Title: INTERPRETATION OF POTENTIAL INTERMITTENCE TITRATION TECHNIQUE EXPERIMENTS FOR VARIOUS Li-INTERCALATION ELECTRODES
Author(s): M.D.Levi, D.Aurbach (Department of Chemistry, Bar-Ilan University, Ramat-Gan 52900, Israel), M.A.Vorotyntsev (LSEO, Facult\'{e} des Sciences Gabriel, Universit\'{e} de Bourgogne, 6 boulevard Gabriel, 21000 Dijon, France)

In this paper we compare two different approaches for the calculation of the enhancement factor $W_i$, based on its definition as the ratio of the chemical and the component diffusion coefficients for species in mixed-conduction electrodes, originated from the ``dilute solution'' or ``lattice gas'' models for the ion system. The former approach is only applicable for small changes of the ion concentration while the latter allows one to consider a broad range of intercalation levels. The component diffusion coefficient of lithium ions has been determined for a series of lithium intercalation anodes and cathodes. A new ``enhancement factor'' for the ion transport has been defined and its relations to the intercalation capacitance and the intercalation isotherm have been established. A correlation between the dependences of the differential capacitance and the partial ion conductivity on the potential has been observed. It is considered as a prove that the intercalation process is controlled by the availability of sites for Li-ion insertion rather than by the concurrent insertion of the counter-balancing electronic species.

Key words: Li-ion battery, binary component, chemical diffusion coefficient, ionic conductivity, lattice gas model
PACS: 84.60.Dn, 66.30.Dn