JP6265019B2 - 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 interrupting device is disposed between the terminal and the current collecting tab (positive current collecting tab or negative current collecting tab). Patent Document 1 discloses a current interrupting device in which a deformable plate connected to a terminal and an energizing plate connected to a current collecting tab are joined. When the pressure in the case of the power storage device rises and exceeds a predetermined value, the current interrupt device operates to separate the deformed 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 seal member is in contact with the terminal and the terminal wall, and seals between the two. 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. Therefore, it is conceivable that the sealing member is brought into contact with the insulating member so that the terminal and the terminal wall are not directly opposed between the sealing member and the insulating member. According to this structure, it can suppress that a terminal and a terminal wall short-circuit. However, when the pressure in the case rises, a relatively high pressure acts on the seal member, and the seal member may shift away from the insulating member (that is, on the outside of the case). When the seal member is displaced to the outside of the case, a space in which the terminal and the terminal wall directly face each other is formed between the seal member and the insulating member, and the terminal and the terminal wall may be short-circuited. For this reason, the occurrence of a short circuit between the terminal and the terminal wall cannot be sufficiently suppressed only by bringing the seal member and the insulating member into contact with each other.

  In this specification, the technique which suppresses that a terminal and a terminal wall short-circuit more 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 a conductive state to a 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, an O-ring that seals the inside and outside of the case by contacting both the terminal and the terminal wall and goes around the columnar portion is disposed. In the space between the terminal and the terminal wall, an insulating member that goes around the columnar portion is arranged on the inner side of the case than the O-ring. The end surface on the O-ring side of the insulating member is inclined so that the radial position changes from the terminal wall-side surface to the terminal-side surface, and the O-ring is in contact with the end surface of the insulating member.

  In the above power storage device, the end surface of the insulating member that is in contact with the O-ring is inclined so that the radial position changes from the terminal wall side surface to the terminal side surface. For this reason, the contact position between the O-ring and the end surface of the insulating member is closer to the inside of the case than the position on the outermost side of the case among the end surfaces of the insulating member. Therefore, even if the pressure in the case rises and the O-ring moves away from the insulating member (ie, the case outside), the end of the O-ring inside the case is the most of the end surfaces of the insulating member. The terminal and the terminal wall do not directly face each other between the O-ring and the insulating member as long as it is located on the case inner side with respect to the outer side position. That is, if the distance that the O-ring is displaced is within the range that satisfies the above-described conditions, the terminal and the terminal wall do not directly face each other, and even if a high voltage is applied between the terminal and the terminal wall, It is possible to suppress a short circuit with the terminal wall. For this reason, it can suppress that a terminal and a terminal wall short-circuit compared with the conventional structure. The “inside of the case” means the direction from the outside of the case toward the inside in the space that communicates the outside and inside of the case, and the “outside of the case” means the space that communicates the outside and inside of the case. Represents the direction from the inside to the outside of the case. Therefore, when the space between the terminal wall and the terminal (the space communicating the inside and outside of the case) extends in parallel with the terminal wall in the case, the direction away from the opening of the terminal wall is the “inside of the case” The direction close to the opening is the “case outer side”.

  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. 2A is a partially enlarged view in the vicinity of the O-ring in FIG. 2 and shows a state before the pressure in the case rises, and FIG. 2B is a partially enlarged view in the vicinity of the O-ring in FIG. The state after the shut-off device operates is shown. 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 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) One of the terminal wall and the terminal may be formed with a protruding portion that protrudes toward the other of the terminal wall and the terminal. The protruding portion may be disposed on the case outer side than the O-ring, and the O-ring may be in contact with the protruding portion. According to this configuration, even if the pressure in the case rises and a force in the case outside direction acts on the O-ring, the protrusions suppress the positional deviation of the O-ring. For this reason, it can suppress more that a terminal and a terminal wall directly face due to the position shift of an O-ring.

