Current collector, battery and power automobile

Abstract

The utility model discloses a current collector, a battery and a power automobile. The current collector comprises a supporting layer, an anti-shrinkage viscous layer and a metal layer, at least one side of the supporting layer is provided with an anti-shrinkage viscous layer; a metal layer is arranged on one side, far away from the supporting layer, of the anti-shrinkage viscous layer; according to the application, the anti-shrinkage viscous layer is arranged between the supporting layer and the metal layer, and the anti-shrinkage viscous layer is of a layer structure with viscosity and shrinkage resistance during curing. Based on the current collector comprising the anti-shrinkage viscous layer, the bonding between the supporting layer and the metal layer of the current collector can be realized, and the instability when the supporting layer and the metal layer are directly bonded is overcome; the whole current collector is stable in structure and performance. Meanwhile, on the basis of the current collector, production interference factors are reduced, and production operation is facilitated; and at least when the anti-shrinkage viscous layer is ensured to provide viscosity, possible adverse effects during curing are reduced, and the production difficulty of the current collector is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of battery materials, and more specifically, to a current collector, a battery and a power vehicle. Background Art

[0002] The composite current collector for lithium batteries is a new type of current collector material with a "sandwich" structure. The intermediate support layer usually uses a polymer insulating resin such as PET (polyethylene terephthalate), PP (polypropylene), PI (polyimide), etc. as a film substrate. Then, a metal layer, such as a copper foil layer, is made on the surface of the film substrate by magnetron sputtering, vacuum evaporation, water electroplating, or a combination of multiple processes to form a composite current collector sandwich structure. Compared with the metal current collector formed by traditional all-metal materials, the composite current collector has the advantages of high energy density and low metal consumption. Therefore, the replacement of traditional metal current collectors by composite current collectors has become the current development trend of batteries.

[0003] While composite current collectors offer certain advantages over traditional all-metal current collectors, they still have drawbacks. Composite current collector support layers are made of materials such as PET, PP, and PI, and the metal layer has weak adhesion to these support layers, making it easy for the layer to separate from the support layer, impacting the stability of the current collector. To address this issue, existing technologies have proposed methods such as adhesion-enhancing layers to address the bonding problem between the support layer and the metal layer. These methods involve coating the support layer with a viscous adhesive, which forms a viscous layer that is then bonded to the metal layer. However, there will be new problems in the production process based on this type of technology. The curing process includes the gel setting stage of evaporating water and other components and the maturation stage after compounding. However, the viscous layer will shrink in the planar direction during the maturation process. When the viscous layer shrinks, it will drive the support layer and metal layer on both sides of it to shrink, resulting in the overall shrinkage of the collector, and it is impossible to obtain a qualified collector. On the other hand, it may cause part of the viscous glue to separate from the support layer and be unable to spread completely on the support layer, and it may cause partial deformation of the support layer, such as warping, and gaps between different layers, resulting in a weakening of the bonding effect between the support layer and the metal layer, which is prone to subsequent separation.

[0004] Therefore, the prior art urgently needs an adhesive layer that can be applied to provide a bonding effect between the support layer and the metal layer, and at the same time has anti-shrinkage performance during curing to overcome the adverse effects caused by shrinkage during the actual production process. Utility Model Content

[0005] The present invention aims to overcome at least one of the shortcomings of the above-mentioned prior art and provide a current collector, a battery and a power vehicle. The current collector based on the anti-shrinkage adhesive layer contained in the present application can effectively avoid the adverse effects caused by shrinkage during the curing process during the production process, and ensure and improve the stable bonding between the support layer and the metal layer.

[0006] The technical solution adopted by the present invention is a current collector, comprising a support layer, an anti-shrinkage adhesive layer, and a metal layer; the support layer is provided with an anti-shrinkage adhesive layer on at least one side; the anti-shrinkage adhesive layer is provided with a metal layer on the side away from the support layer. Furthermore, the anti-shrinkage adhesive layer is adhesive; and the curing shrinkage rate is ≤3%. The anti-shrinkage adhesive layer is a layer structure with adhesiveness and anti-shrinkage during curing. Based on the anti-shrinkage adhesive layer in the current collector of this application, adhesion between the support layer and the metal layer can be achieved, overcoming the instability when the support layer and the metal layer are directly bonded; at the same time, in the specific current collector production process, the anti-shrinkage adhesive layer of this application can effectively prevent shrinkage during the curing stage, prevent shrinkage from causing deformation and wrinkling of the support layer and the metal layer, facilitate maintaining the planar shape, and closely fit with the plane of the support layer and the metal layer; and can also prevent the anti-shrinkage adhesive layer from shrinking after shrinkage, thereby ensuring the adhesive action area and improving the bonding strength. Furthermore, the shrinkage rate of the anti-shrinkage adhesive layer upon curing is ≤2%; furthermore, the shrinkage rate of the anti-shrinkage adhesive layer upon curing is in the range of 0.1% to 0.5%.

