JP6160513B2 - Power storage device and method for discharging power storage device - Google Patents

Description

  The present specification discloses a technology relating to a power storage device including a current interrupt device and a method for discharging the power storage device. In particular, this specification discloses a method of discharging a power storage device after the current interrupt device is driven.

  2. Description of the Related Art A power storage device is known that includes a current interrupt device that interrupts a current flowing between electrode terminals (a positive electrode terminal and a negative electrode terminal) when the power storage device is overcharged or a short circuit occurs inside. The current interrupting device is disposed between the electrode terminal and the electrode (between the positive electrode terminal and the positive electrode or between the negative electrode terminal and the negative electrode). In Patent Document 1, the first energizing member (electrode terminal) is caulked and fixed to the case, the second energizing member connected to the electrode is disposed at a position facing the first energizing member, and the first energizing member and the second energizing member are arranged. A power storage device in which a deformable member is arranged between members is disclosed. The first through member is provided with a through hole. A cap is fixed to the through-hole outside the case. An end portion of the deformable member is fixed to the first energizing member, and a central portion is connected to the second energizing member. In the current interrupt device of Patent Document 1, when the pressure in the power storage device exceeds a predetermined value, the central portion of the deformable member is separated from the second energizing member, and the first energizing member and the second energizing member are made non-conductive. Is used to block conduction between the electrode terminal and the electrode.

  In Patent Document 1, after the current interrupting device is driven, the cap is broken and the insulating rod is inserted from the through hole of the first energizing member. Then, the insulating rod is pushed in to bring the deformable member into contact with the second energizing member. Alternatively, after the current interrupt device is driven, the cap is broken, gas is injected from the through hole of the first energizing member, and the deformable member is brought into contact with the second energizing member. In Patent Document 1, the power storage device is discharged by bringing the deformable member into contact with the second energizing member and electrically connecting the electrode terminal and the electrode again.

JP 2013-101889 A

  The power storage device after the current interrupting device is driven needs to be completely discharged for safe disassembly and disposal. That is, it is necessary to ensure that the deformable member and the second energizing member are in contact until the power storage device is completely discharged. In Patent Document 1, the power storage device is discharged by using an insulating rod or injecting gas. When using an insulating rod, it is necessary to keep pushing the insulating rod until the discharge is completed. Furthermore, if the insertion depth of the insulating rod is not accurately positioned, the deformable member and the second energizing member may not come into contact with each other, or the deformable member may be damaged by the insulating rod. Further, when gas is injected, for example, if the deformable member is damaged when it is separated from the second energizing member, the deformable member cannot be moved to the second energizing member side even if gas is injected. obtain. The present specification provides a power storage device that can reliably perform a discharging operation by a simple method after the current interrupting device is driven, and a method for discharging the power storage device.

  The present specification discloses a method for discharging a power storage device after the pressure in the case exceeds a predetermined value and the current interrupting device is driven. The current interrupt device includes a first energization member, a second energization member, and a deformation member. The first energizing member is provided with a through hole. A bolt groove in which the first bolt is fastened is provided on the wall surface of the through hole. One end of the first energizing member is located in the case. The other end of the first current-carrying member is crimped and deformed outside the case and fixed to the case. The second energization member is disposed at a position facing the first energization member at a distance from the first energization member. The deformable member is disposed between the first energizing member and the second energizing member. An end of the deformable member is connected to the first energizing member. A central portion of the deformable member is connected to the second energizing member. The deformable member is disconnected from the second energizing member when the pressure in the case exceeds a predetermined value. The discharge method disclosed in the present specification includes a first step and a second step. In the first step, the first bolt is removed from the first energizing member after the deformable member is disconnected from the second energizing member. In the second step, a second bolt longer than the first bolt is tightened in the bolt groove, and the deformable member is brought into contact with the second energizing member.

  According to the above discharge method, after the current interrupt device is driven, the power storage device can be discharged by tightening the second bolt in the bolt groove until the deformable member comes into contact with the second energizing member. If the second bolt having an appropriate length is prepared, the deformable member can be brought into contact with the second energizing member with certainty. That is, according to the above discharge method, even if the first bolt is replaced with the second bolt, even if the discharge takes a long time, the deformable member and the second energizing member are reliably brought into contact until the power storage device is completely discharged. Can continue to.

