Uncovering Se, P co-doping effect in MnO₂ toward high-performance aqueous zinc-ion batteries

MnO₂, a promising cathode material for aqueous zinc ion batteries (AZIBs), is vigorously developed. The development of MnO₂ as the electrode for AZIBs is inevitably limited by low conductivity and slow reaction kinetics. Herein, Se, P co-doping MnO₂ (Se, P-MnO₂) nanorods are proposed as high-performance cathodes for AZIBs. Benefitting from the synthetic effect, the stability and reaction kinetics of Se, P-MnO₂ cathode are significantly improved. The capacity of Se, P-MnO₂ cathode is up to 295 mAh g⁻¹ at 0.5 A g^-1, surpassing that of MnO₂ (126 mAh g⁻¹), Se-MnO₂ (216 mAh g⁻¹) and P-MnO₂ (250 mAh g⁻¹). And Se, P-MnO₂ cathode also displays stability with the capacity of 232 mAh g⁻¹ at 1 A g^-1 after 1000 cycles, and outstanding rate performance (122.4 mAh g⁻¹ at 5.0 A g^-1). Besides, the theoretical calculation verifies that doping Se and P with low electronegativity to replace O with high electronegativity can tune the inherent electronic structure of MnO₂, equilibrate H⁺/Zn²⁺ adsorption–desorption, and impair the electrostatic interaction between MnO₂ and H⁺/Zn²⁺, thus accelerating the reaction kinetics and endowing tremendous redox ability. This study indicates that Se and P co-doping is a successful tactic to upgrade the electrochemical performance of MnO₂ cathode, which provides innovative viewpoints on the advance of suitable cathode materials for AZIBs, as well as fresh ideas for the logical design of electrode materials in alternative battery systems.