JP6500205B2 - Method of manufacturing storage device - Google Patents

Description

  The present invention relates to a storage device used in various electronic devices, industrial devices, automotive devices and the like, and a method of manufacturing the same.

  With the increasing frequency of electronic devices, a large-capacity electrolytic capacitor excellent in equivalent series resistance (hereinafter referred to as ESR) characteristics in a high frequency region is also required for an electrolytic capacitor which is one of storage devices. Recently, in order to reduce ESR in such a high frequency region, a solid electrolytic capacitor using a solid electrolyte such as a conductive polymer having a higher conductivity than that of a conventional electrolytic solution as an electrolyte is studied and commercialized. There is. In addition, to meet the demand for larger capacity, a wound solid electrolyte having a configuration in which a conductive polymer is filled in the element wound with a separator interposed between the anode foil and the cathode foil. Capacitors have been commercialized.

  However, in the solid electrolytic capacitor as described above, since only the solid electrolyte having poor repairability of the dielectric oxide film is used as the electrolyte, the leakage current increases or the electrolytic capacitor using the conventional electrolytic solution increases. A short circuit failure or the like is likely to occur due to the occurrence of dielectric oxide film defects. Therefore, it is difficult for a solid electrolytic capacitor to constitute a capacitor with a high withstand voltage.

  On the other hand, for the purpose of solving the above-mentioned problems, an electrolytic capacitor using both a solid electrolyte formed of a conductive polymer and an electrolytic solution as an electrolyte has been proposed. In this electrolytic capacitor, a separator paper such as manila paper or kraft paper, or a porous film or a synthetic fiber non-woven fabric is used as a separator substrate. The separator base material is made conductive by depositing a conductive polymer, and the conductive separator (hereinafter, conductive separator) is interposed between the anode foil and the cathode foil to form a capacitor element. The capacitor element thus formed is impregnated with an electrolytic solution and used (for example, Patent Document 1).

Unexamined-Japanese-Patent No. 7-283086 gazette

  As described above, in the electrolytic capacitor using both the solid electrolyte and the electrolytic solution as the electrolyte, it was possible to achieve both ESR and withstand voltage. However, in the recent trend of increasing the frequency of electronic devices, further reduction of ESR is required.

  Then, this invention aims at providing the electrical storage device which reduced ESR especially in the electrical storage device using a conductive separator, and its manufacturing method.

  In order to achieve the above object, an electricity storage device according to the present invention comprises an anode body, an electricity storage element having a cathode body facing the anode body, a separator interposed between the anode body and the cathode body, and an electrolytic solution And the separator has a separator substrate on which the conductive polymer is deposited, and the density of the first surface of the separator substrate opposite to the anode body is the density of the second surface opposite to the cathode body. Lower than.

  In addition, the method of manufacturing the electricity storage device of the present invention has the following configuration.

  A liquid agent impregnating step of impregnating a separator base material with a liquid agent which is a solution or dispersion liquid of a conductive polymer, an anode body facing the first surface of the separator base body, and a cathode body on the second surface of the separator base material It is provided with a storage element forming step of forming a storage element opposite to each other, and an electrolytic solution impregnation step of impregnating the storage element with an electrolytic solution, and the density of the first surface side of the separator base opposite to the anode is The density is lower than the density on the opposing second surface side.

  According to the power storage device and the method of manufacturing the same of the present invention, the ESR of the power storage device can be reduced.

Sectional view of an electrolytic capacitor according to an embodiment of the present invention (A) An exploded perspective view of capacitor element 12 of the electrolytic capacitor shown in FIG. 1, (b) A diagram for explaining the stacking relationship of the anode body, the cathode body and the separator in capacitor element 12 shown in FIG. Partial cross-sectional schematic view of the capacitor element shown in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the dimensions are changed for easy understanding.

