Structural supercapacitor based on 3D printing and preparation method thereof
Through 3D printing technology, the tenon and mortise structures are formed on the carbon fiber electrode, and combined with polymer gel electrolytes, the problems of uncontrollable ion transport channels and inaccurate energy storage areas in the prior art are solved, the electrochemical and mechanical properties of structural supercapacitors are improved, and the preparation process is simplified.
Patent Information
- Application Number
- CN202510803325.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-17
- Publication Date
- 2025-08-22
AI Technical Summary
The existing structural supercapacitor preparation method cannot achieve controllable preparation of ion transport channels or precise control of energy storage areas, resulting in limited electrochemical performance and a need for a diaphragm to hinder ion transport.
3D printing technology is used to form a tenon and mortise microarray structure on the carbon fiber electrode, combined with polymer gel electrolyte, forming a tenon structure, and encapsulated through a vacuum-assisted resin transfer molding process to avoid diaphragms and achieve uniform distribution of ion transmission channels.
The straight distribution of the ion transport channel is achieved, the electrochemical and mechanical properties are improved, and the materials are easy to obtain and the preparation efficiency is high, making them suitable for large-scale production.
Smart Images
Figure CN120527162A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the field of structural supercapacitors. Background Art
[0002] With the continuous development of energy storage and conversion technologies, structural supercapacitors, as a new type of energy storage device with superior energy storage capacity and mechanical stability, have attracted much attention. Researchers have also proposed a variety of preparation processes for structural supercapacitors. However, current preparation methods for structural supercapacitors cannot achieve controllable preparation of ion transport channels or precise control of the energy storage area. Among current related technologies, micro-nano 3D printing technology is expected to achieve controllable manufacturing, but there is currently no relevant 3D printing method for preparing structural supercapacitors.
[0003] Currently, there are two most common forms of structural supercapacitors. One is the use of polymer dual-continuous phase solid electrolytes. This form of structural supercapacitor realizes the coupling of the energy storage area and the load-bearing area; the other is the use of uncoupled energy storage area and load-bearing area. The energy storage area of this form is relatively concentrated. Although this form can realize the heterogeneous design of the energy storage area, the current preparation process makes it difficult to accurately control the shape and size of the energy storage area, and it is impossible to accurately prepare the structure designed according to performance, resulting in a large difference between the actual performance of the actual device and the design value.
[0004] The first type of structural supercapacitor, such as the preparation method in the literature Zhang, J., Yan, J., Zhao, Y. et al. High-strength and machinable load-bearing integrated electrochemical capacitors based on polymeric solidelectrolyte. Nat Commun 14, 64 (2023), uses a dual-continuous phase solid electrolyte, in which the polymer and ionic liquid form a dual-continuous phase structure. The polymer provides a porous skeleton and transmission channels for the ionic liquid. This structure allows for efficient ion conduction while maintaining mechanical stability and good interfacial compatibility. The mechanical properties of the polymer porous structure directly affect the transport of ions and thus the electrochemical performance of the solid electrolyte. In particular, when used in structure-energy storage integrated devices, the solid electrolyte will be subjected to the effects of external loads. Although this structure achieves good coupling of mechanical and electrochemical properties, since the process can only randomly generate pore structures, the ion transmission channels in the porous structure of the dual-continuous phase electrolyte are tortuous, which greatly limits the electrochemical performance. If the controllable preparation of the porous structure can be achieved and the pore structure can be precisely controlled according to performance requirements, the electrochemical performance of this type of electrolyte and structural supercapacitor will be greatly improved.
[0005] The second common structural supercapacitor form is shown in patent CN115938814A. The energy storage and load-bearing functions of this type of structural supercapacitor are uncoupled. Due to the concentration of the energy storage area, its mechanical properties are greatly affected, and an area with extremely poor mechanical properties is formed in the energy storage area. However, in this type, since ion transmission is blocked by obstacles, its electrochemical performance is more fully exerted.
