# US 2025/0096332 A1 · Separator for lithium secondary battery and lithium secondary battery including same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2025/0096332 A1 - Document ID: US20250096332A1 - Status: Published application - Kind: A1 - Application number: 18/729,254 - Filed: 2023-02-20 - Published: 2025-03-20 - Earliest claimed: 2022-04-15 - Assignees: Samsung SDI Co., Ltd. - Applicants: Samsung SDI Co., Ltd. - Inventors: Dongwan SEO; Jinyoung KIM; Hyeonseon CHOI - Web page: https://patentgrep.com/patent/US20250096332A1 ## CPC - H01M 10/4235: {Safety or regulating additives or arrangements in electrodes, separators or electrolyte (H01M10/4242 takes precedence)} - H01M 10/052: Li-accumulators - H01M 50/411: Organic material - H01M 50/417: Polyolefins - H01M 50/42: Acrylic resins - H01M 50/426: Fluorocarbon polymers - H01M 50/434: Ceramics - H01M 50/443: Particulate material - H01M 50/446: Composite material consisting of a mixture of organic and inorganic materials - H01M 50/449: having a layered structure - H01M 50/451: comprising layers of only organic material and layers containing inorganic material - H01M 50/457: comprising three or more layers - 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 Examples of the disclosure include a separator for a lithium secondary battery, and a lithium secondary battery including the separator. The separator for a lithium secondary battery includes a porous substrate; and a coating layer which is located on at least one side of the porous substrate and that includes polyethylene particles and ceramics, wherein the ceramics have an aspect ratio of 1.5-3.0. ## Claims ### Claim 1 A separator for a lithium secondary battery, the separator comprising: a porous substrate; and a coating layer located on at least one surface of the porous substrate and that includes polyethylene particles and ceramics, wherein the ceramics have an aspect ratio of 1.5 to 3.0. ### Claim 2 (depends on 1) The separator for a lithium secondary battery as claimed in claim 1, wherein the ceramics are cubic. ### Claim 3 (depends on 1) The separator for a lithium secondary battery as claimed in claim 1, wherein the polyethylene particles have a melting temperature (Tm) of 100° C. to 120° C. ### Claim 4 (depends on 1) The separator for a lithium secondary battery as claimed in claim 1, wherein an average molecular weight (Mw) of the polyethylene particles is 1000 g/mol to 5000 g/mol. ### Claim 5 (depends on 1) The separator for a lithium secondary battery as claimed in claim 1, wherein the ceramics comprise at least one of Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, SrTiO3, BaTiO3, Mg(OH)2, and boehmite. ### Claim 6 (depends on 1) The separator for a lithium secondary battery as claimed in claim 1, wherein a cross-sectional thickness of the coating layer is 0.5 μm to 5 μm. ### Claim 7 (depends on 1) The separator for a lithium secondary battery as claimed in claim 1, wherein the coating layer further includes a binder. ### Claim 8 (depends on 7) The separator for a lithium secondary battery as claimed in claim 7, wherein the binder comprises one of a dispersion binder, a curable binder, and an aqueous binder. ### Claim 9 (depends on 8) The separator for a lithium secondary battery as claimed in claim 8, wherein the dispersion binder comprises at least one of sodium polyacrylate, ammonium polyacrylate, and potassium polyacrylate. ### Claim 10 (depends on 8) The separator for a lithium secondary battery as claimed in claim 8, wherein the curable binder comprises at least one of polyglycidyl ether, isocyanate, epoxy, an acrylic copolymer, and a fluorine-based binder. ### Claim 11 (depends on 8) The separator for a lithium secondary battery as claimed in claim 8, wherein the aqueous binder comprises at least one of a styrene-butadiene rubber, an acrylated styrene-butadiene rubber, polyvinyl alcohol, a copolymer of propylene and a C2 to C8 olefin, poly acrylamide, and a copolymer of (meth)acrylic acid and (meth)acrylic acid alkyl ester. ### Claim 12 (depends on 1) The separator for a lithium secondary battery as claimed in claim 1, wherein the separator further includes an adhesive layer on one surface of the coating layer. ### Claim 13 (depends on 12) The separator for a lithium secondary battery as claimed in claim 12, wherein the adhesive layer includes a binder and a filler. ### Claim 14 (depends on 13) The separator for a lithium secondary battery as claimed in claim 13, wherein the binder comprises at least one of (meth)acrylic acid, (meth)acrylate, (meth)acrylonitrile, (meth)acrylamidosulfonic acid, a (meth)acrylamidosulfonate salt, styrene, ethylhexyl acrylate, and a copolymer thereof. ### Claim 15 (depends on 13) The separator for a lithium secondary battery as claimed in claim 13, wherein the filler comprises at least one of polyvinylidene fluoride, a polyvinylidene fluoride-hexafluoropropylene copolymer, and polytetrafluoroethylene. ### Claim 16 (depends on 13) The separator for a lithium secondary battery as claimed in claim 13, wherein a mixing ratio of the binder and filler in the adhesive layer is 1:1 to 1:5 by weight. ### Claim 17 (depends on 12) The separator for a lithium secondary battery as claimed in claim 12, wherein a cross-sectional thickness of the adhesive layer is 0.1 μm to 4.0 μm. ### Claim 18 (depends on 1) A lithium secondary battery comprising a negative electrode including a negative electrode active material; a positive electrode including a positive electrode active material; the separator as claimed in claim 1 between the negative electrode and the positive electrode; and a non-aqueous electrolyte.