Search NASA⌕ Search

SEARCH · Search NASA

Results for “lithium halides”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2

Liquid-like solid-state diffusion of lithium ions in super-halide-rich argyrodite

The development of solid electrolytes with high ionic conductivity is essential for advancing safer, high-energy-density solid-state batteries, where lithium site distribution in the sublattice strongly affects ion transport. Here, we report a super-halide-rich argyrodite, Li 5.3 PS 4.3 Cl 1.7 , with remarkable room-temperature ionic conductivity (11.4 ± 0.7 mS cm -1 ) due to population of two additional interstitial lithium sites induced by vacancy redistribution. Prominent lithium density between lithium sites and elevated atomic displacement parameters indicate liquid-like diffusive behavior resembling sublattice melting. Combining electrochemical impedance spectroscopy, pulsed-field gradient NMR, and T 1 relaxation methods, we demonstrate that the augmented conductivity partly arises from a low energy barrier (0.08 eV) at the local scale, attributed to a three-site lithium distribution that drives correlated lithium dynamics. This work advances our understanding of the structure-dynamics interplay in super-halide-rich argyrodites, and highlighting their potential as solid-state battery electrolytes in cells with a coated single-crystal NMC82 cathode that achieve 170 mAh/g capacity at a 0.2 C rate .

25 ENERGY STORAGE↗

Halide segregation to boost all-solid-state lithium-chalcogen batteries

Mixing electroactive materials, solid-state electrolytes, and conductive carbon to fabricate composite electrodes is the most practiced but least understood process in all-solid-state batteries, which strongly dictates interfacial stability and charge transport. Here, we report on universal halide segregation at interfaces across various halogen-containing solid-state electrolytes and a family of high-energy chalcogen cathodes enabled by mechanochemical reaction during ultrahigh-speed mixing. Bulk and interface characterizations by multimodal synchrotron x-ray probes and cryo–transmission electron microscopy show that the in situ segregated lithium halide interfacial layers substantially boost effective ion transport and suppress the volume change of bulk chalcogen cathodes. Various all-solid-state lithium-chalcogen cells demonstrate utilization close to 100% and extraordinary cycling stability at commercial-level areal capacities.

36 MATERIALS SCIENCE↗

Fluorine-Substituted Lithium Chloride Solid Electrolytes for High-Voltage All-Solid-State Lithium-Ion Batteries

Lithium ternary halides are promising solid electrolytes, owing to their high ionic conductivity and reasonably high oxidative and chemical stability. Recently, fluorine substitution in Li 3 MCl 6 has been suggested as a promising approach for further enhancing oxidation stability. Accordingly, this study outlines a material design strategy for F-substituted Li 3 MCl 6 through systematic theoretical analyses. Calculations reveal that the mixing limit of F in Li 3 MCl 6–x F x is in the range of 0.5–1.5, and the resulting Li 3 MCl 6–x F x phases can retain ionic conductivity above 1 mS/cm up to x = 1.0. Additionally, the calculations also predict that the formation of F-containing passivating phases could increase the oxidation potential for Li3MCl5F to ~6.3 V. The proposed material design strategy is validated through the synthesis of Li 3 YCl 5 F, which is confirmed to show both high ionic conductivity and enhanced oxidation stability. The design guidelines presented herein can accelerate the potential use of halide-based electrolyte chemistries in high-voltage all-solid-state batteries.

25 ENERGY STORAGE↗

Applying in Situ Bias During TOF-SIMS Analysis to Investigate Ion Migration in Perovskite Devices

An in situ electrical bias was placed on a perovskite device through the device thickness while under investigation with time-of-flight secondary ion mass spectrometry. The applied bias resulted in an observed reversible migration of halide and lithium ions on the timescale of minutes. The results show a framework that can be used for further study of ion migration in perovskite materials and devices.

14 SOLAR ENERGY↗

Tunable Lithium-Ion Transport in Mixed-Halide Argyrodites Li 6–x PS 5–x ClBr x : An Unusual Compositional Space

Argyrodites, with fast lithium-ion conduction, are promising for applications in rechargeable solid-state lithium-ion batteries. In this article, we report a new compositional space of argyrodite superionic conductors, Li 6– x PS 5– x ClBr x [0 ≤ x ≤ 0.8], with a remarkably high ionic conductivity of 24 mS/cm at 25 °C for Li 5.3 PS 4.3 ClBr 0.7 . In addition, the extremely low lithium migration barrier of 0.155 eV makes Li 5.3 PS 4.3 ClBr 0.7 highly promising for low-temperature operation. Average and local structure analyses reveal that bromination ( x > 0) leads to (i) retention of the parent Li 6 PS 5 Cl structure for a wide range of x in Li 6– x PS 5– x ClBr x (0 ≤ x ≤ 0.7), (ii) co-occupancy of Cl – , Br – , and S 2– at 4a/4d sites, and (iii) gradually increased Li + -ion dynamics, eventually yielding a “liquid-like” Li-sublattice with a flattened energy landscape when x approaches 0.7. In addition, the diversity of anion species and Li-deficiency in halogen-rich Li 6– x PS 5– x ClBr x induce hypercoordination and coordination entropy for the Li-sublattice, also leading to enhanced Li + -ion transport in Li 6– x PS 5– x ClBr x . This study demonstrates that mixed-anion framework can help stabilize highly conductive structures in a compositional space otherwise unstable with lower anion diversity.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Correction to “Stacking Faults Assist Lithium-Ion Conduction in a Halide-Based Superionic Conductor”

