JP2015159229A - Exterior package for electrochemical device and electric double layer capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exterior package for an electrochemical device capable of enhancing long-term reliability of the electrochemical device and energy density per unit area of the electrochemical device.SOLUTION: The exterior package for an electrochemical device includes an exterior package body having housing part. At the housing part, an opening is formed. The housing part includes: a bottom surface part positioned on the opposite side of the opening; and a side surface part extending from the bottom surface part to the opening side. A depth of the housing part is shorter than a length of sides constituting the bottom surface part.

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. 12 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. 13 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. 13, the positive electrode current collector positioned at the boundary X <b> 1 is reinforced with the aluminum foil 131, and the negative electrode current collector positioned at the boundary X <b> 2 is reinforced with 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. 13, the positive electrode current collector or the negative electrode current collector may be broken due to vibration of the electric double layer capacitor or the like.

  As a method of preventing this problem, a method of using a cushioning material can be considered. FIG. 14A is a plan view showing the internal structure of the electric double layer capacitor provided with the buffer material, and FIG. 14B is a cross-sectional view taken along the line XIVB-XIVB shown in FIG. 14 (c) is a cross-sectional view taken along the line XIVC-XIVC shown in FIG. 14 (a). 14A to 14C do not illustrate a specific configuration of the electrode body 20.

  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. 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 a housing portion. An opening is formed in the housing 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 opening. The depth of the accommodating part is shorter than the length of the side which comprises a bottom face part.

  In the present invention, the long-term reliability of the electric double layer capacitor and the energy density per unit volume of the electric double layer capacitor can be increased.

It is sectional drawing of the exterior for electrochemical devices of one Embodiment of this invention. (A) is a top view of the electric double layer capacitor of one Embodiment of this invention, (b)-(d) is an electric double layer from the IIB, IIC, and IID direction shown to Fig.2 (a), respectively. It is a top view when a capacitor is seen. It is a top view of a positive electrode plate, a negative electrode plate, and a separator. It is sectional drawing in the IV-IV line shown in FIG. It is principal part sectional drawing of the side part by which a positive electrode terminal and a negative electrode terminal penetrate and are provided. 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), (b) is a side view which shows 1 process of the manufacturing method of the electrical double layer capacitor of one Embodiment of this invention. (A), (b) is a side view of the electric double layer capacitor of the modification of this invention. (A) is a top view of the electric double layer capacitor of the modification of this invention, (b)-(d) is an electric double layer from the IXB, IXC, and IXD directions shown to Fig.9 (a), respectively. It is a top view when a capacitor is seen. 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. It is a side view of the electric double layer capacitor of one modification of the present invention. 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 shock absorbing material, (b) is sectional drawing in the XIVB-XIVB line | wire shown to Fig.14 (a), (c) is a figure. It is sectional drawing in the XIVC-XIVC line shown to 14 (a).

[Description of Embodiment of Present Invention]
The exterior for an electrochemical device according to the present embodiment includes an exterior body having a housing portion. An opening is formed in the housing 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 opening. The depth of the accommodating part is shorter than the length of the side which comprises a bottom face part.

  In the above-described exterior for an electrochemical device, since the depth of the accommodating portion is shorter than the length of the side constituting the bottom surface portion, the thickness direction of the electrode body is parallel to the depth direction of the accommodating portion inside the accommodating portion. The electrode body is arranged so that 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. Further, the vibration resistance of the electric double layer capacitor can be improved without arranging a member (for example, a buffer material) 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 opening side from 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.

  The “depth of the housing portion” means the size of the housing portion in the direction perpendicular to the bottom surface portion. The “depth direction of the housing portion” means a direction perpendicular to the bottom surface portion. The “side that constitutes the bottom surface portion” is the length of the boundary between the bottom surface portion and the side surface portion. The “thickness direction of the electrode body” is parallel to the thickness direction of the positive electrode plate, the negative electrode plate or the separator constituting the electrode body, and is parallel to the stacking direction of the positive electrode plate, the separator and the negative electrode plate. .

