Regulating electrode–electrolyte interfaces by grain refinement effect for propelling polysulfide transformation reaction

The excellent energy density of lithium-sulfur batteries (LSBs) offers high promising for the next-generation secondary battery and replacement of the state-of-the-art lithium-ion cell. However, the shuttling effect of the intermediate polysulfide (LiPS) presents a bottleneck that could reduce cycling life and sulfur utilization. Solid polymer electrolytes (SPEs), which could inhibit the shuttle effect and provide safety, are emerging as promising alternatives to conventional liquid electrolytes. However, the poor interaction between the SPE and electrodes remains a challenge that could prevent their practical applications. Herein, we proposed an innovative novel strategy to develop reinforced MXene into polyvinylidene fluoride–co–hexafluoropropylene with Li salt (RM−PHL), with enriched functional group to improve the Li ion dissociation and strengthen the interaction between electrode–electrolyte. Gaining benefit from the improved electrode–electrolyte interfaces, the RM−PHL SPE-based LSB demonstrated a high specific capacity of 907 mAh·g⁻¹ with outstanding durability of 100 cycles and retention rate of 87 %. Moreover, the SPEs demonstrated a good mechanical strength with enhanced fire-retardant properties. This finding offers a treasured insight into the development of innovative SPE for next-generation batteries, paving the way for the commercial opportunity of all-solid-state Li-based batteries and other energy storage and conversion devices.