Engineering topics

Brahmbhatt, Teerth

Publications and source records attributed to Brahmbhatt, Teerth.

4 records

DOE OSTI2023

Navigating the complexities of solvent and binder selection for solution processing of sulfide solid-state electrolytes

We introduce a paradigm of solvent and binder selection for solution-processing Li 6 PS 5 Cl solid-state electrolyte particles based on Hansen solubility parameters. Treatment of the Li 6 PS 5 Cl in selected solvents results in particle morphological change, but crystallographic structure remains intact. Although solution processing reduced the Li 6 PS 5 Cl ionic conductivity, it promotes interfacial stability by alleviating reduction of the solid electrolyte in contact with Li metal. In conclusion, these findings have the potential to enhance the stability, structural integrity, and performance of sulfide solid-state electrolytes in practical applications.

25 ENERGY STORAGE↗

DOE OSTI2021

Investigation of glass-ceramic lithium thiophosphate solid electrolytes using NMR and neutron scattering

Solid-state Li batteries require solid electrolytes which have high Li+ conductivity and good chemical/mechanical compatibility with Li metal anodes and high energy cathodes. Structure/function correlations which relate local bonding to macroscopic properties are needed to guide development of new solid electrolyte materials. This study combines diffraction measurements with solid-state nuclear magnetic resonance spectroscopy (ssNMR) and neutron pair distribution function (nPDF) analysis to probe the short-range vs. long-range structure of glass-ceramic Li 3 PS 4 -based solid electrolytes. Here, we demonstrate how different synthesis conditions (e.g., solvent selection and thermal processing) affect the resulting polyanionic network. More specifically, structures with high P coordination numbers (e.g., PS 4 3– and P 2 S 7 4– ) correlate with higher Li + mobility compared to other polyanions (e.g., (PS 3 ) n n– chains and P 2 S 6 4– ). Overall, this work demonstrates how ssNMR and nPDF can be used to draw key structure/function correlations for solid-state superionic conductors.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Cathode–Sulfide Solid Electrolyte Interfacial Instability: Challenges and Solutions

All-solid-state batteries are a candidate for next-generation energy-storage devices due to potential improvements in energy density and safety compared to current battery technologies. Due to their high ionic conductivity and potential scalability through slurry processing routes, sulfide solid-state electrolytes are promising to replace traditional liquid electrolytes and enable All-solid-state batteries, but stability of cathode-sulfide solid-state electrolytes interfaces requires further improvement. Herein we review common issues encountered at cathode-sulfide SE interfaces and strategies to alleviate these issues.

25 ENERGY STORAGE↗

DOE OSTI2020

Solvent-Mediated Synthesis of Amorphous Li 3 PS 4 /Polyethylene Oxide Composite Solid Electrolytes with High Li + Conductivity

Solvent-mediated routes have emerged as an effective, scalable, and low-temperature method to fabricate sulfide-based solid-state electrolytes. However, tuning the synthesis conditions to optimize the electrolyte’s morphology, structure, and electrochemical properties is still underexplored. Here, we report a new class of composite solid electrolytes (SEs) containing amorphous Li 3 PS 4 synthesized in situ with a poly(ethylene oxide) (PEO) binder using a one-pot, solvent-mediated route. The solvent and thermal processing conditions have a dramatic impact on the Li 3 PS 4 structure. Conducting the synthesis in tetrahydrofuran resulted in crystalline β-Li 3 PS 4 whereas acetonitrile led to amorphous Li 3 PS 4 . Annealing at 140 °C increased the Li + conductivity of an amorphous composite (Li 3 PS 4 + 1 wt % PEO) by 3 orders of magnitude (e.g., from 4.5 × 10 –9 to 8.4 × 10 –6 S/cm at room temperature) because of: (i) removal of coordinated solvent and (ii) rearrangement of the polyanionic network to form P 2 S 7 4– and PS 4 3– moieties. The PEO content in these composites should be limited to 1–5 wt % to ensure reasonable Li+ conductivity (e.g., up to 1.1 × 10 –4 S/cm at 80 °C) while providing enough binder to facilitate scalable processing. Here, the results of this study highlight a new strategy to suppress crystallization in sulfide-based SEs, which has important implications for solid-state batteries.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