[0007] Furthermore, the support layer is directly bonded to the metal layer through the anti-shrinkage adhesive layer to form a negative electrode current collector. Compared with forming a metal layer on the support structure base film by magnetron sputtering or water electroplating on the surface of the support layer, the present application utilizes the adhesive properties of the anti-shrinkage adhesive layer to directly compound the metal layer on the anti-shrinkage adhesive layer, thereby forming a corresponding negative electrode current collector. The process of forming the negative electrode current collector is simpler and faster, does not require complex and expensive production equipment, is easy to achieve mass production, and overcomes the problem that the existing technology is difficult to mass produce. The anti-shrinkage adhesive layer can be a pre-formed semi-cured layer structure, which is directly compounded with the support layer and the metal layer; or the anti-shrinkage adhesive layer can be formed by coating an anti-shrinkage viscous liquid on the surface of the support layer, and further compounded with the metal layer.

[0008] Furthermore, the tensile strength of the anti-shrinkage adhesive layer is ≥250 MPa, and the elongation at break is ≥80%. Furthermore, the tensile strength of the anti-shrinkage adhesive layer is 280 MPa to 400 MPa; further, the tensile strength of the anti-shrinkage adhesive layer is 280 to 350 MPa; further, the bonding force between the anti-shrinkage adhesive layer and the metal layer is in the range of 3 N / 25 mm to 30 N / 25 mm; further, the bonding force between the anti-shrinkage adhesive layer and the metal layer is in the range of 3 N / 25 mm to 30 N / 25 mm; further, the bonding force between the anti-shrinkage adhesive layer and the metal layer is in the range of 3 N / 25 mm to 30 N / 25 mm. In addition to its adhesive properties, the anti-shrinkage adhesive layer also has excellent mechanical properties, including tensile strength and elongation at break. Positioned between the support layer and the metal layer, its mechanical properties can be utilized to further improve the toughness and safety of the current collector based on the support layer substrate.

[0009] Furthermore, the adhesive force between the anti-shrinkage adhesive layer and the support layer ranges from 3N / 25mm to 30N / 25mm; the adhesive force between the anti-shrinkage adhesive layer and the metal layer ranges from 3N / 25mm to 30N / 25mm.

[0010] Furthermore, a cavity for accommodating a functional solid filler is reserved within the anti-shrinkage viscous layer. The anti-shrinkage viscous layer can be filled with a functional solid filler to further improve the performance of the anti-shrinkage viscous layer without affecting the thickness. The functional solid filler includes at least one of silicon dioxide, aluminum hydroxide, aluminum oxide, talc, aluminum nitride, boron nitride, silicon carbide, barium sulfate, barium titanate, strontium titanate, boehmite, calcium carbonate, calcium silicate, mica, graphite, magnesium oxide, magnesium hydroxide, kaolin, starch, montmorillonite, titanium dioxide, zinc sulfide, calcium bicarbonate, calcium phosphate, calcium hydrogen phosphate, calcium sulfate, carbon black, graphite, multi-walled and single-walled carbon nanotubes, carbon nanofibers, polytetrafluoroethylene particles, polyurethane particles, rubber particles, polyamide particles, organosilicon particles, graphene, nanotube structures, and antimony trioxide.

[0011] Furthermore, the support layer has a thickness of 1.9 to 6 μm; the anti-shrinkage adhesive layer has a thickness of 0.8 to 4 μm; and the metal layer has a thickness of 0.8 to 3.5 μm. Furthermore, the metal layer has a thickness of 0.8 to 1.5 μm; and even more preferably, the metal layer has a thickness of 1 to 1.5 μm. Furthermore, the total thickness of the current collector ranges from 6 to 12 μm.

