LiNO) was formed by the deprotonation of N-hydroxybenzenesulfonamide with phenyllithium in aprotic, deoxygenated conditions. LiNO exhibited antiferromagnetic paramagnetism as determined by SQUID magnetometry, consistent with a triplet ground state of NO−. LiNO reacted with HCl to yield nitrous oxide consistent with HNO formation and dimerization. LiNO consumed O2 in a pH-dependent manner to initially produce peroxynitrite and eventually nitrite. Consistent with the reduction potential of NO, LiNO exhibited an oxidation potential of approximately +0.80 V as determined by reactions with a series of viologen electron acceptors. LiNO also reacted with ferric tetraphenylporphyrin chloride (Fe(TPP)Cl), potassium tetracyanonickelate (K2Ni(CN)4) and nitrosobenzene in a manner that is identical to other HNO/NO− donors. We conclude that the physical and chemical characteristics of LiNO are indistinguishable from the experimentally and theoretically derived data on oxonitrrate (1−) anion. The bulk synthesis and isolation of a stable 3NO− salt described here allows the chemical and physical properties of this elusive nitrogen oxide to be thoroughly studied as this once elusive nitrogen oxide is now attainable. PMID:23107606

  7. Uas Topographic Mapping with Velodyne LiDAR Sensor

    NASA Astrophysics Data System (ADS)

    Jozkow, G.; Toth, C.; Grejner-Brzezinska, D.

    2016-06-01

    Unmanned Aerial System (UAS) technology is nowadays willingly used in small area topographic mapping due to low costs and good quality of derived products. Since cameras typically used with UAS have some limitations, e.g. cannot penetrate the vegetation, LiDAR sensors are increasingly getting attention in UAS mapping. Sensor developments reached the point when their costs and size suit the UAS platform, though, LiDAR UAS is still an emerging technology. One issue related to using LiDAR sensors on UAS is the limited performance of the navigation sensors used on UAS platforms. Therefore, various hardware and software solutions are investigated to increase the quality of UAS LiDAR point clouds. This work analyses several aspects of the UAS LiDAR point cloud generation performance based on UAS flights conducted with the Velodyne laser scanner and cameras. The attention was primarily paid to the trajectory reconstruction performance that is essential for accurate point cloud georeferencing. Since the navigation sensors, especially Inertial Measurement Units (IMUs), may not be of sufficient performance, the estimated camera poses could allow to increase the robustness of the estimated trajectory, and subsequently, the accuracy of the point cloud. The accuracy of the final UAS LiDAR point cloud was evaluated on the basis of the generated DSM, including comparison with point clouds obtained from dense image matching. The results showed the need for more investigation on MEMS IMU sensors used for UAS trajectory reconstruction. The accuracy of the UAS LiDAR point cloud, though lower than for point cloud obtained from images, may be still sufficient for certain mapping applications where the optical imagery is not useful.

  8. Oral health of individuals aged 3-80 years in Jönköping, Sweden, during 40 years (1973-2013). I. Review of findings on oral care habits and knowledge of oral health.

    PubMed

    Norderyd, Ola; Kochi, Göran; Papias, Apostolos; Köhler, Alkisti Anastassaki; Helkimo, Anna Nydell; Brahm, Carl-Otto; Lindmark, Ulrika; Lindfors, Ninita; Mattsson, Anna; Rolander, Bo; Ullbro, Christer; Gerdin, Elisabeth Wárnberg; Frisk, Fredrik

