Ionic conduction mechanisms of lithium gel polymer electrolytes investigated by the conductivity and diffusion coefficient

Conduction properties of the polymer gel electrolytes of lithium were investigated based on the electrical conductivity and diffusion coefficient using the pulsed gradient spin echo NMR technique. The gel electrolytes prepared by the phase inversion method showed characteristic features in diffusive behavior depending on the kind of immiscible solvent used during the preparation process of the porous polymer membranes. The diffusion coefficients of several kinds of gel were composed of two components that were attributed to the different phases, the trapped solution in the cavities in the membrane and the swollen polymer chains due to the immersed solution. The swollen polymer dominates the high conductivity of this type of gel electrolytes due to the homogenous network appropriate for carrier migration through the chains.