Formation of 2D Amorphous Lithium Sulfide Enabled by Mo<sub>2</sub>C Clusters Loaded Carbon Scaffold for High‐Performance Lithium Sulfur Batteries
Huadong Yuan, Jianhui Zheng, Gongxun Lu, Liang Zhang, Tianran Yan, Jianmin Luo, Yao Wang, Yujing Liu, Tianqi Guo, Zhongchang Wang, Jianwei Nai, Xinyong Tao
Abstract
Abstract Lithium‐sulfur (Li‐S) batteries, operated through the interconversion between sulfur and solid‐state lithium sulfide, are regarded as next‐generation energy storage systems. However, the sluggish kinetics of lithium sulfide deposition/dissolution, caused by its insoluble and insulated nature, hampers the practical use of Li‐S batteries. Herein, leaf‐like carbon scaffold (LCS) with the modification of Mo 2 C clusters (Mo 2 C@LCS) is reported as host material of sulfur powder. During cycles, the dissociative Mo ions at the Mo 2 C@LCS/electrolyte interface are detected to exhibit competitive binding energy with Li ions for lithium sulfide anions, which disrupts the deposition behavior of crystalline lithium sulfide and trends a shift in the configuration of lithium sulfide toward an amorphous structure. Combining the related electrochemical study and first‐principle calculation, it is revealed that the formation of amorphous lithium sulfides shows significantly improved kinetics for lithium sulfide deposition and decomposition. As a result, the obtained Mo 2 C@LCS/S cathode shows an ultralow capacity decay rate of 0.015% per cycle at a high mass loading of 9.5 mg cm −2 after 700 cycles. More strikingly, an ultrahigh sulfur loading of 61.2 mg cm −2 can also be achieved. This work defines an efficacious strategy to advance the commercialization of Mo 2 C@LCS host for Li‐S batteries.