Anionic Doping in Layered Transition Metal Chalcogenides for Robust Lithium-Sulfur Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-sulfur batteries (LSBs) are a promising next-generation energy storage technology.
• Slow lithium-sulfur reaction kinetics at the cathode limit LSB energy and power densities.
• Catalysts are needed to accelerate Li-S conversion and improve battery performance.

Purpose of the Study:

• To develop an effective catalyst for accelerating Li-S reaction kinetics in LSBs.
• To investigate the catalytic mechanism of anionic-doped transition metal chalcogenides.
• To evaluate the performance of a novel Te-Bi2Se3-x@C sulfur host in LSB cathodes.

Main Methods:

• Synthesis of tellurium-doped, carbon-supported bismuth selenide with Se vacancies (Te-Bi2Se3-x@C).
• Characterization using X-ray absorption and in situ X-ray diffraction.
• Electrochemical testing of LSBs with Te-Bi2Se3-x@C/S cathodes.

Main Results:

• Te doping and Se vacancies in Te-Bi2Se3-x@C promote catalytic activity and polysulfide trapping.
• LSBs demonstrated high specific capacities (1508 mAh/g at 0.1 C) and excellent rate performance (655 mAh/g at 5 C).
• Exceptional cycle stability (>1000 cycles) and performance under high sulfur loading and lean electrolyte conditions were achieved.

Conclusions:

• Anionic-doped Te-Bi2Se3-x@C is an effective catalyst for accelerating Li-S reactions.
• The developed catalyst significantly enhances LSB energy density, power density, and cycle life.
• This work offers a promising strategy for advancing high-performance lithium-sulfur battery technology.