JP6597290B2 - Power storage device - Google Patents

Description

  The present invention relates to a power storage device including a current interrupt mechanism that interrupts a current in an energization path by deformation of a deformation plate when an internal pressure of a case reaches a set pressure.

  Conventionally, secondary batteries such as lithium ion secondary batteries have been installed in vehicles such as EVs (Electric Vehicles) and PHVs (Plug in Hybrid Vehicles) as power storage devices for storing electric power used in electrical components. Yes. The secondary battery includes a case, an electrode assembly housed in the case, and two electrode terminals that protrude outside the case and have different polarities. As an electrode assembly, there is an electrode assembly in which sheet-like positive electrodes and sheet-like negative electrodes are alternately laminated with a separator interposed therebetween.

  Some secondary batteries include a current interrupt mechanism that interrupts current in response to an increase in internal pressure of the case. The current interruption mechanism is provided on an energization path that electrically connects the electrode terminal of one polarity and the electrode assembly (see, for example, Patent Document 1).

  As shown in FIG. 10, the sealed secondary battery disclosed in Patent Document 1 includes a rivet 101. The rivet 101 is caulked and fixed to a lid 102, and electrically connected to a Z terminal 103. It is connected. The Z terminal 103 is electrically connected to a positive electrode terminal (not shown). The Z terminal 103 is insulated from the lid 102 by the upper gasket 104. The large-diameter portion 101a of the rivet 101 has a space 101b where the reversing plate is reversed.

  A reversing plate 106 is fixed to the large-diameter portion 101 a of the rivet 101 so as to cover the space 101 b, and the reversing plate 106 is electrically connected to the positive current collector plate 107. The large diameter portion 101 a of the rivet 101 is insulated from the lid body 102 by the lower gasket 105. The lower gasket 105 integrally holds the large-diameter portion 101a, the reverse plate 106, and the positive electrode current collector plate 107. The positive electrode current collector plate 107 is electrically connected to the positive electrode of the wound electrode body 108.

  When the gas is generated due to overcharging or the like, the internal pressure of the case is abnormally increased, and the abnormal internal pressure acts on the positive current collector plate 107, the connection portion between the positive current collector plate 107 and the reverse plate 106 is separated. Then, the reversing plate 106 is reversed toward the space 101b of the large diameter portion 101a. As a result, the electrical connection between the positive electrode current collector plate 107 and the reversing plate 106 is interrupted, and the current is interrupted.

JP 2013-157200 A

By the way, when an external force or vibration is transmitted to the secondary battery during the initial charging or use of the secondary battery, the reversing plate of the current interrupting mechanism may be reversed and the current interrupting device may malfunction.
An object of the present invention is to provide a power storage device that can suppress malfunction of a current interrupt mechanism.

  A power storage device for solving the above-described problems is an electrode assembly in which electrodes of different polarities are insulated and stacked, a case housing the electrode assembly, and the electrode having the same polarity electrically A pair of conductive members disposed between a wall portion of the case and an end face of the electrode assembly facing the wall portion, and electrically connected to the conductive member of the same polarity; A pair of electrode terminals fixed to the wall, a deformed plate on which one of the internal pressures of the case acts on one surface and the external pressure of the case acts on the other surface, and the electrode terminal and the electrode of one polarity It constitutes a part of an electrically energizing path with the assembly, and is arranged between the end face and the wall portion. When the internal pressure of the case reaches a set pressure, the deformation plate deforms. A power supply for cutting off the current in the current path A second insulating mechanism, a first insulating portion interposed between the pair of conductive members and the wall portion, a second insulating portion interposed between the current interrupting mechanism and the end surface, and integral with the first insulating portion; And having an insulating portion.

  According to this, the conductive member and the wall portion can be insulated by the first insulating portion, and the current interrupt mechanism and the electrode assembly can be insulated by the second insulating portion. Since the first insulating portion is interposed between the conductive member and the wall portion, the first insulating portion is unlikely to vibrate even when the power storage device receives an external force or vibrates. Since the second insulating part is integrated with the first insulating part that is less likely to vibrate, the second insulating part is also less likely to vibrate. And the 2nd insulating part has covered and protected the electric current interruption mechanism from the electrode assembly side. For this reason, even if the power storage device receives an external force or vibrates and the electrode assembly vibrates and moves toward the current interruption mechanism, the current interruption mechanism is protected from the electrode assembly by the second insulating portion. And the malfunction of the current interrupt mechanism can be suppressed.

  In the power storage device, the electrode terminal having the one polarity includes a base that protrudes into the case from the wall, and the power storage device is provided between the base and an end surface of the electrode assembly. A third insulating part may be provided, and the third insulating part may be integrated with the first insulating part and the second insulating part.

  According to this, in the configuration in which the current interrupting mechanism and the electrode terminal electrically connected to the current interrupting mechanism are not aligned in the facing direction that connects the wall portion and the end surface of the electrode assembly, Electrode terminals are arranged side by side. In this case, the current interruption mechanism is insulated from the electrode assembly by the second insulating portion, and the electrode terminal is insulated from the electrode assembly by the third insulating portion. And since the 1st insulating part, the 2nd insulating part, and the 3rd insulating part are integrated, the component for insulation of a conductive member, the component for insulation of an electric current interruption mechanism, and the component for insulation of an electrode terminal As compared with the case where is separately provided, the number of parts of the power storage device can be reduced and the assembly can be facilitated.

  Further, regarding the power storage device, when the surface of the base of the electrode terminal of one polarity facing the end surface of the electrode assembly is a terminal end surface, the deformation plate of the current interrupting mechanism is integrated with the terminal end surface. Has been.

  According to this, the deformation plate can be directly protected by the second insulating portion, and even if the power storage device receives an external force or vibrates and the electrode assembly vibrates, the deformation is caused by the second insulating portion. The plate can be protected from the electrode assembly, and malfunction of the current interrupting mechanism due to malfunction of the deformable plate can be suppressed.

  The power storage device is a secondary battery.

  According to the present invention, malfunction of the current interrupt mechanism can be suppressed.

The perspective view which shows the secondary battery of embodiment. The partially broken front view which shows the secondary battery of embodiment. The disassembled perspective view which shows the secondary battery of embodiment. The fragmentary sectional view showing the secondary battery of an embodiment. The perspective view which shows an insulation cover. FIG. 6A is a cross-sectional view taken along the line 6a-6a in FIG. 4 showing the mounting state of the insulating cover, and FIG. 6B is a cross-sectional view taken along the line 6b-6b in FIG. The perspective view which shows the mounting state of an insulating cover. FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. Sectional drawing which shows the secondary battery of another example. The figure which shows background art.

Hereinafter, an embodiment in which the power storage device is embodied as a secondary battery will be described with reference to FIGS.
As shown in FIG. 1 or FIG. 3, the secondary battery 10 as a power storage device includes a case 11, and an electrode assembly 12 is accommodated in the case 11. The case 11 includes a square box-shaped case member 14 and a lid member 15 as a rectangular flat plate-like wall portion that closes the opening 14 a of the case member 14. In addition, the secondary battery 10 of this embodiment is a lithium ion battery.

