Dual Anions Doping Enhanced Conductivity and Stability of Layered <i>δ</i>‐MnO₂ Cathode for Aqueous Zinc‐Ion Battery

Abstract

Abstract Manganese‐based oxides have been identified as promising cathodes for aqueous zinc‐ion batteries (AZIBs) due to their high theoretical energy density and cost‐effectiveness. However, their low electronic conductivity and tendency to dissolve during cycling have limited their applications in AZIBs. Herein, a one‐step calcination method is proposed to incorporate sulfur and nitrogen anions into the MnO 2 structure (referred to as NS‐MnO 2 ). Characterizations and theoretical calculations confirm that the sulfur and nitrogen dopants improve the intrinsic electronic conductivity and structural stability of MnO 2 . Specifically, sulfur doping accelerates the diffusion of Zn 2+ , while the formation of Mn─N bonds strengthens the Mn─O bonds, thereby stabilizing the structure of MnO 2 during cycling. In addition, the doping process creates oxygen vacancies that facilitate Zn 2+ diffusion kinetics. As a result, the NS‐MnO 2 demonstrates a specific capacity of 295 mAh g ‒1 at a current density of 0.2 A g ‒1 and exhibits high cycling stability of 120 mAh g ‒1 at 1 A g ‒1 over 1500 cycles. This study highlights the effectiveness of dual anions doping in modifying the structure of transition metal oxides and suggests its potential application in designing other materials for energy storage.