To improve holding performance of a solvent of a polymer electrolyte and adhesion of the polymer electrolyte and an electrode active material by forming a copolymer on the basis of a vinylidene fluoride and perfluoro (alkyl vinyl ether) as a matrix, and containing solution composed of a solute of lithium salt and a solvent capable of dissolving the lithium salt.
A matrix is obtained by copolymerizing a polymerization unit on the basis of a vinylidene fluoride and a polymerization unit expressed by formula I or formula II in a range of the weight ratio of 95/5 to 5/95. In the formula, (a) and (d) are an integer of 0 to 3; and (b) and (e) are an integer of 0 to 8; and (c) and (f) are 0 or 1; and X and Y are F, CF3 or Cl. Carbonic ester is desirable as a solvent of a lithium salt solution. One or more kinds of either lithium salt using ClO4-, CF3SO3- or the like as an anion are used as lithium salt, and are dissolved in the solvent in concentration of 0.2 to 1.5 mol/l, and the lithium salt solution is desirably contained by 30 to 80 wt.% in the matrix.
HIRATSUKA KAZUYA
KAZUHARA MANABU
IKEDA KATSUHARU
