JP2015167184A - Outer sheath for electrochemical device and electric double layer capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an outer sheath for electrochemical device capable of enhancing the long-term reliability of the electrochemical device and the energy density per unit volume of the electrochemical device.SOLUTION: An outer sheath for an electrochemical device includes: an outer sheath body having a housing part having an opening; and a lid body closing the opening of the housing part. The housing part includes: a bottom surface which is located on the side opposite to the opening; and a side surface extending toward the lid body from the bottom surface. A recess recessed toward the inner side of the housing part is formed on the side surface.

Description

  The present invention relates to an exterior for an electrochemical device and an electric double layer capacitor.

  An electrochemical device is a device capable of mutually converting chemical energy and electrical energy, and plays an important role in energy saving or reduction of environmental pollution. Such electrochemical devices are used in a wide variety of applications from portable device power supplies to automobile power supplies. Examples of electrochemical devices include secondary batteries, fuel cells, and capacitors. Although there are many types of capacitors, an electric double layer capacitor has recently attracted particular attention as a capacitor having a large capacity (for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 2000-200738

  It has been proposed to increase the capacity of an electric double layer capacitor by using a current collector made of a porous material. FIG. 17 is a side view showing one step of a method of manufacturing an electric double layer capacitor having a current collector made of a porous body. In addition, the matter shown below can be said not only for an electric double layer capacitor but for all electrochemical devices.

  First, the electrode body 20 is formed. Specifically, a portion where the positive electrode current collector made of a porous body is exposed from the positive electrode active material (hereinafter referred to as “positive electrode exposed portion”) 31 and a portion where the positive electrode active material is supported on the positive electrode current collector (hereinafter referred to as “positive electrode exposed portion”). A positive electrode plate including a negative electrode current collector 32 (hereinafter referred to as a “negative electrode exposed portion”) 41 and a negative electrode active material. A negative electrode plate including a portion (hereinafter, referred to as “negative electrode coating portion”) 42 in which a substance is supported on a negative electrode current collector is prepared, and a separator 50 is prepared. The separator 50 is disposed between the positive electrode coating part 32 and the negative electrode coating part 42, and the positive electrode exposed part 31 and the negative electrode exposed part 41 protrude from the separator 50 in opposite directions. Thereby, the electrode body 20 is formed. Although the laminated electrode body has been exemplified as the electrode body 20, the electrode body 20 is not limited to the laminated electrode body.

  When the electrode body 20 is formed, the tips of the positive electrode current collector in the positive electrode exposed portion 31 are collectively connected to one positive electrode lead 33, and the tips of the negative electrode current collector in the negative electrode exposed portion 41 are collectively grouped into one negative electrode lead 43. Connect to. At this time, since the positive electrode current collector is pulled toward the positive electrode lead 33, a load is applied to the boundary X <b> 1 between the positive electrode exposed portion 31 and the positive electrode coating portion 32. Since the negative electrode current collector is pulled toward the negative electrode lead 43, a load is applied to the boundary X <b> 2 between the negative electrode exposed portion 41 and the negative electrode coating portion 42. Here, the strength of the current collector made of a porous material is lower than that of a plate-shaped or foil-shaped current collector. Therefore, when the obtained electric double layer capacitor vibrates, the positive electrode current collector may break at the boundary X1, and the negative electrode current collector may break at the boundary X2.

  FIG. 18 is a side view showing one step of a method for manufacturing another electric double layer capacitor. In the electrode body 820 shown in FIG. 18, the positive electrode current collector located at the boundary X <b> 1 is reinforced by the aluminum foil 131, and the negative electrode current collector located at the boundary X <b> 2 is reinforced by the aluminum foil 141. Thereby, even if the obtained electric double layer capacitor vibrates, the positive electrode current collector is hardly broken at the boundary X1, and the negative electrode current collector is hardly broken at the boundary X2.

  However, when the positive electrode exposed part 31 and the aluminum foil 131 are ultrasonically welded, the ultrasonic oscillating element is pressed against the positive electrode exposed part 31 and the porous skeleton of the positive electrode current collector in the positive electrode exposed part 31 may be destroyed. is there. When the negative electrode exposed portion 41 and the aluminum foil 141 are ultrasonically welded, the same problem occurs.

  Further, when the positive electrode exposed portion 31 and the positive electrode lead 33 are ultrasonically welded, the porous skeleton of the positive electrode current collector in the positive electrode exposed portion 31 may be destroyed by pressing the ultrasonic vibration element against the positive electrode exposed portion 31. is there. When the negative electrode exposed portion 41 and the negative electrode lead 43 are ultrasonically welded, the same problem occurs. Therefore, even in the case shown in FIG. 18, the positive electrode current collector or the negative electrode current collector may be broken due to vibration of the electric double layer capacitor.

  As a method of preventing this problem, a method of using a cushioning material can be considered. FIG. 19A is a plan view showing the internal structure of the electric double layer capacitor provided with the buffer material, and FIG. 19B is a cross-sectional view taken along line XIXB-XIXB shown in FIG. 19 (c) is a cross-sectional view taken along line XIXC-XIXC shown in FIG. 19 (a). Note that, in FIGS. 19A to 19C, a specific configuration of the electrode body 20 is not illustrated.

  The electrode body 20 is disposed inside the exterior body 911, and the buffer material 913 is disposed between the exterior body 911 and the electrode body 20. Thereby, the freedom degree of the movement of the electrode body 20 in the exterior main body 911 falls. Therefore, even if the electric double layer capacitor vibrates, the positive electrode current collector at the boundary X1 or the positive electrode exposed portion 31 is prevented from being broken, and the negative electrode current collector at the boundary X2 or the negative electrode exposed portion 41 is prevented from being broken. The detailed configuration of the electric double layer capacitor will be described later in [Mode for Carrying Out the Invention].

  However, impurities may be generated from the buffer material 913, leading to a decrease in performance of the electric double layer capacitor. Sometimes. When the buffer material 913 is not excellent in heat resistance or chemical resistance, the buffer material 913 deteriorates as the electric double layer capacitor is used. Therefore, the positive electrode current collector or the negative electrode current collector is caused by vibration of the electric double layer capacitor. May cause breakage. In addition, since the member (buffer material 913) that does not contribute to the battery reaction is disposed inside the exterior body 911, the energy density per unit volume of the electric double layer capacitor is reduced.

  This invention is made | formed in view of this point, The place made into the objective is the electrochemical device which can improve the long-term reliability of an electrochemical device, and the energy density per unit volume of an electrochemical device. To provide an exterior. Another object of the present invention is to provide an electric double layer capacitor having such an exterior for an electrochemical device.

  The exterior for an electrochemical device of the present invention includes an exterior body having an accommodating portion in which an opening is formed, and a lid that closes the opening of the accommodating portion. The accommodating part has a bottom part located on the opposite side to the opening, and a side part extending from the bottom part toward the lid. A concave portion that is recessed toward the inside of the housing portion is formed in the side surface portion.

  In the present invention, the long-term reliability of the electrochemical device and the energy density per unit volume of the electrochemical device can be increased.

