Separator for nonaqueous secondary battery, method for producing the same, and nonaqueous secondary battery

摘要

The present invention is to provide a separator that is excellent in heat resistance, shutdown function, flame retardancy and handling property. The separator for a nonaqueous secondary battery of the invention is a separator for a nonaqueous secondary battery that has a polyolefin microporous membrane at least one surface of which is laminated with a heat resistant porous layer containing a heat resistant resin, and is characterized by containing an inorganic filler containing a metallic hydroxide that undergoes dehydration reaction at a temperature of 200 to 400° C.

主权项

1. A separator for a nonaqueous secondary battery comprising a polyolefin microporous membrane at least one surface of which is laminated with a heat resistant porous layer consisting of a heat resistant resin and an inorganic filler,
wherein the inorganic filler contains a metallic hydroxide that undergoes dehydration reaction at a temperature of 200 to 400° C., the heat resistant resin is a least one of wholly aromatic polyamide, polyimide, polyamideimide, polysulfone, polyketone, polyetherketone, polyetherimide and cellulose, and a coated amount of the heat resistant porous layer is 2 to 10 g/m2, wherein the heat resistant porous layer contains the inorganic filler in an amount of 50 to 95% by weight, and wherein the heat resistant resin has a molecular weight distribution Mw/Mn of 5≦Mw/Mn≦100 and a weight average molecular weight of 8.0×103 to 1.0×106.