  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. The electrode body is disposed inside the housing portion so that the thickness direction thereof is parallel to the depth direction of the housing portion. 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. Further, the vibration resistance of the electric double layer capacitor can be improved without arranging a member (for example, a buffer material) that does not contribute to the battery reaction inside the housing portion.

  At least one of the positive electrode plate and the negative electrode plate preferably 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 portion is preferably connected to an external terminal via a lead. In the current collector, the amount of metal contained in the connection portion between the exposed portion and the lead or the external terminal 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 or the external terminal 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.

  The “connection portion between the exposed portion and the external terminal” includes a connection portion in which the exposed portion and the external terminal are directly connected and a connection portion in which the exposed portion and the external terminal are indirectly connected. It is. In the “connection portion in which the exposed portion and the external terminal are directly connected”, the exposed portion and the external terminal are in contact with each other. In the “connection portion in which the exposed portion and the external terminal are indirectly connected”, one or more conductive members (for example, leads) are disposed between the exposed portion and the external terminal, and the conductive member The exposed portion and the external terminal are connected via the. The “external terminal” is a positive electrode terminal or a negative electrode terminal described later.

  It is preferable that the exterior for electrochemical devices has a lid that closes the opening of the accommodating portion. The electrode body is preferably sandwiched between the bottom surface portion of the housing portion and the lid body. Thereby, the vibration resistance of the electric double layer capacitor is further improved.

  The exterior for an electrochemical device may be configured by connecting two exterior bodies. In this case, it is preferable that the housing part of one exterior body communicates with the housing part of the other exterior body, and the electrode body is provided in each of the housing part of one exterior body and the housing part of the other exterior body. It is preferable that it is arranged inside. This also further improves the vibration resistance of the electric double layer capacitor. In addition, an electric double layer capacitor having about twice the capacity can be obtained without changing the production line.

  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.

[Details of the embodiment of the present invention]
Hereinafter, the exterior for an electrochemical device and the electric double layer capacitor 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 is a cross-sectional view of an exterior for an electrochemical device according to a first embodiment. 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. The accommodating portion 12 has a bottom surface portion 12A located on the side opposite to the opening, and a side surface portion 12B extending from the bottom surface portion 12A toward the opening side. An electrode body (second embodiment to be described later) is disposed inside the housing portion 12.

  The depth D of the accommodating part 12 is shorter than the length of the side which comprises the bottom face part 12A. Accordingly, the electrode body is disposed inside the housing portion 12 so that the thickness direction of the electrode body is parallel to the depth direction of the housing portion 12. Therefore, even if the thickness of the electrode body is less than the depth of the housing portion 12 or the thickness of the electrode body exceeds the depth of the housing portion 12, the electrode body is pressed by the lid body 15 and the lid The opening of the accommodating portion 12 can be sealed with the body 15. 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). As described above, even when the electric double layer capacitor is used for a long time, the current collector constituting the electrode body can be prevented from being broken, and the connected state between the current collector and the lead or the external terminal can be maintained. For these reasons, 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, components of the exterior for an electrochemical device 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 except the depth D of the accommodating part 12 being shorter than the length of the edge | side which comprises the bottom face part 12A. 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 side surface portion 12B may extend perpendicular to the bottom surface portion 12A, or may extend in a direction inclined at a predetermined angle from a direction perpendicular to the bottom surface portion 12A.

  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 exterior body 11 may have a flange that extends from the side surface portion 12 </ b> B of the housing portion 12 toward the outside of the housing portion 12. In this case, the lid body 15 is preferably connected to the exterior body 11 at the collar portion of the exterior body 11.

  A safety valve 17 is preferably provided on one side surface portion 12B of the accommodating portion 12, and a positive electrode terminal 35 and a negative electrode terminal 45 are preferably provided so as to penetrate therethrough, and an injection hole is formed. Preferably it is. These will be described in a second embodiment described later.

