Affiliation:
1. Nanoyang Group Tianjin Key Laboratory of Advanced Carbon and Electrochemical Energy Storage School of Chemical Engineering and Technology Tianjin University Tianjin 300072 China
2. Interdisciplinary Research Center for Sustainable Energy Science and Engineering School of Chemical Engineering Zhengzhou University Zhengzhou 450001 China
Abstract
AbstractCatalysis is crucial to improve redox kinetics in lithium–sulfur (Li–S) batteries. However, conventional catalysts that consist of a single metal element are incapable of accelerating stepwise sulfur redox reactions which involve 16‐electron transfer and multiple Li2Sn (n = 2–8) intermediate species. To enable fast kinetics of Li–S batteries, it is proposed to use high‐entropy alloy (HEA) nanocatalysts, which are demonstrated effective to adsorb lithium polysulfides and accelerate their redox kinetics. The incorporation of multiple elements (Co, Ni, Fe, Pd, and V) within HEAs greatly enhances the catalytically active sites, which not only improves the rate capability, but also elevates the cycling stability of the assembled batteries. Consequently, HEA‐catalyzed Li–S batteries achieve a high capacity up to 1364 mAh g−1 at 0.1 C and experience only a slight capacity fading rate of 0.054% per cycle over 1000 cycles at 2 C, while the assembled pouch cell achieves a high specific capacity of 1192 mAh g−1. The superior performance of Li–S batteries demonstrates the effectiveness of the HEA catalysts with maximized synergistic effect for accelerating S conversion reactions, which opens a way to catalytically improving stepwise electrochemical conversion reactions.