졸-겔법에 의해 제조된 정극 활물질 LiNi0.8Co0.2-xMxO2[M=Al]의 전기화학적 특성

Abstract : The LiNi0.8Co0.2O2 has shown outstanding electrochemical properties. The microstructure of LiN0.8Co0.2O2 cathode was investigated by using TEM (transmission electron microscopy) and X-ray diffraction techniques. The LiNi0.8Co0.2O2 was produced by sol-gel method to synthesize fine particles less than 1 mm in the average diameter. In this study, emphasis was given to the examination and interpretation of the microstructural change during charge-discharge cycling experiments, which appeared to be one of the main causes of early degradation of rechargeable batteries. Results showed that the LiNi0.8Co0.2O2 cathode produced by sol-gel method had high reversible capacity and excellent cycling stability due to its homogeneous distribution of Ni and Co cations on an atomic scale. In particular, the LiNi0.8Co0.2O2 cathode did not show severe strain induced structural defects or cubic spinel disordering during cycling experiments, which had been observed in the conventional LiCoO2 cathode. The LiNi0.8Co0.2-xMx [M=Al] compounds show good reversibility but low discharge capacity.