Dual catalysis-adsorption function modified separator towards high-performance Li-Se battery

Lithium-selenium (Li-Se) batteries have recently attracted increasingly attentions due to the high electronic conductivity and volumetric capacity of Se. However, the low selenium utilization and inferior electrode kinetics hamper the practical application of Li-Se batteries. In this work, a MoSe2@CNT/GO hybrid interlayer modified polypropylene (PP) (MoSe2@CNT/GO-PP) separator is designed to realize high-performance Li-Se batteries. The MoSe2@CNT/GO interlayer not only facilitates fast kinetic process by catalyzing the conversion of Li2Se, but also has strong chemisorption of Li2Se. These largely improve the selenium utilization. As a result, the Li-Se batteries with MoSe2@CNT/GO-PP separators exhibit a high reversible capacity of 547.2 mAh g−1 after 300 cycles at 0.5C and an excellent rate capability of 390.2 mAh g−1 at 5C. This work provides a new insight for enhancing the electrochemical performance of Li-Se batteries via modifying the separator.