Electrolytic capacitor

Abstract

An electrolytic capacitor according to the present disclosure comprises a capacitor element including: an anode body extending in a first direction; a dielectric layer covering at least a part of the anode body; and a cathode lead-out layer containing a conjugated polymer and covering at least a part of the dielectric layer. The anode body has a solid electrolyte formation part in which a solid electrolyte layer is formed at least partially along the first direction, an anode part, and a separation part provided between the solid electrolyte formation part and the anode part. The conjugated polymer includes a conductive polymer, and when defining the solid electrolyte layer formed between the cathode lead-out layer and the dielectric layer as a first solid electrolyte layer, the full width at half maximum of the peak is 50 cm-1 to 70 cm-1 when the peak attributed to the CC stretching vibration derived from the conjugated polymer is fitted by a Lorentz function in the Raman spectrum of the first solid electrolyte layer.

Description

electrolytic capacitor

[0001] The present invention relates to an electrolytic capacitor.

[0002] The electrolytic capacitor has a capacitor element including, for example, an anode body, a dielectric layer covering at least a portion of the anode body, a solid electrolyte layer covering at least a portion of the dielectric layer, and a cathode extraction layer covering at least a portion of the solid electrolyte layer. In the capacitor element, the anode body has, for example, a solid electrolyte forming portion at least partially covered with the solid electrolyte layer, an anode portion, and a separator provided between the solid electrolyte forming portion and the anode portion. It is known that such a capacitor element uses a solid electrolyte layer containing a conductive polymer.

[0003] Patent Document 1 listed below describes a solid electrolytic capacitor in which a forbidden zone (corresponding to a separator) is provided in a roughened or porous layer formed on the surface of a valve metal to prevent penetration of a conductive polymer material so as to form at least a boundary between an anode lead portion and a capacitor element portion, and a dielectric oxide film layer, a conductive polymer layer, and a conductor layer are sequentially formed on the surface of the capacitor element portion separated by this forbidden zone, and terminals are attached to the surface of the anode lead portion and to the conductor layer, respectively. Patent Document 1 also describes that the solid electrolytic capacitor configured as described above significantly reduces the probability that the conductive polymer layer will reach the anode lead portion, causing insulation failure or insulation breakdown.

[0004] Patent Document 2 below describes a solid electrolytic capacitor having a shielding layer (corresponding to a separator) formed by laminating multiple layers in a region separating an anode region and a cathode region of a solid electrolytic capacitor substrate having a porous layer on its surface. Patent Document 2 below also describes the use of a first shielding layer, which is formed by laminating directly on the solid electrolytic capacitor substrate, of the laminated shielding layers. Patent Document 2 below also describes the use of a first shielding layer formed from a solution or dispersion of a heat-resistant resin or its precursor, which does not contain a shielding layer modifying additive (excluding a silane coupling agent) or contains 0.1 mass% or less of the shielding layer modifying additive (based on the mass of the heat-resistant resin or its precursor). Patent Document 2 below also describes that the solid electrolytic capacitor configured as described above can more reliably insulate the anode region and the cathode region.

[0005] JP 2000-243665 A International Publication No. 2008 / 038584

[0006] In the electrolytic capacitor described above, the solid electrolyte layer containing the conductive polymer may come into contact with air, and the conductive polymer may be oxidized and deteriorated by the oxygen contained in the air. If the conductive polymer is oxidized and deteriorated, the electrolytic capacitor may not be able to fully exhibit its characteristics.

[0007] However, in any of the known documents, including Patent Documents 1 and 2, sufficient consideration has not yet been given to fully suppressing the oxidative degradation of conductive polymers.

[0008] Therefore, the present disclosure provides an electrolytic capacitor that can sufficiently suppress oxidative degradation of conductive polymers.

[0009] One aspect of the present invention is an electrolytic capacitor including a capacitor element including an anode body extending in a first direction, a dielectric layer covering at least a portion of the anode body, a solid electrolyte layer containing a conjugated polymer and covering at least a portion of the dielectric layer, and a cathode extraction layer covering at least a portion of the solid electrolyte layer, wherein the anode body has, along the first direction, a solid electrolyte forming portion on at least a portion of which the solid electrolyte layer is formed, an anode portion, and a separation portion provided between the solid electrolyte forming portion and the anode portion, the conjugated polymer contains a conductive polymer, and when the solid electrolyte layer formed between the cathode extraction layer and the dielectric layer is referred to as a first solid electrolyte layer, when a peak attributable to a CC stretching vibration derived from the conjugated polymer in a Raman spectrum of the first solid electrolyte layer is fitted with a Lorentzian function, the full width at half maximum of the peak is 50 cm. －１ 70cm or more －１ The following relates to electrolytic capacitors.

[0010] According to the present disclosure, it is possible to provide an electrolytic capacitor that can sufficiently suppress oxidative degradation of a conductive polymer.

[0011] 1A and 1B are cross-sectional views schematically illustrating a capacitor element according to an embodiment of the present disclosure, and an electrolytic capacitor according to an embodiment of the present disclosure.

[0012] Below, embodiments of the present disclosure will be described using examples, but the present disclosure is not limited to the examples described below. In the following description, specific numerical values ​​and materials may be exemplified, but other numerical values, materials, etc. may be applied as long as the effects of the present disclosure are obtained. Note that known components may be applied to components characteristic of the present disclosure. In this specification, when a "range from numerical value A to numerical value B" is mentioned, the range includes numerical value A and numerical value B.

[0013] In the following description, when lower and upper limits of numerical values ​​relating to specific physical properties, conditions, etc. are exemplified, any of the exemplified lower limits and any of the exemplified upper limits can be arbitrarily combined, as long as the lower limit is not equal to or greater than the upper limit. When multiple materials are exemplified, one of them can be selected and used alone, or two or more can be used in combination, unless otherwise specified.

[0014] The present disclosure encompasses any combination of two or more features arbitrarily selected from the appended claims, i.e., any combination of two or more features arbitrarily selected from the appended claims can be combined unless a technical contradiction arises.

[0015] [Electrolytic Capacitor] An electrolytic capacitor according to an embodiment of the present disclosure has a capacitor element including an anode body extending in a first direction, a dielectric layer covering at least a portion of the anode body, a solid electrolyte layer containing a conjugated polymer and covering at least a portion of the dielectric layer, and a cathode extraction layer covering at least a portion of the solid electrolyte layer. In the capacitor element, the anode body has, along the first direction, a solid electrolyte forming portion at least a portion of which is formed with the solid electrolyte layer, an anode portion, and a separation portion provided between the solid electrolyte forming portion and the anode portion. In the capacitor element, the conjugated polymer includes a conductive polymer, and when the solid electrolyte layer formed between the cathode extraction layer and the dielectric layer is defined as a first solid electrolyte layer, when a Lorentzian function is fitted to a peak in the Raman spectrum of the first solid electrolyte layer that is attributed to CC stretching vibration derived from the conjugated polymer, the full width at half maximum of the peak is 50 cm. －１ More than 70cm －１ The following is the result.

