JP2018073599A - Electrochemical element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a configuration capable of preventing a terminal from being impaired, in a laminate film exterior body, even if an electrochemical element was bent, in the electrochemical element where the electrode was covered with the laminate film exterior body.SOLUTION: A laminate battery (1) includes an electrode body (10), a laminate film exterior body (20), and a negative electrode terminal (52) connected electrically with the electrode body (10), and extending outward of the laminate film exterior body (20). The negative electrode terminal (52) has a negative electrode connection (35) formed integrally with the electrode body (10), and a negative electrode connection terminal (42) connected with the negative electrode connection (35) and extending outward of the laminate film exterior body (20) from the inside thereof. The negative electrode terminal (52) has a bent portion (37) bent in the longitudinal direction so as to overlap in the thickness direction, in the laminate film exterior body (20).SELECTED DRAWING: Figure 2

Description

  The present invention relates to an electrochemical element in which an electrode is covered with a laminate film outer package.

  Conventionally, an electrochemical element in which an electrode is covered with a laminate film outer package is known. In such an electrochemical element, the terminal part electrically connected to the electrode extends from the electrode toward the outside of the laminate film outer package. The terminal portion includes a connection portion formed integrally with the electrode and a connection terminal connected to the connection portion.

  For example, in Patent Document 1, as an electrochemical element having the above-described configuration, an electrode unit obtained by laminating an electrode sheet having an electrode layer formed on a current collector via a separator, and an electrode unit A power storage device is disclosed that includes an outer container in which the battery is housed, and an electrode terminal having one end electrically connected to the current collector in the outer container and the other end protruding outside the outer container. . The electrode terminal and the current collector are connected via a sheet-like lead member.

  Patent Document 1 also discloses that the lead member can be deformed in the longitudinal direction, and the lead member has a buffering function against an external force. Patent Document 1 discloses a plurality of through openings provided in the lead member as an example of the buffer function.

  In the electricity storage device disclosed in Patent Document 1, when the lead member is provided with the through opening as described above, when mounted on a moving body such as an automobile or a buoy, the vibration of the moving body is caused. The lead member can be prevented from being broken due to metal fatigue.

JP 2013-93498 A

  By the way, the application of the electrochemical element in which the electrode is covered with the laminate film outer package as described above has been studied for devices in various fields. Recently, it has been studied to mount an electrochemical element on a flexible small and thin device, or to arrange the electrochemical element in a bent state in the device in accordance with the downsizing of the device. ing.

  In such a case, bending deformation may occur in the components inside the electrochemical element. Specifically, bending deformation may occur not only in the electrode arranged in the laminate film exterior body of the electrochemical element, but also in the terminal portion electrically connected to the electrode. If it does so, in the said terminal part, since force is added to the connection part of the connection part and connection terminal which were formed integrally with the said electrode, this connection part may be damaged.

  In the configuration disclosed in Patent Document 1, as described above, a plurality of through openings are provided in the lead member that connects the current collector and the electrode terminal, so that the vibration of the moving body is provided in the lead member. It is possible to suppress the occurrence of tearing due to metal fatigue due to the above. However, in the configuration disclosed in Patent Document 1, when bending deformation as described above occurs in the lead member, it is considered that stress concentrates on the peripheral portion of the through opening. When stress concentrates on the peripheral portion of the through opening as described above, the lead member may be broken by starting from the peripheral portion of the through opening.

  An object of the present invention is to provide an electrochemical element in which an electrode body is covered with a laminate film exterior body, and even when the electrochemical element is bent, the terminal portion is damaged inside the laminate film exterior body. The structure which can prevent is obtained.

  An electrochemical element according to an embodiment of the present invention includes a sheet-like laminate having a sheet-like positive electrode and a negative electrode laminated in the thickness direction, and a sheet-like laminate in which the outer peripheral side is welded in a state of covering the electrode body A film exterior body, and a plurality of plate-like terminal portions that are electrically connected to the electrode body and extend outward from the electrode body toward the laminate film exterior body. The plurality of terminal portions are each formed integrally with the electrode body and located inside the laminated film exterior body, and connected to the connection portion and outside the laminate film exterior body. And a connection terminal extending toward the direction. At least one terminal portion of the plurality of terminal portions has a bent portion bent in the longitudinal direction so as to overlap the thickness direction inside the laminate film exterior body (first configuration).

