One-step preparation of MnO2 electrode for secondary aqueous zinc ion batteries by electrodeposition

As the cathode material, manganese oxides have been a research hotspot in the secondary aqueous zinc ion batteries due to their various advantages such as multiple crystal structures, low-cost, and environmentally friendliness. However, most of the current research focuses on the material modification, and little research has been done on the development of synthesis methods. Herein, a MnO2 electrode is directly prepared by a one-step electrodeposition method from the aqueous solution containing manganese ions. It is found that a porous electrode with the nano MnO2 particulates as the active material can be obtained from the 0.3 M MnSO4 solution. The porous structure provides numerous reaction sites that facilitates the electrochemical processes on the electrode. As a result, it delivers the area specific capacity of 0.35 mAh cm−2 at the current density of 0.5 mA cm−2 and a high coulombic efficiency of 100% after 1000 cycles at 1.5 mA cm−2. These excellent electrochemical properties suggest that this convenient one-step electrodeposition method can be effectively applied for the large-scale commercialization of the aqueous zinc ion batteries.