Organic/Inorganic Complex Coating Porous Separator And Secondary Battery Using The Same

Abstract

There is provided an organic/inorganic complex coating porous separator including a porous substrate, and an organic/inorganic complex coating layer formed in a single layer or multiple layers on a single surface or both surfaces of the porous substrate or at least a part of a pore portion of the porous substrate using a coating solution comprising a binder dispersed or suspended in a certain size and selectively comprising inorganic particles, and a secondary battery including the same. According to the present invention, since the coating solution comprising the binder dispersed in a certain size or less in a solvent is coated/dried on the porous substrate, a organic/inorganic complex coating porous separator having excellent air permeability and adhesive strength and a secondary battery including the organic/inorganic complex coating porous separator are provided.

1 . A coating porous separator comprising:
 a porous substrate; and   a coating layer formed in a single layer or multiple layers on one or more regions selected from the group consisting of a single surface or both surfaces of the porous substrate or at least a part of a pore portion of the porous substrate using a coating solution comprising a binder dispersed or suspended in the form of particles in a solvent,   wherein a mean particle diameter of the binder dispersed or suspended in the solvent is less than one and a half times a mean pore diameter of the porous substrate.   
     
     
         2 . The coating porous separator of  claim 1 , wherein the coating solution further comprises dispersed inorganic particles. 
     
     
         3 . The coating porous separator of  claim 2 , wherein the mean particle diameter of the binder is a half or less of a mean diameter of the inorganic particles. 
     
     
         4 . The coating porous separator of  claim 1 , wherein the binder is one or two or more selected from latex or emulsions or suspensions formed by dispersing polymer compounds selected from the group consisting of polystyrene-based, styrene butadiene-based, nitrile-based, polyvinyl chloride-based, polyolefin-based, acryl-based, acetate-based, polyvinylidene fluoride-based, ethylene-vinyl acetate-based, polyvinyl butyral-based, polytetrafluoro ethylene-based, polyimide-based, polyethylene oxide-based, cellulose-based, polyvinyl alcohol-based, and starch-based polymers and copolymers, in an organic solvent or a water-based solvent. 
     
     
         5 . The coating porous separator of  claim 1 , wherein the inorganic particles include one or two or more selected from the group consisting of SnO 2 , BaTiO 2 , Al 2 O 3 , CeO 2 , SiO 2 , TiO 2 , Li 3 PO 4 , NiO, ZnO, MgO, Mg(OH) 2 , CaO, ZrO 2 , and Y 2 O 3 , and have a sphere shape, a plate shape, or an irregular shape having a mean particle diameter of 0.1 to 5 μm. 
     
     
         6 . The coating porous separator of  claim 1 , wherein in the coating solution, a weight ratio of the inorganic particles:the binder is 4:1 to 140:1. 
     
     
         7 . The coating porous separator of  claim 1 , wherein the coating solution further comprises a second organic binder to be dissolved in the solvent, and wherein the second organic binder includes one or two or more selected from the group consisting of phosphoric ester, phosphoric acryl-based copolymer, modified polyacrylate-based copolymer, modified polyacrylic acid-based copolymer, polyester- and amine amide-based copolymer, polycarboxylic acid-based copolymer, polyalkylol- and amino amide-based copolymer, siloxane- and acryl-based copolymer, siloxane- and carboxylic acid-based copolymer, polyalkoxylate-based copolymer, acryl- and ether-based copolymer, and metallic salts thereof. 
     
     
         8 . The coating porous separator of  claim 1 , wherein the coating solution further comprises one or more additives selected from the group consisting of a polymer dispresion agent, a wetting agent, an antifoaming and defoaming agent, a leveling agent, a thickener, a rheology additive, an adhesion promoter, an additive for surface, and a UV absorber. 
     
     
         9 . The coating porous separator of  claim 1 , wherein the porous substrate has a thickness of 1 to 100 μm and a porosity of 5 to 90%. 
     
     
         10 . A secondary battery comprising the coating separator according to  claim 1 . 
     
     
         11 . The secondary battery of  claim 10 , wherein the secondary battery is a lithium secondary battery. 
     
     
         12 . The secondary battery comprising the coating separator according to  claim 2 . 
     
     
         13 . The secondary battery of  claim 12 , wherein the secondary battery is a lithium secondary battery. 
     
     
         14 . The secondary battery comprising the coating separator according to  claim 3 . 
     
     
         15 . The secondary battery of  claim 14 , wherein the secondary battery is a lithium secondary battery. 
     
     
         16 . The secondary battery comprising the coating separator according to  claim 4 . 
     
     
         17 . The secondary battery of  claim 16 , wherein the secondary battery is a lithium secondary battery. 
     
     
         18 . The secondary battery comprising the coating separator according to  claim 5 . 
     
     
         19 . The secondary battery of  claim 18 , wherein the secondary battery is a lithium secondary battery. 
     
     
         20 . The secondary battery comprising the coating separator according to  claim 6 . 
     
     
         21 . The secondary battery of  claim 20 , wherein the secondary battery is a lithium secondary battery. 
     
     
         22 . The secondary battery comprising the coating separator according to  claim 7 . 
     
     
         23 . The secondary battery of  claim 22 , wherein the secondary battery is a lithium secondary battery. 
     
     
         24 . The secondary battery comprising the coating separator according to  claim 8 . 
     
     
         25 . The secondary battery of  claim 24 , wherein the secondary battery is a lithium secondary battery. 
     
     
         26 . The secondary battery comprising the coating separator according to  claim 9 . 
     
     
         27 . The secondary battery of  claim 26 , wherein the secondary battery is a lithium secondary battery.