Porous composite copper foil, negative electrode current collector, battery and vehicle
By setting coating areas on both sides of the thin film substrate of the composite copper foil and forming a three-dimensional porous copper coating, the problem of poor adhesion of traditional composite copper foil is solved, the heat dissipation and lithium-ion diffusion capacity of the electrode are improved, the bonding force of the negative electrode material is enhanced, and the fast charging performance of the battery is improved.
Patent Information
- Application Number
- CN202422554677.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-22
- Publication Date
- 2025-11-07
- Estimated Expiration
- 2034-10-22
Smart Images
Figure CN223527187U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of composite copper foil, in particular to a porous composite copper foil, a negative current collector, a battery and a vehicle. BACKGROUND
[0002] At present, the negative conductive current collector of lithium ion battery is mainly copper foil, which is generally obtained by electrolysis or calendering method, also known as electrolytic copper foil. The composite copper foil is formed by replacing part of copper with polymer material. The use of composite copper foil has the advantages of high energy density and low cost.
[0003] However, the plating layer of the traditional composite copper foil does not have a spatial structure, and the adhesion between the plating layer and the negative material is poor, which may cause wrinkles during the secondary processing of the pole piece.
[0004] Therefore, it is necessary to develop a porous composite copper foil, a negative current collector, a battery and a vehicle to overcome the above difficulties. CONTENT OF THE INVENTION
[0005] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application provides a porous composite copper foil, a negative current collector, a battery and a vehicle.
[0006] The first aspect of the present application provides a porous composite copper foil, comprising: a film substrate and a copper plating layer; the opposite sides of the film substrate are respectively provided with a plating layer area; the surface of the plating layer area is provided with a rough surface structure having voids and unevenness; the copper plating layer is formed on the rough surface structure of the plating layer area, and is a three-dimensional hole structure.
[0007] Preferably, the porosity of the copper plating layer is 25%-74%.
[0008] Preferably, the plating layer area is the entire surface or a partial area of the film substrate.
[0009] Preferably, the plating layer area is exposed to the chemical plating catalyst by etching treatment; the exposed chemical plating catalyst makes the surface of the plating layer area a rough surface structure having voids and unevenness.
[0010] Preferably, the chemical plating catalyst is CuFe2Oσ (σ≤4) particles.
[0011] Preferably, the thickness of the film substrate is set to be between 1 μm and 20 μm.
[0012] Preferably, the thickness of the copper layer is set to be between 0.5 μm and 20 μm.
[0013] The second aspect of the present application provides a negative current collector comprising the above-mentioned porous composite copper foil.
[0014] The third aspect of the present application provides a battery comprising a positive electrode sheet, a separator and a negative electrode sheet arranged in layers, wherein the negative electrode sheet comprises the above-mentioned negative current collector.
[0015] The fourth aspect of the present application provides a vehicle comprising the above-mentioned battery.
[0016] Specifically, compared with the prior art, the beneficial effects of the present application are as follows:
[0017] The porous composite copper foil in the present application is provided with a plating layer area on the opposite two side surfaces of the film substrate, and the surface of the plating layer area is provided with a rough surface structure with voids and unevenness. When a copper plating layer is formed on the rough surface structure through copper plating treatment subsequently, the copper plating layer irregularly grows on the rough surface structure to have a three-dimensional pore structure. The copper plating layer with the three-dimensional pore structure has more voids, i.e., a larger specific surface. When the electrode sheet is made, the negative electrode material can be embedded into the voids, so that the foil has a strong binding force and a strong restraining force on the negative electrode material. The foil with the three-dimensional pore structure can restrain the expansion of the negative electrode material, and thus wrinkles are less likely to occur in the process of secondary processing of the electrode sheet.
[0018] The negative current collector in the present application has more voids and a larger specific surface due to the use of the porous composite copper foil, so that the electrode sheet has more excellent heat dissipation performance. The three-dimensional pore structure has more contact interfaces with the negative electrode material, which can improve the adhesion between the material and the foil and thus reduce the amount of adhesive, so as to achieve the purpose of improving the capacity density and reducing the impedance. Meanwhile, the three-dimensional pore structure also improves the lithium ion diffusion capacity, reduces the tortuosity of lithium ion diffusion, and improves the lithium precipitation window of the material, so that the battery has more excellent fast charging performance. BRIEF DESCRIPTION OF DRAWINGS
[0019] Figure 1 It is a schematic diagram of the layer structure of the porous composite copper foil in the embodiments of the present application.
