Zinc battery negative electrode modified material, preparation method and application thereof

Abstract

The invention discloses a zinc battery negative electrode modified material as well as a preparation method and application thereof. The zinc battery negative electrode modified material is prepared from the following raw materials: a silane coupling agent modified attapulgite-based composite material and a fluorine-containing polymer. The zinc battery negative electrode modified material is coated on the zinc foil, so that the zinc battery negative electrode modified material has double effects of hydrophobic barrier and ion channel regulation and control, hydrogen evolution side reaction and passivation are inhibited, a zinc ion electrostatic accelerated migration channel is constructed, uniform nucleation of zinc is guided, and growth of zinc dendrites is avoided.

Description

Technical Field

[0001] This application relates to the field of electrochemical energy storage technology, specifically to a zinc battery negative electrode modification material, its preparation method, and its application. Background Technology

[0002] Energy storage technology, as a core component supporting the consumption of renewable energy and the stable operation of smart grids, directly determines the development progress of clean energy systems through its performance and cost. Currently, while lithium-ion batteries dominate the energy storage market, their application still faces bottlenecks such as high manufacturing costs and insufficient thermal stability, making it difficult to fully meet the comprehensive demands of large-scale energy storage for safety, economy, and environmental friendliness. Against this backdrop, aqueous rechargeable zinc-ion batteries, with their significant advantages such as abundant zinc resources, environmentally friendly electrolytes, and inherent safety, are gradually becoming an important research direction and potential alternative technology in the field of large-scale energy storage. Zinc metal itself possesses a low redox potential, high theoretical mass specific capacity, and high volumetric specific capacity, exhibiting excellent theoretical performance. However, in actual charge-discharge cycles, the zinc anode still faces a series of critical issues that urgently need to be addressed, severely restricting the cycle stability, reversibility, and commercialization progress of aqueous zinc batteries.

[0003] Zinc anodes are prone to zinc dendrite growth during operation. Due to the "sharp effect" during zinc deposition, zinc ions preferentially deposit on protruding parts of the electrode surface, gradually forming dendritic zinc dendrites. These dendrites not only pierce the battery separator, causing internal short circuits, but also exacerbate side reactions on the electrode surface. Simultaneously, when the zinc anode comes into direct contact with aqueous electrolytes, interfacial corrosion and hydrogen evolution side reactions easily occur. Water molecules react with zinc to generate hydrogen gas, significantly reducing the battery's coulombic efficiency and inducing the deposition of inert byproducts such as basic zinc sulfate on the electrode surface, leading to corrosion and passivation of the zinc anode and irreversible consumption of active zinc. To compensate for zinc loss during cycling, actual battery designs often require zinc foil with several times the theoretical capacity as the anode. This design not only significantly increases battery costs but also severely limits the improvement of energy density in aqueous zinc batteries, becoming one of the core obstacles hindering their commercial application.

[0004] To address the aforementioned challenges of zinc anodes, researchers have conducted extensive studies. However, most existing protective layers fail to simultaneously and synergistically suppress zinc dendrite growth, hydrogen evolution reaction, and corrosion passivation, thus failing to fundamentally resolve the multidimensional performance defects of zinc anodes. Therefore, developing a zinc anode modification method that is simple to prepare, cost-effective, and can synergistically suppress zinc dendrite growth, hydrogen evolution reaction, and corrosion passivation is of significant practical importance and urgent need for overcoming the performance bottlenecks of aqueous zinc batteries and promoting their practical application in large-scale energy storage. Summary of the Invention

[0005] The purpose of this application is to solve the problems of zinc dendrite formation, hydrogen evolution side reaction and passivation reaction in zinc batteries.

[0006] To achieve the above objectives, the technical solution adopted in this application is as follows: to provide a zinc battery negative electrode modification material, the raw materials of which include attapulgite-based composite material modified with silane coupling agent and fluoropolymer.

