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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. 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

  3. 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.

  4. 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.

  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. 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.

  10. 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.

  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. 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.

  5. 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

  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. 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.

  9. (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.

  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. 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.

  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. 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

  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. 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.

  3. 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

  4. 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

  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. 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.

  11. 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.

  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. 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.

  16. 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.

  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. 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 .

  5. 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.

  6. 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.

  7. 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.

  8. [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

  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. 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.

  11. 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.

  12. 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).

  13. 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.

  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. 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

  2. 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.

  3. 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

  4. 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

  5. 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.

  6. 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.

  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. 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

  9. 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.

  10. 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.

  11. 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

  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. 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.

  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. 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.

  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. 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.

  15. 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.

  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. 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

  19. 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.

  20. 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

  1. 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

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

    NASA Astrophysics Data System (ADS)

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

    2015-07-01

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

  3. 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. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  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. 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.

  16. 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

  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. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  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. 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.

  13. 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

  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. 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.

  16. 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.

  17. 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.

  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. 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.

  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. 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.

  3. 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.

  4. 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

  5. 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

  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. 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

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. 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.

  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. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  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. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 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.

  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. 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

  6. 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

  7. 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.

  8. 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.

  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. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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.