A kind of pro-zinc integration matrix material and aqueous zinc ion battery

Abstract

The application discloses a kind of affinity-zinc integration matrix material and aqueous zinc ion battery, it is related to aqueous zinc ion battery technical field.The affinity-zinc integration matrix material is prepared by the following steps: carbon source precursor and zincophilic metal salt precursor are dispersed in solvent, stirring is uniformly obtained precursor solution;The precursor solution is electrospun, and spinning film is obtained;Spinning film is calcined in air with first preset temperature, then high-temperature annealing is carried out to spinning film under argon hydrogen mixed atmosphere with second preset temperature, and the carbon fiber matrix loaded with zincophilic nanoparticles is obtained;The carbon fiber matrix loaded with zincophilic nanoparticles is carried out zinc plating pre-zincification and obtains the affinity-zinc integration matrix material;The affinity-zinc integration matrix material can make zinc ion directional, uniformly deposited on its surface as negative electrode matrix, effectively inhibit dendrite growth on negative electrode and side reaction occurs, so as to improve the cycle stability and energy density of aqueous zinc ion battery.

Description

Technical Field

[0001] This invention relates to the field of aqueous zinc-ion battery technology, specifically to an integrated zinc-philic and zinc-repellent matrix material and an aqueous zinc-ion battery. Background Technology

[0002] Aqueous zinc-ion batteries are advantageous due to their high safety, environmental friendliness, low cost, abundant zinc resources, and relatively high theoretical capacity (up to 820 mAh·g). -1 With advantages such as low redox potential (as low as -0.76V vs. SHE, SHE: standard hydrogen electrode), it is regarded as an ideal candidate for the next generation of clean and efficient energy storage devices and has broad application prospects.

[0003] However, the zinc anode of aqueous zinc-ion batteries is susceptible to dendrite formation and side reactions (hydrogen evolution, corrosion, passivation, etc.) during charge-discharge cycles, leading to reduced coulombic efficiency and even battery failure. To address this issue, some studies have attempted to reduce side reactions by constructing protective coatings on the zinc anode surface. However, these coatings struggle to maintain stable interfacial protection during high current densities and long-cycle periods. Other studies have designed zinc-affinity or zinc-repellent substrate materials to regulate zinc deposition behavior. While zinc-affinity substrates can lower the nucleation barrier and provide more nucleation sites, the dispersed active sites still make it difficult to prevent localized zinc protrusions and deficiencies. Zinc preferential deposition occurs in the crater, where dendrites easily grow (dendrites increase the contact area between the electrolyte and the zinc anode, leading to more severe side reactions such as hydrogen evolution, corrosion, and passivation, and may even puncture the battery separator, causing battery failure). Furthermore, excessively rapid local deposition can cause the zinc anode to expand in volume and produce dead zinc (unreacted free zinc), resulting in poor cycle stability and low energy density. On the other hand, a single zinc-repellent matrix, due to its limited nucleation sites, is more prone to inducing dendrite growth, leading to uneven zinc deposition on the matrix surface. Currently, research on aqueous zinc-ion batteries still lacks effective methods to achieve directional and uniform zinc deposition on the anode, severely limiting the application of aqueous zinc-ion batteries in high current density and long cycle scenarios. Summary of the Invention

[0004] To address the aforementioned issues, this invention provides an integrated zinc-philic and zinc-repellent matrix material, which aims to guide the uniform deposition of zinc on the negative electrode through the integrated zinc-philic and zinc-repellent matrix, thereby suppressing dendrite growth and side reactions, and improving the cycle stability and energy density of aqueous zinc-ion batteries.

[0005] The preparation steps of the zinc-philic-zinc-repellent integrated matrix material are as follows:

[0006] S1, disperse the carbon source precursor and the zinc-loving metal salt precursor in a solvent and stir until uniform to obtain a precursor solution;

[0007] S2, electrospinning the precursor solution to obtain a spun film;

[0008] S3, the spun film is calcined and shaped in air at a first preset temperature, and then the calcined and shaped spun film is annealed at a second preset temperature in an argon-hydrogen mixed atmosphere to obtain a carbon fiber matrix loaded with zinc-loving nanoparticles; wherein, the second preset temperature is higher than the first preset temperature.

