2B-4
Investigation of Charge-Discharge Properties and Local/average Structures in Li₂(Ru, Mn)O₃ Cathodes for Lithium-ion Secondary Battery, T. Iwata (Tokushima Univ.) et al.

The structural variations of Li-rich layered oxides (Li₂MnO₃, Li₂RuO₃, and Li₂Ru_0.5Mn_0.5O₃) during charge?discharge cycling was investigated by pair distribution function (PDF) analysis. The PDF profile, G(r), obtained by Fourier transformation of the X-ray diffraction structure factor, S(Q), was used to evaluate local and long-range structural changes. Characteristic variations in the G(r) profiles were observed in the 4.5 - 8 Å region, corresponding to distortions of the MO₆(M=Mn Ru) octahedra, and these variations depended on the M species. These results suggest that charge compensation during delithiation is related to octahedral distortion, particularly in Ru-containing systems.