JP2018006120A - Power storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage device that is able to insulate a tab group and a case easily.SOLUTION: A secondary battery 10 comprises a first insulation cover 81. The first insulation cover 81 has: a first wall insulation part 82 insulating an electrode joint part 51a of a cathode electrode member 51 and a lid member 15; a first tab insulation part 83 insulating one-end side of a tab group 36 of each electrode in a stacking direction and a case member 14; and a first locking pawl 85a that locks in a holder 40. The secondary battery 10 comprises a second insulation cover 91. The secondary insulation cover 91 has: a second wall insulation part 92 insulating an electrode joint part 52a of an anode conductive member 52 and the lid member 15; a second tab insulation part 93 insulating the other end of the tab group 36 of each the electrode and the case member 14 in the stacking direction; and a second locking pawl 96a that locks in the terminal connection part 52b of an anode conductive member 52.SELECTED DRAWING: Figure 1

Description

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

  A vehicle such as an EV (Electric Vehicle) or a PHV (Plug in Hybrid) is equipped with a secondary battery as a power storage device that stores power supplied to a traveling motor. In general, a secondary battery includes a case that accommodates an electrode assembly, and the electrode assembly is accommodated in the case. And extraction of the electric power from a secondary battery is performed through the electrode terminal connected via the electroconductive member to the positive electrode and negative electrode of an electrode assembly.

As the electrode assembly, for example, there is a stacked electrode assembly in which a separator is interposed between a plurality of positive electrodes and a plurality of negative electrodes.
In general, a case made of a metal such as aluminum having excellent durability is often used for a case of a secondary battery. An insulating film is disposed between the electrode assembly and the case in order to insulate the metal case from the electrode assembly.

  In the power storage device disclosed in Patent Document 1, the positive electrode current collector member (conductive member) and the negative electrode current collector member (conductive member) have a positive electrode so that the connection surface of the current collector group (tab group) faces the electrode assembly. A current collecting member and a negative electrode current collecting member are disposed. In the case, an insulating cover having a U-shaped cross section is disposed between the positive electrode current collecting member and the negative electrode current collecting member and the terminal wall (lid member) of the case, and the facing surface and the lid member are separated from each other. ing.

Republished WO2013 / 157433

  By the way, in one method of manufacturing a secondary battery, there is a lid terminal assembly in which an electrode terminal is fixed to a lid member and a conductive member is joined to the electrode terminal, and the lid member, the electrode terminal and the conductive member are unitized. There is a method of assembling in advance. In this method, after joining the conductive member of the lid terminal assembly and the tab group of the electrode assembly, the electrode assembly is inserted into the case member, and the lid member is fixed to the case member.

  In this method, after the electrode terminal is joined to the conductive member, the insulating cover having a U-shaped cross section as disclosed in Patent Document 1 cannot be attached, and the outermost layer of the tab group and the case are insulated. In addition, the insulating film must be disposed not only in the active material layer of the electrode assembly but also in the position of the tab group. Therefore, in a secondary battery manufactured using a lid terminal assembly, in order to insulate the outermost layer of the tab group from the case, an insulating cover having a U-shaped cross section is attached before the electrode terminal is joined to the conductive member. Therefore, the assembly process is required to be reduced.

  An object of the present invention is to provide a power storage device that can easily insulate a tab group from a case.

  A power storage device for solving the above problems includes an electrode assembly in which sheet-like positive and negative electrodes are alternately stacked and a tab having a shape protruding from a part of one side of the electrode. A tab group laminated with the same polarity, a case member containing the electrode assembly and the tab group, a case having a lid member closing the opening of the case member, and fixed to the lid member, A pair of conductive members disposed between a pair of electrode terminals having a base projecting from the lid member toward the electrode assembly, the lid member, and an end surface of the electrode assembly facing the lid member A first wall insulation that insulates one of the conductive members and the lid member when the lamination direction is a direction in which the electrodes are laminated, and a holder that insulates the lid member and the base of the electrode terminal. Direction of the tab group of each part and both poles A first tab insulating portion that insulates the one end side and the case member; a first insulating cover having a first locking claw that engages the one conductive member or the holder; the other conductive member and the lid; A second wall insulating portion that insulates the member, a second tab insulating portion that insulates the case member from the other end side in the stacking direction of the tab group of both poles, and a second engaging portion with the other conductive member or the holder. And a second insulating cover having two locking claws.

