WO2024070288A1 - Condensateur à électrolyte solide et procédé de fabrication - Google Patents

Condensateur à électrolyte solide et procédé de fabrication Download PDF

Info

Publication number
WO2024070288A1
WO2024070288A1 PCT/JP2023/029439 JP2023029439W WO2024070288A1 WO 2024070288 A1 WO2024070288 A1 WO 2024070288A1 JP 2023029439 W JP2023029439 W JP 2023029439W WO 2024070288 A1 WO2024070288 A1 WO 2024070288A1
Authority
WO
WIPO (PCT)
Prior art keywords
electrolyte layer
conductive polymer
solid electrolyte
acid
solid electrolytic
Prior art date
Application number
PCT/JP2023/029439
Other languages
English (en)
Japanese (ja)
Inventor
健太 佐藤
健治 町田
克己 茂垣
恭平 吉岡
Original Assignee
日本ケミコン株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP2023037760A external-priority patent/JP2024050386A/ja
Application filed by 日本ケミコン株式会社 filed Critical 日本ケミコン株式会社
Publication of WO2024070288A1 publication Critical patent/WO2024070288A1/fr

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G9/00—Electrolytic capacitors, rectifiers, detectors, switching devices, light-sensitive or temperature-sensitive devices; Processes of their manufacture
    • H01G9/004—Details
    • H01G9/022—Electrolytes; Absorbents
    • H01G9/025—Solid electrolytes
    • H01G9/028—Organic semiconducting electrolytes, e.g. TCNQ
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G9/00—Electrolytic capacitors, rectifiers, detectors, switching devices, light-sensitive or temperature-sensitive devices; Processes of their manufacture
    • H01G9/145—Liquid electrolytic capacitors
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G9/00—Electrolytic capacitors, rectifiers, detectors, switching devices, light-sensitive or temperature-sensitive devices; Processes of their manufacture
    • H01G9/15—Solid electrolytic capacitors