[0009] S4, the carbon fiber matrix loaded with zinc-loving nanoparticles is electroplated and pre-zincified to obtain an integrated zinc-loving and zinc-repellent matrix material.

[0010] Optionally, the carbon source precursor is at least one of polyacrylonitrile, polyvinyl alcohol, polyimide, polyvinyl chloride, cellulose, and chitosan.

[0011] Optionally, the carbon source precursor is polyacrylonitrile, the solvent is N,N-dimethylformamide, and the content of polyacrylonitrile in the precursor solution is 0.05~0.5 g·mL. -1 .

[0012] Optionally, in step S2, the parameters of electrospinning include: the DC voltage between the spinning needle and the collector is 18kV, and the distance between the spinning needle and the collector is 18cm.

[0013] Optionally, the standard reduction potential of the zinc-loving nanoparticles is higher than that of zinc.

[0014] Optionally, the zinc-loving nanoparticles are at least one of copper nanoparticles, tin nanoparticles, and nickel nanoparticles, or the zinc-loving nanoparticles are alloy nanoparticles formed from two or more elements of copper, tin, and nickel.

[0015] Optionally, the zinc-loving nanoparticles are copper nanoparticles; the zinc-loving metal salt precursor is at least one of copper nitrate, copper chloride, copper sulfate, copper acetate, copper propionate, copper trifluoromethanesulfonate, and copper acetylacetonate.

[0016] Optionally, the copper content in the precursor solution is 0.5~10 mmol.

[0017] Optionally, the first preset temperature is 200℃, and the calcination time is 2~6h.

[0018] Optionally, the second preset temperature is 400~1000℃, and the heating rate for high-temperature annealing is 1~5℃·min. -1 High-temperature annealing time is 3~12 hours.

[0019] Optionally, the pre-zinc plating specifically includes:

[0020] The carbon fiber matrix loaded with zinc-philic nanoparticles was placed in an electroplating bath, using zinc foil as the counter electrode, and an electroplating temperature of 2-5 mol·L⁻¹ was applied. -1 Using a zinc salt solution as the electroplating solution, zinc is deposited on the carbon fiber matrix loaded with zinc-loving nanoparticles under a preset stirring speed and a preset deposition capacity.

[0021] Optionally, the zinc salt is at least one of zinc sulfate, zinc chloride, or zinc trifluoromethanesulfonate.

[0022] Optionally, the preset stirring speed is 200~500 rpm, and the preset deposition capacity is 0.1~10 mAh·cm³. -2 .

[0023] The present invention also provides an aqueous zinc-ion battery, which includes a negative electrode, a positive electrode, an electrolyte, and a separator, wherein the negative electrode is the zinc-affin integrated matrix material described above.

[0024] The present invention has the following beneficial effects:

[0025] 1. This invention prepares a carbon fiber matrix loaded with zinc-loving nanoparticles by electrospinning a mixed solution of a carbon source precursor and a zinc-loving metal salt precursor, followed by calcination and high-temperature annealing. A large number of zinc-loving nanoparticles are uniformly and densely distributed on the carbon fiber surface. The carbon fiber not only has good electrical conductivity but also exhibits weak zinc adsorption capacity, demonstrating good zinc repellency. The zinc-loving nanoparticles, on the other hand, possess good zinc affinity and can serve as growth sites for zinc. During charging, the zinc-loving carbon fiber absorbs Zn... 2+ It exhibits a repulsive tendency, while zinc-loving nanoparticles are attracted to Zn. 2+ It has significant attraction and nucleation capabilities, thereby driving Zn 2+ Directed migration and uniform deposition on zinc-loving nanoparticles achieve a uniform and smooth metallic zinc deposition layer;

[0026] 2. Due to the high density and uniform distribution of zinc-loving nanoparticles on the carbon fiber surface, the local current density and deposition rate at each deposition site are balanced, which avoids the rapid accumulation of zinc at a single protrusion and significantly inhibits dendrite nucleation and epitaxial growth. At the same time, the dense and flat deposition layer can reduce the area of ​​the reaction interface between the electrolyte and active zinc metal, thereby inhibiting side reactions such as hydrogen evolution, corrosion and passivation.