A typographical error needs to be corrected in the Results section, subsection “2.5. Evaluation of Li + Ion Conduction Properties”, fourth paragraph, where the activation energy barriers derived from PFG-NMR were swapped for components 1 and 2, for both BM-LYC and SS-LYC. The same error should also corrected in the second paragraph of the Discussion section.

99 GENERAL AND MISCELLANEOUS↗

Molten salt compositions with enhanced heat transfer and reduced corrosion properties

A heat transfer (exchange) composition comprising a halide salt matrix having dispersed therein nanoparticles comprising elemental carbon in the absence of water and surfactants, wherein said halide is fluoride or chloride, wherein the halide salt may be an alkali halide salt (e.g., lithium fluoride, sodium fluoride, potassium fluoride, rubidium fluoride, sodium chloride, potassium chloride, rubidium chloride, and eutectic mixtures thereof) or an alkaline earth halide salt (e.g., fluoride or chloride salt of beryllium, magnesium, calcium, strontium, or barium), and wherein the nanoparticles comprising elemental carbon may be solid or hollow, and wherein the composition may further include nanoparticles comprising a fissile material (e.g., U, Th, or Pu) dispersed within the composition. Molten salt reactors (MSRs) containing these heat transfer compositions in coolant loops in thermal exchange with a reactor core, as well operation of such MSRs, are also described.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

Halogenation of used aluminum matrix test reactor fuel – a bench-scale demonstration with surrogate materials

In this work, experiments with surrogate materials were performed at bench scale to demonstrate a halogenation technique applicable to treatment of used aluminum matrix test reactor fuel. The technique involves dissolution and separation of aluminum from used aluminum matrix test reactor fuel in molten-halide salt systems prior to treatment and disposition of the fuel’s uranium and fission products. Demonstration of the halogenation technique was performed with neodymium metal as a non-radiological surrogate for uranium metal. Experiments involved blending forms of aluminum and neodymium metal with ammonium and lithium chloride or ammonium and lithium bromide, which upon heating decomposed into ammonia gas and the respective hydrogen chloride or bromide gas. The latter reacted with the metals to form the respective aluminum and neodymium halides. At elevated temperatures, aluminum halides gasified away from the respective neodymium halides, which fused with their respective lithium halides. Samples of fused and distillate salts were collected and analyzed, yielding extents of aluminum removal that ranged from 94.5–98.2% for chlorination runs and 91.4–97.8% for bromination runs. No neodymium was detected in the distillate fractions. Some experiments were repeated with excess reactants, and a portion of aluminum chloride distillate was processed into a consolidated waste form.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Microscopic Mechanisms of Superionic Na-ion Conductivity in Crystalline and Amorphous NaMOCl 4 (M = Nb, Ta) Solid Electrolytes

Sodium-ion solid electrolytes offer a sustainable route toward next-generation batteries, but few match the performance of their lithium counterparts. Halide-based NaMOCl 4 (M = Nb, Ta) has recently emerged as a promising analogue to LiMOCl 4 , yet its structure–transport relationships remain unclear due to poor crystallinity in experiments. Here, we combine density functional theory and machine-learned molecular dynamics to reveal that crystalline NaMOCl 4 exhibits negligible room-temperature conductivity with high activation barriers arising from vacancy-mediated diffusion below an order–disorder transition. Above this transition, rotational and translational motion of the [MO 2/2 Cl 4 – ] ∞ chains create new Na sites and enhances transport. In contrast, the amorphous phase inherently supports facile, three-dimensional Na diffusion through dynamic framework flexibility. These results show that ordered crystalline phases hinder ionic transport, while disorder – either thermally induced or structural – facilitates it, revising prior assumptions from the Li system and providing design principles for high-conductivity Na halide electrolytes.

