Interfacial chemical binding and improved kinetics assisting stable aqueous Zn-MnO2 batteries

The major limitation of low-cost and high-safety aqueous Zn-MnO2 batteries for grid storage is largely hampered by their poor cyclic stability, which is usually caused by the manganese dissolution and interfacial kinetics. Herein, we demonstrated that an effective surface coating of MnO2 with an interfacial Mn-N bonding can effectively alleviate the manganese dissolution and facilitate the interfacial kinetics. As expected, the MnO2/polypyrrole electrode shows lower electrochemical polarization compared to the bare MnO2 and possesses no capacity fading at both low current density (50 cycles at 100 mA g(-1)) and high current density (500 cycles at 1000 mA g(-1)). The fundamental mechanism revealed in this work will contribute to establishing a rational strategy to further optimize the cycle life of the aqueous zinc-ion batteries. (C) 2020 Elsevier Ltd. All rights reserved.