JP6152817B2 - Current interrupt device and power storage device including the same - Google Patents

Description

  The present specification relates to a current interrupt device and a power storage device including the current interrupt device.

  The power storage device may be provided with a current interrupt device that interrupts energization when overcharge or the like occurs (for example, Patent Document 1). The current interrupting device is provided on an energization path that connects the electrode assembly and the terminal. The current interrupt device includes a deformable plate connected to the terminal, an energizing plate connected to the deformable plate and the electrode assembly, and a support member (holder) that supports the energizing plate (current collector) with respect to the terminal. ing. When the internal pressure in the case exceeds the set pressure due to overcharging or the like, the deformed plate is deformed and the energizing plate is broken. As a result, the current flowing through the energization path is interrupted. In this current interrupt device, a through hole is formed in the energizing plate, and a boss that penetrates the through hole of the energizing plate is formed in the support member. The energizing plate and the support member are fixed by caulking the boss of the support member. By directly fixing the energizing plate to the support member using heat caulking, the number of parts is reduced and the structure is simplified.

JP 2013-225500 A

  Some of these types of current interrupting devices have a structure including two current-carrying plates and one deformation plate. That is, in such a current interrupting device, the deformation plate is disposed outside the two current-carrying plates (inside the case), and the pressure in the case acts on the deformation plate. When the pressure in the case rises, the deformed plate is deformed toward the energizing plate and collides with the energizing plate, thereby interrupting energization. In this current interrupt device, the space between the two energization plates and the space in the case are sealed by the seal ring. Thereby, the pressure in a case does not act on an electricity supply board, and stabilization of the operating pressure of an electric current interruption apparatus is achieved. In addition, the pressure of the space between two electricity supply plates acts on the inner surface of the seal ring, and the pressure in the case acts on the outer surface.

  The current interrupting device having the above structure employs a structure in which the energization plate is directly fixed to the support member using heat caulking, and the support member is fixed to the energization plate outside the seal ring. For this reason, even if the pressure in the case rises and the pressure acting on the outer surface of the seal ring rises, the pressure rise cannot be supported by the support member. As a result, there is a possibility that the sealing performance may be deteriorated due to the position of the seal ring being shifted inward. When the sealing performance of the seal ring is lowered, various problems occur. For example, the pressure in the case acts on the energization plate, and the operating pressure of the current interrupt device may change.

  This specification provides the technique which can suppress the fall of the sealing performance of a seal ring, fixing an electricity supply board and a supporting member using heat caulking.

  The current interrupt device disclosed in the present specification is provided on an energization path that connects a terminal provided in a case and an electrode assembly accommodated in the case, and the terminal and the electrode when the internal pressure in the case exceeds a set pressure. The current flowing to and from the assembly is cut off. The current interrupting device has a first energization plate whose outer peripheral portion is fixed to the terminal, a first energization plate, and a central portion fixed to the central portion of the first energization plate. A second energizing plate electrically connected to the assembly, a deforming plate disposed opposite to a surface of the second energizing plate opposite to the surface facing the first energizing plate, and an insulating material And a support member fixed to the second energization plate and supporting the second energization plate with respect to the terminal, and disposed in a space surrounded by the terminal, the first energization plate, the second energization plate, and the support member, A seal ring that seals between the terminal and the second energization plate outside the outer peripheral edge of the first energization plate. The deformation plate receives the pressure of the internal space of the case on the surface opposite to the surface facing the second energizing plate, and applies the pressure of the space isolated from the internal space of the case to the surface facing the second energizing plate. receive. When the pressure in the internal space of the case exceeds the set value, the deforming plate is deformed to the second energizing plate side, whereby the second energizing plate is broken and the current flowing between the terminal and the electrode assembly is interrupted. A through hole is formed in the outer peripheral portion of the second energization plate. The support member has a heat caulking boss that is inserted into the through hole and fixes the support member to the second current-carrying plate. A projecting portion that projects toward the second energizing plate is formed on the surface of the terminal facing the second energizing plate at a position inside the seal ring. An insulating ring member made of an insulating material is disposed between the protruding portion and the second current plate.

  In the current interrupting device, a protrusion is formed on the surface of the terminal facing the second energization plate, and an insulating ring member is disposed between the protrusion and the second energization plate. That is, the protrusion and the insulating ring member are disposed at a position inside the seal ring. For this reason, even if the pressure in a case rises and the pressure which acts on the outer surface of a seal ring increases, this pressure can be received by a protrusion part and an insulating ring member. As a result, displacement and deformation of the seal ring can be suppressed, and deterioration of the sealing performance of the seal ring can be suppressed.

