JP5910888B2 - Sealed battery - Google Patents

Description

  The present invention relates to a sealed battery, and more particularly to a sealed battery provided with a current interruption mechanism.

  In recent years, lithium-ion secondary batteries, nickel-metal hydride batteries, and other secondary batteries have become increasingly important as power sources mounted on vehicles using electricity as a drive source, or power sources mounted on personal computers, portable terminals, and other electrical products. ing. As a typical structure of such a secondary battery, a battery (sealed battery) having a sealed structure in which an electrode body, which is a power generation element, is sealed in a battery case. Such a sealed battery is generally used in a state where it is controlled so as to be within a predetermined voltage range (for example, 3.0 V or more and 4.2 V or less). It is assumed that an overcharged state is exceeded by exceeding a predetermined voltage. At the time of such overcharge, there is a possibility that problems such as decomposition of the electrolyte and generation of gas in the battery case, or increase in the temperature of the battery due to heat generation of the active material may occur. Therefore, in order to prevent such a problem, a battery provided with a mechanism (current interruption mechanism: CID) that interrupts current when an overcharged state is detected by battery temperature, battery internal pressure, or the like has been proposed. .

  Such a current interruption mechanism is typically disposed in a conductive path between the external connection terminal in the sealed battery and the electrode body accommodated in the case body of the battery case. In general, in consideration of the battery configuration, assembling workability, and the like, the battery case is integrated and disposed inside the lid of the battery case of the sealed battery. Further, various current blocking mechanisms have been proposed, but essentially include a reversing part and an easily breakable part. The reversal part and the easily breakable part are typically formed as a part of the deformable member and the current collector, respectively. Usually, the deformable member and the current collector are formed at the reversal part and the easily breakable part. It is mechanically and electrically connected by welding or the like. The deformable member is typically electrically connected to an external connection terminal via a lead member, and when the pressure in the battery case rises, the reversing portion of the deformable member is displaced outward from the battery case. It is configured. The current collector is typically electrically connected to an electrode body that is a power generation element, and is configured such that the easily breakable portion is easily broken when a certain stress is applied. Therefore, for example, when the internal pressure of the battery rises in an overcurrent state and the reversing part is displaced, the easily breakable part of the current collector is broken and separated from the current collector, so that the conductivity between the deformable member and the current collector is reduced. The route is blocked.

  In a sealed battery equipped with such a current interrupting mechanism, there is a concern that the current interrupting mechanism may malfunction due to vibration or impact generated in a battery-equipped device or the like, and vibration or impact is not transmitted to the current interrupting mechanism. Ingenuity is given. In particular, for sealed batteries for automobiles and the like, the frequency of occurrence of such vibrations and impacts is high, and the vibrations and impacts are expected to be large. It is required to be surely prevented. Therefore, for example, in Patent Document 1, after the current collector and the deformable member are supported by the current collector holder in a state in which impact and vibration are suppressed from being applied to the joint portion between the easily breakable portion and the reversing portion, A configuration is disclosed in which the current collector holder is fixed to a lid body by fitting the current collector holder to an insulating plate.

JP 2008-066254 A JP 2010-277936 A

  However, in the technique described in Patent Document 1, it is possible to suppress the vibration from being applied to the joint portion between the easily breakable portion and the reversing portion, but the configuration is likely to generate vibration in other portions. For example, in the configuration disclosed in Patent Document 1, there may be a gap in the fitting portion between the current collector holder and the insulating plate due to a manufacturing error or the like, and when such a gap occurs, the current collector holder itself May easily vibrate and the current interrupting mechanism may malfunction. In addition, since the current collector holder and the insulating plate are generally made of a resin material and also have a function of holding the electrode body, it is necessary when sufficient strength (tensile strength) cannot be obtained. There was a risk of loosening or breakage of the fitting portion.

  The present invention has been created in view of such a conventional situation, and an object of the present invention is to combine a current collector and a current collector holder so as to suppress vibration and shock from being applied to the current interrupting mechanism. And providing a sealed battery in which sufficient mechanical strength (for example, tensile strength) is ensured in the joint portion.

  In order to solve the above problems, the sealed battery provided by the present invention includes an electrode body, a battery case that houses the electrode body, an external connection terminal that protrudes outward from the battery case, and the battery case. A current collector that is housed in the electrode body and is electrically connected to the electrode body, and a conductive path that electrically connects the external connection terminal and the current collector, and can block the conductive path. A current interrupting mechanism; and a current collector holder made of an insulating material, disposed on the inner surface of the battery case, and provided with a fixing portion for fixing the current collector. In such a sealed battery, the fixing portion of the current collector holder includes a shaft portion projecting inward of the battery case, and a tip of the shaft portion in a direction perpendicular to the shaft rather than the shaft portion. And a head having a large size. Further, the current collector is provided with a hole through which the shaft portion of the fixed portion of the current collector holder passes, and the current collector holder is provided from the outer surface of the battery case to the inside of the shaft portion. A recess is provided for intrusion. And here, the battery case has a projection that fits into the recess of the current collector holder, and the projection of the battery case and the recess of the current collector holder are fitted together. In addition, the shaft portion of the current collector holder penetrates the hole of the current collector, and the head locks the current collector.

The present inventors have found that by adopting a heat caulking process using a rivet structure for a configuration for fixing peripheral members of the current interrupting mechanism, it is possible to suppress vibration and impact from being applied to the current interrupting mechanism. For example, specifically, as shown in FIG. 9, a lead member and a deformable member are arranged in the current collector holder, and the current collector is placed on the current collector in a state where the current collector is mounted thereon. These members are integrated by caulking with a holder. Here, the caulking is performed by passing the fixing portion of the current collector holder through the hole provided in the current collector and pressing the hot plate against the tip of the fixing portion (so-called heat caulking process). Thus, a head portion is formed along the outer surface of the current collector by the melted portion of the fixed portion, and the current collector is locked by the head portion.
However, in such a configuration, when the heat is transmitted only to the vicinity of the contact portion of the hot plate in the fixing portion of the current collector holder, for example, the fixing portion of the current collector holder is formed as shown in FIG. 10A. There was a possibility that an unmelted portion X was generated between the head and the head. When such an unmelted portion X is generated, the remaining thickness of the current collector holder indicated by t1 in FIG. 10A is reduced, and the strength sufficient to fix the current collector and the electrode body to the lid (both heat caulking strength) Could not be obtained.
Therefore, in order to prevent the occurrence of the unmelted portion X, for example, as shown in FIG. 10B, a convex portion T is formed at the periphery of the hole portion of the current collector, and the current collector is also heated during the heat caulking process. Thus, it is also possible to prevent the generation of the unmelted portion X by securing the heat entering the unmelted portion X. However, even in such a case, the remaining thickness of the current collector holder indicated by t2 in FIG. 10B is lowered, and there is a possibility that sufficient heat caulking strength of the current collector holder cannot be obtained. Further, when the remaining thickness t2 of the current collector holder is increased in order to secure the heat caulking strength, the thickness of the head protruding from the current collector surface increases, and the electrode body in the battery case is relatively accommodated. Space is getting smaller.