  When the electrochemical element having a plurality of plate-like terminal portions that are electrically connected to the electrode body and extend from the electrode body toward the outside of the laminate film exterior body is bent in the longitudinal direction, the laminate film Bending deformation occurs in the terminal portion inside the exterior body. The terminal portion includes a connection portion between a connection portion formed integrally with the electrode body and a connection terminal connected to the connection portion, inside the laminate film exterior body. Therefore, when the electrochemical element is bent as described above, the connection portion may be damaged.

  On the other hand, at least one terminal portion of the plurality of terminal portions is provided with a bent portion bent in the longitudinal direction so as to overlap the thickness direction inside the laminate film exterior body, Bending deformation occurring in the terminal portion when the electrochemical element is bent can be absorbed by the bent portion. Thereby, the bending stress which acts on the said connection part of the said terminal part can be reduced. Therefore, it is possible to prevent the connection portion of the terminal portion from being damaged when the electrochemical element is bent.

  In the first configuration, a U-shaped slit is formed in one of the connection portion and the connection terminal in the at least one terminal portion in plan view. The bent portion is configured by a region surrounded by the slit in one of the connection portion and the connection terminal in the at least one terminal portion. The bent portion is connected to the other of the connection portion and the connection terminal in the at least one terminal portion (second configuration).

  Accordingly, since the bent portion is formed by the slit, the dimension in the thickness direction of the terminal portion provided with the bent portion is compared with the configuration in which one of the connecting portion of the terminal portion and the connecting terminal is bent and overlapped with the other. Can be reduced. Therefore, with the above-described configuration, the first configuration can be realized, and the electrochemical element can be miniaturized.

  In the second configuration, at least one of both end portions of the slit extends in a direction different from the longitudinal direction (third configuration).

  When the bent portion is formed by a slit, force is applied to both end portions of the slit due to bending deformation generated in the bent portion when the electrochemical element is bent. In this case, there is a possibility that stress concentrates on both ends of the slit and the both ends are broken.

  On the other hand, as described above, both ends of the slit extend in a direction different from the longitudinal direction, so that even when bending deformation occurs in the bent portion, both ends of the slit are formed. Stress concentration can be prevented. Therefore, it can prevent that the both ends of the said slit fracture.

  In the first configuration, the bent portion is bent in the longitudinal direction so that one of the connection portion and the connection terminal in the at least one terminal portion overlaps in the thickness direction. The other of the connection part and the connection terminal in the at least one terminal part is connected to the bent part (fourth configuration).

  Thereby, the bending part which can absorb the bending deformation which arises in a terminal part when an electrochemical element is bent can be formed easily.

  In any one of the first to fourth configurations, the connection portion of the plurality of terminal portions has a dimension in the thickness direction smaller than that of the connection terminal. The bent portion is provided in the connection portion of the at least one terminal portion (fifth configuration).

  Since the connecting part of the terminal part has a dimension in the thickness direction smaller than that of the connecting terminal, by providing a bent part in the connecting part, the bent part is deformed with good followability when the electrochemical element is bent. Arise. Therefore, when the electrochemical element is bent, the terminal portion can be more reliably prevented from being damaged.

  In addition, by providing the connecting portion with a bent portion, the electrochemical device can be made smaller than when the connecting terminal is provided with a bent portion.

  In any one of the first to fifth configurations, the electrochemical element is a secondary battery. The plurality of terminal portions include a positive electrode terminal portion electrically connected to the positive electrode and a negative electrode terminal portion electrically connected to the negative electrode. The positive terminal portion is electrically connected to the positive electrode. The negative electrode terminal portion is electrically connected to the negative electrode. The bent portion is provided in the negative terminal portion (sixth configuration).

  When the electrochemical element is a secondary battery, the negative electrode terminal portion may be configured by welding a connection portion made of a copper alloy and a connection terminal made of a nickel alloy. That is, dissimilar metals are connected to each other at the connection portion between the connection portion and the connection terminal in the negative electrode terminal portion. Therefore, in such a configuration, the strength of the connection portion between the connection portion and the connection terminal in the negative electrode terminal portion is generally weaker than that of the positive electrode terminal portion in which the same kind of metals are connected.

  Therefore, as described above, by providing the bent portion in the negative electrode terminal portion, the negative electrode terminal portion can be prevented from being damaged when the electrochemical element is bent. Therefore, the strength against bending of the electrochemical element can be improved more reliably.

  In any one of the first to sixth configurations, the electrode body includes a plurality of the positive electrodes and the negative electrodes. Each of the plurality of terminal portions includes a plurality of the connection portions and the connection terminals. The plurality of connection portions and the plurality of connection terminals are respectively stacked in the thickness direction. The bent portion is provided in at least one part of the plurality of connection parts or at least one part of the plurality of connection terminals (seventh configuration).

