Abstract: A polyolefin-based porous separator, including a first polyolefin-based porous film on a first surface of a second polyolefin-based porous film, and a third polyolefin-based porous film on a second surface of the second polyolefin-based porous film, each of the first and third polyolefin-based porous films containing inorganic particles having an average particle size of 10 nm to 100 nm, a thickness ratio of the first polyolefin-based porous film, the second polyolefin-based porous film, and the third polyolefin-based porous film being 0.5 to 1.5:1 to 6:0.5 to 1.5, and thermal shrinkage rates of the separator in a machine direction and a transverse direction measured after standing at 120° C. for 1 hour each being 5% or less, and air permeability of the separator being 250 sec/100 cc or less.

Abstract: A heat resistant porous layer composition for a separator for an electrochemical battery includes a compound represented by Formula 1, a polyvinylidene fluoride (PVdF)-based polymer, the PVdF-based polymer including one or more of a PVdF-based homopolymer or a PVdF-hexafluoropropylene-based copolymer in which a unit originating from hexafluoropropylene is present in an amount of 15 wt % or less based on the total weight of the PVdF-hexafluoropropylene-based copolymer, the PVdF-hexafluoropropylene-based copolymer having a weight average molecular weight of 600,000 g/mol or more, an initiator; and a solvent, wherein Formula 1 is defined herein.

Abstract: A method for manufacturing a polyolefin separator, including forming a sheet including a polyolefin resin and a plasticizer; stretching the sheet E1 times in a longitudinal direction at a temperature of T1, followed by stretching the sheet E2 times in a transverse direction at a temperature of T2, wherein T1<115° C., T2<115° C., and T2?T1, and E1×E2=55 to 80, E1?7, and E2?7; and extracting the plasticizer from the stretched sheet.

Abstract: A heat resistant porous layer composition for a separator for an electrochemical battery includes a compound represented by Formula 1, a polyvinylidene fluoride (PVdF)-based polymer, the PVdF-based polymer including one or more of a PVdF-based homopolymer or a PVdF-hexafluoropropylene-based copolymer in which a unit originating from hexafluoropropylene is present in an amount of 15 wt % or less based on the total weight of the PVdF-hexafluoropropylene-based copolymer, the PVdF-hexafluoropropylene-based copolymer having a weight average molecular weight of 600,000 g/mol or more, an initiator; and a solvent, wherein Formula 1 is defined herein.

Abstract: A polyolefin-based porous separator, including a first polyolefin-based porous film on a first surface of a second polyolefin-based porous film, and a third polyolefin-based porous film on a second surface of the second polyolefin-based porous film, each of the first and third polyolefin-based porous films containing inorganic particles having an average particle size of 10 nm to 100 nm, a thickness ratio of the first polyolefin-based porous film, the second polyolefin-based porous film, and the third polyolefin-based porous film being 0.5 to 1.5:1 to 6:0.5 to 1.5, and thermal shrinkage rates of the separator in a machine direction and a transverse direction measured after standing at 120° C. for 1 hour each being 5% or less, and air permeability of the separator being 250 sec/100 cc or less.

Abstract: A method for manufacturing a polyolefin separator, including forming a sheet including a polyolefin resin and a plasticizer; stretching the sheet E1 times in a longitudinal direction at a temperature of T1, followed by stretching the sheet E2 times in a transverse direction at a temperature of T2, wherein T1<115° C., T2<115° C., and T2?T1, and E1×E2=55 to 80, E1?7, and E2?7; and extracting the plasticizer from the stretched sheet.