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
Affiliations
Junhee Heo
Department of Hydrogen & Renewable Energy, Kyungpook National University, Daegu 41566, Republic of Korea
Gyeonguk Min
Department of Hydrogen & Renewable Energy, Kyungpook National University, Daegu 41566, Republic of Korea
Jae Bin Lee
Department of Hydrogen & Renewable Energy, Kyungpook National University, Daegu 41566, Republic of Korea
Patrick Joohyun Kim
Department of Applied Chemistry, Kyungpook National University, Daegu 41566, Republic of Korea
Kyuchul Shin
Department of Applied Chemistry, Kyungpook National University, Daegu 41566, Republic of Korea
In Woo Cheong
Department of Applied Chemistry, Kyungpook National University, Daegu 41566, Republic of Korea
Hyunchul Kang
School of Integrative Engineering, Chung-Ang University, 84, Heukseok-ro, Dongjak-Gu, Seoul 06974, Republic of Korea
Songhun Yoon
School of Integrative Engineering, Chung-Ang University, 84, Heukseok-ro, Dongjak-Gu, Seoul 06974, Republic of Korea
Won-Gwang Lim
Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
Jinwoo Lee
Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
Jin Joo
Department of Hydrogen & Renewable Energy, Kyungpook National University, Daegu 41566, Republic of Korea
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.