JP5756843B2 - Current interrupt device and power storage device using the same - Google Patents

Description

  The present specification discloses a technology related to a current interrupt device and a power storage device using the current interrupt device.

  The power storage device includes a current interrupt device that interrupts an energization path that connects the electrode assembly in the case and an external terminal provided in the case when the power storage device is overcharged or a short circuit occurs inside. May be equipped. The current interrupting devices of Patent Literatures 1 and 2 include an internal terminal plate and a conductive plate disposed to face the internal terminal plate. The outer peripheral portion of the conductive plate is connected to the external terminal plate, and the central portion of the conductive plate is connected to the central portion of the internal terminal plate. The outer peripheral portion of the internal terminal plate is connected to the electrode assembly. When the pressure in the case increases, the conductive plate and the internal terminal plate are separated from each other, the conduction between the conductive plate and the internal terminal plate is cut off, and the current flowing between the electrode assembly and the external terminal is cut off.

Japanese Patent Laid-Open No. 08-185849 Japanese Patent Laid-Open No. 08-115715

  In this type of current interrupting device, when the conductive plate and the internal terminal plate are separated, a large voltage may be applied between the conductive plate and the internal terminal plate. In such a case, in the range where the conductive plate and the internal terminal plate face each other, if there is an electrolytic solution in the case between the two, a conductive foreign matter is generated from the electrolytic solution, resulting in liquid junction, and the conductive plate and the internal terminal plate. May re-energize. For this reason, in the conventional current interruption device, the two sealing members are provided so that the electrolyte in the case does not enter the gap between the conductive plate and the internal terminal plate, resulting in a complicated structure. That is, the first seal member is provided in the gap between the conductive plate and the internal terminal plate, and the second seal member in contact with the outer peripheral surface of the conductive plate and the outer peripheral surface of the internal terminal plate is disposed. The present specification provides a technique for realizing a liquid junction between two current-carrying members with a simple structure.

The current interrupt device disclosed in the present specification interrupts an energization path connecting an external terminal provided in a case and an electrode assembly accommodated in the case when an internal pressure in the case exceeds a predetermined value. The current interrupting device includes a first current-carrying member electrically connected to the external terminal, a second current-carrying member disposed opposite to the first current-carrying member and electrically connected to the electrode assembly, An insulating seal member that is provided between the energization member and the second energization member and seals a gap between the first energization member and the second energization member. The first energization member and the second energization member are energized to form a part of the energization path when the pressure in the case is below a predetermined value, and separated from each other when the pressure in the case exceeds the predetermined value. Shut off the current path. The seal member has a first contact portion that contacts the vicinity of the outer peripheral edge of the first current-carrying member, and a second contact portion that contacts the outer periphery of the second current-carrying member, and the first current-carrying member and the second current-carrying member The space between is separated into a first space inside the first contact portion and the second contact portion and a second space outside. The second space communicates with the space in the case. The first space is sealed from the space in the case by a seal member. When the first energizing member, the second energizing member, and the seal member are viewed in plan, the seal member covers the entire area outside the first contact portion and the second contact portion within a range where the first energizing member and the second energizing member face each other. Is located. Furthermore, at least one of the first energizing member and the second energizing member has an opposing surface that opposes the other of the first energizing member and the second energizing member, and tapers at a corner formed by the opposing surface and the outer peripheral surface. And the seal member is in contact with the tapered portion. Here, the plan view means that the first energizing member and the second energizing member are viewed from a direction perpendicular to the surfaces facing each other. In other words, in the positional relationship between the first energization member and the second energization member, the second energization member is viewed from the side where the first energization member is located, or the second energization member is second. This means viewing from the side where the energizing member is located.

