KR20030006461A - Solid Electrolyte And Method For Preparing The Same - Google Patents

Abstract

PURPOSE: A solid electrolyte and a method for fabricating the same are provided to form the solid electrolyte having high electric conductivity by using a mixed solution of poly solution or poly suspension and organic solvent or organic acid or inorganic acid. CONSTITUTION: A mixed solution is fabricated by mixing poly solution or poly suspension with organic solvent, organic acid, or inorganic acid. The mixed solution of the poly solution or the poly suspension and the organic solvent, the organic acid or the inorganic acid is coated on a base material. A solid electrolyte is fabricated by drying the mixed solution coated on the base material. The mixing amount of the organic solvent, the organic acid or the inorganic acid corresponds to 0.01 to 100 weight percent when the poly solution or the poly suspension is 100 weight percent.

Description

Solid Electrolyte And Method For Preparing The Same

The present invention relates to a solid electrolyte prepared by an electrolyte solution in which an organic solvent or an organic or inorganic acid is mixed with an aqueous poly (3,4-ethylenedioxythiophene) solution or a water suspension, and a method for preparing the same. The present invention also relates to a solid electrolytic capacitor comprising the solid electrolyte and a method of manufacturing the same. The solid electrolyte prepared by the present invention has high electrical conductivity, and the solid electrolytic capacitor produced by the present invention has high capacitance and low loss value (tan δ).

The role of the electrolyte is one of the most important parts in electrolytic capacitors, line patterning of electrochromic devices. In the past, liquid electrolytes were used, but they were inconvenient to carry and had disadvantages of physical properties. It is used.

The polymer electrolyte should satisfy the following basic conditions in electrochemical aspects. It must be chemically stable, have high electrical conductivity over a wide temperature range, and electrochemically stable over a wide range of potentials. It should also be highly stable and nontoxic.

In the case of an electrolytic capacitor, an electrolyte is prepared by coating manganese dioxide (MnO ₂ ) on heat treated tantalum pellets. Tantalum electrolytic capacitors using manganese dioxide (MnO ₂ ) as an electrolyte have the advantages of being stable in temperature characteristics, high in reliability and excellent in frequency characteristics, but due to the low electrical conductivity of manganese dioxide (<10 ^-1 S / cm) And low impedance is difficult to achieve. In addition, it has the disadvantage of complexity and energy waste of impregnating tantalum oxide in Mn (NO ₃ ) ₂ solution and pyrolyzing it at 250 ~ 320 ℃ to form manganese dioxide as a solid electrolyte on the inner and outer surfaces of the sintered body. .

Recently, in Japan, research has been conducted to eliminate such disadvantages by coating polypyrrole, a conductive polymer having high electrical conductivity (> 10 S / cm), using electrochemical methods for the past 10 years. More than 100 patents are reported. However, coating using an electrochemical method has a disadvantage in that the process is cumbersome and the film thickness is not uniform.

The conductive polymer solid electrolytes known to date have excellent electrical properties, but have a disadvantage in that physical properties such as mechanical properties and processability are inferior to conventional functional polymers.

In addition, most conductive polymer solid electrolytes have a disadvantage in that transparency is greatly reduced because they absorb a lot of light in the visible region when they exhibit electrical conductivity. Therefore, these conductive polymer solid electrolytes are limited to their use only in places where transparency is not required.

Recently, however, Bayer, Germany, has made poly (3,4) by polymerizing 3,4-ethylenedioxythiophene having ethylenedioxy group in the form of ring in the structure of thiophene. Ethylenedioxythiophene (PEDOT) was prepared. Poly (3,4-ethylenedioxythiophene) (PEDOT) is known to have a band gap of about 1.6 eV. The optical bandgap (760-780 nm, 1.6-1.7 eV) is lower than the conventional thiophene by the electron donating effect by ethylene dioxy group. Poly (3,4-ethylenedioxythiophene) (PEDOT) also has much more transparent properties than conventional conductive polymers. However, because PEDOT itself is difficult to expect the mechanical strength of the film itself, and processing is not easy, Bayer Co., Ltd. uses polystyrenesulfonate (PSS) or silicate as a polymer additive to polymerize EDOT in an aqueous solution, and is mixed with additives. We sell solution products (name: Baytron P). Baytron P, commercially available from Bayer, has excellent thermal atmospheric stability, but has low electrical conductivity, ranging from 10 ⁻¹ to 10 ⁰ S / cm.

Accordingly, it is an object of the present invention to provide a solid electrolyte having a high electrical conductivity and a method of manufacturing the same, in which the above problems of the prior art are solved.

It is also an object of the present invention to provide a solid electrolyte having excellent properties in terms of adhesion, hardness and strength required as a solid electrolyte as well as high electrical conductivity, and a method for producing the same.

It is also an object of the present invention to provide a solid electrolytic capacitor having a high capacitance and a low loss value (tan δ) using a solid electrolyte having high electrical conductivity and a method of manufacturing the same.

FIG. 1 is an absorbance spectrum up to near infrared ray of an electrolyte solution in which DMSO, a polar organic solvent, is added in a weight ratio to Baytron P (a water suspension of Formula 1).

FIG. 2 is an absorption spectrum of near-infrared rays of an electrolyte solution in which a polar organic solvent (DMSO, DMF, NMP, EG) is added in a weight ratio of 1 to 7 in Baytron P. FIG.

3 is a capacitance value of a tantalum electrolytic capacitor device manufactured according to the change in concentration of the electrolyte solution prepared in Example 4. FIG.

4 is a loss value tan δ of the tantalum electrolytic capacitor device manufactured according to the concentration change of the electrolyte solution prepared in Example 4. FIG.

5 is a capacitance value of the tantalum electrolytic capacitor device manufactured according to the concentration change of the electrolyte solution prepared in Example 5.

6 is a loss value tan δ of the tantalum electrolytic capacitor device manufactured according to the change in concentration of the electrolyte solution prepared in Example 5. FIG.

FIG. 7 is a graph of tensile strength of an electrolyte film to which polyvinyl alcohol (PVA) is added at various weight ratios in Example 6. FIG.