<Second Embodiment>
<Structure of electric double layer capacitor>
FIG. 2A is a plan view of the electric double layer capacitor of the second embodiment, and FIGS. 2B to 2D are IIB, IIC and IID shown in FIG. 2A, respectively. It is a top view when the electric double layer capacitor of this embodiment is seen from the direction. In FIG. 2A, the internal structure of the electric double layer capacitor is illustrated through the lid 15. 2B and 2D, the internal structure of the electric double layer capacitor is illustrated through one side surface portion 12B of the housing portion 12. Moreover, in FIG.2 (b), the specific structure of the electrode body 20 is not illustrated.

  The electric double layer capacitor of the present embodiment is configured by arranging the electrode body 20 together with the electrolyte in the housing portion 12 of the exterior body 11 of the electrochemical device exterior 10 of the first embodiment. The electrode body 20 is disposed inside the housing portion 12 so that the thickness direction thereof is parallel to the depth direction of the housing portion 12. Thereby, the effect described in the first embodiment can be obtained. Preferably, the electrode body 20 is sandwiched between the lid body 15 and the bottom surface portion 12 </ b> A of the housing portion 12. Thereby, even if the electric double layer capacitor vibrates, it is possible to further prevent the electrode body 20 from vibrating inside the housing portion 12, and thus the long-term reliability of the electric double layer capacitor can be 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. 3 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. The anion constituting the ionic liquid is preferably an imide compound such as hexafluorophosphate, tetrafluoroborate, bis (fluorosulfonyl), metal chloride ion, metal fluoride ion, or bis (fluorosulfonyl) imide.

  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 depth of the accommodating part 12 is shorter than the length of the side which comprises the bottom face part 12A of the accommodating part 12, the long-term reliability of an electric 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 and the negative electrode lead 43 are disposed on the side surface portion 12B located on the opposite sides.

  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 a portion different from the connection portion. Preferably, 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 1.05 times or more and 50 times the amount of metal contained in a portion different from the connection portion. It is as follows.

  Since 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 of the positive electrode current collector different from the connection portion, the positive electrode exposed portion 31 and the positive electrode lead 33. Connection strength increases. 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 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 between the negative electrode exposed portion 41 and the negative electrode lead 43 is larger than the amount of metal contained in a portion different from the connection portion. Preferably, 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 1.05 times or more and 50 times the amount of metal contained in a portion different from the connection portion. It is as follows. 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.

  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 positive electrode lead 33 is preferably disposed on the side surface portion 12B of the housing portion 12 with the insulating member 38 interposed therebetween, thereby preventing an internal short circuit between the exterior body 11 and the positive electrode lead 33.

  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 negative electrode lead 43 is preferably disposed on the side surface portion 12B of the housing portion 12 with the insulating member 48 interposed therebetween, thereby preventing an internal short circuit between the exterior body 11 and the negative electrode lead 43.

  The positive electrode terminal 35 is provided so as to penetrate through the side surface portion 12B different from the side surface portion 12B provided with the positive electrode lead 33 and the negative electrode lead 43, and a gasket is provided between the positive electrode terminal 35 and the side surface portion 12B. 37 is provided. The negative electrode terminal 45 is provided so as to penetrate through the same side surface portion 12B as the positive electrode terminal 35, and a gasket 47 is provided between the negative electrode terminal 45 and the side surface portion 12B.

<Sealing structure with safety valve>
4 is a cross-sectional view taken along line IV-IV shown in FIG. A through hole 16 a is formed in the side surface portion 12 </ b> B provided through the positive electrode terminal 35 and the negative electrode terminal 45, and the through hole 16 a is closed by the 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.

  In addition, as shown in FIG. 5, not only the through-hole 16a but the through-hole 16b may be formed in the side surface part 12B in which the positive electrode terminal 35 and the negative electrode terminal 45 are penetrated. FIG. 5 is a cross-sectional view of a main part of another side surface portion 12B in which the positive electrode terminal 35 and the negative electrode terminal 45 are provided so as to penetrate therethrough. In the case shown in FIG. 5, the electrolytic solution is injected into the accommodating portion 12 through the through hole 16 b.