  According to the electrochemical device of one embodiment of the present invention, the plurality of terminal portions extending from the electrode body toward the outside of the laminate film exterior body are each connected to the connection portion on the inside of the laminate film exterior body. It has a connection part with a terminal. In such a configuration, at least one terminal portion has a bent portion bent in the longitudinal direction so as to overlap in the thickness direction inside the laminate film exterior body.

  Thereby, when an electrochemical element is bent, the deformation | transformation which arises in the said terminal part in the said laminated film exterior body can be absorbed by the said bending part. Therefore, when the electrochemical element is bent, the connection portion of the terminal portion can be prevented from being damaged in the laminate film exterior body.

FIG. 1 is a perspective view showing a configuration of a laminated battery according to Embodiment 1. FIG. 2 is a cross-sectional view taken along line II-II in FIG. FIG. 3 is an enlarged perspective view showing a positive electrode connecting portion and a negative electrode connecting portion each provided with a bent portion. FIG. 4 is an enlarged perspective view showing the negative electrode connecting portion. FIG. 5 is a diagram schematically showing how the laminated battery is bent in the longitudinal direction. FIG. 6 is an enlarged cross-sectional view showing the configuration of the negative electrode terminal portion of the laminated battery according to the second embodiment. FIG. 7 is an enlarged cross-sectional view of the configuration of the negative electrode terminal portion of the laminated battery according to the third embodiment. FIG. 8 is a view corresponding to FIG. 4 showing a stress relaxation portion provided in a slit of a laminated battery according to another embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are denoted by the same reference numerals and description thereof will not be repeated. In the following description, “folding” is a concept including bending.

<Embodiment 1>
(overall structure)
FIG. 1 is a perspective view showing a schematic configuration of a laminated battery 1 (electrochemical element) according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional view showing a schematic configuration of the laminated battery 1. The laminated battery 1 is a secondary battery having a rectangular shape in a plan view in which an electrode body 10 functioning as a power generator is covered with a laminate film outer package 20. The laminated battery 1 is used as a power source for a card or a small portable device, for example.

  As shown in FIGS. 1 and 2, the laminated battery 1 includes an electrode body 10 and a laminate film exterior body 20 that covers the electrode body 10. The laminated battery 1 includes a positive electrode connection terminal 41 and a negative electrode connection terminal 42 (connection terminal) that are electrically connected to the positive electrode 11 and the negative electrode 12 of the electrode body 10, respectively. Note that a non-aqueous electrolyte is also enclosed in the laminated battery 1.

  The laminate film outer package 20 is made of a material in which one surface side of an aluminum metal foil is covered with nylon and the other surface side is covered with polypropylene. That is, the laminate film outer package 20 is made of a material obtained by laminating aluminum with nylon and polypropylene. Thereby, the laminate film exterior body 20 is welded by applying pressure while heating the laminate film exterior bodies 20 in a state where the laminate film exterior bodies 20 are overlapped. The metal foil is not limited to aluminum but may be formed of other metal materials such as stainless steel.

  Moreover, the laminate film exterior body 20 is formed in a substantially rectangular shape. By welding the outer peripheral sides of the laminate film exterior body 20 with the electrode body 10 sandwiched between the pair of laminate film exterior bodies 20, the bulging portion 1a and the seal portion 1b as shown in FIGS. Is formed. That is, the swelled portion 1a is formed by covering the electrode body 10 with the laminate film exterior body 20, and the swelled portion 1a is surrounded by welding the laminate film exterior body 20 around the swelled portion 1a. A seal portion 1b is formed.

  In the present embodiment, the electrode body 10 is formed in a rectangular parallelepiped shape. Therefore, as shown in FIG. 1, the bulging portion 1 a is formed in a rectangular shape in a plan view of the laminate film exterior body 20 (hereinafter also simply referred to as a plan view). The seal portion 1b is formed around the bulging portion 1a so that the laminated battery 1 has a rectangular shape in plan view.

  In addition, as shown in FIG. 1, the pair of laminated film exterior bodies 20 includes the laminated battery 1 having a flat portion 1 c on one side in the thickness direction of the electrode body 10 and the other side in the thickness direction of the electrode body 10. The outer peripheral sides of the laminate film outer package 20 are welded to each other with the electrode body 10 interposed therebetween so as to have the above-described bulged portion 1a. That is, of the pair of laminate film exterior bodies 20, one laminate film exterior body 20 is arranged along the outer shape of the electrode body 10.