[0012] Furthermore, the support layer is made of at least one of PET, PP, PI, PE, PVC, PBT, PC, PS, ABS, PA, PASF, PVDF, PEDOT, PANI and PPy; that is, PET (polyethylene terephthalate), PP (polypropylene), PI (polyimide), PE (polyethylene), PVC (polyvinyl chloride), PBT (polybutylene terephthalate), PC (polycarbonate), PS (polystyrene), ABS (acrylonitrile (A)-butadiene ( A support layer is formed of at least one material selected from the group consisting of a terpolymer of B)-styrene (S)), PA (polyamide), PASF (polyarylsulfone), PVDF (polyvinylidene fluoride), PEDOT (poly(3,4-ethylenedioxythiophene), PANI (polyaniline) and PPy (polypyrrole). Furthermore, the metal layer is at least one of copper, aluminum, titanium, nickel, cadmium, iron and silver. Furthermore, the metal layer is a copper layer. The metal layer is a copper foil layer; and the number of pinholes on the copper foil layer is ≤5 / m2, and the pinhole diameter is ≤0.1 mm.

[0013] Furthermore, it also includes a protective layer, which is provided on the surface of the metal layer away from the support layer; the protective layer is formed of at least one material selected from chromium, tungsten, molybdenum, nickel, iron, titanium, niobium, zirconium, gold, silver, platinum, carbon, chromate compounds, silane compounds, and benzotriazole and its modified compounds. On the basis of the basic composite current collector structure, a protective layer structure can be added. The protective layer can prevent the conductive layer of the current collector from chemical corrosion or oxidation, and can also enhance the mechanical strength of the current collector, and can improve the current flow capacity of the current collector and the electrode. Furthermore, the thickness of the protective layer is 0.01 to 0.15 μm; it is convenient to provide the protective layer function while having almost no effect on the overall current collector thickness.

[0014] Furthermore, the surface roughness of the metal layer Ra≤0.3μm; however, the metal layer also has a certain surface roughness, which, in addition to directly improving the conductive performance, can promote the formation of a mechanical bite interface between the metal layer and the insulating adhesive layer, thereby enhancing the bonding between the metal layer and the insulating adhesive layer.

[0015] Furthermore, the heat shrinkage of the anti-shrinkage adhesive layer after treatment at 150°C for 30 minutes is ≤3%; further, the elongation of the current collector is ≥3%. Furthermore, the heat shrinkage of the anti-shrinkage adhesive layer after treatment at 150°C for 30 minutes is 0.9-2.5%. Furthermore, the surface resistance of the current collector is ≤23 mΩ. In this application, the anti-shrinkage adhesive layer is not produced by stretching on a specific length production line, but is directly coated and then cured. Its transverse and longitudinal mechanical properties are similar. Although the testing process is based on the longitudinal length, the actual heat shrinkage, tensile strength, and elongation at break are almost equal in the longitudinal and transverse directions, with an error of no more than 3%. The heat shrinkage, elongation at break, and tensile strength of the anti-shrinkage adhesive layer in this application should be understood as values ​​that do not distinguish between the longitudinal and transverse directions, or can be considered to represent values ​​in both the longitudinal and transverse directions. The heat shrinkage of the anti-shrinkage adhesive layer in this application is tested according to JIS C2151 specifications. The anti-shrinkage adhesive layer of the present application has a heat shrinkage rate of ≤3%, has excellent heat resistance and thermal stability, and is beneficial to improving the safety of battery applications.

[0016] Another object of the present application is to provide a battery comprising the aforementioned current collector. The current collector of the present application is conducive to mass production, and is also conducive to forming a battery with high energy density and stable performance, and promoting the development of corresponding negative electrode current collector application products.

[0017] Another object of the present application is to provide a power vehicle comprising the aforementioned current collector or the aforementioned battery.

