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At least 919 records · Page 51
All sourcesNASA NTRSDOE OSTI
DOE OSTI2013

CO 2 capture properties of lithium silicates with different ratios of Li 2 O/SiO 2 : an ab initio thermodynamic and experimental approach

The lithium silicates have attracted scientific interest due to their potential use as high-temperature sorbents for CO 2 capture. The electronic properties and thermodynamic stabilities of lithium silicates with different Li 2 O/SiO 2 ratios (Li 2 O, i 8 SiO 6 , Li 4 SiO 4 , Li 6 Si 2 O 7 , Li 2 SiO 3 , Li 2 Si 2 O 5 , Li 2 Si 3 O 7 , and a-SiO 2 ) have been investigated by combining first-principles density functional theory with lattice phonon dynamics. All these lithium silicates examined are insulators with band-gaps larger than 4.5 eV. By decreasing the Li 2 O/SiO 2 ratio, the first valence bandwidth of the corresponding lithium silicate increases. Additionally, by decreasing the Li 2 O/SiO 2 ratio, the vibrational frequencies of the corresponding lithium silicates shift to higher frequencies. Based on the calculated energetic information, their CO 2 absorption capabilities were extensively analyzed through thermodynamic investigations on these absorption reactions. We found that by increasing the Li 2 O/SiO 2 ratio when going from Li 2 Si 3 O 7 to Li 8 SiO 6 , the corresponding lithium silicates have higher CO 2 capture capacity, higher turnover temperatures and heats of reaction, and require higher energy inputs for regeneration. Based on our experimentally measured isotherms of the CO 2 chemisorption by lithium silicates, we found that the CO 2 capture reactions are two-stage processes: (1) a superficial reaction to form the external shell composed of Li 2 CO 3 and a metal oxide or lithium silicate secondary phase and (2) lithium diffusion from bulk to the surface with a simultaneous diffusion of CO 2 into the shell to continue the CO 2 chemisorption process. The second stage is the rate determining step for the capture process. By changing the mixing ratio of Li 2 O and SiO 2 , we can obtain different lithium silicate solids which exhibit different thermodynamic behaviors. Based on our results, three mixing scenarios are discussed to provide general guidelines for designing new CO2 sorbents to fit practical needs.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2023

Understanding and controlling lithium morphology in solid polymer and gel polymer systems: mechanisms, strategies, and gaps

Lithium metal anode promises the highest theoretical energy density and may enable high energy designs such as lithium–sulfur and lithium–air batteries. However, stable lithium plating and stripping remains a challenge in all electrolyte systems including liquids, polymers, and ceramic electrolytes. In this perspective, we examine literature studies of lithium morphologies in solid polymer and gel polymer systems and compare that with well-studied liquid electrolytes. In solid polymer electrolytes, current density and mechanical properties are both governing parameters for lithium morphology, differing from conventional liquid electrolytes. Stable lithium electrodeposition may be accomplished by a polymer electrolyte with good stiffness operating at significantly lower current densities than its limiting current density, which is defined by the Sand equation. In gel polymer electrolytes, the reported lithium morphology is more similar to that in liquid electrolytes, suggesting similar nucleation and growth mechanisms. Based on experimental evidence and theoretical guidance, current strategies to control lithium morphology in solid polymer and gel polymer electrolytes are summarized. The limitations of these strategies are discussed. In particular, we note the knowledge gap in understanding the solid electrolyte interphase in solid polymer systems and the critical role it can play in regulating lithium morphologies.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Visualizing diverse lithium growth and stripping behaviors in anode-free solid-state batteries with operando X-ray tomography