  According to this, in one method of manufacturing the power storage device, the electrode terminal is fixed to the lid member, the conductive member is joined to the electrode terminal, the lid terminal assembly is manufactured in advance, and then the tab group is formed on the conductive member. There is a method of housing the electrode assembly in a case member after joining and integrating the lid terminal assembly and the electrode assembly.

  In this method, after the lid terminal assembly is manufactured, the first wall insulating portion of the first insulating cover is inserted between the lid member and one of the conductive members from one end side in the stacking direction, and the second insulating member is assembled. The second wall insulating portion of the cover is inserted between the lid member and the other conductive member from the other end side in the stacking direction. Then, a pair of insulating covers are assembled to the lid terminal assembly. And it can suppress that both insulation covers move in the direction which leaves | separates mutually along the lamination direction in an electrode assembly by the latching of the latching claw with respect to a conductive member or a holder.

  In the power storage device, the lid member and one conductive member are insulated by the first wall insulating portion, and the lid member and the other conductive member are insulated by the second wall insulating portion. Further, the outermost layer on one end side in the stacking direction of the tab groups of both poles is insulated from the case member by the first tab insulating portion, and the outermost layer on the other end side in the stacking direction of the tab groups of both poles is connected to the case member by the second tab insulating portion. Insulated. Therefore, even in a power storage device manufactured by attaching an insulating cover after the lid terminal assembly is assembled, the outermost layer of the tab group can be insulated from the case member without increasing the number of steps for the insulation. Can be insulated.

  In the power storage device, when the direction in which the pair of conductive members are arranged is a parallel direction, and the opposing surface of the conductive member facing the parallel direction is the front end surface of each conductive member, the first insulating cover is The second insulating cover may include an abutting surface that abuts against the distal end surface of one of the conductive members, and the second insulating cover includes an abutting surface that abuts against the distal end surface of the other conductive member.

  According to this, the conductive member is fixed to the lid member and cannot be moved. By bringing the contact surface of each insulating cover into contact with the tip surface of the conductive member, the movement of the insulating covers in the juxtaposed direction can be suppressed. The movement of each insulating cover in the stacking direction can be suppressed by the locking of the locking claw. Therefore, the movement of each insulating cover in both the stacking direction and the juxtaposed direction can be suppressed by the contact between the front end surface of the conductive member and the contact surface of the insulating cover and the locking claw.

  In the power storage device, the first insulating cover includes a first terminal insulating portion that insulates the base joined to one conductive member from the electrode assembly, and the second insulating cover includes the other insulating cover. You may provide the 2nd terminal insulation part which insulates the said base part joined with the electrically-conductive member from the said electrode assembly.

  According to this, by attaching the first insulating cover to the electrode assembly, it is possible to insulate not only one conductive member and the tab group of both electrodes but also one electrode terminal from the electrode assembly. Further, by attaching the second insulating cover to the electrode assembly, not only the other conductive member and the tab group of both electrodes but also the other electrode terminal can be insulated from the electrode assembly.

  The power storage device is a secondary battery.

  According to the present invention, the tab group and the case can be easily insulated.

The disassembled perspective view which shows the secondary battery of embodiment. The perspective view which shows the secondary battery of embodiment. The perspective view which shows the state which assembled | attached the 1st insulating cover and the 2nd insulating cover. The perspective view which shows a cover terminal assembly. The top view which shows a cover terminal assembly. The perspective view which mounts the 1st insulating cover and the 2nd insulating cover to a lid terminal assembly. FIG. 7 is a sectional view taken along line 7-7 in FIG. The top view which shows another example.

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. 2, 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 rectangular box-shaped case member 14 and a rectangular flat plate-shaped lid member 15 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 direction in which the positive electrode 21 and the negative electrode 31 are stacked is defined as the stacking direction of the electrode assembly 12.

  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 includes a tab side end surface 12b as an end surface. The tab side end face 12 b is formed by gathering together one side 21 a of the positive electrode 21, one side 31 a 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 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.

  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. A direction in which the positive electrode conductive member 51 and the negative electrode conductive member 52 are arranged side by side along the tab-side end surface 12b is referred to as a side-by-side direction X.

