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Sample records for li surub hollywoodi

  1. 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

  2. Photoionization of Li2

    NASA Astrophysics Data System (ADS)

    Li, Y.; Pindzola, M. S.; Ballance, C. P.; Colgan, J.

    2014-05-01

    Single and double photoionization cross sections for Li2 are calculated using a time-dependent close-coupling method. The correlation between the outer two electrons of Li2 is obtained by relaxation of the close-coupled equations in imaginary time. Propagation of the close-coupled equations in real time yields single and double photoionization cross sections for Li2. The two active electron cross sections are compared with one active electron distorted-wave and close-coupling results for both Li and Li2. This work was supported in part by grants from NSF and US DoE. Computational work was carried out at NERSC in Oakland, California, NICS in Knoxville, Tennessee, and OLCF in Oak Ridge, Tennessee.

  3. Presence of Li clusters in molten LiCl-Li

    DOE PAGESBeta

    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

  4. 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

  5. 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.

  6. 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

  7. 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,…

  8. 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+.

  9. First determination of the 8Li valence neutron asymptotic normalization coefficient using the 7Li(8Li,7Li)8Li reaction

    NASA Astrophysics Data System (ADS)

    Howell, D.; Davids, B.; Greene, J. P.; Kanungo, R.; Mythili, S.; Ruiz, C.; Ruprecht, G.; Thompson, I. J.

    2013-08-01

    We report here a determination of the asymptotic normalization coefficient of the valence neutron in 8Li from a measurement of the angular distribution of the 7Li(8Li,7Li)8Li reaction at 11 MeV. Using isospin symmetry the 8B ANC has also been calculated and used to infer a value for S17(0) of 20.2 ± 4.4 eV b.

  10. Galactic evolution of 7Li

    NASA Astrophysics Data System (ADS)

    Matteucci, Francesca

    2010-04-01

    Lithium represents a key element in cosmology, as it is one of the few nuclei synthesized during the Big Bang. The primordial abundance of 7Li allows us to impose constraints on the primordial nucleosynthesis and on the baryon density of the universe. However, 7Li is not only produced during the Big Bang but also during galactic evolution: measures of stellar Li in our Galaxy suggest an almost constant Li abundance (the so-called Spite plateau) at low metallicities and a subsequent increase in the disk stars, leading to a Li abundance in Population I stars higher by a factor of ten than in Population II stars. This means that there must exist several possible stellar sources of 7Li: asymptotic giant branch stars, supernovae, novae, red giant stars. 7Li is also partly produced in spallation processes while 6Li is entirely produced by such processes. All of these sources have been included in galactic chemical evolution models and constraints have been derived on the primordial 7Li and its evolution, as well on stellar models. I will review these models and their results and what we have learned about 7Li evolution. Some still open problems, such as the disagreement between the primordial 7Li abundance as derived by WMAP and as measured in Population II stars, and the uncertainties about the main sources of stellar 7Li will be discussed.

  11. 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

  12. Understanding Li diffusion in Li-intercalation compounds.

    PubMed

    Van der Ven, Anton; Bhattacharya, Jishnu; Belak, Anna A

    2013-05-21

    Intercalation compounds, used as electrodes in Li-ion batteries, are a fascinating class of materials that exhibit a wide variety of electronic, crystallographic, thermodynamic, and kinetic properties. With open structures that allow for the easy insertion and removal of Li ions, the properties of these materials strongly depend on the interplay of the host chemistry and crystal structure, the Li concentration, and electrode particle morphology. The large variations in Li concentration within electrodes during each charge and discharge cycle of a Li battery are often accompanied by phase transformations. These transformations include order-disorder transitions, two-phase reactions that require the passage of an interface through the electrode particles, and structural phase transitions, in which the host undergoes a crystallographic change. Although the chemistry of an electrode material determines the voltage range in which it is electrochemically active, the crystal structure of the compound often plays a crucial role in determining the shape of the voltage profile as a function of Li concentration. While the relationship between the voltage profile and crystal structure of transition metal oxide and sulfide intercalation compounds is well characterized, far less is known about the kinetic behavior of these materials. For example, because these processes are especially difficult to isolate experimentally, solid-state Li diffusion, phase transformation mechanisms, and interface reactions remain poorly understood. In this respect, first-principles statistical mechanical approaches can elucidate the effect of chemistry and crystal structure on kinetic properties. In this Account, we review the key factors that govern Li diffusion in intercalation compounds and illustrate how the complexity of Li diffusion mechanisms correlates with the crystal structure of the compound. A variety of important diffusion mechanisms and associated migration barriers are sensitive to

  13. Invariant-mass spectroscopy of 10Li and 11Li

    NASA Astrophysics Data System (ADS)

    Zinser, M.; Humbert, F.; Nilsson, T.; Schwab, W.; Simon, H.; Aumann, T.; Borge, M. J. G.; Chulkov, L. V.; Cub, J.; Elze, Th. W.; Emling, H.; Geissel, H.; Guillemaud-Mueller, D.; Hansen, P. G.; Holzmann, R.; Irnich, H.; Jonson, B.; Kratz, J. V.; Kulessa, R.; Leifels, Y.; Lenske, H.; Magel, A.; Mueller, A. C.; Münzenberg, G.; Nickel, F.; Nyman, G.; Richter, A.; Riisager, K.; Scheidenberger, C.; Schrieder, G.; Stelzer, K.; Stroth, J.; Surowiec, A.; Tengblad, O.; Wajda, E.; Zude, E.

    1997-02-01

    Break-up of secondary 11Li ion beams (280 MeV/nucleon) on C and Pb targets into 9Li and neutrons is studied experimentally. Cross sections and neutron multiplicity distributions are obtained, characterizing different reaction mechanisms. Invariant-mass spectroscopy for 11Li and 10Li is performed. The E1 strength distribution, deduced from electromagnetic excitation of 11Li up to an excitation energy of 4 MeV comprises ˜8% of the Thomas-Reiche-Kuhn energy-weighted sumrule strength. Two low-lying resonance-like structures are observed for 10Li at decay energies of 0.21(5) and 0.62(10) MeV, the former one carrying 26(10)% of the strength and likely to be associated with an s-wave neutron decay. A strong di-neutron correlation in 11Li can be discarded. Calculations in a quasi-particle RPA approach are compared with the experimental results for 10Li and 11Li.

  14. Charge transfer in Li2+ + He2+ and Li2+ + Li3+ collisions

    NASA Astrophysics Data System (ADS)

    Bräuning, H.; Trassl, R.; Theiß, A.; Diehl, A.; Salzborn, E.; Keim, M.; Achenbach, A.; Lüdde, H. J.; Kirchner, T.

    2005-07-01

    True one-electron collision systems provide an ideal testing ground for theory. Absolute cross sections for charge transfer in the collision systems Li2+ + He2+ and Li2+ + Li3+ have been measured for centre-of-mass energies between 52 and 148 keV and 6 and 63 keV, respectively. The data are compared with calculations using the two-centre basis generator method. A fair agreement between the experimental data and the calculations is found.

  15. 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.

  16. 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.

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

    DOE PAGESBeta

    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

  18. 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.

  19. 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. PMID:10813684

  20. 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.

  1. 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

  2. Electron-impact ionization of Li2 and Li2+

    NASA Astrophysics Data System (ADS)

    Pindzola, M. S.; Robicheaux, F.; Ballance, C. P.; Colgan, J.

    2008-10-01

    Electron-impact ionization cross sections for Li2 and Li2+ 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 (r,θ) , 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 Schrödinger equation is then solved for continuum distorted waves with S -matrix boundary conditions. Total ionization cross sections for Li2 at an equilibrium internuclear separation of R=5.0a.u. and for Li2+ at an equilibrium internuclear separation of R=5.9a.u. are presented.

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. Photoionization of Li

    NASA Astrophysics Data System (ADS)

    Colgan, James

    2011-05-01

    The time-dependent close-coupling approach to multiple photoionization of lithium is presented. Double photoionization of lithium can be treated as a two-electron ejection process where the outgoing electrons move in the field of a ``frozen-core'' Li2+ 1 s state. Recent calculations of this process have resulted in total and triple differential cross sections that are in good agreement with other close-coupling approaches. The time-dependent approach can also be extended to treat the interaction of all three lithium electrons, as is required if triple photoionization is examined, that is, the simultaneous ejection of all three electrons from lithium. The most detailed information about this process is found in the fully angular and energy differential cross sections, which provide information as to how the ionized electrons leave the atom. We present our formulation of the fully differential cross section expression, and provide some convergence studies of the angular distributions. The Los Alamos National Laboratory is operated by Los Alamos National Security, LLC for the National Nuclear Security Administration of the U.S. Department of Energy under Contract No. DE-AC5206NA25396.

  8. Ionic Pathways in Li13Si4 investigated by (6)Li and (7)Li solid state NMR experiments.

    PubMed

    Dupke, Sven; Langer, Thorsten; Winter, Florian; Pöttgen, Rainer; Winter, Martin; Eckert, Hellmut

    2015-02-01

    Local environments and dynamics of lithium ions in the binary lithium silicide Li13Si4 have been studied by (6)Li MAS-NMR, (7)Li spin-lattice relaxation time and site-resolved (7)Li 2D exchange NMR measurements as a function of mixing time. Variable temperature experiments result in distinct differences in activation energies characterizing the transfer rates between the different lithium sites. Based on this information, a comprehensive picture of the preferred ionic transfer pathways in this silicide has been developed. With respect to local mobility, the results of the present study suggests the ordering Li6/Li7>Li5>Li1>Li4 >Li2/Li3. Mobility within the z=0.5 plane is distinctly higher than within the z=0 plane, and the ionic transfer between the planes is most facile via Li1/Li5 exchange. The lithium ionic mobility can be rationalized on the basis of the type of the coordinating silicide anions and the lithium-lithium distances within the structure. Lithium ions strongly interacting with the isolated Si(4-) anions have distinctly lower mobility than those the coordination of which is dominated by Si2(6-) dumbbells. PMID:25524128

  9. Theoretical investigation of intermediate phases between Li2NH and LiNH2

    NASA Astrophysics Data System (ADS)

    Zhang, Feng; Wang, Yan; Chou, Mei-Yin

    2010-03-01

    The cycling between Li imide (Li2NH) and Li amide (LiNH2) represents the key reactions in the Li-N-H hydrogen storage system. It is important to know whether there exist intermediate phases between these two stable compounds in order to fully understand the mechanism of these reactions. We investigate from first principles possible intermediate compounds Li2-xNH1+x and Li1+xNH2-x with x equal to 1/8 and 1/4. Li2-xNH1+x is created by replacing a certain amount of NH^2- with NH2^- in pure Li imide and removing a proper amount of Li^+ to satisfy charge neutrality. Similarly, Li1+xNH2-x is created by replacing a certain amount of NH2^- with NH^2- in Li amide and adding a suitable amount of Li^+. At T=0 K, Li2-xNH1+x is energetically favorable with respect to phase separation into pure Li2NH and LiNH2. On the amide side, Li1+xNH2-x is only slightly less stable than the phase-separated mixture of amide and imide. These findings suggest that the intermediate phases may appear during the cycling reactions at finite temperatures. Electronic signatures for the intermediate phases resulting from the coexistence of NH2^- and NH^2- anions will also be discussed.

  10. Li2 - Li reactive collisions at high initial j

    NASA Astrophysics Data System (ADS)

    Rosenberry, Mark; Marhatta, Ramesh; Stewart, Brian

    2014-05-01

    Inelastic molecular collisions are a fundamental process in astronomy and chemistry. We are studying collisions of 7Li2 with 7Li in a heat pipe oven, and looking for nuclear parity-changing events that signal a chemical reaction. Previous work in our group studied such reactions for low initial j; we are now working to collect data for the case of high initial j, where quasi-resonant phenomena occur. We have also incorporated new corrections for multiple collisions in our analysis. Quasi-classical trajectory calculations are used to model these reactions and extract physical insight.

  11. 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.

  12. 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

  13. Effects of Li content on precipitation in Al-Cu-(Li)-Mg-Ag-Zr alloys

    SciTech Connect

    Huang, B.P.; Zheng, Z.Q.

    1998-01-06

    Although much attention has been paid to Al-Cu-Li-Mg-Ag-Zr alloys, there are sparse reports about the influence of Li on precipitation in these alloys. The aim of the present study is to determine the effects of Li on modifying precipitation in a baseline aluminum alloy 2195 and the accompanying variants with 0--1.6 wt.% Li.

  14. 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.

  15. 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.

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

    SciTech Connect

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

    1992-01-01

    The invention relates to a process for obtaining Li metal selectively recovered from Li-Al or Al-Li alloy scrap by: (1) removing Li from aluminum-lithium alloys at temperatures between about 400 C-750 C in a molten salt bath of KC1-LiCl using lithium titanate (Li2O.3TiO2) as an engineered scavenger compound (ESC); and (2) electrodepositing of Li from the loaded ESC to a stainless steel electrode. By use of the second step, the ESC is prepared for reuse. A molten salt bath is required in the invention because of the inability of molten aluminum alloys to wet the ESC.

  17. Electrochemical behaviors of a Li3N modified Li metal electrode in secondary lithium batteries

    NASA Astrophysics Data System (ADS)

    Wu, Meifen; Wen, Zhaoyin; Liu, Yu; Wang, Xiuyan; Huang, Lezhi

    2011-10-01

    A lithium conductive Li3N film is successfully prepared on Li metal surface by the direct reaction between Li and N2 gas at room temperature. X-ray diffraction (XRD), Auger electron spectroscopy (AES), cyclic voltammetry (CV), scanning electron microscopy (SEM), AC impedance, cathodic polarization and galvanostatic charge/discharge cycling tests are applied to characterize the film. The experimental results show that the Li3N protective film is tight and dense with high stability in the electrolyte. Its thickness is more than 159.4 nm and much bigger than that of a native SEI film formed on the lithium surface as received. An exchange current as low as 3.244 × 10-7 A demonstrates the formation of a complete SEI film at the electrode|electrolyte interface with Li3N modification. The SEI film is very effective in preventing the corrosion of the Li electrode in liquid electrolyte, leading to a decreased Li|electrolyte interface resistance and an average short distance of 3.16 × 10-3 cm for Li ion diffusion from electrolyte to Li surface. The Li cycling efficiency depends on N2 exposing time and is obviously enhanced by the Li3N (1 h) modification. After cycling, a dense and homogeneous Li layer deposits on the Li3N (1 h) modified Li surface, instead of a loose and inhomogeneous layer on the Li surface as received.

  18. Sympathetic cooling of {sup 6}Li atoms

    SciTech Connect

    van Abeelen, F.A.; Verhaar, B.J.; Moerdijk, A.J.

    1997-06-01

    We use recently measured cold photoassociation and two-photon data to extract the singlet and triplet accumulated radial phases of interacting ground-state lithium atoms. Using the resulting values we predict scattering lengths, Feshbach resonances, and exchange decay rates for cold collisions between {sup 7}Li and {sup 6}Li atoms that are of interest for the possibility of sympathetic cooling of {sup 6}Li and for the coexistence of the bosonic and fermionic quantum-degenerate phases of {sup 7}Li and {sup 6}Li. In addition, we calculate scattering lengths and exchange decay rates for cold collisions between identical lithium isotopes in different hyperfine states. These quantities are used to examine the possibilities of coexisting {sup 7}Li Bose condensates and of evaporatively cooling coexisting {sup 6}Li subsystems. {copyright} {ital 1997} {ital The American Physical Society}

  19. 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

  20. Neutron transfer reactions induced by Li8 on Be9

    NASA Astrophysics Data System (ADS)

    Guimarães, V.; Lichtenthäler, R.; Camargo, O.; Barioni, A.; Assunção, M.; Kolata, J. J.; Amro, H.; Becchetti, F. D.; Jiang, Hao; Aguilera, E. F.; Lizcano, D.; Martines-Quiroz, E.; Garcia, H.

    2007-05-01

    Angular distributions for the elastic scattering of Li8 on Be9 and the neutron transfer reactions Be9(Li8,Li7)Be10 and Be9(Li8,Li9)Be8 were measured with a 27 MeV Li8 radioactive nuclear beam. Spectr- oscopic factors for Li8 ⊗n= Li9 and Li7 ⊗n= Li8 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 Li7(n,γ)Li8 and Li8(n,γ)Li9 were calculated in the framework of a potential model.

  1. Effects of Li concentration and a Mg addition on serrated flow in Al-Li alloys

    SciTech Connect

    Zambo, S.J.; Wert, J.A. . Dept. of Materials Science and Engineering)

    1993-12-15

    Serrated flow phenomena have been reported in a variety of precipitation-strengthened aluminum alloys. In the particular case of precipitation-strengthened Al-Li alloys, serrated flow effects of similar character have been reported in binary Al-Li alloys and in commercial-type Al-Li alloys containing multiple alloying elements. Observations of serrated flow in binary Al-Li alloys indicate that the presence of Li alone is sufficient to produce serrated flow. Aging time has been used to probe the mechanisms that cause serrated flow in individual Al-Li alloys, and several investigators have noted that serrated flow disappears when Al-Li alloys are aged to peak strength or overaged. Much of the available experimental evidence supports dislocation-[delta][prime] interactions as the cause of serrated flow in Al-Li alloys, rather than dislocation-solute atom interactions to which serrated flow phenomena are traditionally attributed. Additional support for this conclusion could be provided by comparison of stress-strain curves for a solid solution Al-Li binary alloy of the same composition as the matrix phase of a precipitation-strengthened Al-Li binary alloy. The purpose of the present paper is to show stress--strain curves for Al-1.38Li, Al-1.80Li and Al-1.39Li-1.0Mg alloys, and to interpret the results in terms of the interactions proposed to account for serrated flow in Al-Li alloys.

  2. Decameric uracil complexes around Li+.

    PubMed

    Zins, Emilie-Laure; Pepe, Claude; Schröder, Detlef

    2010-07-01

    Electrospray ionization (ESI) in combination with mass spectrometry (MS) experiments were carried out to study decameric uracil complexes cationized with Li(+) ion. A previous study has shown that, under specific experimental conditions, a particularly intense peak of the decamer U(10)Li(+) is formed, which was referred to as an indication for so-called 'magic number' cluster. In order to gain more insight on the structure of this decameric complex, here, we report experimental studies concerning the kinetics of the fragmentation. In accordance with the new experimental data, structural models were constructed and fully optimized using ab initio and density functional theory quantum chemistry calculations. The theoretical study allowed us to propose a stable gas-phase structure which is compatible with all experimental findings. PMID:20564575

  3. Role of native defects in the Li amide/Li imide hydrogen storage reaction

    NASA Astrophysics Data System (ADS)

    Hoang, Khang; van de Walle, Chris G.

    2010-03-01

    Reversible reaction involving Li amide/Li imide (LiNH2 + LiH <-> Li2NH + H2) has been shown to be a potential mechanism for hydrogen storage [1]. Recent synchrotron x-ray diffraction refinement suggests that the transformation between LiNH2 and Li2NH is a bulk reaction that occurs through non-stoichiometric processes [2]. To build a deeper understanding of these processes, we have carried out first-principles studies based on density functional theory of native point defects and defect complexes in LiNH2 and Li2NH. Among the native defects, we find that positively and negatively charged Li and H interstitials and vacancies have the lowest formation energies. Some of the Li-related defects are found to be very mobile, and should be the dominant migratory species in the systems. Our first-principles results suggest specific mechanisms for the role of native defects in the Li amide/Li imide reaction. [1] P. Chen et al., Nature 420, 302 (2002). [2] W. I. F. David et al., J. Am. Chem. Soc. 129, 1594 (2007).

  4. Ultralong Lifespan and Ultrafast Li Storage: Single-Crystal LiFePO4 Nanomeshes.

    PubMed

    Zhang, Yan; Zhang, Hui Juan; Feng, Yang Yang; Fang, Ling; Wang, Yu

    2016-01-27

    A novel LiFePO4 material, in the shape of a nanomesh, has been rationally designed and synthesized based on the low crystal-mismatch strategy. The LiFePO4 nanomesh possesses several advantages in morphology and crystal structure, including a mesoporous structure, its crystal orientation that is along the [010] direction, and a shortened Li-ion diffusion path. These properties are favorable for their application as cathode in Li-ion batteries, as these will accelerate the Li-ion diffusion rate, improve the Li-ion exchange between the LiFePO4 nanomesh and the electrolyte, and reduce the Li-ion capacitive behavior during Li intercalation. So the LiFePO4 nanomesh exhibits a high specific capacity, enhanced rate capability, and strengthened cyclability. The method developed here can also be extended to other similar systems, for instance, LiMnPO4 , LiCoPO4 , and LiNiPO4 , and may find more applications in the designed synthesis of functional materials. PMID:26643716

  5. 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.

  6. 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.

  7. 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.

  8. (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.

  9. 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.

  10. Li7 NMR Investigation of Li-Li Pair Ordering in the Paraelectric Phase of Weakly Substitutionally Disordered K1-xLixTaO3

    NASA Astrophysics Data System (ADS)

    Zalar, Boštjan; Lebar, Andrija; Ailion, David C.; Kuzian, R. O.; Kondakova, I. V.; Laguta, V. V.

    2010-11-01

    Breaking of the average cubic symmetry in Li-doped potassium tantalate was observed with quadrupole-perturbed Li7 NMR at temperatures (150-400 K) far above the nominal glass transition temperature (≈50K for Li concentration x=0.03). The observed spectrum consists of contributions from both isolated Li ions (i.e., with no nearest-neighbor Li) and from Li-Li pairs. The isolated Li ions move among six equivalent off-center sites in a potential having cubic symmetry. These have zero average electric field gradient and, hence, exhibit no quadrupole splitting. In addition, very low intensity, but well resolved, quadrupole satellites having a temperature-dependent splitting were observed. This splitting indicates that the various Li-Li pair configurations are not all equally probable. These are the first direct observations of biased Li ion ordering that persists in the paraelectric phase at temperatures high above the glass phase.

  11. 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.

  12. 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.

  13. Lithiation of Li2SnO3 and Li2SnS3 in context of Li-ion battery materials

    NASA Astrophysics Data System (ADS)

    Howard, Jason; Holzwarth, N. A. W.

    The closed pack layered crystal material (space group 15 (C 2 / c)) Li2 SnO3 has been studied as a possible anode material since the late 1990's. The material undergoes an irreversible decomposition to Li2 O and LiX Sn alloys during the first lithiation cycle. The crystal material Li2 SnS3 of the same structure was recently proposed as an electrolyte material. The question is posed whether Li2 SnS3 would be a good electrolyte or whether it could function as an anode material similar to Li2 SnO3 . In this research a model is proposed for the lithiation process of Li2 SnO3 and Li2 SnS3 ; Li - Li2 SnS3 interfaces are also examined. The results show Li2 SnO3 begins to decompose at approximately Li2 + 0 . 5 SnO3 . In Li2 SnS3 the lithiation process shows it can lithiate to Li2 + 1 SnS3 without significant lattice distortion, volume expansion, or decomposition. Li - Li2 SnS3 interfaces are shown to be unstable, showing the formation of Li2 S . Supported by NSF Grant DMR-1105485 and DMR-1507942.

  14. 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.

  15. 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.

  16. Kinetic measurement and prediction of the hydrogen outgassing from the polycrystalline LiH/Li 2O/LiOH system

    NASA Astrophysics Data System (ADS)

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

    2005-12-01

    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. The technique of temperature-programmed reaction/decomposition (TPR) was employed in combination with the isoconversion method of thermal analysis to determine the outgassing kinetics of H 2O from pure LiOH and H 2 and H 2O from this thin LiOH film. H 2 production via the reaction of LiH with LiOH, forming a lithium oxide (Li 2O) interlayer, is thermodynamically favored, with the rate of further reaction limited by diffusion through the Li 2O and the stability of the decomposing LiOH. Lithium hydroxide at the LiOH/vacuum interface also decomposes easily to Li 2O, releasing H 2O which subsequently reacts with LiH in a closed system to form H 2. At the onset of dry decomposition, where H 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 2O/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 predict a hydrogen evolution profile in good agreement with hydrogen release observed during long term isothermal storage.

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

    PubMed

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

    2016-05-01

    We described a lithium-oxygen (Li-O2) battery comprising a graphene electrode, a dimethoxyethane-based electrolyte, and H2O and lithium iodide (LiI) additives, lithium hydroxide (LiOH) being the predominant discharge product. We demonstrate, in contrast to the work of Shen et al., that the chemical reactivity between LiOH and the triiodide ion (I3 (-)) to form IO3 (-) indicates that LiOH can be removed on charging; the electrodes do not clog, even after multiple cycles, confirming that solid products are reversibly removed. PMID:27151859

  18. 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

  19. 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.

  20. Investigations of Li-containing SiCN(O) ceramics via 7Li MAS NMR.

    PubMed

    Gumann, Sina; Nestle, Nikolaus; Liebau-Kunzmann, Verena; Riedel, Ralf

    2007-04-01

    Lithium-containing silicon (oxy)carbonitride ceramics (SiCN(O):Li) were synthesized via precursor-to-ceramic-transformation of Li-containing (poly)silazanes. The precursors were obtained by lithiation of 2,4,6-trimethyl-2,4,6-trivinylcyclotrisilazane with n-butyllithium and by reaction of a commercial poly(organosilazane) VL20 with metallic lithium. The annealing treatment was carried out at temperatures between 200 and 1400 degrees C in argon (DeltaT=200 degrees C) and yielded Li-containing silicon (oxy)carbonitride. X-ray powder diffraction revealed that the resulting SiCN(O):Li ceramics were basically amorphous up to temperatures of 1000 degrees C and formed LiSi(2)N(3), graphite and silicon carbide as crystalline phases at higher temperatures. (7)Li MAS NMR spectroscopy was carried out to investigate the structure of the Li-containing phases and to study the reaction path of metallic Li with polysilazane. Based on the NMR spectra, there is almost no difference found in the chemical shift of the SiCN(O):Li ceramics obtained at different temperatures. Accordingly, Li is assigned to be mainly coordinated to N and O present as contaminant element. Relaxation time measurements showed that the most mobile Li(+) species seems to be present in the product obtained in the pyrolysis temperature range between 600 and 1000 degrees C. PMID:17418540

  1. 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.

  2. 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

  3. 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.

  4. 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. PMID:27158717

  5. 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.

  6. 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.

  7. Garnet-type solid-state fast Li ion conductors for Li batteries: critical review.

    PubMed

    Thangadurai, Venkataraman; Narayanan, Sumaletha; Pinzaru, Dana

    2014-07-01

    Batteries are electrochemical devices that store electrical energy in the form of chemical energy. Among known batteries, Li ion batteries (LiBs) provide the highest gravimetric and volumetric energy densities, making them ideal candidates for use in portable electronics and plug-in hybrid and electric vehicles. Conventional LiBs use an organic polymer electrolyte, which exhibits several safety issues including leakage, poor chemical stability and flammability. The use of a solid-state (ceramic) electrolyte to produce all-solid-state LiBs can overcome all of the above issues. Also, solid-state Li batteries can operate at high voltage, thus, producing high power density. Various types of solid Li-ion electrolytes have been reported; this review is focused on the most promising solid Li-ion electrolytes based on garnet-type metal oxides. The first studied Li-stuffed garnet-type compounds are Li5La3M2O12 (M = Nb, Ta), which show a Li-ion conductivity of ∼10(-6) at 25 °C. La and M sites can be substituted by various metal ions leading to Li-rich garnet-type electrolytes, such as Li6ALa2M2O12, (A = Mg, Ca, Sr, Ba, Sr0.5Ba0.5) and Li7La3C2O12 (C = Zr, Sn). Among the known Li-stuffed garnets, Li6.4La3Zr1.4Ta0.6O12 exhibits the highest bulk Li-ion conductivity of 10(-3) S cm(-1) at 25 °C with an activation energy of 0.35 eV, which is an order of magnitude lower than that of the currently used polymer, but is chemically stable at higher temperatures and voltages compared to polymer electrolytes. Here, we discuss the chemical composition-structure-ionic conductivity relationship of the Li-stuffed garnet-type oxides, as well as the Li ion conduction mechanism. PMID:24681593

  8. Investigation of hydrogen absorption in Li7VN4 and Li7MnN4.

    PubMed

    He, Guang; Herbst, J F; Ramesh, T N; Pinkerton, F E; Meyer, M S; Nazar, Linda

    2011-05-21

    The hydrogen storage properties of Li(7)VN(4) and Li(7)MnN(4) were investigated both by experiment and by density functional theory calculations. Li(7)VN(4) did not sorb hydrogen under our experimental conditions. Li(7)MnN(4) was observed to sorb 7 hydrogen atoms through the formation of LiH, Mn(4)N, and ammonia gas. An applied pressurized mixture of H(2)/Ar and H(2)/N(2) gases was helpful to mitigate the release of NH(3) but could not prevent its formation. The introduction of N(2) also caused weight gain of the sample by re-nitriding the absorbed products LiH and Mn(4)N, which correlated with the presence of Li(2)NH, LiNH(2), and Mn(2)N detected by X-ray diffraction. While our observed results for Li(7)VN(4) and Li(7)MnN(4) differ in detail, they are in overall qualitative agreement with our theoretical work, which strongly suggests that both compounds are unlikely to form quaternary hydrides. PMID:21455525

  9. 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

  10. Density functional study of Li4NH and Li1.5NH1.5 as intermediary compounds during hydrogenation of Li3N

    NASA Astrophysics Data System (ADS)

    Crivello, J.-C.; Gupta, M.; Černý, R.; Latroche, M.; Chandra, D.

    2010-03-01

    Recent experimental data suggest the formation of two new compounds, namely, Li4NH and Li1.5NH1.5 , during the hydrogenation process of Li3N . The formation of these compounds could modify the hydrogen absorption and desorption characteristics of Li3N . We present here the results of our density functional theory calculations concerning their formation. We find that the direct hydrogenation reaction of Li3N to Li2NH is predominantly favored but the formation of Li4NH is possible through the direct formation involving Li3N and LiH with an enthalpy of reaction much less negative than for the direct formation of Li2NH . The formation of this compound through the release of ammonia is not possible. This compound readily reacts with H2 exothermically with an enthalpy of reaction less negative than for the direct process. We also find that the formation of the intermediate phase Li2-xNH1+x for x=0.5 between imide (x=0) and amide (x=1) is possible. Li1.5NH1.5 is found to form in a cubic Li-vacant-type compound. After full relaxations of several structural models, the Li1.5NH1.5 compound presents a coexistence of ordered [NH]2- and [NH2]- anions. These results are discussed in terms of an analysis of the electronic structures of these compounds.

  11. First Principles Investigation of Li/Fe-Oxide as a High Energy Material for Hybrid All-in-One Li-ion/Li-O2 Batteries

    NASA Astrophysics Data System (ADS)

    Kinaci, Alper; Trahey, Lynn; Thackeray, Michael M.; Kirklin, Scott; Wolverton, Christopher; Chan, Maria K. Y.; CenterElectrical Energy Storage Collaboration

    2014-03-01

    We recently introduced a vision for high energy all-in-one electrode/electrocatalyst materials that can be used in hybrid Li-ion/Li-O2 (Li-air) cells. Recent experiments using Li5FeO4 demonstrated substantially smaller voltage polarizations and hence higher energy efficiency compared to standard Li-O2 cells forming Li2O2. The mechanism by which the charge process activates the Li5FeO4, however, is not well understood. Here, we present first principles density functional theory (DFT) calculations to establish the thermodynamic conditions for the extraction of Li/Li +O from Li5FeO4. A step-by-step, history-dependent, removal process has been followed and the stability of the Li and Li +O deficient samples is investigated on the basis of the energies of the extraction reactions. Various stages of Li/Li +O removal are identified, and structural changes and electronic structure evolution, as well as computed XRD, XANES, and PDF characterizations are reported.

  12. Single and double photoionization of Li2

    NASA Astrophysics Data System (ADS)

    Pindzola, M. S.; Li, Ye; Colgan, J.

    2015-01-01

    Time-dependent close-coupling methods are used to study the single and double photoionization of Li2. Formulations for both one-active and two-active electron methods make use of Hartree with local exchange potentials for the core electrons. Both the single and double photoionization cross sections for Li2 are found to be larger for linear polarization than for circular polarization, in sharp contrast to that found before for H2. In particular the double photoionization cross sections for Li2 are found to be approximately five times larger than for H2 and thus more easily observed by future experiments.

  13. Anharmonicity in LiBH4-LiI induced by anion exchange and temperature

    NASA Astrophysics Data System (ADS)

    Borgschulte, A.; Gremaud, R.; Kato, S.; Stadie, N. P.; Remhof, A.; Züttel, A.; Matsuo, M.; Orimo, S.-I.

    2010-07-01

    The feasibility of spatially resolved Raman spectroscopy probing diffusion multiples as a high-throughput method to study phase transformations in Li-ion conductors is demonstrated. The method is applied to the pseudobinary LiBH4-LiI system, which shows high Li-ion conductivity in the HT-phase of LiBH4. The vibrational properties measured as a function of composition and temperature corroborate the formation of a solid solution of Li(BH4)1-cIc over nearly the entire phase diagram (0

  14. Kinetics Tuning of Li-Ion Diffusion in Layered Li(NixMnyCoz)O2.

    PubMed

    Wei, Yi; Zheng, Jiaxin; Cui, Suihan; Song, Xiaohe; Su, Yantao; Deng, Wenjun; Wu, Zhongzhen; Wang, Xinwei; Wang, Weidong; Rao, Mumin; Lin, Yuan; Wang, Chongmin; Amine, Khalil; Pan, Feng

    2015-07-01

    Using ab initio calculations combined with experiments, we clarified how the kinetics of Li-ion diffusion can be tuned in LiNixMnyCozO2 (NMC, x + y + z = 1) materials. It is found that Li-ions tend to choose oxygen dumbbell hopping (ODH) at the early stage of charging (delithiation), and tetrahedral site hopping (TSH) begins to dominate when more than 1/3 Li-ions are extracted. In both ODH and TSH, the Li-ions surrounded by nickel (especially with low valence state) are more likely to diffuse with low activation energy and form an advantageous path. The Li slab space, which also contributes to the effective diffusion barriers, is found to be closely associated with the delithiation process (Ni oxidation) and the contents of Ni, Co, and Mn. PMID:26098282

  15. 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.

  16. Thermal process dependence of Li configuration and electrical properties of Li-doped ZnO

    NASA Astrophysics Data System (ADS)

    Zhang, Z.; Knutsen, K. E.; Merz, T.; Kuznetsov, A. Yu.; Svensson, B. G.; Brillson, L. J.

