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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 343 records · Page 19
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Unveiling a high capacity multi-redox (Nb 5+ /Nb 4+ /Nb 3+ ) NASICON-Nb 2 (PO 4 ) 3 anode for Li- and Na-ion batteries

Sodium superionic conductor (NASICON)-type materials are widely explored as Li- and Na-ion cathodes and solid-state electrolytes but are largely ignored as anodes due to their lower capacities and higher intercalation voltages, which reduce the overall energy densities of Li- and Na-ion batteries (LIBs and SIBs). Herein, we unveil high capacity multi-redox empty NASICON-Nb 2 (PO 4 ) 3 as a potential anode material for LIBs and SIBs, which reversibly delivers 167 and 150 mA h g -1 at the average voltages of 1.86 V vs. Li + /Li 0 and 1.46 V vs. Na + /Na 0 , respectively. The Li and Na intercalation reactions proceed via multiple phase transitions, leading to short-range ordered Li 3 Nb 2 (PO 4 ) 3 and triclinic (P$\overline{1}$ with combining macron]) Na 3 Nb 2 (PO 4 ) 3 , as revealed by in situ X-ray diffraction studies. Our density functional theory calculations are also in agreement with the in situ measurements in predicting a stable Na 3 Nb 2 (PO 4 ) 3 composition in the Na–Nb 2 (PO 4 ) 3 pseudo-binary system. X-ray absorption spectroscopy confirms the participation of multi-redox Nb 5+ /Nb 4+ /Nb 3+ couples. The Nb 2 (PO 4 ) 3 anode delivers capacities greater than 124 and 106 mA h g -1 at 1C rate in Li and Na cells, respectively. In conclusion, pairing Nb 2 (PO 4 ) 3 with suitable cathodes and electrolytes can lead to high energy density batteries.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

Floating zone crystal growth, structure, and properties of a cubic Li 5.5 La 3 Nb 1.5 Zr 0.5 O 12 garnet-type lithium-ion conductor

As a promising candidate for solid-state electrolytes in Li-ion batteries, the garnet-type Li-ion conductor series Li 5+x La 3 Nb 2-x Zr x O 12 (LLNZO) (0 ≤ x ≤ 2) exhibits high ionic conductivity at room temperature. However, no previous single-crystal growth or characterization has been reported for LLNZO compositions 0 ≤ x ≤ 1. To obtain a complete understanding of the trend in the structure–property relationship in this class of materials, we used the floating zone (FZ) method to grow a single crystal of Li 5.5 La 3 Nb 1.5 Zr 0.5 O 12 that was 4 mm in diameter and 10 mm in length. Using Laue neutron single-crystal diffraction, two distinct Li sites were observed: tetrahedral 24d and octahedral 96h sites. The maximum entropy method (MEM) based on neutron single-crystal diffraction data was used to map Li nuclear density and estimate that the bottleneck of Li transport exists between neighboring tetrahedral and octahedral sites, and that Li is delocalized between split octahedral sites. Room-temperature Li-ion conductivity in Li 5.5 La 3 Nb 1.5 Zr 0.5 O 12 measured with electrochemical impedance spectroscopy (EIS) was 1.37 × 10 -4 S cm -1 . The Li migration activation energy was estimated to be 0.50 eV from EIS and 0.47 eV from dielectric relaxation measurements. The Li-ion jump attempt rate was estimated to be 1.47 × 10 12 Hz while the time scale of successful migration is 10 -7 to 10 -6 s.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2026

Controlled lithium stripping enables a stable interface for long-cycling anode-free solid-state batteries

Anode-free solid-state batteries (AFSSBs) are a promising route toward achieving high energy density. In these cells, the anode contains no pre-stored lithium (Li). Instead, the entire Li inventory originates from the cathode and is freshly deposited onto a bare current collector during charging. However, achieving uniform and defect-free Li plating on this bare current collector remains a major challenge, often resulting in low Li plating/stripping efficiency and rapid capacity decay. Here, for the first time, operando neutron imaging is employed to visualize Li plating/stripping behavior in an anode-free full cell with LiNi0.82Mn0.07Co0.11O2 (NMC) as the cathode. Operando measurements reveal that complete stripping of Li leaves isolated Li residues on the current collector, which degrades the interfacial contact between the current collector and the solid-state electrolyte. To mitigate this interfacial issue and promote more uniform Li deposition, we implement a discharge-cutoff-voltage strategy that intentionally retains a thin residual Li layer after stripping. This preserved Li-containing interfacial reservoir not only improves interfacial contact but also serves as an in situ formed seed layer that enables more homogeneous subsequent Li plating. As a result, the optimized anode-free cell with limited stripping depth exhibits excellent long-term cycling stability, maintaining a discharge capacity of 112.1 mAh g−1 with a capacity retention of 80.6% and an average coulombic efficiency of approximately 99.9% after 500 cycles at 0.25 C. In contrast, the cell with a conventional discharge cutoff voltage of 2.8 V exhibits rapid capacity decay, retaining only 59.7 mAh g−1 after 50 cycles with a capacity retention of 40.7%. This work demonstrates that limiting deep stripping to preserve a thin Li-containing interfacial layer can effectively improve the cycling stability of sulfide-based AFSSBs.