  In the portion of the seal portion 1b located on the end side in the longitudinal direction of the laminated battery 1, the laminate film is in a state where the positive electrode connection terminal 41 and the negative electrode connection terminal 42 are sandwiched between the pair of laminate film exterior bodies 20. The exterior bodies 20 are fixed by welding.

  In the present embodiment, the outer peripheral sides of the pair of laminate film exterior bodies 20 are welded to each other. However, the present invention is not limited to this, and one laminate film exterior body is folded and welded so as to sandwich the electrode body 10 therebetween. May be. The direction in which the laminate film exterior body is folded back may be the extending direction of the positive electrode connection terminal 41 and the negative electrode connection terminal 42 with respect to the electrode body 10 or may be the width direction.

  As shown in FIG. 2, the electrode body 10 is a laminated body formed by superposing a positive electrode 11 and a negative electrode 12 each formed in a sheet shape so that a sheet-like separator 13 is positioned between them. is there.

  In FIG. 2, as an example of the electrode body 10, a laminated body in which the positive electrode 11 and the negative electrode 12 are laminated in a total of five layers is illustrated. It may be a body or a laminate of 6 or more layers.

In the positive electrode 11, a positive electrode active material layer containing a positive electrode active material is provided on both surfaces or one surface of a positive electrode current collector made of a metal foil such as aluminum. Specifically, the positive electrode 11 is formed by applying a positive electrode mixture containing a positive electrode active material that is a lithium-containing oxide capable of occluding and releasing lithium ions, a conductive additive, and a binder onto a positive electrode current collector made of aluminum foil or the like. And then dried. As the lithium-containing oxide as the positive electrode active material, for example, a lithium composite oxide such as lithium cobalt oxide such as LiCoO ₂ , lithium manganese oxide such as LiMn ₂ O ₄ , lithium nickel oxide such as LiNiO ₂ is used. Is preferred. Note that only one type of material may be used as the positive electrode active material, or two or more types of materials may be used. Further, the positive electrode active material is not limited to the above-described materials.

  In the negative electrode 12, negative electrode active material layers containing a negative electrode active material are provided on both sides of a negative electrode current collector made of a metal foil such as copper. Specifically, the negative electrode 12 is formed by applying and drying a negative electrode mixture containing a negative electrode active material capable of occluding and releasing lithium ions, a conductive additive and a binder on a negative electrode current collector made of copper foil or the like. It is formed. As the negative electrode active material, for example, it is preferable to use a carbon material (such as graphite, pyrolytic carbon, coke, or glassy carbon) that can occlude and release lithium ions. The negative electrode active material is not limited to the above-described materials.

  The positive electrode 11 of the electrode body 10 is integrally provided with a positive electrode connection portion 31 (connection portion) to which the positive electrode active material layer is not formed and to which the positive electrode connection terminal 41 is connected (see FIG. 3). Specifically, the positive electrode connection portion 31 is formed integrally with a positive electrode current collector (not shown) of the positive electrode 11 so as to protrude from the positive electrode 11, and is formed in a rectangular shape in a plan view, for example. Although not particularly illustrated, the positive electrode connection portion 31 is disposed in a space formed by the laminate film outer package 20.

  Also on the negative electrode 12, a negative electrode active material layer is not formed, and a negative electrode connection part 35 (connection part) to which the negative electrode connection terminal 42 is connected is integrally provided (see FIGS. 2 and 3). Specifically, the negative electrode connecting portion 35 is formed integrally with a negative electrode current collector (not shown) of the negative electrode 12 so as to protrude from the negative electrode 12, and is formed in a rectangular shape in plan view, for example. As shown in FIG. 2, the negative electrode connection portion 35 is also disposed in the space formed by the laminate film exterior body 20, as with the positive electrode connection portion 31.

  As shown in FIG. 3, the positive electrode connecting portion 31 and the negative electrode connecting portion 35 are formed with substantially U-shaped slits 32 and 36, respectively, in plan view. Thereby, as for the positive electrode connection part 31 and the negative electrode connection part 35, the part enclosed by the slits 32 and 36 comprises the bending parts 33 and 37, respectively. A positive electrode connection terminal 41 is connected to the bent portion 33 of the positive electrode connection portion 31 by welding. A negative electrode connection terminal 42 is connected to the bent portion 37 of the negative electrode connection portion 35 by welding. The detailed configuration of the bent portions 33 and 37 will be described later.

  The positive electrode connection terminal 41 is made of an aluminum metal foil formed in a rectangular shape in plan view. One side in the longitudinal direction of the positive electrode connection terminal 41 is connected to the positive electrode connection portion 31 by welding, and the other side in the longitudinal direction is located outside the laminate film exterior body 20 (see FIG. 1). That is, the positive electrode connection terminal 41 is sandwiched by the laminate film exterior body 20 and extends outward from the inside of the laminate film exterior body 20.

