Dual‐Metallic‐Doped Manganese Oxide Enabling Long Lifetime and High‐Capacity of Zn‐Ion Batteries

Energy and environmental issues threaten human survival and development, urging the enhancement of technological levels to address these problems. Aqueous zinc‐ion batteries (AZIBs) have attracted the attention of numerous researchers due to their low cost and guaranteed safety. However, the AZIB cathode is still limited by low capacity and poor stability. Herein, we report a Fe–Cu co‐doped and carbon‐coated MnO nanosheet (FeCuMnO@C), which was derived by a trimetallic organic framework and exhibits excellent cyclic stability and specific capacity. Due to the synergistic effect of Fe–Cu ions co‐doped, which ameliorates electrical conductivity, accelerates electron transfer kinetics, inhibits the Jahn–Teller effect, and enhances structural stability, thereby exhibiting excellent energy storage performance. In addition, the carbon layer provides an extra protective barrier to further optimize the structure. Specifically, with the bimetallic co‐doped and carbon layer form coupling effect, the FeCuMnO@C electrode battery shows excellent cycling capacity performance of 128.9 mAh g ⁻¹ (80.4%) after 2500 cycles at 1.0 A g ⁻¹ , and ultralong lifetime 6000 and 7000 cycles at 2.0 and 3.0 A g ⁻¹ , respectively, as well as excellent rate performance. This work offers a crucial viewpoint that a trimetallic organic framework‐derived bimetallic co‐doped MnO@C can serve as an efficient cathode for AZIBs.