# US 9,005,795 B2 · Separator having porous coating layer, manufacturing method of the same, and electrochemical device having the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,005,795 B2 - Document ID: US9005795B2 - Status: Granted - Kind: B2 - Application number: 13/060,530 - Filed: 2011-02-24 - Published: 2011-12-15 - Granted: 2015-04-14 - Earliest claimed: 2008-08-25 - Assignees: LG Chem, Ltd. - Applicants: Pil-Kyu Park; Jong-Hun Kim; Jang-Hyuk Hong; Byoung-Jin Shin; In-Chul Kim - Inventors: Pil-Kyu Park; Jong-Hun Kim; Jang-Hyuk Hong; Byoung-Jin Shin; In-Chul Kim - Web page: https://patentgrep.com/patent/US9005795B2 ## CPC - H01M 50/44: Fibrous material - H01M 50/42: Acrylic resins - H01M 50/423: Polyamide resins - H01M 50/426: Fluorocarbon polymers - H01M 50/429: Natural polymers - H01M 6/14: Cells with non-aqueous electrolyte - H01M 10/052: Li-accumulators - H01M 50/431: Inorganic material - Y02E 60/10: Energy storage using batteries - H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract A separator includes a planar non-woven fabric substrate having a plurality of pores, and a porous coating layer provided on at least one surface of the non-woven fabric substrate and made of a mixture of a plurality of inorganic particles and a binder polymer, wherein the non-woven fabric substrate is made of superfine fibers having an average thickness of 0.5 to 10 μm, and wherein, among the pores in the non-woven fabric substrate, pores having a wide diameter of 0.1 to 70 μm are 50% or above of the entire pores. The above separator having the porous coating layer may generate the generation of leak current without increasing a loading weight of the porous coating layer since the non-woven fabric substrate having a controlled pore side by using superfine fibers of a predetermined thickness is used. ## Claims ### Claim 1 A separator comprising: (A) a planar non-woven fabric substrate having a plurality of fibers and pores; and (B) a porous coating layer provided on at least one surface of the non-woven fabric substrate and made of a mixture of a plurality of inorganic particles and a binder polymer, wherein: (1) the fibers of the non-woven fabric substrate consist of superfine fibers, the fibers having an average thickness of 0.5 to 10 μm; (2) among the distribution of pore size in the non-woven fabric substrate, pores having a wide diameter of 0.1 to 70 μm are 50% or above of the entire pores; and (3) a loading weight of the porous coating layer with respect to the non-woven fabric substrate is 5 to 20 g/m2, which prevents leak current generation of the separator wherein the superfine fibers have a melt temperature of 200° C. or above, and wherein the superfine fibers are made of any polymer selected from the group consisting of polyester, polyacetal, polycarbonate, polyimide, polyetheretherketone, polyethersulfone, polyphenylene oxide, polyphenylene sulfide, polyethylene naphthalene and mixtures thereof. ### Claim 2 (depends on 1) The separator of claim 1, wherein the average thickness of the superfine fibers is 1 to 7 μm. ### Claim 3 (depends on 1) The separator of claim 1, wherein the non-woven fabric substrate has a thickness of 9 to 30 μm. ### Claim 4 (depends on 1) The separator of claim 1, wherein a weight ratio of the inorganic particles to the binder polymer is 50:50 to 99:1. ### Claim 5 (depends on 1) The separator of claim 1, wherein the inorganic particles have a size of 0.001 to 10 μm. ### Claim 6 (depends on 1) The separator of claim 1, wherein the binder polymer has a solubility parameter of 15 to 45 Mpal/2. ### Claim 7 (depends on 1) The separator of claim 1, wherein the binder polymer is any binder polymer selected from the group consisting of polyvinylidene fluoride-co-hexafluoropropylene, polyvinylidene fluoride-co-trichloroethylene, polymethyl methacrylate, polyacrylonitrile, polyvinylpyrrolidone, polyvinyl acetate, polyethylene-co-vinyl acetate, polyethylene oxide, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethyl pullulan, cyanoethyl polyvinyl alcohol, cyanoethyl cellulose, cyanoethyl sucrose, pullulan, carboxylmethyl cellulose, and their mixtures. ### Claim 8 A method for manufacturing a separator, comprising: (A) preparing a planar non-woven fabric substrate having a plurality of fibers, the fibers consist of superfine fibers, the fibers having an average thickness of 0.5 to 10 μm and having a distribution of pore sizes among which pores having a wide diameter of 0.1 to 70 μm are 50% or above of the entire pores; and (B) coating at least one surface of the non-woven fabric substrate with a binder polymer solution in which inorganic particles are dispersed, and drying the surface of the non-woven fabric substrate; wherein a loading weight of the inorganic particles and the binder polymer with respect to the non-woven fabric substrate is controlled in the range of 5 to 20 g/m2, wherein the superfine fibers have a melt temperature of 200° C. or above, and wherein the superfine fibers are made of any polymer selected from the group consisting of polyester, polyacetal, polycarbonate, polyimide, polyetheretherketone, polyethersulfone, polyphenylene oxide, polyphenylene sulfide, polyethylene naphthalene and mixtures thereof. ### Claim 9 (depends on 8) The method of claim 8, wherein, in the binder polymer solution in which inorganic particles are dispersed, a weight ratio of the inorganic particles to the binder polymer is controlled into the range of 50:50 to 99:1. ### Claim 10 (depends on 1) An electrochemical device comprising a cathode, an anode, and a separator interposed between the cathode and the anode, wherein the separator is the separator of claim 1. ### Claim 11 (depends on 10) The electrochemical device according to claim 10, wherein the electrochemical device is a lithium secondary battery. ### Claim 12 A separator comprising: (A) a planar non-woven fabric substrate having a plurality of fibers and pores; and (B) a porous coating layer provided on at least one surface of the non-woven fabric substrate and made of a mixture of a plurality of inorganic particles and a binder polymer, wherein: (1) the fibers of the non-woven fabric substrate consist of superfine fibers, the fibers having an average thickness of 0.5 to 10 μm; (2) among the distribution of pore size in the non-woven fabric substrate, pores having a wide diameter of 0.1 to 70 μm are 50% or above of the entire pores; and (3) a loading weight of the porous coating layer with respect to the non-woven fabric substrate is 5 to 20 g/m2, wherein the superfine fibers have a melt temperature of 200° C. or above, and wherein the superfine fibers are made of any polymer selected from the group consisting of polyester, polyacetal, polycarbonate, polyimide, polyetheretherketone, polyethersulfone, polyphenylene oxide, polyphenylene sulfide, polyethylene naphthalene and mixtures thereof.