Breaking the Passivation Effect for MnO₂ Catalysts in Li−S Batteries by Anion‐Cation Doping

Abstract

Abstract Transition metal oxides (TMOs) are recognized as high‐efficiency electrocatalyst systems for restraining the shuttle effect in lithium‐sulfur (Li−S) batteries, owing to their robust adsorption capabilities for polysulfides. However, the sluggish catalytic conversion of Li 2 S redox and severe passivation effect of TMOs exacerbate polysulfide shuttling and reduce the cyclability of Li−S batteries, which significantly hinders the development of TMOs electrocatalysts. Here, through the anion‐cation doping approach, dual incorporation of phosphorus and molybdenum into MnO 2 (P,Mo‐MnO 2 ) was engineered, demonstrating effective mitigation of the passivation effect and allowing for the simultaneous immobilization of polysulfides and rapid redox kinetics of Li 2 S. Both experimental and theoretical investigations reveal the pivotal role of dopants in fine‐tuning the d‐band center and optimizing the electronic structure of MnO 2 . Furthermore, this well‐designed configuration processes catalytic selectivity. Specifically, P‐doping expedites rapid Li 2 S nucleation kinetics by minimizing reaction‐free energy, while Mo‐doping facilitates robust Li 2 S dissolution kinetics by mitigating decomposition barriers. This dual‐doping approach equips P,Mo‐MnO 2 with robust bi‐directional catalytic activity, effectively overcoming passivation effect and suppressing the notorious shuttle effect. Consequently, Li−S batteries incorporating P,Mo‐MnO 2 ‐based separators demonstrate favorable performance than pristine TMOs. This design offers rational viewpoint for the development of catalytic materials with superior bi‐directional sulfur electrocatalytic in Li−S batteries.