Lead-based composite material and method for producing same, lead-acid battery composite current collector, and lead-acid battery

Abstract

The application discloses a lead-based composite material and a preparation method thereof, a lead-acid battery composite current collector and a lead-acid battery, wherein the lead-based composite material comprises: a substrate; a conductive MXene layer arranged on the surface or part of the surface of the substrate; a metal modification layer arranged on the surface of the conductive MXene layer, wherein the metal type of the metal modification layer is selected from one or more of copper, nickel, silver, gold, platinum, magnesium, zinc, tin, chromium, antimony and bismuth; and a lead-based layer arranged on the surface of the metal modification layer. By jointly using the metal modification layer and the conductive MXene layer, the problem of poor composite bonding force between different substrate surfaces and the lead-based layer can be solved.

Description

Technical Field

[0001] This invention belongs to the field of lead-acid batteries, and in particular relates to lead-based composite materials and their preparation methods, composite current collectors for lead-acid batteries, and lead-acid batteries. Background Technology

[0002] In the current battery market, lead-acid batteries remain the most widely used and have a large market share, especially in large-scale energy storage applications, due to their advantages such as high cost-effectiveness, high recyclability, wide operating temperature range, and greater safety and reliability compared to lithium batteries. Lead-acid batteries are among the most produced types of batteries in my country, and my country ranks first in the world in lead-acid battery production. The positive and negative grids of existing lead-acid batteries are made of pure lead metal or lead alloys with trace amounts of alloying elements. Their main function is to coat the lead paste, the active material required for battery operation, and they also serve as current collectors.

[0003] The main drawbacks of commercial lead-acid batteries are their low energy density and short cycle life. This is primarily because the positive and negative grids of lead-acid batteries are composed of 98%–99% metallic lead and small amounts of other alloying elements such as calcium, aluminum, and tin. The density of metallic lead is 11.34 g / cm³. 3 A single lead-acid battery may use 50 or even more grids, making the grids a significant portion of the battery's weight. Since the grids do not participate in the battery's charge-discharge cycles as active materials (especially at the negative electrode), they drastically reduce the overall energy density of the lead-acid battery. Even though commercially available lead-acid batteries currently employ three-dimensional grid structures to reduce grid mass, the grids still significantly drag down the battery's energy density. Summary of the Invention

[0004] The purpose of this invention is to address the technical problem of low energy density in lead-acid batteries where the grid (current collector) material is metallic lead or lead alloy, which has excessively high density. This invention provides a low-density lead-based composite material and its preparation method.

[0005] The first aspect of the present invention provides a lead-based composite material, comprising: a matrix; a conductive MXene layer disposed on the surface or part of the surface of the matrix; a metal modification layer disposed on the surface of the conductive MXene layer, wherein the metal of the metal modification layer is selected from one or more of copper, nickel, silver, gold, platinum, magnesium, zinc, tin, chromium, antimony, and bismuth; and a lead base layer disposed on the surface of the metal modification layer.

[0006] In some embodiments, the aforementioned metal modification layer is deposited and grown on the surface of the conductive MXene layer using electroplating or chemical plating.

[0007] In some embodiments, the matrix is ​​selected from polymers, ceramics, or glass; preferably, the glass is glass fiber.

[0008] In some embodiments, the lead base layer described above is made of metallic lead or a lead alloy.

[0009] In some embodiments, the conductive MXene layer contains MXene material; preferably, the content of the MXene material is between 50 wt.% and 100 wt.%.

[0010] In some embodiments, the substrate is a fibrous braid, or a perforated sheet; or a mesh; or a film.

[0011] In some embodiments, the thickness of the conductive MXene layer is between 3 nm and 50 μm; preferably, between 10 nm and 10 μm; more preferably, between 100 nm and 5 μm; and even more preferably, between 200 nm and 2 μm.

[0012] In some embodiments, the thickness of the metal modification layer is between 10 nm and 50 μm; preferably, between 100 nm and 10 μm; more preferably, between 100 nm and 5 μm; and even more preferably, between 200 nm and 2 μm.

[0013] In some embodiments, the thickness of the lead substrate is between 1 μm and 300 μm; preferably, between 1 μm and 100 μm; more preferably, between 1 μm and 50 μm; and even more preferably, between 1 μm and 20 μm.

[0014] In some embodiments, the thickness of the lead-based composite material is between 2 μm and 500 μm; preferably, between 5 μm and 300 μm; more preferably, between 10 μm and 100 μm.

[0015] A second aspect of the present invention provides a method for preparing the above-mentioned lead-based composite material, comprising the following steps:

[0016] Coating step: Coating MXene material onto the surface of the substrate to form a conductive MXene layer;

[0017] Modification step: Electroplating or electroless plating a metal modification layer on the surface of the conductive MXene layer to obtain an intermediate composite;

[0018] Composite lead step: The surface of the intermediate composite is coated with a metallic lead layer to obtain the lead-based composite material.

[0019] In some embodiments, the above-described composite lead step, more specifically, includes: coating molten metallic lead or lead alloy onto the surface of the intermediate composite, and after cooling and solidification, obtaining the lead-based composite material.

[0020] In some embodiments, the above-described composite lead step, more specifically, includes: immersing the intermediate composite in the molten metallic lead or lead alloy, and then cooling and solidifying it after removal to obtain the lead-based composite material.

[0021] In some embodiments, the above-described composite lead step, more specifically, includes: electroplating metallic lead onto the surface of the intermediate composite to form the lead base layer.

[0022] In some embodiments, the molten metallic lead or lead alloy is enriched with MXene material; preferably, the amount of MXene material added is between 0.1 wt.% and 5 wt.%.

[0023] In some embodiments, the above-described coating step, more specifically, includes: spraying, coating, or impregnating the substrate in an MXene dispersion, and forming the conductive MXene layer after drying; preferably, the MXene dispersion includes MXene material and a solvent, and the concentration of the MXene material is between 0.1 mg / ml and 80 mg / ml.

