Graphene and zinc metastannate composite material as well as preparation method and application thereof
By using a nano-hollow cubic structure of graphene and zinc stannate composite material, the problems of poor specific capacitance and conductivity of supercapacitor electrode materials have been solved, achieving higher energy density and cycle stability.
Patent Information
- Application Number
- CN202511010434.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-22
- Publication Date
- 2025-12-12
AI Technical Summary
Existing supercapacitor electrode materials suffer from limited specific capacity, poor conductivity, and easy agglomeration of nanoparticles, which affect their energy density and cycle stability.
A nano-hollow cube was prepared using a graphene-zinc stannate composite material. The graphene was dispersed with nano-ZnSnO3 to increase the specific surface area and reaction sites, thereby improving conductivity and cycle stability.
It effectively improves the specific capacitance and cycle stability of supercapacitors, and enhances the conductivity of electrode materials and the utilization rate of active materials.
Smart Images
Figure CN121122933A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of electrochemical energy storage and conversion technology, specifically relating to a graphene-zinc stannate composite material, its preparation method and application, for use as a high-performance electrode material in supercapacitors, and particularly to a controllable synthesis process of graphene-zinc stannate nanocube composite. Background Technology
[0002] Supercapacitors have attracted widespread attention due to their high power density and long cycle life, but their low energy density limits their applications. Traditional electrode materials (such as activated carbon) have limited specific capacity, while metal oxides (such as...) Although theoretically high, it has poor conductivity. Zinc metastannate (ZnSnO3) is a semiconductor material with good conductivity. When nanoscale hollow particles are used as capacitor electrode materials, they can effectively increase the contact area with the electrolyte during charging and discharging while reducing the material weight, providing more reaction sites, and ultimately improving the material's energy density and cycle stability. However, nanoscale hollow particles are prone to agglomeration, which reduces the specific surface area to some extent.
[0003] Therefore, given the shortcomings of existing technologies, it is necessary to propose a technical solution to address the technical problems existing in the current technology. Summary of the Invention
[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a method for preparing a graphene-zinc stannate composite material for supercapacitor electrodes. This composite material is nano-hollow cubic zinc stannate (G / ZnSnO3). As a supercapacitor electrode material, graphene can disperse nano-ZnSnO3 to prevent its agglomeration, increase the specific surface area and reaction sites, and improve the specific capacitance and cycle stability of the supercapacitor.
[0005] To achieve the above objectives, the present invention adopts the following technical solution: A method for preparing a graphene-zinc metastannate composite material includes the following steps: S1. Zinc nitrate and ethylenediaminetetraacetic acid (EDTA) are dissolved in deionized water at a certain molar ratio and magnetically stirred at room temperature to form a homogeneous solution A. Tin tetrachloride is dissolved in ethanol at a certain concentration to obtain solution B. The ethanol solution B is added to the homogeneous solution A to obtain a mixed solution C. A certain concentration of sodium hydroxide solution is then added to the mixed solution C to obtain solution D. Solution D is transferred to a polytetrafluoroethylene (PTFE) reactor and subjected to a hydrothermal reaction at 160-200 °C in a vacuum drying oven, maintaining this temperature. After the reaction is complete, the mixture is centrifuged, filtered, and washed. The resulting precipitate is dried at 60-80 °C. After drying, a precursor powder is obtained. S2. Place the precursor powder obtained in step S1 in a tube furnace and calcine it under a nitrogen or argon protective atmosphere to obtain zinc metastannate solid powder. S3. Measure 0.25 ml of monolayer graphene ethanol solution into a beaker, add 50-100 ml of anhydrous ethanol to dilute again, seal the beaker and then perform ultrasonic dispersion treatment; take 20-50 ml of the dispersed graphene ethanol solution, add 5-10 mg of zinc metastannate material, and stir evenly at room temperature. S4. Place the mixed solution obtained in step S3 into a drying oven and dry it at 60-80℃ to obtain a graphene-zinc stannate composite material.
