JP2014002901A - Electric current cutout device, and power storage device provided with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric current cutoff device provided with a mechanism which prevents a cut off electric conduction path from being reconnected, and to provide a power storage device provided with the same.SOLUTION: An electric current cutoff device has: a deformation plate which is arranged so as to form an outside surface of the electric current cutoff device, and is deformed when inner pressure inside a case rises exceeding a prescribed level; a contact plate electrically connected to an external terminal; and an electric conduction plate which is arranged so as to be sandwiched between the deformation plate and the contact plate and is connected in series between an electrode assembly and the contact plate within an electric conduction path. The deformation plate has: a pressure-receiving part capable of pressure-receiving the inner pressure inside the case; and a projection which projects toward the electric conduction plate from the pressure-receiving part. On an external surface of the projection, a locking part is provided. The projection abuts to the electric conduction plate by the deformation plate deforming in such a way as moving to an electric conduction plate side, and cuts off the electric conduction path while separating at least a part of the electric conduction plate. The locking part of the projection is locked to the separated electric conduction plate, and keeps the state where the electric conduction plate is separated.

Description

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

  In order to cut off the energization path when the pressure in the battery case increases due to the gas generated from the electrode assembly, for example, when the battery is overcharged, a current interruption device may be installed in the case. When the energization path is interrupted by such a current interrupting device, the pressure in the case that has once increased turns down, and the energization path may be reconnected. Patent Document 1 describes a pressure detection type current interrupting device including a holding mechanism that prevents reconnection of an energization path after current interrupting, and a sealed battery including the same. The current interrupting device includes a partition plate that is electrically connected to the positive electrode of the electrode assembly, a drive member that connects the energization path by contacting the partition plate, and a holding mechanism formed by an elastic member. Yes. When the pressure in the battery case rises, the drive member rises and is separated from the partition plate, and the energization path is interrupted. When the drive member is further raised, the lower end portion of the drive member and the holding mechanism are engaged to prevent the drive member from being lowered in the direction of the partition plate and reconnected.

JP-A-6-290767

  In Patent Document 1, in order to connect or disconnect the energization path, an elastic member holding mechanism that does not contribute to the connection and disconnection of the energization path is separately installed, and the configuration is complicated and expensive.

  The current interrupting device disclosed in this specification electrically connects an electrode assembly including a positive electrode and a negative electrode to either a positive or negative external terminal, and an internal pressure in a case housing the electrode assembly exceeds a predetermined level. When it rises, the current-carrying path between the electrode assembly and the external terminal is cut off. This current interrupting device is arranged to be the outer surface of the current interrupting device, a deformation plate that deforms when the internal pressure in the case rises above a predetermined level, a contact plate that is electrically connected to the external terminal, It has an electricity supply plate which is arranged so as to be sandwiched between the deformation plate and the contact plate, and is connected in series between the electrode assembly and the contact plate in the electricity supply path. The deformable plate has a pressure receiving portion capable of receiving the internal pressure in the case, and a protrusion protruding from the pressure receiving portion toward the energizing plate. A locking portion is provided on the outer surface of the protrusion. The protrusion abuts on the energization plate by deforming the deformable plate so as to move toward the energization plate, and separates at least a part of the energization plate to block the energization path. The locking portion of the protrusion is locked to the separated energizing plate and maintains the state where the energizing plate is separated.

  In the above current interrupting device, when the internal pressure in the case rises above a predetermined level, the deforming plate is deformed, whereby the protrusion separates the energizing plate, so that the energization path between the electrode assembly and the external terminal is established. Blocked. A locking portion is provided on the outer surface of the protrusion. When the locking portion is locked by the separated energizing plate, the state where the energizing plate is separated is maintained and the energizing path is interrupted. Maintained. According to the above-described current interrupt device, there is no need to provide another member for preventing reconnection of the energization path unlike the protection mechanism of Patent Document 1, and it is possible to reliably prevent reconnection of the energization path with a simple configuration. be able to.

  In the above current interrupting device, the locking portion may be a concave portion or a convex portion provided on the outer surface of the protrusion.

  In the above current interrupting device, the energization plate includes a latch receiving portion that curves in a direction from the deformation plate side toward the energization plate side around the projection, and the latch receiving portion is provided when the energization plate is separated by the projection. You may engage with the latching | locking part of protrusion.

  The present specification also discloses a power storage device including the current interrupt device. This power storage device may be a secondary battery.

  ADVANTAGE OF THE INVENTION According to this invention, the electric current interruption apparatus and electric storage apparatus which can make compatible the interruption | blocking of an electric current reliably at the time of abnormal operation | movement of an electrical storage apparatus, and avoiding the electric current interruption at the time of electricity supply operation can be provided.

