A method for preparing an extruded 3D printed conductive hydrogel supercapacitor

Abstract

The application discloses a preparation method of an extrusion type 3D printing conductive hydrogel super capacitor, and belongs to the technical field of electrochemical energy storage. The super capacitor comprises a current collector, a grid electrode, a gel electrolyte and a packaging layer. The application adopts a core method of "doping before condensation" to prepare the conductive hydrogel printing ink, firmly locks the uniformly dispersed conductive filler in the network, forms a composite structure of "conductive filler-polymer network" penetrating each other, guarantees excellent printable performance and stable conductive performance of the ink, and realizes accurate forming of the super capacitor electrode. Meanwhile, the porous structure is beneficial to the transmission of electrolyte ions, and good electrochemical performance is obtained. The conductive hydrogel based super capacitor has high volume specific capacitance, rate performance, energy density and power density, has great potential in the field of flexible energy storage, and promotes the development of the super capacitor in the direction of customization, integration and flexibility.

Description

Technical Field

[0001] This invention belongs to the field of advanced manufacturing and energy storage device technology, specifically relating to a method for preparing a supercapacitor using extrusion 3D printing of conductive hydrogel. Background Technology

[0002] Conductive hydrogels are a new type of hydrogel material with excellent electrical conductivity, good stretchability, and printability. They are one of the ideal materials for fabricating conductive hydrogel electrodes and supercapacitor energy storage devices, and have been widely used in flexible sensors, wearable energy storage devices, and flexible electronics.

[0003] 3D printing enables integrated design and manufacturing, greatly simplifying the molding process, reducing manufacturing costs, and offering high production efficiency while facilitating personalized customization. Extrusion 3D printing, one of many 3D printing technologies, achieves extrusion molding by controlling the rheological properties of ink. Combined with computer-aided design and a 3D control platform, it enables continuous and precise printing of 3D structures, offering advantages such as low cost, high efficiency, and a wide range of printable materials. Extrusion 3D printing technology can achieve uniform deposition of conductive hydrogels and construct intricate and complex 3D macroscopic structures.

[0004] Currently, there are still many bottlenecks in the fabrication of high-performance conductive hydrogel electrodes and supercapacitors:

[0005] (1) Commonly used conductive hydrogels are prepared by simply blending conductive fillers with hydrogel matrix. After printing, the conductive network of the electrode is prone to agglomeration or breakage, resulting in low electron transport efficiency and difficulty in achieving both high specific capacitance and excellent rate performance.

[0006] (2) Insufficient matching between the rheological properties of the ink and the molding precision during the printing process can easily lead to problems such as loose interlayer bonding or structural collapse, affecting the continuity of the ion transport channels inside the electrode.

[0007] To address this, a method for preparing supercapacitors using extrusion 3D printing of conductive hydrogels is proposed. Summary of the Invention

[0008] The purpose of this section is to outline some aspects of the embodiments of the present invention and to briefly describe some preferred embodiments.

[0009] In view of the problems existing in the above and / or prior art, the present invention is proposed.

[0010] This invention first provides a method for preparing a supercapacitor using extrusion-based 3D printing of conductive hydrogel. The supercapacitor includes a substrate, a current collector, a grid electrode, a gel electrolyte, and an encapsulation layer. The current collector is made of any one of foamed silver, foamed copper, or foamed nickel. The positive electrode material of the grid electrode is sodium carboxymethyl cellulose / poly(3,4-ethylenedioxythiophene):polystyrene sulfonate / phytic acid conductive composite hydrogel. The negative electrode material of the grid electrode is polyvinylidene fluoride / carbon black / acetylene black. The gel electrolyte is polyvinyl alcohol / phytic acid / dilute sulfuric acid. The encapsulation layer is made of any one of polyimide or polydimethylsiloxane.