  In the present specification, a power storage device that realizes the discharging method is also disclosed. The power storage device includes a current interrupt device that interrupts conduction between the electrode terminal and the electrode when the pressure in the case exceeds a predetermined value. The current interrupting device is provided with a bolt groove on the wall surface of the through hole, one end is located in the case, and the other end is crimped and deformed outside the case and fixed to the case. Between the 1st electricity supply member, the 2nd electricity supply member arrange | positioned in the position which opposes the said 1st electricity supply member at intervals with the said 1st electricity supply member, Between the said 1st electricity supply member and the said 2nd electricity supply member And the end portion is connected to the first energization member, the center portion is connected to the second energization member, and the second pressure is applied when the pressure in the case exceeds a predetermined value. A deformation member is provided that is non-conductive with the energization member. By using this power storage device, the above discharge method can be executed.

  According to the technology disclosed in this specification, after the current interrupt device is driven, the power storage device can be reliably discharged by a simple method.

Sectional drawing of the electrical storage apparatus of 1st Example is shown. The expanded sectional view of the electric current interruption apparatus used with the electrical storage apparatus of 1st Example is shown. The expanded sectional view after the electric current interruption apparatus used with the electrical storage apparatus of 1st Example drives is shown. 1 shows a discharge process 1 of a power storage device according to a first embodiment. The electric discharge process 2 of the electrical storage apparatus of 1st Example is shown.

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

  The power storage device includes a case, an electrode assembly, an electrode terminal, and a current interrupt device. The electrode assembly is housed in a case and may include a positive electrode and a negative electrode. The electrode terminal may be connected to a conductive component (hereinafter referred to as a first current-carrying member) passing through the inside and outside of the case outside the case. The current interrupt device may be connected to the negative terminal and the negative electrode. In this case, the current interrupt device is disposed on the energization path between the negative electrode terminal and the negative electrode, and switches the negative electrode terminal and the negative electrode from the conductive state to the non-conductive state when the internal pressure of the case exceeds a predetermined value. The current interruption device may be connected to the positive electrode terminal and the positive electrode. In this case, the current interrupt device is disposed on the energization path between the positive electrode terminal and the positive electrode, and switches the positive electrode terminal and the positive electrode from the conductive state to the non-conductive state when the internal pressure of the case exceeds a predetermined value.

  The current interrupt device may include a first energization member, a second energization member, and a deformation member. The first energization member may be fixed to the case of the power storage device. The first energizing member and the case may be insulated. One end of the first energization member may be located inside the case, and the other end may be located outside the case. The other end of the first energizing member may be crimped (pressurized) outside the case. The first energization member may be fixed to the case by caulking and deforming the other end of the first energization member. The 1st electricity supply member may be provided with the through-hole. The through hole may extend from the inside of the case to the outside. A bolt groove may be provided on the wall surface of the first energizing member that defines the through hole.

  The 2nd electricity supply member may be arrange | positioned in the position which opposes a 1st electricity supply member at intervals with a 1st electricity supply member. The thickness of the center part of the second energizing member may be thinner than the thickness of the end part. A rupture groove may be provided in the central portion of the second energization member that serves as a rupture starting point when the pressure in the case exceeds a predetermined value. The breaking groove may be continuously or intermittently made in the center of the second energizing member. In addition, the fracture | rupture groove | channel should just be a weak part used as the starting point of a fracture | rupture when the pressure in a case exceeds predetermined value, and may be provided locally in the center part of the 2nd electricity supply member. The pressure in the case may be directly applied to the second energizing member, and the second energizing member may be broken. Alternatively, another part to which the pressure in the case is applied is provided near the second energizing member, and when the pressure in the case exceeds a predetermined value, the other part comes into contact with the second energizing member to cause the second energization. The member may be broken. When the current interrupt device is viewed in plan (observation of the second energization member from the direction in which the through hole extends), the fracture groove may be located inside the through hole.

