CN111883777A - Composite current collector, preparation method thereof and lithium battery pole piece - Google Patents

Composite current collector, preparation method thereof and lithium battery pole piece Download PDF

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Publication number
CN111883777A
CN111883777A CN202010738084.4A CN202010738084A CN111883777A CN 111883777 A CN111883777 A CN 111883777A CN 202010738084 A CN202010738084 A CN 202010738084A CN 111883777 A CN111883777 A CN 111883777A
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CN
China
Prior art keywords
current collector
composite current
polymer film
porous polymer
metal
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202010738084.4A
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Chinese (zh)
Inventor
王磊
曹勇
许涛
牛亚如
王晓燕
任明秀
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Gotion High Tech Co Ltd
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Gotion High Tech Co Ltd
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Publication date
Application filed by Gotion High Tech Co Ltd filed Critical Gotion High Tech Co Ltd
Priority to CN202010738084.4A priority Critical patent/CN111883777A/en
Publication of CN111883777A publication Critical patent/CN111883777A/en
Pending legal-status Critical Current

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    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00Electrodes
    • H01M4/02Electrodes composed of, or comprising, active material
    • H01M4/64Carriers or collectors
    • H01M4/66Selection of materials
    • H01M4/665Composites
    • H01M4/667Composites in the form of layers, e.g. coatings
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00Secondary cells; Manufacture thereof
    • H01M10/05Accumulators with non-aqueous electrolyte
    • H01M10/052Li-accumulators
    • H01M10/0525Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00Electrodes
    • H01M4/02Electrodes composed of, or comprising, active material
    • H01M4/04Processes of manufacture in general
    • H01M4/0402Methods of deposition of the material
    • H01M4/0404Methods of deposition of the material by coating on electrode collectors
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00Electrodes
    • H01M4/02Electrodes composed of, or comprising, active material
    • H01M4/13Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10Energy storage using batteries

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Materials Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Composite Materials (AREA)
  • Cell Electrode Carriers And Collectors (AREA)

Abstract

The invention discloses a composite current collector, which comprises: the porous polymer film comprises a metal coating attached to the surface of the porous polymer film and a conductive coating attached to the surface of the metal coating. The invention also discloses a preparation method of the composite current collector. The invention also discloses a lithium battery pole piece. The invention adopts the extremely thin porous polymer film, can improve the physical and chemical properties of the current collector, reduce the occurrence of broken belts, reduce the weight of the battery and improve the energy density of the battery; after the ultrathin porous polymer film is plated with metal, micropores on the surface of the ultrathin porous polymer film are filled with the metal, metal plating layers on two sides of the ultrathin porous polymer film are communicated, an electronic channel is increased, and internal resistance is effectively reduced, so that when a battery is prepared, metal tabs do not need to be additionally introduced at the tabs, the phenomenon of material leakage of electrode slurry during subsequent coating can be ensured, and the ultrathin porous polymer film can be better introduced into production.

