JP6731831B2 - Electrochemical cell - Google Patents

Description

The present invention relates to electrochemical cells.

Some electrochemical cells, such as non-aqueous electrolyte secondary batteries and electric double layer capacitors, are formed in a button shape (hereinafter, also including a coin shape and a cylinder shape). Button-type electrochemical cells are used as power sources for various devices. As one form of the button type electrochemical cell, for example, a battery as disclosed in Patent Document 1 below has been proposed.

Patent Document 1 discloses a configuration in which a metal negative electrode case that also serves as a negative electrode terminal and a metal positive electrode case that also serves as a positive electrode terminal are fitted through an insulating gasket. Specifically, in Patent Document 1, the positive electrode case is fitted to the negative electrode case through an insulating gasket by caulking. In the inner space defined by the positive electrode case and the negative electrode case, the electrode body is enclosed together with the non-aqueous electrolyte.

JP 2002-298803 A

However, when the negative electrode case and the positive electrode case are caulked, the caulking load acting on each case at the time of caulking may damage the negative electrode case and the positive electrode case, and the airtightness inside the battery may deteriorate. Further, if caulking is performed with foreign matter sandwiched between the cases, a gap may be formed between the negative electrode case and the positive electrode case due to the foreign matter, and the airtightness inside the battery may deteriorate.
Further, in the case where the respective cases are sealed by the crimping process, it is necessary to provide the negative electrode case and the positive electrode case with sufficient strength to withstand the crimping load in order to mechanically enhance the airtightness. Therefore, the thickness of the negative electrode case and the positive electrode case increases, the effective volume for accommodating the electrode body decreases, and the energy density decreases. Therefore, in the conventional electrochemical cell, there is room for improvement in that the airtightness is improved to improve the reliability and the energy density is improved.

Therefore, the present invention provides a button-type electrochemical cell having high reliability and high energy density.

The electrochemical cell of the present invention includes an electrode body including a positive electrode body and a negative electrode body, and an exterior body in which the electrode body is housed. The exterior body is formed in a bottomed cylindrical shape, and has a first peripheral wall portion. A first container having a, and a second container that is formed in a cylindrical shape with a bottom, has a second peripheral wall portion that surrounds the first peripheral wall portion, and that houses the electrode body between the first container and the second container, A fusion-bonding member that is interposed between the first peripheral wall portion and the second peripheral wall portion and is fused to the first peripheral wall portion and the second peripheral wall portion is provided.
According to the present invention, the space between the first container and the second container in which the electrode body is housed can be sealed without caulking. At this time, even when there is a scratch on the fusion-bonding surface of each peripheral wall portion with the fusion-bonding member, or when a foreign substance is sandwiched between the first peripheral wall portion and the second peripheral wall portion, it is melted during fusion bonding. The fusing member can fill the scratches and the surroundings of the foreign matter. As a result, the airtightness inside the electrochemical cell can be improved as compared with the configuration in which the exterior body is formed by caulking the first container and the second container.
When the outer body is formed by caulking the first container and the second container, in order to give the first container and the second container sufficient strength to withstand the caulking, It is necessary to secure the thickness of a predetermined value or more. According to the present invention, since the space between the first container and the second container is sealed by fusion bonding with the fusion bonding member, the exterior body is formed by caulking the first container and the second container. In comparison with, the first container and the second container can be made thinner. As a result, a large volume can be secured inside the outer package, and the energy density of the electrochemical cell can be improved.
Therefore, a button-shaped electrochemical cell having high reliability and high energy density can be provided.

In the above electrochemical cell, it is preferable that the first container is made of a metal material and the second container is made of a laminated film containing a metal material and a resin material.
According to the present invention, since the second container is formed of the laminated film, the weight of the electrochemical cell can be reduced as compared with the configuration in which the first container and the second container are formed of a metal material. Moreover, since the first peripheral wall portion is formed of the metal material, the second peripheral wall portion surrounding the first peripheral wall portion is heated by heating means or the like when the fusion bonding member is fused to the first peripheral wall portion and the second peripheral wall portion. Thus, the second peripheral wall portion can be supported by the first peripheral wall portion when pressed from the outside. Therefore, the electrochemical cell can be easily manufactured to have a desired outer shape.

In the above electrochemical cell, a through hole is formed in the bottom wall of the second container, and an electrode terminal that is electrically connected to either the positive electrode body or the negative electrode body is inserted into the through hole. Is desirable.
According to the present invention, since the electrode terminal that is electrically connected to either the positive electrode body or the negative electrode body is inserted into the through hole penetrating the second container, either one of the positive electrode body and the negative electrode body is packaged. Can be easily conducted to a lead wire or the like outside. Therefore, in the electrochemical cell using the laminate film for the outer package, it is possible to realize a configuration in which the inside and outside of the outer package are electrically connected.

In the above electrochemical cell, it is desirable that the inner peripheral surface of the through hole be covered with an insulating material.
Since the second container is formed of a laminated film, the metal material may be exposed on the inner peripheral surface of the through hole. According to the present invention, since the inner peripheral surface of the through hole is covered with the insulating material, it is possible to prevent the electrode terminal inserted into the through hole from short-circuiting with the metal material forming the second container. Further, it is possible to suppress the metal material forming the second container from being exposed to the outside, and suppress the corrosion of the metal material. Therefore, the reliability of the electrochemical cell can be improved.

In the above electrochemical cell, it is preferable that the electrode terminal includes a flange portion that is arranged to face an inner surface of the bottom wall portion of the second container.
According to the present invention, the distance of the path from the exterior of the exterior body to the interior of the exterior body through the through hole can be increased as compared with the configuration in which the electrode terminal does not include the flange portion. This can reduce the amount of water entering the exterior body through the through hole. Therefore, the reliability of the electrochemical cell can be improved.

In the above electrochemical cell, it is preferable that an external terminal member that is electrically connected to the electrode terminal is provided outside the exterior body.
According to the present invention, the external terminal member is formed of a metal material such as SUS which is easy to join with an external lead wire by soldering or the like, so that the electrode terminal is a material such as aluminum that is difficult to join by soldering or the like. Can be formed by. Therefore, the material of the electrode terminal can be easily selected.

In the above electrochemical cell, the electrode terminal includes a shaft portion that extends along the axial direction of the second container in the outer package, and the shaft portion includes one of the positive electrode body and the negative electrode body. It is desirable that one of the electrodes is conducted and the electrode body is wound.
According to the present invention, since the shaft portion can be used as the core of the electrode body, the number of parts can be reduced as compared with the configuration using the core which is separate from the electrode terminal. In addition, since either the positive electrode body or the negative electrode body is electrically connected to the shaft portion, it is possible to electrically connect either the positive electrode body or the negative electrode body to the electrode terminal without using a separate member. The points can be reduced. Therefore, a low-cost electrochemical cell can be obtained.

In the above electrochemical cell, it is desirable that the first peripheral wall portion includes an inner peripheral wall portion and an outer peripheral wall portion that surrounds the inner peripheral wall portion.
According to the present invention, the strength of the first peripheral wall portion can be improved as compared with the case where the first peripheral wall portion is configured by one peripheral wall portion. Thereby, when the fusion bonding member is fused to the first circumferential wall portion and the second circumferential wall portion as compared with the case where the first circumferential wall portion is composed of one circumferential wall portion, the second circumferential wall portion is made to have the first circumferential wall portion. It can be pressed strongly toward the part. Therefore, the fusing member can be more reliably fused to the first peripheral wall portion and the second peripheral wall portion, and the airtightness inside the electrochemical cell can be improved. Further, it is possible to improve work efficiency and yield when the fusion bonding member is fused to the first peripheral wall portion and the second peripheral wall portion.

