YVO4 nanoparticles decorated on mesoporous carbon as bidirectional catalysts promoting Li2S precipitation/dissolution for advanced Li-S batteries

The shuttle effect induced by the dissolution of lithium polysulfides (LiPSs) and the sluggish kinetic con -version between LiPSs and Li2S2/Li2S is key bottlenecks preventing commercial application of lithium-sulfur batteries (LSBs). Herein, a granular composite consisting of acetylene black (AB) wrapped with bimetallic oxides YVO4 was designed by a simple hydrothermal and calcination method to modify of separators on LSBs. Combining the inherent electrical conductivity and high surface area of AB with the strong polarity and abundant oxygen vacancies of YVO4, the YVO4/AB composite has a powerful capability to anchor the LiPSs and catalyze the transformation between LiPSs and Li2S2/Li2S bidirectionally. Therefore, the LSBs assembled with the YVO4/AB/PP modified separator possess a high initial specific capacity of 1237 mAh g-1 at 0.2 C, stable cycling performance of over 1000 cycles at 2 C with a capacity decay rate of only 0.057% per cycle, and good rate performance of 656 mAh g-1 at 3 C. Moreover, the battery achieves an area capacity of 5.5 mAh cm-2 under a high sulfur loading of 5 mg cm-2, providing a compelling exploration of the practical applications of LSBs.(c) 2023 Published by Elsevier B.V.