It is sectional drawing of the electric current interruption apparatus which concerns on Example 1, and an electrical storage apparatus provided with the same. It is a figure which expands and shows the vicinity of the electric current interruption apparatus of FIG. 1, and has shown the state at the time of normal operation of an electrical storage apparatus. It is a figure which expands and shows the vicinity of the protrusion of FIG. It is a figure which expands and shows the vicinity of the protrusion of FIG. 2, and has shown the state which the deformation | transformation board rose and the protrusion isolate | separated the electricity supply board at the time of the overcharge of the electrical storage apparatus. It is a figure which expands and shows the vicinity of the protrusion of FIG. 2, and has shown the state which the deformation | transformation board fell after a protrusion isolate | separated the electricity supply board at the time of the overcharge of an electrical storage apparatus. It is a figure which shows the vicinity of the protrusion of the electric current interruption apparatus which concerns on a modification. It is a figure which shows the vicinity of the protrusion of the electric current interruption apparatus which concerns on Example 2, and has shown the state at the time of normal operation of an electrical storage apparatus. It is a figure which shows the vicinity of the protrusion of the electric current interruption apparatus which concerns on Example 2, and has shown the state which the deformation | transformation board rose and the protrusion isolate | separated the electricity supply board at the time of the overcharge of an electrical storage apparatus. It is a figure which shows the vicinity of the protrusion of the electric current interruption apparatus which concerns on Example 2, and has shown the state which the deformation | transformation board fell after a protrusion isolate | separated the electricity supply board at the time of the overcharge of an electrical storage apparatus. It is a figure which shows the vicinity of the protrusion of the electric current interruption apparatus which concerns on Example 3, and has shown the state at the time of normal operation of an electrical storage apparatus. It is a figure which shows the vicinity of the protrusion of the electric current interruption apparatus which concerns on Example 3, and has shown the state which the deformation | transformation board rose and the protrusion isolate | separated the electricity supply board at the time of the overcharge of an electrical storage apparatus. It is a figure which shows the vicinity of the protrusion of the electric current interruption apparatus which concerns on Example 3, and has shown the state which the deformation | transformation board rose and the protrusion isolate | separated the electricity supply board at the time of the overcharge of an electrical storage apparatus. It is a figure which shows the vicinity of the protrusion of the electric current interruption apparatus which concerns on Example 3, and after the protrusion isolate | separated the electricity supply board at the time of the overcharge of an electrical storage apparatus, it has shown the state which the deformation | transformation board fell. It is a figure which shows the vicinity of the protrusion of the electric current interruption apparatus which concerns on a modification, and has shown the state at the time of normal operation of an electrical storage apparatus. It is a figure which shows the vicinity of the protrusion of the electric current interruption apparatus which concerns on a modification, and shows the state which the deformation | transformation board fell, after a deformation | transformation board raises and the protrusion isolate | separates the electricity supply board at the time of overcharge of an electrical storage apparatus.

  The current interrupting device disclosed in this specification can be used for a conventionally known power storage device such as a sealed secondary battery and a sealed capacitor. Furthermore, specific examples of the secondary battery include secondary batteries such as lithium ion batteries, nickel metal hydride batteries, nickel cadmium batteries, and lead storage batteries that are charged and discharged with a relatively high capacity and a large current. The power storage device may be mounted on a vehicle, an electric device, or the like.

  A power storage device disclosed in the present specification includes an electrode assembly including a positive electrode and a negative electrode, a case that accommodates the electrode assembly, and conductive members (a positive electrode conductive member and a negative electrode conductive member) that are electrically connected to the electrode assembly. And an external terminal (positive external terminal, negative external terminal) and a current interrupting device. As the electrode assembly, for example, an electrode assembly including a pair of electrodes in a state where a positive electrode sheet and a negative electrode sheet sandwich a sheet-like separator between them can be mentioned. Examples include a stacked electrode assembly in which a large number of pairs are stacked, and a wound electrode assembly in which this electrode pair is wound around a predetermined axis. The electrode assembly may be immersed in the electrolyte.

  The current interrupting device disclosed in this specification electrically connects an electrode assembly including a positive electrode and a negative electrode to either a positive or negative external terminal, and an internal pressure in a case housing the electrode assembly exceeds a predetermined level. When it rises, the current-carrying path between the electrode assembly and the external terminal is cut off. This current interrupting device is arranged to be the outer surface of the current interrupting device, a deformation plate that deforms when the internal pressure in the case rises above a predetermined level, a contact plate that is electrically connected to the external terminal, An energization plate is disposed so as to be sandwiched between the deformation plate and the contact plate, and is connected in series between the electrode assembly and the contact plate in the energization path.

  More specifically, the current-carrying plate is electrically connected to the positive electrode or the negative electrode of the electrode assembly, and is connected to an external terminal (positive electrode external terminal and negative electrode) corresponding to the electrode on the connected side via the contact plate. One of the external terminals) is electrically connected to form an energization path. The current interrupting device is connected in series with an external terminal or the like in the energization path, and is configured to be able to interrupt the energization path by separating the energization plate. The current interruption path may be installed only in one of the positive-electrode side and the negative-electrode side, or may be installed in both.

