Li+-conductive polymer electrolytes derived from poly(1,3-dioxolane) and polytetrahydrofuran

Polymer electrolytes comprising poly(1,3-dioxolane) and polytetrahydrofuran complexes of LiClO4 have been prepared, and characterized using infrared spectroscopy, differential scanning calorimetry, and electrochemical techniques. Room temperature conductivities of 4.3 × 10−6 and 1.2 × 10−6 Ω−1 cm −1 have been determined for the poly(1,3-dioxolane) and polytetrahydrofuran electrolytes, respectively. These values are significantly higher than that of the corresponding poly(ethylene oxide) electrolyte and are attributed to the increased amorphous nature and chain-flexibility of the polymer hosts. Attempts to polymerize 2-[2-(2-methoxyethoxy)ethoxy]-1,3-dioxolane and 2-methyoxy-1,3-dioxolane using cationic initiators were unsuccessful. The polytetrahydrofuran electrolyte exhibited at Li+ transport number of 0.6. Because of apparent chemical reactions between Li and poly(1,3-dioxolane), an accurate Li+ transport number could not be determined for electrolytes based on this polymer.