According to the configuration of the present invention, the current collector holder is provided with the concave portion that is recessed from the outer surface of the battery case into the shaft portion, and is in a so-called thinned state. In addition, the battery case (typically, the lid) has a protrusion that fits into the recess of the current collector holder, and the protrusion of the battery case and the recess of the current collector holder fit into each other. Has been. Therefore, in the heat caulking process, the fixing portion of the current collector holder can be heated not only from the tip but also from the inside through the protrusion. Therefore, the current collector holder is not only heated and melted from the current collector holder side by the hot plate, but also from the battery case side (typically the lid side), that is, the back surface side, for example, through the protrusion. It is possible to input heat into the water and prevent the unmelted portion from occurring. Thereby, the remaining height can be formed so as to coincide with the thickness of the head of the current collector holder, and the tensile strength in the thickness direction of the head, that is, the caulking portion having sufficient heat caulking strength is provided. It becomes possible to form. As a result, even a current collector that supports the electrode body can be firmly fixed to the battery case for a long period of time. In addition, by fitting the protrusion of the battery case (lid) and the recess of the current collector holder, positioning when fixing the electric holder and the battery case can be performed accurately and easily.
Further, the shaft portion of the current collector holder passes through the hole of the current collector, and the head of the current collector holder locks the current collector, so that each member can be fixed without generating a gap. Can do. Thereby, it can suppress that a vibration and an impact are added to an electric current interruption mechanism.

  Conventionally, in the configuration of a sealed battery, as a method for hermetically sealing the electrolyte injection hole provided in the lid of the battery case, a packing is provided for the injection hole after the electrolyte is injected. There is known a configuration in which the blind rivet is caulked through (see, for example, Patent Document 2). However, in such a caulking structure, since the blind rivet is made of a metal material, in addition to being essentially excellent in thermal conductivity, it has high strength and is not melted by heat caulking. The problem of the occurrence of the part and the problem of the lack of tensile strength hardly occur. Further, the present invention is not applied when fixing a member such as a current collector that supports a heavy object such as an electrode body, and may be essentially different from the configuration of the present application.

In a preferred embodiment of the sealed battery of the present invention, at least the protrusion of the battery case is made of a metal material.
The protrusion is preferably made of a material having excellent heat conductivity in order to increase the heat conduction efficiency to the unmelted portion, and more preferably made of a high strength material, for example. Therefore, it is preferable that this protrusion part is comprised from various metal materials (an intermetallic compound, an alloy, etc. are included), for example. Thereby, generation | occurrence | production of an unmelted part can be prevented more reliably, and the attachment structure of the high intensity | strength electric current interruption mechanism is implement | achieved.

In a preferred embodiment of the sealed battery of the present invention, at least the shaft portion and the head portion of the current collector holder are made of a thermoplastic resin.
For example, a material that melts or softens by heating and solidifies by cooling can be preferably used for at least the shaft and the head of the current collector holder to which the above heat caulking treatment is performed. In the present invention, for example, various thermoplastic resins can be preferably used. Thereby, it becomes possible to simply configure the sealed battery using a thermoplastic resin that can be softened and melted reversibly.

In a preferred embodiment of the sealed battery of the present invention, the surface from the shaft portion to the head portion of the fixed portion of the current collector holder is a surface from the hole portion of the current collector to the inner surface of the battery case. It is characterized by being formed along.
In the heat caulking process in the sealed battery having the above-described configuration, the fixing portion of the current collector holder can be heated not only from the tip but also from the back side through the protrusion, and the occurrence of an unmelted portion can be prevented. Therefore, an indented portion due to an unmelted portion is not formed on the surface from the shaft portion to the head portion of the fixed portion of the current collector holder. As a result, the heat caulking strength (tensile strength in the thickness direction of the head portion of the fixing portion) does not decrease, the strength in the axial direction of the fixing portion of the current collector holder is improved, and the current collector holder and the current collector A sealed battery is provided in which the body is firmly bonded.

In a preferred embodiment of the sealed battery of the present invention, the opening of the current collector hole on the inner side of the battery case is chamfered, and from the shaft portion of the fixed portion of the current collector holder. The surface reaching the head is formed along the chamfered surface.
According to said structure, since the opening part of the battery case inner side of the hole part of a collector is chamfered, the head part of the fixing part of the collector holder formed along this is a shaft part. The thickness increases as it approaches. Thereby, the heat caulking strength is further increased, the axial strength of the fixing portion of the current collector holder is improved, and a sealed battery in which the current collector holder and the current collector are firmly coupled is provided. The

In a preferred embodiment of the sealed battery of the present invention, the opening on the battery case inner side of the hole of the current collector is a locking step that receives the head of the fixed part of the current collector holder. A surface extending from the shaft portion to the head portion of the fixing portion of the current collector holder is formed along the locking step portion, and a battery case inner surface of the current collector And the said head of the fixing | fixed part of the said collector holder is characterized by being flush.
According to this configuration, the head of the current collector holder is formed so as to be embedded in the current collector. Therefore, the head of the current collector holder does not protrude from the current collector, and it is possible to secure more space for accommodating the electrode body in the battery case. Thereby, for example, the electrode body accommodated in the battery case can be further increased in size, and the battery capacity can be increased.

In a preferred embodiment of the sealed battery of the present invention, the thickness in the axial direction of the head of the fixed portion of the current collector holder, the thickness in the vicinity of the boundary between the shaft and the head is It is characterized by being 1/2 or more of the axial length of the shaft portion.
According to such a configuration, the axial thickness of the head portion of the fixing portion of the current collector holder can be secured, and the tensile strength in the axial direction can be sufficiently increased. As described above, the heat caulking strength between the current collector holder and the current collector is improved, so that even when a large electrode body is joined by the current collector, the electrode body on which the current collector is applied is a battery. It is possible to reliably hold it at a predetermined position in the case.

In a preferred embodiment of the sealed battery of the present invention, the protruding portion of the battery case has a tip that is 2/3 or more of the axial length of the shaft portion from the base end of the shaft portion of the current collector holder. It is characterized by the length to reach the position.
According to such a configuration, it is possible to more reliably input heat through the protrusion even in a place where an unmelted portion of the fixed portion of the current collector holder is likely to occur. Therefore, the occurrence of the unmelted portion can be prevented in advance, and a caulking portion having sufficient heat caulking strength can be formed.