Anode-free solid-state batteries (SSBs), which eliminate the need for lithium metal use during cell assembly, have the potential to enable high energy densities and simplified manufacturing. However, the factors that control lithium growth/stripping at the anode current collector are not well understood. Here, we use operando X-ray microcomputed tomography to comprehensively image and quantify lithium deposition and stripping under various conditions in three different Li|Li 6 PS 5 Cl|current collector cells, revealing diverse behavior that depends on interface morphology, cell resistance, and solid-state electrolyte (SSE) microstructure. A cell with high resistance exhibits extensive lithium filament growth across the entire current collector interface, with filaments that grow around pre-existing pores in the SSE rather than lithium filling these pores. Lithium filament formation is partially reversible, with the cracks shrinking as lithium metal is stripped. Uniform lithium deposition is achievable at low current densities in low-resistance cells, whereas higher current densities in these cells cause an increase in interfacial roughness, which is correlated with subsequent filamentary growth at the edges of the cell. These results provide insight into filamentary vs. planar lithium growth and highlight that the evolution of lithium is sensitively dependent on SSE microstructure and electrochemical processes.

25 ENERGY STORAGE↗
DOE OSTI2023

High capacity, air-stable, structurally isomorphous lithium alloy multilayer porous foams

The invention relates to composite multilayer lithium ion battery anodes that include a porous metal alloy foam, and a lithium ion conductor coating applied to the metal alloy foam. The metal alloy foam can include structurally isomorphous alloys of lithium and, optionally, lithium and magnesium. The lithium ion conductor coating can include ternary lithium silicate, such as, lithium orthosilicate. Lithium ions from the ternary lithium silicate may be deposited within the pores of the metal alloy foam. Optionally, the lithium ion conductor coating may include a dopant. The dopant can include one or more of magnesium, calcium, vanadium, niobium and fluorine, and mixtures and combinations thereof.

Kumta, Prashant N.↗
DOE OSTI2023

Probing the Effectiveness in Stabilizing Lithium Metal Anodes through Functional Additives

A variety of electrolyte additives were comprehensively evaluated to understand their relative capability in stabilizing lithium metal anode. Although the Li||Cu test is an effective test to rule out ineffective additives, a reliable assessment of individual additives cannot be obtained just by a single evaluation method. Therefore, various methods must be combined to truly assess the stabilization of a lithium anode. Moreover, it was also discovered that a significant depletion of electrolytes occurred during the end-of-life of the lithium batteries, which partially contributed to the sudden failure of the lithium batteries during cycling. However, the main culprit of the sudden failure was identified as the significant increase in the resistance of the lithium metal anode. Further, when used as an additive, cyclic fluorinated carbonates are the most effective in stabilizing the lithium anode and improving the cycling performance of lithium batteries among all the common additives. Despite its cost-effectiveness, the additive in the conventional electrolyte approach provides insufficient protection for lithium metal due to the complete consumption of the additive materials, which is necessary to repair the solid-electrolyte interphase (SEI). Therefore, it is suggested that a larger ratio (>15 wt %) of the SEI former should be employed to achieve effective lithium stabilization.

25 ENERGY STORAGE↗
DOE OSTI2021

Life Cycle Assessment and Techno-Economic Assessment of Lithium Recovery from Geothermal Brine

Lithium-ion batteries (LIB) play an essential role in the electrification of the transportation sector, and battery demand for lithium compounds will see a significant increase in the coming decades. This has raised concerns on the supply of lithium, and as a result, technologies are being developed to process unconventional lithium sources. One promising technology is to extract lithium from geothermal brine using lithium-aluminum-layered double hydroxide chloride (LDH) sorbent and forward osmosis. A combined life cycle assessment (LCA) and techno-economic assessment (TEA) is conducted to evaluate the environmental and economic performance of this technology. It is assumed that the lithium extraction unit is an add-on to a 50 MW geothermal power plant located in California. The analysis is based on lab-scale experimental data and stoichiometry while considering the economy of scale for an industrial system. LCA results suggest that, compared with conventional LiOH and Li 2 CO 3 production pathways, the new technology achieves 1–95% reduction in environmental impacts. Even higher reduction can be achieved for LiOH produced via electrolysis. This add-on unit for lithium extraction could achieve a payback period of less than 1 year and reach net present values of $454M and $315M and internal rates of return of 792 and 1130% for LiOH and Li 2 CO 3 production pathways, respectively. The favorable environmental and economic performance suggests that LDH sorption coupled with forward osmosis has great potential to enable the domestic production of battery lithium compounds and that further development should be carried out.