[0018] Compared with the prior art, the beneficial effects of the present application are as follows: the current collector of the present application is provided with an anti-shrinkage adhesive layer between the support layer and the metal layer, and the anti-shrinkage adhesive layer is a layer structure with adhesiveness and anti-shrinkage during curing. Based on the current collector of the present application including the anti-shrinkage adhesive layer, the adhesion between the current collector support layer and the metal layer can be achieved, overcoming the instability when the support layer and the metal layer are directly bonded; the overall current collector exhibits stable structure and performance. At the same time, based on the current collector of the present application, production interference factors are reduced, and production operations are facilitated; at least while ensuring that the anti-shrinkage adhesive layer provides viscosity, the adverse effects that may be caused during curing are reduced, reducing the difficulty of current collector production. For example, in the specific current collector production process, the anti-shrinkage adhesive layer of the present application can effectively prevent shrinkage during the curing stage, preventing shrinkage from causing deformation of the support layer, metal layer, and even the entire current collector, facilitating the maintenance of the planar shape so as to closely fit with the metal layer and support layer plane; and it can also prevent the anti-shrinkage adhesive layer from shrinking after shrinkage. The coverage area is reduced, ensuring the viscosity effect area, and improving the bonding strength; effectively avoiding the impact of the curing process on the bonding effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the current collector hierarchical structure of this application;

[0020] Figure 2 This is a schematic diagram of the hierarchical structure of the current collector including the protective layer of this application;

[0021] Figure 3 This is an electron microscope image of the current collector hierarchical structure of this application;

[0022] Description of the drawings: current collector 100 , support layer 110 , anti-shrinkage adhesive layer 120 , metal layer 130 , protective layer 140 . DETAILED DESCRIPTION

[0023] The drawings in this utility model are for illustrative purposes only and are not to be construed as limiting the scope of this utility model. To better illustrate the following embodiments, some components in the drawings may be omitted, enlarged, or reduced in size, and do not represent the actual dimensions of the products. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted from the drawings.

[0024] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and specific embodiments, but those skilled in the art will understand that the embodiments described below are part of the embodiments of the present invention, rather than all of the embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present invention. If specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0025] Example 1

[0026] This embodiment discloses a current collector 100, comprising a support layer 110, an anti-shrinkage adhesive layer 120, and a metal layer 130; the support layer 110 is provided with the anti-shrinkage adhesive layer 120 on at least one side; and the metal layer 130 is provided on the side of the anti-shrinkage adhesive layer 120 away from the support layer 110. In this embodiment, the anti-shrinkage adhesive layer 120 and the metal layer 130 can be sequentially provided on both sides of the support layer 110 in a direction away from the support layer 110, such as Figure 1 Specifically, the electron microscope image of the five-layer structure of this embodiment is as shown Figure 3 As shown. Furthermore, the anti-shrinkage adhesive layer 120 is adhesive; and the curing shrinkage rate is ≤3%. The anti-shrinkage adhesive layer 120 is a layer structure that is adhesive and anti-shrinkage during curing; it can be formed of at least a viscous material that is anti-shrinkage during curing. Furthermore, the curing shrinkage rate of the anti-shrinkage adhesive layer 120 is ≤2%; furthermore, the curing shrinkage rate of the anti-shrinkage adhesive layer 120 is in the range of 0.1% to 0.5%. Furthermore, in this embodiment, the temperature range of the gel setting stage during the curing process of the anti-shrinkage adhesive layer 120 is 80 to 90°C, and the temperature range of the post-compounding aging stage is 50 to 90°C. Specifically, after the anti-shrinkage adhesive layer 120 is composited with the support layer 110 and the metal layer 130, it is placed at 50 to 90°C for 24 to 48 hours for aging to obtain the current collector 100. The aging process can fully utilize the performance of the anti-shrinkage adhesive layer 120 and improve the composite effect.