  The positive electrode conductive member 51 includes a plate-like 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.

  The negative electrode conductive member 52 includes a plate-like 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.

  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 insertion holes 15e at both ends in the longitudinal direction. Each insertion hole 15e penetrates the lid member 15 in the thickness 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 near one end in the longitudinal direction. The anti-rotation portion 58 has a shape recessed in a quadrangular shape from the front surface 57c toward the back surface 57a. 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, movement of the external connection terminal 66 in the direction along the surface 57c of the outer insulating member 57 is suppressed, and in particular, rotation on the surface 57c of the outer insulating member 57 is suppressed.

  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 protrudes from the base portion 60b, a connecting shaft portion 60a that is electrically connected to a terminal connecting member 44 described later, a base portion 60b that is electrically connected to the terminal connecting portion 51b of the positive electrode conductive member 51, and the base portion 60b. And a crimped portion (not shown) continuously provided in the axial direction. 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 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 the connecting shaft portion 60a includes the insertion hole 40a of the holder 40, the insertion hole 15e of the lid member 15, It penetrates the insertion hole 57 d of the outer insulating member 57 and the insertion hole 47 a of the terminal connection member 44. The caulking portion penetrates the positive electrode conductive member 51 and protrudes toward the electrode assembly 12. The crimped portion is crimped and is in contact with the terminal connecting portion 51b.

  The positive electrode terminal structure 16 has 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 base portion 60 b. The positive electrode terminal structure 16 has the above-described holder 40 through which the connecting shaft portion 60a is inserted. The dimension of the holder 40 along the short direction of the lid member 15 is larger than the dimension of the positive electrode conductive member 51 along the short direction. For this reason, the holder 40 protrudes from the positive electrode conductive member 51 along the short direction of the lid member 15.

  Inside the holder 40, an O-ring 73 supported by the terminal connecting portion 51b is disposed. The connecting shaft portion 60a penetrating the insertion hole 47a of the terminal connecting member 44 and the caulking portion penetrating the terminal connecting portion 51b are caulked in the axial direction, whereby the connecting shaft portion 60a and the caulking portion cause the positive electrode conductive member 51, the holder 40, the lid member 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.

  As shown in FIG. 2, the tip end portion of the connecting shaft portion 60a of the positive electrode lead terminal 60 is locked to the surface of the fixed piece 47 of the terminal connection member 44, and the positive electrode lead terminal 60 and the terminal are locked by this lock. The connection member 44 is electrically 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.

  As shown in FIG. 1, in the negative electrode terminal structure 17, the negative electrode lead terminal 61 is electrically connected to the connecting shaft portion 62 electrically connected to the negative terminal connecting member 44 and the terminal connecting portion 52 b of the negative electrode conductive member 52. And a base 63 that is connected in a continuous manner in the axial direction. The connecting shaft portion 62 of the negative electrode lead terminal 61 is inserted through the insertion hole 40 a of the holder 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.

  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 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 has a cylindrical holder 40 through which the connecting shaft portion 62 is inserted. An O-ring 73 supported by the base 63 is arranged inside the holder 40. The holder 40 is interposed between the lid member 15 and the base portion 63 of the negative electrode lead terminal 61, restricts the contact between the lid member 15 and the base portion 63, and insulates the lid member 15 from the negative electrode lead terminal 61. To do. The negative electrode holder 40 covers the outer peripheral surface of the base 63 and insulates the negative electrode lead terminal 61 from the case 11.

  As shown in FIG. 2, in the negative electrode terminal structure 17, the distal end portion of the connecting shaft portion 62 that penetrates the insertion hole 47 a of the terminal connecting member 44 is crimped in the axial direction, so that the connecting shaft portion 62 and the base portion 63 The holder 40, the lid 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.

Next, the insulating cover in the case 11 will be described.
As shown in FIG. 7, the secondary battery 10 includes a first insulating cover 81 attached from one end side of the electrode assembly 12 in the stacking direction and a second cover attached from the other end side of the electrode assembly 12 in the stacking direction. And an insulating cover 91. In each insulating cover 81, 91, the direction along the juxtaposed direction X 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 each insulating cover 81, 91 and perpendicular to the longitudinal direction is The short direction.