  In the above current interrupting device, the gap between the first energizing member and the second energizing member is separated into the first space and the second space by the seal member, and the second space communicates with the space in the case. For this reason, the electrolytic solution in the case may enter the second space. However, in the second space, the sealing member is located in the entire range where the first energizing member and the second energizing member are opposed to each other, and the first energizing member and the second energizing member are in a state where the electrolyte exists between them. Direct facing is prevented. Thereby, the liquid junction between the first energizing member and the second energizing member is prevented. That is, even if the electrolyte enters the second space between the first energization member and the second energization member, the seal member is appropriately disposed between the two, and thus the liquid junction between the two can be prevented. it can. Further, in this current interrupting device, since the electrolyte solution is allowed to enter between the first energizing member and the second energizing member, it is not necessary to use two sealing members as in the prior art, and the structure is simple. A liquid junction can be prevented.

Further, a taper is provided at a corner formed by the above-described opposing surface and the outer peripheral surface thereof, and the seal member is in contact with the portion where the taper is formed. According to such a configuration, when the internal pressure in the case rises and the internal pressure acts on the seal member, the seal member on which the internal pressure acts can be received at the portion where the taper is formed. For this reason, a sealing member can be hold | maintained in the appropriate position between a 1st electricity supply member and a 2nd electricity supply member.

Cross section of power storage device Diagram showing current interrupting device when terminal and electrode are energized Diagram showing current interrupting device when terminal and electrode are not energized The figure which expands and shows the part 200 enclosed with the dotted line of FIG. 2A The figure which shows the other example of the seal structure for preventing a liquid junction The figure which shows the further another example of the seal structure for preventing a liquid junction

Hereinafter, some technical features of the embodiments disclosed in this specification will be described. The items described below have technical usefulness independently.

(Feature 1) In the current interrupt device disclosed in the present specification, the seal member is a member that is arranged along the outer peripheral portion of the first energizing member or the second energizing member and goes around the outer peripheral portion. Also good. According to such a configuration, since the seal member is constituted by one member that goes around the outer periphery of the first energization member or the second energization member, the two energization members and the seal member can be easily assembled. it can.

(Characteristic 2) In the current interrupt device disclosed in the present specification, an insulating member provided in the first space between the first energization member and the second energization member and in contact with the first energization member and the second energization member is further provided. You may have. According to such a configuration, when the energization is interrupted, the insulation state between the first energization member and the second energization member can be favorably maintained.

(Example)
Hereinafter, the power storage device 100 of the first embodiment will be described. The power storage device 100 is a lithium ion secondary battery that is a type of secondary battery. As shown in FIG. 1, the power storage device 100 includes a case 4, an electrode assembly 2, a negative electrode terminal 30 as an electrode terminal, a positive electrode terminal 10, and a current interrupt device 70. The case 4 is made of metal and has a substantially rectangular parallelepiped shape. Inside the case 4, the electrode assembly 2 and the current interrupt device 70 are accommodated. Further, the inside of the case 4 is filled with an electrolytic solution. On the upper surface 4 a of the case 4, the negative electrode terminal 30 and the positive electrode terminal 10 are exposed to the outside of the case 4. Through holes 4 b and 4 c are formed in the upper surface 4 a of the case 4. The negative terminal 30 passes through the through hole 4b, and the positive terminal 10 passes through the through hole 4c. An insulating first seal member 42 is attached to the through hole 4b. An insulating second seal member 22 is attached to the through hole 4c. Note that the shape of the case 4 is not limited, and may be, for example, a cylindrical shape, a rectangular parallelepiped shape, or a sheet shape formed of a film.

  The negative electrode terminal 30 includes an external nut 36, an internal nut 32, and a bolt 34. The external nut 36 is used for connection between the negative electrode terminal 30 and a negative electrode wiring (not shown). The inner nut 32 is attached to the first seal member 42. A part of the inner nut 32 passes through the through hole 4b. The bolt 34 is fastened to the internal nut 32. A third seal member 40 is interposed between the bolt 34 and the case 4. The negative electrode terminal 30 is insulated from the case 4 by the seal members 40 and 42. The inner nut 32 is electrically connected to the negative electrode lead 44 via the current interrupt device 70 and the connection terminal 72. The negative electrode lead 44 is insulated from the case 4 by the first seal member 42. The negative electrode terminal 30 is energized with the negative electrode of the electrode assembly 2 via the current interrupt device 70, the connection terminal 72, and the negative electrode lead 44. The current interrupt device 70 will be described later.

