A nickel-zinc battery includes a battery housing, a nickel oxide positive electrode supported in the battery housing, a metal substrate negative electrode supported in the battery housing, a spacer disposed between the positive and negative electrodes, an electrolyte contained within the battery housing and a means for circulating electrolyte in fluid communication with the housing for circulating the electrolyte between the positive and negative electrodes. The electrolyte contains zinc and the metal substrate is adapted for deposition of the zinc during charging of the battery. The spacer maintains the positive electrode in a spaced relationship apart from the negative electrode.