  The deformable member may be disposed between the first energizing member and the second energizing member. The end portion of the deformable member may be connected to the first energizing member, and the central portion of the deformable member may be connected to the second energizing member. The central portion of the deformable member may be fixed to the second energizing member at a position surrounded by the fracture groove. The deformable member may be disconnected from the second energizing member by deforming when the pressure in the case exceeds a predetermined value. When the pressure in the case exceeds a predetermined value, the deformable member may move toward the first energizing member with the central portion being separated from the second energizing member. When the deformable member is connected to the second energizing member, the central portion projects toward the second energizing member, and when not connected to the second energizing member, the central portion is directed to the first energizing member. It may be deformed into a sudden state. When the pressure in the case exceeds a predetermined value, the central portion of the second energizing member may be broken and the deformable member may be separated from the second energizing member. The electrode terminal and the electrode may be conductive when the deforming member is connected to the second energizing member, and the electrode terminal and the electrode may be non-conducting when the deforming member is separated from the second energizing member. When the current interrupting device is viewed in plan, the connecting portion between the deformable member and the second energizing member may be located inside the through hole.

  The 2nd deformation member may be arranged on the opposite side to the above-mentioned deformation member to the 2nd energization member. That is, the current interrupt device may include two deformable members. Hereinafter, the deformable member disposed between the first energizing member and the second energizing member may be referred to as a first deformable member, and the second deformable member may be referred to as a second deformable member. The 2nd electricity supply member may be provided between the 1st deformation member and the 2nd deformation member. The second deformation member may be provided between the second energization member and the electrode assembly. The second deformation member may separate the inside and the outside of the current interrupt device. That is, the second deformable member may constitute the outer surface of the current interrupt device, and the pressure in the case may act directly on the second deformable member. The second deformable member may be fixed to the second energizing member. A protrusion having a shape protruding toward the second energization member may be provided at the center of the second deformable member on the second energization member side. The protrusion may face a portion surrounded by the fracture groove of the second energizing member in a state of being separated from the second energizing member. The protrusion may be insulative. A 2nd electricity supply member may be fractured | ruptured when protrusion (2nd deformation member) contacts a 2nd electricity supply member.

  During use of the power storage device, the first bolt may be tightened in the bolt groove. The tip end of the first bolt may be opposed to the first energization member with a gap from the first deformation member. After the current interrupting device is driven (the first deforming member is disconnected from the second energizing member), the first bolt is removed from the first energizing member (first step), and the second bolt longer than the first bolt is removed. The bolt groove may be tightened (second step). In the second step, the first deformation member may be in a state before deformation. That is, the first deforming member may be moved to the second energizing member side using the second bolt, and the first deforming member and the second energizing member may be brought into contact with each other. In the second step, the second bolt may move the first deformable member to a position before the first deformable member is disconnected from the second energizing member.

  As examples of the power storage device disclosed in this specification, a secondary battery, a capacitor, and the like can be given. As an example of an electrode assembly of a secondary battery, a stacked electrode assembly in which a plurality of cells having electrode pairs (a negative electrode and a positive electrode) opposed via a separator are stacked, and a sheet having an electrode pair opposed via a separator And a wound electrode assembly in which the cells are spirally processed. Further, the power storage device disclosed in this specification is mounted on, for example, a vehicle and can supply electric power to a motor. Hereinafter, the structure of the power storage device will be described. In the following description, a power storage device in which a current interrupting device is connected to a negative electrode terminal and a negative electrode will be described. The technology disclosed in this specification can also be applied to a power storage device in which a current interrupting device is connected to a positive electrode terminal and a positive electrode. In the following description, a power storage device in which the current interrupt device includes two deformable members will be described. The technology disclosed in this specification can also be applied to a power storage device in which the current interrupting device includes one deformable member.

(First embodiment)
The structure of the power storage device 100 will be described with reference to FIG. The power storage device 100 includes a case 28, an electrode assembly 62, a positive terminal 18, a negative terminal 46, and a current interrupt device 58. The case 28 is made of metal and has a substantially rectangular parallelepiped shape. The case 28 includes a lid portion 28a and a main body portion 28b. An electrode assembly 62 and a current interrupt device 58 are accommodated in the case 28. The electrode assembly 62 includes a positive electrode and a negative electrode (not shown). The positive electrode tab 26 is fixed to the positive electrode, and the negative electrode tab 34 is fixed to the negative electrode. An electrolyte is injected into the case 28.

