An ultraconformal chemo-mechanical stable cathode interface for high-performance all-solid-state batteries at wide temperatures

Abstract

The state-of-the-art all-solid-state lithium batteries (ASSLBs) based on Ni-rich layered oxides suffer from notorious solid–solid interface issues especially at the cathode side, leading to deteriorating interfacial transportation and rapid performance degradation. Here we report a transformative mechanical strategy to build an ultraconformal cathode interface between Ni-rich layered metal oxides and halide solid electrolytes (SEs). The composite cathodes with ultraconformal interface show excellent mechanical properties with high Young's modulus and Vickers hardness, which significantly suppresses the chemo-mechanical deformation and facilitates the interfacial transport of lithium ions and electrons. This approach remarkably enhances the capacity to 216.4 mA h g⁻¹ at 0.1C with a superior initial coulomb efficiency of 91.6%, which rivals that of the Ni-rich layered cathode in organic liquid batteries. Furthermore, the proposed ASSLBs demonstrate ideal low-temperature performance with capacities of 172.5 and 118.4 mA h g⁻¹ at 0 and −20 °C, respectively, the highest values in the state-of-the-art ASSLBs. This study offers a promising strategy to construct an ultraconformal chemo-mechanical stable cathode interface for high-performance ASSLBs in a wide temperature range.