[0016] In the electrolytic capacitor according to the embodiment of the present disclosure, it is important that a part of the solid electrolyte layer included in the capacitor element satisfies a specific condition. Specifically, when the solid electrolyte layer formed between the cathode extraction layer and the dielectric layer is defined as the first solid electrolyte layer, when the Lorentzian function of the peak attributable to the CC stretching vibration derived from the conjugated polymer is fitted in the Raman spectrum of the first solid electrolyte layer, the full width at half maximum of the peak must be 50 cm or less.－１ 70cm or more －１ The following is important. The reasons for this are explained below.

[0017] In an anode body having a solid electrolyte forming portion at least partially formed with a solid electrolyte layer along a first direction, an anode portion, and a separator provided between the solid electrolyte forming portion and the anode portion, i.e., in an anode body in which the anode portion, the separator, and the solid electrolyte forming portion are arranged in this order from one end to the other end in the first direction, atmospheric air penetrates into the solid electrolyte layer from one end to the other end in the first direction. When the solid electrolyte layer contains a conductive polymer as a conjugated polymer, the conductive polymer is oxidized and deteriorated by the air that has penetrated into the solid electrolyte layer. When atmospheric air sufficiently penetrates to the other end in the first direction, i.e., when the air sufficiently penetrates into the first solid electrolyte layer formed between the cathode extraction layer and the dielectric layer, oxidative deterioration of the conductive polymer in the first solid electrolyte layer becomes significant. When oxidative deterioration of the conductive polymer in the first solid electrolyte layer becomes significant, the first solid electrolyte layer becomes poor in conductivity, resulting in a decrease in the reliability (e.g., capacity retention) of the electrolytic capacitor.

[0018] However, in the electrolytic capacitor according to the embodiment of the present disclosure, when the Lorentzian function of the peak attributable to the CC stretching vibration derived from the conjugated polymer is fitted in the Raman spectrum of the first solid electrolyte layer, the full width at half maximum of the peak is 50 cm. －１ 70cm or more －１ The following is true. That is, the first solid electrolyte layer contains a highly crystalline conductive polymer. Therefore, it is believed that such a highly crystalline conductive polymer forms a dense structure in the first solid electrolyte layer, which is likely to be able to sufficiently prevent atmospheric air from penetrating into the first solid electrolyte layer. As a result, it is believed that significant oxidative degradation of the conductive polymer due to atmospheric air can be sufficiently prevented in the first solid electrolyte layer.

[0019] As described above, in the Raman spectrum of the first solid electrolyte layer, when fitting the Lorentzian function of the peak attributed to the CC stretching vibration derived from the conjugated polymer, the full width at half maximum of the peak is 50 cm －１ 70cm or more －１ The fact that the first solid electrolyte layer contains a conductive polymer with high crystallinity means that the first solid electrolyte layer contains a conductive polymer with high crystallinity. To increase the crystallinity of the conductive polymer in the first solid electrolyte layer, it is preferable to improve the orientation of the conductive polymer in the first solid electrolyte layer. To improve the orientation of the conductive polymer, it is preferable to polymerize the monomer (hereinafter simply referred to as the monomer) constituting the conductive polymer over a certain period of time. For example, when obtaining a conductive polymer by polymerizing the monomer through electrolytic polymerization, it is preferable to appropriately adjust the electrical energy (e.g., voltage, current, etc.) applied to the region of the solid electrolyte forming section where the first solid electrolyte layer is formed. The higher the electrical energy, the more quickly the monomer is polymerized, resulting in a conductive polymer with lower crystallinity. On the other hand, the lower the electrical energy, the more time it takes for the monomer to polymerize, resulting in a conductive polymer with higher crystallinity.

[0020] Furthermore, when a conductive polymer is obtained by polymerizing a monomer by electrolytic polymerization, it is preferable to gradually apply electrical energy to a region of the solid electrolyte forming portion where a first solid electrolyte layer can be formed. For example, it is preferable to apply electrical energy from one end side (anode portion side) of the anode body toward the other end side (solid electrolyte layer forming portion side). This allows the first solid electrolyte layer to be formed in the solid electrolyte forming portion so as to include a conductive polymer with high crystallinity. Note that, when a solid electrolyte layer (a second solid electrolyte layer described later) is also formed on the separation portion side of the first solid electrolyte layer, the conductive polymer contained in this second solid electrolyte layer may be polymerized quickly or over a certain period of time. In other words, the conductive polymer contained in the second solid electrolyte layer may have low or high crystallinity. For example, the conductive polymer contained in the second solid electrolyte layer may have a peak full width at half maximum of 50 cm or more. －１ 70cm or more－１ The following characteristics may or may not be satisfied.

[0021] In this specification, the Raman spectrum of the first solid electrolyte layer is measured under the following conditions on a cut surface of the first solid electrolyte layer at a predetermined position in the thickness direction.

[0022] Conditions: Raman spectrometer: RamanFORCE PAV manufactured by NanoPhoton, Inc.; Diffraction grating: 600 gr / cm; Measurement wavenumber range: 0 cm －１ More than 2500cm －１ Temperature: 25°C. The wavelength of the irradiated laser light, the laser power density, and the exposure time are determined depending on the type of conjugated polymer. For example, when the conjugated polymer is polypyrrole, the wavelength of the irradiated laser light is 532 nm, and the laser power density is 140 W / cm. ２ When the conjugated polymer is poly(3,4-ethylenedioxythiophene) (PEDOT), the wavelength of the irradiated laser light is 785 nm and the laser power density is 660 W / cm. ２ and the exposure time is 60 seconds.

[0023] For measuring the Raman spectrum, samples collected by the following procedure can be used. The half-width of the peak in the Raman spectrum may be the arithmetic mean value of the measured values ​​for the following measurement samples A to C.

