Fibrous supercapacitor and preparation method and application thereof
By using a wet spinning process involving a mixture of sodium alginate and humic acid aqueous solution, followed by carbonization, a fibrous supercapacitor suitable for large-scale production was prepared. This solved the problems of high cost and complex processes in existing technologies, and enabled the preparation of a low-cost and environmentally friendly high-performance fibrous supercapacitor.
Patent Information
- Application Number
- CN202511966453.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-24
- Publication Date
- 2026-02-24
AI Technical Summary
The preparation of existing high-performance fibrous/wire supercapacitors relies on advanced nanomaterials such as carbon nanotubes, graphene, or conductive polymers. These materials are costly, have complex preparation processes, and impose a heavy environmental burden, which limits their large-scale production and practical application.
A fibrous supercapacitor was prepared by mixing sodium alginate and humic acid aqueous solution, followed by wet spinning and carbonization. This simplified the preparation process and utilized the excellent electrochemical activity of humic acid to perform in-situ functionalization modification of sodium alginate spun fibers.
A fibrous supercapacitor with excellent electrochemical performance was prepared, which is suitable for large-scale industrial production, low in cost and environmentally friendly.
Smart Images
Figure CN121565694A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of fibrous supercapacitors, and specifically relates to fibrous supercapacitors, their preparation methods, and applications. Background Technology
[0002] With the rapid development of wearable electronic devices, smart textiles, and implantable medical devices, the development of flexible, lightweight, and efficient energy storage units has become a cutting-edge and crucial research area. Among numerous energy storage devices, supercapacitors are highly favored due to their unique advantages such as high power density, rapid charge and discharge capabilities, and long cycle life. However, traditional bulk and planar supercapacitors are difficult to integrate efficiently and conveniently with wearable systems. Against this backdrop, fibrous / wire-like supercapacitors have emerged with their unique one-dimensional morphological structure. This structure not only provides versatile configurations (such as winding and weaving) for device design, facilitating integration with textile matrices, but also offers a promising solution for achieving lightweight and integrated energy supply because its electrode materials can directly serve as carriers for charge storage and transfer.
[0003] Currently, the fabrication of high-performance fibrous / wire supercapacitors largely relies on advanced nanomaterials such as carbon nanotubes, graphene, or conductive polymers. While these materials exhibit excellent electrochemical performance, their high cost, complex fabrication processes, and potential environmental burden significantly limit their large-scale production and practical applications. Therefore, exploring widely available, low-cost, and environmentally friendly alternative materials is crucial. Summary of the Invention
[0004] The purpose of this invention is to at least partially solve the above-mentioned technical problems and provide a fibrous supercapacitor, its preparation method and application.
[0005] In a first aspect, the present invention provides a method for preparing a fibrous supercapacitor, the method comprising the following steps:
[0006] S1. Mix sodium alginate aqueous solution and humic acid aqueous solution to obtain spinning solution;
[0007] S2. The spinning solution is subjected to wet spinning to obtain fibers;
[0008] S3. The fiber is washed, dried, and then carbonized to obtain a fibrous supercapacitor.
[0009] Furthermore, the preparation method of the sodium alginate aqueous solution is as follows: dissolve sodium alginate in water, adjust the pH value to 8-9, and stir at 40-60℃ to dissolve it, thereby obtaining a sodium alginate aqueous solution.
[0010] Furthermore, the preparation method of humic acid aqueous solution is as follows: dissolve humic acid in water, adjust the pH value to 10-12, stir to dissolve, and obtain humic acid aqueous solution.
[0011] Furthermore, in the spinning solution, the mass ratio of sodium alginate to humic acid is 3:(1.5-6).
[0012] Furthermore, the concentration of the sodium alginate aqueous solution is 0.03-0.05 g / mL.
[0013] Furthermore, the concentration of the humic acid aqueous solution is 0.03-0.15 g / mL.
[0014] Furthermore, in step S2, the conditions for wet spinning are: an extrusion speed of 800-1000 μl / min and a coagulation bath of CaCl2 aqueous solution.
[0015] Furthermore, in step S3, the carbonization specifically involves performing gradient temperature carbonization under N2 conditions.
[0016] Secondly, the present invention provides a fibrous supercapacitor prepared by the above-described preparation method.
