JP6135557B2 - Power storage device - Google Patents

Description

  The technology disclosed in this specification relates to a power storage device including a current interrupt device.

  In the technical field of power storage devices, the development of a current interrupting device that cuts off the current flowing between the terminals (positive terminal and negative terminal) when the power storage device is overcharged or when a short circuit occurs inside is being promoted. Yes. The current interrupt device is disposed between the terminal and the current collector (positive electrode current collector or negative electrode current collector). Patent Document 1 discloses a current interrupting device in which an energizing plate connected to a current collector and a deforming plate connected to a terminal are joined. When the pressure in the power storage device rises and exceeds a predetermined value, the current interrupt device operates to separate the deformable plate from the energizing plate. As a result, the current between the terminal and the energizing plate is interrupted.

JP 2012-38529 A

  In the power storage device of Patent Document 1, the terminal is fixed to the opening formed in the terminal wall of the case. An insulating seal member and an insulating member are disposed between the terminal and the terminal wall. The insulating member is disposed on the inner side of the case with respect to the seal member and spaced from the seal member. For this reason, a space is formed between the seal member and the insulating member. In the space, the terminal and the terminal wall face each other directly. Here, the electrolytic solution in the case may enter the space through the gap between the insulating member and the terminal and / or the terminal wall. When a high voltage is applied between the terminal and the terminal wall in a state where the space is filled with the electrolytic solution after the current interrupting device is operated, the terminal and the terminal wall are separated by the electrolytic solution filled in the space. There is a possibility of short circuit. In particular, in a power storage device module in which a plurality of power storage devices are connected in series, when one current interrupt device operates, a very high voltage is applied between the terminal and the terminal wall, so that the terminal and the terminal wall can be short-circuited. The sex becomes higher.

  In this specification, the technique which suppresses that a terminal and a terminal wall short-circuit is provided.

  The power storage device disclosed in this specification includes a case, a terminal, and a current interrupt device. The case can accommodate an electrode assembly including a positive electrode and a negative electrode, and an electrolytic solution. The terminal communicates with the inside and outside of the case through an opening formed in the terminal wall of the case. The current interrupt device is housed in the case, and is electrically connected to the terminal and the positive electrode or the terminal and the negative electrode, and switches the terminal and the positive electrode or the negative electrode from the conductive state to the non-conductive state. It has a conductive member. The terminal includes a columnar portion inserted through the opening, and a base portion disposed at one end of the columnar portion and positioned inside the case. The base portion is larger than the opening in a state where the terminal wall is seen in a plan view, and is electrically connected to the conductive member. Between the terminal and the terminal wall, a seal member that goes around the columnar portion is arranged. An insulating first insulating member that goes around the columnar portion is disposed between at least one of the sealing member and the terminal and between the sealing member and the terminal wall. The seal member seals between the terminal and the terminal wall together with the first insulating member. An insulating second insulating member that circulates around the columnar portion is disposed in the first space inside the case with respect to the seal member in the space between the terminal and the terminal wall. In the first space, any one of the seal member, the first insulating member, and the second insulating member is disposed from the end surface on the case outer side of the first space to the end surface on the case inner side.

  In the above power storage device, the seal member seals between the terminal and the terminal wall together with the first insulating member. For this reason, it is suppressed that the electrolyte solution in a case leaks into the space of a case exterior side rather than a sealing member and a 1st insulating member. In the above power storage device, any one of the seal member, the first insulating member, or the second insulating member is disposed in the first space from the end surface on the case outer side of the first space to the end surface on the case inner side. Yes. For this reason, the terminal and the terminal wall do not directly face each other in the first space. Therefore, even if a high voltage is applied between the terminal and the terminal wall, it is possible to suppress a short circuit between the terminal and the terminal wall.

  Details of the technology disclosed in this specification and further improvements will be described in detail in the detailed description and examples.

1 is a longitudinal sectional view of a power storage device according to Embodiment 1. FIG. The elements on larger scale near the crimping terminal which comprises the negative electrode terminal of FIG. The elements on larger scale of the crimping terminal vicinity which comprises the positive electrode terminal of FIG. The elements on larger scale near the crimping terminal which comprises the negative electrode terminal of the electrical storage apparatus of the modification 1. The elements on larger scale near the crimping terminal which comprises the negative electrode terminal of the electrical storage apparatus of Example 2. FIG. FIG. 9 is a partially enlarged view of the vicinity of a caulking terminal that constitutes a negative electrode terminal of a power storage device of Example 3. The elements on larger scale near the crimping terminal which comprises the negative electrode terminal of the electrical storage apparatus of Example 4. FIG. The elements on larger scale near the crimping terminal which comprises the negative electrode terminal of the electrical storage apparatus of Example 5. FIG. FIG. 10 is a partially enlarged view of the vicinity of the negative electrode terminal of the power storage device of Example 6.

  The main features of the embodiments described below are listed. The technical elements described below are independent technical elements and exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Absent.

(Characteristic 1) The end surface of the first insulating member on the case inner side may be in contact with the end surface of the second insulating member on the case outer side. According to this structure, it can suppress that a terminal and a terminal wall directly oppose in 1st space.

(Characteristic 2) The groove | channel which becomes concave in the direction orthogonal to the end surface may be formed in the end surface of the case exterior side of a 2nd insulating member over the circumferential direction. The end surface on the case inner side of the first insulating member may be located in the groove. According to this configuration, when the terminal wall is viewed in plan, the first insulating member and the second insulating member overlap in the groove. For this reason, even if the position of the 1st insulating member or the 2nd insulating member shifts for some reason, it can control that a terminal and a terminal wall directly counter in the 1st space.

(Feature 3) In addition to the feature 2, the width of the groove may be equal to or less than the thickness of the first insulating member before the first insulating member is disposed in the groove. According to this configuration, the first insulating member in the groove is in contact with the side surface of the groove. For this reason, it is difficult for the relative positional relationship between the first insulating member and the second insulating member to change, and the terminal and the terminal wall can be prevented from directly facing each other in the first space.