<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. 6 is a flowchart showing the manufacturing method of the electric double layer capacitor of this embodiment in the order of steps. 7A and 7B are side views showing one step of the method for manufacturing the electric double layer capacitor of the present embodiment. In FIGS. 7A and 7B, the internal structure of the electric double layer capacitor is illustrated through one side surface portion 12 </ b> B of the housing portion 12, but a specific configuration of the electrode body 20 is illustrated. Not shown.

  First, in step S <b> 201, the electrode body 20 is manufactured using the positive electrode plate 30, the negative electrode plate 40, and the separator 50.

  Next, in step S <b> 202, the positive electrode exposed portion 31 and the positive electrode terminal 35 are connected inside the housing portion 12, and the negative electrode exposed portion 41 and the negative electrode terminal 45 are connected. Specifically, first, the insulating member 38 and the positive electrode lead 33 are sequentially provided on one side surface portion 12B orthogonal to the side surface portion 12B provided through the positive electrode terminal 35 and the negative electrode terminal 45. . The insulating member 48 and the negative electrode lead 43 are sequentially provided on the side surface portion 12B located on the opposite side to the side surface portion 12B on which the positive electrode lead 33 is provided.

  Thereafter, the positive electrode current collector in the positive electrode exposed portion 31 and the negative electrode current collector in the negative electrode exposed portion 41 are bent so that the tip faces upward. And the electrode body 20 is arrange | positioned inside the accommodating part 12. FIG. At this time, a portion of the positive electrode exposed portion 31 where the positive electrode current collector is bent is disposed on the positive electrode lead 33, and a portion of the negative electrode exposed portion 41 where the negative electrode current collector is bent is disposed on the negative electrode lead 43. It arrange | positions (FIG. 7 (a)).

  Thereafter, laser light is irradiated from the front end side of the positive electrode exposed portion 31. Thereby, the part which the laser beam was irradiated among the positive electrode exposed parts 31 is melted, and the melt of a positive electrode electrical power collector is produced | generated. The generated melt moves to the portion where the positive electrode current collector 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 connected in this way, 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 different from the connection portion. 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. Thereby, the negative electrode exposed part 41 and the negative electrode lead 43 are connected, and in the negative electrode current collector, the amount of metal contained in the connection part between the negative electrode exposed part 41 and the negative electrode lead 43 is included in a part different from the connection part. 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, the positive electrode current collector is cut at the tip side from the connection portion between the positive electrode exposed portion 31 and the positive electrode lead 33, and the negative electrode current collector is cut at the tip side from the connection portion between the negative electrode exposed portion 41 and the negative electrode lead 43. To do. Thereafter, as shown in FIG. 7B, the opening of the accommodating portion 12 is sealed with the lid 15.

  Subsequently, in step S <b> 203, an electrolytic solution is injected into the housing portion 12 and sealed with the safety valve 17. In the case where only the through hole 16a is formed in the side surface portion 12B through which the positive electrode terminal 35 and the negative electrode terminal 45 are provided (FIG. 4), the electrolytic solution is injected from the through hole 16a, and the through hole 16a is connected to the safety valve. 17 (the former method). On the other hand, when the through hole 16a and the through hole 16b are formed in the side surface portion 12B through which the positive electrode terminal 35 and the negative electrode terminal 45 are provided (FIG. 5), the through hole 16a is closed by the safety valve 17. Then, an 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.

<First Modification>
FIGS. 8A and 8B are side views of the electric double layer capacitor of the first modification, and correspond to a plan view when the electric double layer capacitor is viewed from the IIB direction shown in FIG. 2A. To do. In the following, points different from the first and second embodiments are mainly shown.

