Conductivity behaviour of proton conducting polymer gel electrolytes with PVdF-HFP

Electrical conductivity of polymer gel electrolytes containing different hydroxy substituted benzoic acids and polyvinylidenefluoride-hexafluoropropylene (PVdF-HFP) has been studied. The conductivity of solution and gel electrolytes shows ortho effect and has been found to depend upon the acidity constant of the acid used and varies as sigma (ortho-) > sigma (meta-) > sigma (para-). The addition of PVdF-HFP to solution electrolytes results in an increase in conductivity and the conductivity of gel electrolytes has been found to be higher than that of the corresponding liquid electrolytes for all the three acids studied i.e. sigma (gel) > sigma (liquid). The increase in conductivity with polymer addition has also been found to depend upon the acid concentration. (C) 2002 Elsevier Science Ltd. All rights reserved.