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Results for “Lithium borates”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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11 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1985

The preparation and characterization of a lithium borate glass prepared by the gel technique

The preparation of an amorphous lithium borate gel by the metal organic procedure is described. In addition, a preliminary evaluation of the behavior of the gel upon heating is given. In particular the crystallization tendency of the gel is studied with the aid of DTA and X-ray diffraction, and the structural changes in the gel are monitored with the aid of IR spectroscopy. The glass produced from the lithium borate gel is compared to both the gel precursor material and a glass of similar composition prepared by conventional techniques. Specifically, the relevant water contents, crystallization behavior, and structural features are contrasted.

Weinberg, M. C.↗
NASA NTRS1988

Crystal nucleation in lithium borate glass

Crystal nucleation measurements were made on three lithium borate compositions in the vicinity of Li2O-2Br2O3. All nucleation measurements were performed at 500 C. Certain aspects of the nucleation behavior indicated (tentatively) that it proceeded by a homogeneous mechanism. The steady state nucleation rate was observed to have the largest value when the Li2O concentration was slightly in excess of the diborate composition. The change in nucleation rate with composition is controlled by the variation of viscosity as well as the change in free energy with composition. The variation of nucleation rate is explained qualitatively in these terms.

Smith, Gary L.↗
NASA NTRS1992

Crystallization of lithium borate glasses

The glass-forming ability and crystallization behavior of lithium borate compositions, in the diborate-to-metaborate-range, were studied. In particular, the nature and sequence of formation of crystalline phases and the tendency toward devitrification were investigated as functions of temperature, thermal history and batch composition. It was found that the sequence of crystalline phase formation was sensitive to all of the three latter factors, and it was observed that under certain conditions metastable defect structures of the metaborate can appear.

Goktas, A. A.↗
NASA NTRS2011

The Evaluation of Triphenyl Phosphate as a Flame Retardant Additive to Improve the Safety of Lithium-Ion Battery Electrolytes

With the intent of improving the safety characteristics of lithium ion cells, electrolytes containing flame retardant additives have been investigated. A number of triphenyl phosphate-containing electrolytes were evaluated in both coin cells and experimental three electrode lithium-ion cells (containing reference electrodes). A number of chemistries were investigated, including MCMB carbon/LiNi(0.8)Co(0.2)O2 (NCO), graphite/LiNi(0.8)Co(0.15)Al(0.05)O2 (NCA), Li/Li(Li(0.17)Ni(0.25)Mn(0.58))O2, Li/LiNiMnCoO2 (NMC) and graphite/LiNiMnCoO2 (NMC), to study the effect that different electrolyte compositions have upon performance. A wide range of TPP-containing electrolytes were demonstrated to have good compatibility with the C/NCO, C/NCA, and Li/NMC systems, however, poor performance was initially observed with the high voltage C/NMC system. This necessitated the development of improved electrolytes with stabilizing additives, leading to formulations containing lithium bis(oxalato)borate (LiBOB) that displayed substantially improved performance.

rechargable batteries↗
NASA NTRS2012

Electrolytes with Improved Safety Developed for High Specific Energy Li-Ion Cells with Si-Based Anodes

A number of electrolyte formulations that have improved safety characteristics have been developed for use with high capacity silicon-based anodes. To improve the compatibility with Si-based anodes, a number of technical approaches have been employed, including: (1) the use of mono-fluoroethylene carbonate (FEC) in conjunction with, or in lieu of, ethylene carbonate (EC), (2) the use of high proportions of fluorinated co-solvents, (3) the use of vinylene carbonate (VC) to stabilize the Si/C electrode, and (4) the use of lithium bis(oxalato)borate (LiBOB) to improve the compatibility of the electrolyte when Si/C electrodes are used in conjunction with high voltage cathodes. Candidate electrolytes were studied in Li/Si-C and Si-C/ Li(MnNiCo)O2 (NMC) coin cells, as well as in larger Si-C/NMC three-electrode cells equipped with lithium reference electrodes. In summary, many electrolytes that contain triphenyl phosphate (TPP), which is used as a flame retardant additive up to concentrations of 15 volume percent, and possess FEC as a co-solvent have been demonstrated to outperform the all-carbonate baseline electrolytes when evaluated in Si-C/ Li(MnNiCo)O2 cells.