  The negative electrode connection terminal 42 is configured by a metal foil such as copper or nickel formed in a rectangular shape in plan view. As shown in FIG. 2, one side in the longitudinal direction of the negative electrode connection terminal 42 is connected to the negative electrode connection portion 35 by welding, and the other side in the longitudinal direction is located outside the laminate film exterior body 20. That is, the negative electrode connection terminal 42 is sandwiched by the laminate film exterior body 20 and extends outward from the inside of the laminate film exterior body 20.

  By using the positive electrode connection terminal 41 and the negative electrode connection terminal 42 having the above-described configuration for the laminated battery 1, the impedance can be reduced as compared with the configuration in which the connection terminal is drawn to the outside through other connection components. it can.

  A positive electrode terminal portion 51 (terminal portion) that is electrically connected to the positive electrode 11 of the electrode body 10 is configured by the positive electrode connection terminal 41 and the positive electrode connection portion 31 having the above-described configuration. The positive electrode terminal portion 51 is formed in a plate shape extending from the electrode body 10 toward the outside of the laminate film exterior body 20.

  Similarly, the negative electrode connection terminal 42 and the negative electrode connection portion 35 having the above-described configuration constitute a negative electrode terminal portion 52 (terminal portion) that is electrically connected to the negative electrode 12 of the electrode body 10. Similarly to the positive electrode terminal portion 51, the negative electrode terminal portion 52 is also formed in a plate shape extending from the electrode body 10 toward the outside of the laminate film exterior body 20.

  As shown in FIGS. 1 and 2, on the surface of the positive electrode connection terminal 41 and the negative electrode connection terminal 42, the positive electrode side resin portion 45 and the negative electrode side resin portion are respectively sandwiched by the laminate film outer package 20. 46 is formed. That is, the positive electrode side resin portion 45 is positioned between the laminate film outer package 20 and the positive electrode connection terminal 41, and the negative electrode side resin portion 46 is positioned between the laminate film outer package 20 and the negative electrode connection terminal 42.

  Accordingly, the adhesive strength between the laminate film exterior body 20 and the positive electrode connection terminal 41 and the negative electrode connection terminal 42 sandwiched between the laminate film exterior body 20 can be improved, and the positive electrode connection terminal 41 and the negative electrode connection can be improved. The terminal 42 and the laminate film exterior body 20 can be more reliably electrically insulated.

  The positive electrode side resin part 45 and the negative electrode side resin part 46 are each configured by a rectangular sheet in plan view made of a resin material such as polypropylene (PP). With this sheet extending in a direction orthogonal to the positive electrode connection terminal 41 and the negative electrode connection terminal 42 and arranged so as to sandwich the positive electrode connection terminal 41 and the negative electrode connection terminal 42, respectively, the positive electrode connection terminal 41 and the negative electrode connection terminal The positive electrode side resin part 45 and the negative electrode side resin part 46 are respectively formed by being deposited on each surface of 42.

(Folding part)
Next, the configuration of the bent portions 33 and 37 provided in the positive electrode connecting portion 31 and the negative electrode connecting portion 35 will be described in detail with reference to FIGS. 2 and 3. Since the bent portions 33 and 37 have the same configuration, only the configuration of the bent portion 37 will be described below.

  The bent portion 37 is configured by a portion of the negative electrode connecting portion 35 that is surrounded by a slit 36 provided in the negative electrode connecting portion 35. The slit 36 is formed in a substantially U shape in plan view. In the present embodiment, the slits 36 are formed in all of the negative electrode connecting portions 35 that are stacked in the thickness direction. The substantially U shape of the slit 36 is not limited to the U shape, and a shape in which the start point and the end point of the slit 36 do not coincide with each other so that the portion surrounded by the slit 36 is not separated from the negative electrode connecting portion 35. Including. Moreover, the slit 36 may be provided only in a part on the surface layer side among the negative electrode connection portions 35 laminated in the thickness direction.

  As shown in FIG. 4, the slit 36 includes a pair of long side portions 36a extending in the longitudinal direction of the negative electrode connecting portion 35 having a rectangular shape in plan view, and a pair of long side portions 36a on the electrode body 10 side in the longitudinal direction. And a short side portion 36b to be connected. As a result, the bent portion 37 composed of the portion surrounded by the slit 36 is connected to the negative electrode connecting portion 35 on the distal end side in the longitudinal direction of the negative electrode connecting portion 35.

