JP6597292B2 - Power storage device - Google Patents

Description

  The present invention relates to a power storage device having an insulating cover.

  Conventionally, vehicles such as EVs (Electric Vehicles) and PHVs (Plug in Hybrid Vehicles) have been mounted with lithium-ion secondary batteries or nickel-hydrogen secondary batteries as power storage devices that store power supplied to electric motors and the like. . Generally, a secondary battery includes an electrode assembly in which a positive electrode and a negative electrode having an active material layer are stacked in layers, and a case for housing the electrode assembly. Some cases include a case member having an opening for inserting the electrode assembly and a lid member for closing the opening of the case member. Electrode terminals of each electrode are electrically connected to the positive electrode and the negative electrode through a conductive member.

  In one of the secondary battery assembly methods, a lid terminal assembly in which a lid member, a conductive member, and an electrode terminal are unitized is assembled in advance, and the lid terminal assembly and the electrode assembly are integrated. There is a method of inserting the electrode assembly into the case member and fixing the lid to the case member (see, for example, Patent Document 1).

  As shown in FIG. 9, the battery of Patent Document 1 has a configuration in which a battery lid unit 101 is fixed to an upper opening of a battery case 100. The battery lid unit 101 includes a terminal 103 as an electrode terminal fixed by caulking to the center portion of the lid plate 102 and a terminal plate 104 integrated with the terminal 103 outside the lid plate 102. The battery lid unit 101 includes a packing 107 that insulates the terminal 103 and the lid plate 102 from the outside of the lid plate 102. Furthermore, the battery lid unit 101 includes a current collecting washer 105 as a conductive member disposed in the battery case 100, and the current collecting washer 105 is electrically connected to the terminal 103 in the battery case 100. Yes. In the battery case 100, the current collecting washer 105 is insulated from the lid plate 102 by a packing 106 as an insulating cover. The current collecting washer 105 includes a horizontal plate portion 105 a and a vertical plate portion 105 b protruding from the long edge portion of the horizontal plate portion 105 a, and the vertical plate portion 105 b is directed from the lid plate 102 into the battery case 100. It has a protruding shape. A positive electrode current collector is joined to the vertical plate portion 105b, and the current collecting washer 105 and the positive electrode current collector are electrically connected.

  In assembling the battery of Patent Document 1, first, the battery lid unit 101 is assembled, and then the positive electrode current collector is joined to the vertical plate portion 105b of the current collecting washer 105 of the battery lid unit 101 by welding. Thereafter, the positive electrode current collector is accommodated in the battery case 100, and the battery lid unit 101 is joined to the battery case 100, whereby the assembly of the battery is completed. In the battery of Patent Document 1, the battery case 100 serves as a negative electrode output terminal, and the terminal 103 and the terminal plate 104 in the battery lid unit 101 serve as a positive electrode output terminal.

JP-A-9-147832

  By the way, in the battery of Patent Document 1, when the positive electrode current collector is joined to the current collecting washer 105 of the battery lid unit 101, the packing 106 may be melted by heat generated by welding.

  The present invention can eliminate the influence of heat on the insulating cover when welding the conductive member and the electrode.

  A power storage device for solving the above problems includes an electrode assembly in which a plurality of electrodes having different polarities are insulated from each other and stacked, a case housing the electrode assembly, and a wall portion of the case A base part protruding toward the electrode assembly, and a pair of electrode terminals fixed to the wall part, an electrode joint part joined to the electrode of the same polarity, and a base part of the electrode terminal are electrically connected A pair of conductive members disposed between a wall portion of the case and an end surface of the electrode assembly facing the wall portion, and between the wall portion and the terminal connection portion. An insulating member interposed; a first insulating portion interposed between the pair of electrode joining portions and the wall portion; and a second insulating portion interposed between the base portion and an end surface of the electrode assembly. An insulating cover having an odor When the direction along the parallel arrangement direction of the pair of conductive members is the longitudinal direction and the direction orthogonal to the longitudinal direction is the short direction, the insulating cover is the first insulation in a side view along the longitudinal direction. A connecting portion that separates the second insulating portion from the second insulating portion and connects the second insulating portion to each other, and is provided at one end portion in the short direction, and between the first insulating portion and the second insulating portion that are opposed in the side view. The gist of the present invention is to provide a gap that opens to the other end portion in the short-side direction and reaches the connecting portion.

