WO2021244672A1 - 隔膜、隔膜卷、电芯以及动力锂电池 - Google Patents

隔膜、隔膜卷、电芯以及动力锂电池 Download PDF

Info

Publication number
WO2021244672A1
WO2021244672A1 PCT/CN2021/108715 CN2021108715W WO2021244672A1 WO 2021244672 A1 WO2021244672 A1 WO 2021244672A1 CN 2021108715 W CN2021108715 W CN 2021108715W WO 2021244672 A1 WO2021244672 A1 WO 2021244672A1
Authority
WO
WIPO (PCT)
Prior art keywords
base film
porous base
diaphragm
adhesive layer
battery
Prior art date
Application number
PCT/CN2021/108715
Other languages
English (en)
French (fr)
Inventor
平翔
华超
钟宝诚
叶小宝
杨雪梅
陈秀峰
Original Assignee
江苏星源新材料科技有限公司
深圳市星源材质科技股份有限公司
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by 江苏星源新材料科技有限公司, 深圳市星源材质科技股份有限公司 filed Critical 江苏星源新材料科技有限公司
Priority to US18/000,654 priority Critical patent/US20230198098A1/en
Publication of WO2021244672A1 publication Critical patent/WO2021244672A1/zh

Links

Images

Classifications

    • 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
    • H01M50/46—Separators, membranes or diaphragms characterised by their combination with electrodes
    • H01M50/461—Separators, membranes or diaphragms characterised by their combination with electrodes with adhesive layers between electrodes and separators
    • 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
    • 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
    • H01M10/0587—Construction or manufacture of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • 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
    • H01M50/403—Manufacturing processes of separators, membranes or diaphragms
    • 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
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • 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
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/411—Organic material
    • H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
    • 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
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/411—Organic material
    • H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
    • H01M50/417—Polyolefins
    • 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
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/411—Organic material
    • H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
    • H01M50/42—Acrylic resins
    • 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
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/431—Inorganic material
    • H01M50/434—Ceramics
    • 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
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/44—Fibrous material
    • 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
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/443—Particulate material
    • 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
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/446—Composite material consisting of a mixture of organic and inorganic materials
    • 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
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/449—Separators, membranes or diaphragms characterised by the material having a layered structure
    • 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
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/449—Separators, membranes or diaphragms characterised by the material having a layered structure
    • H01M50/451—Separators, membranes or diaphragms characterised by the material having a layered structure comprising layers of only organic material and layers containing inorganic material
    • 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
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/449—Separators, membranes or diaphragms characterised by the material having a layered structure
    • H01M50/457—Separators, membranes or diaphragms characterised by the material having a layered structure comprising three or more layers
    • 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
    • H01M50/46—Separators, membranes or diaphragms characterised by their combination with 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
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
    • 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
    • H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
    • H01M50/491—Porosity
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2220/00—Batteries for particular applications
    • H01M2220/20—Batteries in motive systems, e.g. vehicle, ship, plane
    • 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

