Improved formation efficiencies for positive pasted plates used in lead-acid batteries are provided by treatment of the positive plates with a stabilized aqueous alkaline persulfate solution to effect the conversion of lead monoxide to lead dioxide. Use of the alkaline persulfate solution enhances both formation and initial performance of the fabricated batteries. A stabilizing agent is added to the alkaline persulfate solution to stabilize the lead sulfate and basic lead sulfates in the paste. A preferred method for producing positive plates of a lead-acid battery comprises the steps of (a) heating the pasted plate, (b) spray coating with or dipping the plate in a persulfate solution, and (c) reheating the plate to accelerate the reaction of lead monoxide with persulfate to form lead dioxide. The persulfate treatment may be applied to uncured pasted plates and used with plate paste containing free lead, and the spray-coating procedure offers an easy and efficient manufacturing step.