[0007] As a preferred embodiment, the preparation method of the silane coupling agent modified attapulgite-based composite material is as follows: acidified attapulgite and silane coupling agent are dispersed in a solvent, the solid product is separated and dried after continuous stirring to obtain the silane coupling agent modified attapulgite-based composite material.

[0008] As a preferred embodiment, the fluoropolymer is polyvinylidene fluoride.

[0009] As another preferred embodiment, the silane coupling agent is any one or a combination of KH-550, KH-570, and KH-590.

[0010] This application also provides a method for preparing a modified zinc battery negative electrode material. The method involves acidifying attapulgite with hydrochloric acid, dispersing the acidified attapulgite powder with a silane coupling agent in a solvent, continuously stirring, separating the solid product, and drying it to obtain a silane coupling agent-modified attapulgite-based composite material. The silane coupling agent-modified attapulgite-based composite material is then mixed with a fluoropolymer to obtain the modified zinc battery negative electrode material.

[0011] As a preferred embodiment, the mass ratio of the silane coupling agent modified attapulgite-based composite material to the fluoropolymer is (6~10):1.

[0012] This application also provides a method for preparing a zinc battery negative electrode, which is prepared by coating a zinc battery negative electrode modified material as described above onto a zinc foil and drying it, or by coating a zinc battery negative electrode modified material prepared by the above preparation method onto a zinc foil and drying it.

[0013] As a preferred embodiment, the coating thickness of the zinc battery negative electrode modifier on the zinc foil is 5~15 µm.

[0014] More preferably, the zinc foil has a thickness of 50~100 µm.

[0015] This application also provides a zinc battery, including a positive electrode, a separator, a positive electrode electrolyte, a negative electrode electrolyte, and a zinc battery negative electrode prepared by any of the above-described preparation methods.

[0016] Compared with the prior art, the beneficial effects of this application are as follows: (1) This application uses zinc battery negative electrode modification material coated on zinc foil, which has the dual functions of hydrophobic barrier and ion channel regulation, to suppress hydrogen evolution side reaction and passivation, construct zinc ion electrostatic accelerated migration channel, guide zinc uniform nucleation, and avoid zinc dendrite growth; (2) This application constructs an elastic buffering effect between silane coupling agent modified attapulgite-based composite material and fluorinated polymer, which reduces the irreversible consumption of zinc, adapts to the micro-volume expansion during zinc deposition / stripping, ensures the stability of the electrode interface, and achieves stable cycling of zinc battery for more than 1200 cycles. (3) The preparation process of this application is simple and low-cost, and the raw materials are abundant and easy to obtain. The coating is formed by scraping, which does not require complex equipment and special conditions. Compared with the existing process, this application reduces the cost of raw materials and manufacturing, which meets the needs of large-scale energy storage for economy and easy industrialization. Attached Figure Description

[0017] Figure 1 Digital image of attapulgite-based composite material modified with silane coupling agent.

[0018] Figure 2 A digital image of zinc foil coated with zinc battery negative electrode modification material.

[0019] Figure 3 Comparison images of zinc foil coated with zinc battery negative electrode modification material and uncoated zinc foil.

[0020] Figure 4 A digital image of a button cell assembled in Example 1.

[0021] Figure 5 The voltage-time curve is for the symmetrical cell in control group 1.

[0022] Figure 6 The voltage-time curves are for the symmetrical cells in the experimental group.

[0023] Figure 7 The figure shows the coulombic efficiency and cycle stability curves of the control group's three semi-symmetric cells.

[0024] Figure 8 The figure shows the coulombic efficiency and cycle stability curves of the control group's two semi-symmetric cells.

[0025] Figure 9 High-magnification scanning electron microscope image of MPS-ATP powder prepared in Example 1.

[0026] Figure 10 This is a high-magnification scanning electron microscope image of the negative electrode of the control group zinc battery after cycling.

[0027] Figure 11 This is a high-magnification scanning electron microscope image of the negative electrode of the zinc battery in the experimental group after cycling. Detailed Implementation

[0028] The present application will be further described below with reference to specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0029] The terms “comprising” and “having”, and any variations thereof, in the specification and claims of this application are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.