In the above electrochemical cell, the first peripheral wall portion includes a connecting portion that connects the inner peripheral wall portion and the outer peripheral wall portion over the entire circumference, and the connecting portion has a thickness of the first peripheral wall portion. Desirably, it extends along a direction.
According to the present invention, when an external force in the thickness direction acts on the first peripheral wall portion, the connection portion can function as a rib to suppress deformation of the first peripheral wall portion. Therefore, the strength of the first peripheral wall portion against the external force in the thickness direction of the first peripheral wall portion can be improved. This makes it possible to strongly press the second peripheral wall portion toward the first peripheral wall portion when the fusion bonding member is fused to the first peripheral wall portion and the second peripheral wall portion. Therefore, the fusing member can be more surely fused to the first peripheral wall portion and the second peripheral wall portion, and the airtightness inside the electrochemical cell can be improved. Further, it is possible to improve work efficiency and yield when the fusion bonding member is fused to the first peripheral wall portion and the second peripheral wall portion.

In the above electrochemical cell, the electrode body is formed by stacking the positive electrode body and the negative electrode body, and the electrode body intersects a stacking portion of the positive electrode body and the negative electrode body in a stacking direction. It is desirable to have tabs that project in the direction.
According to the present invention, by pulling the tab around the inside of the exterior body, the positive electrode body and the negative electrode body can be easily electrically connected to other members via the tab. Therefore, the structure inside the outer package can be prevented from becoming complicated, and a low-cost electrochemical cell can be obtained.

According to the present invention, it is possible to provide a button-shaped electrochemical cell having high reliability and high energy density.

It is a perspective view of the battery which concerns on 1st Embodiment. FIG. 3 is an exploded perspective view of the battery according to the first embodiment. It is an explanatory view of the formation method of the positive electrode object concerning a 1st embodiment, and is a top view of a positive electrode sheet. It is an expanded side view in the vicinity of the opening of the second container according to the first embodiment. It is a perspective view explaining the formation method of the exterior body which concerns on 1st Embodiment. It is a perspective view of the electrode body which concerns on the 1st modification of 1st Embodiment. It is a perspective view of the electrode body which concerns on the 2nd modification of 1st Embodiment. It is a perspective view of the electrode body which concerns on the 3rd modification of 1st Embodiment. It is a perspective view of the electrode terminal concerning the 4th modification of 1st Embodiment. It is a perspective view of the electrode terminal concerning the 5th modification of 1st Embodiment. It is a perspective view of the electrode terminal concerning the 6th modification of 1st Embodiment. It is a perspective view of the battery concerning the 7th modification of 1st Embodiment. It is a perspective view of the 2nd container concerning the 8th modification of 1st Embodiment. It is a perspective view of the battery which concerns on 2nd Embodiment. It is a perspective view of the electrode terminal which concerns on 2nd Embodiment. It is a perspective view of the electrode terminal which concerns on 2nd Embodiment. It is a perspective view of the electrode terminal which concerns on the 1st modification of 2nd Embodiment. It is a perspective view of the electrode terminal which concerns on the 2nd modification of 2nd Embodiment. It is a perspective view of the electrode terminal concerning the 3rd modification of 2nd Embodiment. It is a perspective view of the electrode terminal concerning the 4th modification of 2nd Embodiment. It is a perspective view of the battery concerning the 5th modification of 2nd Embodiment. It is a perspective view of the battery which concerns on 3rd Embodiment. It is a disassembled perspective view of the electrode body which concerns on 3rd Embodiment. It is a perspective view of the battery which concerns on 4th Embodiment. It is a disassembled perspective view of the battery which concerns on 4th Embodiment. It is a perspective view of the battery concerning the modification of 4th Embodiment. It is sectional drawing of the 1st container which concerns on 5th Embodiment.

Embodiments of the present invention will be described below with reference to the drawings. In the following description, a button-shaped, coin-shaped, or cylinder-shaped electrochemical cell formed in a cylindrical shape will be referred to as a lithium-ion secondary battery (hereinafter simply referred to as “battery”), which is a type of non-aqueous electrolyte secondary battery. .) as an example.

[First Embodiment]
First, the battery 1 of the first embodiment will be described.
FIG. 1 is a perspective view of the battery according to the first embodiment. FIG. 2 is an exploded perspective view of the battery according to the first embodiment.
As shown in FIGS. 1 and 2, the battery 1 is a so-called button type battery, and includes an electrode body 10 including a positive electrode body 11 and a negative electrode body 12, and an exterior body 20 in which the electrode body 10 is housed. Mostly equipped.

As shown in FIG. 2, the electrode body 10 is formed in a column shape in which a strip-shaped positive electrode body 11 and a strip-shaped positive electrode body 12 are stacked and wound. Specifically, the electrode body 10 has a structure in which the band-shaped positive electrode body 11 and the negative electrode body 12 are wound around the winding axis P in a state where they are stacked via a separator (not shown). Any of the positive electrode body 11, the negative electrode body 12, and the separator may be arranged on the outermost periphery of the electrode body 10. The electrode body 10 may include a winding core, which is used when winding the positive electrode body 11 and the negative electrode body 12, on the winding axis P.

The electrode body 10 includes a positive electrode tab 13 (tab) and a negative electrode tab 14 (tab). Each of the tabs 13 and 14 intersects with the laminated portion of the positive electrode body 11 and the negative electrode body 12 in the laminating direction (the direction orthogonal to the winding axis P) from the outer peripheral portion of the positive electrode body 11 and the negative electrode body 12 ( In the example shown in the drawing, each of the protrusions protrudes to one side (in the axial direction of the winding axis P). The positive electrode tab 13 is formed integrally with the positive electrode current collector of the positive electrode body 11 and is electrically connected to the positive electrode body 11. The negative electrode tab 14 is integrally formed with the negative electrode current collector of the negative electrode body 12, and is electrically connected to the negative electrode body 12.

FIG. 3 is an explanatory diagram of the method of forming the positive electrode body according to the first embodiment, and is a plan view of the positive electrode sheet.
As shown in FIG. 3, the positive electrode body 11 is formed by punching out a positive electrode sheet 15 in which a positive electrode 11b containing a positive electrode active material is arranged with a constant width on a surface of a metal foil which is a positive electrode current collector 11a. To be done. At this time, the portion of the positive electrode sheet 15 on which the positive electrode 11b is arranged is punched out into a strip shape to form the positive electrode body 11 in which the positive electrode 11b is arranged on the surface of the positive electrode current collector 11a. Further, by punching the region of the positive electrode sheet 15 where the positive electrode 11b is not arranged together with the positive electrode body 11, the positive electrode tab 13 protruding from the positive electrode body 11 and electrically connected to the positive electrode current collector 11a can be formed. The method of forming the negative electrode body 12 is the same as the method of forming the positive electrode body 11.

