3D printing carbon fiber electrode multistage spiral structure supercapacitor and preparation method thereof
The carbon fiber electrodes were prepared through 3D printing technology and the multi-stage helical braided structure was used to solve the problems of fiber orientation control difficulties and insufficient performance in the prior art, and the specific capacitance improvement and performance enhancement were achieved, providing a high-performance supercapacitor solution for wearable electronic products.
Patent Information
- Application Number
- CN202411785033.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-06
- Publication Date
- 2025-04-29
AI Technical Summary
Existing 3D printed supercapacitors cannot accurately control fiber orientation in multi-material structures, resulting in insufficient mechanical and electrochemical properties, and lack of research on the performance of multi-stage helical structure electrodes.
Carbon fiber electrodes were prepared by 3D printing technology, electrode slurry was prepared by activated carbon, carbon black and polyvinylidene fluoride, uniformly coated on carbon fiber yarn, forming a multi-stage spiral braided electrode, and gel electrolyte was prepared using 1-ethyl-3-methylimidazole chloride, chitosan and hydroxyethyl methacrylate, and in-situ packaged through a coaxial nozzle system.
It is achieved that the specific capacitance of the multi-stage helical structure supercapacitor is 40% higher under the same active material load, which significantly improves the electrochemical performance and enhances the tensile strength and long-term cycle stability.
Smart Images
Figure CN119905357A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of supercapacitors, and in particular relates to a 3D printed carbon fiber electrode multi-level spiral structure supercapacitor and a preparation method thereof. Background Art
[0002] At present, most of the 3D printed supercapacitors use non-direct writing printing methods, and the continuous fiber 3D printing technology methods used for energy storage devices have the limitation of being unable to accurately control the fiber orientation in multi-material structures. There is almost no way to 3D print energy storage devices in the shape of continuous fibers with minimal post-processing. The multi-level spiral structure characteristics studied in this invention are believed to cause a significant improvement in the mechanical properties of the resulting supercapacitors, and also improve their electrochemical properties to varying degrees. However, there is almost no research on the electrochemical and mechanical properties of multi-level spiral structure electrodes in other 3D printed supercapacitors. Summary of the invention
[0003] In order to solve the above problems, the present invention provides a 3D printed carbon fiber electrode multi-level spiral structure supercapacitor and a preparation method thereof.
[0004] The preparation method of a 3D printed carbon fiber electrode multi-level spiral structure supercapacitor comprises the following steps:
[0005] Step 1, preparing electrode slurry using activated carbon, carbon black and polyvinylidene fluoride;
[0006] Step 2, evenly coating the electrode slurry on the carbon fiber yarn to obtain a carbon fiber electrode;
[0007] Step 3, preparing a gel electrolyte using 1-ethyl-3-methylimidazole chloride, chitosan and hydroxyethyl methacrylate, and coating the gel electrolyte on the surface of a carbon fiber flexible substrate to obtain a composite substrate;
[0008] Step 4, intertwining and weaving two carbon fibers to obtain a unit braided electrode, and intertwining and weaving multiple groups of unit braided electrodes again to obtain an overall multi-level spiral braided electrode;
[0009] Step 5: Place the multi-stage spiral braided electrode and silicone resin in a multi-axis extrusion system. The multi-axis extrusion system uses a coaxial nozzle to synchronously mix and extrude the multi-stage spiral braided electrode and silicone resin onto the surface of the composite substrate to obtain a 3D printed carbon fiber electrode multi-stage spiral structure supercapacitor.
[0010] Furthermore, in step 1, the method for preparing the electrode slurry is specifically as follows: the ground activated carbon, carbon black and vacuum-dried polyvinylidene fluoride are mixed in a mass ratio of (70-80):20:5 in 3000 μL 1-methyl-2-pyrrolidone, and stirred evenly for more than 2 hours to prepare the electrode slurry.