Description

Composite current collector, preparation method thereof and lithium battery pole piece
Technical Field
The invention relates to the technical field of lithium batteries, in particular to a composite current collector, a preparation method thereof and a lithium battery pole piece.
Background
The lithium battery pole piece usually selects metal foil as a current collector, wherein the positive electrode selects aluminum foil, and the negative electrode selects copper foil. For higher energy density, this can be achieved by reducing the weight of the current collector, which requires us to use thinner metal foils or to use new composite current collectors. Due to the limitation of the production process, the current copper foil with the thickness less than 6 microns and the aluminum foil with the thickness less than 8 microns are difficult to produce in mass, and the reduction of the thickness of the metal foil inevitably causes the reduction of the physical and chemical properties. Another new type of composite current collector, which uses a polymer film as a substrate and is plated with metal on the surface, is receiving more and more attention. The composite current collector is smaller in weight and better in processability, and can solve the problem of belt breakage in the production process of the pole piece. However, the polymer film in the middle of the composite current collector has good insulation, so that electrons of metal layers on two sides cannot be conducted, the resistance of the current collector can be increased, the internal resistance of the pole piece and the battery can be increased, and the performance of the battery is further influenced.
The 201820356745.5 and 201810282703.6 patents improve these problems by introducing metal tabs that are welded to both side surfaces of the composite current collector. However, the metal tab and the composite current collector are foils made of two different materials, the welding effect of the metal tab and the composite current collector has great influence on the internal resistance of the pole piece and the battery, and the introduction of the metal tab can also increase the weight of the battery and reduce the energy density of the battery.
Disclosure of Invention
Based on the technical problems in the background art, the invention provides a composite current collector, a preparation method thereof and a lithium battery pole piece, which can improve the physical and chemical properties of the current collector, reduce the occurrence of broken strips, reduce the weight of a battery and improve the energy density of the battery; when the battery is prepared, no metal tab needs to be additionally introduced, the phenomenon of material leakage of electrode slurry during subsequent coating can be ensured, and the battery can be better introduced into production.
The invention provides a composite current collector, which comprises: the porous polymer film comprises a metal coating attached to the surface of the porous polymer film and a conductive coating attached to the surface of the metal coating.
Preferably, the thickness of the porous polymer film is 1-4 μm, the diameter of the micropores in the polymer film is 10-40 μm, and the center-to-center distance between the micropores is 30-100 μm.
Preferably, the material of the porous polymer film is one of polyethylene terephthalate, polypropylene, polyethylene, polyvinyl chloride or polyimide.
Preferably, the metal plating layer is an aluminum plating layer having a thickness of 0.5 to 2 μm or a copper plating layer having a thickness of 0.5 to 1.5 μm.
Preferably, the conductive coating is carbon black, graphite, carbon nanotubes or graphene, and the thickness of the conductive coating is 0.5-2 μm.
The invention also provides a preparation method of the composite current collector, which comprises the following steps: and (3) plating a metal coating on the surface of the porous polymer film after corona treatment or plasma cleaning treatment, and then coating a conductive coating on the surface of the metal coating to obtain the composite current collector.
The invention also provides a lithium battery pole piece, which comprises: the composite current collector comprises the composite current collector and active materials coated on the surfaces of the two sides of the composite current collector.
Preferably, when the metal coating in the composite current collector is an aluminum coating, the active material is a positive active material, and is selected from one of lithium manganate, lithium cobaltate, lithium iron phosphate, lithium nickel cobalt manganate or lithium nickel cobalt aluminate.
Preferably, when the metal coating in the composite current collector is a copper coating, the active material is a negative active material, and is selected from one of graphite, silicon carbon or lithium titanate.
Has the advantages that:
the invention adopts the extremely thin porous polymer film, can improve the physical and chemical properties of the current collector, reduce the occurrence of broken belts, reduce the weight of the battery and improve the energy density of the battery; after the ultrathin porous polymer film is plated with metal, micropores on the surface of the ultrathin porous polymer film are filled with the metal, metal plating layers on two sides of the ultrathin porous polymer film are communicated, an electronic channel is increased, and internal resistance is effectively reduced, so that when a pole piece is manufactured, a metal pole lug does not need to be additionally introduced at the pole lug, the phenomenon of material leakage of electrode slurry during coating can be ensured, and the ultrathin porous polymer film can be better introduced into production.
Detailed Description
The technical solution of the present invention will be described in detail below with reference to specific examples.
Example 1
A preparation method of a composite current collector comprises the following steps:
taking a porous polyethylene glycol terephthalate film with the thickness of 3 mu m, the diameter of micropores of 25 mu m and the center distance between the micropores of 60 mu m, and carrying out plasma cleaning to ensure that the surface of the film has enough adhesive force and is tightly combined with the metal coating;
then the degree of vacuum was adjusted to 10-4Pa, performing vacuum evaporation on the surface of the porous polyethylene glycol terephthalate film to form metal aluminum to obtain an aluminum plating layer with the thickness of 1 mu m;
and then coating a layer of carbon black with the thickness of 1 mu m on the surface of the aluminum plating layer to be used as a conductive coating so as to obtain the composite current collector.
Comparative example 1
A composite current collector, the method of making comprising:
s1, obtaining a composite film by the same method as the embodiment 1 except that the polyethylene terephthalate film does not contain micropores;
and S2, introducing a metal foil (Al foil is adopted as the metal foil in the comparative example) at the edge because the aluminum plating layers on the two sides of the composite film can not be conducted, and welding according to the structure of the metal foil, the composite film and the metal foil to obtain the composite current collector with two sides capable of being conducted.
The composite current collectors described in example 1 and comparative example 1 were taken, cut to a size of 40mm x 100mm, and the resistance of the composite current collector was measured at a distance of 90mm in the length direction of the opposite surfaces thereof, and the results are shown in table 1.
TABLE 1
Grouping Example 1 Comparative example 1
Internal resistance of 38.63mΩ 87.34mΩ
As can be seen from table 1, the resistance value of the composite current collector obtained in example 1 is much smaller than that of comparative example 1.
Example 2
A preparation method of a lithium battery positive pole piece comprises the following steps: taking the composite current collector described in the embodiment 1, coating positive electrode slurry containing a positive electrode active material on the surfaces of the two sides of the composite current collector (compared with the thickness of the composite current collector, the thickness of an active material layer is larger, so that the surface of the current collector is very flat after coating), then baking in an oven at 100 ℃ for 12 hours in vacuum, rolling, and then slitting, laser cutting or die cutting to obtain a positive electrode piece;
the preparation method of the positive electrode slurry comprises the following steps: adding a positive electrode active material (the positive electrode active material is nickel cobalt lithium manganate NCM622), a conductive agent CNTs and a binder PVDF into an organic solvent NMP according to the weight ratio of 97.8:1.1:1.1, and uniformly stirring to obtain positive electrode slurry;
when coating, the density of the two surfaces of the pole piece is 410g/m2The compacted density of the roll was 3.35g/cm3
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.