    2012-01-01

    We used depth-resolved cathodoluminescence spectroscopy (DRCLS) to describe the strong dependence of Li acceptor formation on thermal treatment in Li-doped ZnO. Within a 500-600 °C annealing temperature range, subsequent quenching ZnO leaves Li as interstitial donors, resulting in low room temperature resistivity, while slow cooling in air allows these interstitials to fill Zn vacancies forming Li acceptors 3.0 eV below the conduction band edge. DRCLS reveals an inverse relationship between the optical emission densities of lithium on zinc sites versus zinc vacancy sites, demonstrating the time dependence of Li interstitials to combine with zinc vacancies in order to form substitutional Li acceptors.

  17. First-Principles Studies of Li Nucleation on Graphene.

    PubMed

    Liu, Mingjie; Kutana, Alex; Liu, Yuanyue; Yakobson, Boris I

    2014-04-01

    We study the Li clustering process on graphene and obtain the geometry, nucleation barrier, and electronic structure of the clusters using first-principles calculations. We estimate the concentration-dependent nucleation barrier for Li on graphene. While the nucleation occurs more readily with increasing Li concentration, possibly leading to the dendrite formation and failure of the Li-ion battery, the existence of the barrier delays nucleation and may allow Li storage on graphene. Our electronic structure and charge transfer analyses reveal how the fully ionized Li adatoms transform to metallic Li during the cluster growth on graphene. PMID:26274475

  18. Reactivity and acidity of Li in LiAlO[sub 2] phases

    SciTech Connect

    Dronskowski, R. )

    1993-01-06

    Nuclear physicists were interested in the [gamma]-modification of LiAlO[sub 2]. Because of its good performance under high neutron and electron radiation, the phase appears to be a promising lithium ceramic suitable as an in situ trituim-breeding material in future fusion reactors. With the help of semiempirical electronic structure calculations, the authors seek to understand why solid [alpha]-LiAlO[sub 2] exchanges Li[sup +] with H[sup +] while in contact with molten benzoic acid but [gamma]-LiAlO[sub 2] does not. After critically examining the structural data for LiAlO[sub 2] modifications, they calculate the binding and both the static and dynamic reactivity and the static and dynamic acidity of [alpha]- and [gamma]-LiAlO[sub 2], with a special interpretative emphasis on the Li ion. The reason for Li being solely extractable in [alpha]-LiAlO[sub 2] is found to arise from (1) a difference in Li electrophilicity between [alpha]- and [gamma]-phase (frontier band argument), (2) a significantly smaller energy for Li binding to its neighboring atoms in [alpha]-compared to [gamma]-phase (thermodynamic argument), and (3) a dramatic difference in energetic behavior upon dislocating a Li atom from its equilibrium position in [alpha]- and [gamma]-phase (kinetic argument). Additionally, the authors show how the movement of a local atomic carrier of reactivity and acidity within a nonequilibrium structure can be easily observed by use of computation. 64 refs., 12 figs., 3 tabs.

  19. Line shift, line asymmetry, and the ^6Li/^7Li isotopic ratio determination

    NASA Astrophysics Data System (ADS)

    Cayrel, R.; Steffen, M.; Chand, H.; Bonifacio, P.; Spite, M.; Spite, F.; Petitjean, P.; Ludwig, H.-G.; Caffau, E.

    2007-10-01

    Context: Line asymmetries are generated by convective Doppler shifts in stellar atmospheres, especially in metal-poor stars, where convective motions penetrate to higher atmospheric levels. Such asymmetries are usually neglected in abundance analyses. The determination of the ^6Li/^7Li isotopic ratio is prone to suffering from such asymmetries, as the contribution of ^6Li is a slight blending reinforcement of the red wing of each component of the corresponding ^7Li line, with respect to its blue wing. Aims: The present paper studies the halo star HD 74000 and estimates the impact of convection-related asymmetries on the Li isotopic ratio determination. Methods: Two methods are used to meet this aim. The first, which is purely empirical, consists in deriving a template profile from another element that can be assumed to originate in the same stellar atmospheric layers as Li I, producing absorption lines of approximately the same equivalent width as individual components of the ^7Li I resonance line. The second method consists in conducting the abundance analysis based on NLTE line formation in a 3D hydrodynamical model atmosphere, taking into account the effects of photospheric convection. Results: The results of the first method show that the convective asymmetry generates an excess absorption in the red wing of the ^7Li absorption feature that mimics the presence of ^6Li at a level comparable to the hitherto published values. This opens the possibility that only an upper limit on ^6Li/^7Li has thus far been derived. The second method confirms these findings. Conclusions: From this work, it appears that a systematic reappraisal of former determinations of ^6Li abundances in halo stars is warranted. Based on observations carried out at the European Southern Observatory (ESO), under prog. ID 75.D-0600. Tables 1-3, and additional references are only available in electronic form at http://www.aanda.org

  20. 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.

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

    DOE PAGESBeta

    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.

  2. Deviation from Universality in Collisions of Ultracold Li26 Molecules

    NASA Astrophysics Data System (ADS)

    Wang, Tout T.; Heo, Myoung-Sun; Rvachov, Timur M.; Cotta, Dylan A.; Ketterle, Wolfgang

    2013-04-01

    Collisions of Li26 molecules with free Li6 atoms reveal a striking deviation from universal predictions based on long-range van der Waals interactions. Li2 closed-channel molecules are formed in the highest vibrational state near a narrow Feshbach resonance and decay via two-body collisions with Li2, Li, and Na. For Li2+Li2 and Li2+Na, the decay rates agree with the universal predictions of the quantum Langevin model. In contrast, the rate for Li2+Li is exceptionally small, with an upper bound 10 times smaller than the universal prediction. This can be explained by the low density of available decay states in systems of light atoms [G. Quéméner, J.-M. Launay, and P. Honvault, Phys. Rev. A 75, 050701 (2007)PLRAAN1050-2947], for which such collisions have not been studied before.

  3. Quantum effects in the case of (6)Li+ and (7)Li+ ions evolving in a neutral (6)Li gas at a wide range of temperatures.

    PubMed

    Bouchelaghem, F; Bouledroua, M

    2014-02-01

    This work deals with the quantum-mechanical calculation of the temperature-dependent mobility of ionic lithium atoms diffusing in their parent gas. The computation of the quantal phase shifts in connection with the gerade and ungerade potential-energy curves, through which Li(+) approaches Li(2s), leads to the computation of the charge-transfer and diffusion cross sections. The behavior of the coefficients of diffusion and mobility with temperature is also examined. Throughout this work, the isotopic effects in the (6)Li(+)-(6)Li and (7)Li(+)-(6)Li collisions are emphasized. PMID:24326775

  4. 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.

  5. Ferromagnetism in Li doped ZnO nanoparticles: The role of interstitial Li

    NASA Astrophysics Data System (ADS)

    Ullah Awan, Saif; Hasanain, S. K.; Bertino, Massimo F.; Hassnain Jaffari, G.

    2012-11-01

    ZnO nanoparticles doped with Li (Zn1-yLiyO, y ≤ 0.1) have been investigated with emphasis on the correlation between their magnetic, electronic, and structural properties. In particular, defects such as interstitial Li and Zn atoms, substitutional Li atoms, and oxygen vacancies have been identified by X-ray photoelectron spectroscopy (XPS) and their respective roles in stabilization of the magnetic moment are discussed. X-ray diffraction (XRD) and XPS give clear evidence of Li presence at both substitutional and interstitial sites. XPS studies further show that the amount of substitutional Li defects (Lizn) and interstitial Li defects (Lii) vary non-monotonically with the Li concentration, with the Lii defects being noticeably high for the y = 0.02, 0.08, and 0.10 concentrations, in agreement with the XRD results. Magnetization studies show room temperature ferromagnetism in these nanoparticles with the moment being largest for the particles with high concentration of interstitial lithium and vice versa. Both interstitial Zn (Zni) defects and Zn-O bonds were determined from the Zn LMM Auger peaks; however, the variation of these with Li concentrations was not large. Oxygen vacancies (Vo) concentrations are estimated to be relatively constant over the entire Li concentration range. We relate the Lii and Zni defects to the formation and stabilization of Zn vacancies and thus stabilizing the p-type ferromagnetism predicted for cation (zinc) vacancy in the ZnO type oxides.

  6. 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.

  7. [100]-Oriented LiFePO4 Nanoflakes toward High Rate Li-Ion Battery Cathode.

    PubMed

    Li, Zhaojin; Peng, Zhenzhen; Zhang, Hui; Hu, Tao; Hu, Minmin; Zhu, Kongjun; Wang, Xiaohui

    2016-01-13

    [100] is believed to be a tough diffusion direction for Li(+) in LiFePO4, leading to the belief that the rate performance of [100]-oriented LiFePO4 is poor. Here we report the fabrication of 12 nm-thick [100]-oriented LiFePO4 nanoflakes by a simple one-pot solvothermal method. The nanoflakes exhibit unexpectedly excellent electrochemical performance, in stark contrast to what was previously believed. Such an exceptional result is attributed to a decreased thermodynamic transformation barrier height (Δμb) associated with increased active population. PMID:26694590

  8. NMR study of Li adsorbed on the Si (111) - (3×1) -Li surface

    NASA Astrophysics Data System (ADS)

    Bromberger, C.; Jänsch, H. J.; Kühlert, O.; Schillinger, R.; Fick, D.

    2004-06-01

    Li adsorption on the (3×1) -Li reconstructed Si(111) surface has been studied by β -nuclear magnetic resonance experiments (measurements of T1 times). A rich variety of temperature, coverage, and magnetic field dependencies were observed, which reflect a metal-semiconductor-metal transition while adsorbing Li with increasing coverage on a (7×7) -reconstructed Si(111) surface in such a way that the (3×1) reconstruction is driven. With the aid of a formulated concept of Li donors localized on a semiconducting surface the temperature dependence of relaxation rates for Li adsorbed at extremely low coverages (up to 0.01 ML ) could be understood consistently. The donor energy of adsorbed Li on the (3×1) surface has been determined to be ED ≈100 meV . This success proves additionally that the theoretical results of a completely ionized Li chain in the (3×1) reconstruction are correct. The observed semiconductor-metal transition for adsorption of 0.14 ML additional Li on the already (3×1) -reconstructed surface points to the existence of an empty state near the Fermi energy (probably the so-called S-1 state). The diffusion energy of Li on the Si (111) - (3×1) surface could be estimated to be Ediff ≈410 meV .

  9. 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.

  10. Li + grafting of ion irradiated polyethylene

    NASA Astrophysics Data System (ADS)

    Švorčík, V.; Rybka, V.; Vacík, J.; Hnatowicz, V.; Öchsner, R.; Ryssel, H.

    1999-02-01

    Foils of oriented polyethylene (PE) were irradiated with 63 keV Ar + and 155 keV Xe + ions to different fluences at room temperature and then doped from water solution of LiCl. The as irradiated and irradiated plus doped samples were examined by IR, EPR and neutron depth profiling (NDP) technique. The sheet resistance was also measured by the standard two points method. After Li salt doping of ion modified layer of PE, a reaction between degraded macromolecules and Li occur and thus a new chemical structure C-Li + is formed. Owing to the presence of these cations on the polymer chain, the irradiated plus doped layer exhibits higher electric conductivity compared to as-irradiated ones.

  11. 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.

  12. Triplet state photoassociation of LiNa

    NASA Astrophysics Data System (ADS)

    Rvachov, Timur; Jamison, Alan; Jing, Li; Jiang, Yijun; Zwierlein, Martin; Ketterle, Wolfgang

    2015-05-01

    Ultracold molecules have promise to become a useful tool for studies in quantum simulation and ultracold chemistry. We aim to produce ultracold fermionic 6Li23Na molecules in the triplet ground state. Due to the small mass, small spin-orbit coupling, and fermionic character of LiNa, the triplet ground state is expected to be long lived. We report on photoassociation spectra of LiNa to its triplet excited states from an ultracold mixture. This is the first observation of these excited triplet potentials, which have been previously difficult to observe in heat-pipe experiments due to the small spin-orbit coupling in the system. Determining the excited state potentials is a key milestone towards forming triplet ground state LiNa via two-photon STIRAP. Work supported by the NSF, AFOSR-MURI, ARO-MURI, and NSERC.

  13. 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).

  14. 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

  15. Microscopic Structure of Contact Ion Pairs in Concentrated LiCl- and LiClO4-Tetrahydrofuran Solutions Studied by Low-Frequency Isotropic Raman Scattering and Neutron Diffraction with (6)Li/(7)Li Isotopic Substitution Methods.

    PubMed

    Kameda, Yasuo; Ebina, Saki; Amo, Yuko; Usuki, Takeshi; Otomo, Toshiya

    2016-05-26

    Low-frequency isotropic Raman scattering and time-of-flight neutron diffraction measurements were carried out for (6)Li/(7)Li and H/D isotopically substituted *LiCl- and *LiClO4-tetrahydrofuran (*THF) solutions in order to obtain microscopic insight into solvated Li(+), Li(+)···Cl(-) and Li(+)···ClO4(-) contact ion pairs formed in concentrated THF solutions. Symmetrical stretching vibrational mode of solvated Li(+) in LiCl and LiClO4 solutions was observed at ν = 181-184 and 140 cm(-1), respectively. The stretching vibrational mode of Li(+)···Cl(-) and Li(+)···ClO4(-) solvated contact ion pairs formed in 4 mol % (6)LiCl-THF-h8 and (7)LiCl-THF-h8 solutions was found at ν = 469 and 435 cm(-1), respectively. Detailed structural properties of solvated Li(+) and the contact ion pairs were derived from the least-squares fitting analyses of the first-order difference function, ΔLi(Q), obtained from neutron diffraction measurements on (6)Li/(7)Li isotopically substituted THF-d8 solutions. It has been revealed that Li(+) takes 4-fold coordination in the average local structure of Li(+)X(-)(THF)3, X = Cl and ClO4. The nearest neighbor Li(+)···O(THF) distance was determined to be 2.21 ± 0.01 Å and 2.07 ± 0.01 Å for 4 mol % *LiCl- and 10 mol % *LiClO4-THF-d8 solutions, respectively. The Li(+)···anion distances for Li(+)···Cl(-) and Li(+)···O(ClO4(-)) contact ion pairs were determined to be 2.4 ± 0.1 Å and 2.19 ± 0.01 Å, respectively. The nearest neighbor Li(+)···THF interaction is significantly modified by the anion in the first solvation shell. PMID:27157529

  16. 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

  17. On Li-7 production in nova explosions

    NASA Technical Reports Server (NTRS)

    Starrfield, S.; Truran, J. W.; Sparks, W. M.; Arnould, M.

    1978-01-01

    Calculations of Li-7 production occurring as a concomitant of thermonuclear runaways in hydrogen envelopes of white dwarfs are reported. It is found that sufficient Li-7 can be produced in models displaying fast-nova-like features to suggest that the corresponding objects represent significant contributors to the enrichment of galactic matter. The sensitivities of these results to various assumptions and uncertainties are discussed.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Li diffusion through doped and defected graphene.

    PubMed

    Das, Deya; Kim, Seungchul; Lee, Kwang-Ryeol; Singh, Abhishek K

    2013-09-28

    We investigate the effect of nitrogen and boron doping on Li diffusion through defected graphene using first principles based density functional theory. While a high energy barrier rules out the possibility of Li- diffusion through the pristine graphene, the barrier reduces with the incorporation of defects. Among the most common defects in pristine graphene, Li diffusion through the divacancy encounters the lowest energy barrier of 1.34 eV. The effect of nitrogen and boron doping on the Li diffusion through doped defected-graphene sheets has been studied. N-doping in graphene with a monovacancy reduces the energy barrier significantly. The barrier reduces with the increasing number of N atoms. On the other hand, for N doped graphene with a divacancy, Li binds in the plane of the sheet, with an enhanced binding energy. The B doping in graphene with a monovacancy leads to the enhancement of the barrier. However, in the case of B-doped graphene with a divacancy, the barrier reduces to 1.54 eV, which could lead to good kinetics. The barriers do not change significantly with B concentration. Therefore, divacancy, B and N doped defected graphene has emerged as a better alternative to pristine graphene as an anode material for Li ion battery. PMID:23925460

  3. 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

  4. Li(+) Local Structure in Hydrofluoroether Diluted Li-Glyme Solvate Ionic Liquid.

    PubMed

    Saito, Soshi; Watanabe, Hikari; Ueno, Kazuhide; Mandai, Toshihiko; Seki, Shiro; Tsuzuki, Seiji; Kameda, Yasuo; Dokko, Kaoru; Watanabe, Masayoshi; Umebayashi, Yasuhiro

    2016-04-01

    Hydrofluoroethers have recently been used as the diluent to a lithium battery electrolyte solution to increase and decrease the ionic conductivity and the solution viscosity, respectively. In order to clarify the Li(+) local structure in the 1,1,2,2-tetrafluoroethyl 2,2,3,3-tetrafluoropropyl ether (HFE) diluted [Li(G4)][TFSA] (G4, tetraglyme; TFSA, bis(trifluoromethanesulfonyl)amide) solvate ionic liquid, Raman spectroscopic study has been done with the DFT calculations. It has turned out that the HFE never coordinates to the Li(+) directly, and that the solvent (G4) shared ion pair of Li(+) with TFSA anion (SSIP) and the contact ion pair between Li(+) and TFSA anion (CIP) are found in the neat and HFE diluted [Li(G4)][TFSA] solvate ionic liquid. It is also revealed that the two kinds of the CIP in which TFSA anion coordinates to the Li(+) in monodentate and bidentate manners (hereafter, we call them the monodentate CIP and the bidentate CIP, respectively) exist with the SSIP of predominant [Li(G4)](+) ion-pair species in the neat [Li(G4)][TFSA] solvate ionic liquid, and that the monodentate CIP decreases as diluting with the HFE. To obtain further insight, X-ray total scattering experiments (HEXTS) were carried out with the aid of MD simulations, where the intermolecular force field parameters, mainly partial atomic charges, have been newly proposed for the HFE and glymes. A new peak appeared at around 0.6-0.7 Å(-1) in X-ray structure factors, which was ascribed to the correlation between the [Li(G4)][TFSA] ion pairs. Furthermore, MD simulations were in good agreement with the experiments, from which it is suggested that the terminal oxygen atoms of the G4 in [Li(G4)](+) solvated cation frequently repeat coordinating/uncoordinating to the Li(+), although almost all of the G4 coordinates to the Li(+) to form [Li(G4)](+) solvated cation in the neat and HFE diluted [Li(G4)][TFSA] solvate ionic liquid. PMID:26959344

  5. 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.

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

    NASA Astrophysics Data System (ADS)

    Chaboyer, Brian; Demarque, P.

    1994-10-01

    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 Teff 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 Teff which is not present in the observations. Possible causes for this discrepancy are discussed.

  7. 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.

  8. forced overdischarge related safety aspects of Li/SO2 and Li/SOCl2 cells

    NASA Technical Reports Server (NTRS)

    Abraham, K. M.

    1983-01-01

    Results of an experiment investigating overdischarge behavior of two types of Li/SO2 cells are presented. Forced overdischarges of the Li/LiBr, CH3CN/SO2 cell can result in unsafe behavior such as venting with fire and release of toxic gases. The hazards may be minimized or eliminated by careful cell design considerations and practice of high standards of quality contol in cell manufacture. Seemingly safe cells at 25 C when forced overdischarged at -25 C, even at low currents, exhibited incipient signs of hazards. Their cathodes indicated signs of shock sensitivity. Cathode limited Li/SOCl2 cells were safe during forced overdischarge for long periods of time. Lithium limited Li/SOCl2 cells in which practically all Li had been used up before cell reversal did not exhibit hazardous behavior. Anode limited Li/SOCl2 cells, but not Li limited, exhibited detonations, all during overdischarges at relatively low current densities of or = 1 mA/sq cm 2. Anode potentials 4v with large oscillations preceeded the events. The events were confined to the anode and the temperature rose high enough to melt Ni grids.

  9. 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

  10. Trimethylsilyl Chloride-Modified Li Anode for Enhanced Performance of Li-S Cells.

    PubMed

    Wu, Meifen; Wen, Zhaoyin; Jin, Jun; Chowdari, Bobba V R

    2016-06-29

    A facile and effective method to modify Li anode for Li-S cells by exposing Li foils to tetrahydrofuran (THF) solvent, oxygen atmosphere and trimethylsilyl chloride ((CH3)3SiCl) liquid in sequence is proposed. The results of SEM and XPS show the formation of a homogeneous and dense film with a thickness of 84 nm on Li metal surface. AC impedance and polarization test results show the improved interfacial stability. The interfacial resistances as well as polarization potential difference have obviously decreased as compared with that of a pristine Li anode. CV and charge-discharge test results demonstrate that more reversible discharge capacity and higher Coulombic efficiency can be achieved. Specific capacity of 760 mAh g(-1) and an average Coulombic efficiency of 98% are retained after 100 cycles at 0.5C without LiNO3 additive. Additionally, the Li-S cell with a modified Li anode displays a greatly improved rate performance with ∼425 mAh g(-1) at 5C, making it more attractive and competitive in the applications of high-power supply. PMID:27269577

  11. 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.

  12. The anharmonic vibration of Li in lithium amide

    NASA Astrophysics Data System (ADS)

    Paik, B.; Hasegawa, T.; Ishii, I.; Michigoe, A.; Suzuki, T.; Udagawa, M.; Ogita, N.; Ichikawa, T.; Kojima, Y.

    2012-04-01

    A large amplitude rattling-type anharmonic vibration of Li is possible without guest-host type structure, as we report here for tetragonal LiNH2 crystal. The low temperature (0.4-300 K) specific heat capacity and Raman spectroscopy support the phonon model of site-specific Li activities governed by the symmetry of the potential energy distribution around the Li atoms in LiNH2, which yields the anharmonic Li3 vibration (optical) in one direction (either X or Y axis of the crystal), while the Li1 and Li2 atoms remain silent. Our finding may help to correlate ionic conductivity, thermal, and hydrogenation properties of LiNH2.

  13. First Principles Study of Al-Li Intermetallic Compounds

    NASA Astrophysics Data System (ADS)

    Yu, Hai-li; Duan, Xiao-hui; Ma, Yong-jun; Zeng, Min

    2012-12-01

    The structural properties, heats of formation, elastic properties, and electronic structures of four compositions of binary Al-Li intermetallics, Al3Li, AlLi, Al2Li3, and Al4Li9, are analyzed in detail by using density functional theory. The calculated formation heats indicate a strong chemical interaction between Al and Li for all the Al-Li intermetallics. In particular, in the Li-rich Al-Li compounds, the thermodynamic stability of intermetallics linearly decreases with increasing concentration of Li. According to the computational single crystal elastic constants, all the four Al-Li intermetallic compounds considered here are mechanically stable. The polycrystalline elastic modulus and Poisson's ratio have been deduced by using Voigt, Reuss, and Hill approximations, and the calculated ratios of bulk modulus to shear modulus indicate that the four compositions of binary Al-Li intermetallics are brittle materials. With the increase of Li concentration, the bulk modulus of Al-Li intermetallics decreases in a linear manner.

  14. Characteristic of Absorption Heat Transfer using LiBr+LiI Solution

    NASA Astrophysics Data System (ADS)

    Tsujimori, Atsushi; Ozaki, Eiichi; Nakao, Kazushige

    LiBr-H20 absorption chiller is widely used in Japan, and many research have been made for absorption characteristic in terms of enhancing heat transfer. Another study have been performed for widening working range with higher crystallization limits, and it was reported that adding LiI salt to LiBr-H20 working fluid provide about 5 [mass%] higher crystallization limit under the condition of absorption pressure range. It is necessary to reveal absorption heat transfer performance to utilize this working fluid pair for absorption chiller. In this study absorption heat transfer characteristic was investigated for horizontal and vertical tube. As a result, it was found that heat transfer coefficient increased as mass flow rate of solution increased and mass concentration of solution decrease and that these characteristic were almost the same as LiBr solution, though this solution gave slightly less heat transfer coefficient than LiBr solution.

  15. Coupling of Li+ relaxators to the soft mode in KTaO3:Li

    NASA Astrophysics Data System (ADS)

    Prosandeev, S. A.; Trepakov, V. A.; Savinov, M. E.; Kapphan, S. E.

    2001-01-01

    The complex dielectric permittivity of K1-xLixTaO3 (KTL) single crystals with x = 0.006 has been experimentally studied in detail in the temperature interval from 5 to 300 K and at frequencies from 100 Hz to 1 MHz. In agreement with previous studies, a very large effect of the Li impurities on the dielectric response, even for such a small Li concentration, is found. It consists in the appearance of a pronounced low-temperature dielectric dispersion with giant magnitude. This unusually large dielectric response cannot be caused only by the relaxation of the Li+-impurity off-centres themselves, because the Li concentration is too small. Also, the host lattice response itself cannot give such a large dispersion, as evidenced. We present a theoretical model, which considers the coupling of the Li+-related relaxators to the TO soft mode, giving a good description of the experimental data obtained.

  16. A 2D MOT design optimized for dual-species 6 Li-7 Li experiments

    NASA Astrophysics Data System (ADS)

    Cai, Yanping; Evans, Jesse; Wright, Kevin

    2016-05-01

    We have built a 2D MOT optimized for simultaneous capture and cooling of 6 Li and 7 Li. The design includes a vapor source located very close to the capture region, which reduces depletion of the low-velocity part of the oven flux. The source is angled so that the most probable longitudinal velocity of captured atoms is near optimal for transferring to a 3D MOT, even without a push beam. Because 6 Li D2 repump light can impede capture and cooling of 7 Li, we have characterized the system performance with 6 Li repumped on both the D1 and D2 transitions. This design provides ample cold atom flux to load a dual-species 3D MOT for quantum degenerate gas experiments.

  17. 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.

  18. 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.

  19. Control of Li configuration and electrical properties of Li-doped ZnO

    NASA Astrophysics Data System (ADS)

    Zhang, Z.; Knutsen, K. E.; Merz, T.; Kuznetsov, A. Yu; Svensson, B. G.; Brillson, L. J.

    2012-09-01

    Li-doped ZnO after different thermal treatments was characterized by depth-resolved cathodoluminescence spectroscopy (DRCLS), secondary ion mass spectrometry, surface photovoltage spectroscopy (SPS), coupled with other surface science techniques. It is found that the Li configuration and electrical properties of Li-doped ZnO could be controlled by different thermal processes. Within a 500-600 °C annealing temperature range, subsequent quenching of ZnO leaves Li as interstitial donors, resulting in n-type low room temperature resistivity. In contrast, slower cooling in air enables these interstitials to fill Zn vacancies, forming Li acceptors 3.0 eV below the conduction band edge. Emergence of this acceptor and the resultant resistivity increase agree with the calculated diffusion lengths based on published diffusion coefficients. In general, these acceptors are compensated by residual intrinsic and extrinsic donors, resulting in a semi-insulating material. DRCL spectra exhibit a 3.0 eV optical signature of the LiZn acceptor and its depth distribution in slow-cooled ZnO. A 3.0 eV SPS absorption feature corresponding to a conduction band-to-acceptor level transition confirms this acceptor assignment. Nanoscale SPS spectra reveal p-type band bending localized near ZnO surface nano-mounds, where VZn and LiZn acceptor densities increase. The slow-cooled and quenched Li-doped ZnO spectra display an inverse relationship between the optical emission densities of lithium on zinc versus zinc vacancy sites, demonstrating the time dependence of Li interstitial diffusion to reach zinc vacancies and form substitutional Li acceptors.

  20. 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.

  1. Anharmonicity and phase stability of antiperovskite Li3OCl

    NASA Astrophysics Data System (ADS)

    Chen, Min-Hua; Emly, Alexandra; Van der Ven, Anton

    2015-06-01

    A lattice-dynamics study of the cubic Li3OCl antiperovskite, a candidate solid electrolyte in lithium-ion batteries, reveals the presence of dynamical instabilities with respect to rotations of the Li6O octahedra. Calculated energy landscapes in the subspace of unstable octahedral rotational modes are very shallow with at most a 1 meV per formula unit reduction in energy upon breaking the cubic symmetry. While Li3OCl is not stable relative to decomposition into Li2O and LiCl at 0 K, estimates of the vibrational free energy suggest that Li3OCl antiperovskite should become entropically stabilized above approximately 480 K.

  2. First-Principles Study of LiPON Solid Electrolyte

    NASA Astrophysics Data System (ADS)

    Santosh, K. C.; Xiong, Ka; Cho, Kyeongjae

    2011-03-01

    There has been much interest in the thin-film solid electrolyte for solid state battery and ionics applications. LiPON is a representative material developed by Oak Ridge National Laboratory. In this work, we use first principles calculations based on the density functional theory to investigate the Li- ion migration mechanisms of LiPON family materials. We investigate atomic structures, electronic structures and defect formation energies of these materials. To determine the migration path of Li diffusion, the activation energies are calculated. This study helps us to understand fundamental mechanisms of Li-ion migration and to improve Li ion conductivity in the solid electrolytes.

  3. Mechanism of Li intercalation/deintercalation into/from the surface of LiCoO2.

    PubMed

    Moradabadi, Ashkan; Kaghazchi, Payam

    2015-09-21

    Mechanism of Li diffusion at the LiCoO2(101[combining overline]4) surface and in bulk LiCoO2 is studied using density functional theory calculations. We find that there is almost no barrier for the diffusion of Li between the two topmost surface layers. The results show that Li intercalation occurs by the diffusion of Li ions from the first layer to the divacancy of Li sites created by removal of two neighboring Li ions in the first and second layer. However, Li deintercalation occurs by the diffusion of Li ions from the second layer to the missing row of topmost Li sites. The energy barrier for the process of intercalation/deintercalation of Li between the second and third surface layers is also lower than that in the bulk. This finding indicates that nanosized LiCoO2 with a large surface area/volume ratio is a promising cathode material for fast charging/discharging Li-ion batteries. PMID:26267222

  4. 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.

  5. 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.

  6. 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

  7. The high stability of boron-doped lithium clusters Li 5B, Li 6B +/- and Li 7B: A case of the phenomenological shell model

    NASA Astrophysics Data System (ADS)

    Tai, Truong Ba; Nguyen, Minh Tho

    2010-04-01

    A quantum chemical investigation of the clusters Li 5B, Li 6B +, Li 6B - and Li 7B was performed using the DFT, MP2 and CCSD(T) methods. The high symmetry structures ( C4v, 1A 1), ( Oh, 1A 1g) and ( D5h, 1A1') turnout to be the global minima for Li 5B, Li 6B + and Li 7B, respectively. These clusters are predicted to be highly stable species with large vertical ionization energies, and large HOMO-LUMO gaps. Chemical bonding of clusters was probed using an electron localizability indicator (ELI) which indicates a large aromatic character. The high stability of these clusters can be accounted for by the phenomenological shell model.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Hydrogen storage in LiH: A first principle study

    NASA Astrophysics Data System (ADS)

    Banger, Suman; Nayak, Vikas; Verma, U. P.

    2014-04-01

    First principles calculations have been performed on the Lithium hydride (LiH) using the full potential linearized augmented plane wave (FP-LAPW) method within the framework of density functional theory. We have extended our calculations for LiH+2H and LiH+6H in NaCl structure. The structural stability of three compounds have been studied. It is found that LiH with 6 added Hydrogen atoms is most stable. The obtained results for LiH are in good agreement with reported experimental data. Electronic structures of three compounds are also studied. Out of three the energy band gap in LiH is ˜3.0 eV and LiH+2H and LiH+6H are metallic.

  16. 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.

  17. LiMn2O4-based cathode thin films for Li thin-film batteries

    NASA Astrophysics Data System (ADS)

    Yim, Haena; Shin, Dong-Wook; Choi, Ji-Won

    2016-01-01

    Substitution methods for Mn3+ in a spinel lithium manganese oxide with other cations have been used to prevent capacity degradation during the electrochemical charge and discharge of Li-batteries by increasing the average valence of Mn. In particular, in this review we outlin the effects of Sn substitution on the cycling performance of LiMn2O4 thin films that can be used as positive electrode in Li-batteries. The thin films were prepared by using pulsed laser deposition and solution deposition with regard to the structural and the electro-chemical characteristics.

  18. Heating of Li in hydrogen: possible synthesis of LiHx

    NASA Astrophysics Data System (ADS)

    Kuno, K.; Matsuoka, T.; Nakagawa, T.; Hirao, N.; Ohishi, Y.; Shimizu, K.; Takahama, K.; Ohta, K.; Sakata, M.; Nakamoto, Y.; Kume, T.; Sasaki, S.

    2015-01-01

    We report the first laser heating experiments on Li in hydrogen at high pressures. X-ray diffraction and Raman scattering measurements suggest the possible formation of polyhydride (temporary named LiH?-II) that is considered to contain H? molecules in its crystal lattice. LiH?-II was found to be a transparent insulator at pressures below 62 GPa. This paper was presented at the LIIth European High Pressure Research Group (EHPRG 52) Meeting in Lyon (France), 7-12 September 2014.

  19. 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. PMID:27151860

  20. 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

  1. 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.

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

    PubMed

    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

  3. 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.

  4. Li Diffusion and High-Voltage Cycling Behavior of Thin-Film LiCoO2 Cathodes

    SciTech Connect

    Jang, Y.-I.

    2001-10-02

    Mass transport and thermodynamic properties of Li{sub x}CoO{sub 2} were studied by the potentiostatic intermittent titration technique (PITT) using solid-state thin-film batteries that provide a well-defined diffusion geometry. Both the chemical diffusion coefficient and the thermodynamic factor have minima at the phase boundaries of the Li/vacancy ordered phase ''Li{sub 0.5}CoO{sub 2}''. The self-diffusion coefficient of Li has a minimum at x = 0.5 associated with the Li/vacancy ordering. As the degree of ordering increases, the nonmonotonic variations become more pronounced when approaching x = 0.5 in Li{sub x}CoO{sub 2}. We also show that thin-film LiCoO{sub 2} cathodes having grains of sub-micrometer size combined with the Li upon electrolyte exhibit excellent capacity retention when charged up to 4.5 V.

  5. Lithium intercalation cells LiMn 2O 4/LiTi 2O 4 without metallic lithium

    NASA Astrophysics Data System (ADS)

    Manickam, M.; Takata, M.

    Rechargeable lithium cells can be made with two different intercalation compounds as the positive and negative electrodes, which are safer than the battery technology using pure Li metal. In this paper, we present our study of the Li ion type battery that uses LiTi 2O 4 as the negative electrode, which is coupled with a strongly oxidizing intercalation compound, spinel LiMn 2O 4, as the positive electrode has been found to solve problems associated with the use of metallic lithium at the expense of lowering the overall cell voltage. Preliminary electrochemical data revealed that this Li ion type battery "LiMn 2O 4/LiTi 2O 4" exhibits a low performance in terms of capacity. Li cycling efficiency is examined with mixed solvents as electrolyte. With improvements in capacity, materials such as these could improve the over all performance of secondary lithium intercalation cells.