[0024] A second aspect of the present invention provides the above-described lead-based composite material; or, the application of the lead-based composite material obtained by the above-described preparation method in lead-acid batteries.

[0025] A third aspect of this invention provides a method for preparing a composite current collector for lead-acid batteries, comprising the following steps:

[0026] Coating step: Spraying, coating, or impregnating MXene dispersion onto the surface of a polymer matrix or glass fiber matrix, and forming a conductive MXene layer after drying; Modification step: Electroplating or electroless plating a metal modification layer onto the surface of the conductive MXene layer to obtain an intermediate composite; Lead composite step: Coating the surface of the intermediate composite with molten lead or lead alloy, and forming a lead base layer after cooling.

[0027] In some embodiments, the metal type of the metal modification layer is selected from one or more of the following: copper, nickel, silver, gold, platinum, magnesium, zinc, tin, chromium, antimony, and bismuth.

[0028] In some embodiments, the thickness of the conductive MXene layer is between 3 nm and 50 μm; preferably, between 10 nm and 10 μm; more preferably, between 100 nm and 5 μm; and even more preferably, between 200 nm and 2 μm.

[0029] In some embodiments, the thickness of the metal modification layer is between 10 nm and 50 μm; preferably, between 100 nm and 10 μm; more preferably, between 100 nm and 5 μm; and even more preferably, between 200 nm and 2 μm.

[0030] In some embodiments, the thickness of the lead substrate is between 1 μm and 300 μm; preferably, between 1 μm and 100 μm; more preferably, between 1 μm and 50 μm; and even more preferably, between 1 μm and 20 μm.

[0031] In some embodiments, the thickness of the lead-acid battery composite current collector is between 2 μm and 500 μm; preferably, between 5 μm and 300 μm; more preferably, between 10 μm and 100 μm.

[0032] The fourth aspect of the present invention provides a lead-acid battery composite current collector obtained by the above-mentioned method for preparing the lead-acid battery composite current collector.

[0033] The fifth aspect of the present invention provides a lead-acid battery comprising the lead-based composite material described above; or, the lead-based composite material obtained by the preparation method described above; or, the lead-acid battery composite current collector described above.

[0034] A sixth aspect of the present invention provides a means of transportation, including the aforementioned lead-acid battery. This means of transportation may be an electric car, an electric motorcycle, a battery-powered bicycle, an electric toy car, an electric boat, etc.

[0035] The technical problem this application aims to solve lies in the fact that, in order to reduce the weight of lead-acid battery grids, the applicant uses electroplating to electroplat metallic lead onto a substrate containing a conductive MXene layer. During this research and development process, it was discovered that after electroplating a portion of the lead base layer onto the conductive MXene layer surface, due to the difference in surface energy, lead ions selectively deposit on the lead base layer surface rather than on the MXene surface of the substrate. Although a lead base layer can be electroplated onto the surface of the conductive MXene layer, the bonding force between the lead base layer and the conductive MXene layer is poor. A lead base layer of a certain thickness and uniformity cannot be electroplated onto the surface of the conductive MXene layer, and dendritic lead easily forms around the edges of the grid. When used as a grid in a lead-acid battery, the thinner lead layer may corrode and detach during long-term cycling or immersion in sulfuric acid, leading to a decrease in the grid's conductivity and a loss of battery capacity.

[0036] To address this technical problem, the applicant has chosen to place a metal modification layer between the conductive MXene layer and the lead substrate. This metal modification layer, on the one hand, can form an alloy with metallic lead, meaning it exhibits good affinity with lead, thus ensuring strong adhesion between the metal modification layer and the lead substrate. On the other hand, utilizing the hydrophilicity and conductivity of the conductive MXene layer, the metal can be deposited and grown on the surface of the conductive MXene layer in an aqueous plating solution via electroplating or electroless plating, achieving good adhesion with the conductive MXene layer. Based on the above requirements, the metal types of the metal modification layer can optionally include one or more of the following: copper, nickel, silver, gold, platinum, magnesium, zinc, tin, chromium, antimony, and bismuth. By using the metal modification layer and the conductive MXene layer in combination, the problem of poor adhesion between composite lead substrates on different substrate surfaces can be solved. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the structure of a lead-based composite material in Embodiment 1 of the present invention.

[0038] Figure 2 The images show: (a) a photograph of the PP / MXene composite obtained by spraying MXene dispersion onto the surface of a polypropylene sheet in Example 2 of the present invention; (b) and (c) photographs of the intermediate composite PP / MXene / Cu with copper electroplated on a portion of the PP / MXene composite; and (d) a photograph of the lead-based composite PP / MXene / Cu / Pb obtained by electroplating lead on a portion of the intermediate composite PP / MXene / Cu.

[0039] Figure 3 This is a cross-sectional SEM image of the lead-based composite material PP / MXene / Cu / Pb in Example 2 of the present invention.

[0040] Figure 4 Photographs of (a) PET / MXene / Pb and (b) PP / MXene / Cu / Pb composites in Example 3 of the present invention.

[0041] Figure 5 The images show (a) of the intermediate composite GF / MXene / Cu obtained by electroplating metallic copper on the surface of a glass fiber braid coated with a conductive MXene layer in Example 4 of the present invention; and (b) of the lead-based composite material GF / MXene / Cu / Pb obtained by electroplating lead on the surface of the intermediate composite GF / MXene / Cu.

[0042] Figure 6 This is a photograph of the lead-based composite material GF / MXene / Cu / Pb obtained by coating the surface of the intermediate composite GF / MXene / Cu with molten lead alloy in Example 5 of the present invention.

[0043] Figure 7 This is a photograph of the lead-based composite material GF / MXene / Cu / Pb obtained by impregnating the intermediate composite GF / MXene / Cu in molten lead alloy and pulling it out in Example 6 of the present invention.

[0044] Figure 8 This is a photograph of another lead composite current collector PP / MXene / Cu / Pb in Embodiment 6 of the present invention.

[0045] Figure 9 This is a photograph of the lead-based composite material PI / MXene / Cu / Pb with PI film as the matrix in Example 9 of the present invention.

