JP6191015B2 - Electrolytic capacitor - Google Patents

Description

  The present invention relates to an electrolytic capacitor having an explosion-proof structure.

  The electrolytic capacitor includes a capacitor element, a bottomed cylindrical outer case in which the capacitor element is accommodated, and a sealing member that seals an opening of the outer case (see, for example, Patent Document 1). In an electrolytic capacitor, gas may be generated in the outer case during operation or short-circuiting. This gas is, for example, an electrolyte that has evaporated due to heat generated when the electrolytic capacitor is operated or short-circuited. When gas is generated, the internal pressure of the electrolytic capacitor increases and the electrolytic capacitor may burst.

  Conventionally, an explosion-proof structure for preventing the electrolytic capacitor from bursting has been proposed. As an example, a technique has been proposed in which a cross-shaped notch is provided on the outer surface of the bottom of the outer case, and the depth of the notch is adjusted so that gas can escape from the notch before the capacitor element ruptures (for example, Patent Documents). 2). As another example, a technique of providing a gas vent valve or a pressure adjustment valve on the sealing member has been proposed (see, for example, Patent Document 3 or 4).

JP 2007-103532 A Japanese Utility Model Publication No. 48-53543 JP 2006-108185 A JP 2007-335775 A

  However, the above-described conventional explosion-proof structure can be applied to a large electrolytic capacitor, but is difficult to apply to a small electrolytic capacitor mounted on an electronic device such as a mobile phone or a digital camera. . Specifically, in a small electrolytic capacitor, even if a cut is provided on the outer surface of the bottom of the outer case, it is difficult to accurately adjust the depth of the cut. Further, in a small electrolytic capacitor, the sealing member is small, and therefore it is difficult to provide a gas vent valve or a pressure regulating valve for the sealing member.

  Accordingly, an object of the present invention is to provide an electrolytic capacitor that exhibits high explosion-proof performance even if it is small.

  A first electrolytic capacitor according to the present invention includes a capacitor element, a bottomed cylindrical outer case that accommodates the capacitor element, and a sealing member that is fitted into an opening of the outer case. The capacitor element has an anode member, a cathode member, and a dielectric film formed on the surface of the anode member. The sealing member has a side peripheral surface that comes into contact with the inner peripheral surface of the exterior case when the sealing member is inserted into the opening, and the side peripheral surface is directed from one of the upper edge and the lower edge toward the other. An extended groove or slit is formed. And in the state by which the sealing member was inserted by the opening part, at least one part of a groove | channel or a slit is obstruct | occluded.

  A second electrolytic capacitor according to the present invention includes a capacitor element, a bottomed cylindrical outer case in which the capacitor element is accommodated, and a sealing member fitted into an opening of the outer case. The capacitor element has an anode member, a cathode member, and a dielectric film formed on the surface of the anode member. The inner peripheral surface of the exterior case has an inner peripheral region in contact with the side peripheral surface of the sealing member, and at least the inner peripheral region extends from one of the upper edge and the lower edge toward the other. Grooves are formed. And at least one part of this groove | channel is obstruct | occluded when a part of sealing member enters into the inside.

  The electrolytic capacitor according to the present invention can exhibit high explosion-proof performance even if it is small.

FIG. 1 is a cross-sectional view showing an electrolytic capacitor according to a first embodiment of the present invention. 2A is a perspective view and FIG. 2B is a top view showing the shape of the sealing member included in the electrolytic capacitor according to the first embodiment before being inserted into the outer case. FIG. 3 is a cross-sectional view taken along line III-III shown in FIG. FIG. 4 is a top view showing various modifications of the sealing member. FIG. 5 is a top view showing another modification of the sealing member. FIG. 6A is a perspective view and FIG. 6B is a cross-sectional view showing the shape of the outer case provided in the electrolytic capacitor according to the second embodiment of the present invention before lateral drawing. FIG. 7 is a diagram showing a part of a cross section obtained along the same line as the line III-III shown in FIG. 1 for the electrolytic capacitor according to the second embodiment. FIG. 8 is a cross-sectional view showing various modifications of the exterior case. FIG. 9 is a cross-sectional view showing a preferred positional relationship between the exterior case and the sealing member.

