Hydrogen bonding effect on the poly(ethylene oxide), phenolic resin, and lithium perchlorate-based solid-state electrolyte

The interaction behavior of solid-state polymer electrolytes composed of poly(ethylene oxide) (PEO)/novolac-type phenolic resin and lithium perchlorate (Li-ClO4) was investigated in detail by DSC, FTIR, ac impedance, DEA, solid-state NMR, and TGA. The hydrogen bonding between the hydroxyl group of phenolic and ether oxygen of the PEO results in higher basicity of the PEO. The higher basicity of the ether group can dissolve the lithium salts more easily and results in a greater fraction of free anions and thus higher ionic conductivity. DEA results demonstrated that addition of the phenolic increases the dielectric constant because of the partially negative charge on the ether group induced by the hydrogen bonding interaction between ether oxygen and the hydroxyl group. The study showed that the blend of PEO(100)/LiClO4(25)/phenolic(15) possesses the highest ionic conductivity (1.5 X 10(-5) S cm(-1)) with dimensional stability. (C) 2003 Wiley Periodicals, Inc.