  The electrode assembly 12 includes a plurality of sheet-like positive electrodes 21 and a plurality of sheet-like negative electrodes 31, and the positive electrodes 21 and the negative electrodes 31 are electrodes having different polarities. Although not shown in detail, the positive electrode 21 has a positive metal foil (in this embodiment, an aluminum foil) and a positive electrode active material layer present on both surfaces of the positive metal foil. The negative electrode 31 has a negative electrode metal foil (copper foil in this embodiment) and a negative electrode active material layer present on both surfaces of the negative electrode metal foil. The electrode assembly 12 is a layered type in which a separator 24 is interposed between a plurality of positive electrodes 21 and a plurality of negative electrodes 31 to interpose them.

  The positive electrode 21 has a tab 25 having a shape protruding from a part of one side 21 a of the positive electrode 21. The negative electrode 31 has a tab 35 having a shape protruding from a part of one side 31 a of the negative electrode 31. The plurality of positive electrode tabs 25 and the plurality of negative electrode tabs 35 are respectively provided at positions where the positive electrode tab 25 and the negative electrode tab 35 do not overlap with each other in a state where the positive electrode 21 and the negative electrode 31 are stacked. . The electrode assembly 12 has a tab side end face 12b formed by gathering together one side 21a of the positive electrode 21, one side 31a of the negative electrode 31, and one side of the separator 24. The positive electrodes 21 constituting the electrode assembly 12 are stacked such that the tabs 25 are arranged in a row along the stacking direction. Similarly, the negative electrodes 31 constituting the electrode assembly 12 are stacked such that the tabs 35 are arranged in a row along the stacking direction.

  The secondary battery 10 has a positive electrode tab group 36 protruding from the tab-side end face 12b. The tab group 36 gathers all the positive electrode tabs 25 together on one end side in the stacking direction of the electrode assembly 12, and stacks them. Configured. Further, the secondary battery 10 has a negative electrode tab group 36 protruding from the tab side end face 12 b, and this tab group 36 gathers all the negative electrode tabs 35 toward one end side in the stacking direction of the electrode assembly 12. It is configured by stacking. In the secondary battery 10, the inner surface 15 d of the lid member 15 as a wall portion of the case 11 faces the tab groups 36 accommodated in the case 11 and the tab side end surface 12 b of the electrode assembly 12. . A direction in which the inner surface 15d of the lid member 15 and the tab side end surface 12b of the electrode assembly 12 are connected with the shortest distance is defined as a facing direction Z.

  As shown in FIG. 3 or FIG. 4, a positive electrode conductive member 51 for electrically connecting the electrode assembly 12 and a positive electrode terminal structure 16 described later is joined to the positive electrode tab group 36. Further, the negative electrode tab group 36 is joined with a negative electrode conductive member 52 for electrically connecting the electrode assembly 12 and a negative electrode terminal structure 17 described later. A positive electrode conductive member 51 and a negative electrode conductive member 52 are disposed between the inner surface 15 d of the lid member 15 and the tab side end surface 12 b of the electrode assembly 12.

  The positive electrode conductive member 51 includes a U-shaped electrode joint portion 51 a joined to the tab group 36 on one end side in the longitudinal direction. Further, the positive electrode conductive member 51 includes a flat-plate-like terminal connection portion 51b connected to the positive electrode lead terminal 60 described later on the other end in the longitudinal direction, and the electrode joint portion 51a and the terminal connection portion 51b are continuous in the longitudinal direction. Yes. Further, the positive electrode conductive member 51 includes an insertion hole 51c in the terminal connection portion 51b.

  The negative electrode conductive member 52 includes a U-shaped electrode joint portion 52 a electrically joined to the tab group 36 on one end side in the longitudinal direction. The negative electrode conductive member 52 includes a terminal connection portion 52b electrically connected to a negative electrode lead terminal 61, which will be described later, on the other end in the longitudinal direction, and the electrode joint portion 52a and the terminal connection portion 52b are continuous in the longitudinal direction. Yes.

  Next, the positive terminal structure 16 and the negative terminal structure 17 will be described. In addition, since the positive electrode terminal structure 16 and the negative electrode terminal structure 17 are basically the same except for the current interrupt mechanism, common members will be described using the same member numbers.

  First, the configuration of the lid member 15 for providing the positive terminal structure 16 and the negative terminal structure 17 will be described. The lid member 15 has an outer surface 15c facing the outer side of the case 11 and an inner surface 15d facing the inner side of the case 11. In the lid member 15, a direction connecting the outer surface 15c and the inner surface 15d with the shortest distance is a thickness direction.

  The lid member 15 includes locking recesses 18 on both sides in the longitudinal direction. Each locking recess 18 has a shape recessed from the outer surface 15c along the thickness direction. When the lid member 15 is viewed from the outer surface 15c, the outer shape of the locking recess 18 is a square shape. The lid member 15 includes a protrusion 19 protruding from the inner surface 15d. The protrusion 19 has a shape protruding from the inner surface 15d by denting the locking recess 18, and the outer shape of the protrusion 19 is a quadrangular shape. The lid member 15 is provided with insertion holes 15e outside the respective locking recesses 18 in the longitudinal direction.

  The positive terminal structure 16 and the negative terminal structure 17 include an outer insulating member 57 disposed on the outer surface 15 c of the lid member 15. The outer insulating member 57 insulates the positive external connection terminal 66 and positive electrode lead terminal 60 from the lid member 15 and insulates the negative external connection terminal 66 and negative electrode lead terminal 61 from the lid member 15. The outer insulating member 57 is made of synthetic resin. The outer insulating member 57 has a rectangular shape when viewed from the outer surface 15 c of the lid member 15. The direction connecting the front surface 57c and the back surface 57a of the outer insulating member 57 is the thickness direction.

  The outer insulating member 57 includes a rotation stopper 58 that protrudes in the thickness direction from the back surface 57a near one end in the longitudinal direction. The anti-rotation part 58 has a shape protruding in a square hole shape from the front surface 57c toward the back surface 57a. The square shape formed by connecting the four outer surfaces of the rotation stopper 58 is similar to the square shape formed by connecting the four inner surfaces of the locking recess 18 of the lid member 15. The outer insulating member 57 is installed on the lid member 15 in a state where the rotation stopper 58 is inserted into the locking recess 18. The four outer surfaces of the rotation stopper 58 are in contact with the four inner surfaces of the locking recess 18. By this contact, movement of the outer insulating member 57 in the direction along the outer surface 15c of the lid member 15 is restricted, and in particular, rotation on the outer surface 15c is restricted. The outer insulating member 57 includes an insertion hole 57d near the other end in the longitudinal direction. The insertion hole 57d is at a position that coincides with the insertion hole 15e of the lid member 15.