  6. Current collectors for rechargeable Li-Air batteries

    SciTech Connect

    Veith, Gabriel M; Dudney, Nancy J

    2011-01-01

    Here we report the negative influence of porous nickel foam for use as current collectors in rechargeable Li-air batteries. Uncoated nickel foam promotes the decomposition of LiPF6-organic carbonate electrolytes under normal charging conditions reported for rechargeable Li-air cells. We have identified Ni free porous carbon supports as more appropriate cathode current collectors.

  7. 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.

  8. 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

  9. Formation of small polarons in Li2O2 and implications for Li-air batteries

    NASA Astrophysics Data System (ADS)

    Kang, Joongoo; Jung, Yoon-Seok; Wei, Su-Huai; Dillon, Anne

    2012-02-01

    Lithium-air batteries (LABs) have recently been revitalized as a promising electrical energy storage system due to their exceptionally high theoretical energy density. However, its usage is limited by poor rate capability and large polarization in the cell voltage due primarily to the formation of Li2O2 in the air cathode. Here, using hybrid density functional theory, we found that the formation of small polarons in Li2O2 is the origin that limits the electron transport in Li2O2. Consequently, the low electron mobility contributes to the hysteresis in cell voltage and limits the power density of the LABs. We suggest that similar behavior should exist in other peroxides, and p-type doping in Li2O2 could significantly improve the performance of LABs at high current densities.

  10. Diffusion-limited Kinetic Pathway for Hydrogen Release from LiNH2/LiH

    NASA Astrophysics Data System (ADS)

    Rolih, Biljana; Ozolins, Vidvuds

    2011-03-01

    From experimental work on decomposition of hydrogen storage materials it has been suggested that bulk diffusion of metal species is the bottleneck for hydrogen release. In this work we study the underlying mechanism for diffusion reactions in the dehydrogenation of Li NH2 . Using first-principle, density functional theory methods we have calculated concentration gradients and diffusivities of neutral and charged defects in Li NH2 and Li 2 NH phases. The overall activation energy is obtained from these calculations. The calculated activation energies are found to agree well with experimental work on the kinetics of Li NH2 decomposition, suggesting that diffusion of metal species is a possible method for dehydrogenation of Lithium Amide.

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

    NASA Astrophysics Data System (ADS)

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

    2015-05-01

    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 and electron energy loss spectroscopy 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 can guide the design and improvement of LiFePO4 cathode for high-energy and high-power rechargeable battery for electric transportation.

  12. 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.

  13. Bulk thermal capacity determination for Li/BCX and Li/SOClN2 cells

    NASA Technical Reports Server (NTRS)

    Kalu, E. E.; White, R. E.; Darcy, E. C.

    1992-01-01

    The bulk heat capacities of Li/BCX and Li/SOClN2 cells were determined at 0 and 100 percent depth-of-discharge for 2.0 V cut-off voltage, in the temperature range 0 to 60 C by a method that did not involve the destruction of the cell nor the contact of cell with a liquid. The heat capacities are found to be dependent on state-of-charge, increasing with depth-of-discharge. The Li/BCX DD-cell has a lower heat capacity than a high rate Li/SOCl2 D-cell. The results obtained by this method compare favorably well with results reported in the literature through other methods. The bulk heat capacities of the cells did not change significantly in the temperature range 0 to 60 C.

  14. Ultrafine LiCoO2 powders derived from electrospun nanofibers for Li-ion batteries

    NASA Astrophysics Data System (ADS)

    Ou, Yun; Wen, Jingjing; Xu, Haiping; Xie, Shuhong; Li, Jiangyu

    2013-02-01

    Sol-gel based electrospinning has been developed to synthesize phase pure LiCoO2 powders at relatively low temperature with excellent crystallinity and ultrafine particle size. Compared to LiCoO2 powders synthesized from regular sol-gel processes, the nanofiber derived powders possess high initial discharge capacity and good cyclic stability, and the retention of initial capacity is also much higher than bare LiCoO2 nanofibers reported in literature. With additional surface modification of La2O3 coating, the retention of initial capacity is increased to 91% at 30th cycle and 83% at 50th cycle without decreasing its initial capacity, making it attractive for Li-ion batteries.

  15. 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

  16. On the reduction of generalized polylogarithms to Li n and Li2 ,2 and on the evaluation thereof

    NASA Astrophysics Data System (ADS)

    Frellesvig, Hjalte; Tommasini, Damiano; Wever, Christopher

    2016-03-01

    We give expressions for all generalized polylogarithms up to weight four in terms of the functions log, Li n , and Li2,2, valid for arbitrary complex variables. Furthermore we provide algorithms for manipulation and numerical evaluation of Li n and Li2,2, and add codes in Mathematica and C++ implementing the results. With these results we calculate a number of previously unknown integrals, which we add in appendix C.

  17. 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

  18. Lithium concentration and Li isotopic compositions of carbonatitic complexes

    NASA Astrophysics Data System (ADS)

    Halama, R.; McDonough, W. F.; Rudnick, R. L.; Ash, R. D.; Keller, J.; Klaudius, J.; Trumbull, R.

    2005-12-01

    To evaluate the Li isotopic signatures of the mantle sources of carbonatites and the influence of magmatic differentiation and post-magmatic processes on δ7Li, we determined the Li concentrations and isotopic compositions of carbonatites and spatially associated silicate rocks, spanning a wide range in composition and age. Natrocarbonatites from Oldoinyo Lengai (1995 and 2000 eruptions) have high Li concentrations (211-292 ppm) and uniform Li isotopic signatures (δ7Li = +4.4 to +5.1 per mil). Associated silicate rocks (melilitite, nephelinite and phonolite) have lower Li concentrations (16-47 ppm) and trend towards lighter Li isotopic values (δ7Li = 0 to +3.5 per mil). Clinopyroxenes from these lavas are significantly lighter than the whole rocks by 1 to 6 per mil. Since the lavas appear to be fresh, this suggests fractionation of Li isotopes between minerals and whole rocks. In comparison to the modern natrocarbonatites, Proterozoic calciocarbonatites from Greenland (Grønnedal-Ika) and Cretaceous calciocarbonatites from Namibia (Kalkfeld) are poor in Li (< 2 ppm) and have more scattered Li isotopic compositions (δ7Li = -1 to +4 and -0.5 to +5 per mil, respectively). The lower δ7Li values may reflect contamination by crustal Li, since the low Li contents in the carbonatites make them susceptible to this. Silicate lavas from Kalkfeld have higher Li concentrations (11-12 ppm) than their associated carbonatites, but overlapping isotopic compositions (δ7Li = +4 to +6 per mil). At Grønnedal-Ika, clinopyroxene separates from nepheline syenites vary considerably in δ7Li from -6 to +5. Since Li is preferentially partitioned into fenitizing fluids [1] and an enrichment of light 6Li in fluids during degassing can be anticipated [2], the trend towards negative δ7Li can be interpreted as a result of variable interaction with metasomatizing fluids. However, fractionation of Li isotopes between minerals and melts may also have played a role. Our preliminary data

  19. 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.

  20. Observational evidence for a broken Li Spite plateau and mass-dependent Li depletion

    NASA Astrophysics Data System (ADS)

    Meléndez, J.; Casagrande, L.; Ramírez, I.; Asplund, M.; Schuster, W. J.

    2010-06-01

    We present NLTE Li abundances for 88 stars in the metallicity range -3.5 < [Fe/H] < -1.0. The effective temperatures are based on the infrared flux method with improved E(B-V) values obtained mostly from interstellar Na I D lines. The Li abundances were derived through MARCS models and high-quality UVES+VLT, HIRES+Keck and FIES+NOT spectra, and complemented with reliable equivalent widths from the literature. The less-depleted stars with [Fe/H] < -2.5 and [Fe/H] > -2.5 fall into two well-defined plateaus of ALi = 2.18 (σ = 0.04) and ALi = 2.27 (σ = 0.05), respectively. We show that the two plateaus are flat, unlike previous claims for a steep monotonic decrease in Li abundances with decreasing metallicities. At all metallicities we uncover a fine-structure in the Li abundances of Spite plateau stars, which we trace to Li depletion that depends on both metallicity and mass. Models including atomic diffusion and turbulent mixing seem to reproduce the observed Li depletion assuming a primordial Li abundance ALi = 2.64, which agrees well with current predictions (ALi = 2.72) from standard Big Bang nucleosynthesis. Adopting the Kurucz overshooting model atmospheres increases the Li abundance by +0.08 dex to ALi = 2.72, which perfectly agrees with BBN+WMAP. Based in part on observations obtained at the W. M. Keck Observatory, the Nordic Optical Telescope on La Palma, and on data from the HIRES/Keck archive and the European Southern Observatory ESO/ST-ECF Science Archive Facility.Table 1 is only available in electronic form at http://www.aanda.org

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Quantum chemical treatment of Li/Li+ doped defected carbon nanocapsules

    NASA Astrophysics Data System (ADS)

    Peköz, Rengin; Erkoç, Şakir

    2008-06-01

    Structural and electronic properties of nLi and nLi+ ( n=1-3) doped mono-vacancy defected carbon nanocapsule (CNC) systems have been investigated theoretically by performing semi-empirical self-consistent-field (SCF) molecular orbital (MO) and density functional theory (DFT) methods. Semi-empirical SCF MO method at PM3 level has been considered to optimize fully the geometry of the CNCs in their ground states. The total energies of these structures were calculated using B3LYP exchange-correlation functional in DFT method with 6-31G basis set. The studied systems include nLi/nLi+ doped (5,5) and (9,0) single-walled CNCs with mono-atom vacancies. The molecular properties, energies, some selected MO eigenvalues and dipole moments of the studied capsules have been reported. Furthermore, molecular dynamics simulations have been performed to study the structural properties and energetics of nLi/nLi+ doped mono-vacancy defected CNCs.

  6. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2015-07-01

    This 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. The crystallographic b-axis was revealed as a fast expansion direction, while negligible thermal expansion was 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.

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

    DOE PAGESBeta

    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

  9. Thermal Stability of Li-Ion Cells

    SciTech Connect

    ROTH,EMANUEL P.

    1999-09-17

    The thermal stability of Li-ion cells with intercalating carbon anodes and metal oxide cathodes was measured as a function of state of charge and temperature for two advanced cell chemistries. Cells of the 18650 design with Li{sub x}CoO{sub 2} cathodes (commercial SONY cells) and Li{sub x}Ni{sub 0.8}Co{sub 0.2}O{sub 2} cathodes were measured for thermal reactivity in the open circuit cell condition. Accelerating rate calorimetry (ARC) was used to measure cell thermal runaway as a function of state of charge (SOC). Microcalorimetry was used to measure the time dependence of heat generating side reactions also as a function of SOC. Components of cells were measured using differential scanning calorimetry (DSC) to study the thermal reactivity of the individual electrodes to determine the temperature regimes and conditions of the major thermal reactions. Thermal decomposition of the SEI layer at the anodes was identified as the initiating source for thermal runaway. The cells with Li{sub x}CoO{sub 2} cathodes showed greater sensitivity to SOC and higher accelerating heating rates than seen for the cells with Li{sub x}Ni{sub 0.8}Co{sub 0.2}O{sub 2}cathodes. Lower temperature reactions starting as low as 40 C were also observed that were SOC dependent but not accelerating. These reactions were also measured in the microcalorimeter and observed to decay over time with a power-law dependence and are believed to result in irreversible capacity loss in the cells.

  10. 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.

  11. An Ultra-high-Resolution Survey of the Interstellar 7Li/6Li Isotope Ratio in the Solar Neighborhood

    NASA Astrophysics Data System (ADS)

    Knauth, David C.; Federman, S. R.; Lambert, David L.

    2003-03-01

    In an effort to probe the extent of variations in the interstellar 7Li/6Li ratio seen previously, ultra-high-resolution (R~360,000), high signal-to-noise spectra of stars in the Perseus OB2 and Scorpius OB2 associations were obtained. These measurements confirm our earlier findings of an interstellar 7Li/6Li ratio of about 2 toward ο Per, the value predicted from models of Galactic cosmic-ray spallation reactions. Observations of other nearby stars yield limits consistent with the isotopic ratio of ~12 seen in carbonaceous chondrite meteorites. If this ratio originally represented the gas toward ο Per, then to decrease the original isotope ratio to its current value an order of magnitude increase in the Li abundance is expected, but it is not seen. The elemental K/Li ratio is not unusual, although Li and K are formed via different nucleosynthetic pathways. Several proposals to account for the low 7Li/6Li ratio were considered, but none seems satisfactory. Analysis of the Li and K abundances from our survey highlighted two sight lines where depletion effects are prevalent. There is evidence for enhanced depletion toward X Per, since both abundances are lower by a factor of 4 when compared to other sight lines. Moreover, a smaller Li/H abundance is observed toward 20 Aql, but the K/H abundance is normal, suggesting enhanced Li depletion (relative to K) in this direction. Our results suggest that the 7Li/6Li ratio has not changed significantly during the last 4.5 billion years and that a ratio of ~12 represents most gas in the solar neighborhood. In addition, there appears to be a constant stellar contribution of 7Li, indicating that one or two processes dominate its production in the Galaxy.

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. Ab-initio studies on Li doping, Li-pairs, and complexes between Li and intrinsic defects in ZnO

    NASA Astrophysics Data System (ADS)

    Vidya, R.; Ravindran, P.; Fjellvâg, H.

    2012-06-01

    First-principles density functional calculations have been performed on Li-doped ZnO using all-electron projector augmented plane wave method. Li was considered at six different interstitial sites (Lii), including anti-bonding and bond-center sites and also in substitutional sites such as at Zn-site (Lizn) and at oxygen site (Lio) in the ZnO matrix. Stability of LiZn over Lii is shown to depend on synthetic condition, viz., LiZn is found to be more stable than Lii under O-rich conditions. Hybrid density functional calculations performed on LiZn indicate that it is a deep acceptor with (0/-) transition taking place at 0.74 eV above valence band maximum. The local vibrational frequencies for Li-dopants are calculated and compared with reported values. In addition, we considered the formation of Li-pair complexes and their role on electronic properties of ZnO. Present study suggests that at extreme oxygen-rich synthesis condition, a pair of acceptor type LiZn-complex is found to be stable over the compensating Lii + LiZn pair. The stability of complexes formed between Li impurities and various intrinsic defects is also investigated and their role on electronic properties of ZnO has been analyzed. We have shown that a complex between LiZn and oxygen vacancy has less formation energy and donor-type character and could compensate the holes generated by Li-doping in ZnO.

  17. 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.

  18. Structural analysis of Li-intercalated hexagonal boron nitride

    SciTech Connect

    Sumiyoshi, A.; Hyodo, H.; Kimura, K.

    2012-03-15

    A structural investigation of Li-intercalated hexagonal boron nitride (Li-h-BNIC) was performed by synchrotron powder X-ray diffraction analysis and transmission electron microscopy. The host BN framework of Li-h-BNIC was expanded by Li-intercalation. The intralayer B-N bond length was increased by 2.48(1)% and the interlayer distance was expanded by 12.86(1)%. No superlattice structure of intercalated Li was observed. - Graphical abstract: XRD pattern fitting of the sample and schematic view of host h-BN lattice. Highlights: Black-Right-Pointing-Pointer Li-intercalated h-BN was investigated by synchrotron radiation powder XRD. Black-Right-Pointing-Pointer Lattice parameter of host h-BN lattice was increased by intercalation. Black-Right-Pointing-Pointer Increase ratio of B-N bond length was considerably larger than those of Li GICs.

  19. Modeling interfaces between solids: Application to Li battery materials

    NASA Astrophysics Data System (ADS)

    Lepley, N. D.; Holzwarth, N. A. W.

    2015-12-01

    We present a general scheme to model an energy for analyzing interfaces between crystalline solids, quantitatively including the effects of varying configurations and lattice strain. This scheme is successfully applied to the modeling of likely interface geometries of several solid state battery materials including Li metal, Li3PO4 , Li3PS4 , Li2O , and Li2S . Our formalism, together with a partial density of states analysis, allows us to characterize the thickness, stability, and transport properties of these interfaces. We find that all of the interfaces in this study are stable with the exception of Li3PS4/Li . For this chemically unstable interface, the partial density of states helps to identify mechanisms associated with the interface reactions. Our energetic measure of interfaces and our analysis of the band alignment between interface materials indicate multiple factors, which may be predictors of interface stability, an important property of solid electrolyte systems.

  20. Nanoscale coating of LiMO2 (M = Ni, Co, Mn) nanobelts with Li+-conductive Li2TiO3: toward better rate capabilities for Li-ion batteries.

    PubMed

    Lu, Jun; Peng, Qing; Wang, Weiyang; Nan, Caiyun; Li, Lihong; Li, Yadong

    2013-02-01

    By using a novel coating approach based on the reaction between MC(2)O(4)·xH(2)O and Ti(OC(4)H(9))(4), a series of nanoscale Li(2)TiO(3)-coated LiMO(2) nanobelts with varied Ni, Co, and Mn contents was prepared for the first time. The complete, thin Li(2)TiO(3) coating layer strongly adheres to the host material and has a 3D diffusion path for Li(+) ions. It is doped with Ni(2+) and Co(3+) ions in addition to Ti(4+) in LiMO(2), both of which were found to favor Li(+)-ion transfer at the interface. As a result, the coated nanobelts show improved rate, cycling, and thermal capabilities when used as the cathode for Li-ion battery. PMID:23301844

  1. 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.

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

    DOE PAGESBeta

    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.

  3. 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.

  4. 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

  5. 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

  6. 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

  7. Electronic structure and bonding of HBeLi, HmgLi, and HCaLi in their bent equilibrium geometries.

    PubMed

    Penotti, Fabio E

    2012-01-14

    Compact, yet accurate, non-orthogonal multi-configuration wavefunctions have been computed for HBeLi, HMgLi, and HCaLi in their respective nonlinear equilibrium geometries. They appear to be dominated by just two configurations, "orbitally relaxed" versions of the single-configuration spin-coupled and generalized valence bond (GVB) wavefunctions, respectively, with a smaller contribution from a self-consistent field (SCF)-like configuration. Double excitations out of the main configurations, while required for quantitative accuracy, enter the wavefunction with such small weights that they do not alter the qualitative picture that emerges from the orbital structure of the two main configurations. For comparison, calculations have also been carried out with two orthogonality-free configurations as reference, and no GVB-like or SCF-like configuration. Atoms-in-molecules (AIM) topological analyses of the overall electron densities, and considerations of local energetics in the differential neighbourhood of the equilibrium geometries, have been used to provide independent assessments of the nature of bonding in these molecules. Orbital structure and AIM results together suggest the existence of three-centre two-electron M-H-M' bonds through hydrogen in all three molecules. Orbital pictures suggest these bonds are at least partially covalent, while a strict interpretation of values of the electron density Laplacian at AIM bond critical points would imply closed-shell interactions. Also for all three molecules, the orbital structures of the two main configurations suggest the presence of a one-electron two-centre bond between Li and the alkaline-earth atom. This bond may provide at least a partial explanation for the relative shortness of the inter-metallic distances, but is apparently too spread out to show up in AIM analyses of the total electron density. Considerations of local energetics support the more nuanced description of bonding that emerges, for these three

  8. Facile synthesis of nano-Li4 Ti5O12 for high-rate Li-ion battery anodes

    NASA Astrophysics Data System (ADS)

    Jin, Yun-Ho; Min, Kyung-Mi; Shim, Hyun-Woo; Seo, Seung-Deok; Hwang, In-Sung; Park, Kyung-Soo; Kim, Dong-Wan

    2012-01-01

    One of the most promising anode materials for Li-ion batteries, Li4Ti5O12, has attracted attention because it is a zero-strain Li insertion host having a stable insertion potential. In this study, we suggest two different synthetic processes to prepare Li4Ti5O12 using anatase TiO2 nanoprecursors. TiO2 powders, which have extraordinarily large surface areas of more than 250 m2 g-1, were initially prepared through the urea-forced hydrolysis/precipitation route below 100°C. For the synthesis of Li4Ti5O12, LiOH and Li2CO3 were added to TiO2 solutions prepared in water and ethanol media, respectively. The powders were subsequently dried and calcined at various temperatures. The phase and morphological transitions from TiO2 to Li4Ti5O12 were characterized using X-ray powder diffraction and transmission electron microscopy. The electrochemical performance of nanosized Li4Ti5O12 was evaluated in detail by cyclic voltammetry and galvanostatic cycling. Furthermore, the high-rate performance and long-term cycle stability of Li4Ti5O12 anodes for use in Li-ion batteries were discussed.

  9. 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.

  10. Li-Metal-Free Prelithiation of Si-Based Negative Electrodes for Full Li-Ion Batteries.

    PubMed

    Zhou, Haitao; Wang, Xuehang; Chen, De

    2015-08-24

    Most of the high-capacity positive-electrode materials [for example, S, O2 (air), and MOx (M: V, Mn, Fe, etc.)] are Li-deficient and require the use of a Li-metal electrode or prelithiation. Herein, we report a novel electrolytic cell in which the Si electrode can be prelithiated in a well-controlled manner from Li-containing aqueous solution in a Li-metal-free way. MnOx/Si and S/Si Li-ion full cells were assembled by using the prelithiated Si negative electrodes, which resulted in high specific energies of 349 and 732 Wh kg(-1), respectively. The MnOx/Si full cell still retains 138 Wh kg(-1) even at a high specific power of 1710 W kg(-1). This is the first report of a whole process of making a full Li-ion battery with both Li-deficient electrodes without the use of Li metal as the Li source. This novel prelithiation process, with high controllability, no short circuiting, and an abundant Li source, is expected to contribute significantly to the development of safe, green, and powerful Li-ion batteries. PMID:26216592

  11. Enhancement of electrochemical behavior of nanostructured LiFePO4/Carbon cathode material with excess Li

    NASA Astrophysics Data System (ADS)

    Bazzi, K.; Nazri, M.; Naik, V. M.; Garg, V. K.; Oliveira, A. C.; Vaishnava, P. P.; Nazri, G. A.; Naik, R.

    2016-02-01

    We have synthesized carbon coated LiFePO4 (C-LiFePO4) and C-Li1.05FePO4 with 5 mol% excess Li via sol-gel method using oleic acid as a source of carbon for enhancing electronic conductivity and reducing the average particle size. Although the phase purity of the crystalline samples was confirmed by x-ray diffraction (XRD), the 57Fe Mössbauer spectroscopy analyses show the presence of ferric impurity phases in both stoichiometric and non-stoichiometric C-LiFePO4 samples. Transmission electron microscopy measurements show nanosized C-LiFePO4 particles uniformly covered with carbon, with average particle size reduced from ∼100 nm to ∼50 nm when excess lithium is used. Electrochemical measurements indicate a lower charge transfer resistance and better electrochemical performance for C-Li1.05FePO4 compared to that of C-LiFePO4. The aim of this work is to systematically analyze the nature of impurities formed during synthesis of LiFePO4 cathode material, and their impact on electrochemical performance. The correlation between the morphology, charge transfer resistance, diffusion coefficient and electrochemical performance of C-LiFePO4 and C- Li1.05FePO4 cathode materials are discussed.

  12. 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

  13. 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.

  14. Tailored Oxygen Framework of Li4Ti5O12 Nanorods for High-Power Li Ion Battery.

    PubMed

    Song, Kyeongse; Seo, Dong-Hwa; Jo, Mi Ru; Kim, Yong-Il; Kang, Kisuk; Kang, Yong-Mook

    2014-04-17

    Here we designed the kinetically favored Li4Ti5O12 by modifying its crystal structure to improve intrinsic Li diffusivity for high power density. Our first-principles calculations revealed that the substituted Na expanded the oxygen framework of Li4Ti5O12 and facilitated Li ion diffusion in Li4Ti5O12 through 3-D high-rate diffusion pathway secured by Na ions. Accordingly, we synthesized sodium-substituted Li4Ti5O12 nanorods having not only a morphological merit from 1-D nanostructure engineering but also sodium substitution-induced open framework to attain ultrafast Li diffusion. The new material exhibited an outstanding cycling stability and capacity retention even at 200 times higher current density (20 C) compared with the initial condition (0.1 C). PMID:26269981

  15. 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

  16. Influence of surface modification of LiCoO2 by organic compounds on electrochemical and thermal properties of Li/LiCoO2 rechargeable cells

    NASA Astrophysics Data System (ADS)

    Takeuchi, Takashi; Kyuna, Tomohiro; Morimoto, Hideyuki; Tobishima, Shin-ichi

    2011-03-01

    LiCoO2 is the most famous positive electrode (cathode) for lithium ion cells. When LiCoO2 is charged at high charge voltages far from 4.2 V, cycleability of LiCoO2 becomes worse. Causes for this deterioration are instability of pure LiCoO2 crystalline structure and an oxidation of electrolyte solutions LiCoO2 at higher charge voltages. This electrolyte oxidation accompanies with the partial reduction of LiCoO2. We think more important factor is the oxidation of electrolyte solutions. In this work, influence of 10 organic compounds on electrochemical and thermal properties of LiCoO2 cells was examined as electrolyte additives. As a base electrolyte solution, 1 M (M: mol L-1) LiPF6-ethylene carbonate (EC)/ethylmethyl carbonate (EMC) (mixing volume ratio = 3:7) was used. These compounds are o-terphenyl (o-TP), Ph-X (CH3)n (n = 1 or 2, X = N, O or S) compounds, adamantyl toluene compounds, furans and thiophenes. These additives had the oxidation potentials (Eox) between 3.4 and 4.7 V vs. Li/Li+. These Eox values were lower than that (6.30 V vs. Li/Li+) of the base electrolyte. These additives are oxidized on LiCoO2 during charge of the LiCoO2 cells. Oxidation products suppress the excess oxidation of electrolyte solutions on LiCoO2. As a typical example of these organic compounds, o-TP (Eox: 4.52 V) was used to check the fundamental properties of these organic additives. Charge-discharge cycling tests were carried out for the Li/LiCoO2 cells with and without o-TP. Constant current charge at 4.5 V is mainly used as a charge method. Cells with 0.1 wt.% o-TP exhibited slightly better cycling performance and lower polarization than those without additives. Lower polarization arises from a decrease in a resistance of interface between electrolyte solutions and LiCoO2 by surface film formation resulted from oxidation of o-TP. Oxidation products were found by mass spectroscopy analysis to be mixture of several polycondensation compounds made from two to four terphenly

  17. 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.

  18. 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.

  19. 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.

  20. Impedance studies on Li-ion cathodes

    SciTech Connect

    NAGASUBRAMANIAN, GANESAN

    2000-04-17

    This paper describes the author's 2- and 3-electrode impedance results of metal oxide cathodes. These results were extracted from impedance data on 18650 Li-ion cells. The impedance results indicate that the ohmic resistance of the cell is very nearly constant with state-of-charge (SOC) and temperature. For example, the ohmic resistance of 18650 Li-ion cells is around 60 m{Omega} for different SOCS (4.1V to 3.0V) and temperatures from 35 C to {minus}20 C. However, the interfacial impedance shows a modest increase with SOC and a huge increase of between 10 and 100 times with decreasing temperature. For example, in the temperature regime (35 C down to {minus}20 C) the overall cell impedance has increased from nearly 200 m{Omega} to 8,000 m{Omega}. Most of the increase in cell impedance comes from the metal oxide cathode/electrolyte interface.

  1. 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.

  2. Fully and partially Li-stuffed diamond polytypes with Ag-Ge structures: Li2AgGe and Li2.53AgGe2.

    PubMed

    Henze, Alexander; Hlukhyy, Viktor; Fässler, Thomas F

    2015-02-01

    In view of the search for and understanding of new materials for energy storage, the Li-Ag-Ge phase diagram has been investigated. High-temperature syntheses of Li with reguli of premelted Ag and Ge led to the two new compounds Li(2)AgGe and Li(2.80-x)AgGe(2) (x = 0.27). The compounds were characterized by single-crystal X-ray diffraction. Both compounds show diamond-polytype-like polyanionic substructures with tetrahedrally coordinated Ag and Ge atoms. The Li ions are located in the channels provided by the network. The compound Li(2)AgGe crystallizes in the space group R3̅m (No. 166) with lattice parameters of a = 4.4424(6) Å and c = 42.7104(6) Å. All atomic positions are fully occupied and ordered. Li(2.80-x)AgGe(2) crystallizes in the space group I4(1)/a (No. 88) with lattice parameters of a = 9.7606(2) Å and c = 18.4399(8) Å. The Ge substructure consists of unique (1)(∞)[Ge(10)] chains that are interconnected by Ag atoms to build a three-dimensional network. In the channels of this diamond-like network, not all of the possible positions are occupied by Li ions. Li atoms in the neighborhood of the vacancies show considerably enlarged displacement vectors. The occurrence of the vacancy is traced back to short Li-Li distances in the case of the occupation of the vacancy with Li. Both compounds are not electron-precise Zintl phases. The density of states, band structure, and crystal orbital Hamilton population analyses of Li(2.80-x)AgGe(2 )reveal metallic properties, whereas a full occupation of all Li sites leads to an electron-precise Zintl compound within a rigid-band model. Li(2)AgGe reveals metallic character in the ab plane and is a semiconductor with a small band gap along the c direction. PMID:25521213

  3. 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. PMID:27029789

  4. Supertransferred hyperfine fields at {sup 7}Li: Variable temperature {sup 7}Li NMR studies of LiMn{sub 2}O{sub 4}-based spinels

    SciTech Connect

    Gee, B.; Horne, C.R.; Cairns, E.J.; Reimer, J.A. |

    1998-12-10

    The temperature dependence of the {sup 7}Li NMR shift was measured for LiMn{sub 2}O{sub 4}, LiMn{sub 2{minus}y}Ni{sub y}O{sub 4} (y = 0.1, 0.25, 0.33), LiMn{sub 2{minus}y}Co{sub y}O{sub 4} (y = 0.25, 0.5, 1.0), Li[Mn{sub 2{minus}y}Li{sub y}]O{sub 4} (y = 0.1, 0.33), and {lambda}-MnO{sub 2} spinel oxides. The {sup 7}Li NMR shift can be separated into temperature-independent and -dependent components. The temperature-dependent shift follows the Curie-Weiss behavior of the bulk magnetic susceptibility. The temperature-independent shift is attributed to contributions from van Vleck and diamagnetic susceptibilities. Pauli susceptibility may also contribute to the temperature-independent shift in the nickel- and cobalt-substituted spinels. Supertransferred hyperfine (STH) coupling constants were derived from the {sup 7}Li NMR shifts and bulk magnetic susceptibility data. The progressive increase in average nominal manganese oxidation state from +3.5 to +4 results in an increase in the supertransferred hyperfine field at the {sup 7}Li nucleus in the lithium-substituted samples. Replacement of manganese by either cobalt or nickel also results in a larger STH field at the {sup 7}Li nuclei. The increase in STH field for the lithium-, nickel-, and cobalt-substituted spinel oxides may arise from a greater covalence in these materials relative to the parent LiMn{sub 2}O{sub 4} spinel oxide.

  5. 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.

  6. 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. PMID:26595122

  7. 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.

  8. Nodal versus nodeless superconductivity in isoelectronic LiFeP and LiFeAs

    NASA Astrophysics Data System (ADS)

    Nourafkan, R.

    2016-06-01

    Nodal superconductivity is observed in LiFeP while its counterpart LiFeAs with similar topology and orbital content of the Fermi surfaces is a nodeless superconductor. We explain this difference by solving, in the two-Fe Brillouin zone, the frequency-dependent Eliashberg equations with the spin-fluctuation-mediated pairing interaction. Because of Fermi surface topology details, in LiFeAs all the Fe -t2 g orbitals favor a common pairing symmetry. By contrast, in LiFeP the dx y orbital favors a pairing symmetry different from dx z /y z and their competition determines the pairing symmetry and the strength of the superconducting instability: dx y orbital strongly overcomes the others and imposes the symmetry of the superconducting order parameter. The leading pairing channel is a dx y-type state with nodes on both hole and electron Fermi surfaces. As a consequence, the dx z /y z electrons weakly pair, leading to a reduced transition temperature in LiFeP.

  9. 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.

  10. Potential energy surfaces of the electronic states of Li2F and Li2F(.).

    PubMed

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

    2016-07-21

    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. PMID:27448886

  11. Primordial Li abundance and massive particles

    NASA Astrophysics Data System (ADS)

    ðapo, H.

    2012-10-01

    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 4HeX-+2H-->6Li+X-, where the X- is the negatively charged massive particle. We demonstrate the dominance of long-range part of the potential on the cross-section.

  12. 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.

  13. Li2OHCl Crystalline Electrolyte for Stable Metallic Lithium Anodes

    SciTech Connect

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

    2016-01-01

    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 solid 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. To understand this excellent stability, we show that SEI formation is critical in stabilizing the interface between metallic lithium and the Li2OHCl solid electrolyte.

  14. 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.

  15. Li2OHCl crystalline electrolyte for stable metallic lithium anodes

    DOE PAGESBeta

    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

  16. 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

  17. 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.

  18. 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.

  19. Spectroscopy of Li9Λ by electroproduction

    NASA Astrophysics Data System (ADS)

    Urciuoli, G. M.; Cusanno, F.; Marrone, S.; Acha, A.; Ambrozewicz, P.; Aniol, K. A.; Baturin, P.; Bertin, P. Y.; Benaoum, H.; Blomqvist, K. I.; Boeglin, W. U.; Breuer, H.; Brindza, P.; Bydžovský, P.; Camsonne, A.; Chang, C. C.; Chen, J.-P.; Choi, Seonho; Chudakov, E. A.; Cisbani, E.; Colilli, S.; Coman, L.; Craver, B. J.; De Cataldo, G.; de Jager, C. W.; De Leo, R.; Deur, A. P.; Ferdi, C.; Feuerbach, R. J.; Folts, E.; Fratoni, R.; Frullani, S.; Garibaldi, F.; Gayou, O.; Giuliani, F.; Gomez, J.; Gricia, M.; Hansen, J. O.; Hayes, D.; Higinbotham, D. W.; Holmstrom, T. K.; Hyde, C. E.; Ibrahim, H. F.; Iodice, M.; Jiang, X.; Kaufman, L. J.; Kino, K.; Kross, B.; Lagamba, L.; LeRose, J. J.; Lindgren, R. A.; Lucentini, M.; Margaziotis, D. J.; Markowitz, P.; Meziani, Z. E.; McCormick, K.; Michaels, R. W.; Millener, D. J.; Miyoshi, T.; Moffit, B.; Monaghan, P. A.; Moteabbed, M.; Camacho, C. Muñoz; Nanda, S.; Nappi, E.; Nelyubin, V. V.; Norum, B. E.; Okasyasu, Y.; Paschke, K. D.; Perdrisat, C. F.; Piasetzky, E.; Punjabi, V. A.; Qiang, Y.; Reimer, P. E.; Reinhold, J.; Reitz, B.; Roche, R. E.; Rodriguez, V. M.; Saha, A.; Santavenere, F.; Sarty, A. J.; Segal, J.; Shahinyan, A.; Singh, J.; Širca, S.; Snyder, R.; Solvignon, P. H.; Sotona, M.; Subedi, R.; Sulkosky, V. A.; Suzuki, T.; Ueno, H.; Ulmer, P. E.; Veneroni, P.; Voutier, E.; Wojtsekhowski, B. B.; Zheng, X.; Zorn, C.; Jefferson Lab Hall A Collaboration

    2015-03-01

    Background: In the absence of accurate data on the free two-body hyperon-nucleon interaction, the spectra of hypernuclei provides information on the details of the effective hyperon-nucleon interaction. Purpose: To obtain a high-resolution binding-energy spectrum for the 9Be (e ,e'K+) Li9Λ reaction. Method: Electroproduction of the hypernucleus Li9Λ has been studied for the first time with sub-MeV energy resolution in Hall A at Jefferson Lab on a 9Be target. In order to increase the counting rate and to provide unambiguous kaon identification, two superconducting septum magnets and a ring imaging Cherenkov detector were added to the Hall A standard equipment. Results: The cross section to low-lying states of Li9Λ is concentrated within 3 MeV of the ground state and can be fit with four peaks. The positions of the doublets agree with theory while a disagreement could exist with respect to the relative strengths of the peaks in the doublets. The Λ separation energy, BΛ, of 8.36 ±0.08 (stat.) ±0.08 (syst.) MeV was measured, in agreement with an earlier experiment.