  According to this, the conductive member, the insulating member, and the electrode terminal are integrally assembled to the lid member, and the opening of the gap of the insulating cover is directed to the pair of conductive members in a state where the electrode is bonded to the electrode bonding portion. In the state, the insulating cover is moved along the short direction. Then, the first insulating portion is inserted between the pair of electrode joint portions and the wall portion while the pair of conductive members enter the gap. As a result, the first insulating portion is disposed at a position where the wall portion and the electrode joint portion can be insulated, and at the same time, the second insulating portion is disposed at a position where the electrode terminal and the electrode assembly can be insulated.

  Therefore, even if the conductive member is integrated with the lid member in advance and the electrode is joined to the conductive member, the insulating cover can be disposed, and the influence of heat when welding the conductive member and the electrode is affected. It does not reach the insulation cover.

  In the power storage device, the insulating cover protrudes from the second insulating portion toward the first insulating portion in the side view at a position opposite to the connecting portion at the other end portion in the short side direction. And the latching claw which latches to the said electrically-conductive member or the said insulating member may be provided.

  According to this, when the insulating cover is arranged and the connecting portion is brought into contact with the conductive member or the insulating member on the one end side in the short side direction, the locking claw is connected to the conductive member or the insulating member on the other end side in the short side direction. Lock to the member. Then, the insulating cover is restricted from moving in the short direction.

  In addition, the power storage device includes a current interrupt mechanism that interrupts an electrical energization path between the electrode terminal of one polarity and the electrode assembly when the internal pressure of the case reaches a set pressure, and the current interrupt mechanism is The base portion and the terminal connection portion may be electrically connected, and the locking claw may be locked to the electrode joint portion of the conductive member on the one polarity side.

  According to this, the current interrupting mechanism tends to be larger in the dimension along the short direction of the insulating cover than the base part of the electrode terminal, and since the base part provided with this current interrupting mechanism is insulated from the wall part, the insulating member is also insulated. The dimension along the short direction of the cover is increased, and the terminal connection portion is also increased. For this reason, the insulating member on one electrode terminal side is larger than the insulating member on the other electrode terminal side, and if the engaging claw is engaged with the insulating member on one electrode terminal side, the insulating cover is short. Increase in size in the direction. Therefore, on one electrode terminal side, the size of the insulating cover in the short direction can be avoided by locking the locking claws to the electrode joint portion instead of the insulating member and the enlarged terminal connection portion. Can do.

Moreover, about the electrical storage apparatus, the said latching claw may be latched by the said insulation member in the other polarity side which is not provided with the said current interruption mechanism.
According to this, the insulating member is manufactured larger than the terminal connection portion in order to insulate the wall portion and the terminal connection portion. However, it is smaller than the current interruption mechanism and the insulating member on the one electrode terminal side. Therefore, when the insulating cover is slid, the locking claw is locked to the insulating member before the terminal connecting portion, and the mounting of the insulating cover becomes smooth.

  The power storage device is a secondary battery.

  According to the present invention, it is possible to eliminate the influence of heat when welding the conductive member and the electrode on the insulating cover.

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 mounting | wearing of an insulation cover. Sectional drawing which shows the external connection terminal vicinity. 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. Compared with the terminal connection part 52b, the electrode joint part 52a has a shape with a small dimension along the short direction of the negative electrode conductive member 52 and is smaller than the dimension along the short direction of the lid member 15. Further, the terminal connection portion 52 b has a dimension extending over the entire width of the lid member 15.

