Thermal Stability and Morphology Analysis of Polymer Electrolyte Membranes Prepared from Cellulose Acetate-LiClO4

Abstract

Polymer electrolyte membranes of cellulose acetate-LiClO4 were prepared from the cellulose acetate with various ratios of lithium perchlorate in tetrahydrofuran (THF) as solvent. The properties of polymer electrolyte membranes with various ratios of lithium perchlorate were studied by Thermogravimetric Analysis (TGA) and Scanning Electron Microscopy (SEM). The obtained TGA curves showed that these membranes were degraded thermally in three steps, which were attributed to dehydration, the main thermal degradation of the cellulose acetate chains, and the carbonization of the product to form ash. The thermal stability of the membrane decreased with the increase in LiClO4 content. The initial temperatures of the main degradation process decreased gradually from 330 °C in pure cellulose acetate membrane to 258 °C in cellulose acetate membrane containing 25% lithium perchlorate. The morphology of the membranes transformed from dense to the more porous membrane along with the increase in lithium perchlorate ratios on membranes.