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

    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.

  1. 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

  2. Vibrationally Inelastic Collision Between Li2(ν = 0) and Li: Direct and Postponed Elongation Mechanisms.

    PubMed

    Corongiu, Giorgina; Mella, Massimo

    2015-12-31

    The mechanism for vibrational inelastic excitation during the collision between Li2(ν = 0) and Li was investigated exploiting classical trajectory simulations over a potential energy surface generated by fitting valence full configuration interaction calculations employing a large basis set. From the trajectory results, it emerges that the vibrational excitation in noncapture collisions presents uniquely a forward-scattered projectile for the highest levels of excitation (ΔE(0 → ν') ≃ Ecoll). For lower ν', a minor contribution presenting a backward-scattered projectile appears, which, however, has its major contribution coming from a "slingshot"-like (orbiting) mechanism exploiting the attractive features of the Li3 potential energy surface rather than a direct recoil. PMID:26652287

  3. Experimental simulation of internal short circuit in Li-ion and Li-ion-polymer cells

    NASA Astrophysics Data System (ADS)

    Cai, Wei; Wang, Hsin; Maleki, Hossein; Howard, Jason; Lara-Curzio, Edgar

    A multi-parameter controlled pinch test was developed to study the occurrence of internal short circuits in Li-ion and Li-ion-polymer cells. By tuning the control parameters (i.e., cell voltage as well as pinching area, load, and speed), the pinch test can reproducibly create an internal short between a cell jelly-roll's inner layer electrodes as small as 1-mm wide. This recreates conditions similar to those that may occur during service. In this paper we demonstrate the use of the pinch test as a means to assess design and manufacturing changes in Li-ion-polymer cells on their thermal stability and to identify features or characteristics that lower risk of potential thermal events created by internal short circuits.

  4. Electronic binding energy and thermal relaxation of Li and LiNa atomic alloying clusters.

    PubMed

    Bo, Maolin; Guo, Yongling; Wang, Yan; Liu, Yonghui; Peng, Cheng; Sun, Chang Q; Huang, Yongli

    2016-05-11

    We examined the effects of atomic hetero- and under-coordination on the relaxation of the interatomic bonding and electronic binding energy of Li and LiNa cluster alloying using a combination of the bond-order-length-strength correlation and density functional theory calculations. We found that bond nature alteration by heterocoordination, bond relaxation by thermal excitation and atomic coordination contribute intrinsically to the core-level energy shifts with resolution of the binding energy at the atomic sites of terrace edges, facets, and bulk of the LiNa alloy nanoclusters. Our strategies may simplify the complexity of core electron binding energies in analyzing the experimental data of the irregularly coordinating atoms. PMID:27117008

  5. 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

  6. A Stable, Magnetic, and Metallic Li3O4 Compound as a Discharge Product in a Li-Air Battery.

    PubMed

    Yang, Guochun; Wang, Yanchao; Ma, Yanming

    2014-08-01

    The Li-air battery with the specific energy exceeding that of a Li ion battery has been aimed as the next-generation battery. The improvement of the performance of the Li-air battery needs a full resolution of the actual discharge products. Li2O2 has been long recognized as the main discharge product, with which, however, there are obvious failures on the understanding of various experimental observations (e.g., magnetism, oxygen K-edge spectrum, etc.) on discharge products. There is a possibility of the existence of other Li-O compounds unknown thus far. Here, a hitherto unknown Li3O4 compound as a discharge product of the Li-air battery was predicted through first-principles swarm structure searching calculations. The new compound has a unique structure featuring the mixture of superoxide O2(-) and peroxide O2(2-), the first such example in the Li-O system. The existence of superoxide O2(-) creates magnetism and hole-doped metallicity. Findings of Li3O4 gave rise to direct explanations of the unresolved experimental magnetism, triple peaks of oxygen K-edge spectra, and the Raman peak at 1125 cm(-1) of the discharge products. Our work enables an opportunity for the performance of capacity, charge overpotential, and round-trip efficiency of the Li-air battery. PMID:26277938

  7. 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.

  8. 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.

  9. Cation ordering in Li containing garnets: synthesis and structural characterisation of the tetragonal system, Li7La3Sn2O12.

    PubMed

    Percival, J; Kendrick, E; Smith, R I; Slater, P R

    2009-07-14

    In this paper we report synthesis, conductivity and structural data for the novel tetragonal garnet-related system, Li7La3Sn2O12. Neutron diffraction data shows that the tetragonal distortion is related to ordering of Li in three sites within the structure to ensure no short Li-Li interactions. Consistent with the ordered nature of the Li ions, the conductivity is low, with a high activation energy. The results are relevant to related highly conducting cubic garnets, Li5+xLn3-xAxM2O12 (Ln=rare earth, A=alkaline earth; M=Nb, Ta, Sb), showing how a high Li content can be accommodated by Li ordering within the garnet structure, supporting previous suggestions by Cussen for the cubic garnets, who proposed the presence of local ordering/clustering of Li in tetrahedral and "octahedral" sites to limit unfavourable short Li-Li interactions. PMID:19562179

  10. Microstructure and mechanical behavior of spray-deposited high-Li Al-Li alloys

    SciTech Connect

    Del Castillo, L.; Wu, Y.; Hu, H.M.; Lavernia, E.J.

    1999-05-01

    High-Li alloys, with the composition Al-3.8Li-XCu-1.0Mg-0.4Ge-0.2Zr, were synthesized using a spray deposition technique (wt. pct, X = 0 {approximately} 1.5). The microstructure of the spray-deposited Al-Li alloys consisted of equiaxed grains with an average grain size in the range from 20 to 50 {micro}m. The grain-boundary phases were fine and discrete. The spray-deposited and thermomechanically processed materials were isothermally heat treated at 150 C and 170 C to investigate the age-hardening kinetics. It was noted that the spray-deposited Al-3.8Li-XCu-1.0Mg-0.4Ge-0.2Zr alloys exhibited relatively sluggish aging behavior. The peak-aged condition was achieved at 170 C in the range from 20 to 90 hours. It was noted that Cu increases the hardness of alloys during aging. Moreover, the influence of Cu on age-hardening kinetics is marginal. The mechanical properties of the spray-deposited and extruded Al-Li alloys were studied in the underaged, peak-aged, and overaged conditions. For example, the peak-aged yield strength, tensile strength, and ductility of Al-3.8Li-1.0Cu-1.0Mg-0.4Ge-0.2Zr are 455 MPa, 601 MPa, and 3.1 pct, respectively. Moreover, an increase in the Cu content of the alloy led to improvements in strength, with only slight changes in ductility, for Cu contents up to 1.0 wt pct. Beyond this range, an increase in Cu content led to decreases in both strength and ductility.

  11. 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.

  12. Li/MoSe/sub 3/S secondary battery

    SciTech Connect

    Abraham, K.M.; Pasquariello, D.M.; McAndrews, G.F.

    1987-11-01

    A new Li insertion cathode for ambient temperature secondary lithium batteries, namely, MoSe/sub 3/S, has been identified and characterized. It exhibits a specific capacity of approximately 4 Li per mole of the chalcogenide. The discharge behavior of Li/MoSe/sub 3/S cells at various temperatures and their rechargeability have been assessed utilizing THF:2Me-TH:F/LiAsF/sub 6/ and PC/LiClO/sub 4/ electrolyte solutions. The quasi-theoretical specific energy of 380 Wh/kg realized with a practical MoSe/sub 3/S electrode compares favorably with that in a Li/TiS/sub 2/ cell.

  13. Elastic properties of Li+ doped lead zinc borate glasses

    NASA Astrophysics Data System (ADS)

    Rajaramakrishna, R.; Lakshmikantha, R.; Anavekar, R. V.

    2014-04-01

    Glasses in the system 0.25PbO-(0.25-x) ZnO-0.5B2O3-xLi2O have been prepared by the melt quenching technique. Elastic properties, DSC studies have been employed to study the role of Li2O in the present glass system. Elastic properties and Debye temperature have been determined using pulsed echo ultrasonic interferometer operating at 10MHz. Sound velocities Vl, Vt and elastic moduli decrease up to 5 mol% and then gradually increase with increase in Li2O concentration. Debye temperature and the glass transition temperature decreases with increase in Li2O. Densities remains almost constant up to 15 mol% Li2O concentration and increases monotonically while the molar volume decreases with the increase of Li2O concentration. The results are discussed in view of the borate structural network and dual role of Zn and Pb in these glasses.

  14. 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.

  15. Photoionization of the alkali dimer cations Li+2, Na+2 and LiNa+

    NASA Astrophysics Data System (ADS)

    Dumitriu, Irina; Vanne, Yulian V.; Awasthi, Manohar; Saenz, Alejandro

    2007-05-01

    Photoionization cross sections for the three alkali dimer cations (Li+2, Na+2 and LiNa+) were calculated at the equilibrium internuclear distance for parallel, perpendicular and isotropic orientations of the molecular axis with respect to the field. A model-potential method was used for the description of the cores. The influence of the model-potential parameters on the photoionization spectra was investigated. Two different methods, a time-independent and a time-dependent one, were implemented and used for computing the cross sections.

  16. Ultracold Fermionic gases of Li atoms and LiNa molecules

    NASA Astrophysics Data System (ADS)

    Christensen, Caleb; Choi, Jae; Lee, Ye-Ryoung; Jo, Gyu-Boong; Ketterle, Wolfgang; Pritchard, Dave

    2010-03-01

    We present recent data on the stability and basic properties of ultracold gases of ^6Li and ^23Na, including fermionic LiNa molecules. A cold, dense mixture of atoms is produced in an IR optical dipole trap. The magnetic field is brought to the vicinity of Feshbach resonances, and short lived states are populated by driving RF transitions from noninteracting to interacting states. Absorption imaging of the atoms is used to study the formation and lifetime of Feshbach molecules. We also present recent work on the potential for a ferromagnetic state of a gas of lithium atoms.

  17. 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.

  18. 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.

  19. 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.

  20. Electrical conduction of LiF interlayers in organic diodes

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

    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 < Eg ˜ 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 1025/m3. 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.

  1. 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.

  2. Valence and excited states of LiH-

    NASA Astrophysics Data System (ADS)

    Gutsev, Gennady L.; Nooijen, Marcel; Bartlett, Rodney J.

    1998-03-01

    Valence and excited dipole-bound states of the LiH- anion are calculated with the recently developed electron-attachment equation-of-motion coupled-cluster technique. It is found that the first dipole-bound state of LiH- corresponds to the second dissociation channel LiH--->Li-(1S)+H(2S). The second (excited) dipole-bound state of LiH- is below the neutral ground-state potential energy curve only for some range of the Li-H internuclear distance. This state appears at bond lengths larger than ~2.0 Å and decays at Li-H distances longer than ~4.2 Å, where the dipole moment of LiH becomes smaller than the critical value of 2.5 D. The adiabatic electron affinity of LiH calculated at the coupled-cluster level with the iterative inclusion of all single, double, and triple excitations and a large atomic natural orbital basis set is 0.327 eV, almost matching the recently obtained experimental value of 0.342+/-0.012 eV.

  3. NMR Studies of the Li-Mg-N-H Phases.

    NASA Astrophysics Data System (ADS)

    Bowman, Robert; Reiter, J. W.; Kulleck, J. G.; Hwang, S.-J.; Luo, Weifang

    2007-03-01

    Solid state NMR including magic-angle-spinning (MAS) and cross-polarization (CP) MAS experiments have been used to characterize various amide and imide phases containing Li and/or Mg. MAS-NMR spectra for the ^1H, ^6Li, ^7Li, and ^15N nuclei have been obtained to improve understanding on formation, processing, and degradation behavior. Only limited information could be obtained from the proton and ^7Li MAS-NMR spectra to due large dipolar interactions and small chemical shifts. However, more success was obtained from the ^6Li and ^15N nuclei although their very long spin-lattice relaxation times did impact signal acquisition times. For example, three distinct ^6Li peaks were resolved from LiNH2 phases that were clearly separated from the LiH secondary phase in these samples. While the ^15N spectra for LiNH2 phase in isotopically enriched samples exhibited only a single peak at least three distinct ^15N peaks were observed from the similarly enriched Mg amide samples. These differences will be related to crystal structures. The NMR spectra also revealed very little motion in these hydrides upon to nearly 500 K.

  4. Increasing Discharge Capacities of Li-(CF)(sub n) Cells

    NASA Technical Reports Server (NTRS)

    Whitacre, Jay; West, William

    2008-01-01

    An electrolyte additive has shown promise as a means of increasing the sustainable rates of discharge and, hence, the discharge capacities, of lithiumpoly(carbon monofluoride) electrochemical power cells. Lithium-poly(carbon monofluoride) [Li-(CF)n] cells and batteries offer very high specific energies practical values of about 600 W.h/g and a theoretical maximum value of 2,180 W.h/kg. However, because Li-(CF)n cells and batteries cannot withstand discharge at high rates, they have been relegated to niche applications that involve very low discharge currents over times of the order of hundreds to thousands of hours. Increasing the discharge capacities of Li- (CF)n batteries while maintaining high practical levels of specific energy would open new applications for these batteries. During the discharge of a Li-(CF)n cell, one of the electrochemical reactions causes LiF to precipitate at the cathode. LiF is almost completely insoluble in most non-aqueous solvents, including those used in the electrolyte solutions of Li-(CF)n cells. LiF is electrochemically inactive and can block the desired transport of ions at the cathode, and, hence, the precipitation of LiF can form an ever-thickening film on the cathode that limits the rate of discharge.

  5. 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.

  6. Vacuum level alignment of pentacene on LiF/Au

    NASA Astrophysics Data System (ADS)

    Watkins, N. J.; Gao, Y.

    2003-07-01

    We examined the interfaces of pentacene on LiF/Au substrates as a function of LiF thickness. We found that, regardless of the thickness of LiF, upon pentacene deposition onto LiF, the pentacene vacuum level aligns with that of LiF. We also show that LiF exhibits an interface dipole when deposited onto Au and that the magnitude of the interface dipole increases as the LiF thickness increases. The change in vacuum level as a function of LiF thickness allows the Fermi level position within the band gap of pentacene to be moved from 0.5 eV above the highest occupied molecular orbital to 2.1 eV above the highest occupied molecular orbital. This produces a hole injection barrier of 0.5 eV at the pentacene/Au interface and an electron injection barrier of 0.1 eV at the pentacene/40-Å-LiF/Au interface.

  7. 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

  8. Positron annihilation studies in Li-implanted alumina

    NASA Astrophysics Data System (ADS)

    Gaikwad, Prashant V.; Sharma, S. K.; Mukherjee, S.; Sudarshan, K.; Maheshwari, P.; Pujari, P. K.; Kshirsagar, A.

    2015-06-01

    Depth dependent Doppler broadening of annihilation radiation (DBAR) measurements are carried out for a sample of Li ion implanted in alumina. The effect of Li ion implantation and the subsequent isochronal annealing at the temperatures up to 1100 °C on the Doppler broadening annihilation parameters (S-parameter) are studied. The S-parameter around the Li implantation depth (∼191 nm) increased with annealing temperature up to 700 °C and reduced beyond. The results suggest possible Li cluster formation in annealed sample.

  9. 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.

  10. Recent advances in the development of Li-air batteries

    NASA Astrophysics Data System (ADS)

    Capsoni, Doretta; Bini, Marcella; Ferrari, Stefania; Quartarone, Eliana; Mustarelli, Piercarlo

    2012-12-01

    The global energy demand calls for more efficient storage systems. In this review, the state of the art of Li/air and Li/O2 batteries is discussed with particular attention on the more recent findings regarding all the battery compartments. Both aqueous and non-aqueous systems are considered, and the most critical issues for better battery design are addressed. Whereas the predicted charge/discharge values for these devices do justify the intense research efforts performed nowadays, great problems are still present which must be overcome in order to make Li/air and Li/O2 a reality for future large-scale applications.

  11. Hyperpolarized (6)Li as a probe for hemoglobin oxygenation level.

    PubMed

    Balzan, Riccardo; Mishkovsky, Mor; Simonenko, Yana; van Heeswijk, Ruud B; Gruetter, Rolf; Eliav, Uzi; Navon, Gil; Comment, Arnaud

    2016-01-01

    Hyperpolarization by dissolution dynamic nuclear polarization (DNP) is a versatile technique to dramatically enhance the nuclear magnetic resonance (NMR) signal intensity of insensitive long-T1 nuclear spins such as (6)Li. The (6)Li longitudinal relaxation of lithium ions in aqueous solutions strongly depends on the concentration of paramagnetic species, even if they are present in minute amounts. We herein demonstrate that blood oxygenation can be readily detected by taking advantage of the (6)Li signal enhancement provided by dissolution DNP, together with the more than 10% decrease in (6)Li longitudinal relaxation as a consequence of the presence of paramagnetic deoxyhemoglobin. PMID:26265292

  12. Mechanical properties of Li-Sn alloys for Li-ion battery anodes: A first-principles perspective

    NASA Astrophysics Data System (ADS)

    Zhang, Panpan; Ma, Zengsheng; Jiang, Wenjuan; Wang, Yan; Pan, Yong; Lu, Chunsheng

    2016-01-01

    Fracture and pulverization induced by large stress during charging and discharging may lead to the loss of electrical contact and capacity fading in Sn anode materials. A good understanding of mechanical properties is necessary for their optimal design under different lithiation states. On the basis of first-principles calculations, we investigate the stress-strain relationships of Li-Sn alloys under tension. The results show that the ideal tensile strengths of Li-Sn alloys vary as a function of Li concentration, and with the increase of Li+ concentration, the lowest tensile strength decreases from 4.51 GPa (Sn) to 1.27 GPa (Li7Sn2). This implies that lithiation weakens the fracture resistance of Li-Sn alloys.

  13. Spectroscopic characterization of the first singlet (Ã 1B1) excited state of 7Li16O7Li

    NASA Astrophysics Data System (ADS)

    Bellert, D.; Winn, D. K.; Breckenridge, W. H.

    2003-11-01

    Using laser induced fluorescence (LIF) and resonance enhanced two-photon ionization (R2PI) spectroscopy, several (ν1',ν2',ν3') vibrational bands of the à 1B1(K'=1)←X˜ 1Σg+(0,0,0) perpendicular transition of the 7Li16O7Li molecule have been rotationally resolved and analyzed to yield effective A',B',C' values. The estimated geometry of the à 1B1 state does not vary with ν1' (symmetric stretch mode), but θ' increases and R' decreases slightly as ν2' (bending mode) increases. Extrapolation leads to an estimate for the (0,0,0) state of θ0'=105±5°, R0'=1.86±0.04 Å, and for the potential minimum θe'=102±5°, Re'=1.87±0.04 Å. The strongly bent nature of the à 1B1 state is due to promotion of an O-2 p-electron (b1) from the strongly ionic, linear Li+O-2Li+ ground state to an a1 molecular orbital which has Li/Li bonding character. The Ã1B1 state thus has an approximately Li+1/2O-1Li+1/2 charge distribution, so that the ionic bonding is less strong than in the linear ground state, where (from this study and an earlier stimulation-emission pumping study) R0″=1.611±0.003 Å. In fact, the Li-Li distance in the à 1B1 state, ˜3.0 Å, is quite similar to that of the Li2+1 ion, so the bonding may be described as that of Li2+1 bound ionically to the O-1 ion.

  14. 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).

  15. An aqueous rechargeable lithium battery of high energy density based on coated Li metal and LiCoO2.

    PubMed

    Wang, Xujiong; Qu, Qunting; Hou, Yuyang; Wang, Faxing; Wu, Yuping

    2013-07-14

    Using a coated Li metal as an anode and LiCoO2 as a cathode, an aqueous rechargeable battery is built up, whose average discharge voltage is 3.70 V. This high voltage stability is due to the "cross-over" effect of Li(+) ions, which is different from the traditional ways of increasing overpotentials. The total energy density can be 465 W h kg(-1). PMID:23732678

  16. Thermodynamic studies and the phase diagram of the Li-Mg system

    NASA Astrophysics Data System (ADS)

    Gasior, W.; Moser, Z.; Zakulski, W.; Schwitzgebel, G.

    1996-09-01

    By means of the electromotive force (emf) method of concentration cells of the following scheme: Li (1) / LiCl-LiF (eut) or LiCi-KCl (eut) / Li-Mg (1) or Li (1) / LiCl-LiF (eut) / Li-Mg (s) Li activities for liquid and solid alloys at the (Mg), (Li), and (Mg) + (Li) two-phase region of the Li-Mg system were determined. Liquid alloys were examined at temperatures from 638 to 889 K at various Li concentrations. The (Mg) solid solutions were investigated in two series: at constant temperatures between 773 and 876 K, with varying Li content, and at fixed Li concentrations, equal to 0.125 and 0.160 molar fractions, at different temperatures between 772 and 849 K. At the two-phase region, (Mg) + (Li), emf measurements were performed in the temperature range 773 to 838 K, with fixed Li concentrations equal to 0.20, 0.25, and 0.275 molar fractions. For (Li) solid alloys, experiments were done at temperatures 773 to 849 K for several constant Li concentrations, between 0.30 to 0.45 molar fractions, respectively. Studies on solid alloys enabled us also to determine the boundaries (Li)/[(Mg) + (Li)] and (Mg)/[(Mg) + (Li)] at temperatures 773 to 831 K. The resulting thermodynamic and phase boundary data of this study were used with other selected references for a critical assessment of the Li-Mg system. The Lukas BINGSS optimization program and BINFKT for the calculation of the thermodynamic functions and of the phase diagram were used. The calculated equilibrium phase diagram at temperatures below 750 K indicates a slightly lower solid solubility of Mg in (Li) in comparison with results from thermal analysis and the recently published Saunders evaluation.

  17. Thermodynamic studies and the phase diagram of the Li-Mg system

    SciTech Connect

    Gasior, W.; Moser, Z.; Zakulski, W.; Schwitzgebel, G.

    1996-09-01

    By means of the electromotive force (emf) method of concentration cells of the following scheme: Li (1)/LiCl-LiF (eut) or LiCi-KCl (eut)/Li-Mg (1) or Li (1)/LiCl-LiF (eut)/Li-Mg (s). Li activities for liquid and solid alloys at the (Mg), (Li), and (Mg) + (Li) two-phase region of the Li-Mg system were determined. Liquid alloys were examined at temperatures from 638 to 889 K at various Li concentrations. The (Mg) solid solutions were investigated in two series: at constant temperatures between 773 and 876 K, with varying Li content, and at fixed Li concentrations, equal to 0.125 and 0.160 molar fractions, at different temperatures between 772 and 849 K. At the two-phase region, (Mg) + (Li), emf measurements were performed in the temperature range 773 to 838 K, with fixed Li concentrations equal to 0.20, 0.25, and 0.275 molar fractions. For (Li) solid alloys, experiments were done at temperatures 773 to 849 K for several constant Li concentrations, between 0.30 and 0.45 molar fractions, respectively. Studies on solid alloys enabled the authors also to determine the boundaries (Li)/[(Mg) + (Li)] and (Mg)/[(Mg) + (Li)] at temperatures 773 to 831 K. The resulting thermodynamic and phase boundary data of this study were used with other selected references for a critical assessment of the Li-Mg system. The Lukas BINGSS optimization program and BINFKT for the calculation of the thermodynamic functions and of the phase diagram were used. The calculated equilibrium phase diagram at temperatures below 750 K indicates a slightly lower solid solubility of Mg in (Li) in comparison with results from thermal analysis and the recently published Saunders evaluation.

  18. Magnetization studies and spin Hamiltonian modelling of Li2 (Li1 - xFex) N

    NASA Astrophysics Data System (ADS)

    Atkinson, James H.; Jesche, Anton; Del Barco, Enrique; Canfield, Paul C.

    2015-03-01

    The study of ferromagnetic materials has yielded many examples of compounds which exhibit large energy barriers to a reversal of magnetization and correspondingly wide magnetization versus field hysteresis loops. Some materials, such as members of the class called ``single-molecule magnets'' (SMMs), even display vivid signatures of quantum tunneling effects, manifested as step-like features in hysteresis loop measurements of crystalline ensembles. The compound Li2(Li1-xFex)N has been previously shown to display an extremely high blocking temperature (~ 20 K) and large coercive fields (>11 T), as well as step-like features like those seen in SMMs. Here we report the results of low-temperature Hall sensor magnetization studies on a crystalline sample of Li2(Li1-0.006Fe0.006)N in which we detail evidence of a preferential orientation for the observed features, as well as their dependence upon transverse component fields in their magnitude, behavior which we attempt to model with a giant spin Hamiltonian. This work is supported by the US DOE, Basic Energy Sciences under Contract No. DE-AC02-07CH11358.

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

    DOE PAGESBeta

    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

  20. Thermal and tritium transport in Li 2O and Li 2ZrO 3

    NASA Astrophysics Data System (ADS)

    Billone, M. C.

    1996-10-01

    Lithium oxide (Li 2O) and lithium zirconate (Li 2ZrO 3) are promising tritium breeder ceramics for fusion reactors. The thermal and tritium transport databases for these materials are reviewed. Algorithms are presented for predicting the temperature and retained-tritium profiles across sintered-product and pebble-bed regions. The thermal conductivity of sintered-product material has been measured and correlated over a wide range of temperatures and densities. A modified Hall and Martin model gives good agreement with data for the effective conductivity of pebble beds of these ceramics. Laboratory data for tritium behavior in Li 2O have been used to determine model parameters in the TIARA code, which has been validated to 20 post-irradiation inventory data points. As the fundamental database for Li 2ZrO 3 is less complete, a residency-time correlation, based on 31 inventory data points, is proposed. The two ceramics are compared in the context of an ITER breeding-blanket design.

  1. Systematic Phase Diagram of LiSi and LiAl compounds from Minima Hopping Method

    NASA Astrophysics Data System (ADS)

    Romero, Aldo; Marques, Miguel; Botti, Silvana; Sarmiento-Pérez, Rafael; Valencia-Jaime, Irais; Amsler, Max; Goedecker, Stefan

    2014-03-01

    We performed an extensive theoretical exploration of the structural phase diagram of LiSi and LiAl alloys through global structural prediction. These compounds have very interesting properties. For example, LiSi alloys have been considered for high energy density anodes for future rechargeable battery technology, while LiAl alloys are expected to have applications in the field of structural components due to its light weight and maleability. The global structural prediction was performed with the minima hopping method. In this method the low energy structures are obtained by solving a set of dynamical equations of motion that allows efficient visits to local minima on the Born Oppenheimer surface. We found very good agreement between our simulations and previously reported stoichiometries. Moreover, we were able to identify several novel thermodynamically stable compositions that have not been previously synthesized. The ground-state structures were further characterized both structurally and electronically. Our calculations show that global structural prediction is a very powerful tool to predict new thermodynamically stable materials, and that it consistently outperforms other methods commonly used. Support from ACS-PRF #54075-ND10 is recognized.

  2. Electrodeposition of Mg-Li-Al-La Alloys on Inert Cathode in Molten LiCl-KCl Eutectic Salt

    NASA Astrophysics Data System (ADS)

    Han, Wei; Chen, Qiong; Sun, Yi; Jiang, Tao; Zhang, Milin

    2011-12-01

    Electrochemical preparation of Mg-Li-Al-La alloys on inert electrodes was investigated in LiCl-KCl melt at 853 K (580 °C). Cyclic voltammograms (CVs) and square wave voltammograms (SWVs) show that the existence of AlCl3 or AlF3 could promote La deposition on an active Al substrate, which is predeposited on inert electrodes. All electrochemical tests show that the reduction of La3+ is a one-step reduction process with three electrons exchanged. The reduction of La(III)→La(0) occurred at -2.04 V, and the underpotential deposition (UPD) of La was detected at -1.55 V ( vs Ag/AgCl). The same phenomena concerning La UPD were observed on two inert cathodes, W and Mo. In addition, Mg-Li-Al-La alloys were obtained by galvanostatic electrolysis on the W cathode from La2O3 in LiCl-KCl-MgCl2-KF melts with aluminum as the anode. X-ray diffraction (XRD) measurements indicated that various phases like the Al2La, Al12Mg17, and βLi phase (LiMg/Li3Mg7) existed in the Mg-Li-Al-La alloys. The distribution of Mg, Al, and La in Mg-Li-Al-La alloys from the analysis of a scan electron micrograph (SEM) and energy dispersive spectrometry (EDS) indicated that the elements Mg, Al, and La distributed homogeneously in the alloys.

  3. 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.

  4. Residual stresses and clamped thermal expansion in LiNbO3 and LiTaO3 thin films

    NASA Astrophysics Data System (ADS)

    Bartasyte, A.; Plausinaitiene, V.; Abrutis, A.; Murauskas, T.; Boulet, P.; Margueron, S.; Gleize, J.; Robert, S.; Kubilius, V.; Saltyte, Z.

    2012-09-01

    Residual stresses in LiNbO3 and LiTaO3 epitaxial thin films were evaluated taking into account Li nonstoichiometry by means of Raman spectroscopy and x-ray diffraction. The epitaxial films were grown on C-cut sapphire substrates by pulsed injection metal organic chemical vapour deposition. Clamping of the epitaxial films by the substrate induced a transfer from the in plane thermal expansion to the out of plane component. The temperature of the phase transition of clamped LiTaO3 films was close to that expected for a bulk sample.

  5. Ab initio study of the LiH + molecule, electronic interaction analysis and LiH UV photoelectron spectrum

    NASA Astrophysics Data System (ADS)

    Berriche, Hamid; Gadea, Florent Xavier

    1995-02-01

    All adiabatic curves of LiH + dissociating into Li(2s, 2p, 3s, 3p, 3d) + H + and Li + + H (1s, 2s, 2p) are determined by an ab initio approach involving a non-empirical pseudopotential for the Li(ls 2) core and core valence correlation corrections. The resulting spectroscopic constants and vibrational level spacings of all these states are presented. From the usual semiclassical approximations an analysis of the high energy vibrational level spacing is performed allowing for accurate long range extrapolations. For the lowest curves dissociating into Li + + H (1s) and Li (2s) + H + an analysis of the main electronic interactions is carried out from a diabatic model and reveals the importance of the binding charge delocalisation effects versus the polarisation (charge localised) ones. In addition the LiH photoelectron spectrum is calculated. An interesting feature of that spectrum is that both bound-bound and bound-free transitions coexist due to the particular shape of the LiH and LiH + potential energy curves.

  6. Thin film and bulk investigations of LiCoBO3 as a Li-ion battery cathode

    SciTech Connect

    Bo, Shou-Hang; Veith, Gabriel M; Saccomanno, Michael; Huang, Huafeng; Burmistrova, Polina; Malingowski, Andrew; Sacci, Robert L; Grey, Clare; Khalifah, P.

    2014-01-01

    The compound LiCoBO3 is an appealing candidate for next generation Li-ion batteries based on its high theoretical specific capacity of 215 mAh/g and high expected discharge voltage (more than 4 V vs. Li+/Li). However, this level of performance has not yet been realized in experimental cells, even with nanosized particles. Reactive magnetron sputtering was therefore used to prepare thin films of LiCoBO3, allowing the influence of particle thickness on electrochemical performance to be explicitly tested. Even when ultra-thin films (~15 nm) were prepared, there was a negligible electrochemical response from LiCoBO3. Impedance spectroscopy measurements suggest that the conductivity of LiCoBO3 is many orders of magnitude worse than that of LiFeBO3, and may be severely limiting performance. The band gap and unusual blue color of LiCoBO3 were investigated by spectroscopic techniques, which allowed the determination of an optical gap of 4.2 eV and the assignment of the visible light absorption to a symmetry-allowed e a transition that occurs within the context of a particularly simple electronic configuration.

  7. 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.

  8. Thin-film and bulk investigations of LiCoBO₃ as a Li-ion battery cathode.

    PubMed

    Bo, Shou-Hang; Veith, Gabriel M; Saccomanno, Michael R; Huang, Huafeng; Burmistrova, Polina V; Malingowski, Andrew C; Sacci, Robert L; Kittilstved, Kevin R; Grey, Clare P; Khalifah, Peter G

    2014-07-23

    The compound LiCoBO3 is an appealing candidate for next-generation Li-ion batteries based on its high theoretical specific capacity of 215 mAh/g and high expected discharge voltage (more than 4 V vs Li(+)/Li). However, this level of performance has not yet been realized in experimental cells, even with nanosized particles. Reactive magnetron sputtering was therefore used to prepare thin films of LiCoBO3, allowing the influence of the particle thickness on the electrochemical performance to be explicitly tested. Even when ultrathin films (∼15 nm) were prepared, there was a negligible electrochemical response from LiCoBO3. Impedance spectroscopy measurements suggest that the conductivity of LiCoBO3 is many orders of magnitude worse than that of LiFeBO3 and may severely limit the performance. The unusual blue color of LiCoBO3 was investigated by spectroscopic techniques, which allowed the determination of a charge-transfer optical gap of 4.2 eV and the attribution of the visible light absorption peak at 2.2 eV to spin-allowed d → d transitions (assigned as overlapping (4)A2' to (4)A2″ and (4)E″ final states based on ligand-field modeling). PMID:24809458

  9. 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.

  10. 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. PMID:26541508

  11. 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.

  12. 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

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

    NASA Astrophysics Data System (ADS)

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

    2015-11-01

    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.

  14. 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.

  15. 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.