  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 rotation preventing portion 58 has a shape protruding in a quadrangular 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 electrode terminal structure 16 and the negative electrode terminal structure 17 include an external connection terminal 66 disposed outside the lid member 15, and the external connection terminal 66 electrically connects the secondary batteries 10 to each other outside the lid member 15. The bus bar can be fixed. 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 projection 69 are in contact with and locked with the four inner surfaces of the rotation stopper 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.

  A base portion 60b of the positive electrode lead terminal 60 is disposed so as to protrude from the inner surface 15d of the lid member 15 into the case 11, and a connecting shaft portion 60a includes an insertion hole 51c of the positive electrode conductive member 51, an inner insulation described later. The insertion hole 40 a of the 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 are penetrated.

  The positive electrode terminal structure 16 includes an O-ring 73, and the connecting shaft portion 60 a of the positive electrode lead terminal 60 is inserted into the O-ring 73 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 insulating cover 90 is larger than the dimension of the positive electrode conductive member 51 along the short direction. For this reason, the inner insulating member 40 protrudes from the positive electrode conductive member 51 along the short direction of the insulating cover 90.

  As shown in FIG. 3, 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 square plate shape. The base 63 is larger in size than the positive side base 60b. 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. 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 external pressure (substantially atmospheric pressure) of the case 11 acts on one surface (the surface on the lid member 15 side) of the deformable plate 85 via the shaft hole 64 of the negative electrode lead terminal 61. The internal pressure of the case 11 acts on the other surface of the deformation plate 85 (surface on the electrode assembly 12 side). The deformation plate 85 is configured to be deformed by the pressure and project toward the lid member 15 when an internal pressure larger than the 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 is interposed between the electrode bonding portions 51 a and 52 a and the lid member 15 and insulates both. The insulating cover 90 includes a negative electrode insulating portion 93 as a second insulating portion interposed between the base portion 63 of the negative electrode lead terminal 61 including the current interruption mechanism 80 and the tab side end surface 12b of the electrode assembly 12, and a positive electrode lead-out. And a positive electrode insulating portion 92 as a second insulating portion interposed between the base portion 60 b of the terminal 60 and the tab side end surface 12 b of the electrode assembly 12.

  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. In this case, as can be seen from the perspective view of FIG. 5, the insulating cover 90 is U-shaped in a side view along the longitudinal direction.

  As shown in FIG. 5, the positive electrode insulating portion 92 is integrated with one end portion in the longitudinal direction of the rectangular first insulating portion 91, and the negative electrode insulating portion 93 is the other end portion in the longitudinal direction of the first insulating portion 91. It is integral. 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. As shown in FIG. 6A, 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 bonding portions 51a and 52a.

  As shown in FIG. 4, the insulating 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 portion 51a. , 52a and the lid member 15 are insulated. 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.

  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 projections 19 of the lid member 15 are inserted into the housing recesses 91f, and the longitudinal direction and the short direction of the insulating cover 90 are brought into contact with the outer surface of the projections 19 and the inner surface of the housing recess 91f. The movement of the insulating cover 90 along the line is restricted.

  As shown in FIG. 3 or FIG. 5, the insulating cover 90 includes a connecting portion 94 that is integral with both ends in the longitudinal direction of the side wall 91 b of the first insulating portion 91 and at one end in the short 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 the insulating cover 90, the connecting portion 94 connects the first insulating portion 91, the positive electrode insulating portion 92, and the negative electrode insulating portion 93 so as to be separated from each other and face each other in a side view along the longitudinal direction.

  Therefore, in the side view along the longitudinal direction, the insulating portion main body 91a and the positive electrode insulating portion 92 are separated from each other in the facing direction Z, and the insulating portion main body 91a and the negative electrode insulating portion 93 are separated from each other in the facing direction Z. 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.

