Rechargeable batteries such as aqueous Zn-Air and Zn-MnO2 batteries are being actively investigated as promising candidates to meet these requirements. These Zn anode batteries usually contain no supporting electrolytes. Cyclic voltammograms (CVs) of Zn-anode electrodeposition/dissolution reaction without supporting electrolyte show linear response: the redox current decreases/increases linearly rather than exponentially. In battery systems besides the Zn case, no supporting electrolyte is often added, and such linear responses are often observed in CVs of the electrodeposition/dissolution reaction of metals.