  The positive electrode terminal 18 and the negative electrode terminal 46 are disposed on the same side of the case 28 (the side on which the lid portion 28a is provided). That is, both the positive terminal 18 and the negative terminal 46 are arranged in the same direction with respect to the electrode assembly 62. The positive terminal 18 includes a bolt 16 and a metal plate 14. The positive terminal 18 is connected to the positive crimping member 6. Specifically, the positive caulking member 6 and the bolt 16 are connected by a metal plate 14. The negative terminal 46 includes a bolt 42 and a metal plate 44. The negative terminal 46 is connected to the negative caulking member 52. The negative caulking member 52 and the bolt 42 are connected by a metal plate 44. The positive crimping member 6 and the negative crimping member 52 pass through the inside and outside of the case 28. The positive crimping member 6 and the negative crimping member 52 are fixed to the case 28. In addition, the positive electrode terminal 18 and the positive electrode caulking member 6 can be collectively regarded as a “positive electrode terminal”. Similarly, the negative electrode terminal 46 and the negative electrode caulking member 52 can be collectively regarded as a “negative electrode terminal”.

  The positive electrode terminal 18 is insulated from the case 28 by the insulating member 8. The insulating member 8 includes a protruding portion 8a and a flat plate portion 8b. A part of the bolt 16 (case 28 side) is surrounded by the protruding portion 8a. The metal plate 14 is disposed on the upper surfaces of the protruding portion 8 a and the flat plate portion 8 b, and has a shape bent according to the shape of the insulating member 8. The negative terminal 46 is insulated from the case 28 by an insulating member 48. The insulating member 48 includes a protruding portion 48a and a flat plate portion 48b. A part of the bolt 42 (case 28 side) is surrounded by the protrusion 48a. The metal plate 44 is disposed on the upper surfaces of the protruding portion 48 a and the flat plate portion 48 b, and has a shape bent according to the shape of the insulating member 48. Note that either the positive electrode terminal 18 or the negative electrode terminal 46 may be electrically connected to the case 28.

  A positive electrode lead 24 is connected to the positive electrode caulking member 6. The positive electrode lead 24 is connected to the positive electrode tab 26. The positive crimping member 6 is electrically connected to the positive tab 26 via the positive lead 24. That is, the positive terminal 18 is electrically connected to the positive electrode of the electrode assembly 62. The positive electrode lead 24 is insulated from the case 28 by the insulating sheet 22. A portion of the positive crimping member 6 located in the case 28 is insulated from the case 28 by the insulating member 2. An insulating sealing member 4 is disposed between the positive crimping member 6 and the case 28. A gap between the positive crimping member 6 and the case 28 is sealed by the seal member 4.

  The negative caulking member 52 is connected to the current interrupt device 58. A first bolt 49 is fastened to the negative crimping member 52. Details of the current interrupt device 58 will be described later. The current interrupt device 58 is connected to the negative electrode lead 36 through a metal connection member 38. The negative caulking member 52 is electrically connected to the negative electrode tab 34 via the negative electrode lead 36. That is, the negative electrode caulking member 52 is electrically connected to the negative electrode of the electrode assembly 62. The negative electrode lead 36 is insulated from the case 28 by the insulating sheet 32. A portion of the negative caulking member 52 located in the case 28 is insulated from the case 28 by an insulating member 56. An insulating seal member 54 is disposed between the negative caulking member 52 and the case 28. A gap between the negative caulking member 52 and the case 28 is sealed by a seal member 54.

  In the power storage device 100, the negative electrode terminal 46 and the negative electrode tab 34 are electrically connected via the current interrupt device 58 when the pressure in the case 28 is equal to or lower than a predetermined value. That is, the negative electrode terminal 46 and the negative electrode are electrically connected. When the pressure in the case 28 exceeds a predetermined value, the current interrupt device 58 interrupts conduction between the negative electrode terminal 46 and the negative electrode tab 34, thereby preventing current from flowing through the power storage device 100. FIG. 1 shows a state before the current interrupt device 58 is driven, and the negative electrode terminal 46 and the negative electrode are electrically connected.

  FIG. 2 is an enlarged view of a portion surrounded by a two-dot chain line II in FIG. As shown in FIG. 2, one end of the negative electrode caulking member 52 is located outside the case 28, and the other end is located inside the case 28. One end of the negative electrode caulking member 52 forms a caulking portion 52 a outside the case 28. The other end of the negative caulking member 52 constitutes a base 52 c inside the case 28. The caulking portion 52a and the base portion 52c are connected by a columnar portion 52b. The columnar part 52 b passes through the inside and outside of the case 28. A through hole 50 is provided in the columnar portion 52b. Bolt grooves 52 d are provided on the wall surface defining the through hole 50. The first bolt 49 is fastened to the bolt groove 52d.