  • This application relates to the field of lithium ion batteries, and specifically to a diaphragm, a diaphragm roll, a battery cell, and a power lithium battery.
  • Lithium battery science and industry need to solve a big problem.
  • the cells are assembled into modules, and then the modules are installed in the battery pack to form a three-level assembly mode of "cell-module-battery pack".
  • the design form of combining small single cells into modules is limited by the level of battery materials and battery engineering capabilities in the early stage of the industry, and it is difficult to produce large-capacity cells with good consistency in large quantities.
  • the improvement of engineering capabilities, the elimination of the volume and weight occupied by the modules, bypassing the modules, and directly forming battery packs with cells have become a trend in the development of power batteries, and the energy of lithium batteries is greatly improved through structural optimization. density.
  • the cells of power batteries are mainly divided into cylindrical, soft-packed and square batteries in terms of structural design. Without changing the current materials and electrochemical system, in order to increase the energy density of the system, modules are reduced or eliminated.
  • the main technical means is to increase the capacity of the single cell, which is reflected in the change of the size and shape of the single cell, including the length, width and thickness of the cell. Due to the change of battery size, especially the substantial increase in the width direction, it will bring serious technical challenges to the assembly and long-term stability of the battery cell structure. When the large-size power lithium battery is wound or laminated, the alignment accuracy and stability of its size are a difficult point in the assembly process.
  • the purpose of the embodiments of the present application is to provide a diaphragm, a diaphragm roll, a battery cell, and a power lithium battery.
  • the present application provides a diaphragm, which includes a porous base film and an adhesive layer;
  • the surface of the porous base film includes a blank area in the middle and coated areas at both ends;
  • the adhesive layer is coated on the coated areas at both ends.
  • the size of the coated area along the preset direction is between 2 mm and 15 mm; the size of the blank area along the preset direction is between 50 mm and 1200 mm.
  • the thickness of the adhesive layer is in the range of 0.5 ⁇ m to 4 ⁇ m.
  • the bonding layer is a continuous coating layer or a discontinuous coating layer.
  • the non-continuous coating layer includes a plurality of spaced strip coatings, dot coatings, block coatings or curved coatings.
  • the direction perpendicular to the preset direction is the MD direction
  • the discontinuous coating layer is a strip-shaped coating
  • the angle formed by the strip-shaped coating and the MD direction is between 10° and 170°, but Excluding 90°.
  • the bonding layer is a discontinuous coating layer, and the coverage of the bonding layer in the coating area is between 10% and 90%.
  • the coverage of the adhesive layer in the coating area is between 40% and 80%.
  • the raw material of the bonding layer includes organic matter
  • Organics are selected from polyacrylate, polyacrylic acid, polyacrylate, styrene butadiene rubber, epoxy resin, amino resin, polyamide, polyethyleneimine, polyvinylidene fluoride, polytetrafluoroethylene, polyvinylidene fluoride-hexafluoro At least one of propylene copolymer and polyvinylidene fluoride-tetrafluoroethylene copolymer; optionally, the raw material of the adhesive layer also includes at least one of sodium carboxymethyl cellulose and sodium alginate.
  • the organic matter accounts for 10-100% of the total weight of the adhesive layer.
  • the raw material of the bonding layer includes inorganic substances, and the inorganic substances are selected from one or more of aluminum oxide, titanium oxide, zinc oxide, calcium oxide, magnesium oxide, zirconium oxide, and boehmite.
  • the particle size D50 of the inorganic substance ranges from 0.1 to 2.0 ⁇ m.
  • the inorganic matter accounts for 0-90% of the total weight of the adhesive layer.
  • the porous base film is a single layer; the material of the porous base film is selected from one of polyethylene, polypropylene, polyethylene terephthalate, polyamide, polyimide, and PET non-woven fabric Or several; or
  • the porous base film is a multilayer; the porous base film is made of polyethylene and/or polypropylene with different molecular weights and different melt indexes.
  • the thickness of the porous base film is in the range of 5 ⁇ m to 30 ⁇ m.
  • the porosity of the porous base film is in the range of 20% to 70%.
  • the present application provides a diaphragm roll, which is formed by winding the above-mentioned diaphragm in a direction perpendicular to a preset direction.
  • This application provides a battery including the aforementioned diaphragm
  • a negative electrode sheet, the negative electrode sheet is arranged on one side of the separator, and both ends of the negative electrode sheet are bonded to the adhesive layer coated on the surface of the separator;
  • the positive electrode sheet, the positive electrode sheet is located on the other side of the separator, and the positive electrode sheet overlaps the blank area of the separator.
  • the present application provides a power lithium battery, which includes the aforementioned battery cell.
  • FIG. 1 is a schematic diagram of the first composite diaphragm provided by the embodiment of the present application.
  • Figure 2 is a schematic diagram of a second type of composite diaphragm provided by an embodiment of the present application.
  • FIG. 3 is a schematic diagram of a third type of composite diaphragm provided by an embodiment of the present application.
  • FIG. 4 is a schematic diagram of a fourth type of composite diaphragm provided by an embodiment of the present application.
  • Fig. 5 is a schematic diagram of a battery cell provided by an embodiment of the present application.
  • the embodiments of the present application provide a separator, which includes a porous base film and an adhesive layer;
  • the surface of the porous base film includes a blank area in the middle and coated areas at both ends;
  • the adhesive layer is coated on the coated areas at both ends.
  • the separator by coating the two ends of the porous base film with a bonding layer, can make the bonding layer come into contact with both ends of the negative electrode sheet inside the lithium battery cell during the assembly and molding process of the lithium battery cell. Adhesion, and the adhesive layers can also be bonded to each other. Therefore, the separator can make the position between the battery pole pieces fixed and compact, so that the battery pole pieces and the separator are integrated. Especially for large-size power lithium batteries, it can effectively ensure that the lithium battery can withstand sufficient tension, pressure and vibration during assembly, vibration testing and long-term cycling. The relative movement between the bodies leads to undesirable consequences such as low yield, micro short circuit, self-discharge, increased internal resistance, and loose or damaged welding tabs.
  • the porous base membrane is a single layer.
  • the material of the porous base film is selected from one or more of polyethylene, polypropylene, polyethylene terephthalate, polyamide, polyimide, and PET non-woven fabric.
  • the porous base film is a multilayer.
  • the porous base film is made of polyethylene or polypropylene with different molecular weights and different melt indexes.
  • the porous base film is a multilayer.
  • the porous base film is made of polyethylene and polypropylene with different molecular weights and different melt indexes.
  • the porous base film has three layers.
  • the thickness of the porous base film is in the range of 5 ⁇ m to 30 ⁇ m.
  • the thickness of the porous base film is in the range of 6 ⁇ m to 28 ⁇ m.
  • the thickness of the porous base film is in the range of 10 ⁇ m to 25 ⁇ m.
  • the thickness of the porous base film is 15 ⁇ m, 18 ⁇ m, or 20 ⁇ m.
  • the porosity of the porous base film is in the range of 20% to 70%.
  • the porosity of the porous base film is in the range of 25% to 65%.
  • the porosity of the porous base film is in the range of 30% to 60%.
  • the porosity of the porous base film is 35%, 40%, 45%, or 50%.
  • the raw material of the adhesive layer includes organic matter.
  • the organic material is selected from polyacrylate, polyacrylic acid, polyacrylate, styrene butadiene rubber, epoxy resin, amino resin, polyamide, polyethyleneimine, polyvinylidene fluoride, polytetrafluoroethylene, polyvinylidene fluoride At least one of ethylene-hexafluoropropylene copolymer and polyvinylidene fluoride-tetrafluoroethylene copolymer.
  • the raw material of the adhesive layer further includes at least one of sodium carboxymethyl cellulose and sodium alginate.
  • at least one of the foregoing organic substances is selected to be compounded with at least one of sodium carboxymethyl cellulose and sodium alginate to prepare the adhesive layer.
  • the organic matter accounts for 10-100% of the total weight of the adhesive layer.
  • the organic matter accounts for 15-95% of the total weight of the adhesive layer.
  • the organic matter accounts for 20-80% of the total weight of the adhesive layer in terms of weight percentage.
  • the bonding layer includes 100% organic matter.
  • the raw materials of the aforementioned adhesive layer include organic matter and inorganic matter.
  • inorganic substances By adding inorganic substances, the static electricity generated by the adhesive layer can be reduced to a certain extent, and some undesirable problems caused by static electricity during use can be improved. However, the excessive addition of inorganic substances will affect the adhesion of the adhesive layer. Relay play.
  • the inorganic matter accounts for 0-90% of the total weight of the adhesive layer.
  • the addition amount of the inorganic substance is within the above range, it can effectively improve the static electricity problem during use and ensure a good bonding effect.
  • the inorganic matter accounts for 5-85% of the total weight of the adhesive layer.
  • the inorganic matter accounts for 10-80% of the total weight of the adhesive layer.
  • the adhesive layer includes 20% inorganic matter and 80% organic matter; or the adhesive layer includes 50% inorganic matter and 50% organic matter.
  • the inorganic substance is selected from one or more of aluminum oxide, titanium oxide, zinc oxide, calcium oxide, magnesium oxide, zirconium oxide, and boehmite.
  • the particle size D50 of the inorganic substance ranges from 0.1 to 2.0 ⁇ m.
  • the particle size D50 of the inorganic substance ranges from 0.5 to 1.8 ⁇ m.
  • the particle size D50 of the inorganic substance ranges from 1 to 1.5 ⁇ m.
  • the particle size D50 of the inorganic substance is 0.8 ⁇ m, 1.2 ⁇ m, or 1.4 ⁇ m.
  • the size of the coated area along the preset direction is between 2mm and 15mm; the size of the blank area (width d2 in Figure 1) along the preset direction is between 50mm and 1200mm .
  • the size of the coated area along the preset direction is between 3 mm and 14 mm; the size of the blank area along the preset direction is between 100 mm and 1100 mm.
  • the size of the coated area along the preset direction is between 4 mm and 13 mm; the size of the blank area along the preset direction is between 500 mm and 1000 mm.
  • the size of the coated area along the preset direction is 5mm, 8mm or 10mm; the size of the blank area along the preset direction is 200mm, 400mm, 600mm or 800mm.
  • the adhesive layers of the coating areas at both ends are symmetrical and have the same size.
  • the thickness of the adhesive layer is 0.5 ⁇ m-4 ⁇ m.
  • the thickness of the adhesive layer is 1 ⁇ m to 3.5 ⁇ m.
  • the thickness of the adhesive layer is 1.5 ⁇ m to 3.0 ⁇ m.
  • the thickness of the adhesive layer is 2.0 ⁇ m, 2.5 ⁇ m, 2.6 ⁇ m, 2.8 ⁇ m, or 3.2 ⁇ m.
  • the bonding layer is a continuous coating layer or a discontinuous coating layer.
  • the discontinuous coating layer is coated at intervals along a predetermined direction.
  • the non-continuous coating layer includes a plurality of spaced strip coatings, dot coatings, bulk coatings or curved coatings. For example, a plurality of serpentine-shaped coatings are applied at intervals.
  • the direction perpendicular to the preset direction is the MD direction.
  • the angle ⁇ formed by the strip-shaped coating and the MD direction is between 10° and 170°, but not including 90°.
  • the angle formed by the strip-shaped coating and the MD direction is between 30° and 120°.
  • the adhesive layer is applied to the ends of the two surfaces of the diaphragm, when the two ends are thick and the middle is thin during the coating and winding, after the winding length reaches a certain length, it may cause excessive stress at the ends.
  • the end adopts a non-continuous structure coating, which can partially disperse the concentrated stress at the end, increase the winding length, thereby further improving the efficiency of the coating and use process, and reducing the manufacturing cost.
  • the coverage of the adhesive layer in the coating area is between 10% and 90%.
  • the coverage of the adhesive layer in the coating area is between 40% and 80%.
  • the coverage of the adhesive layer in the coating area is between 50% and 70%.
  • the coverage rate of the adhesive layer in the coating area is 55%, 60%, 65%, 75%, etc.
  • the coverage rate of the binding layer is too low, the polymer content is too small, and the binding force with the two ends of the negative electrode of the lithium battery is too low to effectively play a binding role. If the coverage is too high, the concentrated stress at the end cannot be well dispersed, and the effect of improving the winding length and use efficiency is not significant. Within the above coverage range, the concentrated stress at the end can be effectively dispersed, and the winding length and use efficiency can be improved effectively.
  • a diaphragm is provided.
  • the separator includes a porous base film 100 and an adhesive layer 200.
  • both surfaces of the porous base film 100 are coated with an adhesive layer 200.
  • the adhesive layer 200 is coated on both ends of the porous base film 100, and both surfaces are coated with the adhesive layer 200.
  • the middle area of the porous base film 100 is a blank area 101.
  • the adhesive layer 200 is applied in a continuous coating manner. In FIG. 1, the four adhesive layers 200 are all continuous pure adhesive layers, and the width of the blank area is 600 mm.
  • the adhesive layer 200 only contains organic matter, and the organic matter is selected from a composition of polyacrylate, sodium carboxymethyl cellulose, polyvinylidene fluoride, and polyvinylidene fluoride-hexafluoropropylene copolymer.
  • the thickness of the adhesive layer 200 is 2 um, and the value of its unilateral width is 10 mm.
  • the porous base film 100 is a three-layer polypropylene isolation film composed of different molecular weights and different melt indexes.
  • the aforementioned adhesive layer 200 can also be coated on only one surface of the porous base film 100.
  • a diaphragm is provided. It is basically the same as the separator provided in FIG. 1, except that the adhesive layer 201 is a continuous adhesive layer of a mixture of pure polymers and inorganic substances.
  • the proportion of polymers is 80% by weight, the proportion of inorganic substances is 20% by weight, and the width of the middle blank area 102 is 600 mm.
  • the porous base film 100 is a three-layer polypropylene/polyethylene/polypropylene isolation film composed of different molecular weights and different melt indexes.
  • the thickness of the adhesive layer 201 is 2 um, and the value of its single side width is 10 mm.
  • the organic matter in the bonding layer 201 is selected from the composition of polyacrylate, sodium carboxymethyl cellulose, polyvinylidene fluoride, and polyvinylidene fluoride-hexafluoropropylene copolymer, and the inorganic matter is selected from alumina, and its particle size is The diameter D50 is 0.6um.
  • a diaphragm is provided. It is basically the same as the diaphragm provided in FIG. 1, except that the adhesive layer 202 is a non-continuous point-shaped pure adhesive layer.
  • the coverage rate inside the coating area is 60%, and the width of the blank area 103 is 600 mm.
  • the material of the porous base film 100 is selected from single-layer polypropylene isolation films composed of different molecular weights and different melt indexes.
