Journal of Energy Chemistry ›› 2023, Vol. 79 ›› Issue (4): 148-157.DOI: 10.1016/j.jechem.2022.12.027

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Selenium-doped cathode materials with polyaniline skeleton for lithium-organosulfur batteries

Rong Zou, Wenwu Liu, Fen Ran*   

  1. State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals, School of Materials Science and Engineering, Lanzhou University of Technology, Lanzhou 730050, Gansu, China
  • Received:2022-07-29 Revised:2022-12-20 Accepted:2022-12-21 Online:2023-04-15 Published:2023-05-30
  • Contact: * E-mail address: ranfen@lut.edu.cn (F. Ran).

Abstract: Sulfur-containing polymer (SCP) is considered as an outstanding cathode material for lithium-sulfur bat-teries. However, undesirable soluble polysulfides may shuttle in electrolyte, concluding long-chain Li2Sn (n > 4) and short-chain Li2Sn (n ≤ 4), as well as the sluggish conversion kinetics are yet to be solved to enhance the performance of lithium-sulfur batteries. Here Se-doped sulfurized polyaniline with adjusted sulfur-chain —Sx— (x ≤ 6) contribute to ensure the absence of long-chain polysulfides, and the skeleton with quinoid imine can endow strongly adsorption towards short-chain polysulfides by the reversible transition between deprotonated/protonated imine (—NH+ = and —N =), which offer double insurance against suppressing ‘‘shuttle effect”. Furthermore, Se atoms are doped into sulfurized polysulfides to accelerate the redox conversion and take a frontier orbital theory-oriented view into catalytic mecha-nism. Se-doped sulfurized polyaniline as active materials for lithium-organosulfur batteries delivers good electrochemical performance, including high rate, reversible specific capacity (680 mA h g-1 at 0.1 A g-1), and lower capacity decay rate only of 0.15% with near 100% coulomb efficiency during long-term cycle. This work provides a valuable guiding ideology and promising solution for the chemistry-oriented struc-ture design and practical application for lithium-organosulfur batteries.

Key words: Lithium-organosulfur batteries, Selenium-doped, Cathode materials, Sulfur-containing polymer, Frontier orbital theory