Abstract: The redox reaction of anions in zinc ion batteries was tested and analyzed. Taking the MnO₂ as the research object, the cyclic voltammetry, galvanostatic charge-discharge method and ex situ X-ray photoelectron spectroscopy were applied to analyze the redox reaction of oxygen of MnO₂ in water-in-salt electrolyte. The results show that the oxidation reaction of oxygen exists at high potential when using the 30 mol/kg ZnCl₂, but it does not happen in the diluted electrolyte.

Key words: water-in-salt electrolyte, manganese dioxide, redox reaction of oxygen