[0027] 3. Through the above-mentioned synergistic deposition mechanism, the zinc-philic-repellent integrated matrix material of the present invention can achieve reversible zinc plating / dissolution cycling with high coulombic efficiency at high current density, thereby extending the cycle life of aqueous zinc-ion batteries and improving their energy density, which is especially suitable for high-rate charge-discharge and long-life energy storage scenarios.

[0028] 4. The matrix of the present invention is composed of a carbon fiber skeleton, which is both conductive and flexible, and has a simple process, low cost, and environmental friendliness, and has the potential for industrial application of flexible energy storage devices. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the following drawings are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a flowchart illustrating the preparation process of some embodiments of the zinc-philic-zinc-repellent integrated matrix material of the present invention;

[0031] Figure 2 This is a comparison of the XRD characterization test pattern of the Cu@C matrix prepared in Example 1 of the present invention with the standard XRD pattern of Cu (JCPDS 04-0836);

[0032] Figure 3 This is a SEM image of the Cu@C substrate prepared in Example 1 of this invention;

[0033] Figure 4 The image shows the EDS elemental analysis of the Cu@C matrix prepared in Example 1 of this invention.

[0034] Figure 5 This is a graph showing the zinc plating coulombic efficiency-cycle count test data of the zinc-philic-zinc-repellent integrated matrix material prepared in Example 1 of this invention;

[0035] Figure 6 This is a graph showing the symmetric battery voltage-test time data of the zinc-philic-zinc-repellent integrated matrix material prepared in Example 1 of this invention.

[0036] Figure 7 This is a graph showing the zinc plating coulomb efficiency-cycle test data of the zinc-repellent carbon fiber anode prepared in Comparative Example 1 of the present invention.

[0037] Figure 8 This is a graph showing the zinc plating coulombic efficiency versus cycle count test data of the zinc-loving copper foil negative electrode prepared in Comparative Example 2 of this invention. Detailed Implementation

[0038] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0039] The terms "first," "second," "third," "fourth," etc. (if present) in the specification and drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0040] Experimental methods in the embodiments of this invention that do not specify specific conditions are generally performed under conventional conditions and conditions described in the manual, or under conditions recommended by the manufacturer; the general equipment, materials, reagents, etc. used are commercially available unless otherwise specified.

[0041] See Figure 1 In some embodiments, the zinc-philic-zinc-repellent integrated matrix material provided by the present invention is prepared by the following steps S1 to S4:

[0042] S1, disperse the carbon source precursor and the zinc-loving metal salt precursor in a solvent and stir until homogeneous to obtain a precursor solution.

[0043] In this embodiment of the invention, the core criteria for selecting the carbon source precursor are spinnability, high residual carbon rate, and controllable carbon structure after carbonization. In some embodiments, the carbon source precursor can be selected from synthetic or natural high molecular weight organic compounds, including but not limited to one or more of polyacrylonitrile, polyvinyl alcohol, polyimide, polyvinyl chloride, cellulose, and chitosan. The solvent can be reasonably selected according to the hydrophilicity / hydrophobicity of the carbon source precursor and the requirements of electrospinning process for solution viscosity, surface tension, and conductivity, including but not limited to water and various polar organic solvents.

[0044] In some preferred embodiments, polyacrylonitrile (PAN) is selected as the carbon source precursor, and N,N-dimethylformamide (DMF) is selected as the solvent. PAN molecules have cyano groups, which allow for strong intermolecular interactions. This makes the viscosity and elastic modulus of the spinning solution (precursor solution) easily controllable, resulting in good mechanical properties of the spun fibers. Furthermore, the carbon residue rate is high during PAN carbonization, preserving the fiber morphology and porous structure formed by electrospinning, and the carbon structure after carbonization is controllable. DMF is a strongly polar aprotic solvent with strong solubility for PAN, and its moderate boiling point and conductivity are beneficial to the stability of electrospinning. The concentration of PAN in the DMF solvent is selected as 0.05~0.5 g·mL. -1 Too high or too low a concentration will affect the stability of electrospinning and the fiber morphology and mechanical properties of the final spun film. When dissolving PAN in DMF, the stirring time can be selected as 6~15h to obtain a uniform PAN solution.