(A) is a top view of the exterior for electrochemical devices of one Embodiment of this invention, (b) is sectional drawing in the IB-IB line | wire shown to Fig.1 (a). (A) is a top view of the exterior for electrochemical devices of the modification of this invention, (b) is sectional drawing in the IIB-IIB line | wire shown to Fig.2 (a). (A) is a top view of the exterior for electrochemical devices of the modification of this invention, (b) is sectional drawing in the IIIB-IIIB line | wire shown to Fig.3 (a). (A) is a top view of the exterior for electrochemical devices of the modification of this invention, (b) is sectional drawing in the IVB-IVB line | wire shown to Fig.4 (a). (A) is a top view of the exterior for electrochemical devices of the modification of this invention, (b) is sectional drawing in the VB-VB line | wire shown to Fig.5 (a), (c), It is sectional drawing in the VC-VC line shown to Fig.5 (a). (A) is a top view of the exterior for electrochemical devices of the modification of this invention, (b) is sectional drawing in the VIB-VIB line | wire shown to Fig.6 (a), (c), It is sectional drawing in the VIC-VIC line shown to Fig.6 (a). (A) is a top view of the exterior for electrochemical devices of the modification of this invention, (b) is sectional drawing in the VIIB-VIIB line | wire shown to Fig.7 (a), (c), It is sectional drawing in the VIIC-VIIC line shown to Fig.7 (a). (A) is a top view of the exterior for electrochemical devices of the modification of this invention, (b) is sectional drawing in the VIIIB-VIIIB line | wire shown to Fig.8 (a), (c), It is sectional drawing in the VIIIC-VIIIC line | wire shown to Fig.8 (a). (A) is a top view of the electric double layer capacitor of one Embodiment of this invention, (b) is sectional drawing in the IXB-IXB line | wire shown to Fig.9 (a), (c) is a figure. It is sectional drawing in the IXC-IXC line | wire shown to 9 (a). It is a top view of a positive electrode plate, a negative electrode plate, and a separator. (A) is a top view of a cover body, (b) is sectional drawing in the XIB-XIB line | wire shown to Fig.11 (a). (A) is a top view of another cover body, (b) is sectional drawing in the XIIB-XIIB line | wire shown to Fig.12 (a). It is a flowchart which shows the manufacturing method of the electrical double layer capacitor of one Embodiment of this invention in process order. (A) is a top view of the electric double layer capacitor of the modification of this invention, (b) is sectional drawing in the XIVB-XIVB line | wire shown to Fig.14 (a). It is a side view which shows 1 process of the manufacturing method of the electrical double layer capacitor of one modification of this invention. (A) is a top view of the electric double layer capacitor of the modification of this invention, (b) is sectional drawing in the XVIB-XVIB line | wire shown to Fig.16 (a). It is a side view which shows 1 process of the manufacturing method of an electrical double layer capacitor. It is a side view which shows 1 process of the manufacturing method of an electrical double layer capacitor. (A) is a top view which shows the internal structure of the electric double layer capacitor provided with the buffer material, (b) is sectional drawing in the XIXB-XIXB line | wire shown to Fig.19 (a), (c) is a figure. It is sectional drawing in the XIXC-XIXC line | wire shown to 19 (a).

[Description of Embodiment of Present Invention]
The exterior for an electrochemical device according to the present embodiment includes an exterior body having an accommodating portion in which an opening is formed, and a lid that closes the opening of the accommodating portion. The accommodating part has a bottom part located on the opposite side to the opening, and a side part extending from the bottom part toward the lid. A concave portion that is recessed toward the inside of the housing portion is formed in the side surface portion.

  In the exterior for electrochemical devices of this embodiment, since the recessed part is formed in the side part of an accommodating part, the internal space of an accommodating part becomes narrow. An electrode body is provided inside the housing portion. Thereby, in the exterior for electrochemical devices of this embodiment, since the freedom degree of the movement of the electrode body inside a accommodating part becomes low, the vibration resistance of an electric double layer capacitor improves. Moreover, the vibration resistance of the electric double layer capacitor can be improved without disposing a member that does not contribute to the battery reaction inside the housing portion.

  Both the “bottom surface portion” and the “side surface portion” are part of the accommodating portion. The “bottom surface portion” means a portion where the positive electrode coating portion and the negative electrode coating portion constituting the electrode body are arranged to face each other. The “side surface portion” means a portion located on the lid body side (opening side) with respect to the bottom surface portion. The “side surface portion” may extend perpendicular to the bottom surface portion, may extend in a direction inclined at a predetermined angle from a direction perpendicular to the bottom surface portion, and has a curvature. These two or more may be mixed. “A mixture of two or more of these” means, for example, that the side surface portion includes a portion extending perpendicularly to the bottom surface portion and a portion having a curvature.

  In the exterior for an electrochemical device of this embodiment, the depth of the recess is preferably deeper on the bottom surface side than on the opening side. Thereby, it becomes easy to insert an electrode body into the inside of a storage part. Moreover, it can prevent that an electrode body moves to the opening side from the bottom face part side of an accommodating part. The “depth of the concave portion” means the size of the concave portion in a direction perpendicular to the side surface portion where the concave portion is formed. The “depth direction of the concave portion” means a direction perpendicular to the side surface portion where the concave portion is formed.

  In the exterior for an electrochemical device of the present embodiment, the depth of the recess is preferably deeper at the center side of the side surface where the recess is formed than at the peripheral side of the side surface where the recess is formed. Thereby, it can prevent that an electrode body bends in the center part.

  In the electrochemical device exterior of the present embodiment, the width of the recess is preferably narrower on the opening side than on the bottom surface side. Thereby, it can prevent that a friction generate | occur | produces, when inserting an electrode body into the inside of an accommodating part. The “width of the concave portion” means the size of the concave portion in the side surface portion where the concave portion is formed, and the size of the concave portion in the direction perpendicular to the depth direction of the accommodating portion. The “depth direction of the housing portion” means a direction perpendicular to the bottom surface portion.

  In the exterior for an electrochemical device of this embodiment, the area of the recess is preferably 0.1 to 0.9 times the area of the side surface where the recess is formed in plan view. Thereby, the effect by having formed the recessed part is acquired effectively. The “plan view” means a case where the exterior for an electrochemical device is viewed from the side surface portion side where the concave portion is formed. When a plurality of recesses are formed, “the area of the recesses” means the total area of the recesses. The “area of the concave portion” may be calculated by using the length of the side constituting the concave portion, or may be obtained by calculating the total surface area of the concave portion. The “area of the side surface where the recess is formed” can also be determined by the same method.

  In the electrochemical device exterior of the present embodiment, the maximum depth of the recess is preferably 0.01 times or more and 0.30 times or less the thickness of the exterior body. Thereby, the effect by having formed the recessed part is acquired effectively. The “maximum depth of the concave portion” corresponds to the “depth of the concave portion” when the depth of the concave portion is the same. The “thickness of the exterior body” means the size of the exterior body in a direction perpendicular to the side surface where the recess is formed (depth direction of the recess).

  The electric double layer capacitor of the present embodiment is disposed inside the housing for the electrochemical device exterior of the present embodiment and the exterior body of the electrochemical device exterior, and includes a positive electrode plate, a negative electrode plate, a positive electrode plate, and a negative electrode And an electrode body having a separator disposed between the plates. Thereby, since the freedom degree of a movement of the electrode body inside a accommodating part becomes low, the vibration resistance of an electric double layer capacitor improves. Moreover, the vibration resistance of the electric double layer capacitor can be improved without disposing a member that does not contribute to the battery reaction inside the housing portion.