[0024] (1) A solid electrolytic capacitor is embedded in a curable resin, and the curable resin is cured to obtain a cured body containing the electrolytic capacitor. (2) The cured body is polished or cross-section polished to expose a cross section parallel to the thickness direction of the first solid electrolyte layer (a cross section perpendicular to the first direction of the anode body). When the length of the first solid electrolyte layer along the first direction is 1, the cross sections are defined as a cross section located 0 to 0.05 from one end of the first solid electrolyte layer in the first direction (the end closer to the separator) (hereinafter referred to as the first cross section), a cross section located 0 to 0.05 from the other end of the first solid electrolyte layer in the first direction (the end farther from the separator) (hereinafter referred to as the second cross section), and a cross section located 0 to 0.025 from the center of the first solid electrolyte layer in the first direction (the midpoint between the one end and the other end) to one end and the other end, respectively (hereinafter referred to as the third cross section). In this manner, measurement sample A having a first cross section, measurement sample B having a second cross section, and measurement sample C having a third cross section are obtained. (3) For the first cross section of measurement sample A, the second cross section of measurement sample B, and the third cross section of measurement sample C, Raman spectra are measured for one main surface side of the first solid electrolyte layer (the main surface side on which the cathode extraction layer is formed) and the other main surface side of the first solid electrolyte layer (the main surface side covering the dielectric layer). For the one main surface side of the first solid electrolyte layer, Raman spectra are measured for a portion extending from the one main surface to a depth of 10 nm (hereinafter also referred to as a surface portion). For the other main surface side of the first solid electrolyte layer, if holes and depressions (hereinafter also referred to as pits) are formed from the surface of the anode body toward the center due to surface roughening, Raman spectra are measured for portions of the first solid electrolyte layer formed in the pits. Note that when the surface of the anode body is not roughened, Raman spectra are measured for the surface portion of the other main surface side as well as the one main surface side. The full width at half maximum and peak position of the peak attributed to the C-C stretching vibration are determined by arithmetically averaging the measured values ​​at six locations in an 8 μm × 8 μm region of the surface layer portion and at 12 locations in an 8 μm × 8 μm region of the first solid electrolyte layer formed in the pit.

[0025] The configuration of the electrolytic capacitor according to the embodiment of the present disclosure will be described below.

[0026] <Capacitor Element> As described above, the capacitor element includes an anode body extending in a first direction, a dielectric layer covering at least a portion of the anode body, a solid electrolyte layer containing a conjugated polymer and covering at least a portion of the dielectric layer, and a cathode extraction layer covering at least a portion of the solid electrolyte layer.

[0027] (Anode body) As described above, the anode body has, along the first direction, a solid electrolyte forming portion at least partially formed with a solid electrolyte layer, an anode portion, and a separator provided between the solid electrolyte forming portion and the anode portion. The anode portion is a portion of the anode body where the solid electrolyte layer is not formed. A porous portion may be formed on at least one main surface side of the anode body. A core portion may be disposed on the central side of the anode body. A thin-walled portion is formed in part of the separator, and a separator member is disposed in the thin-walled portion.

[0028] The anode body includes a foil (metal foil) containing a valve metal as a conductive material, or a compact or sintered body of particles containing a valve metal. The compact or sintered body has a porous structure. Examples of valve metals include titanium, tantalum, aluminum, and niobium. The anode body includes one or more of the above valve metals. The anode body may include the above valve metal in the form of an alloy or an intermetallic compound. The thickness of the anode body is not particularly limited. When the anode body is a foil, the thickness of the anode body excluding the thin-walled portion is, for example, 15 μm to 300 μm. The thickness is preferably 80 μm to 250 μm. When the anode body is a compact or sintered body, the thickness of the anode body excluding the thin-walled portion is, for example, 15 μm to 5 mm.

[0029] When the anode body is a foil, it is preferable that at least one main surface of the anode body is roughened by electrolytic etching or the like. This allows a porous portion to be formed on at least one main surface of the foil anode body. When the anode body is a molded body or a sintered body, the entire anode body is often porous. On the other hand, from the viewpoint of increasing strength, it is preferable that the anode body has a porous portion formed on at least one main surface and a deep portion disposed on the central side. The porous portion is a region having a large number of fine pores. The core portion is, for example, a region that has not been electrolytically etched.

[0030] (Dielectric Layer) As described above, the dielectric layer covers at least a portion of the anode body. The dielectric layer is formed on at least a portion of the surface of the anode body. The dielectric layer is formed, for example, by anodizing the valve metal of the anode body by chemical conversion treatment or the like. Therefore, the dielectric layer may contain an oxide of the valve metal. For example, when aluminum is used as the valve metal, the dielectric layer may contain an oxide of Al ２ O ３ When tantalum is used as the valve metal, the dielectric layer contains Ta. ２ O ５ The dielectric layer is not limited to this, and may be any layer that functions as a dielectric.

[0031] (Solid electrolyte layer) As described above, the solid electrolyte layer contains a conjugated polymer and covers a part of the dielectric layer. The solid electrolyte layer is formed on a solid electrolyte forming portion of the anode body. The solid electrolyte layer may be formed so as to cover the entire surface of the dielectric layer.

[0032] The conjugated polymer includes a conductive polymer. Examples of the conductive polymer include polypyrrole, polythiophene, polyfuran, polyaniline, polyacetylene, polyphenylene, polyphenylene vinylene, polyacene, and polythiophene vinylene. The conductive polymer may be used alone or in combination of two or more. The conductive polymer may also be a copolymer of two or more monomers.

[0033] In this specification, polypyrrole, polythiophene, polyfuran, polyaniline, etc. refer to polymers having polypyrrole, polythiophene, polyfuran, polyaniline, etc. as their basic skeletons, respectively. Therefore, polypyrrole, polythiophene, polyfuran, polyaniline, etc. also include their respective derivatives. For example, polythiophene includes poly(3,4-ethylenedioxythiophene) (PEDOT).

[0034] The conductive polymer may be included in the solid electrolyte layer together with a dopant. The dopant may be a monomolecular anion or a polymeric anion. Examples of monomolecular anions include paratoluenesulfonic acid and naphthalenesulfonic acid. Examples of polymeric anions include polyvinylsulfonic acid, polystyrenesulfonic acid, polyallylsulfonic acid, polyacrylicsulfonic acid, polymethacrylicsulfonic acid, poly(2-acrylamido-2-methylpropanesulfonic acid), polyisoprenesulfonic acid, and polyacrylic acid. The dopant may be used alone or in combination of two or more. The dopant may be a polymer of a single monomer or a copolymer of two or more monomers. Among these, a polymeric anion derived from polystyrenesulfonic acid (e.g., PSS) is preferred.

[0035] The conductive polymer can be obtained by chemical oxidative polymerization or electrolytic polymerization of a monomer (hereinafter simply referred to as a monomer) that constitutes the conductive polymer.