<First Embodiment>
FIG. 1 is a cross-sectional view showing an electrolytic capacitor according to a first embodiment of the present invention. As shown in FIG. 1, the electrolytic capacitor includes a capacitor body 10 and a seat plate 40 on which the capacitor body 10 is mounted. The capacitor body 10 includes a capacitor element 1, a bottomed cylindrical outer case 2 in which the capacitor element 1 is accommodated, and a sealing member 3 that is fitted into the opening 21 of the outer case 2. .

  The capacitor element 1 has a wound body 11, an anode lead tab terminal 12, and a cathode lead tab terminal 13. The wound body 11 is configured by overlapping and winding an anode foil, a cathode foil, and a separator. Each of the anode foil and the cathode foil is formed of a valve metal such as aluminum, tantalum, or niobium. A dielectric film is formed on the surface of the anode foil. The separator is superimposed on the anode foil and the cathode foil so as to be interposed between the anode foil and the cathode foil in the wound body 11. The separator is impregnated with a solid or liquid electrolyte, whereby the electrolyte is interposed between the dielectric coating and the cathode foil. The wound body 11 may be formed by winding various forms of anode members and cathode members that are not limited to foil.

  The anode lead tab terminal 12 is electrically connected to the anode foil, and the cathode lead tab terminal 13 is electrically connected to the cathode foil. The anode lead tab terminal 12 and the cathode lead tab terminal 13 are drawn from the lower end surface 11 a of the wound body 11. In the present embodiment, these lead positions are all shifted from the winding center position 11b, and the anode lead tab terminal 12 is the lead position of the cathode lead tab terminal 13 with respect to the winding center position 11b. It is pulled out from the opposite position.

  The anode lead tab terminal 12 and the cathode lead tab terminal 13 penetrate the sealing member 3. Thereby, the capacitor element 1 is fixed to the sealing member 3, and the lead portion 121 of the anode lead tab terminal 12 and the lead portion 131 of the cathode lead tab terminal 13 are drawn out of the outer case 2. Each of the lead portions 121 and 131 penetrates the seat plate 40 and is bent so that the tip portion is along the lower surface 40 a of the seat plate 40. In this way, the external terminals of the electrolytic capacitor are formed by the portions of the lead portions 121 and 131 that are present on the lower surface 40a of the seat plate 40.

  The outer case 2 is made of a metal material such as aluminum. The opening portion 21 of the outer case 2 is formed with a throttle portion 22 for fixing the sealing member 3 to the outer case 2 by performing a horizontal drawing process on the opening portion 21. In the present embodiment, the opening end of the outer case 2 is further curled. The exterior case 2 is not limited to a metal material, and may be formed from various materials including an electrical insulating material.

  The sealing member 3 is made of an elastic material such as rubber. The narrowed portion 22 compresses the sealing member 3 from the periphery to the inside. Thereby, the sealing member 3 is elastically deformed, and the side peripheral surface 3 a thereof is in close contact with the inner peripheral surface 2 a of the exterior case 2. In this way, the opening 21 of the outer case 2 is sealed by the sealing member 3.

  2A and 2B are a perspective view and a top view showing the shape of the sealing member 3 before being fitted into the opening 21 of the exterior case 2, respectively. As shown in FIG. 2A, a groove 31 extending vertically from the upper end edge 3b to the lower end edge 3c is formed on the side peripheral surface 3a of the sealing member 3. In the present embodiment, the groove 31 is a V-shaped groove as shown in FIG. Specifically, the cross section of the groove 31 perpendicular to the extending direction of the groove 31 is V-shaped. In the state where the sealing member 3 is inserted into the opening 21, the groove 31 is closed by the compression of the sealing member 3 by the throttle portion 22 as shown in FIG. 3. Here, the V-shaped groove 31 is easily closed without a gap when the sealing member 3 is inserted into the opening 21. Therefore, high airtightness is realized in the electrolytic capacitor according to the first embodiment. In addition, the groove | channel 31 does not need to be completely obstruct | occluded without the gap about the extending direction, and at least one part should just be obstruct | occluded without the gap.

  According to the electrolytic capacitor according to the first embodiment, when gas is generated in the outer case 2 and the internal pressure of the electrolytic capacitor is increased, the closed portion of the groove 31 is expanded by the internal pressure. Thereby, the gas in the exterior case 2 is discharged to the outside through the groove 31, and as a result, an increase in internal pressure is suppressed. Thus, the electrolytic capacitor according to the first embodiment can exhibit high explosion-proof performance.