  Further, 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 92 b that faces the base portion 60 b of the positive electrode lead terminal 60 and an outer surface 92 d that faces the electrode assembly 12. 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 first insulating portion 91 and the positive electrode insulating portion 92 that face each other in a side view. The positive electrode side gap 95a opens at the other end of the insulating cover 90 in the short direction. 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.

  A locking claw 92 a exists at the other end of the insulating cover 90 in the short direction. The locking claw 92a of the positive electrode insulating portion 92 protrudes from the protruding portion 92e from the positive electrode insulating portion 92 toward the first insulating portion 91 in a side view. The dimension between the opposing surfaces of the connecting portion 94 and the protrusion 92e along the short direction of the insulating cover 90 is longer than the dimension of the electrode joint portion 51a along the short direction, and slightly larger than the dimension of the inner insulating member 40 of the positive electrode. long. In the state where the electrode joint portion 51a enters the positive electrode side gap 95a, the connecting portion 94 comes into contact with one of the edge portions of the inner insulating member 40 facing the short side direction of the insulating cover 90, and the other edge portion. The latching claw 92a is latched.

  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. Further, as shown in FIG. 5, the negative electrode insulating portion 93 includes an inner surface 93 b that faces the deformation plate 85 of the current interrupt mechanism 80 and an outer surface 93 d that faces the electrode assembly 12. 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.

  Therefore, the insulating cover 90 includes the negative electrode side gap 95b between the first insulating portion 91 and the negative electrode insulating portion 93 that are opposed to each other in a side view. That is, the insulating cover 90 includes a negative electrode side gap 95b between the insulating body 91a and the protrusion 93e in the facing direction Z, and the negative electrode side gap 95b is formed at the other end of the insulating cover 90 in the short direction. Open. 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. Then, as shown in FIG. 4, the insulating body 91 a of the insulating cover 90 is supported by the electrode joint 52 a, and the insulating body 91 a is interposed between the electrode joint 52 a and the lid member 15 along the facing direction Z. It is sandwiched.

  As shown in FIG. 6A, the connecting portion 94 is located at one end of the negative-side protrusion 93e and the locking claw 93a at the other end of the both ends along the short direction of the insulating cover 90. Exists. The locking claw 93a of the negative electrode insulating portion 93 protrudes from the protrusion 93e from the negative electrode insulating portion 93 toward the first insulating portion 91 in a side view. 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.

  Further, 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 escape 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, the manufacturing method of the secondary battery 10 will be described together with the operation.
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 51 c of the positive electrode conductive member 51, 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 insertion hole of the outer insulating member 57. 57d and the terminal connection member 44 are inserted into the insertion holes 47a. 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, 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 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, as shown in FIG. 7, 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. The insulating portion main body 91a of the insulating cover 90 is inserted between the lid member 15 and the electrode joint portions 51a and 52a, and the positive electrode conductive member 51 is inserted into the positive electrode side gap 95a and the negative electrode conductive member 52 is inserted into the negative electrode side gap 95b. The insulating cover 90 is slid so as to be inserted.

  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 extraction terminal 60 from the electrode assembly 12 side, and the negative electrode insulation portion 93 insulates the negative electrode extraction terminal 61 including the current interruption mechanism 80 from the electrode assembly 12 side, The deformation plate 85 is protected.

  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.
According to the above embodiment, the following effects can be obtained.

  (1) The insulating cover 90 includes a positive electrode side gap 95a between the insulating part main body 91a and the positive electrode insulating part 92, and a negative electrode side gap 95b between the insulating part main body 91a 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 joining portions 51a and 52a, the positive electrode conductive member 51 is inserted into the positive electrode side gap 95a and the negative electrode conductive material is inserted into the negative electrode side gap 95b. The insulating member main body 91a can be interposed between the electrode joint portions 51a and 52a and the lid member 15 by inserting the member 52. Therefore, the heat at the time of joining the tab group 36 to the electrode joining portions 51a and 52a does not reach the insulating cover 90, the insulating cover 90 is not melted by the heat, and the insulating function by the insulating portion main body 91a is not lowered.