  In the above current interrupting device, the deformable plate has a pressure receiving portion that can receive the internal pressure in the case, and a protrusion that protrudes from the pressure receiving portion toward the energizing plate. A locking portion is provided on the outer surface of the protrusion. The protrusion abuts on the energization plate by deforming the deformable plate so as to move toward the energization plate, and separates at least a part of the energization plate to block the energization path. The locking portion of the protrusion is locked to the separated energizing plate and maintains the state where the energizing plate is separated.

  In the above current interrupting device, the protrusion locking portion may be a recess or a protrusion provided on the outer surface of the protrusion. For example, when the separated energization plate enters the recess as the latching portion or is hooked and engaged with the projection, the projection is locked by the energization plate and the projection is prevented from descending. Moreover, you may comprise a latching | locking part by making the frictional resistance of the outer surface of a protrusion high. More specifically, for example, the frictional resistance of the outer surface of the protrusion can be increased by roughening the outer surface of the protrusion or using a material having a high frictional resistance as the material of the outer surface of the protrusion. The protrusion is locked by the energizing plate due to the friction between the engaging portion having high frictional resistance and the separated energizing plate, and the protrusion is prevented from descending. It is preferable that the locking portion is provided at a proximal portion at least closer to the abutting surface where the protrusion abuts the energizing plate. When the locking portion is provided in the proximal portion of the contact surface, the protrusion can be locked even when the deformation amount of the deformation plate is small, and it is more reliable regardless of the deformation amount of the deformation plate. The protrusion can be locked to the surface. Moreover, it is preferable that a part or all of the protrusions are insulative so that the energization path is not connected through the protrusions in a state where the protrusions and the current-carrying plates are locked.

  In the above current interrupting device, a portion for locking the protrusion to the energizing plate may be further provided. For example, the energization plate includes an engagement receiving portion that curves in the direction from the deformation plate side toward the energization plate side around the protrusion, and the engagement reception portion is a protrusion engagement portion when the energization plate is separated by the protrusion. May be engaged.

  FIG. 1 is a cross-sectional view of the stacked power storage device 100 according to the first embodiment. The power storage device 100 includes a case 1, an electrode assembly 60, current collecting terminals 65 and 67, a first positive electrode conductive member 13, a second positive electrode conductive member 68, a negative electrode conductive member 64, and a positive electrode external. A terminal 19, a negative external terminal 119, insulating members 61 and 66, and a current interrupt device 2 are provided. The electrode assembly 60 is sandwiched between a positive electrode sheet including a positive electrode active material and a positive electrode current collector, a negative electrode sheet including a negative electrode active material and a negative electrode current collector, and the positive electrode sheet and the negative electrode sheet. And a sheet-like separator to be separated. The electrode assembly 60 is a laminate in which a large number of positive electrode sheets, separators, and negative electrode sheets are laminated in this order, and is impregnated with a liquid electrolyte.

  The case 1 is a box-shaped member having a substantially rectangular parallelepiped shape, and has an electrode assembly 60, current collecting terminals 65 and 67, a first positive electrode conductive member 13, a second positive electrode conductive member 68, and a negative electrode conductive therein. The member 64, the insulating members 61 and 66, and the electric current interruption apparatus 2 are accommodated. A positive external terminal 19 and a negative external terminal 119 are provided on the upper end surface of the case 1. The current collectors of the plurality of positive electrode sheets of the electrode assembly 60 are bundled by current collection terminals 67, and the current collectors of the plurality of negative electrode sheets are bundled by current collection terminals 65. The electrode assembly 60 is covered with an insulating film, and protrudes from the insulating film at portions connected to the current collecting terminals 67 and 65.

  The current collecting terminals 65 and 67 extend from the electrode assembly 60 toward the upper end surface of the case 1, bend toward the front side of the paper surface of FIG. 1 in the middle, and have a flat portion substantially parallel to the upper end surface of the case 1. It is formed in the shape to have.

  As shown in FIG. 1, the negative electrode conductive member 64 is a flat conductive member. The negative electrode conductive member 64 extends substantially in parallel to the upper end surface of the case 1 from the current collecting terminal 65 toward the negative electrode external terminal 119. The negative electrode conductive member 64 and the current collecting terminal 65 are fixed by welding. Thus, the negative electrode energization path from the negative electrode of the electrode assembly 60 to the negative electrode external terminal 119 is electrically connected by the current collecting terminal 65 and the negative electrode conductive member 64 connected in series in this order. .