Definitions

  • the present invention relates to a solid electrolytic capacitor that uses a solid electrolyte layer or a combination of a solid electrolyte layer and a liquid component as the electrolyte, and a manufacturing method thereof.
  • An electrolytic capacitor has anode and cathode foils made of valve metals such as tantalum or aluminum.
  • the anode foil is enlarged by forming the valve metal into a sintered or etched foil, and the enlarged surface has a dielectric film formed by a process such as anodizing.
  • An electrolyte is interposed between the anode and cathode foils.
  • Electrolytic capacitors contain electrolyte in the form of an electrolytic solution.
  • the contact area of the electrolyte with the dielectric film of the anode foil increases. This makes it easier to increase the capacitance of the electrolytic capacitor.
  • the electrolyte evaporates to the outside over time, and the electrolytic capacitor experiences a decrease in capacitance and an increase in dielectric tangent over time, leading to drying out.
  • solid electrolytic capacitors using solid electrolytes have been attracting attention.
  • Manganese dioxide and 7,7,8,8-tetracyanoquinodimethane (TCNQ) complexes are known as solid electrolytes.
  • conductive polymers derived from monomers with ⁇ -conjugated double bonds such as poly(3,4-ethylenedioxythiophene) (PEDOT), which has a slow reaction rate and excellent adhesion to dielectric films, have rapidly become popular as solid electrolytes.
  • Conductive polymers use acid compounds such as polyanions as dopants, or have a partial structure within the monomer molecule that acts as a dopant, resulting in high conductivity. Therefore, solid electrolytic capacitors have the advantage of low equivalent series resistance (ESR).
  • Hybrid-type solid electrolytic capacitors have a driving electrolyte that is impregnated into the voids in the capacitor element in which the solid electrolyte layer is formed.
  • Capacitors are used for a variety of purposes. For example, in the field of power electronics, power from an AC power source is converted to DC power by a converter circuit, and this DC power is then converted to the desired AC power by an inverter circuit. In this type of power supply circuit, smoothing capacitors are provided to suppress pulsations in the DC output from the converter circuit and smooth the DC before inputting it to the inverter circuit. In addition, decoupling capacitors are provided near semiconductor switching elements such as gallium nitride to ensure stable operation of the semiconductor switching elements and to remove noise.
  • the present invention has been proposed to solve the above problems, and its purpose is to provide a solid electrolytic capacitor and a manufacturing method that achieves both low ESR and high voltage resistance.
  • the solid electrolytic capacitor of the present embodiment includes a capacitor element having an anode foil, a cathode body, and an electrolyte
  • the anode foil has a surface enlarged by tunnel-shaped etching pits and has a dielectric coating on the surface
  • the cathode body faces the anode foil
  • the electrolyte includes a solid electrolyte layer containing a conductive polymer
  • the solid electrolyte layer has a weight of 250 mg/cm3 or less per unit volume of the capacitor element.
  • the solid electrolyte layer may include the conductive polymer, a solvent for a conductive polymer liquid in which the conductive polymer is dispersed or dissolved, and an additive added to the conductive polymer liquid, and the total weight of the conductive polymer, the solvent, and the additive may be 250 mg/ cm3 or less per unit volume of the capacitor element.
  • the electrolyte may include only the solid electrolyte layer, and the solid electrolyte layer may have a weight per unit volume of the capacitor element of 120 mg/cm 3 or more and 150 mg/cm 3 or less.
  • the electrolyte may include a liquid component that fills the voids in the capacitor element.
  • the electrolyte may include a liquid component that fills voids in the capacitor element, and the solid electrolyte layer may have a weight per unit volume of the capacitor element of 15 mg/cm 3 or more and 250 mg/cm 3 or less.
  • the electrolyte may include a liquid component that fills voids in the capacitor element, and the solid electrolyte layer may have a weight per unit volume of the capacitor element of 60 mg/cm 3 or more and 180 mg/cm 3 or less.
  • the solid electrolyte layer may contain a compound having a hydroxyl group.
  • the compound having a hydroxyl group may be one or more selected from the group consisting of ethylene glycol, butanediol, diethylene glycol, and glycerin.
  • a method for manufacturing a solid electrolytic capacitor is a method for manufacturing a solid electrolytic capacitor having an anode foil, a cathode body, and a solid electrolyte layer, and includes an anode foil forming step of forming a tunnel-shaped etching pit on a surface of the anode foil and further forming a dielectric film on the surface, an element forming step of forming a capacitor element in which the cathode body faces the anode foil, and an electrolyte layer forming step of attaching a conductive polymer solution in which a conductive polymer is dispersed or dissolved between the anode foil and the cathode body to form the solid electrolyte layer containing the conductive polymer, a solvent for the conductive polymer solution in which the conductive polymer is dispersed or dissolved, and an additive added to the conductive polymer solution, and in the electrolyte layer forming step, the conductive
  • the solid electrolytic capacitor achieves both low ESR and high voltage resistance.
  • Examples 1 to 7 is a graph showing the relationship between the weight of a solid electrolyte layer and the withstand voltage, and the relationship between the weight of a solid electrolyte layer and ESR, in accordance with Examples 1 to 7.
  • 11 is a graph showing the relationship between the weight of the solid electrolyte layer and the withstand voltage, and the relationship between the weight of the solid electrolyte layer and the ESR, relating to Examples 8 to 14.
  • a solid electrolytic capacitor has a pair of electrode bodies and an electrolyte layer.
