BINDER FOR ELECTRICITY STORAGE DEVICE

摘要

Provided is a binder for an electricity storage device, said binder showing a good adhesion in an electrode, having a high flexibility and being capable of achieving satisfactory charge and discharge characteristics when employed in a secondary battery. The binder for an electricity storage device is characterized by comprising a fluorine-containing copolymer, which comprises structural unit (a) based on tetrafluoroethylene and structural unit (b) based on propylene at a molar ratio (a)/(b) of 40/60-50/50, and in which the sum of the structural units (a) and (b) is 90 mol% or greater relative to the total structural units.