Crystal Structure and Nuclear Density Distribution of LiCo_(1/3)Ni_(1/3)Mn_(1/3)O_2 Analyzed by Rietveld/Maximum Entropy Method

摘要

The neutron powder diffraction measurement of LiCo_(1/3)Ni_(1/3) Mn_(1/3)O_2 was carried out and the crystal structure and scattering density distribution were analyzed by Rietveld refinement and the maximum entropy method (MEM) to estimate the Li diffusing pathway. Rietveld refinement showed that the structure was basically the same as LiCoO_2: a R-3m space group, with Li and O mainly occupying the 3a and 6c sites, and Co, Ni, and Mn randomly occupying the 3b site. Approximately 4% of the Li and Ni atoms exchanged their original sites (3a and 3b) to occupy 3b and 3a, respectively. Based on MEM analyses, we surmise that Li atoms moved on the (001), (003), and (00-3) planes and diffused through the 3a-9e-3a sites on these planes.