In a preferred embodiment of the sealed battery of the present invention, the head portion of the fixed portion of the current collector holder is formed by melting a member that is in an axially extended position of the shaft portion by a heat caulking process. It is characterized by.
The head of the fixed part of the current collector holder in the sealed battery of the present invention can exhibit the same effects as described above regardless of the manufacturing method as long as any of the above-described forms is realized. However, such a head can be suitably formed by a heat caulking process, and an effect peculiar to such a process that generation of an unmelted portion can be prevented when forming by a heat caulking process can be exhibited. Therefore, in the case where the head of the fixed portion of the current collector holder is formed by heat caulking, the configuration of the present invention is preferable because it can work more effectively.

In a preferred embodiment of the sealed battery of the present invention, the protrusion of the battery case and the recess of the current collector holder are fitted by press-fitting.
As long as the protrusion part of a battery case and the recessed part of a collector holder are mutually fitted, there is no restriction | limiting in particular in the form of fitting.
However, for example, when the size of the concave portion of the current collector holder is slightly smaller than the size of the protruding portion of the battery case, these can be fitted by press fitting, and both of them can be fitted by such fitting. Can be integrated. Thereby, in manufacture of a sealed battery, it becomes possible to fix a battery case and a collector holder easily.

  The sealed battery as described above, for example, can prevent propagation of vibration and shock to the current interruption mechanism even when vibration or impact is applied to the battery. The possibility can be provided as a highly safe and reliable one. Accordingly, the sealed battery disclosed herein can be suitably used as a power source for driving a vehicle or the like used for movement or transportation of people or articles, in particular, a hybrid vehicle in which a large electrode body can be disposed, Furthermore, it is preferably used as a battery for a vehicle drive power supply mounted on a vehicle such as a plug-in hybrid vehicle or an electric vehicle having a high level required for capacity (for example, 3 to 30 Ah, more specifically 10 to 30 Ah). Can do.

It is a schematic perspective view of the sealed battery which concerns on one Embodiment. It is the cross-sectional schematic diagram along the II-II cross section of FIG. 1, Comprising: It is the figure which illustrated the state before the electric current interruption mechanism of a sealed battery act | operates. It is a schematic diagram explaining the structure of the electrode body with which the sealed battery which concerns on one Embodiment is equipped. It is a principal part disassembled perspective view of the periphery of the electric current interruption mechanism of the sealed battery of FIG. It is the figure which illustrated the A-A 'cross section in FIG. 4A, and the B-B' cross section of the same structure as this. 4A is a partially enlarged view of FIG. 4A, (a) is a P view of the lid, (b) is an enlarged view of the current collector holder, and (c) is an enlarged view of the current collector. FIG. It is the figure which illustrated a mode that the electrical power collector in a sealed battery was fixed to the electrical power collector holder by heat caulking process. FIG. 6B is a schematic cross-sectional view illustrating a state of fixing the current collector and the current collector holder that have been heat-caulked in FIG. 6A. It is the cross-sectional schematic diagram which illustrated the mode of the cover body, the collector holder, and the collector before the heat-caulking process in one Embodiment. It is the cross-sectional schematic diagram which illustrated the mode of the cover body, the collector holder, and the collector in the middle of the heat crimping process in one Embodiment. It is the cross-sectional schematic diagram which illustrated the mode of the cover body, the collector holder, and the collector in the middle of the heat crimping process in one Embodiment. It is the cross-sectional schematic diagram which illustrated the mode of the cover body, the collector holder, and the collector after the heat crimping process in one Embodiment. It is the cross-sectional schematic diagram which showed an example of the heat caulking process structure of a cover body, a collector holder, and a collector. It is the cross-sectional schematic diagram which showed another example of the heat caulking process structure of a cover body, a collector holder, and a collector. It is the cross-sectional schematic diagram which showed another example of the heat caulking process structure of a cover body, a collector holder, and a collector. It is the cross-sectional schematic diagram which showed an example of the heat caulking process structure of the cover body by the prior art, a collector collector, and a collector. It is the cross-sectional schematic diagram which showed an example of the heat-caulking process structure of the collector holder and collector by a prior art. It is the cross-sectional schematic diagram which showed another example of the heat-caulking process structure of the collector holder and collector by a prior art.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings, and the invention disclosed herein will be described in detail. In addition, in the following drawings, the same code | symbol is attached | subjected to the member and site | part which show the same effect | action, and the overlapping description may be abbreviate | omitted or simplified. Moreover, the dimensional relationship (length, width, thickness, etc.) in each drawing does not necessarily reflect the actual dimensional relationship. In particular, the relative dimensions of the lid, the current collector holder, and the current collector, the dimensional relationship of each part, and the like are shown as examples for explaining the configuration according to the present invention. The invention is not limited to the examples specifically shown in the drawings, and various aspects can be considered. Further, matters other than matters specifically mentioned in the present specification and necessary for the implementation of the present invention can be grasped as design matters for those skilled in the art based on the prior art in this field.

  Hereinafter, a lithium secondary battery will be described as a preferred embodiment related to the sealed battery disclosed herein, but the application target of the present invention is not intended to be limited to such a battery. In this specification, the “battery” is a term indicating a general power storage device that can take out electric energy, and includes a primary battery, a secondary battery, and the like. That is, “secondary battery” refers to lithium ion secondary batteries, metallic lithium secondary batteries, sodium secondary batteries, nickel metal hydride batteries, nickel cadmium batteries and other so-called storage batteries (so-called chemical batteries), as well as electric double layer capacitors. Such a capacitor (so-called physical battery) is also included. The technology disclosed herein can be preferably applied to a sealed secondary battery typically.

  FIG. 1 is a schematic perspective view of the lithium ion secondary battery according to the first embodiment, and FIG. 2 is a schematic cross-sectional view taken along the line II-II in FIG. 1 before the current interrupting mechanism operates. It is a figure which shows a state. FIG. 3 is a diagram illustrating the configuration of the electrode body 50 shown in FIG.

  As shown in FIGS. 1 and 2, the sealed battery 1 according to this embodiment typically has a predetermined battery constituent material (active for each positive and negative current collector), like a conventional general lithium ion secondary battery. A wound electrode body 50 including a positive electrode and a negative electrode on which substances are held, a separator, and the like is housed in a battery case 10 together with an appropriate electrolytic solution (not shown). In this embodiment, the sealed battery 1 is a square battery, but the shape of the battery is not limited to a square shape, and may be any shape such as a cylindrical shape or a laminated bag shape. In addition, the electrode body 50 is not limited to the wound electrode body 50, and may be a stacked electrode body 50, for example.