  The positive terminal structure 16 and the negative terminal structure 17 include an external connection terminal 66 disposed outside the lid member 15, and the external connection terminal 66 can fix the bus bar outside the lid member 15. The external connection terminal 66 is made of metal. The external connection terminal 66 includes a prism-shaped bolt head 67, a shaft 68 having a shape protruding from one end surface of the bolt head 67 along the axial direction of the external connection terminal 66, and the other end surface of the bolt head 67. And an engaging projection 69 having a shape protruding from the projection. A nut for fastening a bus bar can be screwed onto the shaft portion 68.

  The engaging projection 69 has a quadrangular shape when viewed in the axial direction. The quadrangular shape formed by connecting the four outer surfaces of the engaging convex portion 69 is similar to the quadrangular shape formed by connecting the four inner surfaces of the anti-rotation portion 58 of the outer insulating member 57. Then, the engaging convex portion 69 of the external connection terminal 66 is inserted into the rotation preventing portion 58 of the outer insulating member 57. The four outer surfaces of the engaging convex portion 69 are in contact with the four inner surfaces of the rotation preventing portion 58. By this contact, the movement of the external connection terminal 66 in the direction along the surface 57c of the outer insulating member 57 is restricted, and in particular, the rotation on the surface 57c of the outer insulating member 57 is restricted.

  The positive electrode terminal structure 16 includes a positive electrode lead terminal 60 as an electrode terminal electrically connected to the positive electrode tab group 36 of the electrode assembly 12 via the positive electrode conductive member 51. The negative electrode terminal structure 17 includes a negative electrode lead terminal 61 as an electrode terminal electrically connected to the negative electrode tab group 36 of the electrode assembly 12 via the negative electrode conductive member 52.

  The positive electrode lead terminal 60 includes a connecting shaft portion 60 a that is electrically connected to a terminal connection member 44 described later and a base portion 60 b that is electrically connected to the terminal connection portion 51 b of the positive electrode conductive member 51 in the axial direction. Prepare. The terminal connection member 44 includes a connection piece 46 connected to the external connection terminal 66 on one end side in the longitudinal direction, and a fixed piece 47 on the other end side in the longitudinal direction. The terminal connection member 44 includes a through hole 46a that penetrates the connection piece 46 in the thickness direction, and the shaft portion 68 of the external connection terminal 66 is inserted into the through hole 46a. The terminal connection member 44 includes an insertion hole 47a that penetrates the fixed piece 47 in the thickness direction.

  The base portion 60 b of the positive electrode lead terminal 60 is disposed so as to protrude from the inner surface 15 d of the lid member 15 toward the electrode assembly 12 in the case 11. The connecting shaft portion 60a includes an insertion hole 51c of the positive electrode conductive member 51, an insertion hole 40a of the inner insulating member 40 described later, an insertion hole 15e of the lid member 15, an insertion hole 57d of the outer insulating member 57, and the terminal connection member 44. It penetrates through the insertion hole 47a.

  The positive electrode terminal structure 16 includes an O-ring 73, and the O-ring 73 is inserted into the connection shaft portion 60 a of the positive electrode lead terminal 60 and supported by the terminal connection portion 51 b of the positive electrode conductive member 51. Further, the positive electrode terminal structure 16 includes the above-described inner insulating member 40 through which the connecting shaft portion 60a is inserted. The inner insulating member 40 has a square plate shape.

  As shown in FIG. 6B, the dimension of the inner insulating member 40 along the short direction of the lid member 15 is longer than the dimension of the positive electrode conductive member 51 along the short direction of the lid member 15. Therefore, the inner insulating member 40 protrudes from the positive electrode conductive member 51 along the short direction of the lid member 15.

  As shown in FIG. 4, an O-ring 73 supported by the terminal connection portion 51 b is disposed inside the inner insulating member 40. The inner insulating member 40 is interposed between the lid member 15 and the terminal connection portion 51b, restricts the contact between the lid member 15 and the terminal connection portion 51b, and insulates the lid member 15 from the positive electrode conductive member 51. To do.

  The tip end portion of the connecting shaft portion 60a penetrating the insertion hole 47a of the terminal connecting member 44 is caulked in the axial direction, whereby the positive electrode conductive member 51, the inner insulating member 40, and the lid member are connected by the connecting shaft portion 60a and the base portion 60b. 15, the outer insulating member 57 and the fixing piece 47 of the terminal connection member 44 are sandwiched. The positive electrode lead terminal 60 is fixed to the lid member 15 by this clamping. The O-ring 73 is in close contact with the periphery of the insertion hole 15 e in the inner surface 15 d of the lid member 15 and seals the insertion hole 15 e of the lid member 15.

  Further, the tip end portion of the connecting shaft portion 60a of the positive electrode lead terminal 60 is locked to the surface of the fixing piece 47 in the terminal connection member 44, and the positive electrode lead terminal 60 and the terminal connection member 44 are electrically connected by this lock. It is connected. Further, the base portion 60 b of the positive electrode lead terminal 60 contacts the terminal connection portion 51 b of the positive electrode conductive member 51, and the positive electrode lead terminal 60 and the positive electrode conductive member 51 are electrically connected by this contact.

  In the negative electrode terminal structure 17, the negative electrode lead terminal 61 includes a connection shaft portion 62 that is electrically connected to the negative electrode terminal connection member 44, and a base portion 63 that is electrically connected to the terminal connection portion 52 b of the negative electrode conductive member 52. Are continuously provided in the axial direction. The connecting shaft portion 62 of the negative electrode lead terminal 61 is inserted into the insertion hole 40 a of the inner insulating member 40, the insertion hole 15 e of the lid member 15, the insertion hole 57 d of the outer insulating member 57, and the insertion hole 47 a of the terminal connection member 44. Yes.

  The base 63 of the negative electrode lead terminal 61 has a quadrangular prism shape. The outer shape of the base 63 is a square shape when the negative electrode lead terminal 61 is viewed from the axial direction. The negative electrode lead terminal 61 includes a shaft hole 64 penetrating in the axial direction, and the shaft hole 64 passes through the connecting shaft portion 62 and the base portion 63. Further, the negative electrode lead terminal 61 includes a terminal end surface 63b on an end surface of the base 63 facing the tab side end surface 12b of the electrode assembly 12, and a recess 63c that is recessed from the terminal end surface 63b toward the connecting shaft portion 62. Prepare. The recess 63 c communicates with the shaft hole 64. Further, the terminal end surface 63b has an annular shape surrounding the recess 63c.

  The negative electrode terminal structure 17 includes an O-ring 73, and a connecting shaft portion 62 is inserted through the O-ring 73 and supported by the base 63. The negative electrode terminal structure 17 includes a cylindrical inner insulating member 40 through which the connecting shaft portion 62 is inserted. An O-ring 73 supported by the base 63 is disposed inside the inner insulating member 40. The inner insulating member 40 is interposed between the lid member 15 and the base portion 63 of the negative electrode extraction terminal 61, restricts the contact between the lid member 15 and the base portion 63, and includes the lid member 15 and the negative electrode extraction terminal 61. Insulate. The negative inner insulating member 40 covers the outer peripheral surface of the base 63 and insulates the negative lead terminal 61 from the case 11.