FIG. 8 is an absorbance spectrum up to near-infrared ray of the electrolyte solution of Example 7 in which water-soluble polypyrrole was added to the solution prepared in Example 1 in various weight ratios.

The method for preparing a solid electrolyte of the present invention comprises the steps of obtaining an electrolyte solution by mixing an organic solvent or an organic or inorganic acid in an aqueous solution or a suspension of poly (3,4-ethylenedioxythiophene) (PEDT or PEDOT), the electrolyte solution Coating on a substrate, and drying the coating to obtain a solid electrolyte.

The poly (3,4-ethylenedioxythiophene) aqueous solution or water suspension used in the present invention is a poly (3,4-ethylenedioxythiophene) aqueous solution or water containing a doping substance represented by the following Chemical Formula 1 It may be a suspension.

In addition, the electrolyte solution of the present invention may further include at least one selected from the group consisting of a conductive polymer, a surfactant, a coupling agent, and a functional polymer.

Accordingly, the solid electrolyte of the present invention is prepared from an electrolyte solution in which an organic solvent or an organic or inorganic acid is mixed with an aqueous poly (3,4-ethylenedioxythiophene) (PEDT or PEDOT) solution or a water suspension, thereby preparing poly (3,4 Ethylenedioxythiophene) and a small amount of organic solvent or organic or inorganic acid.

The present invention also provides a solid electrolytic capacitor and a method for producing the same, which are prepared using the above-described method for producing a solid electrolyte.

Therefore, the method of manufacturing a solid electrolytic capacitor of the present invention comprises the steps of forming an electrolyte solution by mixing an organic solvent or an organic or inorganic acid in an aqueous solution or a suspension of poly (3,4-ethylenedioxythiophene) (PEDT or PEDOT) Coating and drying the electrolyte solution on an oxide dielectric layer of an oxidized valve metal having micropores or etching pits on its surface to form a solid electrolyte layer, and the solid electrolyte layer for electrical connection with an external terminal. Forming a cathode electrode on the substrate.

Accordingly, the solid electrolytic capacitor of the present invention includes a valve metal having micropores or etching pits on its surface as an anode, an oxide of the valve metal as a dielectric layer formed on the valve metal surface, a solid electrolyte layer formed on the dielectric layer, and An anode formed on the solid electrolyte layer, wherein the solid electrolyte layer is an electrolyte in which an organic solvent or an organic or inorganic acid is mixed with a poly (3,4-ethylenedioxythiophene) (PEDT or PEDOT) aqueous solution or a water suspension The solution is formed by coating and drying the dielectric layer on the basis of poly (3,4-ethylenedioxythiophene) and containing a small amount of an organic solvent or an organic or inorganic acid.

Hereinafter, the present invention will be described in detail.

The solid electrolyte of the present invention is formed based on poly (3,4-ethylenedioxythiophene) (PEDOT). In order to prepare the solid electrolyte of the present invention, first, an organic solvent is mixed with an aqueous poly (3,4-ethylenedioxythiophene) solution or a water suspension to obtain an electrolyte solution. Then, the electrolyte solution is coated and dried on a substrate according to a conventional coating forming method to form a solid electrolyte.

As the PEDOT aqueous solution or water suspension used in the present invention, a PEDOT water suspension containing a polystyrene sulfonate represented by Formula 1 as a doping material may be used, and in particular, a product sold under Bayer's trade name Baytron P may be used. Can be. In addition, an aqueous solution of PEDOT or a water suspension containing other doping materials may be used instead of the doping material represented by the formula (1). The amount of PEDOT in the PEDOT aqueous solution or water suspension to be used may have a range suitable for forming a stable aqueous solution or water suspension, and the content of solids may usually range from 1 to 10% by weight.

When preparing the electrolyte solution, the amount of the organic solvent added may range from 0.01 to 100 parts by weight based on 100 parts by weight of an aqueous solution or water suspension containing PEDOT. When the amount of the organic solvent added in the preparation of the electrolyte solution is too small, a solid electrolyte having a high electrical conductivity and a solid electrolytic capacitor having a high capacitance and a low loss value as the object of the present invention cannot be obtained. That is, compared with the case where no organic solvent is added, there is no big difference in the effect. On the other hand, when the amount of the organic solvent added in the preparation of the electrolyte solution is too large, when the solid solution is prepared by coating and drying the electrolyte solution on the substrate, most of the organic solvent is evaporated in the process to form a solid electrolyte. Adding too much organic solvent is not economical as it is removed from the coating layer and is undesirable because too much organic solvent may be added, since delamination of the aqueous and organic layers may occur.

The organic solvent added during the preparation of the electrolyte solution may interact with the PEDOT so that it may remain in the solid electrolyte in a small amount, and the separation between the water and the layer may not be severe depending on the amount added. If it can form, it will not specifically limit. However, as the organic solvent used, a polar aprotic solvent is most preferred. Examples of such polar aprotic solvents are dimethyl sulfoxide (DMSO), N, N' -dimethylformamide (DMF), tetrahydrofuran (THF), N-methyl-2-pyrrolidinone (NMP), 2- Butanone, 4-methyl-2-pentanone, chloroform, dichloromethane and the like. In addition, as the organic solvent used in the present invention, a polar protic solvent such as alcohol may be used. Examples of such solvents include methyl alcohol, ethyl alcohol, 1-butanol, isopropyl alcohol, isobutyl alcohol, t -butyl alcohol, benzyl alcohol, 2,2,2-trifluoroethanol, lauryl alcohol, oleyl alcohol, Ethylene glycol etc. are mentioned. And the organic solvent used in the present invention may include a nonpolar solvent. Examples of such solvents include xylene, benzene and the like.

The solid electrolyte of the present invention prepared by the above method has a very high electrical conductivity. That is, the electrical conductivity of the solid electrolyte of the present invention is about 5 to 500 S / cm, about 10 to 1000 times, compared to that of the solid electrolyte prepared using Bayer's Baytron P water suspension. It is an improvement. The reason why the electrical conductivity of the solid electrolyte of the present invention is high is that the organic solvent is added to the PEDOT aqueous solution or the water suspension, so that the organic solvent dissolves the PEDOT in the electrolyte solution, so that the rules of the PEDOT polymer at the time of forming the solid electrolyte coating layer It is presumed that this is because it contributes to the formation of a specific arrangement, and also that a small amount of organic solvent remaining in the solid electrolyte contributes to the formation and maintenance of a regular arrangement of the PEDOT polymer.

