Macroporous, low density polyethylene films have been used as support systems for polyethylene glycol (PEG) and propylene carbonate (PC)-lithium triflate mixtures. It has been shown that the optimum loading of (electrolyte + salt)/PE of 5.75/1 (w/w) gave conductivities in the range 3 x 10(-4) to 3 x 10(-5) S cm(-1) between 20 degrees C and 80 degrees C and that these values are better than comparable solvent free polymer electrolytes at ambient temperatures. Plots of log conductivity against reciprocal temperature for various [Li+]/[O] ratios obeyed the Arrhenius equation and the temperature dependence of conductivity was lower in the PC system when compared with the PEG-containing films. The systems are simple to prepare, are versatile and strong, and are leak-free at ambient temperatures. These features make them possible competitors for solvent-free polymer electrolytes.