  In the negative electrode terminal structure 17, the distal end portion of the connecting shaft portion 62 penetrating the insertion hole 47 a of the terminal connecting member 44 is caulked in the axial direction, whereby the inner insulating member 40, the lid is covered by the connecting shaft portion 62 and the base portion 63. The member 15, the outer insulating member 57, and the terminal connection member 44 are sandwiched. By this clamping, the negative electrode lead terminal 61 is fixed to the lid member 15. The O-ring 73 is in close contact with the periphery of the insertion hole 15 e in the inner surface 15 d of the lid member 15 and seals the insertion hole 15 e of the lid member 15.

  Further, the distal end portion of the connecting shaft portion 62 of the negative electrode lead terminal 61 is locked to the surface of the fixing piece 47 of the terminal connection member 44, and the negative electrode lead terminal 61 and the terminal connection member 44 are electrically connected by this lock. It is connected.

  The secondary battery 10 includes a current interruption mechanism 80 integrated with the negative electrode lead terminal 61 which is one of the electrode terminals. Therefore, the positive electrode lead terminal 60 becomes the other electrode terminal. The current interrupting mechanism 80 is disposed inside the case 11, and when the internal pressure of the case 11 reaches a predetermined set pressure, the energization that electrically connects the electrode assembly 12 and the negative electrode lead terminal 61. Cut off the current in the path. The current interrupt mechanism 80 is located at the base 63 of the negative electrode lead terminal 61 and the connection part of the terminal connection part 52 b of the negative electrode conductive member 52.

  In this embodiment, the base 63 of the negative electrode lead terminal 61 is electrically connected to the negative electrode conductive member 52 via the current interrupt mechanism 80, and the negative electrode conductive member 52 is electrically connected to the negative electrode tab group 36. Thus, an energization path between the electrode assembly 12 and the negative electrode extraction terminal 61 is configured.

  When the current interruption mechanism 80 is activated by the gas generated inside the case 11, the electric interruption between the base 63 of the negative electrode lead terminal 61 and the negative electrode conductive member 52 is interrupted. That is, the current interruption mechanism 80 constitutes a part of the energization path when not operating, and interrupts the energization path when activated by receiving the pressure of the gas generated inside the case 11.

  The current interruption mechanism 80 has a contact plate 81 joined to the negative electrode conductive member 52 and the base 63. The contact plate 81 is made of a conductive material and has a bowl shape that protrudes toward the electrode assembly 12. The contact plate 81 covers the recess 63c of the base 63 from the electrode assembly 12 side. The outer peripheral portion of the contact plate 81 that protrudes from the recess 63c and the terminal end surface 63b of the base 63 are fixed by welding.

  The portion of the contact plate 81 that faces the recess 63c is convex toward the electrode assembly 12 (downward) in the normal state, and the portion that is convex toward the electrode assembly 12 and the negative electrode conductive member 52. The terminal connection portion 52b is welded. The negative electrode welded portion P, which is a welded portion between the contact plate 81 and the terminal connection portion 52b, is a conductive portion that conducts the negative electrode lead terminal 61 and the negative electrode conductive member 52. Therefore, the negative electrode conductive member 52 and the negative electrode lead terminal 61 are electrically connected via the contact plate 81. The current interrupt mechanism 80 includes an insulating ring 82 disposed between the base 63 and the negative electrode conductive member 52, and a seal ring 83 disposed on the outer peripheral side of the insulating ring 82.

  The negative electrode conductive member 52 has a deformation recess 53a on the surface of the terminal connection portion 52b on the electrode assembly 12 side. The deformation recess 53 a is recessed in a mortar shape from the electrode assembly 12 toward the lid member 15. The negative electrode weld portion P is located on the bottom surface of the deformation recess 53a. The terminal connection portion 52b has a fracture groove (not shown) at a portion that becomes the bottom surface of the deformation recess 53a. The fracture groove has an annular shape surrounding the negative electrode welded portion P.

  The current interrupt mechanism 80 includes a deformable plate 85 that receives the internal pressure of the case 11 and deforms. The deformation plate 85 is a diaphragm made of an elastic material, for example, a metal plate, and is disposed at a position closer to the electrode assembly 12 than the terminal connection portion 52b. The deformation plate 85 has a disk shape and covers the deformation concave portion 53a from the electrode assembly 12 side. The outer peripheral portion of the deformable plate 85 and the terminal connection portion 52b are fixed by welding over the entire periphery of the outer peripheral portion of the deformable plate 85. The deformation plate 85 airtightly separates the inside of the case 11 from the outside of the case 11.

  In the normal state, the deformable plate 85 is convex from the lid member 15 side toward the electrode assembly 12 side (downward), and a portion of the convex portion facing the negative electrode welded portion P is directed to the lid member 15. And has a protrusion 85a protruding. The protrusion 85a is made of an insulating material and faces the negative electrode welded portion P surrounded by the fracture groove.

  The internal pressure of the case 11 acts on one surface of the deformation plate 85 (the surface on the electrode assembly 12 side). Further, external pressure (substantially atmospheric pressure) of the case 11 acts on the other surface (surface on the lid member 15 side) of the deformation plate 85 via the shaft hole 64 of the negative electrode lead terminal 61. The deformation plate 85 is configured to be deformed by the pressure and project toward the lid member 15 when an internal pressure that reaches a set pressure is applied to the surface on the electrode assembly 12 side. Yes.

  In the current interrupt mechanism 80 configured as described above, when the internal pressure of the case 11 reaches a predetermined set pressure, the deformation plate 85 is deformed toward the lid member 15, and the protrusion 85 a is formed between the terminal connection portion 52 b and the contact plate. The negative electrode weld part P with 81 is fractured. As a result, the electrical connection between the negative electrode lead terminal 61 and the negative electrode conductive member 52 is interrupted, and the current in the energization path is interrupted.

Next, the insulating cover 90 in the case 11 will be described.
As shown in FIG. 4, the insulating cover 90 includes a first insulating portion 91 that insulates the electrode joint portions 51 a and 52 a and the lid member 15, a negative electrode lead terminal 61 including a current blocking mechanism 80, and the electrode assembly 12. A negative electrode insulating portion 93 as a second insulating portion to be insulated and a positive electrode insulating portion 92 for insulating the positive electrode lead terminal 60 and the electrode assembly 12 are provided. Here, in the insulating cover 90, the direction along the juxtaposed direction in which the positive electrode conductive member 51 and the negative electrode conductive member 52 are arranged is the longitudinal direction, and the direction along the outer surface of the first insulating portion 91 and perpendicular to the longitudinal direction is short. The direction. The insulating cover 90 is U-shaped when viewed from the side along the longitudinal direction.

  As shown in FIG. 5, the positive electrode insulating portion 92 of the insulating cover 90 is integrated with one end portion of the rectangular first insulating portion 91 in the longitudinal direction, and the negative electrode insulating portion 93 is integrated with the longitudinal direction of the first insulating portion 91. It is integral with the other end part. The first insulating portion 91 is L-shaped in a side view as viewed along the longitudinal direction, and has a rectangular plate-like insulating portion main body 91a and one long edge portion of the insulating portion main body 91a toward the electrode assembly 12. A side wall portion 91b having a protruding shape.