  • the thickness of the adhesive layer 202 is 1.7 um, and the value of its single side width is 15 mm.
  • the adhesive layer 202 only contains organic matter, and the organic matter is selected from a composition of polyacrylate, sodium carboxymethyl cellulose, polyvinylidene fluoride, and polyvinylidene fluoride-hexafluoropropylene copolymer.
  • a diaphragm is provided. It is basically the same as the diaphragm provided in FIG. 1, except that the adhesive layer 203 is a non-continuous strip-shaped pure adhesive layer.
  • the coverage rate inside the coating area is 60%
  • the angle ⁇ formed by the strip-shaped adhesive layer and the MD direction of the porous base film 100 is 45°
  • the width of the blank area 104 is 600 mm.
  • the material of the porous base film 100 is selected from three-layer polypropylene isolation films composed of different molecular weights and different melt indexes.
  • the thickness of the adhesive layer 203 is 2.3 um, and the value of its single side width is 7 mm.
  • the adhesive layer 203 only contains organic matter, and the organic matter is selected from a composition of polyacrylate, sodium carboxymethyl cellulose, polyvinylidene fluoride, and polyvinylidene fluoride-hexafluoropropylene copolymer.
  • the present application also provides a diaphragm roll, which is formed by winding the aforementioned diaphragm in a direction perpendicular to a preset direction.
  • the present application also provides a battery cell, including the aforementioned separator, negative electrode sheet, and positive electrode sheet.
  • the negative electrode sheet is arranged on one side of the separator, and both ends of the negative electrode sheet are bonded to the adhesive layer coated on the surface of the separator.
  • the positive electrode sheet is located on the other side of the separator, and the positive electrode sheet overlaps the blank area of the separator.
  • the adhesive layers at both ends of the separator play the role of bonding with the two ends of the negative pole pieces of the lithium battery and the bonding between the adhesive layers, so that the position between the battery pole pieces is fixed and compact, so that the battery pole pieces and the separator become a whole.
  • it ensures that the lithium battery can withstand sufficient tension, pressure and vibration during assembly, vibration testing, and long-term cycling, and avoids damage between the positive and negative plates of the battery, as well as between the battery cell and the casing.
  • the relative movement between the two leads to low yield, micro short circuit, self-discharge, increased internal resistance, and loose or damaged welding tabs.
  • the bonding layer since the bonding layer has no holes, it will affect the transmission efficiency of lithium ions and thereby affect the capacity of the positive electrode material.
  • the blank area between the two surfaces of the separator provided in the present application is attached to the positive pole piece, namely The adhesive layer does not contact the active material on the positive electrode sheet inside the lithium battery cell, so it will not affect the transmission efficiency of the battery.
  • the diaphragm does not cause the assembly of the lithium battery to be too complicated, and the process cost is low, and can greatly improve the stability of the inner cell of the battery, and ensure the long-term cycle stability of the lithium battery.
  • the cell can be used to manufacture large-size laminated batteries. 5, when the battery is assembled and formed, the positive pole piece is located on one side of the separator, and the positive pole piece is attached to the blank area of the separator (the size of the positive pole piece is smaller than the size of the separator), therefore, the positive pole piece is not It is in contact with the adhesive layer of the separator, so that it will not contact the active material on the positive pole piece, and will not affect the electrical performance of the battery.
  • the size of the negative pole piece and the separator are the same (it can be set slightly smaller than the separator if necessary).
  • the negative pole piece is located on the other side of the separator (under the separator, not shown in Figure 5).
  • the width d1 of the adhesive layer at both ends of the diaphragm is between 2 mm and 15 mm.
  • the adhesive layers at both ends of the separator firmly bond the separator and the negative pole piece together, so that the lithium battery can withstand sufficient tension, pressure and vibration during assembly, vibration testing, and long-term cycling, and avoid damage to the positive and negative poles of the battery.
  • the relative movement between the battery core and the shell may result in low yield, micro-short circuit, self-discharge, increased internal resistance, and loose or damaged welding tab positions.
  • the present application also provides a power lithium battery, which includes the aforementioned battery cell.
  • the power lithium battery is equipped with the above-mentioned battery cell, so that the large-size power lithium battery can withstand sufficient tension, pressure and vibration during the assembly, vibration test and long-term cycle of the lithium battery core, thereby improving long-term cycle performance and battery stability .
  • Preparation of the negative electrode Add graphite, conductive carbon black, thickener sodium carboxymethyl cellulose, and binder styrene butadiene rubber emulsion to deionized water at a mass ratio of 96:1:1:2, stir and disperse evenly in a mixer, Filter with a 150-mesh screen to obtain the desired negative electrode slurry, which is then coated, cold pressed, and slit to form a negative electrode sheet.
  • Preparation of the positive electrode Add lithium iron phosphate, conductive agent, and binder polyvinylidene fluoride to NMP at a mass ratio of 97:1:2, stir and disperse in a mixer, and filter with a 150-mesh screen. The required positive electrode slurry is then coated, cold pressed, and cut into positive electrode sheets.
  • Electrolyte preparation Ethylene carbonate EC, propylene carbonate PC and dimethyl carbonate DMC are prepared into a mixed solvent according to a volume ratio of 3:3:4, and then relevant additives and lithium hexafluorophosphate (LiPF6) are added to prepare a good mixture.
  • LiPF6 lithium hexafluorophosphate
  • the concentration of LiPF6 is 1M, and the electrolyte is obtained after stirring evenly.
  • Preparation of diaphragm add polyacrylate, sodium carboxymethyl cellulose, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer into deionized water at a mass ratio of 6:1:10:83, and stir in a mixer Disperse uniformly, filter with a 150-mesh screen to obtain the required slurry, and then coat the slurry on the two end surfaces of one surface of the isolation membrane by gravure coating, and dry to form a single-sided continuous pure bonding layer .
  • the base material is a three-layer polypropylene porous base film of 18 um, the thickness of the continuous pure bonding layer is 2 um, the width of one side is 10 mm, and the width of the blank area in the middle of the isolation film is 600 mm.
  • Battery assembly The above-mentioned negative pole piece, separator and positive pole piece are laminated into a battery core, packaged with an aluminum-plastic composite film, baked in a vacuum state to remove moisture, and then injected with a quantitative electrolyte.
  • the battery is formed and capacity tested to obtain a thick Lithium-ion batteries in square soft packaging with widths of 25mm, 65mm, and 610mm. Among them, the necessary test items are directly assembled into battery packs with batteries in a certain way.
  • the assembly process of the negative electrode, the positive electrode, the electrolyte, and the battery is the same as in Example 1, except that the separator is different.
  • Preparation of diaphragm add polyacrylate, sodium carboxymethyl cellulose, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer into deionized water at a mass ratio of 6:1:10:83, and stir in a mixer Disperse uniformly, filter with a 150-mesh screen to obtain the required slurry, and then coat the slurry on the two end surfaces of the front and back sides of the isolation membrane by gravure coating, and dry to form a continuous pure bonding layer .
  • the base material is a three-layer polypropylene porous base film of 18 um, the thickness of the continuous pure bonding layer is 2 um, the width of one side is 10 mm, and the width of the blank area in the middle of the isolation film is 600 mm.
  • the assembly process of the negative electrode, the positive electrode, the electrolyte, and the battery is the same as in Example 1, except that the separator is different.
  • Preparation of diaphragm Add polyacrylate, sodium carboxymethyl cellulose, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, and alumina into deionized water at a mass ratio of 6:1:5:68:20 , Stir and disperse uniformly in a mixer, filter with a 150-mesh screen to obtain the required slurry, and then coat the slurry on the two end surfaces of the front and back sides of the isolation membrane by gravure coating, and dry to form a continuous Type of bonding layer of pure polymer and inorganic compound.
  • the base material is a three-layer polypropylene/polyethylene/polypropylene porous base film of 18um, the thickness of the adhesive layer is 2um, the width of one side is 10mm, and the width of the blank area in the middle of the isolation film is 600mm.
  • the assembly process of the negative electrode, the positive electrode, the electrolyte, and the battery is the same as in Example 1, except that the separator is different.
  • Preparation of diaphragm add polyacrylate, sodium carboxymethyl cellulose, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer into deionized water at a mass ratio of 6:1:10:83, and stir in a mixer Disperse uniformly, filter with a 150-mesh screen to obtain the required slurry, and then coat the slurry on the two end surfaces of the front and back sides of the isolation film through an improved gravure roll in the engraving area, and dry to form a non-continuous type Point-like pure bonding layer, in which the coverage rate of the inside of the coating area is 60%.
  • the base material is a single-layer polypropylene porous base film of 18um.
  • the thickness of the non-continuous point-like pure bonding layer is 1.7um, the width of its single side is 15mm, and the width of the blank area in the middle of the isolation film is 600mm. .
  • the assembly process of the negative electrode, the positive electrode, the electrolyte, and the battery is the same as in Example 1, except that the separator is different.
  • Preparation of diaphragm add polyacrylate, sodium carboxymethyl cellulose, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer into deionized water at a mass ratio of 6:1:10:83, and stir in a mixer Disperse uniformly, filter with a 150-mesh screen to obtain the required slurry, and then coat the slurry on the two end surfaces of the front and back sides of the isolation film through an improved gravure roll in the engraving area, and dry to form a non-continuous type
  • the strip-shaped pure adhesive layer has a coverage rate of 60% in the coating film area, and the angle formed by the strip-shaped adhesive layer and the MD direction of the porous base film is 45°.
  • the base material is a three-layer polypropylene porous base film of 18um.
  • the thickness of the non-continuous strip-shaped pure adhesive layer is 2.3um, the width of its one side is 7mm, and the width of the blank area in the middle of the isolation film is 600mm. .
  • the assembly process of the negative electrode, the positive electrode, the electrolyte, and the battery is the same as in Example 1, except that the separator is different.
  • Diaphragm A three-layer polypropylene porous base film with a thickness of 18um is used as the diaphragm.
  • the assembly process of the negative electrode, the positive electrode, the electrolyte, and the battery is the same as in Example 1, except that the separator is different.
  • Preparation of diaphragm add polyacrylate, sodium carboxymethyl cellulose, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer into deionized water at a mass ratio of 6:1:10:83, and stir in a mixer Disperse uniformly, filter with a 150-mesh screen to obtain the required slurry, and then coat the slurry on the front and back surfaces of the isolation membrane by gravure coating, and dry to form a continuous type with full coverage on both surfaces Pure bonding layer.
  • the base material is a three-layer polypropylene porous base film of 18 um, and the thickness of the continuous pure bonding layer is 2 um.
  • Electrostatic test on the glued area of the diaphragm Use the SIMCO FMX-004 electrostatic field tester to test the electrostatic value of the glued area of each test sample. Repeat 5 times for each group of samples and calculate the average value.
  • the adhesion test between the glued area and the negative electrode of the lithium battery Cut 5 rectangular samples of 10mm*200mm in the coating area of the isolation film, and cut 5 rectangular samples of 15mm*220mm from the prepared negative electrode. , Take a piece of isolation film and negative electrode piece respectively, heat and press the glued isolation film and the negative electrode piece together under the compound conditions of 2.0Mpa, 90°C, 60s, and then fix one end of the negative electrode piece on the upper clamp of the universal tensile machine , The isolation film is fixed on the lower clamp of the tensile machine, and the adhesion between the negative electrode sheet and the glue isolation film is tested at a constant speed of 50mm/min. Each set of samples is repeated 5 times, and the average value is calculated.
  • Battery assembly yield statistics the process of preparing lithium-ion batteries from the isolation film is counted. Based on the requirements of the shipped products, the number of finished products assembled with 100 batteries is counted, and the yield rate is calculated.
  • Battery cycle performance test Take the lithium ion battery prepared by the isolation film as a sample, and perform a cycle test on the battery at a charge-discharge rate of 1C/1C under an environment of 25°C, and calculate the battery performance at the 1000th cycle of each group Discharge capacity retention rate.
  • Example 2 the isolating film is fully covered with polymer coating. Due to the presence of a large amount of polymer on the surface of the isolating film, the conductivity of lithium ions in the normal working state of the lithium battery is seriously affected, and the electrochemical impedance of the battery is increased. , which in turn leads to the degradation of long-term cycle performance.
  • coating was carried out on both sides. The adhesive area of the isolation film and the negative pole piece of the battery and the adhesive area had higher adhesion. However, because only one surface of the isolation film was coated in the adhesive area, Therefore, the fixing effect on the two ends of the long battery cell is not enough.
  • the isolation film has been coated with glue on both sides, but due to its special structure and surface static electricity, the winding length can only be 1000 meters, otherwise there will be excessive stress on the winding end surface. The local deformation seriously affects the use of the isolation film in the battery assembly process. At the same time, due to the high static electricity on the end surface, it is easy to absorb dust particles in the workshop and affect the flat spreading of the isolation film during the battery assembly process, which leads to the battery assembly. Although the yield rate has been greatly improved, it still cannot meet the requirements for product rate and manufacturing cost control in mass production.
  • Example 3 due to the addition of inorganic oxides in the polymer coating formula, a certain degree of adhesion between the coating area of the separator film and the negative electrode of the battery and the coating area is maintained.
  • the static electricity is greatly reduced, and the battery assembly yield can reach more than 99%, which greatly improves the production efficiency and reduces the cost.
  • the structure of the lithium battery cell is guaranteed under normal and extreme conditions. Stability, its capacity cycle retention rate and anti-vibration test pass rate is high.
  • the assembly of the lithium battery will not be too complicated, the process cost is low, and the stability of the internal cells of the battery can be greatly improved, and the long-term cycling stability of the lithium battery can be ensured.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Inorganic Chemistry (AREA)
  • Ceramic Engineering (AREA)
  • Composite Materials (AREA)
  • Cell Separators (AREA)

