Operando Investigation of Aqueous Zinc Manganese Oxide Batteries: Multi-Stage Reaction Mechanism Revealed Daren Wu, Steven King, Nahian Sadique, Lu Ma, Steven N. Ehrlich, Sanjit Ghose, Jianming Bai, Hui Zhong, Shan Yan, David C Bock, Esther S. Takeuchi, Amy C Marschilok, Lisa Housel, Lei Wang and Kenneth James Takeuchi Abstract Aqueous Zn/MnO2 batteries with mildly acidic electrolytes are promising candidates for low cost, high safety electrochemical energy storage for grid-scale applications.