  As shown in FIG. 4, the dimension of a straight line connecting the opposing surfaces of the pair of inner insulating members 40 along the parallel direction is defined as a dimension N. In the insulating cover 90, the dimension in the longitudinal direction of the first insulating portion 91 is slightly shorter than the dimension N. For this reason, one end surface of both end surfaces in the longitudinal direction of the first insulating portion 91 can be brought into contact with the inner surface of the inner insulating member 40 of the positive electrode, and the other end surface can be brought into contact with the inner surface of the inner insulating member 40 of the negative electrode. It is in a position where it can touch. For this reason, the movement of the insulating cover 90 in the longitudinal direction is restricted by the contact between the first insulating portion 91 and one of the inner insulating members 40. The dimension in the short direction of the first insulating portion 91 is slightly longer than the dimension in the short direction of the electrode joint portions 51a and 52a.

  The insulating main body 91a of the first insulating portion 91 is interposed between the positive and negative electrode joint portions 51a and 52a and the lid member 15 in the facing direction Z, and the electrode joint portions 51a and 52a and the lid member 15 Insulate. Further, the side wall portion 91 b of the first insulating portion 91 is interposed between each tab group 36 and the inner surface of the long side wall of the case member 14 to insulate each tab group 36 from the case member 14.

  As shown in FIG. 4 or FIG. 8, the insulating cover 90 includes housing recesses 91f at both longitudinal ends of the insulating body 91a. The housing recess 91 f has a shape that is recessed in a square shape from the outer surface 91 c of the insulating portion main body 91 a toward the electrode assembly 12. The protrusions 19 of the lid member 15 are inserted into the respective housing recesses 91f, and in the longitudinal direction and the short direction of the insulating cover 90 due to the contact between the outer surface of the protrusions 19 and the inner surface of the housing recess 91f. The movement of the insulating cover 90 along is restricted.

  As shown in FIG. 3 or FIG. 4, the insulating cover 90 includes a connecting portion 94 that is integral with both end portions in the longitudinal direction of the side wall portion 91 b of the first insulating portion 91 and at one end portion in the lateral direction. And the positive electrode insulation part 92 is connected with the connection part 94 of the longitudinal direction one end, and the negative electrode insulation part 93 is connected with the connection part 94 of the longitudinal direction other end of the side wall part 91b.

  In a side view along the longitudinal direction, the insulating portion main body 91a and the positive electrode insulating portion 92, and the insulating portion main body 91a and the negative electrode insulating portion 93 are separated in the facing direction Z by the connecting portion 94. The insulating portion main body 91 a includes an inner surface 91 d on a surface facing the tab side end surface 12 b of the electrode assembly 12.

  The positive electrode insulating portion 92 has a quadrangular shape when viewed from the outer surface 15 c of the lid member 15. The planar view size of the positive electrode insulating portion 92 is larger than the planar view size of the base portion 60 b of the positive electrode lead terminal 60, and the entire base portion 60 b can be covered from the electrode assembly 12 side.

  The positive electrode insulating portion 92 includes an inner surface 92b that faces the base portion 60b of the positive electrode lead terminal 60 and an outer surface 92d that faces the electrode assembly 12, and the outer surface 92d is flat. The positive electrode insulating portion 92 includes a protruding portion 92e near the insulating portion main body 91a in the inner surface 92b, and the protruding portion 92e exists over the entire short direction of the insulating cover 90. Further, the protruding portion 92e is located closer to the positive electrode insulating portion 92 than the insulating portion main body 91a. In the opposing direction Z, the insulating portion main body 91a and the protruding portion 92e do not overlap and are displaced in the longitudinal direction. .

  However, in the side view along the longitudinal direction, the insulating portion main body 91a and the protruding portion 92e are in positions facing the facing direction Z. Therefore, the insulating cover 90 includes the positive electrode side gap 95a between the insulating body 91a and the protrusion 92e in the facing direction Z. The size of the positive electrode side gap 95a along the facing direction Z is larger than the thickness of the electrode joint portion 51a of the positive electrode conductive member 51, and the positive electrode joint portion 51a is inserted into the positive electrode side gap 95a. The insulating body 91a of the insulating cover 90 is supported by the electrode joint 51a, and the insulating body 91a is sandwiched between the electrode joint 51a and the lid member 15 along the facing direction Z.

  Of the both ends along the short direction of the insulating cover 90, the connecting portion 94 is located at one end of the protrusion 92e, and the locking claw 92a is present at the other end. The locking claw 92a of the positive electrode insulating portion 92 protrudes in the facing direction Z from the protruding portion 92e. The dimension between the opposing surfaces of the connecting portion 94 and the protruding portion 92e along the short direction of the insulating cover 90 is longer than the dimension along the short direction of the electrode joint portion 51a and slightly larger than the dimension of the inner insulating member 40 of the positive electrode. long.

  In the state where the electrode bonding portion 51a enters the positive gap 95a, the connecting portion 94 comes into contact with one of the edges of the inner insulating member 40 facing in the short direction of the insulating cover 90, although not shown. As shown in FIG. 6B, a locking claw 92a is locked to the other edge.

  As shown in FIG. 4, the negative electrode insulating portion 93 has a quadrangular shape when viewed from the outer surface 15 c of the lid member 15. The size in plan view of the negative electrode insulating portion 93 is substantially the same as the size in plan view of the base 63 of the negative electrode lead terminal 61 and the current interrupting mechanism 80, and the entire current interrupting mechanism 80 can be covered from the electrode assembly 12 side. The negative electrode insulating portion 93 includes an inner surface 93b that faces the deformation plate 85 of the current interrupt mechanism 80, and an outer surface 93d that faces the electrode assembly 12, and the outer surface 93d is flat. The negative electrode insulating portion 93 includes a protruding portion 93e near the insulating portion main body 91a in the inner surface 93b, and the protruding portion 93e exists over the entire short direction of the insulating cover 90. In the facing direction Z, the insulating portion main body 91a and the protruding portion 93e are in overlapping positions.

  As shown in FIG. 6A, the insulating cover 90 includes a negative electrode side gap 95b between the insulating main body 91a and the protrusion 93e in the facing direction Z. The dimension of the negative electrode side gap 95b along the facing direction Z is larger than the thickness of the electrode joint portion 52a of the negative electrode conductive member 52, and the negative electrode joint portion 52a is inserted into the negative electrode side gap 95b. The insulating body 91a of the insulating cover 90 is supported by the electrode joint 52a, and the insulating body 91a is sandwiched between the electrode joint 52a and the lid member 15 along the facing direction Z.

  Of the both end portions along the short direction of the insulating cover 90, the connecting portion 94 is located at one end portion of the negative-side protruding ridge portion 93e, and the locking claw 93a is present at the other end portion. The locking claw 93a of the negative electrode insulating portion 93 protrudes in the facing direction Z from the protruding portion 93e. The dimension between the opposing surfaces of the connecting portion 94 and the protrusion 93e along the short direction of the insulating cover 90 is slightly longer than the dimension along the short direction of the electrode joint portion 52a. In the state where the electrode joint portion 52a enters the negative electrode side gap 95b, the connecting portion 94 abuts on one of the edge portions of the electrode joint portion 52a facing the short side direction of the insulating cover 90, and the other edge portion. The latching claw 93a is latched to the.

