Understanding Cold Sintering Processes in Densification of Halide-Based Solid Electrolytes

Halide-based ceramics have emerged as promising candidates for solid-state Li battery applications due to their high ionic conductivity and air stability. However, their manufacture and processing pose a challenge for solid-state batteries, as conventional ceramic processing often requires elevated temperatures and pressures. In this study, we develop cold sintering processes (CSPs) for halide-based solid-state electrolytes. We enable densification of these materials below 300°C by studying the impact of liquid-phase additives on dissolution / reprecipitation during pressure-densification. We further explore the influence of pressure, dwell time, temperature, and precursor compositions on the electrolyte’s mechanical and electrochemical properties. The systematic investigation of these parameters provides crucial insights into the underlying mechanisms governing the densification process and contributes to designing and manufacturing of ceramic solid electrolyte architectures.