Further, the configurations of the electrode body 50 and the electrolyte solution of the sealed battery 1 are not particularly described because they do not characterize the present invention. However, based on the common general knowledge of those skilled in the art, an appropriate one according to the purpose and application is used. Can be selected and adopted.
For example, as shown in FIG. 3, the electrode body 50 includes a positive electrode sheet 52 having a positive electrode active material layer on a positive electrode current collector foil, and a negative electrode sheet 54 having a negative electrode active material layer on a negative electrode current collector foil. The wound electrode body 50 can be formed by being laminated and wound while being insulated from each other by the two separators 56. Here, when the positive electrode sheet 52, the negative electrode sheet 54, and the separator 56 are laminated, the exposed portion where the positive electrode current collector foil is not provided without the positive electrode active material layer protrudes to one end, and the negative electrode active material layer is not provided. The exposed portion where the negative electrode current collector foil is exposed is overlapped in a state of protruding to the other end portion and wound, whereby the positive electrode current collector foil is provided at one end portion of the electrode body 50 and the negative electrode is provided at the other end portion. The current collector foil can be projected in a spiral shape. The wound electrode body 50 may be flattened in accordance with the shape of the battery case 10. The cathode current collector 40 is welded to the cathode current collector foil protruding at one end of the electrode body 50 formed in this way, and the anode current collector 90 is welded to the anode current collector foil protruding at the other end. Thus, the electric power generated in the electrode body 50 can be taken out by the external connection terminals 110 and 120, and the electrode body 50 can be positioned in the battery case 10.

Moreover, as electrolyte solution, it can select from the various electrolyte solution used for this kind of general sealed battery 1, and can use it suitably. For example, a lithium secondary battery includes a lithium salt as a supporting salt in an organic solvent (non-aqueous solvent). As such an electrolytic solution, a nonaqueous electrolyte (that is, an electrolytic solution) that is liquid at room temperature can be preferably used. Examples of the lithium salt include LiPF ₆ , LiBF ₄ , LiClO ₄ , LiAsF ₆ , Li (CF ₃ SO ₂ ) ₂ N, LiCF ₃ SO _{3 and the} like. These supporting salts can be used alone or in combination of two or more. A particularly preferred example is LiPF ₆ . Examples of the non-aqueous solvent include carbonates such as ethylene carbonate (EC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), and propylene carbonate (PC). These organic solvents can be used alone or in combination of two or more. Various additives represented by gas generating additives, film forming additives, and the like may be added to the nonaqueous electrolyte as necessary.

  In the present embodiment, the battery case 10 includes a case main body 18 in a form in which one surface (upper surface in FIG. 1) having a rectangular parallelepiped box shape is opened, and a rectangular plate-like lid body 12 that closes the opening. Yes. In addition, as a material which comprises the battery case 10, comparatively lightweight aluminum and aluminum alloy can generally be used. However, the battery case 10 is not limited to this, and for example, the same material as that used in the conventional lithium ion secondary battery can be used. Specifically, for example, a metal material such as steel, or a resin material such as polyphenylene sulfide (PPS) or polyimide resin can be used. Further, the lid body 12 includes a positive external connection terminal 110 electrically connected to the positive electrode 52 of the electrode body 50 and a negative external connection terminal 120 electrically connected to the negative electrode 54 of the electrode body 50. It is provided so as to protrude outward (upper side in the figure) of the case 10. The lid body 12 is further provided with a liquid injection plug 130 and a safety valve 140 for sealing the electrolyte inlet.

Inside the battery case 10 is provided a current interrupt mechanism 30 that is activated by an increase in the internal pressure of the case. In the example of this figure, the current interrupting mechanism 30 is disposed in a conductive path that electrically connects the positive external connection terminal 110 and the positive electrode 52 of the electrode body 50. FIG. 4A is an exploded perspective view illustrating a configuration of a conductive path from positive external connection terminal 110 to current collector (positive electrode current collector 40).
110 in the figure is a positive external terminal as described above, and is formed so as to protrude outward from the battery case 10. Reference numeral 70 denotes a positive electrode external connection terminal retainer, which has a hole through which the positive electrode external terminal passes. The positive external connection terminal presser 70 fixes the positive external connection terminal 110 to the outside of the lid 12 of the battery case 10 and forms a conductive path between the positive external connection terminal 110 and the current interrupt mechanism.

Reference numeral 60 denotes an external insulating member, which is a member that insulates the positive electrode external connection terminal 110 and the presser 70 from the lid body 12. The external insulating member 60 is generally made of a resin material.
12 is a lid as described above, and seals the opening of the case body 18 of the battery case 10. The lid 12 has positive and negative electrodes 52 and 54 of the electrode body 50 housed inside the battery case 10,
A hole 16 for forming a conductive path between the external connection terminals 110 and 120 formed outside the battery case 10 is provided.

  Reference numeral 20 denotes a current collector holder that is disposed on the inner surface side of the battery case 10 of the lid body 12 (hereinafter simply referred to as “inner surface side”). The current collector holder 20 is made of an insulating material and is generally made of a resin material. The current collector holder 20 holds the current collector 40 while accommodating a lead member 32 and a deformable member 32 to be described later. A rising portion having a shape corresponding to the hole 16 of the lid 12 is provided, and the lead member 32, the deformable member 32, and the current collector 40 are insulated from the lid 12 by the rising portion.

  Reference numeral 32 denotes a lead member, which is made of a conductive material such as a metal material. The lead member 32 has a lead body that secures a space where a deformable member 34 described later can be reversed, and a cylindrical portion that extends from the lead body toward the outside of the battery case (upward in FIG. 4A). Such a cylindrical portion passes through holes provided so as to correspond to each of the positive electrode external connection terminal retainer 70, the external insulating member 60, the lid 12 and the current collector holder 20, and is caulked at the tip portion thereof. Thus, these members can be tightly fixed in a sandwiched state. With this configuration, the deformable member 32 and the positive external connection terminal 110 (presser 70) are electrically connected. In FIG. 4A, the lead member (cylindrical portion) 32 shows a shape after caulking.

  Reference numeral 34 denotes a deformable member, which has a reversing portion 36 at its central portion that can be displaced outward from the battery case 10 when the internal pressure of the battery case 10 exceeds a predetermined pressure. The reversing unit 36 is configured to reliably receive the rising pressure in the battery case 10 and easily reverse when the case internal pressure exceeds a certain pressure. Therefore, the deformable member 34 is airtightly joined to the lead body of the lead member 32 at the peripheral edge by welding or the like, for example, and blocks gas flow between the inside and the outside of the battery case 10. The deformable member 34 is formed of a conductive material such as metal in order to form a conductive path when a normal battery is used. The reversing part 36 is typically formed so as to protrude toward an easily breakable part 46 of a current collector 40 to be described later.

  Reference numeral 40 denotes a current collector (positive electrode current collector), which is disposed inward of the battery case 10 with respect to the deformable member 34 and is electrically connected to the positive electrode 52 of the electrode body 50. And it has the easily breakable part 46 made easy to fracture | rupture in the vicinity of the center of the site | part hold | maintained at the collector holder 20. FIG. Further, the deformable member 34 and the current collector 40 are electrically and mechanically joined at the reversing portion 36 and the easily breakable portion 46, respectively. Here, the joining between the inversion part 36 and the easily breakable part 46 can be suitably performed by welding (for example, laser welding, spot welding, etc.), and the two are firmly joined to each other. Thus, the current interrupt mechanism 30 is configured to include at least the deformable member 34 and the current collector 40 as constituent members.

