LITHIUM ION CONDUCTION IN EXTREME POLYMER IN SALT REGIME

Thin films of lithium salt containing polymer composites were prepared from LiI, Li2SO4 and Li3PO4 with PEO, PVA and PEO-PVA (50:50) blends by solution casting method, for various salt concentration (10, 15, 20 mole %). The conductivity and dielectric measurements were carried ou t on these films as a function of frequency at various temperatures. T he highest conductivity was observed in LiI-polymer composites. The va riation of conductivity with salt concentration has been explained on the basis of percolation path. In the case of Li2SO4 and Li3PO4 compos ites, the variation of conductivity with salt composition is found to depend more on the nature of coordination of Lit ions in the composite s rather than the mole % of salt itself. AC conductivity and dielectri c relaxation behavior of these composites were also studied and the re sults are discussed. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.