Batteries (Oct 2023)

PEI/Super P Cathode Coating: A Pathway to Superior Lithium–Sulfur Battery Performance

  • Junhee Heo,
  • Gyeonguk Min,
  • Jae Bin Lee,
  • Patrick Joohyun Kim,
  • Kyuchul Shin,
  • In Woo Cheong,
  • Hyunchul Kang,
  • Songhun Yoon,
  • Won-Gwang Lim,
  • Jinwoo Lee,
  • Jin Joo

DOI
https://doi.org/10.3390/batteries9110531
Journal volume & issue
Vol. 9, no. 11
p. 531

Abstract

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Lithium–sulfur batteries exhibit a high energy density of 2500–2600 Wh/kg with affordability and environmental advantages, positioning them as a promising next-generation energy source. However, the insulating nature of sulfur/Li2S and the rapid capacity fading due to the shuttle effect have hindered their commercialization. In this study, we propose a method to boost the performance of lithium–sulfur batteries by modifying the sulfur cathode with a coating layer composed of polyethyleneimine (PEI) and Super P conductive carbon. The PEI/Super P-modified electrode retained 73% of its discharge capacity after 300 cycles at the 2 C scan rate. The PEI/Super P coated layer effectively adsorbs lithium polysulfides, suppressing the shuttle effect and acting as an auxiliary electrode to facilitate the electrochemical reactions of sulfur/Li2S. We analyzed the PEI/Super P-modified electrodes using symmetric cells, electrochemical impedance spectroscopy, and cyclic voltammetry. The battery manufacturing method presented here is not only cost-effective but also industrially viable due to its compatibility with the roll-to-roll process.

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