In situ XAFS study on cathode material for Li secondary batteries(4)

- Micro XAFS analysis -

Abstract

By using X-ray micro-beam with 1μm, Ni and Co K-edge XANES spectra at local area of LiNi_0.8Co_0.2O₂ were observed, and the valence change of Ni was obtained. The chemical shift of Ni K-edge energy indicates the change of Ni valence accompanied by charging. Comparing between the XANES spectra at any points in the same grain, no apparent difference was found. It was concluded that the property changes during charge-discharge cycling is independent on the position in the grain.