Interpretation of potential intermittence titration technique experiments for various Li-intercalation electrodes∗

摘要

In this paper we compare two different approaches for the calculation of theudenhancement factor Wiud, based on its definition as the ratio of the chemicaludand the component diffusion coefficients for species in mixed-conductionudelectrodes, originated from the “dilute solution” or “lattice gas” models forudthe ion system. The former approach is only applicable for small changesudof the ion concentration while the latter allows one to consider a broadudrange of intercalation levels. The component diffusion coefficient of lithiumudions has been determined for a series of lithium intercalation anodesudand cathodes. A new “enhancement factor” for the ion transport has beenuddefined and its relations to the intercalation capacitance and the intercalationudisotherm have been established. A correlation between the dependencesudof the differential capacitance and the partial ion conductivity onudthe potential has been observed. It is considered as a prove that the intercalationudprocess is controlled by the availability of sites for Li-ion insertionudrather than by the concurrent insertion of the counter-balancing electronicudspecies.