[0030] This application provides a modified negative electrode material for zinc batteries, the raw materials of which include silane coupling agent modified attapulgite-based composite material and fluoropolymer. The silane coupling agent modified attapulgite-based composite material is obtained by grafting silane coupling agent onto attapulgite.

[0031] The zinc battery anode modification material of this application utilizes a hydrophobic silane coupling agent grafted onto the surface of attapulgite. When applied to the zinc anode, it can prevent the penetration of water molecules and effectively suppress the hydrogen evolution reaction. The interior of the zinc battery anode modification material is suitable for forming electrostatically accelerated zinc ion migration channels, which can ensure a stable zinc ion flux, thereby giving the zinc anode uniform and dense nucleation and avoiding the formation of zinc dendrites.

[0032] In some embodiments, the preparation steps of silane coupling agent modified attapulgite are as follows: acidified attapulgite and silane coupling agent are dispersed in a solvent, stirred continuously for 24 hours, the solid product is separated and dried to obtain silane coupling agent modified attapulgite-based composite material, which can be represented as MPS-ATP.

[0033] Preferably, the silane coupling agent is any one or a combination of KH-550, KH-570, and KH-590.

[0034] This application uses a silane coupling agent to modify attapulgite. The silane coupling agent molecules contain hydrophobic groups, and after being grafted onto the surface of attapulgite, a hydrophobic layer can be formed on the surface of the composite material particles. This hydrophobic layer can effectively block water molecules in the electrolyte from penetrating into the zinc foil substrate, reduce the direct contact between zinc and water molecules, fundamentally inhibit the occurrence of hydrogen evolution reaction, avoid the formation of passivation layer, maintain the reactivity of the negative electrode surface, and ensure the reversible deposition / stripping of zinc.

[0035] Unmodified attapulgite is prone to agglomeration and has poor bonding with zinc foil. After grafting with a silane coupling agent, the particle dispersion of the composite material is improved, and the protective layer formed by scraping exhibits a uniform and dense microstructure. This framework can serve as a substrate for zinc deposition, preventing excessive accumulation of zinc ions in local areas and inhibiting dendrite growth from a spatial structural perspective.

[0036] The polar groups of the silane coupling agent can form weak coordination with zinc ions, making the modified attapulgite significantly more effective at adsorbing Zn ions than bare zinc. Simultaneously, the microchannels formed between the nanorod-like particles can construct electrostatically accelerated migration channels for zinc ions, ensuring the adsorption capacity of Zn ions. 2+ The flux within the protective layer is stable and uniform, guiding Zn... 2+ The zinc foil is deposited smoothly on the surface.

[0037] Preferably, the fluoropolymer is polyvinylidene fluoride (PVDF). The silane coupling agent-modified attapulgite-based composite material is a nanorod-shaped powder, which is difficult to form a continuous and uniform coating when used directly. One of the functions of the fluoropolymer is as a polymeric binder, dispersing the silane coupling agent-modified attapulgite-based composite material in the fluoropolymer to form a slurry. The fluoropolymer encapsulates the silane coupling agent-modified attapulgite-based composite material particles, preventing particle agglomeration and obtaining a slurry with good dispersibility and suspension stability. This prevents particle sedimentation during standing and ensures uniform composition of the slurry before coating.

[0038] Secondly, fluoropolymers will provide suitable viscosity, and the viscosity of the slurry can be controlled by selecting fluoropolymers to achieve the fluidity required for the coating process. This ensures that the slurry can be spread evenly on the zinc foil surface, while avoiding defects such as excessively thick / thin coating or missed coating during the coating process, ultimately forming a dense protective layer with controllable thickness.

[0039] During charge-discharge cycles in zinc batteries, the zinc anode undergoes repeated zinc deposition / stripping processes, accompanied by slight volume expansion. If the coating is not firmly bonded to the zinc foil, cracking and detachment can easily occur, leading to modification failure. Fluoropolymers, preferably polyvinylidene fluoride (PVDF), are preferred because the polar groups in its molecular chain can form weak interactions with the hydroxyl groups on the zinc foil surface and the silane coupling agent groups on the attapulgite-based material surface. This tightly fixes the silane coupling agent-modified attapulgite-based composite material protective layer to the zinc foil surface, preventing the coating from separating from the substrate during cycling.

