Characterization, average and electronic structures during charge-discharge cycle in 0.6Li2MnO3-0.4Li(Co1/3Ni1/3Mn1/3)O2 solid solution of a cathode active material for Li-ion battery

The 0.6Li2MnO3-0.4Li(Co1/3Ni1/3Mn1/3)O2 solid solution was prepared by the co-precipitation method. The average structure analysis based on the Rietveld method using neutron diffraction was carried out. As a result, the charging process eliminated Li from the transition metal layer as well as the lithium layer, and the dominant elimination of Li was suggested to be from the 2b site (S.G.; C2/m). The amount of the cation mixing of Ni at the 2c site in the Li layer tended to increase from the first to fifth cycles. It was suggested that Co moved to the 4g site after discharge, but to the 2b site after charging. On the other hand, the opposite tendency was shown for Mn. In addition, an electronic-structure analysis based on the Maximum Entropy Method was carried out. The covalent linkage increased in 4h-4i and 4h-8j between the first and fifth charge processes. It was also found that most of the Li in the 4h site was not extracted at the fifth cycle compared to the first cycle.