  A metal plate 44 and a flat plate portion 48b of the insulating member 48 are disposed between the crimping portion 52a and the case 28. The caulking portion 52 a and the metal plate 44 are insulated from the case 28 by the insulating member 48. The insulating member 48 is also interposed between the columnar portion 52b and the case 28, and insulates the columnar portion 52b from the case 28. An insulating member 56 is disposed between the base 52 c and the case 28. The base 52 c is insulated from the case 28 by the insulating member 56. The negative caulking member 52 is insulated from the case 28 by insulating members 48 and 56. The negative caulking member 52 is an example of a first energizing member.

  The facing surface 64 facing the fracture plate 78 of the base 52c is recessed toward the center. In other words, a recess 76 that is recessed on the side opposite to the fracture plate 78 is provided on the facing surface 64, and the facing surface 64 itself is a recessed surface. More specifically, the facing surface 64 of the base portion 52c is inclined so as to move away from the fracture plate 78 from the end portion toward the center. By providing the depression 76, the distance between the base 52c and the first deformation member 66 becomes longer from the end toward the center. In addition, the opposing surface 64 means the surface where the 1st deformation member 66 is not fixed among the surfaces which oppose the fracture | rupture board 78 of the base 52c. A groove 67 is provided outside the recess 76 on the side of the fracture plate 78 of the base 52c. Details of the first deformable member 66 and the fracture plate 78 will be described later.

  The negative caulking member 52 applies force to the caulking portion 52a in a state where the insulating member 56 is disposed between the base portion 52c and the case 28 and the metal plate 44 and the insulating member 48 are disposed at predetermined positions. The caulking portion 52a is deformed as shown in FIG. 2, and the case 28, the metal plate 44, and the insulating members 48 and 56 are sandwiched between the caulking portion 52a and the base portion 52c. As a result, the negative electrode caulking member 52 is caulked and fixed to the case 28. After the negative caulking member 52 is fixed to the case 28, a bolt groove 52d is formed on the wall surface defining the through hole 50 of the columnar portion 52b. The positive caulking member 6 has substantially the same structure as the negative caulking member 52 except that the columnar part is solid and the base part is not provided with a recess. Therefore, the detailed description about the positive electrode caulking member 6 is omitted.

  The current interrupt device 58 includes a negative electrode caulking member 52, a fracture plate 78, a first deformation member 66, and a second deformation member 75. As described above, the base 52c (negative electrode caulking member 52) is fixed to the case 28. The fracture plate 78 is disposed at a position facing the base 52c with a gap from the base 52c. The fracture plate 78 is an example of a second energizing member. Between the electrode assembly 62 (see also FIG. 1) and the case 28, the second deformable member 75, the fracture plate 78, the first deformable member 66, and the base 52 c are disposed above the electrode assembly 62 in this order.

  A connecting member 38 is fixed to the fracture plate 78. The fracture plate 78 is electrically connected to the negative electrode tab 34 via the connecting member 38 and the negative electrode lead 36 (see also FIG. 1). The thickness of the center part 78a of the fracture | rupture board 78 is thinner than the thickness of the edge part 78b. In addition, a fracture groove 82 is provided in the central portion 78a. The breaking groove 82 continuously makes a round at the central portion 78a. A groove 74 is provided on the base 52 c side of the fracture plate 78. The groove 74 is provided at a position facing the groove 67. Note that the breaking groove 82 is located inside the through hole 50 when the current interrupt device 58 is viewed in plan (observation of the inside of the power storage device 100 from the outside of the power storage device 100 through the through hole 50).

  The first deformation member 66 is a metallic diaphragm. The first deformation member 66 is disposed between the base portion 52 c and the fracture plate 78. The end portion 66b of the first deformation member 66 is fixed to the base portion 52c. More specifically, the end 66b of the first deformation member 66 is welded to the base 52c. A central portion 66a of the first deformation member 66 protrudes toward the fracture plate 78 so as to be away from the base portion 52c. In other words, the first deformation member 66 approaches the fracture plate 78 as it goes from the end portion 66b to the central portion 66a.

  The central portion 66 a of the first deformation member 66 is fixed to the fracture plate 78 inside the fracture groove 82. More specifically, when the current interrupt device 58 is viewed in plan (as viewed from above in FIG. 2), the central portion 66 a is welded to the fracture plate 78 in a range surrounded by the fracture groove 82.