  • One electrode body is an anode foil with a dielectric film formed on the foil surface.
  • the other electrode body is a cathode body.
  • the cathode body is positioned opposite the anode foil.
  • This pair of electrode bodies is positioned opposite each other with an electrolyte layer in between. The assembly of this pair of electrode bodies and electrolyte layer is called a capacitor element.
  • the capacitor element may include a separator.
  • the separator is placed between the pair of electrode bodies to isolate the anode foil and cathode body to prevent short circuits and to hold the electrolyte layer in place. If the shape of the electrolyte layer can be maintained by itself and the pair of electrode bodies can be isolated by the electrolyte layer, the separator can be omitted from the capacitor element.
  • An anode lead is connected to the anode foil, and a cathode lead is connected to the cathode body.
  • the solid electrolytic capacitor is electrically connected to the mounting circuit via these anode and cathode leads. By being conductive to the mounting circuit, the solid electrolytic capacitor becomes a passive element that obtains capacitance through the dielectric polarization action of the dielectric film and stores and discharges electric charge.
  • anode foil is formed in an anode foil formation process, which enlarges the surface area of the anode foil and then forms a dielectric film.
  • This anode foil is then placed opposite a cathode body in the element formation process to form a capacitor element.
  • This capacitor element is then subjected to a repair chemical treatment.
  • an electrolyte layer formation process is carried out in which a conductive polymer liquid in which conductive polymer particles or powder are dispersed or dissolved is impregnated between the anode foil and the cathode body to form an electrolyte layer.
  • the open end of the case into which the capacitor element is inserted is then sealed with a sealant, and aging is carried out to form a solid electrolytic capacitor.
  • the electrode body is a foil body made of a valve metal.
  • a wound type a long strip shape obtained by stretching the valve metal is often used, while in the flat type, a flat plate obtained by stretching the valve metal is often used.
  • Valve metals include aluminum, tantalum, niobium, niobium oxide, titanium, hafnium, zirconium, zinc, tungsten, bismuth, and antimony. The purity is preferably 99.9% or more for the anode foil and 99% or more for the cathode body, but impurities such as silicon, iron, copper, magnesium, and zinc may be contained.
  • a surface expansion layer is formed on one or both sides of the anode foil.
  • the surface expansion layer is an etching layer having numerous tunnel-shaped etching pits.
  • the tunnel-shaped etching pits are holes dug in the thickness direction of the foil.
  • the tunnel-shaped pits may penetrate the foil, or may be long enough so that their deepest parts remain within the foil.
  • the tunnel-shaped etching pits are typically formed by passing a direct current in an acidic aqueous solution, such as hydrochloric acid, that contains halogen ions.
  • the tunnel-shaped etching pits are further enlarged by passing a direct current in an acidic aqueous solution, such as nitric acid.
  • the cathode body may be, for example, a foil-shaped cathode foil.
  • the cathode body may be a laminate of a metal layer such as silver and a carbon layer.
  • a surface expansion layer may be formed on one or both sides of the cathode foil.
  • a plain foil without a surface expansion layer may be used as the cathode foil.
  • the surface expansion layer of the cathode foil is an etching layer, a sintered layer formed by sintering valve metal powder, or a vapor deposition layer formed by vapor-depositing valve metal particles onto the foil.
  • the surface expansion layer of the cathode foil is made up of tunnel-shaped pits, spongy pits, or gaps between densely packed powder or particles.
  • the dielectric film is formed on the uneven surface of the surface expansion layer.
  • the dielectric film is typically an oxide film formed on the surface of the anode foil. If the anode foil is aluminum foil, it is an aluminum oxide layer formed by oxidizing the surface of the surface expansion layer.
  • a voltage is applied to the anode foil in a chemical conversion solution until the desired withstand voltage is achieved.
  • the chemical conversion solution is a solution that does not contain halogen ions, and examples of such solutions include phosphoric acid-based chemical conversion solutions such as ammonium dihydrogen phosphate, boric acid-based chemical conversion solutions such as ammonium borate, and adipic acid-based chemical conversion solutions such as ammonium adipate.
  • the cathode body may have a natural oxide film or a thin oxide film (about 1 to 10 V) formed by chemical conversion treatment.
  • the natural oxide film is formed when the cathode body reacts with oxygen in the air.
  • the electrolyte layer is attached to at least a part of the dielectric film of the anode foil, and serves as the true cathode of the solid electrolytic capacitor. Preferably, the electrolyte layer is in close contact with the entire dielectric film and connected to the surface of the cathode foil.
  • the electrolyte layer is a solid electrolyte layer, or is composed of a solid electrolyte layer and a liquid component.
  • the solid electrolyte layer contains a conductive polymer.
  • the liquid component is a driving electrolyte solution or a solvent portion of the electrolyte solution that is impregnated in the voids of the capacitor element on which the solid electrolyte layer is formed.
  • Conductive polymers are self-doped conjugated polymers doped with dopant molecules within the molecule or doped with external dopant molecules.
  • Conjugated polymers are obtained by chemical oxidative polymerization or electrolytic oxidative polymerization of monomers or their derivatives having ⁇ -conjugated double bonds.
  • Doped conjugated polymers exhibit high electrical conductivity. In other words, electrical conductivity is exhibited by adding a small amount of dopant, such as an acceptor that easily accepts electrons or a donor that easily gives electrons, to a conjugated polymer.