  In the electric double layer capacitor shown in FIG. 8A, the thickness of the electrode body 20 is less than the depth of the housing portion 12, and the lid body 115 is recessed toward the inside of the housing portion 12 and connected to the exterior body 11. ing. At this time, the electrode body 20 is preferably sandwiched between the lid body 115 and the bottom surface portion 12 </ b> A of the housing portion 12. Thereby, even when the electric double layer capacitor vibrates, the electrode body 20 can be further prevented from vibrating inside the housing portion 12. Therefore, the long-term reliability of the electric double layer capacitor can be further improved.

  In the electric double layer capacitor shown in FIG. 8B, the thickness of the electrode body 20 exceeds the depth of the housing portion 12, and the lid body 125 projects toward the outside of the housing portion 12 and is connected to the exterior body 11. Has been. At this time, the electrode body 20 is preferably sandwiched between the lid body 125 and the bottom surface portion 12 </ b> A of the housing portion 12. Thus, the same effect as that shown in FIG. If the depth D of the accommodating part 12 is 0.8 times or more of the thickness of the electrode body 20, it is thought that the effect as described in the said 1st Embodiment is acquired effectively.

<Second Modification>
<Structure of electric double layer capacitor>
FIG. 9A is a plan view of the electric double layer capacitor of the second modified example, and FIGS. 9B to 9D are respectively IXB, IXC and IXD shown in FIG. 9A. It is a top view when the electric double layer capacitor of this modification is seen from the direction. In FIG. 9A, the internal structure of the electric double layer capacitor is illustrated through the lid 15. 9B and 9D, the internal structure of the electric double layer capacitor is illustrated by seeing through one side surface portion 12B of the housing portion 12. FIG. In FIG. 9B, the specific configuration of the electrode body 20 is not shown. In the following, points different from the first and second embodiments are mainly shown.

  In this modification, the positive electrode exposed portion 31 and the negative electrode exposed portion 41 protrude in the same direction with respect to the separator 50, and specifically, the side surface portion 12B provided with the positive electrode terminal 35 and the negative electrode terminal 45 penetrating therethrough. Protrudes to the side. Thereby, since the moving distance of the discharge current and the charging current is shortened, the resistance of the electric double layer capacitor can be reduced.

  In addition, 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 on the side surface portion 12B side where the positive electrode terminal 35 and the negative electrode terminal 45 are provided through. . For this reason, the positive electrode lead 33 and the negative electrode lead 43 are merely arranged on the side surface portion 12B side through which the positive electrode terminal 35 and the negative electrode terminal 45 are provided. Therefore, since the positive electrode lead 33 and the negative electrode lead 43 can be reduced in size, the energy density per unit volume of the electric double layer capacitor is further increased.

  In this modification, 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 terminal 35 is larger than the amount of metal contained in a portion different from the connection portion. Preferably, 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 terminal 35 is 1.05 times or more and 50 times the amount of metal contained in a portion different from the connection portion. It is as follows. As a result, the long-term reliability of the electric double layer capacitor is further improved, and the resistance of the electric double layer capacitor can be reduced (see the second embodiment).

  Similarly, 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 terminal 45 is larger than the amount of metal contained in a portion different from the connection portion. Preferably, 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 terminal 45 is 1.05 times or more and 50 times the amount of metal contained in a portion different from the connection portion. It is as follows. As a result, the long-term reliability of the electric double layer capacitor is further improved, and the resistance of the electric double layer capacitor can be reduced (see the second embodiment).

  Specifically, the side surface portion 12 </ b> B provided through the positive electrode terminal 35 and the negative electrode terminal 45 is inclined at an angle θ (0 ° <θ <90 °, see FIG. 10) with respect to the bottom surface portion 12 </ b> A of the housing portion 12. The positive terminal 35 and the negative terminal 45 extend perpendicularly to the inclined portion 112B. Thereby, according to the method of the said 2nd Embodiment, the positive electrode exposed part 31 and the positive electrode terminal 35 can be connected, and the negative electrode exposed part 41 and the negative electrode terminal 45 can be connected. Therefore, 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 terminal 35 is larger than the amount of metal contained in a portion different from the connection portion. The same applies to the negative electrode current collector.