[0036] Chemical oxidative polymerization can be carried out by chemically oxidizing a monomer using a solvent, an oxidizing agent, a monomer, and, if necessary, a dopant. Examples of solvents that can be used include water, sulfuric acid, methanol, ethanol, propanol, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, chloroform, dichloromethane, carbon tetrachloride, benzene, toluene, xylene, tetrahydrofuran, N-methyl-2-pyrrolidone, and propylene carbonate. The monomer and dopant can be appropriately selected depending on the desired conductive polymer. Examples of oxidizing agents that can be used include ferric oxide, iron(III) tri(p-toluenesulfonate), sodium persulfate, potassium persulfate, ammonium persulfate, hydrogen peroxide, and potassium permanganate. The polymerization conditions for chemical oxidative polymerization can be appropriately selected depending on the types of solvent, oxidizing agent, monomer, and, if necessary, dopant used.

[0037] In electrolytic polymerization, a monomer is polymerized in a solvent to obtain a conductive polymer. In electrolytic polymerization, a dopant may be used as needed. As the solvent, those exemplified above can be used. The monomer and dopant may be appropriately selected depending on the desired conductive polymer.

[0038] Examples of electrolytic polymerization include a method in which a monomer and, if necessary, a dopant compound are dissolved in a solvent (hereinafter referred to as a monomer-containing solvent) by applying a potential sweep method or a constant voltage method using a potentiostat to polymerize the monomer, and a method in which a constant current method is applied to a monomer-containing solvent by using a galvanostat to polymerize the monomer. The dopant compound functions as an electrolyte in the monomer-containing solvent. The conditions for the potential sweep method, constant voltage method, and constant current method can be appropriately selected depending on the type of solvent, monomer, and, if necessary, dopant used.

[0039] The solid electrolyte layer includes at least a first solid electrolyte layer formed between a cathode extraction layer (described later) and a dielectric layer. In addition to the first solid electrolyte layer, the solid electrolyte layer may also include a second solid electrolyte layer formed closer to the separator than the first solid electrolyte layer. The cathode extraction layer is usually not formed on the second solid electrolyte layer. Therefore, the surface of the second solid electrolyte layer is usually exposed. In such cases, the second solid electrolyte layer does not contribute to the development of capacitance of the electrolytic capacitor.

[0040] When the solid electrolyte layer has a second solid electrolyte layer in addition to the first solid electrolyte layer, the thickness L of the first solid electrolyte layer Ｃ１ The thickness L of the second solid electrolyte layer Ｃ２ The ratio (L Ｃ２ / L Ｃ１ ) is L Ｃ２ / L Ｃ１ It is preferable that the relationship of ≦1 / 10 is satisfied. Electropolymerization is usually performed by applying a solvent containing a monomer to a region of the solid electrolyte forming section where a first solid electrolyte layer can be formed (hereinafter referred to as the first region), and then applying electrical energy from the anode section side. For example, it is performed by applying electrical energy to the separation section before the separation member is disposed. At this time, a portion of the solvent containing the monomer may flow from the first region toward the separation section, and a solid electrolyte layer (second solid electrolyte layer) may also be formed in the region between the first region and the separation section (hereinafter referred to as the second region). In such a case, the monomer polymerizes in the second region to form the second solid electrolyte layer, thereby consuming a portion of the electrical energy applied from the anode section side. However, the thickness L of the first solid electrolyte layer Ｃ１ and the thickness L of the second solid electrolyte layer Ｃ２ and satisfy the above relationship, that is, L Ｃ１ L Ｃ２ When the thickness L of the first solid electrolyte layer is sufficiently larger than the thickness L of the first solid electrolyte layer, even if a part of the electrical energy applied from the anode part side is consumed by the polymerization of the monomer in the second region, a sufficient amount of electrical energy can be supplied to the first region. Therefore, even in such a case, the crystallinity of the conductive polymer contained in the first solid electrolyte layer can be sufficiently high.Ｃ１ and the thickness L of the second solid electrolyte layer Ｃ２ can be measured as follows. First, a solid electrolytic capacitor is disassembled to remove the capacitor element, and then a cross-sectional image of the capacitor element is obtained using a scanning electron microscope (SEM). Next, the thicknesses of ten arbitrary points of the first solid electrolyte layer and the second solid electrolyte layer are measured using the image. Then, the measured values ​​obtained for each of the first solid electrolyte layer and the second solid electrolyte layer are arithmetically averaged.

[0041] The solid electrolyte layer may include only the first solid electrolyte layer. By including only the first solid electrolyte layer, as described above, the second region of the solid electrolyte forming portion can be prevented from consuming a portion of the electrical energy applied from the anode portion due to polymerization of the monomer. Therefore, a more sufficient amount of electrical energy can be supplied to the first region, thereby further increasing the crystallinity of the conductive polymer included in the first solid electrolyte layer.

[0042] In the anode body, the separator has a separating member, as described below. When the separator has a separating member, it is preferable that the opposing ends of the first solid electrolyte layer and the separating member in the first direction are spaced apart by 0.18 mm or more. With this configuration, the end of the first solid electrolyte layer and the end of the separating member are sufficiently spaced apart, making it easier to gradually apply electrical energy to the first region, even when electrical energy is supplied from the separator before the separating member is provided, as described above. This makes it easier to further sufficiently increase the crystallinity of the conductive polymer contained in the first solid electrolyte layer.

[0043] As described above, when the separator includes a separating member, the distance in the first direction between the first end of the first solid electrolyte layer and the second end of the separating member facing the first end is preferably 2.8% or more of the length of the anode body. Even in such a configuration, the first end of the first solid electrolyte layer and the second end of the separating member are sufficiently separated from each other, making it easier to gradually apply electrical energy to the first region, even when electrical energy is supplied from the separator before the separating member is provided, as described above. This makes it easier to further sufficiently increase the crystallinity of the conductive polymer contained in the first solid electrolyte layer.

[0044] The first solid electrolyte layer is preferably composed of at least two solid electrolyte layers stacked together. Furthermore, of the at least two solid electrolyte layers, the outermost solid electrolyte layer is preferably formed by electrolytic polymerization. For example, the first solid electrolyte layer preferably includes a first precoat layer and a second layer stacked on the first layer, with the second layer being formed by electrolytic polymerization. The first and second layers preferably contain different conductive polymers. For example, the first layer preferably contains polyaniline as the conductive polymer, and the second layer preferably contains PEDOT / PSS as the conductive polymer. As described above, the first precoat layer contains a conductive polymer, which can increase the rate of electrical energy supply (power supply rate) from the anode when forming the second layer by electrolytic polymerization. This can promote the formation of the second layer. Even when the first solid electrolyte layer is composed of three or more layers, providing a precoat layer as described above as the first layer can promote the formation of the outermost layer when forming this layer by electrolytic polymerization.