Wei, Grace [University of California, Berkeley, CA↗

Site Disorder Drives Cyanide Dynamics and Fast Ion Transport in Li 6 PS 5 CN

Halide argyrodite solid-state electrolytes of the general formula Li 6 PS 5 X exhibit complex static and dynamic disorder that plays a crucial role in ion transport processes. Here, we unravel the rich interplay between site disorder and dynamics in the plastic crystal argyrodite Li 6 PS 5 CN and the impact on ion diffusion processes through a suite of experimental and computational methodologies, including temperature-dependent synchrotron powder X-ray diffraction, AC electrochemical impedance spectroscopy, 7 Li solid-state NMR, and machine learning-assisted molecular dynamics simulations. Sulfide and (pseudo)halide site disorder between the two anion sublattices unilaterally improves long-range lithium diffusion irrespective of the (pseudo)halide identity, which demonstrates the importance of site disorder in dictating bulk ionic conductivity in the argyrodite family. Furthermore, we find that anion site disorder modulates the presence and time scales of cyanide rotational dynamics. Ordered configurations of anions enable fast, quasi-free rotations of cyanides that occur on time scales of 10 11 Hz at T = 300 K. In contrast, we find that cyanide dynamics are slow or frozen in Li 6 PS 5 CN when site disorder between the cyanide and sulfide sublattices is present at T = 300 K. We rationalize the observed differences in cyanide dynamics in the context of elastic dipole interactions between neighboring cyanide anions and local strain induced by the configurations of site disorder that may impact the energetic landscape for cyanide rotational dynamics. Through this study, we find that anion disorder plays a decisive role in dictating the extent and time scales of both lithium ion and cyanide dynamics in Li 6 PS 5 CN.

36 MATERIALS SCIENCE↗

Precise Tailoring of Lithium-Ion Transport for Ultralong-Cycling Dendrite-Free All-Solid-State Lithium Metal Batteries

All-solid-state lithium metal batteries can address crucial challenges regarding insufficient battery cycling life and energy density. The demonstration of long-cycling dendrite-free all-solid-state lithium metal batteries requires precise tailoring of lithium-ion transport of solid-state electrolytes (SSEs). Here, in this work, a proof of concept is reported for precise tailoring of lithium-ion transport of a halide SSE, Li 3 InCl 6 , including intragranular (within grains) but also intergranular (between grains) lithium-ion transport. Lithium-ion migration tailoring mechanism in crystals is developed by unexpected enhanced Li, In, and Cl vacancy populations and lower energy barrier for hopping. The lithium-ion transport tailoring mechanism between the grains is determined by the elimination of voids between grains and the formation of unexpected supersonic conducting grain boundaries, boosting the lithium dendrite suppression ability of SSE. Due to boosted lithium-ion conduction and dendrite-suppression ability, the all-solid-state lithium metal batteries coupled with Ni-rich LiNi 0.83 Co 0.12 Mn 0.05 O 2 cathodes and lithium metal anodes demonstrate breakthroughs in electrochemical performance by achieving extremely long cycling life at a high current density of 0.5 C (2000 cycles, 93.7% capacity retention). This concept of precise tailoring of lithium-ion transport provides a cost, time, and energy efficient solution to conquer the remaining challenges in all-solid-state lithium-metal batteries for fast developing electric vehicle markets.

25 ENERGY STORAGE↗

Refractive index of lithium fluoride at high dynamic stresses

Alkali halides are prototypical ionic solids whose refractive index is a fundamental property related to their lattice structure and ionic polarizability. In particular, lithium fluoride (LiF) has the largest band gap of any known transparent material and maintains transparency at high pressures, making it well suited for use as an optical window in dynamic compression experiments. While empirical fits to the measured density dependence of the refractive index have been provided, a model that is valid over the entire pressure range of experiments and based on a polarization-based theoretical description is lacking. We present a refractive index model for dynamically compressed LiF based on the Lorentz-Lorenz equation, where the molecular polarizability is determined using a single oscillator model with a strain polarizability parameter Λ=0.73. Here, we show that our modeling approach provides an excellent match to the LiF refractive index data for both shock and ramp compression experiments to 900 GPa (density compression greater than threefold). Additionally, updated fits are provided to determine the refractive index correction for LiF windows used in dynamic compression experiments.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

Low-cost iron trichloride cathode for all-solid-state lithium-ion batteries

The dominant chemistries of lithium-ion batteries on the market today still rely on flammable organic liquid electrolytes and cathodes containing scarce metals, such as cobalt or nickel, raising safety, cost and environmental concerns. Here we show a FeCl 3 cathode that costs as little as 1% of the cost of a LiCoO 2 cathode or 2% of a LiFePO 4 cathode. Once coupled with a solid halide electrolyte and a lithium-indium (Li–In) alloy anode, it enables all-solid-state lithium-ion batteries without any liquid components. Notably, FeCl 3 exhibits two flat voltage plateaux between 3.5 and 3.8 V versus Li + /Li, and the solid cell retains 83% of its initial capacity after 1,000 cycles with an average Coulombic efficiency of 99.95%. Combined neutron diffraction and X-ray absorption spectroscopy characterizations reveal a Li-ion (de)intercalation mechanism together with a Fe 2+ /Fe 3+ redox process. Further, our work provides a promising avenue for developing sustainable battery technologies with a favourable balance of performance, cost and safety.