(Characteristic 4) The end surface on the case inner side of the first insulating member may be located on the case inner side with respect to the end portion on the case inner side of the seal member. The seal member may be in contact with the first first insulating member disposed on the terminal and the second first insulating member disposed on the terminal wall at the first seal portion. The area where the first first insulating member is in contact with the terminal and the area where the second first insulating member is in contact with the terminal wall may be larger than the area of the first seal portion of the seal member. According to this configuration, the frictional resistance when the first and second first insulating members or the seal members are moved in the contact surface direction is larger in the first and second first insulating members than in the seal member. Easy to be. For this reason, the first and second first insulating members are less likely to be displaced than the seal members. Therefore, even if the position of the seal member is shifted due to some factor, the first or second first insulating member can suppress the terminal and the terminal wall from directly facing each other in the first space.

(Feature 5) The end surface on the case inner side of the first first insulating member and the end surface on the case inner side of the second first insulating member are located on the case inner side with respect to the end portion on the case inner side of the seal member. It may be. When the internal pressure of the case exceeds a predetermined value, the current interrupt device may switch the terminal and the positive electrode or the terminal and the negative electrode from a conductive state to a non-conductive state. Even if the internal pressure of the case reaches a predetermined value, the relative positional relationship between the first first insulating member and the second insulating member and the relative positional relationship between the second first insulating member and the second insulating member May be held. The internal pressure of the case acts on portions of the seal member, the first and second first insulating members, and the second insulating member facing the inside of the case. For this reason, when the internal pressure of the case increases, the positions of the seal member, the first and second first insulating members, and the second insulating member may be shifted. According to said structure, even if the internal pressure of a case rises and reaches predetermined value, the relative positional relationship of a 1st and 2nd 1st insulating member and a 2nd insulating member does not change. For this reason, it can suppress that a terminal and a terminal wall directly oppose in 1st space.

(Feature 6) In addition to feature 5, the first first insulating member may be fixed to the terminal, and the second first insulating member may be fixed to the terminal wall. According to this configuration, even if the internal pressure of the case increases, the positions of the first and second first insulating members and the second insulating member do not shift. For this reason, it can suppress that a terminal and a terminal wall directly oppose in 1st space.

(Feature 7) The end surface on the case inner side of the first insulating member may be located on the case inner side of the end portion on the case inner side of the seal member. The seal member may be in contact with the first insulating member disposed on one of the terminal or the terminal wall and the other of the terminal or the terminal wall at the second seal portion. The area where the first insulating member is in contact with the terminal or the terminal wall may be larger than the area of the second seal portion of the seal member. According to this configuration, the friction resistance when the first insulating member or the seal member is moved in the contact surface direction is more likely to be greater in the first insulating member than in the seal member. For this reason, the first insulating member is less likely to be displaced than the seal member. Therefore, even if the position of the seal member is shifted for some reason, the first insulating member can suppress the terminal and the terminal wall from directly facing each other in the first space.

  A power storage device 100 according to a first embodiment will be described with reference to FIGS. The power storage device 100 is a lithium ion secondary battery that is a type of secondary battery. As shown in FIG. 1, the power storage device 100 includes a case 1, an electrode assembly 3, crimping terminals 5 and 7, and a current interrupt device 30. Case 1 is made of metal and has a substantially rectangular parallelepiped shape. Inside the case 1, an electrode assembly 3 and a current interrupt device 30 are accommodated. The electrode assembly 3 includes a negative electrode and a positive electrode. The negative electrode current collecting tab 43 is fixed to the negative electrode, and the positive electrode current collecting tab 45 is fixed to the positive electrode. An electrolyte is injected into the case 1.

  Openings 11 and 13 are formed in the case 1. Hereinafter, in the case 1, a wall in which the openings 11 and 13 are formed is particularly referred to as a case upper wall 9. The caulking terminal 5 communicates with the inside and outside of the case 1 through the opening 11, and the caulking terminal 7 communicates with the inside and outside of the case 1 through the opening 13. The lower end of the crimping terminal 5 is located inside the case 1 and is connected to a current interrupt device 30 (described later). The current interrupt device 30 is connected to the negative current collecting tab 43 through the connection terminal 23 and the negative electrode lead 25. The negative electrode lead 25 is insulated from the case upper wall 9 by an insulating sheet 27. On the other hand, the lower end of the crimping terminal 7 is located inside the case 1 and is connected to the positive electrode current collecting tab 45 through the positive electrode lead 41. The positive electrode lead 41 is insulated from the case upper wall 9 by the insulating sheet 29.

  Resin gaskets 62 and 63 are arranged on the upper surface of the case upper wall 9. The gasket 62 has a protruding portion 66 protruding upward from the case upper wall 9 and a flat plate portion 68 extending along the case upper wall 9. The protruding portion 66 is disposed on the center side of the case upper wall 9, and the flat plate portion 68 is disposed on the opening 11 side of the case upper wall 9. External terminals 60 are disposed on the upper surface of the gasket 62 along the shape of the upper surface of the gasket 62. The head of the bolt 64 is disposed in a bottomed hole 62 a formed in the protrusion 66. The shaft portion of the bolt 64 protrudes upward through the opening of the external terminal 60. The caulking terminal 5, the external terminal 60, and the bolt 64 are electrically connected to each other and constitute a negative terminal. The configuration of the gasket 63, the external terminal 61, and the bolt 65 is the same as the configuration of the gasket 62, the external terminal 60, and the bolt 64 described above. The caulking terminal 7, the external terminal 61, and the bolt 65 are electrically connected to each other and constitute a positive terminal.

  Here, the caulking terminal 5 will be described with reference to FIG. FIG. 2 shows an enlarged view of the two-dot chain line portion 200a of FIG. The caulking terminal 5 has a cylindrical portion 14, a base portion 15, and a fixing portion 16. The cylindrical portion 14 has a cylindrical shape and is inserted through the opening 11. A through hole 14 a is formed in the cylindrical portion 14 in the axial direction (vertical direction). For this reason, the inside of the through-hole 14a is maintained at atmospheric pressure. The base portion 15 is formed in an annular shape and is connected to the lower end of the cylindrical portion 14. That is, the base portion 15 is located inside the case 1. The upper surface of the base portion 15 is substantially orthogonal to the axial direction of the cylindrical portion 14. The outer diameter of the base portion 15 is larger than the diameter of the opening 11. The cylindrical portion 14 and the base portion 15 are arranged concentrically. A recess 15 a is formed at the center of the bottom surface of the base portion 15. The center of the recess 15a and the through hole 14a communicate with each other, and the inside of the recess 15a is maintained at atmospheric pressure. The fixed portion 16 is formed in an annular shape and is connected to the upper end of the cylindrical portion 14. That is, the fixing portion 16 is located outside the case 1. The caulking terminal 5 is fixed to the case upper wall 9 by a fixing portion 16. Before the caulking terminal 5 is fixed to the case upper wall 9, the fixing portion 16 extends in the axial direction of the cylindrical portion 14. That is, the cylindrical portion 14 and the fixed portion 16 constitute one cylindrical portion extending in the axial direction (hereinafter, this portion is referred to as a cylindrical portion). The cylindrical portion 14 corresponds to an example of a “columnar portion”.