[0006] Furthermore, in step S1, the molar ratio of zinc nitrate to ethylenediaminetetraacetic acid is 1:(0.3-0.8); the concentration of tin tetrachloride in step S1 is 0.2-0.5 mol / L; and the concentration of the sodium hydroxide solution in step S1 is 0.5 mol / L.
[0007] Furthermore, in step S2, the zinc metastannate solid powder is a hollow cube with an edge length of 300-600 nm.
[0008] Furthermore, in step S2, the calcination temperature is 300-500 ℃, the calcination time is 2-6 h, and the heating rate is 2-5 ℃ / min.
[0009] Furthermore, the zinc nitrate, ethylenediaminetetraacetic acid, tin tetrachloride, ethanol, and sodium hydroxide are all of analytical grade.
[0010] The present invention also discloses a graphene-zinc stannate composite material, which is prepared by the above method, wherein the zinc stannate is a nano-hollow cube and the graphene is distributed between the cubes.
[0011] This invention also discloses an application of a graphene-zinc stannate composite material, which can be used as any one of the following: a supercapacitor electrode material, a lithium-ion battery or sodium-ion battery anode material, or a lithium-sulfur battery cathode material.
[0012] Compared with existing technologies, this invention is inexpensive and reduces material costs. The prepared graphene-ZnSnO3 cubic material can be used as a symmetrical electrode material for supercapacitors. The two-dimensional structure of graphene can effectively increase the specific surface area and also play a dispersing role, preventing the agglomeration of nano-ZnSnO3 cubic materials, thereby further increasing the contact area between the active material and the electrolyte, improving the utilization rate and energy density of the active material. At the same time, due to the excellent conductivity of graphene, it also plays a positive role in enhancing the electrochemical reaction kinetics of supercapacitors. Attached Figure Description
[0013] Figure 1 These are SEM images of the G / ZnSnO3 hollow cubic composite material (b) and the ZnSnO3 control sample (a) provided in Example 1; Figure 2 The nitrogen adsorption-desorption isotherm and pore size distribution curve of the G / ZnSnO3 hollow cubic composite material provided in Example 1 are shown. Figure 3 The electrochemical impedance curves of G / ZnSnO3 as the symmetrical electrode of the supercapacitor provided in Example 1 (wherein ZnSnO3 is the control sample). Figure 4 The 1 A g of G / ZnSnO3 provided in Example 1 is used as the symmetrical electrode of the supercapacitor. -1 Constant current charge-discharge cycle curves at current density (where ZnSnO3 is the control sample). Detailed Implementation
[0014] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.
[0015] To address the shortcomings of existing technologies, the applicant discovered in its research that graphene (G) possesses ultra-high conductivity, ultra-large specific surface area, and abundant surface functional groups. However, the application of graphene-zinc stannate composite materials in the field of supercapacitors is not yet observed in existing technologies. Therefore, this invention provides a graphene-zinc stannate composite material, its preparation method, and its application. This composite material is nano-hollow cubic zinc stannate (G / ZnSnO3), which, as a supercapacitor electrode material, can greatly improve the material's conductivity, disperse nanoparticles, enhance interfacial charge transfer, and provide Faraday capacitance.
[0016] Specifically, the steps include the following: S1. Zinc nitrate and ethylenediaminetetraacetic acid (EDTA) are dissolved in deionized water at a specific molar ratio and magnetically stirred at room temperature to form a homogeneous solution A. Tin tetrachloride is dissolved in ethanol at a specific concentration to obtain solution B. The ethanol solution B is added to the homogeneous solution A to obtain a mixed solution C. A specific concentration of sodium hydroxide solution is then added to the mixed solution C to obtain solution D. Solution D is transferred to a polytetrafluoroethylene (PTFE) reactor and subjected to a hydrothermal reaction at 160–200 °C in a vacuum drying oven for 24 h. After the reaction is complete, the mixture is centrifuged, filtered, and washed. The resulting precipitate is dried at 60–80 °C for 12 h to obtain the precursor powder.