  In the electric double layer capacitor of the present embodiment, at least one of the positive electrode plate and the negative electrode plate has a coating portion in which an active material is carried on a current collector made of a porous material, and the current collector is exposed from the active material. It is preferable to have an exposed portion. The exposed portion is preferably connected to the lead. In the current collector, the amount of metal contained in the connection portion between the exposed portion and the lead is preferably larger than the amount of metal contained in a portion different from the connection portion. Thereby, since the connection strength between the exposed portion and the lead is increased, the vibration resistance of the electric double layer capacitor is further improved. In addition, since the resistance at the connection portion is reduced, the resistance of the electric double layer capacitor can be reduced.

  The “connection portion between the exposed portion and the lead” includes a connection portion in which the exposed portion and the lead are directly connected and a connection portion in which the exposed portion and the lead are indirectly connected. In the “connection portion in which the exposed portion and the lead are directly connected”, the exposed portion and the lead are in contact with each other. In the “connecting portion in which the exposed portion and the lead are indirectly connected”, one or more conductive members are arranged between the exposed portion and the lead, and the exposed portion and the exposed portion are interposed between the exposed portion and the lead. The lead is connected.

  At least one of the positive electrode plate and the negative electrode plate preferably includes a current collector made of an aluminum porous body and carbon nanotubes supported on the current collector. It is preferable that an ionic liquid is provided inside the accommodating portion. Thereby, it is possible to provide an electric double layer capacitor having a large capacity, a high cell voltage, a low resistance, and excellent safety.

  The electric double layer capacitor of the present embodiment is disposed inside an exterior for an electrochemical device and a housing part of an exterior body of the exterior for an electrochemical device, and is between a positive electrode plate, a negative electrode plate, and a positive electrode plate and a negative electrode plate. And an electrode body having a separator. At least one of the positive electrode plate and the negative electrode plate has a coating part in which the active material is carried on a current collector made of a porous body, and an exposed part in which the current collector is exposed from the active material. The exposed part is connected to the lead. In the current collector, the amount of metal contained in the connection portion between the exposed portion and the lead is larger than the amount of metal contained in a portion different from the connection portion. Thereby, since the connection strength between the exposed portion and the lead is increased, the vibration resistance of the electric double layer capacitor is improved. Moreover, the vibration resistance of the electric double layer capacitor can be improved without disposing a member that does not contribute to the battery reaction inside the housing portion.

[Details of the embodiment of the present invention]
Hereinafter, the exterior for electrochemical devices and the electric double layer capacitor of the present invention will be described with reference to the drawings. In addition, the exterior for electrochemical devices is not limited to the exterior of the electric double layer capacitor, and can be used as an exterior for electrochemical devices in general. In the drawings of the present invention, the same reference numerals represent the same or corresponding parts. In addition, dimensional relationships such as length, width, thickness, and depth are changed as appropriate for clarity and simplification of the drawings, and do not represent actual dimensional relationships.

<First Embodiment>
Fig.1 (a) is a top view of the exterior 10 for electrochemical devices of 1st Embodiment, FIG.1 (b) is sectional drawing in the IB-IB line | wire shown to Fig.1 (a). The electrochemical device exterior 10 of the present embodiment includes an exterior body 11 and a lid 15. The exterior body 11 has a housing portion 12. An opening is formed in the accommodating portion 12, and the opening of the accommodating portion 12 is closed by a lid 15. An electrode body (second embodiment described later) is disposed inside the housing portion 12. The accommodating portion 12 includes a bottom surface portion 12A located on the side opposite to the opening, a pair of first side surface portions 12B, and a pair of second side surface portions 12C.

  The first side surface portion 12B is larger than the second side surface portion 12C, and a concave portion 13 that is recessed toward the inside of the housing portion 12 is formed in a part of the first side surface portion 12B. Thereby, since the internal space of the accommodating part 12 becomes narrow, the freedom degree of a movement of the electrode body inside the accommodating part 12 becomes low. Therefore, even when the electric double layer capacitor in which the electrode body is housed in the housing portion 12 vibrates, the electrode body can be prevented from vibrating in the housing portion 12 (the resistance of the electric double layer capacitor). Improved vibration). Therefore, even if the electric double layer capacitor is used for a long period of time, the current collector constituting the electrode body can be prevented from being broken, and the connection state between the current collector and the lead can be maintained. As described above, the long-term reliability of the electric double layer capacitor can be improved.

  In addition, the long-term reliability of the electric double layer capacitor can be improved without disposing a member (for example, a buffer material) that does not contribute to the battery reaction inside the housing portion 12. As a result, the long-term reliability of the electric double layer capacitor can be enhanced without a decrease in energy density per unit volume of the electric double layer capacitor. Hereinafter, the components of the electrochemical device exterior 10 of the present embodiment will be described in order.

  The exterior body 11 is preferably made of, for example, aluminum, an aluminum alloy, or stainless steel. As a method for producing the exterior body 11, for example, a method of pressing a thin plate (thickness of 0.1 mm or more and 5 mm or less) made of aluminum, an aluminum alloy, stainless steel, or the like with a mold having a predetermined shape can be cited. The concave portion formed by this pressing becomes the accommodating portion 12.

  The magnitude | size of the accommodating part 12 is not limited. It is preferable to determine the size of the accommodating portion 12 according to the size of the electrode body accommodated inside. The same can be said for the shape of the accommodating portion 12. For example, the corners of the bottom surface portion 12A may be chamfered as shown in FIG. 1A or may not be chamfered.

  The magnitude | size of the recessed part 13 is not specifically limited. For example, in plan view, the area of the recess 13 is preferably 0.1 to 0.9 times the area of the first side surface 12B. If the area of the recessed part 13 is 0.1 times or more of the area of the 1st side part 12B, the effect by having formed the recessed part 13 can fully be acquired. If the area of the recessed part 13 is 0.9 times or less of the area of the 1st side part 12B, the intensity | strength of the 1st side part 12B can be maintained strongly. More preferably, the area of the recess 13 is not less than 0.2 times and not more than 0.8 times the area of the first side face part 12B in plan view.

  Moreover, it is preferable that the depth of the recessed part 13 is 0.01 times or more and 0.30 times or less of the thickness of the exterior body 11. If the depth of the recess 13 is 0.01 times or more the thickness of the exterior body 11, the effect of forming the recess 13 can be sufficiently obtained. If the depth of the recessed part 13 is 0.30 times or less of the thickness of the exterior main body 11, the space for accommodating an electrode body is securable. Further, the electrode body can be prevented from being damaged when the electrode body is inserted into the recess 13. More preferably, the depth of the recess 13 is not less than 0.02 times and not more than 0.20 times the thickness of the exterior body 11. Such a recess 13 is preferably formed by, for example, pressing.

  The shape of the recessed part 13 is not limited to the shape shown to Fig.1 (a), The shape shown in the below-mentioned 1st-3rd modification may be sufficient.

  The recess 13 may be formed in the second side surface portion 12C, but is preferably formed in the first side surface portion 12B. The first side surface portion 12B is parallel to the positive electrode plate or the negative electrode plate constituting the electrode body. Therefore, if the recessed part 13 is formed in the 1st side part 12B, the effect by having formed the recessed part 13 will be acquired effectively.

  The lid body 15 is preferably made of, for example, aluminum, an aluminum alloy, or stainless steel, and preferably has a thickness of 0.1 mm to 5 mm. The lid 15 is preferably connected to the exterior body 11 and is preferably welded to the exterior body 11 by, for example, a laser welding method, a gas welding method, an arc welding method, or the like.

  The lid 15 is preferably provided with a safety valve 17 and preferably has a liquid injection hole or the like. These will be described in a second embodiment described later.

<Modification>
The configuration of the recess is not limited to the configuration described in the first embodiment, and may be, for example, the configuration shown in the following modification.