In the present embodiment, the tabs 13 and 14 are formed integrally with the current collector, but the present invention is not limited to this, and the tabs 13 and 14 are formed separately from the current collector and are welded to the current collector. It may be attached by. In this case, the positive electrode tab is preferably made of a metal material such as aluminum. In addition, the negative electrode tab is preferably formed of a metal material such as SUS, nickel, or copper. In this case, it is preferable that an insulating tape be attached to the surface of each tab to cover the end surface of each tab and burrs generated by welding to prevent each tab from damaging other members. .. When the positive electrode tab and the negative electrode tab are formed separately from the current collector, each tab can be formed of a material thicker than the metal foil forming the current collector. As a result, the positive electrode tab and the negative electrode tab are less likely to break and reliability is improved.

As shown in FIG. 2, the exterior body 20 includes a first container 21 having a bottomed tubular shape, a second container 25 having a bottomed tubular shape, and a cylindrical fusing member 29. The first container 21, the second container 25, and the fusing member 29 are arranged such that their central axes are coaxial. Hereinafter, the central axis of the first container 21, the second container 25 and the fusion bonding member 29 is the central axis O, the direction along the central axis O is referred to as the axial direction, and the direction orthogonal to the central axis O is referred to as the radial direction. The direction of rotation around the central axis O is called the circumferential direction. In the following description, in the axial direction, the direction toward the center of the battery 1 may be referred to as the inner side, and the direction away from the center of the battery 1 (the direction toward the first container 21 and the second container 25) may be referred to as the outer side. ..

The first container 21 is formed of a conductive metal material. As a material for forming the first container 21, for example, SUS, a clad material made of iron and nickel, or the like can be used, and SUS is more preferable in terms of excellent durability.
The first container 21 includes a first bottom wall portion 21a and a first peripheral wall portion 21b. The first container 21 is open on the second container 25 side in the axial direction. The size of the first container 21 is such that the electrode body 10 can be arranged inside so that the winding axis P is coaxial with the central axis O. The negative electrode tab 14 is connected to the inner surface of the first container 21 by welding or the like. Thereby, the first container 21 functions as a negative electrode terminal of the battery 1.

The second container 25 is formed of a laminated film. The laminate film is formed by laminating a metal foil, a resin-made fusion bonding layer forming the inner side surface of the second container 25, and a resin-made protective layer forming the outer side surface. The fusing layer is formed by using a thermoplastic resin such as polyolefin such as polyethylene or polypropylene. The following materials can be appropriately selected as the polyolefin. Examples of the polyolefin include high-pressure low-density polyethylene (LDPE), low-pressure high-density polyethylene (HDPE), inflation polypropylene (IPP) film, non-oriented polypropylene (CPP) film, biaxially oriented polypropylene (OPP) film, and straight chain. Any material of short-chain branched polyethylene (L-LDPE, metallocene catalyst specification) can be used. The protective layer is formed using, for example, the above-mentioned polyolefin, polyester such as polyethylene terephthalate, nylon, or the like. The fusion bonding layer and the protective layer are bonded to the metal foil via a bonding layer by thermal bonding or an adhesive.

The second container 25 includes a second bottom wall portion 25a and a second peripheral wall portion 25b. The second container 25 is formed such that its axial dimension is the same as that of the first container 21. The inner diameter of the second peripheral wall portion 25b is slightly larger than the outer diameter of the first peripheral wall portion 21b of the first container 21. The second container 25 is open on the first container 21 side in the axial direction. That is, the second container 25 accommodates the first container 21 in a state where the openings are opposed to the first container 21 in the axial direction. The second peripheral wall portion 25b surrounds the first peripheral wall portion 21b. Between the first container 21 and the second container 25 (that is, inside the exterior body 20), a housing portion for housing the electrode body 10 includes a first bottom wall portion 21a, a first peripheral wall portion 21b, and a second bottom portion. It is defined by the wall portion 25a.
A through hole 26 is formed in the second bottom wall portion 25a of the second container 25. The through hole 26 is formed coaxially with the central axis O.

Ring films 31 and 32 formed in an annular shape are disposed on both surfaces of the second bottom wall portion 25a. Each of the ring films 31 and 32 is made of an insulating material. As the insulating material forming the ring films 31 and 32, for example, a thermoplastic resin such as polyethylene or polypropylene can be used.
The first ring film 31 is arranged on the inner surface of the second bottom wall portion 25a. A first film through hole 31 a coaxial with the through hole 26 is formed in the first ring film 31. The first ring film 31 has an annular wall portion 31b extending from the inner peripheral edge thereof toward the outer side in the axial direction. The outer diameter of the wall portion 31b is equal to the inner diameter of the through hole 26. The wall portion 31b is located in the through hole 26.
The first ring film 31 is heat-sealed to the inner surface of the second bottom wall portion 25a, and covers the periphery of the through hole 26 of the second bottom wall portion 25a from the inner side in the axial direction. The wall portion 31 b covers the inner peripheral surface of the through hole 26 in the through hole 26.

The second ring film 32 is arranged on the outer surface of the second bottom wall portion 25a. A second film through hole 32 a coaxial with the through hole 26 is formed in the second ring film 32. The inner diameter of the second film through hole 32a is equal to the inner diameter of the through hole 26, for example. The second ring film 32 is heat-sealed to the outer surface of the second bottom wall portion 25a, and covers the periphery of the through hole 26 of the second bottom wall portion 25a from the outside in the axial direction.

The second bottom wall portion 25a is provided with an electrode terminal 40 for connecting the positive electrode body 11 to an external lead wire or the like. That is, the electrode terminal 40 functions as a positive electrode terminal of the battery 1. The electrode terminal 40 is formed of a metal material such as aluminum or aluminum alloy. The electrode terminal 40 includes a flange portion 41 axially opposed to the inner surface of the second bottom wall portion 25a, and a lead portion 43 extending outward from the center of the flange portion 41 in the axial direction. There is.

The flange portion 41 is arranged coaxially with the central axis O. The outer diameter of the flange portion 41 is smaller than the inner diameter of the first peripheral wall portion 21b of the first container 21. The flange portion 41 is heat-sealed to the second bottom wall portion 25a while sandwiching the first ring film 31. The positive electrode tab 13 is electrically connected to the flange portion 41, more preferably by welding or the like. For the welding of the flange portion 41 and the positive electrode tab 13, for example, ultrasonic welding, laser welding, resistance welding or the like can be applied. Further, an electron conductive material may be interposed between the flange portion 41 and the positive electrode tab 13 in order to assist the electrical connection. At that time, the flange portion 41 and the positive electrode tab 13 are interposed with a conductive paste. You may be connected by making it. Here, since the flange portion 41 and the positive electrode tab 13 are electrically connected, a physical method such as caulking or pressure welding can be applied to both.

The lead-out part 43 is formed in a cylindrical shape. The drawer portion 43 is inserted into the through hole 26 of the second bottom wall portion 25a. The lead-out portion 43 is caulked on the outside of the exterior body 20 (see FIG. 1 ), and sandwiches the second bottom wall portion 25 a and the ring films 31 and 32 with the flange portion 41.

The fusing member 29 is interposed between the first peripheral wall portion 21b of the first container 21 and the second peripheral wall portion 25b of the second container 25. The fusing member 29 is formed of a thermoplastic resin such as polyethylene or polypropylene. The fusing member 29 may be formed as a single layer or may be formed by laminating a plurality of resin materials. The fusing member 29 is heat-fused to the first peripheral wall portion 21b and the second peripheral wall portion 25b. As a result, the inside (accommodation portion) of the exterior body 20 is sealed from the outside of the exterior body 20.