Meanwhile, organic or inorganic acids may be mixed instead of the organic solvent mixed in the electrolyte solution. Examples of the organic or inorganic acid used in the present invention include formic acid, acetic acid, sulfuric acid, nitric acid, hydrochloric acid, trifluoroacetic acid and the like. An organic or inorganic acid is equivalent to the said organic solvent in this invention.

Meanwhile, a conductive polymer, a surfactant, a coupling agent, or a functional polymer may be added to the electrolyte solution.

In the present invention, the surfactant added to the electrolyte solution includes a zwitterionic surfactant, a nonionic surfactant and an anionic surfactant capable of hydrogen bonding and having a ring or alkyl chain. Examples of zwitterionic surfactants used in the present invention include N-lauryl-β-acetic acid, N-lauryl-β-aminopropionic acid (N-lauryl-β- aminopropionic acid), N-lauryl-β-aminobutyric acid, and the like. Examples of nonionic surfactants include sorbitan monooleate and POE sorbent. Non-molecular monooleate, N, N'-dimethylformamide dicyclohexyl acetal, and the like. Examples of anionic surfactants include di-alkyl sulfosuccinates. sulfosuccinate, alkyl-α-sulfocarbonate, alkyl phosphate, petroleum sulfonate and the like. When the solid electrolyte of the present invention is applied to a solid electrolytic capacitor, such a surfactant has a nonpolar portion of a long alkyl chain or ring and a polar portion of a proton, thereby forming structural affinity with a polymer main chain having a nonpolar portion. At the same time, hydrogen bonding with the tantalum oxide device is possible. That is, in the formation of the solid electrolytic capacitor, the solid electrolyte of the present invention has increased permeability into the tantalum oxide device by improved affinity with the tantalum oxide device. Therefore, the electrical conductivity of the solid electrolyte of the present invention can be improved by the addition of such a surfactant, and the capacitance of the solid electrolytic capacitor of the present invention can be improved and the loss value can be reduced. Such surfactants may be added in amounts ranging from 1 to 100 parts by weight based on 100 parts by weight of poly (3,4-ethylenedioxythiophene) in an aqueous solution or water suspension. If the amount of the surfactant added is too small, the advantages of the surfactant as described above cannot be sufficiently obtained, and if the amount of the surfactant added is too large, the performance of the solid electrolyte is not sufficiently exhibited.

In the present invention, the coupling agent mixed in the electrolyte solution is a silane compound or a siloxane compound, and the polymer main chain is bonded to the polymer main chain by a radical reaction or chemical action. In addition, the coupling agent may cause a coupling phenomenon between the coupling agents, and the silicon of the coupling agent forms a chemical interaction by covalent bonding with oxygen of tantalum oxide in the solid electrolytic capacitor. By the action of the coupling agent, the electrical conductivity of the solid electrolyte of the present invention can be improved, and the affinity between the solid electrolyte and tantalum oxide in the solid electrolytic capacitor of the present invention is improved, so that the electrolyte can penetrate into the tantalum oxide device. By increasing, the capacitance of the solid electrolytic capacitor of the present invention can be improved and the loss value can be reduced. Examples of such coupling agents include 3-aminopropyltriethoxysilane, 3-aminopropyldiethoxymethylsilane, 3-aminopropyltrimethoxysilane, vinyltris (β-methoxy) silane, vinyltris (2-methoxy Ethoxy) silane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, etc. are mentioned. Such coupling agents may be added in amounts ranging from 1 to 100 parts by weight based on 100 parts by weight of poly (3,4-ethylenedioxythiophene) in an aqueous solution or water suspension. When the amount of the coupling agent added is too small, the advantages of the coupling agent as described above cannot be sufficiently obtained, and when the amount of the coupling agent added is too large, the performance of the solid electrolyte is not sufficiently exhibited.

In the present invention, the functional polymer added to the electrolyte solution serves to reinforce the function of poly (3,4-ethylenedioxythiophene) used as the main polymer in terms of hardness and strength. Examples of such functional polymers include polyvinyl alcohol (PVA), polyethylene (PE), polypropylene (PP), polymethyl methacrylate (PMMA), polyvinyl butyral (PVB), polyvinylacetate, polyacrylonitrile (PAN), acrylonitrile-butadiene-styrene copolymer (ABS), nylon (Nylon6.66), polyurethane, epoxy, acrylic resin, polyacrylic acid, polymethacrylic acid, styrene-maleic anhydride copolymer, polystyrene sulfonic acid , Polyethylene imine, polyvinyl pyridine, polydiethylamino ethylacrylate, polyacrylamide, polyvinylpyrrolidone, alkyds, polyethylene glycol, polyethylene oxide, polyvinyl methyl ether, carboxy methyl cellulose (CMC), methyl Cellulose (MC), ethyl cellulose (EC), hydroxy ethyl cellulose (HEC), cellulose acetate phthalate (CAP), stearyl cellulose, water soluble acrylic, urethane, There may be mentioned epoxy resins and the like. Such functional polymers may be added in amounts ranging from 1 to 100 parts by weight based on 100 parts by weight of poly (3,4-ethylenedioxythiophene) in an aqueous solution or water suspension. When the amount of the functional polymer added is too small, the advantages of the functional polymer as described above cannot be sufficiently obtained, and when the amount of the functional polymer added is too large, the performance of the solid electrolyte is not sufficiently exhibited.

The conductive polymer added to the electrolyte solution in the present invention is a conductive polymer other than poly (3,4-ethylenedithiophene) used in the present invention, and includes polypyrrole, polyaniline, and polythiophene. That is, in the present invention, a blend of poly (3,4-ethylenedithiophene) and another conductive polymer can be used as a main material of the solid electrolyte. The blend of such conductive polymers may be formed by mixing other conductive polymers with an aqueous solution or water suspension of poly (3,4-ethylenedithiophene) as described above, or may be formed by other methods. Other conductive polymers blended with poly (3,4-ethylenedithiophene) used in the present invention can be used without limitation, known conductive polymers, but preferably water-soluble conductive polymers are used. Examples of such a water-soluble conductive polymer may be a water-soluble conductive polypyrrole, such as the formula (2).