15 GEOTHERMAL ENERGY↗
DOE OSTI2021

Lithium superoxide encapsulated in a benzoquinone anion matrix

Lithium peroxide is the crucial storage material in lithium–air batteries. Understanding the redox properties of this salt is paramount toward improving the performance of this class of batteries. Lithium peroxide, upon exposure to p –benzoquinone (p–C 6 H 4 O 2 ) vapor, develops a deep blue color. This blue powder can be formally described as [Li 2 O 2 ] 0.3 • [LiO 2 ] 0.7 • {Li[p–C 6 H 4 O 2 ]} 0.7 , though spectroscopic characterization indicates a more nuanced structural speciation. Infrared, Raman, electron paramagnetic resonance, diffuse-reflectance ultraviolet-visible and X-ray absorption spectroscopy reveal that the lithium salt of the benzoquinone radical anion forms on the surface of the lithium peroxide, indicating the occurrence of electron and lithium ion transfer in the solid state. As a result, obligate lithium superoxide is formed and encapsulated in a shell of Li[p–C 6 H 4 O 2 ] with a core of Li 2 O 2 . Lithium superoxide has been proposed as a critical intermediate in the charge/discharge cycle of Li–air batteries, but has yet to be isolated, owing to instability. The results reported herein provide a snapshot of lithium peroxide/superoxide chemistry in the solid state with redox mediation.

25 ENERGY STORAGE↗
DOE OSTI2019

A simplified lithium vapor box divertor

A detached divertor plasma is predicted to be necessary to mitigate the heat fluxes and ion energy, and so sputtering, at the divertor plate of a fusion power plant. It has proven difficult in current experiments, however, to prevent the detachment front, once formed, from running up to the main plasma resulting in deterioration of pedestal performance. The lithium vapor box divertor localizes a dense cloud of lithium vapor away from the main plasma, in order to induce detachment at a stable, distant location. The vapor localization is created by local evaporation and nearby condensation, a configuration inaccessible for non-condensing seed impurities. This paper provides simulations of lithium vapor flow using the SPARTA direct simulation Monte Carlo (DSMC) code, in which the lithium vapor dynamics are governed by Li–Li collisions that should dominate in regions with little plasma. Inertia is included in this code, permitting the formation of shocks. The plasma model implemented in SPARTA is based on UEDGE results for the location of ionization and recombination. We find that a simplified lithium vapor box configuration, without baffles, provides robust stabilization of the detachment front and acceptable lithium vapor flow to the main chamber. Lithium is evaporated from a capillary porous surface on the private-flux side of the divertor, distant from the main plasma, and is condensed on the other side walls of the divertor chamber. The condensed lithium flows back to the evaporator through 2 cm internal diameter pipes. The capillary pressure differential at the surface of the evaporator is capable of overcoming MHD back-force in the piping, with a great deal of margin if a sandwich flow channel insert is implemented. Very little lithium should be accumulated on the first wall of the main chamber if it is maintained at 600 °C, as expected for a power-producing fusion system.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2018

Sodium and Lithium Hydride Shields At the Department of Energy's Oak Ridge Reservation - 18412