Abstract

本申请涉及锂离子电池领域，具体而言，涉及一种隔膜、隔膜卷、电芯以及动力锂电池。隔膜包括多孔基膜和粘结层；沿多孔基膜的预设方向，多孔基膜的表面包括中间空白区域和两端的涂覆区域；粘结层涂覆在两个涂覆区域。通过在多孔基膜表面的两端涂覆粘结层，能够在锂电池电芯组装和成型过程中，使得粘结层起到与锂电池电芯内部的负极片的两端接触并粘结，有效地保证锂电池在组装、振动测试以及长期循环过程中承受足够的张力、压力与震动，避免因电池正、负极片之间，电芯与壳体之间的相对运动，导致的成品率低、微短路、自放电、内阻升高以及焊接极耳位松动或破坏等不良后果。

Description

隔膜、隔膜卷、电芯以及动力锂电池
相关申请的交叉引用
本申请要求于2020年6月4日提交中国专利局的申请号为2020105035411、名称为“隔膜、隔膜卷、电芯以及动力锂电池”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请涉及锂离子电池领域，具体而言，涉及一种隔膜、隔膜卷、电芯以及动力锂电池。
背景技术
随着电动汽车的发展，对动力锂电池能量密度和安全性能的要求也越来越高，从锂电池技术原理的角度看，如何有效地同时提高这两个看似相互矛盾的重要性能是当前锂电池科学与工业界需要解决的一大难题。
在传统动力锂电池系统中，由电芯组装成为模组，再将模组安装在电池包里，形成“电芯-模组-电池包”的三级装配模式。其中，将单体小电芯组成模组的设计形式受到产业前期电池材料和电池工程能力的水平的限制，很难大批量地制成一致性良好的大容量电芯，随着材料学和电池工程能力的提升，取消模组所占用的体积和重量，绕开模组，直接用电芯组成电池包便成了一种动力电池发展的趋势，通过结构上的优化来大大提高锂电池的能量密度。有统计显示，采用这种技术设计的动力电池包，其空间利用率提升约20％，相关零部件减少约40％，电池生产效率提升约50％。这样，通过省去模组而省出体积和重量，可以用来增加电量，提高续航。由此可见，将电芯直接组成电池包的设计模式可以拥有更加精简的生产流程和更高的生产效率，也能大幅降低动力电池的制造成本，是提高动力电池整体技术的一种有效的工程解决方法。但在此种工程解决方法的背后，大量的结构设计以及工艺等多方面的技术难题亟待解决。
当前，动力电池的电芯从结构设计上主要分为圆柱、软包和方形电池，在不改变当前材料和电化学体系的前提下，为了实现系统能量密度的提升，减少模组或者取消模组，主要的技术手段就是增加单体电芯的容量，体现在单体电芯上就是其尺寸形态的改变，包括电芯的长度、宽度和厚度。由于电池尺寸的改变，特别是宽度方向尺寸的大幅提升，会给电芯结构的组装和长期使用稳定性带来严重的技术挑战。大尺寸动力锂电池在进行卷绕或叠片工艺时，其尺寸的对位精度和稳定性是组装工艺中的一个难点，此外，在动力电池包 的长期使用过程中，因为振动及内部局部共振的影响，电池正、负极片之间，电芯与壳体之间易于发生相对运动，焊接的极耳位容易松动或破坏，出现结构和性能不稳定的现象，从而导致在生产和使用过程中电池容易发生微短路、自放电、内阻升高等现象，引起电池生产的成品率和可靠性较低等问题。
发明内容
本申请实施例的目的在于提供一种隔膜、隔膜卷、电芯以及动力锂电池。
本申请提供一种隔膜，隔膜包括多孔基膜和粘结层；
沿多孔基膜的预设方向，多孔基膜的表面包括中间空白区域和两端的涂覆区域；
粘结层涂覆在两端的涂覆区域。
可选地，涂覆区域沿预设方向上的尺寸在2mm～15mm之间；空白区域沿预设方向上的尺寸在50mm～1200mm之间。
可选地，粘结层的厚度在0.5μm～4μm范围内。
可选地，粘结层为连续涂覆层或者非连续涂覆层。
可选地，沿预设方向，非连续涂覆层包括多个间隔的条状涂层、点状涂层、块状涂层或者弯曲状涂层。
可选地，垂直于预设方向的方向为MD方向，非连续涂覆层为条状涂层时，条状涂层与MD方向所形成的夹角介于10°～170°之间，但不包括90°。
可选地，粘结层为非连续涂覆层，粘结层在涂覆区域的覆盖率在10％～90％之间。
可选地，粘结层在涂覆区域的覆盖率在40％～80％之间。
可选地，粘结层的原料包括有机物；
有机物选自聚丙烯酸酯、聚丙烯酸、聚丙烯酸盐、丁苯橡胶、环氧树脂、氨基树脂、聚酰胺、聚乙烯亚胺、聚偏氟乙烯、聚四氟乙烯、聚偏氟乙烯-六氟丙烯共聚物、聚偏氟乙烯-四氟乙烯共聚物中的至少一种；可选地，粘结层的原料还包括羧甲基纤维素钠和海藻酸钠中的至少一种。
可选地，以重量百分比计，有机物占粘结层总重量的10～100％。
可选地，粘结层的原料包括无机物，无机物选自氧化铝、氧化钛、氧化锌、氧化钙、氧化镁、氧化锆、勃姆石中的一种或几种。
可选地，无机物的颗粒度D50的取值范围为0.1～2.0μm。
可选地，以重量百分比计，无机物占粘结层总重量的0～90％。
可选地，多孔基膜为单层；多孔基膜的材料选自聚乙烯、聚丙烯、聚对苯二甲酸乙二醇酯、聚酰胺、聚酰亚胺、PET无纺布中的一种或几种；或者
多孔基膜为多层；多孔基膜由不同分子量、不同熔融指数的聚乙烯和/或聚丙烯制成。
可选地，多孔基膜的厚度在5μm～30μm范围内。
可选地，多孔基膜的孔隙率在20％～70％范围内。
本申请提供一种隔膜卷，采用上述的隔膜沿垂直于预设方向收卷形成。
本申请提供一种电芯，包括前述的隔膜；
负极片，负极片设置在隔膜的一侧，且负极片的两端粘接于隔膜表面涂覆的粘结层上；以及
正极片，正极片位于隔膜的另一侧，且正极片与隔膜的空白区域叠合。
本申请提供一种动力锂电池，该动力锂电池包括前述的电芯。
附图说明
为了更清楚地说明本申请实施方式的技术方案，下面将对实施方式中所需要使用的附图作简单介绍，应当理解，以下附图仅示出了本申请的部分内容，因此不应被看作是对范围的限定，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他相关的附图。
图1是本申请实施方式提供的第一种复合隔膜的示意图；
图2是本申请实施方式提供的第二种复合隔膜的示意图；
图3是本申请实施方式提供的第三种复合隔膜的示意图；
图4是本申请实施方式提供的第四种复合隔膜的示意图；
图5是本申请实施方式提供的电池电芯的示意图。
附图标记：100-多孔基膜；200-粘结层；101-空白区域；201-粘结层；102-空白区域；202-粘结层；103-空白区域；203-粘结层；104-空白区域。
具体实施方式
为使本申请实施例的目的、技术方案和优点更加清楚，下面将结合本申请实施例中的附图，对本申请实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例是本申请一部分内容，而不是全部的内容。通常在此处附图中描述和示出的本申请实施例的组件可以以各种不同的配置来布置和设计。
因此，以下对在附图中提供的本申请的实施例的详细描述并非旨在限制要求保护的本申请的范围，而是仅仅表示本申请的一部分内容。基于本申请中的实施例，本领域普通技术人员在没有作出创造性劳动前提下所获得的所有其他实施例，都属于本申请保护的范围。
此外，术语“第一”、“第二”、“第三”等仅用于区分描述，而不能理解为指示或暗示相对重要性。
本申请实施方式提供一种隔膜，隔膜包括多孔基膜和粘结层；
沿多孔基膜的预设方向(图1中箭头方向)，多孔基膜的表面包括中间空白区域和两端的涂覆区域；
粘结层涂覆在两端的涂覆区域。
该隔膜，通过在多孔基膜表面的两端涂覆粘结层，能够在锂电池电芯组装和成型过程中，使得粘结层起到与锂电池电芯内部的负极片的两端接触并粘结，并且粘结层之间相互也能够粘结，因此，该隔膜能够使电池极片之间的位置固定而紧凑，从而使电池极片、隔膜成为一个整体。特别是对于大尺寸动力锂电池而言，能够有效地保证锂电池在组装、振动测试以及长期循环过程中承受足够的张力、压力与震动，避免因电池正、负极片之间，电芯与壳体之间的相对运动，导致的成品率低、微短路、自放电、内阻升高以及焊接极耳位松动或破坏等不良后果。
可选地，多孔基膜为单层。可选地，多孔基膜的材料选自聚乙烯、聚丙烯、聚对苯二甲酸乙二醇酯、聚酰胺、聚酰亚胺、PET无纺布中的一种或几种。
可选地，多孔基膜为多层。多孔基膜由不同分子量、不同熔融指数的聚乙烯或聚丙烯制成。
可选地，多孔基膜为多层。多孔基膜由不同分子量、不同熔融指数的聚乙烯和聚丙烯制成。示例性地，多孔基膜为三层。
可选地，多孔基膜的厚度在5μm～30μm范围内。
可选地，多孔基膜的厚度在6μm～28μm范围内。
可选地，多孔基膜的厚度在10μm～25μm范围内。
示例性地，多孔基膜的厚度为15μm、18μm或者20μm。
可选地，多孔基膜的孔隙率在20％～70％范围内。
可选地，多孔基膜的孔隙率在25％～65％范围内。
可选地，多孔基膜的孔隙率在30％～60％范围内。
示例性地，多孔基膜的孔隙率为35％、40％、45％或者50％。
可选地，粘结层的原料包括有机物。
可选地，有机物选自聚丙烯酸酯、聚丙烯酸、聚丙烯酸盐、丁苯橡胶、环氧树脂、氨基树脂、聚酰胺、聚乙烯亚胺、聚偏氟乙烯、聚四氟乙烯、聚偏氟乙烯-六氟丙烯共聚物、聚偏氟乙烯-四氟乙烯共聚物中的至少一种。
