# US 10,319,971 B2 · Method for making lithium-sulfur battery separator > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,319,971 B2 - Document ID: US10319971B2 - Status: Granted - Kind: B2 - Application number: 15/653,542 - Filed: 2017-07-19 - Published: 2018-03-01 - Granted: 2019-06-11 - Earliest claimed: 2016-08-31 - Assignees: Tsinghua University; Hon Hai Precision Industry Co., Ltd. - Applicants: Tsinghua University; Hon Hai Precision Industry Co., Ltd. - Inventors: Wei-Bang Kong; Jia-Ping Wang; Kai-Li Jiang; Shou-Shan Fan - Web page: https://patentgrep.com/patent/US10319971B2 ## CPC - B32B 3/26: characterised by a particular shape of the outline of the cross-section of a continuous layer; characterised by a layer with cavities or internal voids {(foam layer B32B5/18; layer of synthetic resin characterised by fillers that create voids or cavities B32B27/205); characterised by an apertured layer} - B32B 5/12: characterised by the relative arrangement of fibres or filaments of {different layers, e.g. the fibres or filaments being parallel or perpendicular to each other} - B32B 5/24: one layer being a fibrous or filamentary layer - B32B 9/04: comprising such {particular} substance as the main or only constituent of a layer, {which is} next to another layer of {the same or of} a {different material (next to a glass layer B32B17/06; layered products with at least two ceramic layers composed mainly of ceramic B32B18/00)} - B32B 9/045: {of synthetic resin} - B32B 27/08: of synthetic resin - B32B 27/32: comprising polyolefins {(comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30)} - H01M 50/403: Manufacturing processes of separators, membranes or diaphragms - H01M 50/431: Inorganic material - H01M 50/44: Fibrous material - H01M 50/451: comprising layers of only organic material and layers containing inorganic material - H01M 50/457: comprising three or more layers - H01M 50/463: Separators, membranes or diaphragms characterised by their shape - 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 - B32B 2250/40: Symmetrical or sandwich layers, e.g. ABA, ABCBA, ABCCBA - B32B 2307/202: Conductive - B32B 2307/50: having particular mechanical properties - B32B 2307/732: Dimensional properties - B32B 2457/10: Batteries - H01M 4/38: of elements or alloys - H01M 4/382: {Lithium (H01M4/405 takes precedence)} - H01M 10/052: Li-accumulators - Y02E 60/10: Energy storage using batteries - B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM - 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 relates to a method for making a lithium-sulfur battery separator. The method comprises providing a separator substrate, and forming a functional layer on at least one surface of the separator substrate. A method for forming the functional layer comprises applying a first carbon nanotube layer on the at least one surface; dispersing a plurality of graphene oxide sheets and a plurality of manganese dioxide nanoparticles in a solvent to form a mixture; and depositing the mixture on a surface of the first carbon nanotube layer to form a first graphene oxide composite layer; applying a second carbon nanotube layer on a surface of the first graphene oxide composite layer; and forming a second graphene oxide composite layer on a surface of the second carbon nanotube layer. ## Claims ### Claim 1 A method for making a lithium-sulfur battery separator comprising step (S1), providing a separator substrate comprising a first surface and a second surface opposite to the first surface; and step (S2), forming a functional layer on at least one surface of the first surface and the second surface, and a method for forming the functional layer on at least one surface of the first surface and the second surface comprises sub-steps of: step (S21), applying a first carbon nanotube layer on the at least one surface of the first surface and the second surface; step (S22), providing a plurality of graphene oxide sheets and a plurality of manganese dioxide nanoparticles; dispersing the plurality of graphene oxide sheets and the plurality of manganese dioxide nanoparticles in a solvent to form a mixture; and depositing the mixture on a surface of the first carbon nanotube layer to form a first graphene oxide composite layer; step (S23), applying a second carbon nanotube layer on a surface of the first graphene oxide composite layer; and step (S24), forming a