  As shown in FIG. 1 or FIG. 5, the first insulating cover 81 includes a first wall insulating portion 82. The first wall insulating portion 82 of the first insulating cover 81 is interposed between the electrode joint portion 51a of the positive electrode conductive member 51 serving as one conductive member and the lid member 15, and insulates both. When viewed from the outer surface 15 c of the lid member 15, the first wall insulating portion 82 has a shape that covers almost the entire surface of the electrode bonding portion 51 a. The first insulating cover 81 includes a first tab insulating portion 83 having a shape protruding from one long edge portion of the first wall insulating portion 82 toward the electrode assembly 12. The first tab insulating portion 83 has an elongated plate shape. The first tab insulating portion 83 of the first insulating cover 81 has a dimension that can cover the tab group 36 of both poles from the outside in the stacking direction.

  The first tab insulating portion 83 of the first insulating cover 81 is disposed on one end side in the stacking direction of the electrode assembly 12 and covers one end side in the stacking direction of the tab group 36 of both electrodes from the outside. The first tab insulating portion 83 is located between the outermost tabs 25 and 35 located on one end side in the laminating direction of the tab group 36 of both poles in the laminating direction and a portion facing the one end of the tab group 36 in the case member 14. And insulates the tab group 36 and the case member 14 of both poles.

  The first insulating cover 81 includes an integral connecting portion 84 at one end in the short direction. The first insulating cover 81 includes a first terminal insulating portion 85 integrated with the connecting portion 84. The connecting portion 84 separates the first wall insulating portion 82 and the first terminal insulating portion 85 in the facing direction Z in a side view along the longitudinal direction.

  Therefore, the first wall insulating portion 82 and the first terminal insulating portion 85 are separated in the facing direction Z in a side view along the longitudinal direction. The first terminal insulating portion 85 has a quadrangular shape when viewed from the outer surface 15 c of the lid member 15. The planar view size of the first terminal insulating portion 85 is larger than the planar view size of the caulking portion of the positive electrode lead terminal 60, and the entire caulking portion can be covered from the electrode assembly 12 side.

  The 1st terminal insulating part 85 is provided with the protrusion part 85c in the site | part along 3 sides. In the side view along the longitudinal direction, the first wall insulating portion 82 and the protrusion 85c are in a position facing the facing direction Z. Therefore, the first insulating cover 81 includes a first gap 85d between the first wall insulating portion 82 and the first terminal insulating portion 85 that are opposed in a side view.

  The dimension of the first gap 85d along the facing direction Z is larger than the thickness of the positive electrode conductive member 51, and the positive electrode conductive member 51 is inserted into the first gap 85d. The first insulating cover 81 includes a first locking claw 85 a that protrudes from the protruding portion 85 c of the first terminal insulating portion 85. The 1st latching claw 85a of the 1st terminal insulation part 85 protrudes from the protrusion part 85c toward the 1st wall insulation part 82 from the 1st terminal insulation part 85 by the side view. The dimension between the connecting portion 84 along the short direction of the first insulating cover 81 and the opposing surface of the first locking claw 85a is longer than the dimension of the holder 40 along the short direction. In the state where the terminal connection portion 51b enters the first gap 85d, the connecting portion 84 abuts on one edge portion of the edge portions of the holder 40, and the first engaging claw on the other edge portion. 85a is locked.

  As shown in FIG. 4, the first insulating cover 81 includes a first restricting portion 87 that protrudes from the inner surface of the first tab insulating portion 83 in the short direction. The first restricting portion 87 has a rectangular shape when viewed from the outer surface of the lid member 15. Of the first restricting portion 87, the contact surface 87 a extending in the short direction of the first insulating cover 81 is in contact with the front end surface 51 c of the positive electrode conductive member 51. The front end surface 51 c of the positive electrode conductive member 51 is an end surface of the electrode joint portion 51 a facing the electrode joint portion 52 a of the negative electrode conductive member 52 in the parallel direction X, and is straight in the stacking direction of the electrode assembly 12. It is a surface extending in a shape.