<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. 10 is a side view showing one step of the method for manufacturing the electric double layer capacitor of the present modification. In FIG. 10, the internal structure of the electric double layer capacitor is illustrated through one side surface portion 12 </ b> B of the housing portion 12, but a specific configuration of the electrode body 20 is not illustrated.

  First, after preparing the electrode body 20, the positive electrode exposed portion 31 and the positive electrode terminal 35 are connected inside the housing portion 12, and the negative electrode exposed portion 41 and the negative electrode terminal 45 are connected. Specifically, first, the positive electrode terminal 35 and the negative electrode terminal 45 are provided on the inclined portion 112B of the side surface portion 12B, the positive electrode lead 33 is provided on the positive electrode terminal 35, and the negative electrode lead 43 is provided on the negative electrode terminal 45.

  Thereafter, the positive electrode current collector in the positive electrode exposed portion 31 and the negative electrode current collector in the negative electrode exposed portion 41 are bent so that the tip faces upward. A portion of the positive electrode exposed portion 31 where the positive electrode current collector is bent is disposed on the positive electrode lead 33, and a portion of the negative electrode exposed portion 41 where the negative electrode current collector is bent is disposed on the negative electrode lead 43. The electrode body 20 is disposed inside the housing portion 12 (FIG. 10).

  Thereafter, an electric double layer capacitor is manufactured according to the method described in the second embodiment. Thereby, the electric double layer capacitor of this modification is obtained.

<Third Modification>
<Structure of electric double layer capacitor>
FIG. 11 is a side view of the electric double layer capacitor of the third modification, and corresponds to a plan view when the electric double layer capacitor is viewed from the IID direction shown in FIG. In FIG. 11, the internal structure of the electric double layer capacitor is illustrated through one side surface portion 12 </ b> B of the housing portion 12, but a specific configuration of the electrode body 20 is not illustrated.

  In the electric double layer capacitor of this modification, the electrochemical device exterior is configured by connecting the two exterior bodies 11 and does not include the lid 15. In the electrochemical device exterior of the present modification, the housing portion 12 of one exterior body 11 and the housing portion 12 of the other exterior body 11 are communicated to form one housing portion. An electrode body 20 is disposed inside the housing portion 12 of one exterior body 11, and an electrode body 20 is disposed inside the housing portion 12 of the other exterior body 11.

  When the electric double layer capacitor of this modification is vibrated, the vibration of one electrode body 20 is absorbed by the other electrode body 20. Thereby, since the vibration resistance of the electric double layer capacitor is improved, the long-term reliability of the electric double layer capacitor can be improved.

<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. First, two electric double layer capacitors not provided with the lid 15 are prepared according to the method described in the second modification. Next, the prepared two electric double layer capacitors are arranged so that the electrode bodies 20 face each other. Subsequently, the exterior body 11 of one electric double layer capacitor and the exterior body 11 of the other electrical double layer capacitor are connected. In this way, the electric double layer capacitor of this modification is obtained. Thereby, an electric double layer capacitor having about twice the capacity can be obtained without changing the production line.

  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 of −30 ° C. or lower) 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 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 was obtained.

  Subsequently, cellulose paper (separator) having a thickness of 35 μm was prepared, and a separator was disposed between the positive electrode coating part and the negative electrode coating part. Thereby, an electrode body was obtained.

<Connection with external terminal>
First, an exterior body having an accommodation portion having a depth of 12.5 mm, a width of 110 mm, and a height of 95 mm was prepared.

  Next, an insulating member and a positive electrode lead were provided in this order on a side surface orthogonal to the side surface provided through the positive electrode terminal and the negative electrode terminal. An insulating member and a negative electrode lead were provided in this order on a side surface located opposite to the side surface on which the positive electrode lead was provided.