  When the caulking terminal 5 is fixed to the case upper wall 9, the cylindrical portion is inserted from the inside of the case 1 through the opening 11, the opening of the gasket 62, and the opening of the external terminal 60. Thereafter, the upper part of the cylindrical part (the part protruding to the outside of the case 1) is bent outwardly in the direction perpendicular to the axis and spread. As a result, the cylindrical portion comes into contact with the upper surface of the external terminal 60, and the caulking terminal 5 is caulked and fixed to the case upper wall 9. The cylindrical portion (that is, the bent portion of the cylindrical portion) corresponds to the fixing portion 16. By fixing the caulking terminal 5 to the case upper wall 9, the O-ring 26 (described later), the insulating member 35 (described later), the gasket 62 and the external terminal 60 are sandwiched between the caulking terminal 5 and the case upper wall 9. . At this time, the case upper wall 9, the base portion 15, and the fixing portion 16 are substantially parallel to each other. The external terminal 60 and the case upper wall 9 are insulated by the gasket 62.

  Next, with reference to FIG. 2, the member arrange | positioned between the crimping terminal 5 and the case upper wall 9 is demonstrated. An annular insulating film 22 is bonded to the lower surface of the case upper wall 9. An annular insulating film 24 is adhered to the upper surface of the base portion 15. The films 22 and 24 make a round around the cylindrical portion 14. Polypropylene (PP) is used for the films 22 and 24. The thickness (length in the vertical direction) of the films 22 and 24 is constant. For the adhesive used for bonding the films 22 and 24, a material having resistance to electrolytic solution is used. For this reason, liquid-tightness between the film 22 and the case upper wall 9 and liquid-tightness between the film 24 and the base portion 15 are ensured. The inner diameter of the film 22 is substantially the same as the diameter of the opening 11, and the inner peripheral surface thereof is located at the lower end of the opening 11. The inner diameter of the film 24 is substantially the same as the outer diameter of the cylindrical portion 14, and the inner peripheral surface thereof is in contact with the outer peripheral surface of the cylindrical portion 14. The outer diameter of the film 22 and the outer diameter of the film 24 are substantially the same. For the films 22 and 24, a resin having an electrolytic solution resistance and an insulating property such as polyethylene (PE) or polyphenylene sulfide (PPS) may be used.

  An O-ring 26 is disposed between the film 22 and the film 24. The O-ring 26 makes a round around the cylindrical portion 14. For the O-ring 26, ethylene-propylene rubber (EPM) such as ethylene propylene diene rubber (EPDM) is used. The O-ring 26 is in contact with both the film 22 and the film 24 in the seal portion S <b> 1 and seals between the film 22 and the film 24. Thereby, the space between the case upper wall 9 and the crimping terminal 5 is sealed. The positions of the outer peripheral ends of the films 22 and 24 are more radial than the positions of the outer peripheral ends of the O-ring 26 (strictly speaking, the O-ring 26 sandwiched between the case upper wall 9 and the crimping terminal 5). Located on the outside. The material of the O-ring 26 is not limited to the above, and any material having sealing properties, insulating properties, and electrolytic solution resistance may be used.

  The space 18 is a space in a range occupied by the fixed portion 16 in a range where the case upper wall 9 and the base portion 15 face each other when the case upper wall 9 is viewed in plan. The space 18 makes a round around the cylindrical portion 14. The seal portion S1 is located in the space 18.

  The arrows in FIG. 2 indicate the direction from the outside to the inside of the case 1. Hereinafter, the direction indicated by the arrow is referred to as “case inner side”, and the direction opposite to the direction indicated by the arrow is referred to as “case outer side”. The same applies to other examples and modifications. Of the space between the crimping terminal 5 and the case upper wall 9, a space 20 is formed on the case inner side (that is, radially outer side) than the seal portion S <b> 1. The space 20 makes a round around the cylindrical portion 14. The space 20 communicates with the inside of the case 1. Part of the films 22 and 24 and part of the O-ring 26 are disposed in the space 20. An annular insulating member 35 is disposed in the space 20. PPS is used for the insulating member 35. The insulating member 35 makes a round around the cylindrical portion 14. The insulating member 35 is in contact with the lower surface of the case upper wall 9 and the upper surface of the base portion 15. The outer peripheral ends of the films 22 and 24 are in contact with the inner peripheral surface 35 a at the upper end of the insulating member 35. In addition, the material of the insulating member 35 is not limited to the above, and a material (for example, polyetheretherketone (PEEK)) that has insulating properties and electrolytic solution resistance and has excellent strength characteristics necessary for load support may be used. Good.

  The insulating member 35 extends radially outward from the upper surface of the base portion 15, covers the outer peripheral surface of the base portion 15, and extends to substantially the same height as a fracture plate 34 (described later). For this reason, in the space 20, any one of the films 22 and 24, the O-ring 26, and the insulating member 35 is disposed from the end surface on the case outer side of the space 20 to the end surface on the case inner side. In other words, when the case upper wall 9 is viewed in plan, one of the films 22 and 24, the O-ring 26, and the insulating member 35 is disposed in the entire space 20. In addition, in the up-down direction of the space 20, there may be a space in which the members 22, 24, 26, and 35 are not arranged. The lower end surface of the insulating member 35 is in contact with the insulating member 39. The insulating member 39 covers the outer peripheral portion of the lower surface of the fracture plate 34 in the circumferential direction. An annular metal plate 40 is caulked on the outer peripheral surfaces of the insulating members 35 and 39. Thereby, the base part 15, the deformation | transformation board 32, and the fracture | rupture board 34 are clamped to an up-down direction.