  As shown in FIG. 1, FIG. 3 or FIG. 5, the second insulating cover 91 includes a second wall insulating portion 92. The second wall insulating portion 92 of the second insulating cover 91 is interposed between the electrode joint portion 52a and the lid member 15 and insulates both. When viewed from the outer surface 15 c of the lid member 15, the second wall insulating portion 92 has a shape that covers almost the entire surface of the electrode bonding portion 52 a. The second insulating cover 91 includes a second tab insulating portion 93 having a shape protruding from one long edge portion of the second wall insulating portion 92 toward the electrode assembly 12. The second tab insulating portion 93 has an elongated plate shape. The second tab insulating portion 93 of the second insulating cover 91 has a dimension that can cover the tab group 36 of both poles.

  The second tab insulating portion 93 of the second insulating cover 91 is disposed on the other end side in the stacking direction of the electrode assembly 12 and covers the tab group 36 of both poles from the other end side in the stacking direction. The second tab insulating portion 93 includes, in the stacking direction, tabs 25 and 35 of the outer layer located on the other end side in the stacking direction of the tab group 36 of both poles, and a portion facing the other end of the tab group 36 in the case member 14. Between the two tabs 36 and the case member 14.

  The second insulating cover 91 includes a connecting portion 94 that is integral with one end in the longitudinal direction and one end in the short direction of the second wall insulating portion 92. The second insulating cover 91 includes a second terminal insulating portion 96 that is integral with the connecting portion 94.

  The second terminal insulating portion 96 has a quadrangular shape when viewed from the outer surface 15 c of the lid member 15. The planar view size of the second terminal insulating part 96 is substantially the same as the planar view size of the base 63 of the negative electrode lead terminal 61 and the current interrupting mechanism 80, and the current interrupting mechanism 80 can be covered from the electrode assembly 12 side. The second terminal insulating portion 96 includes a ridge portion 96c along three sides.

  The second insulating cover 91 includes a second gap 96e between the second wall insulating portion 92 and the protruding portion 96c in the facing direction Z. The dimension of the second gap 96e along the facing direction Z is larger than the thickness of the negative electrode conductive member 52, and the negative electrode joint portion 52a is inserted into the second gap 96e.

  In the second terminal insulating portion 96, the connecting portion 94 is located at one end of the protruding portion 96c, and the second locking claw 96a is located at the other end, of both ends along the short direction of the second insulating cover 91. Exists. The second locking claw 96a of the second terminal insulating portion 96 protrudes from the protruding portion 96c from the second terminal insulating portion 96 toward the second wall insulating portion 92 in a side view. The dimension between the opposing surface of the connection part 94 and the 2nd latching claw 96a along the transversal direction of the 2nd insulating cover 91 is slightly longer than the dimension along the transversal direction of the terminal connection part 52b. In the state where the electrode joint portion 52a enters the second gap 96e, the connecting portion 94 comes into contact with one of the edge portions of the terminal connection portion 52b facing in the short direction of the second insulating cover 91, and A second locking claw 96a is locked to the other edge.

  The second insulating cover 91 includes a second restricting portion 97 that protrudes from the inner surface of the second tab insulating portion 93 in the short direction. The second restricting portion 97 has a rectangular shape when viewed from the outer surface of the lid member 15. Of the second restricting portion 97, the contact surface 97 a extending in the short direction of the second insulating cover 91 contacts the tip surface 52 c of the negative electrode conductive member 52. The leading end surface 52 c of the negative electrode conductive member 52 is an end surface of the electrode joint portion 52 a facing the electrode joint portion 51 a of the positive electrode conductive member 51 in the parallel direction X, and is straight in the stacking direction of the electrode assembly 12. It is a surface extending in a shape.

Next, the manufacturing method of the secondary battery 10 will be described together with the operation.
It is assumed that the negative electrode lead terminal 61, the current interruption mechanism 80, and the negative electrode conductive member 52 are integrated in advance.

  First, as shown in FIG. 1, the outer insulating member 57 is disposed on the outer surface 15 c 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, the O-ring 73 and the holder 40 are disposed on the inner surface 15d side of the lid member 15 on the positive electrode side. The connecting shaft portion 62 of the positive lead terminal 60 is inserted into the insertion hole 40 a of the holder 40, the O-ring 73, 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. Insert into. The positive electrode conductive member 51, the holder 40, the O-ring 73, and the lid member 15 are between the caulking portion and the end of the connecting shaft portion 60 a by caulking the positive electrode lead terminal 60 and the connecting shaft portion 60 a. The outer insulating member 57 and the terminal connecting member 44 are integrated.

