Unravelling the Mechanism of Rechargeable Aqueous Zn-MnO₂ Batteries: Implementation of Charging Process by Electrodeposition of MnO₂.

ABSTRACT: Poor cycling stability and mechanistic controversies have hindered the wider application of rechargeable aqueous Zn-MnO₂ batteries. Herein, direct evidence was provided of the importance of Mn²⁺ in this type of battery by using a bespoke cell. Without pre-addition of Mn²⁺ , the cell exhibited an abnormal discharge-charge profile, meaning it functioned as a primary battery. By adjusting the Mn²⁺ content in the electrolyte, the cell recovered its charging ability through electrodeposition of MnO₂ . Additionally, a dynamic pH variation was observed during the discharge-charge process, with a precipitation of Zn₄ (OH)₆ (SO₄ )⋅5H₂ O buffering the pH of the electrolyte. Contrary to the conventional

SUBMITTER: Yang J 

PROVIDER: S-EPMC7496518 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature