New composite polymer electrolytes based on room temperature ionic liquids and polyether

Composite polymer electrolytes based on room temperature ionic liquids and polyether have been designed and synthesized. All room temperature ionic liquids which contain short poly(ethylene oxide) chains have good compatibility with the prepolymer, polyether based on polysiloxane. An ultraviolet polymerization method was utilized for the curing of the composite polymer electrolytes. The composite polymer electrolytes which are composed of the room temperature ionic liquids and polyether based on polysiloxane showed high ionic conductivity and high thermal stability. The ionic conductivity of the composite polymer electrolytes is nearly two magnitudes higher than those electrolytes with pure polyether based on polysiloxane. A maximum conductivity of 1.05 × 10⁻³ S/cm⁻¹ is achieved at 30°C. Thermogravimetic analysis revealed scarcely any thermal weight loss at 80°C and thermal decomposition of the composite polymer electrolytes had not been observed up to 250°C. It retains electrochemical stable till 4.2 V which is acceptable. Copyright © 2006 John Wiley & Sons, Ltd.