  16. Ultrasonic microspectroscopy of congruent LiNbO3 crystals

    NASA Astrophysics Data System (ADS)

    Kushibiki, Jun-ichi; Ohashi, Yuji; Hirohashi, Junji

    2005-12-01

    Experimental procedures for evaluating the compositional homogeneity of LiNbO3 single crystals were developed using the line-focus-beam ultrasonic material characterization system, and the true congruent composition was determined. First, the relationships among leaky surface acoustic wave (LSAW) velocities (VLSAW), chemical compositions, Curie temperatures, densities, and lattice constants were investigated for crystal evaluation, using X-, Y-, and Z-cut substrates prepared from three LiNbO3 crystals grown along the crystallographic Z axis with different Li2O contents of 48.0, 48.5, and 49.0mol%. We selected VLSAW for Z-cut Y-axis propagating (ZY ) LiNbO3 with the highest sensitivity to chemical composition changes [0.0253Li2Omol%/(m/s)], and also VLSAW for Y-cut X-axis propagating (YX ) LiNbO3 [0.0464Li2Omol%/(m/s)] that was advantageous for detailed evaluation of distributions in the chemical composition along the pulling direction as well as the diameter direction.The congruent composition was estimated to be 48.477Li2Omol%. Next, the homogeneities of the three above-mentioned crystals and a commercially available LiNbO3 crystal with a nominally congruent composition were evaluated using data for YX-LiNbO3 specimens. Consequently, compositional changes were observed clearly as VLSAW changes. The commercial crystal specimen had a gradient of -0.0046(m /s)/mm from top to bottom. The VLSAW variations for the entire examined region (60×36mm2) exhibited a maximum change of 0.55m/s, corresponding to the chemical composition change of 0.025Li2Omol%. The relationships between the chemical compositions and the acoustical physical constants (the elastic, piezoelectric, and dielectric constants, and density) were also provided.

  17. 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.

  18. 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.

  19. Potentiometric CO2 Sensor Using Li+ Ion Conducting Li3PO4 Thin Film Electrolyte

    PubMed Central

    Noh, Whyo Sub; Satyanarayana, L.; Park, Jin Seong

    2005-01-01

    Li+ ion conducting Li3PO4 thin film electrolytes with thickness 300nm, 650nm and 1.2μm were deposited on Al2O3 substrate at room temperature by thermal evaporation method. Reference and sensing electrodes were printed on Au interfaces by conventional screen printing technique. The overall dimension of the sensor was 3 × 3 mm and of electrodes were 1 × 1.5 mm each. The fabricated solid state potentiometric CO2 sensors of type: CO2, O2, Au, Li2TiO3-TiO2| Li3PO4 |Li2CO3, Au, CO2, O2 have been investigated for CO2 sensing properties. The electromotive force (emf) and Δemf/dec values of the sensors are dependent on the thickness of the electrolyte film. 1.2μm thickness deposited sensor has shown good sensing behavior than the sensors with less thickness. The Δemf values of the sensor are linearly increased up to 460°C operating temperature and became stable above 460°C. Between 460-500°C temperatures region the sensor has reached an equilibrium state and the experimentally obtained Δemf values are about 80% of the theoretically calculated values. A Nernst's slope of -61mV/decade has been obtained between 250 to 5000 ppm of CO2 concentration at 500°C temperature. The sensor is suitable for ease of mass production in view of its miniaturization and cost effectiveness after some further improvement.

  20. 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. PMID:20885472

  1. Ab initio variational calculations of the vibrational properties of Li + 3, Li2Na + , LiNa + 2, and KLiNa +

    NASA Astrophysics Data System (ADS)

    Searles, D. J.; von Nagy-Felsobuki, E. I.

    1991-07-01

    A rovibrational Hamiltonian has been derived in terms of rectilinear displacement coordinates which is based on the Watson Hamiltonian. Moreover, it is a generalization of the Carney and Porter analysis for D3h triatomic systems [J. Chem. Phys. 65, 3547 (1976)] and Carney et al. analysis for C2v triatomic systems [J. Chem. Phys. 66, 3724 (1977)]. It is therefore the most general form of the Watson Hamiltonian which is applicable to a bent triatomic system. Ab initio variational calculations using this Hamiltonian are presented for vibrational properties of Li+3, Li2Na+, LiNa+2, and KLiNa+.

  2. 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.

  3. 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

  4. Soft dipole excitations in 11Li

    NASA Astrophysics Data System (ADS)

    Esbensen, H.; Bertsch, G. F.

    1992-06-01

    A three-body model of 11Li is extended to include all interactions in unbound states in the continuum. We use a Green function technique to solve the three-body hamiltonian equation, and study the continuum dipole states produced by electromagnetic excitations of the ground state. The final-state interaction modifies the dipole strength function substantially, making it similar to an independent-particle strength function, but the total strength is enhanced by 50% due to ground-state correlations. The dipole strength is concentrated in a peak just above threshold, and the strength distribution is consistent with the measured beam energy dependence of the Coulomb dissociation cross section. This threshold peak also gives a narrow component in the neutron and the residual nucleus momentum distributions. The angular distributions of the neutrons emitted in Coulomb-induced reactions show a surprising anticorrelation, favoring emission with a large opening angle between the directions of the two neutrons in the rest frame of 11Li.

  5. 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.

  6. 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.

  7. 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).

  8. Phonon Dispersion in Equiatomic Li-Based Binary Alloys

    NASA Astrophysics Data System (ADS)

    Aditya, Vora M.

    2008-02-01

    The computations of the phonon dispersion curves (PDC) of four equiatomic Li-based binary alloys, namely Li0.5Na0.5, Li0.5K0.5, Li0.5Rb0.5 and Li0.5Cs0.5, to second order in the local model potential is discussed in terms of the real-space sum of Born von Karman central force constants. Instead of the concentration average of the force constants of metallic Li, Na, K, Rb and Cs, the pseudo-alloy atom (PAA) is adopted to compute directly the force constants of four equiatomic Li-based binary alloys. The exchange and correlation functions due to Hartree (H) and Ichimaru-Utsumi (IU) are used to investigate the influence of screening effects. The phonon frequencies of four equiatomic Li-based binary alloys in the longitudinal branch are more sensitive to the exchange and correlation effects in comparison with the transverse branches. However, the frequencies in the longitudinal branch are suppressed due to IU-screening function than the frequencies due to static H-screening function.

  9. 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.

  10. 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.

  11. Hollow Li20B60 Cage: Stability and Hydrogen Storage.

    PubMed

    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

  12. 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

  13. LiCoO2 Thin-Film Batteries

    SciTech Connect

    Alamgir,F.; Strauss, E.; denBoer, M.; Greenbaum, S.; Whitacre, J.; Kao, C.; Neih, S.

    2005-01-01

    In situ X-ray absorption spectroscopy of a thin-film LiCoO{sub 2}-based secondary battery is reported. Batteries made with thin-film LiCoO{sub 2} cathodes annealed at 500{sup o}C were found to be electrochemically very similar to their counterparts using bulk cathodes. Complementary information from the near-edge and extended structure from the Co K-edge revealed the electronic and atomic structure, respectively, around Co as a function of Li content. The electronic and atomic structure of Li{sub (1-x)}CoO{sub 2} indicates that upon Li removal, charge compensation occurs both by formation of O as well as Co holes until x reaches 0.25, after which it occurs only by formation of Co d-holes.

  14. 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.

  15. Hybrid Air-Electrode for Li/Air Batteries

    SciTech Connect

    Xiao, Jie; Xu, Wu; Wang, Deyu; Zhang, Jiguang

    2010-01-20

    A novel hybrid air-electrode is designed to improve the power density of Li/air batteries operating in an ambient environment. Three lithium insertion materials, MnO2, V2O5, and CFx (x = 1.0 to 1.15), are mixed with activated carbon to prepare different hybrid air-electrodes used in Li/air batteries. When compared with pure carbon-based Li/air batteries, the batteries using hybrid air-electrodes demonstrate significantly improved power capacities, especially for the CFx-based hybrid Li/air batteries. Because it is hydrophobic, CFx also facilitates the formation of air-flow channels in the carbon matrix, and alleviates air-electrode blocking problem during the discharge process. These hybrid air-electrodes provide a promising approach to improve the power density of Li/air batteries.

  16. 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.

  17. 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.

  18. Hollow Li20B60 Cage: Stability and Hydrogen Storage

    NASA Astrophysics Data System (ADS)

    Wang, Jing; Wei, Zhi-Jing; Zhao, Hui-Yan; Liu, Ying

    2016-04-01

    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.

  19. Cross sections for vibrational inhibition at low collision energies for the reaction H + Li2(X1Σ{g/+}) → Li + LiH (X1Σ+)

    NASA Astrophysics Data System (ADS)

    Gao, Shoubao; Zhang, Jing; Song, Yuzhi; Meng, Qing-Tian

    2015-05-01

    A time-dependent wave packet dynamics study of the H + Li2 reaction has been performed on the novel HLi2(X2A') potential energy surface [Y.Z. Song, Y.Q. Li, S.B. Gao, Q.T. Meng, Eur. Phys. J. D 68, 1 (2014)]. The v-dependent reaction probabilities and integral cross sections are presented as a function of collision energies. From the v-dependent behaviour of integral cross sections, it can be seen that the vibrational excitation of the reactant Li2 hinders the reactivity at low collision energies. Furthermore, the comparison of j-dependent reaction probabilities indicates that Li2 rotation also hinders the reaction.

  20. 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.

  1. 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

  2. Structural transformation of LiVOPO4 to Li3V2(PO4)3 with enhanced capacity.

    PubMed

    Kuo, H T; Bagkar, N C; Liu, R S; Shen, C H; Shy, D S; Xing, X K; Lee, J-F; Chen, J M

    2008-09-11

    In the present investigation, we report the transformation of alpha-LiVOPO 4 to alpha-Li 3V 2(PO 4) 3, leading to an enhancement of capacity. The alpha-LiVOPO 4 sample was synthesized by a sol-gel method, followed by sintering at 550-650 degrees C in a flow of 5% H 2/Ar. The structural transformation of a triclinic alpha-LiVOPO 4 structure to a monoclinic alpha-Li 3V 2(PO 4) 3 structure was observed at higher sintering temperatures (700-800 degrees C in a flow of 5% H 2/Ar). The alpha-Li 3V 2(PO 4) 3 phase was characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, thermal gravimetric analysis, and X-ray absorption near edge spectrum (XANES) techniques. The valence shift of vanadium ions from +4 to +3 states was observed using in situ XANES experiments at V K-edge. The structural transformation is ascertained by the shape changes in pre-edge and near edge area of X-ray absorption spectrum. It was observed that the capacity was enhanced from 140 mAh/g to 164 mAh/g via structural transformation process of LiVOPO 4 to Li 3V 2(PO 4) 3. PMID:18636763

  3. Barium Doped Li2FeSiO4 Cathode Material for Li-Ion Secondary Batteries.

    PubMed

    Kim, Cheong; Yoo, Gi Won; Son, Jong Tae

    2015-11-01

    Barium-doped Li2Fe(1-x)Ba(x)SiO4 (x = 0, 0.01) cathode materials were synthesized by the sol-gel and electrospinning processes. The structures of the samples were confirmed by X-ray diffraction and Fourier transform infrared spectroscopy. The sizes and the morphologies of the particles and nanofibers were observed by field emission scanning electron microscopy and atomic force microscopy. The initial discharge capacity of Li2FeSiO4 particles was 28 mAh/g, Li2FeSiO4 nanofibers and barium (Ba)-doped Li2FeSiO4 nanofibers showed the discharge capacities of 78 and 85 mAh/g, respectively. The lithium-ion diffusion coefficients of Li2FeSiO4 particles, Li2FeSiO4 nanofibers and Ba-doped Li2FeSiO4 nanofibers were calculated 5.15 x 10-(16), 3.52 x 10(-16), and 2.27 x 10(-15) cm2/s, respectively. The Ba-doped Li2FeSiO4 cathode material showed the highest lithium-ion diffusion coefficient, and its electrochemical properties were better than that of the pristine material. PMID:26726598

  4. Space matters: Li+ conduction versus strain effect at FePO4/LiFePO4 interface

    NASA Astrophysics Data System (ADS)

    Lv, Weiqiang; Niu, Yinghua; Jian, Xian; Zhang, Kelvin H. L.; Wang, Wei; Zhao, Jiyun; Wang, Zhiming; Yang, Weiqing; He, Weidong

    2016-02-01

    FePO4/LiFePO4 (FP/LFP) interfacial strain, giving rise to substantial variation in interfacial energy and lattice volume, is inevitable in the (de)lithiation process of LiFePO4, a prototype of Li ion battery cathodes. Extensive theoretical and experimental research has been focused on the effect of lattice strain energy on FP/LFP interface propagation orientation and cyclic stability of the electrode. However, the essential effect of strain induced lattice distortion on Li+ transport at the FP/LFP interface is typically overlooked. In this report, a coherent interface model is derived to evaluate quantitatively the correlation between FP/LFP lattice distortion and Li+ conduction. The results illustrate that the effect of lattice strain on Li+ conduction depends strongly on FP/LFP interface orientations. Lattice strain induces a 90% decrease of Li+ conductivity in ac-plane oriented (de)lithiation at room temperature. The opposite effect of lattice strain on delithiation and lithiation for ab- and bc-orientations is elucidated. In addition, the effect of lattice strain tends to be more pronounced at a lower working temperature. This study provides an efficient platform to comprehend and manipulate Li+ conduction in the charge and discharge of lithium ion batteries, the large-scale application of which is frequently challenged by limited in-cell ion conduction.

  5. Gas Phase Chemistry of Li+ with Amides: the Observation of LiOH Loss in Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Guo, Cheng; Zhou, Yuping; Liu, Pengyuan; Chai, Yunfeng; Pan, Yuanjiang

    2012-07-01

    Collision-induced dissociation (CID) of Li+ adducts of three sets of compounds that contains an amide bond, including 2-(4, 6-dimethoxypyrimidin-2-ylsulfanyl)- N-phenylbenzamide, its derivatives and simpler structures was investigated by electrospray ionization tandem mass spectrometry (ESI-MS/MS). Observed fragment ions include those that reflect loss of LiOH. Other product ions result from the Smiles rearrangement and direct C-S bond cleavage. MS/MS of H/D exchange products demonstrated occurrence of a 1,3-H shift from the amide nitrogen atom to the phenyl ring of these compounds. The LiOH loss from Li+ adducts of amides was further examined by CID of [M + Li]+ ions of N-phenylbenzamide and N-phenylcinnamide. Loss of LiOH was essentially the sole fragmentation reaction observed for the former. For the latter, both losses of LiOH and H2O were discovered. The presence of electron-donating substituents of the phenyl ring of these compounds was found to facilitate elimination of LiOH, while that loss was retarded by electron-withdrawing substituents. Proposed fragment ion structures were supported by elemental compositions deduced from ultrahigh resolution Fourier transform ion cyclotron resonance tandem mass spectrometry (FTICR-MS/MS) m/z value determinations. Density functional theory-based (DFT) calculations were performed to evaluate potential mechanisms for these reactions.

  6. The single-electrode Peltier heats of Li-Al alloy electrodes in LiCl-KCl eutectic system

    SciTech Connect

    Amezawa, Koji; Ito, Yasuhiko; Tomii, Yoichi )

    1994-11-01

    This paper presents the single-electrode Peltier heat of cathodic (or anodic) reaction of Li-Al alloy electrode in a coexisting phase state, or an intermetallic compound phase state estimated by thermoelectric-power measurement. The thermoelectric-power measurements of Li-Al alloys in various coexisting phase states were carried out with both potentiometric and potential-sweep methods in the LiCl-KCl eutectic system between 673 and 843 K. The values of the thermoelectric power of Li-Al alloys calculated by using thermodynamic literature data were in good agreement with those obtained by experiment. The single-electrode Peltier heat changes drastically with change of its phase state, and it was found that the formation reactions of [beta] (Li[sub 0.5]Al[sub 0.5]) and [gamma] (Li[sub 0.6]Al[sub 0.4]) phases are exothermic, and those of liquid phase from [beta] and [gamma] phase are endothermic. The single-electrode Peltier heat for the cathodic formation reaction of Li-Al alloy in intermetallic compound [gamma] phase is estimated to be exothermic by using the measured values of thermoelectric powers of Li-Al alloys in ([beta] + [gamma]) and ([gamma] + liq.) regions.

  7. 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.

  8. 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.

  9. Many-body perturbation theory calculations on the electronic states of Li 2, LiNa and Na 2

    NASA Astrophysics Data System (ADS)

    Davies, D. W.; Jones, G. J. R.

    1981-07-01

    Quasi-degenerate many-body perturbation theory with a multi-configuration reference space is used to obtain potential curves for the ground and excited electronic states of Li 2, LiNa and Na 2. Correlation contributions are analyzed and the effect of potential curve crossing on laser action is discussed.

  10. 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.

  11. 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.

  12. Synthesis and decomposition of Li3Na(NH2)4 and investigations of Li-Na-N-H based systems for hydrogen storage.

    PubMed

    Jepsen, Lars H; Wang, Peikun; Wu, Guotao; Xiong, Zhitao; Besenbacher, Flemming; Chen, Ping; Jensen, Torben R

    2016-01-21

    Previous studies have shown modified thermodynamics of amide-hydride composites by cation substitution, while this work systematically investigates lithium-sodium-amide, Li-Na-N-H, based systems. Li3Na(NH2)4 has been synthesized by combined ball milling and annealing of 3LiNH2-NaNH2 with LiNa2(NH2)3 as a minor by-product. Li3+xNa1-x(NH2)4 releases NaNH2 and forms non-stoichiometric Li3+xNa1-x(NH2)4 before it melts at 234 °C, as observed by in situ powder X-ray diffraction. Above 234 °C, Li3+xNa1-x(NH2)4 releases a mixture of NH3, N2 and H2 while a bi-metallic lithium sodium imide is not observed during decomposition. Hydrogen storage performances have been investigated for the composites Li3Na(NH2)4-4LiH, LiNH2-NaH and NaNH2-LiH. Li3Na(NH2)4-4LiH converts into 4LiNH2-NaH-3LiH during mechanochemical treatment and releases 4.2 wt% of H2 in multiple steps between 25 and 340 °C as revealed by Sievert's measurements. All three investigated composites have a lower peak temperature for H2 release as compared to LiNH2-LiH, possibly owing to modified kinetics and thermodynamics, due to the formation of Li3Na(NH2)4 and LiNa2(NH2)3. PMID:26672440

  13. Mobility and dynamics in the complex hydrides LiAlH4 and LiBH4.

    PubMed

    Borgschulte, A; Jain, A; Ramirez-Cuesta, A J; Martelli, P; Remhof, A; Friedrichs, O; Gremaud, R; Züttel, A

    2011-01-01

    The dynamics and bonding of the complex hydrides LiBH4 and LiAlH4 have been investigated by vibrational spectroscopy. The combination of infrared, Raman, and inelastic neutron scattering (INS) spectroscopies on hydrided and deuterided samples reveals a complete picture of the dynamics of the BH4- and AlH4 anions respectively as well as the lattice. The straightforward interpretation of isotope effects facilitates tracer diffusion experiments revealing the diffusion coefficients of hydrogen containing species in LiBH4, and LiAlH4. LiBH4 exchanges atomic hydrogen starting at 200 degrees C. Despite having an iso-electronic structure, the mobility of hydrogen in LiAlH4 is different from that of LiBH4. Upon ball-milling of LiAlH4 and LiAlD4, hydrogen is exchanged with deuterium even at room temperature. However, the exchange reaction competes with the decomposition of the compound. The diffusion coefficients of the alanate and borohydride have been found to be D approximately equal 7 x 10(-14) m2 s(-1) at 473 K and D approximately equal 5 x 10(-16) m2 s(-1) at 348 K, respectively. The BH4 ion is easily exchanged by other ions such as I- or by NH2-. This opens the possibility of tailoring physical properties such as the temperature of the phase transition linked to the Li-ion conductivity in LiBH4 as measured by nuclear magnetic resonance and Raman spectroscopy. Temperature dependent Raman measurements on diffusion gradient samples Li(BH4)1-cIc demonstrate that increasing temperature has a similar impact to increasing the iodide concentration c: the system is driven towards the high-temperature phase of LiBH4. The influence of anion exchange on the hydrogen sorption properties is limited, though. For example, Li4(BH4)(NH2)3 does not exchange hydrogen easily even in the melt. PMID:22455070

  14. Chemical stability enhancement of lithium conducting solid electrolyte plates using sputtered LiPON thin films

    NASA Astrophysics Data System (ADS)

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

    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. The conductivity of the passivated solid electrolyte plates was measured to be 1.0×10 -4 S cm -1, with Arrhenius activation energy of 0.36 eV and an electrochemical stability window of at least 0-5.0 V versus Li/Li +. The passivated solid electrolyte was capable of supporting electrochemical plating and stripping of Li metal, as demonstrated by EIS and CV measurements. These high chemical stability, high Li + conductivity solid electrolyte plates will be useful for solid-state batteries employing Li anodes.

  15. 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. PMID:24997613

  16. A comparative study of NiO(Li), LiFeO[sub 2], and LiCoO[sub 2] porous cathodes for molten carbonate fuel cells

    SciTech Connect

    Makkus, R.C. ); Hemmes, K.; Wit, J.H.W. de . Lab. for Materials Science)

    1994-12-01

    Porous cathodes of NiO(Li), Co-doped LiFeO[sub 2], and LiCoO[sub 2] for the molten carbonate fuel cell (MCFC) were examined in a comparative study using electrochemical impedance spectroscopy at temperature of 923, 973, and 1023 K. Using this technique the contributions of charge transfer and diffusion to the impedance could be separated. The impedance results as a function of gas composition were compared with theoretical predictions using the thin-film model leading to the conclusion that the most predominant diffusing species in porous MCFC electrodes are molecular oxygen and carbon dioxide. The reaction mechanism is probably the same for all three cathodes involving either the reduction of peroxy-carbonate or the reduction of dissociated oxygen. The remaining difference in gas dependencies can then be explained by assuming a low coverage of oxide ions on LiFeO[sub 2] while NiO(Li) and LiCoO[sub 2] have intermediate coverage by oxide ions. From the temperature dependence of the impedance an estimate may be given of the activation energies of the polarization processes.

  17. 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.

  18. Coupling of Li motion and structural distortions in olivine LiMnPO4 from 7Li and 31P NMR

    NASA Astrophysics Data System (ADS)

    Rudisch, Christian; Grafe, Hans-Joachim; Geck, Jochen; Partzsch, Sven; Zimmermann, M. v.; Wizent, Nadja; Klingeler, Rüdiger; Büchner, Bernd

    2013-08-01

    We present a detailed 7Li- and 31P-NMR study on single crystalline LiMnPO4 in the paramagnetic and antiferromagnetic phase (AFM, TN˜34 K). This allows us to determine the spin directions in the field-induced spin-flop phase. In addition, the anisotropic dipolar hyperfine coupling tensor of the 7Li and 31P nuclei is also fully determined by orientation and temperature-dependent NMR experiments and compared to the calculated values from crystal structure data. Deviations of the experimental values from the theoretical ones are discussed in terms of Mn disorder which is induced by Li disorder. In fact, the disorder in the Mn sublattice is directly revealed by diffuse x-ray scattering data. The present results provide experimental evidence for the Li diffusion strongly coupling to structural distortions within the MnPO4 host, which is expected to significantly affect the Li mobility as well as the performance of batteries based on this material.

  19. Li(+) intercalation in isostructural Li2VO3 and Li2VO2F with O(2-) and mixed O(2-)/F(-) anions.

    PubMed

    Chen, Ruiyong; Ren, Shuhua; Yavuz, Murat; Guda, Alexander A; Shapovalov, Viktor; Witter, Raiker; Fichtner, Maximilian; Hahn, Horst

    2015-07-14

    Mixed-anion materials for Li-ion batteries have been attracting attention in view of their tunable electrochemical properties. Herein, we compare two isostructural (Fm3̅m) model intercalation materials Li2VO3 and Li2VO2F with O(2-) and mixed O(2-)/F(-) anions, respectively. Synchrotron X-ray diffraction and pair distribution function data confirm large structural similarity over long-range and at the atomic scale for these materials. However, they show distinct electrochemical properties and kinetic behaviour arising from the different anion environments and the consequent difference in cationic electrostatic repulsion. In comparison with Li2VO3 with an active V(4+/5+) redox reaction, the material Li2VO2F with oxofluoro anions and the partial activity of V(3+/5+) redox reaction favor higher theoretical capacity (460 mA h g(-1)vs. 230 mA h g(-1)), higher voltage (2.5 V vs. 2.2 V), lower polarization (0.1 V vs. 0.3 V) and faster Li(+) chemical diffusion (∼10(-9) cm(2) s(-1)vs. ∼10(-11) cm(2) s(-1)). This work not only provides insights into the understanding of anion chemistry, but also suggests the rational design of new mixed-anion battery materials. PMID:26073634

  20. 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

  1. Thermodynamic modelling of LiF-LnF 3 and LiF-AnF 3 phase diagrams

    NASA Astrophysics Data System (ADS)

    van der Meer, J. P. M.; Konings, R. J. M.; Jacobs, M. H. G.; Oonk, H. A. J.

    2004-12-01

    The phase diagrams of the LiF-LnF3 series, where Ln = La-Sm, and of LiF-AnF3, where An = U, Pu, have been optimized using Redlich-Kister functions. The phase diagrams of LiF-AmF3 and LiF-PuF3-AmF3 have been calculated. The necessary Gibbs energy functions for americium trifluoride were defined by use of a semi-empirical method. The excess Gibbs energy terms, which are expressed as Redlich-Kister polynomials and describe the effect of interaction between the two fluoride components in the liquid phase, were obtained by translating the trends observed in the lanthanide trifluoride series into the actinide series. A single eutectic has been found in the LiF-AmF3 system with the eutectic point at ≃33 mole% AmF3 and at ≃951 K.

  2. Role of Li in the low temperature synthesis of monoclinic celsian from (Ba, Li)-exchanged zeolite-A precursor

    NASA Astrophysics Data System (ADS)

    Ferone, Claudio; Esposito, Serena; Dell'Agli, Gianfranco; Pansini, Michele

    2005-11-01

    A sample of exhaustively Ba-exchanged zeolite-A was subjected to Li-exchange to obtain four samples of zeolite Ba-A bearing different Li amounts. These samples were subjected to thermal treatments at temperatures ranging from 200 to 1100 °C for times up to 28 hours. Samples of fully monoclinic celsian bearing an amount of impurities of 0.62 weight % Na 2O and 0.17 weight % Li 2O, 0.60 Na 2O weight % and 0.29 Li 2O weight %, and 0.67 Na 2O weight % and 0.55 Li 2O weight % were obtained after thermal treatments lasting 10 hours at 1100 °C, 4 hours at 1100 °C, and 4 hours at 1000 °C, respectively.

  3. Mechanism of the ferroelectric phase transitions in LiNbO3 and LiTaO3

    NASA Astrophysics Data System (ADS)

    Ohkubo, Y.; Murakami, Y.; Saito, T.; Yokoyama, A.; Uehara, S.; Kawase, Y.

    2002-02-01

    The temperature dependences of the nuclear-electric-quadrupole frequency ωQ of 117In doped in LiTaO3 (TC=938 K) and Li1-xInx/3TaO3 with x=0.2 (TC=818 K) show that the order-disorder of the Li ions is not the driving mechanism for the ferroelectric instability in LiNbO3 and LiTaO3 systems, and imply that the oxygen order-disorder is the driving mechanism. The significantly different temperature dependences of ωQ of 111Cd in these materials compared, to those of 117In, demonstrate that this order-disorder is of dynamic character.

  4. Performance study of commercial LiCoO 2 and spinel-based Li-ion cells

    NASA Astrophysics Data System (ADS)

    Ramadass, P.; Haran, Bala; White, Ralph; Popov, Branko N.

    The performance of Cell-Batt ® Li-ion cells and Sony 18650 cells using non-stoichiometric spinel and LiCoO 2, respectively, as positive electrode material has been studied under several modes of charging. During cycling, the cells were opened at intermittent cycles and extensive material and electrochemical characterization was done on the active material at both electrodes. Capacity fade of spinel-based Li-ion cells was attributed to structural degradation at the cathode and loss of active material at both electrodes due to electrolyte oxidation. For the Sony cells both primary (Li +) and secondary active material (LiCoO 2)/C) are lost during cycling.

  5. Structure of neutron-rich Isotopes {sup 8}Li and {sup 9}Li and allowance for it in elastic scattering

    SciTech Connect

    Ibraeva, E. T.; Zhusupov, M. A.; Imambekov, O.; Sagindykov, Sh. Sh.

    2008-07-15

    The differential cross sections for elastic proton scattering on the unstable neutron-rich nuclei {sup 8}Li and {sup 9}Li at E = 700 and 60 MeV per nucleon were considered. The {sup 8}Li nucleus was treated on the basis of the three-body {alpha}-t-n model, while the {sup 9}Li nucleus was considered within the {alpha}-t-n and {sup 7}Li-n-n models. The cross sections in question were calculated within Glauber diffraction theory. A comparison of the results with available experimental data made it possible to draw conclusions on the quality of the wave functions and potential used in the calculations.

  6. 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.

  7. Geometry, electronic properties, and thermodynamics of pure and Al-doped Li clusters

    NASA Astrophysics Data System (ADS)

    Lee, Mal-Soon; Gowtham, S.; He, Haiying; Lau, Kah-Chun; Pan, Lin; Kanhere, D. G.

    2006-12-01

    The first-principles density functional molecular dynamics simulations have been carried out to investigate the geometric, the electronic, and the finite temperature properties of pure Li clusters ( Li10 , Li12 ) and Al-doped Li clusters ( Li10Al , Li10Al2 ). We find that the addition of two Al impurities in Li10 results in a substantial structural change, while the addition of one Al impurity causes a rearrangement of atoms. Introduction of Al impurities in Li10 establishes a polar bond between Li and nearby Al atom(s), leading to a multicentered bonding, which weakens the Li-Li metallic bonds in the system. These weakened Li-Li bonds lead to a premelting feature to occur at lower temperatures in Al-doped clusters. In Li10Al2 , Al atoms also form a weak covalent bond, resulting in their dimerlike behavior. This causes Al atoms not to “melt” until 800K , in contrast to the Li atoms which show a complete diffusive behavior above 400K . Thus, although one Al impurity in Li10 cluster does not change its melting characteristics significantly, two impurities results in “surface melting” of Li atoms whose motions are confined around an Al dimer.

  8. Target electron ionization in Li2+-Li collisions: A multi-electron perspective

    NASA Astrophysics Data System (ADS)

    Śpiewanowski, M. D.; Gulyás, L.; Horbatsch, M.; Goullon, J.; Ferreira, N.; Hubele, R.; de Jesus, V. L. B.; Lindenblatt, H.; Schneider, K.; Schulz, M.; Schuricke, M.; Song, Z.; Zhang, S.; Fischer, D.; Kirchner, T.

    2015-04-01

    Target electron removal in Li2+-Li collisions at 2290 keV/amu is studied experimentally and theoretically for ground and excited lithium target configurations. It is shown that in outer-shell ionization a single-electron process plays the dominant part. However, the K-shell ionization results are more difficult to interpret. According to our calculations, the process is shown to be strongly single-particle like. On one hand, a high resemblance between theoretical single-particle ionization and exclusive inner-shell ionization is demonstrated, and contributions from multi-electron processes are found to be weak. On the other hand, it is indicated by the discrepancy between experimental and single-particle theoretical results that multi-electron processes involving ionization from the outer-shell may play a crucial role.

  9. LiCl dehumidifier LiBr absorption chiller hybrid air conditioning system with energy recovery

    SciTech Connect

    Ko, S.M.

    1980-06-03

    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. 4 figs.

  10. Ultrathin coatings on nano-LiCoO2 for Li-ion vehicular applications.

    PubMed

    Scott, Isaac D; Jung, Yoon Seok; Cavanagh, Andrew S; Yan, Yanfa; Dillon, Anne C; George, Steven M; Lee, Se-Hee

    2011-02-01

    To deploy Li-ion batteries in next-generation vehicles, it is essential to develop electrodes with durability, high energy density, and high power. Here we report a breakthrough in controlled full-electrode nanoscale coatings that enables nanosized materials to cycle with durable high energy and remarkable rate performance. The nanoparticle electrodes are coated with Al(2)O(3) using atomic layer deposition (ALD). The coated nano-LiCoO(2) electrodes with 2 ALD cycles deliver a discharge capacity of 133 mAh/g with currents of 1400 mA/g (7.8C), corresponding to a 250% improvement in reversible capacity compared to bare nanoparticles (br-nLCO), when cycled at this high rate. The simple ALD process is broadly applicable and provides new opportunities for the battery industry to design other novel nanostructured electrodes that are highly durable even while cycling at high rate. PMID:21166425

  11. 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.

  12. Performance characteristics of Li//Li{sub 1{+-}}{sub X}CoO{sub 2} cells

    SciTech Connect

    Zou Meijing; Yoshio, Masaki; Gopukumar, S. . E-mail: deepika_41@rediffmail.com; Yamaki, Jun-ichi

    2005-04-20

    Lithium cobalt oxides (LiCoO{sub 2}) with varying lithium stoichiometries viz., 0.97, 1, 1.03, 1.06 and 1.1 have been prepared by a solid-state high temperature technique. Structural determination of the synthesized powders with X-ray diffraction (XRD) reveals single-phase materials while the surface morphologies investigated with scanning electron microscopy (SEM) indicate different particle orientation with increase in lithium content. Electrochemical galvanostatic cycling studies of the synthesized powders in lithium 2032 coin type cells in the voltage range 3.5-4.5 V suggest that initial capacity fading is minimum in samples with lithium stoichiochiometries of either 0.97 or 1.03 and stable capacities are attained after the initial 10 cycles. The effect of lithium stoichiometry on the performance of LiCoO{sub 2} in a lithium rechargeable cell is presented.

  13. 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.