  In the current interrupt device according to the present invention, the current interrupt device can be appropriately operated by suppressing the deterioration of the sealing performance of the seal ring.

Sectional drawing of an electrical storage apparatus. Sectional drawing of an electric current interruption apparatus. The figure which shows the electric current interruption apparatus when the internal pressure in a case rises and the electricity supply between a terminal and an electrode is interrupted | blocked (sectional drawing corresponding to FIG. 2). The figure which expands and shows the part by which the ring member is arrange | positioned. The figure which expands and shows the ring member which concerns on a modification (figure corresponding to FIG. 4).

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 interrupting device disclosed in the present specification, the insulating ring member includes a first portion disposed between the protruding portion and the second current plate, and a second portion disposed outside or inside the protruding portion. You may have. In this case, the shape of the axial section of the first portion may be different from the shape of the axial section of the second portion. According to such a structure, the cross-sectional shape of an insulating ring member can be made into an appropriate shape, and a seal ring can be supported appropriately.

(Characteristic 2) In the current interrupting device disclosed in the present specification, the second portion of the insulating ring member is disposed on the inner side of the protruding portion, and even if a part thereof faces the inner peripheral surface of the protruding portion. Good. According to such a configuration, the insulating ring is appropriately positioned in the current interrupt device, and the pressure in the case acting on the seal ring can be suitably received.

(Characteristic 3) In the current interrupting device disclosed in the present specification, a groove may be formed on a surface of the second energizing plate facing the first energizing plate. And the 2nd part of an insulating ring member may engage with the groove | channel of a 2nd electricity supply board. Even with such a configuration, the insulating ring member can be appropriately positioned, and the pressure in the case acting on the seal ring can be suitably received.

  Hereinafter, the power storage device 100 of the 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 and 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. In addition, an electrolytic solution is injected into the case 4. A negative electrode terminal 30 and a positive electrode terminal 10 are attached to the upper surface 4 a of the case 4. That is, through holes 4 b and 4 c are formed in the upper surface 4 a of the case 4. The negative terminal 30 is attached to the through hole 4b, and the positive terminal 10 is attached to the through hole 4c. An insulating first seal member 42 is disposed in the through hole 4b. An insulating second seal member 22 is disposed in the through hole 4c. 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). 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 a seal member 40 and a support member 92 (described later) of the current interrupt device 70. 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 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. As the negative electrode active material, a material into which lithium ions can be inserted and removed 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 FIGS. 2-4, the electric current interruption apparatus 70 is demonstrated. The current interrupt device 70 is disposed on a current path between the negative electrode terminal 30 and the negative electrode current collecting tab (negative electrode) 46. The current interrupt device 70 may be disposed on the energization path between the positive electrode and the positive electrode terminal 10, or on both the energization path between the negative electrode and the negative electrode terminal 30 and on the energization path between the positive electrode and the positive electrode terminal 10. You may arrange. 2 and 3, the illustration of the seal member 42 interposed between the negative electrode terminal 30 and the case 4 is omitted.

  As shown in FIG. 2, the current interrupt 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 is made of a thermoplastic resin (for example, PPS). The support member 92 is formed in a cylindrical shape, and a space for accommodating the lower end portion of the internal nut 32 and the second reversing plate 90 is formed inside thereof. The upper surface 92 b of the support member 92 is in contact with the case 4. A protruding portion 92 c that protrudes inward is formed at the upper end of the support member 92. The protruding portion 92 c is in contact with the upper surface of the outer peripheral portion of the lower end portion of the internal nut 32. A heat caulking boss 92 a is formed on the lower surface 92 e of the support member 92. The fracture plate 88 is fixed to the support member 92 by the heat caulking boss 92a. That is, the lower end portion of the inner nut 32 and the second reversing plate 90 are accommodated inside the support member 92, and the protruding portion 92c of the support member 92 is in contact with the upper surface of the outer peripheral portion of the lower end portion of the inner nut 32. The fracture plate 88 is fixed to the lower surface 92 e of the support member 92. As a result, the support member 92 supports the first reversing plate 84 and the breaking plate 88 in a stacked state, and the current interrupt device 70 is fixed to the inner nut 32. Since the upper surface 92 b of the support member 92 contacts the case 4, the positions of the internal nut 32, the first reversing plate 84 and the fracture plate 88 with respect to the case 4 are positioned by the support member 92.

