| abstract |
An object of the present invention is to provide a separator and a secondary battery having high ion conductivity and excellent durability. The present invention relates to a separator comprising a fluorine-containing polymer containing a polymerization unit based on vinylidene fluoride and a polymerization unit based on tetrafluoroethylene, and a porous film, wherein the fluorine-containing polymer is a vinylidene fluoride- Is 80.0 to 89.0 mol% based on the total polymerized units, and has a weight average molecular weight of 50,000 to 2,000,000. |