  (2) The insulating cover 90 includes a connecting portion 94 and locking claws 92a, 93a facing in the short direction, and the positive-side locking claw 92a is locked to the inner insulating member 40, and the negative-side locking claw 93a is locked to the electrode joint 52a. By this locking, it is possible to restrict the insulating cover 90 from moving in the short direction, the insulation between the electrode joining portions 51a and 52a and the lid member 15 by the first insulating portion 91 of the insulating cover 90, and the positive electrode insulating portion 92. Insulation between the positive electrode lead terminal 60 and the electrode assembly 12 due to the above, and insulation between the current interruption mechanism 80 and the electrode assembly 12 due to the negative electrode insulation portion 93 can be maintained.

  (3) The negative electrode terminal structure 17 includes a current interrupting mechanism 80, and the negative electrode conductive member 52 connected to the current interrupting mechanism 80 has a wide terminal connection portion 52b serving as a joint with the current interrupting mechanism 80, so that insulation is achieved. The size of the cover 90 is almost the entire length in the short direction. For this reason, the locking claw 93a of the negative electrode insulating portion 93 is locked to the electrode joint portion 52a that is narrower than the terminal connection portion 52b. Therefore, by selecting a part for locking the locking claw 93a, it is possible to prevent the lid member 15 and thus the case 11 from being enlarged.

  (4) The positive electrode terminal structure 16 does not include the current interruption mechanism 80, but the inner insulating member 40 is wider than the terminal connection portion 51 b of the positive electrode conductive member 51, and the terminal is provided along the short direction of the insulating cover 90. It protrudes from the connecting portion 51b. And it was set as the structure which latches the latching claw 92a to the inner side insulation member 40 wider than this terminal connection part 51b. For this reason, when mounting the insulating cover 90, the locking claw 92a is locked to the inner insulating member 40 prior to the terminal connecting portion 51b, and the mounting of the insulating cover 90 becomes smooth.

  (5) 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.

In addition, you may change the said embodiment as follows.
In the insulating cover 90, the housing recess 91f of the first insulating portion 91 may not be provided.
○ If the dimensions of the inner insulating member 40 on the positive electrode side and the terminal connecting portion 51b are the same along the short side direction of the insulating cover 90, the locking claw 92a on the positive electrode side is connected to the inner insulating member 40 and the terminal connecting portion 51b. You may latch to both and you may latch to the terminal connection part 51b.

  ○ If the dimension of the terminal connection part 51b is larger than the dimension of the inner insulating member 40 on the positive electrode side along the short side direction of the insulating cover 90, the positive electrode side locking claw 92a may be locked to the terminal connection part 51b. Good. In this case, the protruding portion 92e and the locking claw 92a may be provided at a position facing the insulating portion main body 91a in the facing direction Z.

○ 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 electrode terminal may not be connected to the external connection terminal 66 via the terminal connection member 44 like the positive electrode lead terminal 60 or the negative electrode lead terminal 61, and may be connected to the positive electrode conductive member 51 or the negative electrode conductive member 52. It may be directly connected.

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 power storage device can also be applied to a secondary battery that does not include the current interrupt mechanism 80. In this case, the second insulating portion covers the base portion of the bipolar electrode terminal from the electrode assembly 12 side.

The wall portion may be the side wall of the case member 14 instead of the lid member 15.
The electrode terminal may not be connected to the external connection terminal 66 via the terminal connection member 44 like the positive electrode lead terminal 60 or the negative electrode lead terminal 61, and may be connected to the positive electrode conductive member 51 or the negative electrode conductive member 52. It may be directly connected.

