Modifying of Graphite Recovering From the Industrial Diamond Remainders as Value‐Added Cathode Material for High‐Performance Aqueous Zinc‐Ion Batteries

To meet the future development of high‐performance aqueous zinc ion batteries (AZIBs) with high energy density, low cost, and excellent cycle stability, an innovative strategy is developed to treat diamond residue graphite and integrate nanostructured MnO 2 onto its surface via simple hydrothermal and heat treatment methods. In the MnO 2 @MG composite, the presence of modified graphite (MG) restricts the degree of freedom of MnO 2 growth, resulting in the formation of smaller MnO 2 structures and avoiding the accumulation and aggregation of MnO 2 , which helps to improve the interface charge transport of composite electrodes. Meanwhile, the MG could effectively slow the structural collapse of MnO 2 during charging/discharging and improve the conductivity of MnO 2 . Based on the synergistic core–shell structure, the AZIBs employing MnO 2 @MG exhibit superior capacity (332.0 mA h g −1 at 100 mA g −1 over 300 cycles), excellent rate capabilities (208.1 mA h g −1 at 500 mA g −1 ), and outstanding cycling performance (48.1% capacity retention after 2000 cycles) at high current density. This work demonstrates the successful and large‐scale conversion of industrial diamond residue graphite into a high‐performance cathode of AZIBs.