  14. Storage and Effective Migration of Li-Ion for Defected β-LiFePO4 Phase Nanocrystals.

    PubMed

    Guo, Hua; Song, Xiaohe; Zhuo, Zengqing; Hu, Jiangtao; Liu, Tongchao; Duan, Yandong; Zheng, Jiaxin; Chen, Zonghai; Yang, Wanli; Amine, Khalil; Pan, Feng

    2016-01-13

    Lithium iron phosphate, a widely used cathode material, crystallizes typically in olivine-type phase, α-LiFePO4 (αLFP). However, the new phase β-LiFePO4 (βLFP), which can be transformed from αLFP under high temperature and pressure, is originally almost electrochemically inactive with no capacity for Li-ion battery, because the Li-ions are stored in the tetrahedral [LiO4] with very high activation barrier for migration and the one-dimensional (1D) migration channels for Li-ion diffusion in αLFP disappear, while the Fe ions in the β-phase are oriented similar to the 1D arrangement instead. In this work, using experimental studies combined with density functional theory calculations, we demonstrate that βLFP can be activated with creation of effective paths of Li-ion migration by optimized disordering. Thus, the new phase of βLFP cathode achieved a capacity of 128 mAh g(-1) at a rate of 0.1 C (1C = 170 mA g(-1)) with extraordinary cycling performance that 94.5% of the initial capacity retains after 1000 cycles at 1 C. The activation mechanism can be attributed to that the induced disorder (such as FeLiLiFe antisite defects, crystal distortion, and amorphous domains) creates new lithium migration passages, which free the captive stored lithium atoms and facilitate their intercalation/deintercalation from the cathode. Such materials activated by disorder are promising candidate cathodes for lithium batteries, and the related mechanism of storage and effective migration of Li-ions also provides new clues for future design of disordered-electrode materials with high capacity and high energy density. PMID:26632008

  15. Bulk nanostructure of the prototypical 'good' and 'poor' solvate ionic liquids [Li(G4)][TFSI] and [Li(G4)][NO3].

    PubMed

    Murphy, Thomas; Callear, Sam K; Yepuri, Nageshwar; Shimizu, Karina; Watanabe, Masayoshi; Canongia Lopes, José N; Darwish, Tamim; Warr, Gregory G; Atkin, Rob

    2016-07-14

    The bulk nanostructures of a prototypical 'good' solvate ionic liquid (SIL) and 'poor' SIL have been examined using neutron diffraction and empirical potential structure refinement (EPSR) simulated fits. The good SIL formed by a 1 : 1 mixture of lithium bis(trifluoromethylsulfonyl)imide (Li[TFSI]) in tetraglyme (G4), denoted [Li(G4)][TFSI], and the poor SIL formed from a 1 : 1 mixture of lithium nitrate (Li[NO3]) in G4, denoted [Li(G4)][NO3], have been studied. In both SILs there are strong Lewis acid-base interactions between Li(+) and ligating O atoms. However, the O atoms coordinated to Li(+) depend strongly on the counter anion present. LiO coordination numbers with G4 are 2-3 times higher for [Li(G4)][TFSI] than [Li(G4)][NO3], and conversely the LiO anion coordination number is 2-3 times higher in [Li(G4)][NO3]. In both solvates the local packing of Li around G4 O atoms are identical but these interactions are less frequent in [Li(G4)][NO3]. In both SILs, Li(+) has a distribution of coordination numbers and a wide variety of different complex structures are present. For [Li(G4)][NO3], there is a significant proportion uncoordinated G4 in the bulk; ∼37% of glyme molecules have no LiO contacts and each G4 molecule coordinates to an average of 0.5 Li(+) cations. Conversely, in [Li(G4)][TFSI] only ∼5% of G4 molecules lack LiO contacts and G4 molecules coordinates to an average of 1.3 Li(+) cations. Li(+) and G4 form polynuclear complexes, of the form [Lix(G4)y](x+), in both solvates. For [Li(G4)][TFSI] ∼35% of Li(+) and G4 form 1 polynuclear complexes, while only ∼10% of Li(+) and G4 form polynuclear complexes in [Li(G4)][NO3]. PMID:26845292

  16. High-capacity phase formation by surface modification of Li3PO4 on nanosized Li2RuO3 electrode for lithium batteries

    NASA Astrophysics Data System (ADS)

    Zheng, Yueming; Taminato, Sou; Xu, Youlong; Suzuki, Kota; Kim, KyungSu; Hirayama, Masaaki; Kanno, Ryoji

    2012-06-01

    Effects of modifying the surface of lithium excess layered rock-salt type electrodes by Li3PO4 is investigated using epitaxial Li2RuO3 model electrodes. A 3.6-nm-thick amorphous Li3PO4 layer is deposited on a 25.5-nm-thick Li2RuO3 film by pulsed laser deposition. X-ray absorption near edge structure reveals that the modified Li2RuO3 surface had different electronic states of Ru from the unmodified Li2RuO3 surface, indicating that Li3PO4 deposition changes the structure of the Li2RuO3 surface. Li3PO4-modified Li2RuO3 has a much higher first discharge capacity (296 mAh g-1) between 2.8 and 4.2 V than unmodified Li2RuO3 (190 mAh g-1). The modified and unmodified Li2RuO3 have irreversible capacities in the first charge/discharge process of 22 and 148 mAh g-1, respectively. The surface modification induced by Li3PO4 deposition enhances the structural stability of the Li2RuO3 surface during the initial charging process.

  17. Study the Effects of Mechanical Activation on Li-N-H Systems With 1H and 6Li Solid-State NMR

    SciTech Connect

    Lu, Chun; Hu, Jian Zhi; Kwak, Ja Hun; Yang, Z Gary; Ren, Ruiming; Markmaitree, Tippawan; Shaw, Leonard D.

    2007-07-10

    To gain insight into the effects of mechanical activation (MA) on the hydrogen desorption of the lithium amide (LiNH2) and lithium hydride (LiH) mixture, LiNH2 and LiH+LiNH2 were mechanically activated by high-energy ball milling. The formed products were studied with in situ 1H and 6Li nuclear magic angle spinning (MAS) magnetic resonance (NMR) spectroscopy from ambient temperature to 180 degrees C. Up-field chemical shift was observed in 6Li MAS NMR spectra with increased milling time, indicating that average local electronic structure around Li nuclei was modified during MA. 1H MAS NMR was used to dynamically probe ammonia release from the activated LiNH2 at temperature as low as 50 degrees C. In the case of activated LiH+LiNH2 mixtures, the 1H MAS NMR results implied that MA enhanced the dehydrogenation reaction of LiNH2+LiH=Li2NH+H2 and suppressed ammonia generation as well.

  18. Study the effects of mechanical activation on Li-N-H systems with 1H and 6Li solid-state NMR

    NASA Astrophysics Data System (ADS)

    Lu, Chun; Hu, Jianzhi; Kwak, Ja Hun; Yang, Zhenguo; Ren, Ruiming; Markmaitree, Tippawan; Shaw, Leon L.

    To gain insight into the effects of mechanical activation (MA) on the hydrogen desorption of the lithium amide (LiNH 2) and lithium hydride (LiH) mixture, LiNH 2 and LiH + LiNH 2 were mechanically activated by high-energy ball milling. The formed products were studied with in situ 1H and 6Li nuclear magic angle spinning (MAS) magnetic resonance (NMR) spectroscopy from ambient temperature to 180 °C. Up-field chemical shift was observed in 6Li MAS NMR spectra with increased milling time, indicating that average local electronic structure around Li nuclei was modified during MA. 1H MAS NMR was used to dynamically probe ammonia release from the activated LiNH 2 at temperature as low as 50 °C. In the case of activated LiH + LiNH 2 mixtures, the 1H MAS NMR results implied that MA enhanced the dehydrogenation reaction of LiNH 2 + LiH = Li 2NH + H 2.

  19. Preparation of Li2TiO3-Li4SiO4 core-shell ceramic pebbles with enhanced crush load by graphite bed process

    NASA Astrophysics Data System (ADS)

    Xiang, Maoqiao; Zhang, Yingchun; Zhang, Yun; Liu, Shuya; Liu, Hui; Wang, Chaofu; Gu, Cheng

    2015-11-01

    Li4SiO4 and Li2TiO3 have been regarded as the most favored ceramic breeders of the test blanket modules (TBMs). The lithium density of Li4SiO4 is higher than that of Li2TiO3; however, the thermo-mechanical stability of Li2TiO3 is better than that of Li4SiO4. Hence, the biphasic yLi2TiO3-(1-y)Li4SiO4 (y = 25%, 50%, 75%, molar ratio) pebbles were fabricated by a graphite bed process for the next generation of advanced tritium breeder materials. The pebbles with interesting core-shell structure (core: Li2TiO3 and Li4SiO4, shell: Li2TiO3) were fabricated for the first time. The thickness of Li2TiO3 shell can be controlled by sintering time. Crystal structure, microstructure, and mechanical properties of the biphasic pebbles were investigated. The experimental results showed that the core-shell structure improved the crush load dramatically. The average crush load of 50%Li2TiO3-50%Li4SiO4 pebbles sintered at 1100 °C for 5 h was up to104.79 N.

  20. Material review of Li ion battery separators

    SciTech Connect

    Weber, Christoph J. Geiger, Sigrid; Falusi, Sandra; Roth, Michael

    2014-06-16

    Separators for Li Ion batteries have a strong impact on cell production, cell performance, life, as well as reliability and safety. The separator market volume is about 500 million m{sup 2} mainly based on consumer applications. It is expected to grow strongly over the next decade for mobile and stationary applications using large cells. At present, the market is essentially served by polyolefine membranes. Such membranes have some technological limitations, such as wettability, porosity, penetration resistance, shrinkage and meltdown. The development of a cell failure due to internal short circuit is potentially closely related to separator material properties. Consequently, advanced separators became an intense area of worldwide research and development activity in academia and industry. New separator technologies are being developed especially to address safety and reliability related property improvements.

  1. Transport measurement of Li doped monolayer graphene

    NASA Astrophysics Data System (ADS)

    Khademi, Ali; Sajadi, Ebrahim; Dosanjh, Pinder; Folk, Joshua; Stöhr, Alexander; Forti, Stiven; Starke, Ulrich

    Lithium adatoms on monolayer graphene have been predicted to induce superconductivity with a critical temperature near 8 K, and recent experimental evidence by ARPES indicates a critical temperature nearly that high. Encouraged by these results, we investigated the effects of lithium deposited at cryogenic temperatures on the electronic transport properties of epitaxial and CVD monolayer graphene down to 3 K. The change of charge carrier density due to Li deposition was monitored both by the gate voltage shift of the Dirac point and by Hall measurements, in low and high doping regimes. In the high doping regime, a saturation density of 2×1013 cm-2 was observed independent of sample type, initial carrier density and deposition conditions. No signatures of superconductivity were observed down to 3 K.

  2. Material review of Li ion battery separators

    NASA Astrophysics Data System (ADS)

    Weber, Christoph J.; Geiger, Sigrid; Falusi, Sandra; Roth, Michael

    2014-06-01

    Separators for Li Ion batteries have a strong impact on cell production, cell performance, life, as well as reliability and safety. The separator market volume is about 500 million m2 mainly based on consumer applications. It is expected to grow strongly over the next decade for mobile and stationary applications using large cells. At present, the market is essentially served by polyolefine membranes. Such membranes have some technological limitations, such as wettability, porosity, penetration resistance, shrinkage and meltdown. The development of a cell failure due to internal short circuit is potentially closely related to separator material properties. Consequently, advanced separators became an intense area of worldwide research and development activity in academia and industry. New separator technologies are being developed especially to address safety and reliability related property improvements.

  3. 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.

  4. 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 %.

  5. [Professor Li Shi-zhen's clinical experiences on compatibility application of hegu (LI 4)].

    PubMed

    Li, Chuan-qi

    2010-02-01

    The present paper introduces professor LI Shi-zhen's clinical experiences on compatibility application of Hegu (LI 4). Hegu (LI 4) is mostly used to treat acute pyreticosis, exterior syndrome of exogenous diseases, mind diseases and deficiency of vital energy. Acupuncture at this acupoint by using reducing method can dispel wind to relieve exterior syndrome, clear away heat to disperse lung. Powerful stimulation by needle can dredge stagnant meridian, open orifice to activate spirit. Acupuncture at this acupoint by using reinforcing method can invigorate qi to strengthen superficies and replenish qi to prevent collapse. Based on this method, reinforcing Zusanli (ST 36) and Baihui (GV 20) can strengthen middle energizer to nourish qi, which show the same benefits as Buzhong Yiqi Decoction; reinforcing Sanyinjiao (SP 6) can nourish both qi and blood, which show the same benefits as Decoction of Eight Ingredients; reducing Neiting (ST 44) can clear away evil heat of qifen in yangming meridians, which show the same benefits as Baihu Decoction. PMID:20214075

  6. 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.

  7. 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.

  8. 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

  9. 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. PMID:26799094

  10. 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

  11. 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.

  12. Medium Modification of α Cluster Size in 6Li

    NASA Astrophysics Data System (ADS)

    Yamagata, T.; Akimune, H.; Nakayama, S.; Shima, T.; Miyamoto, S.

    2015-10-01

    The giant dipole resonance (GDR) in 6Li was investigated via the 6LI(γ, xn) reaction, where x = 1, 2 or 3 at an incident energy range of Eγ =5-55. The(γ, n) cross section was the most dominant cross section among them. The GDR in 6Li was found to consist of two components at Ex = 11 MeV and 33 MeV. The component at Ex = 11 MeV seems to be the intrinsic GDR in 6Li. The other at Ex = 33 MeV is inferred to be the GDR due to the α cluster excitation in 6Li, based on the comparison with the results in light ion reactions. The GDR in free 4He is known to locate at Ex= 26 MeV. However, the GDR excitation energy due tothe α cluster excitation in 6Li is found to be higher than that of the 4He. This fact suggests that the size of the α cluster in 6Li is smaller than that of 4He due to the nuclear medium effect.

  13. Tuning frictions between graphene layers via Li ion intercalation

    NASA Astrophysics Data System (ADS)

    Lu, Aijiang; Wan, Jiayu; Li, Teng; Hu, Liangbing; Univerisyt of Maryland, College Park Team

    Graphite intercalated with Li ions are widely studied and applied in Li ion batteries. It was revealed in experiments that, the Li ion intercalation leads to a phase transition of the graphite with about 10% volume expansion. The increased interlayer distance should contribute to decrease the frictions between the grahene layers, but the Li ion intercalation would take an opposite effect. In order to show the total effect of the Li ion interalation, we studied the frictions between graphene layers with and without lithiation, based on density functional theory (DFT). In a sandwich-like model, slipping of the middle sheet of the graphene was simulated. Displacements between layers were fixed and the other parts were relaxed, thus the energies were record to estimate the energy barriers accordingly. We found that the frictions between the graphene layers with the Li ion intercalation are higher than those without intercalation. The energy barrier appears correlated with the concentration of the intercalated ions. As the atomic ratio between lithium and carbon increases from 0 (no intercalation) to 1:6, the energy barriers increase from 0.01 eV/atom to 0.05 eV/atom or so. Such an interesting result indicates that, just via ion intercalation, we can effectively tune the friction between graphene layers. Tuning frictions between graphene layers via Li ion intercalation.

  14. 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.

  15. Li I AND K I SCATTER IN COOL PLEIADES DWARFS

    SciTech Connect

    King, Jeremy R.; Schuler, Simon C.; Hobbs, L. M.; Pinsonneault, Marc H. E-mail: sschuler@noao.ed E-mail: pinsono@astronomy.ohio-state.ed

    2010-02-20

    We utilize high-resolution (R {approx} 60,000), high signal-to-noise ratio ({approx}100) spectroscopy of 17 cool Pleiades dwarfs to examine the confounding star-to-star scatter in the lambda6707 Li I line strengths in this young cluster. Our Pleiades, selected for their small projected rotational velocity and modest chromospheric emission, evince substantial scatter in the line strengths of lambda6707 Li I feature that is absent in the lambda7699 K I resonance line. The Li I scatter is not correlated with that in the high-excitation lambda7774 O I feature, and the magnitude of the former is greater than the latter despite the larger temperature sensitivity of the O I feature. These results suggest that systematic errors in line strength measurements due to blending, color (or color-based T{sub eff}) errors, or line formation effects related to an overlying chromosphere are not the principal source of Li I scatter in our stars. There do exist analytic spot models that can produce, via line formation effects, the observed Li scatter without introducing scatter in the K I line strengths or the color-magnitude diagram. However, these models predict factor of >=3 differences in abundances derived from the subordinate lambda6104 and resonance lambda6707 Li I features; we find no difference in the abundances determined from these two features. These analytic spot models also predict CN line strengths significantly larger than we observe in our spectra. The simplest explanation of the Li, K, CN, and photometric data is that there must be a real abundance component to the Pleiades Li dispersion. We suggest that this real abundance component is the manifestation of relic differences in erstwhile pre-main-sequence Li burning caused by effects of surface activity on stellar structure. We discuss observational predictions of these effects, which may be related to other anomalous stellar phenomena.

  16. Synthesis and properties of ZnO(Li) crystals

    SciTech Connect

    Nikitenko, V.A.; Mukhin, S.V.; Stoyukhin, S.G.

    1995-10-01

    Dissolution of lithium in ZnO crystals (up to N{sub Li} {approx} 10{sup 19}cm{sup {minus}3}) has little or no effect on their structural perfection. The lithium dopant in ZnO may occupy interstices (Li{sub i}) or may substitute for the Zn site (Li{sub Zn}), acting, respectively, as a shallow donor with the ionization energy E{sub d} = 0.04 eV or as an acceptor with E{sub a}(optical){approx}1 eV (optical depth measured from the edge of the valence band) and the thermal depth Ea (thermal) = 0.2 - 0.4 eV. In an unexcited crystal, the substitutional lithium ion is coordinated by four oxygen ions 0 inch, creating the (Li{sup +}{sub Zn}-0 inch) foot complex. The corresponding lithium states are denoted by Li{sup foot}{sub Zn}. These defects become paramagnetic (Li{sup x}{sub Zn} or, in a more complete notation, (Li{sup +}{sub Zn}-0 foot){sup x}) when a hole is trapped (or an electron is released) by one of the nearest neighbor oxygen ions. The resulting centers are responsible for the yellow-orange luminescence of Zn, O well studied using ESR under light illumination. There exist many contradictions in interpreting the electrical and optical properties of ZnO(Li) crystals. Most of these contradictions stem from the fact that in many cases inadequate attention is paid to prepararation conditions, to the presence of minority defects, as well as to the amphoteric nature of the lithium dopant, which governs the electrical conductivity of the host crystals. In the present work, we summarize our recent results on the synthesis of ZnO(Li) samples with preset often unique properties.

  17. 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.

  18. 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.

  19. 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.

  20. 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}.

  1. 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.

  2. Uncovering the intrinsic delithiation mechanism in Li-excess Li2MnO3 through defect calculations

    NASA Astrophysics Data System (ADS)

    Hoang, Khang

    2015-03-01

    Layered Li-excess Li2MnO3 has been of great interest for lithium-ion battery cathodes because of its high theoretical capacity. The compound is also an important component in xLi2MnO3 .(1 - x)LiMO2 and other high-capacity cathode materials. It has been reported that Li2MnO3 can be made electrochemically active by acid leaching or charging to high voltages. Several different mechanisms have been proposed to explain its unconventional lithium extraction behavior, including one that involves oxidation at the oxygen site. In this talk, we will present a comprehensive computational approach based on first-principles hybrid density functional defect calculations, and illustrate how it helps uncover the defect physics and chemistry and the intrinsic mechanisms for delithiation and electronic and ionic conduction in layered Li2MnO3. In light of our results, we discuss the relevance of the proposed mechanisms and suggest solutions for improving the electronic conduction and hence the electrochemical performance of Li2MnO3 and related materials.

  3. Differentiating allotropic LiCoO2/Li2Co2O4: A structural and electrochemical study

    NASA Astrophysics Data System (ADS)

    Kan, Yongchun; Hu, Yuan; Ren, Yang; Bareño, Javier; Bloom, Ira; Sun, Yang-Kook; Amine, Khalil; Chen, Zonghai

    2014-12-01

    In situ high-energy X-ray diffraction was carried out to investigate the structural transformation of lithium cobalt oxides during the solid-state synthesis. Two allotropic phases were observed during the synthesis process; Li2Co2O4 with a spinel structure was formed within the temperature window between 450 °C and 650 °C, beyond which Li2Co2O4 was converted to its hexagonal counterpart, layered LiCoO2, through a cation exchange between Li and Co. In electrochemical tests, the Li2Co2O4 was estimated to have a very low reversible capacity, ˜20 mAh g-1, and a high initial irreversible capacity loss of about 80 mAh g-1. An interfacial phase between layered LiCoO2 domain and spinel Li2Co2O4 domain was also identified by ex situ high-resolution X-ray diffraction.

  4. 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.

  5. 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.

  6. 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.

  7. 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

    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 (228.2058MHz and 803.5581MHz, respectivly) 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 life-times, 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.

  8. 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

  9. Novel polymer Li-ion binder carboxymethyl cellulose derivative enhanced electrochemical performance for Li-ion batteries.

    PubMed

    Qiu, Lei; Shao, Ziqiang; Wang, Daxiong; Wang, Feijun; Wang, Wenjun; Wang, Jianquan

    2014-11-01

    Novel water-based binder lithium carboxymethyl cellulose (CMC-Li) is synthesized by cotton as raw material. The mechanism of the CMC-Li as a binder is reported. Electrochemical properties of batteries' cathodes based on commercially available lithium iron phosphate (LiFePO4, LFP) and water-soluble binder are investigated. Sodium carboxymethyl cellulose (CMC-Na, CMC) and CMC-Li are used as the binder. After 200 cycles, compared with conventional poly(vinylidene fluoride) (PVDF) binder, the CMC-Li binder significantly improves cycling performance of the LFP cathode 96.7% of initial reversible capacity achieved at 175 mA h g(-1). Constant current charge-discharge test results demonstrate that the LFP electrode using CMC-Li as the binder has the highest rate capability, followed closely by those using CMC and PVDF binders, respectively. Electrochemical impedance spectroscopy test results show that the electrode using CMC-Li as the binder has lower charge transfer resistance than the electrodes using CMC and PVDF as the binders. PMID:25129778

  10. 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.

  11. 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

  12. New insights into the modification mechanism of Li-rich Li1.2Mn0.6Ni0.2O2 coated by Li2ZrO3.

    PubMed

    Zhang, Jicheng; Zhang, Heng; Gao, Rui; Li, Zhengyao; Hu, Zhongbo; Liu, Xiangfeng

    2016-05-21

    Lithium-rich Mn-based layered cathode materials have attracted wide attention due to their high specific capacity for lithium-ion batteries. However, some critical issues i.e. poor rate capability and voltage fade have limited their practical applications. Herein, we propose a synchronous lithiation strategy to coat Li-rich Li1.2Mn0.6Ni0.2O2 (LMNO) with a thin layer of Li(+)-conductive Li2ZrO3. The obtained syn-Li2ZrO3@LMNO integrates the advantages of the Li2ZrO3 coating and Zr(4+) doping, and shows a much higher rate capability and cycling stability than those of the counterpart post-Li2ZrO3@LMNO fabricated by a post-coating method. More importantly, the average voltage of syn-Li2ZrO3@LMNO has been enhanced by 0.15 V and the voltage decay has also been mitigated. New insights into the synergetic modification mechanism of the Li2ZrO3 coating and Zr(4+) doping have been proposed. The coating layer of Li(+)-conductive Li2ZrO3 alleviates the surface side reactions, suppresses the transition metal dissolution and enhances the Li-ion conductivity. Meanwhile, the doping and incorporation of Zr(4+) into the host structure accompanied by the Li2ZrO3 coating expands the interplanar spacing and decreases Li/Ni mixing which facilitates Li(+) diffusion. In addition, the integration of the Li2ZrO3 coating and Zr(4+) doping also further enhances the layered structure stability and mitigates the voltage fade during lithiation/delithiation cycles. Moreover, the proposed synchronous lithiation coating route avoids the duplicated high-temperature calcinations and can also be widely used to modify some other cathode materials. PMID:27121490

  13. Hydrogen as promoter and inhibitor of superionicity: A case study on Li-N-H systems

    NASA Astrophysics Data System (ADS)

    Blomqvist, Andreas; Moysés Araújo, C.; Scheicher, Ralph H.; Srepusharawoot, Pornjuk; Li, Wen; Chen, Ping; Ahuja, Rajeev

    2010-07-01

    Materials which possess a high lithium ion conductivity are very attractive for battery and fuel cell applications. Hydrogenation of the fast-ion conductor lithium nitride (Li3N) leads to the formation of lithium imide (Li2NH) and subsequently of lithium amide (LiNH2) . Using ab initio molecular dynamics simulations, we carried out a comparative study of the Li diffusion in these three systems. The results demonstrate that hydrogen can work as both promoter and inhibitor of Li mobility, with the lowest transition temperature to the superionic state occurring in Li2NH . Furthermore, we show that the creation of Li vacancies strongly affects Li diffusion in Li3N , but not so in Li2NH . Finally, we explain our findings with the help of a simple model.

  14. 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.

  15. 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.

  16. 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

  17. Unexpected Li2O2 Film Growth on Carbon Nanotube Electrodes with CeO2 Nanoparticles in Li-O2 Batteries.

    PubMed

    Yang, Chunzhen; Wong, Raymond A; Hong, Misun; Yamanaka, Keisuke; Ohta, Toshiaki; Byon, Hye Ryung

    2016-05-11

    In lithium-oxygen (Li-O2) batteries, it is believed that lithium peroxide (Li2O2) electrochemically forms thin films with thicknesses less than 10 nm resulting in capacity restrictions due to limitations in charge transport. Here we show unexpected Li2O2 film growth with thicknesses of ∼60 nm on a three-dimensional carbon nanotube (CNT) electrode incorporated with cerium dioxide (ceria) nanoparticles (CeO2 NPs). The CeO2 NPs favor Li2O2 surface nucleation owing to their strong binding toward reactive oxygen species (e.g., O2 and LiO2). The subsequent film growth results in thicknesses of ∼40 nm (at cutoff potential of 2.2 V vs Li/Li(+)), which further increases up to ∼60 nm with the addition of trace amounts of H2O that enhances the solution free energy. This suggests the involvement of solvated superoxide species (LiO2(sol)) that precipitates on the existing Li2O2 films to form thicker films via disproportionation. By comparing toroidal Li2O2 formed solely from LiO2(sol), the thick Li2O2 films formed from surface-mediated nucleation/thin-film growth following by LiO2(sol) deposition provides the benefits of higher reversibility and rapid surface decomposition during recharge. PMID:27105122

  18. 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.

  19. A novel nano structured LiFePO4/C composite as cathode for Li-ion batteries

    NASA Astrophysics Data System (ADS)

    Zhang, Huang; Liu, Dong; Qian, Xiuzhen; Zhao, Chongjun; Xu, Yunlong

    2014-03-01

    A novel network LiFePO4/C composite was prepared by mixing precursor solution with carbon aerogel (CA) via a simple solution impregnation method, characterized by XRD, SEM, EDS and electrochemical analysis. The results revealed that the LiFePO4 nanowire forming on the ektexine of CA intertwined with LiFePO4/CA particles and formed a special web structure. The initial discharge capacity was improved to be 139.3 mAh g-1 at 10 C and the capacity retention is near 100% after 50 cycles. The web structure could improve electron transport and electrochemical activity effectively.

  20. Synthesis and electrochemical property of xLi2MnO3·(1 - x)LiMnO2 composite cathode materials derived from partially reduced Li2MnO3

    NASA Astrophysics Data System (ADS)

    Zhang, Qinggang; Peng, Tianyou; Zhan, Dan; Hu, Xiaohong

    2014-03-01

    xLi2MnO3·(1 - x)LiMnO2 (x = 0.39, 0.48, 0.57, 0.74) composites with a layered structure of C2/m symmetry are firstly synthesized with the assistance of the pyrolysis of in situ formed lithium stearate, which can partially reduce the electrochemically inactive Li2MnO3. The obtained composites used as cathode material of Li-ion battery exhibit excellent electrochemical property such as high reversible capacity (>210 mAh g-1) and good rate performance with an initial charge/discharge profile similar to the Li-rich solid solution materials in the range of 2.0-4.8 V. Among those obtained composites, 0.57Li2MnO3·0.43LiMnO2 has the best cyclic and rate performance, because it contains enough Li2MnO3 to stabilize the structure of LiMnO2 and has a suitable average valence state of Mn to balance the reversible capacity and Jahn-Teller effect. The present findings indicate that the pyrolysis of in situ formed lithium stearate on Li2MnO3 particle surfaces is a simple and effective way to obtain Mn-based layered Li-rich composite cathode materials of Li-ion battery with good cyclic and rate performance.

  1. Li mobility in Nasicon-type materials LiM2(PO4)3, M = Ge, Ti, Sn, Zr and Hf, followed by 7Li NMR spectroscopy.

    PubMed

    Arbi, K; París, M A; Sanz, J

    2011-10-21

    Lithium mobility in LiM(2)(PO(4))(3) compounds, M = Ge and Sn, has been investigated by (7)Li Nuclear Magnetic Resonance (NMR) spectroscopy, and deduced information compared with that reported previously in Ti, Zr and Hf members of the series in the temperature range 100-500 K. From the analysis of (7)Li NMR quadrupole interactions (C(Q) and η parameters), spin-spin T(2)(-1) and spin-lattice T(1)(-1) relaxation rates, structural sites occupancy and mobility of lithium have been deduced. Below 250 K, Li ions are preferentially located at M(1) sites in rhombohedral phases, but occupy intermediate M(12) sites between M(1) and M(2) sites in triclinic ones. In high-temperature rhombohedral phases, a superionic state is achieved when residence times at M(1) and M(12) sites become similar and correlation effects on Li motion decrease. This state can be obtained by large order-disorder transformations in rhombohedral phases or by sharp first order transitions in triclinic ones. The presence of two relaxation mechanisms in T(1)(-1) plots of rhombohedral phases has been associated with departures of conductivity from the Arrhenius behavior. Long term mobility of lithium is discussed in terms of the cation vacancy distribution along conduction paths. PMID:21897945

  2. Rate-dependent, Li-ion insertion/deinsertion behavior of LiFePO4 cathodes in commercial 18650 LiFePO4 cells.

    PubMed

    Liu, Qi; He, Hao; Li, Zhe-Fei; Liu, Yadong; Ren, Yang; Lu, Wenquan; Lu, Jun; Stach, Eric A; Xie, Jian

    2014-03-12

    We have performed operando synchrotron high-energy X-ray diffraction (XRD) to obtain nonintrusive, real-time monitoring of the dynamic chemical and structural changes in commercial 18650 LiFePO4/C cells under realistic cycling conditions. The results indicate a nonequilibrium lithium insertion and extraction in the LiFePO4 cathode, with neither the LiFePO4 phase nor the FePO4 phase maintaining a static composition during lithium insertion/extraction. On the basis of our observations, we propose that the LiFePO4 cathode simultaneously experiences both a two-phase reaction mechanism and a dual-phase solid-solution reaction mechanism over the entire range of the flat voltage plateau, with this dual-phase solid-solution behavior being strongly dependent on charge/discharge rates. The proposed dual-phase solid-solution mechanism may explain the remarkable rate capability of LiFePO4 in commercial cells. PMID:24521163

  3. Emergence of Metallic Properties at LiFePO4 Surfaces and LiFePO4/Li2S Interfaces: An Ab Initio Study.

    PubMed

    Timoshevskii, Vladimir; Feng, Zimin; Bevan, Kirk H; Zaghib, Karim

    2015-08-26

    The atomic and electronic structures of the LiFePO4 (LFP) surface, both bare and reconstructed upon possible oxygenation, are theoretically studied by ab initio methods. On the basis of total energy calculations, the atomic structure of the oxygenated surface is proposed, and the effect of surface reconstruction on the electronic properties of the surface is clarified. While bare LFP(010) surface is insulating, adsorption of oxygen leads to the emergence of semimetallic behavior by inducing the conducting states in the band gap of the system. The physical origin of these conducting states is investigated. We further demonstrate that deposition of Li2S layers on top of oxygenated LFP(010) surface leads to the formation of additional conducting hole states in the first layer of Li2S surface because of the charge transfer from sulfur p-states to the gap states of LFP surface. This demonstrates that oxygenated LFP surface not only provides conducting layers itself, but also induces conducting channels in the top layer of Li2S. These results help to achieve further understanding of potential role of LFP particles in improving the performance of Li-S batteries through emergent interface conductivity. PMID:26237114

  4. Reprocessing of LiH in Molten Chlorides

    NASA Astrophysics Data System (ADS)

    Masset, Patrick J.; Gabriel, Armand; Poignet, Jean-Claude

    2008-06-01

    LiH was used as inactive material to stimulate the reprocessing of lithium tritiate in molten chlorides. The electrochemical properties (diffusion coefficients, apparent standard potentials) were measured by means of transient electrochemical techniques (cyclic voltammetry and chronopotentiometry). At 425 ºC the diffusion coefficient and the apparent standard potential were 2.5 · 10-5 cm2 s-1 and -1.8 V vs. Ag/AgCl, respectively. For the process design the LiH solubility was measured by means of DTA to optimize the LiH concentration in the molten phase. In addition electrolysis tests were carried out at 460 ºC with current densities up to 1 A cm-2 over 24 h. These results show that LiH may be reprocessed in molten chlorides consisting in the production of hydrogen gas at the anode and molten metallic lithium at the cathode.

  5. Electronic and transport properties of LiCoO2.

    PubMed

    Andriyevsky, Bohdan; Doll, Klaus; Jacob, Timo

    2014-11-14

    Using first principles density functional theory (DFT), the electronic and magnetic properties as well as the Li-ion migration in LiCoO2 have been studied with a gradient corrected functional. The magnetic properties were also investigated in addition using a gradient corrected functional in combination with an on-site repulsion U and a hybrid functional. We find LiCoO2 to be non-magnetic under ambient conditions. A magnetic ground state can be obtained by a volume expansion corresponding to a negative pressure of -8 GPa due to a competition between Hund's rules favoring magnetism on the Co(3+) ions and the crystal field splitting, which suppresses magnetism at zero pressure. The barrier for lithium transport is determined to be 0.44 eV from nudged elastic band (NEB) calculations on the Li0.917CoO2 system. PMID:25264622

  6. 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

  7. 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.

  8. 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.

  9. 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

  10. 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.

  11. 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).

  12. 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

  13. Oxygen selective membranes for li-air (o2) batteries.

    PubMed

    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

  14. Heteroclite electrochemical stability of an I based Li7P2S8I superionic conductor

    DOE PAGESBeta

    Rangasamy, Ezhiylmurugan; Liu, Zengcai; Gobet, Mallory; Pilar, Kartik; Sahu, Gayatri; Greenbaum, Steve; Liang, Chengdu

    2015-01-01

    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.

  15. An Iodide-Based Li 7 P 2 S 8 I Superionic Conductor

    DOE PAGESBeta

    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.

  16. 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

  17. 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

  18. Li/SO2 Cell for Galileo. [process control

    NASA Technical Reports Server (NTRS)

    Blagdon, L. J.; Marcoux, L.

    1981-01-01

    Some information on the special process controls for lithium sulfur dioxide (Li/SO2) batteries is presented with reference to how those controls affected the Galileo probe program and the instrument test vehicle program. The general considerations that go into any application for basically any type of battery system are discussed. Particular emphasis is given to some of the design tradeoffs which resulted because of the addition of the safety characteristics of the Li/SO2 system.

  19. 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.

  20. 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.