[Wherein, W is a substituent substituted on the pyrrole ring, sulfonyl chloride (-SO ₂ Cl) or sulfonic acid group (-SO ₃ H), the ratio of substituents substituted on the pyrrole ring is 0.01 ~ per one pyrrole ring Two (or equivalent equivalence ratios of sulfuric acid sulfuric acid to pyrrole monomers in the preparation range from 0.01 to 5). Preferably, the proportion of substituents substituted on the pyrrole ring has a range of 0.1 to 1 per one pyrrole ring (or the equivalent ratio of sulfuric acid sulfuric acid to pyrrole monomers in the preparation is 0.1 to 2). A is a dopant contained in polypyrrole and is a compound represented by Formula 3, Formula 4, or Formula 5.]

[In Formula 3, R and R 'is hydrogen, alkyl of 1 to 25 carbons, alkylalkoxyl, alkylsulfonyl, or alkoxycarbonyl, R and At least one of R 'is not hydrogen. Y is an ethylene group, benzene ring, naphthalene ring or anthraquinone ring having at least one -SO ₃ M or -SO ₃ H, preferably an ethylene group having one -SO ₃ M or -SO ₃ H or Benzene ring. M is a monovalent metal such as Li, Na, K, etc.]

[In Formula 4, R "is an alkyl group, Preferably it is a C1-C6 alkyl group, More preferably, it is a C1-C3 alkyl group.]

Anionic compounds of group III or group V containing fluorine (F) elements

[Anionic compound of the general formula (5) is BF ₄ ^-, and the ^{_{like, PF 6 - -, A S}} F 6.]

The water-soluble conductive polypyrrole of Chemical Formula 2 is described in detail in Korean Patent Application No. 2001-9307 (filed March 2, 2001) filed by the present inventor.

The water-soluble conductive polypyrrole represented by the formula (2) containing the above dopant and having the sulfonyl chloride group (-SO ₂ Cl) introduced into the pyrrole ring can be obtained by introducing the substituent into the polypyrrole containing the above dopant represented by the formula (6). Can be prepared. That is, it may be prepared by reacting polypyrrole of formula 6 with chlorosulfonic acid.

[In Formula 6, A is a compound represented by Formula 3, Formula 4, or Formula 5.]

The reaction of the polypyrrole of the general formula (4) and the sulfuric acid chloride to prepare the water-soluble conductive polypyrrole having the sulfonyl chloride group is -20 ℃ to 150 ℃, specifically at 80 ℃ for 1 minute to 24 hours, Specifically, it can be performed for 30 minutes.

In addition, the water-soluble conductive polypyrrole represented by the formula (2) in which the sulfonic acid (-SO ₃ H) group is introduced is prepared by hydrolyzing the polypyrrole having the sulfonyl chloride group obtained above in neutral conditions or in the presence of an acid or a base. Can be.

The polypyrrole represented by the above formula (6) also has conductivity, but the solubility in water is insignificant. The polypyrrole of Chemical Formula 6 is described in detail in Korean Patent Application No. 1999-21306 (Publication No. 1999-73157) filed by the present inventor.

When the solid polymer electrolyte obtained by using the polymer blend as described above is applied to the EL device and the ECD electrolyte, the threshold voltage according to the difference of the band gap can be adjusted.In addition, when used as the electrolyte of the electromagnetic shielding and absorber, the dielectric constant It provides the advantage that the reflection efficiency and absorption efficiency can be increased by the combination of and electrical conductivity. The ratio between polymers in the above polymer blend is determined by which polymer properties are mainly exhibited. In general, considering the properties of poly (3,4-ethylenedioxythiophene), the amount of other polymers is poly It may be in the range of 1 to 1000 parts by weight based on 100 parts by weight of (3,4-ethylenedioxythiophene).

Therefore, the solid electrolyte of the present invention prepared according to the method of the present invention as described above is based on poly (3,4-ethylenedioxythiophene) and contains a small amount of an organic solvent or an organic or inorganic acid. The polymer of the solid electrolyte prepared according to the method of the present invention has a difference in structure from the polymer of the solid electrolyte prepared by the water suspension or organic solution containing the above polythiophene. This is because the difference between the electrical conductivity of the solid electrolyte formed by the water suspension containing polythiophene and the electrical conductivity of the solid electrolyte formed by the electrolyte solution used in the present invention to which the organic solvent is added is very large. Able to know. In the present invention, by adding an organic solvent to the water suspension containing the polythiophene to form an electrolyte solution and to prepare a solid electrolyte therefrom by the action of the organic solvent or the associated action of the organic solvent and water in the formation of the solid electrolyte The arrangement of the polythiophenes of is formed regularly, and even after a solid electrolyte is formed, a small amount of the organic solvent is contained in the solid electrolyte, and the organic solvent containing the polythiophene is formed so that the arrangement of the polythiophenes is formed and maintained regularly. Interact with polythiophene Therefore, the solid electrolyte of the present invention not only shows a difference in structure compared to the conventional solid electrolyte, but also contains a small amount of organic solvent in the solid electrolyte, and thus shows a difference in constituents of the solid electrolyte as compared with the conventional solid electrolyte. The difference in structure and constituents of such a solid electrolyte allows the solid electrolyte of the present invention to have high electrical conductivity. This difference also allows the solid electrolytic capacitor to have high capacitance and low loss when the solid electrolyte of the present invention is applied to a solid electrolytic capacitor.

On the other hand, it is not easy to directly measure the amount of the organic solvent contained in the solid electrolyte of the present invention in the polymer film state, but the content of the organic solvent depends on the conditions of the solid electrolyte formation process. Can be defined. That is, the amount of the organic solvent or the organic or inorganic acid contained in the solid electrolyte is organic solvent or organic or inorganic based on 100 parts by weight of a water suspension having a poly (3,4-ethylenedioxythiophene) content of 1% by weight. 0.01 to 100 parts by weight of acid is mixed to form a polymer coating layer on a substrate by a conventional solution casting method at a temperature of 100 ° C. and in the air, and the polymer coating layer is dried at room temperature in a temperature of 100 ° C. for 1 to 48 hours. It can be defined by.