[0020] Figure 2 It is a schematic diagram of the surface morphology of the plating layer area in the embodiments of the present application.
[0021] Reference signs: 1, film substrate; 2, copper plating layer. DETAILED DESCRIPTION
[0022] In order to make the purpose, technical solutions and advantages of the present application more clear and explicit, the present application is further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.
[0023] It should be noted that the drawings provided in the embodiments only schematically illustrate the basic concept of the present application, and only the components related to the present application are shown in the drawings, rather than being drawn according to the number, shape and size of the components in actual implementation. The shape, number and proportion of each component in actual implementation can be arbitrarily changed, and the component layout pattern can be more complex.
[0024] The structure, proportion, size, etc. shown in the drawings of the present specification are only used to cooperate with the content disclosed in the specification, so that those skilled in the art can understand and read, and are not used to limit the defined conditions that can be implemented by the present application. Therefore, any modification of the structure, change of the proportion relationship or adjustment of the size, without affecting the effects that can be produced by the present application and the purposes that can be achieved, should still fall within the scope of the technical content disclosed by the present application.
[0025] The orientations or positional relationships indicated by the terms such as "upper", "lower", "left", "right", "intermediate", "longitudinal", "lateral", "horizontal", "inner", "outer", "radial", "circumferential", etc. in the present specification are based on the orientations or positional relationships shown in the drawings, and are only for the purpose of simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation. Therefore, it cannot be understood as a limitation on the present application. In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance.
[0026] Please refer to Figure 1 The present embodiment provides a porous composite copper foil, which is described in detail below, including: a film substrate 1 and a copper plating layer 2, the opposite two side surfaces of the film substrate 1 are respectively provided with a plating layer area, the surface of the plating layer area is provided with a rough surface structure having voids and unevenness; the copper plating layer 2 is formed on the rough surface structure of the plating layer area, the copper plating layer 2 is a three-dimensional hole structure, and the porosity of the copper plating layer 2 is 25%-74%.
[0027] In the present application, the copper plating layer 2 is symmetrically compounded on the plating layer areas on both sides of the film substrate 1, and the copper plating layer 2 is a three-dimensional hole structure with a porosity of 25%-74% such as 25%, 49%, 58%, 67%, and 74%. By forming the copper plating layer 2 on the rough surface structure of the plating layer area, the copper plating layer 2 irregularly grows on the rough surface structure to have a three-dimensional hole structure, so that the porous composite copper foil has a porous structure and a larger specific surface area. The negative electrode material can be embedded in the voids, so that the foil has a strong binding force and a strong restraint force on the negative electrode material. The same adhesive shows a stronger adhesive strength when the electrode piece is made, and the foil with a three-dimensional hole structure can restrain the expansion of the negative electrode material, so that wrinkles are less likely to occur during the secondary processing of the electrode piece.
[0028] It should be noted that when the porosity of the copper plating layer 2 is set to 74%, the porous composite copper foil has more voids and a larger specific surface area, and the negative material can be embedded in more voids, so that the foil has stronger binding force and restraint force on the negative material; when the porosity of the copper plating layer 2 is set to 25%, the porous composite copper foil has more voids and a larger specific surface area, and the negative material can be embedded in more voids, so that the foil has stronger binding force and restraint force on the negative material; when the porosity of the copper plating layer 2 is set to 49%, the porous composite copper foil has more voids and a larger specific surface area, and the thickness of the plating layer is suitable. If the porosity exceeds 74%, although more voids can be generated, the plating layer thickness requires to be thinner, and the copper plating process is relatively difficult; if it is lower than 25%, the porous composite copper foil has fewer voids, the binding force and restraint force of the foil on the negative material are poor, and the thickness of the plating layer is thicker. Therefore, in the present embodiment, the porosity is preferably set to between 49% and 74%.