Silicon-Based Anode↗
NASA NTRS2011

Use of Additives to Improve Performance of Methyl Butyrate-Based Lithium-Ion Electrolytes

This work addresses the need for robust rechargeable batteries that can operate well over a wide temperature range. To this end, a number of electrolyte formulations have been developed that incorporate the use of electrolyte additives to improve the high-temperature resilience, low-temperature power capability, and life characteristics of methyl butyrate-based electrolyte solutions. These electrolyte additives include mono-fluoroethylene carbonate (FEC), lithium oxalate, vinylene carbonate (VC), and lithium bis(oxalato)borate (LiBOB), which have been shown to result in improved high-temperature resilience of all carbonate-based electrolytes. Improved performance has been demonstrated of Li-ion cells with methyl butyrate-based electrolytes, including 1.20M LiPF6 in EC+EMC+MB (20:20:60 v/v %); 1.20M LiPF6 in EC+EMC+MB (20:20:60 v/v %) + 2% FEC; 1.20M LiPF6 in EC+EMC+MB (20:20:60 v/v %) + 4% FEC; 1.20M LiPF6 in EC+EMC+MB (20:20:60 v/v %) + lithium oxalate; 1.20M LiPF6 in EC+EMC+MB (20:20:60 v/v %) + 2% VC; and 1.20M LiPF6 in EC+EMC+MB (20:20:60 v/v %) + 0.10M LiBOB. These electrolytes have been shown to improve performance in MCMB-LiNiCoO2 and graphite-LiNi1/3Co1/3Mn1/3O2 experimental Li-ion cells. A number of LiPF6-based mixed carbonate electrolyte formulations have been developed that contain ester co-solvents, which have been optimized for operation at low temperature, while still providing reasonable performance at high temperature. For example, a number of ester co-solvents were investigated, including methyl propionate (MP), ethyl propionate (EP), methyl butyrate (MB), ethyl butyrate (EB), propyl butyrate (PB), and butyl butyrate (BB) in multi-component electrolytes of the following composition: 1.0M LiPF6 in ethylene carbonate (EC) + ethyl methyl carbonate (EMC) + X (20:60:20 v/v %) [where X = ester co-solvent]. ["Optimized Car bon ate and Ester-Based Li-Ion Electrolytes", NASA Tech Briefs, Vol. 32, No. 4 (April 2008), p. 56.] Focusing upon improved rate capability at low temperatures (i.e., 20 to 40 C), this approach was optimized further, resulting in the development of 1.20M LiPF6 in EC+EMC+MP (20:20:60 v/v %) and 1.20M LiPF6 in EC+EMC+EB (20:20:60 v/v %), which were demonstrated to operate well over a wide temperature range in MCMB-LiNiCoAlO2 and Li4Ti5O12(-)LiNiCoAlO2 prototype cells.

Smart, Marshall C.↗
NASA NTRS2013

Improved Wide Operating Temperature Range of Li-Ion Cells

Future NASA missions aimed at exploring the Moon, Mars, and the outer planets require rechargeable batteries that can operate over a wide temperature range (-60 to +60 C) to satisfy the requirements of various applications including landers, rovers, penetrators, CEV, CLV, etc. This work addresses the need for robust rechargeable batteries that can operate well over a wide temperature range. The Department of Energy (DoE) has identified a number of technical barriers associated with the development of Liion rechargeable batteries for PHEVs. For this reason, DoE has interest in the development of advanced electrolytes that will improve performance over a wide range of temperatures, and lead to long life characteristics (5,000 cycles over a 10-year life span). There is also interest in improving the high-voltage stability of these candidate electrolyte systems to enable the operation of up to 5 V with high specific energy cathode materials. Currently, the state-of-the-art lithium-ion system has been demonstrated to operate over a wide range of temperatures (-40 to +40 C); however, the rate capability at the lower temperatures is very poor. In addition, the low-temperature performance typically deteriorates rapidly upon being exposed to high temperatures. A number of electrolyte formulations were developed that incorporate the use of electrolyte additives to improve the high-temperature resilience, low-temperature power capability, and life characteristics of methyl propionate (MP)-based electrolyte solutions. These electrolyte additives include mono-fluoroethylene carbonate (FEC), lithium oxalate, vinylene carbonate (VC), and lithium bis(oxalate borate) (LiBOB), which have previously been shown to result in improved high-temperature resilience of all carbonate-based electrolytes. These MP-based electrolytes with additives have been shown to have improved performance in experiments with MCMB-LiNiCoAlO2 cells.

