WO2023039820A1 - Adhesive paper, electrochemical device comprising said adhesive paper, and electronic device - Google Patents

Adhesive paper, electrochemical device comprising said adhesive paper, and electronic device Download PDF

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Publication number
WO2023039820A1
WO2023039820A1 PCT/CN2021/119013 CN2021119013W WO2023039820A1 WO 2023039820 A1 WO2023039820 A1 WO 2023039820A1 CN 2021119013 W CN2021119013 W CN 2021119013W WO 2023039820 A1 WO2023039820 A1 WO 2023039820A1
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WO
WIPO (PCT)
Prior art keywords
adhesive
electrode assembly
layer
paper
present application
Prior art date
Application number
PCT/CN2021/119013
Other languages
French (fr)
Chinese (zh)
Inventor
胡克文
Original Assignee
宁德新能源科技有限公司
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Publication date
Application filed by 宁德新能源科技有限公司 filed Critical 宁德新能源科技有限公司
Priority to CN202180025485.8A priority Critical patent/CN115461421B/en
Priority to PCT/CN2021/119013 priority patent/WO2023039820A1/en
Publication of WO2023039820A1 publication Critical patent/WO2023039820A1/en

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    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J7/00—Adhesives in the form of films or foils
    • C09J7/20—Adhesives in the form of films or foils characterised by their carriers
    • C09J7/29—Laminated material
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J7/00—Adhesives in the form of films or foils
    • C09J7/20—Adhesives in the form of films or foils characterised by their carriers
    • C09J7/22—Plastics; Metallised plastics
    • C09J7/24—Plastics; Metallised plastics based on macromolecular compounds obtained by reactions involving only carbon-to-carbon unsaturated bonds
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/04—Construction or manufacture in general
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/04—Construction or manufacture in general
    • H01M10/0422—Cells or battery with cylindrical casing
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/058—Construction or manufacture
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/572—Means for preventing undesired use or discharge
    • H01M50/584—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries
    • H01M50/586—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries inside the batteries, e.g. incorrect connections of electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/572—Means for preventing undesired use or discharge
    • H01M50/584—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries
    • H01M50/59—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries characterised by the protection means
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J2203/00—Applications of adhesives in processes or use of adhesives in the form of films or foils
    • C09J2203/33—Applications of adhesives in processes or use of adhesives in the form of films or foils for batteries or fuel cells
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J2301/00—Additional features of adhesives in the form of films or foils
    • C09J2301/10—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive tape or sheet
    • C09J2301/12—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive tape or sheet by the arrangement of layers
    • C09J2301/122—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive tape or sheet by the arrangement of layers the adhesive layer being present only on one side of the carrier, e.g. single-sided adhesive tape
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J2301/00—Additional features of adhesives in the form of films or foils
    • C09J2301/10—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive tape or sheet
    • C09J2301/16—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive tape or sheet by the structure of the carrier layer
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J2400/00—Presence of inorganic and organic materials
    • C09J2400/20—Presence of organic materials
    • C09J2400/24—Presence of a foam
    • C09J2400/243—Presence of a foam in the substrate
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present application relates to the field of electrochemistry, in particular to an adhesive paper, an electrochemical device and an electronic device containing the adhesive paper.
  • Lithium-ion batteries as a typical representative of electrical energy-chemical energy conversion devices, are more and more widely used in various fields.
  • the expansion adhesive paper currently used is prone to deformation during the electrode assembly process and subsequent high-temperature (>60°C) storage process, resulting in poor binding effect of the expansion adhesive paper on the electrode assembly.
  • the electrolyte content decreases, and the expansion rate of the expansion adhesive paper decreases, which will also lead to the deterioration of the binding effect of the expansion adhesive paper on the electrode assembly, thereby causing safety problems for lithium-ion batteries.
  • the present application provides an adhesive paper, an electrochemical device and an electronic device containing the adhesive paper, so as to improve the high-temperature resistance performance of the adhesive paper and improve the high-temperature safety performance of the electrochemical device.
  • a lithium-ion battery is used as an example of an electrochemical device to explain the present application, but the electrochemical device of the present application is not limited to the lithium-ion battery.
  • the specific technical scheme is as follows:
  • the first aspect of the present application provides an adhesive tape, which includes an adhesive layer, an insulating and heat-resistant layer, and an expansion layer located between the adhesive layer and the insulating and heat-resistant layer; the expansion layer includes syndiotactic polystyrene.
  • the insulating and heat-resistant layer in the adhesive tape provided by this application has the effect of insulation and high temperature resistance, which can effectively prevent the internal and external short circuit of the lithium-ion battery, avoid the thermal shrinkage and deformation of the adhesive tape due to the high temperature outside, and effectively improve the deformation of the adhesive tape due to high temperature deformation. This leads to a problem that the binding effect on the electrode assembly is deteriorated.
  • the expansion layer in the gummed paper provided by the application is located between the bonding layer and the insulating heat-resistant layer, and the expansion layer includes syndiotactic polystyrene.
  • the expansion rate of the gummed paper comprising the expansion layer can reach 150% to 300%.
  • the syndiotactic polystyrene forming the expansion layer has good high temperature resistance, the gummed paper can be used at high temperatures (>60 °C), the shape is stable and not easy to deform, which can effectively maintain the binding effect of the adhesive paper on the electrode assembly at high temperature, and reduce the risk of the electrode assembly shaking in the casing.
  • the reduction of the electrolyte content in the lithium-ion battery has little or no effect on the expansion rate of the gummed paper.
  • the adhesive tape of the present application includes an adhesive layer, an insulating heat-resistant layer, and an expansion layer located between the adhesive layer and the insulating heat-resistant layer, and the expansion layer includes syndiotactic polystyrene.
  • the gummed paper has good expansion rate and high temperature resistance. Apply the gummed paper of the present application to lithium-ion batteries, after the syndiotactic polystyrene in the gummed paper is soaked in the electrolyte, the molecular orientation stress is released, and the molecular chain shrinks, so that the gummed paper shrinks in the longitudinal direction, and in the thickness direction Expansion, the expansion rate can reach 150% to 300%.
  • the thickness of the adhesive paper increases while the volume remains constant, which can effectively fill the gap between the electrode assembly and the casing, thereby constraining the vibration and shaking of the electrode assembly in the casing to buffer the drop and roller stress of the lithium-ion battery, thereby Improve the safety performance of lithium-ion batteries.
  • the reduction of the electrolyte content in the lithium-ion battery reduces the impact on the expansion rate of the gummed paper of the present application, further improving the safety performance of the lithium-ion battery.
  • the adhesive paper is stable in shape at high temperature, is not easy to deform, and can effectively maintain the binding effect of the adhesive paper on the electrode assembly, thereby effectively improving the high-temperature safety performance of the lithium-ion battery.
  • the weight average molecular weight of the syndiotactic polystyrene forming the expansion layer is 100,000 to 700,000, preferably 300,000 to 400,000.
  • the weight average molecular weight of syndiotactic polystyrene is too small, for example, less than 100,000, the tensile strength of syndiotactic polystyrene is too low, the tape is prone to breakage, and the syndiotactic polystyrene with small molecules Soaking in the electrolyte is prone to swelling and dissolution, which makes the electrochemical performance of lithium-ion batteries worse;
  • the weight-average molecular weight of syndiotactic polystyrene is too large, for example, greater than 700,000, and the hardness of syndiotactic polystyrene is too large, which is not conducive to glue Paper production and processing.
  • the melting point of syndiotactic polystyrene is 255° C. to 275° C., indicating that syndiotactic polystyrene has good high temperature resistance, which is beneficial to improve the high temperature resistance of gummed paper.
  • the gummed paper is soaked in the electrolyte at room temperature (23° C. to 26° C.) for 12 hours, and the expansion rate of the gummed paper in the thickness direction is 150% to 300%, preferably 200% to 300%. 300%, indicating that the adhesive paper can have a good expansion rate in the thickness direction after soaking in the electrolyte at room temperature and high temperature, so as to effectively fill the gap between the electrode assembly and the casing, so that the electrode assembly can be fixed.
  • the expansion rate of the adhesive paper in the thickness direction is in the above preferred range, the adhesive paper can more effectively fill the gap between the electrode assembly and the casing, and fix the electrode assembly better.
  • the gummed paper is soaked in the electrolyte at normal temperature for 12 hours, and the shrinkage rate of the gummed paper in the longitudinal direction is 150% to 300%, so that when the gummed paper expands in the thickness direction, Shrinking in the longitudinal direction, the volume of the gummed paper remains stable.
  • the longitudinal direction is perpendicular or approximately perpendicular to the thickness direction of the gummed paper.
  • the gummed paper is soaked in the electrolyte solution at room temperature for 12 hours, and the volume change rate after the gummed paper expands is 0%, indicating that the volume of the gummed paper is stable after being soaked in the electrolyte solution at room temperature and high temperature. constant.
  • the expansion layer further includes a first elastic body, a second elastic body, a filler and a curing agent.
  • the present application has no particular limitation on the type of the first elastic body, as long as the purpose of the present application can be achieved.
  • the first elastomer includes ethylene vinyl acetate (EVA).
  • EVA ethylene vinyl acetate
  • the present application has no particular limitation on the type of the second elastomer, as long as the purpose of the present application can be achieved.
  • the second elastomer includes at least one of styrene-ethylene-butylene-styrene block copolymer (SEBS), polybutadiene (PB), or polyisobutylene (PIB).
  • the present application has no particular limitation on the type of filler, as long as the purpose of the present application can be achieved.
  • the filler includes at least one of titanium dioxide, talc, white carbon black or calcium carbonate.
  • the present application has no particular limitation on the type of curing agent, as long as the purpose of the present application can be achieved.
  • the curing agent includes at least one of amino resin, epoxy resin, or polyisocyanate.
  • the expansion rate of the adhesive paper is avoided to decrease with the reduction of the electrolyte content in the lithium-ion battery, thereby ensuring the adhesion of the adhesive paper to the electrode assembly Fixed effect, effectively improving the safety performance of lithium-ion batteries.
  • the mass proportion of syndiotactic polystyrene is 80% to 100%, preferably 85% to 100%, more preferably 90% to 95%.
  • the mass ratio of the sum of the mass of the first elastomer, the second elastomer, the filler and the curing agent is 0% to 20%, preferably 0% to 15%, more preferably 5% to 10%.
  • the mass ratio of the first elastomer, the second elastomer, the filler and the curing agent is (20-40):(14-34):(31-36):(10-15) , preferably 30:24:36:10.
  • the adhesive tape has a thickness of 20 ⁇ m to 50 ⁇ m.
  • the adhesive layer has a thickness of 5 ⁇ m to 10 ⁇ m. If the thickness of the adhesive layer is too thin, such as less than 5 ⁇ m, the adhesive force between the adhesive paper and the electrode assembly will decrease, and the binding effect of the adhesive paper on the electrode assembly will become worse; if the thickness of the adhesive layer is too thick, for example, it is higher than 10 ⁇ m , so that the thickness of the adhesive paper increases, the distance between the electrode assembly and the casing needs to increase accordingly to meet the gap required by the adhesive paper, which will increase the volume of the lithium-ion battery, thereby reducing the energy density of the lithium-ion battery.
  • the expansion layer has a thickness of 10 ⁇ m to 30 ⁇ m. If the thickness of the expansion layer is too thin, such as less than 10 ⁇ m, the high temperature resistance of the gummed paper will be reduced, which will affect the expansion rate of the gummed paper at high temperature and when the electrolyte content is reduced; if the thickness of the expansion layer is too thick, such as higher than 30 ⁇ m, the As the thickness of the adhesive paper increases, the distance between the electrode assembly and the casing needs to increase accordingly to meet the gap required by the adhesive paper, which will increase the volume of the lithium-ion battery, thereby reducing the energy density of the lithium-ion battery.
  • the insulating heat-resistant layer has a thickness of 5 ⁇ m to 10 ⁇ m. If the thickness of the insulating heat-resistant layer is too thin, such as less than 5 ⁇ m, the insulation and high-temperature resistance of the adhesive tape will be reduced, which is not conducive to preventing the deformation of the adhesive tape at high temperature; if the thickness of the insulating heat-resistant layer is too thick, such as higher than 10 ⁇ m, the As the thickness of the adhesive paper increases, the distance between the electrode assembly and the casing needs to increase accordingly to meet the gap required by the adhesive paper, which will increase the volume of the lithium-ion battery, thereby reducing the energy density of the lithium-ion battery.
  • the material of the adhesive layer of the present application includes polymethyl methacrylate (PMMA) (commonly known as: acrylic), polypropylene (PP), hot-melt styrene-isoprene-styrene (SIS) rubber, polyethylene ( PE) or at least one of polyamide. Selecting the above-mentioned materials as the material of the bonding layer is beneficial to improving the bonding force between the adhesive tape and the electrode assembly.
  • PMMA polymethyl methacrylate
  • PP polypropylene
  • SIS hot-melt styrene-isoprene-styrene
  • PE polyethylene
  • Selecting the above-mentioned materials as the material of the bonding layer is beneficial to improving the bonding force between the adhesive tape and the electrode assembly.
  • the material of the insulating heat-resistant layer of the present application includes at least one of polyethylene terephthalate (PET), polyimide (PI) or polypropylene (PP).
  • PET polyethylene terephthalate
  • PI polyimide
  • PP polypropylene
  • the present application has no special limitation on the preparation method of the gummed paper, as long as the purpose of the present application can be achieved.
