Development and characterization of thiophosphate-based composite cathodes for all-solid-state batteries

All-solid-state batteries (ASSBs) with thiophosphate-based cathodes are a promising emerging energy storage technology. They offer advantages such as increased safety and energy density. However, various material and microstructure-related challenges must be overcome to optimize their performance. This work investigates the kinetics of Li-ion conduction and diffusion in ASSB cathodes made of NCM811 active material and LPSCl solid electrolyte. Chronoamperometric rate tests are employed to quantify resistive and diffusive limitations. The results show that thin, LPSCl-rich, and fine-particulate cathodes with moderate densification pressure exhibit the best Li-ion transport kinetics. In contrast, thicker cathodes with higher NCM811 content tend to face diffusive limitations. Reducing the LPSCl particle size increases the contact area to NCM811 and mitigates these limitations, providing valuable insights for improving cathode performance and developing commercially relevant ASSB cathodes.