Novel protective layer taking silicon dioxide as main body material as well as preparation method and application of novel protective layer

Abstract

The invention discloses a preparation method of a novel protective layer taking silicon dioxide as a main body material, which comprises the following steps: mixing a hard template, a soft template, water and an ethanol solvent, and uniformly dispersing through dispersion treatment; adding a pH regulator and a silicon source precursor into the obtained dispersion liquid, and uniformly stirring through stirring treatment; centrifuging the obtained solution to obtain a black solid; calcining the black solid under a high-temperature condition to obtain silicon dioxide; and mixing the obtained silicon dioxide and an adhesive, adding into a dispersing agent, mixing into slurry, uniformly coating the surface of zinc metal with the slurry, and drying to form a protective layer taking silicon dioxide as a main body material. The preparation method disclosed by the invention is simple and convenient to operate, large-scale, wide in material source and environment-friendly; the obtained silicon dioxide protective layer forms a physical barrier, penetration of zinc dendrites is effectively prevented, on the other hand, uniform nucleation deposition of zinc ions is achieved through an ion channel structure and surface functional groups of the silicon dioxide protective layer, and hydrogen evolution and other side reactions are inhibited.

Description

Technical Field

[0001] This invention belongs to the field of zinc-ion battery materials and surface protection technology, specifically relating to a novel protective layer with silicon dioxide as the main material, its preparation method, and its applications. Background Technology

[0002] Zinc-ion batteries have become a research hotspot for novel energy storage devices due to their high safety, low cost, and environmental friendliness. However, during the repeated deposition and dissolution of the zinc metal anode, problems such as dendrite growth, uneven electric field distribution, hydrogen evolution, and side reactions can easily occur, leading to short circuits, decreased coulombic efficiency, and shortened cycle life. To address these issues, researchers typically stabilize the zinc anode interface by restricting ion channels, constructing a dense and elastic protective layer, and controlling interfacial chemical reactions.

[0003] Currently, the protective layer materials used in zinc-ion batteries include polymer films, inorganic ceramic coatings, and composite layers, but they still have the following shortcomings: (1) Some polymer protective layers have insufficient mechanical strength and are difficult to withstand dendrite penetration; (2) Although dense inorganic coatings can mechanically block dendrites, they usually have low ion transport rates, which leads to increased impedance; (3) The preparation methods are complex or difficult to scale up.

[0004] Therefore, designing a protective layer material that combines mechanical barrier capabilities with a high ion transport channel, and whose preparation method is simple and scalable, is of great significance for improving the stability and lifespan of zinc-ion battery anodes. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a novel protective layer with silicon dioxide as the main material, its preparation method and uses.

[0006] According to a first aspect of the present invention, a method for preparing a novel protective layer with silicon dioxide as the main material is provided, comprising the following steps: mixing a hard template, a soft template, and water and ethanol solvent, and dispersing them uniformly by dispersion treatment; adding a pH adjuster and a silicon source precursor to the obtained dispersion, and stirring until uniform; centrifuging the obtained solution to obtain a black solid; calcining the obtained black solid at high temperature to obtain silicon dioxide; and mixing the obtained silicon dioxide with a binder and adding it to a dispersant to form a slurry, uniformly coating it on a zinc metal surface and drying it to form a protective layer with silicon dioxide as the main material.

[0007] In some exemplary embodiments, the hard template is at least one of carbon nanotubes, layered carbon, mesoporous carbon, and carbon spheres, and the soft template is at least one of cationic surfactants of the quaternary ammonium salt type and pyridine salt type.

[0008] In some exemplary embodiments, the water and ethanol are mixed in a ratio of 3:2, and the dispersion treatment is performed using ultrasound for a duration of at least 6 hours.

[0009] In some exemplary embodiments, the pH adjuster is at least one of sodium hydroxide and potassium hydroxide, and the silicon source precursor is at least one of tetraethoxysilane and tetramethoxysilane.

[0010] In some exemplary embodiments, the stirring process employs magnetic stirring, and the dispersion is incubated overnight under the stirring process to complete the hydrolysis and condensation reactions.

[0011] In some exemplary embodiments, the high-temperature calcination is carried out in an air atmosphere at a temperature of 500–600°C for 5 hours to remove the carbon template.

