Three-dimensional superstructure carbon electrode for supercapacitor and preparation method of three-dimensional superstructure carbon electrode

Abstract

The invention provides a three-dimensional superstructure carbon electrode for a supercapacitor, the interior of the three-dimensional superstructure carbon electrode contains round holes with the aperture of 1-10 microns, the volume of the three-dimensional superstructure carbon electrode is 0.014-0.018 cm <-3 >, and the invention further provides a preparation method of the three-dimensional superstructure carbon electrode. Compared with the prior art, modeling software is adopted to design the three-dimensional superstructure of the carbon electrode, high customization of the electrode structure can be achieved, the method based on computer aided design allows the size and overall layout of unit lattices to be accurately controlled, and therefore the electrode performance is optimized.

Description

Technical Field

[0001] The invention belongs to the technical field of energy storage materials, and in particular relates to a three-dimensional superstructure carbon electrode for a supercapacitor and a preparation method thereof. Background Art

[0002] The rapid development of new energy vehicles and the demand for electricity in extreme environments such as aerospace and submarines have highlighted the safety issues of energy storage systems. Supercapacitors, as emerging energy storage devices, also face the same challenges. Their fast charging and discharging characteristics make them suitable for extreme environments such as engine ignition systems that require high instantaneous power, which places strict requirements on their working stability and anti-destruction performance.

[0003] In supercapacitor devices, operating conditions are largely determined by electrode strength and capacitance performance. Ensuring electrode damage resistance is critical to improve service life and safety, especially in harsh environments with pressure loading. However, it is difficult for current materials used in supercapacitors to achieve high strength while ensuring high capacity. Summary of the invention

[0004] In order to solve the above-mentioned technical problems, the present invention provides a three-dimensional superstructure carbon electrode for supercapacitor and a preparation method thereof to overcome the shortcomings of the prior art.

[0005] The present invention provides a three-dimensional superstructure carbon electrode for a supercapacitor, wherein the interior of the three-dimensional superstructure carbon electrode contains circular holes with a pore size of 1-10 um, and the volume of the three-dimensional superstructure carbon electrode is 0.014-0.018 cm -3 .

[0006] The second object of the present invention is to provide a method for preparing a three-dimensional superstructure carbon electrode, the preparation method specifically comprising the following steps:

[0007] S1. Use modeling software to design a three-dimensional superstructure of a carbon electrode, use thin plate integrated hollow pillars as the unit lattice of the three-dimensional superstructure, design the unit lattice size to be 10 mm, and array it in a 3*2 specification to obtain a TP-HS three-dimensional superstructure model;

[0008] S2, mixing the photocurable resin and the pore-forming filler by ball milling to obtain a mixture;

[0009] S3, first slicing the TP-HS three-dimensional superstructure model obtained in step S1, importing the slicing program into a 3D printer, and using the 3D printer to perform layer-by-layer stereolithography on the mixture obtained in step S2 to obtain a three-dimensional superstructure carbon electrode precursor;

[0010] S4. The three-dimensional superstructure carbon electrode precursor is subjected to carbonization treatment, etching treatment, alkaline solution immersion treatment and activation treatment in sequence, then cooled to room temperature for cleaning and drying, and finally a three-dimensional superstructure carbon electrode is obtained.

[0011] Compared with the prior art, the present invention uses modeling software to design the three-dimensional superstructure of the carbon electrode, which can achieve a high degree of customization of the electrode structure. This computer-aided design-based method allows precise control of the size of the cell lattice (such as 10 mm in this case) and the overall layout (3*2 specification array), thereby optimizing the electrode performance.

[0012] In a possible implementation, in step S2, the photocurable resin is NOVA3D Nova intelligent high-precision matte resin, the pore-forming filler is SiO2 balls with a diameter of 1-3 μm, and the mass ratio of the NOVA3D Nova intelligent high-precision matte resin to the SiO2 balls is 10:3.

[0013] Compared with the prior art, the three-dimensional superstructure carbon electrode (3DC-T) of the present invention adopts a commercial rigid resin with intrinsic strength as a precursor, and the superstructure can provide mechanical strength beyond the intrinsic strength of the material from the perspective of artificial design, thereby comprehensively obtaining excellent mechanical properties; at the same time, the present invention increases the specific surface area of ​​the electrode through SiO2 pore formation, and further introduces oxygen-containing functional groups through KOH activation, thereby comprehensively improving the capacitance performance.

[0014] In a possible implementation manner, in step S2, the parameters of ball milling mixing are as follows: a rotation speed of 280 r / min and a time of 12 h.

