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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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At least 631 records · Page 35
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

Solid lithium electrolyte via addition of lithium salts to metal-organic frameworks

Various embodiments of the invention disclose that the uptake of LiO.sup.iPr in Mg.sub.2(dobdc) (dobdc.sup.4-=1,4-dioxido-2,5-benzenedicarboxylate) followed by soaking in a typical electrolyte solution leads to a new solid lithium electrolyte Mg.sub.2(dobdc).0.35LiO.sup.iPr.0.25LiBF.sub.4.EC.DEC. Two-point ac impedance data show a pressed pellet of this material to have a conductivity of 3.1.times.10.sup.-4 S/cm at 300 K. In addition, the results from variable-temperature measurements reveal an activation energy of approximately 0.15 eV, while single-particle data suggest that intraparticle transport dominates conduction.

25 ENERGY STORAGE↗
DOE OSTI2016

Solid lithium electrolyte via addition of lithium salts to metal-organic frameworks

Various embodiments of the invention disclose that the uptake of LiO.sup.iPr in Mg.sub.2(dobdc) (dobdc.sup.4-=1,4-dioxido-2,5-benzenedicarboxylate) followed by soaking in a typical electrolyte solution leads to a new solid lithium electrolyte Mg.sub.2(dobdc).0.35LiO.sup.iPr.0.25LiBF.sub.4.EC.DEC. Two-point ac impedance data show a pressed pellet of this material to have a conductivity of 3.1.times.10.sup.-4 S/cm at 300 K. In addition, the results from variable-temperature measurements reveal an activation energy of approximately 0.15 eV, while single-particle data suggest that intraparticle transport dominates conduction.

25 ENERGY STORAGE↗
DOE OSTI2014

Dendrite-Suppression Electrolytes for Lithium-Metal and Lithium-Ion Batteries

Lithium (Li) dendrite formation is one of the critical challenges for rechargeable Li-metal batteries and Li-ion batteries, which has not been effectively solved by traditional methods. In this paper, we report the systematic investigation of a novel self-healing electrostatic shield (SHES) mechanism to change the Li deposition behavior by using low-concentration electrolyte additives whose redox potentials are close to that of Li+. The SHES additive cations force Li to be deposited in the region away from protuberant tips due to their preferentially accumulation on the active sites of anode surface. Typical adsorption behavior rather than electrochemical reduction of the additive cation is observed. The existence of Cs+ cations in the electrolytes does not change the components or structure of Li surface films, which is consistent with what the SHES mechanism predicts. The morphologies of deposited Li films on copper substrates are smooth and uniform during repeated deposition-stripping cycles and at various current densities (from 0.1 to 1.0 mA cm-2) by adding only a small amount of Cs+ additive in the electrolytes. Cs+-additive also suppresses Li dendrite growth on carbon anode surface during overcharging, which should improve the safety of Li-ion batteries during abuse conditions. It does not affect the rate capability but improves the long-term cycling stability of Li metal anode, carbon anode and conventional Li-ion cathode materials.

Environmental Molecular Sciences Laboratory↗
DOE OSTI2018

Cobalt-stabilized lithium metal oxide electrodes for lithium batteries

An electrode material comprising a composite lithium metal oxide, which in an initial state has the formula: y[xLi 2 MO 3 .(1-x)LiM'O 2 ].(1-y)Li 1+d Mn 2-z-d M" -z O 4 ; wherein 0.ltoreq.x.ltoreq.1; 0.75.ltoreq.y<1; 0 1+d Mn 2-z-d M" z O 4 component comprises a spinel structure, each of the Li 2 MO 3 and the LiM'O 2 components comprise layered structures, and at least one of M, M', and M" comprises Co. Cells and batteries comprising the electrode material also are described.

Thackeray, Michael M.↗
DOE OSTI2021

Lithium metal—seawater battery cells having protected lithium electrodes

Active metal and active metal intercalation electrode structures and battery cells having ionically conductive protective architecture including an active metal (e.g., lithium) conductive impervious layer separated from the electrode (anode) by a porous separator impregnated with a non-aqueous electrolyte (anolyte). This protective architecture prevents the active metal from deleterious reaction with the environment on the other (cathode) side of the impervious layer, which may include aqueous or non-aqueous liquid electrolytes (catholytes) and/or a variety electrochemically active materials, including liquid, solid and gaseous oxidizers. Safety additives and designs that facilitate manufacture are also provided.