  As shown in FIG. 4, the negative electrode insulating portion 93 includes a relief recess 93f penetrating in the thickness direction at the center, and the deformation plate 85 of the current interrupt mechanism 80 is inserted into the relief recess 93f. The internal pressure of the case 11 acts on the other surface of the deformation plate 85 (the surface on the electrode assembly 12 side) via the escape recess 93f.

Next, a method for manufacturing the secondary battery 10 will be described.
A contact plate 81 is joined to the terminal end face 63b of the negative electrode lead terminal 61 of the negative electrode, and the contact plate 81, the insulating ring 82, the seal ring 83, and the negative electrode conductive member 52 (terminal connection portion 52b) are unitized. Shall. Further, it is assumed that the deformable plate 85 is joined to the terminal connection portion 52b of the negative electrode conductive member 52, and the negative electrode lead terminal 61, the current interruption mechanism 80, and the negative electrode conductive member 52 are integrated in advance.

  First, the outer insulating member 57 is disposed on the outer surface 15 c of the lid member 15 in a state where the rotation preventing portion 58 of the outer insulating member 57 is inserted into each locking recess 18 of the lid member 15. The engaging projection 69 of the external connection terminal 66 is inserted into the rotation stopper 58 of the outer insulating member 57. Next, the shaft portion 68 of the external connection terminal 66 is inserted into the through hole 46 a of the terminal connection member 44.

  Next, on the positive electrode side, the O-ring 73 and the inner insulating member 40 are disposed on the inner surface 15d side of the lid member 15, and the positive electrode conductive member 51 is disposed. The connecting shaft portion 62 of the positive electrode lead terminal 60 is inserted into the insertion hole 51c of the positive electrode conductive member 51, the insertion hole 40a of the inner insulating member 40, the O-ring 73, the insertion hole 15e of the lid member 15, the insertion hole 57d of the outer insulating member 57, and It is inserted into the insertion hole 47 a of the terminal connection member 44. Then, by caulking the connecting shaft portion 60a of the positive electrode lead terminal 60, the positive electrode conductive member 51, the inner insulating member 40, the O-ring 73, the lid member 15, between the base portion 60b and the tip end portion of the connecting shaft portion 60a, The outer insulating member 57 and the terminal connection member 44 are integrated.

  On the negative electrode side, the O-ring 73 and the inner insulating member 40 are arranged on the inner surface 15 d side of the lid member 15. The insertion hole 40 a of the inner insulating member 40, the O-ring 73, the insertion hole 15 e of the lid member 15, and the outer insulating member 57 The connecting shaft portion 62 of the negative electrode lead terminal 61 is inserted into the insertion hole 57 d and the insertion hole 47 a of the terminal connection member 44. The inner insulating member 40, the O-ring 73, the lid member 15, the outer insulating member 57, and the terminal connecting member 44 are interposed between the base portion 63 and the distal end portion of the connecting shaft portion 62 by caulking the connecting shaft portion 62. Are integrated, and the current interruption mechanism 80 is also integrated.

  Then, as shown in FIG. 2, the positive terminal structure 16 and the negative terminal structure 17 are formed on the lid member 15, and the lid terminal assembly 20 is formed. In the lid terminal assembly 20, the outer insulating member 57 is rotated on the lid member 15 by the engagement between the outer surface of the rotation preventing portion 58 of the outer insulating member 57 and the inner surface of the locking recess 18 of the lid member 15. Is regulated. The rotation of the external connection terminal 66 is restricted by the engagement between the inner surface of the rotation stopper 58 of the outer insulating member 57 whose rotation is restricted and the outer surface of the engagement projection 69 of the external connection terminal 66.

  In the lid terminal assembly 20, there is a gap between the lid member 15 in the facing direction Z and the electrode joint portions 51a and 52a. The electrode joint portions 51 a and 52 a are L-shaped, and the electrode joint portions 51 a and 52 a have portions that protrude from the lid member 15.

  The positive electrode tab group 36 of the electrode assembly 12 is joined to the electrode joint portion 51 a of the positive electrode conductive member 51 by laser welding, and the negative electrode tab group 36 is laser-bonded to the electrode joint portion 52 a of the negative electrode conductive member 52. Joined by welding. Then, the lid terminal assembly 20 and the electrode assembly 12 are integrated. Next, the electrode bonding portions 51a and 52a are bent in a U shape, and the tab group 36 is bent.

  Then, as shown in FIG. 7, the insulating portion main body 91a of the insulating cover 90 is inserted between the inner surface 15d of the lid member 15 and the electrode bonding portions 51a and 52a, and the electrode bonding portion 51a is inserted into the positive electrode side gap 95a. Then, the insulating cover 90 is slid so that the electrode joint portion 52a is inserted into the negative gap 95b.

  When the connecting portion 94 comes into contact with one edge of the inner insulating member 40 on the positive electrode side, the locking claw 92 a of the positive electrode insulating portion 92 is locked to the edge of the inner insulating member 40. On the negative electrode side, when the connecting portion 94 comes into contact with one long edge portion of the electrode bonding portion 52a, the locking claw 93a of the negative electrode insulating portion 93 is locked to the other long edge portion of the electrode bonding portion 52a. As a result, the insulating cover 90 is integrally assembled to the positive electrode conductive member 51 and the negative electrode conductive member 52, and the electrode joint portions 51a and 52a are insulated from the lid member 15 by the insulating portion main body 91a.

  Further, the positive electrode insulating portion 92 insulates the base portion 60b of the positive electrode lead terminal 60 from the electrode assembly 12 side, and the negative electrode insulating portion 93 insulates the current interruption mechanism 80 from the electrode assembly 12 side, while protecting the deformation plate 85. It becomes a state.

  Then, the electrode assembly 12 is inserted into the case member 14 from the opening 14 a of the case member 14. At this time, the lid terminal assembly 20 is pushed toward the case member 14 in order to push the electrode assembly 12 into the case member 14. Then, the electrode assembly 12 is pressed while the outer surface 92 d of the positive electrode insulating portion 92 of the insulating cover 90 and the outer surface 93 d of the negative electrode insulating portion 93 are simultaneously in contact with the tab side end surface 12 b of the electrode assembly 12.

Then, after the electrode assembly 12 is inserted into the case member 14, when the lid member 15 is joined to the open end of the case member 14, the secondary battery 10 is assembled.
Next, the operation of the secondary battery 10 will be described.

  In the secondary battery 10, the negative electrode insulating portion 93 of the insulating cover 90 is insulated from the electrode assembly 12 while covering and protecting the deformable plate 85 of the current interrupt mechanism 80 from the electrode assembly 12 side. Further, the positive electrode insulating portion 92 covers the positive electrode lead terminal 60 from the electrode assembly 12 side and insulates it from the electrode assembly 12.

