Mn3O4@NC Composite Nanorods as a Cathode for Rechargeable Aqueous Zn-Ion Batteries

Rechargeable aqueous zinc-ion batteries (ZIBs) have attracted escalating attention recently, owing to their energy density, decreasing cost, advanced safety, and environmental benignity. Nevertheless, ZIBs still lack suitable cathode materials with stable cycling performance, owing to the high polarization of zinc ion. Therefore, developing candidate materials with excellent properties remains a great challenge. Herein, we successfully synthesize a novel Mn3O4@N-doped carbon matrix composite nanorods (Mn3O4@NC Nrs) by using MnOOH nanorods (the self-sacrifice templates) and polypyrrole (carbon and nitrogen source). Benefiting from the N-doped carbon shell and the synergetic effect of Zn2+ and Mn2+ in the electrolyte, the Mn3O4@NC Nrs show superior cycling stability and long cycling features for ZIBs. Specifically, the zinc cell conducts a high reversible capacity of 280mAhg(-1) at 100mAg(-1) and retains a high reversible capacity of 97mAhg(-1) at 1000mAg(-1) after 700 cycles. In addition, the work provides a new approach to fabricate long-term and high-rate capability cathodes for ZIBs.