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

Abstract

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.

Sulfur Reduction Reaction in Lithium–Sulfur Batteries: Mechanisms, Catalysts, and Characterization

“…The calculation results were validated by performing battery experiments, where CoN 4 C showed optimal electrochemical performance. Binding energies of sulfur species on carbides, [119,120] nitrides, [128,129] selenides, [112] and tellurides [261,284] have also been reported.…”

A one-step solvothermal synthesis of the topological insulator Bi2Te3 nanorod-modified TiO2 photocatalyst for enhanced H2-evolution activity

“…9B). 51,52 On the other hand, since the Te-H bond (238 kJ mol À1 ) is close to the Pt-H bond (251 kJ mol À1 ), leading to an appropriate adsorption-desorption ability of H atoms, the Te atoms on the highly conductive surface of Bi 2 Te 3 can serve as H 2 -production active centers to effectively facilitate the interface hydrogen production reaction (the right of Fig. 9B).…”

Artificially Layered CoSe2 Nanosheets by a Dual-Templating Strategy for High-Performance Lithium–Sulfur Batteries

“…The slow reaction kinetics of S 8 -Li 2 S x -Li 2 S in the electrochemical process leads to low capacity and poor rate capability. 15,16 (ii) The soluble lithium polysulfides (LiPSs) in the electrolyte induce an undesirable phenomenon of "shuttle effect", resulting in active material loss and specific capacity degeneration. 17,18 (iii) Not only the starting active material (S) but also the discharging product (Li 2 S) has low electronic/ionic conductivities, leading to poor rate performance.…”

“…One the other hand, lithium–sulfur batteries (LSBs) possessing a high theoretical specific capacity (1675 mAh g –1 ) are promising as the next-generation high-energy-density rechargeable batteries. − Nevertheless, the development of LSBs still encounters several critical issues and obstacles. (i) The slow reaction kinetics of S 8 -Li 2 S x -Li 2 S in the electrochemical process leads to low capacity and poor rate capability. , (ii) The soluble lithium polysulfides (LiPSs) in the electrolyte induce an undesirable phenomenon of “shuttle effect”, resulting in active material loss and specific capacity degeneration. , (iii) Not only the starting active material (S) but also the discharging product (Li 2 S) has low electronic/ionic conductivities, leading to poor rate performance. , (iv) The inert Li 2 S requires an activation potential in the charging process . To overcome these issues, incorporation of active MX 2 electrocatalysts featuring strong chemisorption and high catalytic activity is proposed as a powerful route to enhance the discharge/charge performance. − L-CoSe 2 has the merits of a layered structure for fast Li + diffusion, a metallic conductivity for fast electron transport, and a large surface area providing sufficient catalytic sites for strong immobilization and high catalytic activity.…”