JP2018181447A - Electrochemical element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a configuration capable of preventing the function of an electrochemical element is impaired, even when the electrochemical element is bent in the longitudinal direction, in an electrochemical element where the electrode body is covered with a laminate film exterior body.SOLUTION: A laminated battery 1 includes an electrode body 10, a laminate film exterior body 20, a negative electrode terminal 52, and a regulation member 62. The negative electrode terminal 52 has a negative electrode connection 32, and a negative electrode connection terminal 42. The negative electrode terminal 52 has a folded part 32a folded at least two times in the longitudinal direction, so as to be superposed in the thickness direction in the laminate film exterior body 20. The regulation member 62 covers at least a part of the folded part 32a, so as to allow deformation of the folded part 32a in the longitudinal direction, while regulating movement of at least a part of a positive electrode 11 and a negative electrode 12 in the longitudinal direction.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an electrochemical device in which an electrode body is covered by a laminate film outer package.

  There is known an electrochemical device in which an electrode body is covered by a laminate film outer package. In such an electrochemical device, a terminal portion electrically connected to the electrode body extends outward from the electrode body toward the outside of the laminate film outer package. The terminal portion has a connection portion integrally formed with the electrode body, and a connection terminal connected to the connection portion. The electrochemical device has a rectangular shape elongated in a direction in which the terminal portion extends in plan view.

  For example, in Patent Document 1, as an electrochemical element having a configuration as described above, a positive electrode having a positive electrode active material layer formed on both sides of a positive electrode current collector and a negative electrode active material layer formed on both sides of a negative electrode current collector A non-aqueous electrolyte battery is disclosed that has battery elements in which the negative electrodes are alternately stacked via a separator. In the patent document 1, the battery element is packaged by a packaging material.

JP, 2009-187768, A

  By the way, application of the electrochemical device in which the battery device (electrode assembly) is covered with the outer package (laminated film outer package) as described above is being studied for devices in various fields. Recently, a rectangular thin electrochemical device is mounted on a small and thin flexible device with a plan view, or as the device is miniaturized, the electrochemical device is longitudinally bent in the device and compacted. It is also considered to be placed in the

  When the electrochemical device is bent in the longitudinal direction, bending deformation also occurs in the internal components of the electrochemical device. Specifically, bending deformation occurs in the electrode body disposed in the laminate film outer package of the electrochemical device and the terminal portion electrically connected to the electrode body. Then, in the electrode body, the positive electrode and the negative electrode may move in the longitudinal direction to cause an internal short circuit. Further, the terminal portion may be damaged by bending deformation. Therefore, when the electrochemical device is bent in the longitudinal direction, the function of the electrochemical device may be lost inside the laminate film outer package.

  An object of the present invention is to provide an electrochemical device in which an electrode body is covered with a laminate film sheath, and even when the electrochemical device is bent in the longitudinal direction, the electrochemical device of the present invention is provided inside the laminate film sheath. An arrangement capable of preventing the function from being damaged is obtained.

  An electrochemical device according to an embodiment of the present invention includes an electrode body having a sheet-like positive electrode and a negative electrode laminated in a thickness direction, and a sheet-like laminate film sheath having an outer peripheral side welded in a state covering the electrode body. Body, a plurality of plate-like terminal portions electrically connected to the electrode body and extending from the electrode body toward the outer side of the laminate film sheath, at least one of the positive electrode and the negative electrode in the electrode body And a regulating member that regulates movement of the portion in the longitudinal direction of the terminal portion. The plurality of terminal portions are respectively formed integrally with the electrode body, and are connected to the connection portion positioned inward of the laminate film sheath and the connection portion and are outward from the inside of the laminate film sheath. And a connection terminal extending toward the At least one terminal portion of the plurality of terminal portions has a bent portion folded back at least twice in the longitudinal direction so as to overlap in the thickness direction inside the laminate film outer package. The regulating member is configured to allow the bent portion to be deformed in the longitudinal direction while restricting at least a part of the positive electrode and the negative electrode from moving in the longitudinal direction. Cover at least a part (first configuration).

  An electrochemical element having a plurality of plate-like terminal portions electrically connected to an electrode body and extending outward from the electrode body toward the outer side of the laminate film case is the laminate film when bent in the longitudinal direction. Bending deformation occurs in the terminal portion inside the outer package. Therefore, when the electrochemical device is bent as described above, the terminal portion may be damaged.

  On the other hand, by providing the bent portion in the terminal portion, the bending portion can absorb the bending deformation generated in the terminal portion when the electrochemical element is bent. Thereby, the bending stress which arises in the said terminal part can be reduced. Therefore, when the electrochemical device is bent in the longitudinal direction, the terminal portion can be prevented from being damaged.

  Further, in the electrochemical device, when bent in the longitudinal direction, the positive electrode and the negative electrode of the electrode body may move in the longitudinal direction. On the other hand, by covering at least a part of the bent portion with the restriction member, it is possible to restrict the movement of the positive electrode and the negative electrode of the electrode body in the longitudinal direction. Moreover, the restriction member allows the deformation of the bent portion in the longitudinal direction. Thereby, it is possible to prevent the absorption of the bending deformation by the bending portion as described above from being hindered by the restriction member.

