A study of mass transport processes in lithium-carbon intercalates by means of chronopotentiometry

The electrochemical intercalation of lithium from propylene carbonate solutions into thin film carbon electrodes prepared by the chemical vapor deposition onto support was studied. The overall electrode polarization was divided into the kinetic and dift'usional components by means of pulse galvanostatic method. First component connected with charge transfer through the e!ectrode|solution interface, second one conditioned by the diffusion of the intercalated species. It was shown that polarization dependence of the kinetic current obeys the same regularities as the current – potential dependence for the passivated lithium electrode. On this base the kinetic component of the polarization was attributed to the slow transport of lithium ions Li+ through the surface passive film. Dependencies of diffusion coefficient of lithium-in-carbon and of transport parameters of passive film were studied on temperature and composition of LixG, electrode.