The cause of the voltage “dip” during the high rate discharge of the primary alkaline MnO2/Zn cells

The phenomena of the voltage “dip” during the high rate discharge of the primary alkaline MnO2/Zn cells have been investigated. The “dip” was found anode related. Formation of the type II ZnO film during the high rate discharge was believed to be the cause of the “dip”. The majority of the potential “dip” results from the sharp increase of the Ohmic resistance of the zinc gel matrix; the diffusion overpotential across the ZnO film also contributes to the potential “dip”. The reactivation is believed to have resulted from the removing of the type II film.