(Characteristic 2) In addition to the characteristic 1, the surface of the protruding portion with which the O-ring is in contact may be inclined toward the outer side of the case from the base side to the distal end side of the protruding portion. According to this configuration, the contact position between the O-ring and the inclined surface of the protruding portion can be slid to the outside of the case within a certain range according to the degree of increase in pressure in the case. For this reason, it can suppress that an O-ring deform | transforms excessively due to the force which acts on an O-ring. Therefore, it is possible to suppress the deterioration of the O-ring while suppressing the positional deviation of the O-ring.

(Feature 3) At least one of the terminal or the terminal wall is formed with a groove that goes around the columnar portion, and the O-ring may be fitted into the groove. According to this configuration, even if the pressure in the case rises and a force in the case outside direction acts on the O-ring, the O-ring is not easily displaced.

(Characteristic 4) Moreover, this specification discloses the electrical storage apparatus module provided with two or more said electrical storage apparatuses, and these several electrical storage apparatuses are connected in series. In this power storage device module, in each of the plurality of power storage devices constituting the power storage device module, the end surface of the insulating member that is in contact with the O-ring changes in radial position from the terminal wall side surface to the terminal side surface. Inclined to do. For this reason, even if the pressure in a case rises in each power storage device and the O-ring shifts to the outside of the case, the terminal and the terminal wall are prevented from directly facing each other between the O-ring and the insulating member. Therefore, even if a high voltage is applied between the terminal and the terminal wall, the terminal and the terminal wall can be prevented from being short-circuited, and the function of the power storage device module can be prevented from being deteriorated.

  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. That is, the side where the case upper wall 9 is located with respect to the electrode assembly 3 is the upper side, and the side opposite to the side where the case upper wall 9 is located with respect to the electrode assembly 3 is the lower side. On the lower surface of the case upper wall 9, annular projecting portions 9a and 9b extending downward are formed. The protruding portions 9a and 9b are formed on the outer peripheral portions of the openings 11 and 13 over the entire circumference, respectively. 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. The case upper wall 9 corresponds to an example of a “terminal wall”.

  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 disposed at 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 disposed at 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”.

  A downwardly extending portion 68 a is formed on the outer peripheral portion of the opening formed in the flat plate portion 68 of the gasket 62. The portion 68 a is fitted into the opening 11. 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 of the portion 68 a 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 19 (described later), the insulating member 36 (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. Further, the gasket 62 can be easily positioned by the portion 68a of the gasket 62.

  Next, with reference to FIG.2 and FIG.3 (a), the member arrange | positioned between the crimping terminal 5 and the case upper wall 9 is demonstrated. FIG. 3A shows an enlarged view of the two-dot chain line portion 202 of FIG. An arrow A in FIG. 2 indicates a direction from the outside to the inside of the case 1. Hereinafter, the direction indicated by the arrow A is referred to as “case inner side”, and the direction opposite to the direction indicated by the arrow A is referred to as “case outer side”. The same applies to other examples and modifications. An insulating O-ring 19 is disposed between the crimping terminal 5 and the case upper wall 9. The O-ring 19 makes a round around the cylindrical portion 14. For the O-ring 19, ethylene-propylene rubber (EPM) such as ethylene propylene diene rubber (EPDM) is used. The diameter of the cross section of the O-ring 19 is larger than the distance between the case upper wall 9 and the base portion 15. For this reason, as shown in FIG. 3A, the O-ring 19 abuts against the case upper wall 9 and the base portion 15 at the seal portion S1, thereby sealing between the case upper wall 9 and the crimping terminal 5. doing.