[0017] S2. The obtained precursor powder is placed in a tube furnace and calcined under a nitrogen or argon protective atmosphere to obtain zinc metastannate solid powder; S3. Measure 0.25 ml of monolayer graphene ethanol solution into a beaker, add 50-100 ml of anhydrous ethanol to dilute again, seal with plastic wrap, and sonicate for 1 h. Take 20-50 ml of the dispersed graphene ethanol solution, add 5-10 mg of zinc metastannate material, and stir at room temperature for 2 h.
[0018] S4. Finally, place it in a drying oven at 60-80 ℃ for 12 h to obtain a graphene-zinc stannate (G / ZnSnO3) composite material.
[0019] The specific test parameters for the application of graphene and zinc stannate composite materials in the symmetrical electrode of a supercapacitor are as follows: CR2032 button cell casing, electrode sheets made of G / ZnSnO3 material, aqueous separator NKK-MPF30AC, 6.0 mol / L KOH solution as electrolyte, and supercapacitor assembly. In the charge / discharge test system, the charge / discharge test voltage is 0-1.4 V.
[0020] Example 1
[0021] 0.272 g of zinc nitrate ( 0.701 g of tin tetrachloride (EDTA) and 0.146 g of ethylenediaminetetraacetic acid (EDTA) were dissolved in 20 ml of deionized water and magnetically stirred until homogeneous to obtain solution A. Solution B was obtained by dissolving a sample in 10 ml of ethanol. Solution B was then added to solution A to obtain mixed solution C. 50 ml of 0.5 mol / L sodium hydroxide (NaOH) solution was added, and stirring was continued for 0.5 h to obtain solution D. Solution D was transferred to a polytetrafluoroethylene reactor and subjected to a hydrothermal reaction at 200 °C in a vacuum drying oven for 24 h. After the reaction was completed, the sample was centrifuged, filtered, and washed. The precipitate was dried at 80 °C for 12 h to obtain precursor powder. The precursor powder was then placed in a tube furnace and calcined under a nitrogen or argon atmosphere at 400 °C for 4 h at a heating rate of 2 °C / min to obtain zinc metastannate (ZnSnO3) solid powder. Measure 0.25 ml of monolayer graphene ethanol solution into a beaker, add 50 ml of anhydrous ethanol to dilute again, seal with plastic wrap, and ultrasonically disperse for 1 h. Take 30 ml of the dispersed graphene ethanol solution, add 5 mg of zinc nitrate material, and stir at room temperature for 2 h. Finally, place it in a drying oven at 80 ℃ for 12 h to obtain graphene and zinc stannate (G / ZnSnO3) solid powder.
[0022] G / ZnSnO3 compound powder, Ketjen Black, and PVDF were mixed evenly at a mass ratio of 7:2:1, and the concentration was adjusted with N-methylpyrrolidone. The mixture was stirred for 2 hours to prepare a slurry. The prepared slurry was coated onto a 14 mm diameter circular nickel foam current collector, dried in an oven at 70 °C for 36 hours, and then pressed into a tablet using a tablet press at a pressure of approximately 5 MPa. A symmetrical electrode supercapacitor was then assembled and tested.
