The broader impact/commercial potential of this Small Business Innovation Research (SBIR) project is to explore translation of a rechargeable zinc-metal battery for large-scale energy storage. Renewable but intermittent energy sources require cost-effective storage. The proposed battery essentially converts a primary alkaline battery to a rechargeable form with novel chemical components. This project will demonstrate the long cycle life of zinc-metal batteries under conditions amenable for applications such as backup power for data centers, grid-level needs, and household energy storage use. This SBIR Phase I project proposes to develop Zn-metal batteries in use-inspired battery configurations and cell dimensions. This project is to translate the fundamental understanding of Zinc-salt-based water-in-salt electrolytes that strengthen the inertness of both water molecules of the electrolytes and Zn metal anode. The proposed technology offers stable cycle life with excellent power output in an appropriate footprint. The project will advance the development of new electrolytes that greatly mitigate the hydrogen evolution reaction and eliminate dendrite formation on the Zn metal anode. The new electrolytes address the challenges of both anode and cathode, where the cathode capacity fading issues will be addressed.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.