# US 9,461,288 B2 · Separator film, its fabrication method, supercapacitor, battery and capacitor provided with said film > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,461,288 B2 - Document ID: US9461288B2 - Status: Granted - Kind: B2 - Application number: 13/517,967 - Filed: 2010-12-21 - Published: 2013-02-28 - Granted: 2016-10-04 - Earliest claimed: 2009-12-21 - Assignees: Bollore - Applicants: Philippe Azais; Lucien Tamic; Audrey Anne-Marie Tamic; Marion Anne-Sophie Tamic; Marilyne Gaëlle Tamic; Hélène Marie-France Tamic; Andre Huitric; Frederic Paulais; Xavier Rohel - Inventors: Philippe Azais; Lucien Tamic; Andre Huitric; Frederic Paulais; Xavier Rohel - Web page: https://patentgrep.com/patent/US9461288B2 ## CPC - C08L 23/10: Homopolymers or copolymers of propene - C08J 5/18: Manufacture of films or sheets - C08L 23/14: Copolymers of propene (C08L23/16 takes precedence) - C08L 23/16: Ethylene-propylene or ethylene-propylene-diene copolymers - H01M 10/052: Li-accumulators - H01M 50/417: Polyolefins - H01M 50/491: Porosity - C08J 2323/14: Copolymers of propene (C08J2323/16 takes precedence) - C08J 2423/12: Polypropene - Y02E 60/10: Energy storage using batteries - Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) - C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29) - 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 - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract The invention relates to a separator film for a device used for storing electrical energy, the film being porous and oriented, and being obtained by stretching in a longitudinal direction and in a direction transverse to the longitudinal direction, the film containing a mixture comprising a polypropylene homopolymer, at least 10% of a copolymer obtained from monomers comprising at least propylene and ethylene, and at least one beta-nucleating agent. According to the invention, the ethylene content of the copolymer is ≧1% but <10% and a propylene content of the copolymer is ≧90% for a film thickness of ≧8 microns and ≦30 microns, corresponding to a specified space factor according to the IEC-60674-3-1 standard greater than or equal to 145% and a density of the biaxially stretched film greater than or equal to 0.18 g/cm3 but less than or equal to 0.41 g/cm3. ## Claims ### Claim 1 A separator film for a device used for storing electrical energy, the film being porous and oriented, and being obtained by stretching in a longitudinal direction and in a direction transverse to the longitudinal direction, the film containing a mixture comprising: a polypropylene homopolymer, at least 10% by weight of at least one copolymer of monomers comprising at least propylene and ethylene, at least one beta-nucleating agent, wherein the copolymer has an ethylene content greater than or equal to 1% and less than 10% by weight of the copolymer and a propylene content of at least 90% by weight of the copolymer for a micrometric thickness of the film greater than or equal to 8 microns and less than or equal to 30 microns, corresponding to a space factor determined according to the IEC-60674-3-1 standard greater than or equal to 145% and a density of the film stretched in both directions greater than or equal to 0.18 g/cm3 and less than or equal to 0.41 g/cm3. ### Claim 2 (depends on 1) The film of claim 1, wherein the beta-nucleating agent contains quinacridone. ### Claim 3 (depends on 1) The film of claim 1, wherein the beta-nucleating agent consists of gamma-quinacridone. ### Claim 4 (depends on 1) The film of claim 1, wherein the beta-nucleating agent consists of gamma-quinacridone in a proportion greater than or equal to 0.11% and less than or equal to 0.5% by weight. ### Claim 5 (depends on 1) The film of claim 1, wherein the film stretched in both directions has a Gurley porosity greater than or equal to 50 seconds and less than or equal to 300 seconds per 100 cm3. ### Claim 6 (depends on 1) The film of claim 1, wherein the film stretched in both directions has a porosity in percent greater than or equal to 50%. ### Claim 7 (depends on 1) The film of claim 1, wherein the film has a longitudinal modulus of elasticity greater than or equal to 800 MPa according to the ASTM D882 standard and/or a transverse modulus of elasticity greater than or equal to 300 MPa according to the ASTM D882 standard. ### Claim 8 (depends on 1) The film of any claim 1, wherein the mixture further comprises calcium stearate in a proportion of 25 to 250 mg/kg of mixture. ### Claim 9 (depends on 1) The film of claim 1, wherein the transverse shrinking of the film of micrometric thickness less than or equal to 20 μm at 120° C. is less than 8%. ### Claim 10 (depends on 1) The film of claim 1, wherein for a temperature greater than or equal to 150° C., the film has a Gurley porosity greater than or equal to 5000 seconds. ### Claim 11 A method for fabricating a separator film for a device used for storing electrical energy, the film being porous and oriented, the film containing a mixture comprising: a polypropylene homopolymer, at least 10% by weight of at least one copolymer of monomers comprising at least propylene and ethylene, at least one beta-nucleating agent, wherein the copolymer has an ethylene content greater than or equal to 1% and less than 10% by weight of the copolymer and a propylene content of at least 90% by weight of the copolymer and a propylene content of at least 90% by weight of the copolymer for a micrometric thickness of the film greater than or equal to 8 microns and less than or equal to 30 microns, corresponding to a space factor determined according to the IEC-60674-3-1 standard greater than or equal to 145% and a density of the film stretched in both directions greater than or equal to 0.18 g/cm3 and less than or equal to 0.41 g/cm3, and wherein, during a first step said mixture being melt is passed on a chill roll (CR, 13), which rotates and which has a temperature less than the temperature of the mixture being melt to obtain a primary film (F), the primary film (F) is stretched in its longitudinal conveying direction (MD) during a second step after the first step, the film (F) is stretched in the direction transverse (TD) to the longitudinal direction (MD), the method being characterized in that during the first step, said mixture being melt has a time in contact with the chill roll (CR, 13) greater than or equal to 30 seconds. ### Claim 12 (depends on 1) An electrical supercapacitor, comprising at least two electrical conductors connected to at least two use terminals, wherein at least one separator film of claim 1 and an electrolyte impregnating the film are between the two electrical conductors. ### Claim 13 (depends on 1) A battery for storing electrical energy, comprising at least two electrical conductors connected to at least two use terminals, wherein at least one separator film of claim 1 and an electrolyte impregnating the film are between the two electrical conductors. ### Claim 14 (depends on 1) An electrolytic capacitor, comprising an anode (A) and a cathode (CATH), between which is located at least one separator film of claim 1 and an electrolyte impregnating the film. ### Claim 15 (depends on 14) The electrolytic capacitor of claim 14, wherein cathode is formed by a metal deposition (M) on only one face of said at least one film.