  The bent portion 37 is a bent portion main body 37a formed by the slit 36, and a connecting portion that is located on the distal end side in the longitudinal direction of the bent portion main body 37a and connects the bent portion main body 37a to the negative electrode connecting portion 35. 37b. Therefore, the bent portion 37 is configured to be able to be folded back in the longitudinal direction of the negative electrode connecting portion 35 with the connecting portion 37b as the center. That is, the bent portion 37 is configured to be able to be folded back to the side opposite to the electrode body 10. The bent portion 37 formed by the slit 36 is folded back with the connecting portion 37b as a center, whereby a rectangular hole portion 38 is formed in the negative electrode connecting portion 35 in plan view.

  As shown in FIG. 2, the negative electrode connection terminal 42 is connected to the free end side of the bent portion main body 37a in the bent portion 37 by welding. In the present embodiment, the negative electrode connection terminal 42 is connected to the flat portion 1c side of the laminated battery 1 with respect to the bent portion main body 37a that is folded back toward the distal end side in the longitudinal direction.

  With the above-described configuration, the negative electrode connection terminal 42 can be electrically connected to the negative electrode connection portion 35 provided integrally with the negative electrode 12 of the electrode body 10.

  In addition, by connecting the negative electrode connection terminal 42 to the bent portion 37 of the negative electrode connection portion 35, when the laminated battery 1 is bent in the longitudinal direction as indicated by an arrow in FIG. The bending portion 37 can absorb the bending deformation generated in the negative electrode terminal portion 52. That is, by connecting the negative electrode connection terminal 42 to the bent portion 37 in a state where the bent portion 37 is folded back, the bent portion 37 is connected to the negative electrode connection terminal 42 while being bent in the thickness direction. . Thereby, since the deformation | transformation to the thickness direction of the bending part 37 is accept | permitted, it becomes possible for the bending part 37 to absorb the deformation | transformation of the negative electrode connection part 52. FIG. Therefore, the connection part of the negative electrode connection part 35 and the negative electrode connection terminal 42 in the negative electrode terminal part 52 can be prevented from being damaged by the bending deformation.

  The negative electrode connection portion 35 formed integrally with the negative electrode 12 of the electrode body 10 is generally smaller in thickness than the negative electrode connection terminal 42. Therefore, by providing the above-described bent portion 37 in the negative electrode connecting portion 35, the bent portion 37 can be deformed with good followability with respect to the bending of the laminated battery 1. Therefore, it is possible to more reliably prevent the negative electrode terminal portion 52 from being damaged when the laminated battery 1 is bent.

<Embodiment 2>
FIG. 6 is a cross-sectional view showing the configuration of the laminated battery 100 according to the second embodiment. As shown in FIG. 6, in the laminated battery 100, the configuration of the bent portion 137 of the negative electrode terminal portion 152 is different from the configuration of the first embodiment. In the following, the same components as those of the first embodiment are denoted by the same reference numerals, description thereof is omitted, and only configurations different from those of the first embodiment will be described. As in the first embodiment, the bent portion of the positive electrode terminal portion has the same configuration as that of the bent portion 137 of the negative electrode terminal portion 152. Therefore, only the configuration of the bent portion 137 of the negative electrode terminal portion 152 will be described below. explain.

  The negative electrode connecting portion 135 of the negative electrode terminal portion 152 is formed in a rectangular shape extending outward from the negative electrode 12, similarly to the negative electrode connecting portion 35 of the first embodiment. The negative electrode connecting portion 135 has its longitudinal end folded back in the longitudinal direction so that a portion thereof overlaps in the thickness direction. A bent portion 137 is constituted by the folded portion. A negative electrode connection terminal 42 is connected to the bent portion 137 by welding. In this embodiment, the negative electrode connection terminal 42 is connected to the flat portion 1c side of the laminated battery 100 in the bent portion 137 by welding.

  The bent portion 137 can absorb deformation that occurs in the negative electrode terminal portion 152 when the laminated battery 100 is bent. Thereby, it can prevent that the connection part of the negative electrode connection part 135 and the negative electrode connection terminal 42 in the negative electrode terminal part 152 receives damage.

  Further, the bent portion 137 is formed by folding the distal end side in the longitudinal direction in the longitudinal direction so that the negative electrode connecting portion 135 of the negative electrode terminal portion 152 overlaps in the thickness direction. Therefore, the bent portion 137 can be easily formed.

