Gelled composite electrolyte comprising thermoplastic polyurethane and poly(ethylene oxide) for lithium batteries

Composite polymer electrolyte films consisting of poly(ethylene glycol) bas ed thermoplastic polyurethane blended with poly(ethylene oxide) (denoted as TPU(PEG)/PEO) incorporating LiClO4-PC have been prepared and their electro chemical properties were studied. The thermal analysis of the composite fil ms were performed to demonstrate the miscibility of the polymer blend by us ing differential scanning calorimeter (DSC). TPU(PEG)/PEO based polymer ele ctrolyte shows ionic conductivity of the order 6.4 x 10(-4) S/cm at room te mperature, irrespective of time evolution. Cyclic voltammogram shows that t his composite electrolyte has good electrochemical stability in the working voltage ranging from 2 to 4.5 V. Cycling performances of Li/polymer electr olyte/LiCoO2 cells are also followed. From AC impedance results, the rechar ging ability of the cells is proved to be dominated by the passive layer fo rmation at Li electrode-polymer electrolyte interface. (C) 2001 Elsevier Sc ience B.V. All rights reserved.