A current collector, its preparation method and application

Abstract

This invention discloses a current collector, its preparation method, and its application. The current collector includes a metal conductor and a coating on at least one side of the metal conductor. The coating includes an adjacent dihydroxyl polymer and a carbon conductive material. The current collector of this invention contains an adjacent dihydroxyl structure, which has a strong bonding ability to the surface of the metal conductor. This invention obtains the current collector by coating a coating slurry containing a carbon conductive material and an adjacent dihydroxyl polymer onto the surface of a metal conductor and drying it to form a film. An electrode active material is then coated onto this current collector to prepare an electrode with strong adhesion of the active component and low internal resistance.

Description

Technical Field

[0001] This invention belongs to the field of battery electrode preparation technology, specifically relating to a current collector, its preparation method, and its application. Background Technology

[0002] Lithium-ion batteries, particularly non-aqueous rechargeable batteries, are increasingly being developed for miniaturization and weight reduction in electronic devices, becoming the primary power source for portable electronic devices such as mobile phones and personal computers. The active materials and conductive agents in the electrode structures of lithium-ion batteries are adhered to the current collector using an adhesive. The adhesive strength directly affects the battery's electrical performance. Current battery electrode fabrication involves directly coating the electrode slurry onto the surface of the metal current collector, drying it, and then fixing the active material with an adhesive. However, the limited contact area between the active material particles and the metal current collector, coupled with the limited bonding ability of the adhesive, results in a high interfacial resistance, leading to increased internal resistance and impacting battery performance. During continuous charge and discharge, the active material is prone to detachment from the current collector, causing material shedding and wrinkling on the positive and negative electrodes, further increasing internal resistance and severely affecting the battery's cycle life and safety performance.

[0003] Electrodes are prepared by coating a conductive carbon layer onto the surface of a metal foil to obtain a carbon-coated current collector, which is used in lithium-ion batteries and capacitors. This process can suppress battery polarization, reduce thermal effects, and improve the rate performance of the battery. It also improves the adhesion between the active material and the metal, reducing the amount of binder required. However, with the market's increasing demands for the rate and cycle performance of lithium batteries, coupled with the problems of unstable coating conductivity, poor adhesion, and uneven heat dissipation inherent in currently used carbon-coated current collectors, simply coating aluminum foil with a single conductive material is no longer sufficient to meet the requirements. Summary of the Invention

[0004] To address the aforementioned technical problems, the present invention provides the following technical solution:

[0005] A current collector comprising: a metal conductor and a coating located on at least one side of the surface of the metal conductor; the coating comprising an adjacent dihydroxy polymer and a carbon conductive material.

[0006] The adjacent dihydroxy polymer comprises the structural units shown in formulas (I) and (II):

[0007]

[0008] In equations (I) and (II), R1, R2, R3, R4, R5, and R6 may be the same or different, and are independently selected from H and C. 1-8 Alkyl group; a and c may be the same or different, are independent integers greater than or equal to 0, and a and c are not both 0.

[0009] The adjacent dihydroxy polymer further includes structural units represented by formula (III), formula (IV) and / or formula (V):

[0010]

[0011] In equations (III) and (IV), R1, R2, R3, R4, R5, and R6 may be the same or different, and are independently selected from H and C. 1-8 Alkyl group; b and d may be the same or different, and are independent integers greater than or equal to 0;

[0012] In equation (V), R 19 Selected from no substitution, or arbitrarily selected by one, two or more R c Replacement C 6-20 Aryl; each R c Same or different, selected independently from C 1-12 Alkyl; e is an integer greater than or equal to 0.

[0013] The number-average molecular weight of the adjacent dihydroxy polymer is 2,000 to 200,000.

[0014] The carbon conductive material is selected from at least one of activated carbon, carbon black, graphite, graphene, carbon-supported graphene, fullerene, carbon nanotubes, vapor-grown carbon fibers, carbon nanotubes, carbon nanotube coils, cup-shaped carbon nanotubes, and bamboo-shaped carbon nanotubes.