[0040] The high molecular elasticity of polyvinylidene fluoride can buffer the micro-expansion of volume during zinc deposition / stripping to a certain extent, reduce cracks caused by stress concentration in the protective layer, maintain the structural integrity of the protective layer, and ensure that it can perform its function of inhibiting dendrites and isolating water molecules for a long time.

[0041] This application also provides a method for preparing a zinc battery negative electrode modified material: attapulgite is acidified with hydrochloric acid, the acidified attapulgite powder is dispersed with a silane coupling agent in a solvent, and after continuous stirring, the solid product is separated and dried to obtain a silane coupling agent modified attapulgite-based composite material; the silane coupling agent modified attapulgite-based composite material is mixed and stirred with a fluoropolymer to obtain the zinc battery negative electrode modified material of this application.

[0042] Preferably, the silane coupling agent modified attapulgite-based material is mixed with a fluoropolymer at a mass ratio of (6~10):1.

[0043] The preparation process of this application is simple and easy to control, requiring no complex equipment. The raw material used, attapulgite, is abundant, inexpensive, and readily available, making the overall cost controllable.

[0044] This application also provides a zinc battery negative electrode, which is obtained by coating the above-mentioned zinc battery negative electrode modified material onto zinc foil and drying it.

[0045] In a preferred embodiment, the zinc foil has a thickness of 50-100 µm, and the coating thickness of the zinc battery negative electrode modifier material is 5-15 µm.

[0046] In some preferred embodiments, the zinc foil is cleaned with anhydrous ethanol and deionized water, and after drying, the zinc battery negative electrode modification material is coated onto the clean zinc foil using a scraping method. The foil is then placed in an oven at 50~80 ℃ and dried for more than 10 hours to obtain the zinc battery negative electrode of this application.

[0047] The zinc battery anode of this application features a uniform modified material coating, which gives the zinc anode advantages such as uniform and dense zinc deposition and good reversibility during charge-discharge cycles. This facilitates the induction of zinc deposition and avoids dendrite growth caused by the "point effect." Simultaneously, the modified material coating on the surface of the zinc battery anode prevents zinc from contacting water molecules, inhibits hydrogen evolution reaction, and prevents corrosion and passivation, thereby achieving long-term stable cycling of the zinc-ion battery.

[0048] This application also provides a zinc battery, including a negative electrode, a separator, a positive electrolyte, a negative electrolyte, and the zinc battery negative electrode of the present application.

[0049] Example 1 Preparation of silane coupling agent modified attapulgite-based composite material: Attapulgite powder was placed in an 80 °C hydrochloric acid solution and stirred for 6 hours before separation to obtain acidified attapulgite powder; the acidified attapulgite powder and KH-570 silane coupling agent were dispersed in anhydrous ethanol and stirred continuously for 24 hours. After centrifugation and drying, the silane coupling agent modified attapulgite-based composite material, which can be represented as MPS-ATP, was obtained. The powder exhibited the following appearance: Figure 1 As shown; Preparation of zinc battery anode modification material: MPS-ATP powder and polyvinylidene fluoride (PVDF) were mixed at a mass ratio of 9:1 and magnetically stirred for 12 hours to obtain the zinc battery anode modification material of this application.

[0050] Preparation of zinc battery anode: Cut 10×10 cm thick metal sheets with a thickness of 100 µm. 2 High-purity zinc foil with 99.99% purity was sequentially cleaned with ethanol, deionized water, and ethanol, then dried. The prepared zinc battery anode modification material was uniformly coated onto the zinc foil using a blade coating method to a thickness of 10 µm. After drying in an oven for 12 hours and cooling to room temperature, the zinc battery anode, denoted as MPS-ATP@Zn, was obtained. The zinc foil coated with the zinc battery anode modification material is shown below. Figure 2 As shown in the figure, a comparison diagram with a zinc material electrode is shown below. Figure 3 As shown.

