# US 12,002,987 B2 · Separator for rechargeable lithium battery and rechargeable lithium battery comprising same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,002,987 B2 - Document ID: US12002987B2 - Status: Granted - Kind: B2 - Application number: 17/055,507 - Filed: 2019-03-27 - Published: 2021-07-22 - Granted: 2024-06-04 - Earliest claimed: 2018-05-18 - Assignees: Samsung SDI Co., Ltd.; Samsung Electronics Co., Ltd. - Applicants: Samsung SDI Co., Ltd.; Samsung Electronics Co., Ltd. - Inventors: Minho Cho; Hana Kim; Myungkook Park; Seung Rim Yang; Byungmin Lee; Jungsue Jang; Bokyung Jung - Web page: https://patentgrep.com/patent/US12002987B2 ## CPC - H01M 50/417: Polyolefins - H01M 4/622: {being polymers} - H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries - H01M 50/409: Separators, membranes or diaphragms characterised by the material - H01M 50/42: Acrylic resins - H01M 50/434: Ceramics - H01M 50/443: Particulate material - H01M 50/446: Composite material consisting of a mixture of organic and inorganic materials - H01M 50/457: comprising three or more layers - H01M 50/461: {with adhesive layers between electrodes and separators} - H01M 50/489: Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties - 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 The present disclosure provides a separator for a rechargeable lithium battery and a rechargeable lithium battery including same, the separator includes a porous substrate; and an adhesive layer formed on the porous substrate. The adhesive layer includes a particle-type binder having a core-shell structure including a core and a shell surrounding the core, the core includes a first polymer having a glass transition temperature of less than or equal to 30° C., the shell includes a second polymer having a glass transition temperature of greater than or equal to 40° C., and the particle-type binder has a diameter of 50 nm to 500 nm. ## Claims ### Claim 1 A separator for a rechargeable lithium battery, comprising a porous substrate, and an adhesive layer on the porous substrate, wherein the adhesive layer includes a particle-type binder having a core-shell structure including a core and a shell surrounding the core, the core includes a first polymer having a glass transition temperature of less than or equal to 30° C., the shell includes a second polymer having a glass transition temperature of greater than or equal to 40° C., the particle-type binder has a diameter of 50 nm to 500 nm, wherein the particle-type binder includes one or more (meth)acrylate structural units represented by Chemical Formula 1; at least one selected from among a phenyl group-containing structural unit represented by Chemical Formula 2 and a cyano group-containing structural unit represented by Chemical Formula 3; and an ester group-containing structural unit represented by Chemical Formula 4: wherein, in Chemical Formula 1, R1 is hydrogen or a C1 to C5 alkyl group, R2 is a C1 to C10 alkyl group, * is a linking point; wherein, in Chemical Formula 2 to Chemical Formula 4, R3 to R5 are independently hydrogen or a C1 to C5 alkyl group, R6 is a C1 to C10 alkyl group, Ra to Re are independently hydrogen or a C1 to C5 alkyl group, L1 to L3 are independently a C1 to C5 alkyl group, x, y, and z are independently an integer of 0 to 2, and * is a linking point, and wherein the first polymer includes 0 to 0.2 mole of the phenyl group-containing structural unit represented by Chemical Formula 2 or the cyano group-containing structural unit represented by Chemical Formula 3 and 0.5 mole to 0.8 mole of the ester group-containing structural unit represented by Chemical Formula 4 based on 1 mole of the (meth)acrylate structural unit represented by Chemical Formula 1. ### Claim 2 (depends on 1) The separator for a rechargeable lithium battery of claim 1, wherein the particle-type binder includes a polyacrylic binder or a polyolefin-based binder. ### Claim 3 (depends on 1) The separator for a rechargeable lithium battery of claim 1, wherein the particle-type binder includes two or more types of the (meth)acrylate structural units that are represented by Chemical Formula 1 and different from each other. ### Claim 4 (depends on 1) The separator for a rechargeable lithium battery of claim 1, wherein the first polymer includes 40 wt % to 100 wt % of the one or more (meth)acrylate