FIG. 4 is an enlarged side view in the vicinity of the opening of the second container according to the first embodiment.
As shown in FIG. 4, the fusing member 29 is arranged such that a part thereof is located outside the opening edge of the second peripheral wall portion 25 b of the second container 25. At this time, the fusing member 29 may cover the opening end surface of the second peripheral wall portion 25b by fusion during heat fusion. Thereby, it is possible to prevent a short circuit between the metal foil forming the laminated film forming the second container 25 and the first container 21.

Hereinafter, a method for forming the outer package 20 will be described with reference to FIG.
First, the electrode terminal 40 is assembled to the second container 25. Specifically, with the ring films 31 and 32 and the electrode terminal 40 arranged at predetermined positions, the ring films 31 and 32 are heated and melted. As a result, the electrode terminal 40 is heat-sealed to the second container 25 via the ring films 31 and 32. Next, the drawn-out portion 43 is caulked.

Next, the electrode body 10 is housed inside the first container 21, and the second container 25 is assembled to the first container 21. Specifically, in a state in which the fusing member 29 is arranged between the first peripheral wall portion 21b and the second peripheral wall portion 25b, the fusing member 29 is heated and melted, so that the fusing member 29 is moved to the first circumferential wall. The portion 21b and the second peripheral wall portion 25b are heat-sealed.

FIG. 5 is a perspective view illustrating a method of forming an outer package according to the first embodiment.
As shown in FIG. 5, heat fusion between the first peripheral wall portion 21b and the second peripheral wall portion 25b can be performed by pressing a heating material such as metal or ceramics, and more preferably, a roll-shaped heating roll. 50 is used. Specifically, the heating roll 50 heated to a temperature at which the fusing member 29 can be melted is pressed against the second peripheral wall portion 25b from the outside in the radial direction, whereby the fusing member 29 is melted. Then, by cooling the fusing member 29, the fusing member 29 is heat-fused to the first peripheral wall portion 21b and the second peripheral wall portion 25b. At this time, heat fusion can be performed by pressing a plurality of heated products sequentially or simultaneously. The heating roll 50 is formed of a metal material having high thermal conductivity, and for example, brass or aluminum can be used. A tape of fluorine resin, silicone resin, polyimide resin, or the like may be arranged on the surface of the heating roll 50 to prevent the heated second peripheral wall portion 25b from adhering.

The fusing member 29 may be heat-fused to the first container 21 in advance. In this case, after arranging the fusing member 29 so as to surround the first peripheral wall portion 21b, the heated heating roll 50 is pressed against the fusing member 29 to move the fusing member 29 to the first peripheral wall portion. 21b can be heat-fused. The first peripheral wall portion 21b may be degreased and washed in advance, and the fusing member 29 may be treated with a primer to improve the adhesion of the fusing member 29.

As described above, in the present embodiment, the fusing member 29 is provided between the first peripheral wall portion 21b of the bottomed tubular first container 21 and the second peripheral wall portion 25b of the bottomed tubular second container 25. And the fusing member 29 is fused to the first peripheral wall portion 21b and the second peripheral wall portion 25b.
According to this configuration, the space between the first container 21 and the second container 25 in which the electrode body 10 is housed can be sealed without caulking. At this time, even when there are scratches on the fusion surfaces of the peripheral wall portions 21b and 25b with the fusion member 29, or when foreign matter is sandwiched between the first peripheral wall portion 21b and the second peripheral wall portion 25b. The fusing member 29 melted at the time of heat fusion can fill the scratch and the periphery of the foreign matter. As a result, the airtightness inside the battery 1 can be improved as compared with the configuration in which the outer package is formed by caulking the first container and the second container.
When the outer body is formed by caulking the first container and the second container, in order to give the first container and the second container sufficient strength to withstand the caulking, It is necessary to secure the thickness of a predetermined value or more. According to the present embodiment, since the space between the first container 21 and the second container 25 is sealed by heat fusion with the fusion bonding member 29, the exterior body is caulked between the first container and the second container. The first container 21 and the second container 25 can be made thinner than the configuration formed by processing. As a result, a large internal volume of the outer package 20 can be secured and the energy density of the battery 1 can be improved.
Therefore, it is possible to provide the button-shaped battery 1 having high reliability and high energy density.

Moreover, since the second container 25 is formed of a laminated film, the battery 1 can be made lighter than the configuration in which the first container and the second container are formed of a metal material. Moreover, since the first peripheral wall portion 21b is formed of the metal material, the second peripheral wall portion 21b is surrounded by the first peripheral wall portion 21b and the second peripheral wall portion 25b when the fusion bonding member 29 is heat-sealed. When the peripheral wall portion 25b is pressed from the outside by the heating roll 50, the first peripheral wall portion 21b can support the second peripheral wall portion 25b. Therefore, the battery 1 can be easily manufactured to have a desired outer shape.

In addition, since the electrode terminal 40 that is electrically connected to the positive electrode body 11 is inserted into the through hole 26 that penetrates the second container 25, the positive electrode body 11 can be easily electrically connected to a lead wire or the like outside the exterior body 20. You can Therefore, in the battery 1 in which the laminate film is used for the exterior body 20 (second container 25), a configuration in which the inside and outside of the exterior body 20 are electrically connected can be realized.

Further, since the second container 25 is formed of a laminated film, the metal material (metal foil) may be exposed on the inner peripheral surface of the through hole 26. According to the present embodiment, since the inner peripheral surface of the through hole 26 is covered with the first ring film 31 made of an insulating material, the electrode terminal 40 inserted into the through hole 26 is made of the metal forming the second container 25. It can prevent short circuit with the foil. Further, it is possible to suppress the metal foil forming the second container 25 from being exposed to the outside and suppress the corrosion of the metal foil. Therefore, the reliability of the battery 1 can be improved. The material of the ring films 31 and 32 may be a single resin material, but more preferably, a layered material of two or more types of resins can be used. In particular, an olefin resin non-woven fabric can be used as one of the layered resins.

Further, since the electrode terminal 40 includes the flange portion 41 that is arranged so as to face the inner surface of the second bottom wall portion 25a, the through hole is provided from the outside of the exterior body 20 as compared with the configuration in which the electrode terminal does not include the flange portion. The distance of the route to the inside of the exterior body 20 through 26 can be increased. As a result, the amount of water entering the exterior body 20 through the through holes 26 can be reduced. Therefore, the reliability of the battery 1 can be improved.

Further, since the electrode body 10 has the tabs 13 and 14, by pulling the tabs 13 and 14 inside the exterior body 20, the positive electrode body 11 and the negative electrode body 12, and other members (for example, the electrode terminal 40 and The first container 21) and the first container 21) can be easily connected to each other via the tabs 13 and 14. Therefore, the structure inside the outer package 20 can be prevented from becoming complicated, and the battery 1 can be manufactured at low cost.

In addition, in the said 1st Embodiment, although the negative electrode body 12 and the 1st container 21 are electrically connected via the negative electrode tab 14, it is not limited to this. For example, by disposing the negative electrode current collector of the negative electrode body 12 on the outermost periphery of the electrode body 10, the negative electrode body 12 and the inner surface of the first container 21 may be electrically connected.