可选地，粘结层的原料还包括羧甲基纤维素钠和海藻酸钠中的至少一种。示例性地， 选择前述有机物中的至少一种与羧甲基纤维素钠和海藻酸钠中的至少一种复配制备粘结层。
可选地，以重量百分比计，有机物占粘结层总重量的10～100％。
可选地，以重量百分比计，有机物占粘结层总重量的15～95％。
可选地，以重量百分比计，有机物占粘结层总重量的20～80％。
示例性地，粘结层包括100％的有机物。
可选地，上述的粘结层的原料包括有机物和无机物。通过加入无机物，能够在一定程度上降低粘结层所产生的静电，改善使用过程中因静电产生所引发的一些不良问题，但无机物添加量的过多，又会影响到粘结层粘接力的发挥。
可选地，以重量百分比计，无机物占粘结层总重量的0～90％。
无机物的添加量在上述的范围内时，能够有效地改善使用过程中静电问题，并保证良好的粘接效果。
可选地，以重量百分比计，无机物占粘结层总重量的5～85％。
可选地，以重量百分比计，无机物占粘结层总重量的10～80％。
示例性地，以重量百分比计，粘结层包括20％的无机物和80％的有机物；或者粘结层包括50％的无机物和50％的有机物。
可选地，无机物选自氧化铝、氧化钛、氧化锌、氧化钙、氧化镁、氧化锆、勃姆石中的一种或几种。
可选地，无机物的颗粒度D50的取值范围为0.1～2.0μm。
可选地，无机物的颗粒度D50的取值范围为0.5～1.8μm。
可选地，无机物的颗粒度D50的取值范围为1～1.5μm。
示例性地，无机物的颗粒度D50为0.8μm、1.2μm或者1.4μm。
可选地，涂覆区域沿预设方向上的尺寸(图1中宽度d1)在2mm～15mm之间；空白区域(图1中宽度d2)沿预设方向上的尺寸在50mm～1200mm之间。
可选地，涂覆区域沿预设方向上的尺寸在3mm～14mm之间；空白区域沿预设方向上的尺寸在100mm～1100mm之间。
可选地，涂覆区域沿预设方向上的尺寸在4mm～13mm之间；空白区域沿预设方向上的尺寸在500mm～1000mm之间。
示例性地，涂覆区域沿预设方向上的尺寸为5mm、8mm或者10mm；空白区域沿预设方向上的尺寸为200mm、400mm、600mm或者800mm。
可选地，两端的涂覆区域的粘结层对称且尺寸相等。
可选地，粘结层的厚度为0.5μm～4μm。
可选地，粘结层的厚度为1μm～3.5μm。
可选地，粘结层的厚度为1.5μm～3.0μm。
示例性地，粘结层的厚度为2.0μm、2.5μm、2.6μm、2.8μm或者3.2μm。
可选地，粘结层为连续涂覆层或者非连续涂覆层。
可选地，非连续涂覆层是沿预设方向间隔涂覆。非连续涂覆层包括多个间隔的条状涂层、点状涂层、块状涂层或者弯曲状涂层。例如，多个蛇形弯曲状涂层间隔涂覆。
参照图4，可选地，垂直于预设方向的方向为MD方向。非连续涂覆层为条状涂层时，条状涂层与MD方向所形成的夹角α介于10°～170°之间，但不包括90°。
可选地，非连续涂覆层为条状涂层时，条状涂层与MD方向所形成的夹角介于30°～120°之间。
由于在隔膜两个表面的端部涂覆粘结层，在涂覆收卷时，因为两端厚，中间薄，在收卷长度达到一定长度后，有可能造成端部应力过大，在两端采用非连续结构的涂层，可以部分分散端部的集中应力，增加收卷长度，从而进一步提高涂覆和使用过程中的效率，并降低了制造成本。
可选地，粘结层为非连续涂覆层时，粘结层在涂覆区域的覆盖率在10％～90％之间。
可选地，粘结层在涂覆区域的覆盖率在40％～80％之间。
可选地，粘结层在涂覆区域的覆盖率在50％～70％之间。
示例性地，粘结层在涂覆区域的覆盖率为55％、60％、65％或者75％等。
粘结层覆盖率太低时，聚合物含量过少，与锂电池负极两端的粘结力太低，不能有效地起到粘结作用。而如果覆盖率太高，又不能很好地分散端部的集中应力，对收卷长度和使用效率的改善效果不显著。在上述的覆盖率范围内，能够有效地分散端部集中应力，对收卷长度和使用效率起到良好的改善效果。
可选地，参照图1，提供一种隔膜。隔膜包括多孔基膜100和粘结层200。可选地，多孔基膜100的两个表面均涂覆有粘结层200。粘结层200涂覆在多孔基膜100两端，且两个表面均涂覆有粘结层200。多孔基膜100的中间区域为空白区域101。粘结层200采用连续涂覆的方式涂覆。图1中，4个粘结层200均为连续型纯粘结层，空白区的宽度是600mm。粘结层200只包含有机物，有机物选自聚丙烯酸酯、羧甲基纤维素钠、聚偏氟乙烯、聚偏氟乙烯-六氟丙烯共聚物的组合物。粘结层200的厚度为2um，其单边宽度的取值为10mm。多孔基膜100为由不同分子量、不同熔融指数组成的三层聚丙烯隔离膜。
可选地，上述的粘结层200也可以只涂覆在多孔基膜100的一个表面。
可选地，参照图2，提供一种隔膜。其与图1中提供隔膜基本相同，不同之处在于，粘结层201为连续型纯聚合物和无机物混合的粘结层。其中聚合物所占比例为80wt％，无机物所占比例为20wt％，中间空白区域102的宽度是600mm。多孔基膜100是不同分子量、 不同熔融指数组成的三层聚丙烯/聚乙烯/聚丙烯隔离膜。粘结层201厚度为2um，其单边宽度的取值为10mm。粘结层201中的有机物选自聚丙烯酸酯、羧甲基纤维素钠、聚偏氟乙烯、聚偏氟乙烯-六氟丙烯共聚物的组合物，无机物选自氧化铝，其颗粒度粒径D50为0.6um。
可选地，参照图3，提供一种隔膜。其与图1中提供隔膜基本相同，不同之处在于，粘结层202为非连续型点状纯粘结层。涂膜区内部的覆盖率为60％，空白区域103的宽度是600mm。多孔基膜100的材料选自由不同分子量、不同熔融指数组成的单层聚丙烯隔离膜。粘结层202的厚度为1.7um，其单边宽度的取值为15mm。粘结层202中只包含有机物，有机物选自聚丙烯酸酯、羧甲基纤维素钠、聚偏氟乙烯、聚偏氟乙烯-六氟丙烯共聚物的组合物。
可选地，参照图4，提供一种隔膜。其与图1中提供隔膜基本相同，不同之处在于，粘结层203为非连续型条状纯粘结层。涂膜区内部的覆盖率为60％，且条状粘结层与多孔基膜100的MD方向所形成的夹角α为45°，空白区域104的宽度是600mm。多孔基膜100的材料选自由不同分子量、不同熔融指数组成的三层聚丙烯隔离膜。粘结层203的厚度为2.3um，其单边宽度的取值为7mm。粘结层203中只包含有机物，有机物选自聚丙烯酸酯、羧甲基纤维素钠、聚偏氟乙烯、聚偏氟乙烯-六氟丙烯共聚物的组合物。
本申请还提供一种隔膜卷，采用前述的隔膜沿垂直于预设方向收卷形成。
本申请还提供一种电芯，包括前述的隔膜、负极片、以及正极片。
负极片设置在隔膜的一侧，且负极片的两端粘接于隔膜表面涂覆的粘结层上。
正极片位于隔膜的另一侧，且正极片与隔膜的空白区域叠合。
该隔膜两端的粘结层起到与锂电池负极极片两端的粘结以及粘结层相互之间的粘结作用，使电池极片之间的位置固定而紧凑，从而使电池极片、隔膜成为一个整体。特别是对于大尺寸叠片电池而言，保证了锂电池在组装、振动测试以及长期循环过程中能够承受足够的张力、压力与震动，避免因电池正、负极片之间以及电芯与壳体之间的相对运动而导致的成品率低、微短路、自放电、内阻升高以及焊接极耳位松动或破坏等不良后果。
可选地，由于粘结层没有孔，会影响到锂离子的传输效率，进而影响到正极材料容量的发挥，而本申请提供的隔膜两个表面的中间空白区域与正极极片贴合，即粘结层不与锂电池电芯内部的正极片上的活性物质接触，因此不会对电池的传输效率造成影响。该隔膜不会导致锂电池组装过于复杂，工艺成本较低，且能够极大地提高电池内部电芯的稳定性，保证锂电池长期循环的稳定性。
该电芯能够用于制造大尺寸叠片电池。参照图5，在电芯组装成型时，正极极片位于隔膜的一侧，且正极极片贴合在隔膜的空白区域内(正极极片的尺寸小于隔膜的尺寸)，因此，正极极片不与隔膜的粘结层接触，从而不会接触正极极片上的活性物质，不会对电池 的电性能造成影响。负极极片与隔膜大小相等(根据需要还可设置为略小于隔膜)。负极极片位于隔膜的另一侧(隔膜的下方，图5中未示出)。
可选地，隔膜两端的粘结层的宽度d1均在2mm～15mm之间。
隔膜两端的粘结层将隔膜与负极极片稳固地粘接在一起，从而使得锂电池在组装、振动测试以及长期循环过程中能够承受足够的张力、压力与震动，避免因电池正、负极片之间，电芯与壳体之间的相对运动而导致的成品率低、微短路、自放电、内阻升高以及焊接极耳位松动或破坏等不良后果。
本申请还提供一种动力锂电池，该动力锂电池包括前述的电芯。
该动力锂电池通过设置上述的电芯，使得大尺寸动力锂电池在保证锂电芯在组装、振动测试以及长期循环过程中能够承受足够的张力、压力与震动，从而提高长期循环性能和电池稳定性。
下面结合实施例和对比例对本申请的特征和性能进行详细描述。
实施例1
提供一种动力锂电池，是这样制得的：
负极的制备：将石墨、导电炭黑、增稠剂羧甲基纤维素钠、粘结剂丁苯橡胶乳液按质量比96:1:1:2加入去离子水，在搅拌机中搅拌分散均匀，用150目筛网过滤得到所需的负极浆料，然后经过涂布、冷压、分切制成负极片。
正极的制备：将磷酸铁锂、导电剂、粘结剂聚偏氟乙烯按质量比97:1:2加入氮甲基吡咯烷酮(NMP)，在搅拌机中搅拌分散均匀，用150目筛网过滤得到所需的正极浆料，然后经过涂布、冷压、分切制成正极片。
