In situ formed interfacial layer for all-solid-state lithium batteries with sulfide electrolyte films

Sulfide solid-state electrolytes (SEs) are considered as a promising alternative to traditional liquid electrolytes, owing to their low interfacial resistance and high ionic conductivity. Nevertheless, Li dendritic growth in SEs have greatly restricted the development of the high energy of All-solid-state lithium batteries (ASSLBs). In this study, a protective layer is synthesized at the Li metal surface via a solvent-free brushing method with the chemical reaction between Li metal and P2S5 particles. The P2S5@Li layer have satisfactory high interfacial energy, which is verified by density functional theory calculation. The P2S5@Li/LPSCl films/P2S5@Li symmetrical cells can cycle for >500 h at 0.1 mA cm−2. Notably, the P2S5@Li/LPSCl films/LiNbO3@LiNi0.8Co0.1Mn0.1O2 cells can deliver a discharge capacity of 155.7 mA h g−1 and excellent capacity retention of 75.5% over 400 cycles at 0.5C. This study has developed an innovative approach to ameliorate the interface of Li metal anode and practical application of ASSLBs.