[0006] In existing devices such as the two structural supercapacitors mentioned above, due to the requirements of the preparation process, a layer of diaphragm needs to be added between the two electrodes to prevent the two electrodes from contacting, which makes the capacitor unable to work normally. This layer of diaphragm also hinders the transmission of ions to a certain extent, and to a certain extent limits the electrochemical performance of the device.
[0007] To sum up, the existing devices and their preparation methods at this stage have a certain impact on their mechanical properties and electrochemical properties due to their structural and preparation process limitations, and are unable to meet performance requirements and accurately design and prepare corresponding devices. This invention is proposed when the research on structural supercapacitors is just in its initial stage and there is relatively little research on the precise and controllable preparation of structural supercapacitors. Summary of the Invention
[0008] To address the above problems, the present invention proposes a structural supercapacitor based on 3D printing, and the technical solutions adopted are as follows: A 3D-printed structural supercapacitor consists of two carbon fiber electrodes. Specific structures with tenon and mortise microarrays are formed on the surfaces of the two carbon fiber electrodes through 3D printing. When the two carbon fiber electrodes are combined into a mortise and tenon structure, in-plane slippage does not occur, and a cavity is formed between the two carbon fiber electrodes, into which a polymer gel electrolyte is perfused.
[0009] Preferably, the cavity enclosed by the tenon and the mortise is a matrix structure such as a regular triangle, a square, a circle or a regular hexagon.
[0010] Further preferably, the 3D printing-based structural supercapacitor is connected to the tabs and then encapsulated by epoxy resin.
[0011] To address the above problems, the present invention proposes a method for preparing a structural supercapacitor based on 3D printing. The specific steps of the method are as follows: (1) 3D printing of carbon fiber electrodes: The carbon fiber cloth is cut and set aside, and the cut carbon fibers are arranged in a micro-nano 3D printer. High-strength resin is printed onto the carbon fiber cloth according to a designed specific structure to obtain a carbon fiber electrode; the specific structure is a tenon and mortise structure formed on the carbon fiber electrode, so that after the two carbon fiber electrodes are combined into a mortise and tenon structure, in-plane slippage does not occur, and a cavity is formed between the two carbon fiber electrodes.
[0012] Preferably, the high-strength resin in step (1) is a photosensitive resin, and the carbon fiber cloth is a woven carbon fiber fabric.
[0013] (2) Preparation of polymer gel electrolyte solution: Dissolve polyethylene oxide (PEO), lithium salt and ionic liquid in acetone at a mass ratio of PEO (40-60): LiTFSI (15-20): IL (70-80) and stir magnetically at 50°C for 24 hours to obtain a viscous homogeneous polymer gel electrolyte solution for later use.
[0014] Preferably, in step (2), the lithium salt is lithium bis(trifluoromethane)sulfonyl imide (LiTFSI), and the ionic liquid is 1-ethyl-3-methylimidazolium tetrafluoroborate.
[0015] (3) Structural supercapacitor combination: The polymer gel electrolyte solution prepared in step (2) is dripped into the two carbon fiber electrode specific structures for forming the cavity, and is filled to 1 / 2; then, the two carbon fiber electrodes are placed in a vacuum oven, and the acetone is evaporated at a temperature of 60°C, so that the polymer gel electrolyte solution is converted into a gel electrolyte and attached to the two carbon fiber electrode specific structures; Then, the electrolyte solution was dripped into the cavity of a carbon fiber electrode until the liquid level reached 3 / 4 of the cavity height. After the dripping was completed, the two carbon fiber electrodes were pressed together so that the specific structures were connected to each other into a mortise and tenon structure, and the electrolyte was encapsulated in the cavity surrounded by the specific structure. Finally, the sample was placed in a vacuum drying oven at 60°C and dried for 48 hours to remove residual acetone.
[0016] (4) Structural supercapacitor packaging: The assembled structural supercapacitor is connected to the tabs and then manufactured using a vacuum assisted resin transfer molding (VARTM) process.