[0012] In some exemplary embodiments, the adhesive is at least one of polyvinylidene fluoride, styrene-butadiene rubber, and sodium carboxymethyl cellulose, and the dispersant is at least one of N-methylpyrrolidone and N,N-dimethylformamide.

[0013] According to a second aspect of the present invention, a novel protective layer with silicon dioxide as the main material is provided, which is prepared by the above-described method for preparing a novel protective layer with silicon dioxide as the main material.

[0014] According to a third aspect of the present invention, a zinc metal anode is provided, which is coated with a protective layer made of silicon dioxide as the main material prepared by the above-described method for preparing a novel protective layer made of silicon dioxide as the main material. The protective layer is tightly adhered to the zinc metal anode, and the thickness of the protective layer is 10-50 μm, with a coverage of ≥95%.

[0015] According to a fourth aspect of the present invention, an electrochemical energy storage device is provided, comprising the aforementioned zinc metal negative electrode, wherein the electrochemical energy storage device is an aqueous or non-aqueous electrolyte battery, and the aqueous or non-aqueous electrolyte battery is an aqueous zinc-ion battery or a solid zinc-ion battery.

[0016] According to a fifth aspect of the present invention, there is a use of a novel protective layer with silicon dioxide as the main material, wherein the novel protective layer with silicon dioxide as the main material is prepared by the above-described method for preparing a novel protective layer with silicon dioxide as the main material, and the protective layer is used as an artificial solid electrolyte interface layer or protective coating in a zinc-ion battery system.

[0017] According to the present invention, compared with the prior art, the superior effects are as follows: the protective layer structure with silica as the main material can include, but is not limited to, various forms such as nanotubes, hollow spheres, nanoparticles and porous networks. These structures not only provide good mechanical support and dendrite barrier function, but also achieve uniform transport of zinc ions through their diverse pores and channels; the protective layer formed by silica material with tight adhesion and controllable pore structure optimizes the transport path and interface stability of zinc ions; the materials used are environmentally friendly, and the preparation process is simple and inexpensive. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A flowchart of the preparation method of the novel protective layer with silicon dioxide as the main material of the present invention is shown.

[0020] Figure 2 This is a scanning electron microscope (SEM) schematic diagram of the surface of the silica nanotube protective layer prepared in an embodiment of the present invention.

[0021] Figure 3 This is a transmission electron microscope cross-sectional view of the silica nanotube protective layer prepared in an embodiment of the present invention.

[0022] Figure 4 This is a nitrogen adsorption-desorption test and corresponding pore size distribution diagram of the silica nanotube protective layer prepared in the embodiments of the present invention.

[0023] Figure 5 This is a scanning electron microscope (SEM) schematic diagram of the surface of a zinc foil coated with a silica nanotube protective layer prepared according to an embodiment of the present invention.

[0024] Figure 6 This is a cross-sectional scanning electron microscope (SEM) image of a zinc foil coated with a silica nanotube protective layer prepared according to an embodiment of the present invention.

[0025] Figure 7 This is a static contact angle test diagram of a zinc foil coated with a silica nanotube protective layer prepared according to an embodiment of the present invention.

[0026] Figure 8 This is a cycle life diagram of an aqueous zinc-ion symmetric battery using a silica nanotube protective layer prepared according to embodiments of the present invention.

[0027] Figure 9This is a coulombic efficiency diagram of a zinc-copper half-symmetric solar cell using a silica nanotube protective layer prepared according to embodiments of the present invention.

[0028] Figure 10 This is a capacity cycle performance diagram of an aqueous zinc-manganese dioxide full battery prepared using the silica nanotube protective layer obtained by the present invention. Detailed Implementation

[0029] The essence of the technical solution of this invention will be explained in detail below.

[0030] This invention employs a hard template and a soft template, which are mixed and dispersed uniformly with water and ethanol solvents; a silicon source precursor is added to the resulting dispersion, and after stirring and reaction, a black solid is obtained by centrifugation; the black solid is calcined under high temperature conditions to obtain silicon dioxide; and the obtained silicon dioxide is mixed with a binder to form a slurry, which is uniformly coated on the surface of zinc metal and dried to form a novel protective layer with silicon dioxide as the main material.