  The first inversion plate 84 is a circular plate material and is fixed to the lower surface of the fracture plate 88. Since the fracture plate 88 is fixed and supported by the support member 92, the first reverse plate 84 is also supported by the support member 92. An insulating 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. 3, a gap is formed between the protrusion 86 and the central portion 88 b of the breaking 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 is isolated from the space in the case 4, 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 disposed between the first reverse plate 84 and the second reverse plate 90. That is, the breaking plate 88 has an upper surface facing the second reversing plate 90 and a lower surface facing the first reversing plate 84. A connection terminal 72 is connected to a part of the outer edge of the fracture plate 88. A groove 88 a is formed at the center of the lower surface of the fracture plate 88. When the broken plate 88 is viewed from the bottom, the groove 88a is formed in a circular shape. As shown in FIG. 2, the cross-sectional shape of the groove 88a is 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.

  A plurality of through holes 88d are formed in the vicinity of the outer peripheral edge of the outer peripheral portion 88c of the breaking plate 88. Specifically, the through hole 88d is formed at a position corresponding to the heat caulking boss 92a of the support member 92 in the vicinity of the outer peripheral edge of the outer peripheral portion 88c. The heat caulking boss 92a of the support member 92 is inserted into the through hole 88d. The heat caulking boss 92a is in close contact with the inner surface of the through hole 88d by the heat caulking process, and the diameter D2 of the lower end thereof is larger than the diameter D1 of the through hole 88d (D2> D1). As a result, the support member 92 and the fracture plate 88 are fixed.

  The second reversing plate 90 is a circular plate material and is disposed above the fracture plate 88. In the state shown in FIG. 2, the central portion of the second reversing plate 90 is convex downward, and is fixed to the central portion 88 b of the fracture plate 88. Specifically, the central portion of the second reversing plate 90 is joined to the central portion 88b of the fracture plate 88 by welding. Moreover, the outer peripheral part of the 2nd inversion board 90 is joined to the lower end part of the internal nut 32 by welding. A welded portion between the second reverse plate 90 and the internal nut 32 is formed over the entire circumference of the outer peripheral portion of the second reverse plate 90. As apparent from the above, the negative electrode terminal 30 is connected to the electrode assembly 2 via the second reversing 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 isolated from the space in the case 4.

  A ring member 82 and a seal ring 89 are arranged in a space 96 surrounded by the second reverse plate 90, the fracture plate 88, and the support member 92. The seal ring 89 is a ring-shaped member and hermetically seals the space 96 (specifically, the space 96 inside the space 96 inside the seal ring 89) and the space in the case 4. For the seal ring 89, for example, a known O-ring or the like can be used. As shown in FIG. 4, the seal ring 89 is accommodated in a notch 92 f formed in the lower surface 92 e of the support member 92. That is, the seal ring 89 is accommodated in a space formed by the notch portion 92 f and the fracture plate 88. At the lower end of the outer peripheral portion of the inner nut 32, a protruding portion 32a protruding toward the fracture plate 88 side is formed (see FIGS. 2 and 4). The protrusion 32a partially closes the opening of the space formed by the notch 92f and the breaking plate 88. That is, a gap is formed between the projecting portion 32 a and the breaking plate 88, and insulation between the internal nut 32 and the breaking plate 88 is ensured. The outer peripheral corner of the lower end of the protrusion 32a is chamfered. Thereby, the lower end outer peripheral part of the protrusion part 32a is formed in the taper shape.

  As is apparent from FIGS. 2 and 4, the seal ring 89 is in contact with the support member 92 at the seal position C1, and is in contact with the fracture plate 88 at the seal position C2. Further, the protrusion 32a (specifically, the protrusion 32a And a seal position C3. That is, the seal ring 89 hermetically seals the space 96 and the space in the case 4 at three locations C1, C2, and C3. Further, the protruding portion 32a of the inner nut 32 is located inside the seal ring 89, and the inner peripheral surface of the seal ring 89 is in contact with the protruding portion 32a. The outer peripheral surface of the seal ring 89 is not in contact with the support member 92.

