Improved Interface Stability and Room-Temperature Performance of Solid-State Lithium Batteries by Integrating Cathode/Electrolyte and Graphite Coating

Poor interface stability is a crucial problem hindering the electrochemical performance of solid-state lithium batteries. In this work, a novel approach for interface stability was proposed to integrate the cathode/solid electrolyte by forming an electrolyte buffer layer on the rough surface of the cathode and coating a layer of graphite on the side of the electrolyte facing the lithium anode. This hybrid structure significantly improves the integration and the interface stability of the electrode/electrolyte. The interfacial resistance was dramatically reduced, the stability of the plating/stripping of Li metal was enhanced, and the growth of lithium dendrites was also inhibited due to the formation of the LiC6 transition layer. The obtained solid-state lithium battery shows enhanced rate performance at room temperature from 0.5 to 4 C and stable cycling performance at 1 C with a retention capacity of 100 mAh g–1 after 200 cycles. This integrated electrode/electrolyte design approach is expected to be widely used to improve interfacial stability and room-temperature electrochemical performance of solid-state batteries.