A Robust Mn₂O₃/C Host with Dual-Network Structure via MOF Derivatization for Ultra-Stable Aqueous Zinc-Ion Batteries

Manganese-based oxides are promising cathodes for aqueous zinc-ion batteries but often suffer from structural instability, manganese dissolution, and poor conductivity. Herein, we propose a "dual-network synergistic construction" strategy through the in-situ derivation of a metal–organic framework to concurrently address these challenges. This strategy ingeniously constructs an oxygen-deficient network and a conductive carbon network within a hierarchical Mn₂O₃/C composite (O d -Mn₂O₃/C-400). The formed interfacial Mn–O–C bonds effectively enhance structural integrity and regulate the concentration of oxygen vacancies. As a cathode for aqueous zinc-ion batteries, the O d -Mn₂O₃/C-400 composite demonstrates exceptional electrochemical performance, delivering a remarkable specific capacity of 425 mAh·g⁻¹ at 3 A·g⁻¹. More importantly, it exhibits outstanding long-term cyclability, retaining 87.67% of its capacity (174 mAh·g⁻¹) after 5,000 cycles at a high current density of 5 A·g⁻¹. When configured into a zinc-ion hybrid supercapacitor (O d -Mn₂O₃/C-400//AC), the device achieves a high energy density of 119 Wh·kg⁻¹ at 189 W·kg⁻¹, and maintains 78.6% capacity retention with 97.5% Coulombic efficiency over 3,000 cycles. This work provides an effective material design paradigm for developing high-performance manganese-based electrodes for advanced energy storage systems.