  A seal member 68 is disposed between the base portion 52 c and the fracture plate 78. The seal member 68 is an insulating O-ring. The seal member 68 insulates the base portion 52c and the fracture plate 78 and keeps the inside of the current interrupt device 58 airtight. That is, the seal member 68 seals the base 52 c and the breaker plate 78 to block the space inside the current interrupt device 58 from the space outside the current interrupt device 58 (the space in the case 28).

  An insulating member 72 is disposed between the base portion 52 c and the fracture plate 78. The insulating member 72 is disposed inside the seal member 68. The insulating member 72 maintains the distance between the base portion 52 c and the breaking plate 78. The insulating member 72 prevents the base 52c and the fracture plate 78 from coming into direct contact. That is, the insulating member 72 prevents the base 52c and the fracture plate 78 from being directly connected. Both end portions of the insulating member 72 are located in the grooves 67 and 74. For this reason, the insulating member 72 is restricted from moving toward the first deformation member 66 and the seal member 68. In addition, since the movement of the insulating member 72 is restricted, even if the seal member 68 tries to move toward the first deformation member 66, the seal member 68 does not contact the insulating member 72 and move further inward. .

  The second deformation member 75 is disposed on the opposite side of the fracture plate 78 from the first deformation member 66. That is, the fracture plate 78 is disposed between the first deformation member 66 and the second deformation member 75. The second deformable member 75 is a metal diaphragm. An end portion 75 b of the second deformable member 75 is fixed to the fracture plate 78. More specifically, the end 75 b of the second deformable member 75 is welded to the fracture plate 88.

  An insulating protrusion 79 is provided on the fracture plate 68 side of the second deformable member 75. The protrusion 79 is disposed at the central portion 75 a of the second deformable member 75 and has a shape protruding toward the fracture plate 68. The protrusion 79 faces the central portion 68 a of the fracture plate 68. More specifically, when the current interrupt device 58 is viewed in plan (observation of the first deformable member 66 from the outside of the current interrupt device 58 through the through hole), the projection 79 is within the range surrounded by the fracture groove 82. Is located. The second deformable member 75 protrudes away from the fracture plate 68 as it goes from the end 75b to the central portion 75a.

  A support member 85 supports the base portion 52 c and the fracture plate 78. The support member 85 includes a metal outer portion 90, an insulating first inner portion 88, and an insulating second inner portion 86. The first inner portion 88 is disposed inside the outer portion 90 and is disposed above the second inner portion 86 (on the case 28 side). The first inner portion 88 is formed integrally with the insulating member 56. The second inner portion 86 is disposed inside the outer portion 90 and is disposed below the first inner portion 88 (on the electrode assembly 62 side). The outer portion 90 positions the base portion 52 c and the fracture plate 78. Specifically, after the first inner portion 88 and the second inner portion 84 are disposed at predetermined positions, the fracture plate 78 is fixed to the base portion 52c by caulking the outer portion 90. The inner portions 86 and 88 insulate the base portion 52 c and the fracture plate 78.

  When the internal pressure of the case 28 is equal to or lower than a predetermined value, the negative electrode terminal 46 is electrically connected to the negative electrode through the negative electrode caulking member 52, the deformable member 66, the fracture plate 78, the connecting member 38, the negative electrode lead 36, and the negative electrode tab 34. (FIGS. 1 and 2). For example, when the power storage device 100 is overcharged, the internal pressure of the case 28 increases and exceeds a predetermined value. When the internal pressure of the case 28 exceeds a predetermined value, a pressure difference is generated between the inside and outside of the current interrupt device 58. As a result, the pressure in the case 28 (outside the current interrupt device 58) is applied to the second deformable member 75, and the second deformable member 75 is deformed so as to face the fracture plate 78. That is, the center part 78 a moves toward the center part 88 a of the fracture plate 78. In other words, the second deformation member 75 is reversed with the end portion 78b as a fulcrum. The protrusion 79 comes into contact with the breaking plate 78, and the breaking plate 78 breaks starting from the breaking groove 82. When the internal pressure of the case 28 exceeds a predetermined value, the fracture plate 78 breaks starting from the fracture groove 82. As a result, the first deformable member 66 is deformed and separated from the fracture plate 78, and the first deformable member 66 and the fracture plate 78 become non-conductive (FIG. 3). Since the negative electrode terminal 46 and the negative electrode become non-conductive, it is possible to prevent a current from flowing between the positive electrode terminal 18 and the negative electrode terminal 46 (see also FIG. 1).

