Cobalt oxyhydroxide coat on the surface of nickel hydroxide particles is finished employing a simple ball milling process. The structure, morphology, and surface composition of the coated Ni(OH)(2) particles is characterized by using X-ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy tests. The results show that numerous strip-like particles of a mixture of Ni(OH)(2) and CoOOH aggregate on the surface of the Ni(OH)(2) particles, and a structure of beta-Ni(OH)(2) is preserved. Compared to the Ni(OH)(2) electrodes with a mixed CoO additive, the electrochemical activity of the electrodes with ball milled CoOOH coat can be improved as shown by using electrochemical impedance spectroscopy test, thus resulting in charge-discharge and cycle life performance improvement of the electrodes.