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Constructing Wide-Temperature Lithium-Sulfur Batteries by Using a Covalent Organic Nanosheet Wrapped Carbon Nanotube.

Acheng ZhuShaokai LiYuting YangBo PengYuwen ChengQi KangZechao ZhuangLianbo MaJie Xu
Published in: Small (Weinheim an der Bergstrasse, Germany) (2023)
Lithium-sulfur (Li-S) batteries hold the superiority of eminent theoretical energy density (2600 Wh kg -1 ). However, the ponderous sulfur reduction reaction and the issue of polysulfide shuttling pose significant obstacles to achieving the practical wide-temperature operation of Li-S batteries. Herein, a covalent organic nanosheet-wrapped carbon nanotubes (denoted CON/CNT) composite is synthesized as an electrocatalyst for wide-temperature Li-S batteries. The design incorporates the CON skeleton, which contains imide and triazine functional units capable of chemically adsorbing polysulfides, and the underlaid CNTs facilitate the conversion of captured polysulfides enabled by enhanced conductivity. The electrocatalytic behavior and chemical interplay between polysulfides and the CON/CNT interlayer are elucidated by in situ X-ray diffraction detections and theoretical calculations. Resultantly, the CON/CNT-modified cells demonstrate upgraded performances, including wide-temperature operation ranging from 0 to 65 °C, high-rate performance (625 mAh g -1 at 5.0 C), exceptional high-rate cyclability (1000 cycles at 5.0 C), and stable operation under high sulfur loading (4.0 mg cm -2 ) and limited electrolyte (5 µL mg s -1 ). These findings might guide the development of advanced Li-S batteries.
Keyphrases
  • solid state
  • carbon nanotubes
  • ion batteries
  • ionic liquid
  • magnetic resonance
  • density functional theory
  • water soluble
  • electron microscopy
  • crystal structure
  • reduced graphene oxide
  • dual energy