  As described above, the protrusion 9 a is formed on the lower surface of the case upper wall 9 along the outer peripheral edge of the opening 11. The protruding portion 9 a is located on the case outer side than the seal portion S <b> 1 of the O-ring 19. The inner peripheral surface 10a of the protruding portion 9a (that is, the surface outside the case) and the peripheral surface of the opening 11 form a continuous continuous surface. The outer peripheral surface 12a of the protruding portion 9a (that is, the surface on the inside of the case) is inclined to the outside of the case as it goes downward. In other words, the outer peripheral surface 12a is inclined so that the radial position thereof changes from the base portion of the protruding portion 9a to the distal end portion toward the outside of the case. The O-ring 19 is in contact with the outer peripheral surface 12a of the protruding portion 9a in the seal portion S2. For this reason, seal part S2 is located in the case exterior side rather than seal part S1. Further, the seal portion S2 is located on the base side of the protruding portion 9a. Since the O-ring 19 is made of an insulating material, the insulation between the crimp terminal 5 and the case upper wall 9 is maintained. The material of the O-ring 19 is not limited to the above, and any material having a sealing property, an insulating property, and an electrolytic solution resistance may be used.

  As shown in FIG. 2, an annular insulating member 36 is disposed on the case inner side than the seal portion S <b> 1 of the O-ring 19. For the insulating member 36, polyphenylene sulfide (PPS) is used. The insulating member 36 makes a round around the cylindrical portion 14. On the outside of the case of the insulating member 36, a thick portion 36a having a large thickness in the vertical direction is formed. The thick part 36 a is in contact with both the case upper wall 9 and the base part 15. The space between the case upper wall 9 and the base portion 15 is determined by the thick portion 36a. That is, the thick part 36a serves as a spacer. As shown in FIG. 3A, the end surface 37 on the case outer side of the thick portion 36a is inclined toward the inner side of the case as it goes downward. In other words, the end surface 37 is inclined such that its radial position changes from the upper surface to the lower surface of the thick portion 36a toward the inside of the case. Therefore, the angle formed by the end surface 37 and the upper surface of the base portion 15 is an acute angle, and passes through the position E1 of the end surface 37, the upper surface of the base portion 15, and the end surface 37 of the insulating member 36 on the outermost side of the case, A space 24 is formed in a range surrounded by a surface substantially orthogonal to the base portion 15 (that is, a surface extending in the vertical direction). A part of the O-ring 19 on the case inner side is located in the space 24. In other words, a part of the insulating member 36 on the case outer side overlaps a part of the O-ring 19 on the case inner side in a state where the case upper wall 9 is viewed in plan. The O-ring 19 is in contact with the end surface 37 of the thick portion 36a in the seal portion S3.

  As shown in FIG. 2, a thin portion 36b having a thin thickness in the vertical direction is formed on the inner side of the case from the thick portion 36a of the insulating member 36. The thin portion 36b extends from the upper surface of the base portion 15 toward the inside of the case and then bends downward to cover the outer peripheral surface of the base portion 15 and extend to substantially the same height as the fracture plate 34 (described later). Yes. The lower end surface of the insulating member 36 (strictly, the thin portion 36b) is in contact with the insulating member 39. The insulating member 39 is made of PPS. The insulating member 39 covers the entire outer periphery of the lower surface of the fracture plate 34. An annular metal plate 40 is disposed on the outer peripheral surfaces of the insulating members 36 and 39, and the plate 40 is fixed to the insulating members 36 and 39 by caulking. Thereby, the base part 15, the deformation | transformation board 32 (after-mentioned) and the fracture | rupture board 34 (after-mentioned) are clamped and fixed to an up-down direction. The insulating members 36 and 39 maintain the insulation between the plate member 40 and the base portion 15, the deformation plate 32, and the fracture plate 34. The material of the insulating members 36 and 39 is not limited to the above, and a material (for example, polyetheretherketone (PEEK)) that has insulating properties and resistance to an electrolytic solution and has excellent strength characteristics necessary for load support is used. May be.

  Of the space between the crimping terminal 5 and the case upper wall 9, the space inside the case relative to the seal portion S <b> 1 is a space 20 (see FIG. 2), and the space 20 makes a round around the periphery of the cylindrical portion 14. Yes. The space 24 is included in the space 20. The space 20 includes the entire O-ring 19 in the entire plane direction (that is, the plane direction substantially orthogonal to the axial direction of the cylindrical portion 14) (that is, from the end surface on the case outer side to the end surface on the case inner side). A part and an insulating member 36 are arranged.

