Addressing the Prominent Li+ Intercalation Process of Metal Sulfide Catalyst in Li-S Batteries

Various catalysts are adopted to boost the conversion chemistry of Lithium sulfur (Li-S) batteries, but most of them are electrochemical-active in a working Li-S cell, and the changes of their chemical state and the induced influence toward the Li-S catalytic mechanism are unclear. Herein, a dynamic catalytic mechanism is proposed by the selection of Li+-interaction-reversible VS2 catalyst as a representative species to address this issue. The VS2 catalyst with ultrastable Li+ intercalation/deintercalation characteristics, fast charge transport capability, and active capacity contribution can provide a strong and dynamic chemisorption toward polysulfide (LiPS). The resulting Li-S batteries exhibit excellent cyclability at 3 C with capacity attenuation of 81.23% over 250 cycles and good rate capability up to 8 C. Moreover, a new insight toward the dynamic catalytic changes induced by the prominent Li+ intercalation process of metal sulfide is proposed, which can provide more opportunities for the evolutional design for Li-S catalysts.