[0027] The anti-shrinkage viscous layer 120 has insulation, tensile strength, extensibility and viscosity, and can be formed by curing an anti-shrinkage viscous liquid; the anti-shrinkage viscous liquid includes a mixed component A and a component B, wherein the component A is at least one of a polyurethane resin, an acrylic resin, an epoxy resin, a polyester resin, a polyimide, a silicone polymer and a modified compound thereof; the liquid B is at least one of an amino resin, an isocyanate, an aziridine cross-linking agent, a carbodiimide, a silane coupling agent and a silicone tackifier; wherein the weight ratio of component A to component B is: (90-99): (1~5), and 93:3 can be selected in this embodiment. The polyurethane resin described in component A of this embodiment has a polyester backbone portion and a polyether backbone portion, and the mass ratio of the polyester backbone portion to the polyether backbone portion in the polyurethane resin is in the range of (1:9) to (5:5); the polyester backbone can be formed by a polyester polyol compound, which is formed by low molecular weight polyols such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, neopentyl glycol, 1,2-butanediol, Compounds produced by reacting bisphenol A, 1,3-butanediol, 1,4-butanediol, 3-methylpentanediol, 1,6-hexanediol, hydrogenated bisphenol A, trimethylolpropane, and glycerol with polybasic acids such as succinic acid, glutaric acid, adipic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, tetrahydrophthalic acid, methylene-terminated tetrahydrophthalic acid, and hexahydrophthalic acid have an ester structure and terminal hydroxyl groups. The polyether backbone can be formed from a polyether polyol, preferably a compound obtained by adding an alkylene oxide having 2 to 4 carbon atoms (such as ethylene oxide, propylene oxide, and butylene oxide) to a diol containing a bisphenol backbone. Examples of the diol containing a bisphenol backbone include methylene bisphenol, ethylidene bisphenol, butylidene bisphenol, and isopropylidene bisphenol. The number of added moles of alkylene oxide is preferably 1 to 10. The amino resin in component B can be selected from commercially available Cytec 216, Cytec 301, Cytec 303, Cytec 327, Cytec 325, Cytec 370, Cytec 385, Cytec 659, Cytec 683, Cytec 1156, Cytec 1123, Cytec MM-100, INEOS 717, INEOS 718, INEOS R747, INEOS R757, INEOS 917, INEOS MF927, INEOS MF984, INEOS MF985, INEOS MF986, INEOS MF988, INEOS M195, INEOS MR921, INEOS CE7103, INEOS CE8824, OS 303-98, OS At least one of 325-80, methyl etherified amino resin 5717W, fully methyl etherified amino resin MR603, MELCROSS-83, Changxing ETERMINO9411, and ETERMINO9412; other amino resins may also be used.In this embodiment, the polyester backbone part, the polyether backbone part and their mass ratio in the polyurethane resin of component A are selected according to actual needs, and the specific amino resin in component B is selected so that after mixing components A and B, an anti-shrinkage viscous liquid with a tensile strength of ≥250 MPa and an elongation at break ≥80% after curing is formed.

[0028] In order to enhance the performance of the anti-shrinkage viscous layer 120, the anti-shrinkage viscous liquid may further include a filler component C, wherein the ratio of component A, component B, and filler component C is: (90-99): (1-5): (1-5), and in this embodiment, 93:3:3 can be selected; the filler component C includes at least one of silicon dioxide, aluminum hydroxide, aluminum oxide, talc, aluminum nitride, boron nitride, silicon carbide, barium sulfate, barium titanate, strontium titanate, boehmite, calcium carbonate, calcium silicate, mica, graphite, magnesium oxide, magnesium hydroxide, kaolin, starch, montmorillonite, titanium dioxide, zinc sulfide, calcium bicarbonate, calcium phosphate, calcium hydrogen phosphate, calcium sulfate, carbon black, graphite, multi-walled and single-walled carbon nanotubes, carbon nanofibers, polytetrafluoroethylene particles, polyurethane particles, rubber particles, polyamide particles, silicone particles, graphene, nanotube structure, and antimony trioxide.

[0029] The support layer 110 is directly bonded to the metal layer 130 via the anti-shrinkage adhesive layer 120 to form the current collector 100. The anti-shrinkage adhesive layer 120 can be a semi-cured layer structure pre-formed with an anti-shrinkage adhesive liquid, which is directly bonded to the support layer 110 and the metal layer 130. Alternatively, the anti-shrinkage adhesive layer 120 can be formed by coating the surface of the support layer 110 with an anti-shrinkage adhesive liquid, and then further bonded to the metal layer 130.

[0030] In this embodiment, the aforementioned anti-shrinkage adhesive liquid or other existing anti-shrinkage adhesive materials are selected to ensure that the tensile strength of the anti-shrinkage adhesive layer 120 is ≥250 MPa and the elongation at break is ≥80%. To improve the mechanical properties of the composite current collector 100, the tensile strength of the anti-shrinkage adhesive layer 120 can be 280 MPa to 400 MPa, or more specifically, 280 to 350 MPa. The bonding force between the anti-shrinkage adhesive layer 120 and the support layer 110 is in the range of 3 N / 25 mm to 30 N / 25 mm. The bonding force between the anti-shrinkage adhesive layer 120 and the metal layer 130 is in the range of 3 N / 25 mm to 30 N / 25 mm, or can be 3 N / 25 mm to 20 N / 25 mm. More preferably, the bonding force between the anti-shrinkage adhesive layer 120 and the metal layer 130 is in the range of 3 N / 25 mm to 15 N / 25 mm.