  • the present application can adopt the following method for preparing gummed paper, which includes the following steps:
  • the raw materials such as syndiotactic polystyrene are pretreated according to the formula of this application and then transported to the extrusion system. After being melted and plasticized, the melt is extruded from the die head, and the melt is cast to form a syndiotactic polystyrene with a specific crystal structure. Orientational stretching of syndiotactic polystyrene film, followed by heat treatment at a temperature of 150°C to 200°C, in order to reduce the thermal shrinkage rate of syndiotactic polystyrene and improve dimensional stability, and obtain 10 ⁇ m up to 30 ⁇ m expansion layer;
  • the present application has no special limitation on the pretreatment method of raw materials such as syndiotactic polystyrene during the preparation of the expansion layer, as long as the purpose of the present application can be achieved.
  • the present application has no particular limitation on the type of the aforementioned extrusion system, as long as the purpose of the present application can be achieved.
  • the directional stretch when the syndiotactic polystyrene film is directional stretched, the directional stretch can be uniaxial stretching or biaxial stretching.
  • the direction of uniaxial stretching is stretching along the longitudinal direction or transverse direction of the gummed paper
  • the direction of biaxial stretching is stretching along the longitudinal direction and transverse direction of the gummed paper.
  • the present application has no particular limitation on the tension and method of directional stretching, as long as the purpose of the present application can be achieved.
  • the second aspect of the present application provides an electrochemical device, which includes an electrode assembly, a casing, and the adhesive paper provided in the first aspect of the present application. Therefore, when the electrochemical device is dropped or rolled, the relative movement between the electrode assembly and the casing can be effectively prevented, and serious consequences such as voltage drop failure, pole piece breakage or tab breakage caused by the electrochemical device can be avoided, thereby effectively improving the performance of the electrochemical device. in the safety performance.
  • the electrochemical device is in a high temperature environment, and the tape has good high temperature resistance, which further avoids the problem of heat shrinkage and deformation of the tape due to high temperature, which significantly improves the binding effect of the tape on the electrode assembly due to high temperature deformation. The problem of further improving the high temperature safety performance of the electrochemical device.
  • the electrode assembly is a laminated structure or a winding structure
  • the adhesive paper is arranged between the outer surface of the electrode assembly and the casing
  • the insulating heat-resistant layer is adjacent to the casing to effectively prevent the external high temperature. Deform the adhesive paper; based on the total area of the outer surface of the electrode assembly, the projected area of the adhesive paper on the outer surface of the electrode assembly accounts for 30% to 100%.
  • the electrode assembly is a winding structure
  • the adhesive paper is arranged on the inner surface of the electrode assembly; based on the total area of the inner surface of the electrode assembly, the ratio of the projected area of the adhesive paper on the inner surface of the electrode assembly is: 30% to 100%.
  • the electrode assembly is a wound structure
  • the adhesive paper is arranged between the outer surface of the electrode assembly and the casing
  • the adhesive paper is arranged on the inner surface of the electrode assembly, based on the total area of the outer surface of the electrode assembly
  • the ratio of the projected area of the adhesive tape on the outer surface of the electrode assembly is 30% to 100%, based on the total area of the inner surface of the electrode assembly, the ratio of the projected area of the adhesive paper on the inner surface of the electrode assembly is 30% to 100%.
  • the area ratio of the adhesive paper within the above range is selected to fully fill the gap between the electrode assembly and the casing and improve the fixing effect of the electrode assembly.
  • the proportion of the projected area of the adhesive paper on the outer surface and/or inner surface of the electrode assembly within the above range the high temperature safety performance of the electrochemical device can be effectively improved.
  • the above-mentioned "inner surface” only exists in the electrode assembly of the wound structure, specifically, after the electrode assembly is wound, it forms a structure similar to a hollow cylinder, which includes an outer surface formed by a large circle and a small circle.
  • the "inner surface” of the present application can be understood as the inner surface formed by small circles, and those skilled in the art should understand that the large circle and small circle here are approximately circular, and can also be selected according to actual conditions in production. Ellipse or quasi-ellipse.
  • the electrode assembly includes a separator, a positive electrode tab, and a negative electrode tab.
  • the separator is used to separate the positive pole piece and the negative pole piece to prevent the internal short circuit of the electrochemical device, which allows the electrolyte ions to pass freely to complete the electrochemical charge and discharge process.
  • the present application has no special limitation on the number and type of the separator, the positive pole piece and the negative pole piece, as long as the purpose of the present application can be achieved.
  • the casing may include an inner layer and an outer layer, and the inner layer is sealed and connected with the partition, so the material of the inner layer may include a polymer material to achieve a good sealing effect; at the same time, the combination of the inner layer and the outer layer can effectively protect Internal structure of an electrochemical device.
  • the material of the inner layer includes at least one of polypropylene, polyester, p-hydroxybenzaldehyde, polyamide, polyphenylene ether, polyurethane, and the like.
  • the material of the outer layer there is no particular limitation on the material of the outer layer, as long as the purpose of this application can be achieved.
  • the material of the outer layer may include at least one of aluminum foil, aluminum oxide layer, silicon nitride layer and the like.
  • the casing can also be an aluminum-plastic film, and the aluminum-plastic film includes a nylon layer, an aluminum foil layer, a polypropylene (PP) layer and/or a matte layer.
  • PP polypropylene
  • the thickness of the casing there is no particular limitation on the thickness of the casing, as long as the purpose of the present application can be achieved.
  • the shell may have a thickness of 50 ⁇ m to 500 ⁇ m, preferably 50 ⁇ m to 300 ⁇ m, more preferably 50 ⁇ m to 200 ⁇ m.
  • the casing within the above thickness range can effectively protect the internal structure of the electrochemical device.
  • the present application has no particular limitation on the type of electrolyte, as long as the purpose of the present application can be achieved.
  • ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate (DEC), ethyl propionate (EP), ethyl methyl carbonate (EMC), dimethyl carbonate (DMC) After mixing at least one of fluoroethylene carbonate (FEC) and the like according to a certain mass ratio to obtain an organic solution, add lithium salt to dissolve and mix evenly.
  • FEC fluoroethylene carbonate
  • FEC fluoroethylene carbonate
  • DMC dimethyl carbonate
  • the application does not limit the type of lithium salt, as long as the purpose of the application can be achieved.
  • lithium salts may include LiPF 6 , LiBF 4 , LiAsF 6 , LiClO 4 , LiB(C 6 H 5 ) 4 , LiCH 3 SO 3 , LiCF 3 SO 3 , LiN(SO 2 CF 3 ) 2 , LiC(SO 2 At least one of CF 3 ) 3 , LiSiF 6 , LiBOB or lithium difluoroborate.
  • LiPF 6 can be selected as the lithium salt because it can give high ion conductivity and improve cycle characteristics.
  • the electrochemical device of the present application is not particularly limited, and may include, but not limited to, lithium metal secondary batteries, lithium ion secondary batteries (lithium ion batteries), lithium polymer secondary batteries, or lithium ion polymer secondary batteries.
  • an electrochemical device can be manufactured through the following process: a separator is placed between the positive pole piece and the negative pole piece, and it is wound or stacked as required and put into the case, and the electrolyte is injected into the case and sealed.
  • anti-overcurrent elements, guide plates, etc. can also be placed in the casing as needed, so as to prevent pressure rise and overcharge and discharge inside the electrochemical device.
  • the third aspect of the present application provides an electronic device, which includes the electrochemical device provided in the second aspect of the present application.
  • the electronic device has good high temperature safety performance.
  • the electronic devices of the present application are not particularly limited, and may include, but are not limited to: notebook computers, pen-input computers, mobile computers, e-book players, portable phones, portable fax machines, portable copiers, portable printers, head-mounted stereo earphones , VCR, LCD TV, Portable Cleaner, Portable CD Player, Mini Disc, Transceiver, Electronic Notepad, Calculator, Memory Card, Portable Recorder, Radio, Backup Power, Motor, Automobile, motorcycle, Assisted Bicycle, Bicycle , Lighting appliances, toys, game consoles, clocks, electric tools, flashlights, cameras, large household batteries and lithium-ion capacitors, etc.
  • the application provides an adhesive paper, an electrochemical device and an electronic device containing the adhesive paper.
  • the adhesive paper includes an adhesive layer, an insulating heat-resistant layer, and an expansion layer located between the adhesive layer and the insulating heat-resistant layer.
  • the layer comprises syndiotactic polystyrene.
  • the gummed paper has good expansion rate and high temperature resistance.
  • the expansion rate of the adhesive paper can reach 150% to 300%, and when the electrolyte solution content in the electrochemical device decreases, the adhesive paper can still maintain the expansion rate and effectively fix the electrode assembly.
  • the shape of the adhesive tape is stable and not easily deformed at high temperature, and the binding effect of the adhesive tape on the electrode assembly can be effectively maintained. Therefore, the electrochemical device of the present application has good high-temperature safety performance.
  • the electronic device of the present application includes the electrochemical device of the present application, therefore, the electronic device also has good high-temperature safety performance.
  • Fig. 1 is the structural representation of the gummed paper of some embodiments of the present application.
  • Fig. 2 is a schematic diagram of the action principle of gummed paper in electrochemical devices in some embodiments of the present application
  • Fig. 3 is a schematic diagram of the principle of action of syndiotactic polystyrene in the gummed paper of some embodiments of the present application in the electrolyte;
  • FIG. 4 is a schematic structural diagram of an electrochemical device in some embodiments of the present application.
  • Fig. 5 is a schematic structural diagram of electrochemical devices according to other embodiments of the present application.
  • Electrode assembly 20. Adhesive tape; 21. Adhesive layer; 22. Expansion layer; 23. Insulation and heat-resistant layer; 30. Shell.
  • a lithium-ion battery is used as an example of an electrochemical device to explain the present application, but the electrochemical device of the present application is not limited to the lithium-ion battery.
  • Fig. 1 shows a schematic structural view of adhesive tapes according to some embodiments of the present application.
  • adhesive tape 20 comprises adhesive layer 21, expansion layer 22 and insulating heat-resistant layer 23, and expansion layer 22 is positioned between adhesive layer 21 and insulating heat-resistant layer 23, is arranged on adhesive tape 20 in electrochemical device, its The bonding layer 21 is bonded to the inner surface and/or the outer surface of the electrode assembly, and the insulating heat-resistant layer 23 is adjacent to the casing.
  • Fig. 2 shows a schematic diagram of the working principle of adhesive tapes in some embodiments of the present application in an electrochemical device.
  • the electrode assembly 10 (a) in FIG. 2 is the electrode assembly 10, (b) in FIG. 2 is a schematic diagram of the principle of winding the adhesive paper 20 on the electrode assembly 10, and (c) in FIG. 2 is that the adhesive paper 20 is pasted on the electrode.
  • Schematic diagram of the structure of the assembly 10 (d) in Figure 2 is a schematic structural diagram of the electrode assembly 10 after the adhesive tape 20 is pasted in (c) and loaded into the housing 30,
  • (e) in Figure 2 is an electrochemical device Schematic diagram of the structure of the gummed paper 20 expanding after the electrolyte solution is injected into it.
  • the adhesive paper 20 is pasted on the outer surface of the electrode assembly 10. After the electrolyte is injected into the electrochemical device, the adhesive paper 20 shrinks and expands, the thickness of the adhesive paper 20 in the thickness direction x increases, and the longitudinal direction z is glued. The height of the paper 20 shrinks, and the volume of the gummed paper 20 remains unchanged. After the adhesive paper 20 expands in the thickness direction x, the gap between the electrode assembly 10 and the casing 30 is filled. In some other embodiments of the present application, when the electrode assembly 10 has a wound structure, the adhesive paper 20 may also be disposed on the inner surface of the electrode assembly 10 .
  • FIG. 3 is a schematic diagram of the working principle of syndiotactic polystyrene in the gummed paper of some embodiments of the present application in the electrolyte.
  • (f) in FIG. 3 is a schematic structural diagram of syndiotactic polystyrene before soaking in the electrolyte
  • (g) in FIG. 3 is a schematic structural diagram of syndiotactic polystyrene after soaking in the electrolyte.
  • the molecular orientation stress is released, the molecular chain shrinks, the volume constant area decreases, and the thickness increases.
  • FIG. 4 is a schematic structural diagram of an electrochemical device according to some embodiments of the present application. Wherein, (h) in FIG. 4 is a schematic cross-sectional structure diagram of the electrochemical device, and (i) in FIG. 4 is a top view of the electrochemical device. As shown in FIG. 4 , the adhesive paper 20 is disposed between the outer surface A of the electrode assembly 10 and the casing 30 , and the adhesive paper 20 is bonded on the outer surface A of the electrode assembly 10 .
  • FIG. 5 is a schematic structural diagram of electrochemical devices according to other embodiments of the present application.
  • (j) in FIG. 5 is a schematic cross-sectional structure diagram of the electrochemical device
  • (k) in FIG. 5 is a top view of the electrochemical device.
  • the adhesive paper 20 is arranged between the outer surface A of the electrode assembly 10 and the casing 30, and the adhesive paper 20 is bonded on the outer surface A of the electrode assembly 10; and the adhesive paper 20 is arranged on the inner surface of the electrode assembly 10 on B.
  • Expansion rate thickness after expansion/thickness before expansion ⁇ 100%.
  • the lithium-ion battery at 25°C for 60 minutes, test the voltage, internal resistance, and capacity, then put the battery into a special fixture, set the height of the roller to 1m, and the contact surface between the roller and the battery is the metal contact surface, 5min/cycle , a total of 500 laps, every 100 laps test record voltage, internal resistance, check the appearance and take pictures.