[0023] Figure 1 (a) The SEM image of the ZnSnO3 solid powder prepared in this embodiment shows that ZnSnO3 is a uniform nanocube with an edge length of ~500 nm and is hollow; (b) The SEM image of the G / ZnSnO3 composite material prepared in this embodiment shows that graphene is distributed between the cubes and plays the role of dispersion and conductive network. Figure 2 The figures show the nitrogen adsorption-desorption isotherm and pore size distribution curve of the G / ZnSnO3 hollow cubic composite material prepared in this embodiment. It can be seen that the prepared G / ZnSnO3 adsorption-desorption isotherm is type IV, indicating a mesoporous structure. Figure 3 The electrochemical impedance spectroscopy curves for the G / ZnSnO3 prepared in this embodiment as the symmetrical electrode of the supercapacitor are shown (where ZnSnO3 is the control sample). The G / ZnSnO3 exhibits a lower impedance, demonstrating that the addition of graphene helps improve the electrode conductivity. Figure 4The figures show the constant current charge-discharge cycle curves and voltage-time relationship curves of the G / ZnSnO3 supercapacitor symmetrical electrode prepared in this embodiment. The results indicate that the G / ZnSnO3 composite material prepared in this example exhibits good performance at 1 A g / L. -1 The initial discharge specific capacity at the given current density is 76.3 F g. -1 After 10,000 cycles, it still retains 56.8 F g. -1 The initial capacity of the control sample ZnSnO3 was 18.3 F g. -1 After 10,000 cycles, the capacity is 18.0 F g. -1 .
[0024] Compared with the prior art, the graphene added to ZnSnO3 in this embodiment, as a symmetrical electrode material for supercapacitors, can effectively increase the contact area of the reaction surface, improve electrode conductivity, provide pseudocapacitance, and significantly improve the specific capacitance.
[0025] Example 2
[0026] This embodiment provides a graphene-zinc metastannate composite material, its preparation method, and its application, which differs from Embodiment 1 in that: 0.272 g of zinc nitrate ( ) and 0.087 g of ethylenediaminetetraacetic acid (EDTA) were dissolved in 20 ml of deionized water and magnetically stirred until homogeneous to obtain solution A. 1.052 g of tin tetrachloride ( Solution B was obtained by dissolving a compound in 10 ml of ethanol. Solution B was added to solution A to obtain mixed solution C. Then, 50 ml of 0.5 mol / L sodium hydroxide (NaOH) solution was added, and stirring was continued for 0.5 h to obtain solution D. Solution D was transferred to a polytetrafluoroethylene reactor and subjected to hydrothermal reaction at 160 °C in a vacuum drying oven for 24 h. After the reaction was completed, the mixture was centrifuged, filtered, and washed. The precipitate was dried at 70 °C for 12 h to obtain precursor powder. The precursor powder was placed in a tube furnace and calcined under a nitrogen or argon protective atmosphere at 300 °C for 2 h at a heating rate of 5 °C / min to obtain zinc metastannate (ZnSnO3) solid powder. Measure 0.25 ml of monolayer graphene ethanol solution into a beaker, add 100 ml of anhydrous ethanol for further dilution, seal with plastic wrap, and ultrasonically disperse for 1 h. Take 50 ml of the dispersed graphene ethanol solution, add 5 mg of zinc nitrate material, and stir at room temperature for 2 h. Finally, place it in a drying oven at 60 ℃ for 12 h to obtain graphene and zinc stannate (G / ZnSnO3) solid powder.
[0027] G / ZnSnO3 compound powder, Ketjen Black, and PVDF were mixed evenly at a mass ratio of 7:2:1, and the concentration was adjusted with N-methylpyrrolidone. The mixture was stirred for 2 hours to prepare a slurry. The prepared slurry was coated onto a 14 mm diameter circular nickel foam current collector, dried in an oven at 70 °C for 36 hours, and then pressed into a tablet using a tablet press at a pressure of approximately 5 MPa. A symmetrical electrode supercapacitor was then assembled and tested.
[0028] The electrochemical performance test results of this embodiment show that the prepared G / ZnSnO3 material can achieve a performance of 1 A g. -1 The initial discharge specific capacity at the given current density is 30.5 F g. -1 The specific capacity after 10,000 cycles was 24.8 F g. -1 The electrochemical performance of this embodiment is lower than that of Example 1.
