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

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 (similar to 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.

Automated summary

By utilizing multimetallic high-entropy alloy nanoparticles as sulfur hosts, this work successfully resolves the challenge of shuttling effect and slow redox kinetics in Li-S batteries. The resulting cathode exhibits excellent electrocatalytic activity and enhanced LiPS adsorbability, leading to improved rate capacity and cycling stability.