  • Negative electrode active material graphite powder, conductive agent conductive carbon black (Super P), and binder styrene-butadiene rubber (SBR) are mixed according to the weight ratio of 96:1.5:2.5, and then deionized water is added as a solvent to prepare a solid content of 70% of the slurry and stir well.
  • the slurry was uniformly coated on one surface of the negative electrode current collector copper foil with a thickness of 8 ⁇ m, and dried at 110° C. to obtain a negative electrode sheet with a coating thickness of 130 ⁇ m coated with negative active material on one side.
  • the single-side coating of the negative electrode sheet has been completed.
  • the above steps are repeated on the other surface of the negative electrode sheet to obtain a negative electrode sheet coated with negative active materials on both sides. After the coating is completed, the negative electrode sheet is cut for use.
  • NMP N-methylpyrrolidone
  • the organic solvent ethylene carbonate (EC), ethyl methyl carbonate (EMC) and diethyl carbonate (DEC) were mixed with a mass ratio of 30:50:20 to obtain an organic solution, and then added to the organic solvent Add lithium salt lithium hexafluorophosphate to dissolve and mix evenly to obtain an electrolyte solution with a lithium salt concentration of 1.15 mol/L.
  • Ceramic slurry Aluminum oxide and polyvinylidene fluoride were mixed according to a mass ratio of 90:10 and dissolved in deionized water to form a ceramic slurry with a solid content of 50%. Subsequently, the ceramic slurry was uniformly coated on one side of the porous substrate (polyethylene, thickness 7 ⁇ m, average pore diameter 0.073 ⁇ m, porosity 26%) by micro-recess coating method, and dried to obtain a ceramic coating The thickness of the ceramic coating is 50 ⁇ m with the double-layer structure of the porous substrate.
  • PVDF Polyvinylidene fluoride
  • polyacrylate was mixed in a mass ratio of 96:4 and dissolved in deionized water to form a polymer slurry with a solid content of 50%. Subsequently, the polymer slurry is uniformly coated on the two surfaces of the above-mentioned ceramic coating layer and the porous substrate double-layer structure by a dimple coating method, and is dried to obtain a separator, wherein the single-layer coating formed by the polymer slurry The layer thickness was 2 ⁇ m.
  • Syndiotactic polystyrene is mixed with the first elastomer, the second elastomer, filler and curing agent according to the mass ratio in Table 1, wherein the mass ratio and type of EVA, SEBS, amino resin and titanium dioxide are as shown in the table
  • the syndiotactic polystyrene film is obtained after treatment, and after the syndiotactic polystyrene film is bidirectionally stretched, heat treatment is carried out at 180 ° C to obtain an expansion layer.
  • the thickness of the expansion layer is shown in Table 1;
  • one side of the expansion layer coats the material of the bonding layer to obtain the bonding layer, wherein the material and thickness of the bonding layer are as shown in Table 1;
  • the above prepared positive electrode sheet, separator, and negative electrode sheet are stacked in order, so that the separator is in the middle of the positive and negative electrodes to play the role of isolation, and wound/stacked to obtain an electrode assembly with a wound structure/laminated structure.
  • Example 1 to Example 33 Comparative Example 1 to Comparative Example 4, ⁇ Preparation of Negative Electrode Sheet>, ⁇ Preparation of Positive Electrode Sheet>, ⁇ Preparation of Electrolyte>, ⁇ Preparation of Diaphragm>, ⁇ Preparation of Adhesive Paper
  • the preparation steps of preparation> and ⁇ preparation of lithium-ion battery> are the same as the above-mentioned preparation steps, the changes of relevant preparation parameters are shown in Table 1, and the changes of relevant effect parameters are shown in Table 2:
  • Example 5 It can be seen from Example 5 and Comparative Examples 1 to 4 that the high-temperature safety performance of the lithium-ion battery changes with the composition of the expansion layer. Lithium-ion batteries that include syndiotactic polystyrene in the expansion layer have significantly better high-temperature safety performance.
  • the types and mass ratios of the first elastomer, the second elastomer, the filler and the curing agent usually affect the high-temperature safety performance of the lithium-ion battery.
  • Example 3 Example 6 to Example 10, and Example 14 to Example 15, as long as the types and mass ratios of the first elastomer, the second elastomer, filler and curing agent are within the content range of the application Within, a lithium-ion battery with good high-temperature safety performance can be obtained.
  • the thickness of the expansion layer usually also affects the high-temperature safety performance of lithium-ion batteries. It can be seen from Example 3, Example 10 to Example 13 that as long as the thickness of the expansion layer is within the content range of the present application, a lithium-ion battery with good high-temperature safety performance can be obtained.
  • the weight-average molecular weight and melting point of syndiotactic polystyrene usually also affect the high-temperature safety performance of lithium-ion batteries. From Example 3, Example 16 to Example 18, and Example 33, it can be seen that as long as the weight-average molecular weight and melting point of syndiotactic polystyrene are within the scope of this application, a lithium-ion battery with good high-temperature safety performance can be obtained .
  • the thickness and material type of the bonding layer also generally have an impact on the high-temperature safety performance of lithium-ion batteries. From Example 3, Example 19 to Example 22, it can be seen that as long as the thickness and material type of the adhesive layer are within the scope of the application, a lithium-ion battery with good high-temperature safety performance can be obtained.
  • the thickness and material type of the insulating heat-resistant layer usually also affect the high-temperature safety performance of lithium-ion batteries. From Example 3, Example 23 to Example 26, it can be seen that as long as the thickness and material type of the insulating heat-resistant layer are within the scope of this application, a lithium-ion battery with good high-temperature safety performance can be obtained.
  • the thickness and temperature of the adhesive tape will also affect the high temperature safety performance of lithium-ion batteries. From Example 3, Example 19 to Example 20, and Example 23 to Example 24, it can be seen that as long as the thickness of the adhesive paper is within the scope of the application, a lithium-ion battery with good high-temperature safety performance can be obtained.
  • the proportion of the projected area of the tape on the outer surface and/or inner surface of the electrode assembly usually also affects the high temperature safety performance of lithium ions. From Example 3, Example 27 to Example 31, it can be seen that as long as the proportion of the projected area of the adhesive tape on the outer surface and/or inner surface of the electrode assembly is within the content range of the application, high temperature safety performance can be obtained Good lithium-ion battery.
  • the gummed paper of the present application has a good expansion rate, and it will not shrink or deform when stored in a high temperature environment for a long time.
  • the adhesive tape of the present application is applied to an electrochemical device, and the failure rate of the electrochemical device is low through a roller test and a drop test. It can be seen that by using the tape of the present application, the high-temperature safety performance of the electrochemical device is significantly improved, and has good high-temperature safety performance.

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Abstract

The present application provides an adhesive paper, an electrochemical device comprising said adhesive paper, and an electronic device. The adhesive paper comprises a bonding layer, an insulating heat-resistant layer, and an expansion layer located between the bonding layer and the insulating heat-resistant layer. The expansion layer comprises syndiotactic polystyrene. The adhesive paper has a good expansion rate and high temperature resistance. When the adhesive paper is applied to the electrochemical device, the expansion rate of the adhesive paper can reach 150% to 300%, and when the content of an electrolyte in the electrochemical device is reduced, the adhesive paper can still maintain the expansion rate and effectively fix an electrode assembly. Moreover, the adhesive paper is stable in shape and not prone to deformation at a high temperature, and a binding effect of the adhesive paper on the electrode assembly can be effectively maintained. Therefore, the electrochemical device of the present application has good high-temperature safety performance. The electronic device of the present application comprises the electrochemical device of the present application. Therefore, the electronic device has good high-temperature safety performance.

Description

一种胶纸、包含该胶纸的电化学装置和电子装置A kind of gummed paper, electrochemical device and electronic device comprising the gummed paper 技术领域technical field
本申请涉及电化学领域，具体涉及一种胶纸、包含该胶纸的电化学装置和电子装置。The present application relates to the field of electrochemistry, in particular to an adhesive paper, an electrochemical device and an electronic device containing the adhesive paper.
背景技术Background technique
锂离子电池作为利用电能-化学能转换装置的典型代表，越来越广泛地应用于各个领域中。Lithium-ion batteries, as a typical representative of electrical energy-chemical energy conversion devices, are more and more widely used in various fields.
现有的圆柱形锂离子电池由于电极组件与壳体之间存在一定的间隙，在跌落、滚筒过程中，电极组件与壳体发生相对运动，造成电压降失效、极片断裂、极耳断裂等严重后果。为了解决上述问题，本领域技术人员往往利用膨胀胶纸浸泡电解液后沿厚度方向发生膨胀，以填充电极组件与壳体之间的间隙，从而束缚电极组件在壳体内的震动摇晃，进而缓冲跌落、滚筒应力，提高锂离子电池的安全性。Due to the gap between the electrode assembly and the shell of the existing cylindrical lithium-ion battery, the relative movement of the electrode assembly and the shell occurs during the process of dropping or rolling, resulting in failure of voltage drop, breakage of pole pieces, breakage of tabs, etc. Serious consequences. In order to solve the above problems, those skilled in the art often use expansion tape to soak the electrolyte and then expand along the thickness direction to fill the gap between the electrode assembly and the casing, thereby restraining the vibration and shaking of the electrode assembly in the casing, and then buffering the drop , Roller stress, improve the safety of lithium-ion batteries.
然而，目前使用的膨胀胶纸在电极组件制程及后续高温(＞60℃)存储过程中容易发生变形，导致膨胀胶纸对电极组件的束缚效果变差。另外，随着锂离子电池的循环，电解液含量变少，膨胀胶纸的膨胀率随之降低，也会导致膨胀胶纸对电极组件的束缚效果变差，从而造成锂离子电池的安全问题。However, the expansion adhesive paper currently used is prone to deformation during the electrode assembly process and subsequent high-temperature (>60°C) storage process, resulting in poor binding effect of the expansion adhesive paper on the electrode assembly. In addition, as the lithium-ion battery cycles, the electrolyte content decreases, and the expansion rate of the expansion adhesive paper decreases, which will also lead to the deterioration of the binding effect of the expansion adhesive paper on the electrode assembly, thereby causing safety problems for lithium-ion batteries.
发明内容Contents of the invention
本申请提供了一种胶纸、包含该胶纸的电化学装置和电子装置，以提高胶纸的耐高温性能，改善电化学装置的高温安全性能。The present application provides an adhesive paper, an electrochemical device and an electronic device containing the adhesive paper, so as to improve the high-temperature resistance performance of the adhesive paper and improve the high-temperature safety performance of the electrochemical device.
需要说明的是，在以下内容中，以锂离子电池作为电化学装置的例子来解释本申请，但是本申请的电化学装置并不仅限于锂离子电池。具体技术方案如下：It should be noted that, in the following content, a lithium-ion battery is used as an example of an electrochemical device to explain the present application, but the electrochemical device of the present application is not limited to the lithium-ion battery. The specific technical scheme is as follows:
本申请第一方面提供了一种胶纸，其包括粘结层、绝缘耐热层以及位于粘结层和绝缘耐热层之间的膨胀层；膨胀层包括间规聚苯乙烯。The first aspect of the present application provides an adhesive tape, which includes an adhesive layer, an insulating and heat-resistant layer, and an expansion layer located between the adhesive layer and the insulating and heat-resistant layer; the expansion layer includes syndiotactic polystyrene.
本申请提供的胶纸中的绝缘耐热层具有绝缘及耐高温的效果，能够有效防止锂离子电池内外短路，避免外界的高温使胶纸发生热收缩变形，从而有效改善胶纸因高温变形而导致对电极组件束缚效果变差的问题。The insulating and heat-resistant layer in the adhesive tape provided by this application has the effect of insulation and high temperature resistance, which can effectively prevent the internal and external short circuit of the lithium-ion battery, avoid the thermal shrinkage and deformation of the adhesive tape due to the high temperature outside, and effectively improve the deformation of the adhesive tape due to high temperature deformation. This leads to a problem that the binding effect on the electrode assembly is deteriorated.
本申请提供的胶纸中的膨胀层位于粘结层和绝缘耐热层之间，膨胀层包括间规聚苯 乙烯。在电解液中浸泡后，包含该膨胀层的胶纸的膨胀率可达150％至300％，由于形成膨胀层的间规聚苯乙烯具备良好的耐高温性，使得胶纸在高温(＞60℃)下形状稳定不易变形，能够有效保持胶纸在高温下对电极组件的束缚效果，降低电极组件在壳体内晃动的风险。同时，锂离子电池中电解液含量的减少对胶纸膨胀率的影响变小甚至不影响。The expansion layer in the gummed paper provided by the application is located between the bonding layer and the insulating heat-resistant layer, and the expansion layer includes syndiotactic polystyrene. After soaking in the electrolyte, the expansion rate of the gummed paper comprising the expansion layer can reach 150% to 300%. Because the syndiotactic polystyrene forming the expansion layer has good high temperature resistance, the gummed paper can be used at high temperatures (>60 °C), the shape is stable and not easy to deform, which can effectively maintain the binding effect of the adhesive paper on the electrode assembly at high temperature, and reduce the risk of the electrode assembly shaking in the casing. At the same time, the reduction of the electrolyte content in the lithium-ion battery has little or no effect on the expansion rate of the gummed paper.
