A rechargeable battery is provided such that the positive electrode comprises lead dioxide, the negative electrode comprises a metal selected from the group consisting of iron, zinc, cadmium, lanthanum/nickel alloys and titanium/zirconium alloys, and the electrolyte is an aqueous alkali-metal acetate. Upon discharge, the lead dioxide is reduced to lead oxide, and the electrolyte remains unchanged. The reactions are reversed when the battery is charged.