The feasibility study of composite electrolytes comprising thermoplastic polyurethane and poly(ethylene oxide)

Composite polymer electrolyte films consisting of poly(ethylene glycol)-based thermoplastic polyurethane (TPU-PEG2000 and TPU-PEG400) blended with linear poly(ethylene oxide) incorporating 100 wt.% LiClO₄-PC and LiClO₄-PC/EC have been prepared for investigating their ionic conductivities and electrochemical stability with lithium metal. Alternating current (AC) impedance experiments were performed to determine the ionic conductivities of gel-type electrolytes. One of the composite polymer electrolytes exhibits an ionic conductivity of 1.6 × 10^-3 S cm^-1 at room temperature. AC impedance was also used to study the stability of bulk resistance and interfacial resistance between Li metal and electrolytes. Results of linear sweep voltammetry (LSV) and cyclic voltammetry (CV) show that the composite electrolytes have good electrochemical stability up to the working voltage 5.5 V and good reversibility for lithium kinetics.