[0015] The thickness of the coating is 0.1 μm to 20 μm.

[0016] Furthermore, in the coating, the mass ratio of the adjacent dihydroxy polymer and the carbon conductive material is 1:(0.2-2).

[0017] Furthermore, the metal conductor is selected from at least one of aluminum, copper, stainless steel, nickel, and iron.

[0018] Furthermore, the coating is located on one side surface of the metal conductor or on both sides surface of the metal conductor.

[0019] A method for preparing the current collector, the method comprising: preparing a slurry comprising a carbon conductive material and an adjacent dihydroxy polymer, coating the slurry onto at least one side surface of a metal conductor, and drying to obtain the current collector.

[0020] A battery electrode comprising the aforementioned current collector and an active material layer located on at least one side surface of the current collector containing an adjacent dihydroxy polymer.

[0021] A non-aqueous electrolyte secondary battery, the battery comprising the above-mentioned current collector or the above-mentioned battery electrode.

[0022] A capacitor comprising the aforementioned current collector.

[0023] Beneficial effects of the present invention

[0024] The current collector of this invention contains a polymer with adjacent dihydroxyl structures, which have a strong binding ability to the surface of a metal conductor. This invention involves coating a coating slurry containing a carbon conductive material and an adjacent dihydroxyl polymer onto the surface of a metal conductor, drying it to form a film, and then coating this current collector with an electrode active material to prepare an electrode with strong adhesion of the active component and low internal resistance. Attached Figure Description

[0025] Figure 1 This is a structural diagram of the current collector of the present invention.

[0026] Figure 2 The electrode structure diagram of the present invention.

[0027] 01-Metallic conductor, 02-Coating, 03-Electrode active material layer. Detailed Implementation

[0028] As previously stated, the present invention provides a current collector comprising a metal conductor and a coating located on at least one side of the surface of the metal conductor, the coating comprising an adjacent dihydroxy polymer and a carbon conductive material.

[0029] According to an embodiment of the present invention, the adjacent dihydroxy polymer comprises the structural units shown in formulas (I) and (II):

[0030]

[0031] In equations (I) and (II), R1, R2, R3, R4, R5, and R6 may be the same or different, and are independently selected from H and C. 1-8 Alkyl group; a and c may be the same or different, are independent integers greater than or equal to 0, and a and c are not both 0.

[0032] According to embodiments of the present invention, the adjacent dihydroxy polymer may further include at least one of the structural units shown in formula (III), formula (IV) and formula (V):

[0033]

[0034] In equations (I) and (II), R1, R2, R3, R4, R5, and R6 may be the same or different, and are independently selected from H and C. 1-8 Alkyl group; b and d may be the same or different, and are independent integers greater than or equal to 0;

[0035] In equation (V), R19 Selected from no substitution, or arbitrarily selected by one, two or more R c Replacement C 6-20 Aryl; each R c Same or different, selected independently from C 1-12 Alkyl group; e is an integer greater than or equal to 0.

[0036] According to an embodiment of the present invention, in formulas (I) to (II), R1, R2, R3, R4, R5, and R6 may be the same or different, and are independently selected from H and C. 1-6 alkyl.

[0037] According to embodiments of the present invention, in formulas (III) and (IV), R1, R2, R3, R4, R5, and R6 may be the same or different, and are independently selected from H and C. 1-6 alkyl.

[0038] According to an embodiment of the present invention, in formula (V), R 19 Selected from no substitution, or arbitrarily selected by one, two or more R c Replacement C 6-14 Aryl; each R c Same or different, selected independently from C 1-6 alkyl.

[0039] For example, the adjacent dihydroxy polymer contains structural units shown in formulas (I), (II), (III) and (IV).

[0040] For example, the adjacent dihydroxy polymer contains structural units shown in formulas (I), (II), (III), (IV) and (V).