  Here, with reference to FIG. 3 (a), (b), the position shift of the O-ring 19 accompanying the pressure change in case 1 is demonstrated. The O-ring 19 (strictly, the O-ring 19 exposed in the space 24) is connected to the case via a minute gap between the insulating member 36 and the case upper wall 9 and / or the base portion 15. A pressure within 1 can act. When gas is generated inside the case 1 because the power storage device 100 is overcharged, the pressure in the case 1 rises. If the force acting on the O-ring 19 by this pressure exceeds the first predetermined value, the O-ring 19 may be displaced from the position shown in FIG. That is, the O-ring 19 is shifted in a direction away from the insulating member 36 and enters the space where the outer peripheral surface 12a of the protruding portion 9a and the base portion 15 face each other. Thereby, the position and area of each seal part S1, S2, S3 of the O-ring 19 change. Specifically, the seal portion S1 moves to the outside of the case, and the area of the seal portion S2 increases (in other words, the contact position between the O-ring 19 and the outer peripheral surface 12a slides to the outside of the case. ) The area of the seal portion S3 is reduced.

  When the pressure in the case 1 further increases from the first predetermined value, the O-ring 19 is separated from the insulating member 36 (that is, the area of the seal portion S3 becomes zero). Further, when the pressure in the case 1 further increases from the first predetermined value and exceeds the second predetermined value, the current interrupt device 30 operates (described later). In this embodiment, as shown in FIG. 3B, the O-ring 19 is arranged such that a part of the O-ring 19 inside the case is located in the space 24 even after the current interrupting device 30 is operated. The material and the positional relationship of the protrusion 9a and the insulating member 36 are adjusted. For this reason, even after the current interrupting device 30 is operated, a part of the O-ring 19 and the insulating member 36 are disposed in the space 20 in the entire planar direction.

  Next, the caulking terminal 7 and the members disposed between the caulking terminal 7 and the case upper wall 9 will be described with reference to FIG. FIG. 4 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 base portion 95 is connected to the positive electrode lead 41. 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 19, the insulating member 116, the gasket 63 and the external terminal 61 are sandwiched between the crimping terminal 7 and the case upper wall 9. At this time, the case upper wall 9, the base portion 95, and the fixing portion 96 are parallel to each other. The O-ring 19 is in contact with the case upper wall 9 and the base 95 at the seal portion S4, thereby sealing between the case upper wall 9 and the crimping terminal 7. Further, as described above, the protruding portion 9 b is formed on the lower surface of the case upper wall 9 along the outer peripheral edge of the opening 13. The outer peripheral surface 12b of the protruding portion 9b is inclined to the outside of the case as it goes downward. The O-ring 19 is in contact with the outer peripheral surface 12b of the protruding portion 9b at the seal portion S5. Further, an annular insulating member 116 is arranged on the inner side of the case than the O-ring 19. The insulating member 116 is in contact with both the case upper wall 9 and the base portion 95. An end surface 117 of the insulating member 116 on the outer side of the case is inclined toward the inner side of the case as it goes downward. The O-ring 19 is in contact with the end surface 117 at the seal portion S6. The insulating member 116 extends from the upper surface of the base portion 95 toward the inside of the case, and the end surface on the inner side of the case is located at the outer peripheral end of the upper surface of the base portion 95. Of the space between the crimping terminal 7 and the case upper wall 9, if the space inside the case relative to the seal portion S4 is the space 22, the space 22 includes a part of the O-ring 19 and the entire space in the plane direction. An insulating member 116 is disposed. The caulking terminal 7 is not limited to a solid member, and a through hole may be formed in the cylindrical portion 94.

  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. As described above, the base portion 15, the deformation plate 32, and the fracture plate 34 are sandwiched and fixed by the plate material 40 via the annular insulating members 36 and 39. 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 deformable plate 32 corresponds to an example of “conductive member”.