Embodiment
FIG. 1 is a cross-sectional view of an electrolytic capacitor 1 which is an example of a power storage device according to an embodiment of the present invention. FIG. 2A is an exploded perspective view of a capacitor element 12 to be a storage element of the electrolytic capacitor 1 shown in FIG. FIG. 2 (b) is a view showing a stacking relationship for describing the structure of the capacitor element 12. FIG. 3 shows a capacitor element 12 having a positive electrode 21 and a negative electrode 22 shown in FIGS. 2A and 2B and a separator 23 interposed between the positive electrode 21 and the negative electrode 22 and an electrolyte 16. It is a partial cross section schematic diagram for explaining.

  The electrolytic capacitor 1 has a capacitor element 12, an electrolytic solution 16 and an exterior body 15. As shown in FIG. 2A, the capacitor element 12 includes an anode body 21 made of anode foil, a cathode body 22 made of cathode foil, and a separator 23 interposed between the anode body 21 and the cathode body 22. Prepare.

  An anode lead 11 A is connected to the anode body 21, and a cathode lead 11 B is connected to the cathode body 22. As shown in FIG. 2B, in the capacitor element 12, an anode body 21, a separator 23, and a cathode body 22 are stacked. The exterior body 15 is formed of a bottomed cylindrical case 13 and a sealing body 14, and seals the capacitor element 12 and the electrolytic solution 16.

  The anode body 21 is formed by subjecting the roughened surface of the metal foil 21A made of a valve metal such as aluminum to a chemical conversion treatment. That is, the anode body 21 has the dielectric oxide film 21B on the surface. On the other hand, the cathode body 22 is formed of metal foil such as aluminum. In addition, the cathode body 22 may be provided with a chemical conversion film on the surface of a metal foil such as aluminum, or may be provided with a film of a dissimilar metal or a nonmetal. Examples of dissimilar metals and nonmetals include metals such as titanium and nonmetals such as carbon.

As shown in FIG. 2B, the anode lead 11A and the cathode lead 11B, each of which has one end formed flat, are joined to the strip-like anode body 21 and the cathode body 22 by ultrasonic welding, needle caulking, etc. There is. The other end of the anode lead 11A and the cathode lead 11B is drawn out from the same end face of the capacitor element 12. It is preferable that the junctions of at least the anode body 21 and the cathode body 22 of the anode lead 11A and the cathode lead 11B be made of the same material as the anode body 21 and the cathode body 22.

  As shown in FIG. 3, the conductive polymer 25 serving as a solid electrolyte is attached to the separator substrate 24 over substantially the entire thickness direction of the separator 23 as shown in FIG. The conductive polymer 25 deposited on the side 23A and the conductive polymer 25 deposited on the second surface side 23B are electrically connected to each other through the conductive polymer 25.

The separator base 24 has a first surface 231 A facing the anode body 21 and a second surface 232 A facing the cathode body 22. In the separator base 24, the density of the separator base 24 is lower on the first surface side 23A than on the second surface side 23B. Specifically, it is preferable that the first surface side 23A has a density lower than that of the second surface side 23B by 0.05 g / cm ³ or more.

  Here, the first surface side 23A of the separator substrate 24 is a region including the first surface 231A of the separator substrate 24 and not overlapping the second surface side 23B, and the second surface side 23B of the separator substrate 24 and Is a region including the second surface 232A of the separator base material and not overlapping the first surface side 23A.

  Paper or nonwoven fabric containing non-conductive fibers such as cellulose, polyethylene terephthalate, polybutylene terephthalate, polyphenylene sulfide, polyphenylene sulfide, nylon, aromatic polyamide, polyimide, polyamide imide, polyether imide, rayon, vitreous, etc. as the separator substrate 24 Can be used. Alternatively, a woven fabric may be used as the separator substrate 24.

  Examples of the conductive polymer 25 include polypyrrole, polythiophene, polyfuran, polyaniline, polyacetylene, polyphenylene, polyphenylene vinylene, polyacene, polythiophene vinylene and the like. These may be used alone, may be used in combination of 2 or more types, and may be a copolymer of 2 or more types of monomers. In the present specification, polypyrrole, polythiophene, polyfuran, polyaniline and the like mean a polymer having polypyrrole, polythiophene, polyfuran, polyaniline and the like as a basic skeleton, respectively. Thus, polypyrrole, polythiophene, polyfuran, polyaniline and the like may also include their respective derivatives. For example, polythiophene includes poly (3,4-ethylenedioxythiophene) and the like.