[0041] According to an embodiment of the present invention, the number average molecular weight of the adjacent dihydroxy polymer is 2,000 to 200,000, and exemplary values ​​are 2,000, 5,000, 6,700, 7,560, 10,000, 14,500, 15,000, 20,000, 50,000, 62,500, 67,700, 92,300, 100,000, 143,000, 150,000, and 200,000.

[0042] Preferably, in the adjacent dihydroxy polymer, a is an integer between 0 and 3000, and a and c are not both 0; preferably, a is an integer between 50 and 2000.

[0043] Preferably, in the adjacent dihydroxy polymer, b is an integer between 0 and 200.

[0044] Preferably, in the adjacent dihydroxy polymer, c is an integer between 0 and 3000, and a and c are not both 0. Preferably, c is an integer between 0 and 300.

[0045] Preferably, in the adjacent dihydroxy polymer, d is an integer between 0 and 100.

[0046] Preferably, in the adjacent dihydroxy polymer, e is an integer between 0 and 2000.

[0047] Preferably, in the adjacent dihydroxy polymer, (a+c) / (a+b+c+d) ≥ 0.5, more preferably 0.6 to 1.0. For example, it is 0.5, 0.6, 0.66, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 0.97, 0.98 or 1.

[0048] Preferably, in the adjacent dihydroxy polymer, e / (a+b+c+d) is selected from 0 to 5.0; exemplary values ​​are 0, 1, 1.5, 2, 2.5, 2.9, 3, 3.5, 4, 4.5, and 5.

[0049] In this invention, the adjacent dihydroxy polymer is a bonding polymer.

[0050] According to the present invention, the carbon conductive material is selected from at least one of the following carbon-based conductive materials: activated carbon, carbon black, graphite, graphene, carbon-supported graphene, fullerene, carbon nanotubes, vapor-grown carbon fiber (VGCF), carbon nanotubes, carbon nanotube coils, cup-shaped carbon nanotubes, bamboo-shaped carbon nanotubes, etc.

[0051] According to the present invention, the thickness of the coating is 0.1 μm to 20 μm.

[0052] According to the present invention, in the coating, the mass ratio of adjacent dihydroxy polymer and carbon conductive material is 1:(0.2-2), preferably 1:(0.4-1.5), and exemplary ratios are 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:1, 1:1.2 or 1:1.5.

[0053] According to the present invention, the metal conductor is selected from at least one of aluminum, copper, stainless steel, nickel and iron.

[0054] According to the present invention, the coating may be located on one side surface of the metal conductor or on both sides surface of the metal conductor.

[0055] The present invention also provides a method for preparing the above-mentioned current collector, the method comprising: preparing a slurry comprising a carbon conductive material and an adjacent dihydroxy polymer, coating the slurry onto at least one side surface of a metal conductor, and drying to obtain the current collector.

[0056] According to the present invention, the method specifically includes: preparing a slurry comprising a carbon conductive material and an adjacent dihydroxy polymer, coating the slurry onto both sides of a metal conductor, and drying it to obtain the current collector.

[0057] According to the present invention, the slurry further includes a solvent.

[0058] According to the present invention, the solvent is selected from one or a mixture of water, methanol, ethanol, acetone, formic acid, acetic acid, N-methyl-2-pyrrolidone (NMP), N,N-dimethylformamide (DMF), N,N-dimethylacetamide, N,N-dimethyl sulfoxide, etc.; preferably ethanol, NMP or DMF.

[0059] According to the present invention, in the slurry, the mass ratio of adjacent dihydroxy polymer and carbon conductive material is 1:(0.2-2), preferably 1:(0.4-1.5), and exemplary ratios are 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:1, 1:1.2 or 1:1.5.

[0060] According to the present invention, the concentration of the adjacent dihydroxy polymer in the slurry is 0.1 wt% to 25 wt%; exemplaryly, it is 0.1 wt%, 1 wt%, 5 wt%, 8 wt%, 10 wt%, 12 wt%, 15 wt%, 18 wt%, 20 wt%, or 25 wt%.

[0061] According to the present invention, the drying temperature is 80 to 120°C, and the drying time is 0.1 to 10 hours.