  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 second predetermined value that is larger than the first predetermined value, the deformable plate 32 is inverted and changes to an upwardly convex state. 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 power storage device 100 described above, the end surface 37 of the insulating member 36 that comes into contact with the O-ring 19 is inclined, whereby the space 24 is formed. For this reason, even if the O-ring 19 is displaced as the pressure in the case 1 increases and is separated from the end surface 37 of the insulating member 36 (that is, the O-ring 19 is not in contact with the end surface 37), As long as a part of the O-ring 19 is positioned in the space 24, the case upper wall 9 and the base portion 15 do not directly face each other in the space between the O-ring 19 and the insulating member 36. Therefore, after the operation of the current interrupting device 30, a high voltage is applied between the crimping terminal 5 and the case upper wall 9 in a state where the space between the O-ring 19 and the insulating member 36 is filled with the electrolytic solution. Moreover, it can suppress that the crimping terminal 5 and the case upper wall 9 short-circuit.

  In particular, in the present embodiment, a protruding portion 9a extending downward from the case upper wall 9 is formed on the case outer side than the seal portion S1 of the O-ring 19. 1 Since it is less than the predetermined value, the seal portion S2 is in contact with the protruding portion 9a. For this reason, even if the pressure in the case 1 rises and a force toward the outside of the case acts on the O-ring 19, the protruding portion 9 a functions as a stopper that suppresses the positional deviation of the O-ring 19. Can be suppressed. Accordingly, it is possible to further suppress the case upper wall 9 and the base portion 15 from directly facing each other due to the positional deviation of the O-ring 19.

  Furthermore, in the present embodiment, the outer peripheral surface 12a of the protruding portion 9a with which the O-ring 19 is in contact is inclined to the outside of the case as it goes downward. For this reason, the O-ring 19 can be slid to the outside of the case within a certain range in accordance with the degree of increase in the pressure in the case 1. Thereby, it is possible to suppress the O-ring 19 from being excessively deformed by the force acting on the O-ring 19. Further, the positional deviation amount of the O-ring 19 can be controlled by adjusting the inclination angle of the outer peripheral surface 12a. For this reason, by tilting the outer peripheral surface 12a, it is possible to suppress the O-ring 19 from being deteriorated due to excessive deformation while suppressing the positional deviation of the O-ring 19.

  In the present embodiment, even after the operation of the current interrupting device 30, a part of the O-ring 19 and the insulating member 36 are disposed in the space 20 in the entire planar direction. For this reason, in the space 20, the case upper wall 9 and the base portion 15 do not directly face each other in a space other than the space 24. For this reason, even if a high voltage is applied between the caulking terminal 5 and the case upper wall 9 in a state where the electrolytic solution is present in the space 20, it is possible to prevent the caulking terminal 5 and the case upper wall 9 from being short-circuited. Can do. Note that the same effect as described above can also be achieved by disposing the O-ring 19 and the insulating member 116 in the space between the crimping terminal 7 and the case upper wall 9. The same applies to other embodiments and modifications.

  In a power storage device module including a plurality of power storage devices 100, each power storage device 100 is connected in series until a desired voltage is obtained. Thereby, a high-output and large-capacity power storage device module can be configured. In such a power storage device module, a high voltage is easily applied between the caulking terminal 5 and the case upper wall 9 in each power storage device 100. For this reason, the possibility of a short circuit can be effectively reduced by adopting the configuration of this embodiment in each power storage device 100 configuring the power storage device module.

(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 embodiments. The two-dot chain line portion 300a in FIG. 5 corresponds to the two-dot chain line portion 200a in FIG. In the present modification, a groove 15 b that goes around the circumference of the cylindrical portion 14 is formed on the upper surface of the base portion 15. The diameter of the groove 15b (strictly speaking, the intermediate diameter between the outer diameter and the inner diameter of the groove 15b) is substantially the same as the diameter of the O-ring 19, and the O-ring 19 is fitted in the groove 15b. For this reason, the O-ring 19 abuts the case upper wall 9 and the bottom surface of the groove 15b at the seal portion S7, thereby sealing between the case upper wall 9 and the crimping terminal 5. Also with this configuration, the same effects as the power storage device 100 of the first embodiment can be obtained. Further, when the O-ring 19 is fitted into the groove 15b, the O-ring 19 is not easily displaced even when the pressure inside the case 1 increases and a force on the outside of the case acts on the O-ring 19. Further, when the O-ring 19 is disposed on the base portion 15, the O-ring 19 can be easily positioned.