  As shown in FIG. 1, the first positive electrode conductive member 13 is connected in series between the current interrupt device 2 and the second positive electrode conductive member 68, and is fixed to each other by welding. The second positive electrode conductive member 68 is a flat conductive member. The second positive electrode conductive member 68 extends substantially parallel to the upper end surface of the case 1 toward the positive electrode external terminal 19. The second positive electrode conductive member 68 is fixed to the current collecting terminal 67 by welding. The current interrupt device 2 is fixed to the positive external terminal 19 on the upper surface side. The positive external terminal 19 and the first positive electrode conductive member 13 are electrically connected via the current interrupt device 2. As described above, the positive electrode energization path from the positive electrode of the electrode assembly 60 to the positive electrode external terminal 19 has a current collecting terminal 67, a second positive electrode conductive member 68, and a first positive electrode conductive material connected in series in this order. The member 13 and the current interrupt device 2 are electrically connected. An insulating member 66 is provided between the negative electrode conductive member 64, the first positive electrode conductive member 13, the second positive electrode conductive member 68, and the upper end surface of the case 1, thereby the negative electrode conductive member. 64, the first positive electrode conductive member 13 and the second positive electrode conductive member 68 are insulated from the case 1.

  As shown in FIG. 2, the current interrupt device 2 includes a deformable plate 3, a current-carrying plate 4, a contact plate 5, sealing materials 14 and 17, support members 11 and 20, and protrusions 12. The energization plate 4 is electrically connected to the first positive electrode conductive member 13. The contact plate 5 is electrically connected to the positive external terminal 19 through the sealing lid body 7. In the direction from the positive electrode external terminal 19 side to the electrode assembly 60 side (the direction from the top to the bottom in FIG. 2), the contact plate 5, the current plate 4 and the deformation plate 3 are arranged in this order. A sealing material 17 is sandwiched between the contact plate 5 and the energizing plate 4, and a sealing material 14 is sandwiched between the energizing plate 4 and the deformation plate 3.

  The sealing lid 7 is sandwiched by an insulating support member 11 so as to be in electrical contact with the contact plate 5 at the outer peripheral portion. In addition, the sealing lid 7 has a concave portion 18 that is recessed upward at the inner surface portion other than the outer peripheral end constituting the contact plate 5 and the contact portion, and the contact plate 5 is deformed upward by deformation of the deformation plate 3 to be described later. A permissible space is formed.

  An insulating sealing member 10 is mounted between the upper surface of the sealing lid 7 and the inner surface of the case 1, and the sealing lid 7 and the case 1 are electrically insulated. The support member 11 is insulative, is formed by a resin mold, and is formed in a ring shape with a substantially U-shaped cross section. The substantially U-shaped inner surface of the support member 11 covers the outer peripheral portion of the deformable plate 3, the sealing materials 14 and 17, the outer peripheral portion of the energizing plate 4 and the outer peripheral portion of the sealing lid body 7, and these members are laminated. It is clamped and held together. A metal caulking support member 20 is covered on the outer surface of the support member 11.

  The deformation plate 3 is made of a thin plate, for example, a metallic diaphragm, and is fixed by the support member 11 at the outer peripheral portion. The inside of the current interrupt device 2 is sealed with the seal member 14 from the electrode assembly 60 side in the case 1. The deformation plate 3 is disposed so as to be the outer surface of the current interrupting device 2, the lower surface side thereof faces a region on the electrode assembly 60 side in the case 1, and the upper surface side thereof is the current interrupting device 2. Facing inside. By the deformation plate 3, the inside of the current interrupt device 2 is separated from the region on the electrode assembly 60 side in the case 1. In addition, an insulating protrusion 12 that protrudes toward the energizing plate 4 is provided at the center of the deformable plate 3. The protrusion 12 has a cylindrical shape, and the surface on the current-carrying plate 4 side is the contact surface 24. The lower surface side of the deformable plate 3 facing the electrode assembly 60 is a planar pressure receiving portion 22. As shown in FIG. 3, the protrusion 12 includes a locking portion 12 a in the proximal portion (the upper end portion of the protrusion 12 shown in FIG. 3 and the like) that is in the vicinity of the contact surface 24. The locking portion 12 a is a convex portion formed in the entire circumferential direction of the protrusion 12 in the proximal portion of the protrusion 12. As shown in FIG. 3, the locking portion 12 a has a triangular shape in a cross section obtained by cutting the protrusion 12 in the height direction, and the center portion in the vertical direction protrudes most, and the protrusion 12 extends in the vertical direction from the center portion. The shape gradually decreases toward the side of the cylindrical shape.