  Next, the caulking terminal 7 and members disposed between the caulking terminal 7 and the case upper wall 9 will be described with reference to FIG. FIG. 3 shows an enlarged view of the two-dot chain line portion 200b of FIG. The description of the same configuration as in FIG. 2 is omitted. The caulking terminal 7 has a cylindrical portion 94, a base portion 95, and a fixing portion 96. The caulking terminal 7 is solid, and no through hole and recess are formed. The caulking terminal 7 is caulked and fixed to the case upper wall 9 by bending the fixing portion 96 outward in the axial direction. As a result, the O-ring 26, the insulating member 115, the gasket 63 and the external terminal 61 are sandwiched between the crimping terminal 7 and the case upper wall 9. The base portion 95 is connected to the positive electrode lead 41.

  An annular insulating member 115 is disposed in the space 20. The insulating member 115 is made of the same material as the insulating member 35. The outer peripheral ends of the films 22 and 24 are in contact with the inner peripheral surface 115 a of the insulating member 115. The insulating member 115 extends from the upper surface of the base portion 95 radially outward to the position of the outer peripheral surface of the base portion 95. For this reason, in the space 20, any one of the films 22 and 24, the O-ring 26, and the insulating member 115 is disposed from the end surface on the case outer side of the space 20 to the end surface on the case inner side. In other words, when the case upper wall 9 is viewed in plan, one of the films 22 and 24, the O-ring 26, and the insulating member 115 is disposed in the entire space 20.

  Returning to FIG. 2, the current interrupt device 30 will be described. The current interrupt device 30 includes a metal deformation plate 32 and a metal break plate 34. The outer peripheral portion of the deformable plate 32 is connected to the outer peripheral portion of the lower surface of the base portion 15, and the lower end of the recess 15 a of the base portion 15 is covered with the deformable plate 32. Since the inside of the recess 15 a is maintained at atmospheric pressure, atmospheric pressure acts on the upper surface of the deformation plate 32. The base portion 15, the deformation plate 32, and the fracture plate 34 are sandwiched between annular insulating members 35 and 39 and a plate material 40. The deformation plate 32 is a circular conductive diaphragm, and protrudes downward. The central portion of the deformation plate 32 is connected to the break plate 34. The fracture plate 34 is a circular plate material and is located below the deformation plate 32. The connection terminal 23 is connected to the breaking plate 34. A groove 34 a is formed at the center of the lower surface of the fracture plate 34. The fracture plate 34 and the central portion of the deformation plate 32 are connected inside the groove 34a. The mechanical strength of the fracture plate 34 at the position where the groove 34a is formed is lower than the mechanical strength of the fracture plate 34 at a position other than the groove 34a. A vent hole 34 b is formed in the breaking plate 34, and a space 46 between the deformation plate 32 and the breaking plate 34 communicates with a space in the case 1. An annular insulating member 38 is disposed between the outer periphery of the deformable plate 32 and the outer periphery of the fracture plate 34.

  The current interrupt device 30 has an energization path that connects the connection terminal 23, the fracture plate 34, the deformation plate 32, and the crimping terminal 5 in series. For this reason, the electrode assembly 3 and the caulking terminal 5 are electrically connected via the energization path of the current interrupt device 30.

  Here, the interruption operation of the current interruption device 30 will be described. In the power storage device 100 described above, the caulking terminal 5 and the caulking terminal 7 can be energized. When the pressure in the case 1 increases, the pressure acting on the lower surface of the deformable plate 32 increases through the vent hole 34b. On the other hand, atmospheric pressure acts on the upper surface of the deformation plate 32. For this reason, when the internal pressure of the case 1 rises and reaches a predetermined value, the deformable plate 32 is inverted and changes to a convex state upward. Then, the break plate 34 connected to the central portion of the deformable plate 32 breaks starting from the mechanically fragile groove 34a. As a result, the energization path connecting the fracture plate 34 and the deformation plate 32 is interrupted, and the energization between the electrode assembly 3 and the crimping terminal 5 is interrupted. At this time, the deformable plate 32 is insulated from the connection terminal 23, and the fracture plate 34 is insulated from the caulking terminal 5.

  The effect of the electrical storage apparatus 100 of Example 1 is demonstrated. In the following description, “crimp terminal 5” can be read as “crimp terminal 7” unless otherwise specified. The same applies to the effects of the other embodiments and modifications. In the above power storage device 100, the space between the case upper wall 9 and the crimping terminal 5 is sealed at the seal portion S <b> 1 of the O-ring 26 via the films 22 and 24. For this reason, it is suppressed that the electrolyte solution in case 1 leaks out of case 1 rather than seal part S1. In the space 20, any of the films 22 and 24, the O-ring 26, and the insulating member 35 is always disposed when the case upper wall 9 is viewed in plan. For this reason, the caulking terminal 5 and the case upper wall 9 do not directly face each other in the space 20. Therefore, even if the electrolytic solution enters the space 20 after the current interrupting device 30 is operated and a high voltage is applied between the caulking terminal 5 and the case upper wall 9, the caulking terminal 5 and the case upper wall 9 are not connected. Short circuit can be suppressed. Although the plate member 40 and the case upper wall 9 are directly opposed to each other, the plate member 40 is insulated from the energization path by the insulating member 35. Therefore, it should be noted that there is no particular problem even if the plate member 40 is electrically connected to the case upper wall 9.