  Next, Example 2 will be described with reference to FIG. The two-dot chain line portion 400a in FIG. 6 corresponds to the two-dot chain line portion 200a in FIG. In this embodiment, an O-ring 119 that makes a round around the cylindrical portion 14 is disposed between the case upper wall 9 and the fixed portion 16. The O-ring 119 is in contact with the case upper wall 9 and the fixing portion 16 at the seal portion S8, thereby sealing between the case upper wall 9 and the crimping terminal 5. A gasket 62 and an external terminal 60 are arranged on the case outer side of the O-ring 119. The O-ring 119 is in contact with the end surface of the gasket 62 and the end surface of the external terminal 60 at the seal portion S9. That is, in this modification, no protrusion is formed on the outer side of the case with respect to the seal portion S8 of the O-ring 119.

  An insulating member 136 that circulates around the cylindrical portion 14 is disposed on the inner side of the case than the seal portion S8 of the O-ring 119. The end surface 137 of the insulating member 136 on the outer side of the case is inclined toward the outer side of the case as it goes downward. The O-ring 119 is in contact with the end surface 137 at the seal portion S10. A lower portion of the insulating member 136 is fitted into the opening 11. Further, an insulating member 138 that goes around the cylindrical portion 14 is disposed between the case upper wall 9 and the base portion 15. An upper portion of the insulating member 138 is fitted into the opening 11, and an upper end surface thereof is in contact with a lower end surface of the insulating member 136. The remaining portion of the insulating member 138 extends from the upper surface of the base portion 15 toward the outside of the case and then bends downward to cover the outer peripheral surface of the base portion 15 and extend to substantially the same height as the fracture plate 34. . A plate 40 is caulked and fixed to the outer peripheral surfaces of the insulating members 138 and 39.

  Of the spaces between the caulking terminals 5 and the case upper wall 9, if the space inside the case with respect to the seal portion S8 is defined as a space 120, the space 120 makes a round around the cylindrical portion 14. In the space 120, a part of the O-ring 119 and the insulating members 136 and 138 are disposed throughout the space 120. When the pressure in the case 1 rises and exceeds a predetermined value, the O-ring 119 can be displaced to the outside of the case. In the present embodiment, even after the pressure in the case 1 further increases and the current interrupting device 30 operates (that is, even after the O-ring 119 is further displaced to the outside of the case), the space The material and positional relationship of each member are adjusted so that a part of the O-ring 119 and the insulating members 136 and 138 are arranged on the whole 120. Here, “the entire space 120” means the entire planar direction of the space 120 in the space where the case upper wall 9 and the fixed portion 16 face each other and in the space where the case upper wall 9 and the base portion 15 face each other. However, there may be a space in which the O-ring 119 and the insulating members 136 and 138 are not arranged in the vertical direction of the space 120. Further, “the entire space 120” means the entire vertical direction of the space 120 in the space where the case upper wall 9 and the cylindrical portion 14 are opposed to each other. There may be a space where 136 and 138 are not arranged. Also with this configuration, the same effects as the power storage device 100 of the first embodiment can be obtained. Further, in this embodiment, the gasket 62 and the external terminal 60 function as a stopper that suppresses the positional deviation of the O-ring 119, so that the effect of suppressing the positional deviation of the O-ring 119 can be obtained without forming a protruding portion.

  Next, Embodiment 3 will be described with reference to FIG. The two-dot chain line portion 500a in FIG. 7 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 portion 15, the first deformation plate 75, the fracture plate 73 and the second deformation plate 71 are supported by insulating insulating members 36 and 78. A metal plate 79 is caulked on the outer peripheral surfaces of the insulating members 36 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, when the pressure in the case 1 exceeds the third predetermined value, the second deformable plate 71 is reversed and changes from a downward convex state to an upward convex state. 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. In the present embodiment, a part of the O-ring 19 and the insulating member 36 are disposed in the entire space 20 even after the current interrupting device 70 is operated. 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.