  An insulating ring member 82 is disposed in the gap between the protruding portion 32a and the breaking plate 88. The ring member 82 is an insulating material and is formed so as to have higher rigidity than the seal ring 89. As a material of the ring member 82, for example, PP (polypropylene) or PPS (polyphenylene sulfide) is used. For this reason, when the same external force acts on the ring member 82 and the seal ring 89, the deformation amount of the ring member 82 becomes smaller than the deformation amount of the seal ring 89. The ring member 82 includes a first portion 82a positioned between the protruding portion 32a and the breaker plate 88, and a second portion 82b positioned inside the protruding portion 32a. The lower surface of the first portion 82 a is in contact with the fracture plate 88. The upper surface of the first portion 82a is not in contact with the protruding portion 32a, and a slight gap is formed between them. The first portion 82 a extends to the vicinity of the outer peripheral end of the protrusion 32 a, that is, to the vicinity of the seal ring 89. The second portion 32b is located on the inner side of the protruding portion 32a, and the upper portion thereof faces the inner peripheral surface of the protruding portion 32a. As is apparent from FIG. 4, the cross-sectional shape of the first portion 82a is long in the horizontal direction and becomes a rectangular shape extending toward the seal ring 89, while the cross-sectional shape of the second portion 82b is long in the vertical direction and the protruding portion 32a. It is a rectangular shape along. That is, the ring member 82 is a deformed ring member in which the cross-sectional shape of the first portion 82a and the cross-sectional shape of the second portion 82b are different, and the overall cross-sectional shape is L-shaped.

  In the power storage device 100 described above, in the state shown in FIG. 2, 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. 4, the fracture plate 88 breaks at the groove 88a, and the outer peripheral portion (88e to 88g) of the fracture plate 88 and the second The energization path between the reversing plates 90 (internal 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. 2). Since the space 94 is isolated from the space in the case 4, the pressure acting on the upper surface of the first reversing plate 84 (that is, the pressure in the space 94) is not easily affected by the pressure increase in the space in the case 4. For this reason, when the internal pressure in the case 4 exceeds a predetermined value (set pressure), 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 88b of the breaking plate 88, and the first reversing plate 84 are displaced upward (in FIG. 4). State). As a result, the energization path connecting the fracture plate 88 and the second reversing plate 90 is interrupted, and the energization between the electrode assembly 2 and the negative electrode terminal 30 is interrupted.

  Here, when the pressure in the space in the case 4 increases, the pressure acting on the outer surface of the seal ring 89 increases. On the other hand, since the space 96 is hermetically sealed from the space in the case 4 by the seal ring 89, the pressure acting on the inner surface of the seal ring 89 does not change. For this reason, a force is applied to the seal ring 89 to displace the seal ring 89 inward. In the present embodiment, the inner surface of the seal ring 89 abuts against the protruding portion 32 a of the internal nut 32, and a ring member 82 is disposed in the gap between the protruding portion 32 a and the breaking plate 88. For this reason, position shift to the inner side of the seal ring 89 can be prevented, and deterioration of the sealing performance of the seal ring 89 can be suppressed. In particular, when the ring member 82 is not disposed in the gap between the protruding portion 32a and the fracture plate 88, the seal ring 89 protrudes into the gap, and there is a high possibility that the sealing performance of the seal ring 89 is deteriorated. However, in the present embodiment, the ring member 82 disposed in the gap between the protruding portion 32a and the fracture plate 88 prevents the seal ring 89 from protruding, and the deterioration of the sealing performance of the seal ring 89 can be suitably suppressed. . For this reason, the electric current interruption apparatus 70 can be operated appropriately. For example, when the sealing performance of the seal ring 89 is lowered, there is a possibility that the electrolyte enters the space 96 between the second reversing plate 90 and the fracture plate 88. When the electrolytic solution enters the space 96, liquid electrolyte may be generated between the second reversing plate 90 and the fracture plate 88 by the electrolytic solution. When a liquid drop is generated between the second reversing plate 90 and the fracture plate 88, the energization cannot be interrupted even after the current interrupting device 70 is activated.

  In the power storage device 100 of the present embodiment, the fracture plate 88 is fixed to the lower surface 92e of the support member 92 that contacts the case 4 using heat caulking, and the internal nut 32 is held by the support member 92. . That is, the position of each member (32, 88, 90, etc.) with respect to the case 4 is controlled by the support member 92. For this reason, the dimensional accuracy of the whole current interrupting device 70 can be improved only by improving the dimensional accuracy of the support member 92. Since the dimensional accuracy of the current interrupt device 70 can be improved, the tolerance of each member (32, 88, 90, etc.) of the current interrupt device 70 can be set small, and the current interrupt device 70 can be miniaturized.