[0031] In addition to the aforementioned method of adding the C filler component before forming the anti-shrinkage adhesive layer 120, a cavity for accommodating a functional solid filler can also be provided within the anti-shrinkage adhesive layer 120 during its formation. When other materials are used to form the anti-shrinkage adhesive layer 120, performance can also be improved by reserving a cavity and filling it with a functional solid filler. The anti-shrinkage adhesive layer 120 can be filled with a functional solid filler to further improve its performance without affecting its thickness. The functional solid filler includes at least one of silicon dioxide, aluminum hydroxide, aluminum oxide, talc, aluminum nitride, boron nitride, silicon carbide, barium sulfate, barium titanate, strontium titanate, boehmite, calcium carbonate, calcium silicate, mica, graphite, magnesium oxide, magnesium hydroxide, kaolin, starch, montmorillonite, titanium dioxide, zinc sulfide, calcium bicarbonate, calcium phosphate, calcium hydrogen phosphate, calcium sulfate, carbon black, graphite, multi-walled and single-walled carbon nanotubes, carbon nanofibers, polytetrafluoroethylene particles, polyurethane particles, rubber particles, polyamide particles, silicone particles, graphene, nanotube structures, and antimony trioxide.

[0032] In this embodiment, the support layer 110 has a thickness of 1.9 to 6 μm; the anti-shrinkage adhesive layer 120 has a thickness of 0.8 to 4 μm; and the metal layer 130 has a thickness of 0.8 to 3.5 μm. Taking into account the thickness, performance, and metal content of the current collector 100, the thickness of the metal layer 130 may be 0.8 to 1.5 μm; more preferably, the thickness of the metal layer 130 is 1 to 1.5 μm. In this embodiment, the total thickness of the current collector 100 ranges from 6 to 12 μm. The support layer 110 is made of at least one of PET, PP, PI, PE, PVC, PBT, PC, PS, ABS, PA, PASF, PVDF, PEDOT, PANI, and PPy; and the metal layer 130 is made of at least one of copper, aluminum, titanium, nickel, cadmium, iron, or silver. In this embodiment, the metal layer 130 is a copper layer. The metal layer 130 is a copper foil layer; the number of pinholes on the copper foil layer is ≤5 / ㎡, and the diameter of the pinholes is ≤0.1mm.

[0033] In addition to the basic hierarchical structure, the current collector 100 of this embodiment may also include a protective layer 140, such as Figure 2 As shown, the protective layer 140 is disposed on the surface of the metal layer 130 away from the support layer 110. The protective layer 140 is formed of at least one material selected from the group consisting of chromium, tungsten, molybdenum, nickel, iron, titanium, niobium, zirconium, gold, silver, platinum, carbon, chromate compounds, silane compounds, and benzotriazole and its modified compounds. The thickness of the protective layer 140 is 0.01 to 0.15 μm.

[0034] In the current collector 100 formed in this embodiment, the surface roughness Ra of the metal layer 130 is ≤ 0.3 μm; and the surface dyne value of the metal layer 130 is ≥ 46.

[0035] The heat shrinkage rate of the anti-shrinkage adhesive layer 120 after treatment at 150°C for 30 minutes is ≤3%; the elongation of the current collector 100 is ≥3%. Furthermore, the heat shrinkage rate of the anti-shrinkage adhesive layer 120 after treatment at 150°C for 30 minutes is 0.9-2.5%. The surface resistance of the current collector 100 is ≤23mΩ. In this embodiment, whether it is the anti-shrinkage adhesive liquid formed by mixing components A and B, or the anti-shrinkage adhesive liquid that meets the properties of the anti-shrinkage adhesive layer 120 after curing using existing technology, both are coated on a carrier to form the anti-shrinkage adhesive layer 120. Therefore, the anti-shrinkage adhesive layer 120 is not produced by stretching on a specific length production line, but is directly coated and then cured, resulting in similar transverse and longitudinal mechanical properties. Although the testing process is based on the longitudinal length, the actual heat shrinkage rate, tensile strength, and elongation at break are almost equal in the longitudinal and transverse directions, with an error of no more than 3%. The thermal shrinkage rate, elongation at break, and tensile strength of the anti-shrinkage adhesive layer 120 described in this application should be understood as values ​​that do not distinguish between the longitudinal and transverse directions, or can also be considered to represent both longitudinal and transverse values. The thermal shrinkage rate of the anti-shrinkage adhesive layer 120 in this application is tested in accordance with JIS C2151 specifications.

