Electrolyte Study with in Operando pH Tracking Providing Insight into the Reaction Mechanism of Aqueous Acidic Zn//MnO2 Batteries

• DOI: 10.1002/celc.202100888
• Publication Date: 2021-08-20T17:14:18Z
• Authors: Oliver Fitz; Christian Bischoff; Manuel Bauer; Harald Gentischer; Kai Peter Birke; Hans‐Martin Henning; Daniel Biro
• Keywords: 621; 02 engineering and technology; 0210 nano-technology; 3. Good health

Abstract The reaction mechanisms (RM) during cycling of aqueous rechargeable Zn//MnO 2 batteries (ARZIBs) are still controversially discussed. present study different acidic electrolyte compositions (0.9 mM H SO 4 , 0.5 M MnSO ZnSO +0.5 ) and their pH behaviour is therefore designed as an alternative approach to investigate the RM. In operando tracking shows periodic changes for each electrolyte, highlighting role pH‐relevant ions OH − + in chemical processes, major influence MnO deposition/dissolution buffering zinc hydroxide sulphate (ZHS) precipitation. Innovative coupled cyclic voltammetry (CV) measurements can link CV redox peaks a change corresponding reaction. It was found that Zn 2+ (de‐)intercalation has little or no on capacity. 2− ‐free Zn(CF 3 underlines pH‐dependant processes. results contribute debate RMs ARZIBs other battery chemistries by introducing novel measurement technique.