[0062] The present invention also provides a battery electrode, the electrode comprising the aforementioned current collector and an active material layer located on at least one side surface of the current collector containing an adjacent dihydroxy polymer. According to the present invention, the active material layer comprises an electrode active material.

[0063] According to the present invention, the electrode active material is selected from positive electrode active materials or negative electrode active materials.

[0064] According to the present invention, the positive electrode active material is selected from substances with the general formula LiMY2; in the general formula, M is at least one of transition metals such as Co, Ni, Fe, Mn, Cr, and V, and Y is O or S.

[0065] Specifically, the positive electrode active material is, for example, lithium cobalt oxide, lithium iron phosphate, etc.

[0066] According to the present invention, the negative electrode active material may be selected from natural graphite, artificial graphite, coke, activated carbon, or powdered carbon materials such as phenolic resin and asphalt after sintering and carbonization.

[0067] According to the present invention, the active material layer further includes a binder and a conductive agent.

[0068] According to the present invention, the adhesive is selected from polyvinylidene fluoride homopolymers and copolymers thereof, such as polyvinylidene fluoride or copolymers of polyvinylidene fluoride with monomers such as vinyl fluoride, trifluoroethylene, trifluorochloroethylene, tetrafluoroethylene, and hexafluoropropylene.

[0069] According to the present invention, the conductive agent is selected from conductive carbon powder.

[0070] According to the present invention, the conductive carbon powder is, for example, carbon black.

[0071] This invention also provides a method for preparing the above-mentioned battery electrode, the method comprising:

[0072] Prepare the slurry for the active substance layer;

[0073] Prepare the current collector;

[0074] The active material layer is coated with a slurry onto at least one side surface of the current collector containing the adjacent dihydroxy polymer;

[0075] The battery electrode is obtained.

[0076] According to the present invention, the slurry for the active material layer includes the above-mentioned electrode active material.

[0077] Furthermore, the slurry for the active material layer also includes the aforementioned binder, conductive agent, and solvent.

[0078] According to the present invention, the solvent is, for example, NMP.

[0079] According to the present invention, the current collector is prepared by the above-described method for preparing the current collector.

[0080] The present invention also provides a non-aqueous electrolyte secondary battery, the battery comprising the above-mentioned current collector or the above-mentioned battery electrode.

[0081] According to the present invention, the battery includes a positive electrode, a negative electrode, an electrolyte, and a separator; the positive electrode is selected from the above-mentioned battery electrodes.

[0082] The present invention also provides a capacitor, the capacitor including the current collector.

[0083] Terminology Definitions and Explanations

[0084] Unless otherwise stated, the terms and descriptions in the context of this invention have the meanings described below.

[0085] "More than" means three or more.

[0086] Term "C"1-12 "Alkyl" should be understood as representing a straight-chain or branched saturated monovalent hydrocarbon group having 1 to 12 carbon atoms. For example, "C 1-8 "Alkyl" refers to straight-chain and branched alkyl groups having 1, 2, 3, 4, 5, 6, 7, or 8 carbon atoms. 1-6 "Alkyl" means a straight-chain or branched alkyl group having 1, 2, 3, 4, 5, or 6 carbon atoms. The alkyl group is, for example, methyl, ethyl, propyl, butyl, pentyl, hexyl, isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, 2-methylbutyl, 1-methylbutyl, 1-ethylpropyl, 1,2-dimethylpropyl, neopentyl, 1,1-dimethylpropyl, 4-methylpentyl, 3-methylpentyl, 2-methylpentyl, 1-methylpentyl, 2-ethylbutyl, 1-ethylbutyl, 3,3-dimethylbutyl, 2,2-dimethylbutyl, 1,1-dimethylbutyl, 2,3-dimethylbutyl, 1,3-dimethylbutyl, or 1,2-dimethylbutyl, or their isomers.

