The preparation, conductivity, viscosity and mechanical properties of polymer electrolytes and new hybrid ionic rubber electrolytes

The preparation and characterization of new ionic rubber electrolytes based on the ternary LiClO₄LiNO₃LiOAc and the high molecular weight PEO (m wt 8 × 10⁶) is reported. The conductivity, viscosity and shear modulus have been measured. The decrease in conductivity due to incorporation of 9% PEO (m wt 8 × 10⁶) in the salt mixture is small (factor of 5), but the increases in viscosity is enormous (eg factor of ~5000 with only 5% PEO). 10% PEO (m wt 8 × 10⁶) can give rise to a rubbery plateau above T_g which extends to about 130 °C transition to liquid defined by the onset temperature of the varnishing of the shear modulus. These characteristics combined with the high Li cation transport number make this kind of material very promising. Results are compared with those of the conventional salts-in-polymer electrolytes and the crossover to the polymer-in-salts region is identified by a maximum in the rubbery modulus.