[0017] Preferably, the specific process of step (4) is as follows: the epoxy resin and the corresponding curing agent are mixed in a required ratio and degassed to obtain an epoxy resin solution for standby use; The assembled structural supercapacitor was connected to the tabs and transferred to a vacuum infusion device. A vacuum pump was used to evacuate the vacuum infusion device to a negative pressure of -0.06 MPa. The epoxy resin solution was then poured in, the pressure was maintained, and the device was placed in an oven at 30°C for curing for 72 hours to obtain a finished structural supercapacitor.
[0018] The advantages of the present invention are: (1) The structural supercapacitors prepared by using 3D printing technology to form related structures fill the gap in the current preparation methods for the precise and controllable preparation of structural supercapacitors with certain performance requirements.
[0019] (2) The structural supercapacitor prepared by the preparation method described in the present invention can have the advantages of the devices prepared by the existing preparation methods. It can achieve uniform dispersion distribution in the ion transmission channel (energy storage area) while making the transmission channel straight. In addition, compared with the traditional preparation method, the preparation method of the present invention does not require the addition of a diaphragm such as glass fiber between the two electrodes, making the ion transmission smoother and allowing the device to fully exert its mechanical and electrochemical properties.
[0020] (3) The materials used in the present invention are easy to obtain, have high preparation efficiency, and are suitable for large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 Flowchart for preparing 3D printed structured supercapacitors; Figure 2 This is a structural diagram of the carbon fiber electrode 1; Figure 3 is the structural diagram of carbon fiber electrode 2; Figure 4 Figure 1 is a diagram of the electrode pressing structure; Figure 5 a structured supercapacitor electrode having a circular cavity microarray structure; Figure 6 A structural supercapacitor electrode having a regular hexagonal cavity microarray structure; Figure 7 The results of three-point bending mechanical tests; Figure 8 This is the constant current charge and discharge test (GCD) curve. DETAILED DESCRIPTION
[0022] The technical solution of the present invention is further explained and illustrated in the following in the form of specific embodiments.
[0023] (1) 3D printing of carbon fiber electrodes: After cutting the carbon fiber cloth and setting it aside, the cut carbon fiber electrodes are placed in a micro-nano 3D printer, and high-strength resin is printed onto the carbon fiber electrodes according to the designed specific structure. The high-strength resin used for 3D printing is photosensitive resin, and the carbon fiber cloth is woven carbon fiber fabric.
[0024] The specific structure required here on the carbon fiber electrode is to form a tenon and mortise structure on the two electrodes respectively, and to prevent in-plane slip after the two electrodes are combined into a mortise and tenon structure. Figure 2 、 Figure 3 As shown, a structure of a group of carbon fiber electrodes and photosensitive resins after 3D printing is shown. Figure 2 In the electrode shown, a mortise and tenon structure as shown in 202 is formed. In addition, 201 in the figure is a carbon fiber cloth, and 203 is a structure formed after the photosensitive resin 3D printed on the carbon fiber cloth is cured. Figure 3 In the electrode shown, a tenon structure as shown in 302 is formed. The structure is formed by 3D printing and curing of photosensitive resin, and 301 is carbon fiber cloth.
[0025] The specific structural form and size formed by 3D printing are not limited to Figure 2 、 Figure 3 The type shown in the above description can be prepared by the preparation method of the present invention as long as the corresponding tenon and mortise structure can be formed and the tenon and mortise structure can be combined with each other to form a strong mortise and tenon structure after the two electrodes are pressed together. Figure 5 、 Figure 6Two other types of electrode structures are shown respectively. The types to which the preparation method of the present invention can be applied include but are not limited to the above three structures.
[0026] (2) Preparation of electrolyte: Polymer gel electrolyte was prepared by using polyethylene oxide (PEO), lithium bis(trifluoromethane)sulfonyl imide (LiTFSI), ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate (IL) and acetone for corresponding treatment.
