Enhanced Physico‐Chemical Polysulfide Curtailment Using Carbon Nanotube‐Binary Metal Sulfide Nanocomposite for High‐Performance Lithium‐Sulfur Batteries

Abstract

The electrochemical output of lithium‐sulfur batteries is highly restricted by the dissolution and shuttling of polysulfide intermediates, which leads to the polysulfide shuttle effect. The binary metal sulfides offer a greater number of active sites and better polysulfide interaction compared to the unitary metal sulfides. Herein, a nickel cobalt sulfide‐carbon nanotube nanocomposite is devised as a highly efficient separator coater for high‐energy Li‐S batteries. The nanocomposite is featured with superior polysulfide confinement ability due to its dual metal sites and improved ionic and electronic conductivity. The material also possesses enhanced electrolyte wettability, better interfacial properties, and frequent electrolyte uptake. By virtue of the above‐mentioned superiorities, the cell reveals an initial discharge capacity of 1152 mAh g−1 at 0.5 C rate and maintains a retained capacity of 82% after 500 cycles. The cell also shows significant electrochemical results with a magnificent rate delivery of 714 mAh g−1 at 2 C rate and maintains a constant open‐circuit potential for 100 h.