Long and Short Chain Selective Catalytic Conversion of Polysulfides Using Bimetallic Oxides Catalyst of In2o3@Nc-Co3o4 with Nitrogen-Doped Carbon for Lithium-Sulfur Cathode Materials

Lithium-sulfur (Li-S) battery is a promising energy storage technology due to its high energy density, however, severe shuttling effect and sluggish redox kinetics of lithium polysulfides (LiPSs) deteriorate the electrochemical performance of Li-S batteries. Herein, a novel sulfur host material, In2O3@NC-Co3O4, composed of nitrogen-doped carbon (NC) and bimetallic oxides catalysts (In2O3 and Co3O4), has been designed to regulate LiPSs conversion synergistically. This design leads to significant enhancement in the electrochemical performance of Li-S batteries at both room-temperature and low-temperature. Specifically, the introduction of NC improved the electron transport of the materials and enhanced the electrochemical performance. Furthermore, the polar In2O3 and Co3O4 anchor both long and short chain LiPSs, and catalyze long-chain and short-chain LiPSs respectively. Consequently, the assembled Li-S battery with In2O3@NC-Co3O4 cathode materials delivered excellent discharge capacity of 1042.4 mAh g-1 at 1C, and high capacity retention of 85.1% after 500 cycles. Impressively, the In2O3@NC-Co3O4 cathode displays superior performances at high current density and low temperature due to the enhanced redox kinetics, delivering 756 mAh g-1 at 2 C and room temperature and 755 mAh g-1 at 0.1 C and -20 °C. This study presents a feasible approach for synergistically catalyzing LiPSs conversion and facilitates the development of Li-S battery for low-temperature energy storage devices.