    2015-01-01

    The aim of the this study was to present data on oral care habits and knowledge of oral health in 2013, and to compare these data with results from a series of four previous cross-sectional epidemiological studies. All these studies were carried out in the city of Jönköping, Sweden, in 1973, 1983, 1993, 2003, and 2013. The 1973 study constituted a random sample of 1,ooo individuals evenly distributed in the age groups 3, 5, 10, 15, 20, 30, 40, 50, 60, and 70 years. The same age groups with addition of a group of 80-year-olds were included in the 1983, 1993, 2003, and 2013 studies, which comprised 1,104; 1,078; 987; and 1,010 individuals, respectively. A questionnaire about dental care habits and knowledge of oral health was used. The questionnaire contained the same questions in all the five studies, although some had to be slightly modernised during the 40-year period. During the period 1973-2013, a continous increase of individuals in the age group 20-60 years were treated by the Public Dental Service amounting to about 50%. Almost 70% of the 70- and 80-year-olds were treated by private practitioners. In 2013, 10-20% of the individuals in the age groups 30-40 years did not regularly visit neither Public Dental Service nor a private practitioner. The corresponding figures for the individuals 50-80 years old were 4-7%. Similar number of avoidance was reported in the previous studies. In the survey 2013, about 20-30% of the individuals in the age groups 20-50 felt frightened, sick, or ill at ease at the prospect of an appointment with the dentist. These findings were in agreement with the results from the surveys 1973-2003. Among the younger age groups, 0-15 years, a reduction in self-reported "ill at ease" was found in the surveys 2003 and 2013 compared to the previous surveys in this series. In 2013, the knowledge of the etiology of caries was known by about 60% of the individuals which was similar to that reported 1973-2003. Twenty per cent of the individuals

  9. Oral health of individuals aged 3-80 years in Jönköping, Sweden during 40 years (1973-2013). II. Review of clinical and radiographic findings.

    PubMed

    Norderyd, Ola; Koch, Göran; Papias, Apostolos; Köhler, Alkisti Anastassaki; Helkimo, Anna Nydell; Brahm, Carl-Otto; Lindmark, Ulrika; Lindfors, Ninita; Mattsson, Anna; Rolander, Bo; Ullbro, Christer; Gerdin, Elisabeth Wärnberg; Frisk, Fredrik

    2015-01-01

    The aim of this epidemiological study performed in 2013 was to analyze various clinical and radiographic data on oral health and compare the results to those of four cross-sectional studies carried out 1973-2003. In 1973, 1983, 1993, 2003, and 2013 random samples of 1,000; 1,104; 1,078; 987; and 1,010 individuals, respectively, were studied. The individuals were evenly distributed in the age groups 3, 5, 10, 15, 20, 30, 40, 50, 60, 70, and 80o years. Eighty-year-olds were not included in 1973. All subjects were inhabitants of the city of Jönköping, Sweden. The clinical and radiographic examination assessed edentulousness, removable dentures, implants, number of teeth, caries, restorations, oral hygiene, calculus, periodontal status, and endodontic treatment. The frequency of edentulous individuals aged 40-70 years was 16, 12, 8, 1, and 0.3% in 1973, 1983, 1993, 2003, and 2013, respectively. No complete denture weareryounger than 80-years old was found in 2013. During the 40-year period, the mean number of teeth in the age groups 30-80 years increased. In 2013, the 60-year-olds had nearly complete dentitions. Implants were found in all age groups from 30 years of age. The total number of individuals with implants was 36 in 2013. This was higher than earlier surveys, 4 in 1993, and 18 in 2003. The percentage of children and adults without caries and restorations increased during the 40-year period. It was found that the percentage of caries-free 3- and 5-year-olds were 79% and 69%, respectively, of the individuals in 2013. In the age groups 10-20 years, the percentage of caries-free individuals increased between 2003 and 2013. In 2013, 43% of the 15-year-olds were completely free from caries and restorations compared to 20% in 2003. In all age groups 5-60 years, DFS was lower in 2013 compared to the earlier examinations.There was no major change in DFS between 2003 and 2013 in the age groups 70 and 80 years. The most obvious change was the decrease in number of FS

  10. Oral health of individuals aged 3-80 years in Jönköping, Sweden during 30 years (1973-2003). II. Review of clinical and radiographic findings.

    PubMed

    Hugoson, Anders; Koch, Göran; Göthberg, Catharina; Helkimo, Anna Nydell; Lundin, Sven-Ake; Norderyd, Ola; Sjödin, Bengt; Sondell, Katarina

