Interfacial Degradation Mechanism of Nanostructured LiCoO2 for Li6PS5Cl-Based All-Solid-State Batteries

Interfacial degradation of Li 6 PS 5 Cl (LPSCl) with oxide cathode materials during cycling, particularly the formation of interfacial voids, leads to poor electrochemical performance. The formation of these voids is driven by two distinct mechanisms: the volumetric changes of oxide cathode materials during cycling and the volumetric shrinkage of LPSCl due to oxidative decomposition. However, the relative contribution of each route to void formation remains ambiguous, especially for nanostructured cathode materials. This study highlights the predominant influence of oxidative decomposition of LPSCl on the nanostructured LiCoO 2 surface in the formation of interfacial voids when compared to the volumetric changes of LiCoO 2 between charging and discharging. The interfacial degradation behavior is compared between bare LiCoO 2 and LiCoO 2 –Li 2 SnO 3 core–shell nanoparticles. Both types of…