Patent 7579401 was granted and assigned to Nippon Soda Co., Ltd. on August, 2009 by the United States Patent and Trademark Office.
An object of the present invention is to provide a practical solid polymer electrolyte that exhibits excellent thermal characteristics, physical characteristics, and ionic conductivity, and in particular, to provide a completely solid electrolyte and a copolymer composition that functions as the substrate for producing such an electrolyte. A solid polymer electrolyte comprising an electrolyte salt, and a copolymer in which a block chain A containing a repeating unit represented by a formula (I) shown below,