  The positive terminal 10 includes an external nut 16, an internal nut 12, and a bolt 14. The external nut 16 is used for connection between the positive terminal 10 and the positive wiring (not shown). The inner nut 12 is attached to the second seal member 22. A part of the inner nut 12 passes through the through hole 4c. The bolt 14 is fastened to the inner nut 12. A fourth seal member 20 is interposed between the bolt 14 and the case 4. The positive electrode terminal 10 is insulated from the case 4 by the seal members 20 and 22. A positive electrode lead 24 is fixed to the inner nut 12. The inner nut 12 and the positive electrode lead 24 are electrically connected. The positive electrode lead 24 is insulated from the case 4 by the second seal member 22. The positive electrode terminal 10 is energized with the positive electrode of the electrode assembly 2 via the positive electrode lead 24.

(Electrode assembly)
The electrode assembly 2 includes a protrusion 2 a that protrudes toward the upper surface 4 a of the case 4. The electrode assembly 2 includes a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode. Illustration of the positive electrode, the negative electrode, and the separator is omitted. The negative electrode has a negative electrode current collector and a negative electrode active material layer formed on the negative electrode current collector. The negative electrode has a negative electrode current collecting tab 46 at its end. A negative electrode active material layer is not applied to the negative electrode current collecting tab 46. The positive electrode has a positive electrode current collector and a positive electrode active material layer formed on the positive electrode current collector. The positive electrode has a positive electrode current collecting tab 26 at its end. The positive electrode current collecting tab 26 is not coated with a positive electrode active material layer. Note that there are no particular limitations on materials (eg, active material, binder, and conductive additive) included in the active material layer, and materials that are used for electrodes of known power storage devices and the like can be used.

Here, for the positive electrode current collector, for example, aluminum (Al), nickel (Ni), titanium (Ti), stainless steel, or a composite material or alloy thereof can be used. In particular, aluminum or a composite material or alloy containing aluminum is preferable. The positive electrode active material may be any material that allows lithium ions to enter and desorb, and Li ₂ MnO ₃ , Li (NiCoMn) _0.33 O ₂ , Li (NiMn) _0.5 O ₂ , LiMn ₂ O ₄ , LiMnO ₂ , LiNiO ₂ , LiCoO ₂ , LiNi _0.8 Co _0.15 Al _0.05 O ₂ , Li ₂ MnO ₂ , LiMn ₂ O _{4 and the} like can be used. In addition, alkali metals such as lithium and sodium, or sulfur can be used as the positive electrode active material. These may be used alone or in combination of two or more. The positive electrode active material is applied to the positive electrode current collector together with a conductive material, a binder and the like as necessary.

  On the other hand, as the negative electrode current collector, aluminum, nickel, copper (Cu), or a composite material or alloy thereof can be used. In particular, copper or a composite material or alloy containing copper is preferable. Further, as the negative electrode active material, a material in which lithium ions can enter and leave can be used. Alkali metals such as lithium (Li) and sodium (Na), transition metal oxides containing alkali metals, natural graphite, mesocarbon microbeads, highly oriented graphite, carbon materials such as hard carbon, soft carbon, silicon alone or silicon A containing alloy or a silicon-containing oxide can be used. A negative electrode active material is apply | coated to a negative electrode collector with a electrically conductive material, a binder, etc. as needed.

  Note that the separator can be made of an insulating porous material. As the separator, a porous film made of a polyolefin-based resin such as polyethylene (PE) or polypropylene (PP), or a woven or non-woven fabric made of polypropylene, polyethylene terephthalate (PET), methyl cellulose or the like can be used.

The electrolytic solution is preferably a non-aqueous electrolytic solution in which a supporting salt (electrolyte) is dissolved in a non-aqueous solvent. As a non-aqueous solvent, a solvent containing a chain ester such as ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), ethyl acetate, A solvent such as methyl propionate or a mixture thereof can be used. Moreover, as a supporting salt (electrolyte), for _example, can be used LiPF _6, LiBF 4, LiAsF _6, and the like.

