2001 Volume 69 Issue 8 Pages 592-597
A new theoretical approach of the intercalation/deintercalation process of lithium cations into host materials is proposed in that paper taking into account the dependence of the lithium diffusion coefficient on concentration is considered for the integration of the mass balance equation. Numerical simulation of chronopotentiograms is used to solve the diffusion equation. The component and chemical diffusion coefficients corresponding to the Li+ intercalation into Nb2O5 in 1 M LiClO4-PC were determined. It was found that and DLi decrease from 1.4 × 10−10 cm2 s−1 to 5.7 × 10−11 cm2 s−1 and from 1.2 × 10−11 cm2 s−1 to 6.4 × 10−13 cm2 s−1, respectively, with increasing values of the intercalation ratio, y, comprised between 0.4 and 1.6. Impedance measurements performed in an equilibrium situation give and DLi values which were rather constant but higher.