    2005-01-01

    The aim of this epidemiological study was to analyze various clinical and radiographic data on oral health and compare the results to those of three cross-sectional studies carried out in 1973 and 1983, and 1993. In 1973, 1983, 1993, and 2003 a random sample of 1,000; 1,104; 1,078; and 987 individuals, respectively, were studied. The individuals were evenly distributed in the age groups 3, 5, 10, 15, 20, 30, 40, 50, 60, 70, and 80 years. In 1973 80-year-olds were not included. All subjects were inhabitants of the City of Jönköping, Sweden. The clinical and radiographic examination assessed edentulousness, removable dentures, implants, number of teeth, caries, restorations and overhangs, oral hygiene, calculus, periodontal status, endodontic treatment, and periapical status. The number of edentulous individuals in the age groups 40-70 years was reduced from 16 per cent in 1973 to 8 per cent in 1993, and to 1 per cent in 2003. The mean number of teeth increased, and up to the age of 60 years, individuals had more or less complete dentitions. During the 30-year period,the number of carious lesions and restorations decreased in general. In the 15-year-olds the decrease in number of restored tooth surfaces was 900 per cent and the corresponding figure for 30-year-olds was 79 per cent. The age groups 60-800 years showed an increase in number of restored tooth surfaces and had as a mean 50 filled tooth surfaces. The oral health among 3-5-year-olds improved markedly between 1973 and 1993. In 2003, however, there was no further improvement in 3- and 5-year-olds compared to 1993. Generally, restorations in 2003 exhibited a high quality and 90-95 per cent had no proximal overhangs. In 1973 this figure was about 60 per cent. In the age groups 20-50 years there were continuously fewer teeth fitted with crowns or bridges during the 30-year period. In 1973 the 50-year-olds had a mean of 24.5 per cent of the teeth crowned and in 2003 6.8 percent. Compared to data from 1973 there

  11. Oral health of individuals aged 3-80 years in Jönköping, Sweden during 40 years (1973-2013). II. Review of clinical and radiographic findings.

    PubMed

    Norderyd, Ola; Koch, Göran; Papias, Apostolos; Köhler, Alkisti Anastassaki; Helkimo, Anna Nydell; Brahm, Carl-Otto; Lindmark, Ulrika; Lindfors, Ninita; Mattsson, Anna; Rolander, Bo; Ullbro, Christer; Gerdin, Elisabeth Wärnberg; Frisk, Fredrik

    2015-01-01

    The aim of this epidemiological study performed in 2013 was to analyze various clinical and radiographic data on oral health and compare the results to those of four cross-sectional studies carried out 1973-2003. In 1973, 1983, 1993, 2003, and 2013 random samples of 1,000; 1,104; 1,078; 987; and 1,010 individuals, respectively, were studied. The individuals were evenly distributed in the age groups 3, 5, 10, 15, 20, 30, 40, 50, 60, 70, and 80o years. Eighty-year-olds were not included in 1973. All subjects were inhabitants of the city of Jönköping, Sweden. The clinical and radiographic examination assessed edentulousness, removable dentures, implants, number of teeth, caries, restorations, oral hygiene, calculus, periodontal status, and endodontic treatment. The frequency of edentulous individuals aged 40-70 years was 16, 12, 8, 1, and 0.3% in 1973, 1983, 1993, 2003, and 2013, respectively. No complete denture weareryounger than 80-years old was found in 2013. During the 40-year period, the mean number of teeth in the age groups 30-80 years increased. In 2013, the 60-year-olds had nearly complete dentitions. Implants were found in all age groups from 30 years of age. The total number of individuals with implants was 36 in 2013. This was higher than earlier surveys, 4 in 1993, and 18 in 2003. The percentage of children and adults without caries and restorations increased during the 40-year period. It was found that the percentage of caries-free 3- and 5-year-olds were 79% and 69%, respectively, of the individuals in 2013. In the age groups 10-20 years, the percentage of caries-free individuals increased between 2003 and 2013. In 2013, 43% of the 15-year-olds were completely free from caries and restorations compared to 20% in 2003. In all age groups 5-60 years, DFS was lower in 2013 compared to the earlier examinations.There was no major change in DFS between 2003 and 2013 in the age groups 70 and 80 years. The most obvious change was the decrease in number of FS