[0087] Term "C" 6-14 "Aryl" should be understood to preferably represent a monovalent aromatic or partially aromatic monocyclic, bicyclic, or tricyclic hydrocarbon ring ("C") having 6, 7, 8, 9, 10, 11, 12, 13, or 14 carbon atoms. 6-14 Aryl), particularly a ring with 6 carbon atoms (“C6 aryl”), such as phenyl; or biphenyl, or a ring with 9 carbon atoms (“C9 aryl”), such as indenyl or indenyl, or a ring with 10 carbon atoms (“C9 aryl”). 10 Aryl groups, such as tetrahydronaphthyl, dihydronaphthyl, or naphthyl, or rings with 13 carbon atoms (“C”). 13 Aryl groups, such as fluorene groups, or rings with 14 carbon atoms (“C”). 14 Aryl), for example, anthracene. When the C 6-20 When the aryl group is substituted, it can be monosubstituted or polysubstituted. Furthermore, there are no restrictions on the substitution site; for example, it can be ortho, para, or meta substituted.

[0088] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of the present invention, and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0089] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.

[0090] Preparation of adjacent dihydroxy polymers

[0091] Preparation Example 1

[0092] Preparation of adjacent dihydroxy polymer SBSOH:

[0093] The adjacent dihydroxy polymer SBSOH contains structures of formulas (I) to (V), where R1, R2, R3, R4, R5, and R6 are hydrogen atoms, and R... 19 It is a benzene ring.

[0094] Step 1: Synthesize styrene and butadiene block copolymer SBS according to the method disclosed in "Handbook of Synthetic Rubber Industry" (edited by Zhao Xutao and Liu Dahua, second edition, Chemical Industry Press, 2006): SBS is obtained by polymerization of 1,3-butadiene and styrene as raw materials and cyclohexane as solvent, catalyzed by sec-butyllithium. The S / B ratio of the styrene segment to the butadiene segment in the copolymer is 35 / 65.

[0095] Step 2: Using formic acid as a catalyst, the block copolymer SBS prepared in Step 1 is dissolved in a mixed solution of cyclohexane and dichloroethane. 30% hydrogen peroxide is added to the mixed solution, and the double bonds in the polymer molecular structure undergo an epoxidation reaction to prepare an epoxidized polymer solution.

[0096] Step 3: Add 70% perchloric acid aqueous solution to the epoxidized polymer solution. The epoxy group opens to adjacent dihydroxyl groups. The reactants are washed with water and dried to obtain the adjacent dihydroxyl polymer SBSOH.

[0097] The molar percentage of adjacent dihydroxyl structural units in the SBSOH samples is shown in Table 1 below.

[0098] SBSOH-1, SBSOH-2, SBSOH-3, and SBSOH-4 were prepared using the method described in Preparation Example 1. By adjusting the content of butadiene and styrene, SBSOHs with different proportions of adjacent dihydroxyl structural units and number-average molecular weights were obtained, as shown in Table 1 below.

[0099] Table 1

[0100] SBSOH Number average molecular weight e / (a+b+c+d) (a+c) / (a+b+c+d) SBSOH-1 6700 3.0 0.70 SBSOH-2 14500 3.0 0.66 SBSOH-3 67700 1 0.60 SBSOH-4 92300 2.9 0.66

[0101] In Table 1, the ratios of a, b, c, d, and e, as well as the ratios of (a+c) / (a+b+c+d) and e / (a+b+c+d), were calculated from the 1H-NMR test results.

[0102] Preparation Example 2

[0103] Preparation of adjacent dihydroxy polymer PBOH:

[0104] The adjacent dihydroxy polymer PBOH contains structures of formulas (I) to (IV), where R1, R2, R3, R4, R5, and R6 are hydrogen atoms;

[0105] Using 1,3-butadiene as raw material, the PBOH samples shown in Table 2 were prepared according to the method disclosed in Example 1 of CN110964131A.

[0106] PBOH-1, PBOH-2, and PBOH-3 were prepared using the method described in Preparation Example 2. By adjusting the content of 1,3-butadiene, PBOH with different proportions of adjacent dihydroxyl structural units and number-average molecular weights were obtained.

