Ion conducting behaviour and morphology of solid polymer electrolytes based on a regioselectively substituted cellulose ether with PEO side chains

Abstract

The LiCF₃SO₃ complexes of a thermotropic cellulose ether having PEO side chains (TPEOCELL) were prepared and the effects of salt concentration on the conductivity and morphology were investigated. A linear dependence of log (conductivity) on reciprocal temperature occurs in these systems, with activation energies for ion transport in the range 53–73 kJ mol⁻¹. TPEOCELL shows a periodic lamellar-like internal structure which is ascribed to the presence of cholesteric ordering. By contrast, its complexes exhibit an array structure composed of granular-like entities which coalesce irregularly to form a rough morphology. This morphological feature is taken to represent a liquid crystalline polymer–salt network in which a form of anisotropic microphase separation occurs.