[0017] Thirdly, the present invention provides an application of the above-mentioned fibrous supercapacitor in a fibrous material, wherein the fibrous material is one of wearable electronic devices, smart textiles, and implantable medical devices.
[0018] Compared with existing technologies, this invention mixes sodium alginate aqueous solution and humic acid aqueous solution, performs wet spinning, and uses humic acid with excellent electrochemical activity to perform "in-situ functionalization modification" on sodium alginate spun fibers. Then, it performs subsequent carbonization treatment and finally assembles them into fibrous supercapacitors with excellent electrochemical performance. This method does not require complicated modification or doping steps, is simple to prepare, and is suitable for large-scale industrial production. Attached Figure Description
[0019] These and / or other aspects and advantages of the present invention will become apparent and readily understood from the following description of preferred embodiments taken in conjunction with the accompanying drawings, in which:
[0020] Figure 1 Electron micrographs of the carbonized fibers prepared in Examples 1-4 and Comparative Example 1;
[0021] Figure 2 This is a CV comparison chart of samples from Examples 1-4 and Comparative Example 1;
[0022] Figure 3 The specific capacitance curves are for samples from Examples 1-4 and Comparative Example 1. Detailed Implementation
[0023] The technical solution of the present invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings. In this specification, the same or similar reference numerals indicate the same or similar components. The following description of the embodiments of the present invention with reference to the accompanying drawings is intended to explain the overall inventive concept of the present invention and should not be construed as a limitation thereof.
[0024] The materials used in this invention are as follows:
[0025] Acetic acid (Xilong Scientific Co., Ltd.), humic acid (Shanghai Maclean Biochemical Technology Co., Ltd.), sodium alginate (Aladdin Reagent Co., Ltd.), calcium chloride (Shanghai Maclean Biochemical Technology Co., Ltd.), sodium hydroxide (Shanghai Maclean Biochemical Technology Co., Ltd.), ethanol (Shanghai Maclean Biochemical Technology Co., Ltd.).
[0026] An embodiment of the first aspect of the present invention provides a method for preparing a fibrous supercapacitor, the method comprising the following steps:
[0027] S1. Mix sodium alginate aqueous solution and humic acid aqueous solution to obtain spinning solution;
[0028] S2. The spinning solution is subjected to wet spinning to obtain fibers;
[0029] S3. The fiber is washed, dried, and then carbonized to obtain a fibrous supercapacitor.
[0030] In some embodiments of the present invention, the sodium alginate aqueous solution is prepared by dissolving sodium alginate in water, adjusting the pH value to 8-9, and stirring to dissolve it, thereby obtaining a sodium alginate aqueous solution. Adjusting the pH value to 8-9 ensures that the sodium alginate dissolves completely in the water without any particles. Preferably, maintaining the temperature at 40-60°C during stirring can accelerate dissolution.
[0031] In some embodiments of the present invention, the preparation method of the humic acid aqueous solution is as follows: humic acid is dissolved in water, the pH value is adjusted to 10-12, and the solution is stirred to obtain a humic acid aqueous solution. Adjusting the pH value to 10-12 ensures that the humic acid is fully dissolved in the water without any particles. Preferably, the temperature is maintained at 40-60°C during stirring to accelerate dissolution. In some embodiments of the present invention, the mass ratio of sodium alginate to humic acid in the spinning solution is 3:(1.5-6). If the humic acid content is too high, wet spinning to form fibers is impossible. The concentration of the sodium alginate aqueous solution is preferably 0.03-0.05 g / mL. The concentration of the humic acid aqueous solution is preferably 0.03-0.15 g / mL.
[0032] In some embodiments of the present invention, the wet spinning conditions are as follows: an extrusion speed of 800-1000 μl / min. The coagulation bath is preferably an aqueous solution of CaCl2.
[0033] In some embodiments of the present invention, in step S3, the carbonization specifically involves performing gradient temperature carbonization under N2 conditions.
[0034] A second aspect of the present invention provides a fibrous supercapacitor prepared by the above-described preparation method.
[0035] A third aspect of the present invention provides an application of the above-described fibrous supercapacitor in a fibrous material, wherein the fibrous material is one of wearable electronic devices, smart textiles, and implantable medical devices.