[0107] The number-average molecular weight and the molar percentage of adjacent dihydroxyl structural units for the PBOH samples are shown in Table 2.

[0108] Table 2

[0109] PBOH Number average molecular weight (a+c) / (a+b+c+d) PBOH-1 7560 0.97 PBOH-2 62500 0.95 PBOH-3 143000 0.98

[0110] In Table 2, the ratios of a, b, c, d, and (a+c) / (a+b+c+d) are given by... 1 The results were obtained from H-NMR testing.

[0111] Preparation Example 3

[0112] Preparation of current collectors:

[0113] like Figure 1 As shown, a coating 02 is prepared on one side of the metal conductor 01 to obtain a current collector.

[0114] The preparation method of the current collector is as follows: carbon black (SP), a carbon conductive material, and an adjacent dihydroxy polymer solution are mixed evenly. The adjacent dihydroxy polymer solution is obtained by dissolving the adjacent dihydroxy polymer from Preparation Examples 1-2 in a solvent, and the concentration of the adjacent dihydroxy polymer solution is 10 wt%, resulting in a coating slurry. The coating slurry is applied to the surface of a 20 μm metal conductor aluminum foil. After drying, a coating 02 is formed on the surface of the metal conductor aluminum foil, thus obtaining the current collector.

[0115] Dry at 80-120℃ for 8 hours.

[0116] Coating thickness: 2μm.

[0117] Adhesion test

[0118] Perform a standard cross-cut test according to ASTM D3359. Use a utility knife to cut 100 squares (1 mm each) at 11 column and 11 row intervals. Adhere transparent tape to the surface of the squares, inspect the surface condition of the surface that detaches with the tape, and evaluate it.

[0119] Level 1: No surface peeling;

[0120] Level 2: Stripped area < 5%;

[0121] Level 3: Peeling area 5-15%;

[0122] Level 4: Stripping area 15-35%;

[0123] Level 5: Stripped area 35-65%;

[0124] Level 6: Complete stripping.

[0125] Examples 1-12

[0126] Following the preparation method of Preparation Example 3 above, current collectors of different thicknesses were prepared using different adjacent dihydroxy polymers, different mass ratios of adjacent dihydroxy polymers to carbon conductive materials, and different solvents; wherein, the selection of adjacent dihydroxy polymers, solvents, and mass ratios are shown in Table 3 below.

[0127] The adhesion force of the current collectors prepared in Examples 1-12 was tested, and the test results are shown in Table 3 below.

[0128] Table 3. Test results of current collectors and their adhesion ability in Examples 1-12

[0129]

[0130] Examples 13-19 and Comparative Examples 1-2

[0131] 1. Preparation of positive electrode sheet

[0132] like Figure 2 As shown, a coating 02 is prepared on one side of the metal conductor 01 to obtain a current collector, and an electrode active material layer 03 is coated on one side of the current collector to make its surface contain an active material layer, thus preparing a positive electrode sheet.

[0133] Specifically, the preparation method of the positive electrode is as follows:

[0134] Three parts by weight of PVDF (Solvay 6020) and 100 parts by weight of NMP were mixed and stirred until dissolved. Then, three parts by weight of carbon black (Super P) were added, and the mixture was ground to obtain an electrode slurry with a solid content of 50 wt%. The electrode slurry was coated onto the current collectors of Examples 2, 4, 6-7, and 10-12 using a scraper, and then dried at 200°C. Lithium iron phosphate slurry was then coated onto the surface of the dried product to obtain an electrode sheet, i.e., a positive electrode sheet.

[0135] Comparative Example 1

[0136] Commercially available carbon-coated aluminum foil was used as the current collector (super P(SP) coated carbon-coated aluminum foil (PVDF:SP = 1:1, PVDF is a carbon conductive material binder, coating thickness 2μm), and the rest was the same as in Examples 13-19.

[0137] Comparative Example 2

[0138] Aluminum foil is used as the current collector, and the rest is the same as in Examples 13-19.