URS-CH2M Oak Ridge LLC (UCOR) is responsible for cleanup of the U.S. Department of Energy's (DOE) East Tennessee Technology Park (ETTP) in Oak Ridge, Tennessee. Formerly known as the K-25 site, the facility enriched uranium for major defense and energy programs for more than 40 years. DOE is seeking the safest, most environmentally protective and fiscally responsible treatment for its large inventory of radioactive-contaminated metals known as 'shields'. The 66 sodium and lithium shields were constructed for use in experiments at the Tower Shielding Facility (TSF), Oak Ridge National Laboratory (ORNL). The TSF operated from 1954 to 1992 and was designed and built for radiation-shielding studies. The shield containers are constructed of aluminum or stainless steel of varying sizes and shapes that were then filled with either sodium metal or lithium hydride material. The historical records indicate the sodium shields were constructed at the Molten Salt Reactor for use in experiments in the 1971 time frame, while the lithium shields were constructed at the Y-12 site and were used in experiments as early as 1961. A subset of the sodium and lithium shields contain depleted uranium. The sodium and lithium shields were initially used at the TSF to perform in-depth measurements of the neutron transport through the shield materials. Based on process knowledge, the shields are managed as radiologically contaminated containers. Efforts have been made over the last fifteen years to find recycle markets for both the sodium and lithium hydride shields. This includes an onsite operation that was initiated at the East Tennessee Technology Park (ETTP) in 2004. After an operational exothermic reaction incident occurred soon after startup, the onsite ETTP recycling action was discontinued and a search for offsite recycling facilities was initiated. In 2016, the Y-12 National Security Complex was contacted regarding recycle/repurpose of the lithium shields; however, the lithium was determined to not be acceptable for their current repurpose process. To date, no offsite recycling outlets have been identified. Recent progress on the waste disposal actions, a shipment of 22 small sodium shields have been shipped and treated offsite. Therefore, the current shield inventory consists of 29 sodium shields located at ETTP and 15 sodium and lithium hydride shields staged at ORNL. The time period needed to reasonably identify safe disposition or recycling outlets for the shields was expected to exceed the one-year Land Disposal Restrictions storage time limit; therefore, approval was received to add the shields to the Site Treatment Plan (STP) in March, 2017. Until a disposition path is found, the shields will continue to be stored in a safe configuration that is protective of human health and the environment. This engineering evaluation identifies and screens the alternatives for dispositioning the shields at the Oak Ridge(ORR). Four alternatives were evaluated including; (1) macro-encapsulation, (2) deactivation, (3) recycle and (4) leave-in-place. An initial screening was performed, and the alternative passing the initial screening are then evaluated in more detail. The evaluation criteria used included environmental risk, technical feasibility, administrative feasibility, worker safety, nuclear safety, transportation safety, and cost. (author)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2015

Effects of lithium salt concentration on graphited carbon microbead anodes in the piperidinium-based hybrid electrolytes

Graphical abstract: “Lithium aggregates” usually cause a significant decrease in Li{sup +} mobility and transfer efficiency. Therefore, as important as the problem of SEI, the content of lithium salt and the interaction between Li{sup +} and ILs’ anions should be taken into consideration in the optimization of ILs-based electrolytes for Li-ion batteries. - Highlights: • “Lithium aggregates” in piperidinium-based electrolytes are evidenced by IR and NMR. • High LiPF{sub 6} content could decrease Li{sup +} mobility due to “ionic aggregates”. • Lithium salt concentration is an important factor affecting graphite performances. - Abstract: The variations in LiPF{sub 6} concentration lead to the very different electrochemical performances of carbon microbeads anodes in the piperidinium-based hybrid electrolytes. The “two peaks” behaviors of lithium plating observed in cyclic voltammetry tests, and some detailed changes in infrared spectra and nuclear magnetic resonance indicates that the formation of “ionic aggregates” related to lithium ions”. Therefore, the excessive lithium salts in the piperidinium-based hybrid electrolytes, usually cause a significant decrease in Li{sup +} mobility and transfer efficiency. The main behaviors are that, when LiPF{sub 6} concentrations increased from 0.2 to 1.2 mol kg{sup −1}, the apparent migration energies (E{sub a}) increase largely from 8.83 to 21.16 kJ mol{sup −1}, while the lithium transference numbers (t{sub Li{sup +}}) drop markedly from 0.538 to 0.292.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Incombustible Polymer Electrolyte Boosting Safety of Solid–State Lithium Batteries: A Review