[0011] Furthermore, in step 3, the specific method for preparing the gel electrolyte using 1-ethyl-3-methylimidazolium chloride, chitosan and hydroxyethyl methacrylate comprises the following steps:
[0012] Step 3.1, preparing a chitosan / 1-ethyl-3-methylimidazolium chloride solution by mixing chitosan and 1-ethyl-3-methylimidazolium chloride at a weight ratio of 3:80 at 80° C. for 4 hours, then mixing the solution with hydroxyethyl methacrylate at a mass ratio of 83:17, and then subjecting the mixture to UV photopolymerization for 45 minutes to obtain a gel;
[0013] Step 3.2: Add 20-30% by mass of deionized water into the gel of step 1 and keep it for 1 hour.
[0014] The 3D printed carbon fiber electrode multi-level spiral structure supercapacitor is prepared by the above method.
[0015] The present invention has the following beneficial technical effects:
[0016] The present invention helps to create a woven flexible solid-state supercapacitor in one step. The method prepares a woven electrode by using continuous carbon fiber as a flexible substrate and a carbon-based active material as an active material. The entire electrode assembly is coated with 1-ethyl-3-methylimidazole chloride / chitosan / hydroxyethyl methacrylate electrolyte, and then the woven electrode and silica gel are extruded through a coaxial nozzle by direct writing technology, thereby achieving in-situ encapsulation of the woven electrode. The woven electrode of the present invention adopts a multi-level spiral structure, so that under the same active material loading, the multi-level spiral structure has a specific capacitance that is 40% higher than that of the ordinary structure, which illustrates the significant enhancement of the electrochemical performance of the supercapacitor by the multi-level spiral structure of the present invention. The present invention can produce a free-form flexible solid-state supercapacitor with enhanced tensile strength, excellent long-term cycle stability and low diffusion resistance, and consistent performance in various bending states, paving the way for the next generation of wearable electronic products. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 It is a schematic diagram of the method of the present invention;
[0018] Figure 2 cyclic voltammetry diagram of a unit supercapacitor obtained by the present invention;
[0019] Figure 3 This is an AC impedance diagram of a unit supercapacitor obtained by the present invention;
[0020] Figure 4 This is a constant current charge and discharge diagram of a unit supercapacitor obtained by the present invention;
[0021] Figure 5 The constant current charge and discharge diagram of the unit supercapacitor with different winding densities obtained by the present invention;
[0022] Figure 6 cyclic voltammetry diagram of the overall supercapacitor obtained by the present invention;
[0023] Figure 7 This is an AC impedance diagram of the overall supercapacitor obtained by the present invention;
[0024] Figure 8 This is a constant current charge and discharge diagram of the overall supercapacitor obtained by the present invention;
[0025] Fig. 9 The constant current charge and discharge diagram of the overall supercapacitor obtained by the present invention with different winding densities;
[0026] Fig.10 This is a tensile stress curve diagram of a unit supercapacitor obtained by the present invention;
[0027] Fig.11 is a tensile stress curve diagram of the overall supercapacitor obtained by the present invention;
[0028] Fig.12 The tensile stress curves of the overall and unit supercapacitors obtained by the present invention are as follows;
[0029] Fig.13 The fracture strain curves of the overall and unit supercapacitors obtained by the present invention are shown;
[0030] Fig.14 The toughness curve diagram of the overall and unit supercapacitor obtained by the present invention;
[0031] Fig.15 The constant current charge-discharge comparison curves of the overall and unit supercapacitors obtained by the present invention under the condition of the same active material loading amount;
[0032] The components represented by the reference numerals in the accompanying drawings are as follows:
[0033] 1. Silicone resin; 2. Multi-level spiral braided electrodes; 3. Temperature control board DETAILED DESCRIPTION
[0034] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.
