Effects of ZrO2 Coating on LiNi1/3Mn1/3Co1/3O2 Particle with Microwave Pyrolysis

In this paper, ZrO2-coated LiNi1/3Mn1/3Co1/3O2 is successfully prepared by the microwave pyrolysis method. The structure and electrochemical properties of the ZrO2-coated LiNi1/3Co1/3Mn1/3O2 are investigated using x-ray diffraction, AC impedance, and charge/discharge tests, indicating that the lattice structure of LiNi1/3Co1/3Mn1/3O2 is unchanged after the coating but the cycling stability is improved. As the coating amount is 2 wt.%, initial capacity of the coated LiNi1/3Co1/3Mn1/3O2 decreases slightly. However, the cycling stability increases remarkably over the cut-off voltages of 2.75~4.3 V and the capacity retention reaches 93.1% after 50 cycles. Electrochemical impedance spectra results show that the increase of charge transfer resistance during cycling is suppressed significantly by coating with ZrO2.