Further, in the first embodiment, the positive electrode tab 13 and the negative electrode tab 14 project from the outer peripheral portions of the positive electrode body 11 and the negative electrode body 12, but the invention is not limited to this.
FIG. 6 is a perspective view of an electrode body according to a first modification of the first embodiment. FIG. 7 is a perspective view of an electrode body according to a second modification of the first embodiment.
As shown in FIG. 6, the positive electrode tab 13 and the negative electrode tab 14 may protrude from the inner peripheral portions of the positive electrode body 11 and the negative electrode body 12. Further, as shown in FIG. 7, one of the positive electrode tab 13 and the negative electrode tab 14 (the positive electrode tab 13 in the illustrated example) may protrude from the inner peripheral portion, and the other may protrude from the outer peripheral portion.

In the first embodiment and the first and second modifications thereof, the positive electrode tab 13 and the negative electrode tab 14 project in the same direction from the laminated portion of the positive electrode body 11 and the negative electrode body 12. Not limited to. The positive electrode tab 13 and the negative electrode tab 14 may project from the laminated portions of the positive electrode body 11 and the negative electrode body 12 in different directions (for example, one side and the other side in the axial direction of the winding axis P).
Further, the positive electrode tab 13 and the negative electrode tab 14 may be bent in any direction after protruding from the laminated portion of the positive electrode body 11 and the negative electrode body 12 along the axial direction of the winding axis P.

Moreover, you may combine each modification mentioned above suitably. For example, one of the positive electrode tab 13 and the negative electrode tab 14 projects from the inner peripheral portions of the positive electrode body 11 and the negative electrode body 12 to one side in the axial direction of the winding axis P, and is further bent outward in the radial direction. The other may project from the outer peripheral portions of the positive electrode body 11 and the negative electrode body 12 to the other side in the axial direction of the winding axis P, and may be further bent inward in the radial direction. Further, one of the positive electrode tab 13 and the negative electrode tab 14 projects from the inner peripheral portion of the positive electrode body 11 and the negative electrode body 12 to one side in the axial direction of the winding axis P, and is further bent inward in the radial direction, The other may protrude from the inner peripheral portions of the positive electrode body 11 and the negative electrode body 12 to the other side in the axial direction of the winding axis P, and may be further bent inward in the radial direction.

In this way, by bending the positive electrode tab 13 and the negative electrode tab 14 toward the inner side in the radial direction, the positive electrode tab 13 and the negative electrode tab 14 can be wound around the winding axis P without shortening the positive electrode tab 13 and the negative electrode tab 14. It can be easily formed in a shape that does not protrude from the laminated portion of the positive electrode body 11 and the negative electrode body 12 when viewed in the axial direction of.

FIG. 8 is a perspective view of an electrode body according to a third modified example of the first embodiment.
Further, as shown in FIG. 8, each of the positive electrode tab 13 and the negative electrode tab 14 may be bent a plurality of times. Specifically, the positive electrode tab 13 projects from the outer peripheral portions of the positive electrode body 11 and the negative electrode body 12 to one side in the axial direction of the winding axis P. The positive electrode tab 13 is bent toward the inner side in the radial direction at the base end portion, and is bent toward the outer side in the radial direction at the intermediate portion. The negative electrode tab 14 projects from the outer peripheral portions of the positive electrode body 11 and the negative electrode body 12 to the other side in the axial direction of the winding axis P. The negative electrode tab 14 is bent toward the inner side in the radial direction at the base end portion, and is bent toward the outer side in the radial direction at the intermediate portion in the extending direction.

In addition, a plurality of positive electrode tabs 13 may be formed, and may be connected to each other by welding or the like. The same applies to the negative electrode tab 14.

Further, in the first embodiment described above, the lead-out portion 43 of the electrode terminal 40 is formed in a cylindrical shape, but the present invention is not limited to this.
FIG. 9 is a perspective view of an electrode terminal according to a fourth modified example of the first embodiment. FIG. 10 is a perspective view of an electrode terminal according to a fifth modified example of the first embodiment. FIG. 11 is a perspective view of an electrode terminal according to a sixth modified example of the first embodiment.
As shown in FIG. 9, the lead-out portion 43 may be formed in a cylindrical shape. Further, as shown in FIG. 10, the lead-out portion 43 may be formed in a cylindrical shape, and the inner peripheral surface on the opening side may be formed in a tapered shape whose diameter gradually increases from the inner side toward the outer side in the axial direction. .. In addition, as shown in FIG. 11, a plurality of slits 44 may be formed in the drawer portion 43.

FIG. 12 is a perspective view of a battery according to a seventh modified example of the first embodiment.
Further, as shown in FIG. 12, the battery 1 may include an external terminal member 5. The external terminal member 5 is made of a metallic material such as SUS, nickel, or nickel-plated copper, and has a long rectangular plate shape. An insertion hole into which the lead-out portion 43 of the electrode terminal 40 is inserted is formed at one end of the external terminal member 5 in the extending direction. The external terminal member 5 is sandwiched by the crimped extraction portion 43 and the second ring film 32 in a state where the extraction portion 43 is inserted into the insertion hole. Furthermore, the external terminal member 5 is curved in a U shape so that the other end in the extending direction covers the tip of the lead-out portion 43, and the other end is connected to the lead-out portion 43 by welding or the like.

According to this structure, the external terminal member 5 is formed of a metal material such as SUS that is easy to join with an external lead wire by soldering, so that it is difficult to join the electrode terminal 40 by soldering aluminum or the like. It can be formed of a material. Here, in the example shown in FIG. 12, the external terminal member 5 is formed in a U shape, but it may be formed in a flat plate shape or an L shape, and may be used for soldering with an external lead wire or the like. Alternatively, the battery 1 may be directly bonded to the circuit board of the device to which the power is supplied via the external terminal member 5. Further, the external terminal member 5 can be screwed to a circuit board, a terminal or the like of a device to which power is supplied. Therefore, the material of the electrode terminal 40 can be easily selected.
Furthermore, the external terminal member 5 can be screwed to the electrode terminal 40 and screwed. As a result, workability at the time of battery replacement can be improved in a device using a battery.

FIG. 13 is a perspective view of the second container according to the eighth modified example of the first embodiment.
In addition, as shown in FIG. 13, a groove-shaped weakened portion 27 may be formed in the second container 25. In the illustrated example, the weakened portion 27 is formed in an annular shape so as to be coaxial with the central axis O on the outer surface of the second bottom wall portion 25a.
As described above, by providing the weakened portion 27 in the second container 25 formed of the laminated film, when the gas is generated inside the battery 1 and the internal pressure rises, the outer casing 20 is broken in the weakened portion 27. As a result, the internal pressure can be reduced. That is, the weakening portion 27 can function as a safety valve.

[Second Embodiment]
Next, the battery 101 of the second embodiment will be described.
FIG. 14 is a perspective view of the battery according to the second embodiment.
In the first embodiment shown in FIGS. 1 and 2, the battery 1 has a so-called button shape. On the other hand, the second embodiment shown in FIG. 14 differs from the first embodiment in that the battery 101 is formed in a so-called cylinder shape. The same components as those in the first embodiment shown in FIGS. 1 and 2 are designated by the same reference numerals and detailed description thereof will be omitted (the same applies to the following embodiments).

As shown in FIG. 14, the first container 121 is formed such that its axial dimension is larger than that of the second container 25. The second peripheral wall portion 25b of the second container 25 surrounds the open end of the first peripheral wall portion 121b of the first container 121. An electrode terminal 140 is provided on the second bottom wall portion 25 a of the second container 25.