[0035] like Figure 1As shown, activated carbon, carbon black and polyvinylidene fluoride (PVDF) dried in vacuum at 70°C were first mixed in a ratio of 80:10:10 in 3000 μL of 1-methyl-2-pyrrolidone (NMP), totaling 800 mg, and stirred at 700 rpm for 2 hours with a magnetic stirrer to prepare an electrode slurry. The electrode slurry was evenly coated on 1k carbon fiber yarn by an electrode coater and vacuum dried at 70°C for 12 hours to obtain electrode carbon fiber.
[0036] Mix 3g 1-ethyl-3-methylimidazole chloride with 0.1125g chitosan. Stir the solution at 200 rpm for 4h at 80°C with a magnetic stirrer to dissolve the mixed solution. Add 0.6375g hydroxyethyl methacrylate to the mixed heated solution and continue stirring for 25min. At the same time, evenly coat the mixed solution on the surface of the electrode carbon fiber. Put the electrode carbon fiber coated with the mixed solution into a UV lamp (365nm 22.4mw / cm 2 ) for 45 minutes, and then the treated electrode was immersed in 20% by mass deionized water for 1 hour.
[0037] The prepared electrode carbon fiber is pre-woven into a spiral structure and further woven into a multi-stage spiral braided electrode to obtain a coaxial nozzle system mounted on a three-axis barrel platform, a multi-stage spiral braided electrode is placed in one of the three-axis barrels, and silicone (silicone) is placed in the other two barrels. Complex 3D structures can be constructed by continuously depositing supercapacitor materials in a wire-by-wire manner. The movement speed of the coaxial nozzle is adjusted to 7.5 mm / s, and the deposition pressure is set to 20 psi. During the printing process, the braided electrode is extruded through the internal outlet of the coaxial nozzle. At the same time, the silicone package stored in the temperature-controlled reservoir is pushed to the external outlet of the nozzle under air pressure to evenly wrap the multi-stage spiral braided electrode. When continuously subjected to air pressure, the braided electrode and silicone seal can be stably deposited on a heated substrate, which is set to 150°C to promote in-situ curing of the extruded supercapacitor. The braided electrode can be encapsulated by the silicone seal within a few seconds to form a sealed supercapacitor.
[0038] Figure 2 and Figure 6 The current-voltage curves of the unit and overall supercapacitors at different scan rates show that all curves are approximately rectangular in shape, revealing the ideal capacitive charge storage behavior. In addition, when the scan rate increases, the rectangular shape is well preserved, indicating that the device has high rate performance.
[0039] Figure 3 and Figure 7The constant current charge-discharge curves of the unit and overall supercapacitors at different current densities show that the voltage drop is relatively small, which is due to the good interface contact between the electrolyte and the electrode. In addition, the constant current charge-discharge curves of all current densities are standard isosceles triangles, which further confirms the excellent electrochemical performance of this supercapacitor.
[0040] Figure 4 and Figure 8 The AC impedance diagram of the unit and overall supercapacitors shows that the supercapacitor shows a lower interfacial impedance value because the photocuring cross-linking of the electrode and the electrolyte improves the interfacial contact.
[0041] Figure 5 and Fig. 9 The constant current charge and discharge diagram of the winding density of the unit and overall supercapacitors is shown. The unit supercapacitor compares the constant current charge and discharge curves of four winding densities (0 turns per meter, 100 turns per meter, 150 turns per meter, and 200 turns per meter). Since the initial increase in winding density will cause the different electrodes to contact more closely, the charge and discharge curve will increase with the increase in winding density. After exceeding the peak value of 150 turns per meter, the winding density is too large, which will cause the electrodes to overstretch and contact, and the electrochemical performance of the capacitor will be reduced. The overall supercapacitor compares the constant current charge and discharge curves of three winding densities (0 turns per meter, 100 turns per meter, and 150 turns per meter), which also shows a similar electrochemical performance trend to the unit supercapacitor, but its peak is at 100 turns per meter.
[0042] Fig.10 and Fig.11 The tensile stress curves of the unit and overall supercapacitors show that the optimal values of the unit supercapacitor and the overall supercapacitor are 2-150 turns per meter and 4-100 turns per meter.