  • the solid electrolyte layer is formed using a conductive polymer liquid.
  • the conductive polymer liquid is a liquid in which conductive polymer particles or powder are dispersed or dissolved. Additives are added to the conductive polymer liquid as necessary. At least the anode foil, the pair of electrode bodies and the separator, or the capacitor element are immersed in the conductive polymer liquid and then dried after immersion. In addition to immersion, the conductive polymer liquid may be applied by dripping or spraying. As a result, some or all of the unvolatilized solvent remains in the conductive polymer liquid, and the conductive polymer and additives adhere to it, forming the solid electrolyte layer.
  • This solid electrolyte layer has a weight of 250 mg/cm3 or less per unit volume of the capacitor element.
  • the conductive polymer liquid is impregnated and dried so that the total weight of the conductive polymer, the remaining solvent in the conductive polymer liquid, and the additives remains in the capacitor element at a ratio of 250 mg/ cm3 or less per unit volume of the capacitor element.
  • the weight is 250 mg/cm3 or less per unit volume of the capacitor element, both low ESR and high withstand voltage are achieved.
  • the weight per unit volume of the capacitor element exceeds 301 mg/ cm3 , the ESR deteriorates.
  • the weight adjustment of the solid electrolyte layer can be adjusted by changing the type and amount of components that volatilize from the solid electrolyte layer using the drying temperature, drying time, and pressure after immersion in the conductive polymer liquid as variables.
  • the solid electrolytic capacitor When the solid electrolytic capacitor is not of the hybrid type but of the non-hybrid type, and the electrolyte layer has only a solid electrolyte layer and does not contain a liquid compound, the solid electrolyte layer preferably has a density of 120 mg/ cm3 or more and 150 mg/ cm3 or less per unit volume of the capacitor element.
  • the non-hybrid type solid electrolyte layer falls within this range, the ESR is particularly low and minimized, and the withstand voltage is particularly high and maximized.
  • the density deviates above or below this range, the ESR increases compared to this range, and the withstand voltage decreases compared to this range, although the absolute values of the ESR and withstand voltage are low.
  • the voids of the capacitor element are impregnated with a liquid component, and the electrolyte layer is composed of a solid electrolyte layer and a liquid component, the solid electrolyte layer is preferably 15 mg/cm 3 or more and 250 mg/cm 3 or less per unit volume of the capacitor element.
  • the conductive polymer liquid is preferably impregnated and dried so that the total weight of the conductive polymer, the conductive polymer solvent, and the additives remains in the capacitor element at a ratio of 15 mg/cm 3 or more and 250 mg/cm 3 or less per unit volume of the capacitor element.
  • the ESR is particularly low and the withstand voltage is particularly high.
  • the range is deviated above or below, the ESR increases compared to this range, and the withstand voltage decreases compared to this range, although the absolute values are low ESR and high withstand voltage.
  • the solid electrolyte layer is particularly preferably 60 mg/ cm3 to 180 mg/ cm3 per unit volume of the capacitor element. In this range, the ESR is further minimized and the withstand voltage is further maximized.
  • any known conjugated polymer can be used without any particular limitation.
  • Examples include polypyrrole, polythiophene, polyfuran, polyaniline, polyacetylene, polyphenylene, polyphenylenevinylene, polyacene, polythiophenevinylene, etc.
  • conjugated polymers may be used alone, or two or more types may be combined, or they may be copolymers of two or more types of monomers.
  • conjugated polymers formed by polymerizing thiophene or its derivatives
  • conjugated polymers formed by polymerizing 3,4-ethylenedioxythiophene i.e., 2,3-dihydrothieno[3,4-b][1,4]dioxine
  • 3-alkylthiophene 3-alkoxythiophene
  • 3-alkyl-4-alkoxythiophene 3,4-alkylthiophene, 3,4-alkoxythiophene, or derivatives thereof.
  • thiophene derivative a compound selected from thiophenes having substituents at the 3rd and 4th positions is preferred, and the substituents at the 3rd and 4th positions of the thiophene ring may form a ring together with the carbons at the 3rd and 4th positions.
  • the alkyl group or alkoxy group preferably has 1 to 16 carbon atoms.
  • a polymer of 3,4-ethylenedioxythiophene called EDOT i.e., poly(3,4-ethylenedioxythiophene) called PEDOT
  • a substituent may be added to 3,4-ethylenedioxythiophene.
  • an alkylated ethylenedioxythiophene having an alkyl group having 1 to 5 carbon atoms added as a substituent may be used.
  • alkylated ethylenedioxythiophene examples include methylated ethylenedioxythiophene (i.e., 2-methyl-2,3-dihydro-thieno[3,4-b][1,4]dioxine), ethylated ethylenedioxythiophene (i.e., 2-ethyl-2,3-dihydro-thieno[3,4-b][1,4]dioxine), butylated ethylenedioxythiophene (i.e., 2-butyl-2,3-dihydro-thieno[3,4-b][1,4]dioxine), and 2-alkyl-3,4-ethylenedioxythiophene.
  • methylated ethylenedioxythiophene i.e., 2-methyl-2,3-dihydro-thieno[3,4-b][1,4]dioxine
  • ethylated ethylenedioxythiophene i
  • dopant can be used without any particular limitation.
  • a single dopant may be used, or two or more dopants may be used in combination.
  • a polymer or monomer may also be used.
  • dopants include inorganic acids such as polyanions, boric acid, nitric acid, and phosphoric acid, and organic acids such as acetic acid, oxalic acid, citric acid, tartaric acid, squaric acid, rhodizonic acid, croconic acid, salicylic acid, p-toluenesulfonic acid, 1,2-dihydroxy-3,5-benzenedisulfonic acid, methanesulfonic acid, trifluoromethanesulfonic acid, borodisalicylic acid, bisoxalateborate acid, sulfonylimide acid, dodecylbenzenesulfonic acid, propylnaphthalenesulfonic acid, and butylnaphthalenesulfonic acid
