CN101162650B - Flexible thin-film solid-state supercapacitor and manufacturing method thereof - Google Patents

Abstract

The invention discloses a flexible thin-film solid-state supercapacitor and a manufacturing method thereof, comprising positive and negative electrodes, external electrodes and a package film, and a flexible solid-state electrolyte diaphragm is arranged between the positive and negative electrodes. Its manufacturing method is as follows: use printing technology to sequentially apply the external electrode paste, electrode paste, flexible solid electrolyte paste, electrode paste, external electrode paste, packaging paste on the substrate, and cooperate with the corresponding pressing, drying Drying, cutting, and packaging processes, and finally form a flexible film-type solid supercapacitor with an electrode-diaphragm-electrode structure. The flexible film-type solid supercapacitor is suitable for large-scale production, has low internal resistance and good power characteristics, and is very suitable for applications in bendable electronic products such as electronic paper, smart business cards and plastic electronic products.

Description

Flexible thin-film solid-state supercapacitor and manufacturing method thereof

technical field

The invention relates to a capacitor, in particular to a flexible thin-film solid-state supercapacitor and a manufacturing method thereof.

Background technique

Capacitors are indispensable and important components in the electronics industry. Large-capacity capacitors from millifarads to farads can be used as energy storage devices for circuits, but traditional electrolytic capacitors must have a large volume to achieve millifarads to farads.

Supercapacitor is a new type of energy storage device that has emerged in recent years. Its capacity can reach Farad levels or even thousands of Farads, which is several orders of magnitude larger than that of traditional electrolytic capacitors. It has the advantages of high power density of conventional capacitors and high energy density of rechargeable batteries, can be quickly charged and discharged, and has a long service life.

Supercapacitors can be divided into two categories: electric double layer capacitors and electrochemical capacitors.

Activated carbon electric double layer capacitors use activated carbon as the main electrode material, and its working principle is shown in Figure 2. When a metal electrode is inserted into an electrolyte, the net charge on the electrode surface forms an electric double layer with the charged ions in the solution. Because there is a potential barrier on the interface, the two layers of charges cannot cross the boundary and neutralize each other, and a flat-plate capacitor will be formed according to the capacitor principle. Due to the huge surface area of activated carbon, and the thickness of the formed electric double layer is only a few angstroms, which is far smaller than the tens to hundreds of angstroms of the oxide film of general electrolytic capacitors. Therefore, the electric double layer capacitor can obtain the capacity of Farad level.

The working principle of electrochemical supercapacitor: Take the ruthenium oxide electrochemical capacitor as an example, the electrode is ruthenium oxide (RuO _x ), the electrolyte is sulfuric acid, when the metal oxide electrode is charged (discharged) in the electrolyte, hydrogen ions are adsorbed ( Desorption) enters (leaves) the interior of the oxide lattice, and a redox reaction occurs to form a so-called Faraday pseudocapacitor to work, so it is called an electrochemical capacitor. Electrochemical capacitors can achieve higher capacitance than electric double layer capacitors.

At present, electronic products are developing in the direction of short, small, light, and thin. In order to meet this requirement, electronic components are also developing towards chip, integration, and modularization. Although supercapacitors have the advantages of large capacity, high power, and long life, because current supercapacitors use liquid solutions as electrolytes, in order to prevent electrolyte leakage, the packaging of devices must meet high requirements, making it difficult to further reduce the size of supercapacitors. Therefore, the current supercapacitor product structure is only winding type (cylindrical) and button type (similar to a button battery). application.

Joo-Hwan Sunga et al. used gold as a template electrode to prepare a polypyrrole (PPy) electrode by electrochemical synthesis, and made a gel electrolyte with polyvinyl alcohol (PVA) and phosphoric acid (H ₃ PO ₄ ). The electrolyte sticks the polypyrrole electrode to form a flexible supercapacitor. This technology is simple and feasible, and the gold template electrode can be reused. However, the polypyrrole electrode needs to be synthesized by electrolysis, which has low production efficiency and is not suitable for industrial production. It also has high internal resistance and high power performance. Difference.

Contents of the invention

In order to solve the technical problems of high packaging requirements, large volume and low production efficiency of existing supercapacitors, the present invention provides a flexible film-type solid supercapacitor and a manufacturing method thereof.

The technical solution of the present invention to solve the above-mentioned technical problems is to include positive and negative electrodes, external electrodes and packaging film, and is characterized in that a flexible solid electrolyte diaphragm is arranged between the positive and negative electrodes.

In the above-mentioned flexible film-type solid supercapacitor, the positive and negative electrodes are composed of conductive polymers, activated carbon, carbon black, and metal oxides.

In the above-mentioned flexible thin-film solid-state supercapacitor, the flexible solid-state electrolyte diaphragm is a gel state electrolyte or a solid electrolyte.