[0029] Example 3
[0030] This embodiment provides a graphene-zinc metastannate composite material, its preparation method, and its application, which differs from Embodiment 1 in that: 0.272 g of zinc nitrate ( ) and 0.235 g of ethylenediaminetetraacetic acid (EDTA) were dissolved in 20 ml of deionized water and magnetically stirred until homogeneous to obtain solution A. 1.763 g of tin tetrachloride ( Solution B was obtained by dissolving a compound in 10 ml of ethanol. Solution B was added to solution A to obtain mixed solution C. Then, 50 ml of 0.5 mol / L sodium hydroxide (NaOH) solution was added, and stirring was continued for 0.5 h to obtain solution D. Solution D was transferred to a polytetrafluoroethylene reactor and subjected to hydrothermal reaction at 180 °C in a vacuum drying oven for 24 h. After the reaction was completed, the solution was centrifuged, filtered, and washed. The precipitate was dried at 70 °C for 12 h to obtain precursor powder. The precursor powder was placed in a tube furnace and calcined under a nitrogen or argon protective atmosphere at 500 °C for 6 h at a heating rate of 3 °C / min to obtain zinc metastannate (ZnSnO3) solid powder. Measure 0.25 ml of monolayer graphene ethanol solution into a beaker, add 80 ml of anhydrous ethanol to dilute again, seal with plastic wrap, and ultrasonically disperse for 1 h. Take 20 ml of the dispersed graphene ethanol solution, add 6 mg of zinc nitrate material, and stir at room temperature for 2 h. Finally, place it in a drying oven at 70 ℃ for 12 h to obtain graphene and zinc stannate (G / ZnSnO3) solid powder.
[0031] G / ZnSnO3 compound powder, Ketjen Black, and PVDF were mixed evenly at a mass ratio of 7:2:1, and the concentration was adjusted with N-methylpyrrolidone. The mixture was stirred for 2 hours to prepare a slurry. The prepared slurry was coated onto a 14 mm diameter circular nickel foam current collector, dried in an oven at 70 °C for 36 hours, and then pressed into a tablet using a tablet press at a pressure of approximately 5 MPa. A symmetrical electrode supercapacitor was then assembled and tested.
[0032] The electrochemical performance test results of this embodiment show that the prepared G / ZnSnO3 material can achieve a performance of 1 A g. -1 The initial discharge specific capacity at the given current density is 24.7 F g. -1 The specific capacity after 10,000 cycles was 20.9 F g. -1 The electrochemical performance of this embodiment is lower than that of Example 1.
[0033] Example 4
[0034] This embodiment provides a graphene-zinc metastannate composite material, its preparation method, and its application, which differs from Embodiment 1 in that: 0.272 g of zinc nitrate ( ) and 0.146 g of ethylenediaminetetraacetic acid (EDTA) were dissolved in 20 ml of deionized water and magnetically stirred until homogeneous to obtain solution A. 1.406 g of tin tetrachloride ( Solution B was obtained by dissolving a compound in 10 ml of ethanol. Solution B was added to solution A to obtain mixed solution C. Then, 50 ml of 0.5 mol / L sodium hydroxide (NaOH) solution was added, and stirring was continued for 0.5 h to obtain solution D. Solution D was transferred to a polytetrafluoroethylene reactor and subjected to hydrothermal reaction at 180 °C in a vacuum drying oven for 24 h. After the reaction was completed, the solution was centrifuged, filtered, and washed. The precipitate was dried at 80 °C for 12 h to obtain precursor powder. The precursor powder was placed in a tube furnace and calcined under a nitrogen or argon protective atmosphere at 400 °C for 4 h at a heating rate of 4 °C / min to obtain zinc metastannate (ZnSnO3) solid powder. Measure 0.25 ml of monolayer graphene ethanol solution into a beaker, add 60 ml of anhydrous ethanol to dilute again, seal with plastic wrap, and ultrasonically disperse for 1 h. Take 40 ml of the dispersed graphene ethanol solution, add 8 mg of zinc nitrate material, and stir at room temperature for 2 h. Finally, place it in a drying oven at 80 ℃ for 12 h to obtain graphene and zinc stannate (G / ZnSnO3) solid powder.