  The conductive polymer 25 may contain a dopant. As the dopant, for example, polyvinyl sulfonic acid, polystyrene sulfonic acid, polyallyl sulfonic acid, polyacrylic sulfonic acid, polymethacrylic sulfonic acid, poly (2-acrylamido-2-methylpropane sulfonic acid), polyisoprene sulfonic acid, polyacrylic Anions such as acids can be mentioned. Among them, a polyanion derived from polystyrene sulfonic acid is preferable. These may be used alone or in combination of two or more. Moreover, these may be a polymer of a single monomer, or may be a copolymer of two or more monomers.

The conductive polymer 25 functions as a cathode of the electrolytic capacitor. Note that the conductive polymer 25 is impregnated with a solution such as a dispersion in which fine particles of PEDOT or the like are dispersed in a dispersion medium, a solution in which polyaniline or the like is dissolved in a solvent, or the like. The separator substrate 24 is applied. The conductive polymer 25 is formed in the form of connected particles or film, and is attached to the separator substrate 24. The separator 23 is porous having a void inside, and the electrolytic solution 16 enters the void.

  FIG. 3 shows a state in which the particulate conductive polymer 25 is adhered to the separator substrate 24.

  In order to impregnate the separator base 24 with a liquid containing the conductive polymer 25, for example, a method of applying a liquid onto the separator base 24, a method of immersing an element containing the separator base 24 in a liquid, etc. Various methods can be used.

  When the conductive polymer 25 is attached to the separator substrate 24 using a dispersion liquid of the conductive polymer 25, the size of the fine particles of the conductive polymer 25 is preferably 1 μm or less in diameter. If the size of the fine particles of the conductive polymer 25 is larger than 1 μm in diameter, it is difficult for the fine particles to be filled in the void portion of the separator substrate 24, and the ESR of the electrolytic capacitor becomes high.

  Further, as the dispersion medium and the solvent, low viscosity solvents such as water and lower alcohol are preferable. When a low viscosity solvent is used as the dispersion medium or the solvent, the filling effect of the conductive polymer 25 on the separator base 24 is enhanced. Furthermore, since it is easy to remove the dispersion medium and the solvent after impregnating the separator base material 24 with the solution when the solvent having high volatility is used as the dispersion medium and the solvent, the liquid agent can be easily dried.

  Further, by adding a surfactant to the dispersion liquid or solution, the filling property of the conductive polymer 25 to the separator substrate 24 can be further enhanced. The surfactant to be added may, for example, be an anionic surfactant, a cationic surfactant, a non-ionic surfactant or an amphoteric surfactant.

  The capacitor element 12 may be a laminated type in which the anode body 21 and the cathode body 22 are laminated via the separator 23.

  The electrolytic solution 16 functions as a cathode of the electrolytic capacitor 1. The electrolytic solution 16 penetrates into a void in the separator 23 and a hole formed by the etching pit of the anode body 21.

  The electrolytic solution 16 is prepared by dissolving a solute in an organic solvent. As the organic solvent, alcohols, aprotic amide solvents, lactones, sulfoxides and the like can be used. Examples of the alcohol include methanol, ethanol, propanol, butanol, cyclobutanol, cyclohexanol, ethylene glycol, propylene glycol, glycerin, methyl cellosolve, ethyl cellosolve, methoxypropylene glycol, polycondensates of glycols and the like. As an amide solvent, N-methylformamide, N, N-dimethylformamide, N-ethylformamide, N, N-diethylformamide, N-methylacetamide, N, N-dimethylacetamide and the like can be mentioned. As lactones, γ-butyrolactone, β-butyrolactone, α-valerolactone, γ-valerolactone and the like can be mentioned. Sulfoxides include sulfolane, 3-methylsulfolane, dimethylsulfoxide and the like. In the medium-high pressure electrolytic capacitor, ethylene glycol is preferably used as the solvent.