  Therefore, according to the above-mentioned configuration, when the electrochemical device is bent in the longitudinal direction, the function of the electrochemical device can be prevented from being impaired inside the laminate film outer package.

  In the first configuration, the restriction member has a movement permitting portion that allows the bending portion to relatively move in the longitudinal direction on the bending portion side (second configuration).

  Thus, the bending portion can move in the longitudinal direction relative to the movement permitting portion of the regulating member covering at least a part of the bending portion. Therefore, it is possible to more reliably prevent the restriction member from inhibiting the absorption of bending deformation by the bending portion as described above.

  In the second configuration, the movement allowing portion is configured by a film member having no adhesive layer on the surface (third configuration). Thereby, the control member which does not inhibit absorption of the bending deformation by the above-mentioned bending parts is realizable.

  In any one of the first to third configurations, the restriction member has a predetermined gap with the bending portion in the thickness direction (fourth configuration).

  Thus, the bending portion can move in the longitudinal direction on the inner side of the regulating member covering at least a part of the bending portion. Therefore, it is possible to further reliably prevent the absorption of bending deformation by the bending portion as described above from being hindered by the restriction member.

  In any one of the first to fourth configurations, the plurality of terminal portions extend in one direction from the electrode body. The restriction member is made of an electrically insulating material, covers at least a part of the bent portion, and a terminal portion provided with the bent portion among the plurality of terminal portions, and the terminal portion And the adjacent terminal portion (fifth configuration).

  In an electrochemical device in which a plurality of terminal portions extend in one direction from an electrode body, when the electrochemical device is bent in the longitudinal direction, the terminal portions may come in contact with each other to cause a short circuit. On the other hand, as described above, by arranging the restriction member between the terminal portion provided with the bent portion and the terminal portion adjacent to the terminal portion, the terminal portions can be electrically insulated from each other. .

  Therefore, the restriction members prevent the positive electrode and the negative electrode of the electrode body from moving in the longitudinal direction without inhibiting absorption of bending deformation by the bending portion as described above, and the terminal portions are electrically connected to each other. Can be isolated.

  In the fifth configuration, the restriction member has an annular shape that covers the bent portion (sixth configuration).

  As a result, the movement of the positive electrode and the negative electrode of the electrode assembly in the longitudinal direction can be more reliably restricted, and the terminal part provided with the bent part and the terminal part adjacent to the terminal part can be more reliably electrically Can be isolated.

  In any one of the first to sixth configurations, the bending portion is provided in the connection portion (seventh configuration).

  Generally, in the terminal portion, the connection portion has lower strength than the connection terminal. Therefore, when the electrochemical element is bent in the longitudinal direction, the connection portion is susceptible to damage. On the other hand, by providing the bent portion in the connection portion, it is possible to prevent the connection portion from being damaged when the electrochemical element is bent in the longitudinal direction.

  In any one of the first to seventh configurations, the connection portion and the connection terminal are connected by a welding portion. The restriction member covers the bent portion and the welded portion (eighth configuration).

  By welding the connection portion and the connection terminal, asperities are formed on the surface of the weld portion. When the unevenness is formed on the surface of the welded portion, there is a possibility that the projection portion contacts the metal film of the laminate film sheathing material to cause a short circuit. On the other hand, as described above, by covering the welded portion with the regulating member, it is possible to suppress that the protruding portion of the surface of the welded portion contacts the metal film.

  In any one of the first to eighth configurations, each of the positive electrode and the negative electrode has a current collector. An active material layer is provided on one side of the current collector of at least one of the positive electrode and the negative electrode (ninth configuration).

  Thus, when the laminate type battery is bent in the longitudinal direction, the positive electrode and the negative electrode are easily displaced relative to each other in the longitudinal direction. Therefore, when the laminate type battery is bent in the longitudinal direction, it is possible to prevent the positive electrode and the negative electrode from being damaged by applying a force to the contact portion of the positive electrode and the negative electrode.

  Further, as described above, in the configuration in which the positive electrode and the negative electrode are relatively displaced in the longitudinal direction when the laminate type battery is bent in the longitudinal direction, the positive electrode and the negative electrode are in the longitudinal direction. Easy to move to On the other hand, movement of the positive electrode and the negative electrode in the longitudinal direction can be restricted by providing the restriction members having the above-described configurations.

  According to the electrochemical device in accordance with an embodiment of the present invention, at least one of the plurality of terminal portions extending outward from the electrode body of the laminate film sheath is the inner side of the laminate film sheath. And a bent portion folded back at least twice in the longitudinal direction so as to overlap in the thickness direction. The electrochemical device may be configured to allow the bent portion to be deformed in the longitudinal direction while restricting at least a part of the positive electrode and the negative electrode from moving in the longitudinal direction. And a regulating member covering at least a part of

  Thereby, when the electrochemical element is bent in the longitudinal direction, deformation that occurs in the terminal portion in the laminate film outer package can be absorbed by the bent portion. Further, when the electrochemical element is bent in the longitudinal direction, movement of the positive electrode and the negative electrode of the electrode body in the longitudinal direction can be restricted by the restriction member. Therefore, even when the electrochemical device is bent, the function of the electrochemical device can be prevented from being impaired inside the laminate film outer package.