  When the fracture plate 78 is fractured, the central portion 66a of the first deformation member 66 moves from the fracture plate 78 side toward the base portion 52c side. In other words, the first deformation member 66 is reversed. As described above, since the recess 52 is provided in the base 52c, the inversion of the first deformable member 66 is not hindered by the base 52c (negative electrode caulking member 52). It is possible to prevent the first deformable member 66 and the fracture plate 78 from re-conducting after the fracture plate 78 is fractured. As shown in FIG. 3, even if the deforming member moves toward the base portion 52c, the first deforming member 66 and the first bolt 49 do not contact each other.

  The power storage device 100 after the current interrupt device 58 is driven is disposed of without being used any more. In order to safely discard the power storage device 100, the power storage device 100 is completely discharged. Hereinafter, a method for discharging power storage device 100 performed after current interrupting device 58 is driven will be described.

  First, as shown in FIG. 4, the 1st volt | bolt 49 is removed from the negative electrode crimping member 52 (1st process). The central portion 66a of the first deformation member 66 can be confirmed from the outside of the power storage device 100 through the through hole. Next, as shown in FIG. 5, the second bolt 149 is fastened to the bolt groove 52d (second step). The second bolt 149 is longer than the first bolt 49. By tightening the second bolt 149 in the bolt groove 52d, the first deformable member 66 is brought into contact with the fracture plate 78. Specifically, the second bolt 149 moves the first deformable member 66 to a position before the first deformable member 66 is separated from the fracture plate 78 when the second bolt 149 is completely tightened in the bolt groove 52d. The length is adjusted so that it can be moved. As a result, the negative electrode terminal 46 and the negative electrode are reconnected, and the power storage device 100 can be discharged. As shown in FIG. 5, the first deformation member 66 also contacts the outer portion 80 in a range surrounded by the fracture groove 82 (see also FIG. 2) of the fracture plate 78.

  Advantages of the power storage device 100 will be described. As described above, in the power storage device 100, after the current interrupt device 58 is driven, the power storage device 100 can be discharged simply by removing the first bolt 49 and fastening the second bolt 149. After the second bolt 149 is fastened, nothing needs to be done until the discharge is completed. The power storage device 100 can be discharged easily and reliably after the current interrupt device 58 is driven. That is, the power storage device 100 can safely perform the discarding process when an abnormality occurs.

  Another advantage of the power storage device 100 will be described. When the power storage device 100 is used, the first bolt 49 is fastened to the negative electrode caulking member 52 (bolt groove 52d). Therefore, even if the first deformation member 66 is damaged when the current interrupting device 58 is driven, the contents (for example, the electrolytic solution) of the power storage device 100 can be prevented from jumping from the inside to the outside. Further, the fracture groove 82 is located inside the through hole 50 when the current interrupt device 58 is viewed in plan. Therefore, when the second bolt 149 is tightened in the bolt groove 52d, the first deformation member 66 can be brought into contact with the fracture plate 78 outside the portion where the fracture groove 82 of the fracture plate 78 is provided. . When the first deforming member 66 is separated from the breaking groove 82, even if the portion surrounded by the breaking groove 82 is damaged, the first deforming member 66 and the breaking groove 82 can be reliably brought into contact with each other.

  In the above embodiment, the power storage device is described in which the current interrupting device includes the first deformable member and the second deformable member. However, the technology disclosed in this specification can also be applied to a power storage device including one deformable member between the first energizing member (the base portion of the negative electrode caulking member) and the second energizing member (breaking plate). That is, the technique disclosed in the present specification is that the first energization member includes a through hole, and a bolt groove for fastening a bolt is formed on a wall surface defining the through hole. And it is making a deformation | transformation member contact a 2nd electricity supply member after a current interrupting device drives using the volt | bolt fastened to the bolt groove | channel. For this reason, various materials can be used as the structure of the current interrupting device and the material of the parts constituting the power storage device. Hereinafter, materials of components constituting the power storage device will be exemplified for a lithium ion secondary battery which is an example of the power storage device.