[0051] Comparative Example 1 Conventional zinc foil is used as the negative electrode of the zinc battery.

[0052] Comparative Example 2 MPS-ATP material was prepared according to the preparation steps of Example 1. MPS-ATP powder and polyvinylidene fluoride (PVDF) were mixed at a mass ratio of 9:1 and magnetically stirred for 24 hours. The electrode material of Comparative Example 2 was coated on copper foil with a thickness of 10 µm, dried in an oven for 12 hours, and then cooled to room temperature to obtain MPS-ATP@Cu.

[0053] Battery assembly Assembled experimental group of symmetrical cells: Whatman fiber membrane was used as the separator, 2 mol / L ZnSO4 solution was used as the electrolyte, and the zinc battery negative electrode prepared in Example 1 above was used as the positive and negative electrodes, with an electrode surface area of ​​1 cm². 2 The experimental group of symmetrical cells was assembled, such as button cells. Figure 4 As shown.

[0054] Assembled control group 1 symmetrical cell: Whatman fiber membrane was used as the separator, 2 mol / L ZnSO4 solution as the electrolyte, and conventional zinc materials were used as the positive and negative electrodes with an electrode surface area of ​​1 cm². 2 The control group 1 symmetrical cell was assembled.

[0055] Assemble the control group 2 half-symmetric cell: Using Whatman fiber membrane as the membrane and 2 mol / L ZnSO4 solution as the electrolyte, MPS-ATP@Cu prepared in Comparative Example 2 was used as the positive electrode and Zn material as the negative electrode to assemble the control group 2 half-symmetric cell.

[0056] Assembly of a control group three-half-symmetric cell: Using Whatman fiber membrane as the separator, 2 mol / L ZnSO4 solution as the electrolyte, conventional copper material as the positive electrode and Zn material as the negative electrode, a control group three-half-symmetric cell was assembled.

[0057] Performance testing Figure 1 The synthesized MPS-ATP powder, Figure 2 Digital images of zinc foil coated with the zinc battery negative electrode modification material of this application show that an MPS-ATP film is formed on the electrode surface after coating with the slurry, exhibiting a uniform white-gray color. Figure 3 The left side shows a zinc foil coated with the zinc battery negative electrode modification material of this application, and the right side shows a zinc foil that can be used... Figure 3 A more pronounced white-gray film was observed in the comparison image. Figure 4 Digital image of the assembled experimental group of symmetrical button cells.

[0058] The experimental group symmetrical cells and the control group symmetrical cells were subjected to cyclic charge-discharge tests, and voltage-time curves were plotted. The test conditions were 10 mA / cm². 2 and 5 mAh / cm 2 The test results for the symmetrical cell in control group 1 are as follows: Figure 5 As shown, after 105 hours of cycling, the battery voltage fluctuated, subsequently short-circuiting and damaging the battery. The voltage-time curves of the symmetrical battery in the experimental group are shown below. Figure 6 As shown, the battery voltage remains stable throughout, maintaining stable cycling for over 1000 hours. Analysis of the cyclic charge-discharge test results of the experimental group's symmetrical battery and the control group's symmetrical battery revealed that conventional zinc electrode materials easily generate zinc dendrites, causing short circuits and further shortening the lifespan of the zinc battery. However, coating the zinc electrode with the zinc battery negative electrode modification material of this application significantly extends the battery cycle time and ensures stable charge-discharge voltage.

[0059] The coulombic efficiency of control group 2 semi-symmetric cells and control group 3 semi-symmetric cells was tested under the condition of 5 mA / cm². 2 and 2 mAh / cm 2 The cutoff voltage is 0.5 V. Figure 7 The figure shows the coulombic efficiency cycle stability curve of the control group 3 semi-symmetric cell. The control group 3 semi-symmetric cell was damaged after about 190 cycles. The average coulombic efficiency during the stable cycle was about 99.16%. The efficiency fluctuation gradually increased in the later stage of the cycle, and the cycle was eventually terminated due to electrode interface failure.

