Changes in Electronic Structure between Cobalt and Oxide Ions of Lithium Cobalt Phosphate as 4.8-V Positive Electrode Material

Insight into electron exchange in LiCoPO4 electrodes for high-voltage lithium ion battery is presented using X-ray absorption spectroscopy (XAS). Despite the formation of the isolated valence electrons around the Co ion, O K-edge XAS reveals clear evidence that the hybridized orbital between Co and O plays an important role in the electron exchange arising from the electrochemical Li extraction.