  In the power storage device 100, the outer peripheral ends of the films 22 and 24 are located on the radially outer side than the O-ring 26. That is, the caulking terminal 5 and the case upper wall 9 are not directly opposed to each other in the space 20 by the films 22 and 24 and the insulating member 35. The contact area between the film 22 and the case upper wall 9 and the contact area between the film 24 and the crimp terminal 5 are larger than the area of the seal portion S1. For this reason, by appropriately selecting the materials of the films 22 and 24, the friction resistance when the films 22, 24 or the O-ring 26 are moved in the radial direction is made larger in the films 22 and 24 than in the O-ring 26. be able to. In particular, in the first embodiment, since the films 22 and 24 are bonded, it is difficult for the films 22 and 24 to slide relative to the case upper wall 9 or the crimp terminal 5. Therefore, when the internal pressure of the case 1 rises and a force toward the outside direction of the case 1 (that is, the radially inner side of the crimping terminal 5) acts on the films 22 and 24 and the O-ring 26, the films 22 and 24 are better. These positions are more difficult to shift than the O-ring 26. In the conventional configuration in which the films 22 and 24 are not disposed, the O-ring 26 is placed on the inner peripheral surface 35 a at the upper end of the insulating member 35 in order to prevent the crimping terminal 5 and the case upper wall 9 from directly facing each other in the space 20. It was necessary to abut. For this reason, when the internal pressure of the case 1 rises, the O-ring 26 is displaced radially inward and is separated from the inner peripheral surface 35a at the upper end of the insulating member 35, and the crimping terminal 5 and the case upper wall 9 are directly opposed to each other. There was a possibility that both would short-circuit. In this embodiment, the insulating member 35 prevents the case upper wall 9 and the caulking terminal 5 from directly facing each other by coming into contact with a member that is relatively difficult to be displaced (that is, the films 22 and 24). . For this reason, even if the internal pressure of the case 1 rises and the position of the O-ring 26 is displaced, the films 22 and 24 are relatively difficult to be displaced, so that the caulking terminal 5 and the case upper wall 9 directly in the space 20. It can suppress facing.

  Further, in the power storage device 100, the film 24 is positioned by the inner peripheral surface thereof coming into contact with the cylindrical portion 14. Further, the insulating member 35 is fixed to the crimping terminal 5 by the plate material 40. For this reason, even if a radial external force acts on the film 24 and the insulating member 35, the film 24 and the insulating member 35 are unlikely to be displaced. Therefore, even if the internal pressure of the case 1 rises and reaches a predetermined value, the relative positional relationship between the film 24 and the insulating member 35 hardly changes. As a result, it is possible to further suppress the caulking terminal 5 and the case upper wall 9 from directly facing each other in the space 20.

  In the power storage device 100, the seal portion S <b> 1 is located in the space 18. For this reason, between the film 22 and the film 24 (that is, between the caulking terminal 5 and the case upper wall 9) can be tightly sealed in the seal portion S1, and the leakage of the electrolyte solution to the outside of the case 1 is further suppressed. it can.

  In a power storage device module including a plurality of power storage devices 100, each power storage device 100 is connected in series and connected in series until a desired voltage is obtained. Thereby, a high-output and large-capacity power storage device module can be configured.

(Modification 1) Next, Modification 1 will be described with reference to FIG. Hereinafter, only differences from the first embodiment will be described, and detailed description of the same configurations as those of the first embodiment will be omitted. The same applies to other examples and modifications. Unless otherwise specified, the positional relationship of the members between the crimping terminal 7 and the case upper wall 9 is the same as the positional relationship of the members between the crimping terminal 5 and the case upper wall 9.

  The two-dot chain line portion 300a in FIG. 4 corresponds to the two-dot chain line portion 200a in FIG. An annular film 124 is bonded to the upper surface of the crimp terminal 5. The inner diameter of the film 124 is substantially the same as the outer diameter of the cylindrical portion 14, and the outer diameter of the film 124 is slightly larger than the inner diameter of the insulating member 35. When the film 124 is bonded to the crimping terminal 5, first, the cylindrical portion of the crimping terminal 5 is inserted into the insulating member 35, and the insulating member 35 is attached to the crimping terminal 5. Thereafter, the cylindrical portion of the crimping terminal 5 is inserted into the film 124 with the adhesive applied to the lower surface of the film 124. Since the outer diameter of the film 124 is larger than the inner diameter of the insulating member 35, the outer peripheral portion of the film 124 is bonded to the crimp terminal 5 so as to cover a part of the inner peripheral surface 35 a at the upper end of the insulating member 35. Also with this configuration, the same operational effects as the power storage device 100 of the first embodiment are obtained. In addition, since the outer diameter of the film 124 is larger than the inner diameter of the insulating member 35, the film 124 and the insulating member 35 can be reliably brought into contact with each other.

  Next, Example 2 will be described with reference to FIG. The two-dot chain line portion 400a in FIG. 5 corresponds to the two-dot chain line portion 200a in FIG. Grooves 36 and 37 that are recessed in a direction substantially orthogonal to the upper end surface are formed on the inner peripheral surface 135 a at the upper end of the insulating member 135. The groove 36 has a shape in which a corner portion connecting the inner peripheral surface 135a at the upper end of the insulating member 135 and the upper surface is cut out in the circumferential direction. The groove 36 has a side surface 36a substantially orthogonal to the inner peripheral surface 135a at the upper end of the insulating member 135 and a bottom surface 36b substantially orthogonal to the side surface 36a. The length in the vertical direction of the surface 36 b corresponds to the width of the groove 36. The groove 37 has a shape in which a corner portion connecting the inner peripheral surface 135a at the upper end of the insulating member 135 and the lower surface is cut out in the circumferential direction. The groove 37 has a side surface 37a substantially orthogonal to the inner peripheral surface 135a at the upper end of the insulating member 135 and a bottom surface 37b substantially orthogonal to the side surface 37a. The length in the vertical direction of the surface 37 b corresponds to the width of the groove 37.

  The outer periphery of the film 22 is disposed in the groove 36. The width of the groove 36 is substantially the same as the thickness of the film 22. For this reason, the outer peripheral part of the film 22 is in contact with the side surface 36 a of the groove 36 and the case upper wall 9. The outer periphery of the film 24 is disposed in the groove 37. The width of the groove 37 is substantially the same as the thickness of the film 24. For this reason, the outer peripheral portion of the film 24 is in contact with the side surface 37 a of the groove 37 and the base portion 15. The contact surface between the film 22 and the side surface 36 a and the contact surface between the film 24 and the side surface 37 a are located in the space 18.