The present invention provides a method for producing a solid electrolytic capacitor by applying the above-described method for producing a solid electrolyte to a solid electrolytic capacitor, and provides a solid electrolytic capacitor produced by the method.

In order to prepare a solid electrolytic capacitor according to the present invention, first, an organic solvent or an organic or inorganic acid is mixed with an aqueous solution of poly (3,4-ethylenedioxythiophene) (PEDT or PEDOT) or a water suspension to form an electrolyte solution. do. This electrolyte solution is then coated and dried on an oxide dielectric layer of oxidized valve metal with micropores or etching pits on its surface to form a solid electrolyte layer. A cathode electrode is formed on the solid electrolyte layer for electrical connection with an external terminal to obtain a solid electrolytic capacitor.

Except for coating and drying the electrolyte solution on the oxide dielectric layer of the valve metal to form a solid electrolyte layer in the manufacturing process of the solid electrolytic capacitor, all processes are the same as the manufacturing process of the solid electrolytic capacitor using a general valve metal. The production method of such a solid electrolytic capacitor is well known.

The solid electrolytic capacitor of the present invention thus prepared has a high capacitance and a low loss value due to the characteristics of the solid electrolyte layer of the present invention, and thus may be usefully used.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following examples are only intended to present specific examples of the present invention, and should not be construed as limiting the scope of the present invention.

Example 1

Poly (3,4-ethylenedioxythiophene) water suspension was used by purchasing Baytron P from Bayer, Germany. As the organic solvent, Aldrich, TCI product was used as it is.

10 g of poly (3,4-ethylenedioxythiophene) water suspension [Baytron P] was added to a 500 ml beaker and stirred with a magnetic spoon. Dimethyl sulfoxide (DMSO), N, N' -dimethylformamide (DMF), N-methyl-2-pyrrolidinone (NMP), and ethylene glycol (EG), respectively, were prepared according to the weight ratio of , 4-ethylenedioxythiophene) was added to a 500 ml beaker containing 10 g of a water suspension [Baytron P], followed by mixing by stirring with a magnetic spoon. The mixed solution was placed in an ultrasonic cleaner for at least 1 hour to prepare a complete mixed solution.

The poly (3,4-ethylenedioxythiophene) mixed solution to which the organic solvent was added was coated and dried on a glass plate by a solution casting method to prepare a good film. The electrical conductivity of the poly (3,4-ethylenedioxythiophene) film to which the organic solvent was added was measured, and the results are shown in Table 1 below.

Electrical conductivity of the poly (3,4-ethylenedioxythiophene) film to which the organic solvent added in Example 1 was added. Baytron P: Organic Solvent Weight Ratio Electrical Conductivity (S / cm) DMSO DMF NMP EG DMSO DMF NMP EG 100: 0 0.5 0.5 0.5 0.5 50: 1 110 80 70 68 20: 1 210 115 133 119 15: 1 254 136 153 150 10: 1 306 149 171 269 9: 1 423 154 183 312 8: 1 480 176 212 328 7: 1 480 265 250 360 6: 1 440 277 288 416 5: 1 348 317 304 329 4: 1 301 310 285 301 3: 1 291 245 240 258 2: 1 242 211 167 201 1: 1 209 174 101 170

The electrical conductivity of each organic solvent-added poly (3,4-ethylenedioxythiophene) film was prepared by conventional Baytron P water suspension from 70 S / cm to 480 S / cm, as shown in Table 1. 10 to 1000 times higher electrical conductivity than 0.5 S / cm of poly (3,4-ethylenedioxythiophene) film.

Meanwhile, DMSO, an organic solvent, was added to a poly (3,4-ethylenedioxythiophene) water suspension [Baytron P] at various weight ratios to prepare a mixed electrolyte solution, and the absorbance spectrum from the mixed electrolyte solution state to the near infrared region was measured. It measured, and the result is shown in FIG. As shown in the absorbance spectrum results up to the near-infrared region of FIG. 1, when the mixed electrolyte solution in which DMSO, an organic solvent, is added to Baytron P in various weight ratios, the weight ratio of DMSO and Baytron P is 1 to As the increase from 5 to 1 to 7 shows the intensity of the absorbance of the metal in the near-infrared region, it can be seen that the physical properties are excellent, and the physical properties do not increase any more than 1 to 8. From the above results and the results of Table 1, it can be seen that there is an optimum ratio of the organic solvent to the poly (3,4-ethylenedioxythiophene) water suspension for obtaining a solid electrolyte having high electrical conductivity of the present invention. . These optimum ratios are determined by the solubility or interaction of each solvent with respect to poly (3,4-ethylenedioxythiophene), the affinity of each solvent for water, the evaporation rate and characteristics of each solvent in the formation of a solid electrolyte (film). It depends on the back.

On the other hand, the absorbance spectrum to the near-infrared region in the mixed solution (weight ratio of organic solvent: Baytron P aqueous suspension = 7: 1) in which each organic solvent (DMSO, DMF, NMP, EG) is added to the Baytron P aqueous suspension is shown in FIG. Shown in As a result of absorbance spectrum up to near-infrared region of FIG. 2, when the mixed electrolyte solution in which organic solvents (DMSO, DMF, NMP, and EG) were added to Baytron P than the conventionally commercialized Baytron P, the intensity of absorbance exhibited by the metal in the near-infrared region It was found that the mixed electrolyte solution in which the organic solvent (DMSO, DMF, NMP, EG) was added to Baytron P had better physical properties than Baytron P commercially available.

Example 2

Poly (3,4-ethylenedioxythiophene) solution was used to purchase Baytron P of Bayer, Germany. The alcohol solvent was used as Aldrich, TCI product.