[0045] In this embodiment of the invention, a zinc-loving metal salt precursor is used to form zinc-loving nanoparticles during the subsequent high-temperature annealing process. Zinc affinity refers to the affinity between the metal particle surface and Zn. 2+ Ions exhibit zinc affinity activity through chemical adsorption or alloying. Zinc-affinity nanoparticles include, but are not limited to, one or more of copper nanoparticles, tin nanoparticles, and nickel nanoparticles, or alloy nanoparticles formed by two or more of copper, tin, and nickel. The standard reduction potential of zinc-affinity nanoparticles is higher than that of zinc, providing growth sites only for zinc deposition. They do not dissolve or react during the charging and discharging process of the battery.

[0046] In some preferred embodiments, copper nanoparticles are selected as zinc-loving nanoparticles, as copper can form alloys with zinc, thus exhibiting excellent zinc affinity. Accordingly, the zinc-loving metal salt precursor includes, but is not limited to, one or more copper sources such as copper nitrate, copper chloride, copper sulfate, copper acetate, copper propionate, copper trifluoromethanesulfonate, and copper acetylacetonate. The copper content in the precursor solution is preferably 0.5-10 mmol. After adding the copper source to the PAN solution, stirring can be continued for 2-6 hours to obtain a homogeneous precursor solution.

[0047] In other embodiments, when the zinc-loving nanoparticles are selected as tin nanoparticles, the corresponding zinc-loving metal salt precursor can be selected as stannous chloride or tin nitrate; when the zinc-loving nanoparticles are selected as nickel nanoparticles, the corresponding zinc-loving metal salt precursor can be selected as nickel nitrate or nickel acetate; when the zinc-loving nanoparticles are selected as alloy materials, the corresponding zinc-loving metal salt precursor can be selected as a mixed salt composed of two or more metal salt precursors.

[0048] S2, electrospinning the precursor solution to obtain a spun film.

[0049] Electrospinning is a material preparation technology that uses a high-voltage electric field to drive the spinning solution to form ultrafine fibers / spun films. The main steps of electrospinning are as follows: the spinning solution is delivered to the spinning needle at a stable flow rate under the control of a peristaltic pump through a syringe or storage tank. The spinning needle is connected to the positive terminal of a high-voltage power supply, and the collector (such as aluminum foil) is grounded or connected to the negative terminal. The spinning solution is given a uniform positive charge when it flows through the spinning needle. When the electric field strength between the spinning needle and the collector reaches a critical value, the electric field force on the surface of the spinning solution at the tip of the spinning needle will overcome the surface tension and viscosity, causing the originally hemispherical spinning solution droplet to be stretched into a conical structure - a Taylor cone. As the electric field force continues to increase, the tip of the Taylor cone breaks through the constraint, and the spinning solution is ejected as a continuous liquid jet. During the flight, the jet is violently stretched due to the mutual repulsion of surface charges, and its diameter is rapidly reduced to the nanometer scale. While the jet is being stretched, the solvent evaporates during the flight, and finally the liquid jet solidifies into solid ultrafine fibers, which are randomly or directionally deposited on the collector to form a spun film.

[0050] The electrospinning apparatus includes a spinning solution supply system, a high-voltage power supply, spinning needles, and a collector. The electrospinning apparatus used in the embodiments of the present invention can be obtained commercially. In some preferred embodiments, the parameters of electrospinning include: the DC voltage between the spinning needles and the collector is 18kV, and the distance between the spinning needles and the collector is 18cm.

[0051] S3, the spun film is calcined and shaped in air at a first preset temperature, and then the calcined and shaped spun film is annealed at a second preset temperature in an argon-hydrogen mixed atmosphere to obtain a carbon fiber matrix loaded with zinc-loving nanoparticles; the second preset temperature is higher than the first preset temperature.

