Abstract：Electrochemical energy storage technology plays an important role in meeting the energy demand for mobile electronic devices, wearable devices and electric-driven vehicles. Pseudo-capacitor is a kind of electrochemical energy storage device, having the properties of high power density, long lifetime, good rate performance and environmental friendliness. The metal oxides/hydroxides with the variable metallic valence states can act as the electrodes of pseudo-capacitors, and they have high theoretical specific capacitances. Nevertheless, the bad conductivity of metal oxides and the limited energy storage reactions on the shallow surface of metal oxides lead to their low practical specific capacitances. To overcome the existed problems, the combination between conductive materials and metal oxides as well as the reduction of the size of metal oxides are used to improve the energy storage performance of metal oxides. This article summarizes the recent research advances on the nickel-based materials, Mn-based materials and iron-based materials acting as the electrodes for energy storage on the basis of the research work in our group. The energy storage performance of metal oxides is enhanced by combining carbon materials and metal oxides; to reduce the size of metal oxide to 1-2 nm can evidently improve the performance of active materials. We briefly introduce the research work on Zn@C//MnO2 aqueous batteries. The research results reveal that the formation of Zn@C play an important role in enhancing the lifetime of Zn-based battery. Lastly, we provide the outlook on the future of metal oxides electrodes.
2020, Vol. 27 