FIG. 1 is a perspective view showing the configuration of a laminate type battery according to the embodiment. FIG. 2 is a cross-sectional view taken along line II-II in FIG. FIG. 3 is a perspective view showing a schematic configuration of an electrode body, a positive electrode terminal portion and a negative electrode terminal portion. FIG. 4 is a view corresponding to FIG. 3 showing a state in which the positive electrode terminal portion and the negative electrode terminal portion are covered by the restriction members. FIG. 5 is an enlarged cross-sectional view schematically showing a change in the negative electrode terminal portion generated in the inside of the laminate outer package when the laminate type battery is bent in the longitudinal direction.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same or corresponding portions in the drawings have the same reference characters allotted and description thereof will not be repeated.

  In the following description, "bending" and "folding" are concepts including bending. In the following description, the short direction of the laminate type battery 1 when the laminate type battery 1 is viewed in plan is referred to as "width direction", and the lamination direction of the electrode assembly 10 is referred to as "thickness direction".

(overall structure)
FIG. 1 is a perspective view showing a schematic configuration of a laminate type battery 1 (electrochemical device) according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing a schematic configuration of the laminate type battery 1. The laminate type battery 1 is a rectangular secondary battery in a plan view in which an electrode body 10 functioning as a power generation body is covered by a laminate film outer package 20. The laminate type battery 1 is used, for example, as a power supply of a wearable terminal or a small portable device.

  As shown in FIGS. 1 and 2, the laminate type battery 1 includes an electrode body 10 and a laminate film sheath 20 covering the electrode body 10. In addition, the laminate type battery 1 includes a positive electrode connection terminal 41 and a negative electrode connection terminal 42 (connection terminal) electrically connected to the positive electrode 11 and the negative electrode 12 of the electrode body 10, respectively. A non-aqueous electrolyte is also enclosed inside the laminate type battery 1.

  The laminate film sheath 20 is made of a material in which one side of a metal foil made of aluminum is covered with polyethylene terephthalate (PET) and the other side is covered with polypropylene (PP). That is, the laminate film sheath 20 is made of a material obtained by laminating aluminum with PET and PP. Thereby, the laminate film sheath 20 is welded by applying pressure while heating in a state in which the laminate film sheaths 20 are superimposed. The metal foil is not limited to aluminum, and may be formed of another metal material such as stainless steel.

  In addition, the laminate film outer package 20 is formed in a substantially rectangular shape. In a state in which the electrode body 10 is sandwiched between the pair of laminate film sheaths 20, the outer peripheral sides of the laminate film sheaths 20 are welded together to form the bulging portion 1a and the seal portion 1b as shown in FIGS. Is formed. That is, a bulging portion 1a is formed by covering the electrode body 10 with the laminate film sheath 20, and the bulging portion 1a is surrounded by welding the laminate film sheaths 20 around the bulging portion 1a. The seal portion 1 b is formed on the

  The laminate film outer package 20 may be made of a material in which a metal foil is laminated with nylon and PP, or a metal foil is made of a material laminated with at least one of nylon, PET and PP. It may be In addition, the laminate film outer package 20 may be made of a material in which a metal foil is laminated with another resin material.

  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 outer package 20 (hereinafter, also simply referred to as a plan view). The seal portion 1 b is formed around the bulging portion 1 a so that the laminate type battery 1 has a rectangular shape in a plan view.

  Further, as shown in FIG. 2, in the pair of laminate film sheaths 20, the laminate type battery 1 has the 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 together with the electrode body 10 interposed therebetween so as to have the above-described bulging portion 1a. That is, of the pair of laminate film sheaths 20, one laminate film sheath 20 is arranged along the outer shape of the electrode body 10.

  As shown in FIG. 1, the positive electrode connection terminal 41 and the negative electrode connection terminal 42 are sandwiched between the pair of laminate film sheaths 20 at a portion of the seal portion 1 b located on the end side of the laminate type battery 1 in the longitudinal direction. In the closed state, the laminate film outer package 20 is fixed by welding. The positive electrode connection terminal 41 and the negative electrode connection terminal 42 extend in one direction from the inside to the outside of the laminate film outer package 20.

  In the present embodiment, the outer peripheral sides of the pair of laminate film sheaths 20 are welded, but the present invention is not limited to this, and one laminate film sheath is folded and welded so as to sandwich the electrode body 10. May be The direction in which the laminate film outer package is folded back may be the extension 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 laminate formed by overlapping the positive electrode 11 and the negative electrode 12 respectively formed in a sheet shape so that the sheet-like separator 13 is positioned therebetween. is there. In the present embodiment, in the electrode body 10, the negative electrode 12 is disposed at the outermost layer in the stacking direction.

  In addition, the laminated body on which the positive electrode 11 and the negative electrode 12 were laminated | stacked five layers collectively as an example of the electrode body 10 is shown in figure by FIG. However, the electrode body 10 may be a laminate in which four or less layers of the positive electrode 11 and the negative electrode 12 are combined and may be a stacked body in which six or more layers are stacked.