[0036] Example 2

[0037] Based on Example 1, this example prepared corresponding samples using common common viscous materials and adhesive materials with different curing shrinkage rates. The samples were divided into Group A: common non-shrinkage-resistant viscous materials (curing shrinkage rate > 6%); Group B: viscous materials with a curing shrinkage rate of 5%; Group C: shrinkage-resistant viscous materials that met the performance requirements of Example 1 after curing, with a curing shrinkage rate of 2.8% (when using a shrinkage-resistant viscous liquid based on components A and B, the original components and ratios can be adjusted to adjust the curing shrinkage rate); and Group D: shrinkage-resistant viscous materials that met the performance requirements of Example 1 after curing, with a curing shrinkage rate of 0.5%. Performance tests were then conducted on each group.

[0038]

[0039] In the test results, samples in Groups A and B exhibited wrinkling, with gaps or bubbles between the anti-shrinkage adhesive layer 120 and the support layer 110 and metal layer 130, indicating a loose fit between the anti-shrinkage adhesive layer 120 and the metal layer 130. Group A also exhibited more severe wrinkling than Group B, with the overall current collector 100 appearing tightly wrinkled. Groups C and D, on the other hand, showed no significant wrinkling, nor were there any noticeable bubbles or gaps. In terms of adhesion, the anti-shrinkage effect of the anti-shrinkage adhesive layer 120 allowed for smooth adhesion between the different layers in Groups C and D, demonstrating a significant difference in adhesion compared to the other groups. Specifically, Groups C and D exhibited excellent adhesion, with Group D showing the best performance. Groups A and B exhibited poor adhesion.

[0040] Example 3

[0041] This embodiment is based on the production process of Example 1. An anti-shrinkage adhesive layer 120 is separately coated on the release film to produce an adhesive layer with a thickness of 4 μm. Five sets of anti-shrinkage adhesive layers 120 are produced using different weight ratios of component A, component B, and component C. The performance test results are shown in the following table (wherein, the peel strength is based on the test conducted after the metal layer 130 is laminated on one side):

[0042]

[0043] The results show that groups 1 through 4 all exhibit good performance test results, meeting the requirements for use as the support layer 110 of the composite current collector 100. Compared to groups 1 through 3, group 4 exhibits reduced tensile strength, elongation at break, and decreased adhesion. Group 5 exhibits weak adhesion to the metal layer 130, resulting in unstable attachment of the metal layer 130. Its mechanical properties and tensile strength are also significantly weaker than those of groups 1 through 4.

[0044] Example 4

[0045] In this embodiment, a composite current collector 100 was obtained using support layers 110, anti-shrinkage adhesive layers 120, and metal layers 130 of different thicknesses, and corresponding performance tests were conducted. The test results are shown in the following table.

[0046] Includes the following sample groups with different thickness selections:

[0047] a. Metal layer 1μm, anti-shrinkage adhesive layer 2.3μm, support layer 1.9μm;

[0048] b. Metal layer 0.8 μm, anti-shrinkage adhesive layer 1.5 μm, support layer 3 μm;

[0049] c. Metal layer 1.3 μm, anti-shrinkage adhesive layer 0.8 μm, support layer 4.5 μm;

[0050] d. Metal layer 1.5 μm, anti-shrinkage adhesive layer 0.3 μm, support layer 5 μm;

[0051] e. Metal layer 3.6 μm, anti-shrinkage adhesive layer 0.5 μm, support layer 1.5 μm.

[0052] In this embodiment, the metal layer 130 is made of copper foil. The anti-shrinkage adhesive layer 120 can be formed by the anti-shrinkage adhesive liquid formed by the aforementioned ratio of A:B:C=93:3:3. In addition, other existing anti-shrinkage adhesive materials can also be used.