  1. The Reaction Kinetics of LiD with Water Vapor

    SciTech Connect

    Balooch, M; Dinh, L N; Calef, D F

    2003-04-01

    The interaction of LiD with water vapor in the partial pressure range of 10{sup -7} Torr to 20 Torr has been investigated. The reaction probability of water with pure LiD cleaved in an ultra high vacuum environment was obtained using the modulated molecular beam technique. This probability was 0.11 and independent of LiD surface temperature suggesting a negligible activation energy for the reaction in agreement with quantum chemical calculations. The value gradually reduced, however, to .007 as the surface concentration of oxygen containing product (LiOH), which was monitored in-situ by Auger electron spectroscopy on the reaction zone, approached full coverage. As the hydroxide film grew beyond a monolayer, the phase lag of hydrogen product increased from zero to 20 degrees and the reaction probability reduced further until it approached our detection limit ({approx} 10{sup -4}). This phase lag was attributed to a diffusion limited process in this regime. In separate experiments, the film growth has been studied in nitrogen atmosphere with 100% relative humidity using thermogravimetric analysis (TGA) and in air with 50% relative humidity utilizing scanning electron microscopy (SEM). For exposures to environment with high water concentrations and for micrometer thick films, the reaction probability reduced to 4 x 10{sup -7} and was independent of exposure time, The lattice diffusion through the film was no longer controlling the transport of water to the LiD/LiOH interface. Microcracks generated in the film to release stress provided easier pathways to the interface. A modified microscope, capable of both atomic force microscopy (AFM) and nanoindentation, was employed to investigate the surface morphology of LiOH.H{sub 2}O grown on LiOH at high water vapor partial pressures and the kinetics of this growth.

  2. 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.

  3. Double and triple photoionization of Li and Be

    NASA Astrophysics Data System (ADS)

    Colgan, J.; Pindzola, M. S.; Robicheaux, F.

    2005-08-01

    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.

  4. 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.

  5. 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

  6. Activity on a Li-rich giant: DI Psc revisited

    NASA Astrophysics Data System (ADS)

    Kriskovics, Levente; Kővári, Zsolt; Vida, Krisztián; Oláh, Katalin

    2014-08-01

    We present a new Doppler imaging study for the Li-rich single K-giant DI Psc. Surface temperature maps are reconstructed for two subsequent rotation cycles. From the time evolution of the spot distribution antisolar-type differential rotation pattern is revealed. We show marks of non-uniform Li-abundance as well. The possible connection between the current evolutionary phase of the star and its magnetic activity is briefly discussed.

  7. 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

  8. Localization of vacancies and mobility of lithium ions in Li2ZrO3 as obtained by 6,7Li NMR

    NASA Astrophysics Data System (ADS)

    Baklanova, Ya. V.; Arapova, I. Yu.; Buzlukov, A. L.; Gerashenko, A. P.; Verkhovskii, S. V.; Mikhalev, K. N.; Denisova, Т. А.; Shein, I. R.; Maksimova, L. G.

    2013-12-01

    The 6,7Li NMR spectra and the 7Li spin-lattice relaxation rate were measured on polycrystalline samples of Li2ZrO3, synthesized at 1050 K and 1300 K. The 7Li 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 Li2ZrO3. For both samples the line width of the central 7Li transition and the spin-lattice relaxation time decrease abruptly at the temperature increasing above ~500 K, whereas the EFG parameters are averaged (<νQ>=42 (5) kHz) owing to thermally activated diffusion of lithium ions.

  9. 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.

  10. 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.

  11. Modeling LiH Combustion in Solid Fuelled Scramjet Engine

    NASA Astrophysics Data System (ADS)

    Simone, Domenico; Bruno, Claudio

    Lithium Hydride is a hydrogen-rich compound with potential application as fuel, thanks to its high density and low molecular weight. It reacts exothermically with many substances and contains H2, suggesting its use where a much higher density (compared to that of LH2) would be beneficial. In this work LiH (solid at STP) has thus investigated as potential candidate for solid fuelled scramjets (SFSCRJ). Its thermochemical properties and issues associated to its combustion in a hot supersonic stream have been investigated; results show clearly that Li, released by thermal decomposition, plays a key role in the LiH performance. In fact, above the auto-ignition point liquid Li combustion with air increases local temperature and promotes LiH decomposition. To understand quantitatively these effects, a simplified physical model describing LiH “vaporization” and combustion was built and used in simulations of a notional SCRJ chamber by means of a CFD code. Results are intriguing: an intense and stable flame zone is predicted to be present over and downstream of the grain and high temperatures (of order 2900 K) are obtainable. Moreover, specific impulse and thrust density predicted at a flight Mach = 7 are also interesting, being 10,000 m/s and 200-300 m/s, respectively.

  12. 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

  13. 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

  14. 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.

  15. 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.

  16. Neutron scattering studies of the hydration structure of Li+.

    PubMed

    Mason, P E; Ansell, S; Neilson, G W; Rempe, S B

    2015-02-01

    New results derived from the experimental method of neutron diffraction and isotopic substitution (NDIS) are presented for the hydration structure of the lithium cation (Li(+)) in aqueous solutions of lithium chloride in heavy water (D2O) at concentrations of 6, 3, and 1 m and at 1.5 m lithium sulfate. By introducing new and more-accurate data reduction procedures than in our earlier studies (I. Howell and G. W. Neilson, J. Phys: Condens. Matter, 1996, 8, 4455-4463), we find, in the first hydration shell of Li(+), ∼4.3(2) water molecules at 6 m, 4.9(3) at 3 m, 4.8(3) at 1 m in the LiCl solutions, and 5.0(3) water molecules in the case of Li2SO4 solution. The general form of the first hydration shell is similar in all four solutions, with the correlations for Li-O and Li-D sited at 1.96 (0.02) Å and 2.58 (0.02) Å, respectively. The results resemble those presented in 1996, in terms of ion-water distances and local coordination, but the hydration number is significantly lower for the case at 1 m than the 6.5 (1.0) given at that time. Thus, experimental and theoretical results now agree that lithium is hydrated by a small number of water molecules (4-5) in the nearest coordination shell. PMID:25559086

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. Ab initio investigations on lithium-superhalogen (Li-X) complexes (X = LiF2, BeF3, BF4 and PF6): competition between s-block and p-block anions

    NASA Astrophysics Data System (ADS)

    Srivastava, Ambrish Kumar; Misra, Neeraj

    2015-04-01

    In this work, we investigate the formation of Li-X complexes by interaction of Li cation and superhalogen (X) anions belonging to s block (X = LiF2, BeF3) and p block (X = BF4, PF6). We discuss their structures and stabilities using the quantum chemical method at MP2/aug-cc-pVDZ level of theory. Considering polarisable continuum model, solvent effects are taken into account in a polar organic solvent, namely diethyl ether. Our findings establish that electronic and chemical properties of Li-LiF2 and Li-BeF3 closely resemble Li-BF4 and Li-PF6. However, Li-LiF2 may dissociate preferably into LiF salt; Li-BeF3 appears as a close analogue of Li-BF4, which is significantly stabilised by the solvent. Thus, the superhalogen anions possess electronic integrity irrespective of the nature of central atom.

  2. 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.

  3. Solid-state, rechargeable Li/LiFePO 4 polymer battery for electric vehicle application

    NASA Astrophysics Data System (ADS)

    Damen, L.; Hassoun, J.; Mastragostino, M.; Scrosati, B.

    A solid-state polymer lithium metal battery having a LiFePO 4/C composite cathode and a poly(ethylene oxide) PEO-based solid polymer electrolyte was assembled and characterized in terms of specific energy and power according to the protocol for electric vehicle (EV) application set by the USABC-DOE. The results of these tests show that this polymer battery surpasses the goals stated by USABC-DOE and, hence, may be suitable for application in the evolving EV market.

  4. Computed distributions of rotovibrational transitions in LiH (X^1SIGMA^+^) and LiH^+^ (X^2SIGMA^+^).

    NASA Astrophysics Data System (ADS)

    Gianturco, F. A.; Gori Giorgi, P.; Berriche, H.; Gadea, F. X.

    1996-06-01

    Accurate potential energy curves for the ground electronic states of LiH and LiH^+^ are employed to generate vibrational and rotational levels over a broad range of J values for both systems. The corresponding dipole functions are computed and used to obtain the frequency and intensity distributions of all relevant transitions between bound states for pure vibrational excitations, pure rotational excitations and for dipole allowed rovibrational processes. This extensive set of absorption data for both molecules is employed to locate the most likely region in the infrared spectrum where characteristic lines could be observed. Such data should be useful in experimental attempts to search for LiH and LiH^+^ lines at high redshifts. We found that transitions between ionic levels will be markedly less intense than those for the neutral system and that transitions between rotationally `hot' levels will be markedly more intense than those between low-J levels.

  5. The partially reversible formation of Li-metal particles on a solid Li electrolyte: applications toward nanobatteries

    NASA Astrophysics Data System (ADS)

    Arruda, Thomas M.; Kumar, Amit; Kalinin, Sergei V.; Jesse, Stephen

    2012-08-01

    The feasibility of large-scale implementation of Li-air batteries (LABs) hinges on understanding the thermodynamic and kinetic factors that control charge-discharge rates, efficiency and life times. Here, the kinetics of bias-induced reactions is explored locally on the surface of Li-ion conductive glass ceramics, a preferred electrolyte for LABs, using direct current-voltage and strain spectroscopies. Above a critical bias, particle growth kinetics were found to be linear in both the bias and time domains. Partial reversibility was observed for Li particles as evidenced by the presence of anodic peaks following the Li+ reduction, as well an associated reduction in particle height. The degree of reversibility was highest for the smallest particles formed. These observations thus suggest the possibility of producing nanobatteries with an active anode volume of the order of 0.1 al.

  6. Structural phase transition and Li-ion diffusion in Li7La3Zr2O12

    NASA Astrophysics Data System (ADS)

    Hoang, Khang; Bernstein, Noam; Johannes, Michelle

    2013-03-01

    Garnet-type Li7La3Zr2O12 (LLZO) is a promising candidate for solid electrolytes in Li-ion battery applications because of its high ionic conductivity and electrochemical and chemical stability. The material has a low-conductivity tetragonal phase and a high-conductivity cubic phase. It has been reported that the cubic phase can be stabilized at ambient conditions, usually with the incorporation of a certain amount of supervalent impurities. In this talk, we present results from density-functional theory and variable cell shape molecular dynamics simulations, and discuss the origin of structural phase transition, effects of extrinsic impurities, and diffusion of Li ions in LLZO. By identifying relevant mechanisms and critical concentrations of the impurities (Li vacancies) for achieving the high-conductivity phase, this work shows how controlled synthesis could be used to improve the material's electrolytic performance.

  7. 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.

  8. Giants reveal what dwarfs conceal: Li abundance in lower red giant branch stars as diagnostic of the primordial Li

    NASA Astrophysics Data System (ADS)

    Mucciarelli, A.; Salaris, M.; Bonifacio, P.

    2012-01-01

    The discrepancy between cosmological Li abundance inferred from Population II dwarf stars and that derived from big bang nucleosynthesis calculations is still far from being satisfactorily solved. We investigated, as an alternative route, the use of Li abundances in Population II lower red giant branch stars as empirical diagnostic of the cosmological Li. Both theory and observations suggest that the surface Li abundance in metal-poor red giants after the completion of the first dredge-up and before the red giant branch bump is significantly less sensitive to the efficiency of atomic diffusion, compared with dwarf stars. The surface Li abundances in these objects - after the dilution caused by the first dredge-up - are predicted to be sensitive to the total Li content left in the star, i.e. they are affected only by the total amount of Li eventually burned during the previous main-sequence phase. Standard stellar models computed under different physical assumptions show that the inclusion of the atomic diffusion has an impact of about 0.07 dex in the determination of the primordial Li abundance - much smaller than the case of metal-poor main-sequence turnoff stars - and it is basically unaffected by reasonable variations of other parameters (overshooting, age, initial He abundance and mixing length). We have determined from spectroscopy the surface Li content of 17 halo lower red giant branch stars, in the metallicity range between [Fe/H] ˜- 3.4 and ˜- 1.4 dex, evolving before the extramixing episode that sets in at the red giant branch bump. The initial Li (customarily taken as estimate of the cosmological Li abundance A(Li)0) has then been inferred by accounting for the difference between initial and post-dredge-up Li abundances in the appropriate stellar models. It depends mainly on the Teff scale adopted in the spectroscopic analysis, and is only weakly sensitive to the efficiency of atomic diffusion in the models, so long as one neglects Li destruction

  9. 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.

  10. The partially reversible formation of Li-metal particles on a solid Li electrolyte: applications toward nanobatteries

    SciTech Connect

    Arruda, Thomas M; Kumar, Amit; Kalinin, Sergei V; Jesse, Stephen

    2012-01-01

    The feasibility of large-scale implementation of Li-air batteries (LABs) hinges on understanding the thermodynamic and kinetic factors that control charge-discharge rates, efficiency and life times. Here, the kinetics of bias-induced reactions is explored locally on the surface of Li-ion conductive glass ceramics, a preferred electrolyte for LABs, using direct current-voltage and strain spectroscopies. Above a critical bias, particle growth kinetics were found to be linear in both the bias and time domains. Partial reversibility was observed for Li particles as evidenced by the presence of anodic peaks following the Li{sup +} reduction, as well an associated reduction in particle height. The degree of reversibility was highest for the smallest particles formed. These observations thus suggest the possibility of producing nanobatteries with an active anode volume of the order of 0.1 al.

  11. 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.

  12. Electrochemical Codeposition of Al-Li-Mg Alloys at Solid Aluminum Electrode from LiCl-KCl-MgCl2 Molten Salt System

    NASA Astrophysics Data System (ADS)

    Ye, Ke; Zhang, Mi Lin; Chen, Ye; Han, Wei; de Yan, Yong; Cao, Peng

    2010-06-01

    The electrochemical codeposition of Mg and Li at an aluminium electrode in LiCl-KCl (50:50 wt pct) melts containing different concentrations of MgCl2 at 893 K (620 °C) to form Al-Li-Mg alloys was investigated. Cyclic voltammograms showed that the potential of Li metal deposition at an Al electrode, before the addition of MgCl2, is more positive than that of Li metal deposition at an Mo electrode, which indicated the formation of an Al-Li alloy. The underpotential deposition of magnesium at an aluminium electrode leads to the formation of Al-Mg alloys, and the succeeding underpotential deposition of lithium on predeposited Al-Mg alloys leads to the formation of Al-Li-Mg alloys. Chronopotentiometric measurements indicated that the codeposition of Mg and Li occurs at current densities lower than -0.668 A cm-2 in LiCl-KCl-MgCl2 (8 wt pct) melts at an aluminium electrode. The chronoamperometric studies indicated that the onset potential for the codeposition of Mg and Li is -2.000 V, and the codeposition of Mg and Li at an aluminium electrode is formed into Al-Li-Mg alloys when the applied potentials are more negative than -2.000 V. X-ray diffraction and inductively coupled plasma analysis indicated that Al-Li-Mg alloys with different lithium and magnesium contents were prepared via potentiostatic and galvanostatic electrolysis. The microstructure of typical dual phases of the Al-Li-Mg alloy was characterized by an optical microscope and by scanning electron microscopy. The analysis of energy dispersive spectrometry showed that the elements of Al and Mg distribute homogeneously in the Al-Li-Mg alloy. The lithium and magnesium contents of Al-Li-Mg alloys can be controlled by MgCl2 concentrations and by electrolytic parameters.

  13. 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

  14. Efimov physics in {sup 6}Li atoms

    SciTech Connect

    Braaten, Eric; Hammer, H.-W.; Kang, Daekyoung; Platter, Lucas

    2010-01-15

    A new narrow three-atom loss resonance associated with an Efimov trimer crossing the three-atom threshold has recently been discovered in a many-body system of ultracold {sup 6}Li atoms in the three lowest hyperfine spin states at a magnetic field near 895 G. O'Hara and coworkers have used measurements of the three-body recombination rate in this region to determine the complex three-body parameter associated with Efimov physics. Using this parameter as the input, we calculate the universal predictions for the spectrum of Efimov states and for the three-body recombination rate in the universal region above 600 G where all three scattering lengths are large. We predict an atom-dimer loss resonance at 672+-2 G associated with an Efimov trimer disappearing through an atom-dimer threshold. We also predict an interference minimum in the three-body recombination rate at 759+-1 G where the three-spin mixture may be sufficiently stable to allow experimental study of the many-body system.

  15. Voltage equaliser for Li-Fe battery

    NASA Astrophysics Data System (ADS)

    Wu, Jinn-Chang; Jou, Hurng-Liahng; Chuang, Ping-Hao

    2013-10-01

    In this article, a voltage equaliser is proposed for a battery string with four Li-Fe batteries. The proposed voltage equaliser is developed from a flyback converter, which comprises a transformer, a power electronic switch and a resonant clamped circuit. The transformer contains a primary winding and four secondary windings with the same number of turns connected to each battery. The resonant clamped circuit is for recycling the energy of leakage inductance of the transformer and for performing zero-voltage switching (ZVS) of the power electronic switch. When the power electronic switch is switched on, the energy is stored in the transformer; and when the power electronic switch is switched off, the energy stored in the transformer will automatically charge the battery whose voltage is the lowest. In this way, the voltage of individual batteries in the battery string is balanced. The salient features of the proposed voltage equaliser are that only one switch is used, the energy stored in the leakage inductance of the transformer can be recycled and ZVS is obtained. A prototype is developed and tested to verify the performance of the proposed voltage equaliser. The experimental results show that the proposed voltage equaliser achieves the expected performance.

  16. 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.

  17. 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

  18. Diffusion control of an ion by another in LiNbO3 and LiTaO3 crystals

    PubMed Central

    Zhang, De-Long; Zhang, Qun; Qiu, Cong-Xian; Wong, Wing-Han; Yu, Dao-Yin; Yue-Bun Pun, Edwin

    2015-01-01

    Diffusion-doping is an effective, practical method to improve material properties and widen material application. Here, we demonstrate a new physical phenomenon: diffusion control of an ion by another in LiNbO3 and LiTaO3 crystals. We exemplify Ti4+/Xn+ (Xn+ = Sc3+, Zr4+, Er3+) co-diffusion in the widely studied LiNbO3 and LiTaO3 crystals. Some Ti4+/Xn+-co-doped LiNbO3 and LiTaO3 plates were prepared by co-diffusion of stacked Ti-metal and Er-metal (Sc2O3 or ZrO2) films coated onto LiNbO3 or LiTaO3 substrates. The Ti4+/Xn+-co-diffusion characteristics were studied by secondary ion mass spectrometry. In the Xn+-only diffusion case, the Xn+ diffuses considerably slower than the Ti4+. In the Ti4+/Xn+ co-diffusion case, the faster Ti4+ controls the diffusion of the slower Xn+. The Xn+ diffusivity increases linearly with the initial Ti-metal thickness and the increase depends on the Xn+ species. The phenomenon is ascribed to the generation of additional defects induced by the diffusion of faster Ti4+ ions, which favors and assists the subsequent diffusion of slower Xn+ ion. For the diffusion system studied here, it can be utilized to substantially shorten device fabrication period, improve device performance and produce new materials. PMID:25941037

  19. Lithium dimer formation in the Li-conducting garnets Li(5+x)Ba(x)La(3-x)Ta2O12 (0 < x < or =1.6).

    PubMed

    O'Callaghan, Michael P; Cussen, Edmund J

    2007-05-28

    The garnet system Li(5+x)Ba(x)La(3-x)Ta2O12 shows an unprecedented Li+ content (x < or = 1.6) and short Li-Li distances of ca 2.44 A between majority occupied sites suggesting that the high Li+ mobility requires a complex cooperative mechanism. PMID:17713074

  20. Structures of [Li(glyme)](+) complexes and their interactions with anions in equimolar mixtures of glymes and Li[TFSA]: analysis by molecular dynamics simulations.

    PubMed

    Tsuzuki, Seiji; Shinoda, Wataru; Matsugami, Masaru; Umebayashi, Yasuhiro; Ueno, Kazuhide; Mandai, Toshihiko; Seki, Shiro; Dokko, Kaoru; Watanabe, Masayoshi

    2015-01-01

    Molecular dynamics simulations of equimolar mixtures of glymes (triglyme and tetraglyme) and Li[TFSA] (lithium bis(trifluoromethylsulfonyl)amide) show that the glyme chain length affects the coordination geometries of Li(+), which induces the changes in interactions between the [Li(glyme)](+) complex and [TFSA](-) anions and diffusion of ions in the equimolar mixtures. PMID:25407234

  1. Li-Rich Li-Si Alloy As A Lithium-Containing Negative Electrode Material Towards High Energy Lithium-Ion Batteries

    NASA Astrophysics Data System (ADS)

    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.

  2. Li-rich Li-Si alloy as a lithium-containing negative electrode material towards high energy lithium-ion batteries.

    PubMed

    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

  3. Structural and Electrochemical Characterization of Pure LiFePO 4 and Nanocomposite C- LiFePO 4 Cathodes for Lithium Ion Rechargeable Batteries

    DOE PAGESBeta

    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

  4. 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.

  5. 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

  6. Vacancy-driven anisotropic defect distribution in the battery-cathode material LiFePO4.

    PubMed

    Lee, Jaekwang; Zhou, Wu; Idrobo, Juan C; Pennycook, Stephen J; Pantelides, Sokrates T

    2011-08-19

    Li-ion mobility in LiFePO(4), a key property for energy applications, is impeded by Fe antisite defects (Fe(Li)) that form in select b-axis channels. Here we combine first-principles calculations, statistical mechanics, and scanning transmission electron microscopy to identify the origin of the effect: Li vacancies (V(Li)) are confined in one-dimensional b-axis channels, shuttling between neighboring Fe(Li). Segregation in select channels results in shorter Fe(Li)-Fe(Li) spans, whereby the energy is lowered by the V(Li)'s spending more time bound to end-point Fe(Li)'s. V(Li)-Fe(Li)-V(Li) complexes also form, accounting for observed electron energy loss spectroscopy features. PMID:21929178

  7. Vacancy-driven anisotropic defect distribution in the battery-cathode material LiFePO4

    SciTech Connect

    Lee, Jaekwang; Zhou, Wu; Idrobo Tapia, Juan C; Pennycook, Stephen J; Pantelides, Sokrates T.; Biegalski, Michael D

    2011-01-01

    Li-ion mobility in LiFePO{sub 4}, a key property for energy applications, is impeded by Fe antisite defects (Fe{sub Li}) that form in select b-axis channels. Here we combine first-principles calculations, statistical mechanics, and scanning transmission electron microscopy to identify the origin of the effect: Li vacancies (V{sub Li}) are confined in one-dimensional b-axis channels, shuttling between neighboring Fe{sub Li}. Segregation in select channels results in shorter Fe{sub Li}-Fe{sub Li} spans, whereby the energy is lowered by the V{sub Li}'s spending more time bound to end-point Fe{sub Li}'s. V{sub Li}-Fe{sub Li}-V{sub Li} complexes also form, accounting for observed electron energy loss spectroscopy features.

  8. Giant magnetic anisotropy and quantum tunneling of the magnetization in Li2(Li1-xFex)N

    NASA Astrophysics Data System (ADS)

    Jesche, Anton; McCallum, R. William; Thimmaiah, Srinivasa; Jacobs, Jenee L.; Taufour, Valentin; Kreyssig, Andreas; Houk, Robert S.; Bud'Ko, Sergey L.; Canfield, Paul C.

    2014-03-01

    The magnetic anisotropy of 3 d transition metals is usually considered to be weak, mainly due to the widely known paradigm of orbital quenching. However, a rare interplay of crystal electric field effects and spin-orbit coupling causes a large orbital contribution to the magnetic moment of iron in Li2(Li1-xFex)N. This leads, not only to large magnetic moments of ~ 5 μB per iron atom but, also, to an enormous magnetic anisotropy field that extrapolates to more than 200 Tesla. Magnetic hysteresis emerges for T <= 50 K and the coercivity fields of more than 11 Tesla exceed even the hardest 4 f electron based ferromagnets. Li2(Li1-xFex)N not only has a clear and remarkable anisotropy, generally not associated with iron moments, but also shows time-dependence more consistent with molecular magnets. In particular for low iron concentrations x << 1 the spin-inversion is dominated by a macroscopic tunneling process rather than by thermal excitations. It is shown that the huge magnetic anisotropy makes Li2(Li1-xFex)N (i) an ideal model system to study macroscopic quantum effects at elevated temperatures and (ii) a basis for novel magnetic functional materials. This work is supported by the US DOE, Basic Energy Sciences under Contract No. DE-AC02-07CH11358.

  9. 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.

  10. Microwave surface impedance measurements of LiFeAs and LiFe(As,P) single crystals

    NASA Astrophysics Data System (ADS)

    Imai, Y.; Takahashi, H.; Okada, T.; Maeda, A.; Kitagawa, K.; Matsubayashi, K.; Takigawa, M.; Uwatoko, Y.; Nakai, N.; Nagai, Y.; Machida, M.

    2011-03-01

    We report results of microwave surface impedance measurements in LiFeAs and LiFe(As,P) single crystals [1]. These crystals were grown by self-flux method. The surface impedances of crystals were measured by a cavity perturbation technique. The in-plane penetration depth calculated from the surface reactance shows an exponential temperature dependence at low temperatures in both of LiFeAs and LiFe(As,P). This indicates that these materials do not have any nodes in the superconducting gap. The temperature dependence of the superfluid density indicates that LiFeAs and LiFe(As,P) are multi-gap superconductors with at least two isotropic gaps. In addition, the real part of complex conductivity exhibits an enhancement below Tc , which is different from the so-called coherence peak. This is due to the rapid increase of the relaxation time of the quasiparticle below Tc . We believe that this enhancement is rather common to all superconductors where an inelastic scattering is dominant above Tc , irrespective of the strength of the electron correlation. [ 1 ] Y. Imai et al . , J. Phys. Soc. Jpn, in - press .(arXiv: 1009.4628.)

  11. 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.

  12. Structural and dynamic characterization of Li(12)Si(7) and Li(12)Ge(7) using solid state NMR.

    PubMed

    Dupke, Sven; Langer, Thorsten; Pöttgen, Rainer; Winter, Martin; Eckert, Hellmut

    2012-04-01

    Local environments and lithium ion dynamics in the binary lithium silicide Li(12)Si(7), and the analogous germanium compound have been characterized by detailed (6)Li, (7)Li, and (29)Si variable temperature static and magic-angle spinning (MAS) NMR experiments. In the MAS-NMR spectra, individual lithium sites are generally well-resolved at temperatures below 200K, whereas at higher temperatures partial site averaging is observed on the kHz timescale. The observed lithium chemical shift ranges of up to 60 ppm indicate a significant amount of electronic charge stored on the lithium species, consistent with the expectation of the extended Zintl-Klemm-Bussmann concept used for the theoretical description of lithium silicides. Furthermore the strongly diamagnetic chemical shifts observed for the lithium ions situated directly above the five-membered Si(5) rings suggest the possibility of aromatic ring currents in these structural elements. This assignment is confirmed further by (29)Si{(7)Li} CPMAS-heteronuclear correlation experiments. The (29)Si MAS-NMR spectra of Li(12)Si(7), aided by 2-D J-resolved spectroscopy, are well suited for differentiating between the individual sites within the silicon framework, while further detailed connectivity information is available on the basis of 2-D INADEQUATE and radio frequency driven recoupling (RFDR) spectra. Variable temperature static (7)Li NMR spectra reveal the onset of strong motional narrowing effects, illustrating high lithium ionic mobilities in both of these compounds. PMID:21996453

  13. Theoretical investigation of electron transfer and detachment processes in low energy H- + Li and Li- + H collisions

    NASA Astrophysics Data System (ADS)

    Wu, Y.; Lin, X. H.; Yan, B.; Wang, J. G.; Janev, R. K.

    2016-02-01

    The charge exchange and collisional detachment processes in H- + Li and Li- + H collisions have been studied by using the quantal molecular orbital close-coupling (QMOCC) method in the energy ranges of about 0.12-1000 eV u-1 and 0.1 meV-1000 eV, respectively, and the inelastic collision cross sections and rate coefficients have been computed and presented. It is found that the electron transfer process in the H- + Li and Li- + H collisions is due to the Demkov coupling between the 12Σ+ and 22Σ+ states at internuclear distances of about 15a0. The collisional electron detachment in the considered collision system is due to the excitation of the remaining six states, which are all unstable against autodetachment. These states are populated through a series of Landau-Zener couplings of the 22Σ+ state with upper 2Σ+ states and by the rotational 2Σ+-2Π couplings at small internuclear distances. The cross sections for electron transfer in H- + Li and Li- + H collisions in the energy range of 10-1000 eV u-1 attain values in the range of 10-16-10-15 cm2 (reaching their maximum values of about 5 × 10-15 cm2 at 500-600 eV u-1), while the values of the corresponding electron detachment cross sections in this energy range attain generally smaller values.

  14. 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

  15. Systematics of the breakup probability function for 6Li and 7Li projectiles

    NASA Astrophysics Data System (ADS)

    Capurro, O. A.; Pacheco, A. J.; Arazi, A.; Carnelli, P. F. F.; Fernández Niello, J. O.; Martinez Heimann, D.

    2016-01-01

    Experimental non-capture breakup cross sections can be used to determine the probability of projectile and ejectile fragmentation in nuclear reactions involving weakly bound nuclei. Recently, the probability of both type of dissociations has been analyzed in nuclear reactions involving 9Be projectiles onto various heavy targets at sub-barrier energies. In the present work we extend this kind of systematic analysis to the case of 6Li and 7Li projectiles with the purpose of investigating general features of projectile-like breakup probabilities for reactions induced by stable weakly bound nuclei. For that purpose we have obtained the probabilities of projectile and ejectile breakup for a large number of systems, starting from a compilation of the corresponding reported non-capture breakup cross sections. We parametrize the results in accordance with the previous studies for the case of beryllium projectiles, and we discuss their systematic behavior as a function of the projectile, the target mass and the reaction Q-value.

  16. 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.

  17. Effect of Acupuncture Manipulations at LI4 or LI11 on Blood Flow and Skin Temperature.

    PubMed

    Li, Weihui; Ahn, Andrew

    2016-06-01

    Acupuncture induces physiological changes, and patients have reported warm or cool sensations with "Burning Fire" (BF) or "Penetrating Cool" (PC) manipulations. This study aimed to evaluate whether these techniques had distinct effects on skin temperature and blood flow and to examine whether skin temperature correlated with blood flow. The participants were 25 healthy volunteers, each receiving acupuncture manipulations on points LI4 and LI11 bilaterally. Skin temperatures and blood flow were recorded continuously on both arms. The study found that acupuncture significantly increased skin temperature on the needling arm by 0.3514°C on average, but decreased it on the contralateral arm by 0.2201°C on average. Blood flow decreased significantly in both arms during needling (-3.4% and -5.97% for the ipsilateral and the contralateral sides, respectively), but the changes in skin temperature did not correlate with the changes in blood flow. Furthermore, these changes were not significantly different between acupuncture techniques and acupuncture points. In conclusion, acupuncture changes local skin temperature and blood flow independent of the manipulation technique. Moreover, blood flow may not be affected by the increased temperature on the needling arm. These results help to verify traditional Chinese medicine concepts and may help in establishing standards for acupuncture treatments. PMID:27342886

  18. LiDAR Vegetation Investigation and Signature Analysis System (LVISA)

    NASA Astrophysics Data System (ADS)

    Höfle, Bernhard; Koenig, Kristina; Griesbaum, Luisa; Kiefer, Andreas; Hämmerle, Martin; Eitel, Jan; Koma, Zsófia

    2015-04-01

    Our physical environment undergoes constant changes in space and time with strongly varying triggers, frequencies, and magnitudes. Monitoring these environmental changes is crucial to improve our scientific understanding of complex human-environmental interactions and helps us to respond to environmental change by adaptation or mitigation. The three-dimensional (3D) description of the Earth surface features and the detailed monitoring of surface processes using 3D spatial data have gained increasing attention within the last decades, such as in climate change research (e.g., glacier retreat), carbon sequestration (e.g., forest biomass monitoring), precision agriculture and natural hazard management. In all those areas, 3D data have helped to improve our process understanding by allowing quantifying the structural properties of earth surface features and their changes over time. This advancement has been fostered by technological developments and increased availability of 3D sensing systems. In particular, LiDAR (light detection and ranging) technology, also referred to as laser scanning, has made significant progress and has evolved into an operational tool in environmental research and geosciences. The main result of LiDAR measurements is a highly spatially resolved 3D point cloud. Each point within the LiDAR point cloud has a XYZ coordinate associated with it and often additional information such as the strength of the returned backscatter. The point cloud provided by LiDAR contains rich geospatial, structural, and potentially biochemical information about the surveyed objects. To deal with the inherently unorganized datasets and the large data volume (frequently millions of XYZ coordinates) of LiDAR datasets, a multitude of algorithms for automatic 3D object detection (e.g., of single trees) and physical surface description (e.g., biomass) have been developed. However, so far the exchange of datasets and approaches (i.e., extraction algorithms) among LiDAR users

  19. Li abundances in F stars: planets, rotation, and Galactic evolution

    NASA Astrophysics Data System (ADS)

    Delgado Mena, E.; Bertrán de Lis, S.; Adibekyan, V. Zh.; Sousa, S. G.; Figueira, P.; Mortier, A.; González Hernández, J. I.; Tsantaki, M.; Israelian, G.; Santos, N. C.