Visco, Steven J.↗
DOE OSTI2021

Stable fluorinated alkylated lithium malonatoborate salts for lithium-ion battery applications

The invention is directed in a first aspect to electrolyte salt of the general formula Li+Z−, wherein Z− has the following chemical formula: wherein R1 is an alkyl group (R′) containing at least one and up to twelve carbon atoms, and R2 and R3 are independently selected from fluorine atom, hydrocarbon groups R, alkoxy groups (—OR), and ester groups —OC(O)R, wherein R2 and R3 can optionally interconnect via R functionalities to form a boron-containing ring. The invention is also directed to electrolyte compositions in which the above electrolyte salt is incorporated. The invention is further directed to lithium-ion batteries containing these electrolytes.

Sun, Xiao-Guang↗
DOE OSTI2023

Making lithium metal—seawater battery cells having protected lithium electrodes

Active metal and active metal intercalation electrode structures and battery cells having ionically conductive protective architecture including an active metal (e.g., lithium) conductive impervious layer separated from the electrode (anode) by a porous separator impregnated with a non-aqueous electrolyte (anolyte). This protective architecture prevents the active metal from deleterious reaction with the environment on the other (cathode) side of the impervious layer, which may include aqueous or non-aqueous liquid electrolytes (catholytes) and/or a variety electrochemically active materials, including liquid, solid and gaseous oxidizers. Safety additives and designs that facilitate manufacture are also provided.

Visco, Steven J.↗
DOE OSTI2011

Calendar and PHEV Cycle Life Aging of High-Energy, Lithium-Ion Cells Containing Blended Spinel and Layered-Oxide Cathodes

One hundred seven commercially available, off-the-shelf, 1.2-Ah cells were tested for calendar life and CS cycle- and CD cycle-life using the new USABC PHEV Battery Test Manual. Here, the effects of temperature on calendar life, on CS cycle life, and on CD cycle life; the effects of SOC on calendar life and on CS cycle life; and the effects of rest time on CD cycle life were investigated. The results indicated that the test procedures caused performance decline in the cells in an expected manner, calendar < CS cycling < CD cycling. In some cases, the kinetic law changed with test type, from linear-with-time to about t2. Additionally, temperature was found to stress the cells more than SOC, causing increased changes in performance with increasing temperature.

25 ENERGY STORAGE↗
DOE OSTI2018

A look into the voltage plateau signal for detection and quantification of lithium plating in lithium-ion cells

Voltage plateau during relaxation or discharge after charging is a distinct signal associated with stripping of deposited Li metal and hence a feasible tool for online detection of Li plating in Li-ion batteries. In this report we present a physics-based model with incorporation of Li plating and stripping to gain a fundamental understanding of the voltage plateau behavior. Specifically, we focus on the internal cell characteristics when voltage plateau occurs and on key factors affecting the shape and duration of voltage plateau. Furthermore, the validity of using the duration of voltage plateau for estimating Li plating amount is assessed. It is found that the duration of voltage plateau depends on the rate of Li stripping, while the stripping rate is restricted by the capability of Li+ intercalation into graphite. Parameters like intercalation kinetics, solid-state diffusivity of graphite and cell temperature can substantially influence the voltage curves even with the same amount of Li plating. Further, we report an interesting phenomenon that during Li stripping one part of anode near the separator has net oxidation current (local stripping rate > intercalation rate), providing Li+ ions and electrons to the other part of anode near the foil which has net reduction current.

25 ENERGY STORAGE↗
DOE OSTI2015

An atomistically informed mesoscale model for growth and coarsening during discharge in lithium-oxygen batteries