Hereinafter, the connection form of the lid 12, the current collector holder 20, and the current collector 40, which is characteristic in the present invention, will be described in more detail. 4B is an AA ′ section and a BB ′ section in FIG. 4A. FIG. 5A is a P view when the lid 12 is viewed from the direction of the arrow indicated by the symbol P in FIG. 4A.
In this embodiment, as shown in FIG. 4B and FIG. 5A, the lid 12 is 4 at a position corresponding to the apex of a substantially square at the periphery of the hole 16 for forming a conductive path on the inner surface side. There are two protrusions 14 (14a to 14d). The protrusions 14 (14a to 14d) are used when the lid 12 and the current collector holder 20 are fitted together. The protrusions 14 (14a to 14d) correspond to the back side of the heat-caulking structure (in this figure, the outer side of the battery case 10) in the heat caulking process between the current collector holder 20 and the current collector 40 described later. Used for effective heat input to the caulking portion. Such heat input from the back surface side can prevent the occurrence of an unmelted portion in the caulking portion of the current collector holder 20. Although the length of the protrusion 14 depends on the material of the current collector holder 20 and the design dimensions of each part, the length of the protrusion 14 cannot be generally specified. However, as a rough guide, the tip of the protrusion 14 is a shaft of the current collector holder 20 described later. The length is preferably 2/3 or more, for example, 4/5 or more of the axial length of the shaft portion 24 from the base end of the portion 24. Since the protrusion 14 has such a length, the melting failure of the portion from the shaft portion 24 to the head portion 26 of the fixed portion 22 of the current collector holder 20 where the unmelted portion is likely to occur is eliminated, and the current collector holder Good welding between the 20 crimped portions and the current collector 40 can be realized. Although the material of the lid 12 is not specifically limited, it is preferable that at least the protrusions 14 are made of a highly conductive metal material typified by aluminum and an aluminum alloy.

  As shown in FIG. 5B, the current collector holder 20 has a fixing portion 22 for fixing the current collector 20 from the main body of the current collector holder 20 toward the inner side of the battery case 10. It is provided to protrude. In the example of FIG. 5B, the fixing portion 22 (22a to 22d) is formed at a position corresponding to the protrusion 14 (14a to 14d) of the lid. Further, in the sealed battery 1 after assembly, the fixed portion 22 (22a to 22d) includes a shaft portion 24 (24a to 24d) that protrudes inward of the battery case 10 and the shaft portion 24 (24a to 24d). ) At the tip of the head portion 26 (see FIG. 6B, etc.) having a larger dimension in the direction perpendicular to the shaft than the shaft portion 24 (24a to 24d). Further, the surface of the current collector holder 20 located on the outer side of the battery case 10 is provided with recesses 28 (28a to 28d) that are recessed into the shafts 24 (24a to 24d). .

  In the present invention, the head portion 26 can typically be formed by a heat caulking process. In order to more suitably perform the heat caulking process and more reliably weld the current collector holder 20 and the current collector 40, at least the shaft portion 24 and the head portion 26 of the current collector holder 20 are made of a thermoplastic resin. It is preferable that it is comprised by these. Further, the thickness in the axial direction of the head portion 26, and the thickness in the vicinity of the boundary portion between the shaft portion 24 and the head portion 26 is ½ or more of the axial length of the shaft portion 24, for example, 3 / 5 or more is preferable. By setting the head portion 26 to such a thickness, it is possible to sufficiently ensure the tensile strength in the axial direction at the joint between the current collector holder 20 and the current collector 40. Thereby, for example, even when vibration or impact is applied to the sealed battery 1 while the current collector 40 supports the electrode body 50 having a large capacity, the current holder 20 and the current collector 40 It is possible to prevent problems such as breakage and occurrence of cracks at the joints.

  On the other hand, in the sealed battery 1 before assembly, the fixing portion 22 is typically formed with a shaft portion 24 and a head portion so as to protrude from the main body of the current collector holder 20 toward the inside of the battery case 10. Member 26 '(26'a-26'd) is provided. The head forming member 26 ′ is melted by a heat caulking process to form the head 26. The shaft portion 24 and the head forming member 26 ′ are typically formed continuously with no difference in dimension in a direction orthogonal to the shaft.

  For example, as shown in FIG. 5C, the current collector 40 typically has a fixed portion to which the current collector holder 20 is fixed, and extends from the fixed portion to the inside of the battery case 10. It is comprised from the electrode part 50 and the arm part joined. Near the center of the fixed portion, an easily breakable portion 46 that is easily broken by a predetermined pressure is formed. Further, at the periphery of the fixed portion, the hole portion 42 (42a) is provided at a position corresponding to the shaft portion 24 (24a to 24d) and the head forming member 26 '(26'a to 26'd) of the current collector holder 20. To 42d).

The lid body 12 and the current collector holder 20 are integrated with each other by fitting the protrusions 14 (14a to 14d) of the lid body 12 with the recesses 28 (28a to 28d) of the current collector holder 20. It has become. Since the protrusion 14 (14a to 14d) of the lid 12 and the recess 28 (28a to 28d) of the current collector holder 20 are formed in advance, the lid 12 and the current collector holder 20 can be joined. Positioning can be performed accurately and easily.
Here, the cross-sectional shape orthogonal to the protruding direction of the protrusion 14 (14a to 14d) of the lid 12 and the cross-sectional shape orthogonal to the axial direction of the concave portion 28 (28a to 28d) of the battery case 10 were compared. Sometimes, it is also preferable to form at least a part of the cross-sectional shape of the recess 28 (28a to 28d) of the battery case 10 slightly smaller. For example, it can be formed in a slightly smaller similar shape. Alternatively, it is also preferable to form protrusions or the like on the side wall surfaces in the recesses 28 (28a to 28d) so that the cross-sectional dimension is reduced. According to this configuration, the fitting between the lid 12 and the current collector holder 20 can be realized as a press-fit structure. By fitting the lid 12 and the battery case 10 by press-fitting, the two members can be integrated and handled as one member, and the sealed battery 1 can be assembled more easily. In addition, heat input from the protruding portion 14 to the fixed portion 22 is more efficiently performed during the heat caulking process.

Moreover, it mounts | wears with the fixing | fixed part 22 (22a-22a) of the collector holder 20 integrated with the cover body 12 so that the hole 42 (42a-42d) of the collector 40 may be penetrated, and the front-end | tip ( That is, the current collector 40 and the current collector holder 20 can be tightly joined by caulking the head forming member 26 ') by heat caulking.
Here, the lead member 32 and the deformable member 34 are disposed between the current collector holder 20 and the current collector 40. For example, the lead member 32 and the deformable member 34 can be disposed in a space that is solidified by the four fixing portions 22 (22a to 22a) protruding from the current collector holder 20. The lead member 32 and the deformable member 34 can be positioned by forming the shape of the base end of the fixing portion 22 (22a to 22a) according to the shape of the lead member 32.