[0027] The preparation process is as follows: PEO, lithium bis(trifluoromethane)sulfonyl imide (LiTFSI) and IL are dissolved in a small amount of acetone in a mass ratio of 50:18:75, and magnetically stirred at 50°C for 24 hours to obtain a viscous homogeneous solution (PLI) for later use.
[0028] (3) Preparation of structural supercapacitors: The prepared electrolyte is dripped into the cavity of a specific structure 3D printed on the two carbon fiber electrodes in a certain amount (filled to half of the electrode cavity), and then placed in a vacuum oven at a temperature of 60°C to evaporate the acetone for 1 hour to form a gel electrolyte. Then continue to add the electrolyte solution to one electrode until the liquid level reaches 3 / 4 of the cavity height. After the addition is completed, press the two electrodes together according to the designed structure of the other electrode to form a relatively strong mortise and tenon structure, and encapsulate the electrolyte in the cavity surrounded by the mortise and tenon structure. Finally, place the sample in a vacuum drying oven at 60°C and dry for 48 hours to remove residual acetone. The structure formed after pressing is as follows Figure 4 As shown, 401 is a carbon fiber cloth, 402 is a mortise and tenon structure formed by combining the tenon and mortise structure, so that there is no slip between the two electrodes after pressing, ensuring that the relative position between the two electrodes will not change in the subsequent preparation process, and 403 is a gel electrolyte, which has been fully infiltrated with the carbon fiber electrode after the above treatment and will not leak.
[0029] The two electrodes pressed together are manufactured using a vacuum-assisted resin transfer molding process (VARTM). The specific process is as follows: epoxy resin and the corresponding curing agent, here taking epoxy resin TJ-2000 and its curing agent TJ-2060 as an example, TJ-2000 and TJ-2060 are mixed in a mass ratio of 10:3, and stirred continuously at 400 rpm for 30 minutes using a mechanical stirrer at room temperature. Then, vacuum degassing is performed to obtain a uniform and clear epoxy resin solution. Then, the device to be molded is transferred to a vacuum infusion device (the tabs are exposed outside the vacuum device to avoid being encapsulated by the epoxy resin), and a vacuum pump is used to evacuate to a negative pressure of -0.06MPa. Then, the epoxy resin solution is poured in, the pressure is maintained, and it is placed in a 30°C oven for curing for 72 hours to obtain a finished structural supercapacitor.
[0030] According to the above-mentioned method for preparing the structural supercapacitor, a structural supercapacitor sample for testing was prepared. The area of the sample containing the electrolyte accounted for 30% of the total device area. The bottom surface of the structural supercapacitor was a rectangular parallelepiped with a side length of 5 cm and a thickness of 1.77 mm. The sample was made of Figure 2 and Figure 3 Each of the enclosed electrolyte cavities in the type has a bottom area of 0.3 cm 2 Square, 0.2mm high cuboid, on the device according to Figure 2 and Figure 3 The distribution shown in Figure 2 shows 25 such cavities evenly distributed. After fabrication, the samples were subjected to mechanical and electrochemical performance tests. The mechanical performance test was a three-point bending test, and the electrochemical performance test was a constant current charge and discharge (GCD) test.
[0031] The structural supercapacitor was subjected to three-point bending mechanical testing using a tensile testing machine. Following the ASTM D790 standard, we used an LVDT as the bending deformation probe (maximum range 10mm). The clamp span was 33mm and the descent rate was set to 1mm∙min. -1 . Figure 7 These are the results of a three-point bending test. Calculated bending modulus of the supercapacitor is 12.8 GPa, and bending strength is 126.0 MPa.
[0032] At 0.16 mA∙cm -2 Current density (5*5cm 2 As a benchmark), the output constant current charge and discharge test (GCD) curve is as follows: Figure 8 As shown, the corresponding device surface capacitance is 27.4 mF∙cm -2 .