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 having different polarities are stacked while being insulated from each other and a tab having a shape protruding from the electrode are stacked, and a tab group of each polarity protruding from the tab side end surface of the electrode assembly A case housing the electrode assembly and the tab group, an external connection terminal disposed outside the wall portion of the case, the tab-side end surface, and the wall portion, and the tab group. A conductive member electrically connected to the conductive member, a lead terminal connected to the conductive member outside the tab group in the juxtaposition direction of the tab group, and protruding outward from the wall portion; and the wall portion A terminal connection member that is disposed outside and connects the lead-out terminal and the external connection terminal; insulates the external connection terminal and the wall portion outside the wall portion; and The lead terminal along the protruding direction of the lead terminal An electrical storage device comprising an outer insulating member penetrating and an insulating cover interposed between the pair of conductive members and the wall portion, wherein the outer insulating member has an engaging convex portion of the external connection terminal A state in which a locking part to be locked protrudes toward the wall part, and a protruding part having a locking recess to which the wall locking part protrudes toward the insulating cover. And the insulating cover includes a housing recess for housing 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 an electrical storage device, 11 ... Case, 12 ... Electrode assembly, 12b ... Tab side end surface, 15 ... Lid member as a wall part, 21 ... Positive electrode, 31 ... Negative electrode, 40 ... Inner insulating member 51 ... Positive electrode conductive member, 51a, 52a ... Electrode junction, 51b, 52b ... Terminal connection part, 52 ... Negative electrode conductive member, 60 ... Positive electrode lead terminal as electrode terminal, 60b, 63 ... Base part, 61 ... As electrode terminal Negative electrode lead terminal, 80 ... current interrupting mechanism, 90 ... insulating cover, 91 ... first insulating part, 92 ... positive electrode insulating part as second insulating part, 92a, 93a ... locking claw, 93 ... as second insulating part Negative electrode insulating part, 94 ... connecting part, 95a ... positive electrode side gap, 95b ... negative electrode side gap.

Claims (5)

An electrode assembly in which a plurality of electrodes of different polarities are insulated and stacked;
A case containing the electrode assembly;
A pair of electrode terminals provided with a base projecting from the wall of the case toward the electrode assembly, and fixed to the wall;
An electrode joint portion joined to the electrode of the same polarity, and a terminal connection portion electrically connected to a base portion of the electrode terminal, and an end surface of the electrode assembly facing the wall portion of the case and the wall portion A pair of conductive members disposed between,
An insulating member interposed between the wall portion and the terminal connection portion;
An insulating cover having a first insulating portion interposed between the pair of electrode joining portions and the wall portion and having a second insulating portion interposed between the base portion and an end surface of the electrode assembly; Prepared,
In the insulating cover, when the direction along the juxtaposed direction of the pair of conductive members is the longitudinal direction, and the direction orthogonal to the longitudinal direction is the short direction,
The insulating cover is provided with a connecting portion that separates the first insulating portion and the second insulating portion in a side view along the longitudinal direction and is connected to face each other at one end portion in the short-side direction,
A power storage device comprising a gap between the first insulating portion and the second insulating portion that are opposed to each other in the side view, and that opens to the other end portion in the lateral direction and reaches the connecting portion.   The insulating cover protrudes from the second insulating portion toward the first insulating portion in the side view at a position opposite to the connecting portion at the other end portion in the short direction, and the conductive member or The power storage device according to claim 1, further comprising a locking claw that locks the insulating member.   When the internal pressure of the case reaches a set pressure, the case includes a current interrupting mechanism that interrupts an electrical conduction path between the electrode terminal of one polarity and the electrode assembly, and the current interrupting mechanism includes the base and the terminal. The power storage device according to claim 2, wherein the connection portion is electrically connected, and the locking claw is locked to the electrode joint portion of the conductive member on the one polarity side.   The power storage device according to claim 3, wherein the locking claw is locked to the insulating member on the other polarity side not provided with the current interruption mechanism.   The power storage device according to any one of claims 1 to 4, wherein the power storage device is a secondary battery.

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