 This paper discusses two major challenges faced when trying to develop aqueous sink metal batteries for sustainable stationary storage. Firstly, it explains how to prevent the oxide cathode from being affected by adventitious proton co-intercalation and dissolution, which can cause the battery to malfunction. Secondly, it addresses the issue of parasitic electrolyte reactions caused by zinc dendrites growing at the anode. To solve these problems, the authors propose a cost-effective and nonflammable hybrid eutectic electrolyte, which allows for faster charge transfer at the solid electrolyte interface. This enables dendrite-free zinc plating stripping with a remarkably high average Coulombic efficiency of 99.8%, resulting in a new benchmark in zinc ion battery performance of 4mRcm2 at 8mRcm2 and 85% capacity retention after 100 cycles at 25°C. This article was authored by Charlie, Brian Kingsbury, Arash Deep Singh Finn, and others.