  The energization plate 4 includes a central portion 34 and a peripheral portion 15. The center part 34 is a disk located above the contact surface 24 of the projection 12 of the deformable plate 3, and the peripheral part 15 is a disk having a circular hole at the center thereof. In the state of FIG. 2, the outer diameter of the central hole of the peripheral portion 15 is smaller than the outer diameter of the central portion 34 and the protrusion 12. The upper surface of the central portion 34 is the connection portion 6, and the energization plate 4 is in contact with the contact plate 5 at the connection portion 6. The peripheral portion 15 is formed thinly around the central portion 34 and includes a latch receiving portion 35 that curves in a direction from the deformable plate 3 side toward the energizing plate 4 side (upward direction shown in FIG. 3 and the like). The peripheral edge of the lower surface of the central portion 34 and the upper surface of the end portion of the locking receiving portion 35 of the peripheral portion 15 are joined by welding. When a predetermined force is applied to the central portion 34 in the upward direction, the central portion 34 and the latch receiving portion 35 are separated. The peripheral portion 15 of the energization plate 4 is fixed to the first positive electrode conductive member 13 by welding, and is thereby electrically connected to the positive electrode of the electrode assembly 60.

  The contact plate 5 is made of a conductive flat plate-like thin plate, for example, a conductive metal diaphragm, and is fixed by a support member 11 at the outer peripheral portion. The contact plate 5 is in contact with the connection portion 6 of the energization plate 4 at the connection portion 23 on the lower surface of the central portion. The connection portion 6 of the current plate 4 and the connection portion 23 of the contact plate 5 are fixed to each other by welding and are electrically connected.

  From the electrode assembly 60 toward the positive electrode external terminal 19, the current collecting terminal 67, the second positive electrode conductive member 68, the first positive electrode conductive member 13, the energizing plate 4, the contact plate 5, and the sealing lid body 7 are arranged in this order. Connected in series. The arrows in FIG. 2 indicate the positive electrode energization path 21 from the electrode assembly 60 to the positive electrode external terminal 19.

  The interruption | blocking of the electricity supply path | route 21 by the electrical storage apparatus 100 by the electric current interruption apparatus 2 is demonstrated using FIGS. As shown in FIG. 3, during the normal operation of the power storage device 100, the central portion 34 and the peripheral portion 15 of the energization plate 4 are connected, and the positive electrode energization path 21 is connected.

  When hydrogen gas or the like is generated from the electrode assembly 60 and the pressure on the electrode assembly 60 side in the case 1 rises when the power storage device 100 is overcharged, the deformation plate 3 rises as shown in FIG. The protrusion 12 also rises, the abutting surface 24 abuts on the central portion 34 of the energizing plate 4, and presses upward so as to separate the central portion 34 from the peripheral portion 15. When the projection 12 abuts on the central portion 34, the projection 12 also contacts the end portion of the latch receiving portion 35. Since the locking receiving portion 35 is formed to be thin and curved upward, when pressed by the projection 12, the locking receiving portion 35 is deformed so that the outer diameter of the central hole portion of the peripheral portion 15 is widened. The locking portion 12a passes through the hole in the peripheral portion 15. As a result, the central portion 34 and the peripheral portion 15 are separated from each other, and the positive electrode energizing path 21 is interrupted. The locking portion 12a of the protrusion 12 is gently inclined from the abutment surface 24 side of the protrusion 12 toward the center portion most protruding from the protrusion 12, and the locking receiving portion 35 of the peripheral portion 15 is Since it is curved in the direction, the outer diameter of the hole at the center of the peripheral portion 15 is easily expanded, and the protrusion 12 can pass therethrough. The protrusion 12 does not prevent the central portion 34 from being separated by the engagement of the locking portion 12a and the locking receiving portion 35 or the like.

  When the pressure in the case 1 of the power storage device 100 decreases after the protrusion 12 separates the energizing plate 4, the deformed plate 3 that has once increased is lowered and the protrusion 12 is lowered as shown in FIG. When the projection 12 is lowered, the locking portion 12 a of the projection 12 is locked by the locking receiving portion 35 of the energization plate 4. As a result, the protrusion 12 enters between the central portion 34 and the latch receiving portion 35, and reconnection between the central portion 34 and the latch receiving portion 35 is avoided. Since the latch receiving portion 35 is curved upward, even if the latch receiving portion 35 is pressed downward by the projection 12, the outer diameter of the central hole portion of the peripheral portion 15 widens and the latch portion 12 a of the projection 12 passes through. Never do.

  As described above, in the current interrupt device 2 of the power storage device 100, the deformable plate 3 is deformed when the internal pressure on the electrode assembly 60 side in the case 1 rises above a predetermined level, thereby causing the protrusion 12 to become the energizing plate 4. Is separated from the positive electrode energization path 21 between the electrode assembly 60 and the positive electrode external terminal 19. A locking portion 12 a is provided on the outer surface of the protrusion 12 and is locked to the locking receiving portion 35 of the peripheral portion 15 of the separated energizing plate 4. For this reason, the state where the central portion 34 and the peripheral portion 15 of the energization plate 4 are separated is maintained, and the state where the positive electrode energization path 21 is blocked is maintained. The locking portion 12a of the protrusion 12 can be easily provided by changing the shape of the protrusion 12, and it is not necessary to secure a new installation space. That is, according to the current interrupting device 2 described above, positive electrode energization is ensured with a simple and space-saving configuration of the locking portion 12a formed on the protrusion 12 without providing another member such as the holding mechanism of Patent Document 1. Reconnection of the path 21 can be prevented. Moreover, since the latching | locking part 12a is provided in the proximal part of the contact surface 24, even if it is a case where the deformation amount of the deformation | transformation board 3 is small, it can latch to the latching receiving part 35 reliably.