[0052] In this step, calcining the spun film in air at a first preset temperature aims to induce a pre-oxidation reaction in the carbon source precursor, causing the molecular chains to cross-link and solidify into a non-melting, rigid structure. This preserves the fiber morphology of the spun film for subsequent high-temperature carbonization. Simultaneously, heating at the first preset temperature can trigger the initial thermal decomposition of the zinc-loving metal salt precursor, generating stable metal oxides (e.g., copper nitrate decomposes into copper oxide). The first preset temperature can be specifically set to a temperature lower than the carbonization temperature of the carbon source precursor in air. Annealing the spun film in an argon-hydrogen mixed atmosphere at a second preset temperature aims to... The pre-oxidation product of the source precursor undergoes carbonization to obtain carbon fibers (using an argon-hydrogen mixture to remove H, O, N, and other atoms from the polymer chain). Simultaneously, the metal salt precursor or metal oxide undergoes reduction to form zinc-loving metal nanoparticles. The formation of the carbon fiber matrix and the reduction of zinc-loving metal nanoparticles occur synchronously. During the carbonization process, the carbon fibers encapsulate and anchor the metal nanoparticles, ultimately resulting in a uniformly and densely loaded carbon fiber matrix with zinc-loving nanoparticles. The second preset temperature can be specifically set to be no lower than the temperature at which the carbon source precursor undergoes complete carbonization in an argon-hydrogen mixture and the temperature at which the metal salt precursor is completely reduced to metal.

[0053] In some preferred embodiments, the carbon source precursor is polyacrylonitrile, and the zinc-philic metal salt precursor is one or more of copper nitrate, copper chloride, copper sulfate, copper acetate, copper propionate, copper trifluoromethanesulfonate, and copper acetylacetonate. The first preset temperature is set to 200°C, and the calcination time is 2-6 hours. The second preset temperature is set to 400-1000°C, and the heating rate for high-temperature annealing is 1-5°C / min. -1 High-temperature annealing time is 3~12 hours.

[0054] S4, electroplating pre-zincification of carbon fiber matrix loaded with zinc-loving nanoparticles to obtain zinc-loving-zinc-repellent integrated matrix material.

[0055] Electroplating pre-zincification refers to the deposition of a uniform and dense layer of metallic zinc on the surface of the negative electrode substrate through an electroplating process. This covers the defects of the carbon fiber substrate, laying a good foundation for uniform deposition in subsequent charge-discharge cycles. At the same time, it optimizes the zinc-carbon contact interface, reduces interfacial impedance, and improves the cycle stability of aqueous zinc-ion batteries.

[0056] Specifically, the pre-zinc plating step includes: placing a carbon fiber matrix loaded with zinc-philic nanoparticles in an electroplating bath, using metallic zinc foil as the counter electrode, and applying 2~5 mol·L⁻¹ zinc plating solution. -1 Using a zinc salt solution as the electroplating solution, zinc is deposited on a carbon fiber matrix loaded with zinc-loving nanoparticles under a preset stirring speed and a preset deposition capacity.

[0057] In some embodiments, the zinc salts used for pre-zinc plating include, but are not limited to, one or more of zinc sulfate, zinc chloride, and zinc trifluoromethanesulfonate.

[0058] In some preferred embodiments, the preset stirring speed for pre-zinc electroplating is 200-500 rpm, and the preset deposition capacity is 0.1-10 mAh·cm³. -2 .

[0059] This invention provides an embodiment of a carbon fiber matrix loaded with zinc-loving nanoparticles. This matrix is ​​prepared by electrospinning a mixed solution of a carbon source precursor and a zinc-loving metal salt precursor, followed by calcination and high-temperature annealing. A large number of zinc-loving nanoparticles are uniformly and densely distributed on the carbon fiber surface. The carbon fiber not only has good electrical conductivity but also exhibits weak zinc adsorption capacity, demonstrating good zinc repellency. The zinc-loving nanoparticles, on the other hand, possess good zinc affinity and can serve as growth sites for zinc. When an aqueous zinc-ion battery is charged, the zinc-repellent carbon fiber repels zinc ions, while the zinc-loving nanoparticles attract them, thus forcing zinc ions to migrate directionally to the zinc-loving nanoparticles for deposition. Because the zinc-loving nanoparticles are uniformly and densely distributed on the carbon fiber, the deposition rate of zinc at each growth site is similar, avoiding excessive dendrite growth and excessively rapid zinc deposition caused by localized single-point deposition. Therefore, this invention utilizes a carbon fiber matrix loaded with zinc-loving nanoparticles to guide uniform zinc deposition on the matrix, effectively suppressing dendrite formation and side reactions at the zinc anode.

