High-Entropy Metal Oxide-Coated Carbon Cloth as Catalysts for Long-Life Li–S Batteries

Abstract

Lithium–sulfur (Li–S) batteries with high specific energy density, low cost, and environmental friendliness of sulfur have been regarded as a competitive alternative to replace lithium-ion batteries. However, the shuttle effect and the sluggish conversion rate of lithium polysulfides (LiPSs) have seriously limited the practical application of Li–S batteries. Herein, high-entropy oxides grown on the carbon cloth (CC/HEO) are synthesized by a simple and ultrafast solution combustion method for the sulfur cathode. The as-prepared composites possess abundant HEO active sites for strong interaction with LiPSs, which can significantly promote redox kinetics. Besides, the carbon fiber substrate not only ensures high electrical conductivity but also accommodates large volume change, leading to a stable sulfur electrochemistry. Benefiting from the rational design, the Li–S batteries with CC/HEO as cathode skeleton exhibits good cyclability with a capacity decay rate of 0.057% per cycle after 1000 cycles at 2 C. More importantly, the Li–S batteries with 4.3 mg cm–2 high sulfur loading can still retain a high capacity retention of 78.2% after 100 cycles.