Contribution of Cation Addition to MnO(2) Nanosheets on Stable Co(3)O(4) Nanowires for Aqueous Zinc-Ion Battery

Zinc-based electrochemistry attracts significant attention for practical energy storage owing to its uniqueness in terms of low cost and high safety. In this work, we propose a 2.0-V high-voltage Zn–MnO(2) battery with core@shell Co(3)O(4)@MnO(2) on carbon cloth as a cathode, an optimized aqueous ZnSO(4) electrolyte with Mn(2+) additive, and a Zn metal anode. Benefitting from the architecture engineering of growing Co(3)O(4) nanorods on carbon cloth and subsequently deposited MnO(2) on Co(3)O(4) with a two-step hydrothermal method, the binder-free zinc-ion battery delivers a high power of 2384.7 W kg(−1), a high capacity of 245.6 mAh g(−1) at 0.5 A g(−1), and a high energy density of 212.8 Wh kg(−1). It is found that the Mn(2+) cations are in situ converted to Mn(3)O(4) during electrochemical operations followed by a phase transition into electroactive MnO(2) in our battery system. The charge-storage mechanism of the MnO(2)-based cathode is Zn(2+)/Zn and H(+) insertion/extraction. This work shines light on designing multivalent cation-based battery devices with high output voltage, safety, and remarkable electrochemical performances.