  • Polyanions include, for example, substituted or unsubstituted polyalkylenes, substituted or unsubstituted polyalkenylenes, substituted or unsubstituted polyimides, substituted or unsubstituted polyamides, and substituted or unsubstituted polyesters, and include polymers consisting only of structural units having an anionic group, and polymers consisting of structural units having an anionic group and structural units not having an anionic group.
  • polyanions include polyvinyl sulfonic acid, polystyrene sulfonic acid, polyallylsulfonic acid, polyacrylic sulfonic acid, polymethacrylic acid, poly(2-acrylamido-2-methylpropanesulfonic acid), polyisoprene sulfonic acid, polyacrylic acid, polymethacrylic acid, and polymaleic acid.
  • the solvent for the conductive polymer liquid i.e., the remaining solvent in the solid electrolyte layer, is sufficient as long as the conductive polymer disperses or dissolves, and is preferably water or a mixture of water and an organic solvent.
  • organic solvents include polar solvents, alcohols, esters, hydrocarbons, carbonate compounds, ether compounds, chain ethers, heterocyclic compounds, and nitrile compounds.
  • Polar solvents include N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide, etc.
  • Alcohols include methanol, ethanol, propanol, butanol, etc.
  • Esters include ethyl acetate, propyl acetate, butyl acetate, etc.
  • Hydrocarbons include hexane, heptane, benzene, toluene, xylene, etc.
  • Carbonate compounds include ethylene carbonate, propylene carbonate, etc.
  • Ether compounds include dioxane, diethyl ether, etc.
  • Chain ethers include ethylene glycol dialkyl ether, propylene glycol dialkyl ether, polyethylene glycol dialkyl ether, polypropylene glycol dialkyl ether, etc.
  • Heterocyclic compounds include 3-methyl-2-oxazolidinone, etc.
  • Nitrile compounds include acetonitrile, glutarodinitrile, methoxyacetonitrile, propionitrile, benzonitrile, etc.
  • Additives for the conductive polymer liquid include polyhydric alcohols, organic binders, surfactants, dispersants, defoamers, coupling agents, antioxidants, UV absorbers, etc.
  • polyhydric alcohols include sorbitol, ethylene glycol, propanediol, butanediol, pentanediol, hexanediol, heptanediol, octanediol, diethylene glycol, triethylene glycol, polyoxyalkylene glycol, glycerin, polyglycerin, polyoxyalkylene glycerin, xylitol, erythritol, mannitol, dipentaerythritol, pentaerythritol, sulfolane, methylsulfolane, or a combination of two or more of these.
  • the solvent, additive, or both that make up such a conductive polymer liquid are preferably compounds that have hydrophilic groups such as hydroxyl groups or hydrophilic molecules.
  • hydrophilic groups such as hydroxyl groups or hydrophilic molecules.
  • compounds that have hydroxyl groups include polyhydric alcohols such as ethylene glycol, butanediol, diethylene glycol, and glycerin. Compounds that have hydroxyl groups cause changes in the higher-order structure of the conductive polymer, which reduces the ESR of the solid electrolytic capacitor and improves the voltage resistance.
  • polyhydric alcohols have a high boiling point and tend to remain in the electrolyte layer and form a solid electrolyte layer.
  • butanediol, diethylene glycol, polyoxyethylene glycol, glycerin, and sulfolane are particularly preferred as the solvent, additive, or both that make up such a conductive polymer liquid.
  • the boiling points of butanediol, diethylene glycol, polyoxyethylene glycol, glycerin, and sulfolane are high, for example, at 200°C or higher. Therefore, it is thought that this increases the flexibility of the conductive polymer when it is dried after being immersed in the conductive polymer liquid. A conductive polymer with increased flexibility is more likely to adhere to the electrode body. When the adhesion between the conductive polymer and the electrode body is improved, a low ESR can be maintained even with a small amount of solid electrolyte layer.
  • the liquid component is a driving electrolyte or a solvent portion of the driving electrolyte.
  • the solvent for the driving electrolyte include protic organic polar solvents and aprotic organic polar solvents, which may be used alone or in combination of two or more kinds.
  • Protic organic solvents that serve as solvents include monohydric alcohols, polyhydric alcohols, and oxyalcohol compounds.
  • monohydric alcohols include ethanol, propanol, butanol, pentanol, hexanol, cyclobutanol, cyclopentanol, cyclohexanol, and benzyl alcohol.
  • polyhydric alcohols and oxyalcohol compounds include alkylene oxide adducts of polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, glycerin, methyl cellosolve, ethyl cellosolve, methoxypropylene glycol, dimethoxypropanol, polyglycerin, polyethylene glycol, polyoxyethylene glycerin, and polypropylene glycol.
  • aprotic organic polar solvents include sulfones, amides, lactones, cyclic amides, nitriles, and sulfoxides.
  • sulfones include dimethyl sulfone, ethyl methyl sulfone, diethyl sulfone, sulfolane, 3-methyl sulfolane, and 2,4-dimethyl sulfolane.
  • amides include N-methylformamide, N,N-dimethylformamide, N-ethylformamide, N,N-diethylformamide, N-methylacetamide, N,N-dimethylacetamide, N-ethylacetamide, and N,N-diethylacetamide.
  • lactones and cyclic amides include ⁇ -butyrolactone, ⁇ -valerolactone, ⁇ -valerolactone, N-methyl-2-pyrrolidone, ethylene carbonate, propylene carbonate, butylene carbonate, and isobutylene carbonate.
  • nitriles include acetonitrile, 3-methoxypropionitrile, and glutaronitrile.
  • sulfoxides include dimethyl sulfoxide.
  • the solute of the driving electrolyte When the solute of the driving electrolyte is added to the liquid component, the solute is an anion component and a cation component.
  • the solute is typically a salt of an organic acid, a salt of an inorganic acid, or a salt of a complex compound of an organic acid and an inorganic acid, and is used alone or in combination of two or more kinds.
  • An acid that becomes an anion and a base that becomes a cation may be added separately to the solvent.
  • Organic acids that act as anionic solutes include carboxylic acids such as oxalic acid, succinic acid, glutaric acid, pimelic acid, suberic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, maleic acid, adipic acid, benzoic acid, toluic acid, enanthic acid, malonic acid, 1,6-decanedicarboxylic acid, 1,7-octanedioic acid, azelaic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, t-butyl adipic acid, 11-vinyl-8-octadecenedioic acid, resorcylic acid, phloroglucinic acid, gallic acid, gentisic acid, protocatechuic acid, pyrocatechuic acid, trimellitic acid, and pyromellitic acid, as well as phenol