[0035] G / ZnSnO3 compound powder, Ketjen Black, and PVDF were mixed evenly at a mass ratio of 7:2:1, and the concentration was adjusted with N-methylpyrrolidone. The mixture was stirred for 2 hours to prepare a slurry. The prepared slurry was coated onto a 14 mm diameter circular nickel foam current collector, dried in an oven at 70 °C for 36 hours, and then pressed into a tablet using a tablet press at a pressure of approximately 5 MPa. A symmetrical electrode supercapacitor was then assembled and tested.
[0036] The electrochemical performance test results of this embodiment show that the prepared G / ZnSnO3 material can achieve a performance of 1 A g. -1 The initial discharge specific capacity at the given current density is 26.1 F g. -1 The specific capacity after 10,000 cycles was 20.4 F g. -1 The electrochemical performance of this embodiment is lower than that of Example 1.
[0037] The above description of the embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.
[0038] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A method for preparing a graphene-zinc metastannate composite material, characterized in that, Including the following steps: S1. Zinc nitrate and ethylenediaminetetraacetic acid are dissolved in deionized water at a certain molar ratio and magnetically stirred at room temperature to form a homogeneous solution A. Tin tetrachloride is dissolved in ethanol at a certain concentration to obtain solution B. The ethanol solution B is added to the homogeneous solution A to obtain a mixed solution C. A certain concentration of sodium hydroxide solution is then added to the mixed solution C to obtain solution D. Solution D is transferred to a polytetrafluoroethylene reactor and subjected to a hydrothermal reaction at 160-200 °C in a vacuum drying oven, and maintained at this temperature. After the reaction is complete, the mixture is centrifuged, filtered, and washed. The resulting precipitate is dried at 60-80 °C. After drying, a precursor powder is obtained. S2. Place the precursor powder obtained in step S1 in a tube furnace and calcine it under a nitrogen or argon protective atmosphere to obtain zinc metastannate solid powder. S3. Measure 0.25 ml of monolayer graphene ethanol solution into a beaker, add 50-100 ml of anhydrous ethanol to dilute again, seal the beaker and then perform ultrasonic dispersion treatment; take 20-50 ml of the dispersed graphene ethanol solution, add 5-10 mg of zinc metastannate material, and stir evenly at room temperature. S4. Place the mixed solution obtained in step S3 into a drying oven and dry it at 60-80℃ to obtain a graphene-zinc stannate composite material.
2. The method for preparing a graphene-zinc metastannate composite material according to claim 1, characterized in that, In step S1, the molar ratio of zinc nitrate to ethylenediaminetetraacetic acid is 1:0.3-1:0.8; the concentration of tin tetrachloride in step S1 is 0.2-0.5 mol / L; and the concentration of the NaOH solution in step S1 is 0.5 mol / L.
3. The method for preparing a graphene-zinc stannate composite material according to claim 1, characterized in that, In step S2, the ZnSnO3 solid powder is a hollow cube with an edge length of 300-600 nm.
4. The method for preparing a graphene-zinc metastannate composite material according to claim 1, characterized in that, In step S2, the calcination temperature is 300-500 ℃, the calcination time is 2-6 h, and the heating rate is 2-5 ℃ / min.
5. The method for preparing a graphene-zinc metastannate composite material according to claim 1, characterized in that, The zinc nitrate, ethylenediaminetetraacetic acid, tin tetrachloride, ethanol, and sodium hydroxide were all of analytical grade.
6. The graphene-zinc metastannate composite material obtained by any one of claims 1-5, characterized in that, Zinc metastannate is a nano-hollow cube with graphene distributed between the cubes.
7. The application of the graphene-zinc stannate composite material obtained by any one of claims 1-5, characterized in that, The resulting graphene-zinc metastannate composite material can be used as any one of the following: supercapacitor electrode material, lithium-ion battery or sodium-ion battery anode material, or lithium-sulfur battery cathode material.