Claims
1. A structural supercapacitor based on 3D printing, characterized in that: The structural supercapacitor is composed of two carbon fiber electrodes, each of which has a specific structure with a tenon and mortise microarray formed on its surface by 3D printing. This specific structure prevents in-plane slippage when the two carbon fiber electrodes are combined into a mortise and tenon structure, and forms a cavity between the two carbon fiber electrodes, into which a polymer gel electrolyte is poured.
2. The 3D printed structural supercapacitor according to claim 1, characterized in that: The cavity enclosed by the tenon and the mortise is a matrix structure of an equilateral triangle, square, circle or regular hexagon.
3. The 3D printed structural supercapacitor according to claim 1, characterized in that: The 3D printing-based structural supercapacitor is connected to the tabs and then encapsulated by epoxy resin.
4. The method for preparing a structural supercapacitor based on 3D printing according to claim 1, wherein: The specific steps of this method are as follows: (1) 3D printing of carbon fiber electrodes: The carbon fiber cloth is cut and set aside, and the cut carbon fibers are arranged in a micro-nano 3D printer. High-strength resin is printed onto the carbon fiber cloth according to a designed specific structure to obtain a carbon fiber electrode; the specific structure is a tenon and mortise structure formed on the carbon fiber electrode, so that after the two carbon fiber electrodes are combined into a mortise and tenon structure, in-plane slippage does not occur, and a cavity is formed between the two carbon fiber electrodes.
5. (2) Preparation of polymer gel electrolyte solution: Dissolve polyethylene oxide, lithium salt, and ionic liquid in acetone at a mass ratio of (40-60):(15-20):(70-80), and stir magnetically at 50°C for 24 hours to obtain a viscous homogeneous polymer gel electrolyte solution for later use; (3) Structural supercapacitor combination: The polymer gel electrolyte solution prepared in step (2) is dripped into the two carbon fiber electrode specific structures for forming the cavity, and is filled to 1 / 2; then, the two carbon fiber electrodes are placed in a vacuum oven, and the acetone is evaporated at a temperature of 60°C, so that the polymer gel electrolyte solution is converted into a gel electrolyte and attached to the two carbon fiber electrode specific structures; Then, the electrolyte solution was dripped into the cavity of a carbon fiber electrode until the liquid level reached 3 / 4 of the cavity height. After the dripping was completed, the two carbon fiber electrodes were pressed together so that the specific structures were connected to each other into a mortise and tenon structure, and the electrolyte was encapsulated in the cavity surrounded by the specific structure. Finally, the sample was placed in a vacuum drying oven at 60°C and dried for 48 hours to remove residual acetone.
6. The method for preparing a structural supercapacitor based on 3D printing according to claim 4, characterized in that: The high-strength resin in step (1) is a photosensitive resin, and the carbon fiber cloth is a woven carbon fiber fabric.
7. The method for preparing a structural supercapacitor based on 3D printing according to claim 4, characterized in that: In step (2), the lithium salt is bis(trifluoromethane)sulfonyl imide lithium salt, and the ionic liquid is 1-ethyl-3-methylimidazolium tetrafluoroborate.
8. The method for preparing a structural supercapacitor based on 3D printing according to claim 4, characterized in that: The method further comprises step (4) constructing a supercapacitor package: The assembled structural supercapacitor is connected to the tabs and then manufactured using a vacuum assisted resin transfer molding process.
9. The method for preparing a structural supercapacitor based on 3D printing according to claim 7, characterized in that: The specific process of step (4) is as follows: the epoxy resin and the corresponding curing agent are mixed in the required proportion and degassed to obtain an epoxy resin solution for standby use; The assembled structural supercapacitor was connected to the tabs and transferred to a vacuum infusion device. A vacuum pump was used to evacuate the vacuum infusion device to a negative pressure of -0.06 MPa. The epoxy resin solution was then poured in, the pressure was maintained, and the device was placed in an oven at 30°C for curing for 72 hours to obtain a finished structural supercapacitor.