Active Anchoring Polysulfides of ZnS-Decorated Porous Carbon Aerogel for a High-Performance Lithium-Sulfur Battery

A carbon aerogel composite modified with ZnS (ZnS-CA) was successfully prepared through a simple insitu synthesis and used as a cathode for lithium-sulfur batteries. The nanopore ZnS-CA composites with a high specific surface area and rich mesoporous structure exhibit stronger adsorption and immobilization ability for polysulfides. The ZnS-CA/S cathode materials offer excellent electrochemical performances with lasting cycling stability and high specific capacity. In particular, the 6ZnS-CA/S sample achieves an initial capacity of 1352mAhg(-1) at 0.2C and maintains a high capacity of 1119mAhg(-1) after 100 cycles. Furthermore, after 300 long cycles, it still maintains a high capacity of 730mAhg(-1) at 1C. These excellent performance features are attributed to the strong affinity of ZnS for Li2Sn species, thus polysulfide shuttling can be effectively inhibited from the cathode source. Furthermore, the strong adsorption energy between ZnS and polysulfides was validated by using first-principles theory calculations, which reveals the anchoring and catalytic mechanism.