Chemo-Mechanics in All Solid State Composite Cathodes

Abstract

Decarbonization of transportation systems will require a suite of battery technologies depending on the mode and scale. Solid state batteries are an energy dense and non-flammable alternative to conventional batteries and is currently being explored for passenger vehicles and portable electronics1,2. While there is considerable interest in understanding lithium metal anodes for solid state batteries, many significant challenges still exist in solid state cathodes. Solid state cathodes are composites and usually include a combination of active material, solid electrolyte and binder3. The composition, microstructure, and properties of the cathode has significant implications for rate performance, energy density, and lifetime of these systems. Here we examine composite solid state cathodes comprised of argyrodite Li6PS5Cl and LiNi0.8Co0.1Mn0.1O2. We examine how composition and structure influences performance with a specific lens on understanding how chemo-mechanical transformations and buried solid-solid interfaces evolved during cycle operation. In addition we show how external operating conditions (temperature/pressure) influence stress generation in these systems. In this talk we will discuss how we combine novel bench-top experiments with advanced operando x-ray characterization tools to quantify stress and correlate it to structure.[1]Shen, F., Dixit, M. B., Zaman, W., Hortance, N., Rogers, B., & Hatzell, K. B. (2019). Composite electrode ink formulation for all solid-state batteries. Journal of The Electrochemical Society, 166(14), A3182.[2]Hatzell, K. B., & Zheng, Y. (2021). Prospects on large-scale manufacturing of solid state batteries. MRS Energy & Sustainability, 8(1), 33-39.[3]Ren, Y., Hortance, N., & Hatzell, K. (2022). Mitigating Chemo-Mechanical Failure in Li-S Solid State Batteries with Compliant Cathodes. Journal of The Electrochemical Society.