[0060] This invention also provides an aqueous zinc-ion battery, comprising a negative electrode, a positive electrode, an electrolyte, and a separator. The positive electrode is typically prepared by mixing a positive electrode active material (manganese-based, vanadium-based, organic positive electrode material, etc.) with a conductive agent (such as carbon black, CNT) and a binder. The electrolyte is an electrolyte containing dissolved zinc salts, and its form includes, but is not limited to, liquid electrolytes and hydrogel electrolytes. The separator is sandwiched between the positive and negative electrode sheets to separate the positive and negative electrodes and allow Zn to pass through. 2+ Ions pass through; the negative electrode is the zinc-philic-zinc-hydrophobic integrated matrix material provided in the above embodiments.

[0061] Since the carbon fiber matrix loaded with zinc-loving nanoparticles can guide the uniform deposition of zinc on the matrix, thereby effectively suppressing dendrite formation and side reactions in the zinc anode, aqueous zinc-ion batteries using an integrated zinc-loving / zinc-repellent matrix material as the anode exhibit excellent cycle stability, and the Zn content during charging is significantly reduced. 2+ Uniform deposition on the negative electrode and uniform dissolution of zinc during discharge allow zinc to fully participate in the reaction, effectively improving the energy density of aqueous zinc-ion batteries. Therefore, the aqueous zinc-ion battery proposed in this invention is suitable for applications requiring high current density and long cycle time.

[0062] Furthermore, the uniform deposition of zinc on the negative electrode substrate can effectively reduce the N / P ratio of the full battery (the ratio of the theoretical capacity of the negative electrode active material to the theoretical capacity of the positive electrode active material), thereby improving the overall energy density of the battery. Further, by adjusting the concentration of zinc-loving metal salt precursors during the preparation of the carbon fiber matrix loaded with zinc-loving nanoparticles, the distribution of zinc-loving nanoparticles on the carbon fiber matrix can be adjusted. This allows the zinc-loving / zinc-repellent integrated matrix material prepared in this invention to have the ability to quantitatively control the zinc loading, thereby balancing the battery's safety, cycle life, and actual capacity by regulating the N / P ratio.

[0063] Based on the above embodiments, in order to better illustrate the implementation process and beneficial effects of the technical solution of the present invention, the present invention also proposes the following specific embodiments. It should be noted that the following specific embodiments are merely exemplary and are not intended to limit the scope of protection of the present invention in any way.

[0064] Example 1

[0065] Step 1: Add 1.0 g of polyacrylonitrile to 10 mL of N,N-dimethylformamide and stir for 12 h to fully dissolve the polyacrylonitrile, thus obtaining a homogeneous polyacrylonitrile organic solution.

[0066] Step 2: Add 2 mmol of copper nitrate to the above polyacrylonitrile organic solution, and continue stirring the mixture for 4 hours to obtain a homogeneous precursor solution.

[0067] Step 3: Transfer the above precursor solution to an electrospinning injector equipped with a stainless steel nozzle for electrospinning. Use aluminum foil as a collector and spin at a high voltage of 18kV. The distance between the spinning needle and the collector is 18cm to obtain a spun film.

[0068] Step 4: After electrospinning, the spun film is peeled off from the aluminum foil and calcined in air at 200°C for 3 hours. Then, the spun film is annealed at 600°C for 6 hours in an argon-hydrogen mixed atmosphere. After the annealed film is cooled to room temperature, a carbon fiber matrix loaded with copper nanoparticles (Cu@C matrix) is obtained. The Cu@C matrix is ​​characterized by XRD phase analysis and SEM analysis.