Lithium-ion batteries with their portability, high energy density, and reusability are frequently used in today's world. Under extreme conditions, lithium-ion batteries leak, burn, and even explode. Therefore, improving the safety of lithium-ion batteries has become a focus of attention. Researchers believe using a solid electrolyte instead of a liquid one can solve the lithium battery safety issue. Due to the low price, good processability and high safety of the solid polymer electrolytes, increasing attention have been paid to them. However, polymer electrolytes can also decompose and burn under extreme conditions. Moreover, lithium dendrites are formed continuously due to the uneven charge distribution on the surface of the lithium metal anode. A short circuit caused by a lithium dendrite can cause the battery to thermal runaway. As a result, the safety of polymer solid-state batteries remains a challenge. In this review, the thermal runaway mechanism of the batteries is summarized, and the batteries abuse test standard is introduced. In addition, the recent works on the high-safety polymer electrolytes and the solution strategies of lithium anode problems in polymer batteries are reviewed. Finally, the development direction of safe polymer solid lithium batteries is prospected.

25 ENERGY STORAGE↗
DOE OSTI2016

Atomic Layer Deposition of Li x Al y S Solid-State Electrolytes for Stabilizing Lithium-Metal Anodes

Increasing global demands for energy storage in electric vehicles and the grid necessitate “beyond-lithium-ion” batteries that simultaneously exhibit high capacity, long-term cyclability, and excellent safety. Several candidates, most notably lithium–air and lithium–sulfur batteries, utilize lithium-metal anodes. Although the specific capacity of lithium metal is unrivaled (3860 mA h g –1 ), the capacity fade and risk of catastrophic failure must be overcome. Herein, we describe ultrathin, ionically conducting lithium aluminum sulfide (Li x Al y S) coatings prepared on lithium-metal anodes by using atomic layer deposition, which stabilize the Li–electrolyte interface and reduce (up to five times) the interfacial impedance of lithium–metal anodes in contact with organic electrolyte. Here, we demonstrate that these thin films effectively suppress dendrite formation and preserve a smooth, low-surface-area morphology for electrodeposited lithium metal, thereby doubling the lifetime of Li–Cu asymmetric cells.

25 ENERGY STORAGE↗
DOE OSTI2022

Solvent-Free Manufacturing of Lithium-Ion Battery Electrodes via Cold Plasma

Slurry casting has been used to fabricate lithium-ion battery electrodes for decades, which involves toxic and expensive organic solvents followed by high-cost vacuum drying and electrode calendering. This work presents a new manufacturing method using a nonthermal plasma to create inter-particle binding without using any polymeric binding materials, enabling solvent-free manufacturing electrodes with any electrochemistry of choice. The cold-plasma-coating technique enables fabricating electrodes with thickness (>200 μm), high mass loading (>30 mg cm -2 ), high peel strength, and the ability to print lithium-ion batteries in an arbitrary geometry. This crosscutting, chemistry agnostic, platform technology would increase energy density, eliminate the use of solvents, vacuum drying, and calendering processes during production, and reduce manufacturing cost for current and future cell designs. Here, lithium iron phosphate and lithium cobalt oxide were used as examples to demonstrate the efficacy of the cold-plasma-coating technique. It is found that the mechanical peel strength of cold-plasma-coating-manufactured lithium iron phosphate is over an order of magnitude higher than that of slurry-casted lithium iron phosphate electrodes. Full cells assembled with a graphite anode and the cold-plasma-coating-lithium iron phosphate cathode offer highly reversible cycling performance with a capacity retention of 81.6% over 500 cycles. For the highly conductive cathode material lithium cobalt oxide, an areal capacity of 4.2 mAh cm -2 at 0.2 C is attained. We anticipate that this new, highly scalable manufacturing technique will redefine global lithium-ion battery manufacturing providing significantly reduced plant footprints and material costs.