The positive electrode 11 is a positive electrode active material layer (active material layer) containing a positive electrode active material provided on one side of a positive electrode current collector (current collector) made of metal foil such as aluminum. Specifically, the positive electrode 11 is formed by applying a positive electrode mixture containing a positive electrode active material which is a lithium-containing oxide capable of absorbing and releasing lithium ions, a conductive additive, a binder and the like onto a positive electrode current collector made of aluminum foil or the like. It is formed by drying. As a lithium-containing oxide which is a positive electrode active material, for example, a lithium cobalt oxide such as LiCoO ₂ , a lithium manganese oxide such as LiMn ₂ O ₄ , a lithium composite oxide such as a lithium nickel oxide such as LiNiO ₂ is used Is preferred. As the positive electrode active material, only one type of substance may be used, or two or more types of substances may be used. Moreover, a positive electrode active material is not restricted to the above-mentioned substance.

  The negative electrode 12 is a negative electrode active material layer (active material layer) containing a negative electrode active material provided on one side of a negative electrode current collector (current collector) made of 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 inserting and extracting lithium ions, a conductive additive, a binder, and the like onto a negative electrode current collector made of copper foil or the like. It is formed. As the negative electrode active material, it is preferable to use, for example, a carbon material (graphites, pyrolytic carbons, cokes, glassy carbons, etc.) capable of inserting and extracting lithium ions. The negative electrode active material is not limited to the above-mentioned materials.

  As described above, the positive electrode 11 is provided with the positive electrode active material layer on one side of the positive electrode current collector, and the negative electrode 12 is provided with the negative electrode active material layer on one side of the negative electrode current collector. When the battery 1 is bent in the longitudinal direction, the positive electrode 11 and the negative electrode 12 are easily displaced relative to each other in the longitudinal direction. Thereby, when the laminate type battery 1 is bent in the longitudinal direction, it is possible to prevent the positive electrode 11 and the negative electrode 12 from being damaged by applying a force to the contact portion of the positive electrode 11 and the negative electrode 12.

  The 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 is integrally provided on the positive electrode 11 of the electrode body 10 (see FIG. 3). Specifically, the positive electrode connection portion 31 is integrally formed 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, for example, in a rectangular shape elongated in the protrusion direction in plan view . Although not particularly illustrated, the positive electrode connection portion 31 is disposed in the space formed by the laminate film sheath 20.

  The negative electrode connection portion 32 (connection portion) to which the negative electrode active material layer is not formed and to which the negative electrode connection terminal 42 is connected is also integrally provided on the negative electrode 12 (see FIGS. 2 and 3). Specifically, the negative electrode connection portion 32 is integrally formed on a negative electrode current collector (not shown) of the negative electrode 12 so as to protrude from the negative electrode 12, and is formed, for example, in a rectangular shape elongated in the protruding direction in plan view . As shown in FIG. 2, the negative electrode connection portion 32 is also disposed in the space formed by the laminate film outer package 20 in the same manner as the positive electrode connection portion 31.

  The positive electrode connection portion 31 and the negative electrode connection portion 32 extend in one direction from one side of the electrode body 10 in the longitudinal direction. That is, the positive electrode connection portion 31 and the negative electrode connection portion 32 are provided in the electrode body 10 so as to extend in the same direction from the electrode body 10 side by side in the width direction.

  The positive electrode connection portion 31 and the negative electrode connection portion 32 have bent portions 31a and 32a that are folded back at least twice in the longitudinal direction so as to overlap in the thickness direction. The detailed configuration of the bent portions 31a and 32a will be described later.

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

  The negative electrode connection terminal 42 is made of a metal foil such as copper or nickel formed in a rectangular shape in a plan view. As shown in FIG. 2, one side of the negative electrode connection terminal 42 in the longitudinal direction is connected to the negative electrode connection portion 32 by welding, and the other side in the longitudinal direction is located outside the laminate film sheath 20. That is, the negative electrode connection terminal 42 is sandwiched by the laminate film sheath 20 and extends outward from the inner side of the laminate film sheath 20. The width dimension of the negative electrode connection terminal 42 is smaller than the width dimension of the negative electrode connection portion 32.

  By using the positive electrode connection terminal 41 and the negative electrode connection terminal 42 having the above-described configuration in the laminate type battery 1, the impedance can be reduced compared to the configuration in which the connection terminal is drawn to the outside through another connection component. it can.

  The positive electrode connecting portion 41 (terminal portion) electrically connected to the positive electrode 11 of the electrode body 10 is configured by the positive electrode connecting terminal 41 and the positive electrode connecting portion 31 having the configuration as described above. 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 sheath 20. In addition, in the positive electrode terminal portion 51, a portion where the positive electrode connection terminal 41 and the positive electrode connection portion 31 are joined by welding is a welding portion 51a.

  A part of the positive electrode terminal portion 51 is covered by a cylindrical restriction member 61. Although described in detail later, the restriction member 61 covers the bent portion 31 a of the positive electrode connection portion 31 and the welded portion 51 a of the positive electrode connection terminal 41 and the positive electrode connection portion 31.