[0015] Compared with the prior art, the present invention adopts the above-mentioned ball milling mixing parameters. Long-term ball milling treatment can ensure a very high uniformity between the photocurable resin and the pore-forming filler, which is crucial for the material consistency in the subsequent 3D printing process and helps to ensure the consistency and reliability of the final product performance.

[0016] In a possible implementation manner, in step S3, the slicing process uses AsigaComposer software, and the thickness is 50 μm.

[0017] Compared with the prior art, the present invention adopts the above software for slicing and limits the thickness, mainly because: Asiga Composer is a professional 3D printing slicing software that can provide fine layer thickness settings, and the layer thickness of 50μm is relatively small, which can achieve high detail resolution, which is very important for constructing complex three-dimensional superstructure carbon electrodes because it allows more detailed reproduction of subtle features in the design model.

[0018] In a possible implementation, in step S3, the 3D printer is an Asiga MAX X27 UV printer, and the parameters are set as follows: the UV wavelength is 385 nm, and the chromatographic resolution is 27 μm.

[0019] Compared with the prior art, the present invention adopts the above-mentioned model of 3D printer and further defines the parameters, the functions of which are: the 27μm tomographic resolution means that the thickness of each layer of material is very thin, which can achieve extremely high detail accuracy, which is crucial for three-dimensional superstructure carbon electrodes that require fine structures and complex geometries, because it can ensure that the final product has good morphology retention and surface smoothness; Asiga MAX X27 is an industrial-grade UV light-curing 3D printer that can provide stable printing conditions and precise control; the 385nm UV wavelength is ideal for many photocurable resins because most commercial photosensitive resins have high reaction efficiency in this band, which means that lower energy can be used to quickly and evenly cure each layer, thereby increasing printing speed and reducing the risk of material deformation or stress accumulation.

[0020] In a possible implementation, in step S3, in the layer-by-layer stereolithography process: the single-layer curing time is set to 0.5 s, and the first-layer curing time is set to 1 s.

[0021] Compared with the prior art, the advantages of the present invention using the above parameters are: the shorter single-layer curing time (0.5 seconds) can significantly speed up the overall printing process. This is very beneficial for applications that require rapid iteration of design or large-scale production because it reduces the production time of each part; the longer first layer curing time (1 second) helps to ensure good adhesion between the first layer and the printing platform, which is very important because if the first layer is not firmly adhered to the platform, it may cause the failure or deformation of the entire print.

[0022] In a possible implementation, in step S4, the carbonization treatment is performed in a tubular furnace, and the parameters of the carbonization treatment are as follows: sintering at 900° C. for 3 h under vacuum conditions, with a heating rate and a cooling rate both of 2° C. / min.

[0023] Compared with the prior art, the present invention adopts the above parameters for carbonization treatment, wherein the use of a tubular furnace can provide a uniform heating environment to ensure that the sample is heated uniformly throughout the volume, which is very important for maintaining the consistency of the material and avoiding defects caused by local overheating; carbonization treatment under vacuum conditions can reduce the impact of oxygen and other gases on the material, and prevent oxidation or unnecessary chemical reactions. This helps to form a purer carbon structure and improve the conductivity and stability of the electrode; the slow heating rate (2°C / min) helps to gradually remove organic components and reduce internal stress and crack formation caused by rapid heating, which is conducive to the formation of a denser and complete carbon skeleton; the 3-hour high-temperature treatment time is long enough to ensure that all organic components are completely decomposed and converted into carbon, which can ensure the purity and structural integrity of the final product; the slow cooling rate (2°C / min) also helps to alleviate the thermal stress during the cooling process and prevent cracking or deformation caused by a sudden drop in temperature, which helps to maintain the structural stability and mechanical strength of the carbon electrode.

[0024] In a possible implementation, in step S4, HF acid solution is used for etching, and the etching time is 24 hours.

[0025] The present invention is subjected to etching treatment, wherein HF (hydrofluoric acid) is a powerful corrosive agent, which is particularly suitable for removing silicon-based materials. If the three-dimensional superstructure carbon electrode precursor contains inorganic components such as silicon or other metal oxides, HF can effectively dissolve them, thereby retaining only the required carbon skeleton; through long-term etching treatment, the porosity and specific surface area of ​​the material can be further increased, which is very beneficial for improving the electrochemical activity of the electrode material, because a larger specific surface area means more active sites, which helps to improve the capacitance performance or the energy storage capacity of the battery.