(Current interrupter)
With reference to FIG. 2A and FIG. 2B, the electric current interruption apparatus 70 is demonstrated. The current interrupt device 70 is connected between the negative electrode terminal 30 and the negative electrode current collecting tab (negative electrode) 46. The current interrupt device 70 may be connected between the positive electrode and the positive terminal 10, or may be connected between the negative electrode and the negative terminal 30 and between the positive electrode and the positive terminal 10. Good. 2A and 2B, the illustration of the seal member 42 interposed between the negative electrode terminal 30 and the case 4 is omitted.

  As shown in FIG. 2A, the current interrupting device 70 includes a metal first reversing plate 84, a metal breaking plate 88, a metal second reversing plate 90, and an insulating support member 92. Yes. The support member 92 supports the first reverse plate 84, the fracture plate 88, and the second reverse plate 90. That is, the support member 92 is fitted from the outside with respect to the first reversing plate 84, the breaking plate 88, and the second reversing plate 90, and the first reversing plate 84, the breaking plate 88, and the second reversing plate 90 are stacked. I support it. A metal plate 78 is attached to the outer peripheral surface of the support member 92. Specifically, with the support member 92 sandwiching the lower ends of the first reversing plate 84, the fracture plate 88, the second reversing plate 90, and the internal nut 32 from above and below, the plate material 78 is placed on the outer peripheral surface of the support member 92. It is caulked. Thereby, the current interrupt device 70 is attached to the inner nut 32. Note that openings 93 are formed in part of the circumferential direction on the outer peripheral surfaces of the support member 92 and the plate member 78. The opening 93 communicates with the space in the case 4, and the connection terminal 72 is disposed in the opening 93. As a result, the breaker plate 88 and the negative electrode lead 44 disposed inside the support member 92 and the plate member 78 are connected via the connection terminal 72.

  The first inversion plate 84 is a circular plate material and is disposed below the fracture plate 88. The lower surface of the outer peripheral edge of the first reversing plate 84 is supported by the support member 92 over the entire circumference. An insulating member 80 is disposed on the upper surface of the outer peripheral edge of the first reversing plate 84. The insulating member 80 is a ring-shaped member and insulates the first reversing plate 84 and the fracture plate 88. Further, a protrusion 86 is provided on the upper surface of the first reversing plate 84, and the protrusion 86 is located at the center of the first reversing plate 84. The protrusion 86 protrudes upward toward the fracture plate 88. In the state shown in FIG. 2A, a gap is formed between the protrusion 86 and the central portion 88 b of the fracture plate 88. The pressure in the space in the case 4 acts on the lower surface of the first reversing plate 84, and the pressure in the space 94 between the first reversing plate 84 and the fracture plate 88 acts on the upper surface of the first reversing plate 84. To do. Since the space 94 and the space in the case 4 are sealed, when the pressure in the space in the case 4 increases, the pressure acting on the upper surface and the lower surface of the first reversing plate 84 will be different.

  The fracture plate 88 is a circular plate material, and is disposed between the first reverse plate 84 and the second reverse plate 90. A connection terminal 72 is connected to a part of the outer peripheral portion of the fracture plate 88. A groove 88 a is formed at the center of the lower surface of the fracture plate 88. The groove 88a is formed in a circular shape when viewed from the bottom. Further, as shown in FIG. 2A, the cross-sectional shape of the groove 88a has a triangular shape that protrudes upward. By forming the groove 88a, the mechanical strength of the fracture plate 88 at the position where the groove 88a is formed is lower than the mechanical strength of the fracture plate 88 at a position other than the groove 88a. The fracture plate 88 is divided into a central part 88b surrounded by the groove part 88a and an outer peripheral part 88c located on the outer peripheral side of the groove part 88a by the groove part 88a. The central portion 88b is thin, and the outer peripheral portion 88c is thick.

