Comparison of electrochemical performance for zinc anode via various electrolytes and conducting agents in Zn-air secondary batteries

Abstract

Zn-air batteries have many advantages as energy devices but they show a poor charge-discharge cycle performance. Therefore, this study examined the effects of various types of electrolytes and conducting agents and changed the additive contents to optimize the electrochemical performance of Zn-air secondary batteries. Electrolytes, such as sodium hydroxide (NaOH) and potassium hydroxide (KOH) solutions, and conducting agents, such as super-p, denka black, acetylene black, and ketjen black, were used to increase the electric conductivity. The electrochemical performance of the zinc anode was evaluated from charge-discharge capacities and cycle efficiency. When the capacity was compared according to each electrolyte from one to ten cycles, in contrast, the zinc anode in 6 M KOH showed a higher discharge capacity in the first cycle. Therefore, zinc anode was composed in the 6-M KOH electrolyte and conducting agents were added. The zinc anode included conducting agents with a higher cycle capacity than those without conducting agents, and super-p had a higher first discharge capacity than the others. Therefore, the zinc anode with super-p of 4% shows the highest performance using 6 M KOH in Zn-air secondary batteries.