  For the sealed battery 1 disclosed herein, the heat caulking process is performed from both the inner surface side (upper side in the figure) and the outer surface side (lower side in the figure) of the lid 12 as shown in FIG. 6A, for example. Heating is preferred. In other words, as in a conventionally known method, the heat input by the hot plate 200 from the front end side of the fixing portion 22 of the current collector holder 20 and the protruding portion of the lid body 12 integrated with the current collector holder 20. 14 is preferably joined by simultaneously performing heat input by the hot plate 220 from the back surface side of the current collector holder 20.

The heat caulking process from both surfaces of the current collector holder 20 will be described.
As illustrated in FIG. 7A, the current collector holder 20 disclosed herein includes a fixing portion 22 that fixes the current collector 40. In the state before the sealed battery 1 is assembled, the fixing portion 22 has a shaft portion 24 rising from the main body of the holder 20 and a head forming portion 26 ′ provided at the tip thereof. The current collector holder 20 is further provided with a recess 28 that is recessed from the outer surface of the battery case 10 into the shaft portion 24. The lid 12 is provided with a protrusion 14 that fits into the recess 28 of the current collector holder 20. The current collector 40 is provided with a hole portion 42 through which the shaft portion 24 of the fixing portion 22 of the current collector holder 20 passes.

And the projection part 14 of the cover body 12 and the recessed part 28 of the collector holder 20 are fitted, and the cover body 12 and the collector holder 20 are integrated. Further, the current collector 40 is placed on the lid body 12 and the current collector holder 20 in an integrated state in a state where the fixing portion 22 is passed through the hole 42.
The hot plate 200 is brought into contact with the distal end (head forming portion 26 ') side of the fixing portion 22 in such a state, and the hot plate 200 is pushed down as indicated by an arrow in the drawing to be made of a resin material. The head forming portion 26 'is melted and begins to deform as shown in FIG. 7B. Further, by bringing the heating plate 220 into contact with the lid 12 from below, the projection 14 of the lid 12 is heated, and heat is input from the entire projection 14 to the vicinity of the recess 28 of the shaft portion 24 of the current collector holder 20. It is. The shaft portion 24 is heated and melted from the inside by heat input from the projection portion 14. Here, the hot plate 200 can be provided with a concave portion 202 corresponding to the head portion 26 of the fixing portion 22 formed by, for example, a heat caulking process on the surface to be in contact with the fixing portion 22. The hot plates 200 and 220 are heated by a heater or the like (not shown).

Then, by further pressing down the hot plate 200 in the direction of the arrow, the melted portion of the head forming portion 26 ′ spreads along the recess 202 in a direction perpendicular to the axial direction. Then, as shown in FIG. 7C, when the hot plate 200 is pushed down to a predetermined position, the movement of the hot plate 200 stops. For example, the hot plate 200 may be stopped when it contacts the current collector 40. The melted head forming portion 26 ′ is accommodated in a region surrounded by the recess 202 of the hot plate 200 and the current collector 40. As a result, a head portion 26 having a larger dimension in a direction perpendicular to the shaft than the shaft portion 24 is formed at the tip of the shaft portion 24 of the fixed portion 22.
Note that heat is input to the shaft portion 24 from the outer surface of the battery case 10 of the current collector 40 via the protrusion 14 of the lid 12 by the hot plate 220. For this reason, the shaft portion 24 and the head forming portion 26 ′ are also melted by heat input from the protruding portion 14. Therefore, the shaft portion 24 and the head portion 26 of the current collector holder 20 can realize close welding with the current collector 40 and the inside of the hole portion 42 and the protrusion 14 of the lid 12. In the case of this figure, the surface from the shaft portion 24 to the head portion 26 of the fixed portion of the current collector holder 20 forms a corner portion K, but from the hole 42 of the current collector 40 to the inside of the battery case 10. The surface reaching the side surface is also formed along this corner K. 7D, the shaft portion 24 of the current collector holder 20 passes through the hole 42 of the current collector 40, and the head portion 26 locks the current collector 40, so that the lid body 12 The current collector holder 20 and the current collector 40 are tightly integrated without generating a gap. That is, the connection form of the lid body 12, the current collector holder 20, and the current collector 40 as shown in FIG. 6B is realized.

With this configuration, the lead member 32, the deformable member 34, and the current collector 40 are fixed tightly and stably by the current collector holder 20. The current collector holder 20 is fixed in close contact with the lid body 12. And the head 26 in the fixing | fixed part 22 of the collector holder 20 is formed as what was equipped with sufficient thickness in the axial direction. As a result, even when external vibration or impact is applied to the sealed battery 1, an excessive load is applied to the connection portion between the reversing portion 36 of the deformable member 34 and the easily breakable portion 46 of the current collector 40. Can be prevented, and malfunction of the current interrupting device 30 due to such vibration and impact can be prevented.
Further, since the fixing portion 22 of the current collector holder 20 also receives heat from the protrusion 14 of the lid body 12, heat can be transferred to the entire fixing portion 22 in a short time, and the time required for the heat caulking process can be reduced. It can be shortened.

  Note that if an excessive load is applied to the connecting portion between the reversing portion 36 of the deformable member 34 and the easily breakable portion 46 of the current collector 40, the operating pressure when the current interrupting mechanism 30 is caused varies. On the other hand, in the sealed battery 1 disclosed herein, the propagation of vibration to the connecting portion between the reversing portion 36 and the easily breakable portion 46 is suppressed, and an excessive load is prevented from being generated. Variations in the operating pressure of the current interrupt mechanism 30 can be suppressed. In addition, the caulking structure disclosed here has sufficient tensile strength in the axial direction at the fixed portion 22 of the current collector holder 20 to maintain such stability and reliability over a long period of time. Can do.

  Further, as shown in FIGS. 5A to 5C, the protrusion 14 of the lid 12, the recess 28 and the fixing portion 22 of the current collector holder 20, and the hole 42 of the current collector 40. Can be provided (for example, four in the example of FIG. 5), and more accurate positioning can be performed when each member is assembled, and displacement between the members can be prevented. In particular, the current collector 40 can be held tightly and stably in the current collector holder 20 by heat caulking. Thereby, generation | occurrence | production of the rattling between the collector holder 20 and the collector 40 can be suppressed significantly. Moreover, also in the point which can suppress generation | occurrence | production of such rattling, holding | maintenance of this close and stable collector 40 can be maintained over a long period of time. In addition, since joining by these several crimping structures can be performed simultaneously by one heat crimping process, the process of a heat crimping process does not become complicated.