[0011] In one embodiment of the present invention, the positive electrode of the grid electrode is prepared by the following method: sodium carboxymethyl cellulose is dissolved in a solvent and dispersed evenly, then poly(3,4-ethylenedioxythiophene):polystyrene sulfonate is added, and after magnetic stirring, a uniformly mixed ink is obtained. Phytic acid is added, and the ink is gelled through its cross-linking effect. Then, it is printed onto a substrate by extrusion 3D printing. The solvent is deionized water.

[0012] In one embodiment of the present invention, the mass fraction ratio of sodium carboxymethyl cellulose, poly(3,4-ethylenedioxythiophene):polystyrene sulfonate, and phytic acid is 1:1:1 to 2:1:1, and the total concentration of the three is 160 to 210 mg / mL. -1 After adding sodium carboxymethyl cellulose, the ultrasonic time is 10-30 min; after adding PEDOT:PSS, the magnetic stirring time is 120-240 min; after adding phytic acid, the magnetic stirring time is 60-120 min.

[0013] In one embodiment of the present invention, the negative electrode of the grid electrode is prepared by the following method: carbon black / acetylene black is dissolved in a solvent and dispersed evenly, followed by the addition of polyvinylidene fluoride, and magnetic stirring to obtain a uniformly mixed printable ink, which is then printed onto a substrate by extrusion 3D printing. The solvent is N-methylpyrrolidone.

[0014] In one embodiment of the present invention, the mass fraction ratio of carbon black, acetylene black, and polyvinylidene fluoride is 3:1:3 to 5:1:5, and the total concentration of the three is 90 to 150 mg / mL. -1 After adding carbon black and acetylene black, the ultrasonic time is 60-90 min; after adding polyvinylidene fluoride, the magnetic stirring time is 120-240 min.

[0015] In one embodiment of the present invention, the gel electrolyte is prepared by the following method: polyvinyl alcohol is dissolved in a solvent, dispersed evenly, heated and stirred, and after cooling, phytic acid is added and dispersed evenly. Then, dilute sulfuric acid is added, and after magnetic stirring, a uniformly mixed ink is obtained. Then, it is gelled by freeze-thaw cycles 3 to 5 times, wherein the solvent is deionized water.

[0016] In one embodiment of the present invention, the gel electrolyte is polyvinyl alcohol / phytic acid / dilute sulfuric acid, wherein the mass fraction of polyvinyl alcohol is 5-15 wt%, the mass fraction of phytic acid is 0.5-1.5 wt%, and the concentration of dilute sulfuric acid is 0.5-2 mol / L. -1 .

[0017] This invention also provides a method for preparing a supercapacitor using extrusion 3D printing of conductive hydrogel, the specific preparation steps of which are as follows:

[0018] (1) Dissolve sodium carboxymethyl cellulose in deionized water and disperse it evenly. Then add poly(3,4-ethylenedioxythiophene): polystyrene sulfonate and phytic acid. After magnetic stirring, a uniformly mixed printable ink is obtained.

[0019] (2) Dissolve carbon black / acetylene black in N-methylpyrrolidone and disperse it evenly. Then add polyvinylidene fluoride and stir magnetically to obtain a uniformly mixed printable ink.

[0020] (3) Transfer the ink prepared in steps (1) to (2) into a suitable syringe, install it on the fixture of the injection pump, set the appropriate printing parameters and pattern shape through the computer, print it on the substrate by extrusion 3D printing, and remove it from the substrate to obtain the conductive hydrogel mesh electrode.

[0021] (4) Dissolve polyvinyl alcohol in deionized water, disperse evenly, heat and stir, and after cooling, add phytic acid and disperse evenly. Then add dilute sulfuric acid and stir magnetically to obtain a uniformly mixed ink. Then, gel it by freezing and thawing 3 to 5 times.

[0022] (5) Dissolve anhydrous manganese sulfate in deionized water and disperse it evenly to obtain a concentration of 1 mol / L. -1 A clear and transparent solution was used to immerse the grid electrode in anhydrous manganese sulfate solution. Manganese dioxide was deposited on the grid electrode using cyclic voltammetry through an electrochemical workstation to improve its electrochemical performance.