structural units based on a total mass of the first polymer, and the second polymer includes 0 wt % to 77 wt % of the one or more (meth)acrylate structural units based on a total mass of the second polymer. ### Claim 5 (depends on 1) The separator for a rechargeable lithium battery of claim 1, wherein the second polymer includes 0.5 mole to 5.0 mole of the phenyl group-containing structural unit represented by Chemical Formula 2 or the cyano group-containing structural unit represented by Chemical Formula 3 and 0.5 mole to 1.2 mole of the ester group-containing structural unit represented by Chemical Formula 4 based on 1 mole of the (meth)acrylate structural unit represented by Chemical Formula 1. ### Claim 6 A separator for a rechargeable lithium battery, comprising a porous substrate, and an adhesive layer on the porous substrate, wherein the adhesive layer includes a particle-type binder having a core-shell structure including a core and a shell surrounding the core, the core includes a first polymer having a glass transition temperature of less than or equal to 30° C., the shell includes a second polymer having a glass transition temperature of greater than or equal to 40° C., the particle-type binder has a diameter of 50 nm to 500 nm, and wherein the particle-type binder includes one or more (meth)acrylate structural units represented by Chemical Formula 1; at least one selected from among a phenyl group-containing structural unit represented by Chemical Formula 2 and a cyano group-containing structural unit represented by Chemical Formula 3; and an ester group-containing structural unit represented by Chemical Formula 4: wherein, in Chemical Formula 1, R1 is hydrogen or a C1 to C5 alkyl group, R2 is a C1 to C10 alkyl group, * is a linking point; wherein, in Chemical Formula 2 to Chemical Formula 4, R3 to R5 are independently hydrogen or a C1 to C5 alkyl group, R6 is a C1 to C10 alkyl group, Ra to Re are independently hydrogen or a C1 to C5 alkyl group, L1 to L3 are independently a C1 to C5 alkyl group, x, y, and z are independently an integer of 0 to 2, and * is a linking point, wherein at least one selected from among the first polymer and the second polymer includes a structural unit represented by Chemical Formula 5 or Chemical Formula 6: wherein, in Chemical Formula 5 and In Chemical Formula 6, R7 and R8 are independently a C1 to C5 alkyl group, l and o of the first polymer are each independently 50 mol % to 60 mol %, m and p are each independently 0 mol % to 10 mol %, and n and q are each independently 30 mol % to 50 mol %, l and o of the second polymer are each independently 10 mol % to 30 mol %, m and p are each independently 50 mol % to 70 mol %, and n and q are each independently 10 mol % to 30 mol %, and * is a linking point. ### Claim 7 (depends on 6) The separator for a rechargeable lithium battery of claim 6, wherein the first polymer and the second polymer include structural units represented by the same chemical formula, and l, m, and n of the first polymer and the second polymer or o, p, and q of the first polymer and the second polymer are different from each other. ### Claim 8 (depends on 1) The separator for a rechargeable lithium battery of claim 1, wherein the core and the shell are included in a weight ratio of 1:9 to 3:7 based on a total weight of the particle-type binder. ### Claim 9 (depends on 1) The separator for a rechargeable lithium battery of claim 1, wherein a difference between the glass transition temperature of the core and the glass transition temperature of the shell is greater than or equal to 20° C. ### Claim 10 (depends on 1) The separator for a rechargeable lithium battery of claim 1, wherein the adhesive layer further includes an adhesive binder. ### Claim 11 (depends on 1) The separator for a rechargeable lithium battery of claim 1, which further includes a heat-resistant layer between the porous substrate and the adhesive layer. ### Claim 12 (depends on 11) The separator for a rechargeable lithium battery of claim 11, wherein the heat-resistant layer further includes heat-resistant binder. ### Claim 13 (depends on 1) A rechargeable lithium battery, comprising a positive electrode, a negative electrode, and the separator for the rechargeable lithium battery according to claim 1 disposed between the positive electrode and the negative electrode.