Failure analysis of zinc electrode using hydroponic gel and liquid electrolytes in zinc-air batteries at elevated temperatures

Zinc-air batteries were fabricated separately using hydroponic gel (HPG)-6 M potassium hydroxide (KOH) and 6 M liquid KOH, respectively, as the electrolyte. Both batteries were compared in terms of their self-discharge by measuring their open-circuit voltage (OCV) and discharge characteristics at 25, 40, 60 and 80 °C using a constant current of 50.0 mA. As the temperature increased, the OCV dropped. The highest OCV was approximately 1.5 V at room temperature, and all the OCVs were more than 1.4 V at this temperature. At 40 °C, the capacities of the cells were 662.5 mAh g −1 (liquid electrolyte) and 341.3 mAh g −1 (HPG electrolyte). The failure of the batteries was mainly due to the formation of ZnO rod- and flower-like structures and changes to the shape of the anode.