  The second reversing plate 90 is a circular plate material and is disposed above the fracture plate 88. In the state shown in FIG. 2A, the center portion of the second reversing plate 90 protrudes downward, and is fixed to the center portion 88 b of the fracture plate 88. The outer periphery of the second reversing plate 90 is electrically connected to the internal nut 32. Therefore, the positive electrode terminal 30 is connected to the electrode assembly 2 via the second reversal plate 90, the fracture plate 88, the connection terminal 72, and the negative electrode lead 44. A space 98 is formed between the upper surface of the second reversing plate 90 and the lower surface of the internal nut 32, and the space 98 is sealed from the space in the case 4. An insulating member 82 is disposed between the second reversing plate 90 and the fracture plate 88. The insulating member 82 is a ring-shaped member and is in contact with the outer peripheral portion of the second reversing plate 90 and the outer peripheral portion of the fracture plate 88 to insulate them.

  Here, in this embodiment, a seal member 89 is further disposed between the fracture plate 88 and the outer peripheral portion of the internal nut 32. The seal member 89 is a ring-shaped member having a circular cross section, and is disposed outside the insulating member 82. The seal member 89 is in contact with the lower surface of the internal nut 32 and the upper surface of the fracture plate 88, and makes a round along the outer periphery of the internal nut 32 and the fracture plate 88. The seal member 89 seals (seal) the gap between the internal nut 32 and the fracture plate 88. Therefore, the space located below the second reversing plate 90 and the inner nut and above the breaking plate 88 is separated into the inner space 96 and the outer space 63 (see FIG. 3) by the seal member 89. Yes. For this reason, it can be said that the insulating member 82 is arranged in the space 96 inside the seal member 89. Further, as described above, the space 63 outside the seal member 89 communicates with the space in the case 4 through the support member 92 and the opening 93 formed in the plate member 78. On the other hand, since the space 96 is sealed from the space 63 by the sealing member 89, the space 96 and the space in the case 4 do not communicate with each other.

  As shown in FIG. 3, the seal member 89 is compressed between the inner nut 32 and the fracture plate 88. Further, the inner nut 32 is in contact with the first contact portion 60 in the seal member 89. Further, the fracture plate 88 is in contact with the second contact portion 61 in the seal member 89. As is clear from FIG. 3, when the current interrupt device 70 is viewed in plan, the region 64 outside the first contact portion 60 and the second contact portion 61 is within the range where the internal nut 32 and the fracture plate 88 face each other. The sealing member 89 exists in the whole. That is, the seal member 89 projects outward from the outer peripheral edge of the inner nut 32 and the outer peripheral edge of the fracture plate 88 in the entire circumferential direction. For this reason, in the region 64 outside the first contact portion 60 and the second contact portion 61, the inner nut 32 and the fracture plate 88 do not directly face each other, and the lower surface of the inner nut 32 faces the upper surface of the seal member 89. The upper surface of the fracture plate 88 faces the lower surface of the seal member 89.

  In the power storage device 100 described above, in the state shown in FIG. 2A, the negative electrode terminal 30 and the negative electrode current collecting tab 46 (negative electrode) are energized, and the positive electrode terminal 10 and the positive electrode current collecting tab 26 (negative electrode) are energized. ing. For this reason, the negative electrode terminal 30 and the positive electrode terminal 10 are energized. When the internal pressure in the case 4 rises and exceeds a predetermined value set in advance, as shown in FIG. 2B, the fracture plate 88 breaks at the groove 88a, and the outer peripheral portion 88c of the fracture plate 88 and the second reversing plate 90 ( The energization path between the inner nuts 32) is interrupted. That is, when the internal pressure in the case 4 increases, the pressure acting on the lower surface of the first reversing plate 84 increases (state shown in FIG. 2A). The pressure acting on the upper surface of the first reversing plate 84 (that is, the pressure in the space 94) is not affected by the pressure increase in the case 4 and does not change. For this reason, when the internal pressure in the case 4 exceeds a predetermined value, the first reversing plate 84 is reversed to change from a downward convex state to an upward convex state. When the first reversing plate 84 is reversed, the protrusion 86 of the first reversing plate 84 collides with the central portion 88b of the breaking plate 88, and the breaking plate 88 is broken at the groove 88a. Then, the second reversing plate 90 is also reversed in accordance with the displacement of the first reversing plate 84, and the second reversing plate 90, the central portion of the fracture plate 88, and the first reversing plate 84 are displaced upward (state of FIG. 2B). ). As a result, the energization path connecting the fracture plate 88 and the second reversing plate is interrupted, and the energization between the electrode assembly 2 and the negative electrode terminal 30 is interrupted.

