Proton-conducting and ionic-conducting polymer electrolytes based on polyethylene Oxide(PEO)

Polymer-inorganic composite films of PEO-ZnO-LiClO4, PEO-SnO2-LiCIO4 and PEO-12-TSA(12-TSA: 12-tungstosilicic acid; PEO: polyethylene oxide, Aldrich, MW = 600000) have been prepared through a film-casting method. The interactions between PEO and ZnO nanoparticles and those between PEO and SnO2 nanopartilces decrease the crystallinity of the composite films so as to produce more amorphous regions for charge carriers to transfer, and to release more Li (+) or ClO4 (-) from Li (+) ClO4- ion pairs as charge carriers. As a result, the ionic conductivity of the films is significantly enhanced. The Keggin anions and the polymer molecules are linked together by hydrogen bonds to form a new composite compound of PEO-12-TSA. The ether oxygens of the PEO are associated with H3O (+) cations provided by 12-TSA. 12-TSA not only provides the protons but also favors the formation of the H3O (+) species and increases the proton conductivity of the PEO-12-TSA films.