Moreover, as a base component of the electrolyte component which is a solute, it is a compound which has an alkyl substituted amidine group, and an imidazole compound, a benzimidazole compound, an alicyclic amidine compound (a pyrimidine compound, an imidazoline compound) etc. are mentioned. In addition, quaternary ammonium of a compound having an alkyl-substituted amidine group can also be used as a base component of the electrolyte component, and as quaternary ammonium of a compound having an alkyl-substituted amidine group, an alkyl group having 1 to 11 carbon atoms or Examples include imidazole compounds quaternized with an arylalkyl group, benzimidazole compounds, alicyclic amidine compounds (pyrimidine compounds, imidazoline compounds) and the like. In addition, as a base component, ammonium, primary amine (methylamine, ethylamine, propylamine, butylamine ethylenediamine, monoethanolamine etc.), secondary amine (dimethylamine, diethylamine, dipropylamine, ethylmethylamine, diphenylamine, diethanolamine etc) And tertiary amines (trimethylamine, triethylamine, tributylamine, 1,8-diazabicyclo (5,4,0) -undecene-7, triethanolamine etc.) may be used. Preferably, ammonium, diethylamine or triethylamine is used as the base component of the electrolyte component which is a solute in the medium-high pressure electrolytic capacitor.

  As an acid component of the electrolyte component, aliphatic carboxylic acid such as saturated carboxylic acid, unsaturated carboxylic acid and aromatic carboxylic acid can be used. As aliphatic saturated carboxylic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, 1,6-decanedicarboxylic acid, 5,6-decanedicarboxylic acid Formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, caproic acid, enanthate, caprylic acid, pelargonic acid, lauric acid, myristic acid, stearic acid, behenic acid and the like. Aliphatic unsaturated carboxylic acids include maleic acid, fumaric acid, icotanic acid, acrylic acid, methacrylic acid and oleic acid. Examples of aromatic carboxylic acids include phthalic acid, salicylic acid, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, benzoic acid, resorcinic acid, cinnamic acid, naphthoic acid and the like. Besides these carboxylic acids, nitro derivatives and sulfonic acid derivatives of carboxylic acids, phosphoric acid derivatives which are inorganic acids, boric acid derivatives and the like can be used as the acid component of the electrolyte.

  In the electrolyte component, it is preferable that the acid component be contained in a molar ratio more than the base component. In this case, the acidity of the electrolytic solution is increased, and the effect of suppressing the dedoping reaction of the separator 23 can be exhibited. As an acid component of the electrolyte component which is a solute in a medium-high pressure electrolytic capacitor, octanedicarboxylic acids such as 1,6-decanedicarboxylic acid such as 1,6-decanedicarboxylic acid, 5,6-decanedicarboxylic acid and 1,7-octanedicarboxylic acid It is preferable to use an organic acid such as an acid, azelaic acid or sebacic acid, or a polyhydric alcohol complex of boric acid or boric acid obtained from boric acid and a polyhydric alcohol.

  The exterior body 15 seals the capacitor element 12 and the electrolytic solution 16 in such a manner that the respective end portions of the anode lead 11A and the cathode lead 11B drawn out of the capacitor element 12 are led out to the outside.

  The exterior body 15 has a case 13 and a sealing body 14. The case 13 accommodates the capacitor element 12 and the electrolytic solution 16. The sealing body 14 is provided with through holes 14A and 14B for inserting the anode lead 11A and the cathode lead 11B respectively. The sealing body 14 is disposed at the opening of the case 13 and is compressed by squeezing the outer peripheral surface of the case 13 with the drawing portion 13A, thereby sealing the opening of the case 13.