  FIG. 10A (conventional example) shows a caulking structure in the case where no protrusion 14 is provided on the lid 12 and there is no case where there is no heat input from the back side of the current collector holder 20. When there is no heat input from the inside of the shaft portion 24 of the current collector holder 20, it is difficult for heat to reach the shaft portion 24 and the head forming portion 26 ′ located away from the hot plate 200. Therefore, for example, an unmelted portion is easily formed in the region indicated by X in the drawing. In particular, according to the heat caulking process using the hot plate 200 as described above, the unmelted portion is formed in the axial direction like a tear from the boundary between the shaft portion 24 and the head portion 26. When the unmelted portion having such a portion and shape is formed, the axial thickness of the head portion 26 of the fixing portion 22 of the current collector holder 20 is substantially t1 shown in the drawing. In addition, when a tensile load is applied to the fixed portion 22 of the current collector holder 20 in the axial direction, the load is concentrated on the boundary between the shaft portion 24 and the head 26, so that the current collector holder 20 is pulled in the axial direction. The strength will be extremely low.

On the other hand, for example, as shown in FIG. 10B (reference example), a protrusion T is provided on the inner surface of the battery case 10 in the hole 42 of the current collector 40 to make it difficult to form such an unmelted portion. I can think of that. However, even when the protruding portion T is provided on the current collector 40, the axial thickness of the head portion 26 of the fixing portion 22 of the current collector holder 20 is t2 shown in the figure, and the thicknesses of the other head portions 26 are shown. It is inevitable that the thickness becomes thinner. That is, unless there is sufficient heat input at the boundary between the shaft portion 24 and the head portion 26 of the current collector holder 20, a decrease in tensile strength in the axial direction of the current collector holder 20 is inevitable. Such a tendency can be particularly problematic when the head 26 of the current collector holder 20 is formed so as to be flush with the current collector 40 without protruding.
In the sealed battery 1 disclosed herein, the protrusion 14 is provided on the lid 12, and heat can be input also from the back side of the current collector holder 20. Therefore, such a problem of decrease in tensile strength in the axial direction of the current collector holder 20 can be solved.

Various modes can be considered for the form of coupling between the current collector holder 20 and the current collector 40.
For example, a chamfering C may be applied to the opening portion on the inner side of the battery case 10 of the hole portion 42 of the current collector 40 as shown in FIG. 8A, for example. In this case, it is preferable that the distance between the chamfering C surface and the tip of the protrusion 14 of the lid body 12 is not too large so that sufficient heat input can be performed on the chamfering C surface. Even in the case where the aperture of the current collector 40 is in such a form, the shaft portion 24 and the head forming portion 26 ′ of the fixing portion 22 of the current holder 20 can be obtained by the heat caulking process as described above. It is sufficiently melted and no unmelted part is generated. Therefore, the surface from the shaft portion 24 to the head portion 26 of the fixed portion 22 is formed along the chamfered C surface. According to this configuration, the thickness in the axial direction of the head portion 26 of the fixing portion 22 of the current collector holder 20, and the thickness in the vicinity of the boundary portion between the shaft portion 24 and the head portion 26 is the chamfering C of the current collector 40. Thus, the thickness is increased correspondingly. Thereby, the tensile strength in the axial direction of the fixing portion 22 of the electric holder 20 can be improved.
FIG. 8A illustrates the case where a so-called C-plane is formed as a chamfered surface in which the corners of the apertures of the current collector 40 are dropped, but the chamfering form is limited to this C-plane. Without limitation, various forms such as a so-called R surface with corners dropped may be used.

  Further, for example, as shown in FIG. 8B, for example, an engaging step 44 may be provided in the opening of the hole 42 of the current collector 40 on the inner side of the battery case 10. In this case, the height of the locking step 44, the opening corner K of the locking step 44, and the protrusion 14 of the lid 12 so that sufficient heat input to the locking step 44 is possible. The distance from the tip can be appropriately designed. In the heat caulking process as described above, the hot plate 200 that does not include the concave portion 202 is used. The volume of the head forming portion 26 ′ is made to correspond to the locking step 44. Thereby, since the shaft part 24 and the head forming part 26 ′ of the fixing part 22 of the electric holder 20 are sufficiently melted, the heat caulking process can be performed without generating an unmelted part. Therefore, the surface from the shaft portion 24 to the head portion 26 of the fixed portion 22 is formed along the surface of the locking step portion 44 of the current collector 40. Further, the surface of the head 26 on the inner side of the battery case 10 is formed to be flush with the surface of the current collector 40 on the inner side of the battery case 10. Accordingly, the lid body 12, the current collector holder 20, and the current collector are not projected on the surface of the current collector 40 on the inner side of the battery case 10 without protruding the head portion 26 of the fixing portion 22 of the current collector holder 20. 40 can be tightly integrated. According to such a configuration, it is possible to ensure more space for accommodating the electrode body in the battery case 10. Therefore, for example, the electrode body 50 can be enlarged, and the battery capacity (full charge capacity) can be further increased.

  In addition, for example, as shown in FIG. 8C, for example, both the locking step 44 and the chamfered C surface are provided in the opening of the current collector 40 on the inner side of the battery case 10 of the hole 42. Also good. With this configuration, the tensile strength in the axial direction of the fixing portion 22 of the electric holder 20 can be improved without causing the head portion 26 of the fixing portion 22 to protrude from the surface of the current collector 40.

Next, a structure for electrically connecting the negative electrode terminal 120 to the negative electrode 54 will be described.
As shown in FIG. 4A, the negative electrode terminal 120 is formed so as to protrude outward from the battery case 10, as with the positive electrode external terminal 110. The negative external terminal 120 is fixed to the outside of the lid 12 of the battery case 10 by a negative external connection terminal retainer 72. The negative external connection terminal 120 and the presser 72 are insulated from the lid 12 by a negative external insulation member 62. The negative electrode external insulating member 62 is generally made of a resin material as in the case of the positive electrode.

An inner insulating member 92 is disposed inside the lid 120. In the example of FIG. 4A, since the current interrupt mechanism 30 is not provided on the negative electrode side, the negative electrode current collector 90 is disposed through the internal insulating member 92. The internal insulating member 92 includes a rising portion having a shape corresponding to the hole on the negative electrode side of the lid body 12 described above, and the negative electrode current collector 90 and the lid body 12 are insulated by the rising portion.
The negative electrode current collector 90 is typically bonded to the negative electrode 54 of the electrode body 50 by extending from the fixed part to the inside of the battery case 10 so as to realize stable fixation with the lid 12. And an arm portion to be configured. The arm portion is joined to the negative electrode 54 by welding or the like, for example. The fixed part is provided with a cylindrical part extending upward. The cylindrical portion penetrates through holes provided in the negative electrode external connection terminal retainer 72, the external insulating member 62, the lid 12 and the internal insulating member 92 so as to correspond to each other, and is caulked at the tip portion thereof. These members can be tightly fixed in a sandwiched state. With this configuration, the negative electrode external connection terminal 120 (presser 72) and the electrode body 50 can be electrically connected and the electrode body 50 can be positioned. In FIG. 4A, the cylindrical portion of the negative electrode current collector 90 shows a shape after caulking.