  Similarly, the negative electrode terminal 52 (terminal portion) electrically connected to the negative electrode 12 of the electrode assembly 10 is configured by the negative electrode connection terminal 42 and the negative electrode connection portion 32 having the above-described configuration. 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 outer package 20. In the negative electrode terminal portion 52, a portion where the negative electrode connection terminal 42 and the negative electrode connection portion 32 are joined by welding is a welding portion 52a.

  A part of the negative electrode terminal portion 52 is covered by a cylindrical restriction member 62. Although described in detail later, the restriction member 62 covers the bent portion 32 a of the negative electrode connection portion 32 and the welded portion 52 a of the negative electrode connection terminal 42 and the negative electrode connection portion 32.

  As shown in FIG. 1 and FIG. 2, on the surfaces 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 in portions to be sandwiched by the laminate film sheath 20 respectively. 46 are 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.

  As a result, the adhesive strength between the laminate film outer package 20 and the positive electrode connection terminal 41 and the negative electrode connection terminal 42 sandwiched by the laminate film outer package 20 can be improved, and the positive electrode connection terminal 41 and the negative electrode connection terminal 42 It is possible to electrically insulate the laminate film sheath 20 more reliably.

  Each of the positive electrode side resin portion 45 and the negative electrode side resin portion 46 is formed of, for example, a rectangular sheet in plan view made of a resin material such as polypropylene (PP). The positive electrode connection terminal 41 and the negative electrode connection terminal extend in a direction orthogonal to the positive electrode connection terminal 41 and the negative electrode connection terminal 42 and are disposed so as to sandwich the positive electrode connection terminal 41 and the negative electrode connection terminal 42 respectively. The positive electrode side resin portion 45 and the negative electrode side resin portion 46 are formed by depositing on the respective surfaces 42.

(Fold portion)
Next, the configuration of the bent portions 31 a and 32 a provided in the positive electrode connection portion 31 and the negative electrode connection portion 32 will be described in detail with reference to FIGS. 2, 3 and 5. Since the bending portions 31a and 32a have the same configuration, only the configuration of the bending portion 32a will be described below.

  The bent portion 32 a is provided in the negative electrode connection portion 32 in addition to the welded portion 52 a with the negative electrode connection terminal 42. Specifically, the bending portion 32a has a first bending portion 32b and a second bending portion 32c in which a part in the longitudinal direction of the negative electrode connection portion 32 is folded back in the thickness direction.

  The first bent portion 32 b is formed by being bent in the longitudinal direction at a position closer to the negative electrode 12 than the second bent portion 32 c in the longitudinal direction of the negative electrode connection portion 32. That is, the first bent portion 32 b is a portion formed in the negative electrode connection portion 32 by being folded back in the longitudinal direction toward the negative electrode 12 side.

  In the negative electrode connection portion 32, the second bent portion 32c is folded back at the first bent portion 32b and a portion extending toward the negative electrode 12 side is bent in the longitudinal direction toward the outer side of the laminate film sheath 20. It is formed by being Therefore, in plan view, the second bent portion 32c is located closer to the negative electrode 12 than the first bent portion 32b.

  In the present embodiment, the bending portion 32 a is formed in a Z shape as viewed from the width direction by the above-described first bending portion 32 b and the second bending portion 32 c. That is, in the bending portion 32a, a part of the negative electrode connection portion 32 in the longitudinal direction is folded back at least twice in the thickness direction. Thereby, the negative electrode terminal portion 52 extends from the negative electrode 12 toward the outside of the laminate film outer package 20 while having the bent portion 32 a in a part in the longitudinal direction. In addition, as long as the negative electrode terminal portion 52 extends from the negative electrode 12 toward the outer side of the laminate film outer package 20, the negative electrode connection portion 32 may be folded back three or more times in the longitudinal direction in the bent portion 32a. .

  With the above configuration, as shown in FIG. 5, when the laminate type battery 1 is bent in the longitudinal direction (when the laminate type battery 1 is bent in the direction of the solid arrow shown in FIG. 5), The bending deformation which arises can be absorbed by the bending part 32a. That is, as shown in FIG. 5, when the laminate type battery 1 is bent in the longitudinal direction, the negative electrode connecting portion 32 is also deformed so as to extend in the longitudinal direction. Under the present circumstances, since the bending part 32a is extended in the longitudinal direction of the negative electrode connection part 32 (refer the hatched arrow of FIG. 5), it can prevent that big stress is generate | occur | produced with respect to the negative electrode connection part 32 in a longitudinal direction.

  Therefore, the deformation in the longitudinal direction of the negative electrode connection portion 32 is absorbed by the bent portion 32a. Thereby, when the laminate type battery 1 is bent in the longitudinal direction, the negative electrode connection portion 32 can be suppressed from being damaged.

  In particular, in the present embodiment, in the negative electrode terminal portion 52, the negative electrode connection portion 32 has lower strength than the negative electrode connection terminal 42. Therefore, when the laminate type battery 1 is bent in the longitudinal direction, the negative electrode connection portion 32 is easily damaged. In contrast, by providing the bent portion 32a in the negative electrode connection portion 32 as described above, the negative electrode connection portion 32 is more reliably prevented from being damaged when the laminate type battery 1 is bent in the longitudinal direction. it can.

