High-entropy nanoparticle constructed porous honeycomb as a 3D sulfur host for lithium polysulfide adsorption and catalytic conversion in Li–S batteries

Abstract

The obstinate shuttle effect and torpid redox kinetics in the conversion of sulfur species bring significant challenges for lithium–sulfur (Li–S) batteries, such as poor sulfur utilization, rapid capacity decay, and unstable cell cycling. Utilizing lithium polysulfide (LiPS) adsorptive and efficient electrocatalysts is a practical approach to resolving these issues. Numerous nanoscale high-entropy alloy (HEA) particles possess extraordinary physicochemical properties, especially catalytic activity, and have enormous potential to promote LiPS conversion in Li–S batteries. Nonetheless, multimetallic HEA nanoparticles generally show inadequate adsorbability on LiPSs, leading to unsuppressed LiPS shuttling and reduced catalytic efficiency. Herein, based on multimetallic MgCrMnFeCoNi HEA nanoparticles, a MgCrMnFeCoNi–O honeycomb is constructed via a facile method and serves as a sulfur host. The MgCrMnFeCoNi–O honeycomb shows more than excellent electrocatalytic activity toward LiPS conversion but also markedly enhanced LiPS adsorbability. The Li–S cell with a MgCrMnFeCoNi–O cathode delivers an admirable rate capacity (857.5 mA h g⁻¹ at 3C) and good cycling stability (∼1100 mA h g⁻¹ at 0.5C over 1200 cycles). Moreover, MgCrMnFeCoNi–O reveals good practical applicability in pouch cells. This work provides a low-cost and efficient strategy for the scalable production of highly catalytic HEA products used in advanced Li–S batteries and other electrochemical energy storage devices.