  • Inorganic acids include boric acid, phosphoric acid, phosphorous acid, hypophosphorous acid, carbonic acid, and silicic acid.
  • Examples of composite compounds of organic and inorganic acids include borodisalicylic acid, borodioxalic acid, borodiglycolic acid, borodimalonic acid, borodisuccinic acid, borodiadipic acid, borodiazelaic acid, borodibenzoic acid, borodimaleic acid, borodilactic acid, borodimalic acid, boroditartaric acid, borodicitric acid, borodiphthalic acid, borodi(2-hydroxy)isobutyric acid, borodiresorcylic acid, borodimethylsalicylic acid, borodinaphthoic acid, borodimandelic acid, and borodi(3-hydroxy)propionic acid.
  • examples of at least one salt of an organic acid, an inorganic acid, or a complex compound of an organic acid and an inorganic acid include ammonium salts, quaternary ammonium salts, quaternary amidinium salts, amine salts, sodium salts, potassium salts, etc.
  • examples of quaternary ammonium ions of quaternary ammonium salts include tetramethylammonium, triethylmethylammonium, tetraethylammonium, etc.
  • Examples of quaternary amidinium include ethyldimethylimidazolinium, tetramethylimidazolinium, etc.
  • Examples of amine salts include salts of primary amines, secondary amines, and tertiary amines.
  • Examples of primary amines include methylamine, ethylamine, propylamine, etc.
  • examples of secondary amines include dimethylamine, diethylamine, ethylmethylamine, dibutylamine, etc.
  • examples of tertiary amines include trimethylamine, triethylamine, tributylamine, ethyldimethylamine, ethyldiisopropylamine, etc.
  • additives can be added to the electrolyte.
  • additives include alkylene oxide adducts of polyhydric alcohols such as polyethylene glycol and polyoxyethylene glycerin, complex compounds of boric acid and polysaccharides (mannitol, sorbitol, etc.), complex compounds of boric acid and polyhydric alcohols, boric acid esters, nitro compounds (o-nitrobenzoic acid, m-nitrobenzoic acid, p-nitrobenzoic acid, o-nitrophenol, m-nitrophenol, p-nitrophenol, p-nitrobenzyl alcohol, etc.), and phosphate esters. These may be used alone or in combination of two or more.
  • separator examples include cellulose papers such as kraft, Manila hemp, esparto, hemp, and rayon, and mixed papers thereof; polyester-based resins such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and derivatives thereof; polytetrafluoroethylene-based resins, polyvinylidene fluoride-based resins, vinylon-based resins, polyamide-based resins such as aliphatic polyamides, semi-aromatic polyamides, and fully aromatic polyamides; polyimide-based resins, polyethylene resins, polypropylene resins, trimethylpentene resins, polyphenylene sulfide resins, acrylic resins, and polyvinyl alcohol resins. These resins can be used alone or in combination.
  • Examples 1 to 7 The solid electrolytic capacitors of Examples 1 to 7 and Comparative Example 1 were fabricated as follows. The solid electrolytic capacitors of Examples 1 to 7 and Comparative Example 1 were non-hybrid types, and did not contain any liquid component in the electrolyte layer.
  • both electrodes were made of aluminum foil in the shape of a long strip. Tunnel-shaped pits were formed on both sides of the anode foil by DC etching. A dielectric film was also formed on the anode foil by chemical conversion. In the chemical conversion, the applied voltage reached 650V. Pits were formed on both sides of the cathode foil by AC etching, and an oxide film was formed by chemical conversion at a chemical conversion voltage of 3Vfs. Lead wires were connected to both electrodes, and the two electrodes were wound facing each other with a separator made of Manila hemp in between. A repair chemical conversion was then performed using an aqueous solution of ammonium borate.
  • the capacitor element was immersed in the conductive polymer liquid, and after the conductive polymer liquid was impregnated into the capacitor element, the capacitor element was dried.
  • Polyethylenedioxythiophene doped with polystyrene sulfonic acid (PEDOT/PSS) was dispersed in the conductive polymer liquid as a conductive polymer.
  • the solvent for the conductive polymer liquid was a mixture of water and ethylene glycol. Sorbitol was added to the conductive polymer liquid.
  • the conductive polymer liquid contained 48.5 wt% water, 48.5 wt% ethylene glycol, 1 wt% PEDOT/PSS, and 2 wt% sorbitol.
  • the weight of the solid electrolyte layer differs between Examples 1 to 7 and Comparative Example 1.
  • the weight of the solid electrolyte layer is the weight per unit volume of the capacitor element, and is hereinafter simply referred to as the solid electrolyte layer weight.
  • the solid electrolyte layer weight was adjusted by drying the capacitor element after impregnation with the conductive polymer liquid at 110°C and increasing or decreasing the drying time.
  • the solid electrolytic capacitors of Examples 1 to 7 and Comparative Example 1 were manufactured with the same structure, composition, manufacturing method, and manufacturing conditions, except for the weight of the solid electrolyte layer.
  • the withstand voltage of the solid electrolytic capacitors of Examples 1 to 7 and Comparative Example 1 was measured.
  • the method for measuring the withstand voltage was as follows. That is, a voltage was applied to the solid electrolytic capacitor at 105° C. The initial voltage was 200 V, and the applied voltage was increased by 1 V every 10 seconds. The voltage when the current flowing through the solid electrolytic capacitor reached 1 mA was defined as the withstand voltage.
  • the ESR of the solid electrolytic capacitors of Examples 1 to 7 and Comparative Example 1 was also measured.
  • the method for measuring the withstand voltage is as follows.
  • the ESR was measured at room temperature using an LCR meter manufactured by NF Corporation.
  • the measurement frequency was 100 kHz, and the AC amplitude was a sine wave of 0.5 Vms.
  • Table 1 shows the measurement results of the withstand voltage and ESR together with the weight of the solid electrolyte layer of Examples 1 to 7 and Comparative Example 1.
