Transition Metal Dichalcogenides as Effective Catalysts for High-Rate Lithium-Sulfur Batteries

In today’s renaissance of high-energy-density secondary batteries, lithium-sulfur (Li-S) batteries represent one of the most promising candidates for the next generation of renewable energy storage systems due to sulfur’s high theoretical specific capacity of 1675 mA h g^-1 and high earth abundance. However, despite decades of study, the issues associated with capacity fade via the polysulfide shuttle and sluggish kinetics remain. Through a rigorous and detailed electrochemical study of lithium polysulfides via rotating disk electrode (RDE) voltammetry, we have investigated the kinetics of the redox reactions and explored candidate catalysts to potentially overcome/mitigate the polysulfide shuttle effect. From these RDE studies, supported by comprehensive electronic structure calculations of conversion-type surface reactions, we determined that WSe₂ can effectively catalyze the polysulfide redox reaction, though further studies are necessary to improve the overall Li-S battery performance.