Abstract
To develop the zinc electrode for rechargeable zinc-air batteries, a series of fundamental study were done in this research, e.g the saturated concentration of zincate ion in the KOH solution, the corrosion rate of zinc in KOH solution, and the vapor pressure of electrolyte. Results showed that electrolyte containing 4 M KOH＋2.5 M KF was the best composition, for the sake of low ZnO solubility、high conductivity、similar vapor pressure to environment and low polarization to the electrode. The overall performance of the above electrolyte was batter than 30wt% KOH solution. Manufacturing of zinc electrode was also investigated there, in order to obtain a set of ideal processing conditions. Furthermore, we then built a zinc-air battery system to test electrode performance. The effects of some additives to the electrode were studied for improvement. The electrode we made can be used satisfactorily in primary zinc-air battery, but not good enough for secondary batteries. The addition of 28% Ca(OH)2 did not prevent the shape change problem of electrode. When SnO2 was added, it improved the electrode capacity to some extent, but at the expense of increased rate of corrosion. Future work are need for additional improvement.