  The capacitor element 12 may be housed in the case 13 after the capacitor element 12 is impregnated with the electrolytic solution 16. For example, the electrolytic solution 16 may be injected and sealed in the case 13 after the capacitor element 12 is housed in the case 13, or the capacitor element 12 may be housed in the case 13 after the electrolytic solution is injected into the case 13. It may be sealed.

  In addition to rubber materials such as ethylene propylene rubber and butyl rubber which is a copolymer of isobutyl and isoprene, resin material such as epoxy resin can be used for the sealing body 14.

  The case 13 is made of metal. From the viewpoint of weight reduction, the case 13 is preferably formed of aluminum.

  The manufacturing method of the electrolytic capacitor in embodiment is demonstrated.

  First, the separator substrate 24 is prepared. The separator substrate 24 has one surface as a first surface 231A, the other surface opposite to one surface as a second surface 232A, and the density of the first surface side 23A including the first surface 231A The density is lower than the density of the second surface side 23B including the two surfaces 232A.

  Then, in the liquid agent impregnation step, a liquid agent which is a solution or a dispersion liquid of the conductive polymer 25 is applied to the first surface 231 A of the separator substrate 24, and the liquid agent is applied to the separator substrate from the first surface of the separator substrate 24. The inside of the material 24 is impregnated. Thereafter, the solvent or dispersion medium contained in the solution is evaporated. Next, a liquid agent which is a solution or a dispersion liquid of the conductive polymer 25 is applied to the second surface 232 A of the separator substrate 24, and the liquid agent is applied from the second surface 232 A of the separator substrate 24 to the inside of the separator substrate 24. To impregnate. Thereafter, part or all of the solvent or dispersion medium contained in the solution is evaporated.

  The liquid agent applied to the first surface 231A and the liquid agent applied to the second surface 232A may have different physical properties such as viscosity and concentration of the conductive polymer. For example, the concentration of the conductive polymer of the liquid to be applied to the second surface 232A may be lower than the concentration of the conductive polymer of the liquid to be applied to the first surface 231A. If the concentration of the conductive polymer of the liquid to be applied to the second surface 232A is lower than the concentration of the conductive polymer of the liquid to be applied to the first surface 231A, the liquid will be easily impregnated to the inside of the separator substrate 24. preferable.

  After the solvent or dispersion medium in the solution evaporates, the conductive polymer 25 is deposited over the entire separator substrate 24.

  Next, in the storage element formation step, the anode foil serving as the anode body 21 is opposed to the first surface 231A of the separator base material 24, and the cathode foil serving as the cathode body is opposed to the second surface 232A of the separator base material 24. The capacitor element 12 is formed by winding.

  The anode lead 11A and the cathode lead 11B are bonded to the anode foil and the cathode foil by ultrasonic welding, needle caulking, or the like before winding.

  Next, in the electrolytic solution impregnation step, the electrolytic solution 16 is impregnated into the capacitor element 12 formed in the storage element formation step.

  Then, the capacitor element 12 impregnated with the electrolytic solution 16 is housed in the case 13, and the opening of the case is sealed with the sealing body 14 to make the electrolytic capacitor 1.

  In the electrolyte solution impregnation step, the capacitor element 12 may be first housed in the case 13, and then impregnated with the electrolyte solution 16, and then the opening of the case may be sealed with the sealing body 14.

  As described above, the conductivity is imparted by depositing the conductive polymer 25 on the separator substrate 24, and the ESR of the electrolytic capacitor 1 can be lowered.

Since the density of the separator substrate 24 is lower than that of the second surface 23B, the first surface 23A of the separator substrate 24 has the conductive polymer 25 attached to the first surface 23A. The ratio to be set is higher than the ratio of the conductive polymer 25 deposited on the second surface side 23B. That is, the deposition amount of the conductive polymer 25 deposited on the separator substrate 24 is larger in the vicinity of the anode body 21 than in the vicinity of the cathode body 22.

  As a result, the amount of deposition of the conductive polymer 25 present in the vicinity of the dielectric oxide film 21B on the surface of the anode body 21 or the amount of deposition of the conductive polymer 25 in contact with the dielectric oxide film 21B is large. Thus, the ESR of the electrolytic capacitor 1 can be reduced.