  Even when the breaking plate 88 is broken at the groove 88a (the state shown in FIG. 2B), the negative terminal 30 is connected to the external device, and the breaking plate 88 is connected to the negative electrode of the electrode assembly 2. For this reason, a large voltage may be applied between the negative electrode terminal 30 (that is, the internal nut 32) and the breaker plate 88. Since the space 63 communicates with the space in the case 4, the space 63 However, in the current interrupt device 70 of this embodiment, the first contact portion 60 and the second contact portion are within the range where the inner nut 32 and the fracture plate 88 are opposed to each other. The seal member 89 exists in the entire region 64 outside 61. Therefore, even when a large voltage is applied between the inner nut 32 and the fracture plate 88, conductive foreign matter may be generated from the electrolyte. Suppressed. Fruit, and Ekiraku and internal nut 32 and rupture plate 88, an inner nut 32 and rupture plate 88 can be prevented from being energized again.

  In the above-described current interrupting device 70, the sealing member 89 suppresses liquid drop between the internal nut 32 and the fracture plate 88 and seals the gap between the internal nut 32 and the fracture plate 88. For this reason, since the sealing member 89 that is a single member performs a plurality of functions (a liquid droplet prevention function and a sealing function), the configuration of the current interrupting device 70 can be simplified.

  Finally, the correspondence relationship between the above-described embodiment and the description of the claims will be described. The inner nut 32 and the second reversing plate 90 are an example of a “first energizing member”, the fracture plate 88 is an example of a “second energizing member”, and the space 96 is an example of a “first space”. 63 is an example of a “second space”.

  In the above-described embodiment, the seal member 89 is in contact with only the two members of the inner nut 32 and the fracture plate 88, but the present invention is not limited to such a configuration. For example, in the example shown in FIG. 4, in addition to the inner nut 32 and the fracture plate 88, the seal member 89 is in contact with the support member 92 a at the third contact portion 65. As a result, the seal member 89 is in contact with the internal nut 32, the fracture plate 88, and the support member 92 a at three locations of the first contact portion 60, the second contact portion 61, and the third contact portion 65. Therefore, the second space 63 is separated by the seal member 89 into a space 631 on the first contact portion 60 side and a space 632 on the second contact portion side. Therefore, the electrolyte solution that has entered the space 632 is suppressed from entering the space 631 by the third contact portion 65, and thus a liquid junction between the internal nut 32 and the fracture plate 88 can be more reliably prevented.

  In the above-described embodiment, the lower surface of the inner nut 32 and the upper surface of the fracture plate 88 face each other, and the seal member 89 is in contact with each surface at a position where these surfaces are parallel to each other. The configuration is not limited to this. For example, in the example shown in FIG. 5, the tapered portion 66 is provided at the outer peripheral corner portion (the corner portion formed by the surface facing the fracture plate 88 and the outer peripheral surface of the internal nut 32a) of the surface of the inner nut 32a on the fracture plate 88 side. It has been. The seal member 89 is disposed so as to contact the tapered portion 66 of the inner nut 32a, and is in contact with the tapered portion 66 and the first contact portion 60a. Further, the seal member 89 is in contact with the fracture plate 88 at the second contact portion 61a, and is in contact with the support member 92a at the third contact portion 65. When the pressure in the case rises and an external force 67 directed to the first space 96 acts on the seal member 89, this external force can be received by the tapered portion 66. Thereby, balance of force applied to the seal member 89 is maintained, and an appropriate positional relationship among the seal member 89, the internal nut 32a, and the fracture plate 88 is maintained. Therefore, it is possible to prevent the liquid junction preventing function by the sealing member 89 from being impaired.

  In the example shown in FIGS. 4 and 5, the same reference numerals are given to the same components as those in the embodiment shown in FIG. In addition to the same reference numerals as the corresponding parts in the embodiment shown in FIG.

