Electrochemical properties of ZrO2-coated LiNi0.8Co0.2O2 cathode materials

The effect of a ZrO2 coating on the structure and electrochemical properties of the cathode material LiNi0.8Co0.2O2 was investigated using EPMA, TEM, XRD, and electrochemical impedance spectroscopy (EIS). In particular, we focused on the distribution of the ZrO2 on the particle surface to study the relationship between electrochemical properties of the coated cathode and the distribution of the coating materials in the particle. Based on the results from composition analysis and electrochemical tests, it was found that the coating layer consisted of nano-sized ZrO2 particles attached nonuniformly to the particle surface and the ZrO2 layer significantly improved the electrochemical properties of the cathode by suppressing the impedance growth at the interface between the electrodes and the electrolyte.