Decarbonizing our energy infrastructure will require implementing battery chemistries beyond lithium-ion that are safe-to-operate and contain non-strategic materials. Silver–zinc, a decades-old battery technology with competitive energy and power density to Li-ion, has been used in both the military and civilian sector, but its widespread adoption is hindered by its poor reversibility and short lifespan. Realizing highly reversible, long cycle life, rechargeable Ag–Zn batteries entails simultaneously addressing two challenges: (i) suppressing shape change at the Zn metal anode that leads to dendrite-driven short-circuits, and (ii) suppressing Ag dissolution and migration out of the cathode. With the issues of shape change at the Zn anode solved by recent advancements in electrode architecture by our group,1 we turn our attention to the design of solid-state polymer electrolytes that suppress Ag dissolution and migration. We report on the synthesis and characterization of a suite of alkaline quaternary ammonium-based single-ion conducting polymer electrolytes suitable for use in Ag–Zn batteries. Specifically, we investigate the link between polymer chemistry and structure on ion transport via systematic tailoring of functional groups within the electrolyte. With these simple structural modifications, we can tune the Ag redox mechanism to shift equilibria away from the formation of Ag complexes responsible for dissolution and migration. By combining solid-state polymer electrolytes that suppress Ag transport with an NRL-patented Zn sponge anode, we demonstrate a high capacity, rechargeable Ag–Zn cell. These results serve as the foundation of a new class of solid-state polymer electrolytes to enable advanced rechargeable Ag–Zn batteries. (1) Parker, Joseph F., et al. "Wiring zinc in three dimensions re-writes battery performance–dendrite-free cycling." Energy & Environmental Science 7.3 (2014): 1117-1124.