Aqueous metal ion and alkaline batteries use water-based electrolytes. Aqueous systems offer greatly improved safety and in some designs may offer a lower cost (due to lower raw material cost, open air manufacturing and faster and simpler cell construction). In addition, the ionic conductivity of water-based electrolytes is typically orders of magnitude higher than any other class of electrolytes, allowing for faster charging rates for these batteries. These properties make them attractive for several important applications, such as electric buses, electic ships and grid-storage systems. Our research focuses on understanding the performance and stability of different cathode and anode materials in aqueous systems. Previously, we studied the degradation mechanisms of several common Li-ion battery cathodes in pH-neutral aqueous electrolytes as well as nickel oxide cathodes and iron anodes in alkaline solutions. Current work focuses mostly on developing novel electrolytes and conformal coatings for anode materials to minimize or prevent water decomposition and hydrogen evolution on their surface. The overall goal of the project is to create a stable, high-voltage aqueous battery of 2-3.5V using low-cost aqueous electrolytes and low-cost electrode materials derived from broadly available resources.