Electrochemical recycling of the zinc from spent Zn–MnO2 batteries

In this work, zinc from the spent Zn–MnO2 batteries is recycled. Ionic zinc is recovered from acidic or alkaline solutions using a galvanostatic technique. An optimum current density between 10.0 and 25.0 mA cm−2 was obtained for recovery of ionic zinc from acidic solutions. The optimum current density is equal to 15.0 mA cm−2 for zinc electrodeposition from alkaline solution. The charge efficiency is 80.0% and decreases with increase of current density. In acidic solutions, hydrogen adsorption catalyse Zn2+ electrodeposition. In alkaline solutions, a parallel reaction of the hydrogen evolution inhibits zincate electrodeposition.