K.J. Takeuchi, A.C. Marschilok, E.S. Takeuchi
Stony Brook University,
United States
Keywords: battery, zinc, manganese oxide, aqueous
Summary:
Rechargeable aqueous zinc/ manganese oxide (Zn/alpha-MnO2) batteries are an appealing alternative to lithium ion batteries for scalable stationary energy storage applications due to their low cost, safety and environmentally benign components. However, aqueous zinc systems may display low-capacity retention under use conditions. Recent findings have indicated that in mildly acidic electrolytes, the solid manganese oxide cathode dissolves in the electrolyte as Mn2+ during the discharge (reduction) step and deposits on the cathode as a solid during the charge (oxidation) step. These findings noted that there is residual solid in the cathode suggesting a dynamic balance of solid and solution manganese species. This talk will present out recent findings where operando synchrotron x-ray absorption spectroscopy was used in a specially designed cell to quantify both the solid and solution manganese content over the charge and discharge steps. These insights provide deeper understanding of the mechanism taking place in the battery and can inform future design decisions.