  Although a detailed description is omitted, the positive electrode connection portion 31 is also provided with a bent portion 31 a similar to the bent portion 32 a of the negative electrode connection portion 32. Therefore, the movement of the bent portion 31a when the laminate type battery 1 is bent in the longitudinal direction is the same as that of the bent portion 32a. Therefore, similarly to the negative electrode connection portion 32, when the laminate type battery 1 is bent in the longitudinal direction, the positive electrode connection portion 31 can be prevented from being damaged. In FIG. 3, reference numeral 31 b denotes a first bending portion, and reference numeral 31 c denotes a second bending portion.

(Regulation member)
Next, with reference to FIGS. 2, 4 and 5, the configuration of the restriction members 61 and 62 covering a part of each of the positive electrode terminal portion 51 and the negative electrode terminal portion 52 will be described in detail. Since the regulating members 61 and 62 have the same configuration, only the configuration of the regulating member 62 covering a part of the negative electrode terminal portion 52 will be described below.

  As shown in FIGS. 2 and 4, the restriction member 62 covers the bent portion 32 a of the negative electrode connection portion 32 and the welded portion 52 a of the negative electrode connection terminal 42 and the negative electrode connection portion 32.

  The restriction member 62 is an annular member made of resin. The restriction member 62 is formed, for example, by fixing the winding end of the cylindrically wound film 62a with a fixing tape 62b. Specifically, the restricting member 62 has a cylindrical film 62a (a movable portion, a film member) made of resin and a fixing tape 62b for fixing the winding end of the film 62a.

  The film 62 a covers the bent portion 32 a of the negative electrode connection portion 32 and the welded portion 52 a of the negative electrode connection terminal 42 and the negative electrode connection portion 32. The film 62a is made of a resin material having electrical insulation. The film 62a does not have an adhesive layer on the surface. Thereby, when the laminate type battery 1 is bent in the longitudinal direction, the bent portion 32a is movable in the longitudinal direction of the negative electrode terminal portion 52 with respect to the inner peripheral side (the bent portion 32a side) of the film 62a. .

  Also, the film 62a covers the bending portion 32a so as not to restrict the deformation of the bending portion 32a. That is, the inner diameter of the cylindrically wound film 62a is larger than the width dimension and the thickness dimension of the bent portion 32a. Thus, the regulating member 62 has a predetermined gap with the bent portion 32 a in the thickness direction of the negative electrode terminal portion 52. The predetermined gap is a gap in which the bending portion 32a can be deformed in the longitudinal direction in the cylindrical restriction member 62 when the laminate type battery 1 is bent in the longitudinal direction.

  The fixing tape 62b has an adhesive layer on the surface. The fixing tape 62b can fix the winding end of the film 62a which is cylindrically wound so as to cover the bent portion 32a. Note that, instead of the fixing tape 62b, the winding end of the film 62a may be fixed by any method such as welding or bonding.

  With the above-described configuration, the bending portion 32a is not restricted in the movement and deformation in the longitudinal direction by the inner peripheral side of the film 62a wound in a cylindrical shape. Thus, as described above, even when the laminate type battery 1 is bent in the longitudinal direction, the bent portion 32 a can be deformed in the inward direction of the regulating member 62. Therefore, the restriction member 62 covers the bending portion 32a while allowing the deformation of the bending portion 32a.

  As shown in FIG. 5, when the laminate type battery 1 is bent in the longitudinal direction, the positive electrode 11 and the negative electrode 12 of the electrode assembly 10 move in the longitudinal direction (see open arrows in the figure). In particular, in the case of the present embodiment, the positive electrode 11 is provided with a positive electrode active material layer only on one side of the positive electrode current collector, and the negative electrode 12 is provided with a negative electrode active material layer only on one side of the negative electrode current collector. Therefore, when the laminate type battery 1 is bent in the longitudinal direction as described above, the positive electrode 11 and the negative electrode 12 easily move in the longitudinal direction.

  On the other hand, the movement of the negative electrode 12 of the electrode assembly 10 in the longitudinal direction can be restricted by providing the restriction member 62 in the negative electrode terminal 52 as described above.

  Moreover, in the case of the electrode body 10 of this embodiment, the negative electrode 12 is located in the outermost layer of the lamination direction. Therefore, as described above, by restricting the movement of the negative electrode 12 positioned in the outermost layer in the stacking direction of the electrode body 10 in the longitudinal direction by the restriction member 62, the negative electrode 12 is sandwiched in the stacking direction by the negative electrodes 12. The movement of the other negative electrode 12 and positive electrode 11 in the longitudinal direction can also be restricted. Therefore, the restriction member 62 can restrict the movement of the positive electrode 11 and the negative electrode 12 of the electrode assembly 10 in the longitudinal direction.

