Electrochimica Acta, Vol.53, No.28, 8196-8202, 2008
Enhancement of electrochemical ion/electron-transfer reaction at solid vertical bar liquid interface by polymer coating on solid surface
Controlling the ion/electron-transfer reaction at the electrode vertical bar electrolyte (solid/liquid) interface is a necessary and vitally important point for improving the operation of various electrochemical devices. In this paper, we propose a polymer coating technique which enhances the Li+ ion-transfer reaction at the LiCoO2 vertical bar electrolyte interface. and confirm the effects of the polymer coating by cyclic voltammetry (CV) and AC impedance techniques. The results from the experiments indicated that the application of an F-introduced polymer on the LiCoO2 (LCO) surface decreased the activation barrier for Li+ ion transfer. Besides the electrochemical studies, the present computational results indicated that the Li+ exchange process between two states, which are both solved with ethylene carbonate (EC) and coordinated with an F-introduced polymer, might occur due to the close energy levels of Li+ stability. Accordingly, we inferred that the transition state of this exchange process promotes the observed decrease in activation energy for the interfacial Li+-transfer reaction. (C) 2008 Elsevier Ltd. All rights reserved.
Keywords:polymer coating;lithium-ion battery;electrochemical ion exchange reaction;solid vertical bar liquid interface