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.