  Further, in the current interrupt device 2, the energization plate 4 has the latch receiving portion 35 that curves in the direction from the deformation plate 3 side toward the energization plate 4 side (upward direction shown in FIG. 3 and the like) around the protrusion 12. I have. According to the latch receiving portion 35, when the projection 12 rises, the outer diameter of the hole at the center of the peripheral portion 15 is deformed so that the latch portion 12 a of the projection 12 becomes the center of the peripheral portion 15. It is easy to pass through the hole. Further, according to the latch receiving portion 35, when the central portion 34 and the peripheral portion 15 of the energizing plate 4 are separated by the projection 12, the latch receiving portion 35 is engaged with the latch portion 12 a of the projection 12, and the projection 12 is more reliably locked. Thus, reconnection of the positive electrode energization path 21 can be more reliably prevented. Similarly to the locking portion 12a of the protrusion 12, the locking receiving portion 35 can be easily provided by changing the shape of the energization plate 4 which is a part of the positive electrode energizing path 21, and a new installation space is secured. There is no need to do.

  Further, in the current interrupt device 2, the connecting portions 6 and 23 between the energizing plate 4 and the contact plate 5 are interrupted from the electrolyte atmosphere by the deformation plate 3. 23 can be prevented, and even if an arc (spark) is generated when the energization path is broken, there is no influence on the electrode assembly 60 side in the case 1 where hydrogen gas is generated. Further, since the deformable plate 3 is not in contact with other members except for the fixed portion on the outer periphery, the deformable plate 3 is not affected by the welding strength and is stably operated by the internal pressure.

  Moreover, in said electric current interruption apparatus 2, the 1st connection part 6 and the 2nd connection part 23 are formed in the center part in the electricity supply board 4 and the contact plate 5, respectively. For this reason, the contact surface 24 of the deformation | transformation board 3 can be arrange | positioned in the center part, and the part with a large deformation amount of the deformation | transformation board 3 can be utilized effectively for interruption | blocking.

  Further, in the above current interrupting device 2, the insulating plate 12 that protrudes toward the contact plate 5 is provided at the center of the deformation plate 3, and the contact surface 24 is formed on the projection 12. Yes. For this reason, after the energization path is interrupted, the insulating projection 12 prevents re-contact between the energization plate 4 and the contact plate 5, and the impact force of the projection 12 provided on the deformable plate 3 causes the connection portion 6, The current interrupting pressure is stabilized to compensate for the variation in the breaking load of 23.

  Moreover, in said electric current interruption apparatus 2, the deformation | transformation board 3 and the contact plate 5 are comprised from the thin plate. For this reason, the deformation plate 3 and the contact plate 5 can be easily manufactured. Further, the operations of the deformation plate 3 and the contact plate 5 are stabilized.

(Modification)
In the first embodiment, the columnar protrusion 12 has the locking portion 12a formed in the entire circumferential direction, but is not limited thereto. For example, like the protrusion 112 shown in FIG. 6, you may have the latching | locking part 112a formed in a part of circumferential direction. The locking portion 112a can be freely designed at a position or the like formed within a range where the separated energization plate 4 is not reconnected.

  The power storage device according to the second embodiment is different from the first embodiment in the shape of the protrusion of the current interrupt device. As shown in FIG. 7, in the current interrupting device according to the second embodiment, the protrusion 212 provided on the deformation plate 3 has a hollow circular tube shape. A locking portion 212a having the same shape as the locking portion 12a of the first embodiment is provided at the upper end portion of the outer surface in the circumferential direction of the circular tube-shaped protrusion 212. Since the other configuration of the power storage device is the same as that of the power storage device 100 of the first embodiment, the description thereof is omitted. As shown in FIG. 7, during the normal operation of the power storage device, the central portion 34 and the peripheral portion 15 of the energization plate 4 are connected and the positive electrode energization path is connected.

  When the pressure on the electrode assembly 60 side in the case 1 rises during overcharging of the power storage device, as shown in FIG. 8, the protrusion 212 rises as the deformation plate 3 rises, and the protrusion 212 is brought into contact with the contact surface. Abutting on the lower surface of the central portion 34 of the energization plate 4, the central portion 34 is pressed upward so as to be separated from the peripheral portion 15. At this time, the latch receiving portion 35 also comes into contact with the protrusion 212 and exerts a force on each other. Since the protrusion 212 is a circular tube-shaped hollow member, the outer peripheral surface of the protrusion 212 is deformed so as to enter the inside as shown by the arrow in FIG. The diameter decreases and passes through the central hole of the peripheral portion 15. As a result, the central portion 34 and the peripheral portion 15 are separated from each other, and the positive electrode energization path is interrupted.