Smart, Marshall C.↗
NASA NTRS2012

Wide Operating Temperature Range Electrolytes for High Voltage and High Specific Energy Li-Ion Cells

A number of electrolyte formulations that have been designed to operate over a wide temperature range have been investigated in conjunction with layered-layered metal oxide cathode materials developed at Argonne. In this study, we have evaluated a number of electrolytes in Li-ion cells consisting of Conoco Phillips A12 graphite anodes and Toda HE5050 Li(1.2)Ni(0.15)Co(0.10)Mn(0.55)O2 cathodes. The electrolytes studied consisted of LiPF6 in carbonate-based electrolytes that contain ester co-solvents with various solid electrolyte interphase (SEI) promoting additives, many of which have been demonstrated to perform well in 4V systems. More specifically, we have investigated the performance of a number of methyl butyrate (MB) containing electrolytes (i.e., LiPF6 in ethylene carbonate (EC) + ethyl methyl carbonate (EMC) + MB (20:20:60 v/v %) that contain various additives, including vinylene carbonate, lithium oxalate, and lithium bis(oxalato)borate (LiBOB). When these systems were evaluated at various rates at low temperatures, the methyl butyrate-based electrolytes resulted in improved rate capability compared to cells with all carbonate-based formulations. It was also ascertained that the slow cathode kinetics govern the generally poor rate capability at low temperature in contrast to traditionally used LiNi(0.80)Co(0.15)Al(0.05)O2-based systems, rather than being influenced strongly by the electrolyte type.

Li-ion Battery↗
NASA NTRS2018

Electrolytes for Low Impedance, Wide Operating Temperature Range Lithium-Ion Battery Module

A lithium ion battery cell includes a housing, a cathode disposed within the housing, wherein the cathode comprises a cathode active material, an anode disposed within the housing, wherein the anode comprises an anode active material, and an electrolyte disposed within the housing and in contact with the cathode and anode. The electrolyte consists essentially of a solvent mixture, a lithium salt in a concentration ranging from approximately 1.0 molar (M) to approximately 1.6 M, and an additive mixture. The solvent mixture includes a cyclic carbonate, an non-cyclic carbonate, and a linear ester. The additive mixture consists essentially of lithium difluoro(oxalato)borate (LiDFOB) in an amount ranging from approximately 0.5 weight percent to approximately 2.0 weight percent based on the weight of the electrolyte, and vinylene carbonate (VC) in an amount ranging from approximately 0.5 weight percent to approximately 2.0 weight percent based on the weight of the electrolyte.

Hallac, Boutros↗
NASA NTRS2000

A Compact Ti:Sapphire Laser With its Third Harmonic Generation (THG) for an Airborne Ozone Differential Absorption Lidar (DIAL) Transmitter

A compact and high-pulse-energy Ti:Sapphire laser with its Third Harmonic Generation (THG) has been developed for an airborne ozone differential absorption lidar (DIAL) to study the distributions and concentrations of the ozone throughout the troposphere. The Ti:Sapphire laser, pumped by a frequency-doubled Nd:YAG laser and seeded by a single mode diode laser, is operated either at 867 nm or at 900 nm with a pulse repetition frequency of 20 Hz. High energy laser pulses (more than 110 mJ/pulse) at 867 nm or 900 nm with a desired beam quality have been achieved and utilized to generate its third harmonic at 289nm or 300nm, which are on-line and off-line wavelengths of an airborne ozone DIAL. After being experimentally compared with Beta-Barium Borate (beta - BaB2O4 or BBO) nonlinear crystals, two Lithium Triborate (LBO) crystals (5 x 5 x 20 cu mm) are selected for the Third Harmonic Generation (THG). In this paper, we report the Ti:Sapphire laser at 900 nm and its third harmonic at 300 nm. The desired high ultraviolet (UV) output pulse energy is more than 30 mJ at 300 nm and the energy conversion efficiency from 900 nm to 300 nm is 30%.

Chen, Songsheng↗
NASA NTRS2006

Anion-Intercalating Cathodes for High-Energy-Density Cells

A report discusses physicochemical issues affecting a fluoride-intercalating cathode that operates in conjunction with a lithium ion-intercalating anode in a rechargeable electrochemical cell described in a cited prior report. The instant report also discusses corresponding innovations made in solvent and electrolyte compositions since the prior report. The advantages of this cell, relative to other lithium-ion-based cells, are said to be greater potential (5 V vs. 4 V), and greater theoretical cathode specific capacity (0.9 to 2.2 A-h/g vs. about 0.18 A-h/g). The discussion addresses a need for the solvent to be unreactive toward the lithium anode and to resist anodic oxidation at potentials greater than about 4.5 V vs. lithium; the pertinent innovation is the selection of propylene carbonate (PC) as a solvent having significantly more stability, relative to other solvents that have been tried. The discussion also addresses the need for an electrolyte additive, denoted an anion receptor, to complex the fluoride ion; the pertinent innovation is the selection of tris(hexafluoroisopropyl) borate as a superior alternative to the prior anion receptor, which was tris(pentafluorophenyl) borate.

West, William↗