<First Modification>
2A is a plan view of the electrochemical device outer package 10 of the first modification, and FIG. 2B is a cross-sectional view taken along the line IIB-IIB shown in FIG. Two concave portions 113 having a rectangular shape in plan view are formed on one first side surface portion 12B. Even in this case, the effects described in the first embodiment can be obtained.

<Second Modification>
Fig.3 (a) is a top view of the exterior 10 for electrochemical devices of a 2nd modification, FIG.3 (b) is sectional drawing in the IIIB-IIIB line | wire shown to Fig.3 (a). On one first side surface portion 12B, concave portions 123 having a square shape in plan view are formed in a matrix. Even in this case, the effects described in the first embodiment can be obtained.

<Third Modification>
FIG. 4A is a plan view of the electrochemical device outer package 10 of the third modified example, and FIG. 4B is a cross-sectional view taken along the line IVB-IVB shown in FIG. One concave portion 13 of the first embodiment is formed on one first side surface portion 12B, whereas the concave portion 113 of the first modification is formed on the other first side surface portion 12B. Two are formed. As described above, even when the first side surface portion 12B and the other first side surface portion 12B have different shapes or the number of the concave portions, the effects described in the first embodiment can be obtained. Moreover, even if it is a case where a recessed part is formed only with respect to one 1st side part 12B, the effect as described in the said 1st Embodiment is acquired.

<Fourth Modification>
FIG. 5A is a plan view of the electrochemical device outer package 10 of the fourth modified example, and FIG. 5B is a cross-sectional view taken along line VB-VB shown in FIG. FIG. 5C is a cross-sectional view taken along the line VC-VC shown in FIG.

  As shown in FIG. 5C, the depth of the recess 143 is deeper on the bottom surface portion 12 </ b> A side than the opening side of the housing portion 12. If the depth of the concave portion 143 is smaller on the opening side of the housing portion 12, the concave portion 143 can be prevented from becoming an obstacle when the electrode body is inserted into the concave portion 143. Therefore, the electrode body can be smoothly inserted into the recess 143. Preferably, the depth of the concave portion 143 gradually increases from the opening side of the housing portion 12 toward the bottom surface portion 12A. If the depth of the concave portion 143 is larger on the bottom surface portion 12A side, the electrode body can be prevented from moving from the bottom surface portion 12A side to the opening side of the housing portion 12.

  The depth of the concave portion 143 may be deeper on the opening side of the housing portion 12 than on the bottom surface portion 12A side. In this case, since the strength of the first side surface portion 12B of the housing portion 12 is reduced on the opening side of the housing portion 12, the exterior body 11 is easily deformed. Therefore, when the electrode body 20 is inserted into the housing portion 12, the exterior body 11 can be deformed so that the opening of the housing portion 12 is expanded.

<Fifth Modification>
FIG. 6A is a plan view of the electrochemical device outer package 10 of the fifth modification, and FIG. 6B is a cross-sectional view taken along the line VIB-VIB shown in FIG. 6 (c) is a cross-sectional view taken along the line VIC-VIC shown in FIG. 6 (a).

  The depth of the concave portion 153 is deeper on the bottom surface portion 12A side than the opening side of the housing portion 12, and preferably gradually becomes deeper from the opening side of the housing portion 12 toward the bottom surface portion 12A side. Thereby, the effect described in the fourth modified example can be obtained. For the reason described in the fourth modification, the depth of the recess 153 may be deeper on the opening side of the housing portion 12 than on the bottom surface portion 12A side.

  The depth of the recess 153 is deeper on the center side of the first side surface portion 12B than on the peripheral side of the first side surface portion 12B. Thereby, generation | occurrence | production of the bending in the center part of an electrode body can be prevented. Preferably, the depth of the concave portion 153 gradually increases from the peripheral side of the first side surface portion 12B toward the center side of the first side surface portion 12B. Thereby, generation | occurrence | production of the bending in the center part of an electrode body can be prevented, without damaging an electrode body.

<Sixth Modification>
FIG. 7A is a plan view of the electrochemical device exterior 10 of the sixth modification, and FIG. 7B is a cross-sectional view taken along the line VIIB-VIIB shown in FIG. FIG. 7C is a cross-sectional view taken along line VIIC-VIIC shown in FIG.

  The depth of the recess 163 is deeper on the bottom surface portion 12A side than the opening side of the housing portion 12, and preferably gradually becomes deeper from the opening side of the housing portion 12 toward the bottom surface portion 12A side. Thereby, the effect described in the fourth modified example can be obtained. For the reason described in the fourth modification, the depth of the recess 163 may be deeper on the opening side of the housing portion 12 than on the bottom surface portion 12A side.

  The width of the recess 163 is narrower on the opening side of the housing portion 12 than on the bottom surface portion 12A side. Thereby, friction can be prevented from occurring when the electrode body is inserted into the housing portion 12. Preferably, the width of the concave portion 163 gradually decreases from the bottom surface portion 12A side toward the opening side of the housing portion 12. For example, the concave portion 163 is an isosceles triangle in plan view. Thereby, generation | occurrence | production of the said friction is further prevented.

<Seventh Modification>
FIG. 8A is a plan view of the electrochemical device outer package 10 of the seventh modification, and FIG. 8B is a cross-sectional view taken along the line VIIIB-VIIIB shown in FIG. 8 (c) is a cross-sectional view taken along line VIIIC-VIIIC shown in FIG. 8 (a).

  This modification is a combination of the fourth to sixth modifications. Specifically, the depth of the concave portion 183 located on the center side of the first side surface portion 12B is deeper than the depth of the concave portion 173 located on the peripheral side of the first side surface portion 12B. Thereby, the effect described in the fifth modified example can be obtained.

  The depth of the recess 183 is deeper on the bottom surface portion 12A side than the opening side of the housing portion 12, and preferably gradually becomes deeper from the opening side of the housing portion 12 toward the bottom surface portion 12A side. This is also true for the depth of the recess 173. Thereby, the effect described in the fourth modified example can be obtained. For the reason described in the fourth modification, the recesses 173 and 183 may be deeper on the opening side of the housing portion 12 than on the bottom surface portion 12A side.

  The width of the recess 183 is narrower on the opening side of the housing portion 12 than on the bottom surface portion 12A side, and preferably gradually decreases from the bottom surface portion 12A side toward the opening side of the housing portion 12. For example, the recess 183 is an isosceles triangle in plan view. This is also true for the width of the recess 173. Thereby, the effect described in the sixth modified example can be obtained.

<Second Embodiment>
FIG. 9A is a plan view of the electric double layer capacitor according to the second embodiment, and FIG. 9B is a cross-sectional view taken along line IXB-IXB shown in FIG. (c) is sectional drawing in the IXC-IXC line | wire shown to Fig.9 (a). In addition, in FIG.9 (b), (c), the specific structure of the electrode body 20 is not illustrated.

  The electric double layer capacitor of the present embodiment is a kind of electrochemical device, and is configured such that the electrode body 20 is disposed inside the electrochemical device exterior 10 of the first embodiment together with the electrolyte. Thereby, the effect described in the first embodiment can be obtained. Preferably, the electrode body 20 is sandwiched between the opposing recesses 13. Thereby, since the freedom degree of the movement of the electrode body 20 inside the accommodating part 12 becomes still lower, the vibration resistance of the electric double layer capacitor is further improved, and thus the long-term reliability of the electric double layer capacitor is further improved. . In the following, differences from the first embodiment will be mainly described.