  Further, when the internal pressure decreases due to the gas release, the portion of the groove 31 that has been expanded is closed again due to the elasticity of the sealing member 3. Thus, the electrolytic capacitor according to the first embodiment has reproducibility with respect to its airtightness and explosion-proof performance.

  Further, the groove 31 can be easily formed with respect to the sealing member 3 even when the electrolytic capacitor is small and the sealing member 3 is small.

  FIGS. 4A to 4C are top views showing various modifications of the sealing member 3. The groove 31 may be a groove having a flat bottom as shown in FIG. 4A, or may be a groove having a curved bottom as shown in FIG. 4B. As shown in FIG. 4C, slits 32 may be formed on the side peripheral surface 3 a of the sealing member 3 instead of the grooves 31. However, among these, the V-shaped groove 31 (FIG. 2B) and the slit 32 are preferable because they are easily closed without a gap when the sealing member 3 is inserted into the opening 21, and the V-shaped groove is preferable. 31 is particularly preferred.

  In order to close the groove 31 or the slit 32 without a gap when the sealing member 3 is inserted into the opening 21, the depth of the groove 31 or the slit 32 is preferably smaller than the depth of the throttle portion 22. However, this invention is not limited to this, The depth of the groove | channel 31 or the slit 32 can be adjusted according to the material of the sealing member 3, the shape of the groove | channel 31 or the slit 32, etc. FIG. Alternatively or in addition, the depth of the throttle portion 22 may be adjusted.

  FIG. 5 is a top view showing another modified example of the sealing member 3. As shown in FIG. 5, the groove 31 is preferably formed on the side peripheral surface 3 a of the sealing member 3 at a position in the vicinity of the through hole 33 into which the anode lead tab terminal 12 is inserted. Alternatively, the groove 31 is preferably formed on the side peripheral surface 3a of the sealing member 3 at a position near the through hole 34 into which the cathode lead tab terminal 13 is inserted. That is, in the electrolytic capacitor, the groove 31 is preferably formed on the side peripheral surface 3 a of the sealing member 3 at a position near the anode lead tab terminal 12 or the cathode lead tab terminal 13. The reason is as follows. The same applies to the position where the slit 32 is formed.

  When the electrolytic capacitor is short-circuited, a large amount of gas is generated in the outer case 2 due to a large amount of heat generated in the electrolytic capacitor. As a result, the internal pressure of the electrolytic capacitor rapidly increases, and a large pressure is applied to the sealing member 3 so that it can be removed from the outer case 2. At this time, since the gas is released through the groove 31, when the sealing member 3 is dropped from the outer case 2, the sealing member 3 is inclined starting from the position where the groove 31 is formed. Here, in the electrolytic capacitor according to the modification, the groove 31 is formed at a position in the vicinity of the anode lead tab terminal 12 or the cathode lead tab terminal 13. Therefore, when the sealing member 3 is tilted, the anode lead tab terminal 12 or the cathode lead tab terminal 13 is largely tilted. As a result, the electrical connection between the anode foil and the anode lead tab terminal 12 or the cathode foil and the cathode lead tab terminal 13 is achieved. The electrical connection with is broken. Therefore, according to the electrolytic capacitor according to the above modification, the current path in the electrolytic capacitor can be disconnected at the time of the short circuit, thereby preventing the heat generation due to the short circuit.

  In order to break the current path, it is preferable that the sealing member 3 is largely inclined. Therefore, the groove 31 is located on the opposite side of the through hole 33 from the central position 3d of the sealing member 3 (FIG. 5) or on the opposite side of the through hole 34 from the central position 3d of the sealing member 3. It is particularly preferable that the sealing member 3 is formed on the side peripheral surface 3a.

  In addition, each part structure of this invention is not restricted to 1st Embodiment, A various deformation | transformation is possible within the technical scope as described in a claim. For example, the shape of the groove 31 is not limited to a V shape, a shape with a flat bottom surface, or a shape with a curved bottom surface, and various shapes may be employed. Further, the groove 31 is not limited to the one that extends vertically from the upper end edge 3b to the lower end edge 3c of the side peripheral surface 3a, but may be one that extends obliquely from the upper end edge 3b to the lower end edge 3c. Furthermore, the groove 31 is not limited to the one extending from the upper end edge 3b to the lower end edge 3c, but is interrupted at a position between the upper end edge 3b and the lower end edge 3c while extending from the upper end edge 3b or the lower end edge 3c. There may be. Furthermore, the number of the grooves 31 is not limited to one, and a plurality of grooves 31 may be formed on the side peripheral surface 3a.