电解液的配制：将碳酸乙烯酯EC、碳酸丙烯酯PC和碳酸二甲酯DMC按照体积比3:3:4配制成混合溶剂，然后再加入相关添加剂和锂盐六氟磷酸锂(LiPF6)，配制好的LiPF6的浓度为1M，搅拌均匀后得到电解液。
隔膜的制备：将聚丙烯酸酯、羧甲基纤维素钠、聚偏氟乙烯、聚偏氟乙烯-六氟丙烯共聚物按质量比6:1:10:83加入去离子水，在搅拌机中搅拌分散均匀，用150目筛网过滤得到所需的浆料，然后通过凹版涂覆将所述浆料涂覆在隔离膜一个表面的两个端面上，烘干形成单面连续型纯粘结层。基材选用18um的三层聚丙烯多孔基膜，所述连续型纯粘结层的厚度为2um，其单边宽度的取值为10mm，隔离膜中间部位的空白区宽度是600mm。
电池的组装：将上述负极极片、隔离膜和正极极片叠片成电芯，铝塑复合膜封装，真空状态烘烤除去水分后注入定量电解液，对电池进行化成和容量测试，得到厚宽长分别为25mm、65mm、610mm的方形软包装锂离子电池。其中，对必要的测试项目，按一定方式直接用电芯组装成电池包。
实施例2
提供一种动力锂电池，是这样制得的：
负极、正极、电解液、电池的组装过程与实施例1相同，不同之处在于隔膜不同。
隔膜的制备：将聚丙烯酸酯、羧甲基纤维素钠、聚偏氟乙烯、聚偏氟乙烯-六氟丙烯共聚物按质量比6:1:10:83加入去离子水，在搅拌机中搅拌分散均匀，用150目筛网过滤得到所需的浆料，然后通过凹版涂覆将所述浆料涂覆在隔离膜正、反两面的两个端面上，烘干形成连续型纯粘结层。基材选用18um的三层聚丙烯多孔基膜，所述连续型纯粘结层的厚度为2um，其单边宽度的取值为10mm，隔离膜中间部位的空白区宽度是600mm。
实施例3
提供一种动力锂电池，是这样制得的：
负极、正极、电解液、电池的组装过程与实施例1相同，不同之处在于隔膜不同。
隔膜的制备：将聚丙烯酸酯、羧甲基纤维素钠、聚偏氟乙烯、聚偏氟乙烯-六氟丙烯共聚物、氧化铝按质量比6:1:5:68:20加入去离子水，在搅拌机中搅拌分散均匀，用150目筛网过滤得到所需的浆料，然后通过凹版涂覆将所述浆料涂覆在隔离膜正、反两面的两个端面上，烘干形成连续型纯聚合物和无机物混合的粘结层。基材选用18um的三层聚丙烯/聚乙烯/聚丙烯多孔基膜，所述粘结层的厚度为2um，其单边宽度的取值为10mm，隔离膜中间部位的空白区宽度是600mm。
实施例4
提供一种动力锂电池，是这样制得的：
负极、正极、电解液、电池的组装过程与实施例1相同，不同之处在于隔膜不同。
隔膜的制备：将聚丙烯酸酯、羧甲基纤维素钠、聚偏氟乙烯、聚偏氟乙烯-六氟丙烯共聚物按质量比6:1:10:83加入去离子水，在搅拌机中搅拌分散均匀，用150目筛网过滤得到所需的浆料，然后通过雕刻区改进的凹版辊将所述浆料涂覆在隔离膜正、反两面的两个端面上，烘干形成非连续型点状纯粘结层，其中涂膜区内部的覆盖率为60％。基材选用18um的单层聚丙烯多孔基膜，所述非连续型点状纯粘结层的厚度为1.7um，其单边宽度的取值为15mm，隔离膜中间部位的空白区宽度是600mm。
实施例5
提供一种动力锂电池，是这样制得的：
负极、正极、电解液、电池的组装过程与实施例1相同，不同之处在于隔膜不同。
隔膜的制备：将聚丙烯酸酯、羧甲基纤维素钠、聚偏氟乙烯、聚偏氟乙烯-六氟丙烯共聚物按质量比6:1:10:83加入去离子水，在搅拌机中搅拌分散均匀，用150目筛网过滤得到所需的浆料，然后通过雕刻区改进的凹版辊将所述浆料涂覆在隔离膜正、反两面的两个端 面上，烘干形成非连续型条状纯粘结层，其中涂膜区内部的覆盖率为60％，且条状粘结层与所述多孔基膜的MD方向所形成的夹角为45°。基材选用18um的三层聚丙烯多孔基膜，所述非连续型条状纯粘结层的厚度为2.3um，其单边宽度的取值为7mm，隔离膜中间部位的空白区宽度是600mm。
对比例1
提供一种动力锂电池，是这样制得的：
负极、正极、电解液、电池的组装过程与实施例1相同，不同之处在于隔膜不同。
隔膜：采用厚度为18um的三层聚丙烯多孔基膜作为隔膜。
对比例2
提供一种动力锂电池，是这样制得的：
负极、正极、电解液、电池的组装过程与实施例1相同，不同之处在于隔膜不同。
隔膜的制备：将聚丙烯酸酯、羧甲基纤维素钠、聚偏氟乙烯、聚偏氟乙烯-六氟丙烯共聚物按质量比6:1:10:83加入去离子水，在搅拌机中搅拌分散均匀，用150目筛网过滤得到所需的浆料，然后通过凹版涂覆将所述浆料涂覆在隔离膜正、反两个表面上，烘干形成两个表面全覆盖的连续型纯粘结层。基材选用18um的三层聚丙烯多孔基膜，所述连续型纯粘结层的厚度为2um。
对实施例1～5以及对比例1～2提供的锂离子电池的性能进行考察：
1.隔膜涂胶区静电测试：使用SIMCO FMX-004静电场测试仪，测试每个试验样品涂胶区的静电值，每组样品重复5次，计算其平均值。
2.涂胶区与锂电池负极的粘接力测试：裁取隔离膜涂覆区域10mm*200mm的矩形样条5片，把所制得的负极极片裁取15mm*220mm矩形样条5片，各取一片隔离膜和负极极片，通过2.0Mpa、90℃、60s的复合条件将涂胶隔离膜与负极片热压合在一起，然后将负极片的一端固定在万能拉力机的上夹具，隔离膜固定在拉力机的下夹具，以50mm/min的恒定速度，测试负极片与涂胶隔离膜间的粘接力，每组样品重复5次，计算其平均值。
3.涂胶区之间的粘接力测试：裁取隔离膜涂覆区域15mm*220mm的矩形样条10片，将两片同样的涂胶隔离膜通过2.0Mpa、90℃、60s的复合条件热压合在一起，然后将其中一片隔离膜的一端固定在万能拉力机的上夹具，另一片隔离膜固定在拉力机的下夹具，以50mm/min的恒定速度，测试涂胶隔离膜间的粘接力，每组样品重复5次，计算其平均值。
4.电池组装成品率统计：隔离膜所制备锂离子电池的过程进行统计，以出货产品要求为标准，统计组装100个电池的成品数量，计算得出成品率。
5.电池循环性能测试：取隔离膜所制备出的锂离子电池为样本，在25℃环境下，以1C/1C的充放电倍率对电池进行循环测试，计算每组第1000周循环时电池的放电容量保持 率。
6.依据ISO12405-1:2011标准，用于动力电池锂电池组的振动可靠性测试，主要模拟在动力电池使用过程中因各种因素所引起的随机或规律振动，进而造成动力电池的使用性能和稳定性下降。
测试结果见表1。
表1 性能测试结果
Figure PCTCN2021108715-appb-000001
从上述检测结果可以看出，对于厚、宽、长分别为25mm、65mm、610mm的方形锂离子电池而言，较大的外形尺寸，特别是较长的长度，是对锂电池制作工艺和长期使用可靠性、安全性的一个较大挑战。从表一可以看出，对比例1，由于没有进行两侧涂胶，无法实现两端固定的作用，其电芯组装的成品率较低，严重影响了电芯的制程效率和成本要求。其次，在后续的循环和振动测试中，由于正、负极极片可能发生的相对运动而引发的短路、微短路现象，引起长期循环的容量保持率和抗震动性能较低。对于对比例2，隔离膜进行了全覆盖的聚合物涂覆，由于大量聚合物在隔离膜表面的存在，严重影响了锂电池正常工作状态时锂离子的电导率，增加了电池的电化学阻抗，进而导致长期循环性能的衰减。实施例1，进行了两侧涂覆，隔离膜涂胶区与电池负极极片以及涂胶区之间有较高的粘附力，但涂胶区由于只涂覆了隔离膜的一个表面，所以对长电芯两端的固定作用还不够，在极端使用条件下，还是容易出现因正、负极极片发生相对运动而产生的短路或微短路现象。对于实施例2，隔离膜进行了两侧涂胶的工艺，但由于其特殊结构和表面静电的关系，收卷长度只能做到1000米，否则就会出现收卷端面应力过大而导致的局部变形，严重影响了隔离膜在电池装配过程中的使用，同时，由于端面较高的静电，容易吸附车间内的粉尘颗粒以及影响了电池组装过程中隔离膜的平整铺展，进而导致了电池组装成品率虽有较大提升，但还是不能满足大批量生产时对产品率和制造成本控制的要求。实施例3，在聚合物涂覆 配方中由于添加了无机氧化物，在保持了一定的隔离膜涂胶区与电池负极极片以及涂胶区之间的粘附力的情况下，由于两侧静电的大大降低，电池组装成品率可以达到99％以上，大大提高了生产效率并降低了成本，同时，由于两端较好的固定作用，保证了在正常和极端条件下锂电池电芯的结构稳定性，其容量循环保持率和抗震动测试通过率较高。对于实施例4和5，由于采用了端面非连续型涂覆的工艺，在隔膜收卷时分散了涂胶叠加区的承受应力，使得两侧涂胶的隔离膜收卷长度延长了1000米，大大提高了大规模化使用过程中的效率，降低了成本。同时，隔离膜涂胶区与电池负极极片以及涂胶区之间的粘附力也保持了一定的强度，达到了长电芯端面固定的作用，从而在电池长期循环的容量稳定性和抗振动测试的结果上体现了出来。
以上所述仅为本申请的优选实施例而已，并不用于限制本申请，对于本领域的技术人员来说，本申请可以有各种更改和变化。凡在本申请的精神和原则之内，所作的任何修改、等同替换、改进等，均应包含在本申请的保护范围之内。
工业实用性
通过在锂电池中使用本申请提供的隔膜，不会导致锂电池组装过于复杂，工艺成本较低，且能够极大地提高电池内部电芯的稳定性，保证锂电池长期循环的稳定性。

