Journal of the Electrochemical Society, Vol.164, No.4, A555-A559, 2017
Investigation of the Surface State of LiCoO2 Thin-Film Electrodes Using a Redox Reaction of Ferrocene
One of the reasons of performance deterioration of lithium-ion batteries is the degradation of positive electrode materials. In this study, the degradation mechanism of LiCoO2 was investigated focusing on the surface electron conductivity of LiCoO2. The surface electron conductivity change in LiCoO2 thin-film electrode was investigated using a redox reaction of ferrocene. After chargedischarge cycles, the surface electron conductivity of the LiCoO2 thin-film electrode was increased and this indicates that the electron insulating surface film was not formed and lithium-ion deficit phase Li1-xCoO2 was rapidly formed at the surface region at the 1st cycle. It is found that the use of the redox reaction of ferrocene is useful to evaluate the surface state change in LiCoO2. (C) 2017 The Electrochemical Society. All rights reserved.