Formation of 2D Amorphous Lithium Sulfide Enabled by Mo₂C Clusters Loaded Carbon Scaffold for High‐Performance Lithium Sulfur Batteries

Abstract

Lithium‐sulfur (Li‐S) batteries, operated through the interconversion between sulfur and solid‐state lithium sulfide, have been 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 Mo2C clusters (Mo2C@LCS) is reported as host material of sulfur powder. During cycles, the dissociative Mo ions at the Mo2C@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 towards an amorphous structure. Combining the related electrochemical study and first‐principle calculation, it is revealed that the formation of anorphous lithium sulfides shows significantly improved kinetics for lithim sulfides deposition and decomposition. As a result, the obtained Mo2C@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. Our work defines an efficacious strategy to advance the commercialization of Mo2C@LCS host for Li‐S batteries.This article is protected by copyright. All rights reserved