Batteries are described that include a cathode material, and anode material, and a polymeric material that separates the cathode material from the anode material. The polymeric material has hydroxide ion conductivity of at least about 50 mS/cm, and a diffusion ration of hydroxide ions to at least one type of metal ion of at least about 10:1. Also described are methods of making a battery that include forming a layer of polymeric material between a first electrode and second electrode of the battery. In additional methods, the polymeric material is coated on at least one of the electrodes of the battery. In further methods, the polymeric material is admixed with at least one of the electrode materials to make a composite electrode material that is incorporated into the electrode.