New composite solid electrolytes based on a polymer and ionic liquids

A series of ion-conducting, thin-film polymer electrolytes, based on a polymer (poly(acrylonitrile) [PAN], poly(ethyleneoxide) [PEO] and poly(vinylalcohol) [PVA]), and ionic liquids (IL), polymer–IL, as well as ternary systems PAN–IL–TMS were prepared using the casting technique (TMS is sulpholane, ionic liquids are: 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium hexafluorophosphate and 1-butyl-1-methyl-pyrrolidinium bis(trifluoromethane sulfonyl)imide). The polymer electrolytes showed a rubber-like elasticity. Maximum conductivity was at the level of 15 mS/cm at room temperature. The electrochemical stability window of the electrolytes, determined at the glassy carbon electrode, was of ca. 3 V.