<Electrode body and electrolyte>
The electrode body 20 includes a positive electrode plate 30, a negative electrode plate 40, and a separator 50. FIG. 10 is a plan view of the positive electrode plate 30, the negative electrode plate 40 and the separator 50. The positive electrode plate 30 includes a positive electrode exposed portion 31 located at one end in the longitudinal direction of the positive electrode plate 30 and a positive electrode coating portion 32. The negative electrode plate 40 includes a negative electrode exposed portion 41 located at one end in the longitudinal direction of the negative electrode plate 40 and a negative electrode coating portion 42. The separator 50 is disposed between the positive electrode coating part 32 and the negative electrode coating part 42. In the present embodiment, the positive electrode exposed portion 31 and the negative electrode exposed portion 41 protrude from the separator 50 in opposite directions.

The positive electrode current collector constituting the positive electrode plate 30 is preferably an aluminum porous body. This increases the surface area of the positive electrode current collector. Therefore, even if the positive electrode active material is thinly applied to the positive electrode current collector, an electric double layer capacitor capable of increasing the output and capacity can be obtained. In the present specification, the “aluminum porous body” has a thickness of 1.0 to 5.0 mm, a porosity of 80 to 98%, an aluminum basis weight of 90 to 450 g / m ² , and , Which means a structure having a three-dimensional network structure having a pore diameter of 50 to 1000 μm.

  An example of a method for producing an aluminum porous body is shown below. First, a foamed resin molded body having pores formed therein (hereinafter referred to as “base resin molded body”) is prepared, and the surface of the base resin molded body is made conductive. For example, a thin conductive layer is formed on the surface of the base resin molded body. Next, aluminum plating is performed on the base resin molded body whose surface is made conductive in molten salt. Thereby, an aluminum plating layer is formed on the surface of the conductive base resin molding. Thereafter, the base resin molded body is removed as necessary. In addition, the manufacturing method of an aluminum porous body is not limited to the said method.

The positive electrode active material may be activated carbon having a surface area of 2000 m ² / g or more, but is preferably a carbon nanotube. The carbon nanotube may be a single wall nanotube, a double wall nanotube, or a multiwall nanotube, but is preferably a single wall nanotube. In the present specification, the carbon nanotube used as the positive electrode active material preferably has a diameter of 0.1 nm to 50 nm and a length of 100 nm to 5 μm. If the positive electrode active material is a carbon nanotube, the capacity of the electric double layer capacitor can be increased.

  The positive electrode active material may be used in combination with a conductive additive or a binder. In that case, the content of the positive electrode active material is preferably larger than the content of the conductive additive and the binder, and is preferably 90% or more in terms of the composition ratio after drying (after removal of the solvent). Thereby, the capacity of the electric double layer capacitor can be increased.

  The conductive auxiliary is preferably contained in a mixture of the positive electrode active material and the conductive auxiliary or binder in an amount of 10% by mass or less, and is preferably graphite, ketjen black, acetylene black or carbon fiber. The binder is preferably contained in the above mixture in an amount of 10% by mass or less, and is preferably polyvinylidene fluoride, polytetrafluoroethylene (PTFE), styrene butadiene rubber or the like.

  The positive electrode plate 30 is produced according to the following method. First, a positive electrode paste is obtained by mixing and stirring a carbon nanotube and, if necessary, a conductive additive or a binder. The obtained positive electrode paste is filled in an aluminum porous body and dried. Thereafter, the thickness is adjusted using a roller press or the like as necessary. The positive electrode current collector constituting the positive electrode plate 30 is preferably the above-mentioned aluminum porous body, but the manufacturing method is not limited to the above method.

  The negative electrode current collector constituting the negative electrode plate 40 is preferably the above-mentioned aluminum porous body, but the manufacturing method is not limited to the above method.

  The negative electrode active material contained in the negative electrode plate 40 is preferably a carbon nanotube like the positive electrode active material, and may be used in combination with a conductive additive or a binder. In that case, materials usable in the positive electrode plate can be used as the conductive auxiliary agent and the binder without any particular limitation, and each content of the conductive auxiliary agent and the binder is preferably the same as the content in the positive electrode plate. .

  The separator is preferably made of a cellulose-based material or a resin-based material, and preferably has a thickness of 0.01 mm or more and 0.05 mm or less.

  The electrolytic solution may be an aqueous electrolytic solution or a non-aqueous electrolytic solution, but is preferably a non-aqueous electrolytic solution. Thereby, a voltage can be set high. The aqueous electrolyte preferably contains potassium hydroxide or the like as the electrolyte.

  The non-aqueous electrolyte is preferably an ionic liquid. An ionic liquid consists of only an anion and a cation, and in this specification, means that whose melting | fusing point is 100 degrees C or less. The cation constituting the ionic liquid is preferably lower aliphatic quaternary ammonium, lower aliphatic quaternary phosphonium or imidazolinium, and the anion constituting the ionic liquid is hexafluorophosphate, tetrafluoroborate, bis (fluorosulfonyl). ) An imide compound such as imide, a metal chloride ion or a metal fluoride ion is preferable.

  The non-aqueous electrolyte solution may contain a polar aprotic organic solvent and a supporting salt. The polar aprotic organic solvent is preferably ethylene carbonate, diethyl carbonate, dimethyl carbonate, propylene carbonate, γ-butyrolactone or sulfolane, and the supporting salt is triethylmethylammonium tetrafluoroborate, tetraethylammonium tetrafluoroborate, spirobipyridinium tetra Preferred are fluoroborate, lithium tetrafluoroborate, lithium hexafluorophosphate or imide salt.

  In summary, the positive electrode current collector and the negative electrode current collector are preferably made of the above-mentioned aluminum porous body, the positive electrode active material and the negative electrode active material are preferably made of carbon nanotubes, and the electrolytic solution is made of an ionic liquid. preferable. Thereby, the effect shown below can be acquired.

  Recently, for the purpose of increasing the capacity of electric double layer capacitors, it has been proposed to use a current collector made of a porous material. On the other hand, when a current collector made of a porous material is used, the long-term reliability of the electric double layer capacitor is reduced as compared with the case where a plate-shaped or foil-shaped current collector is used. Therefore, it has been difficult to put into practical use an electric double layer capacitor using a porous current collector. However, in this embodiment, since the recessed part 13 is formed in a part of 1st side part 12B of the accommodating part 12, the long-term reliability of an electrical double layer capacitor improves. Therefore, if the positive electrode current collector and the negative electrode current collector made of the porous aluminum body are used, an electric double layer capacitor having a large capacity, a high cell voltage, low resistance, and excellent long-term reliability can be realized.

  In addition, as shown in the first embodiment, in this embodiment, the long-term reliability of the electric double layer capacitor can be improved without disposing a member that does not contribute to the battery reaction inside the housing portion 12. Therefore, it can prevent that the said aluminum porous body, a carbon nanotube, an ionic liquid, etc. raise | generate a reaction different from a battery reaction. Therefore, if the positive electrode current collector and the negative electrode current collector made of the aluminum porous body are used, the positive electrode active material and the negative electrode active material made of carbon nanotubes are used, and the electrolyte solution made of an ionic liquid is used, the capacity is increased and the cell voltage is increased. High electrical resistance, low resistance, excellent safety, and long-term reliability can be realized.

<Connection structure with external terminals>
The positive electrode exposed portion 31 is connected to the positive electrode terminal 35 via the positive electrode lead 33, and the negative electrode exposed portion 41 is connected to the negative electrode terminal 45 via the negative electrode lead 43.