[0029] Please refer to Figure 1 、 Figure 2 In the present embodiment, it should be noted that the rough surface structure of the plating layer region forms a dense copper plating layer 2 with a three-dimensional hole structure on the surface after copper plating treatment. The surface of the plating layer region is provided with a rough surface structure with voids and unevenness. During subsequent chemical copper plating treatment, metal copper particles are embedded in the pores of the rough surface, and at the same time, the rough surface structure is wrapped and connected to form a dense copper plating layer 2 with a three-dimensional hole structure, and the copper plating layer 2 and the thin film substrate 1 form a strong binding force.
[0030] In one possible way, the plating layer region is dispersed with a chemical plating catalyst. The dispersed chemical plating catalyst makes the surface of the plating layer region a rough surface structure with voids and unevenness on a microscopic scale. The rough surface structure is treated with copper plating, and the chemical plating method commonly used by those skilled in the art can be used, for example, the thin film substrate 1 can be contacted with a chemical copper plating solution. After the chemical plating catalyst in the plating layer region is contacted with the chemical copper plating solution, the chemical plating catalyst can promote the reduction reaction of copper ions in the chemical copper plating solution to generate metal copper particles, which are then embedded in the pores of the rough surface, wrap the surface of the chemical plating catalyst, and connect with each other to quickly form a dense copper plating layer 2 with a three-dimensional hole structure in the plating layer region of the thin film substrate 1.
[0031] In another possible implementation, the electroless plating catalyst can be uniformly doped in the thin film substrate 1, and then the plating layer region on the surface of the thin film substrate 1 is etched by using a laser to expose the electroless plating catalyst, the exposed electroless plating catalyst forms a rough surface structure with micro gaps and unevenness on the surface of the plating layer region, and in the subsequent electroless copper plating, copper is embedded in the pores of the rough surface, wrapped around the surface of the electroless plating catalyst, and connected to each other to form a dense copper plating layer 2 with a three-dimensional pore structure.
[0032] In another possible implementation, the thin film substrate 1 can be formed first, and the electroless plating catalyst is uniformly distributed in the thin film substrate 1. The forming method can use various forming methods in the prior art, which are not specifically limited in the embodiment. In the embodiment, one of the organic substrates such as PP (polypropylene), PE (polyethylene), PC (polycarbonate), PET (polyethylene terephthalate), and PA (polyamide) is used. The electroless plating catalyst is uniformly mixed with the master batch by using a high-speed stirring machine, and then the electroless plating catalyst is uniformly mixed into the plastic particles by using a double-screw extruder. The plastic particles are blown by a blow molding machine to obtain a thin film substrate 1 with a thickness of 1-20 μm. Then, the organic substrate on the surface of the plating layer region of the thin film substrate 1 is removed by using a laser to expose the electroless plating catalyst, and copper is electrolessly plated on the surface of the exposed electroless plating catalyst. The electroless plating and / or electroplating are continued for at least one time to form a dense copper plating layer 2 with a three-dimensional pore structure on the surface of the thin film substrate 1. The content of the electroless plating catalyst is 1-40% based on the mass of the thin film substrate 1. The region of the surface of the thin film substrate 1 from which the organic substrate is not removed, i.e., the untreated region, does not contain the electroless plating catalyst, and the surface thereof is much rougher than the surface of the plating layer region. Therefore, the speed of metal chemical deposition is very slow and the adhesion is very low. In the electroless plating process, basically no metal is deposited, and if a small amount of metal is deposited, it can be easily wiped off.
[0033] It should be noted that the method for electrolessly plating copper on the thin film with exposed catalyst component particles is also known to those skilled in the art. For example, the method can include contacting the etched thin film sample with a copper plating solution containing a copper salt and a reducing agent, and the pH value is 12-13. The reducing agent can reduce the copper ions in the copper salt to copper single substance, for example, the reducing agent can be one or more of glyoxylic acid, hydrazine, and sodium hypophosphite. The specific setting is not specifically limited in the embodiment.
[0034] In the present embodiment, it is also necessary to point out that the organic material on the surface of the film substrate 1 in the plating layer region can be removed in various ways commonly used by those skilled in the art. Preferably, when the plating layer region is the entire surface of the film substrate 1, the organic material in the plating layer region can be removed by laser, corona, chemical etching or grinding. When the plating layer region is part of the surface of the film substrate 1, the organic material in the plating layer region can be removed by laser or corona. The specific choice is not specifically limited in the present embodiment.