  Furthermore, by depositing the conductive polymer 25 over substantially the entire separator substrate 24, the conductive polymer 25 deposited on the first surface side 23A of the separator substrate 24 and the second surface side 23B are formed. Since the conductive polymer 25 deposited is electrically conducted through the conductive polymer 25, the ESR can be further reduced.

  Note that it is preferable to make the thickness of the first surface side 23A with a low density of the separator substrate 24 thicker than the thickness of the second surface side 23B with a high density. By increasing the thickness of the first surface side 23A having a low density, a large amount of the conductive polymer 25 or the electrolytic solution can be attached and held, so that the ESR can be reduced and the life can be prolonged.

  In the present embodiment, after applying and impregnating a liquid agent on the first surface 231A of the separator substrate 24 and adhering the conductive polymer 25 on the first surface side 23A, the liquid agent is applied to the second surface 232A. Is coated and impregnated to deposit the conductive polymer 25 on the second surface 23B, but the present invention is not limited to this order. For example, after a liquid agent is first applied to and impregnated with the second surface 232A of the separator substrate 24 to adhere the conductive polymer 25 to the second surface 23B, the liquid agent is applied to the first surface 231A. The conductive polymer 25 may be deposited on the first surface side 23A by impregnation.

  In addition, the liquid agent is simultaneously applied and impregnated to both surfaces of the first surface 231A and the second surface 232A of the separator substrate 24, and the conductive polymer 25 is simultaneously formed on the first surface side 23A and the second surface side 23B. It may be applied.

  Alternatively, even if the liquid agent is applied and impregnated only from the surface on one side of the separator substrate 24 and the conductive polymer 25 is deposited on the first surface side 23A and the second surface side 23B of the separator substrate 24. good. In this case, the first surface 231A having a low density of the separator substrate 24 may be coated and impregnated with the liquid agent in a shorter time than the second surface 232A having a high density may be coated and impregnated with the liquid agent. It is preferable because the conductive polymer 25 can be deposited on the side 23A and the second surface side 23B.

  In order to change the density in the thickness direction of the separator substrate 24, change the dispersion concentration of fibers in the middle of papermaking, change the kind of fibers, bond a plurality of separator papers having different fiber densities, and attach the separator substrate 24. You may apply methods such as

  It should be noted that after the storage element formation step, the capacitor element may be provided with a liquid agent impregnation step of impregnating a liquid agent to further adhere the conductive polymer 25 to the separator substrate 24. By further depositing the conductive polymer 25 on the separator substrate 24, the conductive polymer 25 can enter into the pits of the anode body 21 to further reduce the ESR of the electrolytic capacitor 1.

  As described above, the conductive polymer 25 may not be deposited over the entire surface of the separator substrate 24. For example, there is a region in the middle of the thickness direction of the separator substrate 24 where the conductive polymer 25 is not deposited, and the conductive polymer 25 deposited on the first surface side 23A and the second surface side 23B are deposited The conductive polymer 25 may not be electrically conducted. With such a configuration, the withstand voltage of the electrolytic capacitor can also be improved.

Further, even if the conductive polymer 25 is attached to the first surface side 23A of the separator substrate 24 and the conductive polymer 25 is not attached to the second surface side 23B, the ESR of the electrolytic capacitor can be obtained. It can be reduced.

  Hereinafter, specific examples of the present invention will be described. The present invention is not limited to these examples.

Example 1
Example 1 will be described.

First, a separator substrate having a thickness of 60 μm made of nonconductive natural fibers was prepared. Density of the first surface of the anode body and the opposite side of the separator base material is 0.45 g / cm ^3, the density of the second surface side of the cathode body side opposed to the 0.75 g / cm ^3, the first The thickness on the surface side was 45 μm, and the thickness on the second surface side was 15 μm.

  The conductive polymer to be deposited on the separator substrate is polyethylenedioxythiophene doped with polystyrene sulfonic acid, and a dispersion in which fine particles of this polyethylenedioxythiophene are dispersed in a dispersion medium is used as a liquid agent for coating.