  12. Compounds of 6Li and natural Li for EPR dosimetry in photon/neutron mixed radiation fields.

    PubMed

    Lund, E; Gustafsson, H; Danilczuk, M; Sastry, M D; Lund, A

    2004-05-01

    Formates and dithionates of 6Li, enriched and 7Li in natural composition of Li offer a possibility to measure the absorbed dose from photons and thermal neutrons in a mixed radiation field for instance at a boron neutron capture therapy (BNCT) facility. Tests with formates and dithionates of enriched 6Li and lithium compounds with natural composition have been performed at the BNCT facility at Studsvik, Sweden. Irradiations have been performed at 3 cm depth in a Perspex phantom in a fluence rate of thermal neutrons 1.8 x 10(9) n cm(-2) s(-1). The compounds were also irradiated in a pure X-ray field from a 4MV linear accelerator at 5 cm depth in a phantom with accurately determined absorbed doses. The signal intensity and shape was investigated within 3 h after the irradiation. A single line spectrum attributed to the CO2- radical was observed after irradiation of lithium formate. An increase in line width occurring after neutron irradiation in comparison with photon irradiation of the 6Li sample was attributed to dipolar broadening between CO2- radicals trapped in the tracks of the alpha particles. A spectrum due to the SO3- radical anion was observed after irradiation of lithium dithionate. The signal amplitude increased using the 6Li in place of the Li with natural composition of isotopes, in studies with low energy X-ray irradiation. Due to the decreased line width, caused by the difference in g(N) and I between the isotopes, the sensitivity with 6Li dithionate may be enhanced by an order of magnitude compared to alanine dosimetry. After comprehensive examination of the different combinations of compounds with different amounts of 6Li and 7Li regarding dosimetry, radiation chemistry and EPR properties these dosimeter material might be used for dose determinations at BNCT treatments and for biomedical experiments. Interesting properties of the radical formation might be visible due to the large difference in ionization density of neutrons compared to photons.

  13. High performance anode for advanced Li batteries

    SciTech Connect

    Lake, Carla

    2015-11-02

    The overall objective of this Phase I SBIR effort was to advance the manufacturing technology for ASI’s Si-CNF high-performance anode by creating a framework for large volume production and utilization of low-cost Si-coated carbon nanofibers (Si-CNF) for the battery industry. This project explores the use of nano-structured silicon which is deposited on a nano-scale carbon filament to achieve the benefits of high cycle life and high charge capacity without the consequent fading of, or failure in the capacity resulting from stress-induced fracturing of the Si particles and de-coupling from the electrode. ASI’s patented coating process distinguishes itself from others, in that it is highly reproducible, readily scalable and results in a Si-CNF composite structure containing 25-30% silicon, with a compositionally graded interface at the Si-CNF interface that significantly improve cycling stability and enhances adhesion of silicon to the carbon fiber support. In Phase I, the team demonstrated the production of the Si-CNF anode material can successfully be transitioned from a static bench-scale reactor into a fluidized bed reactor. In addition, ASI made significant progress in the development of low cost, quick testing methods which can be performed on silicon coated CNFs as a means of quality control. To date, weight change, density, and cycling performance were the key metrics used to validate the high performance anode material. Under this effort, ASI made strides to establish a quality control protocol for the large volume production of Si-CNFs and has identified several key technical thrusts for future work. Using the results of this Phase I effort as a foundation, ASI has defined a path forward to commercialize and deliver high volume and low-cost production of SI-CNF material for anodes in Li-ion batteries.

  14. {sup 10}Li low-lying resonances populated by one-neutron transfer

    SciTech Connect

    Cavallaro, M. Agodi, C.; Carbone, D.; Cunsolo, A.; De Napoli, M.; Cappuzzello, F.; Bondì, M.; Davids, B.; Galinski, N.; Ruiz, C.; Davinson, T.; Sanetullaev, A.; Foti, A.; Kanungo, R.; Lenske, H.; Orrigo, S. E. A.

    2015-10-15

    The {sup 9}Li + {sup 2}H → {sup 10}Li + {sup 1}H one-neutron transfer reaction has been performed at 100 MeV incident energy at TRIUMF using a {sup 9}Li beam delivered by the ISAC-II facility. A setup based on double-sided silicon strip detectors has been used in order to detect and identify the outgoing {sup 9}Li produced by the {sup 10}Li breakup at forward angles and the recoil protons emitted at backward angles. The {sup 10}Li low-lying resonances, whose energies, widths and configurations are still unclear, have been populated with significant statistics.

  15. Device fabrication, characterization, and thermal neutron detection response of LiZnP and LiZnAs semiconductor devices

    NASA Astrophysics Data System (ADS)

    Montag, Benjamin W.; Ugorowski, Philip B.; Nelson, Kyle A.; Edwards, Nathaniel S.; McGregor, Douglas S.