  The positive electrode lead 33 is preferably made of aluminum, an aluminum alloy, stainless steel, or the like, and the thickness thereof is preferably 0.1 mm or more and 5 mm or less. The negative electrode lead 43 is preferably made of aluminum, an aluminum alloy, stainless steel, nickel, copper, or the like, and the thickness thereof is preferably 0.1 mm or more and 5 mm or less.

  The positive electrode terminal 35 is provided so as to penetrate the lid body 15, and a gasket 37 is provided between the positive electrode terminal 35 and the lid body 15. The negative electrode terminal 45 is provided so as to penetrate the lid body 15, and a gasket 47 is provided between the negative electrode terminal 45 and the lid body 15.

<Sealing structure with safety valve>
Fig.11 (a) is a top view of the cover body 15, and FIG.11 (b) is sectional drawing in the XIB-XIB line | wire shown to Fig.11 (a). A through hole 16 a is formed in the lid 15, and the through hole 16 a is closed with a safety valve 17. When the internal pressure of the electrochemical device exterior 10 increases, the safety valve 17 is opened, and thus the gas in the electrochemical device exterior 10 passes through the through hole 16a and is released to the outside of the electrochemical device exterior 10. Further, when the electric double layer capacitor is manufactured, the electrolytic solution is injected into the accommodating portion 12 through the through hole 16a.

  12A is a plan view of the lid body 25 (a lid body different from the lid body 15), and FIG. 12B is a cross-sectional view taken along the line XIIB-XIIB shown in FIG. . The lid body 25 may be formed with not only the through hole 16a but also the through hole 16b. In the case shown in FIGS. 12A and 12B, the electrolytic solution is injected into the accommodating portion 12 through the through hole 16b.

<Manufacture of electric double layer capacitors>
Examples of the method for manufacturing the electric double layer capacitor of the present embodiment include the following method. FIG. 13 is a flowchart showing the manufacturing method of the electric double layer capacitor of this embodiment in the order of steps. In step S <b> 201, first, the electrode body 20 is manufactured using the positive electrode plate 30, the negative electrode plate 40, and the separator 50. The positive electrode lead 33 is connected to the positive electrode exposed portion 31, and the negative electrode lead 43 is connected to the negative electrode exposed portion 41. Next, a case main body and a lid 15 are prepared. Here, the case body has the same configuration as the exterior body 11 except that the recess 13 is not formed. Subsequently, after the positive electrode lead 33 is connected to the positive electrode terminal 35 and the negative electrode lead 43 is connected to the negative electrode terminal 45, the electrode body 20 is inserted into the housing portion of the case body.

  In step S202, the recessed part 13 is formed in the side part of the accommodating part of a case main body using a press processing machine. Thereby, the exterior body 11 is formed. At this time, it is preferable to form the recess 13 so that the recess 13 sandwiches the electrode body 20. Thereafter, the opening of the accommodating portion 12 is sealed with the lid 15 or the lid 25.

  Subsequently, in step S <b> 203, an electrolytic solution is injected into the housing portion 12 and sealed with the safety valve 17. When the opening of the housing portion 12 is sealed with the lid 15, the electrolytic solution is injected from the through hole 16 a and the through hole 16 a is sealed with the safety valve 17 (the former method). On the other hand, when the opening of the housing portion 12 is sealed with the lid 25, the through hole 16a is closed with the safety valve 17, and then the electrolytic solution is injected from the through hole 16b to seal the through hole 16b (the latter Method). Thereby, the electric double layer capacitor of this embodiment is obtained.

  When an electrolytic solution containing an organic solvent is used as the electrolytic solution, it is preferable to perform injection of the electrolytic solution and sealing with the safety valve 17 according to the latter method. On the other hand, when an ionic liquid is used as the electrolytic solution, the electrolytic solution can be injected and sealed by the safety valve 17 according to the former method. This is because the viscosity of the ionic liquid is higher than the viscosity of the electrolytic solution containing the organic solvent, so that the ionic liquid can be prevented from scattering during the injection. Thereby, it can prevent that an ionic liquid adheres to the internal peripheral surface of the through-hole 16a at the time of liquid injection. Therefore, even if the electrolytic solution is injected and the safety valve 17 is sealed in accordance with the former method, the safety valve 17 can be prevented from being deteriorated by the ionic liquid, so that the manufacturing time of the electric double layer capacitor can be shortened. Also from this, it is preferable to use an ionic liquid as the electrolytic solution.

  In the present embodiment, the electrode body 20 may be inserted into the housing portion 12. When the concave portion 13 is formed, the strength of the first side surface portion 12B of the housing portion 12 is reduced, so that the exterior body 11 is easily deformed. Therefore, when the electrode body 20 is inserted into the housing portion 12, the exterior body 11 can be deformed so that the opening of the housing portion 12 is expanded. Moreover, in this embodiment, you may use the exterior body 11 in any one of the said 1st-7th modification instead of the exterior body 11 of the said 1st Embodiment.

<First Modification>
<Structure of electric double layer capacitor>
FIG. 14A is a plan view of the electric double layer capacitor of the first modification, and FIG. 14B is a cross-sectional view taken along the line XIVB-XIVB shown in FIG. In addition, in FIG.14 (b), the specific structure of the electrode body 20 is not illustrated.

  In the positive electrode current collector, the amount of metal contained in the connection portion 39 (see FIG. 15) between the positive electrode exposed portion 31 and the positive electrode lead 33 is larger than the amount of metal contained in a portion different from the connection portion 39. Preferably, in the positive electrode current collector, the amount of metal contained in the connection part 39 between the positive electrode exposed part 31 and the positive electrode lead 33 is 1.05 times or more of the amount of metal contained in a part different from the connection part 39. 50 times or less.

  Since the amount of metal contained in the connection portion 39 between the positive electrode exposed portion 31 and the positive electrode lead 33 is larger than the amount of metal contained in the portion of the positive electrode current collector different from the connection portion 39, the positive electrode exposed portion 31 and the positive electrode The connection strength with the lead 33 is increased. Therefore, even when the electric double layer capacitor vibrates, the connection state between the positive electrode exposed portion 31 and the positive electrode lead 33 is further maintained (further improvement in vibration resistance of the electric double layer capacitor). Therefore, the long-term reliability of the electric double layer capacitor is further increased. In addition, since the resistance at the connection portion 39 between the positive electrode exposed portion 31 and the positive electrode lead 33 is reduced, the resistance of the electric double layer capacitor can be reduced.

  Similarly, in the negative electrode current collector, the amount of metal contained in the connection portion 49 (see FIG. 15) between the negative electrode exposed portion 41 and the negative electrode lead 43 is greater than the amount of metal contained in a portion different from the connection portion 49. There are also many. Preferably, in the negative electrode current collector, the amount of metal contained in the connection portion 49 between the negative electrode exposed portion 41 and the negative electrode lead 43 is 1.05 times or more of the amount of metal contained in a portion different from the connection portion 49. 50 times or less. Thereby, the long-term reliability of the electric double layer capacitor is further increased, and the resistance of the electric double layer capacitor can be reduced.

  In the present modification, it is preferable that the positive electrode lead 33 is disposed inside the housing portion 12 with the insulating member 38 interposed therebetween. Thereby, it can prevent that the exterior main body 11 and the positive electrode lead 33 raise | generate an internal short circuit. Similarly, the negative electrode lead 43 is preferably disposed inside the housing portion 12 with the insulating member 48 interposed therebetween. Thereby, it can prevent that the exterior main body 11 and the negative electrode lead 43 raise | generate an internal short circuit.