整体而言，本申请的胶纸包括粘结层、绝缘耐热层以及位于粘结层和绝缘耐热层之间的膨胀层，膨胀层包括间规聚苯乙烯。该胶纸具有良好的膨胀率及耐高温性能。将本申请的胶纸在应用于锂离子电池中，胶纸中的间规聚苯乙烯浸泡电解液后，分子取向应力释放，分子链收缩，使胶纸在纵向方向上收缩，在厚度方向上膨胀，膨胀率可达150％至300％。这样，胶纸在体积不变的情况下厚度增加，能够有效填补电极组件与壳体之间的间隙，进而束缚电极组件在壳体内的震动摇晃，以缓冲锂离子电池的跌落、滚筒应力，从而提高锂离子电池的安全性能。同时，锂离子电池中电解液含量的减少对本申请胶纸的膨胀率的影响减小，进一步提高了锂离子电池的安全性能。该胶纸在高温下形状稳定，不易发生变形，能够有效保持胶纸对电极组件的束缚效果，从而有效改善锂离子电池的高温安全性能。Generally speaking, the adhesive tape of the present application includes an adhesive layer, an insulating heat-resistant layer, and an expansion layer located between the adhesive layer and the insulating heat-resistant layer, and the expansion layer includes syndiotactic polystyrene. The gummed paper has good expansion rate and high temperature resistance. Apply the gummed paper of the present application to lithium-ion batteries, after the syndiotactic polystyrene in the gummed paper is soaked in the electrolyte, the molecular orientation stress is released, and the molecular chain shrinks, so that the gummed paper shrinks in the longitudinal direction, and in the thickness direction Expansion, the expansion rate can reach 150% to 300%. In this way, the thickness of the adhesive paper increases while the volume remains constant, which can effectively fill the gap between the electrode assembly and the casing, thereby constraining the vibration and shaking of the electrode assembly in the casing to buffer the drop and roller stress of the lithium-ion battery, thereby Improve the safety performance of lithium-ion batteries. At the same time, the reduction of the electrolyte content in the lithium-ion battery reduces the impact on the expansion rate of the gummed paper of the present application, further improving the safety performance of the lithium-ion battery. The adhesive paper is stable in shape at high temperature, is not easy to deform, and can effectively maintain the binding effect of the adhesive paper on the electrode assembly, thereby effectively improving the high-temperature safety performance of the lithium-ion battery.
在本申请的一些实施例中，形成膨胀层的间规聚苯乙烯的重均分子量为100000至700000，优选为300000至400000。例如，不限于任何理论，间规聚苯乙烯的重均分子量过小，例如小于100000，间规聚苯乙烯的拉伸强度过低，胶纸容易发生断裂，且小分子的间规聚苯乙烯浸泡于电解液中容易发生溶胀溶出，使锂离子电池的电化学性能变差；间规聚苯乙烯的重均分子量过大，例如大于700000，间规聚苯乙烯的硬度过大，不利于胶纸的生产加工。In some embodiments of the present application, the weight average molecular weight of the syndiotactic polystyrene forming the expansion layer is 100,000 to 700,000, preferably 300,000 to 400,000. For example, without being limited to any theory, the weight average molecular weight of syndiotactic polystyrene is too small, for example, less than 100,000, the tensile strength of syndiotactic polystyrene is too low, the tape is prone to breakage, and the syndiotactic polystyrene with small molecules Soaking in the electrolyte is prone to swelling and dissolution, which makes the electrochemical performance of lithium-ion batteries worse; the weight-average molecular weight of syndiotactic polystyrene is too large, for example, greater than 700,000, and the hardness of syndiotactic polystyrene is too large, which is not conducive to glue Paper production and processing.
在本申请的一些实施例中，间规聚苯乙烯的熔点为255℃至275℃，表明间规聚苯乙烯的耐高温性能好，有利于改善胶纸的耐高温性能。In some embodiments of the present application, the melting point of syndiotactic polystyrene is 255° C. to 275° C., indicating that syndiotactic polystyrene has good high temperature resistance, which is beneficial to improve the high temperature resistance of gummed paper.
在本申请的一些实施例中，将胶纸在电解液中于常温(23℃至26℃)下浸泡12h，胶纸在厚度方向上的膨胀率为150％至300％，优选为200％至300％，表明胶纸在常温和高温下浸泡电解液后均能够在厚度方向上具有良好的膨胀率，以有效填充电极组件与壳体之间的间隙，使电极组件得以固定。胶纸在厚度方向上的膨胀率在上述优选范围时，胶纸能够更有效地填充电极组件与壳体之间的间隙，更好地固定电极组件。In some embodiments of the present application, the gummed paper is soaked in the electrolyte at room temperature (23° C. to 26° C.) for 12 hours, and the expansion rate of the gummed paper in the thickness direction is 150% to 300%, preferably 200% to 300%. 300%, indicating that the adhesive paper can have a good expansion rate in the thickness direction after soaking in the electrolyte at room temperature and high temperature, so as to effectively fill the gap between the electrode assembly and the casing, so that the electrode assembly can be fixed. When the expansion rate of the adhesive paper in the thickness direction is in the above preferred range, the adhesive paper can more effectively fill the gap between the electrode assembly and the casing, and fix the electrode assembly better.
在本申请的一些实施例中，将胶纸在电解液中于常温下浸泡12h，胶纸在纵向上的收缩率为150％至300％，这样，胶纸在厚度方向上膨胀的同时，在纵向上进行收缩，胶纸 体积保持稳定不变。在本申请中，纵向垂直或近似垂直于胶纸的厚度方向。In some embodiments of the present application, the gummed paper is soaked in the electrolyte at normal temperature for 12 hours, and the shrinkage rate of the gummed paper in the longitudinal direction is 150% to 300%, so that when the gummed paper expands in the thickness direction, Shrinking in the longitudinal direction, the volume of the gummed paper remains stable. In this application, the longitudinal direction is perpendicular or approximately perpendicular to the thickness direction of the gummed paper.
在本申请的一些实施例中，将胶纸在电解液中于常温下浸泡12h，胶纸膨胀后的体积变化率为0％，表明胶纸在常温和高温下浸泡电解液发生膨胀后体积稳定不变。In some embodiments of the present application, the gummed paper is soaked in the electrolyte solution at room temperature for 12 hours, and the volume change rate after the gummed paper expands is 0%, indicating that the volume of the gummed paper is stable after being soaked in the electrolyte solution at room temperature and high temperature. constant.
在本申请的一些实施例中，膨胀层还包括第一弹性体、第二弹性体、填料和固化剂。本申请对第一弹性体的种类没有特别限制，只要能够实现本申请目的即可。例如，第一弹性体包括乙烯-醋酸乙烯共聚物(EVA)。本申请对第二弹性体的种类没有特别限制，只要能够实现本申请目的即可。例如，第二弹性体包括苯乙烯-乙烯-丁烯-苯乙烯嵌段共聚物(SEBS)、聚丁二烯(PB)或聚异丁烯(PIB)中的至少一种。本申请对填料的种类没有特别限制，只要能够实现本申请目的即可。例如，填料包括钛白粉、滑石粉、白炭黑或碳酸钙中的至少一种。本申请对固化剂的种类没有特别限制，只要能够实现本申请目的即可。例如，固化剂包括氨基树脂、环氧树脂或聚异氰酸酯中的至少一种。通过在膨胀层中加入第一弹性体、第二弹性体、填料和固化剂，以避免胶纸的膨胀率随着锂离子电池中电解液含量的减少而降低，进而确保胶纸对电极组件的固定效果，有效改善锂离子电池的安全性能。In some embodiments of the present application, the expansion layer further includes a first elastic body, a second elastic body, a filler and a curing agent. The present application has no particular limitation on the type of the first elastic body, as long as the purpose of the present application can be achieved. For example, the first elastomer includes ethylene vinyl acetate (EVA). The present application has no particular limitation on the type of the second elastomer, as long as the purpose of the present application can be achieved. For example, the second elastomer includes at least one of styrene-ethylene-butylene-styrene block copolymer (SEBS), polybutadiene (PB), or polyisobutylene (PIB). The present application has no particular limitation on the type of filler, as long as the purpose of the present application can be achieved. For example, the filler includes at least one of titanium dioxide, talc, white carbon black or calcium carbonate. The present application has no particular limitation on the type of curing agent, as long as the purpose of the present application can be achieved. For example, the curing agent includes at least one of amino resin, epoxy resin, or polyisocyanate. By adding the first elastomer, the second elastomer, filler and curing agent in the expansion layer, the expansion rate of the adhesive paper is avoided to decrease with the reduction of the electrolyte content in the lithium-ion battery, thereby ensuring the adhesion of the adhesive paper to the electrode assembly Fixed effect, effectively improving the safety performance of lithium-ion batteries.
在本申请的一些实施例中，基于膨胀层的总质量，间规聚苯乙烯的质量比例为80％至100％，优选为85％至100％，更优选为90％至95％。第一弹性体、第二弹性体、填料和固化剂质量之和的质量比例为0％至20％，优选为0％至15％，更优选为5％至10％。通过将间规聚苯乙烯的质量比例以及第一弹性体、第二弹性体、填料和固化剂质量之和的质量比例控制在上述范围内，更有利于提高胶纸的耐高温性能。In some embodiments of the present application, based on the total mass of the expansion layer, the mass proportion of syndiotactic polystyrene is 80% to 100%, preferably 85% to 100%, more preferably 90% to 95%. The mass ratio of the sum of the mass of the first elastomer, the second elastomer, the filler and the curing agent is 0% to 20%, preferably 0% to 15%, more preferably 5% to 10%. By controlling the mass ratio of the syndiotactic polystyrene and the mass ratio of the sum of the first elastomer, the second elastomer, the filler and the curing agent within the above range, it is more beneficial to improve the high temperature resistance of the gummed paper.
在本申请的一些实施例中，第一弹性体、第二弹性体、填料和固化剂的质量比例为(20-40):(14-34):(31-36):(10-15)，优选为30:24:36:10。通过将第一弹性体、第二弹性体、填料和固化剂的质量比例控制在上述范围内，更有利于避免胶纸由于电解液含量的减少而导致膨胀率的下降。In some embodiments of the present application, the mass ratio of the first elastomer, the second elastomer, the filler and the curing agent is (20-40):(14-34):(31-36):(10-15) , preferably 30:24:36:10. By controlling the mass ratio of the first elastomer, the second elastomer, the filler and the curing agent within the above range, it is more beneficial to avoid the reduction of the expansion rate of the gummed paper due to the reduction of the electrolyte content.
在本申请的一些实施例中，胶纸的厚度为20μm至50μm。通过将胶纸的厚度控制在上述范围内，能够通过胶纸的膨胀合理填充电极组件与壳体之间的间隙，有利于提高胶纸对电极组件的束缚效果，并且，有利于减小锂离子电池的体积，进而得以能量密度的提高。In some embodiments of the present application, the adhesive tape has a thickness of 20 μm to 50 μm. By controlling the thickness of the adhesive paper within the above range, the gap between the electrode assembly and the casing can be reasonably filled through the expansion of the adhesive paper, which is conducive to improving the binding effect of the adhesive paper on the electrode assembly, and is conducive to reducing the lithium ion density. The volume of the battery, and thus the energy density can be improved.
在本申请的一些实施例中，粘结层的厚度为5μm至10μm。粘结层的厚度过薄，例如 低于5μm，胶纸与电极组件之间的粘结力降低，胶纸对电极组件的束缚效果将变差；粘结层的厚度过厚，例如高于10μm，使胶纸的厚度增大，电极组件与壳体之间的距离需要随之增大以满足胶纸所需间隙，将增大锂离子电池的体积，从而降低锂离子电池的能量密度。In some embodiments of the present application, the adhesive layer has a thickness of 5 μm to 10 μm. If the thickness of the adhesive layer is too thin, such as less than 5 μm, the adhesive force between the adhesive paper and the electrode assembly will decrease, and the binding effect of the adhesive paper on the electrode assembly will become worse; if the thickness of the adhesive layer is too thick, for example, it is higher than 10 μm , so that the thickness of the adhesive paper increases, the distance between the electrode assembly and the casing needs to increase accordingly to meet the gap required by the adhesive paper, which will increase the volume of the lithium-ion battery, thereby reducing the energy density of the lithium-ion battery.
在本申请的一些实施例中，膨胀层的厚度为10μm至30μm。膨胀层的厚度过薄，例如低于10μm，胶纸的耐高温性能降低，进而影响胶纸在高温下和电解液含量减小时的膨胀率；膨胀层的厚度过厚，例如高于30μm，使胶纸的厚度增大，电极组件与壳体之间的距离需要随之增大以满足胶纸所需间隙，将增大锂离子电池的体积，从而降低锂离子电池的能量密度。In some embodiments of the present application, the expansion layer has a thickness of 10 μm to 30 μm. If the thickness of the expansion layer is too thin, such as less than 10 μm, the high temperature resistance of the gummed paper will be reduced, which will affect the expansion rate of the gummed paper at high temperature and when the electrolyte content is reduced; if the thickness of the expansion layer is too thick, such as higher than 30 μm, the As the thickness of the adhesive paper increases, the distance between the electrode assembly and the casing needs to increase accordingly to meet the gap required by the adhesive paper, which will increase the volume of the lithium-ion battery, thereby reducing the energy density of the lithium-ion battery.
在本申请的一些实施例中，绝缘耐热层的厚度为5μm至10μm。绝缘耐热层的厚度过薄，例如低于5μm，胶纸的绝缘、耐高温作用降低，不利于防止胶纸在高温下的变形；绝缘耐热层的厚度过厚，例如高于10μm，使胶纸的厚度增大，电极组件与壳体之间的距离需要随之增大以满足胶纸所需间隙，将增大锂离子电池的体积，从而降低锂离子电池的能量密度。In some embodiments of the present application, the insulating heat-resistant layer has a thickness of 5 μm to 10 μm. If the thickness of the insulating heat-resistant layer is too thin, such as less than 5 μm, the insulation and high-temperature resistance of the adhesive tape will be reduced, which is not conducive to preventing the deformation of the adhesive tape at high temperature; if the thickness of the insulating heat-resistant layer is too thick, such as higher than 10 μm, the As the thickness of the adhesive paper increases, the distance between the electrode assembly and the casing needs to increase accordingly to meet the gap required by the adhesive paper, which will increase the volume of the lithium-ion battery, thereby reducing the energy density of the lithium-ion battery.