Second Embodiment
Next, an electrolytic capacitor according to a second embodiment of the present invention will be described. Below, the exterior case 2 and the sealing member 3 which are different from the structure of 1st Embodiment among the structures of this embodiment are demonstrated concretely. Since other configurations are the same as those of the first embodiment, description thereof is omitted.

  In the present embodiment, no groove 31 or slit 32 is formed in the sealing member 3. Instead, the configuration shown in FIGS. 6A and 6B is adopted in the outer case 2. Here, FIG. 6A and FIG. 6B are a perspective view and a cross-sectional view showing a shape of the main part of the outer case 2 before the lateral drawing and curling, respectively. As shown in FIG. 6A, the inner peripheral surface 2 a of the outer case 2 has an inner peripheral region 2 b in contact with the side peripheral surface 3 a of the sealing member 3. And the groove | channel 23 which cross | intersects the inner peripheral area | region 2b and was extended vertically is formed in the inner peripheral surface 2a. In this embodiment, the groove | channel 23 is a groove | channel where the bottom face curved, as shown in FIG.6 (b). In a state where the sealing member 3 is inserted into the opening portion 21, as shown in FIG. 7, the sealing member 3 is compressed by the throttle portion 22, so that a part of the sealing member 3 enters the groove 23. As a result, a part of the groove 23 is closed by the sealing member 3. Here, the groove 23 having a curved bottom surface is easily closed by the sealing member 3 without a gap when a part of the sealing member 3 enters the inside. Therefore, high airtightness is realized in the electrolytic capacitor according to the second embodiment. In addition, in the inner peripheral area | region 2b, the groove | channel 23 does not need to be completely obstruct | occluded without the gap about the extension direction, and at least one part should just be obstruct | occluded without the gap.

  According to the electrolytic capacitor according to the second embodiment, when gas is generated in the outer case 2 and the internal pressure of the electrolytic capacitor is increased, the sealing member 3 entering the inside of the groove 23 is pushed away by the internal pressure. Thereby, the gas in the exterior case 2 is discharged to the outside through the groove 23, and as a result, an increase in internal pressure is suppressed. Thus, the electrolytic capacitor according to the second embodiment can exhibit high explosion-proof performance.

  Further, when the internal pressure is reduced due to the release of gas, the portion of the sealing member 3 that has been pushed away closes the groove 23 again due to the elasticity of the sealing member 3. Thus, the electrolytic capacitor according to the second embodiment has reproducibility with respect to its airtightness and explosion-proof performance.

  Further, the groove 23 can be easily formed in the outer case 2 even when the electrolytic capacitor is small and the outer case 2 is small.

  FIG. 8A and FIG. 8B are cross-sectional views showing various modifications of the exterior case 2. The groove 23 may be a V-shaped groove as shown in FIG. 8A, or may be a groove having a flat bottom surface as shown in FIG. 8B. However, among these, the groove 23 having a curved bottom surface (FIG. 6B) is particularly preferable because it is easily closed without a gap by the sealing member 3 when the sealing member 3 is inserted into the opening 21.

  In order to close the groove 23 without a gap when the sealing member 3 is inserted into the opening 21, the depth of the groove 23 is preferably smaller than the depth of the throttle portion 22. However, the present invention is not limited to this, and the depth of the groove 23 can be adjusted according to the material of the sealing member 3, the shape of the groove 23, and the like. Alternatively or in addition, the depth of the throttle portion 22 may be adjusted.

  FIG. 9 is a cross-sectional view showing a preferred positional relationship between the outer case 2 and the sealing member 3. As shown in FIG. 9, it is preferable to adjust the positional relationship between the outer case 2 and the sealing member 3 so that the groove 23 is disposed at a position near the through hole 33 into which the anode lead tab terminal 12 is inserted. . Alternatively, it is preferable to adjust the positional relationship between the outer case 2 and the sealing member 3 so that the groove 23 is disposed at a position near the through hole 34 into which the cathode lead tab terminal 13 is inserted. That is, in the electrolytic capacitor, the groove 23 is preferably formed on the inner peripheral surface 2 a of the outer case 2 at a position near the anode lead tab terminal 12 or the cathode lead tab terminal 13. The reason is as follows.