[0035] In the present embodiment, it is also necessary to point out that the electroless plating catalyst is a metal oxide or a multi-metal composite oxide having active oxygen vacancies; the metal oxide or multi-metal composite oxide has oxygen vacancies, and has structural instability and strong reducing properties that the original metal oxide or multi-metal composite oxide does not have. In the present embodiment, copper ferrite CuFe2Oσ particles with active oxygen vacancies are taken as an example, where σ is the degree of oxygen vacancy in the compound, σ≤4, to illustrate the structural instability and strong reducing properties of the electroless plating catalyst of the present application: (1) there are oxygen vacancies in the copper ferrite (CuFe2Oσ) lattice, which can effectively bind oxygen to the CuFe2Oσ lattice; (2) in the copper ferrite (CuFe2Oσ) crystal, not only is there electron migration between Cu+ / Cu2+ and Fe2+ / Fe3+, but there is also electron migration between Cu+ / Fe3+; the electrons are prone to migrate and easily lose electrons, exhibiting strong reducing properties; (3) in the process of generating copper ferrite (CuFe2Oσ) with active oxygen vacancies by losing oxygen from CuFe2O4, a large number of cations gather in the lattice, causing the lattice gap to expand, the lattice to twist and vary, increasing its chemical potential energy, resulting in structural instability of the copper ferrite with active oxygen vacancies, which needs to capture O 2- to fill the oxygen vacancies, thereby exhibiting strong reducing properties.
[0036] The electroless plating catalyst used in the present embodiment can be directly used as a commercially available product, or can be prepared by oneself, and its preparation method is well known to those skilled in the art. For example, first, a metal oxide / multi-metal composite oxide with a common molecular structure is prepared by a co-precipitation method, a sol-gel method, a hydrothermal method, a solid-phase sintering method and other techniques known to those skilled in the art, or a commercially available sample of a metal oxide / multi-metal composite oxide is directly used; then, high-temperature sintering is performed in a nitrogen or inert gas atmosphere, so that part of the active oxygen in the oxide is lost, thereby generating oxygen vacancies, i.e. the electroless plating catalyst. The specific choice is not specifically limited in the present embodiment.
[0037] In some embodiments, the average particle size of the electroless plating catalyst is 250 nm-350 μm, preferably 300 μm.
[0038] In some embodiments, the thickness of the thin film substrate 1 is set to be between 1 μm and 20 μm, preferably between 5 μm and 20 μm, and more preferably 6 μm. The thickness of the removed organic substrate on the surface of the plating area is several hundred nanometers to several microns, so that the electroless plating catalyst in the plating area is exposed, and the exposed electroless plating catalyst forms a rough surface structure with micro gaps.
[0039] In some embodiments, the thickness of the copper plating layer 2 is set to be between 0.5 μm and 20 μm, and more preferably, the thickness of the copper plating layer 2 is set to be between 0.5 μm and 6 μm. If the thickness exceeds this range, although the strength of the current collector is good, the thickness is too large, so the thickness in this embodiment is mainly selected to be between 0.5 μm and 6 μm.
[0040] The implementation principle of this embodiment is as follows: the electroless plating catalyst is uniformly provided in the thin film substrate 1, the plating area of the thin film substrate 1 is etched by laser, the electroless plating catalyst is exposed, the exposed electroless plating catalyst forms a rough surface structure with micro gaps, the electroless plating catalyst contacts the electroless copper plating solution in the subsequent copper plating process, the electroless plating catalyst promotes the reduction reaction of copper ions in the electroless plating solution to generate metal copper particles, the metal copper particles are wrapped on the surface of the electroless plating catalyst and embedded in the gaps, and the irregular growth of the rough surface structure makes the copper plating layer 2 have a three-dimensional hole structure. The porous composite copper foil has a porous structure and a large specific surface area, the negative electrode material can be embedded in the gaps, the foil has strong adhesion and binding force to the negative electrode material, the same adhesive shows stronger adhesion strength when the electrode sheet is made, and the three-dimensional hole structure of the foil can bind the expansion of the negative electrode material, so that wrinkles are less likely to occur during the secondary processing of the electrode sheet.