[0069] Step 5: Place the Cu@C substrate obtained in Step 4 into an electroplating bath, using zinc foil as the counter electrode, at 2 mol·L⁻¹. -1 Using zinc sulfate solution as the electroplating solution, an electric current was applied between the Cu@C substrate and the counter electrode under a stirring environment of 200 rpm, thereby quantitatively depositing zinc on the Cu@C substrate to obtain a zinc-philic-zinc-repellent integrated substrate material. The zinc-philic-zinc-repellent integrated substrate material was then used as a negative electrode to assemble a battery for electrochemical performance testing.

[0070] Comparative Example 1

[0071] Step 1: Add 1.0 g of polyacrylonitrile to 10 mL of N,N-dimethylformamide and stir for 12 h to dissolve the polyacrylonitrile, thus obtaining a homogeneous polyacrylonitrile organic solution.

[0072] Step 2: The above polyacrylonitrile organic solution is directly electrospun (18kV high voltage, 18cm spinning needle-collector distance, collector is aluminum foil) to obtain a spun film.

[0073] Step 3: After electrospinning, the spun film is peeled off from the aluminum foil and calcined in air at 200°C for 3 hours. Then, the spun film is annealed at 600°C for 6 hours in an argon-hydrogen mixed atmosphere. After the annealed spun film is cooled to room temperature, the zinc-repellent carbon fiber matrix is ​​obtained.

[0074] Step 4: Place the zinc-repellent carbon fiber matrix in an electroplating bath, using zinc foil as the counter electrode, at 2 mol·L⁻¹. -1 Using zinc sulfate solution as the electroplating solution, an electric current was applied between the zinc-repellent carbon fiber matrix and the counter electrode under a stirring environment of 200 rpm to quantitatively deposit zinc on the carbon fiber matrix to obtain a pre-zincified carbon fiber negative electrode. The pre-zincified carbon fiber negative electrode was then assembled into a battery for electrochemical performance testing.

[0075] Comparative Example 2

[0076] Step 1: Place commercial copper foil in an electroplating bath, using zinc foil as the counter electrode, 2 mol·L⁻¹ -1 Using zinc sulfate solution as the electroplating solution, an electric current was applied between copper foil and zinc foil under stirring at 200 rpm to quantitatively deposit zinc on the copper foil to obtain a pre-zincified copper foil negative electrode. The pre-zincified copper foil negative electrode was then assembled into a battery for electrochemical performance testing.

[0077] The XRD characterization results of the Cu@C matrix prepared in Example 1 are as follows: Figure 2 As shown, the XRD pattern has obvious copper diffraction peaks, indicating that copper is loaded on the Cu@C matrix.

[0078] SEM morphology characterization of Cu@C matrix as follows: Figure 3 As shown, the elemental analysis by EDS (energy dispersive spectroscopy) is as follows: Figure 4 As shown, the Cu@C matrix has a distinct fibrous morphology, with a large number of copper nanoparticles uniformly and densely distributed on the carbon fiber surface.

[0079] Figure 5 The figure shows the coulombic efficiency of zinc plating on the Cu@C substrate-based integrated zinc-philic and zinc-repellent material prepared in Example 1. The Cu@C substrate can achieve zinc plating efficiency of 10 mA·cm⁻¹. -2Stable zinc plating / dissolution cycling was performed under high current density, and even after 300 cycles, the coulombic efficiency remained close to 100%, demonstrating that the Cu@C substrate has excellent zinc plating stability.

[0080] Figure 6 For 10mA·cm -2 Current density and 1 mAh·cm -2 The voltage-time curves of a symmetrical cell (a symmetrical cell refers to a cell where the positive and negative electrodes use exactly the same electrode materials, structure, and dimensions, used to evaluate the electrochemical stability of a single electrode material) assembled using a zinc-philic-zinc-hydrophobic integrated matrix material as the negative electrode at the deposition capacity are shown. The symmetrical cell at 10 mA·cm⁻¹... -2 Current density and 1 mAh·cm -2 It can maintain stability for more than 260 hours at the deposition capacity, and the magnified part of the image shows that its voltage-test time curve is very stable.