[0060] Figure 8The figure shows the coulombic efficiency cycle stability curves of the control group's two semi-symmetric cells. The cells maintained stable operation for over 1200 cycles without any cycle termination due to performance failure. The average coulombic efficiency improvement during the stable cycling phase was approximately 99.46%, and the efficiency fluctuations within the 1200 cycles were minimal, consistently remaining within a high stability range.

[0061] The zinc battery anode modification material prepared in this application is used in zinc batteries. This material reduces the formation of zinc dendrites and byproducts, decreases irreversible zinc consumption, and allows more zinc to participate in electrochemical reactions. Furthermore, the zinc battery anode modification material ensures the high reversibility of the zinc deposition / stripping process, avoiding efficiency degradation during cycling.

[0062] The MPS-ATP powder prepared in Example 1 was observed using a high-power scanning electron microscope, such as... Figure 9 As shown, MPS-ATP particles did not exhibit large-scale aggregation; the particle size and distribution were relatively uniform, and no defects such as localized accumulation or structural breakage were observed. MPS-ATP exhibits a clear nanorod-like microstructure. The advantages of this structure are: the nanoscale rod-like morphology provides a larger specific surface area, allowing for more uniform coverage of the zinc foil surface and the formation of a dense protective layer when subsequently mixed with PVDF to prepare a slurry; simultaneously, the rod-like structures can form microchannels, providing pathways for zinc ion migration.

[0063] The uniformly dispersed nanorod structure allows the zinc battery anode modification material subsequently coated onto the zinc foil surface to form a dense interface without significant pores. This avoids localized weak areas such as pores and cracks in the protective layer, effectively preventing excessive zinc ion deposition and dendrite formation in these areas. Simultaneously, the nanorod structure can regulate the deposition path of zinc ions through electrostatic adsorption, guiding uniform zinc nucleation and further inhibiting dendrite growth.

[0064] The tiny gaps naturally formed between the nanorod structures can serve as migration channels for zinc ions. On the one hand, the uniform channel distribution can prevent local accumulation of zinc ions and ensure stable ion flux. On the other hand, the size of the nanoscale channels matches the radius of zinc ions, which can reduce ion migration resistance, improve electrode reaction kinetics, and thus improve the cycle coulombic efficiency of zinc batteries.

[0065] At 10 mA / cm 2 5 mAh / cm 2 Cyclic charge-discharge tests were conducted under the specified conditions, and the negative electrode morphology of the experimental group symmetrical battery and the control group 1 symmetrical battery was characterized and analyzed by SEM. Figure 10The image shows the morphology of the conventional zinc anode in control group 1 after cycling. The zinc deposition on its surface is irregular and does not form a smooth deposition layer. Instead, it exhibits numerous sharp, disordered dendritic structures randomly distributed, with some areas even showing interlocking dendrites, completely destroying the original smoothness of the electrode surface. In addition to dendrites, irregular flocculent or blocky deposits can also be observed on the electrode surface. These are inert byproducts such as basic zinc sulfate, generated from hydrogen evolution reactions between bare zinc and water molecules in the electrolyte or from reactions with sulfate ions. The mixture of byproducts and dendrites further exacerbates the disorder at the electrode interface, indicating that bare zinc not only suffers from dendrite problems during cycling but also experiences severe interfacial parasitic reactions.

[0066] In comparison, the morphology of the zinc battery negative electrode provided in this application after cycling is as follows: Figure 11 As shown, the zinc deposition layer on the electrode surface exhibits a highly uniform, dense, lamellar structure, free from any sharp dendrites or disordered accumulation. The deposition layer is smooth and even overall, with stable bonding to the electrode substrate, and no local protrusions or fractures, demonstrating an ideal zinc deposition morphology. Almost no flocculent or blocky inert byproducts are observed in the image; only a uniform zinc deposition layer exists on the electrode surface, with no residual traces of parasitic reaction products. This indicates that the zinc battery negative electrode modification material of this application effectively isolates zinc from direct contact with water molecules in the electrolyte, inhibits hydrogen evolution and byproduct formation, and keeps the electrode interface clean and stable even after cycling.