  • the weight of the solid electrolyte layer is expressed as the amount of solid electrolyte per unit volume of the element.
  • the weight of the solid electrolyte layer is the weight (mg/ cm3 ) converted to a unit volume of the capacitor element, and was varied from 18 mg/ cm3 to 301 mg/ cm3 so that Examples 1 to 7 and Comparative Example 1 had unique values. Note that the weight of each solid electrolyte layer was calculated by subtracting the weight of the capacitor element before immersion in the conductive polymer liquid from the weight of the capacitor element after immersion in the conductive polymer liquid and drying.
  • the withstand voltage exceeds 200 V, and increases significantly as the weight of the solid electrolyte layer increases from 18 mg/ cm3 to 120 mg/ cm3 .
  • the withstand voltage is maximized from 120 mg/ cm3 to 150 mg/ cm3 .
  • the withstand voltage is significantly higher than 200 V, but drops sharply compared to 150 mg/ cm3 . There is little change in the withstand voltage beyond 180 mg/ cm3 .
  • the ESR rapidly decreases as the weight of the solid electrolyte layer increases from 18 mg/ cm3 to 120 mg/ cm3 .
  • the ESR then reaches a minimum between 120 mg/ cm3 and 180 mg/ cm3 .
  • the ESR starts to increase from 250 mg/ cm3 .
  • the ESR at 301 mg/ cm3 and above reaches about 28 times the ESR at 250 mg/ cm3 .
  • a solid electrolytic capacitor with a solid electrolyte weight of 250 mg/ cm3 or less achieves both low ESR and high withstand voltage.
  • a non-hybrid solid electrolytic capacitor with a solid electrolyte weight of 120 mg/ cm3 or more and 150 mg/ cm3 or less achieves both maximized withstand voltage and minimized ESR.
  • Example 8 to 14 solid electrolytic capacitors of Examples 8 to 14 and Comparative Example 2 were produced.
  • the solid electrolytic capacitors of Examples 8 to 14 and Comparative Example 2 were hybrid types, and the electrolyte layer was composed of a solid electrolyte layer and a liquid component.
  • the liquid component was composed of 59.4 wt% ethylene glycol, 39.6 wt% polyethylene glycol, and 1 wt% ammonium azelaate.
  • the average molecular weight of the polyethylene glycol was 1000.
  • the liquid component was impregnated into the capacitor element.
  • the other configurations, compositions, manufacturing methods, and manufacturing conditions were the same as those of Examples 1 to 7 and Comparative Example 1, except for the weight of the solid electrolyte layer.
  • the withstand voltage was measured for the solid electrolytic capacitors of Examples 8 to 14 and Comparative Example 2.
  • the measuring method and conditions for the withstand voltage and ESR were the same as those of Examples 1 to 7 and Comparative Example 1.
  • the method for confirming the weight of each solid electrolyte layer was also the same as those of Examples 1 to 7 and Comparative Example 1.
  • the weight of the solid electrolyte layer is the weight (mg/ cm3 ) converted to a unit volume of the capacitor element, and was changed from 18 mg/ cm3 to 301 mg/ cm3 so that Examples 8 to 14 and Comparative Example 2 had unique values.
  • Table 2 the relationship between the weight of the solid electrolyte layer and the withstand voltage, and the relationship between the weight of the solid electrolyte layer and the ESR are shown in the graph of Figure 2.
  • the plot of square marks indicates the withstand voltage
  • the plot of circle marks indicates the ESR. Note that the ESR is expressed in logarithm.
  • the withstand voltage greatly exceeds 200 V, and increases significantly as the weight of the solid electrolyte layer increases from 18 mg/ cm3 to 120 mg/ cm3 .
  • the withstand voltage is maximized from 60 mg/ cm3 to 180 mg/ cm3 . After 180 mg/ cm3 , the withstand voltage decreases as the weight of the solid electrolyte layer increases. However, even when the weight of the solid electrolyte layer is 301 mg/ cm3 , the withstand voltage greatly exceeds 200 V.
  • the ESR is maintained low regardless of the weight of the solid electrolyte layer from 18 mg/ cm3 to 250 mg/ cm3 .
  • the ESR significantly deteriorates from 301 mg/ cm3 onwards, reaching about 11 times the ESR at 250 mg/ cm3 .
  • a solid electrolytic capacitor with a solid electrolyte layer weight of 250 mg/ cm3 or less achieves both low ESR and high withstand voltage.
  • a hybrid type solid electrolytic capacitor with a solid electrolyte layer weight of 60 mg/ cm3 or more and 150 mg/ cm3 or less achieves both maximized withstand voltage and particularly low ESR.
  • Example 15 to 18 Furthermore, solid electrolytic capacitors of Examples 15 to 18 were produced.
  • the solid electrolytic capacitors of Examples 15 to 18 were of the same non-hybrid type as Example 4, but the solvent of the conductive polymer liquid was different from that of Example 4. Except for the difference in the solvent of the conductive polymer liquid, the solid electrolytic capacitors of Examples 15 to 18 were produced with the same configuration, composition, manufacturing method, and manufacturing conditions as Example 4.
  • the withstand voltage was measured for the solid electrolytic capacitors of Examples 15 to 18.
  • the measuring method and conditions for the withstand voltage and ESR were the same as those in Example 4.
  • the method for confirming the weight of each solid electrolyte layer was also the same as that in Example 4.
  • the solvent of the conductive polymer liquid in Example 4 is ethylene glycol, whereas in Example 15 it is butanediol, in Example 16 it is diethylene glycol, in Example 17 it is glycerin, and in Example 18 it is sulfolane. That is, the solid electrolyte layer in Example 4 contains ethylene glycol as a compound having a hydroxy group.
  • the solid electrolyte layer in Example 15 contains butanediol as a compound having a hydroxy group.
  • the solid electrolyte layer in Example 16 contains diethylene glycol as a compound having a hydroxy group.
  • the solid electrolyte layer in Example 17 contains glycerin as a compound having a hydroxy group.
  • the solid electrolyte layer in Example 18 contains sulfolane as a high boiling point solvent.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Compositions Of Macromolecular Compounds (AREA)

