Utilizing redox reactions to achieve carbon-coated MnOx-based cathode materials for high-performance zinc-ion batteries

Abstract

Manganese dioxide (MnO₂) are extremely promising materials for zinc-ion batteries because of their high specific capacity, high capacity for operation, affordability, and non-toxicity. However, the low conductivity and capacity degradation issues of MnO₂ limit its application. In this study, composite cathode materials of MnO_x@C are designed using a strategy that combines stirring synthesis with redox reactions. This method allows for the modification of the crystal structure while simultaneously controlling the thickness of the C layer, resulting in the enhancement of both cycle stability and conductivity in MnO_x@C. The MnOx@C composite shows remarkable performance in terms of current density (0.1 A g⁻¹) and capacity (320.3 mAh g⁻¹). Additionally, it exhibits excellent cycling stability, as evidenced by a capacity retention rate of 92% even after 1000 cycles at a current density of 1.0 A g⁻¹. These results surpass the multiplication capability and cycling stability of MnO₂, with a capacity of 254.1 mAh g⁻¹ when a current density of 0.1 A g⁻¹ is used. However, it only retains 70% after 1000 cycles of a current density of 1.0 A g⁻¹. This study offers a workable strategy for creating sophisticated cathodes that will improve zinc-ion battery performance.