An atomistically informed mesoscale model is developed for the deposition of a discharge product in a Li-O{sub 2} battery. This mescocale model includes particle growth and coarsening as well as a simplified nucleation model. The model involves LiO{sub 2} formation through reaction of O{sub 2}{sup −} and Li{sup +} in the electrolyte, which deposits on the cathode surface when the LiO{sub 2} concentration reaches supersaturation in the electrolyte. A reaction-diffusion (rate-equation) model is used to describe the processes occurring in the electrolyte and a phase-field model is used to capture microstructural evolution. This model predicts that coarsening, in which large particles grow and small ones disappear, has a substantial effect on the size distribution of the LiO{sub 2} particles during the discharge process. The size evolution during discharge is the result of the interplay between this coarsening process and particle growth. The growth through continued deposition of LiO{sub 2} has the effect of causing large particles to grow ever faster while delaying the dissolution of small particles. The predicted size evolution is consistent with experimental results for a previously reported cathode material based on activated carbon during discharge and when it is at rest, although kinetic factors need to be included. The approach described in this paper synergistically combines models on different length scales with experimental observations and should have applications in studying other related discharge processes, such as Li{sub 2}O{sub 2} deposition, in Li-O{sub 2} batteries and nucleation and growth in Li-S batteries.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2011

Electrochemically Induced High Capacity Displacement Reaction of PEO/MoS2/Graphene Nanocomposites with Lithium

MoS2/PEO/graphene composite is successfully prepared and the discharge mechanism of MoS2 as an anode material for Li-ion batteries has been investigated systematically in this work. The simultaneous formation of Li2S and Mo at deep discharge depth has been shown for the first time. The deposition of Mo metal with Li residing on the defects after the first discharge increases the intrinsic electronic conductivity of the electrode leading to a superior cycling stability for over 185 cycles. After the first discharge the amorphous Mo matrix allows a large amount of Li+ ions to repeatedly deposit and being oxidized during cycling while the transition between Li2S and S contribute to the capacity above 2.0 V. The interactions between as-formed Mo and S prevents the dissolution of the intermediate polysulfide thus providing clues to immobilize the soluble species in a Li-S battery. Excellent rate performances are achieved in this MoS2/PEO/graphene composite indicating a fast diffusion path of Li+ ions existing not only in the bulk material but also in the interface between the electrode and the electrolyte.

36 MATERIALS SCIENCE↗
DOE OSTI2017

Effect of transition metal composition on electrochemical performance of nickel-manganese-based lithium-rich layer-structured cathode materials in lithium-ion batteries

To evaluate the effect of transition metal composition on the electrochemical properties of Li-rich layer-structured cathode materials, Li{sub 1.2}Ni{sub x}Mn{sub 0.8−x}O{sub 2} (x=0.2, 0.25, 0.3, and 0.4) were synthesized, and their electrochemical properties were investigated. As nickel content x increased in Li{sub 1.2}Ni{sub x}Mn{sub 0.8−x}O{sub 2} (x=0.2, 0.25, 0.3, and 0.4), charge-discharge capacities at a low C-rate (0.05 C) decreased. The results obtained by dQ/dV curves indicate that, as the nickel content increased, the discharge capacity below 3.6 V greatly decreased, but that above 3.6 V increased. As the C-rate of the discharge process increased, the discharge reaction of Li{sub 1.2}Ni{sub x}Mn{sub 0.8−x}O{sub 2} (x=0.2) below 3.6 V greatly decreased. In contrast, that above 3.6 V slightly decreased. This indicates that the discharge reaction above 3.6 V exhibits higher rate performance than that below 3.6 V. For the high-nickel-content cathodes, the ratio of the discharge capacity above 3.6 V to the total discharge capacity was high. Therefore, they exhibited high rate performance. - Graphical abstract: Figure shows the discharge curves of Li{sub 1.2}Ni{sub x}Mn{sub 0.8−x}O{sub 2} (x=0.2 and 0.3) within potential range of 2.5−4.6 V (vs. Li/Li{sup +}) at 0.05 and 3 C. At low C-rate (0.05 C), the discharge capacity of high-nickel-content cathode (Li{sub 1.2}Ni{sub 0.3}Mn{sub 0.5}O{sub 2}) was less than that of low-nickel-content cathode (Li{sub 1.2}Ni{sub 0.2}Mn{sub 0.6}O{sub 2}); however, the discharge potential and capacity of Li{sub 1.2}Ni{sub 0.3}Mn{sub 0.5}O{sub 2} was higher than those of Li{sub 1.2}Ni{sub 0.2}Mn{sub 0.6}O{sub 2} at high C-rate (3 C). This means that the increase in Ni/Mn ratio was effective in improving rate-performance.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