[0046] Explanation of key figure labels:

[0047] 100 Lead-based composite material; 10 Matrix; 20 Conductive MXene layer; 30 Metallic modification layer; 40 Lead base layer. Detailed Implementation

[0048] The technical solution of the present invention is illustrated below through specific embodiments. It should be understood that the one or more steps mentioned in the present invention do not preclude the existence of other methods and steps before or after the combined steps, or that other methods and steps may be inserted between these explicitly mentioned steps. It should also be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Unless otherwise stated, the numbering of each method step is only for the purpose of identifying each method step, and not for limiting the order of each method or limiting the scope of the present invention. Changes or adjustments to their relative relationships, without substantial changes to the technical content, can also be considered as within the scope of the present invention.

[0049] The MXene material used in this embodiment of the invention is Ti3C2T. x Slurry (Jinan Sanchuan New Material Technology Co., Ltd., product model SC02003LW, concentration 5mg / ml, 50mg / ml), this Ti3C2T x The slurry contains two-dimensional MXene Ti3C2T x It was obtained by etching the Al layer in the MAX phase material Ti3AlC2 and then ultrasonically exfoliating it.

[0050] The raw materials and instruments used in the examples are not subject to any specific restrictions on their source; they can be purchased from the market or prepared according to conventional methods known to those skilled in the art.

[0051] Example 1

[0052] This embodiment provides a lead-based composite material and its preparation method, such as... Figure 1As shown, the lead-based composite material includes: a matrix 10, a conductive MXene layer 20, a metal modification layer 30, and a lead base layer 40; wherein the conductive MXene layer 20 is coated on the surface or part of the surface of the matrix 10; the metal modification layer 30 is coated on the surface of the conductive MXene layer 20, and the lead metal layer 40 is coated on the surface of the metal modification layer 30.

[0053] Figure 1 An embodiment is given in which the conductive MXene layer 20, the metal modification layer 30, and the lead base layer 40 are on one side of the substrate; in another embodiment, the conductive MXene layer 20, the metal modification layer 30, and the lead base layer 40 may also be on both sides or part of the surface of the substrate.

[0054] The purpose of the metal finishing layer is to enhance the adhesion of the lead base layer. The metal types of the finishing layer can be selected from one or more of the following: copper, nickel, silver, gold, platinum, magnesium, zinc, tin, chromium, antimony, and bismuth.

[0055] In this invention, the metal modification layer is formed by depositing and growing metal ions on the surface of a conductive MXene layer through electroplating or electroless plating. Electroplating and electroless plating are simple and inexpensive processes, and the thickness of the metal modification layer can be controlled by adjusting the plating time, plating solution preparation, and temperature. In other embodiments, the metal modification layer can also be formed by magnetron sputtering or vapor deposition, but these methods typically require expensive equipment, a vacuum environment, and high energy consumption. Therefore, electroplating or electroless plating is preferred for forming the metal modification layer. Electroplating is even more preferred, as it can complete the plating in a shorter time, is more efficient, and produces better plating results. The electroplating conditions for the electroplated metal modification layer of this invention are optimized through experiments based on different metal ion conditions. Preferably, the electroplating DC voltage is 1V to 5V, and the electroplating current is 0.5 to 100A / dm². 2 Electroplating time is between 10 seconds and 60 minutes; electroplating current is between 2 and 65 A / dm. 2 The electroplating time is between 10 seconds and 5 minutes.

[0056] Specifically, the lead-based composite material of the present invention incorporates a conductive MXene layer, which refers to an MXene film containing MXene material. This conductive MXene layer is formed on the substrate by simple coating, spraying, or impregnation methods. The purpose of incorporating the conductive MXene layer is to utilize the hydrophilicity, conductivity, metallicity, abundant surface functional groups, and two-dimensional structure of MXene material. Based on MXene's hydrophilicity, it can be compatible with aqueous electroplating solutions in electroplating processes. Based on MXene's conductivity, a conductive layer can be formed on the surface of the substrate, enabling the deposition and growth of electroplated metal ions on its surface. Based on MXene's metallic properties and abundant surface functional groups, it provides nucleation sites for electroplated metal deposition, reducing the overpotential of the metal deposition.

[0057] In some embodiments, the conductive MXene layer is an MXene film composed of MXene material; in another embodiment, in order to increase the bonding force between the conductive MXene layer and the substrate, the conductive MXene layer also includes an adhesive, such as LA133 waterborne adhesive, methylcellulose (CMC), polytetrafluoroethylene (PTFE), polyvinyl alcohol (PVA), styrene-butadiene rubber (SBR), waterborne polyurethane, etc.

[0058] The chemical formula of the MXene material in this invention can be represented as M n+1 X n T x In this context, M represents one or more transition metal elements; X represents one or more of carbon, nitrogen, or boron; and T represents a surface functional group; 1 ≤ n ≤ 4, 0 < x ≤ 2; in some embodiments, M is selected from one or more of Ti, Nb, Ta, Nb, V, Mo, Zr, and Cr. MXene materials are typically prepared by etching the A component of the precursor MAX phase. Common MXene materials include Ti3C2T. x Ti2CT x V2CT x Nb2CT x Mo2CT x Ti4C3T x Ta2CT x Ta4C3T x TiNbCT x wait.

[0059] In the lead-based composite material of the present invention, the lead base layer refers to a metallic lead layer or a lead alloy layer, such as a lead-magnesium alloy.

[0060] When the lead-based composite material of the present invention is used as the grid of a lead-acid battery, the matrix material is preferably one or more of polymer, ceramic, or glass. Polymers have low density, which can greatly reduce the amount of grid material and thus increase the energy density of the lead-acid battery; ceramic and glass materials have excellent corrosion resistance and can adapt to the strongly acidic electrolyte environment in lead-acid batteries. The polymer matrix has the advantage of being easy to process and mold. The polymer matrix can be selected from one or more of the following: acrylonitrile-butadiene-styrene copolymer (ABS), polysulfone (PSF or PSU), polycarbonate (PC), phenolic resin, phenolic glass fiber reinforced plastic, nylon, polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polyimide (PI), polypropylene, polyvinyl chloride (PVC), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyphenylene sulfide (PPS), polyphenylene oxide (PPO), polystyrene (PS), polyamide (PA), and derivatives of the above polymers.

