Hexameric Structure-Dependent Catalysis of Oxalate Oxidase for Mitigating Shuttle Effect in High-Temperature Li-S Batteries

Abstract

To address the severe lithium polysulfide (LiPS) shuttle effect and sluggish redox kinetics of lithium–sulfur (Li–S) batteries, especially under high-temperature conditions, we introduce a high-efficiency natural thermostable catalyst, oxalate oxidase (OxOx), into the cathodes. Endowed with a unique hexameric structure, OxOx maintains robust catalytic activity at elevated temperatures (≥60 °C) and facilitates rapid electron/Li⁺ transport via its C-terminal α-helices. More importantly, its manganese-active center enhances LiPS adsorption and accelerates the liquid-solid conversion of sulfur species by lowering reaction energy barriers. Consequently, the OxOx-modified cathode delivers outstanding rate performance, long-cycle stability with ultra-low capacity decay, and effective shuttle suppression even under harsh high-temperature operating conditions.