  The cross-sectional shape of the seal member 89 provided in the above-described embodiment is not limited to a perfect circle shape as shown in the drawing. For example, it may be oval or polygonal. In the above-described embodiment, the connecting member 72 and the breaking plate 88 are provided as separate members, but the connecting member 72 and the breaking plate 88 may be integrally formed.

  Moreover, although the Example mentioned above was the electric current interruption apparatus 70 provided with the two inversion plates 84 and 96, the structure of an electric current interruption apparatus is not restricted to such an example. For example, the current interrupting device may be composed of one reversing plate and a breaking plate. That is, similarly to the current interrupting device shown in FIG. 2A, a breaker plate and a reversing plate (corresponding to a second reversing plate) are provided so that the pressure in the case acts on the reversing plate. In this current interrupt device, when the internal pressure in the case acts on the lower surface of the reversing plate and the differential pressure between the pressures acting on the upper and lower surfaces of the reversing plate exceeds a predetermined value, the reversing plate is reversed and the fracture plate breaks. . In such a current interrupting device, as in the embodiment shown in FIG. 1, a reversing plate is obtained by disposing a seal member between the outer peripheral portion of the fracture plate and the outer peripheral portion of the reversing plate (the outer peripheral portion of the internal nut). And the liquid junction of the broken plate can be prevented.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. For example, the first reversing plate and the second reversing plate need only be deformed under pressure, and are not limited to those having a “reversing” structure. In addition, the technical elements described in the present specification or drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in the present specification or the drawings can achieve a plurality of objects at the same time, and has technical utility by achieving one of the objects.

2: Electrode assembly 4: Case 10: Positive electrode terminal 20, 22: Seal member 24: Positive electrode lead 26: Positive electrode current collecting tab 12, 32: Internal nut 14, 34: Bolt 16, 36: External nut 30: Negative electrode terminal 40 42: seal member 44: negative electrode lead 46: negative electrode current collecting tab 60: first contact portion 61: second contact portion 62: first space 63: second space 64: region 65: third contact portion 66: taper portion 67, 68: force 70: current interrupting device 72: connection member 78: plate member 84: first reversing plate 88: fracture plate 82: insulating member 86: protrusion 89: seal member 90: second reversing plate 92: support member 100 : Power storage device

Claims (4)

A current interrupting device for interrupting an energization path connecting an external terminal provided in a case and an electrode assembly accommodated in the case when an internal pressure in the case exceeds a predetermined value. A first current-carrying member connected to
A second energization member disposed opposite the first energization member and electrically connected to the electrode assembly;
An insulating seal member provided between the first energizing member and the second energizing member and sealing a gap between the first energizing member and the second energizing member;
The first energization member and the second energization member are energized to form a part of the energization path when the internal pressure in the case is less than or equal to a predetermined value, while the internal pressure in the case exceeds a predetermined value And separating the energization path away from each other,
The seal member has a first contact portion that contacts the vicinity of the outer peripheral edge of the first energization member, and a second contact portion that contacts the vicinity of the outer periphery of the second energization member, A gap between the energization member and the second energization member is separated into the first contact portion and the first space inside the second contact portion and the second space outside,
The second space communicates with a space in the case;
The first space is sealed from the space in the case by the seal member,
When the first energization member, the second energization member, and the seal member are viewed in plan, the first contact portion and the second contact portion are within a range where the first energization member and the second energization member face each other. The sealing member is located over the entire outer region;
At least one of the first energizing member and the second energizing member has a facing surface facing the other of the first energizing member and the second energizing member, and a corner formed by the facing surface and the outer peripheral surface. Is provided with a taper,
The seal member is in contact with the tapered portion;
A current interrupting device characterized by that.   2. The current interrupting device according to claim 1, wherein the sealing member is a member that is disposed along an outer peripheral portion of the first energizing member or the second energizing member and makes a round around the outer peripheral portion.   The insulating member which is provided in the 1st space between the 1st electricity supply member and the 2nd electricity supply member, and contacts the 1st electricity supply member and the 2nd electricity supply member is further provided. Current interrupt device.   A power storage device comprising the current interrupt device according to any one of claims 1 to 3.

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