Claims (19)

  1. 一种隔膜，其特征在于，所述隔膜包括多孔基膜和粘结层；
    沿所述多孔基膜的预设方向，所述多孔基膜的表面包括中间空白区域和两端的涂覆区域；
    所述粘结层涂覆在两端的所述涂覆区域。
  2. 根据权利要求1所述的隔膜，其特征在于，
    所述涂覆区域沿所述预设方向上的尺寸在2mm～15mm之间；所述空白区域沿所述预设方向上的尺寸在50mm～1200mm之间。
  3. 根据权利要求1或2所述的隔膜，其特征在于，
    所述粘结层的厚度在0.5μm～4μm范围内。
  4. 根据权利要求1-3任一项所述的隔膜，其特征在于，
    所述粘结层为连续涂覆层或者非连续涂覆层。
  5. 根据权利要求4所述的隔膜，其特征在于，
    沿所述预设方向，所述非连续涂覆层包括多个间隔的条状涂层、点状涂层、块状涂层或者弯曲状涂层。
  6. 根据权利要求5所述的隔膜，其特征在于，
    垂直于所述预设方向的方向为MD方向，所述非连续涂覆层为条状涂层时，所述条状涂层与所述MD方向所形成的夹角介于10°～170°之间，但不包括90°。
  7. 根据权利要求4-6任一项所述的隔膜，其特征在于，
    所述粘结层为非连续涂覆层，所述粘结层在所述涂覆区域的覆盖率在10％～90％之间。
  8. 根据权利要求7所述的隔膜，其特征在于，
    所述粘结层在所述涂覆区域的覆盖率在40％～80％之间。
  9. 根据权利要求1-8任一项所述的隔膜，其特征在于，
    所述粘结层的原料包括有机物；
    所述有机物选自聚丙烯酸酯、聚丙烯酸、聚丙烯酸盐、丁苯橡胶、环氧树脂、氨基树脂、聚酰胺、聚乙烯亚胺、聚偏氟乙烯、聚四氟乙烯、聚偏氟乙烯-六氟丙烯共聚物、聚偏氟乙烯-四氟乙烯共聚物中的至少一种；可选地，所述粘结层的原料还包括羧甲基纤维素钠和海藻酸钠中的至少一种。
  10. 根据权利要求9所述的隔膜，其特征在于，
    以重量百分比计，所述有机物占所述粘结层总重量的10～100％。
  11. 根据权利要求1-10任一项所述的隔膜，其特征在于，
    所述粘结层的原料包括无机物，所述无机物选自氧化铝、氧化钛、氧化锌、氧化钙、氧化镁、氧化锆、勃姆石中的一种或几种。
  12. 根据权利要求11所述的隔膜，其特征在于，
    所述无机物的颗粒度D50的取值范围为0.1～2.0μm。
  13. 根据权利要求11或12所述的隔膜，其特征在于，
    以重量百分比计，所述无机物占所述粘结层总重量的0～90％。
  14. 根据权利要求1-13任一项所述的隔膜，其特征在于，
    所述多孔基膜为单层；所述多孔基膜的材料选自聚乙烯、聚丙烯、聚对苯二甲酸乙二醇酯、聚酰胺、聚酰亚胺、PET无纺布中的一种或几种；或者
    所述多孔基膜为多层；所述多孔基膜由不同分子量、不同熔融指数的聚乙烯和/或聚丙烯制成。
  15. 根据权利要求1-14任一项所述的隔膜，其特征在于，
    所述多孔基膜的厚度在5μm～30μm范围内。
  16. 根据权利要求1-15任一项所述的隔膜，其特征在于，
    所述多孔基膜的孔隙率在20％～70％范围内。
  17. 一种隔膜卷，其特征在于，采用权利要求1-16任一项所述的隔膜沿垂直于所述预设方向收卷形成。
  18. 一种电芯，其特征在于，包括权利要求1-16任一项所述的隔膜；
    负极片，所述负极片设置在所述隔膜的一侧，且所述负极片的两端粘接于所述隔膜表面涂覆的粘结层上；以及
    正极片，所述正极片位于所述隔膜的另一侧，且所述正极片与所述隔膜的空白区域叠合。
  19. 一种动力锂电池，其特征在于，所述动力锂电池包括权利要求18所述的电芯。
PCT/CN2021/108715 2020-06-04 2021-07-27 隔膜、隔膜卷、电芯以及动力锂电池 WO2021244672A1 (zh)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US18/000,654 US20230198098A1 (en) 2020-06-04 2021-07-27 Separator membrane, separator membrane roll, battery cell, and power lithium battery

