To provide a low resistance electrode excellent in adhesiveness of an active substance layer to a collecting body, and a low resistance to the collecting body by having a carbon coat foil layer obtained by coating the carbon coat coating solution including a binder component containing an unsaturate dicarboxylic acid as an essential component on an aluminum foil and the active substance layer, and a lithium ion secondary battery using these electrodes.

The present invention relates to the binder for the carbon coat foil coating solution coating on a metallic foil which is a polymer with a weight average molecular weight of 500,000-3,000,000 and obtained by polymerization of only an unsaturated dicarboxylic acid or a polymer obtained by polymerization of one or more of unsaturated monomers selected from the group consisting of (meth)acrylic acid, a hydroxyalkyl (meth)acrylate, (meth)acrylamide and N-methylol (meth)acrylamide, (meth)acrylonitrile and an alkyl (meth)acrylate, and an unsaturated dicarboxylic acid.