Spectroscopic analysis with high spatial resolution imaging Nanofinder®FLEX

3D Raman image analysis on positive electrode surface of Li-Ion battery

3D Raman mapping on the positive electrode of a degraded Li-Ion battery were done. Distributions of normal electrode material (LiCoO₂) and degraded material (Co₃O₄) can be observed in Raman images.

As a material for the positive electrode of Li-Ion battery, LiCoO₂ is mainly used. The electrode material, however, degrades after repeated discharge and charge cycles and then some areas of the electrode surface turn into Co₃O₄, which can't contribute to charge. Because these materials show different spectra, material distributions on the surface can be observed with specific peak intensity images (red spectrum: LiCoO₂, blue spectrum: Co₃O₄).

Typical Raman spectra

Normal area of the electrode Raman intensity image at LiCoO2 peak (600 cm-1)	Degraded area of the electrode Raman intensity image at Co3O4 peak (700 cm-1)
Overlapped (normal and degraded areas) image.

As shown in the upper images, distributions of normal LiCoO₂ and degraded Co₃O₄ material are completely different.

Overlapped image from above images.