[0023] (6) The supercapacitor is assembled using a typical sandwich structure, consisting of current collector, electrode, electrolyte, electrode and current collector in sequence. The layers are stacked in the order of current collector / positive electrode / electrolyte / negative electrode / current collector, and appropriate pressure is applied. After encapsulation, an asymmetric supercapacitor based on conductive hydrogel is obtained.

[0024] In one embodiment of the present invention, the 3D printing air pressure in step (3) is 0.1~0.6MPa, and the printing speed is 1~10mm / s. -1 The syringe needle diameter is 0.06~0.52mm.

[0025] In one embodiment of the present invention, the substrate material in step (3) is any one of polyethylene terephthalate, polydimethylsiloxane, or glass slide; the current collector material is any one of silver foam, copper foam, or nickel foam.

[0026] In one embodiment of the present invention, the encapsulation layer material in step (6) is either polyimide or polydimethylsiloxane.

[0027] In one embodiment of the present invention, the dispersion method is preferably ultrasonic dispersion.

[0028] In one embodiment of the present invention, the preferred mass fraction ratio of sodium carboxymethyl cellulose, poly(3,4-ethylenedioxythiophene): polystyrene sulfonate and phytic acid is 1.5:1:1, the preferred mass fraction ratio of carbon black, acetylene black and polyvinylidene fluoride is 4.5:1:4.5, and the preferred mass fraction ratio of polyvinyl alcohol, phytic acid and dilute sulfuric acid is 10:1:10.

[0029] In one embodiment of the present invention, the concentration of the dilute sulfuric acid is preferably 1 mol / L. -1 .

[0030] In one embodiment of the present invention, the freeze-thaw cycle is preferably 5 times.

[0031] In one embodiment of the present invention, the preferred printing parameter settings are a printing speed of 10 mm / s, an air pressure of 0.4 MPa, and a syringe needle diameter of 0.34 mm.

[0032] In one embodiment of the present invention, the substrate material is preferably a glass slide, the current collector material is preferably nickel foam, and the encapsulation layer material is preferably polyimide.

[0033] Beneficial effects of this invention:

[0034] (1) The ink direct writing 3D printing technology used in this invention does not require template-assisted preparation, and the process is simple, low-cost, and highly efficient.

[0035] (2) The supercapacitor prepared by the present invention using ink direct writing 3D printing technology has the following advantages: the supercapacitor is prepared by the method of "doping first and then condensing". In the "doping first" step, the conductive filler needs to be evenly dispersed in the solvent during ink preparation. Since the ink has not yet gelled at this time, it is easy to achieve uniform dispersion and gel it before printing. This also avoids the problem of needle clogging during printing caused by maintaining the gel state for a long time during ink preparation, thus ensuring that the ink is easy to prepare and has excellent printability. In the "condensing later" step, the polymer network gathers and shrinks from the solution, fixing the evenly dispersed conductive filler in situ inside the three-dimensional network structure, thereby forming a composite structure in which the "conductive filler-polymer network" are interpenetrated. This ensures the long-term stability of the conductivity and obtains excellent electrochemical performance. It has high volumetric specific capacitance, rate performance, energy density, power density and stable capacitance retention rate, and has great application potential in the field of flexible energy storage. Attached Figure Description

[0036] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0037] Figure 1 This is a schematic diagram illustrating the 3D printing principle used in the embodiments of the present invention.

[0038] Figure 2 This is a schematic diagram of a supercapacitor in an embodiment of the present invention.

[0039] Figure 3 This is a diagram of the supercapacitor prepared in an embodiment of the present invention.

[0040] Figure 4 This is a constant current charge-discharge test diagram of the supercapacitor prepared in an embodiment of the present invention.