Claims (9)

1. A composite current collector, comprising: the porous polymer film comprises a metal coating attached to the surface of the porous polymer film and a conductive coating attached to the surface of the metal coating.
2. The composite current collector of claim 1, wherein the thickness of the porous polymer film is 1-4 μm, the diameter of the micropores in the polymer film is 10-40 μm, and the center-to-center distance between the micropores is 30-100 μm.
3. The composite current collector as claimed in claim 1 or 2, wherein the porous polymer film is made of one of polyethylene terephthalate, polypropylene, polyethylene, polyvinyl chloride or polyimide.
4. The composite current collector of any one of claims 1 to 3, wherein the metal plating layer is an aluminum plating layer or a copper plating layer, wherein the aluminum plating layer has a thickness of 0.5 to 2 μm and the copper plating layer has a thickness of 0.5 to 1.5 μm.
5. The composite current collector of any one of claims 1 to 4, wherein the conductive coating is carbon black, graphite, carbon nanotubes or graphene, and the thickness of the conductive coating is 0.5 to 2 μm.
6. A method for preparing a composite current collector as claimed in any one of claims 1 to 5, characterized in that it comprises the following steps: and (3) plating a metal coating on the surface of the porous polymer film after corona treatment or plasma cleaning treatment, and then coating a conductive coating on the surface of the metal coating to obtain the composite current collector.
7. A lithium battery pole piece, comprising: a composite current collector as claimed in any one of claims 1 to 5 and an active material coated on both side surfaces of the composite current collector.
8. The lithium battery pole piece of claim 7, wherein when the metal coating in the composite current collector is an aluminum coating, the active material is a positive active material selected from one of lithium manganate, lithium cobaltate, lithium iron phosphate, lithium nickel cobalt manganate, or lithium nickel cobalt aluminate.
9. The lithium battery pole piece of claim 7, wherein when the metal coating in the composite current collector is a copper coating, the active material is a negative active material selected from one of graphite, silicon carbon, or lithium titanate.
CN202010738084.4A 2020-07-28 2020-07-28 Composite current collector, preparation method thereof and lithium battery pole piece Pending CN111883777A (en)

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Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112751038A (en) * 2021-02-23 2021-05-04 蜻蜓实验室(深圳)有限公司 Composite current collector and lithium ion battery
CN112928281A (en) * 2021-03-23 2021-06-08 华中科技大学 Ear-free cylindrical battery and preparation method thereof
CN113036150A (en) * 2021-03-03 2021-06-25 珠海冠宇电池股份有限公司 Current collector, battery pole piece and current collector manufacturing method
CN113097493A (en) * 2021-03-31 2021-07-09 珠海冠宇电池股份有限公司 Preparation method of composite current collector and lithium ion battery
CN113488659A (en) * 2021-06-30 2021-10-08 浙江锋锂新能源科技有限公司 Negative current collector complex, preparation method thereof and lithium metal battery
WO2022104214A1 (en) * 2020-11-16 2022-05-19 Novelis Inc. Metal coatings over substrates and use for current collectors in lithium ion batteries
CN114843521A (en) * 2022-04-25 2022-08-02 江阴纳力新材料科技有限公司 Composite current collector and preparation method thereof, electrode plate and secondary battery
CN114883574A (en) * 2022-04-25 2022-08-09 江阴纳力新材料科技有限公司 Composite current collector and preparation method thereof, electrode plate and secondary battery
CN114899551A (en) * 2022-05-30 2022-08-12 安普瑞斯(无锡)有限公司 Composite membrane and lithium ion battery containing same
CN115094383A (en) * 2022-07-01 2022-09-23 江阴纳力新材料科技有限公司 Composite positive current collector preparation device and method based on evaporation
CN115896703A (en) * 2022-11-07 2023-04-04 江阴纳力新材料科技有限公司 Production device and production method for multilayer-structure current collector
WO2023202595A1 (en) * 2022-04-20 2023-10-26 江阴纳力新材料科技有限公司 Composite current collector having metal three-dimensional network structure, preparation method for composite current collector, and electrode plate and battery
WO2023216348A1 (en) * 2022-05-13 2023-11-16 扬州纳力新材料科技有限公司 High-thermal-conductivity current collector of secondary battery and preparation method therefor
WO2024011537A1 (en) * 2022-07-14 2024-01-18 扬州纳力新材料科技有限公司 Composite current collector, preparation method therefor and use thereof
WO2024152246A1 (en) * 2023-01-18 2024-07-25 宁德时代新能源科技股份有限公司 Current collector and preparation device thereof, electrode sheet, battery and electric device