Abstract

Le but de la présente invention est de fournir un condensateur électrolytique solide qui permet d'obtenir à la fois une faible ESR et une tension de tenue élevée. Le condensateur à électrolyte solide comprend une feuille d'électrode positive, un corps d'électrode négative et un élément condensateur ayant un électrolyte. Dans la feuille d'électrode positive, la surface est agrandie par des creux de gravure en forme de tunnel, et un film diélectrique est formé sur la surface. Le corps d'électrode négative fait face à la feuille d'électrode positive. L'électrolyte comprend une couche d'électrolyte solide qui contient un polymère conducteur. Cette couche d'électrolyte solide a un poids de 250 mg/cm3 ou moins par unité de volume de l'élément condensateur.
PCT/JP2023/029439 2022-09-29 2023-08-14 Condensateur à électrolyte solide et procédé de fabrication WO2024070288A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP2022-156870 2022-09-29
JP2022156870 2022-09-29
JP2023037760A JP2024050386A (ja) 2022-09-29 2023-03-10 固体電解コンデンサ及び製造方法
JP2023-037760 2023-03-10

Publications (1)

Publication Number Publication Date
WO2024070288A1 true WO2024070288A1 (fr) 2024-04-04

Family

ID=90477209

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2023/029439 WO2024070288A1 (fr) 2022-09-29 2023-08-14 Condensateur à électrolyte solide et procédé de fabrication

Country Status (1)

Country Link
WO (1) WO2024070288A1 (fr)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011199089A (ja) * 2010-03-23 2011-10-06 Nippon Chemicon Corp 固体電解コンデンサ
JP2013055308A (ja) * 2011-09-06 2013-03-21 Nippon Chemicon Corp 固体電解コンデンサ用分散液の製造方法及び固体電解コンデンサ用分散液、この分散液を用いた固体電解コンデンサの製造方法及び固体電解コンデンサ
JP2014123685A (ja) * 2012-12-21 2014-07-03 Nippon Chemicon Corp 電解コンデンサ及びその製造方法

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011199089A (ja) * 2010-03-23 2011-10-06 Nippon Chemicon Corp 固体電解コンデンサ
JP2013055308A (ja) * 2011-09-06 2013-03-21 Nippon Chemicon Corp 固体電解コンデンサ用分散液の製造方法及び固体電解コンデンサ用分散液、この分散液を用いた固体電解コンデンサの製造方法及び固体電解コンデンサ
JP2014123685A (ja) * 2012-12-21 2014-07-03 Nippon Chemicon Corp 電解コンデンサ及びその製造方法

Similar Documents

Publication Publication Date Title
JP7196919B2 (ja) 固体電解コンデンサ
JP2023176004A (ja) 固体電解コンデンサ
WO2024070288A1 (fr) Condensateur à électrolyte solide et procédé de fabrication
WO2024070287A1 (fr) Condensateur à électrolyte solide
JP2024050386A (ja) 固体電解コンデンサ及び製造方法
JP7509337B1 (ja) 固体電解コンデンサ及び製造方法
TW202414467A (zh) 固體電解電容器及製造方法
TWI838403B (zh) 固體電解電容器
TW202414466A (zh) 固體電解電容器
WO2023171618A1 (fr) Solution électrolytique pour condensateur électrolytique solide et condensateur électrolytique solide
EP4386797A1 (fr) Condensateur à électrolyte solide et son procédé de fabrication
WO2023054502A1 (fr) Condensateur électrolytique solide
WO2024070604A1 (fr) Condensateur à électrolyte solide et procédé de fabrication
WO2023149357A1 (fr) Condensateur à électrolyte solide et procédé de production
WO2024070603A1 (fr) Condensateur à électrolyte solide et son procédé de production
EP4383296A1 (fr) Condensateur à électrolyte solide et procédé de fabrication
JP2022144277A (ja) 導電性高分子分散液、固体電解コンデンサ及び固体電解コンデンサの製造方法

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 23871530

Country of ref document: EP

Kind code of ref document: A1