Vanadium‐Doped Molybdenum Diselenide Accelerates Sulfur Redox Kinetics in Lithium–Sulfur Batteries

Abstract The persistent shuttle effect of polysulfides and slow liquid‐solid redox kinetics remain major obstacles to the practical application of Lithium–Sulfur (Li─S) batteries. In this study, a vanadium‐doped molybdenum diselenide catalyst designed to address these challenges are presented. Experimental analysis and theoretical calculations reveal that V doping slightly disrupts the 2D growth of MoSe 2 , creating structural defects and abundant edge‐active sites. These active sites enhance polysulfide adsorption, facilitate efficient catalytic conversion, and promote the utilization of S species. Additionally, electron redistribution induced by V dopants improves electronic conductivity and accelerates redox kinetics. As a result, Li─S batteries using V 0.1 Mo 0.9 Se 2 as a catalyst deliver a high discharge capacity of 1467.3 mA h g −1 at 0.1 C and maintain a capacity of 651.9 mA h g −1 after 1000 cycles at 1 C, with an ultralow decay rate of 0.036% per cycle. Under high sulfur loading (5.5 mg cm −2 ), the batteries exhibit a specific capacity of 803.9 mA h g −1 after 100 cycles and a decay rate of only 0.11% per cycle. This study demonstrates that V doping effectively activates inert MoSe 2 , providing a promising strategy for designing high‐performance sulfur cathode catalysts and advancing the development of next‐generation Li─S batteries.