    2015-04-01

    Aims: We aim, on the one hand, to study the possible differences of Li abundances between planet hosts and stars without detected planets at effective temperatures hotter than the Sun, and on the other hand, to explore the Li dip and the evolution of Li at high metallicities. Methods: We present lithium abundances for 353 main sequence stars with and without planets in the Teff range 5900-7200 K. We observed 265 stars of our sample with HARPS spectrograph during different planets search programs. We observed the remaining targets with a variety of high-resolution spectrographs. The abundances are derived by a standard local thermodynamic equilibrium analysis using spectral synthesis with the code MOOG and a grid of Kurucz ATLAS9 atmospheres. Results: We find that hot jupiter host stars within the Teff range 5900-6300 K show lower Li abundances, by 0.14 dex, than stars without detected planets. This offset has a significance at the level 7σ, pointing to a stronger effect of planet formation on Li abundances when the planets are more massive and migrate close to the star. However, we also find that the average vsini of (a fraction of) stars with hot jupiters is higher on average than for single stars in the same Teff region, suggesting that rotational-induced mixing (and not the presence of planets) might be the cause for a greater depletion of Li. We confirm that the mass-metallicity dependence of the Li dip is extended towards [Fe/H] ~ 0.4 dex (beginning at [Fe/H] ~-0.4 dex for our stars) and that probably reflects the mass-metallicity correlation of stars of the same Teff on the main sequence. We find that for the youngest stars (<1.5 Gyr) around the Li dip, the depletion of Li increases with vsini values, as proposed by rotationally-induced depletion models. This suggests that the Li dip consists of fast rotators at young ages whereas the most Li-depleted old stars show lower rotation rates (probably caused by the spin-down during their long lifes). We have also

  20. 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

  1. The reaction of clean Li surfaces with small molecules in ultrahigh vacuum. 2: Water

    SciTech Connect

    Zhuang, G.; Ross, P.N. Jr.; Kong, F.P.; McLarnon, F. |

    1998-01-01

    Reactions at the Li/H{sub 2}O interface were studied at 160 to 290 K in ultrahigh vacuum by a combination of spectroscopic ellipsometry and Auger electron spectroscopy. Ice multilayers, ca. 100 ML thick, were deposited on clean Li at 160 K. The evaporation rate of water at 160 K is sufficiently slow that the ice layer remains on the surface for about 1 h. After 10 min at 160 k, a pure LiOH layer ca. 70 {angstrom} thick is produced, and after 1 h there is evidence of a slow conversion to LiOH to Li{sub 2}O in the layer, probably at the Li/LiOH interface. Raising the temperature to 240 K results in desorption of the adsorbed water and conversion of all the LiOH to a porous (60% void) layer composed mostly of Li{sub 2}O (35%) with some metallic Li mixed in. Raising the temperature further to 290 K results in densification of the layer by both collapse of the voids and by diffusion of Li into the interstices of the Li{sub 2}O, increasing the Li content to 27% and shrinking the film thickness to 26 {angstrom}. Based on these results, a model for the behavior of small amounts of water in Li battery electrolyte is presented.

  2. 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.

  3. 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.

  4. Lithium chromium pyrophosphate as an insertion material for Li-ion batteries.

    PubMed

    Reichardt, Martin; Sallard, Sébastien; Novák, Petr; Villevieille, Claire

    2015-12-01

    Lithium chromium pyrophosphate (LiCrP2O7) and carbon-coated LiCrP2O7 (LiCrP2O7/C) were synthesized by solid-state and sol-gel routes, respectively. The materials were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and conductivity measurements. LiCrP2O7 powder has a conductivity of ~ 10(-8) S cm(-1), ~ 10(4) times smaller than LiCrP2O7/C (~ 10(-4) S cm(-1)). LiCrP2O7/C is electrochemically active, mainly between 1.8 and 2.2 V versus Li(+)/Li (Cr(3+)/Cr(2+) redox couple), whereas LiCrP2O7 has limited electrochemical activity. LiCrP2O7/C delivers a reversible specific charge up to ~ 105 mAh g(-1) after 100 cycles, close to the theoretical limit of 115 mAh g(-1). Operando XRD experiments show slight peak shifts between 2.2 and 4.8 V versus Li(+)/Li, and a reversible amorphization between 1.8 and 2.2 V versus Li(+)/Li, suggesting an insertion reaction mechanism. PMID:26634722

  5. 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.

  6. LI-cadherin: a marker of gastric metaplasia and neoplasia

    PubMed Central

    Grotzinger, C; Kneifel, J; Patschan, D; Schnoy, N; Anagnostopoulos, I; Faiss, S; Tauber, R; Wiedenmann, B; Gessner, R

    2001-01-01

    BACKGROUND—Intestinal metaplasia is considered a risk factor for the development of gastric adenocarcinomas of the intestinal type and is found in approximately 20% of gastric biopsies. Conventional histology only detects advanced stages of intestinal metaplasia.
AIMS—To study expression of the enterocyte specific adhesion molecule liver-intestinal (LI)-cadherin in intestinal metaplasia as well as in gastric cancer, and to evaluate its use as a diagnostic marker molecule.
PATIENTS—Gastric biopsies (n=77) from 30 consecutive patients (n=30; aged 28-90 years) as well as surgically resected tissue samples (n=24) of all types of gastric carcinomas were analysed.
METHODS—Single and double label immunofluorescence detection on cryosections of gastric biopsies; alkaline phosphatase antialkaline phosphatase method on paraffin embedded carcinoma tissue sections.
RESULTS—Of 77 biopsies (from 30 patients), 12 (from 10 patients) stained positive for LI-cadherin. LI-cadherin staining correlated with the presence of intestinal metaplasia. Conventional histological diagnosis however failed to detect subtle gastric intestinal metaplasia (three of 10 patients). In contrast, only LI-cadherin and villin were positive in these cases whereas sucrase-isomaltase also failed to detect intestinal metaplasia in four of 10 patients. Well differentiated gastric carcinomas showed intense staining for LI-cadherin while undifferentiated carcinomas showed only weak diffuse cytoplasmic staining.
CONCLUSIONS—To detect early metaplastic changes in the gastric mucosa, LI-cadherin has a sensitivity superior to sucrase-isomaltase and conventional histology and comparable with that of villin. Its specificity exceeds that of villin. Thus LI-cadherin represents a new, reliable, and powerful marker molecule for early detection of gastric intestinal metaplasia and well differentiated adenocarcinomas.


Keywords: stomach; intestinal metaplasia; cadherins; carcinogenesis

  7. 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.

  8. Li-Ion Batteries from LiFePO4 Cathode and Anatase/Graphene Composite Anode for Stationary Energy Storage

    SciTech Connect

    Choi, Daiwon; Wang, Donghai; Viswanathan, Vilayanur V.; Bae, In-Tae; Wang, Wei; Nie, Zimin; Zhang, Jiguang; Graff, Gordon L.; Liu, Jun; Yang, Zhenguo; Duong, Tien Q.

    2009-11-06

    Li-ion batteries based on LiFePO4 cathode and anatase TiO2/graphene anode were investigated for possible stationary energy storage application. Fine-structured LiFePO4 was synthesized by novel molten surfactant approach. Anatase TiO2/graphene nanocomposite was prepared via self assembly method. The full cell that operated at flat 1.6V demonstrated negligible fade after more than 700 cycles. The LiFePO4/TiO2 combination Li-ion battery is inexpensive, environmentally benign, safe and stable. Therefore, it can be practically applied as stationary energy storage for renewable power sources.

  9. {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.

  10. 10Li low-lying resonances populated by one-neutron transfer

    NASA Astrophysics Data System (ADS)

    Cavallaro, M.; De Napoli, M.; Cappuzzello, F.; Agodi, C.; Bondı, M.; Carbone, D.; Cunsolo, A.; Davids, B.; Davinson, T.; Foti, A.; Galinski, N.; Kanungo, R.; Lenske, H.; Orrigo, S. E. A.; Ruiz, C.; Sanetullaev, A.

    2015-10-01

    The 9Li + 2H → 10Li + 1H one-neutron transfer reaction has been performed at 100 MeV incident energy at TRIUMF using a 9Li 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 9Li produced by the 10Li breakup at forward angles and the recoil protons emitted at backward angles. The 10Li low-lying resonances, whose energies, widths and configurations are still unclear, have been populated with significant statistics.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Wet Channel Network Extraction based on LiDAR Data

    NASA Astrophysics Data System (ADS)

    Hooshyar, M.; Kim, S.; Wang, D.; Medeiros, S. C.

    2015-12-01

    The temporal dynamics of stream network is vitally important for understanding hydrologic processes including groundwater interactions and hydrograph recessions. However, observations are limited on flowing channel heads, which are usually located in headwater catchments and under canopy. Near infrared LiDAR data provides an opportunity to map the flowing channel network owing to the fine spatial resolution, canopy penetration, and strong absorption of the light energy by the water surface. A systematic method is developed herein to map flowing channel networks based on the signal intensity of ground LiDAR return, which is lower on water surfaces than on dry surfaces. Based on the selected sample sites where the wetness conditions are known, the signal intensities of ground returns are extracted from the LiDAR point data. The frequency distributions of wet surface and dry surface returns are constructed. With the aid of LiDAR-based ground elevation, the signal intensity thresholds are identified for mapping flowing channels. The developed method is applied to Lake Tahoe area based on eight LiDAR snapshots during recession periods in five watersheds. A power-law relationship between streamflow and flowing channel length during the recession period is derived based on the result.

  16. Degradation reactions in SONY-type Li-ion batteries

    SciTech Connect

    Roth, E.P.; Nagasubramanian, G.

    2000-07-01

    Thermal instabilities were identified in SONY-type lithium-ion cells and correlated with interactions of cell constituents and reaction products. Three temperature regions of interaction were identified and associated with the state of charge (degree of Li intercalation) of the cell. Anodes were shown to undergo exothermic reactions as low as 100 C involving the solid electrolyte interface (SEI) layer and the LiPF{sub 6} salt in the electrolyte (EC:PC:DEC/LiPF{sub 6}). These reactions could account for the thermal runaway observed in these cells beginning at 100 C. Exothermic reactions were also observed in the 200 C--300 C region between the intercalated lithium anodes, the LiPF{sub 6} salt, and the PVDF. These reactions were followed by a high-temperature reaction region, 300 C--400 C, also involving the PVDF binder and the intercalated lithium anodes. The solvent was not directly involved in these reactions but served as a moderator and transport medium. Cathode exothermic reactions with the PVDF binder were observed above 200 C and increased with the state of charge (decreasing Li content). This offers an explanation for the observed lower thermal runaway temperatures for charged cells.

  17. Degradation Reactions in SONY-Type Li-Ion Batteries

    SciTech Connect

    Nagasubramanian, G.; Roth, E. Peter

    1999-05-04

    Thermal instabilities were identified in SONY-type lithium-ion cells and correlated with interactions of cell constituents and reaction products. Three temperature regions of interaction were identified and associated with the state of charge (degree of Li intercalation) of the cell. Anodes were shown to undergo exothermic reactions as low as 100°C involving the solid electrolyte interface (SEI) layer and the LiPF6 salt in the electrolyte (EC: PC: DEC/LiPF6). These reactions could account for the thermal runaway observed in these cells beginning at 100°C. Exothermic reactions were also observed in the 200°C-300°C region between the intercalated lithium anodes, the LiPF6 salt and the PVDF. These reactions were followed by a high- temperature reaction region, 300°C-400°C, also involving the PVDF binder and the intercalated lithium anodes. The solvent was not directly involved in these reactions but served as a moderator and transport medhun. Cathode exotherrnic reactions with the PVDF binder were observed above 200oC and increased with the state of charge (decreasing Li content). This offers an explanation for the observed lower thermal runaway temperatures for charged cells.

  18. Biomass Estimation for Individual Trees using Waveform LiDAR

    NASA Astrophysics Data System (ADS)

    Wang, K.; Kumar, P.; Dutta, D.

    2015-12-01

    Vegetation biomass information is important for many ecological models that include terrestrial vegetation in their simulations. Biomass has strong influences on carbon, water, and nutrient cycles. Traditionally biomass estimation requires intensive, and often destructive, field measurements. However, with advances in technology, airborne LiDAR has become a convenient tool for acquiring such information on a large scale. In this study, we use infrared full waveform LiDAR to estimate biomass information for individual trees in the Sangamon River basin in Illinois, USA. During this process, we also develop automated geolocation calibration algorithms for raw waveform LiDAR data. In the summer of 2014, discrete and waveform LiDAR data were collected over the Sangamon River basin. Field measurements commonly used in biomass equations such as diameter at breast height and total tree height were also taken for four sites across the basin. Using discrete LiDAR data, individual trees are delineated. For each tree, a voxelization methods is applied to all waveforms associated with the tree to result in a pseudo-waveform. By relating biomass extrapolated using field measurements from a training set of trees to waveform metrics for each corresponding tree, we are able to estimate biomass on an individual tree basis. The results can be especially useful as current models increase in resolution.

  19. Enhanced electrochemical properties of LiFePO4 (LFP) cathode using the carboxymethyl cellulose lithium (CMC-Li) as novel binder in lithium-ion battery.

    PubMed

    Qiu, Lei; Shao, Ziqiang; Wang, Daxiong; Wang, Wenjun; Wang, Feijun; Wang, Jianquan

    2014-10-13

    Novel water-based binder CMC-Li is synthesized using cotton as raw material. The mechanism of the CMC-Li as a binder is reported. Electrochemical properties of batteries cathodes based on commercially available lithium iron phosphate (LiFePO4, LFP) and CMC-Li as a water-soluble binder are investigated. CMC-Li is a novel lithium-ion binder. Compare with conventional poly(vinylidene fluoride) (PVDF) binder, and the battery with CMC-Li as the binder retained 97.8% of initial reversible capacity after 200 cycles at 176 mAh g(-1), which is beyond the theoretical specific capacity of LFP. Constant current charge-discharge test results demonstrate that the LFP electrode using CMC-Li as the binder has the highest rate capability, follow closely by that using PVDF binder. The batteries have good electrochemical property, outstanding pollution-free and excellent stability. PMID:25037391

  20. Ultrahigh energy density Li-ion batteries based on cathodes of 1D metals with -Li-N-B-N- repeating units in α-Li(x)BN₂ (1 ⩽ x ⩽ 3).

    PubMed

    Németh, Károly

    2014-08-01

    Ultrahigh energy density batteries based on α-Li(x)BN2 (1 ⩽ x ⩽ 3) positive electrode materials are predicted using density functional theory calculations. The utilization of the reversible LiBN2 + 2 Li(+) + 2 e(-) ⇌ Li3BN2 electrochemical cell reaction leads to a voltage of 3.62 V (vs Li/Li(+)), theoretical energy densities of 3251 Wh/kg and 5927 Wh/l, with capacities of 899 mAh/g and 1638 mAh/cm(3), while the cell volume of α-Li3BN2 shrinks only 2.8% per two-electron transfer on charge. These values are far superior to the best existing or theoretically designed intercalation or conversion-based positive electrode materials. For comparison, the theoretical energy density of a Li-O2/peroxide battery is 3450 Wh/kg (including the weight of O2), that of a Li-S battery is 2600 Wh/kg, that of Li3Cr(BO3)(PO4) (one of the best designer intercalation materials) is 1700 Wh/kg, while already commercialized LiCoO2 allows for 568 Wh/kg. α-Li3BN2 is also known as a good Li-ion conductor with experimentally observed 3 mS/cm ionic conductivity and 78 kJ/mol (≈0.8 eV) activation energy of conduction. The attractive features of α-Li(x)BN2 (1 ⩽ x ⩽ 3) are based on a crystal lattice of 1D conjugated polymers with -Li-N-B-N- repeating units. When some of the Li is deintercalated from α-Li3BN2 the crystal becomes a metallic electron conductor, based on the underlying 1D conjugated π electron system. Thus, α-Li(x)BN2 (1 ⩽ x ⩽ 3) represents a new type of 1D conjugated polymers with significant potential for energy storage and other applications. PMID:25106604

  1. Defects, stress and abnormal shift of the (0 0 2) diffraction peak for Li-doped ZnO films

    NASA Astrophysics Data System (ADS)

    Lin, Yow-Jon; Wang, Mu-Shan; Liu, Chia-Jyi; Huang, Hsueh-Jung

    2010-10-01

    The effect of changes in Li content on the structural property of sol-gel Li-doped ZnO films was investigated in this study. The observed changes of the Li incorporation-induced strain along c-axis are closely related to the different ratios between the concentrations of Li interstitials (Li i) and Li substituting for Zn (Li Zn) in the films. According to the observed results from X-ray diffraction (XRD) and photoluminescence measurements, we found that the domination of the dissociative mechanism in the Li-doped ZnO films led to transformation from Li Zn to Li i, involving the formation of Zn vacancies (V Zn). In addition, the interaction between these defects (that is, Li Zn, Li i, V Zn and oxygen vacancy) and the crystal structure may lead to the abnormal shift of the (0 0 2) diffraction peak position determined from XRD measurements.

  2. Li2.97Mg0.03VO4: High rate capability and cyclability performances anode material for rechargeable Li-ion batteries

    NASA Astrophysics Data System (ADS)

    Dong, Youzhong; Zhao, Yanming; Duan, He; Singh, Preetam; Kuang, Quan; Peng, Hongjian

    2016-07-01

    Mg-doped composite, Li2.97Mg0.03VO4, with an orthorhombic structure was prepared by a sol-gel method. The effects of the Mg doping on the structure and electrochemical performance of Li3VO4 were investigated. The X-ray diffraction pattern shows that the Mg doping does not change the crystal structure of Li3VO4. The EDS mappings indicated the fairly uniform distribution of Mg throughout the grains of Li2.97Mg0.03VO4. Electronic conductivity of Mg-doped Li3VO4 increased by two orders of magnitude compared to that of pure Li3VO4. CV and EIS measurement confirms that the Li2.97Mg0.03VO4 sample exhibits a smaller polarization and transfer resistance and a higher lithium diffusion coefficient compared with the pure Li3VO4. Due to the better electrochemical kinetics properties, Mg-doped Li3VO4 showed a significant improved performance compared to the pure Li3VO4, especially for the high rate capability. At the higher discharge/charge rate (2C), the discharge and charge capacities of 415.5 and 406.1 mAh/g have been obtained for the Li2.97Mg0.03VO4 which is more than three times higher the discharge/charge capacities of Li3VO4. The discharge and charge capacities of pure Li3VO4 are only 126.4 and 125.8 mAh/g respectively. The excellent electrochemical performance of Li2.97Mg0.03VO4 enables it as a promising anode material for rechargeable lithium-ion batteries.

  3. Nature of Li2O2 oxidation in a Li-O2 battery revealed by operando X-ray diffraction.

    PubMed

    Ganapathy, Swapna; Adams, Brian D; Stenou, Georgiana; Anastasaki, Maria S; Goubitz, Kees; Miao, Xue-Fei; Nazar, Linda F; Wagemaker, Marnix

    2014-11-19

    Fundamental research into the Li-O2 battery system has gone into high gear, gaining momentum because of its very high theoretical specific energy. Much progress has been made toward understanding the discharge mechanism, but the mechanism of the oxygen evolution reaction (OER) on charge (i.e., oxidation) remains less understood. Here, using operando X-ray diffraction, we show that oxidation of electrochemically generated Li2O2 occurs in two stages, but in one step for bulk crystalline (commercial) Li2O2, revealing a fundamental difference in the OER process depending on the nature of the peroxide. For electrochemically generated Li2O2, oxidation proceeds first through a noncrystalline lithium peroxide component, followed at higher potential by the crystalline peroxide via a Li deficient solid solution (Li(2-x)O2) phase. Anisotropic broadening of the X-ray Li2O2 reflections confirms a platelet crystallite shape. On the basis of the evolution of the broadening during charge, we speculate that the toroid particles are deconstructed one platelet at a time, starting with the smallest sizes that expose more peroxide surface. In the case of in situ charged bulk crystalline Li2O2, the Li vacancies preferentially form on the interlayer position (Li1), which is supported by first-principle calculations and consistent with their lower energy compared to those located next to oxygen (Li2). The small actively oxidizing fraction results in a gradual reduction of the Li2O2 crystallites. The fundamental insight gained in the OER charge mechanism and its relation to the nature of the Li2O2 particles is essential for the design of future electrodes with lower overpotentials, one of the key challenges for high performance Li-air batteries. PMID:25341076

  4. Electronic structure, stability and bonding of the Li-N-H hydrogen storage system

    NASA Astrophysics Data System (ADS)

    Song, Y.; Guo, Z. X.

    2006-11-01

    The Li-N-H system holds great promise for on-board hydrogen storage applications, particularly due to reversible interactions among lithium amide (LiNH2) , imide (Li2NH) , and hydride (LiH). However, practical applications of the system are hindered by the relatively high stabilities of the compounds and uncertainty of their reaction paths. Understanding the mechanism of hydrogen interactions with the host structures is essential for further development. Here, we calculated the electronic structures and total energies of lithium hydride (LiH), lithium imide (Li2NH) , and lithium amide (LiNH2) using a first-principles full potential approach. The estimated formation enthalpies for the two-step reactions, Li3N+2H2↔Li2NH+LiH+H2↔LiNH2+2LiH are -162.05 and -40.94kJ/mol , comparable to the experimental values of -165 and -45.5kJ/mol , respectively. The bonding interaction characteristics and the stability of these materials were further analyzed from the electronic structures. It is noted that the N atom bonds unequally with the two H atoms in lithium amide. As a result, the amide LiNH2 can dissociate in two almost equivalent transient steps: Li++(NH2)- ; and (LiNH)-+H+ . The reaction of the relevant species may evolve NH3 as a transient gas in the (LiNH2+LiH) system.

  5. Automated Probabilistic LiDAR Swath Registration

    NASA Astrophysics Data System (ADS)

    Jalobeanu, A.; Gonçalves, G. R.

    2014-12-01

    We recently developed a new point cloud registration algorithm. Compared to Iterated Closest Point (ICP) techniques, it is robust to noise and outliers, and easier to use, as it is less sensitive to initial conditions. It minimizes the entropy of the joint point cloud (including intensity attributes to help register areas with poor relief), uses a voxel space and B-Spline interpolation to accelerate computation. A natural application of registration is swath alignment in airborne light detection and ranging (LiDAR). Indeed, due to uncertainty in the inertial navigation system (INS), attitude angles are subject to time-dependent errors. Such errors can be understood as a sum of three terms: 1) a global term, or boresight error, which can be addressed using several existing techniques; 2) a low-frequency term, which is modeled as a constant attitude error for regions several hundred meters along-track; 3) a high-frequency term, responsible for corduroy artifacts (not addressed here). We propose to use the new registration algorithm to correct the low-frequency attitude variations. Relative geometric errors are significantly reduced, as pairs of swaths are registered onto each other local corrections. Absolute geometric errors are reduced during a second step, by applying all the corrections together to the entire dataset. We used a test area of 200 km2 in Portugal, with a density of 3-4 pts/m2. The point clouds were derived from waveform data, and include predictive range uncertainties estimated within a Bayesian framework. The data collection was supported by FCT and FEDER as part of the AutoProbaDTM research project (2009-2012). Modeling and reducing geometric error helps build consistent uncertainty maps. After correction, residual errors are taken into account in the final 3D error budget. For gridded elevation models a vertical uncertainty map is computed. Finally, it is possible to use the inter-swath registration parameters to estimate the distribution of

  6. Tritex, a forced convection loop with Pb-17Li

    NASA Astrophysics Data System (ADS)

    Feuerstein, H.; Gräbner, H.; Kieser, G.

    1988-07-01

    The loop TRITEX is a pumped loop with circulating Pb-17Li. It is designed to study the behaviour of tritium in a liquid metal blanket. Tritium will be simulated by deuterium. Start of operation is scheduled for the end of 1987. In a number of experiments some other problems were studied. Evaporation tests showed very low evaporation rates even in vacuum. The loss of Li in case of air ingress into the system will be very important. If this happens during loop operation, 25% of Li can be lost to the oxides within one hour, while only 0.3% of Pb oxidizes. Permeation rates of deuterium through steel 1.4922 were determined. Permeation losses of deuterium will be small, and the dissolution of this gas in the structural materials will not influence the experiments.

  7. Experimental Progress in a 6Li-133Cs Atomic Mixture

    NASA Astrophysics Data System (ADS)

    Feng, Lei; Johansen, Jacob; Parker, Colin; Chin, Cheng

    2015-05-01

    We report experimental progress in a mixture of 6Li and 133Cs. The mass imbalance of this system results in a particular challenge, as gravity has a significant influence on Cs position, but not on Li, separating the two gases at temperatures on the order of 200 nK. We overcome this difficulty using a two color optical dipole trap. We demonstrate mixing of these species below 100 nK in preparation for studies of quantum degenerate mixtures of this system. We further report on progress toward degeneracy and many-body physics measurements in this trap. Finally, we consider Efimov physics in this system, studying the effects of Cs-Cs interaction on the spectrum of LiCsCs trimers by a comparison of Feshbach resonances at 843 and 889 G. This work is supported by NSF and Chicago MRSEC.

  8. Mechanical properties of alloy Mg-Li rod in tension

    NASA Astrophysics Data System (ADS)

    Zhang, Xueyi; Zou, Guangping; Cao, Yang; Yue, Baocheng

    2009-12-01

    Light-weight metal or alloy was widespread in aerospace and aeronautical engineering. Alloy Li-Mg was the lightest metal structural materials. Focus was recently on this alloy. Static mechanical properties were important for materials before they were applied into practical use. Static Testing of a new alloy Li-Mg was accomplished in this paper by universal materials testing system Model INSTRON 5500R. Stress-strain curve was acquired. And ultimate stress, yield stress, elongation in percentage and reduce of area in percentage were measured in detail. The result showed that alloy had higher strength to 250MPa in tension. But the deformation was hardly changed in length or section before it cracked. All the experimental result proved that this material was typical brittle materials. Fractography had been observed by scanning electron microscope (SEM). SEM Photos were also verified alloy Li-Mg was ductile material.

  9. Mechanical properties of alloy Mg-Li rod in tension

    NASA Astrophysics Data System (ADS)

    Zhang, Xueyi; Zou, Guangping; Cao, Yang; Yue, Baocheng

    2010-03-01

    Light-weight metal or alloy was widespread in aerospace and aeronautical engineering. Alloy Li-Mg was the lightest metal structural materials. Focus was recently on this alloy. Static mechanical properties were important for materials before they were applied into practical use. Static Testing of a new alloy Li-Mg was accomplished in this paper by universal materials testing system Model INSTRON 5500R. Stress-strain curve was acquired. And ultimate stress, yield stress, elongation in percentage and reduce of area in percentage were measured in detail. The result showed that alloy had higher strength to 250MPa in tension. But the deformation was hardly changed in length or section before it cracked. All the experimental result proved that this material was typical brittle materials. Fractography had been observed by scanning electron microscope (SEM). SEM Photos were also verified alloy Li-Mg was ductile material.

  10. Screening Li-Ion Batteries for Internal Shorts

    NASA Technical Reports Server (NTRS)

    Darcy, Eric

    2006-01-01

    The extremely high cost of aerospace battery failures due to internal shorts makes it essential that their occurrence be very rare, if not eliminated altogether. With Li-ion cells/batteries, the potentially catastrophic safety hazard that some internal shorts present adds additional incentive for prevention. Prevention can be achieved by design, manufacturing measures, and testing. Specifically for NASA s spacesuit application, a Li-ion polymer pouch cell battery design is in its final stages of production. One of the 20 flight batteries fabricated and tested developed a cell internal short, which did not present a safety hazard, but has required revisiting the entire manufacturing and testing process. Herein are the details of the failure investigation that followed to get to root cause of the internal short and the corrective actions that will be taken. The resulting lessons learned are applicable to most Li-ion battery applications.

  11. Polymer electrolyte-based Li ion batteries for space power

    NASA Astrophysics Data System (ADS)

    Abraham, K. M.; Choe, H. S.; Pasquariello, D. M.

    1997-01-01

    Polyacrylonitrile-based electrolytes have been identified to be appropriate for the fabrication of solid-state Li ion batteries. Prototype battery cells have been fabricated with spinel LiMn2O4 cathode and either a graphite or a petroleum coke anode. Lower capacity fade and longer cycle life were observed in the petroleum coke-based cells. A specific energy of >120 Wh/kg and a cycle life of >500 cycles at the C/3 rate have been demonstrated in these cells. The capacity fade rate in coke/LiMn2O4 cells has been found to be between 0.04 and 0.05% per cycle, about half of that in cells with the graphite anode.

  12. Review on Current State of Li-ion Batteries

    SciTech Connect

    Mukaibo, Hitomi

    2010-06-04

    This is 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.

  13. Characterization of silicate based cathodes for Li Ion Batteries

    NASA Astrophysics Data System (ADS)

    Kumar, Ajay; Nazri, Gholam-Abbas; Nazri, Maryam; Nail, Vaman; Vaishnava, Prem; Naik, Ratna; Energy Group Collaboration; Energy Group Collaboration; Energy Group Collaboration

    2013-03-01

    The silicate compounds Li2MSiO4, where M = Mn, Fe, Co and Ni have gained interest as electrode materials for Lithium ion batteries due to their high theoretical capacity (>330mAh/g), high thermal stability due to strong Si-O covalent bonds, environmental friendliness, and low cost. However, these materials intrinsically have low electrical conductivity. To improve conductivity of these classes of electrode materials, we synthesized Li2MnSiO4 and Li2FeSiO4 by solid state reaction in an argon atmosphere. The lithium transition metal silicates were compounded with graphene nano-sheets and the composites were used as positive electrode in a coin cell configuration.. The materials structure-composition, morphology, conductivity and electrochemical performance were characterized by XRD, XPS, SEM, TEM and electrochemical techniques.The detail structure-composition analysis and electrochemical performance of the silicate electrodes will be reported.

  14. Target structure independent 7Li elastic scattering at lowmomentum transfers

    SciTech Connect

    Momotyuk, O.A.; Keeley, N.; Kemper, K.W.; Roeder, B.T.; Crisp,A.M.; Cluff, W.; Schmidt, B.G.; Wiedeking, M.; Marechal, F.; Rusek, K.; Mezhevych, S.Yu.; Liendo, J.

    2006-07-20

    Analyzing powers and cross sections for the elastic scattering of polarized 7Li by targets of 6Li, 7Li and 12C are shown to depend only on the properties of the projectile for momentum transfers of less than 1.0 fm-1. The result of a detailed analysis of the experimental data within the framework of the coupled channels model with ground state reorientation and transitions to the excited states of the projectile and targets included in the coupling schemes are presented. This work suggests that nuclear properties of weakly-bound nuclei can be tested by elastic scattering experiments, independent of the target used, if data are acquired for momentum transfers less than {approx}1.0 fm-1.

  15. Electrolytes for Li-Ion Cells in Low Temperature Applications

    NASA Technical Reports Server (NTRS)

    Smart, M. C.; Ratnakumar, B. V.; Surampudi, S.

    2000-01-01

    Prototype AA-size lithium-ion cells have been demonstrated to operate effectively at temperatures as low as -30 to -40 C. These improvements in low temperature cell performance have been realized by the incorporation of ethylene carbonate-based electrolytes which possess low melting, low viscosity cosolvents, such as methyl acetate, ethyl acetate, gamma-butyrolactone, and ethyl methyl carbonate. The cells containing a 0.75M LiPF6 EC+DEC+DMC+EMC (1:1:1:1) electrolyte displayed the best performance at -30 C (> 90% of the room temperature capacity at approximately C/15 rate), whereas, at -40 C the cells with the 0.75M LiPF6 EC+DEC+DMC+MA (1:1:1:1) and 0.75M LiPF6 EC+DEC+DMC+EA (1:1:1:1) electrolytes showed superior performance.

  16. Thin Film Li Ion Microbatteries for NASA Applications

    NASA Technical Reports Server (NTRS)

    West, W. C.; Ratnakumar, B. V.; Brandon, E.; Blosiu, J. O.; Surampudi, S.

    1999-01-01

    Rechargeable thin film microbatteries have recently become the topic of widespread research for use in low power applications such as battery-backed CMOS memory, miniaturized implantable medical devices and smart cards. In particular, the Center for Integrated Space Microsystems (CISM) at NASA's Jet Propulsion Laboratory has interest in applying this technology for secondary power systems in miniaturized satellites, microsensors, microactuators and other remote MEMS applications. The general requirements of the microbatteries for these applications are high specific energy, wide range of temperature stability. low self-discharge rate, and flexibility of cell design. The thin film Li ion materials system using LiCoO2(LiPO(x)N(1-x))SnO is expected to fulfill these requirements.

  17. Impedance characteristics of nanoparticle-LiCoO2+PVDF

    NASA Astrophysics Data System (ADS)

    Panjaitan, Elman; Kartini, Evvy; Honggowiranto, Wagiyo

    2016-02-01

    The impendance of np-LiCoO2+xPVDF, as a cathode material candidate for lithium-ion battery (LIB), has been characterized using impedance spectroscopy for x = 0, 5, 10, 15 and 20 volume percentage (%v/v) and for frequencies in the 42 Hz to 5 MHz range. Both real and imaginary components of the impedance were found to be frequency dependent, and both tend to increase for increasing PVDF (polyvinyilidene fluoride) concentration, except that for 10% PVDF both real and imaginary components of impedance are smaller than for 5%. The mechanism for relaxation time for each addition of PVDF was analyzed using Cole-Cole plots. The analysis showed that the relaxation times of the nanostructured LiCoO2 with PVDF additive is relatively constant. Further, PVDF addition increases the bulk resistance and decreases the bulk capacitance of the nanostructured LiCoO2.

  18. Application of LiDAR's multiple attributes for wetland classification

    NASA Astrophysics Data System (ADS)

    Ding, Qiong; Ji, Shengyue; Chen, Wu

    2016-03-01

    Wetlands have received intensive interdisciplinary attention as a unique ecosystem and valuable resources. As a new technology, the airborne LiDAR system has been applied in wetland research these years. However, most of the studies used only one or two LiDAR observations to extract either terrain or vegetation in wetlands. This research aims at integrating LiDAR's multiple attributes (DSM, DTM, off-ground features, Slop map, multiple pulse returns, and normalized intensity) to improve mapping and classification of wetlands based on a multi-level object-oriented classification method. By using this method, we are able to classify the Yellow River Delta wetland into eight classes with overall classification accuracy of 92.5%

  19. UCN detection with 6Li-doped glass scintillators

    NASA Astrophysics Data System (ADS)

    Ban, G.; Bodek, K.; Lefort, T.; Naviliat-Cuncic, O.; Pierre, E.; Plonka, C.; Rogel, G.

    2009-12-01

    We report the results of test measurements aimed at determining the performance of 6Li-doped glass scintillators for ultra-cold neutron detection. Investigations have mainly focused on the reduction of the gamma-ray sensitivity of the scintillators. The probability of gamma interaction has been considerably lowered using very thin glasses. For signals corresponding to full-energy deposition, a background count rate of 8×10 -3 s -1 was obtained for a shielded 0.5 cm 3 GS10 scintillator located near the PF2 turbine at ILL. The neutron-gamma separation has further been improved using a stack with an 6Li-depleted scintillator and an 6Li-enriched one. Neutron captures leading to partial energy deposition (so-called "edge events") have strongly been reduced resulting in a clear separation between the neutron and the gamma contributions.

  20. The high-pressure semiconducting phase of LiBC

    NASA Astrophysics Data System (ADS)

    Zhang, Meiguang

    2016-04-01

    A high-pressure hexagonal semiconducting phase (space group P63mc , 2f.u./cell) of LiBC stable above 108 GPa was predicted through first-principles calculations combined with unbiased swarm structure searching techniques. This new phase consisted of three-dimensional B-C networks which originate from the dramatic out-of-plane distortions of the graphene-like B-C sublattice in the low-pressure P63/mmc phase under compression. Contrary to the metallizations of LiBC under high pressure previously proposed, the resulting three-dimensional B-C framework lacks the system of π bonds with mobile electrons and has more localized electrons, as a result of the semiconducting nature of this high-pressure LiBC phase.