[0139] 2. Performance testing of the positive electrode sheet

[0140] 1) Adhesion test

[0141] The adhesion strength of the positive electrode sheets prepared in Examples 13-19 and Comparative Examples 1-2 was tested according to GB / T 2790-1995 Adhesive 180° Peel Strength Test Method. The test results are listed in Table 4.

[0142] 2) Electrolyte immersion test

[0143] The positive electrode sheets prepared in Examples 13-19 and Comparative Examples 1-2 were subjected to electrolyte immersion tests, and the test results are listed in Table 4.

[0144] 3. Performance testing of the battery including the positive electrode.

[0145] The positive electrode sheets prepared in Examples 13-19 and Comparative Examples 1-2 were punched into electrode sheets with a diameter of 1.0 cm and used as positive electrodes. 4M lithium hexafluorophosphate / [ethyl methyl carbonate EMC95: vinylene carbonate 5 (VC)] was used as the electrolyte, PP separator, and lithium sheet as the negative electrode. 2032 button batteries were assembled in a glove box, and the batteries were subjected to impedance testing. The test results are listed in Table 4.

[0146] Table 4

[0147]

[0148] The embodiments of the present invention have been described above by way of example. However, the scope of protection of the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made by those skilled in the art within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A current collector, characterized in that, It includes: A metallic conductor and a coating located on at least one side of the surface of the metallic conductor, the coating comprising an adjacent dihydroxy polymer and a carbon conductive material; The adjacent dihydroxy polymer comprises the structural units shown in formulas (I) and (II): Equation (I) Equation (II) In equations (I) and (II), R1, R2, R3, R4, R5, and R6 may be the same or different, and are independently selected from H and C. 1-8 Alkyl group; a and c may be the same or different, are independent integers greater than or equal to 0, and a and c are not both 0; The adjacent dihydroxy polymer also includes structural units represented by formula (III), formula (IV) and / or formula (V): Equation (III) Equation (IV) Equation (V) In equations (III) and (IV), R1, R2, R3, R4, R5, and R6 may be the same or different, and are independently selected from H and C. 1-8 Alkyl group; b and d may be the same or different, and are independent integers greater than 0; In equation (V), R 19 Selected from no substitution, or arbitrarily selected by one, two or more R c Replacement C 6-20 Aryl; each R c Same or different, selected independently from C 1-12 Alkyl group; e is an integer greater than 0.

2. The current collector of claim 1, wherein The number average molecular weight of the adjacent dihydroxy polymer is 2000~200000.

3. The current collector of claim 1, wherein The carbon conductive material is selected from at least one of activated carbon, carbon black, graphite, graphene, carbon-supported graphene, fullerene, carbon nanotubes, vapor-grown carbon fibers, carbon nanotubes, carbon nanotube coils, cup-shaped carbon nanotubes, and bamboo-shaped carbon nanotubes.

4. The current collector of claim 1, wherein The thickness of the coating is 0.1 μm to 20 μm.

5. The current collector of claim 1, wherein In the coating, the mass ratio of the adjacent dihydroxy polymer and the carbon conductive material is 1:(0.2~2).

6. The current collector of claim 1, wherein The metallic conductor is selected from at least one of aluminum, copper, stainless steel, nickel, and iron.

7. The current collector according to claim 1, characterized in that, The coating is located on one side of the metal conductor or on both sides of the metal conductor.

8. The method of making a current collector of any of claims 1-7, wherein, The method includes: preparing a slurry comprising a carbon conductive material and an adjacent dihydroxy polymer, coating the slurry onto at least one side surface of a metal conductor, and drying it to obtain the current collector.

9. A battery electrode sheet, characterized by The electrode comprises a current collector as described in any one of claims 1-7 and an active material layer located on at least one side surface of the current collector containing an adjacent dihydroxy polymer.

10. A non-aqueous electrolyte secondary battery, characterized in that, The battery includes the current collector as described in any one of claims 1-7 or the electrode for the battery as described in claim 9.

11. A capacitor characterized by The capacitor includes the current collector as described in any one of claims 1-7.

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