[0026] In a possible implementation, in step S4, the alkaline solution soaking treatment uses a KOH solution with a concentration of 1 mol / L, and the soaking time is 8 hours.

[0027] Compared with the prior art, the purpose of the alkaline solution immersion treatment in the present invention is that KOH is a strong base that can react chemically with certain functional groups (such as carboxyl, hydroxyl, etc.) on the surface of the carbon material, thereby increasing the specific surface area of ​​the material, which helps to provide more active sites. For the electrode material, this means higher capacitance performance; at the same time, through alkaline solution treatment, the pore structure can be further expanded and refined, and the connectivity and distribution uniformity of the pores can be improved, which is very important for the rapid transmission of electrolyte ions and can significantly improve the charge and discharge rate performance of the electrode.

[0028] In a possible implementation, in step S4, the activation treatment is performed in a tube furnace, and the parameters of the activation treatment are as follows: sintering at 800° C. for 1 h in an argon atmosphere, with a heating rate and a cooling rate both of 2° C. / min.

[0029] Compared with the prior art, the present invention can maximize the performance of the three-dimensional superstructure carbon electrode while maintaining the integrity of the material structure by performing an activation treatment at 800°C in an argon atmosphere and strictly controlling the heating rate and the cooling rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a scanning electron microscope image of the three-dimensional superstructure carbon electrode prepared by the present invention;

[0031] Figure 2 The current-voltage (CV) curves of the three-electrode system at different scan rates;

[0032] Figure 3 The current-voltage (CV) curves of aqueous symmetric supercapacitors at different scan rates. DETAILED DESCRIPTION

[0033] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below. It should be noted that the following embodiments are only used to illustrate the implementation method and typical parameters of the present invention, and are not used to limit the parameter range described in the present invention. Reasonable changes derived therefrom are still within the scope of protection of the claims of the present invention.

[0034] It should be noted that the endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed in this article.

[0035] Unless otherwise defined, all terms, symbols and other scientific terms used herein are intended to have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. In some cases, terms with conventionally understood meanings are defined herein for the purpose of clarification or ease of reference, and such definitions herein should not be construed as indicating significant differences from conventional understandings in the art. The technical methods described or cited herein are generally well understood by those skilled in the art and are adopted by conventional methods. Unless otherwise stated, the use of commercially available kits, reagents and instruments is carried out in accordance with the protocols and parameters given by the manufacturer.

[0036] The technical effects of the present invention are described below in conjunction with specific embodiments.

[0037] Example 1

[0038] This embodiment provides a three-dimensional superstructure carbon electrode for a supercapacitor, which is prepared by the following preparation method:

[0039] The three-dimensional superstructure was designed using Solidworks modeling software. Thin-Plate integrated Hollow-Strut was selected as the unit lattice of the superstructure. The lattice size was set to 10 mm, and the TP-HS three-dimensional superstructure model was obtained with a 3*2 specification array.

[0040] Take 0.3g SiO2 and 10ml NOVA3D intelligent high-precision matte resin and put them into a ball mill. Put 20 small ball milling beads and 10 small ball milling beads into the ball mill. Set the speed to 280r / min and mill for 12h.

[0041] The TP-HS three-dimensional superstructure model was sliced ​​using Asiga Composer software with a slice thickness of 50 μm. The slicing program was imported into an Asiga MAX X27 UV printer (UV wavelength of 385 nm, tomographic resolution of 27 μm) to perform stereolithography layer by layer on the ball-milled mixture. The single-layer curing time was set to 0.5 s, and the first-layer curing time was set to 1 s to obtain a carbon electrode precursor.

[0042] The precursor was carbonized in a tube furnace under vacuum conditions, sintered at 900℃ for 3h, and the heating rate was 2℃ / min. After cooling to room temperature, it was taken out and soaked in HF acid for 24h to etch the SiO2 balls, and then deionized water. After soaking in 1mol / L KOH solution for 8h, it was activated in a tube furnace with argon atmosphere, sintered at 800℃ for 1h, and the heating rate was 2℃ / min. It was rinsed with deionized water and dried in an oven at 80℃ to obtain a three-dimensional superstructure carbon electrode (3DC-T)

[0043] The three-dimensional superstructure carbon electrode prepared in this embodiment was observed, and the electron microscope image is as follows: Figure 1 As shown, from Figure 1 It can be seen that circular holes with a pore size of 1-10um are formed inside the carbon electrode through pore making, which effectively increases the specific surface area of ​​the electrode.