[0031] The technical solution of this invention is described below with reference to specific embodiments, but the conditions and results described in the implementation do not constitute a limitation on the scope of protection of this application. Furthermore, unless otherwise specified, the experimental methods described in the following embodiments are conventional methods; and unless otherwise specified, the reagents and materials are commercially available.

[0032] Figure 1 A schematic flowchart illustrating the preparation method of the novel protective layer using silicon dioxide as the main material according to the present invention is shown. Figure 1 As shown, the method for preparing the novel protective layer with silicon dioxide as the main material of the present invention includes the following steps.

[0033] In step 101, the hard template, the soft template, and water and ethanol solvent are mixed and dispersed evenly through a dispersion treatment.

[0034] In this embodiment, the hard template is at least one of carbon nanotubes, layered carbon, mesoporous carbon, and carbon spheres, and the soft template is at least one of cationic surfactants of quaternary ammonium salt type and pyridinium salt type. The mixing ratio of water and ethanol is 3:2. The dispersion treatment is performed by ultrasonic treatment for at least 6 hours.

[0035] In step 102, a pH adjuster is added to the resulting dispersion.

[0036] In the embodiments of this application, the pH adjuster is at least one of sodium hydroxide and potassium hydroxide.

[0037] In step 103, a silicon source precursor is added to the obtained dispersion and stirred until homogeneous.

[0038] In this embodiment, the silicon source precursor is at least one of tetraethoxysilane (TEOS) and tetramethoxysilane (TMOS). The stirring process employs magnetic stirring. Preferably, the dispersion is incubated overnight under the stirring process to complete the hydrolysis and condensation reactions.

[0039] It should be noted that steps 102 and 103 can be performed simultaneously, or a silicon source precursor can be added in step 102, and a pH adjuster can be added in step 103 and stirred until homogeneous.

[0040] In step 104, the resulting solution is centrifuged to obtain a black solid.

[0041] In this embodiment, the solution is centrifuged to obtain the black solid. Preferably, the black solid obtained by centrifugation is also washed and dried in this step.

[0042] In step 105, the obtained black solid is calcined at high temperature to obtain silicon dioxide.

[0043] In this embodiment, the high-temperature calcination is carried out at a temperature of 500–600°C, and preferably for a holding time of 5 hours. Preferably, the black solid is calcined at high temperature in air to remove the carbon template.

[0044] In step 106, the obtained silica is mixed with the binder and added to the dispersant to form a slurry. This slurry is then applied to the zinc metal surface and dried to form a protective layer with silica as the main material.

[0045] In the embodiments of this application, the adhesive is at least one of polyvinylidene fluoride (PVDF), styrene-butadiene rubber (SBR), and sodium carboxymethyl cellulose (CMC-Na), and the dispersant is at least one of N-methylpyrrolidone (NMP) and N,N-dimethylformamide (DMF). The coating process involves using a pipette to take 50 μl of the prepared slurry containing silica, adhesive, and dispersant and applying it to the zinc metal surface.

[0046] Preferably, the zinc metal is a zinc metal negative electrode in an electrochemical energy storage device, and the protective layer is used as an artificial solid electrolyte interface (SEI) or protective coating. The protective layer is tightly attached to the zinc metal negative electrode, the thickness of the protective layer is 10-50 μm, the coverage is ≥95%, and the structural integrity is maintained during cycling, allowing zinc ions to be transported through the channel.

[0047] In addition, preferably, the zinc metal negative electrode is a zinc metal foil, sheet or deposited layer, and the electrochemical energy storage device is an aqueous or non-aqueous electrolyte battery, such as an aqueous zinc-ion battery or a solid zinc-ion battery.

[0048] According to this application, compared with the prior art, the superior effects are as follows: the protective layer structure with silica as the main material can include, but is not limited to, various forms such as nanotubes, hollow spheres, nanoparticles, and porous networks. These structures not only provide good mechanical support and dendrite barrier function, but also achieve uniform transport of zinc ions through their diverse pores and channels; by forming a tightly attached and controllable pore structure protective layer with silica material, the transport path and interface stability of zinc ions are optimized, thereby greatly improving the cycle life and coulombic efficiency of aqueous zinc-ion batteries; furthermore, the materials used are environmentally friendly, and the preparation process is simple and inexpensive.

[0049] Example 1:

[0050] The method for preparing the novel protective layer with silicon dioxide as the main material in this embodiment includes the following steps.