<Manufacture of electric double layer capacitors>
As a manufacturing method of the electric double layer capacitor of this modification, for example, the following method can be cited. FIG. 15 is a side view showing one step of the method for manufacturing the electric double layer capacitor of the present modification. In addition, in FIG. 15, the specific structure of the electrode body 20 is not illustrated. First, the electrode body 20 is produced according to the method described in the second embodiment. Next, the positive electrode current collector in the positive electrode exposed part 31 and the negative electrode current collector in the negative electrode exposed part 41 are bent so that the tip faces upward. Subsequently, the positive electrode lead 33 is provided so as to contact the outer peripheral surface of the bent portion of the positive electrode exposed portion 31, and the negative electrode lead 43 is provided so as to contact the outer peripheral surface of the bent portion of the negative electrode exposed portion 41.

  Subsequently, laser light is irradiated from the front end side of the positive electrode exposed portion 31. Thereby, the part irradiated with the laser beam in the positive electrode exposed part 31 is melted, and the melted product of the positive electrode current collector is generated. The generated melt moves to the portion where the positive electrode exposed portion 31 is bent by its own weight. Thereby, the positive electrode exposed part 31 and the positive electrode lead 33 are connected. Since the positive electrode exposed portion 31 and the positive electrode lead 33 are thus connected, in the positive electrode current collector, the amount of metal contained in the connection portion 39 between the positive electrode exposed portion 31 and the positive electrode lead 33 is other than the connection portion 39. More than the amount of metal contained in the part.

  Similarly, laser light is irradiated from the tip side of the negative electrode exposed portion 41. As a result, the negative electrode exposed portion 41 and the negative electrode lead 43 are connected, and in the negative electrode current collector, the amount of metal contained in the connecting portion 49 between the negative electrode exposed portion 41 and the negative electrode lead 43 is included in a portion other than the connecting portion 49. More than the amount of metal.

  The irradiation condition of the laser beam is not particularly limited. For example, the wavelength of the laser beam is preferably from 100 nm to 10,000 nm, the intensity of the laser beam is preferably from 1 W to 100 W, and the irradiation time of the laser beam is preferably from 1 minute to 30 minutes. As the laser device, for example, an Nd-YAG laser device, a KrF / ArF excimer laser device, a carbon dioxide laser device, a titanium-sapphire laser device, or the like can be used.

  Thereafter, if necessary, the positive electrode current collector is cut at the front end side from the connection portion 39 between the positive electrode exposed portion 31 and the positive electrode lead 33, and the front end side from the connection portion 49 between the negative electrode exposed portion 41 and the negative electrode lead 43. To cut the negative electrode current collector. With the insulating member 38 provided outside the positive electrode lead 33 and the insulating member 48 provided outside the negative electrode lead 43, the electrode body 20 is inserted into the case body. Thereafter, the electric double layer capacitor of this modification can be manufactured according to the method described in the second embodiment.

<Second Modification>
FIG. 16A is a plan view of the electric double layer capacitor of the second modification, and FIG. 16B is a cross-sectional view taken along line XVIB-XVIB shown in FIG.

  In the present modification, the electrode body 20 is disposed inside the exterior body 911 where no recess is formed. The connection form of the positive electrode exposed part 31 and the positive electrode lead 33 is the form described in the first modification, and the connection form of the negative electrode exposed part 41 and the negative electrode lead 43 is the form described in the first modification. is there.

  That is, in the positive electrode current collector, the amount of metal contained in the connection portion between the positive electrode exposed portion 31 and the positive electrode lead 33 is larger than the amount of metal contained in the portion other than the connection portion. Further, in the negative electrode current collector, the amount of metal contained in the connection portion between the negative electrode exposed portion 41 and the negative electrode lead 43 is larger than the amount of metal contained in portions other than the connection portion. Thereby, the connection strength between the positive electrode exposed portion 31 and the positive electrode lead 33 is increased, and the connection strength between the negative electrode exposed portion 41 and the negative electrode lead 43 is increased. Therefore, even when the electric double layer capacitor vibrates, the connection between the positive electrode exposed portion 31 and the positive electrode lead 33 is maintained, and the connection between the negative electrode exposed portion 41 and the negative electrode lead 43 is maintained. Even in such a case, since the vibration resistance of the electric double layer capacitor is improved, the long-term reliability of the electric double layer capacitor is increased. In addition, the long-term reliability of the electric double layer capacitor can be improved without disposing a member that does not contribute to the battery reaction inside the housing portion.

  Based on the method described in the second embodiment and the method described in the first modified example, the electric double layer capacitor of the modified example can be manufactured. In detail, in this modification, the process of forming a recessed part in the 1st side part of an accommodating part is not performed. Further, according to the method described in the first modification, the positive electrode exposed portion 31 and the positive electrode lead 33 are connected, and the negative electrode exposed portion 41 and the negative electrode lead 43 are connected.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these.

<Example 1>
<Preparation of porous aluminum>
First, a urethane foam was prepared as a base resin molded body. The prepared urethane foam has a porosity of 95 to 98%, a pore number (cell number) per inch of about 46, a pore diameter of about 552 μm, a thickness of 1 mm, and a long length. Was 1000 mm. An aluminum film (weight per unit area: 10 g / m ² ) was formed on the surface of this urethane foam by sputtering. Thereby, the surface of the urethane foam was subjected to a conductive treatment.

Next, the urethane foam was set as a workpiece on a jig having a power feeding function. Then, this jig was put in a glove box having an argon atmosphere and low moisture (dew point -30 ° C. or less), and immersed in a molten salt aluminum plating bath (33 mol% EMIC-67 mol% AlCl ₃ ) at a temperature of 40 ° C. The jig was connected to the cathode side of the rectifier, and a counter electrode aluminum plate (purity 99.99%) was connected to the anode side. Then, a direct current having a current density of 3.6 A / dm ² was applied for 90 minutes to plate the urethane foam. As a result, an aluminum structure having an aluminum plating layer of 80 to 150 g / m ² formed on the surface of the urethane foam was obtained. In plating the urethane foam, stirring was performed with a stirrer using a Teflon (registered trademark) rotor. Here, the current density is a value calculated using the apparent area of the urethane foam.

Subsequently, the obtained aluminum structure was immersed in a LiCl—KCl eutectic molten salt at a temperature of 500 ° C., and a negative potential of −1 V was applied to the aluminum structure for 30 minutes. Bubbles were generated in the molten salt due to the decomposition reaction of the polyurethane. Thereafter, the aluminum structure was cooled to room temperature in the atmosphere. Then, the aluminum structure was washed with water to remove the molten salt from the aluminum structure. In this way, an aluminum porous body from which the base resin molded body was removed was obtained. The obtained porous aluminum body had continuous air holes, and the porosity of the porous body was as high as that of the urethane foam used as the core material. The obtained aluminum porous body has a purity of 99.99% or more, a thickness of 1 mm, a porosity of 95 to 98%, an aluminum basis weight of 80 to 150 g / m ² , and a pore diameter of It was 552 μm.

<Production of electrode body>
First, the thickness of the aluminum porous body was adjusted to 0.2 mm using a roller. Carbon nanotubes (positive electrode active material: “single wall nanotube SO-P” manufactured by Meijo Nanocarbon Co., Ltd.) and ionic liquid (electrolytic solution (1-ethyl-3-methyl-imidazolium-tetrafluoroborate) ) Was mixed at a mass ratio of 11:89 to obtain a positive electrode paste. The obtained positive electrode paste was filled in a positive electrode current collector except for a welding margin. In this way, a positive electrode plate with a positive electrode lead was obtained.