[0041] In this embodiment, the application further provides a negative current collector including the above-mentioned porous composite copper foil.
[0042] In this embodiment, the application further provides a battery including a positive electrode sheet, a separator, and a negative electrode sheet arranged in layers, wherein the negative electrode sheet includes the above-mentioned negative current collector.
[0043] In the production of the battery, the parameters of the negative electrode sheet and the positive electrode sheet are set respectively, for example, the electrode sheet parameters of the negative electrode sheet: graphite: binder: CMC glue: conductive agent = 96: 1.5: 1.5: 1, and the double-sided area density is 155-165 g / m 2 , and the compaction density after secondary rolling is 1.58-1.6 g / cm 3 .
[0044] The binder can be styrene butadiene rubber emulsion (SBR), the CMC glue is CMC (sodium carboxymethyl cellulose), and the conductive agent can be conductive carbon black (SP).
[0045] The electrode parameters of the positive electrode sheet: lithium iron phosphate: carbon nanotube: lithium battery binder: conductive agent = 96: 1: 2: 1, double-sided area density 350-360 g / m 2 , the compaction density after secondary rolling is 2.55-2.6 g / cm 3 .
[0046] The lithium battery binder can be polyvinylidene fluoride (PVDF), and the conductive agent can be conductive carbon black (SP).
[0047] Example 1
[0048] Step 1, mix PET plastic particles with CuFe2Oσ (σ≤4) uniformly, preferably add 5% mass percentage of electroless plating catalyst, then granulate through an extruder to obtain modified PET masterbatch, and then blow molding to obtain a film substrate containing electroless plating catalyst, which is uniformly distributed in the film substrate, preferably a 6 μm thick film substrate.
[0049] Step 2, remove the organic matrix on the selected area of the film substrate surface by a 3-4 W laser, and then expose the electroless plating catalyst with a thickness of 0.5 μm in the corresponding area.
[0050] Step 3, electroless copper plating is performed on the exposed electroless plating catalyst plating area, the copper plating time is 0.5 h, the plating thickness H is tested after drying, the mass of the film per unit area before copper plating M1, the mass of the copper plated M2, the density of pure copper p = 8.96 g / m3, and the porosity = 1-((M2-M1) / H*P); the copper plated foil per unit area is weighed and the thickness is measured.
[0051] Step 4, battery making: ① negative electrode sheet parameters: graphite: SBR (binder): CMC (sodium carboxymethyl cellulose): SP (conductive agent) = 96: 1.5: 1.5: 1, double-sided area density 155 g / m 2 , the compaction density after secondary rolling is 1.58 g / cm 3 ; ② positive electrode sheet parameters: LFP (lithium iron phosphate): CNTs (carbon nanotube): PVDF (lithium battery binder): SP (conductive agent) = 96: 1: 2: 1, double-sided area density 350 g / m 2 , the compaction density after secondary rolling is 2.55 g / cm 3 , make the same specification small soft package battery for testing, record the temperature rise change, test the cycle capacity retention rate, and record the test data.
[0052] Example 2
[0053] Example 2 is the same as the steps of Example 1, the difference is that the plating copper time in step 3 is controlled to 1 h.
[0054] Example 3
[0055] Example 3 is the same as the steps of Example 1, the difference is that the plating copper time in step 3 is controlled to 1.5 h, and the three-electrode lithium stripping test is increased.
[0056] Example 4
[0057] Example 4 is the same as the steps of Example 1, the difference is that the plating copper time in step 3 is controlled to 2 h.
[0058] Comparative Example 1
[0059] Step 1: cleaning and roughening: preferably 4 μm PET is cleaned with surfactant, deionized water and anhydrous ethanol for 15 min; then immersed in 50℃ 1 mol / L sodium hydroxide solution for 60 min, and washed with deionized water after taking out;
[0060] Step 2: activation: the cleaned polymer film is immersed in 0.1 mol / L PdCl2 solution at a temperature of 35℃ for 5 min, and washed with deionized water after taking out. Then the polymer film is immersed in 0.1 mol / L NaBH4 solution for 5 min, and washed with deionized water after taking out, to obtain a polymer film with catalytically active Ni loaded on the surface;
[0061] Step 3: chemical plating: the activated polymer film is immersed in a copper plating solution at 50℃ for chemical plating for 5 min, and then washed with deionized water after the end, to obtain a composite copper foil (Cu@PET),
[0062] Step 4: battery making: ① negative electrode parameters: graphite: SBR: CMC: SP = 96: 1.5: 1.5: 1, double-sided area density 165 g / m 2 , the compaction density after secondary rolling is 1.6 g / cm 3 ; ② positive electrode parameters: LFP: CNTs: PVDF: SP = 96: 1: 2: 1, double-sided area density 360 g / m 2 , the compaction density after secondary rolling is 2.6 g / cm 3 ; make the same specification small soft package battery, test, test record temperature rise change, test cycle capacity retention rate, and record test data.