  When the electrolytic capacitor is short-circuited, a large amount of gas is generated in the outer case 2 due to a large amount of heat generated in the electrolytic capacitor. As a result, the internal pressure of the electrolytic capacitor rapidly increases, and a large pressure is applied to the sealing member 3 so that it can be removed from the outer case 2. At this time, since the gas is released through the groove 23, when the sealing member 3 is detached from the exterior case 2, the sealing member 3 is inclined with the position of the groove 23 as a starting point. Here, according to the positional relationship described above, the groove 23 is disposed at a position in the vicinity of the anode lead tab terminal 12 or the cathode lead tab terminal 13. Therefore, when the sealing member 3 is tilted, the anode lead tab terminal 12 or the cathode lead tab terminal 13 is largely tilted. As a result, the electrical connection between the anode foil and the anode lead tab terminal 12 or the cathode foil and the cathode lead tab terminal 13 is achieved. The electrical connection with is broken. Therefore, when the electrolytic capacitor is short-circuited, the current path in the electrolytic capacitor can be disconnected, thereby preventing heat generation due to the short-circuit.

  In order to break the current path, it is preferable that the sealing member 3 is largely inclined. Therefore, the groove 23 is disposed at a position opposite to the center position 3d of the sealing member 3 with respect to the anode lead tab terminal 12 (FIG. 9) or the center of the sealing member 3 with respect to the cathode lead tab terminal 13. It is particularly preferable to adjust the positional relationship between the outer case 2 and the sealing member 3 so as to be disposed at a position opposite to the position 3d.

  In addition, each part structure of this invention is not restricted to the said embodiment, A various deformation | transformation is possible within the technical scope as described in a claim. For example, the shape of the groove 23 is not limited to a shape in which the bottom surface is curved, a shape in which the bottom surface is flat, or a V shape, and various shapes may be employed. Moreover, the groove | channel 23 should just be formed in the internal peripheral area | region 2b at least among the internal peripheral surfaces 2a of the exterior case 2. As shown in FIG. Furthermore, the groove 23 is not limited to the one extending vertically, but may be one extending obliquely. Furthermore, the groove 23 is not limited to the one extending from the upper end edge to the lower end edge of the inner peripheral region 2b, but is interrupted at a position between the upper end edge and the lower end edge while extending from the upper end edge or the lower end edge. There may be. The number of grooves 23 is not limited to one, and a plurality of grooves 23 may be formed in the inner peripheral region 2b.

  As an example of the first embodiment, the inventor of the present application manufactured an electrolytic capacitor (rated voltage: 16 V, capacitance: 39 μF) under the following conditions (first example). That is, in the capacitor element 1, aluminum foil was used as the anode foil and the cathode foil, and a conductive polymer made of polythiophene was used as the electrolyte. As the outer case 2, an aluminum can having a diameter of 6.3 mm and a height of 6.0 mm was used. Butyl rubber was used as an elastic material constituting the sealing member 3, and a groove 31 having a V shape and a depth of 0.2 mm was formed on the side peripheral surface 3 a of the sealing member 3. At this time, the groove 31 was formed at a position opposite to the center position 3d of the sealing member 3 with respect to the through hole 33 into which the anode lead tab terminal 12 was inserted. After the sealing member 3 was inserted into the opening 21 of the outer case 2, the outer case 2 was subjected to a horizontal drawing process to form a drawn portion 22 having a depth of 0.45 mm.

  In addition, as an example of the second embodiment, the inventor of the present application manufactured an electrolytic capacitor (rated voltage: 16 V, capacitance: 39 μF) under the following conditions (second example). That is, in the capacitor element 1, aluminum foil was used as the anode foil and the cathode foil, and a conductive polymer made of polythiophene was used as the electrolyte. An aluminum can having a diameter of 6.3 mm and a height of 6.0 mm is used as the outer case 2, and the inner peripheral surface 2 a of the outer case 2 has a curved bottom surface and a depth of A groove 23 of 0.2 mm was formed. Butyl rubber was used as an elastic material constituting the sealing member 3. After the sealing member 3 was inserted into the opening 21 of the outer case 2, the outer case 2 was subjected to a horizontal drawing process to form a drawn portion 22 having a depth of 0.45 mm. At this time, the outer casing 2 and the sealing member 3 are arranged such that the groove 23 is disposed at a position opposite to the center position 3d of the sealing member 3 with respect to the through hole 33 into which the anode lead tab terminal 12 is inserted. The positional relationship was adjusted.