15 and 16 are perspective views of the electrode terminal according to the second embodiment.
As shown in FIGS. 14 to 16, the electrode terminal 140 includes a flange portion 41, a lead-out portion 43, and a shaft portion 145. The shaft portion 145 is formed in a cylindrical shape. Between the first container 121 and the second container 25 (accommodation part), it extends from the center of the flange part 41 along the axial direction toward the opposite side to the extraction part 43. The tip end surface of the shaft portion 145 (the surface facing the first bottom wall portion 121a in the axial direction) is axially separated from the first bottom wall portion 121a. The shaft portion 145 may be formed integrally with the flange portion 41, or may be fitted into a hole provided in the flange portion 41. The electrode body 10 (see FIG. 2) is wound around the shaft portion 145. That is, the shaft portion 145 is used as a winding core of the electrode body 10. A positive electrode current collector of the positive electrode body 11 (see FIG. 2) is connected to the shaft portion 145 by welding or the like so as to be in conduction.

According to this configuration, since the shaft portion 145 can be used as the core of the electrode body 10, it is possible to reduce the number of parts as compared with the configuration in which the core different from the electrode terminal 140 is used. Further, since the positive electrode body 11 is electrically connected to the shaft portion 145, it is possible to electrically connect the positive electrode body 11 and the electrode terminal 140 without using a separate member (for example, the positive electrode tab 13 shown in FIG. 2), and the number of parts is increased. Can be reduced. Therefore, the battery 101 can be manufactured at low cost.

In addition, in the second embodiment, the shaft portion 145 of the electrode terminal 140 is formed in a cylindrical shape, but is not limited to this.
FIG. 17 is a perspective view of the electrode terminal according to the first modification of the second embodiment. FIG. 18 is a perspective view of an electrode terminal according to a second modified example of the second embodiment. FIG. 19 is a perspective view of an electrode terminal according to a third modification of the second embodiment. FIG. 20 is a perspective view of an electrode terminal according to a fourth modified example of the second embodiment.
As shown in FIG. 17, the shaft portion 145 may be formed in a cylindrical shape. According to this structure, the weight of the electrode terminal 140 can be reduced.
Further, as shown in FIG. 18, the shaft portion 145 may be formed in a cylindrical shape and may include at least one slit 146. In the illustrated example, each slit 146 penetrates the shaft portion 145 in the radial direction and extends in the axial direction. With this configuration, when the shaft portion 145 is used as the winding core of the electrode body 10, the positive electrode current collector of the positive electrode body 11 can be sandwiched in the slit 146. Therefore, the positive electrode body 11 and the shaft portion 145 can be electrically connected without welding, and the manufacturing cost of the battery 101 can be reduced. Further, as shown in FIG. 19, the slit 146 may be formed in a corrugated shape.

Further, as shown in FIG. 20, a flat surface portion 145a may be formed on a part of the outer peripheral surface of the shaft portion 145 so as to spread in a direction orthogonal to a predetermined radial direction. By welding the positive electrode current collector of the positive electrode body 11 to the flat surface portion 145a, the positive electrode body 11 and the shaft portion 145 can be more firmly connected. The shaft portion 145 may have a polygonal cross-sectional shape orthogonal to the axial direction.

Further, in the second embodiment, the flange portion 41 of the electrode terminal 140 is arranged to face the inner surface of the second bottom wall portion 25a of the second container 25, but the invention is not limited to this.
FIG. 21 is a perspective view of a battery according to a fifth modified example of the second embodiment.
As shown in FIG. 21, the flange portion 41 may be arranged to face the outer surface of the second bottom wall portion 25 a of the second container 25. In this case, the second ring film 32 (see FIG. 14) is arranged between the flange portion 41 and the second bottom wall portion 25a, and the flange portion 41 and the second bottom wall are interposed via the second ring film 32. The portion 25a is heat-sealed.
According to this configuration, when gas is generated inside the battery 101 and the internal pressure rises, the flange portion 41 is separated from the second bottom wall portion 25a to open the through hole 26 (see FIG. 2), and the internal pressure is increased. Can be reduced. That is, the flange portion 41 can function as a safety valve.

[Third Embodiment]
Next, the battery 201 of the third embodiment will be described.
FIG. 22 is a perspective view of the battery according to the third embodiment.
In the first embodiment shown in FIGS. 1 and 2, the battery 1 has a so-called button shape. On the other hand, in the third embodiment shown in FIG. 22, the battery 201 is different from the first embodiment in that it is formed in a so-called coin shape.

FIG. 23 is an exploded perspective view of the electrode body according to the third embodiment.
As shown in FIG. 23, the electrode body 210 is configured by alternately stacking a plurality of positive electrode bodies 211 and negative electrode bodies 212 in the axial direction with a separator (not shown) interposed therebetween.
The positive electrode body 211 is formed in a circular shape when viewed in the axial direction. The positive electrode body 211 includes a positive electrode current collector 211a made of a circular metal foil, and a positive electrode 211b arranged on the surface of the positive electrode current collector 211a.
A notch portion 211c, which is linearly notched in a direction orthogonal to a predetermined radial direction, is formed in a part of the positive electrode body 211 in the circumferential direction. A positive electrode tab 213 protruding from the cutout portion 211c is integrally formed with the positive electrode current collector 211a. The positive electrode tab 213 projects outward in the radial direction (direction intersecting the stacking direction) from one side in the circumferential direction of the cutout portion 211c. Therefore, the positive electrode tabs 213 are overlapped with each other in the axial direction.

The negative electrode body 212 is formed in a circular shape when viewed in the axial direction. The negative electrode body 212 includes a negative electrode current collector 212a made of a circular metal foil and a negative electrode 212b arranged on the surface of the negative electrode current collector 212a.
A notch portion 212c, which is linearly notched in a direction orthogonal to a predetermined radial direction, is formed in a part of the negative electrode body 212 in the circumferential direction. A negative electrode tab 214 protruding from the cutout 212c is integrally formed with the negative electrode current collector 212a. The negative electrode tab 214 projects radially outward from the other circumferential side of the cutout 212c. Therefore, the negative electrode tabs 214 are overlapped with each other in the axial direction. Further, in the electrode body 210, the positive electrode tab 213 and the negative electrode tab 214 are arranged at positions where they do not overlap each other in the axial direction.

The positive electrode 211b is arranged inside the outer peripheral edge of the negative electrode 212b when viewed in the axial direction. The positive electrode tabs 213 are connected to each other by welding or the like, and are connected to the flange portion 41 (see FIG. 2) of the electrode terminal 40 to be electrically connected. The negative electrode tabs 214 are connected to each other by welding or the like, and are connected to the first container 21 (see FIG. 22) to be electrically connected.

As described above, the electrode body 210 is formed by alternately stacking the positive electrode bodies 211 and the negative electrode bodies 212 formed in a circular shape, so that the axial dimension shown in FIG. 22 is sufficiently smaller than the outer diameter. The electrode body 210 can be housed in the exterior body 220 of the formed coin-shaped battery 201.

The electrode body included in the battery 201 is not limited to the form shown in FIG. The electrode body included in the battery 201 may be formed in a flat plate shape by compressing an electrode body wound in the same manner as the electrode body 10 shown in FIG. 2 in the direction orthogonal to the winding axis. As a result, the electrode body can be housed in the exterior body 220 of the coin-shaped battery 201.