[0036] Example 1
[0037] Step 1: Dissolve 3g of sodium alginate in 100mL of water, adjust the pH to 8 with sodium hydroxide solution, and react for 40min at 50℃ and 800r / min with stirring to ensure complete dissolution and prepare an aqueous solution of sodium alginate.
[0038] Step 2: Dissolve 1.5g of humic acid in 40mL of water, adjust the pH to 10 with sodium hydroxide to dissolve it, and after it is completely dissolved, mix it with the dissolved sodium alginate aqueous solution at 50℃ for 10min to prepare the spinning solution.
[0039] Step 3: Load the above spinning solution into a syringe, squeeze it into the coagulation bath (2% CaCl2 solution) for wet spinning, and collect the fibers. The extrusion speed during spinning is 1000 μl / min.
[0040] Step 4: Ultrasonically wash the fibers three times (20 min) with 2% acetic acid; ultrasonically wash three times (20 min) with pure water; ultrasonically wash three times (20 min) with ethanol solution.
[0041] Step 5: The washed fibers were placed in a tube furnace for carbonization. The carbonization conditions were: 300℃ for 1 h, 600℃ for 1 h, and 800℃ for 2 h under N2 conditions. Finally, a fibrous supercapacitor (0.175 mm in diameter) was successfully prepared.
[0042] Example 2
[0043] Step 1: Dissolve 3g of sodium alginate in 100mL of water, adjust the pH to 8 with sodium hydroxide solution, and react for 40min at 50℃ and 800r / min with stirring to ensure complete dissolution and prepare an aqueous solution of sodium alginate.
[0044] Step 2: Dissolve 3g of humic acid in 40 mL of water, adjust the pH to 10 with sodium hydroxide to dissolve it, and after it is completely dissolved, mix it with the dissolved sodium alginate aqueous solution at 50℃ for 10 min to prepare the spinning solution.
[0045] Step 3: Load the above spinning solution into a syringe, squeeze it into the coagulation bath (2% CaCl2 solution) for wet spinning, and collect the fibers. The extrusion speed during spinning is 1000 μl / min.
[0046] Step 4: Ultrasonic wash 3 times (20 min) with 2% acetic acid; ultrasonic wash 3 times (20 min) with purified water; ultrasonic wash 3 times (20 min) with ethanol solution.
[0047] Step 5: The washed fibers were placed in a tube furnace for carbonization. The carbonization conditions were: 300℃ for 1 h, 600℃ for 1 h, and 800℃ for 2 h under N2 conditions. Finally, a fibrous supercapacitor (0.193 mm in diameter) was successfully prepared.
[0048] Example 3
[0049] Step 1: Dissolve 3g of sodium alginate in 100mL of water, adjust the pH to 8 with sodium hydroxide solution, and react for 40min at 50℃ and 800r / min with stirring to ensure complete dissolution and prepare an aqueous solution of sodium alginate.
[0050] Step 2: Dissolve 4.5g of humic acid in 40mL of water, adjust the pH to 10 with sodium hydroxide to dissolve it, and after it is completely dissolved, mix it with the dissolved sodium alginate aqueous solution at 50℃ for 10min to prepare the spinning solution.
[0051] Step 3: Load the above spinning solution into a syringe, squeeze it into the coagulation bath (2% CaCl2 solution) for wet spinning, and collect the fibers. The extrusion speed during spinning is 1000 μl / min.
[0052] Step 4: Ultrasonic wash 3 times (20 min) with 2% acetic acid; ultrasonic wash 3 times (20 min) with purified water; ultrasonic wash 3 times (20 min) with ethanol solution.
[0053] Step 5: The washed fibers were placed in a tube furnace for carbonization. The carbonization conditions were: 300℃ for 1 h, 600℃ for 1 h, and 800℃ for 2 h under N2 conditions. Finally, a fibrous supercapacitor (0.240 mm in diameter) was successfully prepared.
[0054] Example 4
[0055] Step 1: Dissolve 3g of sodium alginate in 100mL of water, adjust the pH to 8 with sodium hydroxide solution, and react for 40min at 50℃ and 800r / min with stirring to ensure complete dissolution and prepare an aqueous solution of sodium alginate.