    2016-11-01

    Nowotny-Juza compounds continue to be explored as candidates for solid-state neutron detectors. Such a device would have greater efficiency, in a compact form, than present day gas-filled 3He and 10BF3 detectors. The 6Li(n,t)4He reaction yields a total Q-value of 4.78 MeV, larger than 10B, an energy easily identified above background radiations. Hence, devices fabricated from semiconductor compounds having either natural Li (nominally 7.5% 6Li) or enriched 6Li (usually 95% 6Li) as constituent atoms may provide a material for compact high efficiency neutron detectors. Starting material was synthesized by preparing equimolar portions of Li, Zn, and As sealed under vacuum (10-6 Torr) in quartz ampoules lined with boron nitride and subsequently reacted in a compounding furnace [1]. The raw synthesized material indicated the presence high impurity levels (material and electrical property characterizations). A static vacuum sublimation in quartz was performed to help purify the synthesized material [2,3]. Bulk crystalline samples were grown from the purified material [4,5]. Samples were cut using a diamond wire saw, and processed into devices. Bulk resistivity was determined from I-V curve measurements, ranging from 106-1011 Ω cm. Devices were characterized for sensitivity to 5.48 MeV alpha particles, 337 nm laser light, and neutron sensitivity in a thermal neutron diffracted beam at the Kansas State University TRIGA Mark II nuclear reactor. Thermal neutron reaction product charge induction was measured with a LiZnP device, and the reaction product spectral response was observed.

  16. Electrochemical reduction of UO2 in LiCl-Li2O molten salt using porous and nonporous anode shrouds

    NASA Astrophysics Data System (ADS)

    Choi, Eun-Young; Won, Chan Yeon; Cha, Ju-Sun; Park, Wooshin; Im, Hun Suk; Hong, Sun-Seok; Hur, Jin-Mok

    2014-01-01

    Electrochemical reductions of uranium oxide in a molten LiCl-Li2O electrolyte were carried out using porous and nonporous anode shrouds. The study focused on the effect of the type of anode shroud on the current density by running experiments with six anode shrouds. Dense ceramics, MgO, and MgO (3 wt%) stabilized ZrO2 (ZrO2-MgO) were used as nonporous shrouds. STS 20, 100, and 300 meshes and ZrO2-MgO coated STS 40 mesh were used as porous shrouds. The current densities (0.34-0.40 A cm-2) of the electrolysis runs using the nonporous anode shrouds were much lower than those (0.76-0.79 A cm-2) of the runs using the porous shrouds. The ZrO2-MgO shroud (600-700 MPa at 25 °C) showed better bending strength than that of MgO (170 MPa at 25 °C). The high current densities achieved in the electrolysis runs using the porous anode shrouds were attributed to the transport of O2- ions through the pores in meshes of the shroud wall. ZrO2-MgO coating on STS mesh was chemically unstable in a molten LiCl-Li2O electrolyte containing Li metal. The electrochemical reduction runs using STS 20, 100, and 300 meshes showed similar current densities in spite of their different opening sizes. The STS mesh shrouds which were immersed in a LiCl-Li2O electrolyte were stable without any damage or corrosion.

  17. Cr and Si Substituted-LiCo0.9Fe0.1PO4: Structure, full and half Li-ion cell performance

    NASA Astrophysics Data System (ADS)

    Allen, Jan L.; Allen, Joshua L.; Thompson, Travis; Delp, Samuel A.; Wolfenstine, Jeff; Jow, T. Richard

    2016-09-01

    The use of LiCoPO4 as a Li-ion cathode material can enable high energy 5 V batteries. However, LiCoPO4 shows limited cycle life and much less than theoretical energy density. In order to address these shortcomings, Fe, Cr and Si substituted-LiCoPO4(Cr,Si-LiCo0.9Fe0.1PO4) was investigated as an improved LiCoPO4 based cathode material. Fe substitution greatly improves the cycle life and increases the energy density. Cr substitution further increases the energy density, cycle life and rate capability. Si substitution reduces the reactivity of the cathode with electrolyte thereby increasing cycle life. In combination, the substituents lead to a LiCoPO4 based cathode material with no capacity fade over 250 cycles in Li/Cr,Si-LiCo0.9Fe0.1PO4 half cells, a discharge capacity of 140 mAh g-1 at C/3 at an average discharge voltage of 4.78 V giving an energy density of 670 Wh per kg of cathode. In graphite/Cr,Si-LiCo0.9Fe0.1PO4 full Li-ion cells, the cathode material shows an energy density of 550 Wh per kg of cathode material at 1C rate for the initial cycles and 510 Wh per kg of cathode material at the 250th cycle.