[0053] Performance Testing unit a b c d e Average total thickness μm 8.5 7.6 8.7 8.6 19.7 tensile strength Mpa 260 276 289 289 170 Elongation ％ 3.5 3.6 3.7 3.3 2.8

[0054] The results show that, overall, the current collector 100 with a certain thickness of the anti-shrinkage adhesive layer 120 based on the present application has excellent mechanical properties. In terms of performance, the anti-shrinkage adhesive layer 120 can significantly improve tensile strength and elongation. The metal layer 130 also has a significant impact on factors such as tensile strength. It is important to note that the cooperation between the anti-shrinkage adhesive layer 120, the support layer 110, and the metal layer 130 can synergistically ensure the overall excellent performance of the corresponding current collector 100.

[0055] Example 5

[0056] This embodiment discloses a battery, including the negative electrode current collector 100 described in the aforementioned embodiment 1. The battery of this embodiment has high energy density, tight bonding between different layers, and stable performance.

[0057] Example 6

[0058] This embodiment discloses the application of the negative electrode current collector 100 of Example 1 or the battery described in Example 5 in a power vehicle.

[0059] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the technical solution of the present invention, and are not intended to limit the specific implementation methods of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the claims of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A current collector, characterized in that: The invention comprises a supporting layer, an anti-shrinkage adhesive layer and a metal layer; the anti-shrinkage adhesive layer is provided on at least one side of the supporting layer; and the metal layer is provided on the side of the anti-shrinkage adhesive layer away from the supporting layer.

2. The current collector according to claim 1, characterized in that The tensile strength of the anti-shrinkage adhesive layer is ≥250 MPa; and the elongation at break is ≥80%.

3. The current collector according to claim 1, characterized in that The adhesive force between the anti-shrinkage adhesive layer and the support layer ranges from 3N / 25mm to 30N / 25mm; the adhesive force between the anti-shrinkage adhesive layer and the metal layer ranges from 3N / 25mm to 30N / 25mm.

4. The current collector according to claim 1, characterized in that A cavity for accommodating functional solid fillers is reserved in the anti-shrinkage adhesive layer.

5. The current collector according to claim 4, characterized in that The functional solid filler includes silicon dioxide, aluminum hydroxide, aluminum oxide, talc, aluminum nitride, boron nitride, silicon carbide, barium sulfate, barium titanate, strontium titanate, boehmite, calcium carbonate, calcium silicate, mica, graphite, magnesium oxide, magnesium hydroxide, kaolin, starch, montmorillonite, titanium dioxide, zinc sulfide, calcium bicarbonate, calcium phosphate, calcium hydrogen phosphate, calcium sulfate, carbon black, multi-walled and single-walled carbon nanotubes, carbon nanofibers, polytetrafluoroethylene particles, polyurethane particles, rubber particles, polyamide particles, silicone particles, graphene, nanotube structure or antimony trioxide.

6. The current collector according to claim 1, characterized in that The thickness of the support layer is 1.9 μm to 6 μm; the thickness of the anti-shrinkage adhesive layer is 0.8 μm to 4 μm; and the thickness of the metal layer is 0.8 μm to 3.5 μm.

7. The current collector according to any one of claims 1 to 6, characterized in that: The total thickness of the current collector is 6 μm to 12 μm.

8. The current collector according to any one of claims 1 to 6, characterized in that: The support layer is one of PET, PP, PI, PE, PVC, PBT, PC, PS, ABS, PA, PASF, PVDF, PEDOT, PANI and PPy.

9. The current collector according to any one of claims 1 to 6, characterized in that: The metal layer is one of copper, aluminum, titanium, nickel, cadmium, iron and silver.

10. The current collector according to any one of claims 1 to 6, characterized in that: It also includes a protective layer, which is arranged on the side of the metal layer away from the supporting layer; the protective layer is formed of a material selected from the group consisting of chromium, tungsten, molybdenum, nickel, iron, titanium, niobium, zirconium, gold, silver, platinum, carbon, chromate compounds, silane compounds, benzotriazole and its modified compounds.

11. A battery, characterized in that: The current collector comprises the current collector according to any one of claims 1 to 10.

12. A powered vehicle, characterized in that: The present invention comprises the current collector according to any one of claims 1 to 10 or the battery according to claim 11.

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