[0061] When the lead-based composite material of the present invention is used as the grid of a lead-acid battery, the shape of the matrix is ​​preferably a porous material, such as a mesh-like or porous sheet or a woven fiber, to facilitate the penetration of electrolyte and the transport of lead ions during the cycle. At the same time, the porous structure increases the contact area between the active material and the sulfuric acid electrolyte, which can improve the utilization rate of the active material, increase the energy density of the lead-acid battery, and extend its service life.

[0062] This embodiment also provides a method for preparing the above-mentioned lead-based composite material, the steps of which include:

[0063] S01 Coating Step: Coating the surface of the substrate with MXene material to form a conductive MXene layer;

[0064] SO2 modification step: Electroplating or electroless plating of a metal modification layer on the surface of the conductive MXene layer to obtain an intermediate composite;

[0065] S03 composite lead step: The surface of the intermediate composite is coated with a metallic lead layer to obtain the lead-based composite material.

[0066] In the S01 coating step, the coating method for forming a conductive MXene layer by coating the substrate with MXene material can be either a dry process or a wet process. The dry process involves forming a film layer on the surface of the substrate using MXene powder and binders under solvent-free conditions. The wet process involves coating the substrate surface with an MXene dispersion through spraying, dipping, or coating methods, and then drying to remove the solvent to form a conductive MXene layer. The dry process avoids the solvent removal step, simplifying the process flow. However, forming a stable and continuous conductive layer requires the addition of a binder; non-conductive binders reduce the continuous conductivity of the conductive MXene layer surface. Therefore, the wet process is preferred. The advantage of the wet process is that the MXene material can be more uniformly dispersed on the substrate surface. Although it includes a solvent removal step, due to the good hydrophilicity of MXene material, aqueous solvents (including water and / or alcohol solvents) are typically used. These aqueous solvents have the advantages of low cost and easy removal. In one specific embodiment, the method includes: coating the surface of a substrate with an MXene dispersion by spraying and / or coating it once or several times to form an MXene film, and then drying it to form a conductive MXene layer; in another specific embodiment, the method includes: repeatedly lifting and / or immersing the substrate in the MXene dispersion to allow the two-dimensional MXene sheets in the dispersion to be oriented and continuously coated on the surface of the substrate under the action of surface tension, and then drying it to form a conductive MXene layer.

[0067] In one embodiment, the S03 composite lead step more specifically includes: coating molten metallic lead or lead alloy onto the surface of the intermediate composite, and after cooling and solidification, obtaining the lead-based composite material; or, more specifically, the step includes: immersing the intermediate composite in the molten metallic lead or lead alloy, and after removal, cooling and solidification, obtaining the lead-based composite material. Optionally, the molten metallic lead or lead alloy contains MXene material, which can reduce the surface tension of the molten lead or lead alloy to promote the spread of the molten lead or lead alloy to form a lead base layer; preferably, the amount of MXene material added is between 0.1 wt.% and 5 wt.%.

[0068] In another embodiment, the S03 composite lead step more specifically includes: electroplating metallic lead onto the surface of the intermediate composite to form the lead base layer.

[0069] The electroplating conditions for the electroplated metal modification layer of the present invention were optimized through experiments based on different metal ion conditions; preferably, the electroplating DC voltage is 1V to 5V, and the electroplating current is 0.5 to 100A / dm. 2 The electroplating time is between 10 seconds and 60 minutes.

[0070] Example 2

[0071] This embodiment provides a lead-based composite material and its preparation method, wherein the matrix is ​​a porous polypropylene (PP) sheet with a thickness of 0.8 mm, and the metal modification layer is metallic copper. The preparation method includes the following steps:

[0072] (1) Prepare Ti3C2T with a mass concentration of 1 mg / ml x Aqueous dispersion containing 0.5 wt.% CMC binder;

[0073] (2) The Ti3C2T x The aqueous dispersion was sprayed onto the surface of PP porous sheets using a sprayer. After air drying, it was placed in a vacuum oven and vacuum dried at 50°C for 4 hours to obtain the PP / MXene composite (e.g. Figure 2 (as shown in a);

[0074] (3) The dried PP / MXene composite is placed in an electroplating apparatus for copper electroplating. The specific copper electroplating process includes:

[0075] a. Electroplating solution formulation for electrodeposition of copper: copper sulfate pentahydrate with a copper ion concentration of 80 g / L, concentrated sulfuric acid of 100 g / L, concentrated hydrochloric acid of 15 mg / L, polyethylene glycol (PEG) of 5 mg / L, hydroxyethyl cellulose (HEC) of 8 mg / L, sodium polydithiopropane sulfonate (SP) of 3 mg / L, and collagen of 10 mg / L.

[0076] b. At an operating temperature of 50℃ and a current density of 9A / dm 2 Under the conditions of 2V DC electrodeposition for 45s, an electroplated copper layer is formed on the surface of the PP / MXene composite layer. After cleaning and drying, the intermediate composite material of electroplated copper of the present invention (labeled as PP / MXene / Cu) is obtained.

[0077] (4) The intermediate composite material after copper plating is placed in the electroplating apparatus again for lead plating. The specific lead plating process includes:

[0078] a. Formula for preparing electroplating solution for lead electrodeposition: 15g / L lead acetate, 25ml / L titanium trichloride, 60g / L ethylenediaminetetraacetic acid (EDTA), 120g / L trisodium citrate, pH value 9-10.

[0079] b. Operating temperature is room temperature, current density is 2A / dm² 2 Under the conditions of 2V DC electrodeposition for 5 minutes, an electroplated lead base layer is formed on the surface of the PET / MXene / Cu composite layer. After cleaning and drying, the lead-based composite material of the present invention (labeled as PP / MXene / Cu / Pb) is obtained.