  The anode foil to be an anode body was an aluminum foil having a dielectric oxide film formed by anodizing treatment after the surface was roughened by etching treatment.

  The cathode foil to be a cathode body was an etched aluminum foil.

  More specifically, first, in the solution impregnation step, a solution which is a dispersion liquid of polyethylenedioxythiophene is applied to the separator substrate from the first surface of the separator substrate which is the surface of the separator substrate facing the anode body. The conductive polymer was deposited on the first surface side including the first surface of the separator substrate 24 by volatilizing the dispersion medium in the impregnated and coated liquid agent. Subsequently, a solution, which is a dispersion of polyethylenedioxythiophene, is applied and impregnated from the second surface of the separator substrate, which is the surface of the separator substrate facing the cathode body, to volatilize the dispersion medium. A conductive polymer is deposited on the second surface side including the second surface of the substrate 24 and a conductive polymer deposited on the first surface side and a conductive height deposited on the second surface side The molecules were allowed to conduct electricity electrically.

  Next, in the storage element formation step, the anode body is made to face the first surface of the separator substrate on which the conductive polymer is deposited in the liquid agent impregnation step, and the second surface of the separator substrate is one surface of the cathode body. Made to face. Furthermore, on the other surface of the cathode body, the conductive polymer of the same specification as the separator substrate on which the conductive polymer is adhered, which is opposed to the one surface of the cathode body but is separate but is attached The second surfaces of the resulting separator substrates were opposed to each other and wound to form a wound capacitor element.

  Next, as the electrolytic solution impregnation step, the capacitor element formed in the storage element formation step is immersed in an electrolytic solution prepared by dissolving ammonium 1,6-decanedicarboxylate in ethylene glycol under reduced pressure conditions, The electrolyte solution was impregnated in the void portion of

  And after inserting the capacitor | condenser element in which the electrolyte solution was impregnated with the sealing body which is a molded object of resin vulcanization butyl rubber in a cylindrical aluminum case with a bottom, the opening part of the case was sealed by the curling process.

  Thus, an electrolytic capacitor with a rated voltage of 400 V and a capacitance of 22 μF was produced.

(Example 2)
Next, Example 2 will be described.

  In Example 2, the separator base material, the conductive polymer, and the liquid agent obtained by dispersing the same in a dispersion medium to make a dispersion, the anode body, the cathode body, the electrolyte, the sealing body, the case, etc. are the same as Example 1. The thing was used. Then, a conductive polymer was attached to the separator base material by a method different from that of Example 1, and an electrolytic capacitor was manufactured according to a different procedure.

  More specifically, first, in the element forming step, the anode body is made to face the first surface of the separator base material with lower density, and the second surface of the separator base material with the higher density is one side of the cathode body. The same specifications as the separator base facing the other side of the cathode body, facing the other side of the cathode body, but the second side of the separator base which is a separate body is made to face and overlap The product was wound to form an element in which the conductive polymer was contained in the separator substrate.

  Next, in the liquid agent impregnating step, the element formed in the element forming step is impregnated with a liquid agent which is a dispersion liquid of the conductive polymer, and the dispersion medium is evaporated, whereby the conductive polymer is applied to substantially the entire separator substrate. By depositing, a capacitor element having a conductive separator was formed.

  Next, in the electrolytic solution impregnation step, the capacitor element having the conductive separator formed is immersed in an electrolytic solution prepared by dissolving ammonium 1,6-decanedicarboxylate in ethylene glycol under reduced pressure conditions, The electrolyte solution was impregnated in the void portion of

  And after inserting the capacitor | condenser element in which the electrolyte solution was impregnated with the sealing body which is a molded object of resin vulcanization butyl rubber in a cylindrical aluminum case with a bottom, the opening part of the case was sealed by the curling process.

  Thus, an electrolytic capacitor with a rated voltage of 400 V and a capacitance of 22 μF was produced.