Wang, Jiwei [Northeastern University, Boston]↗
DOE OSTI2025

Thermal evaporation of thin Li films

Thermal evaporation of lithium is considered a promising technique for the fabrication of clean lithium thin films for solid-state batteries. Here, in this study, we present a practical investigation of nanometer scale lithium films prepared by evaporation on different substrates. These substrates include Li-alloying and nonalloying metals as well as different classes of solid-state lithium-ion conductors. The deposition rate was also varied. For films less than 100 nm thick, the data show that the deposition rate has the biggest impact on the surface coverage. At 50 Å/s, Li forms small particles <1 μm in diameter while higher deposition rate of 150 Å/s resulted in more uniform film morphology on all the substrates. At the lower deposition rates, the wetting of Li to the substrate will impact the particle morphology. We also used the particles to estimate a contact angle between Li and the substrate to qualitatively compare the adhesion from substrate to substrate. The smallest contact angle was observed from lithium films on Li 7 La 3 Zr 2 O 12 and LiPON (nominal Li 2.94 PO 3.5 N 0.31 ) solid-state electrolytes.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

Editors’ Choice—Methods—Pressure Control Apparatus for Lithium Metal Batteries

Lithium (Li) metal anodes are essential for developing next-generation high-energy-density batteries. However, Li dendrite/whisker formation caused short-circuiting issue and short cycle life have prevented lithium metal from being viably used in rechargeable batteries. Numerous works have been done to study how to regulate the Li growth in electrochemical cycling by using external stacking forces. While it is widely agreed that stack pressure positively affects the lithium plating/stripping process, the optimized pressure range provided by different works varies greatly because of the difference in the pressure control setup. In this work, a pressure control apparatus is designed for Li metal batteries with liquid and solid-state electrolytes (SSE). With considerations of minimizing cell to cell variation, a reusable split cell and pressure load cell are made for testing electrochemical cells with high precision pressure control. The capability of the designed setup is demonstrated by studying the pressure effect on the Li plating/stripping process.

25 ENERGY STORAGE↗
DOE OSTI2022

Technical Report

MEST has developed Materials Navigator, a machine-learning software tool, to extract/combine data from disparate sources of materials information, which can be used to make suggestions for new directions of search and discovery of materials. The goal is to create a flexible software which can help materials science researchers quickly focus on a small group of promising materials and conduct fewer and less expensive experiments for maximum impact. Materials domains of interest for the Materials Navigator include solid state electrolytes for batteries, materials for fuel cells, photovoltaics, caloric cooling materials, and permanent magnets. Our solution is useful to materials researchers in academics and industry. To date, the MEST team has already developed a prototype of the Materials Navigator, which can be used to visualize a large number of materials compounds in their “descriptor space” where materials properties are encoded in machine learning based quantities. We have used Materials Navigator to make a list of potential new materials for batteries. It has also led to the experimental discovery of a new tantalum oxide superconductor.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Vehicle Technology Office Battery Project (FY22Q4 Quarterly Report)

The project has two primary objectives: (1) down select three-dimensional (3D) printing and post-processing approaches for solid-state electrolyte (SSE) / cathode integration, and (2) understand battery failure mechanisms via ex situ and in situ characterization.

25 ENERGY STORAGE↗
DOE OSTI2023

Vehicle Technology Office Battery Project (FY23Q1 Quarterly Report)

The project has two primary objectives: (1) down select three-dimensional (3D) printing and post-processing approaches for solid-state electrolyte (SSE) / cathode integration, and (2) understand battery failure mechanisms via ex situ and in situ characterization.