According to the above embodiment, the following effects can be obtained.
(1) The current interruption mechanism 80 is covered from the electrode assembly 12 side by the negative electrode insulating portion 93 of the insulating cover 90. And the negative electrode insulation part 93 is integral with the 1st insulation part 91, and the 1st insulation part 91 is pinched | interposed between the cover member 15 and each electrode junction part 51a, 52a, and is hard to receive a vibration. Therefore, when the secondary battery 10 is initially charged or when the secondary battery 10 is used, even if an external force acts on the secondary battery 10 or receives vibration, the insulating cover 90 itself hardly vibrates. The state where the current interrupting mechanism 80 is protected by the insulating portion 93 can be maintained. As a result, it is possible to suppress the tab-side end surface 12b of the electrode assembly 12 that has vibrated from coming into contact with the deformation plate 85 by the negative electrode insulating portion 93, and to prevent the deformation plate 85 from being deformed. Can be prevented from malfunctioning.

  (2) The insulating cover 90 includes a first insulating portion 91 that insulates the electrode joining portions 51a and 52a and the lid member 15, a positive insulating portion 92 that insulates the positive electrode lead terminal 60 from the electrode assembly 12, and a current interruption mechanism. A negative electrode insulating portion 93 that insulates 80 from the electrode assembly 12 is integrally provided. Therefore, as compared with the case where the electrode joining portions 51a and 52a and the insulating member of the lid member 15, the positive electrode lead terminal 60 and the insulating member of the electrode assembly 12, and the current blocking mechanism 80 and the insulating member of the electrode assembly 12 are provided separately. And the number of parts of the secondary battery 10 can be reduced, and the assembly work of the secondary battery 10 becomes easy.

  (3) The insulating cover 90 includes housing recesses 91f at both ends in the longitudinal direction of the insulating body 91a, and the protrusions 19 of the lid member 15 are inserted into the housing recesses 91f. The protrusion 19 is a portion into which the rotation preventing portion 58 of the outer insulating member 57 enters in order to restrict the rotation of the outer insulating member 57 on the lid member 15. Therefore, while the secondary battery 10 includes the protrusion 19 that restricts the rotation of the outer insulating member 57 on the lid member 15, the protrusion 19 does not interfere with the mounting state of the insulating cover 90.

  (4) The insulating cover 90 includes a positive electrode side gap 95 a between the insulating part main body 91 a and the positive electrode insulating part 92, and a negative electrode side gap 95 b between the insulating part main body 91 a and the negative electrode insulating part 93. Therefore, even after the lid terminal assembly 20 is formed and the tab group 36 is joined to the electrode joint portions 51a and 52a, the conductive members 51 and 52 are inserted into the gaps 95a and 95b, so that the insulating cover is obtained. 90 can be attached to the positive electrode conductive member 51 and the negative electrode conductive member 52. Therefore, the heat at the time of joining the tab group 36 to the electrode joint portions 51a and 52a does not reach the insulating cover 90, and the insulating cover 90 is not melted by the heat.

  (5) The insulating cover 90 includes a connecting portion 94 and locking claws 92a and 93a at each end in the lateral direction. The connecting portion 94 and the locking claw 92a are locked to the inner insulating member 40 on the positive electrode side, and the connecting portion 94 and the locking claw 93a are locked to the electrode joint portion 52a on the negative electrode side. By this locking, it is possible to restrict the insulating cover 90 from moving in the short direction, insulation between the electrode joining portions 51a and 52a and the lid member 15 by the first insulating portion 91, and a positive lead terminal by the positive insulating portion 92. Insulation between the electrode assembly 12 and the electrode assembly 12, and insulation between the current interruption mechanism 80 and the electrode assembly 12 by the negative electrode insulation portion 93 can be maintained.

  (6) The insulating cover 90 is provided with a relief recess 93f in the negative electrode insulation portion 93, and a deformation plate 85 is accommodated in the escape recess 93f. For this reason, the deformation plate 85 that protrudes toward the electrode assembly 12 can be protected by the negative electrode insulating portion 93.

  (7) The insulating cover 90 includes a relief recess 93f in the negative electrode insulation portion 93, and the deformation plate 85 of the current interrupt mechanism 80 enters the escape recess 93f. The outer surface 93d of the negative electrode insulating portion 93 can be disposed closer to the lid member 15 by the dimension that the deformable plate 85 escapes and enters the concave portion 93f, which can contribute to reducing the space where the electrode assembly 12 is not disposed.

In addition, you may change the said embodiment as follows.
The current interruption mechanism may not be integrated with the terminal end surface 63 b of the negative electrode lead terminal 61. As shown in FIG. 9, in this case, the negative electrode terminal 201 as one of the electrode terminals protrudes from the negative electrode base 201a toward the lid member 15 from the negative electrode base 201a and has a screw groove on the outer peripheral surface. And a columnar negative electrode shaft portion 201b. The negative electrode shaft portion 201 b protrudes outside the case 11 through the lid member 15. The negative electrode shaft portion 201 b is inserted through the inner insulating member 210. The inner insulating member 210 insulates the lid member 15 and the negative electrode terminal 201 within the case 11. A nut 203 is screwed onto the negative electrode shaft portion 201b from above the outer insulating member 211, and the negative electrode terminal 201 is fixed to the lid member 15. The outer insulating member 211 insulates the negative electrode terminal 201 from the lid member 15 outside the case 11.

  The negative electrode base 201 a of the negative electrode terminal 201 is electrically connected to the negative electrode of the electrode assembly 12 through the first negative electrode conductive member 204, the deformation plate 205, and the second negative electrode conductive member 206. The first negative electrode conductive member 204 has a rectangular plate shape, and one end portion in the longitudinal direction is fixed to the negative electrode base portion 201 a and the other end portion in the longitudinal direction is disposed so as to approach the center in the longitudinal direction of the lid member 15. The first negative electrode conductive member 204 includes a through hole 204a at the other end in the longitudinal direction.

  The second negative electrode conductive member 206 has a rectangular plate shape and a crank shape, and one end side in the longitudinal direction is supported closer to the electrode assembly 12 than the first negative electrode conductive member 204 via the support member 207. The other end of the second negative electrode conductive member 206 in the longitudinal direction is electrically connected to the negative electrode tab group 36 of the electrode assembly 12.

  The current interruption mechanism 200 includes a deformation plate 205. The deformation plate 205 is a diaphragm made of a conductive material. The deformation plate 205 has a disk shape. The deformation plate 205 is located between the first negative electrode conductive member 204 and the electrode assembly 12 and covers the through hole 204 a of the first negative electrode conductive member 204. The outer peripheral part protruding from the through hole 204a in the deformation plate 205 and the peripheral part of the through hole 204a in the first negative electrode conductive member 204 are joined by welding.