[0051] 150 mg of carbon nanotubes (CNTs) and 0.62 g of hexadecyltrimethylammonium bromide (CTAB) were dispersed at room temperature in a mixed solution containing 150 mL of deionized water and 100 mL of ethanol. The mixture was ultrasonically treated for 6 hours to ensure uniform dispersion (step 101). Subsequently, 300 mL of 1 M sodium hydroxide aqueous solution was added under magnetic stirring; 1.2 mL of tetraethoxysilane (TEOS) was slowly added dropwise, and the mixture was stirred overnight to complete the hydrolysis and condensation reaction (steps 102, 103). The resulting black solid was collected by centrifugation, thoroughly washed, and dried (step 104). Finally, the dried product was calcined in air at 550 °C for 5 hours to remove the CNT template and surfactant, yielding silica nanotubes (SNTs) (step 105). The obtained SNTs were mixed with PVDF and NMP to form a slurry, which was then uniformly coated onto a zinc metal surface to form a silica nanotube protective layer (step 106).

[0052] Regarding the product prepared by the method steps of Example 1 above, the inventors performed the following verification and characterization.

[0053] Figure 2 This is a scanning electron microscope (SEM) schematic diagram of the surface of the silica nanotube protective layer prepared in an embodiment of the present invention. Figure 3 This is a transmission electron microscope cross-sectional view of the silica nanotube protective layer prepared in an embodiment of the present invention. Figure 4 This is a nitrogen adsorption-desorption test and corresponding pore size distribution diagram of the silica nanotube protective layer prepared in the embodiments of the present invention. Figure 5 This is a scanning electron microscope (SEM) schematic diagram of the surface of a zinc foil coated with a silica nanotube protective layer prepared according to an embodiment of the present invention. Figure 6This is a cross-sectional scanning electron microscope (SEM) image of a zinc foil coated with a silica nanotube protective layer prepared according to an embodiment of the present invention. Figure 7 This is a static contact angle test diagram of a zinc foil coated with a silica nanotube protective layer prepared according to an embodiment of the present invention.

[0054] like Figure 2 , 3 As shown, the product prepared by the method in Example 1 above was characterized by scanning electron microscopy and transmission electron microscopy, revealing it to be a multilayered mesoporous nanotube structure. Nitrogen adsorption-desorption tests and the corresponding pore size distribution are shown below. Figure 4 As shown, this demonstrates that the SNT exhibits a high performance of up to 787.7m. 2 The specific surface area is approximately 1 / g, exhibiting a bimodal pore size distribution concentrated at 2-3 nm and 9-10 nm, respectively. The approximately 10 nm hollow core originates from the hard template of CNTs, while the approximately 2 nm mesopores are attributed to the soft template of CTABs. Figure 5 , 6 As shown, the front and cross-section of the zinc foil demonstrate the excellent mechanical adhesion and structural integrity of this SNT protective layer. Static contact angle testing is as follows... Figure 7 As shown, the contact surface has excellent wettability, which promotes the rapid transport of zinc ions at the interface.

[0055] Figure 8 This is a cycle life diagram of an aqueous zinc-ion symmetric battery of the present invention using a silica nanotube protective layer prepared by the method of Example 1 above. It can be seen that at 3 mA·cm⁻¹, -2 Current density, 1 mAh·cm -2 At the capacity density, the aqueous zinc-ion symmetric battery coated with SNT protective layer can achieve stable cycling for more than 4500 hours, which is 1000% higher than the cycle life of the aqueous zinc-ion battery composed of zinc foil alone, indicating that it has excellent cycle life. Figure 9 This is the coulombic efficiency diagram of the zinc-copper half-symmetric solar cell of the present invention, which uses a silica nanotube protective layer prepared by the method of Example 1 above. It can be seen that at 3 mA·cm⁻¹, -2 Current density, 1 mAh·cm -2 At the capacity density, the zinc-copper semi-symmetric cell coated with SNT protective layer can achieve a coulombic efficiency of nearly 99% after 1200 cycles, which is 200% higher than the stable coulombic efficiency of 250 cycles for the pure zinc-copper semi-symmetric cell. Figure 10 This is a capacity cycling performance diagram of an aqueous zinc-manganese dioxide full cell using a silica nanotube protective layer prepared by the method of Example 1 above. The aqueous zinc-manganese dioxide full cell coated with the SNT protective layer has a capacity cycling performance of 1 Ag. -1 It maintains an almost constant capacity output even after 4200 cycles, demonstrating its excellent cycling performance.