[0080] To facilitate demonstration of the state of each layer of the lead-based composite material of the present invention, a portion of the PP / MXene composite obtained in step (2) was placed in a copper plating solution, resulting in an intermediate composite material with a conductive MXene layer on top and a copper-plated metal modification layer (copper plating layer) on the bottom. Figure 2 As shown in b and c), the electroplated copper layer is uniformly distributed on the surface of the conductive MXene layer and has good adhesion, remaining intact even after multiple bends (greater than or equal to 20). A portion of this intermediate composite was then placed in a lead-plating electroplating solution to obtain a lead-based composite material partially electroplated with lead (e.g., ...). Figure 2 As shown in d), metallic lead is uniformly distributed on the surface of the electroplated copper layer. This is evident from the cross-sectional SEM image (…). Figure 3 It can be seen that the thickness of the conductive MXene layer in the PP / MXene / Cu / Pb composite is about 2 to 3 μm, the thickness of the electroplated copper layer is 3 to 4 μm, and the thickness of the lead base layer is about 16 to 18 μm.

[0081] Example 3

[0082] To illustrate the function of the metal modification layer of the present invention, this embodiment provides a comparison of electroplating lead on the surface of the conductive MXene layer and the surface of the metal modification layer, respectively. The specific implementation method is as follows:

[0083] (1) Prepare Ti3C2T with a mass concentration of 1 mg / ml x Aqueous dispersion (binder-free);

[0084] (2) The Ti3C2T x The aqueous dispersion was sprayed onto the surface of a 10μm thick PET film using a sprayer, and after air drying, it was placed in a vacuum oven and vacuum dried at 50℃ for 4 hours to obtain the PET / MXene composite.

[0085] (3) The dried PET / MXene composite was placed in an electroplating device for copper electroplating. The specific copper electroplating process was the same as in Example 2, and PP / MXene / Cu composite was obtained.

[0086] (4) A PET / MXene composite and a PP / MXene / Cu composite were placed together in an electroplating apparatus for lead electroplating. The specific lead electroplating process was the same as in Example 2, resulting in PET / MXene / Pb and PP / MXene / Cu / Pb composites, respectively. Figure 4As shown, the surface of the PET / MXene / Pb composite is rough, indicating selective and non-uniform deposition of lead ions on the conductive MXene layer surface; the surface of the PP / MXene / Cu / Pb composite is smooth and uniform, indicating that lead ions have excellent electroplating effect on the conductive MXene layer on the metal modification layer (electroplated copper layer).

[0087] Example 4

[0088] This embodiment provides another lead-based composite material and its preparation method, wherein the matrix is ​​a glass fiber woven fabric (GF) with a thickness of [thickness missing], and the metal modification layer is copper. The preparation method includes the following steps:

[0089] (1) Prepare Ti3C2T with a mass concentration of 1 mg / ml x Aqueous dispersion containing 0.5 wt.% CMC binder;

[0090] (2) Impregnate the glass fiber woven fabric with Ti3C2T x After being removed from the aqueous dispersion and dried, the mixture was then impregnated and dried again, and this process was repeated several times to form a conductive MXene layer on the surface of the glass fiber. In this embodiment, the mixture was impregnated three times and then vacuum dried at 50°C for 4 hours to obtain the GF / MXene composite.

[0091] (3) The dried GF / MXene composite was placed in an electroplating device for copper electroplating. The specific copper electroplating process was similar to that in Example 2, except that the electroplating time was 3 minutes, and the GF / MXene / Cu intermediate composite was obtained.

[0092] (4) The intermediate composite GF / MXene / Cu after copper electroplating is placed in the electroplating device again for lead electroplating. The specific lead electroplating process is the same as in Example 2, and the lead-based composite material of the present invention (labeled as GF / MXene / Cu / Pb) is obtained.

[0093] pass Figure 5 As can be seen, the metal modification layer (electroplated copper layer) can be uniformly electroplated onto the glass fiber woven substrate coated with MXene material, and the lead base layer can be uniformly electroplated on the surface of the electroplated copper layer, resulting in a lead-based composite material with glass fiber inside. Using this composite material as the current collector of lead-acid batteries can greatly reduce the density of the lead grid. At the same time, due to the excellent stability of glass material, it can withstand the strong corrosive environment of lead-acid electrolyte.

[0094] Example 5

[0095] This embodiment provides another lead-based composite material and its preparation method, the steps of which include: preparing a GF / MXene / Cu intermediate composite material by a method similar to that in Example 4; then coating the surface of the GF / MXene / Cu intermediate composite material with molten lead or lead alloy in a glove box under an argon atmosphere, and forming a lead base layer after cooling.

[0096] More specific implementation steps include: under an argon atmosphere in a glove box, heating 98% metallic lead and 2% tin to 400°C to melt and stirring until homogeneous, then using a scraper to coat the molten lead alloy onto the surface of the GF / MXene / Cu intermediate composite. After cooling, a lead base layer is formed, resulting in the lead-based composite material GF / MXene / Cu / Pb (e.g., ...). Figure 6 (As shown).

[0097] Example 6

[0098] This embodiment provides another lead-based composite material and its preparation method. Similar to Example 4, it uses the same GF / MXene / Cu intermediate composite. The difference is that the lead coating step involves impregnating the GF / MXene / Cu intermediate composite with molten lead or a lead alloy and then pulling it out. More specifically, 98% metallic lead and 2% tin are heated to 400°C to melt and stirred evenly. The GF / MXene / Cu intermediate composite is then impregnated in this mixture, and the molten lead alloy surface is pulled out to obtain the final product. A photograph of the resulting lead-based composite material GF / MXene / Cu / Pb is shown below. Figure 7 As shown, metallic lead is uniformly distributed on the surface of the GF / MXene / Cu intermediate complex.