[0041] Figure 5 This is a capacitance retention rate test diagram of the supercapacitor prepared in the embodiment of the present invention.

[0042] Figure 6 This is a diagram showing the supercapacitor series connection and the device illumination in the embodiments of the present invention.

[0043] Figure 7 These are rheological curve test diagrams of the inks prepared in Example 1, Comparative Example 1, and Comparative Example 2 of the present invention. Detailed Implementation

[0044] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the examples in the specification.

[0045] This invention employs a core method of "pre-doping followed by coagulation" to prepare conductive hydrogel printing ink. "Pre-doping" involves uniformly dispersing conductive fillers in a hydrogel precursor solution. Through the synergistic effect of ultrasonic dispersion and mechanical stirring, combined with the introduction of a dispersant, the van der Waals forces between the conductive fillers are broken, preventing agglomeration and ensuring that the conductive fillers are uniformly doped into the precursor system in a dispersed or low-agglomeration state, laying the foundation for the subsequent formation of a continuous conductive network. "Post-coagulation" involves triggering a controlled coagulation and cross-linking reaction in the hydrogel precursor after doping by controlling the temperature or introducing a cross-linking agent. This causes the polymer chains to entangle and form a three-dimensional network structure, while simultaneously locking the uniformly dispersed conductive fillers firmly within the network, forming a composite structure of "conductive filler-polymer network" that permeates each other. The conductive hydrogel ink prepared using this method possesses both excellent rheological properties and stable conductivity, meeting the requirements of ink-based extrusion 3D printing and effectively solving problems such as uneven conductive networks, insufficient mechanical strength, and poor molding stability in existing technologies.

[0046] The present invention will now be described in further detail with reference to the accompanying drawings.

[0047] Reference Figures 1-2 A method for preparing a supercapacitor using extrusion 3D printing of conductive hydrogel includes the following steps:

[0048] (1) Dissolve sodium carboxymethyl cellulose in deionized water and disperse it evenly. Then add poly(3,4-ethylenedioxythiophene): polystyrene sulfonate and phytic acid. After magnetic stirring, a uniformly mixed printable ink is obtained.

[0049] (2) Dissolve carbon black / acetylene black in N-methylpyrrolidone and disperse it evenly. Then add polyvinylidene fluoride and stir magnetically to obtain a uniformly mixed printable ink.

[0050] (3) The inks prepared in steps (1) and (2) are printed onto the substrate using an extrusion 3D printing method. The ink prepared in step (1) is used to print the positive electrode, and the ink prepared in step (2) is used to print the negative electrode. The printing principle diagram is shown below. Figure 1As shown, the prepared solution is installed on the fixture of the syringe pump. The specifications of the syringe 2 are set on the computer control panel, and the printing speed value is set. The appropriate air pressure is set by the air pump 1 to make the printing material flow out stably from the metal nozzle 3. By adjusting the distance between the metal nozzle 3 and the receiving substrate, the ideal printing effect can be achieved. The computer controls the automatic increase of a specific printing height after each layer is printed. After printing is completed, the conductive hydrogel mesh electrode is removed from the substrate.

[0051] (4) Dissolve polyvinyl alcohol in deionized water, disperse evenly, heat and stir, and after cooling, add phytic acid and disperse evenly. Then add dilute sulfuric acid and stir magnetically to obtain a uniformly mixed ink. Then gel it through freeze-thaw cycle.

[0052] (5) Dissolve anhydrous manganese sulfate in deionized water and disperse it evenly to obtain a concentration of 1 mol / L. -1 A clear and transparent solution was used to immerse the grid electrode in anhydrous manganese sulfate solution. Manganese dioxide was deposited on the grid electrode using cyclic voltammetry through an electrochemical workstation to improve its electrochemical performance.

