Zinc/ Manganese Oxide Aqueous Electrolyte Batteries: Electrochemical Reaction Mechanisms Beyond Ion Insertion

Abstract

The consistent delivery of clean electrical energy is a global challenge where the current electric grid infrastructure distributes electrical energy from the generation source to the end user. Widespread integration of inherently intermittent renewable energy sources such as wind and solar into the electric grid electrical energy storage into the electric grid demands incorporation of energy storage. Further, energy storage would enable control over when the electrical energy is used improving grid reliability and resiliency. Thus, stationary energy storage for the electric grid is a critical and timely application for batteries.Rechargeable aqueous zinc/ manganese oxide (Zn/MnO2) batteries are an appealing target for scalable stationary energy storage applications due to their low cost, safety, and environmentally benign components. Notably, manganese oxide is a versatile material where several polymorphs are viable cathode materials in aqueous zinc ion batteries. However, there is need for more complete understanding of the electrochemical reaction mechanisms, to continue to advance the system. This presentation will feature investigations of the reaction mechanisms with a focus on operando methods. X-ray diffraction, Mn K-edge X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) measurements supported by ex situ transmission electron microscopy (TEM) will be presented. The findings provide a foundation for advancing the battery systems based on aqueous electrolyte zinc anode chemistries suitable for scalable stationary energy storage.