[0045] The second solid electrolyte layer is preferably formed solely by electrolytic polymerization. Electrolytic polymerization allows for relatively easy adjustment of the magnitude of electrical energy. Therefore, when the second solid electrolyte layer is formed solely by electrolytic polymerization, it becomes easier to adjust the crystallinity of the conductive polymer contained in the second solid electrolyte layer by adjusting the magnitude of electrical energy. This allows for relatively easy enhancement of the crystallinity of the conductive polymer contained in the second solid electrolyte layer, resulting in the second solid electrolyte layer having excellent heat resistance.

[0046] (Cathode Extraction Layer) As described above, the cathode extraction layer covers at least a portion of the solid electrolyte layer. The cathode extraction layer may be formed so as to cover the entire surface of the solid electrolyte layer. The cathode extraction layer is formed so as to cover at least the first solid electrolyte layer.

[0047] The cathode extraction layer has, for example, a carbon layer and a metal (for example, silver) paste layer formed on the surface of the carbon layer. The cathode extraction layer is not limited to the above configuration and may have any configuration as long as it has a current collecting function.

[0048] <Carbon Layer> The carbon layer contains a carbon material and has electrical conductivity. The carbon material is not particularly limited. Examples of the carbon material include graphite, carbon black, graphene flakes, and carbon nanotubes.

[0049] The carbon layer may contain at least one of a binder resin and an additive, as needed. The binder resin is not particularly limited, and known binder resins used in the manufacture of capacitor elements can be used. Examples of binder resins include thermosetting resins and thermoplastic resins. Examples of thermosetting resins include epoxy resins, polyimide resins, silicone resins, phenolic resins, urea resins, melamine resins, unsaturated polyester resins, and curable acrylic resins. Examples of thermoplastic resins include polyamide resins, polyamideimide resins, polyolefin resins, and polyester resins. Examples of additives include dispersants, surfactants, antioxidants, preservatives, bases, and acids.

[0050] <Metal Paste Layer> The metal paste layer contains a metal material. The metal material is not particularly limited. From the viewpoint of electrical conductivity, the metal material preferably contains silver.

[0051] The volume percentage of the metal material contained in the metal paste layer is not particularly limited as long as it exceeds 0%. In terms of the tendency for the resistance to become low, the volume percentage may be 60% or more, 70% or more, or 80% or more.

[0052] The metal paste layer may contain a binder resin. The volume ratio of the binder resin in the metal paste is not particularly limited. From the viewpoint of electrical resistance, the volume ratio may be 60% or less, 20% or less, or 10% or less. The volume ratio may be 0.1% or more, or may be 0%. The volume ratio of each component in the metal paste layer can be confirmed, for example, by energy dispersive X-ray spectroscopy (SEM-EDX).

[0053] The thickness of the metal paste layer is not particularly limited. For example, the thickness of the metal paste layer may be 0.1 μm or more and 50 μm or less, or 1 μm or more and 20 μm or less. The thickness of the metal paste layer is the arithmetic average value of any five points on a cross section in the thickness direction.

[0054] (Separating Member) The separating member preferably has high insulating properties. The separating member covers at least a portion of the surface of the separating part. This prevents a short circuit from occurring between the anode part and the cathode extraction layer.

[0055] The separation member may be a conventionally known insulating tape (resist tape). The separation member may be formed by adhering a resin composition containing a curable resin to at least a portion of the surface of the separation section. The curable resin may be a thermosetting resin or a photocurable resin. The photocurable resin may be a resin that cures under visible light or ultraviolet light. Examples of curable resins include epoxy resins, polyimide resins, silicone resins, phenolic resins, urea resins, melamine resins, unsaturated polyester resins, furan resins, polyurethane resins, curable acrylic resins, and photoresist resins. The resin composition may contain a curing agent, a curing accelerator, a flame retardant, a filler, a coupling agent, a colorant, a release agent, and an inorganic ion scavenger, as needed. Various known agents may be used. The resin composition may contain a thermoplastic resin (e.g., a polyamide resin, a polyamideimide resin, a polyolefin resin, or a polyester resin) in addition to the curable resin.

[0056] The electrolytic capacitor according to the embodiment of the present disclosure may include at least one of the above-described capacitor elements. For example, when the electrolytic capacitor according to the embodiment of the present disclosure includes multiple capacitor elements, at least one of the multiple capacitor elements may be the above-described capacitor element, and the remaining capacitor elements may be conventionally known capacitor elements. However, in such a case, it is preferable that all of the multiple capacitor elements are the above-described capacitor elements.

[0057] When the electrolytic capacitor according to the embodiment of the present disclosure has multiple capacitor elements, the multiple capacitor elements are stacked. The number of stacked capacitor elements is not particularly limited. The number of stacked capacitor elements is, for example, 2 or more and 20 or less. The anode portions of the stacked capacitor elements are joined by welding or the like and electrically connected to each other. The cathode extraction layers of the stacked capacitor elements are also electrically connected to each other, similar to the anode portions.

[0058] <Exterior Body> The electrolytic capacitor according to the embodiment of the present disclosure may include an exterior body that seals the capacitor element. The exterior body protects the capacitor element from impact, moisture, and the like. The exterior body is configured to cover the entire capacitor element. The exterior body is preferably a resin exterior body. For example, an epoxy resin can be used as the material for the resin exterior body.

[0059] <Lead Frame> The electrolytic capacitor according to the embodiment of the present disclosure may include a lead frame connected to the capacitor element. The electrolytic capacitor according to the embodiment of the present disclosure may include an anode lead frame connected to the anode portion of the capacitor element and a cathode lead frame connected to the cathode lead layer of the capacitor element. The anode lead frame is connected to the anode portion by, for example, welding. The cathode lead frame is connected to the cathode lead layer by, for example, a conductive adhesive or solder, or by resistance welding or laser welding. The conductive adhesive is, for example, a mixture of a curable resin and at least one of carbon particles and metal particles.

[0060] The material of the lead frame is not particularly limited as long as it is electrochemically and chemically stable and conductive. The material of the lead frame may be either metallic or non-metallic. The shape of the lead frame is also not particularly limited. From the viewpoint of reducing the height, the thickness of the lead frame (the distance between the opposing main surfaces of the lead frame) is preferably 25 μm or more and 200 μm or less, and more preferably 25 μm or more and 100 μm or less.

[0061] A portion of the lead frame is sealed together with the capacitor element in an outer package, and the remaining portion of the lead frame exposed from the outer package is joined to a substrate via solder.

