pH‐Buffer Contained Electrolyte for Self‐Adjusted Cathode‐Free Zn–MnO2 Batteries with Coexistence of Dual Mechanisms

Aqueous Zn–MnO 2 batteries have received much attentions for large‐scale applications because of high safety and low cost. However, the energy storage mechanisms of Zn–MnO 2 system are still in dispute. Herein, a cathode‐free Zn–MnO 2 battery is provided with the coexistence of dual mechanisms in mild acidic environment, in which the decisive guiding effect of the pH value in electrolyte on the mechanism is deeply investigated. On this basis, acetic acid (HAc) is used as a buffering additive to effectively suppress the “fluctuation” phenomenon during the operation, hence achieving the “self‐adjust” mechanism. The assembled soft package battery possesses a long lifetime of 2000 cycles with the Coulombic efficiency of 99.6%, improved high‐loading performance and rate capability. A new idea is provided for the exploration of energy storage mechanism of Zn–MnO 2 battery as well as a guidance on the optimization strategies especially the battery construction.