[0099] Examples 4 to 6 further illustrate that the present invention first forms a conductive MXene layer on the substrate surface, and then uses an electroplating method to set a metal modification layer. Through the combined action of the conductive MXene layer and the metal modification layer, it can adapt to different substrate materials, enabling it to serve as a composite substrate for lead metal. This provides excellent bonding between metallic lead and the substrate, offering more substrate options for weight reduction in lead composite current collectors. Preferably, the substrate material is selected from polymers or glass; more preferably, polymers are preferred because polymers have lower density and are easy to mold and process. By pre-processing a polymer substrate framework, and then coating the polymer framework with MXene material and electroplated metal modification layer, it is composited with lead or lead alloys. Lead-based composite current collectors or grids with polymer substrates also have the beneficial effect of easy processing and molding.

[0100] In another embodiment, a method similar to that in Example 6 is used, except that the substrate is replaced with a PP-molded frame. The resulting lead composite current collector PP / MXene / Cu / Pb is shown in the image. Figure 8 As shown.

[0101] Example 7

[0102] This embodiment provides another lead-based composite material and its preparation method. Additives that reduce the surface tension of molten lead or lead alloys, such as inorganic ceramic particles, are added to molten lead or lead alloys. In this embodiment, MXene is added at an amount between 0.1 wt.% and 5 wt.%, resulting in a molten mixture. This reduces the surface tension of the molten lead or lead alloy, making it easier for the molten lead or lead alloy to adhere to the surface of the metal-modified layer of the composite, forming a lead base layer. The specific implementation method is similar to that of Example 6, except that 1 wt.% of MXene Ti3C2T is added to the molten lead alloy. x The powder is stirred evenly, and then the GF / MXene / Cu intermediate composite is impregnated in it and obtained by pulling out the molten lead alloy surface.

[0103] It is understood that the GF / MXene / Cu intermediate composite in this embodiment can also be replaced with composites of other matrices, such as polymer matrices or ceramic materials.

[0104] In this embodiment, molten lead or lead alloy containing additives can also be composited with the substrate by coating. In another embodiment, the scraper coating method described in Example 5 is used.

[0105] In the step of composite lead or lead alloy, the present invention provides an electroplating lead method (Examples 2 to 4) and a molten lead coating or pulling method (Examples 5 to 7), wherein the molten lead coating or pulling method is preferred for the following reasons: 1) The electroplating lead composite method can form a better coating on the surface of the metal modification layer, but lead dendrite growth (e.g., ...) is still unavoidable at the edges. Figure 5 (b) As shown in the figure, the electroplating effect of the lead base layer inevitably differs between the periphery and the center, thus affecting the uniformity of the lead composite. However, molten lead coating or lifting does not have this problem and can obtain a lead base layer with good uniformity. 2) The molten lead coating or lifting method is simple and easy to operate, and can quickly form a lead base layer of a certain thickness. Electroplating lead requires a long time for lead ion deposition and growth to form a lead base layer of a certain thickness, which is not efficient. 3) The electroplating lead process involves the use of lead-containing solutions, resulting in lead-containing waste liquid treatment, which is environmentally harmful.

[0106] Between melt coating and dip-coating, dip-coating is preferred. Dip-coating can easily control the thickness of the lead substrate by controlling the lifting speed, thus obtaining a lead substrate with uniform thickness. Dip-coating is also easier to automate in industrial production.

[0107] Example 8

[0108] This embodiment provides another lead-based composite material and its preparation method, wherein the matrix is ​​a glass fiber woven fabric with a thickness of 1.5, and the metal modification layer is metallic nickel. The preparation method is similar to that of Example 3, except that the copper electroplating step is replaced by nickel electroplating.

[0109] Example 9

[0110] This embodiment provides another lead-based composite material and its preparation method, wherein the matrix is ​​a polyimide (PI) film with a thickness of 10 μm, and the preparation method includes the following steps:

[0111] (1) Prepare Ti3C2T with a mass concentration of 50 mg / ml x Aqueous dispersion (binder-free, viscous slurry);

[0112] (2) The slurry-like dispersion was coated onto the PI film using a doctor blade. The coating thickness could be easily controlled by the gap between the doctor blade and the PI film. The PI / MXene composite was obtained by vacuum drying at 50°C for 4 hours.

[0113] (3) The dried PI / MXene composite was placed in an electroplating device for copper electroplating. The specific copper electroplating process was similar to that in Example 2, except that the electroplating time was 1 min, and the PI / MXene / Cu intermediate composite was obtained.

[0114] (4) One side of the intermediate composite PI / MXene / Cu after copper electroplating is coated with molten metallic lead in an argon atmosphere in a glove box, more specifically by scraping with a scraper, to form the lead-based composite PI / MXene / Cu / Pb (e.g., ...). Figure 9 (As shown)

[0115] Using a method similar to that in Examples 3 to 9, we replaced the material type of the substrate and the type of metal in the metal modification layer, as shown in the table below. We found that the method of the present invention is universal and can obtain lead-based composite materials with a uniform lead base layer.

[0116]

[0117]

[0118] Example 10

[0119] This embodiment provides an implementation method for forming a metal modification layer by electroless plating, and the specific implementation steps include:

[0120] The GF / MXene composite obtained in Example 4 was immersed in a chemical copper plating solution at 45°C. Specifically, the chemical copper plating solution consisted of 7 g / L copper sulfate, 10 g / L sodium carbonate, 75 g / L potassium sodium tartrate, 0.01 g / L thiourea, 10 ml / L triethanolamine, and 20 g / L sodium hydroxide, with a pH of 12. The immersion time was 25 min to 60 min, resulting in a GF / MXene / Cu intermediate composite. Molten lead or a lead alloy was then coated onto the surface of the GF / MXene / Cu intermediate composite. After cooling and solidification, a lead base layer was formed, yielding a lead-based composite material. In one specific embodiment, the immersion time was 30 min.

[0121] Example 11

[0122] This embodiment also provides an application of the obtained lead-based composite material as an electrode grid for a lead-acid battery, or provides a composite current collector for a lead-acid battery, or a grid for a lead-acid battery.

