Nanosized zinc oxides-based materials for electrochemical energy storage and conversion: Batteries and supercapacitors

Transition metal oxides (TMO) bring a novel direction for the development of energy store materials due to their excellent stability. They not only have high capacity and good cycle performance, but also are cheap and easily available. Zinc oxide (ZnO) as an important part of TMO have gradually attracted attention in the research of electrochemistry. ZnO, as a metal semiconductor with the advantages of wide band gap, possesses high ion migration rate, good chemical stability, simple preparation and low cost, and is widely used in various fields. However, poor conductivity, low permittivity and quick capacity decays quickly impede the commercial application of these electrodes. In recent years, in order to improve the structural stability, ion diffusion and conductivity of zinc oxides-based anodes, various strategies have been raised, such as structural design, surface modification and composition control. In this paper, the recent advances of zinc oxides-based materials for batteries and hybrid supercapacitors (SCs) were introduced. We comprehensively reviewed the prepared process, reaction mechanism and electrochemical performance and discussed the shortcoming of zinc oxides-based nanomaterials. In particular, several insights toward the future research development, practical applications and commercialization of energy storage devices are also proposed for improving the performance of zinc oxides-based materials.