25 ENERGY STORAGE↗
DOE OSTI2016

High-pressure/high-temperature synthesis and characterization of the first palladium or platinum containing lithium transition-metal sulfides Li{sub 2}M{sub 3}S{sub 4} (M=Pd, Pt)

The new lithium transition-metal sulfides Li{sub 2}M{sub 3}S{sub 4} (M=Pd, Pt) were obtained via multianvil high-pressure/high-temperature syntheses at 8 GPa and 1150 °C starting from a stoichiometric mixture of lithium nitride, sulfur, and palladium or platinum. Single crystal structure analyses indicated the space group P2{sub 1}/c (no. 14) with the following lattice parameters and refinement results: a=492.9(1), b=1005.9(2), c=614.9(2) pm, β=110.9 (1)°, R1=0.0165, wR2=0.0308 (all data) for Li{sub 2}Pd{sub 3}S{sub 4} and a=498.2(1), b=1005.5(2), c=613.0(2) pm, β=110.8(1)°, R1=0.0215, wR2=0.0450 (all data) for Li{sub 2}Pt{sub 3}S{sub 4}. The crystal structures are built up from two distinct Pd/Pt sites, one of which is a special position (0,0,0), two sulfur sites, and one lithium site. The atoms Pd2/Pt2 form isolated square planar PdS{sub 4}/PtS{sub 4} units, whereas the Pd1/Pt1 atoms form pairs of square planar PdS{sub 4}/PtS{sub 4} units, which are connected via a common edge. These two structural motives built up a three-dimensional network structure by linking through common corners. The lithium atoms are positioned inside of the so formed channels. Li{sub 2}M{sub 3}S{sub 4} (M=Pd, Pt) are isostructural to the minerals jaguéite, Cu{sub 2}Pd{sub 3}Se{sub 4} and chrisstanleyite, Ag{sub 2}Pd{sub 3}Se{sub 4}, which are up to now the only representatives of this structure type. Both compounds were studied with respect to their magnetic properties and can be classified as Pauli paramagnetic or diamagnetic. Regarding the possibility of lithium mobility inside the channels, of the structure, solid state {sup 7}Li NMR and high-temperature single crystal investigations revealed localization of the lithium atoms on their crystallographic sites. - Graphical abstract: The ternary lithium transition-metal sulfides Li{sub 2}M{sub 3}S{sub 4} (M=Pd, Pt) were prepared via multianvil high-pressure/high-temperature syntheses. They are built up from square planar PtS{sub 4}/PdS{sub 4} units with lithium located in the channels of the crystal structure. - Highlights: • Li{sub 2}M{sub 3}S{sub 4} (M=Pd, Pt) are the missing sulfide analogue compounds to Cu{sub 2}Pd{sub 3}Se{sub 4} and Ag{sub 2}Pd{sub 3}Se{sub 4}. • The compounds are the first Pd or Pt containing lithium transition-metal sulfides. • Li mobility was investigated via temp. dependent XRD and solid state {sup 7}Li NMR. • Magnetic properties revealed Pauli paramagnetic or diamagnetic contributions.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2017

Flowing liquid lithium plasma-facing components – Physics, technology and system analysis of the LiMIT system

The use of low atomic number liquid metals has been shown to have the potential to solve many of the prevalent problems like erosion and radiation losses associated with the interaction of fusion plasma with the plasma facing component (PFC) structures in tokamaks. Since the first evidence of lithium increasing plasma performance in TFTR [1], the benefits of using lithium in fusion environments have been seen in many devices, including CDX-U [2], NSTX [3], LTX [4], and DIII-D [5]. While both fast flow and slow flow concepts have been studied with regards to liquid lithium first wall alternatives, this report will focus on efforts placed on fast flow research and will mainly focus on advancements in the LiMIT device that help to eliminate concerns over the broad use of liquid lithium. Due to the promising TFTR results along with results obtained at the University of Illinois at Urbana-Champaign [6], suitably designed trench structures holding liquid lithium could be an appropriate fast flow candidate for PFC modules in future fusion devices. There are four potential shortcomings of this approach: (1) Droplet ejection, (2) Wetting control, (3) Tritium retention, and (4) Limited heat flux handling. Droplet ejection is discussed in a companion publication [7], while this paper addresses the topics of wetting control and heat flux handling. Limitations in wetting and prevention of lithium creep (i.e. getting and keeping the lithium only where it should be) have been solved by laser-texturing the base material with extreme short laser pulses (pico – femto second) of high power (several 10 s of W). Micro- and nano-structuring results indicate that the textured substrates displayed significant change in their wetting properties, increasing the temperature needed to wet from 310 °C to 390 °C. Lastly, initial designs for the Lithium Metal Infused Trenches (LiMIT) [6] showed dryout above 3 MW/m 2 , but new designs of the trench shaping show potential to be able to handle up to 10 MW/m 2 . Dryout is accompanied by lithium evaporation which is shown to mitigate the incident heat flux, which may be viewed as beneficial [8]. The advances shown here will increase the viability of the LiMIT system in large-scale testing, and allow for extensive design iteration to begin tackling the large powers and heat fluxes present in reactor-relevant systems.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Uncovering the Relationship between Aging and Cycling on Lithium Metal Battery Self-Discharge