[0123] The foregoing description of specific exemplary embodiments of the invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A lead-based composite material for use in a lead-acid battery, characterized in that, The application relates to a lead-based composite material, which comprises: a substrate; a conductive MXene layer arranged on the surface or part of the surface of the substrate; a metal modification layer arranged on the surface of the conductive MXene layer, wherein the metal modification layer is made of one or more of copper, nickel, silver, gold, platinum, magnesium, zinc, tin, chromium, antimony and bismuth; and a lead-based layer arranged on the surface of the metal modification layer; wherein the substrate is made of a polymer, a ceramic or a glass material. The metal modification layer is formed on the surface of the conductive MXene layer by electroplating or electroless plating. The metal modification layer is formed on the surface of the conductive MXene layer by electroplating. The glass is a glass fiber. The lead-based layer is made of metallic lead or a lead alloy. The substrate is a fiber woven fabric, a perforated sheet or a mesh or a film.

2. The lead-based composite material for lead-acid batteries as claimed in claim 1, characterized in that, The content of the MXene material in the conductive MXene layer is 50wt.%-100wt.%.

3. The lead-based composite material for lead-acid batteries as claimed in claim 1, characterized in that, The thickness of the conductive MXene layer is 3nm-50mu.

4. The lead-based composite material for lead acid batteries of claim 1, wherein, The thickness of the metal modification layer is 10nm-50mu. The thickness of the lead-based layer is 1mu-300mu. The thickness of the lead-based composite material is 2mu-500mu.

5. The lead-based composite material for lead acid batteries of claim 1, wherein, The thickness of the conductive MXene layer is 10nm-10mu.

6. The lead-based composite material for lead acid batteries of claim 1, wherein, The thickness of the metal modification layer is 100nm-10mu. The thickness of the lead-based layer is 1mu-100mu. The thickness of the conductive MXene layer is 100nm-5mu. The thickness of the metal modification layer is 100nm-5mu.

7. The lead-based composite material for lead-acid batteries as claimed in claim 1, wherein, The thickness of the lead-based layer is 1mu-50mu. The thickness of the conductive MXene layer is 200nm-2mu. The thickness of the metal modification layer is 200nm-2mu.

8. The lead-based composite material for lead-acid batteries as claimed in claim 1, wherein, The thickness of the lead-based layer is 1mu-20mu. The application relates to a lead-based composite material, which comprises: a substrate; a conductive MXene layer arranged on the surface or part of the surface of the substrate; a metal modification layer arranged on the surface of the conductive MXene layer, wherein the metal modification layer is made of one or more of copper, nickel, silver, gold, platinum, magnesium, zinc, tin, chromium, antimony and bismuth; and a lead-based layer arranged on the surface of the metal modification layer; wherein the substrate is made of a polymer, a ceramic or a glass material. The metal modification layer is formed on the surface of the conductive MXene layer by electroplating or electroless plating.

9. The lead-based composite material for lead-acid batteries as claimed in claim 1, wherein, The metal modification layer is formed on the surface of the conductive MXene layer by electroplating. The glass is a glass fiber. The lead-based layer is made of metallic lead or a lead alloy.

10. A method of producing a lead-based composite material for lead-acid batteries as claimed in any one of claims 1 to 9, characterized in that the step The substrate is a fiber woven fabric, a perforated sheet or a mesh or a film. The content of the MXene material in the conductive MXene layer is 50wt.%-100wt.%. The thickness of the conductive MXene layer is 3nm-50mu. The thickness of the metal modification layer is 10nm-50mu.

11. The method of claim 10, wherein the lead-based composite material for lead acid batteries is prepared by the steps of: The thickness of the lead-based layer is 1mu-300mu.

12. The method of claim 10, wherein the lead-based composite material for lead acid batteries is prepared by the steps of: The thickness of the lead-based composite material is 2mu-500mu.

13. The method of claim 10, wherein the lead-based composite material for lead acid batteries is prepared by the steps of: The thickness of the conductive MXene layer is 10nm-10mu.

14. The method of claim 11 or 12, wherein the lead-based composite material for lead-acid batteries is prepared by the steps of: The thickness of the metal modification layer is 100nm-10mu.

