Conduction properties of lithium gel electrolytes investigated by impedance spectroscopy and pulsed-field gradient NMR with electric field

Gel polymer electrolytes were prepared by two different techniques, casting and phase inversion methods. The conductivity of them showed almost the same behavior as a function of temperature. The diffusion coefficients obtained from the pulsed-field gradient NMR revealed characteristic features depending on the kinds of gel. The gels by phase inversion method showed two components in diffusion process. This reflects the presence of two phases in the initial state of the gel, one is of the electrolyte solution in the cavities of the polymer and the other is the swollen polymer by the solution which is present among the polymer chains. The gel in the equilibrium condition after ageing revealed one component of diffusion coefficient. The mobilities of the lithium ion and the anion using the electric applying NMR were 3.6 × 10^-5 and 9.4 × 10^-5 cm² s^-1 V^-1, respectively.