Accelerating Sulfur Redox Reactions by Topological Insulator Bi₂Te₃ for High-Performance Li-S Batteries

Polysulfide shuttling and sluggish sulfur redox kinetics hinder the cyclability and rate capability of lithium-sulfur (Li-S) batteries. Accelerating sulfur redox reactions is considered a promising way toward the capture and utilization of soluble sulfur species. Herein, topological insulator (TI) Bi₂Te₃ is reported as an electrocatalyst for accelerated sulfur electrochemistry. The findings indicate that Bi₂Te₃ can effectively anchor soluble sulfur species and form seamless electron transport pathways with the adsorbed polysulfides. Both the sulfur reduction reactions and the reverse processes are found to be boosted by Bi₂Te₃. The incorporation of Bi₂Te₃ enables efficient operation of Li-S batteries in terms of impressive rate capability of 857 mAh g⁻¹ at 3 C and very low capacity decay of 0.033% per cycle over 1000 cycles. This work extends the application of TI to the field of Li-S electrochemistry and may inspire further explorations.