Critical impact of volume changes in sulfide-based all-solid-state batteries operating under practical conditions

Owing to their enhanced safety and potentially high energy density, all-solid-state batteries (ASSBs) are gaining discernible attention in the emerging era of electric mobility. However, maintaining the physical contact between the solid components of ASSBs during repeated charging and discharging cycles is a formidable challenge, particularly when the cell constituents undergo large volume changes. High stack pressure is often required to compensate for this volume change and tighten the interparticle contact, but elevation of the pressure beyond the range that is commercially adoptable (typically below 1 MPa) would render the entire technology impractical for vehicular applications. To overcome this technical hurdle, a variety of strategies has been developed in the battery community at both the material and cell levels. This paper comprehensively summarizes the effect of volume change on the performance of ASSBs and highlights recent studies that offer solutions to circumvent the relevant issues. Additionally, we propose strategic approaches for addressing the drawbacks related to the volume change of cell components toward realizing highly reliable ASSBs operating under low stack pressure.