  The power storage device according to the second embodiment has the same effects as the power storage device 100 according to the first embodiment. In this embodiment, the outer peripheral portions of the films 22 and 24 are disposed in the grooves 36 and 37, respectively. For this reason, when the case upper wall 9 is viewed in plan, the outer peripheral portions of the films 22 and 24 overlap the upper end portion of the insulating member 135. Therefore, even if the internal pressure of the case 1 rises and any of the positions of the insulating member 135, the films 22, 24, and the O-ring 26 is displaced, the outer peripheral portion of the films 22, 24 and the upper end of the insulating member 135 are As long as they overlap in a plan view, the caulking terminal 5 and the case upper wall 9 can be prevented from directly facing each other in the space 20. As a result, it is possible to further suppress a short circuit between the caulking terminal 5 and the case upper wall 9 as compared with a configuration in which the grooves 36 and 37 are not formed. In particular, in this embodiment, the film 22 and the side surface 36a of the groove 36 are in contact with each other, and the film 24 and the side surface 37a of the groove 37 are in contact with each other. For this reason, even if the pressure in the case 1 rises and a radially inward force acts on the film 22 and the insulating member 135, the film 22 and the insulating member are caused by the frictional force generated between the film 22 and the side surface 36a. It can suppress that the relative positional relationship with 135 changes. Thereby, it can suppress more that the crimping terminal 5 and the case upper wall 9 directly oppose in the space 20. FIG. The same applies to the film 24 and the side surface 37a. Further, in this embodiment, since the contact portion between the film 22 and the side surface 36a and the contact portion between the film 24 and the side surface 37a are located in the space 18, an external force is applied to the films 22, 24 and the insulating member 135. When acting, the frictional force in the radial direction of the contact portion further increases.

  Next, Embodiment 3 will be described with reference to FIG. The two-dot chain line portion 500a in FIG. 6 corresponds to the two-dot chain line portion 200a in FIG. An annular film 222 is bonded to the upper surface of the case upper wall 9, and an annular film 224 is bonded to the lower surface of the fixing portion 16. An O-ring 26 is disposed between the film 222 and the film 224. The O-ring 26 seals between the case upper wall 9 and the crimping terminal 5 via the films 222 and 224 in the seal portion S2. The positions of the inner peripheral ends of the films 222 and 224 are located on the radially inner side of the position of the inner peripheral end of the O-ring 26. The space 218 represents a space in a range where the case upper wall 9 and the fixed portion 16 face each other when the case upper wall 9 is viewed in plan. The seal portion S2 is located in the space 218.

  Of the space between the crimp terminal 5 and the case upper wall 9, a space 220 is formed on the case inner side (that is, radially inward and downward) than the seal portion S <b> 2. An insulating member 235 and an insulating member 238 are disposed in the space 220. A groove 236 and a groove 237 are formed on the inner peripheral surface 235 a at the upper end of the insulating member 235. The thicknesses of the films 222 and 224 are substantially the same as the widths of the grooves 236 and 237, respectively. The inner peripheral portion of the film 222 is disposed in the groove 236, and the inner peripheral portion of the film 224 is disposed in the groove 237. The lower end surface of the insulating member 235 is in contact with the upper end surface of the insulating member 238. The insulating member 238 extends radially outward from the upper surface of the base portion 15, covers the outer peripheral surface of the base portion 15, and extends to substantially the same height as the fracture plate 34. For this reason, any one of the films 222 and 224, the O-ring 26, the insulating member 235, and the insulating member 238 is disposed in the space 220 from the end surface on the case outer side to the end surface on the case inner side of the space 220. In other words, when the case upper wall 9 is viewed in plan, one of the films 222 and 224, the O-ring 26, the insulating member 235, and the insulating member 238 is disposed in the entire space 220. Also with this configuration, the same effects as the power storage device of the second embodiment can be obtained.

  Next, Example 4 will be described with reference to FIG. The two-dot chain line portion 600a in FIG. 7 corresponds to the two-dot chain line portion 200a in FIG. An annular seal member 322 is disposed on the lower surface of the case upper wall 9. The seal member 322 has an inner peripheral end 322a that is thicker than other portions. The length in the radial direction of the end portion 322a before the seal member 322 is disposed on the lower surface of the case upper wall 9 is longer than the length between the cylindrical portion 14 of the crimping terminal 5 and the opening 11. An annular seal member 324 is disposed on the upper surface of the crimp terminal 5. The inner peripheral surface of the seal member 324 is in contact with the cylindrical portion 14. The outer diameters of the seal member 322 and the seal member 324 are substantially the same. The seal members 322 and 324 are formed of the same material as the O-ring 26. The outer peripheral portion of the seal member 322 is disposed in the groove 36 of the insulating member 135. The thickness excluding the end 322 a of the seal member 322 before the outer peripheral portion of the seal member 322 is disposed in the groove 36 is thicker than the width of the groove 36. The outer peripheral portion of the seal member 324 is disposed in the groove 37. The thickness of the seal member 324 before the seal member 324 is disposed in the groove 37 is thicker than the width of the groove 37. An O-ring 26 is disposed between the seal member 322 and the seal member 324. The O-ring 26 seals between the seal member 322 and the seal member 324 (that is, between the case upper wall 9 and the crimp terminal 5) in the seal portion S3.

  The power storage device according to the fourth embodiment can achieve the same effects as the power storage device 100 according to the second embodiment. Further, the seal member 322 has a sealing property, and can ensure liquid tightness between the case upper wall 9 and the seal member 322. Similarly, the seal member 324 can also ensure liquid tightness between the crimping terminal 5 and the seal member 324. Therefore, it is not necessary to bond the sealing members 322 and 324 to the case upper wall 9 and the crimping terminal 5 with an adhesive, and the manufacturing cost of the power storage device can be reduced. Further, the seal member 322 is positioned by the end portion 322 a being disposed in the opening 11. For this reason, the position of the seal member 322 becomes difficult to shift with respect to the increase in the internal pressure of the case 1, and the case upper wall 9 and the crimping terminal 5 can be prevented from directly facing each other in the space 20. Further, the outer peripheral portions of the seal members 322 and 324 are thicker than the widths of the grooves 36 and 37, respectively. Therefore, the case upper wall 9 and the caulking terminal 5 are sealed at the contact surface between the seal member 322 and the side surface 36a and the contact surface between the seal member 324 and the side surface 37a. Therefore, it is possible to suppress the electrolyte from entering the space surrounded by the O-ring 26, the seal members 322 and 324, and the insulating member 135, and to further suppress a short circuit between the case upper wall 9 and the crimping terminal 5. it can.

  Next, Example 5 will be described with reference to FIG. 700a in FIG. 8 corresponds to the two-dot chain line portion 200a in FIG. In this power storage device, the configuration of the current interrupt device is different from that of the first embodiment, and other configurations are the same as those of the first embodiment.