[0056] Step 2: Dissolve 6g of humic acid in 40mL of water, adjust the pH to 10 with sodium hydroxide to dissolve it, and after it is completely dissolved, mix it with the dissolved sodium alginate aqueous solution at 50℃ for 10min to prepare the spinning solution.
[0057] Step 3: Load the above spinning solution into a syringe, squeeze it into the coagulation bath (2% CaCl2 solution) for wet spinning, and collect the fibers. The extrusion speed during spinning is 1000 μl / min.
[0058] Step 4: Ultrasonic wash 3 times (20 min) with 2% acetic acid; ultrasonic wash 3 times (20 min) with purified water; ultrasonic wash 3 times (20 min) with ethanol solution.
[0059] Step 5: The washed fibers were placed in a tube furnace for carbonization. The carbonization conditions were: 300℃ for 1 h, 600℃ for 1 h, and 800℃ for 2 h under N2 conditions. Finally, a fibrous supercapacitor (0.255 mm in diameter) was successfully prepared.
[0060] Comparative Example 1
[0061] Step 1: Dissolve 3g of sodium alginate in 100mL of water, adjust the pH of the system to 8 with sodium hydroxide solution, and react for 40min at 50℃ and 800 r / min with stirring to ensure complete dissolution.
[0062] Step 2: Load the above spinning solution into a syringe and squeeze it into a coagulation bath (2% CaCl2 solution) for wet spinning, then collect the fibers. The extrusion speed during spinning is 1000 μl / min.
[0063] Step 3: Wash three times (20 min) with 2% acetic acid; wash three times (20 min) with pure water; wash three times (20 min) with ethanol solution.
[0064] Step 4: Place the washed fibers into a tube furnace for carbonization. The carbonization conditions are: 300℃ for 1 h, 600℃ for 1 h, and 800℃ for 2 h under N2 conditions to obtain carbonized fibers (0.156 mm in diameter).
[0065] Comparative Example 2
[0066] Step 1: Dissolve 3g of sodium alginate in 100mL of water, adjust the pH to 8 with sodium hydroxide solution, and react for 40min at 50℃ and 800r / min with stirring to ensure complete dissolution and prepare an aqueous solution of sodium alginate.
[0067] Step 2: Dissolve 6g of humic acid in 40mL of water, adjust the pH to 10 with sodium hydroxide to dissolve it, and after it is completely dissolved, mix it with the dissolved sodium alginate aqueous solution at 50℃ for 10min to prepare the spinning solution.
[0068] Step 3: Load the above spinning solution into a syringe and squeeze it into a coagulation bath (acetic acid) for wet spinning. The extrusion speed during spinning is 1000 μl / min, which does not form fibers.
[0069] Comparative Example 3
[0070] Step 1: Dissolve 3g of sodium alginate in 100mL of water, adjust the pH to 8 with sodium hydroxide solution, and react for 40min at 50℃ and 800r / min with stirring to ensure complete dissolution and prepare an aqueous solution of sodium alginate.
[0071] Step 2: Dissolve 4.5g of humic acid in 40mL of water, adjust the pH to 10 with sodium hydroxide to dissolve it, and after it is completely dissolved, mix it with the dissolved sodium alginate aqueous solution at 50℃ for 10min to prepare the spinning solution.
[0072] Step 3: When the above spinning solution is loaded into a syringe and squeezed into the coagulation bath (ethanol) for wet spinning, the extrusion speed is 1000 μl / min, and no fibers can be formed.
[0073] Comparative Example 4
[0074] Step 1: Dissolve 3g of sodium alginate in 100mL of water, adjust the pH to 8 with sodium hydroxide solution, and react for 40min at 50℃ and 800r / min with stirring to ensure complete dissolution and prepare an aqueous solution of sodium alginate.
[0075] Step 2: Dissolve 7g of humic acid in 40mL of water, adjust the pH to 10 with sodium hydroxide to dissolve it, and after it is completely dissolved, mix it with the dissolved sodium alginate aqueous solution at 50℃ for 10min to prepare the spinning solution.
[0076] Step 3: When the above spinning solution is loaded into a syringe and squeezed into a coagulation bath (2% CaCl2 solution) for wet spinning, the extrusion speed is 1000 μl / min, and no fibers can be formed.