10 g of poly (3,4-ethylenedioxythiophene) water suspension [Baytron P] was added to a 500 ml beaker and stirred with a magnetic spoon. Methanol, ethanol, butanol and t-butanol, eco-friendly protic solvents, were added to a 500 ml beaker containing 10 g of poly (3,4-ethylenedioxythiophene) water suspension [Baytron P] at the weight ratios shown in Table 2 below. After stirring, the mixture was stirred well with a magnetic spoon. The mixed solution was placed in an ultrasonic cleaner for at least 1 hour to prepare a complete mixed solution, which was then coated and dried on a glass plate by a solution casting method to form a good film. The electrical conductivity of the poly (3,4-ethylenedioxythiophene) film to which the alcohol solvent was prepared was measured, and the results are shown in Table 2 below.

Electrical conductivity of the poly (3,4-ethylenedioxythiophene) film to which the alcohol solvent prepared in Example 2 was added. Baytron P: Alcohol Weight Ratio Electrical Conductivity (S / cm) Methanol ethanol Butanol t -butanol Methanol ethanol Butanol t -butanol 100: 0 0.5 0.5 0.5 0.5 50: 1 4 4.5 7 6.3 6: 1 30 33 66 60 1: 1 10 12 18 14

As shown in Table 2, the electrical conductivity of the poly (3,4-ethylenedioxythiophene) film to which each alcohol solvent was added was 4 S / cm to 66 S / cm. The (3,4-ethylenedioxythiophene) film showed 10 to 100 times higher electrical conductivity than 0.5 S / cm.

Example 3

Poly (3,4-ethylenedioxythiophene) water suspension was used by purchasing Baytron P from Bayer, Germany. The organic acid solvent was used as it is TCI product.

10 g of poly (3,4-ethylenedioxythiophene) water suspension [Baytron P] was added to a 500 ml beaker and stirred with a magnetic spoon. Formic acid, acetic acid, 1 mole sulfuric acid, and 1 mole hydrochloric acid were each added to a 500 ml beaker containing 10 g of poly (3,4-ethylenedioxythiophene) water suspension [Baytron P] at the weight ratios shown in Table 3, followed by magnetic stirring. Stir well with dog and mix. The mixed solution was placed in an ultrasonic cleaner for at least 1 hour to prepare a complete mixed solution, which was then coated and dried on a glass plate by a solution casting method to produce a good film. The electrical conductivity of the poly (3,4-ethylenedioxythiophene) film to which the acid solvent prepared above was added was measured, and the results are shown in Table 3 below.

Electrical Conductivity of Poly (3,4-ethylenedioxythiophene) Film Added with Acid Solvent Prepared in Example 3. Baytron P: Organic Acid Solvent Weight Ratio Electrical Conductivity (S / cm) Formic acid Acetic acid 1 mole hydrochloric acid 1 mole sulfuric acid Formic acid Acetic acid 1 mole hydrochloric acid 1 mole sulfuric acid 100: 0 0.5 0.5 0.5 0.5 50: 1 45 43 3 61 6: 1 150 135 25 250 1: 1 102 98 19 165

As shown in Table 3, the electrical conductivity of the poly (3,4-ethylenedioxythiophene) film to which each acid solvent was added was 3 S / cm to 250 S / cm. The (3,4-ethylenedioxythiophene) film showed 10 to 100 times higher electrical conductivity than 0.5 S / cm.

Example 4

The electrolyte solution was prepared by adding 0.1 to 1.0% by weight of laurylaminopropionic acid as a surfactant to the mixed Baytron P and DMSO solution (weight ratio = 7: 1) prepared in Example 1. The oxidized tantalum pellet was immersed in the prepared poly (3,4-ethylenedioxythiophene) 2 wt% electrolyte solution for 20 minutes, uniformly coated to the pores inside the pellet, and dried at 100 ° C. for 30 minutes. The same process was repeated five times to coat the prepared electrolyte solution inside and outside the oxidized tantalum pellet. An electrolytic capacitor was prepared by coating carbon paste and silver paste on oxidized tantalum pellets (oxidized aluminum pellets) coated with a solid electrolyte. The capacitance and loss of this tantalum solid electrolytic capacitor were measured at 120 Hz and 1 kHz, and the results are shown in FIGS. 3 and 4 and Table 4.

Capacitance and loss values (tan δ) of the tantalum electrolytic capacitor device manufactured in Example 4. Electrical Conductivity (S / cm) Capacitance (120 Hz) Loss value (tan δ) (120 Hz) Baytron p 0.5 82 to 85 ㎌ 15-12 Electrolyte of Example 1 480 96-100 kPa 7 to 3 Electrolyte of Example 4 395 100 to 105 ㎌ 4 to 1

As shown in Table 4, FIG. 3, and FIG. 4, the tantalum solid electrolytic capacitor (D Size) manufactured in Example 4 exhibited a capacitance of 100 to 105 mA and a loss of 4 to 1 at 120 Hz. This is due to the capacitance of the tantalum solid electrolytic capacitor having a solid electrolyte formed by the existing Baytron P 82-85 ㎌, the loss value 15-12 and the electrolyte solution prepared in Example 1 (Baytron P + DMSO (7: 1 weight ratio) The tantalum solid electrolytic capacitor having the formed solid electrolyte showed better properties than the capacitance of 96 to 100 mA and the loss of 9 to 4.

Example 5

An electrolyte solution was prepared by adding 0.1 wt% to 1.0 wt% of a vinyltris (beta-methoxy) silane as a coupling agent to a mixed solution of Baytron P and DMSO prepared in Example 1 (weight ratio = 7: 1). The oxidized tantalum pellet was immersed in the prepared poly (3,4-ethylenedioxythiophene) 2 wt% electrolyte solution for 20 minutes, uniformly coated to the pores inside the pellet, and dried at 100 ° C. for 30 minutes. The same process was repeated five times to coat the prepared electrolyte solution inside and outside the oxidized tantalum pellet. An electrolytic capacitor was prepared by coating carbon paste and silver paste on oxidized tantalum pellets (oxidized aluminum pellets) coated with a solid electrolyte. The capacitance and loss of this tantalum solid electrolytic capacitor were measured at 120 Hz and 1 kHz, and the results are shown in FIGS. 5 and 6 and Table 5.