  The current interrupt device 70 includes a metal first deformable plate 75, a metal fracture plate 73, and a metal second deformable plate 71. The base 15, the first deformation plate 75, the fracture plate 73 and the second deformation plate 71 are supported by insulating insulating members 35 and 78. A metal plate 79 is caulked on the outer peripheral surfaces of the insulating members 35 and 78. Thereby, the base part 15, the 1st deformation board 75, the fracture | rupture board 73, and the 2nd deformation board 71 are clamped to an up-down direction.

  The second deformable plate 71 is disposed below the fracture plate 73, and its central portion protrudes downward. An insulating member 81 is disposed on the outer peripheral portion of the upper surface of the second deformation plate 71. A projecting portion 83 that projects upward is provided at the center of the upper surface of the second deformable plate 71. Above the projecting portion 83, a central portion 73b (a portion surrounded by the groove portion 73a) of the fracture plate 73 is located. The pressure of the space in the case 1 acts on the lower surface of the second deformation plate 71. The pressure of the space 86 between the second deformation plate 71 and the fracture plate 73 acts on the upper surface of the second deformation plate 71 (described later). The space 86 is sealed from the space in the case 1.

  The fracture plate 73 is disposed between the second deformation plate 71 and the first deformation plate 75. The fracture plate 73 is divided into a central part 73b surrounded by the groove part 73a and an outer peripheral part 73c located on the outer peripheral side of the groove part 73a by the groove part 73a. The central portion 73b is thin, and the outer peripheral portion 73c is thick. A vent hole 73d is formed in the fracture plate 73. The space 86 communicates with the space 88 between the first deformable plate 75 and the fracture plate 73 through the vent hole 73d.

  The first deformation plate 75 is disposed above the fracture plate 73. The first deformation plate 75 has substantially the same configuration as the deformation plate 32 of the first embodiment. An insulating member 85 is disposed between the first deformation plate 75 and the fracture plate 73. A space 87 is formed between the upper surface of the first deformation plate 75 and the lower surface of the base portion 15. The space 87 is maintained at atmospheric pressure. A seal member 89 is disposed between the break plate 73 and the outer peripheral portion of the base portion 15 to seal the gap between the base portion 15 and the break plate 73.

  The current interrupt device 70 has an energization path that connects the connection terminal 23, the fracture plate 73, the first deformation plate 75, and the crimping terminal 5 in series. For this reason, the electrode assembly 3 and the caulking terminal 5 are electrically connected via the energization path of the current interrupt device 70.

  Here, the interruption operation of the current interruption device 70 will be described. In the power storage device described above, the caulking terminal 5 and the caulking terminal 7 can be energized. When the internal pressure of the case 1 increases, the pressure acting on the lower surface of the second deformation plate 71 increases. On the other hand, the pressure of the space 86 sealed from the space in the case 1 acts on the upper surface of the second deformation plate 71. For this reason, if the pressure in case 1 exceeds a predetermined value, the 2nd deformation board 71 will reverse and it will change from the state of convex to the state of convex to the upper part. At this time, the air in the space 86 moves to the space 88 through the vent 73d, and the pressure in the space 88 increases. When the second deformable plate 71 is reversed, the protruding portion 83 of the second deformable plate 71 collides with the central portion 73b of the breakable plate 73, and the breakable plate 73 is broken at the groove 73a. As a result, the first deformation plate 75 is inverted, and the first deformation plate 75 and the central portion 73b of the fracture plate 73 are displaced upward. For this reason, the energization path which connects the fracture | rupture board 73 and the 1st deformation board 75 is interrupted | blocked, and the continuity between the electrode assembly 3 and the crimping terminal 5 is interrupted | blocked. At this time, the first deformation plate 75 is insulated from the connection terminal 23, and the fracture plate 73 is insulated from the caulking terminal 5. Also with this configuration, the same effects as the power storage device 100 of the first embodiment can be obtained. In addition, said electric current interruption apparatus 70 may be attached to the electrical storage apparatus of another Example and modification.

  Next, Example 6 will be described with reference to FIG. The two-dot chain line portion 800a in FIG. 9 corresponds to the two-dot chain line portion 200a in FIG. In this power storage device, the configuration of the negative electrode terminal 405 is different from that of the first embodiment. The negative terminal 405 has a cylindrical portion 414 and a base portion 415. A film 22 and a film 24 are bonded to the lower surface of the case upper wall 9 and the upper surface of the base portion 15, respectively. When fixing the negative electrode terminal 405 to the case upper wall 9, the cylindrical portion 414 is inserted from the inside of the case 1 to the case upper wall 9 with the O-ring 26, the insulating member 35, and the plate member 40 inserted through the cylindrical portion 414. Insert through the opening 11. Then, the annular insulating member 17 is attached to the cylindrical portion 414 from the outside of the case 1. Thereafter, the nut 21 is fastened to the cylindrical portion 414 from the outside of the case 1. Thereby, the negative terminal 405 is fixed to the case upper wall 9, and the O-ring 26 and the insulating member 35 are sandwiched between the base portion 415 and the case upper wall 9. The O-ring 26 seals between the base portion 415 and the case upper wall 9 at the seal portion S4. The space 418 represents a range where the base portion 415 and the case upper wall 9 face each other when the case upper wall 9 is viewed in plan, and a range occupied by the nut 21. The seal portion S4 is located in the space 418. A space 420 is formed outside the seal portion S4 in the radial direction in the space between the negative electrode terminal 405 and the case upper wall 9. In the space 420, any of the films 22 and 24, the O-ring 26, and the insulating member 35 is disposed from the end surface on the case outer side to the end surface on the case inner side of the space 420. In other words, when the case upper wall 9 is viewed in plan, one of the films 22 and 24, the O-ring 26, and the insulating member 35 is disposed in the entire space 420. A through hole 414a is formed in the negative electrode terminal 405 in the axial direction (vertical direction). A bus bar bolt 47 is attached to the through hole 414a. A bus bar 49 is disposed between the head of the bus bar bolt 47 and the negative terminal 405. Also with this configuration, the same effects as the power storage device 100 of the first embodiment can be obtained. Further, according to this configuration, the direction of the tightening force exerted on the case upper wall 9 by the nut 21 is the same as the direction of the compressive force for sealing the base portion 415 and the case upper wall 9, and the base in the seal portion S 4. The space between the portion 415 and the case upper wall 9 can be firmly sealed. Note that the configurations of other examples and modifications may be applied to the negative electrode terminal 405 described above.