[0044] Example 2

[0045] This embodiment provides a three-electrode system, configured with 1M H2SO4 as an electrolyte, the three-dimensional superstructure carbon electrode prepared in Example 1 as a working electrode, Ag / AgCl as a reference electrode, and the three-electrode system is assembled to test the chemical properties of the three-electrode system. The results are as follows: Figure 2 As shown, from Figure 2 It can be seen that the CV curve of a single electrode presents a curved rectangle, indicating that the electrode material has pseudocapacitive behavior and the capacitance performance is stable at different scan rates.

[0046] Example 3

[0047] This embodiment provides that 1M H2SO4 is configured as an electrolyte, the three-dimensional superstructure carbon electrode prepared in Example 1 is used as a working electrode, a symmetrical supercapacitor system is assembled, and the chemical properties of the symmetrical supercapacitor system are tested. The results are as follows Figure 3 As shown, from Figure 3 It can be seen that the CV curve of the symmetric supercapacitor presents a curved rectangle, with pseudocapacitive behavior, and the capacitance performance of the supercapacitor is stable at different scan rates.

[0048] It can be seen from the above results that the present invention assembles the three-dimensional superstructure carbon electrodes into a symmetrical supercapacitor, which exhibits excellent electrochemical performance under the charge / discharge curves at different current densities and has a high area energy density.

[0049] Although the disclosure is disclosed as above, the protection scope of the disclosure is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the disclosure, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A three-dimensional superstructure carbon electrode for supercapacitors, characterized in that: The interior of the three-dimensional superstructure carbon electrode contains circular holes with a pore size of 1-10 μm, and the volume of the three-dimensional superstructure carbon electrode is 0.014-0.018 cm -3 .

2. A method for preparing a three-dimensional superstructure carbon electrode as claimed in claim 1, characterized in that: The preparation method specifically comprises the following steps: S1. Use modeling software to design a three-dimensional superstructure of a carbon electrode, use thin plate integrated hollow pillars as the unit lattice of the three-dimensional superstructure, design the unit lattice size to be 10 mm, and array it in a 3*2 specification to obtain a TP-HS three-dimensional superstructure model; S2, mixing the photocurable resin and the pore-forming filler by ball milling to obtain a mixture; S3, first slicing the TP-HS three-dimensional superstructure model obtained in step S1, importing the slicing program into a 3D printer, and using the 3D printer to perform layer-by-layer stereolithography on the mixture obtained in step S2 to obtain a three-dimensional superstructure carbon electrode precursor; S4. The three-dimensional superstructure carbon electrode precursor is subjected to carbonization treatment, etching treatment, alkaline solution immersion treatment and activation treatment in sequence, then cooled to room temperature for cleaning and drying, and finally a three-dimensional superstructure carbon electrode is obtained.

3. The preparation method according to claim 2, characterized in that: In the step S2, the photocurable resin is NOVA3D Nova intelligent high-precision matte resin, the pore-forming filler is SiO2 balls with a diameter of 1-3 μm, and the mass ratio of the NOVA3D Nova intelligent high-precision matte resin to the SiO2 balls is 10:

3.

4. The preparation method according to claim 2, characterized in that: In step S2, the parameters of ball milling mixing are as follows: rotation speed is 280 r / min, and time is 12 h.

5. The preparation method according to claim 2, characterized in that: In step S3, the slicing process is performed using the Asiga Composer software, and the thickness is 50 μm.

6. The preparation method according to claim 2, characterized in that: In step S3, the 3D printer is an Asiga MAXX27 UV printer, and the parameters are set as follows: UV wavelength is 385nm, and the chromatographic resolution is 27μm; And / or, in the step S3, in the layer-by-layer stereolithography process: the single layer curing time is set to 0.5 s, and the first layer curing time is set to 1 s.

7. The preparation method according to claim 2, characterized in that: In step S4, the carbonization treatment is carried out in a tubular furnace, and the parameters of the carbonization treatment are as follows: sintering at 900° C. for 3 h under vacuum conditions, and the heating rate and cooling rate are both 2° C. / min.

8. The preparation method according to claim 2, characterized in that: In step S4, HF acid solution is used for etching, and the etching time is 24 hours.

9. The preparation method according to claim 2, characterized in that: In step S4, the alkaline solution soaking treatment uses a KOH solution with a concentration of 1 mol / L, and the soaking time is 8 hours.

10. The preparation method according to claim 2, characterized in that: In the step S4, the activation treatment is carried out in a tube furnace, and the parameters of the activation treatment are as follows: sintering at 800° C. for 1 h in an argon atmosphere, and the heating rate and cooling rate are both 2° C. / min.

Images