The electrochemical characteristics of Li x Ni y Co1−y O2 (0.5<y<0.9) prepared by a co-precipitation method were reported. Slow scan cyclic voltammetry (SSCV) and electrochemical impedance spectroscopy (EIS) were used to investigate the kinetic behavior of the composite electrodes. Kinetic data such as the Tafel slope and the charge-transfer resistance were determined based on the experimental results. An equivalent circuit model was proposed to simulate the impedance spectra and gave a good data fit. The present study also demonstrated that the kinetic data were composition-sensitive to varying lithium content and nickel content in the mixed oxide electrodes.