[0053] (6) The supercapacitor is assembled using a typical sandwich structure, consisting of current collector, electrode, electrolyte, electrode and current collector in sequence. A schematic diagram of the supercapacitor is shown below. Figure 2 As shown, the current collector 7 is dried, and then the printed grid electrodes 4 and 6 are loaded onto the current collector 7. The electrolyte 5 is cut into thin layers slightly larger than the grid electrodes and stacked in the order of current collector / positive electrode / electrolyte / negative electrode / current collector. Appropriate pressure is applied to reduce the interfacial contact resistance. The current collector height is 0.5 mm, the electrode height is 2 mm, the electrode size is 2 cm × 2 cm, and the electrolyte height is 3 mm. Finally, the device is encapsulated with polyimide, resulting in an asymmetric supercapacitor based on conductive hydrogel. Figure 3 As shown.

[0054] Example 1

[0055] (1) Weigh 0.3g sodium carboxymethyl cellulose, dissolve it in 3mL deionized water, sonicate for 20min, then add 0.2mL poly(3,4-ethylenedioxythiophene):polystyrene sulfonate, stir magnetically for 20min, add 0.2mL phytic acid, stir magnetically for 20min to gel it, and record it as ink1;

[0056] (2) Weigh 0.18g of carbon black and 0.04g of acetylene black, dissolve them in 2mL of N-methylpyrrolidone, and sonicate for 80min; weigh 0.18g of polyvinylidene fluoride, dissolve it in 1mL of N-methylpyrrolidone, and stir magnetically at 70℃ until completely dissolved; after cooling, mix the two solutions and stir magnetically for 30min.

[0057] (3) Select a glass slide substrate, install the solutions prepared in steps (1) and (2) onto the fixture of the syringe pump, set the specifications of syringe 2 on the computer control panel, and then set the printing speed value. Set the appropriate air pressure through air pump 1 to make the printing material flow out stably from the metal nozzle 3. By adjusting the distance between the metal nozzle 3 and the receiving substrate, the ideal printing effect can be achieved. The computer controls the automatic increase of a specific printing height after each layer is printed. The printing principle diagram is as follows. Figure 1 As shown, the printing parameters are: printing speed of 10 mm / s, printing height of 0.2 mm, air pressure of 0.4 MPa, and syringe needle diameter of 0.34 mm; a conductive hydrogel mesh electrode is obtained by removing it from the substrate.

[0058] (4) Weigh 10g of polyvinyl alcohol and dissolve it in 90mL of deionized water. Stir magnetically at 90℃ for 3 hours to obtain a clear and transparent solution. After cooling to room temperature, add 1mL of phytic acid and continue stirring magnetically for 30 minutes to mix it evenly. Then add 10mL of 1mol L3 solution. -1 Dilute sulfuric acid was used to magnetically stir the mixture for 1 hour to obtain a uniformly mixed ink, which was then gelled by five freeze-thaw cycles.

[0059] (5) The supercapacitor is assembled using a typical sandwich structure, consisting of current collector, electrode, electrolyte, electrode and current collector in sequence. A schematic diagram of the supercapacitor is shown below. Figure 2 As shown, the current collector 7 is dried, and then the printed grid electrodes 4 and 6 are loaded onto the current collector 7 respectively. The electrolyte 5 is cut into a thin layer slightly larger than the grid electrode and stacked in the order of current collector / positive electrode / electrolyte / negative electrode / current collector. Appropriate pressure is applied to reduce the interfacial contact resistance. The height of the current collector is 0.5 mm, the height of the electrode is 2 mm, the size of the electrode is 2 cm × 2 cm, and the height of the electrolyte is 3 mm.

[0060] Finally, polyimide was used to encapsulate the device, resulting in an asymmetric supercapacitor based on conductive hydrogel, such as... Figure 3 As shown.

[0061] Example 2

[0062] (1) Weigh 151g of anhydrous manganese sulfate, dissolve it in 800mL of deionized water, and stir it with a glass rod in a water bath at 40℃ to obtain a clear and transparent solution.

