High pressure NMR and electrical conductivity studies of gel electrolytes based on poly(acrylonitrile)

The effect of high pressure on electrical conductivity and NMR in gels prepared from lithium or sodium perchlorate, ethylene carbonate, dimethyl carbonate and poly(acrylonitrile) (PAN) has been determined. The corresponding liquids were also studied. Complex impedance studies at frequencies from 10 to 10(8) Hz and NMR measurements of T-1 were carried out as a function of pressure up to 0.25 GPa. Activation volumes for NMR relaxation and ionic conductivity were calculated from the variable pressure data. Both activation volumes were found to be approximately the same in the liquids. For the gels, however, the NMR activation volumes are the same or lower than for the liquid while the electrical conductivity pressure dependences are larger. The implications of these results are discussed in terms of possible effects of the PAN on the ionic solvation shell.