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108336357A (en) * 2017-12-14 2018-07-27 合肥国轩高科动力能源有限公司 Ultra-light lithium ion battery current collector and preparation method thereof
CN108682788A (en) * 2018-04-02 2018-10-19 合肥国轩高科动力能源有限公司 Flexible lithium battery electrode
CN111020521A (en) * 2019-11-26 2020-04-17 浙江长宇新材料有限公司 Preparation method of metal-plated film for battery

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108336357A (en) * 2017-12-14 2018-07-27 合肥国轩高科动力能源有限公司 Ultra-light lithium ion battery current collector and preparation method thereof
CN108682788A (en) * 2018-04-02 2018-10-19 合肥国轩高科动力能源有限公司 Flexible lithium battery electrode
CN111020521A (en) * 2019-11-26 2020-04-17 浙江长宇新材料有限公司 Preparation method of metal-plated film for battery

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2022104214A1 (en) * 2020-11-16 2022-05-19 Novelis Inc. Metal coatings over substrates and use for current collectors in lithium ion batteries
CN112751038A (en) * 2021-02-23 2021-05-04 蜻蜓实验室(深圳)有限公司 Composite current collector and lithium ion battery
CN113036150A (en) * 2021-03-03 2021-06-25 珠海冠宇电池股份有限公司 Current collector, battery pole piece and current collector manufacturing method
CN112928281A (en) * 2021-03-23 2021-06-08 华中科技大学 Ear-free cylindrical battery and preparation method thereof
CN112928281B (en) * 2021-03-23 2022-07-05 华中科技大学 Ear-free cylindrical battery and preparation method thereof
CN113097493A (en) * 2021-03-31 2021-07-09 珠海冠宇电池股份有限公司 Preparation method of composite current collector and lithium ion battery
CN113488659A (en) * 2021-06-30 2021-10-08 浙江锋锂新能源科技有限公司 Negative current collector complex, preparation method thereof and lithium metal battery
CN113488659B (en) * 2021-06-30 2022-07-08 浙江锋锂新能源科技有限公司 Negative current collector complex, preparation method thereof and lithium metal battery
WO2023202595A1 (en) * 2022-04-20 2023-10-26 江阴纳力新材料科技有限公司 Composite current collector having metal three-dimensional network structure, preparation method for composite current collector, and electrode plate and battery
CN114883574B (en) * 2022-04-25 2023-11-03 江阴纳力新材料科技有限公司 Composite current collector, preparation method thereof, electrode plate and secondary battery
CN114843521B (en) * 2022-04-25 2023-10-24 江阴纳力新材料科技有限公司 Composite current collector, preparation method thereof, electrode plate and secondary battery
CN114883574A (en) * 2022-04-25 2022-08-09 江阴纳力新材料科技有限公司 Composite current collector and preparation method thereof, electrode plate and secondary battery
CN114843521A (en) * 2022-04-25 2022-08-02 江阴纳力新材料科技有限公司 Composite current collector and preparation method thereof, electrode plate and secondary battery
WO2023216348A1 (en) * 2022-05-13 2023-11-16 扬州纳力新材料科技有限公司 High-thermal-conductivity current collector of secondary battery and preparation method therefor
CN114899551A (en) * 2022-05-30 2022-08-12 安普瑞斯(无锡)有限公司 Composite membrane and lithium ion battery containing same
CN115094383A (en) * 2022-07-01 2022-09-23 江阴纳力新材料科技有限公司 Composite positive current collector preparation device and method based on evaporation
WO2024011537A1 (en) * 2022-07-14 2024-01-18 扬州纳力新材料科技有限公司 Composite current collector, preparation method therefor and use thereof
CN115896703A (en) * 2022-11-07 2023-04-04 江阴纳力新材料科技有限公司 Production device and production method for multilayer-structure current collector
CN115896703B (en) * 2022-11-07 2023-11-14 江阴纳力新材料科技有限公司 Production device and production method for multilayer structure current collector
WO2024152246A1 (en) * 2023-01-18 2024-07-25 宁德时代新能源科技股份有限公司 Current collector and preparation device thereof, electrode sheet, battery and electric device

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Application publication date: 20201103