Study of Polyethers/Lii Systems by Addition of Alumina Ceramic Powders Prepared by Two Synthesis Methods

Abstract

Composites of alumina ceramic powders prepared by co-precipitation and sol-gel methods with Lithium Iodide based polymer electrolytes are described. The polyether matrices Poly(ethylene oxide) (PEO) and block copolymer Poly(propylene glycol-ethylene glycolpropylene glycol) (Triblock) with Lil in a ratio [O]:[Li] = 20:1 are used with up to 17 wt% of α-A1203 (medium grain size). Differential Scanning Calorimetry (DSC) studies show that Tg values for PEO based composites are higher whereas those for Triblock based composites are lower than the Tg value of the polymer/salt system.Conductivity measurements as a function of temperature show that there is no significant change in conductivity above the melting points for the electrolytes after α-A1203 powder addition (σ approximately 10−3 S.cm−l at 100°C), whereas better mechanical properties are observed for the ceramic reinforced samples. An increase in conductivity is obtained for the Triblock based composites near room temperature as a consequence of the lower melting point of these materials (26°C) in comparison to the PEO based composites (54°C).