  Further, for comparison with the first and second embodiments, the inventor of the present application produced an electrolytic capacitor having no groove 31 in the sealing member 3 in the first embodiment as a conventional electrolytic capacitor (conventional example).

  The inventor of the present application prepared 10 electrolytic capacitors of the first and second embodiments and the conventional example. For these electrolytic capacitors, it was confirmed to what extent the phenomenon that the current path was broken at the time of short-circuiting occurred. As a condition at this time, each electrolytic capacitor was short-circuited by applying a DC voltage of 80 V (current 0.5 A) thereto, and then a 5 A energizing current was passed through the electrolytic capacitor.

  As a result, in the electrolytic capacitors of the first and second examples, disconnection of the current path was confirmed for all ten capacitors. On the other hand, in the conventional electrolytic capacitor, disconnection of the current path was only confirmed for two of the ten capacitors. Therefore, according to the first and second embodiments, the current path can be reliably disconnected at the time of a short circuit, and this has been confirmed by the above test.

DESCRIPTION OF SYMBOLS 1 Capacitor element 2 Exterior case 2a Inner peripheral surface 2b Inner peripheral area | region 3 Sealing member 3a Side peripheral surface 3b Upper end edge 3c Lower end edge 3d Center position 10 Capacitor body 11 Winding body 11a Lower end surface 11b Center position 12 Anode lead tab terminal 13 Cathode lead tab Terminal 21 Opening portion 22 Restriction portion 23 Groove 31 Groove 32 Slit 33, 34 Through hole 40 Seat plate 40a Lower surface 121, 131 Lead portion

Claims (8)

A capacitor element having an anode member, a cathode member, and a dielectric film formed on a surface of the anode member;
A bottomed cylindrical outer case containing the capacitor element;
A sealing member fitted into the opening of the outer case, and
The sealing member has a side peripheral surface that comes into contact with the inner peripheral surface of the exterior case when fitted into the opening, and the side peripheral surface has one of its upper edge and lower edge to the other. An electrolytic capacitor in which a groove or a slit extending toward is formed, and at least a part of the groove or the slit is closed in a state where the sealing member is fitted into the opening.   The electrolytic capacitor according to claim 1, wherein a cross section of the groove perpendicular to an extending direction of the groove has a V shape.   The said exterior case is formed with the throttle part for fixing the said sealing member to this, The depth of the said groove | channel or slit is smaller than the depth of the said throttle part, The claim 1 or Claim 2 Electrolytic capacitor.   The capacitor element further includes an anode lead tab terminal electrically connected to the anode member and a cathode lead tab terminal electrically connected to the cathode member, wherein the anode lead tab terminal and the cathode lead tab terminal are The through-hole is penetrated and the said groove | channel or slit is formed in the side peripheral surface of the said sealing member in the position of the vicinity of the said anode lead tab terminal or the said cathode lead tab terminal. The electrolytic capacitor as described in any one. A capacitor element having an anode member, a cathode member, and a dielectric film formed on a surface of the anode member;
A bottomed cylindrical outer case containing the capacitor element;
A sealing member fitted into the opening of the outer case, and
The inner peripheral surface of the outer case has an inner peripheral region in contact with the side peripheral surface of the sealing member, and at least the inner peripheral region is directed from one of its upper edge and lower edge to the other. An electrolytic capacitor in which an extended groove is formed, and at least a part of the groove is closed by a part of the sealing member entering the inside.   The electrolytic capacitor according to claim 5, wherein the groove has a curved bottom surface. The outer case is formed with a throttle portion for fixing the sealing member to the outer case,
The electrolytic capacitor according to claim 5, wherein a depth of the groove is smaller than a depth of the throttle portion.   The capacitor element further includes an anode lead tab terminal electrically connected to the anode member and a cathode lead tab terminal electrically connected to the cathode member, wherein the anode lead tab terminal and the cathode lead tab terminal are 8. The device according to claim 5, wherein the sealing member penetrates the groove, and the groove is formed in an inner peripheral region of the outer case at a position near the anode lead tab terminal or the cathode lead tab terminal. The electrolytic capacitor as described in one.