Chip−like high−entropy oxide catalysts enhance fast sulfur evolution reaction for long−life lithium−sulfur batteries

Abstract

Many catalysts have shown excellent activity for the sulfur reduction reaction (SRR), but sluggish electrochemistry kinetics have hindered the development of lithium–sulfur batteries. It has been found that the activity of catalysts for the sulfur evolution reaction (SER) plays a crucial role in determining the overall reaction kinetics. To address this issue, the rational design of catalysts is crucial. Here, we proposed a popular rule to accelerate SER by using chip–like high–entropy perovskite oxide La0.7Sr0.3(Fe0.2Co0.2Ni0.2Zn0.2Mn0.2)O3-δ (LMO–HEO) as advanced electrocatalysts. The strong interaction between the adjacent metal atoms in different metals of LMO–HEO electrocatalysts could lead to a "cocktail effect", which not only greatly improved the catalytic capacity toward sulfur species, but also accelerated the oxidation reaction kinetics of Li2S. As a result, the S/La0.7Sr0.3(Fe0.2Co0.2Ni0.2Zn0.2Mn0.2)O3-δ cathodes delivered excellent cyclic stability with a capacity decay of only 0.025% after 1200 cycles at 2 C. This work has provided a rational design idea for new multifunctional electrocatalysts with high catalytic capacity.