  Next, a comparative example will be described below.

(Comparative example 1)
In Comparative Example 1, an electrolytic capacitor was produced in the same manner as in Example 1 except that the separator base material was changed.

In Comparative Example 1, as the separator substrate, one having a thickness of 60 μm and a density of 0.75 g / cm ³ made of non-conductive natural fibers was used.

(Evaluation)
Twenty electrolytic capacitors of each of Examples 1 and 2 and Comparative Example 1 were produced, 10 were subjected to withstand voltage measurement, and 10 were subjected to ESR measurement. With respect to the withstand voltage, a constant current of 5 mA was applied to the electrolytic capacitor in an atmosphere of 105 ° C., a voltage at which dielectric breakdown occurred was measured, and this voltage was evaluated as the withstand voltage. ESR was measured at 100 kHz in a 20 ° C. environment. The results are shown in Table 1. In addition, the values of the withstand voltage and ESR described in Table 1 are relative values when Comparative Example 1 is 100.

セパレータ基材の陽極体と対向する側の第１面側の密度を、陰極体と対向する側の第２面側の密度よりも低くした実施例１、２では、セパレータ基材の陽極体と対向する側の第１面側の密度と、陰極体と対向する側の第２面側の密度が同じである比較例１に比較して、ＥＳＲを低減できた。

In Examples 1 and 2 in which the density of the first surface on the side facing the anode body of the separator substrate is lower than the density on the second surface side of the side facing the cathode body, the anode body of the separator substrate The ESR can be reduced as compared with Comparative Example 1 in which the density on the first surface side on the opposite side and the density on the second surface side on the side opposite to the cathode body are the same.

  In the description of the above embodiment, the storage element is in the form of an electrolytic capacitor in which an anode body, a cathode body, and a separator are wound together and wound, but the present invention is not limited to this form, and The present invention can also be applied to a form of storage element.

  The electricity storage device of the present invention can be applied to a device such as an electrolytic capacitor that uses an electrolytic solution and a conductive polymer that is a solid electrolyte in combination.

DESCRIPTION OF SYMBOLS 11A Anode lead 11B Cathode lead 12 Capacitor element 13 Case 13A Drawing part 14 Sealing body 14A, 14B Through-hole 15 Exterior body 16 Electrolyte 21 Anode body (anode foil)
21A metal foil 21B dielectric oxide film 22 cathode body (cathode foil)
23 separator 23A first surface side 23B second surface side 24 separator base material 25 conductive polymer 231A first surface 232A second surface

Claims (3)

An electric storage device in which an electrolytic solution is impregnated in an electric storage element having an anode body having a dielectric film on the surface, a cathode body facing the anode body, and a separator interposed between the anode body and the cathode body. A manufacturing method,
A separator substrate made of paper or nonwoven fabric, having a first surface and a second surface on the back side of the first surface, wherein the density on the first surface side is lower than the density on the second surface side The first step of
After the first step, a second step of applying a liquid agent in which a conductive polymer is dissolved or dispersed in a solvent or a dispersion medium on the first surface of the separator substrate;
After the second step, a third step of impregnating the liquid agent from the first surface into the inside of the separator substrate;
After the third step, a fourth step of forming the separator in which the conductive polymer is adhered to the separator substrate by evaporating the solvent or dispersion medium of the liquid agent;
A fifth step of forming the storage element by causing the first surface of the separator substrate to face the anode body and the second surface of the separator substrate to face the cathode body after the fourth step;
And a sixth step of impregnating the storage element with the electrolytic solution after the fifth step. The method according to claim 1, wherein in the third step, at least a part of the liquid agent is penetrated to the second surface. An anode foil having a dielectric film on the surface is used as the anode body,
A cathode foil is used as the cathode body,
In the fourth step, the electric storage element is formed by winding the first surface of the separator base on the anode foil and the second surface of the separator base on the cathode foil so as to face each other. The manufacturing method of the electrical storage device of Claim 1 or 2 characterized by the above-mentioned.

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