[0062] A method for manufacturing an electrolytic capacitor according to an embodiment of the present disclosure includes at least a capacitor element fabrication step of fabricating a capacitor element, the capacitor element fabrication step including a dielectric layer formation substep of forming a dielectric layer to cover at least a portion of an anode body, a solid electrolyte layer formation substep of forming a solid electrolyte layer containing a conjugated polymer to cover at least a portion of the dielectric layer, and a cathode extraction layer formation substep of covering at least a portion of the solid electrolyte layer.

[0063] The dielectric layer forming substep can be performed by subjecting at least a portion of the anode body to a chemical conversion treatment. The chemical conversion treatment can be performed, for example, by immersing at least a portion of the anode body in a chemical conversion solution to impregnate at least a portion of the surface of the anode body with the chemical conversion solution, and then applying a voltage between the anode body as an anode and a cathode immersed in the chemical conversion solution.

[0064] The solid electrolyte layer formation substep can be performed, for example, by attaching a monomer of a conductive polymer (hereinafter simply referred to as the monomer) to at least a portion of the dielectric layer, and then chemically oxidizing or electrolytically polymerizing the monomer on at least a portion of the dielectric layer to form a conductive polymer layer. The attachment of the monomer to at least a portion of the dielectric layer can be performed by immersing at least a portion of the anode body on which the dielectric layer has been formed in a polymerization solution containing the monomer. When the anode body has an anode portion, a separator, and a solid electrolyte forming portion in this order along the first direction as described above, the solid electrolyte forming portion may be immersed in the polymerization solution to a position a predetermined distance away from the separator, and then chemically oxidizing polymerization and electrolytic polymerization may be performed. When electrolytically polymerizing the monomer, a voltage in the range of 1 V to 5 V may be applied to the anode body as electrical energy. Furthermore, electrical energy may be applied from the separator using a power supply tape.

[0065] The conductive polymer layer may be formed by applying a treatment liquid containing a conductive polymer onto a dielectric layer to form a coating film, and then drying the coating film. For example, poly(3,4-ethylenedioxythiophene) (PEDOT) is used as the conductive polymer. For example, polystyrene sulfonic acid (PSS) is used as the dopant. The treatment liquid is a dispersion or solution of the conductive polymer. For example, the dispersion medium (solvent) may be water, an organic solvent, or a mixture thereof.

[0066] The cathode extraction layer forming substep can be performed by, for example, sequentially laminating a carbon layer and a silver paste layer on at least a portion of the solid electrolyte layer.

[0067] The method for manufacturing an electrolytic capacitor according to an embodiment of the present disclosure may include, in addition to the capacitor element manufacturing process, a lead frame connecting process for connecting a lead frame to the capacitor element, and a sealing process for sealing the capacitor element and the lead frame.

[0068] In the lead frame joining step, the anode lead frame is connected to the anode body of the capacitor element, and the cathode lead frame is connected to the cathode extraction layer of the capacitor element. The anode lead frame is connected to the anode body by, for example, welding, and the cathode lead frame is connected to the cathode extraction layer by, for example, a conductive adhesive.

[0069] In the sealing process, the entire capacitor element and at least a portion of the anode lead frame and the cathode lead frame are covered with a sealing resin. In the sealing process, an exterior body is formed from the sealing resin. For example, an epoxy resin can be used as the sealing resin. The remaining portions of the anode lead frame and the cathode lead frame exposed from the exterior body are joined to a substrate via solder.

[0070] Hereinafter, a capacitor element according to an embodiment will be described with reference to Fig. 1, and an electrolytic capacitor according to an embodiment will be described with reference to Fig. 2. However, the embodiments of the present disclosure are not limited to the following aspects.

[0071] FIG. 1 is a cross-sectional view schematically showing a capacitor element according to one embodiment.

[0072] Capacitor element 110 has, for example, a sheet shape. Capacitor element 110 includes anode body 11 extending in a first direction, dielectric layer 12 covering at least a portion of the anode body, solid electrolyte layer 13 covering at least a portion of dielectric layer 12, and cathode extraction layer 14 covering at least a portion of solid electrolyte layer 13. Cathode extraction layer 14 has carbon layer 141 and metal paste layer 142. Note that in capacitor element 110 shown in FIG. 1 , solid electrolyte layer 13 is the first solid electrolyte layer. That is, a second solid electrolyte layer is not shown in FIG. 1 .

[0073] The anode body 11 has a solid electrolyte forming portion 11c at least partially covered with a solid electrolyte layer 13, an anode portion 11a, and a separation portion 11b provided between the solid electrolyte forming portion 11c and the anode portion 11a. In the example shown in FIG. 1 , porous portions (not shown) are formed on both main surfaces of the anode body 11. A core portion (not shown) is interposed between the two porous portions formed on both main surfaces. A thin portion is formed in part of the separation portion 11b. A separation member 15 is disposed on the surface of the thin portion.

[0074] 2 is a cross-sectional view schematically illustrating an electrolytic capacitor according to one embodiment. Electrolytic capacitor 100 includes one or more capacitor elements 110, an anode lead frame 120A joined to an anode portion 11a, a cathode lead frame 120B joined to a cathode extraction layer, and a sealing resin 130 that seals capacitor elements 110.

[0075] (Additional Note) The above description discloses the following technology: (Technology 1) An electrolytic capacitor including a capacitor element including an anode body extending in a first direction, a dielectric layer covering at least a portion of the anode body, a solid electrolyte layer containing a conjugated polymer and covering at least a portion of the dielectric layer, and a cathode extraction layer covering at least a portion of the solid electrolyte layer, wherein the anode body has, along the first direction, a solid electrolyte forming portion at least a portion of which is formed with the solid electrolyte layer, an anode portion, and a separation portion provided between the solid electrolyte forming portion and the anode portion, the conjugated polymer includes a conductive polymer, and when the solid electrolyte layer formed between the cathode extraction layer and the dielectric layer is defined as a first solid electrolyte layer, in a Raman spectrum of the first solid electrolyte layer, a peak attributed to CC stretching vibration derived from the conjugated polymer is fitted with a Lorentz function, the full width at half maximum of the peak is 50 cm －１ More than 70cm －１ The solid electrolyte forming portion has a second solid electrolyte layer formed closer to the separator than the first solid electrolyte layer, and a thickness L of the first solid electrolyte layer is Ｃ１ the thickness L of the second solid electrolyte layer Ｃ２ The ratio (L Ｃ２ / L Ｃ１ ) is L Ｃ２ / L Ｃ１≦1 / 10。 (Technology 3) The electrolytic capacitor according to Technology 1, wherein the solid electrolyte forming portion has only the first solid electrolyte layer. (Technology 4) The electrolytic capacitor according to any one of Technology 1 to 3, wherein the separating portion has a separating member, and wherein opposing end portions of the first solid electrolyte layer and the separating member in the first direction are spaced apart by 0.18 mm or more. (Technology 5) The electrolytic capacitor according to any one of Technology 1 to 3, wherein the separating portion has a separating member, and wherein the length in the first direction between a first end portion of the first solid electrolyte layer and a second end portion of the separating member opposing the first end portion is 2.8% or more of the length of the anode body. (Technology 6) The electrolytic capacitor according to any one of Technology 1 to 5, wherein the first solid electrolyte layer is configured by stacking at least two solid electrolyte layers. (Technology 7) The electrolytic capacitor according to Technology 6, wherein the outermost solid electrolyte layer of the at least two solid electrolyte layers is formed by electrolytic polymerization. (Technology 8) The electrolytic capacitor according to any one of Technology 2 and Technology 4 to 7, wherein the second solid electrolyte layer is formed only by electrolytic polymerization.