Capacitance and loss value (tan δ) of the tantalum electrolytic capacitor device manufactured in Example 5 Electrical Conductivity (S / cm) Capacitance (120 Hz) Loss value (tan δ) (120 Hz) Baytron p 0.5 82 to 85 ㎌ 15-12 Electrolyte of Example 1 480 96-100 kPa 7 to 3 Electrolyte of Example 5 436 110 to 115 ㎌ 1 to 0.1

As shown in Table 5, FIG. 5 and FIG. 6, the tantalum electrolytic capacitor coated with the electrolyte prepared in Example 5 exhibited a capacitance of 110 to 115 mA and a loss of 1 to 0.1 at 120 Hz. This is because the capacitance of the electrolyte using only Baytron P alone was 82 to 85 kV and the loss value 15 to 12, and the electrolyte prepared in Example 1 [Baytron P + DMSO (7: 1 weight ratio)] was 96 to 100 kPa and the loss of the electrolyte. Properties superior to values 9-4 were shown.

Example 6

Polyvinyl alcohol (PVA), which is a functional polymer, was added to a mixed electrolyte solution of DMSO and Batron P prepared in Example 1 (Batron P: DMSO = 7: 1) by weight of poly (3,4-ethylenedioxythiophene) 100 10 to 100 parts by weight of the mixed electrolyte was mixed to prepare a mixed electrolyte solution. After the preparation of the electrolyte film by the electrolyte solution, the tensile strength of the electrolyte film was measured and the results are shown in FIG. 7.

As shown in FIG. 7, it can be seen that the tensile strength of the electrolyte film reinforced by polyvinyl alcohol was increased by 10 times or more than the film formed by Baytron P and the electrolyte film prepared in Example 1. In addition, when the amount of polyvinyl alcohol added is about 40% by weight or less with respect to the weight of poly (3,4-ethylenedioxythiophene), the effect of improving the tensile strength is not significant. It can be seen that is large.

Example 7

To 100 parts by weight of water-soluble polypyrrole, a water-soluble conductive polymer, in a mixed electrolyte solution of DMSO and Batron P prepared in Example 1 (weight ratio of Batron P: DMSO = 7: 1) was added to poly (3,4-ethylenedioxythiophene). 5 to 800 parts by weight of the mixed solution was prepared. Absorption intensity to the near infrared region was measured for this mixed electrolyte solution and the results are shown in FIG. 8.

As shown in FIG. 8, it can be seen that the absorption intensity of the near-infrared region is lower than that of Batron P and the electrolyte solution prepared in Example 1, but the optical band energy is shifted toward the lower energy. Therefore, when a solid electrolyte of an EL device and an ECD is prepared using a mixed electrolyte solution in which a blend of two polymers is formed by adding an organic solvent and a water-soluble polypyrrole to a poly (3,4-ethylenedioxythiophene) water suspension. Threshold voltage can be adjusted according to the gap difference, and the anti-corrosion effect, electromagnetic shielding, and the manufacturing of the electrolyte of the absorber can improve the reflection efficiency and absorption efficiency according to the combination of dielectric constant and electrical conductivity.

On the other hand, the water-soluble polypyrrole used in this example was invented by the present inventors, and in the formula (2), the doping material is di (2-ethylhexyl) sulfosuccinic acid, and the water-soluble polypyrrole whose substituent is a sulfonyl chloride group. This water-soluble conductive polypyrrole was prepared as follows.

5 g of polypyrrole powder containing di (2-ethylhexyl) sulfosuccinic acid as a dopant and having no substituent was slowly added to 300 ml of 1,2-dichloroethane at 80 deg. Separately, 9.5 g of chlorosulfonic acid (or ratio of polypyrrole powder to sulfuric acid sulfuric acid was 0.01 to 20 mol) in 20 ml of 1,2-dichloroethane was slowly dissolved. 20 ml of 1,2-dichloroethane in which 9.5 g of chlorosulfonic acid is dissolved at 80 ° C. is dissolved in 300 ml of 1,2-dichloroethane in which 5 g of dopant-containing polypyrrole powder is dissolved for 10 minutes (or 5 minutes). 1 hour) was added slowly. After addition, the reaction was carried out for 1 hour (or 1 minute to 10 hours). After the reaction was completed, the reaction solution was washed with 1,2-dichloroethane in a Buchner funnel, filtered, and the obtained fragment was dissolved in water to prepare a polypyrrole solution substituted with sulfonyl chloride functional groups, or filtered Then, the obtained pieces were put in a drying tube connected to a vacuum line and dried under a dynamic vacuum (10 ^-3 torr) for 5 hours to replace polypyrrole substituted with sulfonyl chloride functional group, a water-soluble and conductive polymer having high solubility. To prepare a powder (Formula 2).

As can be seen from the above, the present invention provides high electrical conductivity by preparing a solid electrolyte and a solid electrolytic capacitor using a poly (3,4-ethylenedioxythiophene) aqueous solution or a mixed electrolyte solution in which an organic solvent is added to an aqueous suspension. A solid electrolyte having a solid electrolyte and a solid electrolytic capacitor having a high capacitance and a low loss value can be obtained. In addition, according to the present invention, a solid electrolyte having improved hardness and strength can be obtained by adding a functional polymer to the mixed electrolyte solution, and a threshold voltage of an EL device can be controlled by adding another conductive polymer, or electromagnetic shielding and corrosion prevention can be obtained. The effect, the reflection efficiency and the absorption efficiency of an absorber can be improved.

