Investigation of the Conduction Mechanisms of Lithium Gel Polymer Electrolytes Based on Electrical Conductivity and Diffusion Coefficient Using NMR

Abstract

Conduction mechanisms of the polymer gel electrolytes of lithium were investigated from the electrical conductivity and diffusion coefficient by pulsed gradient spin echo NMR. The gel electrolytes prepared by the phase inversion method showed characteristic features in conductivity depending on the kind of the nonsolvent used during the polymer preparation process. This is first due to the solution content retained in the polymer. The diffusion coefficients of some gels were composed of two components which are attributed to the two phases: the trapped solution in the cavities in the polymer framework structure and the swollen polymer chains. The swollen polymer is closely correlated with the high conductivity of this type of gel electrolyte through the interactive effect between the electrolyte and the polymer chains.