  Moreover, since the bent portion 137 is provided in the negative electrode connecting portion 135 having a dimension in the thickness direction smaller than that of the negative electrode connecting terminal 42 as in the first embodiment, the followability when the laminated battery 1 is bent. It can be deformed well. Thereby, when the laminated battery 1 is bent, it can prevent more reliably that the negative electrode terminal part 252 is damaged.

<Embodiment 3>
In FIG. 7, the structure of the laminated battery 200 which concerns on Embodiment 3 is shown with a cross section. As shown in FIG. 7, in the laminated battery 200, the configuration of the bent portion 237 of the negative electrode terminal portion 252 is different from the configuration of the first embodiment. In the following, the same components as those of the first embodiment are denoted by the same reference numerals, description thereof is omitted, and only configurations different from those of the first embodiment will be described. As in the first embodiment, the bent portion of the positive electrode terminal portion has the same configuration as that of the bent portion 237 of the negative electrode terminal portion 252, and therefore only the configuration of the bent portion 237 of the negative electrode terminal portion 252 will be described below. explain.

  The negative electrode connection terminal 242 is folded back in the longitudinal direction so that the end in the longitudinal direction located inside the laminate film outer package 20 overlaps in the thickness direction. A bent portion 237 is formed by the folded portion. A negative electrode connecting portion 235 is connected to the flat portion 1c side of the laminated battery 200 in the bent portion 237 by welding.

  The bent portion 237 can absorb the deformation of the negative electrode terminal portion 252 when the laminated battery 200 is bent. Thereby, the connection part of the negative electrode connection part 235 and the negative electrode connection terminal 242 in the negative electrode terminal part 252 can be prevented from being damaged.

(Other embodiments)
While the embodiments of the present invention have been described above, the above-described embodiments are merely examples for carrying out the present invention. Therefore, the present invention is not limited to the above-described embodiment, and the above-described embodiment can be appropriately modified and implemented without departing from the spirit of the invention.

  In each of the embodiments described above, one bent portion 37, 137, 237 is provided in the negative electrode terminal portion 52, 152, 252. However, two or more bent portions may be provided in the longitudinal direction of the negative electrode connecting portion 52, or two or more bent portions may be provided in the width direction of the negative electrode connecting portion 52. Moreover, the bending part may be bent twice or more.

  In each of the above embodiments, the bent portions 35, 37, 137, and 237 are provided on both the positive terminal portion 51 and the negative terminal portions 52, 152, and 252. However, the bent portions 37, 137, and 237 may be provided only in the negative electrode terminal portions 52, 152, and 252. For example, when the negative electrode connection terminals 42 and 242 are made of nickel metal foil, the nickel negative electrode connection terminals 42 and 242 and the copper negative electrode connection portion 35 are welded so-called different metals. In such a case, the bonding strength is lower than that of the welded portion of the positive electrode connection terminal 41 and the positive electrode connection portion 31 that are made of an aluminum metal foil. Therefore, by providing the bent portions 37, 137, and 237 in the negative electrode connecting portions 52, 152, and 252, when the laminated batteries 1, 100, and 200 are bent in the longitudinal direction, the negative electrode is connected within the laminate film outer package 20. The parts 52, 152, and 252 can be prevented from being damaged. Therefore, the strength against bending of the electrochemical elements 1, 100, 200 can be improved more reliably.

  In each of the embodiments described above, the positive electrode connection portion 51 and the negative electrode connection portions 52, 152, and 252 are disposed so as to extend in the same direction with respect to the electrode body 10. However, the positive electrode connecting portion 51 and the negative electrode connecting portions 52, 152, and 252 may be arranged to extend in different directions with respect to the electrode body 10.

  In each of the embodiments, the laminated battery 1 is formed in a rectangular shape in plan view. However, the laminated battery may have other shapes such as a polygonal shape.

  In each of the embodiments described above, the laminated battery 1 is a lithium ion battery. However, the laminated battery 1 may be a battery other than a lithium ion battery. Moreover, you may apply the structure of each said embodiment not only to the laminated battery 1 but to the electrochemical element containing a capacitor. That is, the configuration of each of the above embodiments can be applied to a thin electrochemical element that can store or generate electric power and bend and deform.

  In the first and second embodiments, the negative electrode connection terminal 42 is connected to the flat portion 1 c side of the laminated battery 1, 100 with respect to the bent portions 37, 137. However, the negative electrode connection terminal 42 may be connected to the bulging portion 1 a side of the laminated battery 1, 100 with respect to the bent portions 37, 137.

