Synergistic Effect of In 2 O 3 /NC-Co 3 O 4 Interface on Enhancing the Redox Conversion of Polysulfides for High-Performance Li-S Cathode Materials at Low Temperatures.

Lithium-sulfur (Li-S) batteries are considered as a promising energy storage technology due to their high energy density; however, the shuttling effect and sluggish redox kinetics of lithium polysulfides (LiPSs) severely deteriorate the electrochemical performance of Li-S batteries. Herein, we report a novel configuration wherein In 2 O 3 and Co 3 O 4 are incorporated into N-doped porous carbon as a sulfur host material (In 2 O 3 @NC-Co 3 O 4 ) using metal-organic framework-based materials to synergistically tune the catalytic abilities of different metal oxides for different reaction stages of LiPSs, achieving a rapid redox conversion of LiPSs. In particular, the introduction of N-doped carbon improved the electron transport of the materials. The polar interface of In 2 O 3 and Co 3 O 4 anchors both long- and short-chain LiPSs and catalyzes long-chain and short-chain LiPSs, respectively, even at low temperatures. Consequently, the Li-S battery with In 2 O 3 @NC-Co 3 O 4 cathode materials delivered an excellent discharge capacity of 1042.4 mAh g -1 at 1 C and a high capacity retention of 85.1% after 500 cycles. Impressively, the In 2 O 3 @NC-Co 3 O 4 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 (room temperature) and 755 mAh g -1 at 0.1 C (-20 °C).