In the above-mentioned flexible film-type solid supercapacitor, the gel state electrolyte is composed of electrolyte salt, polymer, plasticizer, and inorganic additives, and the solid electrolyte is composed of polyoxyethylene or polyoxypropylene and electrolyte salt.

In the above-mentioned flexible thin-film solid-state supercapacitor, the electrolyte salt is a quaternary ammonium salt, an ionic liquid or a lithium salt.

In the above flexible film-type solid supercapacitor, the quaternary ammonium salt is (C ₂ H ₅ ) ₁ NBF ₄ or CH ₃ (C ₂ H ₅ ) ₃ NBF ₁ , and the ionic liquid is [EMIm]BF ₄ , [BMIm] BF ₄ , [BMIm]PF ₆ , [EMIm]NTf ₂ or [BMPy]NTf ₂ , and the lithium salt is LiBF ₄ , LiPF6 or LiAsF6.

A method for manufacturing a flexible film-type solid-state supercapacitor, comprising the following steps:

Separately prepare external electrode paste, electrode paste, flexible solid electrolyte paste, packaging paste;

Printing the external electrode paste on the organic base film, drying the printed film after printing to obtain the positive external electrode film;

Printing the electrode paste on the dried outer electrode film, exposing one end of the outer electrode and covering the rest, drying the printed film after printing to obtain the positive electrode film;

Printing the electrolyte slurry on the dried positive electrode film so that the electrolyte film completely covers the positive electrode film and is slightly wider than each side of the positive electrode film, and drying the printed film after printing to obtain a solid electrolyte film;

Printing the electrode paste on the dried solid electrolyte membrane, the printing area is the same as that of the positive electrode film, and its position is just opposite to the positive electrode film, and drying the printed film after printing to obtain the negative electrode film;

Printing the external electrode paste on the dried negative electrode film, the printing area and position are the same as the positive external electrode film, and drying the printed film after printing to obtain the negative external electrode film;

Printing the encapsulation paste on the dried negative external electrode film, exposing the leading edge of the positive external electrode film and the negative external electrode film, and completely covering the rest, drying the printed film after printing to obtain the encapsulation film.

The external electrodes, positive and negative electrodes, electrolytes, and packaging manufactured by the technology of the present invention have good flexibility, so flexible devices can be manufactured on a flexible substrate; Thin-film devices are produced, and mass production is easy to achieve. To sum up, flexible thin-film supercapacitors with a thickness of 0.2-1.0 mm can be manufactured in batches by adopting the technology of the present invention.

The flexible film-type solid supercapacitor is suitable for large-scale production, has low internal resistance and good power characteristics, and is very suitable for the application of bendable electronic products (flexible electronic products), such as electronic paper, smart business cards and plastic electronic products.

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

Description of drawings

Fig. 1 is a structural diagram of the flexible thin-film solid-state supercapacitor of the present invention.

Figure 2 is a schematic diagram of the working principle of the activated carbon electric double layer supercapacitor.

Fig. 3 is a schematic diagram of the manufacturing process of the flexible film-type solid supercapacitor of the present invention.

Detailed ways

The structure of the flexible film-type solid-state supercapacitor of the present invention is as shown in Figure 1, by positive and negative two electrodes (3,5), the flexible solid electrolyte diaphragm 4 between two electrodes, external electrode 2,6 and flexible encapsulation film 1 .

Example 1:

(1) Preparation of electrode slurry: Stir and mix 80 g of activated carbon, 10 g of carbon black, 10 g of polyvinylidene fluoride (PVDF) and 500 g of N-methylpyrrolidone for 3 hours.

(2) Preparation of electrolyte slurry: mix 100g of polyvinyl alcohol powder (PVA) with 800g of deionized water, heat to 95°C and stir for 2 hours, then add 1g of SiO ₂ micropowder with particle size <5μm, 15g of tetraethyl tetrafluoroborate Ammonium was stirred for 10 hours to mix well.

(3) Preparation of external electrode slurry: Mix 10g of polyvinyl alcohol powder (PVA) with 100g of deionized water, heat to 90°C and stir for 1 hour, then add 20g of nickel powder (-200 days) and 10g of silver powder (-200 mesh), stirred for 2 hours.

(4) Preparation of encapsulation slurry: Stir and mix 50 g of polyvinylidene fluoride (PVDF) and 500 g of deionized water for 3 hours.

(5) Prepare printing templates for printing the outer electrode film, electrode film, electrolyte film, and packaging film in advance.

(6) Print positive external electrode film: Print the external electrode paste on a 0.1 mm thick silicone rubber base film, printing area: 4.0×2.0 mm, thickness: 30-100 μm, as shown in the first step of Figure 3 . After printing, the printed film is dried in an oven at 60° C. to 120° C. for 30 minutes to obtain a positive external electrode film.

