First-principles study on electrode – solid electrolyte interfaces in solid-state battery via efficient structure prediction method*

Understanding the origin of high interfacial resistances between electrodes and solid-electrolytes is crucial for commercial application of solid-state batteries (SSBs). [Chem. Mater. 26, 4248-4255] [ACS Appl. Mater. Interfaces 9, 286-292]. Here we utilized the CALYPSO structure prediction method [Physical Review B 82, 094116] to investigate the interface structures between LiCoO₂ cathode and β-Li₃PS₄ sulfide electrolyte. About 20000 configurations are sampled to search the stable interface structures. The results show that the interfacial reaction layer is formed accompanied by the cation mixing and anion mixing. It is confirmed that the preferential Li depletion can occur at interface upon charging, even in very distorted region. Furthermore, CALYPSO interface structure prediction method can be applied to the solid-solid interface systems beyond the SSBs.