Electrochemical Investigation of Temperature‐Dependent Zinc Anode Behavior for Zn–MnO ₂ Batteries Under Alkaline and Mildly Acidic Conditions

This work presents a systematic comparison of temperature‐dependent zinc anode performance in aqueous, alkaline (6 M KOH), and mildly acidic (2 M ZnSO ₄ ) electrolytes in a temperature window of 0°C to 40°C, i.e., relevant for practical application. Galvanostatic and electrochemical analyses reveal fundamentally different kinetic and transport properties, reflected in significantly lower absolute overpotentials and higher Coulombic efficiencies in alkaline media. Despite these differences, both systems exhibit remarkably similar relative temperature dependencies of hysteresis and nucleation overpotentials. Corrosion studies show strongly accelerated kinetics with increasing temperature, with rates in KOH exceeding those in ZnSO ₄ by several orders of magnitude, accompanied by distinct passivation behavior. While alkaline electrolytes promote ZnO‐based passivation, ZnSO ₄ enables continuous active dissolution without stable film formation. The results demonstrate that comparable macroscopic performance trends can arise from different physicochemical origins, providing a unified perspective on temperature effects in aqueous zinc systems.