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202010503541.1 2020-06-04
CN202010503541.1A CN111564593B (zh) 2020-06-04 2020-06-04 隔膜、隔膜卷、电芯以及动力锂电池

Publications (1)

Publication Number Publication Date
WO2021244672A1 true WO2021244672A1 (zh) 2021-12-09

Family

ID=72073716

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2021/108715 WO2021244672A1 (zh) 2020-06-04 2021-07-27 隔膜、隔膜卷、电芯以及动力锂电池

Country Status (3)

Country Link
US (1) US20230198098A1 (zh)
CN (1) CN111564593B (zh)
WO (1) WO2021244672A1 (zh)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114613943A (zh) * 2022-03-22 2022-06-10 上海兰钧新能源科技有限公司 极片、电芯、极片制备工艺及电芯制备工艺

Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111564593B (zh) * 2020-06-04 2021-08-20 江苏星源新材料科技有限公司 隔膜、隔膜卷、电芯以及动力锂电池
CN114725623A (zh) * 2020-12-22 2022-07-08 华为技术有限公司 电池、电子设备、移动装置
CN112750973A (zh) * 2020-12-31 2021-05-04 蜂巢能源科技有限公司 极片单元及其制备方法
CN113285110A (zh) * 2021-03-24 2021-08-20 中航锂电（洛阳）有限公司 电池、涂胶方法及电芯的制造方法
CN113224467A (zh) * 2021-05-27 2021-08-06 江苏星源新材料科技有限公司 一种涂层隔膜
CN216120418U (zh) * 2021-10-28 2022-03-22 宁德时代新能源科技股份有限公司 锂离子电池及其隔离膜
CN114204206B (zh) * 2021-11-25 2024-05-07 湖南立方新能源科技有限责任公司 一种隔膜、电芯结构以及二次电池
CN114447442A (zh) * 2022-02-07 2022-05-06 珠海冠宇电池股份有限公司 电芯和电池
CN115101893B (zh) * 2022-06-02 2024-04-12 界首市天鸿新材料股份有限公司 利用高熔指和低熔指聚丙烯制备锂电池隔膜的方法
CN217589312U (zh) * 2022-07-19 2022-10-14 宁德时代新能源科技股份有限公司 隔膜、电池单体、热压模具、电池和用电装置
CN115360477B (zh) * 2022-09-15 2023-11-28 珠海冠宇电池股份有限公司 隔膜和电池
CN115939672A (zh) * 2023-03-15 2023-04-07 宁德时代新能源科技股份有限公司 隔膜及制备方法、电极组件、电池单体、电池、用电装置

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105703015A (zh) * 2016-04-01 2016-06-22 庄新国 一种叠片式锂离子电池
CN107004812A (zh) * 2014-12-15 2017-08-01 帝人株式会社 非水电解质电池用隔膜、非水电解质电池及非水电解质电池的制造方法
CN107316968A (zh) * 2017-05-11 2017-11-03 东莞市赛普克电子科技有限公司 一种粘性电池隔膜及使用该隔膜的锂离子电池
CN108598338A (zh) * 2017-12-27 2018-09-28 上海恩捷新材料科技股份有限公司 一种隔离膜及包含该隔离膜的电化学装置
CN109244517A (zh) * 2017-07-10 2019-01-18 宁德新能源科技有限公司 电芯及电化学装置
CN111564593A (zh) * 2020-06-04 2020-08-21 江苏星源新材料科技有限公司 隔膜、隔膜卷、电芯以及动力锂电池

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060159999A1 (en) * 2001-07-23 2006-07-20 Kejha Joseph B Method of automated prismatic electrochemical cells production and method of the cell assembly and construction
KR101084909B1 (ko) * 2009-12-07 2011-11-17 삼성에스디아이 주식회사 전극조립체블록 및 그 제조 방법, 이차전지 및 그 제조 방법
KR101636393B1 (ko) * 2012-11-30 2016-07-05 주식회사 엘지화학 가스 배출성이 개선된 전기화학소자용 기재, 그의 제조방법 및 그를 포함하는 전기화학소자
KR101676446B1 (ko) * 2013-09-30 2016-11-15 주식회사 엘지화학 리튬 이차전지용 세퍼레이터의 제조방법, 그 방법에 의해 제조된 세퍼레이터, 및 이를 포함하는 리튬 이차전지
JP6032497B2 (ja) * 2013-12-19 2016-11-30 トヨタ自動車株式会社 非水電解液二次電池
CN104577004B (zh) * 2014-12-25 2017-01-04 山东精工电子科技有限公司 一种固定隔膜的聚合物锂离子电池及其制作方法
US10511063B2 (en) * 2016-01-19 2019-12-17 Gs Yuasa International Ltd. Negative electrode plate, energy storage device, method for manufacturing negative electrode plate, and method for manufacturing energy storage device
CN105845872A (zh) * 2016-05-04 2016-08-10 合肥国轩高科动力能源有限公司 一种用于粘结锂电池隔膜与极片的涂层浆料及其制备方法
CN111224047A (zh) * 2019-10-17 2020-06-02 上海恩捷新材料科技有限公司 一种隔膜及包含该隔膜的电化学装置
EP4084172A1 (en) * 2019-12-27 2022-11-02 Zeon Corporation Secondary battery and manufacturing method therefor

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107004812A (zh) * 2014-12-15 2017-08-01 帝人株式会社 非水电解质电池用隔膜、非水电解质电池及非水电解质电池的制造方法
CN105703015A (zh) * 2016-04-01 2016-06-22 庄新国 一种叠片式锂离子电池
CN107316968A (zh) * 2017-05-11 2017-11-03 东莞市赛普克电子科技有限公司 一种粘性电池隔膜及使用该隔膜的锂离子电池
CN109244517A (zh) * 2017-07-10 2019-01-18 宁德新能源科技有限公司 电芯及电化学装置
CN108598338A (zh) * 2017-12-27 2018-09-28 上海恩捷新材料科技股份有限公司 一种隔离膜及包含该隔离膜的电化学装置
CN111564593A (zh) * 2020-06-04 2020-08-21 江苏星源新材料科技有限公司 隔膜、隔膜卷、电芯以及动力锂电池

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114613943A (zh) * 2022-03-22 2022-06-10 上海兰钧新能源科技有限公司 极片、电芯、极片制备工艺及电芯制备工艺
CN114613943B (zh) * 2022-03-22 2024-03-29 上海兰钧新能源科技有限公司 极片、电芯、极片制备工艺及电芯制备工艺

Also Published As

Publication number Publication date
CN111564593A (zh) 2020-08-21
CN111564593B (zh) 2021-08-20
US20230198098A1 (en) 2023-06-22

Similar Documents

Publication Publication Date Title
WO2021244672A1 (zh) 隔膜、隔膜卷、电芯以及动力锂电池
CN111540881B (zh) 一种负极片、制备方法及包含其的锂离子电池
CN111969214B (zh) 一种异型结构的正极片及包括该正极片的锂离子电池
CN111540879B (zh) 一种正极片、制备方法及包含其的锂离子电池
CN110071293B (zh) 电芯和电池、保液涂料和电池极片及其制备方法
CN113013549B (zh) 一种轻量化锂离子电池隔膜用涂层材料及其制备方法和轻量化锂离子电池复合隔膜
CN111564661A (zh) 一种高安全性的锂离子电池
CN104078246A (zh) 一种锂离子电池电容器
CN113078282A (zh) 一种正极片和锂离子电池
WO2021232904A1 (zh) 一种电化学装置隔离膜及其制备方法
US10230086B2 (en) Separator
CN114361717B (zh) 复合隔膜及电化学装置
CN111725511A (zh) 一种锂离子二次电池极片及锂离子二次电池
WO2023184230A1 (zh) 一种正极及使用其的电化学装置及电子装置
CN113285056B (zh) 一种正极片及电池
CN114204038A (zh) 集流体及其应用
WO2022253032A1 (zh) 一种负极片及电池
WO2021189467A9 (zh) 一种电极组件和包含所述电极组件的电化学装置及电子装置
CN204857827U (zh) 一种软包装锂电池的卷芯结构
CN115528380A (zh) 电池隔膜及其制备方法和锂电池
CN113097440A (zh) 电化学装置及用电设备
JP2023515152A (ja) セパレータ、その製造方法およびその関連する二次電池、電池モジュール、電池パックならびに装置
TW483186B (en) Method for fabricating a lithium battery with self-adhesive polymer electrolyte
CN114023952B (zh) 一种正极活性材料、正极片及锂离子电池
CN216435939U (zh) 一种电芯及电池

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 21817315

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 21817315

Country of ref document: EP

Kind code of ref document: A1

32PN Ep: public notification in the ep bulletin as address of the adressee cannot be established

Free format text: NOTING OF LOSS OF RIGHTS PURSUANT TO RULE 112(1) EPC (EPO FORM 1205A DATED 06/06/2023)

122 Ep: pct application non-entry in european phase

Ref document number: 21817315

Country of ref document: EP

Kind code of ref document: A1