Separator for secondary battery, method for manufacturing the same and lithium secondary battery containing the same
Provided is a separator for a secondary battery including: a porous substrate; and a coating layer formed on the porous substrate, wherein the coating layer includes a plurality of inorganic particles and a binder for binding the plurality of inorganic particles, and the binder includes a copolymer of a monomer mixture including an acrylamide-based monomer, a vinyl cyanide monomer, and an acrylic monomer having a carboxyl group.
1. A separator for a secondary battery comprising:
a porous substrate; and a coating layer formed on the porous substrate,
wherein the coating layer includes a plurality of inorganic particles and a binder for binding the plurality of inorganic particles, and
wherein the binder includes a copolymer of a monomer mixture including 30 to 50 wt % of an acrylamide-based monomer, 20 to 40 wt % of a vinyl cyanide monomer, 5 to 20 wt % of an acrylic monomer having a carboxyl group, and 5 to 20 wt % of an acrylic monomer having a hydroxyl group, based on a total amount of the copolymer.
2. The separator for a secondary battery of claim 1 , wherein the coating layer includes 70 to 99.5 wt % of inorganic particles and 0.5 to 30 wt % of a binder, based on a total amount of the coating layer.
3. The separator for a secondary battery of claim 1 , wherein the binder has a particle phase.
4. The separator for a secondary battery of claim 3 , wherein the inorganic particle and the binder particle have an average particle diameter of 10 nm to 2 μm.
5. The separator for a secondary battery of claim 1 , wherein the binder has a glass transition temperature of 150 to 200° C.
6. The separator for a secondary battery of claim 1 , wherein the copolymer has a weight average molecular weight of 100,000 to 1,000,000 g/mol.
7. A method for manufacturing a separator for a secondary battery, comprising:
a) applying an aqueous slurry including inorganic particles, a binder, and water on a porous substrate; and
b) forming a coating layer by heat drying after applying the aqueous slurry,
wherein the binder includes a copolymer of a monomer mixture including 30 to 50 wt % of an acrylamide-based monomer, 20 to 40 wt % of a vinyl cyanide monomer, 5 to 20 wt % of an acrylic monomer having a carboxyl group, and 5 to 20 wt % of an acrylic monomer having a hydroxyl group, based on a total amount of the copolymer.
8. The method of claim 7 , wherein a drying temperature in step b) ranges from 60 to 100° C.
9. A lithium secondary battery comprising the separator for a secondary battery of claim 1 .