25 ENERGY STORAGE↗

Epitaxy of LiNbO 3 : Historical Challenges and Recent Success

High-quality epitaxial growth of thin film lithium niobate (LiNbO 3 ) is highly desirable for optical and acoustic device applications. Despite decades of research, current state-of-the-art epitaxial techniques are limited by either the material quality or growth rates needed for practical devices. In this paper, we provide a short summary of the primary challenges of lithium niobate epitaxy followed by a brief historical review of lithium niobate epitaxy for prevalent epitaxial techniques. Available figures of merit for crystalline quality and optical transmission losses are given for each growth method. The highest crystalline quality lithium niobate thin film was recently grown by halide-based molecular beam epitaxy and is comparable to bulk lithium niobate crystals. However, these high-quality crystals are grown at slow rates that limit many practical applications. Given the many challenges that lithium niobate epitaxy imposes and the wide variety of methods that have unsuccessfully attempted to surmount these barriers, new approaches to lithium niobate epitaxy are required to meet the need for simultaneously high crystalline quality and sufficient thickness for devices not currently practical by existing techniques.

36 MATERIALS SCIENCE↗

Dendrite inhibiting electrolytes for metal-based batteries

A metal-based battery includes at least one metal electrode immersed within an electrolyte that includes: (1) an aprotic solvent; (2) a simple halogen containing material; and (3) optionally a metal salt that includes a complex halogen containing anion. The simple halogen containing material may include a metal halide salt that includes a metal cation selected from the group including but not limited to lithium and sodium metal cations. The metal halide salt may also include a halide anion selected from the group consisting of fluoride, chloride, bromide and iodide halide anions. The use of the metal halide salt within the metal-based battery provides enhanced cycling ability within the metal-based battery. Also contemplated are additional simple halogen containing material additives that may enhance cycling performance of a metal-based battery.

Archer, Lynden A.↗

Amorphous Oxyhalide Matters for Achieving Lithium Superionic Conduction

The recently surged halide-based solid electrolytes (SEs) are great candidates for high-performance all-solid-state batteries (ASSBs), due to their decent ionic conductivity, wide electrochemical stability window, and good compatibility with high-voltage oxide cathodes. In contrast to the crystalline phases in halide SEs, amorphous components are rarely understood but play an important role in Li-ion conduction. Here, we reveal that the presence of amorphous component is common in halide-based SEs that are prepared via mechanochemical method. The fast Li-ion migration is found to be associated with the local chemistry of the amorphous proportion. Taking Zr-based halide SEs as an example, the amorphization process can be regulated by incorporating O, resulting in the formation of corner-sharing Zr–O/Cl polyhedrons. This structural configuration has been confirmed through X-ray absorption spectroscopy, pair distribution function analyses, and Reverse Monte Carlo modeling. The unique structure significantly reduces the energy barriers for Li-ion transport. As a result, an enhanced ionic conductivity of (1.35 ± 0.07) × 10 –3 S cm –1 at 25 °C can be achieved for amorphous Li 3 ZrCl 4 O 1.5 . In addition to the improved ionic conductivity, amorphization of Zr-based halide SEs via incorporation of O leads to good mechanical deformability and promising electrochemical performance. In conclusion, these findings provide deep insights into the rational design of desirable halide SEs for high-performance ASSBs.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Halide sublattice dynamics drive Li-ion transport in antiperovskites

Here, in this work, we resolve how proton dynamics and halide mixing enhance or impede ionic conduction in protonated lithium antiperovskites (pLiAP) at compositions near the eutectic points of the halide salts. As a material class, pLiAPs of the form Li 3-x OH x X, (X = Cl, Br) show vast compositional design freedom; however, the resulting properties are susceptible to synthesis and processing methodologies. Proton incorporation and halide mixing stabilize the perovskite cubic phase at low temperatures (<50 °C) and using halide mixtures near the eutectic points (~250 to 300 °C) offer possibilities of lower temperature and faster synthesis and processing conditions (<1 h). Mixed-halide compositions such as Li 2 OHCl 0.37 Br 0.63 lead to a 30-fold improvement in room temperature ionic conductivity of a single halide structure, 1.5 × 10 -6 vs. 4.9 × 10 -8 S cm -1 (Li 2 OHCl). We combine infrared spectroscopy and nuclear magnetic resonance with first-principles density functional theory calculations to deconvolute halide mixing effects from local proton dynamics on Li-ion transport. In contrast to what has been supposed, our findings suggest that the halide sublattice dynamics, besides the OH rotation, correlate strongly with the fast-ion conduction at high temperatures.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