在本申请的一些实施例中，对本申请粘结层的材料的种类没有特别限制，只要能够实现本申请目的即可。例如，粘结层的材料包括聚甲基丙烯酸甲酯(PMMA)(俗称：亚克力)、聚丙烯(PP)、热熔型苯乙烯-异戊二烯-苯乙烯(SIS)橡胶、聚乙烯(PE)或聚酰胺中的至少一种。选用上述材料作为粘结层的材料，有利于提高胶纸与电极组件之间的粘结力。In some embodiments of the present application, there is no particular limitation on the type of material of the adhesive layer of the present application, as long as the purpose of the present application can be achieved. For example, the material of the adhesive layer includes polymethyl methacrylate (PMMA) (commonly known as: acrylic), polypropylene (PP), hot-melt styrene-isoprene-styrene (SIS) rubber, polyethylene ( PE) or at least one of polyamide. Selecting the above-mentioned materials as the material of the bonding layer is beneficial to improving the bonding force between the adhesive tape and the electrode assembly.
在本申请的一些实施例中，对本申请绝缘耐热层的材料的种类没有特别限制，只要能够实现本申请目的即可。例如，绝缘耐热层的材料包括聚对苯二甲酸乙二醇酯(PET)、聚酰亚胺(PI)或聚丙烯(PP)中的至少一种。通过选用上述材料作为绝缘耐热层的材料，有利于提高绝缘耐热层的绝缘和耐高温性能，进而有效防止由于外界的高温造成的胶纸变形。In some embodiments of the present application, there is no particular limitation on the type of material of the insulating heat-resistant layer of the present application, as long as the purpose of the present application can be achieved. For example, the material of the insulating heat-resistant layer includes at least one of polyethylene terephthalate (PET), polyimide (PI) or polypropylene (PP). By selecting the above-mentioned materials as the material of the insulating and heat-resistant layer, it is beneficial to improve the insulation and high-temperature resistance performance of the insulating and heat-resistant layer, thereby effectively preventing the deformation of the adhesive tape caused by the high temperature outside.
本申请对胶纸的制备方法没有特别限制，只要能够实现本申请目的即可。例如，本申请可以采用如下制备胶纸的方法，其包括以下步骤：The present application has no special limitation on the preparation method of the gummed paper, as long as the purpose of the present application can be achieved. For example, the present application can adopt the following method for preparing gummed paper, which includes the following steps:
(1)将间规聚苯乙烯等原料按照本申请的配方预处理后输送至挤出***，经熔融塑化后从模头挤出熔体，熔体经流延后形成特定晶体结构的间规聚苯乙烯薄膜，将间规聚 苯乙烯薄膜进行定向拉伸，再在150℃至200℃的温度下进行热处理，以降低间规聚苯乙烯的热收缩率、提高尺寸稳定性，得到10μm至30μm的膨胀层；(1) The raw materials such as syndiotactic polystyrene are pretreated according to the formula of this application and then transported to the extrusion system. After being melted and plasticized, the melt is extruded from the die head, and the melt is cast to form a syndiotactic polystyrene with a specific crystal structure. Orientational stretching of syndiotactic polystyrene film, followed by heat treatment at a temperature of 150°C to 200°C, in order to reduce the thermal shrinkage rate of syndiotactic polystyrene and improve dimensional stability, and obtain 10μm up to 30 μm expansion layer;
(2)在膨胀层的一面涂布粘结层的材料，得到5μm至10μm的粘结层；(2) Coating the material of the bonding layer on one side of the expansion layer to obtain a bonding layer of 5 μm to 10 μm;
(3)在膨胀层的另一面热压复合绝缘耐热层的材料，得到5μm至10μm的绝缘耐热层；即得到本申请的胶纸。(3) On the other side of the expansion layer, thermally press the material of the composite insulating and heat-resistant layer to obtain an insulating and heat-resistant layer of 5 μm to 10 μm; that is, obtain the adhesive tape of the present application.
本申请对膨胀层制备过程中，间规聚苯乙烯等原料的预处理方法没有特别限制，只要能够实现本申请目的即可。本申请对前述挤出***的种类没有特别限制，只要能够实现本申请目的即可。The present application has no special limitation on the pretreatment method of raw materials such as syndiotactic polystyrene during the preparation of the expansion layer, as long as the purpose of the present application can be achieved. The present application has no particular limitation on the type of the aforementioned extrusion system, as long as the purpose of the present application can be achieved.
在本申请中，对间规聚苯乙烯薄膜进行定向拉伸时，定向拉伸可以为单向拉伸，也可以为双向拉伸。优选地，单向拉伸的方向为沿胶纸的纵向方向或横向方向拉伸，双向拉伸的方向为沿胶纸的纵向方向和横向方向拉伸。这样，间规聚苯乙烯的抗拉强度得以有效提高，能够更加适应生产加工需要。本申请对定向拉伸的拉力和方法没有特别限制，只要能够实现本申请目的即可。In the present application, when the syndiotactic polystyrene film is directional stretched, the directional stretch can be uniaxial stretching or biaxial stretching. Preferably, the direction of uniaxial stretching is stretching along the longitudinal direction or transverse direction of the gummed paper, and the direction of biaxial stretching is stretching along the longitudinal direction and transverse direction of the gummed paper. In this way, the tensile strength of syndiotactic polystyrene can be effectively improved, which can better meet the needs of production and processing. The present application has no particular limitation on the tension and method of directional stretching, as long as the purpose of the present application can be achieved.
本申请的第二方面提供了一种电化学装置，其包括电极组件、壳体和本申请第一方面提供的胶纸。因此，当电化学装置在跌落或滚筒时，能够有效防止电极组件与壳体发生相对运动，避免电化学装置产生电压降失效、极片断裂或极耳断裂等严重后果，从而有效提高电化学装置在的安全性能。电化学装置处于高温环境下，胶纸具有良好的耐高温性，进一步避免胶纸由于受到高温而发生热收缩变形的问题，这样显著改善了胶纸因高温变形而导致对电极组件束缚效果变差的问题，进一步改善了电化学装置的高温安全性能。The second aspect of the present application provides an electrochemical device, which includes an electrode assembly, a casing, and the adhesive paper provided in the first aspect of the present application. Therefore, when the electrochemical device is dropped or rolled, the relative movement between the electrode assembly and the casing can be effectively prevented, and serious consequences such as voltage drop failure, pole piece breakage or tab breakage caused by the electrochemical device can be avoided, thereby effectively improving the performance of the electrochemical device. in the safety performance. The electrochemical device is in a high temperature environment, and the tape has good high temperature resistance, which further avoids the problem of heat shrinkage and deformation of the tape due to high temperature, which significantly improves the binding effect of the tape on the electrode assembly due to high temperature deformation. The problem of further improving the high temperature safety performance of the electrochemical device.
在本申请的一些实施例中，电极组件为叠片结构或卷绕结构，胶纸设置于电极组件外表面与壳体之间，绝缘耐热层与壳体相邻，以有效防止外界的高温使胶纸发生变形；基于电极组件外表面的总面积，胶纸在电极组件外表面上的投影面积的占比为30％至100％。In some embodiments of the present application, the electrode assembly is a laminated structure or a winding structure, the adhesive paper is arranged between the outer surface of the electrode assembly and the casing, and the insulating heat-resistant layer is adjacent to the casing to effectively prevent the external high temperature. Deform the adhesive paper; based on the total area of the outer surface of the electrode assembly, the projected area of the adhesive paper on the outer surface of the electrode assembly accounts for 30% to 100%.
在本申请的一些实施例中，电极组件为卷绕结构，胶纸设置于电极组件内表面上；基于电极组件内表面的总面积，胶纸在电极组件内表面上的投影面积的占比为30％至100％。In some embodiments of the present application, the electrode assembly is a winding structure, and the adhesive paper is arranged on the inner surface of the electrode assembly; based on the total area of the inner surface of the electrode assembly, the ratio of the projected area of the adhesive paper on the inner surface of the electrode assembly is: 30% to 100%.
在本申请的一些实施例中，电极组件为卷绕结构，胶纸设置于电极组件外表面与壳 体之间、以及胶纸设置于电极组件内表面上，基于电极组件外表面的总面积，胶纸在电极组件外表面上的投影面积的占比为30％至100％，基于电极组件内表面的总面积，胶纸在电极组件内表面上的投影面积的占比为30％至100％。In some embodiments of the present application, the electrode assembly is a wound structure, the adhesive paper is arranged between the outer surface of the electrode assembly and the casing, and the adhesive paper is arranged on the inner surface of the electrode assembly, based on the total area of the outer surface of the electrode assembly, The ratio of the projected area of the adhesive tape on the outer surface of the electrode assembly is 30% to 100%, based on the total area of the inner surface of the electrode assembly, the ratio of the projected area of the adhesive paper on the inner surface of the electrode assembly is 30% to 100%. .
根据电极组件与壳体之间的距离，选择上述范围内的胶纸的面积比例，以充分填充电极组件与壳体之间的间隙，改善电极组件的固定效果。通过将胶纸在电极组件外表面和/或内表面上的投影面积的占比控制在上述范围内，能够有效改善电化学装置的高温安全性能。需要说明，上述“内表面”仅存在于卷绕结构的电极组件中，具体是指，电极组件经卷绕后，形成类似于空心圆柱体形的结构，该结构包括大圆形成的外表面和小圆形成的内表面，本申请的“内表面”可以理解为小圆形成的内表面，本领域技术人员应当理解，这里的大圆和小圆为近似圆形，在生产中也可以根据实际情况选择为椭圆形或类椭圆形。According to the distance between the electrode assembly and the casing, the area ratio of the adhesive paper within the above range is selected to fully fill the gap between the electrode assembly and the casing and improve the fixing effect of the electrode assembly. By controlling the proportion of the projected area of the adhesive paper on the outer surface and/or inner surface of the electrode assembly within the above range, the high temperature safety performance of the electrochemical device can be effectively improved. It should be noted that the above-mentioned "inner surface" only exists in the electrode assembly of the wound structure, specifically, after the electrode assembly is wound, it forms a structure similar to a hollow cylinder, which includes an outer surface formed by a large circle and a small circle. Formed inner surface, the "inner surface" of the present application can be understood as the inner surface formed by small circles, and those skilled in the art should understand that the large circle and small circle here are approximately circular, and can also be selected according to actual conditions in production. Ellipse or quasi-ellipse.
在本申请中，电极组件包含隔膜、正极极片和负极极片。隔膜用以分隔正极极片和负极极片，以防止电化学装置内部短路，其允许电解质离子自由通过，完成电化学充放电过程的作用。本申请对隔膜、正极极片和负极极片的数量和种类没有特别限制，只要能够实现本申请目的即可。In this application, the electrode assembly includes a separator, a positive electrode tab, and a negative electrode tab. The separator is used to separate the positive pole piece and the negative pole piece to prevent the internal short circuit of the electrochemical device, which allows the electrolyte ions to pass freely to complete the electrochemical charge and discharge process. The present application has no special limitation on the number and type of the separator, the positive pole piece and the negative pole piece, as long as the purpose of the present application can be achieved.
本申请对壳体没有特别限制，只要能够实现本申请目的即可。例如，壳体可以包含内层和外层，内层与隔板密封连接，因此内层的材料可以包括高分子材料，从而实现良好的密封效果；同时内层和外层的结合能够有效得保护电化学装置的内部结构。具体地，内层的材料包括聚丙烯、聚酯、对羟基苯甲醛、聚酰胺、聚苯醚、聚氨酯等中的至少一种。在本申请中，对外层的材料没有特别限制，只要能实现本申请的目的即可。例如，外层的材料可以包括铝箔、氧化铝层、氮化硅层等中的至少一种。此外，壳体也可以为铝塑膜，铝塑膜包含尼龙层、铝箔层和聚丙烯(PP)层和/或哑光层。The present application has no special limitation on the casing, as long as the purpose of the present application can be achieved. For example, the casing may include an inner layer and an outer layer, and the inner layer is sealed and connected with the partition, so the material of the inner layer may include a polymer material to achieve a good sealing effect; at the same time, the combination of the inner layer and the outer layer can effectively protect Internal structure of an electrochemical device. Specifically, the material of the inner layer includes at least one of polypropylene, polyester, p-hydroxybenzaldehyde, polyamide, polyphenylene ether, polyurethane, and the like. In this application, there is no particular limitation on the material of the outer layer, as long as the purpose of this application can be achieved. For example, the material of the outer layer may include at least one of aluminum foil, aluminum oxide layer, silicon nitride layer and the like. In addition, the casing can also be an aluminum-plastic film, and the aluminum-plastic film includes a nylon layer, an aluminum foil layer, a polypropylene (PP) layer and/or a matte layer.
在本申请中，对壳体的厚度没有特别限制，只要能实现本申请的目的即可。例如，壳体的厚度可以为50μm至500μm，优选为50μm至300μm，更优选为50μm至200μm。在上述厚度范围内的壳体可以有效保护电化学装置的内部结构。In the present application, there is no particular limitation on the thickness of the casing, as long as the purpose of the present application can be achieved. For example, the shell may have a thickness of 50 μm to 500 μm, preferably 50 μm to 300 μm, more preferably 50 μm to 200 μm. The casing within the above thickness range can effectively protect the internal structure of the electrochemical device.
