MOF-Based Construction of Oxygen Vacancies ZnMn₂O₄ for Superior Zinc Storage

Manganese-based oxides are widely used as cathode materials for aqueous zinc-ion batteries (ZIBs) due to their high theoretical specific capacity, abundant reserves, and high operating voltage. However, their practical applications are limited by inherent issues such as active material dissolution, structural collapseor changes, and slow reaction kinetics. In this study, a cathode material for zinc batteries, ZnO-ZnMn₂O₄ (MZ), is synthesized based on a metal-organic framework (MOF). Synergistic strategies involving atomic composition modulation and defect engineering are employed to address the inherent issues of ZnMn₂O₄, stabilize the material structure, inhibit the disproportionation of Mn³⁺, and reduce the Jahn-Teller effect. Additionally, the material benefits from enhanced oxygen vacancies and a smaller particle size, which promote faster reaction kinetics. Electrochemical tests show that MZ-550 delivers a high specific capacity of 314.5 mA h g^-1 at 100 mA g^-1 and cycling stability, with a capacity retention of 96.6% after 1500 cycles at 1000 mA g^-1. In addition, the material demonstrates outstanding electrochemical performance under extreme conditions, with specific capacities of 86.4 mA h g^-1 at -20 °C and 331.1 mA h g^-1 at 40 °C. This study provides insights for the development of high-performance cathode materials for ZIBs in advanced energy storage systems.