  Finally, the correspondence relationship between the above-described embodiment and the description of the claims will be described. The first reverse plate 84 is an example of a “deformable plate”, the second reverse plate 90 is an example of a “first current plate”, the fracture plate 88 is an example of a “second current plate”, and the ring member 82. Is an example of an “insulating ring member”.

  As mentioned above, although the specific example of the technique disclosed by this specification was demonstrated in detail, this is only an illustration and does not limit a claim. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.

  For example, in the above-described embodiment, the ring member 82 is disposed in the gap between the protruding portion 32a of the internal nut 32 and the breaking plate 88, but the shape of the ring member disposed between the protruding portion and the breaking plate takes various forms. be able to. For example, as shown in FIG. 5, the ring member 182 may be disposed in the gap between the protruding portion 32 a of the internal nut 32 and the fracture plate 188. The ring member 182 includes a first portion 182a disposed in the gap between the protruding portion 32a and the fracture plate 188, and a second portion 182b disposed inside the protruding portion 32a. The second portion 182b is bent from the inner peripheral end of the first portion 182a toward the fracture plate 188. A groove 188a is formed on the upper surface of the fracture plate 188, and a second portion 182b is disposed in the groove 188a. According to such a configuration, the displacement of the ring member 182 is regulated by the groove 188 a, and the force from the seal ring 89 can be suitably received by the ring member 182. Further, the shape of the ring member is not limited to the shape shown in FIGS. 4 and 5, and the one having both the shape of FIG. 4 and the shape of FIG. 5, that is, the second portion arranged inside the protrusion 32 a is upward ( It may protrude downward (protruding portion 32a side) and downward (rupture plate side). Moreover, in each Example mentioned above, although 2nd part 82b, 182b was arrange | positioned inside the protrusion part 32a, a 2nd part may be located in the outer side of the protrusion part 32a. In this case, the inner surface of the seal ring comes into contact with the second portion of the ring member.

  The technical elements described in this specification or the 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 24: Positive electrode lead 12, 32: Internal nut 14, 34: Bolt 16, 36: External nut 30: Negative electrode terminal 44: Negative electrode lead 70: Current interruption device 84: First Reverse plate 88: Breaking plate 90: Second reverse plate 100: Power storage device

Claims (5)

Provided on a current-carrying path connecting a terminal provided in the case and the electrode assembly accommodated in the case, and flows between the terminal and the electrode assembly when an internal pressure in the case exceeds a set pressure A current interrupting device for interrupting current,
A first energization plate whose outer periphery is fixed to the terminal;
A second energization plate disposed opposite to the first energization plate and having a central portion fixed to the central portion of the first energization plate and electrically connected to the electrode assembly;
A deformation plate disposed opposite to a surface opposite to the surface facing the first current plate of the second current plate;
A support member formed of an insulating material and fixed to the second current-carrying plate, and supporting the second current-carrying plate with respect to the terminal;
The terminal, the first energizing plate, the second energizing plate, and the support member are disposed in a space between the terminal and the second energizing plate outside the outer peripheral edge of the first energizing plate. And a seal ring for sealing
The deformation plate receives the pressure of the internal space of the case on a surface opposite to the surface facing the second energization plate and is isolated from the internal space of the case on a surface facing the second energization plate. Under the pressure of
When the pressure in the internal space of the case exceeds a set value, the deforming plate is deformed to the second energizing plate side, whereby the second energizing plate is broken and flows between the terminal and the electrode assembly. Cut off the current,
A through hole is formed in the outer peripheral portion of the second energization plate,
The support member is inserted into the through hole, and has a heat caulking boss that fixes the support member to the second current plate.
The surface of the terminal facing the second energizing plate is formed with a protruding portion that protrudes toward the second energizing plate at a position inside the seal ring.
An electric current interrupting device, wherein an insulating ring member made of an insulating material is disposed between the protruding portion and the second current plate. The insulating ring member has a first portion disposed between the protruding portion and the second current-carrying plate, and a second portion disposed outside or inside the protruding portion,
2. The current interrupting device according to claim 1, wherein a shape of the first portion in a straight axial section is different from a shape of the second portion in a right straight section.   3. The current interrupting device according to claim 2, wherein the second portion of the insulating ring member is disposed on an inner side than the protruding portion, and a part of the second portion opposes an inner peripheral surface of the protruding portion. A groove is formed on a surface of the second energizing plate facing the first energizing plate,
The current interrupting device according to claim 2, wherein the second portion of the insulating ring member is engaged with the groove of the second current plate.   An electrical storage apparatus provided with the electric current interruption apparatus as described in any one of Claims 1-4.

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