(7) Print positive electrode film: print the electrode paste on the dried external electrode film, printing area: 2.0×2.0mm, thickness: 30-100μm, so that 2.0mm is exposed at one end of the external electrode, and the rest is covered, as shown in the figure 3 as shown in the second step. After printing, the printed film was dried in an oven at 60° C. to 120° C. for 30 minutes to obtain a positive electrode film.

(8) Printing solid electrolyte membrane: Print the electrolyte slurry on the dried positive electrode film, printing area: 3.0×3.0mm, thickness: 30-100μm, so that the electrolyte film completely covers the positive electrode film The average width of each side is 0.5mm, as shown in the third step of Figure 3. After printing, dry the printed film in an oven at 60° C. to 120° C. for 30 minutes to obtain a solid electrolyte membrane.

(9) Printing negative electrode film: Print the electrode paste on the dried solid electrolyte membrane, printing area: 2.0×2.0mm, thickness: 30-100μm, so that each side of the negative electrode film is 0.5mm narrower than the electrolyte membrane , that is, the negative electrode film is exactly opposite to the positive electrode film, as shown in the fourth step of FIG. 3 . After printing, dry the printed film in an oven at 60° C. to 120° C. for 30 minutes to obtain a negative electrode film.

(10) Printing negative external electrode film: Print the external electrode paste on the dried negative electrode film. mm, and the rest are just covered, as shown in the fifth step of Figure 3. After printing, the printed film was dried in an oven at 60° C. to 120° C. for 30 minutes to obtain a negative external electrode film.

(11) Printing packaging film: Print packaging paste on the dried negative external electrode film, printing area: 4.0×4.0mm, thickness: 50-100μm, so that the positive external electrode film and the negative external electrode film face outward 1.0mm is exposed on each side, and the rest is completely covered, as shown in the sixth step of Figure 3. After printing, dry the printed film in an oven at 60° C. to 120° C. for 30 minutes to obtain an encapsulation film.

Example 2:

(1) Electrode slurry preparation: 60g of activated carbon, 25g of manganese dioxide, 5g of carbon black, 10g of polyvinylidene fluoride (PVDF) and 500g of N-methylpyrrolidone were stirred and mixed for 3 hours.

(2) Electrolyte slurry preparation: mix 100g polyvinyl alcohol powder (PVA) with 800g deionized water, heat to 95°C and stir for 2 hours, then add 1g SiO2 micropowder with particle size <5μm, 15g tetraethylammonium tetrafluoroborate , and stirred for 10 hours to mix well.

(3) Preparation of external electrode slurry: Heat 10g of polyvinylidene fluoride powder (PVDF) and 100g of N-methylpyrrolidone to 60°C and stir for 1 hour, then add 20g of nickel powder (-200 mesh) and 10g of silver powder (-200 mesh), stirred for 2 hours.

(4) Preparation of encapsulation slurry: Stir and mix 50 g of polyvinylidene fluoride (PVDF) and 500 g of deionized water for 3 hours.

(5) According to the process steps of Example 1, the external electrode paste, electrode paste, flexible solid electrolyte paste, electrode paste, external electrode paste, and packaging paste are accurately applied to the organic base film ( Any one of PVDF, PVC, polyurethane, silicone rubber, and natural rubber), with the corresponding pressing, drying, cutting, and packaging processes, and finally form a flexible film-type solid supercapacitor with an electrode-diaphragm-electrode structure.

Example 3:

(1) Electrode slurry preparation: 85g of polypyrrole (PPy), 5g of carbon black, 10g of polyvinylidene fluoride (PVDF) and 500g of N-methylpyrrolidone were stirred and mixed for 3 hours.

(2) Electrolyte slurry preparation: mix 100g copolymer P(VDF-HFP) with 800g NMP, stir for 2 hours, add 30ml dibutyl phthalate (DBP), stir for 1 hour, then add 0.3g Al ₂ O ₃ nanometer powder (average particle size <60nm), 15g tetraethylammonium tetrafluoroborate, stir for 1 hour and mix well.

(3) Preparation of external electrode slurry: Heat 10g of polyvinylidene fluoride powder (PVDF) and 100g of N-methylpyrrolidone to 60°C and stir for 1 hour, then add 20g of nickel powder (-200 mesh) and 10g of silver powder (-200 mesh), stirred for 2 hours.

(4) Preparation of encapsulation slurry: Stir and mix 50 g of polyvinylidene fluoride (PVDF) and 500 g of deionized water for 3 hours.