[0063] Comparative Example 2
[0064] The experimental procedure is the same as that of Comparative Example 1, except that the chemical plating time is controlled to be 10 min.
[0065] Comparative Example 3
[0066] The experimental procedure is the same as that of Comparative Example 1, except that the chemical plating time is controlled to be 15 min.
[0067] Comparative Example 4
[0068] The experimental procedure is the same as that of Comparative Example 1, except that the chemical plating time is controlled to be 20 min; and a three-electrode lithium stripping test is additionally performed.
[0069] Comparative Example 5
[0070] The experimental procedure is the same as that of Comparative Example 1, except that the chemical plating time is controlled to be 25 min.
[0071] Comparative Example 6
[0072] The experimental procedure is the same as that of Comparative Example 1, except that the chemical plating time is controlled to be 30 min.
[0073] In the examples and comparative examples, the surface and cross-section micro-morphology of the samples are characterized by a scanning electron microscope (SEM, Hitachi, SU-70), and the copper plating thickness is measured by Smil e view;
[0074] The mass of the copper foil in the examples and comparative examples is measured by a Mettler analytical balance me204;
[0075] The high-temperature cycle test of the battery cell in the examples and comparative examples is performed by a new Wei CT-4096 charge-discharge cabinet.
[0076] Table 1 test data
[0077]
[0078] As can be seen from the test data in Table 1 above, the porous composite copper foil prepared in the examples has more excellent performance than the comparative examples under the same copper surface density, for example, the porosity of the porous copper foil prepared in Example 1 is 74%, which has more voids, i.e., a larger specific surface area, to accelerate heat dissipation and have a stronger adhesion strength to the coated material. However, to obtain a larger porosity, according to the above table, the plating layer thickness needs to be thinner and the copper plating time needs to be shorter, but the copper plating process is relatively difficult. Therefore, in the present embodiment, the porosity of the porous copper foil is preferably set to be between 49% and 74%.
[0079] In the present embodiment, the application further provides a vehicle comprising the above-mentioned battery.
[0080] Any combination of the technical features in the above embodiments can be made, and for the sake of brevity, not all possible combinations are described above, however, as long as the combination of the technical features does not exist in contradiction, it shall be considered within the scope of the present disclosure.
[0081] The above embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it shall not be understood as a limitation on the patent scope of the present application. It shall be pointed out that, for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, and these shall be within the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.
Claims
1. A porous composite copper foil, characterized by, The porous composite copper foil comprises: a film substrate (1) and a copper plating layer (2); opposite sides of the film substrate (1) are respectively provided with a plating layer area; a surface of the plating layer area is provided with a rough surface structure having gaps and unevenness; the copper plating layer (2) is formed on the rough surface structure of the plating layer area and has a three-dimensional hole structure.
2. The porous composite copper foil according to claim 1, wherein: a porosity of the copper plating layer (2) is 25%-74%.
3. The porous composite copper foil according to claim 1, wherein: the plating layer area is the entire surface or a partial area of the film substrate (1).
4. The porous composite copper foil according to claim 1, wherein: a thickness of the film substrate (1) is set to be between 1 μm and 20 μm.
5. The porous composite copper foil according to claim 1, wherein: a thickness of the copper plating layer (2) is set to be between 0.5 μm and 20 μm.
6. A negative current collector, characterized by: A battery comprising the porous composite copper foil according to any one of claims 1-5.
7. A battery, characterized by: A battery comprising the negative electrode current collector according to claim 6.
8. A vehicle characterized by: A battery comprising the battery according to claim 7.