[0063] (2) After cooling to room temperature, transfer the solution to a 1L volumetric flask, add deionized water to the flask up to 1cm below the graduation mark, and then use a dropper to add deionized water drop by drop until the solution level is level with the graduation mark. Tighten the stopper of the volumetric flask, shake it up and down 10 times to mix the solution completely, and obtain a concentration of 1mol / L. -1 Anhydrous manganese sulfate solution;

[0064] (3) Transfer the prepared solution to a dry reagent bottle, label it, and store it at room temperature in a sealed container away from light;

[0065] (4) Immerse the grid electrode printed in Example 1 into a solution with a concentration of 1 mol L. -1 The electrode is placed in an anhydrous manganese sulfate solution and connected to the working electrode clip (green) of the electrochemical workstation (the one used is the Shanghai Chenhua Chi660F electrochemical workstation), the counter electrode clip (red) is connected to the counter electrode, and the reference electrode clip (white) is connected to the reference electrode. The counter electrode is a platinum sheet electrode, and the reference electrode is a silver / silver chloride electrode.

[0066] (5) Deposition was performed using cyclic voltammetry on an electrochemical workstation. The deposition parameters were set as follows: minimum voltage 0V, maximum voltage 1V, scan rate 10mV / s, and scan number 2000 cycles.

[0067] After deposition, the cyclic voltammetry curve shape is closer to a rectangle, the electrochemical performance of the electrode is significantly improved, and the energy storage effect is better.

[0068] The electrochemical tests of the supercapacitor finally obtained according to the process of Example 1 are as follows: Figures 4-5 As shown. Specifically, electrochemical tests are performed in a three-electrode environment, where the counter electrode clamp is connected to a platinum sheet electrode, the reference electrode clamp is connected to a silver / silver chloride electrode, and the working electrode clamp is connected to the electrode to be tested. The counter electrode and the working electrode must be placed parallel and directly opposite each other. A 1 mol / L electrolyte is used. -1 dilute sulfuric acid; Figure 4 The charging and discharging curves are basically symmetrical, indicating that the fabricated device has good electrochemical reversibility and high charging efficiency during charging and discharging. Figure 5 This indicates that the fabricated device retains 95% of its capacitance after 5000 cycles, demonstrating its excellent cycle stability.

[0069] (6) Connecting two supercapacitors in series can illuminate the device, such as Figure 6 As shown.

[0070] Comparative Example 1

[0071] (1) Weigh 0.6g sodium carboxymethyl cellulose, dissolve it in 3mL deionized water, sonicate for 20min, then add 0.2mL poly(3,4-ethylenedioxythiophene):polystyrene sulfonate, stir magnetically for 20min, add 0.2mL phytic acid, stir magnetically for 20min to gel it, and record it as ink2;

[0072] Comparative Example 2

[0073] (1) Weigh 0.1g sodium carboxymethyl cellulose, dissolve it in 3mL deionized water, sonicate for 20min, then add 0.2mL poly(3,4-ethylenedioxythiophene):polystyrene sulfonate, stir magnetically for 20min, add 0.2mL phytic acid, stir magnetically for 20min to gel it, and record it as ink3;

[0074] like Figure 7 As shown, the ink (ink1) prepared in Example 1 has suitable rheological properties for printing, satisfying the shear thinning rheological characteristics required for printing; the ink (ink2) prepared in Comparative Example 1 has too high viscosity, making it impossible to obtain continuous lines during printing and easily causing clogging of the printing needle; the ink (ink3) prepared in Comparative Example 2 has too low viscosity, and after extrusion, the ink spreads on the substrate in a short time, failing to maintain the shape of the printed pattern.

