Electrolytic dendritic-zinc powders of high surface area are prepared from an alkaline solution by a galvanostatic electrodeposition method. The surface morphology and microstructure of these powders are examined by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Cylindrical AA-size alkaline zinc–manganese dioxide (Zn–MnO2) batteries made with powders in anode gels are assembled and tested. The electrochemical characteristics of the batteries are evaluated by means of the ac impedance method and the constant-current discharge experiments. It is found that the high-rate performance of cells with dendritic-zinc powders is much better than that of cells with conventional molten-zinc powders.