[0043] Fig.12 , Fig.13 and Fig.14 The tensile stress curve, fracture strain curve and toughness curve of the overall and unit supercapacitors are shown in Figure 1. The multi-stage spiral structure of the present invention shows that the tensile strength is increased while the elongation and toughness are also increased, while other structures increase the tensile strength while the elongation and toughness are decreased. This shows the advantages of the multi-stage spiral structure of the present invention.
[0044] Fig.15 The constant current charge and discharge comparison curves of the overall and unit supercapacitors obtained by the present invention under the same active material loading amount are as follows. Due to the multi-level spiral structure of the present invention, under the same active material loading amount, the specific capacitance of the multi-level spiral structure is 40% higher than that of the ordinary structure, indicating that the multi-level spiral structure of the present invention significantly enhances the electrochemical performance of the supercapacitor.
[0045] The above is an example of the best implementation of the present invention, and the parts not described in detail are common knowledge of ordinary technicians in the field. The protection scope of the present invention shall be based on the content of the claims, and any equivalent transformation based on the technical enlightenment of the present invention is also within the protection scope of the present invention.
Claims
1. A method for preparing a 3D printed carbon fiber electrode multi-level spiral structure supercapacitor, characterized in that: The following steps are involved: Step 1, preparing electrode slurry using activated carbon, carbon black and polyvinylidene fluoride; Step 2, evenly coating the electrode slurry on the carbon fiber yarn to obtain a carbon fiber electrode; Step 3, preparing a gel electrolyte using 1-ethyl-3-methylimidazole chloride, chitosan and hydroxyethyl methacrylate, and coating the gel electrolyte on the surface of a carbon fiber flexible substrate to obtain a composite substrate; Step 4, intertwining and weaving two carbon fibers to obtain a unit braided electrode, and intertwining and weaving multiple groups of unit braided electrodes again to obtain an overall multi-level spiral braided electrode; Step 5: Place the multi-stage spiral braided electrode and silicone resin in a multi-axis extrusion system. The multi-axis extrusion system uses a coaxial nozzle to synchronously mix and extrude the multi-stage spiral braided electrode and silicone resin onto the surface of the composite substrate to obtain a 3D printed carbon fiber electrode multi-stage spiral structure supercapacitor.
2. The method for preparing a 3D printed carbon fiber electrode multi-level spiral structure supercapacitor according to claim 1, characterized in that: In step 1, the method for preparing the electrode slurry is specifically as follows: the ground activated carbon, carbon black and vacuum-dried polyvinylidene fluoride are mixed in 3000 μL 1-methyl-2-pyrrolidone in a mass ratio of (70-80):20:5, and the electrode slurry is prepared by uniformly stirring for more than 2 hours.
3. The method for preparing a 3D printed carbon fiber electrode multi-level spiral structure supercapacitor according to claim 1, characterized in that: In step 3, the specific method for preparing the gel electrolyte using 1-ethyl-3-methylimidazolium chloride, chitosan and hydroxyethyl methacrylate comprises the following steps: Step 3.1, preparing a chitosan / 1-ethyl-3-methylimidazolium chloride solution by mixing chitosan and 1-ethyl-3-methylimidazolium chloride at a weight ratio of 3:80 at 80° C. for 4 hours, then mixing the solution with hydroxyethyl methacrylate at a mass ratio of 83:17, and then subjecting the mixture to UV photopolymerization for 45 minutes to obtain a gel; Step 3.2: Add 20-30% by mass of deionized water into the gel of step 1 and keep it for 1 hour.
4. The method for preparing a 3D printed carbon fiber electrode multi-level spiral structure supercapacitor according to claim 1, characterized in that: In the step 3, the composite substrate is placed on a temperature control plate, and the temperature control plate is used to heat the composite substrate. 5.3D printed carbon fiber electrode multi-level spiral structure supercapacitor, characterized in that: Prepared by the method according to any one of claims 1 to 4.