A polymer battery which includes a cell assembly having a positive
electrode, a negative electrode, and a separator composed primarily of a
fluoropolymer is manufactured by impregnating the cell assembly with an
electrolyte composition containing (A) an ion-conductive salt, (B) a
solvent in which the ion-conductive salt is soluble and (C) a compound
having at least two reactive double bonds per molecule, then reacting the
component C compound to form a three-dimensional network structure. The
polymer battery has a high safety, a good thermal cycling resistance and
robust characteristics even when held at an elevated temperature, making
it particularly suitable for use as a lithium secondary cell or a lithium
ion secondary cell.