本申请对电解液的种类没有特别限制，只要能够实现本申请目的即可。例如，将碳酸亚乙酯(EC)、碳酸亚丙酯(PC)、碳酸二乙酯(DEC)、丙酸乙酯(EP)、碳酸甲乙酯(EMC)、碳酸二甲酯(DMC)或碳酸氟代亚乙酯(FEC)等中的至少一种按照一定质量比例混合得到有机溶液后，加入锂盐溶解并混合均匀即可。本申请对锂盐的种类没有限 制，只要能够实现本申请目的即可。例如，锂盐可以包括LiPF 6、LiBF 4、LiAsF 6、LiClO 4、LiB(C 6H 5) 4、LiCH 3SO 3、LiCF 3SO 3、LiN(SO 2CF 3) 2、LiC(SO 2CF 3) 3、LiSiF 6、LiBOB或二氟硼酸锂中的至少一种。优选地，锂盐可以选用LiPF 6，因为它可以给出高的离子电导率并改善循环特性。 The present application has no particular limitation on the type of electrolyte, as long as the purpose of the present application can be achieved. For example, ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate (DEC), ethyl propionate (EP), ethyl methyl carbonate (EMC), dimethyl carbonate (DMC) After mixing at least one of fluoroethylene carbonate (FEC) and the like according to a certain mass ratio to obtain an organic solution, add lithium salt to dissolve and mix evenly. The application does not limit the type of lithium salt, as long as the purpose of the application can be achieved. For example, lithium salts may include LiPF 6 , LiBF 4 , LiAsF 6 , LiClO 4 , LiB(C 6 H 5 ) 4 , LiCH 3 SO 3 , LiCF 3 SO 3 , LiN(SO 2 CF 3 ) 2 , LiC(SO 2 At least one of CF 3 ) 3 , LiSiF 6 , LiBOB or lithium difluoroborate. Preferably, LiPF 6 can be selected as the lithium salt because it can give high ion conductivity and improve cycle characteristics.
本申请的电化学装置没有特别限制，其可以包括但不限于：锂金属二次电池、锂离子二次电池(锂离子电池)、锂聚合物二次电池或锂离子聚合物二次电池等。The electrochemical device of the present application is not particularly limited, and may include, but not limited to, lithium metal secondary batteries, lithium ion secondary batteries (lithium ion batteries), lithium polymer secondary batteries, or lithium ion polymer secondary batteries.
电化学装置的制备过程为本领域技术人员所熟知的，本申请没有特别限制，只要能够实现本申请目的即可。例如电化学装置可以通过以下过程制造：在正极极片和负极极片之间放入隔膜，并根据需要将其卷绕或堆叠后放入壳体内，将电解液注入壳体并封口。此外，也可以根据需要将防过电流元件、导板等置于壳体中，从而防止电化学装置内部的压力上升、过充放电。The preparation process of an electrochemical device is well known to those skilled in the art, and there is no particular limitation in this application, as long as the purpose of this application can be achieved. For example, an electrochemical device can be manufactured through the following process: a separator is placed between the positive pole piece and the negative pole piece, and it is wound or stacked as required and put into the case, and the electrolyte is injected into the case and sealed. In addition, anti-overcurrent elements, guide plates, etc. can also be placed in the casing as needed, so as to prevent pressure rise and overcharge and discharge inside the electrochemical device.
本申请第三方面提供了一种电子装置，其包括本申请第二方面提供的电化学装置。该电子装置具有良好的高温安全性能。The third aspect of the present application provides an electronic device, which includes the electrochemical device provided in the second aspect of the present application. The electronic device has good high temperature safety performance.
本申请的电子装置没有特别限制，其可以包括但不限于：笔记本电脑、笔输入型计算机、移动电脑、电子书播放器、便携式电话、便携式传真机、便携式复印机、便携式打印机、头戴式立体声耳机、录像机、液晶电视、手提式清洁器、便携CD机、迷你光盘、收发机、电子记事本、计算器、存储卡、便携式录音机、收音机、备用电源、电机、汽车、摩托车、助力自行车、自行车、照明器具、玩具、游戏机、钟表、电动工具、闪光灯、照相机、家庭用大型蓄电池和锂离子电容器等。The electronic devices of the present application are not particularly limited, and may include, but are not limited to: notebook computers, pen-input computers, mobile computers, e-book players, portable phones, portable fax machines, portable copiers, portable printers, head-mounted stereo earphones , VCR, LCD TV, Portable Cleaner, Portable CD Player, Mini Disc, Transceiver, Electronic Notepad, Calculator, Memory Card, Portable Recorder, Radio, Backup Power, Motor, Automobile, Motorcycle, Assisted Bicycle, Bicycle , Lighting appliances, toys, game consoles, clocks, electric tools, flashlights, cameras, large household batteries and lithium-ion capacitors, etc.
本申请提供了一种胶纸、包含该胶纸的电化学装置和电子装置，胶纸包括粘结层、绝缘耐热层以及位于粘结层和绝缘耐热层之间的膨胀层，该膨胀层包括间规聚苯乙烯。该胶纸具有良好的膨胀率及耐高温性能。将该胶纸在应用于电化学装置中，胶纸的膨胀率可达150％至300％，电化学装置中电解液含量减少时，该胶纸仍能保持膨胀率，有效固定电极组件。且胶纸在高温下形状稳定不易变形，能够有效保持胶纸对电极组件的束缚效果。由此，本申请的电化学装置具有良好的高温安全性能。本申请的电子装置包括本申请的电化学装置，因此，该电子装置也具有良好的高温安全性能。The application provides an adhesive paper, an electrochemical device and an electronic device containing the adhesive paper. The adhesive paper includes an adhesive layer, an insulating heat-resistant layer, and an expansion layer located between the adhesive layer and the insulating heat-resistant layer. The layer comprises syndiotactic polystyrene. The gummed paper has good expansion rate and high temperature resistance. When the adhesive paper is applied to an electrochemical device, the expansion rate of the adhesive paper can reach 150% to 300%, and when the electrolyte solution content in the electrochemical device decreases, the adhesive paper can still maintain the expansion rate and effectively fix the electrode assembly. Moreover, the shape of the adhesive tape is stable and not easily deformed at high temperature, and the binding effect of the adhesive tape on the electrode assembly can be effectively maintained. Therefore, the electrochemical device of the present application has good high-temperature safety performance. The electronic device of the present application includes the electrochemical device of the present application, therefore, the electronic device also has good high-temperature safety performance.
附图说明Description of drawings
为了更清楚地说明本申请实施例和现有技术的技术方案，下面对实施例和现有技术 中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本申请的一些实施例。In order to more clearly illustrate the technical solutions of the embodiments of the present application and the prior art, the following briefly introduces the accompanying drawings required in the embodiments and the prior art. Obviously, the accompanying drawings in the following description are only the present invention. Some examples of applications.
图1为本申请一些实施例的胶纸的结构示意图；Fig. 1 is the structural representation of the gummed paper of some embodiments of the present application;
图2为本申请一些实施例的胶纸在电化学装置中的作用原理示意图；Fig. 2 is a schematic diagram of the action principle of gummed paper in electrochemical devices in some embodiments of the present application;
图3为本申请一些实施例的胶纸中的间规聚苯乙烯在电解液中的作用原理示意图；Fig. 3 is a schematic diagram of the principle of action of syndiotactic polystyrene in the gummed paper of some embodiments of the present application in the electrolyte;
图4为本申请一些实施例的电化学装置的结构示意图；FIG. 4 is a schematic structural diagram of an electrochemical device in some embodiments of the present application;
图5为本申请另一些实施例的电化学装置的结构示意图。Fig. 5 is a schematic structural diagram of electrochemical devices according to other embodiments of the present application.
附图标记：10.电极组件；20.胶纸；21.粘结层；22.膨胀层；23.绝缘耐热层；30.壳体。Reference signs: 10. Electrode assembly; 20. Adhesive tape; 21. Adhesive layer; 22. Expansion layer; 23. Insulation and heat-resistant layer; 30. Shell.
具体实施方式Detailed ways
为使本申请的目的、技术方案及优点更加清楚明白，以下参照附图和实施例，对本申请进一步详细说明。显然，所描述的实施例仅仅是本申请一部分实施例，而不是全部的实施例。基于本申请中的实施例，本领域普通技术人员所获得的所有其他技术方案，都属于本申请保护的范围。In order to make the purpose, technical solution and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. Apparently, the described embodiments are only some of the embodiments of this application, not all of them. All other technical solutions obtained by persons of ordinary skill in the art based on the embodiments in this application belong to the protection scope of this application.
需要说明的是，本申请的具体实施方式中，以锂离子电池作为电化学装置的例子来解释本申请，但是本申请的电化学装置并不仅限于锂离子电池。It should be noted that, in the specific embodiments of the present application, a lithium-ion battery is used as an example of an electrochemical device to explain the present application, but the electrochemical device of the present application is not limited to the lithium-ion battery.
图1示出了本申请一些实施例的胶纸的结构示意图。其中，胶纸20包括粘结层21、膨胀层22和绝缘耐热层23，膨胀层22位于粘结层21和绝缘耐热层23之间，设置于电化学装置中的胶纸20，其粘结层21与电极组件内表面和/或外表面粘结，绝缘耐热层23与壳体相邻。Fig. 1 shows a schematic structural view of adhesive tapes according to some embodiments of the present application. Wherein, adhesive tape 20 comprises adhesive layer 21, expansion layer 22 and insulating heat-resistant layer 23, and expansion layer 22 is positioned between adhesive layer 21 and insulating heat-resistant layer 23, is arranged on adhesive tape 20 in electrochemical device, its The bonding layer 21 is bonded to the inner surface and/or the outer surface of the electrode assembly, and the insulating heat-resistant layer 23 is adjacent to the casing.
图2示出了本申请一些实施例的胶纸在电化学装置中的作用原理示意图。其中，图2中的(a)为电极组件10、图2中的(b)为在电极组件10卷绕贴胶纸20的原理示意图、图2中的(c)为胶纸20粘贴于电极组件10后的结构示意图、图2中的(d)为(c)中的粘贴胶纸20后的电极组件10装入壳体30后的结构示意图、图2中的(e)为电化学装置中注入电解液后胶纸20发生膨胀的结构示意图。如图2所示，将胶纸20粘贴于电极组件10外表面，在电化学装置中注入电解液后，胶纸20发生收缩膨胀，厚度方向x上胶纸20的厚度增加，纵向z上胶纸20的高度缩小，胶纸20的体积不变。胶纸20在厚度方向x上发生膨胀后，填补了电极组件10与壳体30之间的间隙。在本申请的另一些实施例中， 电极组件10为卷绕结构时，胶纸20也可以设置于电极组件10内表面上。Fig. 2 shows a schematic diagram of the working principle of adhesive tapes in some embodiments of the present application in an electrochemical device. Among them, (a) in FIG. 2 is the electrode assembly 10, (b) in FIG. 2 is a schematic diagram of the principle of winding the adhesive paper 20 on the electrode assembly 10, and (c) in FIG. 2 is that the adhesive paper 20 is pasted on the electrode. Schematic diagram of the structure of the assembly 10, (d) in Figure 2 is a schematic structural diagram of the electrode assembly 10 after the adhesive tape 20 is pasted in (c) and loaded into the housing 30, (e) in Figure 2 is an electrochemical device Schematic diagram of the structure of the gummed paper 20 expanding after the electrolyte solution is injected into it. As shown in Figure 2, the adhesive paper 20 is pasted on the outer surface of the electrode assembly 10. After the electrolyte is injected into the electrochemical device, the adhesive paper 20 shrinks and expands, the thickness of the adhesive paper 20 in the thickness direction x increases, and the longitudinal direction z is glued. The height of the paper 20 shrinks, and the volume of the gummed paper 20 remains unchanged. After the adhesive paper 20 expands in the thickness direction x, the gap between the electrode assembly 10 and the casing 30 is filled. In some other embodiments of the present application, when the electrode assembly 10 has a wound structure, the adhesive paper 20 may also be disposed on the inner surface of the electrode assembly 10 .
图3为本申请一些实施例的胶纸中的间规聚苯乙烯在电解液中的作用原理示意图。其中，图3中的(f)为间规聚苯乙烯在电解液中浸泡前的结构示意图、图3中的(g)为间规聚苯乙烯在电解液中浸泡后的结构示意图。如图3所示，间规聚苯乙烯浸泡于电解液后，分子取向应力释放，分子链收缩，体积不变面积减小，厚度增加。Fig. 3 is a schematic diagram of the working principle of syndiotactic polystyrene in the gummed paper of some embodiments of the present application in the electrolyte. Among them, (f) in FIG. 3 is a schematic structural diagram of syndiotactic polystyrene before soaking in the electrolyte, and (g) in FIG. 3 is a schematic structural diagram of syndiotactic polystyrene after soaking in the electrolyte. As shown in Figure 3, after the syndiotactic polystyrene is soaked in the electrolyte, the molecular orientation stress is released, the molecular chain shrinks, the volume constant area decreases, and the thickness increases.