  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, the inclination direction of the end surface 37 of the insulating member 36 is not limited to the configuration of the above-described embodiment, and may be configured to be inclined toward the outside of the case as it goes downward.

  Further, the protruding portions 9a and 9b may not be formed over the entire circumference on the outer peripheral edges of the openings 11 and 13, respectively. For example, a plurality of protruding portions 9a and 9b may be formed at intervals in the circumferential direction. In this case, the protrusions 9a and 9b are preferably formed in a distributed manner in the circumferential direction. Also with this configuration, the positional deviation of the O-ring 19 can be suppressed, and a short circuit between the case upper wall 9 and the crimping terminal 5 can be suppressed. Further, before the pressure in the case 1 rises, the O-ring 19 may not be in contact with the outer peripheral surfaces 12a and 12b of the protruding portions 9a and 9b. A configuration in which the O-ring 19 contacts the outer peripheral surfaces 12a and 12b when the pressure in the case 1 increases and the O-ring 19 is displaced to the outside of the case may be employed. In this case, even after the current interrupting device 30 is operated, the case upper wall 9 and the crimping terminal 5 can be used as long as a part of the O-ring 19 and the insulating member 36 are arranged in the entire planar direction of the space 20. And short circuit can be suppressed. Moreover, the outer peripheral surfaces 12a and 12b of the protrusions 9a and 9b may extend in the vertical direction without being inclined. Further, the inner peripheral surfaces of the protruding portions 9 a and 9 b may not be continuous with the peripheral surfaces of the openings 11 and 13.

  Further, the groove into which the O-ring 19 is fitted may be formed in the case upper wall 9 instead of being formed in the caulking terminal 5, or may be formed in both the caulking terminal 5 and the case upper wall 9.

  In the third embodiment, the insulating member 81 may not be disposed. In addition, a communication hole that communicates the space 87 and the space 88 may be formed in the first deformation plate 75, and the spaces 86 and 88 may be maintained at atmospheric pressure.

  In the above embodiment, the crimping terminals 5 and 7 are attached to the case upper wall 9, but the terminal is not limited to the crimping terminal, and a terminal of a type that is fastened with a nut from the outside of the case may be used.

  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: Case upper wall, 9a, 9b: Projection, 11: Opening, 12a, 12b: Outer peripheral surface, 13: Opening, 14: Cylindrical portion, 15: base portion, 15b: groove, 16: fixing portion, 19: O-ring, 20, 30: current interrupting device, 32: deformation plate, 34: fracture plate, 36: insulating member, 37: end face, 100 : Power storage device,

Claims (5)

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 is 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, an O-ring that seals the inside and outside of the case by contacting both the terminal and the terminal wall and makes a round of the columnar part is disposed,
In the space between the terminal and the terminal wall, an insulating member that goes around the columnar portion is arranged on the case inner side than the O-ring,
The end surface on the O-ring side of the insulating member is inclined so that the radial position changes from the terminal wall side surface to the terminal side surface,
The O-ring is in contact with the end face of the insulating member;
Power storage device. One of the terminal wall and the terminal is formed with a protruding portion that protrudes toward the other of the terminal wall and the terminal,
The protrusion is disposed on the case exterior side of the O-ring,
The power storage device according to claim 1, wherein the O-ring is in contact with the protruding portion.   3. The power storage device according to claim 2, wherein a surface of the protruding portion with which the O-ring is in contact is inclined toward an outer side of the case as it goes from the base side to the tip side of the protruding portion.   The groove | channel which makes a round of the said columnar part is formed in at least one of the said terminal or the said terminal wall, The said O-ring fits into the said groove | channel, The Claim 1 characterized by the above-mentioned. Power storage device.   A power storage device module comprising a plurality of the power storage devices according to claim 1, wherein the plurality of power storage devices are connected in series.

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