  18. Synthesis of LiFePO4/Li2SiO3/reduced Graphene Oxide (rGO) Composite via Hydrothermal Method

    NASA Astrophysics Data System (ADS)

    Arifin, M.; Iskandar, F.; Aimon, A. H.; Munir, M. M.; Nuryadin, B. W.

    2016-08-01

    LiFePO4 is a type of cathode active material used for lithium ion batteries. It has a high electrochemical performance. However, it suffers from certain disadvantages such as a very low intrinsic electronic conductivity and low ionic diffusion. This study was conducted to increase the conductivity of LiFePO4. We have investigated the addition of Li2SiO3 and reduced graphene oxide (rGO) to LiFePO4. The objective of this research was to synthesize LiFePO4/Li2SiO3/rGO via hydrothermal method. Fourier transform infrared spectroscopy (FTIR) measurement showed that the peaks corresponded to the vibration of LiFePO4/Li2SiO3. Further, X-ray diffraction (XRD) measurement confirmed a single phase of LiFePO4. Finally, scanning electron microscopy (SEM) images showed that rGO was distributed on the LiFePO4/Li2SiO3 structure.

  19. High Performance Cathodes for Li-Air Batteries

    SciTech Connect

    Xing, Yangchuan

    2013-08-22

    The overall objective of this project was to develop and fabricate a multifunctional cathode with high activities in acidic electrolytes for the oxygen reduction and evolution reactions for Li-air batteries. It should enable the development of Li-air batteries that operate on hybrid electrolytes, with acidic catholytes in particular. The use of hybrid electrolytes eliminates the problems of lithium reaction with water and of lithium oxide deposition in the cathode with sole organic electrolytes. The use of acid electrolytes can eliminate carbonate formation inside the cathode, making air breathing Li-air batteries viable. The tasks of the project were focused on developing hierarchical cathode structures and bifunctional catalysts. Development and testing of a prototype hybrid Li-air battery were also conducted. We succeeded in developing a hierarchical cathode structure and an effective bifunctional catalyst. We accomplished integrating the cathode with existing anode technologies and made a pouch prototype Li-air battery using sulfuric acid as catholyte. The battery cathodes contain a nanoscale multilayer structure made with carbon nanotubes and nanofibers. The structure was demonstrated to improve battery performance substantially. The bifunctional catalyst developed contains a conductive oxide support with ultra-low loading of platinum and iridium oxides. The work performed in this project has been documented in seven peer reviewed journal publications, five conference presentations, and filing of two U.S. patents. Technical details have been documented in the quarterly reports to DOE during the course of the project.

  20. Li abundance in the stars with solar-type activity

    NASA Astrophysics Data System (ADS)

    Mishenina, T. V.; Soubiran, C.; Kovtyukh, V. V.; Katsova, M. M.; Livshits, M. A.

    Li abundances, atmospheric parameters and rotational velocities for 150 dwarfs have been determined from the high resolution, high signal to noise echelle spectra, obtained with the ELODIE spectrograph at the OHP (France). Among them, there are 101 stars with a determined level of activity, a large part of them being of the BY Dra type. The level of chromospheric and coronal activity of the targets has been evaluated through the logR'_HK index and X-ray flux. We examined the Li abundance behavior with T_eff, vsini and level of the activity. Some correlations between the Li abundances, level of the chromospheric activity and rotational velocities vsini are confirmed. The correlation between the Li abundances and index of the chromospheric activity logR'_HK was found, especially for dwarfs with 5700>T_eff> 5200 K. Those correlations mainly demonstrate that measurable values of the lithium content (higher than the upper limit) refer to the stars with large spot areas in their photospheres. Considering the wider set of stars with high activity levels one can affirm that such a conclusion is valid also for the cooler, earlier K dwarfs. Our results confirm that basic factors of formation of detectable Li abundance and high activity are determined principally by smaller age and fast axial rotation, respectively; and apparently by the depth of the convective zone.