Lithium metal is considered the “holy grail” material to replace typical Li-ion anodes due to the absence of a host structure coupled with a high theoretical capacity. The absence of a host structure results in large volumetric changes when lithium is electrodeposited/dissolved, making the lithium prone to stranding and parasitic reactions with the electrolyte. Lithium research is focused on enabling highly reversible lithium electrodeposition/dissolution, which is important to achieving long cycle life. Understanding the various mechanisms of self-discharge is also critical for realizing practical lithium metal batteries but is often overlooked. In contrast to previous work, it is shown here that self-discharge via galvanic corrosion is negligible, particularly when lithium is cycled to relevant capacities. Rather, the continued electrochemical cycling of lithium metal results in self-discharge when periodic rest is applied during cycling. The extent of self-discharge can be controlled by increasing the capacity of plated lithium, tuning electrolyte chemistry, incorporating regular rest, or introducing lithiophilic materials. Finally, the Coulombic losses that occur during periodic rest are largely reversible, suggesting that the dominant self-discharge mechanism in this work is not an irreversible chemical process but rather a morphological process.

25 ENERGY STORAGE↗
DOE OSTI2025

Unveiling the Role of Lithium Iodide in Stabilizing Solid Interfaces in All-Solid-State Li Metal Batteries

A critical challenge in all-solid-state lithium metal batteries (ASSLMBs) is achieving a stable interface between the lithium metal anode and the solid electrolyte. Leveraging its success in Li/I 2 batteries, lithium iodide has garnered significant attentions for its potential to enhance interfacial stability and overall cell performance in ASSLMBs. Here, we elucidate the role of lithium iodide in stabilizing the solid interface in all-solid-state Li metal batteries with a Li argyrodite electrolyte, particularly focusing on its influence on lithium deposition behavior and interfacial evolution. Through in situ optical imaging, we demonstrate more uniform lithium deposition on an iodide-contained argyrodite electrolyte compared to a chloride-based counterpart. Complementary density functional theory calculations attribute improved lithium plating behavior to the enhanced lithiophilicity and better ionic conductivity of lithium iodide at the solid interface, effectively reducing localized current density. In conclusion, these findings provide useful insights into the mechanisms through which lithium iodide enhances the interfacial stability in ASSLMBs.

Anions↗
DOE OSTI2024

Evaluation of lithium as a tritium storage medium for betavoltaics

Lithium foils were demonstrated to absorb surrogate protium for tritium-powered betavoltaics. 20μm thick lithium foils were hole-punched from a ribbon of electrodeposited lithium on copper foil. The lithium foils were loaded with hydrogen in a custom Sievert apparatus where the pressure drop showed full hydriding at a hydrogen pressure of 2 bar and at all loading temperatures above the lithium melting point at 190, 200, 225, 250, and 300. Lithium hydride formation was confirmed with Raman spectroscopy after hydrogen loading. The kinetics of experimental hydride formation was compared to the diffusion-limited Mintz–Bloch model. While the Mintz–Bloch model showed good fit with the experimental loadings, the model overpredicted the loading kinetics starting at 250 °C and at higher temperatures. In conclusion, The overprediction was either caused by lithium hydride outgassing due to some reduction with some residual lithium hydroxide created from brief air exposure when sealing the lithium in the reactor or a transition from diffusion-limited hydride growth to surface or metal–hydride interface-limited hydride growth.

25 ENERGY STORAGE↗