NiOOH was prepared by one-step electrolysis of spherical Ni(OH)2 and the effects of electrolysis parameters were examined. The highly pure NiOOH was obtained after electrolysis at a current density of 60mA center dot g(-1) and 30 degrees C with anodic potential controlled in the range of 1.73-1.85V (vs. Zn/ZnO) for 360min. The NiOOH samples were characterized by X-ray powder diffraction (XRD) and scanning electron microscope (SEM) analysis. Results indicate that the electrolysis product is spherical NiOOH doped with graphite. Charge and discharge tests show that the prepared NiOOH offers a discharge capacity of over 270mAh center dot g(-1) at current density of 30mA center dot g(-1) and can be directly used as cathode material of alkaline Zn/NiOOH batteries. Galvanostatic charge/discharge and cyclic voltammetry (CV) tests reveal good cycling reversibility of the NiOOH electrode.