  Subsequently, the positive electrode current collector in the positive electrode exposed part and the negative electrode current collector in the negative electrode exposed part were bent so that the tip was directed upward. The portion of the positive electrode exposed portion where the positive electrode current collector is bent is disposed on the positive electrode lead, and the portion of the negative electrode exposed portion where the negative electrode current collector is bent is disposed on the negative electrode lead. It arrange | positioned inside the accommodating part.

  Subsequently, laser light was irradiated from the tip side of the positive electrode exposed portion, and laser light was irradiated from the tip side of the negative electrode exposed portion. Thereby, the positive electrode exposed part was connected to the positive electrode lead, and the negative electrode exposed part was connected to the negative electrode lead. An Nd-YAG laser device was used as the laser device. The wavelength of the irradiated laser beam was 1064 nm, its intensity was 12 W, its pulse width was 2 msec, its scanning speed was 4 mm / sec, and its overlay rate was 70%.

  Subsequently, an unnecessary positive electrode current collector was cut, and an unnecessary negative electrode current collector was cut. Then, the opening of the accommodating part was closed with a lid.

<Injection of electrolyte, sealing with safety valve>
An ionic liquid (electrolytic solution) composed of 1-ethyl-3-methyl-imidazolium ion (cation) and tetrafluoroborate ion (anion) was prepared. The prepared ionic liquid was injected from the through hole formed in the side surface portion of the housing portion into the housing portion, and the through hole was sealed with a safety valve. Thus, an 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 main body 911 shown in FIG. 14 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. 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, in accordance with the method described in JIS D 1401: 2009 (Testing method of electric performance of electric double layer capacitor for hybrid electric vehicle), the electric double layer capacitors of Example 1, Comparative Example 1 and Comparative Example 2 were used. Capacitance was measured.

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

Next, the electric double layer capacitors of Example 1, Comparative Example 1 and Comparative Example 2 were vibrated in accordance with the method described in JIS D 1601: 1995 (Automobile parts vibration test method). 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 part 12B Side part 15,115,125 Cover body 16a, 16b Through-hole 17 Safety valve 20,820 Electrode body 30 Positive electrode plate 31 Positive electrode exposed part 32 Positive electrode coating Part 33 Positive electrode lead 35 Positive electrode terminal 37, 47 Gasket 38, 48 Insulating member 40 Negative electrode plate 41 Negative electrode exposed part 43 Negative electrode lead 42 Negative electrode coating part 45 Negative electrode terminal 50 Separator 112B Inclined part 131, 141 Aluminum foil 913 Buffer material

Claims (6)

An exterior body having a housing portion;
An opening is formed in the housing part,
The accommodating portion has a bottom surface portion located on the side opposite to the opening, and a side surface portion extending from the bottom surface portion toward the opening side,
The depth of the accommodating part is the exterior for electrochemical devices shorter than the length of the side that constitutes the bottom part. The exterior for an electrochemical device according to claim 1,
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. Prepared,
The electric double layer capacitor, wherein the electrode body is disposed inside the housing portion such that a thickness direction thereof is parallel to a depth direction of the housing portion. 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 an external terminal via a lead,
The amount of metal contained in a connection portion between the exposed portion and the lead or the external terminal in the current collector is larger than an amount of metal contained in a portion different from the connection portion. Electric double layer capacitor. The exterior for an electrochemical device has a lid that closes the opening of the housing portion,
The electric double layer capacitor according to claim 2 or 3, wherein the electrode body is sandwiched between the bottom surface portion of the housing portion and the lid body. The exterior for an electrochemical device is configured by connecting the two exterior bodies, and the housing part of one of the exterior bodies communicates with the housing part of the other exterior body,
The said electrode body is arrange | positioned inside each of the said accommodating part of the said one said exterior main body, and the said accommodating part of the said other said exterior main body, The any one of Claims 2-4 Electric double layer capacitor. 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 any one of claims 2 to 5, wherein an ionic liquid is provided inside the housing portion.

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