First In Situ Observation of the LiCoO₂ Electrode/Electrolyte Interface by Total‐Reflection X‐ray Absorption Spectroscopy

Abstract

Surface analysis: In situ total-reflection fluorescence X-ray absorption spectroscopy showed that reduction of cobalt at the surface of a LiCoO2 electrode occurs by contact with a liquid electrolyte. An irreversible behavior was observed at the surface of LiCoO2 during a first charge/discharge process whereas the bulk material showed a reversible behavior. This Co reduction is an initial electrode deterioration.