[0067] The zinc battery anode modification material and related technologies presented in this scheme have significant technical advantages. It is made from silane coupling agent-modified attapulgite-based composite materials and fluoropolymers through a simple and controllable preparation process, requiring no complex equipment. Furthermore, attapulgite resources are abundant and inexpensive, making the overall cost controllable. After being coated onto zinc foil to form the anode, this modified material effectively inhibits hydrogen evolution reaction and corrosion passivation by isolating water molecules through the hydrophobic silane coupling agent grafted onto the attapulgite surface. Simultaneously, the electrostatically accelerated migration channels for zinc ions formed internally ensure a stable ion flux, inducing uniform and dense zinc nucleation and avoiding zinc dendrite growth caused by the "point effect." Zinc batteries using this anode exhibit excellent performance; for example, the symmetrical cells in the experimental group achieved a performance of 10 mA / cm². 2 and 5 mAh / cm 2 Under certain conditions, it can cycle stably for over 1000 hours, and the related semi-symmetric cells can cycle stably for more than 1200 times with an average coulombic efficiency of about 99.46%. After cycling, the zinc deposition layer on the negative electrode surface is uniform and dense, without dendrites or inert byproducts, which greatly improves the cycle stability, reversibility and safety of aqueous zinc batteries, laying the foundation for their large-scale energy storage applications.

[0068] The basic principles, main features, and advantages of this application have been described above. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely the principles of this application. Various changes and modifications can be made to this application without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection claimed by this application is defined by the appended claims and their equivalents.

Claims

1. A zinc battery negative electrode modification material, characterized in that, The raw materials for preparation include attapulgite-based composite materials modified with silane coupling agents and fluoropolymers.

2. The zinc battery negative electrode modification material as described in claim 1, characterized in that, The preparation method of the silane coupling agent modified attapulgite-based composite material is as follows: acidified attapulgite and silane coupling agent are dispersed in a solvent, and after continuous stirring, the solid product is separated and dried to obtain the silane coupling agent modified attapulgite-based composite material.

3. The zinc battery negative electrode modification material as described in claim 1, characterized in that, The fluoropolymer is polyvinylidene fluoride.

4. The zinc battery negative electrode modification material as described in claim 1, characterized in that, The silane coupling agent is any one or a combination of KH-550, KH-570, and KH-590.

5. A method for preparing a zinc battery negative electrode modification material, characterized in that, Attapulgite is acidified with hydrochloric acid, and the acidified attapulgite powder is dispersed with a silane coupling agent in a solvent. After continuous stirring, the solid product is separated and dried to obtain a silane coupling agent modified attapulgite-based composite material. The silane coupling agent modified attapulgite-based composite material is mixed with a fluoropolymer to obtain the zinc battery negative electrode modified material.

6. The preparation method according to claim 5, characterized in that, The mass ratio of the silane coupling agent-modified attapulgite-based composite material to the fluoropolymer is (6~10):

1.

7. A method for preparing a zinc battery negative electrode, characterized in that, It is prepared by coating zinc foil with the zinc battery negative electrode modification material according to any one of claims 1 to 4 and drying it, or by coating zinc foil with the zinc battery negative electrode modification material prepared by the preparation method according to claim 5 or 6 and drying it.

8. The preparation method according to claim 7, characterized in that, The coating thickness of the zinc battery negative electrode modification material on the zinc foil is 5~15 µm.

9. The preparation method according to claim 7, characterized in that, The zinc foil has a thickness of 50~100 µm.

10. A zinc battery, characterized in that, It includes a positive electrode, a separator, a positive electrode electrolyte, a negative electrode electrolyte, and a zinc battery negative electrode prepared by any of the preparation methods described in claims 7 to 9.

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