Unlocking Mo, P co-doping to boost proton intercalation in MnO2 as a high-performance cathode material for aqueous zinc-ion batteries†

Abstract

Manganese-based oxides, with various oxidation states and crystal structures, are treated as one of the most brilliant zinc storage cathode materials in aqueous zinc ion batteries (AZIBs). However, the practical application of manganese-based oxide cathode materials is still limited by poor structural stability, slow diffusion kinetics, and inherently low conductivity. In this paper, anionic and cationic Mo, P co-doped MnO₂ (Mo, P–MnO₂) nanoflowers are constructed as cathode materials for AZIBs. Theoretical calculations imply that Mo, P co-doping enlarges the layer spacing to accelerate ion transport, as well as reducing the insertion energy of H⁺ to increase the intercalation contribution of H⁺. These synergistic effects enhance the structural stabilization and reaction kinetics of the Mo, P–MnO₂ electrode during cycling. As a result, the Mo, P–MnO₂ electrode showed excellent rate capacity (146.6 mA h g⁻¹ at 5 A g⁻¹), and cycling stability (retaining a capacity of 216 mA h g⁻¹ after 1100 cycles at 1 A g⁻¹). The concepts introduced in this study promise a fantastic guarantee for the development of elevated-performance oxide-based energy repository materials.