  In the above-described embodiment of the present invention, details of the specific configuration and arrangement position of the current interrupt mechanism 30 are not limited to this example. For example, some of the components of the current interrupt mechanism 30 can be modified. In addition, the electric current interruption mechanism 30 may be provided in any of the positive electrode side and the negative electrode side, and may be provided in both of these. In the current collector 40, the positive electrode current collector is generally formed of aluminum or an aluminum alloy, and the negative electrode current collector is formed of copper or a copper alloy. When these are compared, aluminum or an aluminum alloy can be advantageous in terms of processing the easily breakable portion 46 of the current collector 40. Therefore, it is shown as a preferable example that the current interrupting mechanism 30 is provided on the positive electrode side. In addition, since the structure and method in the case of applying the electric current interruption mechanism 30 to the conductive path of a negative electrode are the same as that of the case of a positive electrode, description is abbreviate | omitted here.

  Further, the easily breakable portion 46 of the current collector 40 is configured to be more easily broken than other portions of the current collector 40. Therefore, the easily breakable portion 46 may be formed thinner than other portions of the current collector 40, for example. Moreover, the notch 63 may be provided along the peripheral part of the easily breakable part 46, and it may be comprised by this notch 63 part so that it may fracture | rupture more easily than another part. Moreover, it is not limited to this, For example, it is good also as the easily breakable part 46 by forming the hole corresponding to the inversion part 36 in the fixing | fixed part of the collector 40, and arrange | positioning a metal sheet etc. so that this hole may be covered. . Further, the current collector 40 may have a gas circulation port (not shown) so that the internal pressure of the battery case 10 can be easily transmitted to the deformable member 34.

DESCRIPTION OF SYMBOLS 1 Sealed battery 10 Battery case 12 Cover body 14 Protrusion part 16 Hole part 18 Case main body 20 Current collector holder 22 Fixing part 24 Shaft part 26 Head part 26 'Head formation part 28 Recess part 30 Current interruption mechanism 32 Lead member 34 Deformation Member 36 Reversing part 40 Current collector 42 Hole part 44 Step part 46 Easily breakable part 50 Electrode body 52 Positive electrode 54 Negative electrode 56 Separator 60, 62 External insulation member 70, 72 External connection terminal retainer 90 Negative electrode current collector 92 Internal insulation member 110 Positive external connection terminal 120 Negative external connection terminal 130 Liquid injection plug 140 Safety valve

Claims (11)

An electrode body;
A battery case that houses the electrode body;
An external connection terminal formed to protrude outward from the battery case;
A current collector housed in the battery case and electrically connected to the electrode body;
A current interruption mechanism that is disposed in a conductive path that electrically connects the external connection terminal and the current collector, and can cut off the conductive path;
A current collector holder made of an insulating material, disposed on the inner surface of the battery case, and provided with a fixing portion for fixing the current collector ;
A sealed battery comprising:
The fixed part of the current collector holder includes a shaft part projecting inward of the battery case, a head part having a larger dimension in a direction perpendicular to the axis than the shaft part at the tip of the shaft part , Have
The current collector is provided with a hole through which the shaft portion of the fixed portion of the current collector holder passes,
The current collector holder is provided with a recess that is recessed from the outer surface of the battery case into the shaft.
here,
The battery case has a protrusion that fits into the recess of the current collector holder,
The protrusion of the battery case and the recess of the current collector holder are fitted,
The shaft portion of the current collector holder passes through the hole of the current collector, and the head locks the current collector ,
The sealed battery , wherein the current collector is fixed by heat caulking without generating a gap between the shaft portion and the head portion .   The sealed battery according to claim 1, wherein at least the protrusion of the battery case is made of a metal material.   The sealed battery according to claim 1, wherein at least the shaft portion and the head portion of the current collector holder are made of a thermoplastic resin.   The surface from the shaft portion of the fixed portion of the current collector holder to the head is formed along the surface from the hole of the current collector to the inner surface of the battery case. The sealed battery according to any one of?   The axial thickness of the head portion of the fixed portion of the current collector holder, and the thickness in the vicinity of the boundary portion between the shaft portion and the head portion is 1 / th of the axial length of the shaft portion. The sealed battery according to any one of claims 1 to 4, which is 2 or more.   The projecting portion of the battery case has a length such that a distal end thereof reaches a position that is not less than 2/3 of an axial length of the shaft portion from a base end of the shaft portion of the current collector holder. The sealed battery according to any one of 1 to 5.   The opening of the current collector hole on the inner side of the battery case is chamfered, and the surface from the shaft portion to the head of the fixing portion of the current collector holder is the chamfered surface. The sealed battery according to claim 4, wherein the sealed battery is formed along the line. The opening portion on the battery case inner side of the hole portion of the current collector is provided with a locking step portion that receives the head portion of the fixing portion of the current collector holder,
The surface from the shaft portion to the head portion of the fixed portion of the current collector holder is formed along the locking step portion,
The sealed battery according to claim 4, wherein a surface of the current collector on the inner side of the battery case is flush with a head of the fixing portion of the current collector holder. Wherein said projecting portion of the battery case, and the recess of the current collector holder is fitted by press fitting, sealed battery according to any one of claims 1-8. The sealed battery according to claim 1 , wherein the sealed battery is mounted on a vehicle and used as a power source for driving a vehicle.   An electrode body;
  A battery case containing the electrode body;
  An external connection terminal formed to protrude outward from the battery case;
  A current collector housed in the battery case and electrically connected to the electrode body;
  A current interruption mechanism that is disposed in a conductive path that electrically connects the external connection terminal and the current collector, and can cut off the conductive path;
  A current collector holder made of an insulating material, disposed on the inner surface of the battery case, and provided with a fixing portion for fixing the current collector;
A method for producing a sealed battery comprising:
  The current collector holder includes a holder main body disposed on an inner surface of the battery case, a shaft portion protruding from the holder main body toward the inside of the battery case, and a head portion provided at a tip of the shaft portion. A fixing portion having a forming portion, and a recess that is recessed from the outer surface of the battery case toward the inside of the shaft portion is provided,
  The current collector is provided with a hole through which the head forming portion of the current collector holder and the shaft portion pass,
  The battery case has a protrusion that fits into the recess of the current collector holder,
here,
  Fitting the protrusion of the battery case and the recess of the current collector holder;
  Attaching the current collector to the current collector holder by penetrating the head forming portion of the current collector holder and the shaft portion through the hole of the current collector;
  Heat is applied from the outer surface side of the battery case to the shaft portion of the fixed portion through the protrusion of the battery case, and heat is applied from the front end side of the head forming portion. The head forming part is melted to create a gap between the current collector and the shaft and the head, the head having a larger dimension in the direction orthogonal to the shaft than the shaft. Forming the current collector without fixing the current collector to the current collector holder,
A method for producing a sealed battery, comprising:

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