  In the present embodiment, the restriction member 62 is provided so as to cover the bending portion 32 a. Therefore, the outer diameter of the restricting member 62 is larger than the outer diameter of the restricting member when the restricting member is provided so as to cover the other portion of the negative electrode terminal portion 52. As a result, when the laminate type battery 1 is bent in the longitudinal direction, movement of the positive electrode 11 and the negative electrode 12 of the electrode assembly 10 in the axial direction can be more reliably restricted by the restriction member 62.

  Further, as described above, by providing the regulating member 62 so as to cover the bent portion 32a, the laminate type battery 1 can be extended in the longitudinal direction as compared with the case where the regulating member is provided at a position different from the bent portion 32a. It can be made compact.

  In addition, by forming the film 62 a of the regulating member 62 of a resin material having electrical insulation, the positive electrode terminal 51 and the negative electrode terminal 52 can be electrically insulated by the regulating member 62. In the laminate type battery 1 of the present embodiment, the distance between the positive electrode terminal portion 51 and the negative electrode terminal portion 52 is narrower than that of the laminate type battery of the general configuration. Therefore, when the laminate type battery 1 is bent in the longitudinal direction, the positive electrode terminal portion 51 and the negative electrode terminal portion 52 may approach or come into contact with each other to cause a short circuit. On the other hand, by covering a part of the negative electrode terminal portion 52 with the film 62a made of a resin material having electrical insulation, the occurrence of a short circuit between the positive electrode terminal portion 51 and the negative electrode terminal portion 52 is suppressed it can.

  Although the detailed description is omitted, the restricting member 61 covers the bent portion 31 a of the positive electrode connecting terminal 41 and the welded portion 51 a of the positive electrode connecting terminal 41 and the positive electrode connecting portion 31. It has the same configuration. Thereby, like the regulating member 62, when the laminate type battery 1 is bent in the longitudinal direction, the positive electrode of the electrode assembly 10 is allowed while allowing the bent portion 31a of the positive electrode connection portion 31 to move in the longitudinal direction. The restriction member 61 can restrict the movement of the portion 11 in the longitudinal direction. Moreover, the positive electrode terminal 51 and the negative electrode terminal 52 can be electrically insulated more reliably by the restriction member 61. In FIG. 4, reference numeral 61 a is a film, and reference numeral 61 b is a fixing tape.

(Other embodiments)
As mentioned above, although embodiment of this invention was described, embodiment mentioned above is only an illustration for implementing this invention. Therefore, without being limited to the embodiment described above, the embodiment described above can be appropriately modified and implemented without departing from the scope of the invention.

  In the said embodiment, one bending part 31a, 32a is provided in the positive electrode terminal part 51 and the negative electrode terminal part 52, respectively. However, a plurality of bent portions may be provided in each of the positive electrode terminal portion and the negative electrode terminal portion, and one or more bent portions may be provided in only one of the positive electrode terminal portion and the negative electrode terminal portion. It is also good.

  Moreover, the bending part may be provided in the positive electrode connection terminal, and may be provided in both the positive electrode connection part and the positive electrode connection terminal. In addition, the bent portion may be provided in the negative electrode connection terminal, or may be provided in both the negative electrode connection portion and the negative electrode connection terminal.

  In the embodiment, the regulating members 61 and 62 are provided on the positive electrode terminal 51 and the negative electrode terminal 52, respectively. However, the restriction member may be provided on only one of the positive electrode terminal portion 51 and the negative electrode terminal portion 52. In addition, it is preferable to provide a control member in the terminal part connected to the electrode located in the outermost layer of the lamination direction in an electrode body. In the case of the present embodiment, since the negative electrode is positioned at the outermost layer in the stacking direction of the electrode body, it is preferable to provide a regulating member at the negative electrode terminal portion.

  In the embodiment, the regulating members 61 and 62 are configured by fixing the winding end ends of the cylindrically wound films 61 a and 62 a with the fixing tapes 61 b and 62 b. However, at least a part of the bent portion of the terminal portion, such as a configuration in which the restriction member is integrally formed in a tubular shape by resin, or a configuration in which the winding end of the film wound in a tubular shape is not fixed. Any configuration may be used as long as it can be covered.

  In the embodiment, the restriction members 61 and 62 are made of a resin material having electrical insulation. However, the restricting member may be a material capable of restricting the movement of the positive electrode and the negative electrode of the electrode body in the longitudinal direction while allowing deformation of the bent portion when the laminate type battery is bent in the longitudinal direction. For example, it may be made of any material. However, the control member needs to be made of a material that can withstand the non-aqueous electrolyte.

  In the embodiment, the restriction members 61 and 62 are cylindrical. However, when the laminate type battery 1 is bent in the longitudinal direction, the restricting member has a shape capable of restricting the movement of the positive electrode and the negative electrode of the electrode body in the longitudinal direction while allowing deformation of the bent portion. For example, any shape such as a C-shaped cross section may be used.

  When the regulating member has a shape other than a cylindrical shape, a part of the regulating member may be fixed to the positive electrode terminal portion or the negative electrode terminal portion so that the regulating member is not separated from the positive electrode terminal portion and the negative electrode terminal portion. preferable. In addition, when the positive electrode terminal portion and the negative electrode terminal portion extend in one direction from the electrode body, it is preferable that the restricting member be disposed so that at least a part is located between the positive electrode terminal portion and the negative electrode terminal portion. .

