Patent ID: 8530110
Filing Date: 2013-09-10
Classification: B32B,H01M,Y02E

Abstract:
1. A lithium-ion secondary battery separator having a porous structure formed by laminating a second polymer layer, a first polymer layer, and a second polymer layer in sequence; wherein the second polymer layer has a melting point lower than that of the first polymer layer; the second polymer layer has a first part formed on a side in contact with the first polymer layer and a second part formed on a side farther from the first polymer layer than is the first part; the first part and the second part have a weight-average molecular weight ratio (first part/second part) of 4 to 19 therebetween; a film of the second part is laminated on a film of the first part; the second polymer layer is a layer constituted by at least one kind of polymer material selected from the group consisting of polyethylene and polypropylene; and the first polymer layer is a layer constituted by at least one kind of polymer material selected from the group consisting of polyacrylonitrile, polyamide-imide, polyvinyl alcohol, and thermoplastic polyimide.