  The electrode assembly will be described. The electrode assembly includes a positive electrode, a negative electrode, and a separator interposed at a position between the positive electrode and the negative electrode. The positive electrode has a positive electrode metal foil and a positive electrode active material layer formed on the positive electrode metal foil. A positive electrode tab is corresponded to the metal foil for positive electrodes in which the positive electrode active material layer is not apply | coated. The negative electrode has a negative electrode metal foil and a negative electrode active material layer formed on the negative electrode metal foil. A negative electrode tab is corresponded to the metal foil for negative electrodes in which the negative electrode active material layer is not apply | coated. 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.

  As the metal foil for the positive electrode, aluminum (Al), nickel (Ni), titanium (Ti), stainless steel, or a composite material thereof can be used. In particular, aluminum or a composite material containing aluminum is preferable. Moreover, the material similar to the metal foil for positive electrodes can be used as a material of a positive electrode lead.

The positive electrode active material only needs to be a material in which lithium ions can 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, and _{LiCoO 2, LiNi 0.8 Co 0.15 Al} 0.05 O 2, Li 2 MnO 2, LiMn 2 O 4 or 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. A positive electrode active material is apply | coated to the metal foil for positive electrodes with a electrically conductive material, a binder, etc. as needed.

  As the metal foil for the negative electrode, aluminum, nickel, copper (Cu), or a composite material thereof can be used. In particular, copper or a composite material containing copper is preferable. Moreover, the material similar to the metal foil for negative electrodes can be used as a material of a negative electrode lead.

  As the negative electrode active material, a material in which lithium ions can enter and leave is 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. The negative electrode active material is particularly preferably a material that does not contain lithium (Li) in order to improve battery capacity. A negative electrode active material is apply | coated to the metal foil for negative electrodes with a electrically conductive material, a binder, etc. as needed.

  As the separator, a porous porous material is used. 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 nonaqueous electrolytic solution in which a supporting salt (electrolyte) is dissolved in a nonaqueous 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.

  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. 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.

28: Case 46: Negative terminal 49: First bolt 50: Through hole 52: First energization member 58: Current interrupt device 66: Deformation member 78: Second energization member 100: Power storage device 149: Second bolt

Claims (4)

A method of discharging the power storage device after the pressure in the case exceeds a predetermined value and the current interrupting device is activated,
The current interrupt device is
One end of the other end in together when located within said case is fixed to the casing outside is caulked deformation of the case, through holes are provided for communicating the inside and outside of the case, the through A first current-carrying member provided with a bolt groove in which a first bolt is fastened to a wall surface of the hole ;
A second energization member disposed at a position facing the first energization member at an interval from the first energization member;
The case is disposed between the first energization member and the second energization member, an end portion is connected to the first energization member, a center portion is connected to the second energization member, and the case A deformation member that is disconnected from the second current-carrying member by being deformed when the internal pressure exceeds a predetermined value,
A first step of removing the first bolt from the first energization member after the deformable member is disconnected from the second energization member;
A second bolt longer than the first bolt is tightened in the bolt groove, the second bolt is brought into contact with the deforming member, the deforming member is moved toward the second energizing member , and the deforming member is moved to the first energizing member . And a second step of contacting the current-carrying member .   The method for processing a power storage device according to claim 1, wherein in the second step, the deformable member is brought into a state before deformation. A power storage device having a current interrupt device that interrupts conduction between the electrode terminal and the electrode when the pressure in the case exceeds a predetermined value,
The current interrupt device is
A bolt groove is provided in the wall surface of the through hole, one end is located in the case, and the other end is crimped and deformed outside the case and fixed to the case;
A second energization member disposed at a position facing the first energization member at an interval from the first energization member;
The case is disposed between the first energization member and the second energization member, an end portion is connected to the first energization member, a center portion is connected to the second energization member, and the case A deformation member that becomes non-conductive with the second energization member by deforming when the pressure inside exceeds a predetermined value;
A first bolt that is fastened to the bolt groove in a non-contact state with the deformable member to close the through hole, and that can be removed from the first current-carrying member ;
The first bolt includes the deforming member so that the end portion on the second energizing member side is not in contact with the deforming member even when the central portion of the deforming member protrudes toward the first energizing member side. A power storage device that is fastened to the bolt groove with an interval . The power storage device according to claim 3 , wherein the power storage device is a secondary battery.

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