A Delicately Designed Sulfide Graphdiyne Compatible Cathode for High-Performance Lithium/Magnesium-Sulfur Batteries

Abstract

Novel sulfur cathodes hold the key to the development of metal-sulfur batteries, the promising candidate of next-generation high-energy-storage systems. Herein, a fascinating sulfur cathode based on sulfide graphdiyne (SGDY) is designed with a unique structure, which is composed of a conducting carbon skeleton with high Li⁺ mobility and short sulfur energy-storing unites. The SGDY cathode can essentially avoid polysulfide dissolution and be compatible with commercially available carbonate-based electrolytes and Grignard reagent-based electrolytes (all phenyl complex (APC) type electrolytes). Both the assembled Li-S and Mg-S batteries exhibit excellent electrochemical performances including large capacity, superior rate capability, high capacity retention, and high Coulombic efficiency. More importantly, this is the first implementation case of a reliable Mg-S system based on nucleophilic APC electrolytes.

Keywords: high Li+ mobility; metal-sulfur batteries; short sulfide unites; shuttle effect; sulfide graphdiyne.