15. The method of claim 14, wherein the lead-based composite material for lead acid batteries is prepared by the steps of: The thickness of the lead-based layer is 1mu-100mu. The thickness of the conductive MXene layer is 100nm-5mu. The thickness of the metal modification layer is 100nm-5mu. The thickness of the lead-based layer is 1mu-50mu. The thickness of the conductive MXene layer is 200nm-2mu. The thickness of the metal modification layer is 200nm-2mu. The thickness of the lead-based layer is 1mu-20mu. The application relates to a lead-based composite material, which comprises: a substrate; a conductive MXene layer arranged on the surface or part of the surface of the substrate; a metal modification layer arranged on the surface of the conductive MXene layer, wherein the metal modification layer is made of one or more of copper, nickel, silver, gold, platinum, magnesium, zinc, tin, chromium, antimony and bismuth; and a lead-based layer arranged on the surface of the metal modification layer; wherein the substrate is made of a polymer, a ceramic or a glass material. The application relates to a lead-based composite material, which comprises: a substrate; a conductive MXene layer arranged on the surface or part of the surface of the substrate; a metal modification layer arranged on the surface of the conductive MXene layer, wherein the metal modification layer is made of one or more of copper, nickel, silver, gold, platinum, magnesium, zinc, tin, chromium, antimony and bismuth; and a lead-based layer arranged on the surface of the metal modification layer; wherein the substrate is made of a polymer, a ceramic or a glass material. The metal modification layer is formed on the surface of the conductive MXene layer by electroplating or electroless plating. The metal modification layer is formed on the surface of the conductive MXene layer by electroplating. The glass is a glass fiber. The lead-based layer is made of metallic lead or a lead alloy. The substrate is a fiber woven fabric, a perforated sheet or a mesh or a film. The content of the MXene material in the conductive MXene layer is 50wt.%-100wt.%. The thickness of the conductive MXene layer is 3nm-50mu. The thickness of the metal modification layer is 10nm-50mu. The thickness of the lead-based layer is 1mu-300mu. The thickness of the lead-based composite material is 2mu-500mu. The thickness of the conductive MXene layer is 10nm-10mu. The thickness of the metal modification layer is 100nm-10mu. The thickness of the lead-based layer is 1mu-100mu. The thickness of the conductive MXene layer is 100nm-5mu. The thickness of the metal modification layer is 100nm-5mu. The thickness of the lead-based layer is 1mu-50mu. The thickness of the conductive MXene layer is 200nm-2mu. The thickness of the metal modification layer is 200nm-2mu. The thickness of the lead-based layer is 1mu-20mu. The application relates to a lead-based composite material, which comprises: a substrate; a conductive MXene layer arranged on the surface or part of the surface of the substrate; a metal modification layer arranged on the surface of the conductive MXene layer, wherein the metal modification layer is made of one or more of copper, nickel, silver, gold, platinum, magnesium, zinc, tin, chromium, antimony and bismuth; and a lead-based layer arranged on the surface of the metal modification layer; wherein the substrate is made of a polymer, a ceramic or a glass material. The application relates to a lead-based composite material, which comprises: a substrate; a conductive MXene layer arranged on the surface or part of the surface of the substrate; a metal modification layer arranged on the surface of the conductive MXene layer, wherein the metal modification layer is made of one or more of copper, nickel, silver, gold, platinum, magnesium, zinc, tin, chromium, antimony and bismuth; and a lead-based layer arranged on the surface of the metal modification layer; wherein the substrate is made of a polymer, a ceramic or a glass material. The metal modification layer is formed on the surface of the conductive MXene layer by electroplating or electroless plating. The metal modification layer is formed on the surface of the conductive MXene layer by electroplating. The glass is a glass fiber. The lead-based layer is made of metallic lead or a lead alloy. The substrate is a fiber woven fabric, a perforated sheet or a mesh or a film. The content of the MXene material in the conductive MXene layer is 50wt.%-100wt.%. The thickness of the conductive MXene layer is 3nm-50mu. The thickness of the metal modification layer is 10nm-50mu. The thickness of the lead-based layer is 1mu-300mu. The thickness of the lead-based composite material is 2mu-500mu. The thickness of the conductive MXene layer is 10nm-10mu. The thickness of the metal modification layer is 100nm-10mu. The thickness of the lead-based layer is 1mu-100mu. The thickness of the conductive MXene layer is 100nm-5mu. The thickness of the metal modification layer is 100nm-5mu. The thickness of the lead-based layer is 1mu-50mu. The thickness of the conductive MXene layer is 200nm-2mu. The thickness of the metal modification layer is 200nm-2mu. The thickness of the lead-based layer is 1mu-20mu. The application relates to a lead-based composite material, which comprises: a substrate; a conductive MXene layer arranged on the surface or part of the surface of the substrate; a metal modification layer arranged on the surface of the conductive MXene layer, wherein the metal modification layer is made of one or more of copper, nickel, silver, gold, platinum, magnesium 16. The method of producing a lead-based composite material for lead-acid batteries according to any one of claims 11 to 13, characterized in that, The coating step, more specifically, includes: spraying, coating, or impregnating the substrate with an MXene dispersion, and forming the conductive MXene layer after drying.

17. The method of claim 16, wherein the lead-based composite material for lead acid batteries is prepared by the steps of: The MXene dispersion comprises MXene material and a solvent, wherein the concentration of the MXene material is between 0.1 mg / ml and 80 mg / ml.

18. A lead-based composite material obtained by the preparation method according to any one of claims 10 to 17.

19. The application of a lead-based composite material as described in any one of claims 1 to 9 and 18 in a lead-acid battery.

20. A method of making a lead acid battery composite current collector, characterized by the steps of include: Coating step: Spray, coat, or impregnate MXene dispersion on the surface of a polymer matrix or glass fiber matrix, and form a conductive MXene layer after drying; Modification step: Electroplating a metal modification layer on the surface of the conductive MXene layer to obtain an intermediate composite. The metal type of the metal modification layer is selected from one or more of the following: copper, nickel, silver, gold, platinum, magnesium, zinc, tin, chromium, antimony, and bismuth. Composite lead step: The surface of the intermediate composite is coated with molten lead or lead alloy, and after cooling, a lead base layer is formed.

21. The method of making a lead acid battery composite current collector of claim 20, wherein, The thickness of the conductive MXene layer is between 3 nm and 50 μm; And / or, the thickness of the metal modification layer is between 10 nm and 50 μm; and / or, the thickness of the lead base layer is between 1 μm and 300 μm; And / or, the thickness of the lead-acid battery composite current collector is between 2 μm and 500 μm.

22. The method of making a lead acid battery composite current collector of claim 20, wherein, The thickness of the conductive MXene layer is between 10 nm and 10 μm; And / or, the thickness of the metal modification layer is between 100 nm and 10 μm; And / or, the thickness of the lead base layer is between 1 μm and 100 μm; And / or, the thickness of the lead-acid battery composite current collector is between 5 μm and 300 μm.

23. The method of making a lead acid battery composite current collector of claim 20, wherein, The thickness of the conductive MXene layer is between 100 nm and 5 μm; And / or, the thickness of the metal modification layer is between 100 nm and 5 μm; And / or, the thickness of the lead substrate is between 1 μm and 50 μm; And / or, the thickness of the lead-acid battery composite current collector is between 10 μm and 100 μm.

24. The method for preparing the lead-acid battery composite current collector as described in claim 20, characterized in that, The thickness of the conductive MXene layer is between 200 nm and 2 μm; And / or, the thickness of the metal modification layer is between 200 nm and 2 μm; And / or, the thickness of the lead base layer is between 1 μm and 20 μm.

25. A lead-acid battery composite current collector obtained by the preparation method of the lead-acid battery composite current collector as described in any one of claims 20 to 24.

26. A lead-acid battery characterized by Includes lead-based composite materials as described in any one of claims 1 to 9 and 18.

27. A lead-acid battery characterised in that, Includes the lead-acid battery composite current collector as described in claim 25.

28. A vehicle, characterized by Including the lead-acid battery as described in claim 26 or 27.

Images