  A contact portion Q between the outer peripheral portion of the deformable plate 205 and the first negative electrode conductive member 204 is fixed by welding, and the gap between the deformable plate 205 and the first negative electrode conductive member 204 is sealed by this welding. The current interruption mechanism 200 has a second space S2 defined between the through hole 204a of the first negative electrode conductive member 204, the deformation plate 205, and the insulating plate 202, and the second space S2 is sealed. Yes. The deformation plate 205 defines a first space S1 and a second space S2 in the case 11. In the deformable plate 205, external pressure acts on the other surface facing the second space S2, and internal pressure acts on the one surface facing the first space S1.

  The deformable plate 205 is convex toward the second negative electrode conductive member 206 before being deformed, and the convex portion of the second negative electrode conductive member 206 is bonded to the second negative electrode conductive member 206, and the bonded portion is a negative electrode. It is a welded portion P. Thereby, the deformable plate 205 electrically connects the negative electrode terminal 201 and the electrode assembly 12 via the first negative electrode conductive member 204 and the second negative electrode conductive member 206.

  In the secondary battery 10, when the internal pressure of the case 11 rises, the deformation plate 205 is deformed into a convex shape toward the first negative electrode conductive member 204 by the internal pressure of the case 11. Along with this, in the secondary battery 10, the second negative electrode conductive member 206 is broken, the conductive path between the negative electrode terminal 201 and the second negative electrode conductive member 206 is physically cut off, and the current is cut off. .

  The insulating cover 90 includes a first insulating portion 91 interposed between the first negative electrode conductive member 204 and the second negative electrode conductive member 206 and the lid member 15, and a second current covering mechanism 200 that covers the current interruption mechanism 200 from the electrode assembly 12 side. The insulating portion 97 and the negative electrode terminal 201 are integrally provided with the third insulating portion 98 from the electrode assembly 12 side.

  According to this configuration, the current interrupt mechanism 200 and the negative electrode terminal 201 are arranged side by side along the juxtaposition direction. In this case, the current interrupt mechanism 200 is insulated from the electrode assembly 12 by the second insulating portion 97, and the negative terminal 201 is insulated from the electrode assembly 12 by the third insulating portion 98. And since the 1st insulation part 91, the 2nd insulation part 97, and the 3rd insulation part 98 are integrated, compared with the case where each insulation part 91-93 is a different body, the number of parts of the secondary battery 10 is shown. And can be easily assembled.

The insulating cover 90 may include a first insulating portion 91 and a negative electrode insulating portion 93 as a second insulating portion, and may not include the positive electrode insulating portion 92.
In the insulating cover 90, the housing recess 91f of the first insulating portion 91 may not be provided.

In the insulating cover 90, the locking claws 92a and 93a may be omitted.
In the insulating cover 90, if the negative electrode insulating portion 93 is separated along the facing direction Z so as not to contact the deformation plate 85 of the current interrupt mechanism 80, the relief recess 93f may be omitted.

The power storage device can also be applied to a secondary battery having a current interruption mechanism 80 integrated with the positive electrode lead terminal 60.
The wall portion may be the side wall of the case member 14 instead of the lid member 15.

The power storage device can also be applied to power storage devices other than secondary batteries, such as capacitors.
The positive electrode 21 and the negative electrode 31 may have a structure in which an active material layer is present on one side of a metal foil.

  The secondary battery 10 may be a lithium ion secondary battery or another secondary battery. In short, any ion may be used as long as ions move between the active material for the positive electrode and the active material for the negative electrode and charge is transferred.

Next, the technical idea that can be grasped from the above embodiment and other examples will be described below.
(1) An electrode assembly in which electrodes of different polarities are laminated while being insulated from each other, a tab having a shape protruding from the electrode, and a tab group of each polarity protruding from an end surface of the electrode assembly; A case housing the electrode assembly and the tab group, an external connection terminal disposed outside a wall portion of the case, and disposed between the end surface and the wall portion, and electrically connected to the tab group A connected conductive member, a lead terminal connected to the conductive member outside the tab group in the juxtaposition direction of the tab group, and protruding outside from the wall portion, and disposed outside the wall portion And a terminal connecting member connecting the lead terminal and the external connection terminal, insulating the external connection terminal and the wall part outside the wall part, and projecting the lead terminal from the wall part The lead-out terminal penetrates along the direction An electrical storage device comprising an insulating member and an insulating cover interposed between the pair of conductive members and the wall portion, wherein the outer insulating member is engaged with an engaging convex portion of the external connection terminal In addition to providing a state in which the anti-rotation part protrudes toward the wall part, the wall part is provided in a state of protruding a protrusion having an engaging recess that the anti-rotation part engages toward the insulating cover, The power storage device, wherein the insulating cover includes a housing recess that houses the protrusion.

  According to this, the protrusion is a portion into which the rotation preventing portion of the outer insulating member enters in order to restrict the rotation of the outer insulating member on the wall portion. Thus, the power storage device includes a protrusion on the wall that restricts the rotation of the outer insulating member, but the protrusion does not interfere with the state of mounting the insulating cover.

  DESCRIPTION OF SYMBOLS 10 ... Secondary battery as a power storage device, 11 ... Case, 12 ... Electrode assembly, 12b ... Tab side end face as end face, 15 ... Lid member as wall, 21 ... Positive electrode, 31 ... Negative electrode, 51 ... Positive electrode conductive member, 52 ... Negative electrode conductive member, 60 ... Positive electrode lead terminal as electrode terminal, 60b, 63 ... Base, 61 ... Negative electrode lead terminal as one electrode terminal, 63b ... Terminal end face, 80, 200 ... Current interruption mechanism 85, 205 ... deformation plate, 91 ... first insulating part, 93 ... negative electrode insulating part as the second insulating part, 97 ... second insulating part, 98 ... third insulating part.

Claims (4)

An electrode assembly in which electrodes of different polarities are laminated and insulated from each other;
A case containing the electrode assembly;
A pair of conductive members electrically connected to the electrodes of the same polarity and disposed between a wall portion of the case and an end surface of the electrode assembly facing the wall portion;
A pair of electrode terminals electrically connected to the conductive member of the same polarity and fixed to the wall of the case;
A part of the electrical conduction path between the electrode terminal of one polarity and the electrode assembly is provided with a deformation plate on which one side is subjected to the internal pressure of the case and the other side is subjected to the external pressure of the case. And a current interruption mechanism that is arranged between the end face and the wall portion and interrupts the current of the energization path by deformation of the deformation plate when the internal pressure of the case reaches a set pressure. ,
A first insulating portion interposed between the pair of conductive members and the wall portion;
A power storage device, comprising: a second insulating portion that is interposed between the current interrupt mechanism and the end surface and is integral with the first insulating portion.   The electrode terminal of the one polarity includes a base portion that protrudes into the case from the wall portion, and the power storage device is a third insulating member disposed between the base portion and an end surface of the electrode assembly. 2. The power storage device according to claim 1, wherein the third insulating portion is integrated with the first insulating portion and the second insulating portion.   3. The deformation plate of the current interrupt mechanism is integrated with the terminal end surface when a surface facing the end surface of the electrode assembly is a terminal end surface in the base portion of the electrode terminal of the one polarity. The power storage device described in 1.   The power storage device according to any one of claims 1 to 3, wherein the power storage device is a secondary battery.

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