(5) According to the process steps of Example 1, the external electrode paste, electrode paste, flexible solid electrolyte paste, electrode paste, external electrode paste, and packaging paste are accurately applied to the substrate (PVDF, Any one of PVC, polyurethane, silicone rubber, natural rubber), with the corresponding pressing, drying, cutting, and packaging processes, and finally form a flexible film-type solid supercapacitor with an electrode-diaphragm-electrode structure.

Example 4:

(1) Electrode slurry preparation: 85g of polyaniline (PANI), 5g of carbon black, 10g of polyvinylidene fluoride (PVDF), and 500g of N-methylpyrrolidone were stirred and mixed for 3 hours.

(2) Electrolyte slurry preparation: mix 100g copolymer P(VDF-HFP) with 800g NMP, stir for 2 hours, add 30ml dibutyl phthalate (DBP), stir for 1 hour, then add 0.3g Al ₂ O ₃ nanometer powder (average particle size <60nm), 15g of trimethyl-ethylammonium tetrafluoroborate, stirred for 1 hour and mixed evenly.

(3) Preparation of external electrode slurry: Heat 10g of polyvinylidene fluoride powder (PVDF) and 100g of N-methylpyrrolidone to 60°C and stir for 1 hour, then add 20g of nickel powder (-200 mesh) and 10g of silver powder (-200 mesh), stirred for 2 hours.

(4) Preparation of encapsulation slurry: Stir and mix 50 g of polyvinylidene fluoride (PVDF) and 500 g of deionized water for 3 hours.

(5) According to the process steps of Example 1, the external electrode paste, electrode paste, flexible solid electrolyte paste, electrode paste, external electrode paste, and packaging paste are accurately applied to the substrate (PVDF, Any one of PVC, polyurethane, silicone rubber, natural rubber), with the corresponding pressing, drying, cutting, and packaging processes, and finally form a flexible film-type solid supercapacitor with an electrode-diaphragm-electrode structure.

The properties of the supercapacitors manufactured in the above examples are shown in Table 1.

Table 1

electrode material Electrolyte membrane material Product size/mm Capacity/mF Internal resistance/Ω Leakage current/μA Example 1 Activated carbon + carbon black Polyvinyl alcohol+Et₄NBF₄ 2×2×0.3 2.2±20% 51.5±15% 0.10±20% Example 2 Activated carbon + manganese dioxide + carbon black Polyvinyl alcohol+Et₄NBF₄ 5×4×0.4 2.9±20% 58.8±15% 0.20±20% Example 3 Polypyrrole + carbon black P(VDF-HFP)+Et₄NBF₄ 5×4×0.4 3.5±20% 46.4±15% 0.20±20% Example 4 polyaniline + carbon black P(VDF-HFP)+Me₃Et NBF₄ 5×4×0.4 3.8±20% 43.6±15% 0.15±20%

As can be seen from Table 2, the flexible film type solid supercapacitor with excellent performance can be manufactured according to the present invention.

The above are only a few examples of the present invention, and do not illustrate that the present invention is limited to the content described in the following examples. The products manufactured by those skilled in the art according to the claims of the present invention all belong to the content of the present invention.

Claims (3)

1. the manufacture method of a flexible thin film type solid-state super capacitor may further comprise the steps:

Prepare external electrode slurry, electrode slurry, flexible solid electrolyte slurry, packaging slurry respectively;

The external electrode slurry is printed on organic basement membrane, after the printing print film oven dry is obtained anodal outer electrode membrane;

Electrode slurry is printed on the outer electrode membrane of having dried, external electrode one end is exposed, all the other positions cover, and after the printing print film oven dry are obtained cathode film;

Electrolyte slurry is printed on the cathode film of having dried, makes dielectric film cover cathode film fully, and all slightly wideer than each limit of cathode film, after the printing print film oven dry is obtained solid electrolyte membrane;

Electrode slurry is printed on the solid electrolyte membrane of having dried, and printing area is identical with cathode film, and its position is just in time relative with cathode film, after the printing print film oven dry is obtained negative electrode film;

The external electrode slurry is printed on the negative electrode film of having dried, and its printing area and position are identical with anodal outer electrode membrane, after the printing print film oven dry are obtained the negative pole outer electrode membrane;

Packaging slurry is printed on the negative pole outer electrode membrane of having dried, the limit of drawing of anodal outer electrode membrane and negative pole outer electrode membrane is exposed, all the other places cover fully, after the printing print film oven dry are obtained encapsulating film.

2. the manufacture method of flexible thin film type solid-state super capacitor according to claim 1, described flexible solid electrolyte slurry is gel state electrolyte or solid electrolyte.

3. the manufacture method of flexible thin film type solid-state super capacitor according to claim 1, organic basement membrane be PVDF, PVC, polyurethane, silicon rubber, natural rubber any.

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