Unveiling the Role of Electric Double‐Layer in Sulfur Catalysis for Batteries

• Published in: Advanced materials (Weinheim) Vol. 36; no. 38; pp. e2407741 - n/a
• Main Authors: Geng, Chuannan, Jiang, Xin, Hong, Shuang, Wang, Li, Zhao, Yufei, Qi, Jiangshan, Shi, Jiwei, Wang, Junjie, Peng, Linkai, Hu, Zhonghao, Guo, Yong, Jin, Feng‐Min, Yang, Quan‐Hong, Lv, Wei
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.09.2024
• Subjects: Adsorption; Alloying; Catalysis; Catalysts; Electric double layer; Electrolytes; graphene Li–S battery; Lithium; Lithium sulfur batteries; Mass transport; microwave heating; nanoalloy; Sulfur; Zinc base alloys; microwave heating; catalysis; graphene Li–S battery; nanoalloy
• ISSN: 0935-9648; 1521-4095; 1521-4095
• DOI: 10.1002/adma.202407741

The metal‐catalyzed sulfur reaction in lithium–sulfur (Li–S) batteries usually suffers from the strong binding of sulfur species to the catalyst surface, which destroys the electric double layer (EDL) region there. This causes rapid catalyst deactivation because it prevents the desorption of sulfur species and mass transport through the EDL is hindered. This work introduces a competitive adsorption factor (fsulfur) as a new indicator to quantify the competitive adsorption of sulfur species in the EDL and proposes an alloying method to change it by strengthening the p–d hybridization of alloying metals with electrolyte solvents. A cobalt–zinc alloy catalyst with a moderate fsulfur lowers the activation energy of the rate‐limiting step of the conversion of lithium polysulfides to lithium sulfide, giving a platform capacity proportion that is 96% of the theoretical value and has a greatly improved anti‐passivation ability, especially at high sulfur loadings and lean electrolyte conditions (a low E/S ratio of 5 µL mgS−1). A pouch cell using this approach has a high energy density of up to 464 Wh kg−1. Such a competitive adsorption indicator and alloying strategy offer a new guideline for catalyst design and a practical electrocatalysis solution for Li–S batteries. This work introduces a competitive adsorption factor (fsulfur) to describe the sulfur adsorption in the electric double layer on the metal catalyst surface. An alloying method to alter it by enhancing p–d hybridization with electrolyte solvents is proposed, and a cobalt–zinc alloy catalyst with a moderate fsulfur shows enhanced activity and anti‐passivation ability simultaneously in lithium–sulfur batteries.