Synthesis and characterization of mixing soft-segmented waterborne polyurethane polymer electrolyte with room temperature ionic liquid

Composite polymer electrolytes based on mixing soft-segment waterborne polyurethane (WPU) and 1-butyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide (BMImTFSI) have been prepared and characterized. The addition of BMImTFSI results in an increase of the ionic conductivity. At high BMImTFSI concentration (BMImTFSI/WPU = 3 in weight ratio), the ionic conductivity reaches 4.27 × 10−3 S/cm at 30 °C. These composite polymer electrolytes exhibit good thermal and electrochemical stability, which are high enough to be applied in lithium batteries.