[0076] While the present invention has been described in terms of presently preferred embodiments, such disclosure should not be interpreted as limiting. Various changes and modifications will no doubt become apparent to those skilled in the art to which the present invention pertains upon reading the above disclosure. It is therefore intended that the appended claims be interpreted to cover all changes and modifications that do not depart from the true spirit and scope of the invention.

[0077] Hereinafter, the present disclosure will be specifically described based on examples and comparative examples, but the present disclosure is not limited to the following examples.

[0078] (Example 1) (1) Fabrication of Capacitor Element An aluminum foil (thickness: 100 μm) was prepared as an anode body. Then, both main surfaces of this aluminum foil were subjected to an etching treatment to obtain an anode body having porous portions (thickness: 35 μm on both main surfaces) on both main surfaces. While the anode body was immersed in a phosphoric acid solution with a concentration of 0.3 mass % (liquid temperature: 70° C.), a direct current voltage of 70 V was applied for 20 minutes to form aluminum oxide (Al ２ O ３ A dielectric layer containing SiO 2 was formed.

[0079] The anode body on which the dielectric layer was formed was divided into an anode portion, a solid electrolyte forming portion, and a separation portion interposed therebetween, and part of the separation portion was compressed by press working to form a thin portion (thickness: 35 μm).An insulating resist tape (separation member) was then attached to the thin portion.

[0080] The solid electrolyte forming portion of the anode body was immersed in a liquid composition containing a conductive material (polyaniline) to form a precoat layer on the solid electrolyte forming portion. The solid electrolyte forming portion was immersed in the liquid composition up to a position 0.18 mm away from the separation portion. A polymerization solution containing pyrrole (a monomer of a conductive polymer), naphthalenesulfonic acid (a dopant), and water was prepared. The solid electrolyte forming portion with the precoat layer formed thereon was immersed in the obtained polymerization solution, and then electrolytic polymerization was performed at an applied voltage of 3 V to form a solid electrolyte layer on the precoat layer. This solid electrolyte layer corresponds to the first solid electrolyte layer described in the above embodiment section. Voltage was applied from the separation portion using a power supply tape. The solid electrolyte forming portion was also immersed in the polymerization solution up to a position 0.18 mm away from the separation portion.

[0081] A dispersion of graphite particles dispersed in water was applied to the surface of the solid electrolyte layer to form a coating, and the coating was then dried. This resulted in a carbon layer being formed on the solid electrolyte layer. Next, a silver paste containing silver particles and a binder resin (epoxy resin) was applied to the surface of the carbon layer to form a coating, and the coating was then heated to harden the binder resin. This resulted in a silver paste layer (15 μm thick) being formed on the carbon layer. In this way, a cathode extraction layer composed of a carbon layer and a silver paste layer was formed so as to cover a portion of the solid electrolyte layer, thereby obtaining a capacitor element according to Example 1.

[0082] The above procedure was repeated to produce seven capacitor elements according to Example 1, and then these seven capacitor elements were stacked so that the ends of the anode portions and the ends of the cathode extraction layers were aligned to obtain a laminate of capacitor elements. The seven anode portions in this laminate of capacitor elements were then joined together by laser welding.

[0083] (2) Assembly of the electrolytic capacitor Two lead frames (Sn-plated copper lead frames) were joined to the laminate of the capacitor elements. Next, the entire laminate of the capacitor elements and parts of each lead frame were sealed with a sealing material containing a biphenyl-type epoxy resin to form an exterior package. This resulted in the electrolytic capacitor of Example 1.

[0084] Example 2 An electrolytic capacitor according to Example 2 was obtained in the same manner as in Example 1, except that the solid electrolyte forming portion was immersed in the liquid composition up to a position 0.29 mm away from the separation portion to form a precoat layer, and the solid electrolyte forming portion was immersed in the polymerization liquid up to a position 0.29 mm away from the separation portion to form a solid electrolyte layer on the precoat layer.

[0085] Example 3 An electrolytic capacitor according to Example 3 was obtained in the same manner as in Example 1, except that the solid electrolyte forming portion was immersed in the liquid composition up to a position 0.22 mm away from the separation portion to form a precoat layer, and the solid electrolyte forming portion was immersed in the polymerization liquid up to a position 0.22 mm away from the separation portion to form a solid electrolyte layer on the precoat layer.

[0086] Example 4 An electrolytic capacitor according to Example 4 was obtained in the same manner as in Example 1, except that the solid electrolyte forming portion was immersed in the liquid composition up to a position 0.27 mm away from the separation portion to form a precoat layer, and the solid electrolyte forming portion was immersed in the polymerization liquid up to a position 0.27 mm away from the separation portion to form a solid electrolyte layer on the precoat layer.

[0087] Example 5 An electrolytic capacitor according to Example 5 was obtained in the same manner as in Example 1, except that the solid electrolyte forming portion was immersed in the liquid composition up to a position 0.25 mm away from the separation portion to form a precoat layer, and the solid electrolyte forming portion was immersed in the polymerization liquid up to a position 0.25 mm away from the separation portion to form a solid electrolyte layer on the precoat layer.

[0088] Comparative Example 1 An electrolytic capacitor according to Comparative Example 1 was obtained in the same manner as in Example 1, except that the solid electrolyte forming portion was immersed in a liquid component up to the boundary with the separation portion to form a precoat layer, and the solid electrolyte forming portion was immersed in a polymerization liquid up to the boundary with the separation portion to form a solid electrolyte layer on the precoat layer.

