Study of Zinc Compounds for Improving the Reversibility of the Zinc Anode in Zinc–Air Secondary Batteries

Several studies have focused on rechargeable zinc–air batteries. Among them, the formation of zincate ions has been studied to enhance the reversibility of the zinc anode. In this study, zinc compounds, such as zinc oxide, chloride, and acetate, showed different solubility in KOH; this is related to the generation of zincate ions. A full‐cell test was carried out to compare the electrochemical properties of electrodes. Zinc oxide has a high second discharge capacity of 178 mAh/g. To increase the solubility, the particle size of microsized ZnO was changed to nanosized ZnO. In addition, in the full‐cell test, nanosized ZnO showed a higher cycle capacity than microsized ZnO. The reduction peaks were indicated clearly until 10 cycles in the three‐electrochemical cell. Therefore, it is essential that microsized ZnO be converted easily to zincate ions.