[0056] In summary, the method for preparing the novel protective layer based on silica as the main material of this invention has the advantages of readily available raw materials and a simple preparation process, making it easy to scale up. Furthermore, the protective layer prepared by this method, based on silica as the main material, can ensure excellent cycle life and coulombic efficiency of aqueous zinc-ion batteries, and has high application value in the field of battery energy storage.

[0057] It should be understood that the phrase "an embodiment" or "one embodiment" throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of this application. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification do not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It should be understood that in the various embodiments of this application, the sequence numbers of the above-described processes do not imply a sequential order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application. The sequence numbers of the above-described embodiments are merely descriptive and do not represent the superiority or inferiority of the embodiments.

[0058] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0059] The above description is merely an embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for preparing a novel protective layer using silicon dioxide as the main material, characterized in that, Includes the following steps: The hard template and soft template are mixed with water and ethanol solvent, and then dispersed evenly through a dispersion treatment. Add a pH adjuster and a silicon source precursor to the obtained dispersion, and stir until homogeneous. The resulting solution was centrifuged to obtain a black solid; The resulting black solid was calcined at high temperature to obtain silicon dioxide; and The obtained silica is mixed with the binder and added to the dispersant to form a slurry. This slurry is then uniformly coated onto the zinc metal surface and dried to form a protective layer with silica as the main material.

2. The method for preparing a novel protective layer with silicon dioxide as the main material according to claim 1, characterized in that, The hard template is at least one of carbon nanotubes, layered carbon, mesoporous carbon, and carbon spheres. The soft template is at least one of cationic surfactants, specifically quaternary ammonium salts and pyridine salts.

3. The method for preparing a novel protective layer with silicon dioxide as the main material according to claim 1 or 2, characterized in that, The mixing ratio of water and ethanol is 3:

2. The dispersion process employs ultrasonic treatment, and the ultrasonic treatment time is at least 6 hours.

4. The method for preparing a novel protective layer with silicon dioxide as the main material according to claim 1, characterized in that, The pH adjuster is at least one of sodium hydroxide and potassium hydroxide. The silicon source precursor is at least one of tetraethoxysilane and tetramethoxysilane.

5. The method for preparing a novel protective layer with silicon dioxide as the main material according to claim 1 or 4, characterized in that, The stirring process employs magnetic stirring. The dispersion was left to stand overnight under stirring to complete the hydrolysis and condensation reactions.

6. The method for preparing a novel protective layer with silicon dioxide as the main material according to claim 1, characterized in that, The high-temperature calcination is carried out in an air atmosphere at a temperature of 500–600°C for 5 hours to remove the carbon template.

7. The method for preparing a novel protective layer with silicon dioxide as the main material according to claim 1, characterized in that, The adhesive is at least one of polyvinylidene fluoride, styrene-butadiene rubber, and sodium carboxymethyl cellulose. The dispersant is at least one of N-methylpyrrolidone and N,N-dimethylformamide.

8. A novel protective layer using silicon dioxide as the main material, characterized in that, The novel protective layer with silicon dioxide as the main material is prepared by any one of claims 1-7.

9. A zinc metal negative electrode, characterized in that, A protective layer with a silica-based main material prepared by the method for preparing a novel protective layer with silica as the main material according to any one of claims 1-7. The protective layer is tightly adhered to the zinc metal negative electrode, and the thickness of the protective layer is 10-50 μm with a coverage of ≥95%.

10. An electrochemical energy storage device, characterized in that, The device includes the zinc metal negative electrode as described in claim 9, wherein the electrochemical energy storage device is an aqueous or non-aqueous electrolyte battery, and the aqueous or non-aqueous electrolyte battery is an aqueous zinc-ion battery or a solid zinc-ion battery.

11. The use of a novel protective layer with silicon dioxide as the main material, characterized in that, The novel protective layer with silicon dioxide as the main material is prepared by the preparation method of the novel protective layer with silicon dioxide as the main material according to any one of claims 1-7. The protective layer is used as an artificial solid electrolyte interface layer or protective coating in the zinc-ion battery system.

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