[0075] Traditional physical blending methods require a large amount of conductive filler to reach the percolation threshold. However, the "pre-doping followed by coagulation" method achieves better dispersion through "pre-doping" and forms a tight conductive network through "post-coagulation," resulting in the use of less conductive filler to reach the percolation threshold. In traditional hydrogel electrodes, the conductive filler inside the electrode is prone to separation during stretching and bending, leading to the breakage of the internal conductive transmission network and a significant decrease in capacitance. However, the composite structure formed by "pre-doping followed by coagulation," where "conductive filler and polymer network" are interwoven, allows the polymer network to carry the conductive filler along with it during stretching and bending, making the conductive network less prone to breakage and overcoming the technical defects of traditional processes.

[0076] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the present invention.

Claims

1. A method for preparing a supercapacitor using extrusion 3D printing of conductive hydrogel, characterized in that: include, Sodium carboxymethyl cellulose was dissolved in deionized water and dispersed evenly. Poly(3,4-ethylenedioxythiophene):polystyrene sulfonate was added and dispersed evenly. Phytic acid was added and the mixture was magnetically stirred to obtain a uniformly mixed printable ink A. Carbon black / acetylene black was dissolved in N-methylpyrrolidone and dispersed evenly. Polyvinylidene fluoride was added and magnetically stirred to obtain a uniformly mixed printable ink B. Printable ink A and printable ink B are transferred into a syringe, printing parameters and pattern shape are set, and printed onto a substrate by extrusion 3D printing. The conductive hydrogel mesh electrode is removed from the substrate, and positive and negative electrode materials are obtained respectively. Polyvinyl alcohol is dissolved in deionized water and dispersed evenly. After heating and stirring, phytic acid is added and dispersed evenly. Dilute sulfuric acid is added and stirred to obtain a uniformly mixed ink. The ink is gelled by freezing and thawing 3 to 5 times to obtain an electrolyte. Anhydrous manganese sulfate was dissolved in deionized water and dispersed evenly to obtain a concentration of 1 mol / L. -1 A clear and transparent solution was used to immerse the conductive hydrogel grid electrode in anhydrous manganese sulfate solution to deposit manganese dioxide on the grid electrode. The current collector, positive electrode, electrolyte, negative electrode, and current collector are stacked in the order of current collector, positive electrode, electrolyte, negative electrode, and current collector, and then encapsulated to obtain an asymmetric supercapacitor based on conductive hydrogel.

2. The preparation method according to claim 1, characterized in that: The printable ink A contains sodium carboxymethyl cellulose, poly(3,4-ethylenedioxythiophene):polystyrene sulfonate, and phytic acid in a mass ratio of 1:1:1 to 2:1:1, with a total concentration of 160 to 210 mg / mL. -1 .

3. The preparation method according to claim 1 or 2, characterized in that: The printable ink B contains carbon black, acetylene black, and polyvinylidene fluoride in a mass ratio of 3:1:3 to 5:1:5, with a total concentration of 90 to 150 mg / mL. -1 .

4. The preparation method according to claim 3, characterized in that: The electrolyte comprises polyvinyl alcohol with a mass fraction of 5-15 wt%, phytic acid with a mass fraction of 0.5-15 wt%, and dilute sulfuric acid with a concentration of 0.5-2 mol / L. -1 .

5. The preparation method according to claim 1, characterized in that: The 3D printing air pressure is 0.1~0.6MPa, and the printing speed is 1~10mm / s. -1 The syringe needle diameter is 0.06~0.52mm.

6. The preparation method according to claim 1 or 5, characterized in that: The substrate material is any one of polyethylene terephthalate, polydimethylsiloxane, or glass slide.

7. The preparation method according to claim 6, characterized in that: The current collector material is any one of foamed silver, foamed copper, or foamed nickel.

8. The preparation method according to claim 7, characterized in that: The encapsulation layer material is either polyimide or polydimethylsiloxane.

9. The preparation method according to claim 1, characterized in that: The current collector has a thickness of 0.5 mm, the electrode has a thickness of 2 mm, and the electrolyte has a thickness of 3 mm.

10. A supercapacitor prepared by any one of the preparation methods described in claims 1 to 9.

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