图4为本申请一些实施例的电化学装置的结构示意图。其中，图4中的(h)为电化学装置的剖面结构示意图、图4中的(i)为电化学装置的俯视图。如图4所示，胶纸20设置于电极组件10外表面A与壳体30之间，胶纸20粘结在电极组件10外表面A上。Fig. 4 is a schematic structural diagram of an electrochemical device according to some embodiments of the present application. Wherein, (h) in FIG. 4 is a schematic cross-sectional structure diagram of the electrochemical device, and (i) in FIG. 4 is a top view of the electrochemical device. As shown in FIG. 4 , the adhesive paper 20 is disposed between the outer surface A of the electrode assembly 10 and the casing 30 , and the adhesive paper 20 is bonded on the outer surface A of the electrode assembly 10 .
图5为本申请另一些实施例的电化学装置的结构示意图。其中，图5中的(j)为电化学装置的剖面结构示意图、图5中的(k)为电化学装置的俯视图。如图5所示，胶纸20设置于电极组件10外表面A与壳体30之间，胶纸20粘结在电极组件10外表面A上；并且，胶纸20设置于电极组件10内表面B上。Fig. 5 is a schematic structural diagram of electrochemical devices according to other embodiments of the present application. Wherein, (j) in FIG. 5 is a schematic cross-sectional structure diagram of the electrochemical device, and (k) in FIG. 5 is a top view of the electrochemical device. As shown in Figure 5, the adhesive paper 20 is arranged between the outer surface A of the electrode assembly 10 and the casing 30, and the adhesive paper 20 is bonded on the outer surface A of the electrode assembly 10; and the adhesive paper 20 is arranged on the inner surface of the electrode assembly 10 on B.
实施例Example
以下，举出实施例及对比例来对本申请的实施方式进行更具体地说明。各种的试验及评价按照下述的方法进行。另外，只要无特别说明，“份”、“％”为质量基准。Hereinafter, the embodiment of the present application will be described more specifically with reference to examples and comparative examples. Various tests and evaluations were performed according to the following methods. In addition, unless otherwise specified, "part" and "%" are based on mass.
测试方法和设备：Test method and equipment:
膨胀率的测试：Expansion test:
将胶纸贴合在50μm离型膜或离型纸上，用2kg橡胶压辊来回各3次，要求平整无褶皱，剪取规格宽×长＝20mm×100mm，浸泡在电解液中，常温浸泡电解液12h或85℃浸泡4h后查看膨胀情况，用万分尺测量胶纸膨胀后的厚度。Lay the adhesive tape on the 50μm release film or release paper, and use a 2kg rubber roller to go back and forth 3 times each. Check the expansion after soaking in the electrolyte for 12 hours or 85°C for 4 hours, and use a micrometer to measure the thickness of the expanded adhesive tape.
膨胀率＝膨胀后厚度/膨胀前厚度×100％。Expansion rate=thickness after expansion/thickness before expansion×100%.
耐高温效果测试：High temperature resistance effect test:
将胶纸置于80℃烘箱1h后取出，观察外观。Place the gummed paper in an oven at 80°C for 1 hour, take it out, and observe the appearance.
滚筒测试：Roller test:
将锂离子电池在25℃环境下静置60min后测试电压、内阻、容量后，将电池装入专用夹具中，设置滚筒高度为1m，滚筒与电池接触的面为金属接触面，5min/圈，共滚动 500圈，每100圈测试记录电压、内阻，检查外观并拍照。Put the lithium-ion battery at 25°C for 60 minutes, test the voltage, internal resistance, and capacity, then put the battery into a special fixture, set the height of the roller to 1m, and the contact surface between the roller and the battery is the metal contact surface, 5min/cycle , a total of 500 laps, every 100 laps test record voltage, internal resistance, check the appearance and take pictures.
跌落测试：Drop test:
将锂离子电池在25℃环境下静置60min后测试电压、内阻、容量后，将电池装入专用夹具中，采用专用跌落设备自由跌落，电池放置位置距离地面1.9m，自由跌落300次，每跌落100次测量记录电压、内阻，检查外观并拍照。Put the lithium-ion battery at 25°C for 60 minutes, test the voltage, internal resistance, and capacity, then put the battery into a special fixture, and use a special drop device to drop it freely. Measure and record the voltage and internal resistance every 100 drops, check the appearance and take pictures.
<负极极片的制备><Preparation of Negative Electrode Sheet>
将负极活性材料石墨粉末、导电剂导电炭黑(Super P)、粘结剂丁苯橡胶(SBR)按照重量比96:1.5:2.5进行混合，然后加入去离子水作为溶剂，调配成为固含量为70％的浆料，并搅拌均匀。将浆料均匀涂覆在厚度为8μm的负极集流体铜箔的一个表面上，110℃条件下烘干，得到涂层厚度为130μm的单面涂布负极活性材料的负极极片。以上步骤完成后，即已完成负极极片的单面涂布。之后，在该负极极片的另一个表面上重复以上步骤，即得到双面涂布负极活性材料的负极极片。涂布完成后，将负极极片裁切待用。Negative electrode active material graphite powder, conductive agent conductive carbon black (Super P), and binder styrene-butadiene rubber (SBR) are mixed according to the weight ratio of 96:1.5:2.5, and then deionized water is added as a solvent to prepare a solid content of 70% of the slurry and stir well. The slurry was uniformly coated on one surface of the negative electrode current collector copper foil with a thickness of 8 μm, and dried at 110° C. to obtain a negative electrode sheet with a coating thickness of 130 μm coated with negative active material on one side. After the above steps are completed, the single-side coating of the negative electrode sheet has been completed. Afterwards, the above steps are repeated on the other surface of the negative electrode sheet to obtain a negative electrode sheet coated with negative active materials on both sides. After the coating is completed, the negative electrode sheet is cut for use.
<正极极片的制备><Preparation of positive electrode sheet>
将正极活性材料钴酸锂(LiCoO 2)、导电剂纳米导电炭黑、粘结剂聚偏二氟乙烯(PVDF)按照重量比97.5:1.0:1.5进行混合，加入N-甲基吡咯烷酮(NMP)作为溶剂，调配成为固含量为75％的浆料，并搅拌均匀。将浆料均匀涂覆在厚度为9μm的正极集流体铝箔的一个表面上，90℃条件下烘干，得到涂层厚度为110μm的正极极片。以上步骤完成后，即完成正极极片的单面涂布。之后，在该正极极片的另一个表面上重复以上步骤，即得到双面涂布正极活性材料的正极极片。涂布完成后，将正极极片裁切待用。 Mix the positive active material lithium cobaltate (LiCoO 2 ), the conductive agent nano-conductive carbon black, and the binder polyvinylidene fluoride (PVDF) according to a weight ratio of 97.5:1.0:1.5, and add N-methylpyrrolidone (NMP) As a solvent, prepare a slurry with a solid content of 75%, and stir evenly. The slurry was uniformly coated on one surface of a positive electrode current collector aluminum foil with a thickness of 9 μm, and dried at 90° C. to obtain a positive electrode sheet with a coating thickness of 110 μm. After the above steps are completed, the single-side coating of the positive electrode sheet is completed. Afterwards, the above steps are repeated on the other surface of the positive electrode sheet to obtain a positive electrode sheet coated with positive active materials on both sides. After the coating is completed, the positive electrode sheet is cut for use.
<电解液的制备><Preparation of Electrolyte Solution>
在干燥氩气气氛中，将有机溶剂碳酸乙烯酯(EC)、碳酸甲乙酯(EMC)和碳酸二乙酯(DEC)以质量比30:50:20混合得到有机溶液，然后向有机溶剂中加入锂盐六氟磷酸锂溶解并混合均匀，得到锂盐的浓度为1.15mol/L的电解液。In a dry argon atmosphere, the organic solvent ethylene carbonate (EC), ethyl methyl carbonate (EMC) and diethyl carbonate (DEC) were mixed with a mass ratio of 30:50:20 to obtain an organic solution, and then added to the organic solvent Add lithium salt lithium hexafluorophosphate to dissolve and mix evenly to obtain an electrolyte solution with a lithium salt concentration of 1.15 mol/L.
<隔膜的制备><Preparation of separator>
将氧化铝与聚偏氟乙烯依照质量比90:10混合并将其溶入到去离子水中以形成固含量为50％的陶瓷浆料。随后采用微凹涂布法将陶瓷浆料均匀涂布到多孔基材(聚乙烯，厚度7μm，平均孔径为0.073μm，孔隙率为26％)的其中一面上，经过干燥处理以获得陶 瓷涂层与多孔基材的双层结构，陶瓷涂层的厚度为50μm。Aluminum oxide and polyvinylidene fluoride were mixed according to a mass ratio of 90:10 and dissolved in deionized water to form a ceramic slurry with a solid content of 50%. Subsequently, the ceramic slurry was uniformly coated on one side of the porous substrate (polyethylene, thickness 7 μm, average pore diameter 0.073 μm, porosity 26%) by micro-recess coating method, and dried to obtain a ceramic coating The thickness of the ceramic coating is 50 μm with the double-layer structure of the porous substrate.
将聚偏二氟乙烯(PVDF)与聚丙烯酸酯依照质量比96:4混合并将其溶入到去离子水中以形成固含量为50％的聚合物浆料。随后采用微凹涂布法将聚合物浆料均匀涂布到上述陶瓷涂层与多孔基材双层结构的两个表面上，经过干燥处理以获得隔膜，其中聚合物浆料形成的单层涂层厚度为2μm。Polyvinylidene fluoride (PVDF) and polyacrylate were mixed in a mass ratio of 96:4 and dissolved in deionized water to form a polymer slurry with a solid content of 50%. Subsequently, the polymer slurry is uniformly coated on the two surfaces of the above-mentioned ceramic coating layer and the porous substrate double-layer structure by a dimple coating method, and is dried to obtain a separator, wherein the single-layer coating formed by the polymer slurry The layer thickness was 2 μm.
<胶纸的制备><Preparation of Adhesive Paper>
(1)将间规聚苯乙烯与第一弹性体、第二弹性体、填料和固化剂按照表1中的质量比例混合，其中EVA、SEBS、氨基树脂和钛白粉的质量比例和种类如表1所示，经处理后得到间规聚苯乙烯薄膜，将间规聚苯乙烯薄膜进行双向定向拉伸后，在180℃下进行热处理，得到膨胀层，膨胀层的厚度如表1所示；(1) Syndiotactic polystyrene is mixed with the first elastomer, the second elastomer, filler and curing agent according to the mass ratio in Table 1, wherein the mass ratio and type of EVA, SEBS, amino resin and titanium dioxide are as shown in the table As shown in 1, the syndiotactic polystyrene film is obtained after treatment, and after the syndiotactic polystyrene film is bidirectionally stretched, heat treatment is carried out at 180 ° C to obtain an expansion layer. The thickness of the expansion layer is shown in Table 1;
(2)在膨胀层的一面涂布粘结层的材料，得到粘结层，其中，粘结层的材料和厚度如表1所示；(2) one side of the expansion layer coats the material of the bonding layer to obtain the bonding layer, wherein the material and thickness of the bonding layer are as shown in Table 1;
(3)在膨胀层的另一面热压复合绝缘耐热层的材料，得到绝缘耐热层，其中，绝缘耐热层的材料和厚度如表1所示；即得到胶纸。(3) On the other side of the expansion layer, thermally press and composite the material of the insulating and heat-resistant layer to obtain the insulating and heat-resistant layer, wherein the material and thickness of the insulating and heat-resistant layer are as shown in Table 1; namely, to obtain the gummed paper.
<锂离子电池的制备><Preparation of lithium ion battery>
将上述制备的正极极片、隔膜、负极极片按顺序叠好，使隔膜处于正负极中间起到隔离的作用，并卷绕/叠片得到卷绕结构/叠片结构的电极组件。在电极组件的内表面和/或外表面贴上胶纸后装入铝塑膜壳体中，并在80℃下脱去水分，注入配好的电解液，经过真空封装、静置、化成、抽气等工序得到锂离子电池。The above prepared positive electrode sheet, separator, and negative electrode sheet are stacked in order, so that the separator is in the middle of the positive and negative electrodes to play the role of isolation, and wound/stacked to obtain an electrode assembly with a wound structure/laminated structure. Paste adhesive paper on the inner surface and/or outer surface of the electrode assembly and put it into an aluminum-plastic film case, remove moisture at 80°C, inject the prepared electrolyte, and vacuum seal, stand still, form, A lithium-ion battery is obtained through processes such as air extraction.
实施例1至实施例33、对比例1至对比例4中，<负极极片的制备>、<正极极片的制备>、<电解液的制备>、<隔膜的制备>、<胶纸的制备>及<锂离子电池的制备>的制备步骤均与上述各制备步骤相同，相关制备参数的变化如表1所示，相关效果参数的变化如表2所示：In Example 1 to Example 33, Comparative Example 1 to Comparative Example 4, <Preparation of Negative Electrode Sheet>, <Preparation of Positive Electrode Sheet>, <Preparation of Electrolyte>, <Preparation of Diaphragm>, <Preparation of Adhesive Paper The preparation steps of preparation> and <preparation of lithium-ion battery> are the same as the above-mentioned preparation steps, the changes of relevant preparation parameters are shown in Table 1, and the changes of relevant effect parameters are shown in Table 2:
表1Table 1
Figure PCTCN2021119013-appb-000001
Figure PCTCN2021119013-appb-000001
Figure PCTCN2021119013-appb-000002
Figure PCTCN2021119013-appb-000002
Figure PCTCN2021119013-appb-000003
Figure PCTCN2021119013-appb-000003
注：表1中的“\”表示无对应制备参数。Note: "\" in Table 1 indicates that there is no corresponding preparation parameter.
