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.