  Next, the thickness of the aluminum porous body was adjusted to 0.2 mm using a roller. Carbon nanotubes (negative electrode active material: “single wall nanotube SO-P” manufactured by Meijo Nanocarbon Co., Ltd.) and ionic liquid (electrolytic solution (1-ethyl-3-methyl-imidazolium-tetrafluoroborate) And 11) by weight in a ratio of 11:89 to obtain a negative electrode paste. The obtained negative electrode paste was filled in a negative electrode current collector except for a welding margin. In this way, a negative electrode plate with a negative electrode lead was obtained.

  Subsequently, cellulose paper (separator) having a thickness of 35 μm was prepared. And the positive electrode plate with a positive electrode lead, the negative electrode plate with a negative electrode lead, and the separator were laminated | stacked in order of the positive electrode plate with a positive electrode lead, a separator, the negative electrode plate with a negative electrode lead, and a separator. As a result, an electrode body was obtained. The obtained electrode body was inserted into the housing part of the case body.

<Formation of recess>
A case main body having an accommodating portion having a depth of 12.5 mm, a width of 110 mm, and a length of 95 mm was prepared. Using a press machine, a recess having a depth of 0.3 mm, a width of 96 mm, and a length of 81 mm was formed on the first side surface of the housing portion of the case body. Thereby, the exterior main body in which the recessed part shown in FIG. 1 was formed in the 1st side part was obtained.

<Injection of electrolyte>
An ionic liquid (electrolytic solution) composed of 1-ethyl-3-methyl-imidazolium ion (cation) and tetrafluoroborate ion (anion) was prepared. And this ionic liquid was supplied to the inside of the accommodating part of an exterior main body. Thereafter, the opening of the exterior body was sealed with a lid. As a result, the electric double layer capacitor of this example was obtained.

<Comparative Example 1>
An electric double layer capacitor of Comparative Example 1 was obtained according to the method described in Example 1 except that the exterior body 911 shown in FIG. 19 was used.

<Comparative Example 2>
An electric double layer capacitor of Comparative Example 2 was obtained according to the method described in Comparative Example 1 except that the cushioning material 913 shown in FIG. 19 was provided inside the exterior body 911. As the buffer material 913, an ethylene propylene rubber sheet having a thickness of 0.5 mm, a width of 96 mm, and a length of 81 mm was used.

<Vibration test>
First, the capacitance of the electric double layer capacitors of Example 1, Comparative Example 1 and Comparative Example 2 according to the method described in JIS D 1401: 2009 (Test Method for Electric Performance of Electric Double Layer Capacitor for Hybrid Electric Vehicle) Was measured.

  Further, the internal resistance of the electric double layer capacitors of Example 1, Comparative Example 1 and Comparative Example 2 was determined by the method described in JIS D 1401: 2009 (Testing method of electric performance of electric double layer capacitor for hybrid electric vehicle). It was measured.

Next, the electric double layer capacitors of Example 1, Comparative Example 1 and Comparative Example 2 were vibrated by the method described in JIS D 1401: 2009 (Test Method for Electric Performance of Electric Double Layer Capacitor for Hybrid Electric Vehicle). It was. The frequency was adjusted to the maximum acceleration (28 to 33 Hz). The acceleration was 89 ± 1 m / s ² .

  Then, according to the said method, the electrostatic capacitance and internal resistance of the electric double layer capacitor were measured. Moreover, the electrode body was taken out from the inside of the exterior body, and the positive electrode current collector and the negative electrode current collector were observed.

  The results are shown in Table 1. In Table 1, “A1” is indicated when no breakage is observed in the positive electrode current collector and the negative electrode current collector, and “B1” is indicated when breakage is confirmed in the positive electrode current collector and the negative electrode current collector. ing.

  As shown in Table 1, in Comparative Example 1, there was no significant change in the capacitance before and after the vibration test, but the internal resistance increased. In addition, after the vibration test, breakage was confirmed in the positive electrode current collector and the negative electrode current collector.

  In Comparative Example 2, no breakage was observed in the positive electrode current collector and the negative electrode current collector after the vibration test. However, an increase in capacitance and an increase in internal resistance were confirmed before and after the vibration test. The reason is considered to be that impurities are generated from the buffer material.

  On the other hand, in Example 1, no fracture was confirmed in the positive electrode current collector and the negative electrode current collector after the vibration test. Further, before and after the vibration test, no significant changes were observed in the capacitance and the internal resistance.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 10 Electrochemical device exterior 11,911 Exterior body 12 Housing | casing part 12A Bottom surface part 12B 1st side surface part 12C 2nd side surface part 13,113,123,143,153,163,173,183 Recessed part 15,25 Cover 16a, 16 b Through-hole 17 Safety valve 20, 820 Electrode body 30 Positive electrode plate 31 Positive electrode exposed portion 32 Positive electrode coating portion 33 Positive electrode lead 35 Positive electrode terminal 37, 47 Gasket 38, 48 Insulating member 39, 49 Connection portion 40 Negative electrode plate 41 Negative electrode exposed portion 42 Negative electrode coating portion 43 Negative electrode lead 45 Negative electrode terminal 50 Separator 131, 141 Aluminum foil 913 Buffer material

Claims (9)

An exterior body having an accommodating portion in which an opening is formed;
A lid that closes the opening of the housing portion;
The accommodating part has a bottom part located on the side opposite to the opening, and a side part extending from the bottom part toward the lid,
An exterior for an electrochemical device, wherein the side surface is formed with a recess that is recessed toward the inside of the housing.   The exterior for an electrochemical device according to claim 1, wherein the depth of the concave portion is deeper on the bottom surface side than on the opening side.   The electrochemical device according to claim 1 or 2, wherein a depth of the concave portion is deeper at a center side of the side surface portion where the concave portion is formed than at a peripheral side of the side surface portion where the concave portion is formed. For exterior.   The exterior for an electrochemical device according to any one of claims 1 to 3, wherein the width of the concave portion is narrower on the opening side than on the bottom surface side.   5. The electricity according to claim 1, wherein, in a plan view, the area of the recess is 0.1 to 0.9 times the area of the side surface where the recess is formed. Exterior for chemical devices.   The maximum depth of the said recessed part is 0.01 times or more and 0.30 times or less of the thickness of the said exterior body, The exterior for electrochemical devices of any one of Claims 1-5. The exterior for an electrochemical device according to any one of claims 1 to 6,
An electrode body that is disposed inside the housing portion of the exterior body of the electrochemical device exterior and has a positive electrode plate, a negative electrode plate, and a separator disposed between the positive electrode plate and the negative electrode plate. Electric double layer capacitor provided. At least one of the positive electrode plate and the negative electrode plate has a coating part in which an active material is carried on a current collector made of a porous body, and an exposed part in which the current collector is exposed from the active material. And
The exposed portion is connected to a lead;
The electric double layer capacitor according to claim 7, wherein in the current collector, an amount of metal contained in a connection portion between the exposed portion and the lead is larger than an amount of metal contained in a portion different from the connection portion. . At least one of the positive electrode plate and the negative electrode plate includes a current collector made of an aluminum porous body, and carbon nanotubes supported on the current collector,
The electric double layer capacitor according to claim 7 or 8, wherein an ionic liquid is provided inside the housing portion.

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