表2Table 2
Figure PCTCN2021119013-appb-000004
Figure PCTCN2021119013-appb-000004
Figure PCTCN2021119013-appb-000005
Figure PCTCN2021119013-appb-000005
Figure PCTCN2021119013-appb-000006
Figure PCTCN2021119013-appb-000006
从实施例1至实施例5和实施例32可以看出，锂离子电池的高温安全性能随着间规聚苯乙烯在膨胀层中的质量比例的变化而变化。选用间规聚苯乙烯的质量比例在本申请含量范围内的锂离子电池，其高温安全性能明显更好。It can be seen from Examples 1 to 5 and Example 32 that the high-temperature safety performance of lithium-ion batteries changes with the mass ratio of syndiotactic polystyrene in the expansion layer. The lithium-ion battery whose mass ratio of syndiotactic polystyrene is selected within the content range of the present application has significantly better high-temperature safety performance.
从实施例5和对比例1至对比例4可以看出，锂离子电池的高温安全性能随着膨胀层中成分的变化而变化。膨胀层中包括间规聚苯乙烯的锂离子电池，其高温安全性能明显更好。It can be seen from Example 5 and Comparative Examples 1 to 4 that the high-temperature safety performance of the lithium-ion battery changes with the composition of the expansion layer. Lithium-ion batteries that include syndiotactic polystyrene in the expansion layer have significantly better high-temperature safety performance.
第一弹性体、第二弹性体、填料和固化剂的种类和质量比例通常会对锂离子电池的高温安全性能产生影响。从实施例3、实施例6至实施例10、实施例14至实施例15可以看出，只要使得第一弹性体、第二弹性体、填料和固化剂的种类和质量比例在本申请含量范围内，就能够得到高温安全性能良好的锂离子电池。The types and mass ratios of the first elastomer, the second elastomer, the filler and the curing agent usually affect the high-temperature safety performance of the lithium-ion battery. As can be seen from Example 3, Example 6 to Example 10, and Example 14 to Example 15, as long as the types and mass ratios of the first elastomer, the second elastomer, filler and curing agent are within the content range of the application Within, a lithium-ion battery with good high-temperature safety performance can be obtained.
膨胀层的厚度通常也会对锂离子电池的高温安全性能产生影响。从实施例3、实施例10至实施例13可以看出，只要使得膨胀层的厚度在本申请含量范围内，就能得到高温安全性能良好的锂离子电池。The thickness of the expansion layer usually also affects the high-temperature safety performance of lithium-ion batteries. It can be seen from Example 3, Example 10 to Example 13 that as long as the thickness of the expansion layer is within the content range of the present application, a lithium-ion battery with good high-temperature safety performance can be obtained.
间规聚苯乙烯的重均分子量和熔点通常也会对锂离子电池的高温安全性能产生影响。从实施例3、实施例16至实施例18、实施例33可以看出，只要使得间规聚苯乙烯的重均分子量和熔点在本申请范围内，就能够得到高温安全性能良好的锂离子电池。The weight-average molecular weight and melting point of syndiotactic polystyrene usually also affect the high-temperature safety performance of lithium-ion batteries. From Example 3, Example 16 to Example 18, and Example 33, it can be seen that as long as the weight-average molecular weight and melting point of syndiotactic polystyrene are within the scope of this application, a lithium-ion battery with good high-temperature safety performance can be obtained .
粘结层的厚度和材料种类通常也会对锂离子电池的高温安全性能产生影响。从实施例3、实施例19至实施例22可以看出，只要使得粘结层的厚度和材料种类在本申请范围内，就能够得到高温安全性能良好的锂离子电池。The thickness and material type of the bonding layer also generally have an impact on the high-temperature safety performance of lithium-ion batteries. From Example 3, Example 19 to Example 22, it can be seen that as long as the thickness and material type of the adhesive layer are within the scope of the application, a lithium-ion battery with good high-temperature safety performance can be obtained.
绝缘耐热层的厚度和材料种类通常也会对锂离子电池的高温安全性能产生影响。从实施例3、实施例23至实施例26可以看出，只要使得绝缘耐热层的厚度和材料种类在本申请范围内，就能够得到高温安全性能良好的锂离子电池。The thickness and material type of the insulating heat-resistant layer usually also affect the high-temperature safety performance of lithium-ion batteries. From Example 3, Example 23 to Example 26, it can be seen that as long as the thickness and material type of the insulating heat-resistant layer are within the scope of this application, a lithium-ion battery with good high-temperature safety performance can be obtained.
胶纸的厚度和通常也会对锂离子电池的高温安全性能产生影响。从实施例3、实施例19至实施例20、实施例23至实施例24可以看出，只要使得胶纸的厚度在本申请范围内，就能够得到高温安全性能良好的锂离子电池。The thickness and temperature of the adhesive tape will also affect the high temperature safety performance of lithium-ion batteries. From Example 3, Example 19 to Example 20, and Example 23 to Example 24, it can be seen that as long as the thickness of the adhesive paper is within the scope of the application, a lithium-ion battery with good high-temperature safety performance can be obtained.
胶纸在电极组件外表面和/或内表面上的投影面积的占比通常也会对锂离子的高温安全性能产生影响。从实施例3、实施例27至实施例31可以看出，只要使得胶纸在电极组 件外表面和/或内表面上的投影面积的占比在本申请含量范围内，就能够得到高温安全性能良好的锂离子电池。The proportion of the projected area of the tape on the outer surface and/or inner surface of the electrode assembly usually also affects the high temperature safety performance of lithium ions. From Example 3, Example 27 to Example 31, it can be seen that as long as the proportion of the projected area of the adhesive tape on the outer surface and/or inner surface of the electrode assembly is within the content range of the application, high temperature safety performance can be obtained Good lithium-ion battery.
综合上述分析可知，本申请的胶纸具有良好的膨胀率，其在高温环境下长时间存储，不收缩不变形。将本申请的胶纸应用于电化学装置中，进行滚筒测试和跌落测试，电化学装置的失效率低。可以看出，通过使用本申请的胶纸，电化学装置的高温安全性能得到明显提升，具有良好的高温安全性能。Based on the above analysis, it can be seen that the gummed paper of the present application has a good expansion rate, and it will not shrink or deform when stored in a high temperature environment for a long time. The adhesive tape of the present application is applied to an electrochemical device, and the failure rate of the electrochemical device is low through a roller test and a drop test. It can be seen that by using the tape of the present application, the high-temperature safety performance of the electrochemical device is significantly improved, and has good high-temperature safety performance.
以上所述仅为本申请的较佳实施例，并不用以限制本申请，凡在本申请的精神和原则之内，所做的任何修改、等同替换、改进等，均应包含在本申请保护的范围之内。The above descriptions are only preferred embodiments of the application, and are not intended to limit the application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the application shall be included in the protection of the application. within the range.

Claims (14)

  1. 一种胶纸，包括粘结层、绝缘耐热层以及位于所述粘结层和所述绝缘耐热层之间的膨胀层；An adhesive paper, comprising an adhesive layer, an insulating and heat-resistant layer, and an expansion layer between the adhesive layer and the insulating and heat-resistant layer;
    其中，所述膨胀层包括间规聚苯乙烯。Wherein, the expansion layer includes syndiotactic polystyrene.
  2. 根据权利要求1所述的胶纸，其中，所述间规聚苯乙烯满足以下特征中的至少一者：The gummed paper according to claim 1, wherein the syndiotactic polystyrene satisfies at least one of the following characteristics:
    (a)所述间规聚苯乙烯的重均分子量为100000至700000；(a) the weight average molecular weight of the syndiotactic polystyrene is 100000 to 700000;
    (b)所述间规聚苯乙烯的熔点为255℃至275℃。(b) The syndiotactic polystyrene has a melting point of 255°C to 275°C.
  3. 根据权利要求1所述的胶纸，其中，将所述胶纸在电解液中于常温下浸泡12h，所述胶纸满足以下特征中的至少一者：The gummed paper according to claim 1, wherein the gummed paper is soaked in the electrolyte for 12h at normal temperature, and the gummed paper satisfies at least one of the following characteristics:
    (c)所述胶纸在厚度方向上的膨胀率为150％至300％；(c) the expansion rate of the gummed paper in the thickness direction is 150% to 300%;
    (d)所述胶纸在纵向上的收缩率为150％至300％；(d) the shrinkage rate of the gummed paper in the longitudinal direction is 150% to 300%;
    (e)所述胶纸膨胀后的体积变化率为0％。(e) The volume change rate of the gummed paper after swelling is 0%.
  4. 根据权利要求1所述的胶纸，其中，所述膨胀层还包括第一弹性体、第二弹性体、填料和固化剂；Adhesive tape according to claim 1, wherein, the expansion layer also includes a first elastomer, a second elastomer, a filler and a curing agent;
    所述第一弹性体包括乙烯-醋酸乙烯共聚物；The first elastomer comprises ethylene-vinyl acetate copolymer;
    所述第二弹性体包括苯乙烯-乙烯-丁烯-苯乙烯嵌段共聚物、聚丁二烯或聚异丁烯中的至少一种；The second elastomer includes at least one of styrene-ethylene-butylene-styrene block copolymer, polybutadiene, or polyisobutylene;
    所述填料包括钛白粉、滑石粉、白炭黑或碳酸钙中的至少一种；The filler includes at least one of titanium dioxide, talc, white carbon black or calcium carbonate;
    所述固化剂包括氨基树脂、环氧树脂或聚异氰酸酯中的至少一种。The curing agent includes at least one of amino resin, epoxy resin or polyisocyanate.
  5. 根据权利要求4所述的胶纸，其中，基于所述膨胀层的总质量，所述间规聚苯乙烯的质量比例为80％至100％，所述第一弹性体、第二弹性体、填料和固化剂质量之和的质量比例为0％至20％。The gummed paper according to claim 4, wherein, based on the total mass of the expansion layer, the mass ratio of the syndiotactic polystyrene is 80% to 100%, and the first elastomer, the second elastomer, The mass ratio of the sum of the filler and the curing agent is 0% to 20%.
  6. 根据权利要求5所述的胶纸，其中，所述第一弹性体、所述第二弹性体、所述填料和所述固化剂的质量比例为(20-40):(14-34):(31-36):(10-15)。Adhesive tape according to claim 5, wherein, the mass ratio of described first elastomer, described second elastomer, described filler and described curing agent is (20-40):(14-34): (31-36):(10-15).
  7. 根据权利要求1所述的胶纸，其中，所述胶纸的厚度为20μm至50μm。The gummed paper according to claim 1, wherein the thickness of the gummed paper is 20 μm to 50 μm.
  8. 根据权利要求1所述的胶纸，其中，所述胶纸满足以下特征中的至少一者：The adhesive tape according to claim 1, wherein the adhesive tape satisfies at least one of the following characteristics:
    (f)所述粘结层的厚度为5μm至10μm；(f) the thickness of the adhesive layer is 5 μm to 10 μm;
    (g)所述膨胀层的厚度为10μm至30μm；(g) the thickness of the expansion layer is 10 μm to 30 μm;
    (h)所述绝缘耐热层的厚度为5μm至10μm。(h) The thickness of the insulating heat-resistant layer is 5 μm to 10 μm.
  9. 根据权利要求1所述的胶纸，其中，所述粘结层的材料包括聚甲基丙烯酸甲酯、聚丙烯、热熔型苯乙烯-异戊二烯-苯乙烯(SIS)橡胶、聚乙烯或聚酰胺中的至少一种。The adhesive tape according to claim 1, wherein the material of the adhesive layer comprises polymethyl methacrylate, polypropylene, hot-melt styrene-isoprene-styrene (SIS) rubber, polyethylene or at least one of polyamides.
  10. 根据权利要求1所述的胶纸，其中，所述绝缘耐热层的材料包括聚对苯二甲酸乙二醇酯、聚酰亚胺或聚丙烯中的至少一种。The adhesive tape according to claim 1, wherein the material of the insulating and heat-resistant layer comprises at least one of polyethylene terephthalate, polyimide or polypropylene.
  11. 一种电化学装置，其包括电极组件、壳体和权利要求1至10中任一项所述的胶纸。An electrochemical device, comprising an electrode assembly, a casing and the adhesive paper according to any one of claims 1 to 10.
  12. 根据权利要求11所述的电化学装置，其中，所述胶纸设置于所述电极组件外表面与壳体之间，所述绝缘耐热层与所述壳体相邻；The electrochemical device according to claim 11, wherein the adhesive paper is arranged between the outer surface of the electrode assembly and the casing, and the insulating heat-resistant layer is adjacent to the casing;
    基于所述电极组件外表面的总面积，所述胶纸在所述电极组件外表面上的投影面积的占比为30％至100％。Based on the total area of the outer surface of the electrode assembly, the projected area of the adhesive paper on the outer surface of the electrode assembly accounts for 30% to 100%.
  13. 根据权利要求11或12所述的电化学装置，其中，所述电极组件为卷绕结构，所述胶纸设置于所述电极组件内表面上；The electrochemical device according to claim 11 or 12, wherein the electrode assembly is a wound structure, and the adhesive paper is arranged on the inner surface of the electrode assembly;
    基于所述电极组件内表面的总面积，所述胶纸在所述电极组件内表面上的投影面积的占比为30％至100％。Based on the total area of the inner surface of the electrode assembly, the projected area of the adhesive paper on the inner surface of the electrode assembly accounts for 30% to 100%.
  14. 一种电子装置，其包括权利要求11至13中任一项所述的电化学装置。An electronic device comprising the electrochemical device according to any one of claims 11 to 13.
PCT/CN2021/119013 2021-09-17 2021-09-17 Adhesive paper, electrochemical device comprising said adhesive paper, and electronic device WO2023039820A1 (en)

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