Ion transport theory of nonaqueous electrolytes. LiClO4 in gamma-butyrolactone: the quasi lattice approach

As a part of a study on the optimisation of the electrolyte for high-densit y energy lithium batteries, transport properties of concentrated LiClO4 sol utions in gamma -butyrolactone (BL) have been investigated. The effect of t he salt concentration (C) on the viscosity (n) of BL solutions has been dis cussed in term of the Jones-Dole equation. At concentrations higher than 0. 2 M, the molar conductivity (Lambda) of LiClO4 solutions follow a C-1 (3) c ube root law which is predicted by the quasi lattice model first introduced by Gosh. In this model, the: ions of the strong binary electrolyte are dis tributed in a lattice-like arrangement (fcc). The experimental value found for the slope of Lambda vs. C-1 (3) relation is in fair agreement with the calculated one. The effect of the temperature on the viscosity and the cond uctivity of electrolyte solutions have been examined. These two transport p rocesses are well described by Arrhenius type laws from which the activatio n energies for the viscosity E-an and conductivity E-a Lambda are deduced. The variations of E-an and E-a Lambda with salt concentration are respectiv ely dependent on C and C-4 (3) as predicted by the quasi lattice model. (C) 2001 Elsevier Science Ltd. All rights reserved.