[0089] For the electrolytic capacitors of Examples 1 to 5 and the electrolytic capacitor of Comparative Example 1, the Raman spectra of the solid electrolyte layers (first solid electrolyte layers) were measured according to the method described in the above embodiment section, and the full width at half maximum of the peaks attributed to C-C stretching vibrations was determined. The full width at half maximum of the peaks in the first cross section of Sample A, the second cross section of Sample B, and the third cross section of Sample C are shown in Table 1 below. As described above, when the length of the first solid electrolyte layer along the first direction is 1, the first cross section is a cross section located 0 to 0.05 away from one end of the first solid electrolyte layer in the first direction (the end closer to the separation portion), the second cross section is a cross section located 0 to 0.05 away from the other end of the first solid electrolyte layer in the first direction (the end farther from the separation portion), and the third cross section is a cross section located 0 to 0.025 away from the center of the first solid electrolyte layer in the first direction (the midpoint between the end on one end and the end on the other end). In Example 1, the arithmetic mean value of the half width of the peaks in the first to third cross sections was 68.7 cm －１In Example 2, it is 66.2 cm －１ In Example 3, it is 67.1 cm －１ In Example 4, it is 66.4 cm －１ In Example 5, it is 67.5 cm －１ In Comparative Example 1, it is 77.4 cm －１ is.

[0090]

[0091] <Evaluation> Capacitance Change Rate The initial capacitance C0 (μF) of the electrolytic capacitor of each example was measured at a frequency of 120 kHz using a four-terminal LCR meter in an environment of 20°C. The arithmetic average value for 20 electrolytic capacitors was then calculated. Next, an accelerated test was performed by applying a rated voltage to the electrolytic capacitor of each example for 3,000 hours in an environment of 145°C. Thereafter, the capacitance C1 (μF) after the accelerated test was measured in an environment of 20°C using the same procedure as for the initial capacitance, and the arithmetic average value for the 20 electrolytic capacitors was calculated. The capacitance change rate (%) for each electrolytic capacitor of each example was then calculated using the following formula: Capacitance change rate (%) = (C0 - C1) / C0 × 100

[0092] The capacitance change rate (%) of the electrolytic capacitor according to each example is shown in Table 2 below.

[0093]

[0094] Table 2 shows that the electrolytic capacitors according to Examples 1 to 5 had capacitance change rates of less than 10%, i.e., capacitance retention rates of greater than 90%. In contrast, the electrolytic capacitor according to Comparative Example 1 had capacitance change rates of greater than 99%, i.e., capacitance retention rates of less than 1%. This indicates that the electrolytic capacitors according to Examples 1 to 5 were able to adequately maintain capacitance because the conductive polymer contained in the first solid electrolyte layer formed between the cathode extraction layer and the dielectric layer had high crystallinity, whereas the electrolytic capacitor according to Comparative Example 1 was unable to adequately maintain capacitance because the conductive polymer contained in the first solid electrolyte layer had reduced crystallinity. It also indicates that the capacitance retention rate could be increased by separating the end of the separator from the end of the first solid electrolyte layer by 0.18 mm or more.

[0095] (Test Examples 1 to 12) When the distance in the first direction between the first end portion of the first solid electrolyte layer and the second end portion of the separating member facing the first end portion is defined as LA and the length of the anode body is defined as LB, the ratio of LA to LB (LA / LB × 100) was changed as shown in Table 3 below to prepare electrolytic capacitors according to Test Examples 1 to 12. Then, the capacitance retention rates of the electrolytic capacitors according to Test Examples 1 to 12 were evaluated in the same manner as above. The results are shown in Table 3 below.

[0096]

[0097] Table 3 shows that, except for Test Example 10, in which the ratio of LA to LB (LA / LB × 100) was 2.4%, the capacitance change rate was less than 10%, i.e., the capacitance retention rate was greater than 90%, which is a particularly good result. This shows that, for example, by setting LA / LB × 100 to 2.8% or more, the capacitance can be particularly well maintained. This shows that the conductive polymer contained in the first solid electrolyte layer formed between the cathode extraction layer and the dielectric layer exhibits particularly high crystallinity.

[0098] The electrolytic capacitor according to the present disclosure can be used in applications where oxidative degradation of a conductive polymer must be sufficiently suppressed.

[0099] 100: Electrolytic capacitor 110: Capacitor element 11: Anode body 12: Dielectric layer 13: Solid electrolyte layer 14: Cathode lead layer 141: Carbon layer 142: Metal paste layer 15: Separation member 120A: Anode lead frame 120B: Cathode lead frame 130: Sealing resin

Claims

1. An electrolytic capacitor having a capacitor element including an anode body extending in a first direction, a dielectric layer covering at least a portion of the anode body, a solid electrolyte layer containing a conjugated polymer and covering at least a portion of the dielectric layer, and a cathode extraction layer covering at least a portion of the solid electrolyte layer, wherein the anode body has, along the first direction, a solid electrolyte forming portion at least a portion of which is formed with the solid electrolyte layer, an anode portion, and a separation portion provided between the solid electrolyte forming portion and the anode portion, the conjugated polymer includes a conductive polymer, and when the solid electrolyte layer formed between the cathode extraction layer and the dielectric layer is defined as a first solid electrolyte layer, in a Raman spectrum of the first solid electrolyte layer, a peak attributable to CC stretching vibration derived from the conjugated polymer is fitted with a Lorentz function, the full width at half maximum of the peak is 50 cm. －１ 70cm or more －１ Below is an electrolytic capacitor.

2. The solid electrolyte forming portion has a second solid electrolyte layer formed closer to the separating portion than the first solid electrolyte layer, and a thickness L of the first solid electrolyte layer Ｃ１ the thickness L of the second solid electrolyte layer Ｃ２ The ratio (L Ｃ２ / L Ｃ１ ) is L Ｃ２ / L Ｃ１ The electrolytic capacitor according to claim 1 , wherein the relationship: ≦1 / 10 is satisfied.

3. The electrolytic capacitor according to claim 1, wherein the solid electrolyte forming portion has only a first solid electrolyte layer.

4. The electrolytic capacitor according to any one of claims 1 to 3, wherein the separating section has a separating member, and opposing end portions of the first solid electrolyte layer and the separating member in the first direction are spaced apart by 0.18 mm or more.

5. The electrolytic capacitor according to any one of claims 1 to 3, wherein the separating portion has a separating member, and the length in the first direction that is separated between a first end portion of the first solid electrolyte layer and a second end portion of the separating member that faces the first end portion is 2.8% or more of the length of the anode body.

6. The electrolytic capacitor according to any one of claims 1 to 3, wherein the first solid electrolyte layer is formed by laminating at least two solid electrolyte layers.

7. The electrolytic capacitor according to claim 6, wherein the outermost solid electrolyte layer of the at least two solid electrolyte layers is formed by electrolytic polymerization.

8. The electrolytic capacitor according to claim 2, wherein the second solid electrolyte layer is formed solely by electrolytic polymerization.

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