[0077] Figure 1Electron micrographs of the carbonized fibers prepared in Examples 1-4 and Comparative Example 1 are shown. In the examples, a and d are electron micrographs of the carbonized fibers in Examples 1-4, and e is an electron micrograph of the carbonized fibers in the sample prepared in Comparative Example 1. Figure 1 The cross-sectional images under a medium microscope clearly reveal the significant regulatory effect of humic acid content on the overall fiber microstructure. Sodium alginate fibers without added humic acid (Figure e) exhibit a marked smoothness and density. This is because sodium alginate is a linear polysaccharide that undergoes vigorous pyrolysis, shrinkage, and graphitization during carbonization. Its molecular structure is relatively regular, and its gas release and phase separation behavior during pyrolysis are relatively simple, making it difficult to form a dense porous structure. With the addition and increase in concentration of humic acid... Figure 1 (ad) The surface of the composite fiber becomes extremely rough, and its rigidity is significantly enhanced. Some pores can be seen in the SEM image. This is because humic acid itself is a complex macromolecule, rich in aromatic rings, carboxyl groups, phenolic hydroxyl groups, and other active groups. In the early stages of carbonization, these structures can form rigid, cross-linked aromatic clusters, which become the core of the carbon skeleton.
[0078] The electrochemical performance of the samples obtained in Examples 1-4 and Comparative Example 1 was tested, and their specific capacitance was calculated. Figure 2 and Figure 3 .
[0079] Figure 2 Electrochemical characterization was performed using a three-electrode structure in 1 M KOH electrolyte, and the effect of humic acid content on electrode capacitance performance was systematically studied. (5 mV s) -1 Cyclic voltammetry (CV) curves of samples with different humic acid contents were obtained at various scan rates. All curves exhibited an approximately rectangular profile, indicating that charge storage primarily originates from a typical electric double-layer capacitance (EDLC) mechanism. The CV curve closure area of the electrode in Example 3 was significantly larger than that of other components, demonstrating its optimal charge storage capacity at low scan rates.
[0080] Figure 3 It can be seen that the volumetric capacitance of Example 3 at low current density is approximately 250.27 F cm. -3 Compared to control 1 (82.90 F cm⁻¹) without the addition of humic acid, this figure is significantly higher. -3 This represents an improvement of approximately 201.27%. Example 3 exhibits excellent rate capability, maintaining superior performance across all current densities, even at 2.0 A cm⁻¹. -3 Even at high current densities, it still retains approximately 52.26% of its capacitance, demonstrating excellent rate performance.
Claims
1. A method for preparing a fibrous supercapacitor, characterized in that, The preparation method includes the following steps: S1. Mix sodium alginate aqueous solution and humic acid aqueous solution to obtain spinning solution; S2. The spinning solution is subjected to wet spinning to obtain fibers; S3. The fiber is washed, dried, and then carbonized to obtain a fibrous supercapacitor.
2. The preparation method according to claim 1, characterized in that, The sodium alginate aqueous solution is prepared by dissolving sodium alginate in water, adjusting the pH value to 8-9, and stirring at 40-60℃ to dissolve it, thereby obtaining a sodium alginate aqueous solution.
3. The preparation method according to claim 1, characterized in that, The preparation method of humic acid aqueous solution is as follows: dissolve humic acid in water, adjust the pH value to 10-12, stir to dissolve, and obtain humic acid aqueous solution.
4. The preparation method according to claim 1, characterized in that, In the spinning solution, the mass ratio of sodium alginate to humic acid is 3:(1.5-6).
5. The preparation method according to claim 4, characterized in that, The concentration of the sodium alginate aqueous solution is 0.03-0.05 g / mL.
6. The preparation method according to claim 4, characterized in that, The concentration of the humic acid aqueous solution is 0.03-0.15 g / mL.
7. The preparation method according to claim 1, characterized in that, In step S2, the conditions for wet spinning are: an extrusion speed of 800-1000 μl / min and a coagulation bath of CaCl2 aqueous solution.
8. The preparation method according to claim 1, characterized in that, In step S3, the carbonization specifically involves performing gradient temperature carbonization under N2 conditions.
9. The fibrous supercapacitor prepared by the preparation method according to any one of claims 1-8.
10. The application of the fibrous supercapacitor as described in claim 9 in a fibrous material, wherein the fibrous material is one of wearable electronic devices, smart textiles, and implantable medical devices.