INVESTIGATION OF THE (PEG)(X)LICL SYSTEM USING CONDUCTIVITY, DSC AND NMR TECHNIQUES

Electrolytes based on polyethylene glycol (PEG, mol.wt.8000) and LiCl of compositions, (PEG)(x)LiCl, x=4, 6, 8, 10, 12, 40, 60, where x is t he O/Li ratio, were prepared by solution casting from methanol solutio ns. FTIR studies indicate that the ether oxygens of the polymer chain participate in Li+ ion conduction. The presence of a salt-polymer comp lex that melts around 190 degrees C was evidenced by DSC measurements for the electrolytes with compositions x<12. The highest conductivity was obtained at the composition x=10 which was attributed to the prese nce of a mostly amorphous compound. NMR measurements indicated two reg ions of motional narrowing, one attributable to the glass transition a nd another to translational diffusion.