  When passing through the central hole of the peripheral portion 15, the outer diameter at the upper end of the protrusion 212 returns to the original state. When the pressure in the case 1 of the power storage device decreases after the protrusion 212 separates the current-carrying plate 4, as shown in FIG. 9, the once-deformed deformation plate 3 descends and the protrusion 212 descends. Since the outer diameter of the upper end portion of the projection 212 has returned to the original state, when the projection 212 is lowered, the locking portion 212 a of the projection 212 is locked by the locking receiving portion 35 of the energizing plate 4. As a result, the projection 212 enters between the central portion 34 and the latch receiving portion 35, and reconnection between the central portion 34 and the latch receiving portion 35 is avoided.

  As described above, also in the second embodiment, similarly to the first embodiment, it is possible to reliably prevent reconnection of the positive electrode energization path with the simple and space-saving configuration of the locking portion 212a formed on the protrusion 212. Further, since the projection 212 is a hollow member, when the center portion 34 is pressed upward so as to be separated from the peripheral portion 15, the outer diameter is reduced so that it can easily pass through the hole portion of the peripheral portion 15. Can be transformed. For this reason, it is not necessary to make the latch receiving portion 35 of the energization plate 4 thin so as to be easily deformed. As shown in FIG. 2, the latch receiving portion 35 is a part of the positive electrode energizing path 21. According to the second embodiment, it is possible to increase the thickness of the latch receiving portion 35 in order to reduce the electrical resistance during energization.

  The power storage device according to the third embodiment is different from the first embodiment in the shape of the protrusion of the current interrupt device. As shown in FIG. 10, in the current interrupting device according to the third embodiment, the protrusion 312 provided on the deformation plate 3 has a cylindrical shape, and a locking portion 312a is provided at the upper end of the outer surface in the circumferential direction. It has been. The locking portion 312a is a two plate-like member disposed 180 degrees apart in the circumferential direction, and spreads in an obliquely downward direction from the upper end surface serving as the contact surface of the protrusion 312 in the outer peripheral direction of the protrusion 312. Is growing. Since the other configuration of the power storage device is the same as that of the power storage device 100 of the first embodiment, the description thereof is omitted. As shown in FIG. 10, during the normal operation of the power storage device, the central portion 34 and the peripheral portion 15 of the energization plate 4 are connected, and the positive electrode energization path is connected.

  When the pressure on the electrode assembly 60 side in the case 1 rises during overcharging of the power storage device, as shown in FIG. 11, the protrusion 312 rises as the deformation plate 3 rises, and the protrusion 312 is brought into contact with the contact surface. Abutting on the lower surface of the central portion 34 of the energization plate 4, the central portion 34 is pressed upward so as to be separated from the peripheral portion 15. At this time, the latch receiving portion 35 is also in contact with the protrusion 312 and the end portion of the latch receiving portion 35 is in contact with the latch portion 312a. The locking portion 312a is deformed so as to approach the cylindrical side surface of the projection 312 as shown by an arrow in FIG. 11 by contacting the locking receiving portion 35, and the outer diameter at the upper end portion of the projection 312 is increased. The locking portion 312a passes through the central hole of the peripheral portion 15 by becoming smaller. As a result, the central portion 34 and the peripheral portion 15 are separated from each other, and the positive electrode energization path is interrupted.

  When passing through the central hole of the peripheral portion 15, the locking portion 312a returns to its original state as shown in FIG. Thereafter, when the pressure in the case 1 of the power storage device is lowered, as shown in FIG. 13, the deformed plate 3 once raised is lowered and the protrusion 312 is lowered. Since the locking portion 312 a has returned to its original state, when the projection 312 descends, the lower surface of the locking portion 312 a of the projection 312 is locked by the locking receiving portion 35 of the energization plate 4. In this case, the latch receiving portion 35 exerts a force to spread the latching portion 312a in the outer peripheral direction of the projection 312, so that the projection 312 is reliably latched. As a result, the protrusion 312 enters between the central portion 34 and the latch receiving portion 35, and reconnection between the central portion 34 and the latch receiving portion 35 is avoided.

  As described above, also in the third embodiment, similarly to the first and second embodiments, it is possible to reliably prevent reconnection of the positive electrode energization path with the simple and space-saving configuration of the locking portion 312a formed on the protrusion 312. it can. Further, the locking portion 312 a of the protrusion 312 can be deformed so as to easily pass through the hole portion of the peripheral portion 15 when the center portion 34 is pressed upward so as to be separated from the peripheral portion 15. For this reason, similarly to the second embodiment, it is not necessary to make the latch receiving portion 35 of the energizing plate 4 thin so as to be easily deformed, and the latch receiving portion 35 is made thick in order to reduce the electric resistance during energization. It is also possible. Further, when the deformed plate 3 that has been raised is lowered and the projection 312 is lowered, the locking portion 312a is deformed so as to spread in the outer circumferential direction of the projection 312 by the force received from the locking receiving portion 35. Reconnection between the portion 34 and the latch receiving portion 35 can be avoided more reliably.

