Lithium-Polymer Electrolytes Based on Polyurethane Acrylate Prepared by a Solvent-Free Method

A solvent-free, cross-linked polymer electrolyte based on polyurethane acrylate (PUA) containing LiTFSI has been prepared and tested in an all-solid-state lithium-polymer battery (Li/PUA/Li0.33MnO2). It was found that the new polymer electrolyte could be directly membranous in the absence of any solvent and could be coated directly on a lithium foil or a composite cathode to form an ultrathin membrane of 10-50 mum. The PUA electrolyte membrane was thermally stable to 220degreesC at the Li/Li0.33MnO2 system and had a higher ionic conductivity than a polyethylene oxide based polymer electrolyte below 60degreesC. The cell exhibited a high initial capacity (190 mAh/g), a charge-discharge efficiency of above 99%, and could be operated at 40degreesC. (C) 2004 The Electrochemical