[Fourth Embodiment]
Next, the battery 301 of the fourth embodiment will be described.
FIG. 24 is a perspective view of the battery according to the fourth embodiment. FIG. 25 is an exploded perspective view of the battery according to the fourth embodiment.

In the first embodiment shown in FIGS. 1 and 2, ring films 31 and 32 are provided on both surfaces of the second bottom wall portion 25a of the second container 25. On the other hand, in the fourth embodiment shown in FIG. 24 and FIG. 25, the first ring film 331 is provided only on the inner surface of the second bottom wall portion 25 a of the second container 25, and thus the first embodiment. Is different from In addition, in the first embodiment, the first ring film 31 has the wall portion 31 b that covers the inner peripheral surface of the through hole 26. On the other hand, in the fourth embodiment, the first ring film 331 is formed flat along the vertical surface of the central axis O and does not include a wall portion that covers the inner peripheral surface of the through hole 26. Different from the first embodiment. Further, in the seventh modified example of the first embodiment, the electrode terminal 40 including the integrally formed flange portion 41 and the lead-out portion 43 and the external terminal provided outside the exterior body 20 and connected to the lead-out portion 43. And a member 5. On the other hand, in the fourth embodiment, the electrode terminal 340 corresponding to the flange portion 41 described above and the external terminal member 305 provided outside the exterior body 20 and connected to the electrode terminal 340 are provided. Different from the embodiment.

As shown in FIGS. 24 and 25, the first ring film 331 is formed with a first film through hole 331 a coaxial with the through hole 26. The inner diameter of the first film through hole 331 a is smaller than the inner diameter of the through hole 26. The first ring film 331 is heat-sealed to the inner surface of the second bottom wall portion 25a and covers the periphery of the through hole 26 of the second bottom wall portion 25a from the inner side in the axial direction.

The electrode terminal 340 is formed of a metal material such as aluminum or aluminum alloy. The electrode terminal 340 is formed in a disc shape and is arranged coaxially with the central axis O. The outer diameter of the electrode terminal 340 is smaller than the inner diameter of the first peripheral wall portion 21b of the first container 21 and larger than the inner diameter of the through hole 26. The electrode terminal 340 is heat-sealed to the second bottom wall portion 25a while sandwiching the first ring film 331. As a result, communication between the inside and outside of the exterior body 20 through the through hole 26 is blocked. The central portion of the electrode terminal 340 is exposed to the outside in the axial direction through the through hole 26 and the first film through hole 331a. The positive electrode tab 13 is electrically connected to the electrode terminal 340 inside the exterior body 20.

The external terminal member 305 is a long rectangular plate-shaped metal piece formed of a metal material such as aluminum, nickel, or nickel-plated copper. One end of the external terminal member 305 is arranged face-to-face with and electrically connected to the center of the electrode terminal 340 that is exposed to the outside in the axial direction. The external terminal member 305 and the electrode terminal 340 are fixed by ultrasonic welding, laser welding, resistance welding, or the like. The external terminal member 305 is bent at a substantially right angle in the longitudinal middle portion thereof and extends along the axial direction so as to be separated from the exterior body 20. The external terminal member 305 is preferably fixed in advance to the electrode terminal 340 when the battery 301 is assembled.

As described above, according to the present embodiment, by forming the external terminal member 305 with a metal material that can be easily joined to the external lead wire by soldering or the like, the electrode terminal 340 can be joined by soldering aluminum or the like. It can be made of difficult materials. Therefore, the material of the electrode terminal 340 can be easily selected.
Moreover, since the external terminal member 305 extends so as to be separated from the exterior body 20, it is possible to improve the handleability of the battery 301.

In addition, in the said 4th Embodiment, although the external terminal member 305 is a metal piece, it is not limited to this. The external terminal member may be a wire-shaped member such as a copper wire or a tin-plated copper wire. When the external terminal member is a wire-shaped member, the cross-sectional shape has no directivity, and thus is difficult to be cut during handling. In particular, if the external terminal member is a covered wire or a stranded wire formed by bundling several wires, the external terminal member is unlikely to be cut even during handling during connection with an external device.

Further, in the fourth embodiment, the first ring film 331 does not cover the inner peripheral surface of the through hole 26 of the second container 25, but like the first ring film 31 according to the first embodiment, You may have the annular wall part which coat|covers the inner peripheral surface of the through-hole 26. In this case, the wall portion may be configured to project from the through hole 26 in a state before the first ring film is melted so that the wall portion covers the inner peripheral surface of the through hole 26. desirable.

Further, in the fourth embodiment, the external terminal member 305 extends along the axial direction so as to be separated from the exterior body 20, but the present invention is not limited to this.
FIG. 26 is a perspective view of a battery according to a modified example of the fourth embodiment.
For example, as shown in FIG. 26, the external terminal member 306 is formed in the shape of a rectangular flat plate smaller than the first film through hole 331 a, and is arranged face-to-face with the central portion of the electrode terminal 340. It may be electrically connected and fixed to the electrode terminal 340. The shape of the external terminal member 306 is not limited to the illustrated shape, and may be a rectangular shape with rounded corners or a circular shape. In particular, forming the external terminal member 306 in a circular shape is more preferable because the possibility of damaging surrounding members by the corners is reduced.
Even with this configuration, since the external lead wire or the like can be joined to the external terminal member 306, the electrode terminal 340 is formed of a material such as aluminum that is difficult to join by soldering, as in the fourth embodiment. can do. Therefore, the material of the electrode terminal 340 can be easily selected.

[Fifth Embodiment]
Next, the 1st container 421 of the battery of 5th Embodiment is demonstrated.
FIG. 27 is a cross-sectional view through the central axis O of the first container according to the fifth embodiment.
As shown in FIG. 27, the first container 421 of the fifth embodiment is different from the first embodiment shown in FIG. 2 in that it has a first peripheral wall portion 421b formed in a plurality of layers (two layers in the embodiment). Different.

The first container 421 is made of a conductive metal material. The first container 421 includes a first bottom wall portion 21a and a first peripheral wall portion 421b. The first peripheral wall portion 421b extends in the axial direction from the outer peripheral edge of the first bottom wall portion 21a, is then folded back toward the outside in the radial direction, and is returned to the first bottom wall portion 21a side in the axial direction again. Extending towards. In other words, the first peripheral wall portion 421b forms a housing space for housing the electrode body 10 (see FIG. 2) and has a cylindrical inner peripheral wall portion 421c facing the electrode body 10, and the inner peripheral wall portion 421c is radially outward. A cylindrical outer peripheral wall portion 421d that surrounds the entire circumference from the inner peripheral wall portion 421d, and an annular connecting portion 421e that connects the inner peripheral wall portion 421c and the outer peripheral wall portion 421d over the entire circumference in the circumferential direction. ..

The axial dimension of the outer peripheral wall portion 421d is equal to the axial dimension of the inner peripheral wall portion 421c. The inner peripheral wall portion 421c and the outer peripheral wall portion 421d are arranged with a radial gap therebetween. The fusing member 29 (see FIG. 2) is heat-fused to the outer peripheral surface of the outer peripheral wall portion 421d. The connection portion 421e is provided on the opening edge of the first container 421. The connecting portion 421e extends from the edge of the inner peripheral wall portion 421c to the edge of the outer peripheral wall portion 421d. In the illustrated example, the connecting portion 421e is curved so as to expand toward the opening direction of the first container 421 in the axial direction. The central portion in the radial direction of the connecting portion 421e extends along the radial direction (the thickness direction of the first peripheral wall portion 421b). The first container 421 is formed by, for example, drawing.

