Mechanistic Underpinnings of Heterogeneities in Solid-State Battery Cathode

Abstract

Solid-state batteries (SSBs) are regarded as the potential candidate for next-generation energy storage systems due to their enhanced energy density and safety characteristics. However, realizing the true potential of the SSBs is predicated on addressing several interfacial and mechanistic challenges stemming from the mechanically rigid nature of the solid electrolyte (SE). In this regard, the presence of solid-solid point contacts within the solid-state cathode poses a critical bottleneck. Point contacts not only result in transport and kinetic limitations but also lead to stress hotspots within the composite cathode. Moreover, microstructural heterogeneities govern the spatial variability of these point contacts, thereby influencing the coupled electrochemical, thermal, and mechanical signatures. Thus, understanding the critical role of cathode microstructural heterogeneity in dictating the mesoscale interactions and its implications on the SSB performance is necessary. In this work, mechanistic underpinnings of heterogeneities in solid-state cathode will be studied and its implications on the coupled electrochemical-thermal-mechanical response of SSBs will be delineated. Lastly, the effect of cathode architecture will be explored towards achieving high energy density SSBs.