  As described above, the embodiments of the technology disclosed in this specification have been described in detail. However, these are merely examples, and the power storage device disclosed in this specification includes various modifications and changes of the above-described embodiments. It is. For example, in the above embodiment, the film or the seal member is disposed on both the case upper wall 9 and the crimp terminal 5, but the present invention is not limited to this, and the film or the seal member is disposed on one of the case upper wall 9 and the crimp terminal 5. It may be configured.

  Moreover, when a film or a sealing member is arrange | positioned at both the case upper wall 9 and the crimping terminal 5, the outer diameter of two films may differ. The same applies to the seal member.

  Further, instead of adhering the film, the case upper wall 9 and / or the crimped terminal 5 may be coated with a resin coating film.

  Moreover, when the outer peripheral part of a film is arrange | positioned in a groove | channel, the film and the side surface of a groove | channel do not need to contact | abut. In other words, the width of the groove may be longer than the thickness of the film.

  For example, in Example 1, the insulating member 35 functions as a part of a member for fixing the base portion 15, the deformable plate 32, and the fracture plate 34 in the radial direction, but is not limited thereto. If any one of the films 22, 24, the O-ring 26 and the insulating member 35 is disposed in the space 20 from the end surface of the space 20 on the outer side of the case to the end surface on the inner side of the case, the insulating member 35 has the base portion described above. 15, the deformation | transformation board 32 and the fracture | rupture board 34 do not need to function as a member for fixing to radial direction. That is, the insulating member 35 may have a shape in which an end portion on the outer side in the radial direction is located at the outer peripheral end of the base portion 15 of the crimping terminal 5.

  Further, for example, in the first embodiment, there is one insulating member (that is, the insulating member 35) disposed between the case upper wall 9 and the crimping terminal 5, but two or more insulating members are interposed between the two. A member may be arranged. In this case, it is not necessary that all of the plurality of insulating members are in contact with both the case upper wall 9 and the crimping terminal 5. For example, the structure which the insulation member (namely, insulation member 35) arrange | positioned adjacent to a film or a sealing member may contact | abut only to the crimping terminal 5 may be sufficient. The plurality of insulating members are preferably in contact with each other.

  Moreover, the cylindrical part 14 is not restricted to a cylindrical shape, What is necessary is just a cylindrical shape. Further, the cylindrical portion 94 is not limited to a cylindrical shape, and may be a columnar shape.

  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. 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 illustrated in the present specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.

1: case, 3: electrode assembly, 5: caulking terminal, 7: caulking terminal, 9: upper wall of case, 11: opening, 13: opening, 14: cylindrical portion, 15: base portion, 16: fixing portion, 20 : Space, 21: Nut, 22: Film, 24, Film, 26: O-ring, 30: Current interrupting device, 32: Deformation plate, 35: Insulating member, 36: Groove, 37: Groove, 100: Power storage device, 322 : Seal member, 324: Seal member

Claims (8)

A case capable of accommodating an electrode assembly including a positive electrode and a negative electrode, and an electrolyte;
A terminal that communicates with the inside and outside of the case through an opening formed in the terminal wall of the case;
The terminal is accommodated in the case and electrically connected to the terminal and the positive electrode, or the terminal and the negative electrode, and the terminal and the positive electrode or the negative electrode are disconnected from a conductive state. A current interrupting device having a conductive member for switching to a state,
The terminal has a columnar portion inserted through the opening, and a base portion disposed at one end of the columnar portion and positioned inside the case,
The base portion is larger than the opening in a state in plan view of the terminal wall, and is electrically connected to the conductive member,
Between the terminal and the terminal wall, a sealing member that goes around the columnar part is disposed,
An insulating first insulating member that circulates around the columnar portion is disposed between at least one of the sealing member and the terminal and between the sealing member and the terminal wall,
The sealing member seals between the terminal and the terminal wall together with the first insulating member,
Between empty the seal member inside the case side from among the space between the terminal and the terminal wall, insulation of the second insulating member to cycle the columnar portion is disposed,
In all from the end portion of the case outside of the end portion of the casing inner side of the outer periphery of the base portion of the base unit, one of the first insulating member or the second insulating member is disposed, the power storage device .   The power storage device according to claim 1, wherein an end surface of the first insulating member on an inner side of the case is in contact with an end surface of the second insulating member on an outer side of the case. A groove that is recessed in a direction orthogonal to the end surface is formed in the end surface on the case outer side of the second insulating member over the circumferential direction,
The power storage device according to claim 1, wherein an end surface of the first insulating member on an inner side of the case is located in the groove.   4. The power storage device according to claim 3, wherein a width of the groove is equal to or less than a thickness of the first insulating member before the first insulating member is disposed in the groove. The end surface on the case inner side of the first insulating member is located on the case inner side from the end portion on the case inner side of the seal member,
The seal member is in contact with the first first insulating member disposed on the terminal and the second first insulating member disposed on the terminal wall at the first seal portion;
The area where the first first insulating member is in contact with the terminal and the area where the second first insulating member is in contact with the terminal wall are based on the area of the first seal portion of the seal member. The power storage device according to any one of claims 1 to 4, wherein the power storage device is larger. An end surface on the case inner side of the first first insulating member and an end surface on the case inner side of the second first insulating member are located on the case inner side of the end portion on the case inner side of the seal member. And
When the internal pressure of the case exceeds a predetermined value, the current interrupt device switches the terminal and the positive electrode, or the terminal and the negative electrode from a conductive state to a non-conductive state,
Even if the internal pressure of the case reaches a predetermined value, the relative positional relationship between the first first insulating member and the second insulating member and the relationship between the second first insulating member and the second insulating member. The power storage device according to claim 5, wherein the relative positional relationship is maintained.   The first first insulating member is fixed to the terminal, the second first insulating member is fixed to the terminal wall, and the second insulating member is fixed to the terminal or the terminal wall. The power storage device according to claim 6. The end surface on the case inner side of the first insulating member is located on the case inner side from the end portion on the case inner side of the seal member,
The seal member is in contact with the first insulating member disposed on one of the terminal or the terminal wall and the other of the terminal or the terminal wall at a second seal portion,
5. The power storage device according to claim 1, wherein an area in which the first insulating member is in contact with the terminal or the terminal wall is larger than an area of the second seal portion of the seal member. .

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