(Modification)
In the first to third embodiments, the case where the energization plate of the current interrupting device includes the central portion and the peripheral portion has been described as an example, but the present invention is not limited to this. For example, as shown in FIG. 14, current plates 404 a and 404 b that are in contact with each other above the protrusion 412 may be provided. The current-carrying plates 404a and 404b are curved upward in the lateral direction along the contact plate 5 from the first portions 435a and 435b that are curved upward and contact each other above the protrusion 412. In addition, second portions 434a and 434b that contact the contact plate 5 are provided. The protrusion 412 and its locking part 412a are the same as the protrusion 12 and its locking part 12a of the first embodiment. The other configuration is the same as that of the current interrupt device 2 of the first embodiment, and thus the description thereof is omitted.

  When the pressure on the electrode assembly 60 side in the case 1 rises during overcharging of the power storage device, as shown in FIG. 15, the protrusion 312 rises as the deformation plate 3 rises, and the protrusion 412 It enters between 404b and isolate | separates the electricity supply plates 404a and 404b. When the locking portion 412a of the protrusion 412 moves above the current-carrying plates 404a and 404b, the central portion 34 and the peripheral portion 15 are separated from each other, the positive electrode energization path is blocked, and the second portions 434a and 434 are formed below the locking portion 412a. 434b engages. Accordingly, the protrusion 412 enters between the second portions 434a and 434b of the current plates 404a and 404b and the contact plate 5, and reconnection between the contact plate 5 and the current plates 404a and 404b is avoided.

  In addition, in said Example, although the electric current interruption apparatus was arrange | positioned on the positive electrode energization path | route, you may arrange | position on a negative electrode energization path | route. Moreover, although the case where the latching | locking part of protrusion was a convex part was illustrated and demonstrated, the same effect can be acquired even if a latching | locking part is a recessed part. Moreover, you may comprise a latching | locking part by making the frictional resistance of a part of outer surface of a protrusion high. Even in this case, it is possible to reliably prevent reconnection of the positive electrode energization path with a simple and space-saving configuration of the locking portion formed on the protrusion.

  As mentioned above, although embodiment and the Example of this invention were described in detail, these are only illustrations and do not limit a claim. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.

  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 this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

DESCRIPTION OF SYMBOLS 1 Case 2 Current interruption device 3 Deformation plate 4, 404a, 404b Current supply plate 5 Contact plate 12, 112, 212, 312, 412 Protrusion 12a, 112a, 212a, 312a, 412a Locking part 13 1st positive electrode conductive member 15 periphery Unit 19 positive electrode external terminal 21 positive electrode energization path 24 abutment surface 35 locking receiving unit 60 electrode assembly 67, 65 current collecting terminal 68 second positive electrode conductive member 64 negative electrode conductive member 100 power storage device 119 negative electrode external terminal

Claims (5)

An electrode assembly including a positive electrode and a negative electrode is electrically connected to either a positive or negative external terminal, and when the internal pressure in the case housing the electrode assembly rises above a predetermined level, the electrode assembly and the A current interrupting device that interrupts a series current path with an external terminal,
The current interrupt device is
A deformed plate that is arranged to be an outer surface of the current interrupt device and deforms when the internal pressure in the case rises above a predetermined level;
A contact plate electrically connected to the external terminal;
An energization plate that is arranged to be sandwiched between the deformation plate and the contact plate, and is connected in series between the electrode assembly and the contact plate in the energization path;
The deformation plate includes a pressure receiving portion capable of receiving an internal pressure in the case, and a protrusion protruding from the pressure receiving portion toward the energizing plate,
A locking portion is provided on the outer surface of the protrusion,
The protrusion abuts on the energizing plate by deforming the deformable plate so as to move toward the energizing plate, separates at least a part of the energizing plate, and interrupts the energizing path.
The current interrupting device, wherein the locking portion of the protrusion is locked to the separated energization plate and maintains the separated state of the energization plate.   The current interrupting device according to claim 1, wherein the locking portion is a concave portion or a convex portion provided on an outer surface of the protrusion. The energization plate includes a latch receiving portion that curves in a direction from the deformation plate side toward the energization plate side around the protrusion,
The current interrupting device according to claim 1, wherein the locking receiving portion engages with the locking portion of the protrusion when the energization plate is separated by the protrusion.   The electrical storage apparatus provided with the electric current interruption apparatus as described in any one of Claims 1-3.   The power storage device according to claim 4, wherein the power storage device is a secondary battery.

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