  In the third embodiment, the negative electrode connecting portion 235 is connected to the flat portion 1c side of the laminated battery with respect to the bent portion 237. However, the negative electrode connecting portion 235 may be connected to the bulging portion 1 a side of the laminated battery 1, 100 with respect to the bent portion 237.

  In the first embodiment, the slit 36 is formed in a U shape in plan view. However, as shown in FIG. 8, the slits 36 are located on the distal end sides (both ends of the slits) of the negative electrode connection portion 35 in the pair of long side portions 36 a in the longitudinal direction of the negative electrode connection portion 35, and are long. The stress relaxation part 36c extended in the direction different from the direction where the side part 36a extends may be included. Thus, by providing the stress relaxation portions 36 c on the pair of long side portions 36 a of the slit 36, the laminated battery 1 is bent in the longitudinal direction, thereby forming a bent portion 37 formed of a portion surrounded by the slit 36. When force is applied, stress can be prevented from concentrating on the end of the long side portion 36a in the longitudinal direction. Thereby, it can prevent that the edge part of the long side part 36a of the slit 36 fractures | ruptures.

  Note that the stress relaxation portion 36 c may be provided on only one of the pair of long side portions 36 a of the slit 36. Further, the stress relieving portion 36c may have a shape other than the U shape in plan view as long as it has a shape extending in a direction different from the extending direction of the both side portions 36a.

  The present invention can be used for an electrochemical device in which an electrode body is covered with a laminate film outer package.

1, 100, 200 Laminated battery (electrochemical element)
DESCRIPTION OF SYMBOLS 1a Swelling part 1c Plane part 10 Electrode body 11 Positive electrode 12 Negative electrode 20 Laminate film exterior body 31 Positive electrode connection part (connection part)
32, 26 Slit 33, 37, 137, 237 Bent part 35, 135, 235 Negative electrode connection part (connection part)
37a Bent part 37b Connection part 38 Hole part 41 Positive electrode connection terminal (connection terminal)
42, 242 Negative connection terminal (connection terminal)
51 Positive terminal (terminal part)
52, 152, 252 Negative terminal portion (terminal portion)

Claims (7)

An electrode body having a sheet-like positive electrode and a negative electrode laminated in the thickness direction;
A sheet-like laminate film outer package in which the outer peripheral side is welded in a state of covering the electrode body;
A plurality of plate-like terminal portions that are electrically connected to the electrode body and extend from the electrode body toward the outside of the laminate film exterior body,
The plurality of terminal portions are respectively
A connection part formed integrally with the electrode body and positioned inward of the laminate film exterior body;
A connection terminal connected to the connection portion and extending outward from the inside of the laminate film exterior body,
At least one terminal portion among the plurality of terminal portions is an electrochemical element having a bent portion bent in the longitudinal direction so as to overlap in the thickness direction inside the laminate film exterior body. The electrochemical device according to claim 1,
One of the connection part and the connection terminal in the at least one terminal part is formed with a U-shaped slit in plan view,
The bent portion is constituted by a region surrounded by the slit in one of the connection portion and the connection terminal in the at least one terminal portion,
The electrochemical element, wherein the bent portion is connected to the other of the connection portion and the connection terminal in the at least one terminal portion. The electrochemical device according to claim 2,
The slit is an electrochemical element in which at least one of both end portions of the slit extends in a direction different from the longitudinal direction. The electrochemical device according to claim 1,
The bent portion is bent in the longitudinal direction so that one of the connection portion and the connection terminal in the at least one terminal portion overlaps in the thickness direction,
The other of the connection part and the connection terminal in the at least one terminal part is an electrochemical element connected to the bent part. The electrochemical element according to any one of claims 1 to 4,
The connection part in the plurality of terminal parts has a dimension in the thickness direction smaller than the connection terminal,
The bent portion is an electrochemical element provided in the connection portion of the at least one terminal portion. The electrochemical device according to any one of claims 1 to 5,
A secondary battery,
The plurality of terminal portions include a positive electrode terminal portion electrically connected to the positive electrode, and a negative electrode terminal portion electrically connected to the negative electrode.
The positive terminal portion is electrically connected to the positive electrode,
The negative terminal portion is electrically connected to the negative electrode,
The bent portion is an electrochemical element provided in the negative electrode terminal portion. The electrochemical device according to any one of claims 1 to 6,
The electrode body has a plurality of the positive electrode and the negative electrode,
Each of the plurality of terminal portions includes a plurality of the connection portions and the connection terminals,
The plurality of connection portions and the plurality of connection terminals are respectively laminated in the thickness direction,
The bent portion is an electrochemical element provided in at least one part of the plurality of connection parts or at least one part of the plurality of connection terminals.

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