25 ENERGY STORAGE↗
DOE OSTI2025

High Throughput Solvent-free Manufacturing of Battery Electrodes

The project goal is to develop and demonstrate an advanced solvent-free lithium-ion battery electrode process through proposed Advanced Dry Electrode Process (ADEP) equipment, which is expected to exhibit a better binder fibrillization and high throughput and suitable for high performance electrode manufacturing, and commonize the anode and cathode dry processing equipment, supply chain and operation for lithium-ion battery OEMs for replacing the solvent-based slurry casting. Our proposed approach will facilitate low-cost battery production by addressing the following gaps in present dry electrode processing: • Extend the dry electrode fabrication process to lithium-ion battery anode manufacturing • Increase the active material content for anodes and cathodes • Intensify the process through improved mixing, powder rheology and surface modifications • Enable processing of next-generation electrode materials that are not stable to solvent or ambient air exposure. The project objectives include the development of anode-compatible binder and binder fibrillization promoter for low irreversible capacity loss, low electrode binder content yet higher film mechanical strength, and the optimization of solvent-free anode and cathode process for low cost (>60% electrode cost reduction), high performance (10% increase in energy density without sacrificing cycle life) and high throughput to enable next generation lithium-ion battery electrode production. Solvent-free electrode manufacturing will also enable next-generation cell designs based on prelithiated anodes or solid-state electrolytes.

25 ENERGY STORAGE↗
DOE OSTI2020

Chemical interaction and enhanced interfacial ion transport in a ceramic nanofiber–polymer composite electrolyte for all-solid-state lithium metal batteries

This article reports the synergy between ceramic nanofibers and a polymer, and the enhanced interfacial Li-ion transport along the nanofiber/polymer interface in a solid-state ceramic/polymer composite electrolyte, in which a three-dimensional (3D) electrospun aluminum-doped Li 0.33 La 0.557 TiO 3 (LLTO) nanofiber network is embedded in a polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) matrix. Strong chemical interaction occurs between the nanofibers and the polymer matrix. Addition of the ceramic nanofibers into the polymer matrix results in the dehydrofluorination of the PVDF chains, deprotonation of the –CH 2 moiety and amorphization of the polymer matrix. Solid-state nuclear magnetic resonance (NMR) spectra reveal that lithium ions transport via three pathways: (i) intra-polymer transport, (ii) intra-nanofiber transport, and (iii) interfacial polymer/nanofiber transport. In addition, lithium phosphate is coated on the LLTO nanofiber surface before the nanofibers are embedded into the polymer matrix. The presence of lithium phosphate at the LLTO/polymer interface further enhances the chemical interaction between the nanofibers and the polymer, which promotes the lithium ion transport along the polymer/nanofiber interface. This in turn improves the ionic conductivity and electrochemical cycling stability of the nanofiber/polymer composite. As a result, the flexible LLTO/Li 3 PO 4 /polymer composite electrolyte membrane exhibits an ionic conductivity of 5.1 × 10 -4 S cm -1 at room temperature and an electrochemical stability window of 5.0 V vs. Li/Li + . A symmetric Li|electrolyte|Li half-cell shows a low overpotential of 50 mV at a constant current density of 0.5 mA cm -2 for more than 800 h. In addition, a full cell is constructed by sandwiching the composite electrolyte between a lithium metal anode and a LiFePO 4 -based cathode. Such an all-solid-state lithium metal battery exhibits excellent cycling performance and rate capability.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

Synthesis of Fluorine-Doped Lithium Argyrodite Solid Electrolytes for Solid-State Lithium Metal Batteries

Solid-state lithium metal batteries (SSLMBs) that utilize novel solid electrolytes (SEs) have garnered much attention because of their potential to yield safe and high-energy-density batteries. Sulfide-based argyrodite-class SEs are an attractive option because of their impressive ionic conductivity. Recent studies have shown that LiF at the interface between Li and SE enhances electrochemical stability. However, the synthesis of F-doped argyrodites has remained challenging because of the high temperatures used in the state-of-the-art solid-state synthesis methods. In this work, for the f irst time, we report F-doped Li 5+y PS 5 F y argyrodites with a tunable doping content and dual dopants (F-/Cl- and F-/Br-) that were synthesized through a solvent-based approach. Among all compositions, Li 6 PS 5 F 0.5 C l0.5 exhibits the highest Li-ion conductivity of 3.5 x 10 -4 S cm -1 at room temperature (RT). Furthermore, Li symmetric cells using Li 6 PS 5 F 0.5 Cl 0.5 show the best cycling performance among the tested cells. X-ray photoelectron spectroscopy and ab initio molecular dynamics simulations revealed that the enhanced interfacial stability of Li 6 PS 5 F 0.5 C l0.5 SE against Li metal can be attributed to the formation of a stable solid electrolyte interphase (SEI)-containing conductive species (Li 3 P), alongside LiCl and LiF. These findings open new opportunities to develop high-performance SSLMBs using a novel class of F-doped argyrodite electrolytes.

25 ENERGY STORAGE↗