  In the embodiment, the negative electrode 12 is disposed at the outermost layer in the stacking direction of the electrode body 10. However, the positive electrode may be disposed in the outermost layer in the stacking direction of the electrode assembly. As described above, when the positive electrode is disposed in the outermost layer in the stacking direction of the electrode body, when the laminate type battery 1 is bent in the longitudinal direction by providing the restriction member so as to cover the positive electrode terminal portion, The movement of the positive electrode and the negative electrode of the electrode assembly in the longitudinal direction can be restricted.

  In the embodiment, the positive electrode terminal portion 51 and the negative electrode terminal portion 52 extend in one direction from the electrode body 10. However, the positive electrode terminal portion and the negative electrode terminal portion may extend in different directions from the electrode body. In addition, the laminate type battery may have a plurality of positive electrode terminal portions and a plurality of negative electrode terminal portions. That is, the laminate type battery may have a plurality of terminal portions extending outward from the electrode body.

  In the embodiment, the positive electrode active material layer is provided on one side of the positive electrode current collector of the positive electrode 11, and the negative electrode active material layer is provided on one side of the negative electrode current collector of the negative electrode 12. However, the positive electrode active material layer may be provided on both sides of the positive electrode current collector. Further, the negative electrode active material layer may be provided on both sides of the negative electrode current collector.

  In the embodiment, the laminate type battery 1 is formed in a rectangular shape in plan view. However, the laminate type battery may have other shapes such as a polygonal shape.

  In the embodiment, the laminate type battery 1 is a lithium ion battery. However, the laminate type battery 1 may be a battery other than a lithium ion battery. Further, the configuration of the embodiment may be applied to an electrochemical device including not only the laminate type battery 1 but also a capacitor and the like. That is, the configuration of the embodiment can be applied to a thin electrochemical element capable of storing electricity or generating electricity and capable of bending and deforming.

  The present invention is applicable to an electrochemical device in which an electrode body is covered by a laminate film outer package.

DESCRIPTION OF SYMBOLS 1 laminated type battery 10 electrode body 11 positive electrode 12 negative electrode 13 separator 20 laminate film exterior body 31 positive electrode connecting portion 31 a bent portion 31 b first bent portion 31 c second bent portion 32 negative electrode connecting portion 32 a bent portion 32 b first bent Curved portion 32c Second bent portion 41 Positive electrode connection terminal 42 Negative electrode connection terminal 45 Positive electrode side resin portion 46 Negative electrode side resin portion 51 Positive electrode terminal portion 52 Negative electrode terminal portion 61, 62 Regulating member 61a Film (moving allowance portion, film member)
61b fixed tape

Claims (9)

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 while covering the electrode body;
A plurality of plate-like terminal portions electrically connected to the electrode body and extending outward from the electrode body to the laminated film sheath;
A restricting member that restricts movement of at least a part of the positive electrode and the negative electrode in the electrode body in the longitudinal direction of the terminal portion;
Equipped with
The plurality of terminal portions are respectively
A connection portion integrally formed with the electrode body and positioned inward of the laminate film outer package;
A connection terminal connected to the connection portion and extending outward from the inner side of the laminate film outer package;
Have
At least one terminal portion of the plurality of terminal portions has a bent portion turned back at least twice in the longitudinal direction so as to overlap in the thickness direction inside the laminate film outer package,
The regulating member is configured to allow the bent portion to be deformed in the longitudinal direction while restricting at least a part of the positive electrode and the negative electrode from moving in the longitudinal direction. An electrochemical element covering at least a part. In the electrochemical device according to claim 1,
The electrochemical element according to claim 1, wherein the restricting member has a movement permitting portion which allows the bent portion to relatively move in the longitudinal direction on the bent portion side. In the electrochemical device according to claim 2,
The electrochemical element according to claim 1, wherein the movement permitting portion is constituted by a film member having no adhesive layer on the surface. In the electrochemical device according to any one of claims 1 to 3,
The electrochemical device, wherein the restriction member has a predetermined gap with the bent portion in the thickness direction. In the electrochemical device according to any one of claims 1 to 4,
The plurality of terminal portions extend in one direction from the electrode body, and
The restriction member is made of an electrically insulating material, covers at least a part of the bent portion, and a terminal portion provided with the bent portion among the plurality of terminal portions, and the terminal portion An electrochemical element located between the terminal and the adjacent terminal part. In the electrochemical device according to claim 5,
The electrochemical element according to claim 1, wherein the restriction member has an annular shape covering the bent portion. In the electrochemical device according to any one of claims 1 to 6,
The said bending part is an electrochemical element provided in the said connection part. In the electrochemical device according to any one of claims 1 to 7,
The connection portion and the connection terminal are connected by a welding portion,
The electrochemical element covers the bending portion and the welding portion. The electrochemical device according to any one of claims 1 to 8.
Each of the positive electrode and the negative electrode has a current collector,
At least one of the said positive electrode and the said negative electrode is an electrochemical element by which the active material layer is provided in the single side | surface of the said collector.

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