second graphene oxide composite layer on a surface of the second carbon nanotube layer. ### Claim 2 (depends on 1) The method of claim 1, wherein the first carbon nanotube layer comprises at least two carbon nanotube films stacked and crossed with each other. ### Claim 3 (depends on 2) The method of claim 2, wherein the first carbon nanotube layer comprises two carbon nanotube films stacked and crossed with each other, and a method of applying the first carbon nanotube layer on the at least one surface of the first surface and the second surface comprises the following steps: laying a first carbon nanotube film on the at least one surface of the first surface and the second surface; and laying a second carbon nanotube film on a surface of the first carbon nanotube film, wherein a first extending direction of the carbon nanotubes in the first carbon nanotube film intersects with a second extending direction of the carbon nanotubes in the second carbon nanotube film. ### Claim 4 (depends on 2) The method of claim 2, wherein the first carbon nanotube layer comprises more than two carbon nanotube films stacked and crossed with each other, and a method of applying the first carbon nanotube layer on the at least one surface of the first surface and the second surface comprises the following steps: step (S211), laying a first carbon nanotube film on the at least one surface of the first surface and the second surface; step (S212), laying a second carbon nanotube film on a surface of the first carbon nanotube film, wherein a first extending direction of the carbon nanotubes in the first carbon nanotube film intersects with a second extending direction of the carbon nanotubes in the second carbon nanotube film; step (S213), laying a third carbon nanotube film on a surface of the second carbon nanotube film, wherein a third extending direction of the carbon nanotubes in the third carbon nanotube film intersects with the second extending direction of the carbon nanotubes in the second carbon nanotube film; and step (S214), repeating step (S212) and step (S213) until the first carbon nanotube layer is obtained. ### Claim 5 (depends on 1) The method of claim 1, wherein the first carbon nanotube layer is directly laid on the separator substrate after drawn from a carbon nanotube array. ### Claim 6 (depends on 1) The method of claim 1, wherein in step (S21), further comprising fixing the separator substrate to a planar glass before applying the first carbon nanotube layer on the at least one surface of the first surface and the second surface. ### Claim 7 (depends on 1) The method of claim 1, wherein in step (S22), the plurality of graphene oxide sheets and the plurality of manganese dioxide nanoparticles are uniformly dispersed in the solvent by a mechanical stirring. ### Claim 8 (depends on 1) The method of claim 1, wherein in step (S22), the plurality of graphene oxide sheets and the plurality of manganese dioxide nanoparticles are uniformly dispersed in the solvent by an ultrasonic shock. ### Claim 9 (depends on 1) The method of claim 1, wherein a weight ratio between the plurality of manganese dioxide nanoparticles and the plurality of graphene oxide sheets is ranged from about 1:2 to about 1:1. ### Claim 10 (depends on 1) The method of claim 1, wherein a method of depositing the mixture on the surface of the first carbon nanotube layer comprises the following steps: the mixture is uniformly deposited on the surface of the first carbon nanotube layer; the first carbon nanotube layer is impregnated by the mixture; and the solvent in the mixture is removed by heating. ### Claim 11 (depends on 10) The method of claim 10, wherein the mixture is uniformly deposited on the surface of the first carbon nanotube layer by a dropper. ### Claim 12 (depends on 10) The method of claim 10, wherein the mixture is uniformly deposited on the surface of the first carbon nanotube layer by a slow dumping. ### Claim 13 (depends on 1) The method of claim 1, wherein step (S23) and step (S24) are repeated seven times to eleven times. ### Claim 14 (depends on 1) The method of claim 1, wherein a diameter of each of the plurality of manganese dioxide nanoparticles is ranged from about 5 nanometers to about 10 nanometers. ### Claim 15 (depends on 1) The method of claim 1, wherein a thickness of the functional layer is ranged from about 1 micrometer to about 3 micrometers.