As described above, in the present embodiment, the first peripheral wall portion 421b includes the inner peripheral wall portion 421c and the outer peripheral wall portion 421d that surrounds the inner peripheral wall portion 421c. Therefore, the first peripheral wall portion is configured by one peripheral wall portion. The strength of the first peripheral wall portion 421b can be improved as compared with the case. As a result, when the fusing member 29 is fused to the first circumferential wall portion 421b and the second circumferential wall portion 25b, the second circumferential wall portion 25b is different from the case where the first circumferential wall portion is configured by one circumferential wall portion. Can be strongly pressed toward the first peripheral wall portion 421b. Therefore, the fusing member 29 can be more surely fused to the first peripheral wall portion 421b and the second peripheral wall portion 25b, and the airtightness inside the battery can be improved. In addition, the work efficiency and the yield when the fusion bonding member 29 is fused to the first peripheral wall portion 421b and the second peripheral wall portion 25b can be improved.

Moreover, since the radial center portion of the connecting portion 421e extends along the thickness direction (radial direction) of the first peripheral wall portion 421b, an external force in the thickness direction acts on the first peripheral wall portion 421b. At this time, the connection portion 421e can function as a rib to suppress deformation of the first peripheral wall portion 421b. Therefore, the strength of the first peripheral wall portion 421b against the external force in the thickness direction of the first peripheral wall portion 421b can be improved. Thereby, when the fusion bonding member 29 is fused to the first peripheral wall portion 421b and the second peripheral wall portion 25b, the second peripheral wall portion 25b can be strongly pressed toward the first peripheral wall portion 421b. Therefore, the fusing member 29 can be more surely fused to the first peripheral wall portion 421b and the second peripheral wall portion 25b, and the airtightness inside the battery can be improved. Further, the work efficiency and the yield when the fusion bonding member 29 is fused to the first peripheral wall portion 421b and the second peripheral wall portion 25b can be improved.

In the illustrated example, a gap is provided between the inner peripheral wall portion 421c and the outer peripheral wall portion 421d, but the inner peripheral wall portion 421c and the outer peripheral wall portion 421d may be arranged without a gap. Further, in the present embodiment, the inner peripheral wall portion 421c and the outer peripheral wall portion 421d are integrally formed via the connecting portion 421e, but the inner peripheral wall portion and the outer peripheral wall portion are formed separately and laminated. It may be joined in a state.

The present invention is not limited to the above-described embodiments described with reference to the drawings, and various modifications can be considered within the technical scope thereof.
For example, in the above-described embodiment, the first container 21 is electrically connected to the negative electrode body 12 and the electrode terminal 40 is electrically connected to the positive electrode body 11, but the invention is not limited to this. The first container may be electrically connected to the positive electrode body 11, and the electrode terminal may be electrically connected to the negative electrode body 12. In this case, the first container is preferably made of aluminum, an aluminum alloy, or the like. Moreover, it is preferable that the electrode terminals are formed of SUS or the like.

Further, in the above embodiment, the first container 21 is made of a metal material and the second container 25 is made of a laminated film, but the present invention is not limited to this. For example, the first container may be formed of a laminated film and the second container may be formed of a metallic material, or both the first container and the second container may be formed of a metallic material or a laminated film.

Further, in the above-described embodiment, the non-aqueous electrolyte secondary battery has been described as an example of the button type electrochemical cell, but the present invention is not limited to this case, and the above-described electric double layer capacitor, primary battery, or the like is used. The configuration described above can be applied. Note that when a battery is applied as an electrochemical cell, it can occlude or release expensive cations such as Mg ²⁺ and Al ^{3+ in} addition to monovalent cations such as Li ⁺ and Na ⁺ as active materials for the positive electrode and the negative electrode. Materials can be used. When constituting the electric double layer capacitor of the present invention, a high energy density can be realized by using a non-aqueous electrolyte as the electrolyte.

In addition, it is possible to appropriately replace the constituent elements in the above-described embodiments with known constituent elements without departing from the spirit of the present invention, and to appropriately combine the above-described embodiments and modified examples. Good.

1, 101, 201, 301... Battery (electrochemical cell) 5,305, 306... External terminal member 10, 210... Electrode body 11, 211... Positive electrode body 12, 212... Negative electrode body 13, 213... Positive electrode tab (tab) 14, 214... Negative electrode tab (tab) 20, 220... Exterior body 21, 121, 421... 1st container 21b, 121b, 421b... 1st surrounding wall part 25... 2nd container 25a... 2nd bottom wall part (2nd container) Bottom wall portion) 25b... Second peripheral wall portion 26... Through hole 29... Fusing member 40, 140... Electrode terminal 41... Flange portion 145... Shaft portion 340... Electrode terminal (flange portion) 421c... Inner peripheral wall portion 421d... Outer side Peripheral wall portion 421e... Connection portion

Claims (10)

An electrode body including a positive electrode body and a negative electrode body,
An exterior body accommodating the electrode body,
Equipped with
The exterior body is
A first container having a bottomed tubular shape and having a first peripheral wall portion;
A second container having a bottomed tubular shape, having a second peripheral wall portion surrounding the first peripheral wall portion, and accommodating the electrode body between the second container and the first container;
A fusion-bonding member that is interposed between the first peripheral wall portion and the second peripheral wall portion and is fused to the first peripheral wall portion and the second peripheral wall portion;
With
An electrochemical cell characterized by the above. The first container is made of a metal material,
The second container is formed of a laminated film containing a metal material and a resin material,
The electrochemical cell according to claim 1, wherein: A through hole is formed in the bottom wall of the second container,
In the through hole, an electrode terminal that is conductive with one of the positive electrode body and the negative electrode body is inserted.
The electrochemical cell according to claim 2, wherein: The inner peripheral surface of the through hole is covered with an insulating material,
The electrochemical cell according to claim 3, wherein: The electrode terminal includes a flange portion arranged to face an inner surface of the bottom wall portion of the second container,
The electrochemical cell according to claim 3 or 4, wherein On the outer side of the exterior body, an external terminal member that is electrically connected to the electrode terminal is provided.
The electrochemical cell according to any one of claims 3 to 5, wherein: The electrode terminal includes a shaft portion that extends along the axial direction of the second container in the exterior body.
One of the positive electrode body and the negative electrode body is electrically connected to the shaft portion, and the electrode body is wound.
The electrochemical cell according to any one of claims 3 to 6, wherein: The first peripheral wall portion,
An inner peripheral wall portion,
An outer peripheral wall portion surrounding the inner peripheral wall portion,
With
The electrochemical cell according to any one of claims 1 to 7, wherein: The first peripheral wall portion includes a connecting portion that connects the inner peripheral wall portion and the outer peripheral wall portion over the entire circumference,
The connection portion extends along the thickness direction of the first peripheral wall portion,
The electrochemical cell according to claim 8, wherein: The electrode body is formed by stacking the positive electrode body and the negative electrode body,
The electrode body has a tab projecting in a direction intersecting the stacking direction with respect to a stacked portion of the positive electrode body and the negative electrode body.
The electrochemical cell according to any one of claims 1 to 9, which is characterized in that.

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