Claims (22)

Mixing an organic solvent or an organic or inorganic acid in an aqueous solution of poly (3,4-ethylenedioxythiophene) (PEDT or PEDOT) or water suspension, Coating the mixed solution onto a substrate, and Drying the coating to obtain a solid electrolyte. The method of claim 1, The amount of the organic solvent or organic or inorganic acid to be mixed is in the range of 0.01 to 100 parts by weight based on 100 parts by weight of the aqueous solution or water suspension containing the poly (3,4-ethylenedioxythiophene). Method for producing an electrolyte. The method of claim 1, The poly (3,4-ethylenedioxythiophene) aqueous solution or water suspension is a solid, characterized in that the poly (3,4-ethylenedioxythiophene) aqueous solution or water suspension containing the doping material represented by the formula (1). Method for producing an electrolyte. Formula 1 The method of claim 1, The organic solvent is dimethyl sulfoxide (DMSO), N, N' -dimethylformamide (DMF), N-methyl-2-pyrrolidinone (NMP), tetrahydrofuran (THF), 2-butanone, 4- Polar organic solvents and nonpolar organic solvents consisting of methyl-2-pentanone, chloroform, dichloromethane, xylene and benzene and methyl alcohol, ethyl alcohol, 1-butyl alcohol, isopropyl alcohol, isobutyl alcohol, t -butyl alcohol At least one selected from the group consisting of 1-pentyl alcohol, 1-hexyl alcohol, benzyl alcohol, 2,2,2-trifluoroethanol, lauryl alcohol, oleyl alcohol, and ethylene glycol. Method for producing an electrolyte. The method of claim 1, The organic or inorganic acid is at least one selected from the group consisting of formic acid, acetic acid, capric acid, sulfuric acid, hydrochloric acid, nitric acid, and trifluoroacetic acid. The method of claim 1, At least one selected from the group consisting of a conductive polymer, a surfactant, a coupling agent and a functional polymer is further mixed with the mixed solution. The method of claim 6, The conductive polymer is a water-soluble polypyrrole or a water-soluble polyaniline, and the amount thereof is 1 to 1000 parts by weight based on 100 parts by weight of poly (3,4-ethylenedioxythiophene). The method of claim 6, The amount of the surfactant, coupling agent or functional polymer added is 1 to 100 parts by weight based on 100 parts by weight of poly (3,4-ethylenedioxythiophene). Poly (3,4-ethylenedioxythiophene) (PEDT or PEDOT) was prepared by coating and drying an electrolyte solution in which an organic solvent or an organic or inorganic acid was mixed in an aqueous solution or an aqueous suspension on a substrate. Ethylenedioxythiophene) and a solid electrolyte containing a small amount of an organic solvent or an organic or inorganic acid. The method of claim 9, The amount of the organic solvent or organic or inorganic acid contained in the solid electrolyte is 0.01% by weight of the organic solvent or organic or inorganic acid based on 100 parts by weight of a water suspension having a poly (3,4-ethylenedioxythiophene) content of 1% by weight. By mixing ˜100 parts by weight to form a polymer coating layer on a substrate by a conventional solution casting method in a temperature of 100 ℃ and air, by drying the polymer coating layer in a temperature of 100 ℃ and air for 1 to 48 hours at room temperature Method for producing a solid electrolyte, characterized in that defined. The method of claim 9, The poly (3,4-ethylenedioxythiophene) aqueous solution or water suspension is a solid, characterized in that the poly (3,4-ethylenedioxythiophene) aqueous solution or water suspension containing the doping material represented by the formula (1). Electrolyte. Formula 1 The method of claim 9, The organic solvent is dimethyl sulfoxide (DMSO), N, N' -dimethylformamide (DMF), N-methyl-2-pyrrolidinone (NMP), tetrahydrofuran (THF), 2-butanone, 4- Polar organic solvents and nonpolar organic solvents consisting of methyl-2-pentanone, chloroform, dichloromethane, xylene and benzene and methyl alcohol, ethyl alcohol, 1-butyl alcohol, isopropyl alcohol, isobutyl alcohol, t -butyl alcohol At least one selected from the group consisting of 1-pentyl alcohol, 1-hexyl alcohol, benzyl alcohol, 2,2,2-trifluoroethanol, lauryl alcohol, oleyl alcohol, and ethylene glycol. Electrolyte. The method of claim 9, The organic or inorganic acid is at least one selected from the group consisting of formic acid, acetic acid, capric acid, sulfuric acid, hydrochloric acid, nitric acid, and trifluoroacetic acid. The method of claim 9, At least one further selected from the group consisting of conductive polymers, surfactants, coupling agents and functional polymers. The method of claim 14, The conductive polymer is water-soluble polypyrrole or water-soluble polyaniline, and its content is 1 to 1000 parts by weight based on 100 parts by weight of poly (3,4-ethylenedioxythiophene). The method of claim 14, The content of the surfactant, the coupling agent or the functional polymer is 1 to 100 parts by weight based on 100 parts by weight of poly (3,4-ethylenedioxythiophene). Mixing an organic solvent or an organic or inorganic acid in an aqueous solution of poly (3,4-ethylenedioxythiophene) (PEDT or PEDOT) or water suspension to form an electrolyte solution, Coating and drying the electrolyte solution on an oxide dielectric layer of an oxidized valve metal having micropores or etching pits on its surface to form a solid electrolyte layer, and Forming a cathode electrode on the solid electrolyte layer for electrical connection with an external terminal. The method of claim 17, The poly (3,4-ethylenedioxythiophene) aqueous solution or water suspension is a solid, characterized in that the poly (3,4-ethylenedioxythiophene) aqueous solution or water suspension containing the doping material represented by the formula (1). Method of manufacturing an electrolytic capacitor. Formula 1 The method of claim 17, At least one selected from the group consisting of a conductive polymer, a surfactant, a coupling agent, and a functional polymer is further mixed with the electrolyte solution. Valve metal with micropores or etching pits on its surface as an anode, An oxide of the valve metal as a dielectric layer formed on the valve metal surface, A solid electrolyte layer formed on the dielectric layer, and A negative electrode formed on the solid electrolyte layer, The solid electrolyte layer is formed by coating and drying an electrolyte solution in which an organic solvent or an organic or inorganic acid is mixed with an aqueous poly (3,4-ethylenedioxythiophene) (PEDT or PEDOT) solution or a water suspension on the dielectric layer. A solid electrolytic capacitor comprising poly (3,4-ethylenedioxythiophene) as a main ingredient and containing a small amount of an organic solvent or an organic or inorganic acid. The method of claim 20, The poly (3,4-ethylenedioxythiophene) aqueous solution or water suspension is a solid, characterized in that the poly (3,4-ethylenedioxythiophene) aqueous solution or water suspension containing the doping material represented by the formula (1). Electrolytic Capacitors. Formula 1 The method of claim 20, And at least one selected from the group consisting of a conductive polymer, a surfactant, a coupling agent and a functional polymer is further mixed with the electrolyte solution.