[0081] As a control, the zinc-repellent carbon fiber anode of Comparative Example 1 and the zinc-repellent copper foil anode of Comparative Example 2 were also subjected to zinc plating coulombic efficiency tests under the same conditions as in Example 1; Figure 7 As shown, the coulombic efficiency of the zinc-repellent carbon fiber anode used in Comparative Example 1 fluctuated unstablely after only 20 zinc plating cycles, indicating that zinc ions are difficult to deposit uniformly on the zinc-repellent carbon fiber surface; Figure 8 As shown, the zinc-loving copper foil negative electrode used in Comparative Example 2 has slightly better cycling performance than carbon fiber, but its coulombic efficiency fluctuates after about 90 cycles, making it unable to continue stable zinc plating. Figure 5 , 7 The results of Figures 8 and 9 show that the zinc-affinity integrated matrix material provided in Example 1 can effectively achieve uniform zinc deposition and significantly improve the cycle stability of the battery.

[0082] As can be seen from the above embodiments, the present invention constructs a deposition environment that spatially guides zinc ions by uniformly anchoring zinc-loving nanoparticles on a flexible, conductive, and zinc-repellent carbon fiber skeleton. The zinc-loving nanoparticles uniformly and densely distributed on the carbon fiber surface can serve as active sites for zinc deposition, enabling zinc ions to be deposited directionally and uniformly on the surface of the negative electrode substrate. This significantly suppresses dendrite growth and side reactions such as hydrogen evolution, corrosion, and passivation, thereby improving the cycle stability and energy density of aqueous zinc-ion batteries. The process of the present invention is simple, low-cost, and environmentally friendly, and is suitable for flexible energy storage devices, high-power energy storage devices, and their large-scale production.

[0083] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A zinc-philic-zinc-repellent integrated matrix material, characterized in that, Prepared by the following steps: S1, Polyacrylonitrile and copper nitrate are dispersed in N,N-dimethylformamide and stirred until homogeneous to obtain a precursor solution; S2, electrospinning the precursor solution to obtain a spun film; S3, the spun film is calcined and shaped in air at 200°C for 2-6 hours; then, the calcined and shaped spun film is annealed at 600°C in an argon-hydrogen mixed atmosphere at a heating rate of 1-5°C / min. -1 The carbon fiber matrix loaded with copper nanoparticles is obtained by high-temperature annealing for 3 to 12 hours, wherein the copper nanoparticles are distributed on the surface of the carbon fiber. S4, the carbon fiber matrix loaded with copper nanoparticles is electroplated and pre-zincified to obtain an integrated zinc-philic and zinc-repellent matrix material.

2. The zinc-philic-zinc-repellent integrated matrix material according to claim 1, characterized in that, The precursor solution contains 0.05~0.5 g·mL of polyacrylonitrile. -1 .

3. The zinc-philic-zinc-repellent integrated matrix material according to claim 1, characterized in that, In step S2, the parameters for electrospinning include: the DC voltage between the spinning needle and the collector is 18kV, and the distance between the spinning needle and the collector is 18cm.

4. The zinc-philic-zinc-repellent integrated matrix material according to claim 1, characterized in that, The copper content in the precursor solution is 0.5~10 mmol.

5. The zinc-philic-zinc-repellent integrated matrix material according to claim 1, characterized in that, The specific steps of electroplating pre-zincification include: The carbon fiber matrix loaded with copper nanoparticles was placed in an electroplating bath, using zinc foil as the counter electrode, and an electroplating solution of 2~5 mol·L⁻¹ was applied. -1 A zinc salt solution was used as the electroplating solution, and zinc was deposited on the carbon fiber matrix loaded with copper nanoparticles under a preset stirring speed and a preset deposition capacity.

6. The zinc-philic-zinc-repellent integrated matrix material according to claim 5, characterized in that, The preset stirring speed is 200~500 rpm, and the preset deposition capacity is 0.1~10 mAh·cm³. -2 .

7. An aqueous zinc-ion battery, comprising a negative electrode, a positive electrode, an electrolyte, and a separator, characterized in that, The negative electrode is the zinc-philic-zinc-hydrophobic integrated matrix material as described in any one of claims 1-6.

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