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

  Then, as shown in FIG. 6, 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. There is a gap between the lid member 15 and the electrode joint portions 51a and 52a.

  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 tab group 36 is bent.

  Then, from one end side in the stacking direction, the first wall insulating portion 82 of the first insulating cover 81 is inserted between the lid member 15 and the electrode joint portion 51a, and the positive electrode conductive member 51 is inserted into the first gap 85d. Thus, the first insulating cover 81 is slid.

  On the positive electrode side, the first locking claw 85 a of the first terminal insulating portion 85 is locked to the edge of the holder 40. As a result, the first insulating cover 81 is integrally assembled with the positive electrode conductive member 51, and the electrode bonding portion 51 a is insulated from the lid member 15 by the first wall insulating portion 82. At the same time, one end side in the stacking direction of the tab group 36 of both poles is insulated from the side wall of the case 11 by the first tab insulating portion 83. Further, the first terminal insulating portion 85 is in a state in which the crimped portion of the positive electrode lead terminal 60 is insulated from the electrode assembly 12 side.

  In addition, the second wall insulating portion 92 of the second insulating cover 91 is inserted between the lid member 15 and the electrode joining portion 52a from the other end side in the stacking direction, and the negative electrode conductive member 52 is inserted into the second gap 96e. The second insulating cover 91 is slid so as to be inserted.

  Then, on the negative electrode side, the second locking claw 96a of the second terminal insulating portion 96 is locked to the edge of the terminal connecting portion 52b. As a result, the second insulating cover 91 is integrally assembled with the negative electrode conductive member 52, and the electrode joint portion 52 a is insulated from the lid member 15 by the second wall insulating portion 92. At the same time, the other end surface in the stacking direction of the tab group 36 of both poles is insulated from the side wall of the case 11 by the second tab insulating portion 93. Further, the second terminal insulating portion 96 is in a state where the current interrupt mechanism 80 is insulated from the electrode assembly 12 side.

  As a result, as shown in FIG. 7, the first insulating cover 81 and the second insulating cover 91 are assembled to the electrode assembly 12, and the electrode joint portions 51 a and 52 a are the first and second wall insulating portions 82. , 92 are insulated from the lid member 15. At the same time, one end side in the stacking direction of the tab group 36 of both poles is insulated from the side wall of the case 11 by the first tab insulating portion 83, and the other end side in the stacking direction of the tab group 36 of both poles is separated from the case 11 by the second tab insulating portion 93. It will be in the state insulated from the side wall.

  As shown in FIG. 5, the contact surface 87 a of the first restricting portion 87 of the first insulating cover 81 is in contact with the tip surface 51 c of the positive electrode conductive member 51. By this contact, the movement of the first insulating cover 81 in the juxtaposed direction X is suppressed. Further, the contact surface 97 a of the second restricting portion 97 of the second insulating cover 91 is in contact with the distal end surface 52 c of the negative electrode conductive member 52. By this contact, the movement of the second insulating cover 91 in the juxtaposed direction X is suppressed.

  Then, after the first insulating cover 81 and the second insulating cover 91 are attached to the lid terminal assembly 20, the electrode assembly 12 is inserted into the case member 14 from the opening 14 a of the case member 14. Thereafter, when the lid member 15 is joined to the opening end of the case member 14, the secondary battery 10 is assembled.

According to the above embodiment, the following effects can be obtained.
(1) Regarding the manufacture of the secondary battery 10, the lid terminal assembly 20 is manufactured in advance, and each tab group 36 is joined to each electrode joint portion 51 a, 52 a of the lid terminal assembly 20 to thereby form the electrode assembly 12. There is a method of manufacturing the secondary battery 10 by housing the electrode assembly 12 in the case member 14 in a state where the battery is integrated. In this manufacturing method, the first insulating cover 81 and the second insulating cover 91 are formed between the wall insulating portions 82 and 92 between the lid member 15 and the electrode joint portions 51a and 52a after the lid terminal assembly 20 is manufactured. Is inserted.

  Therefore, in the secondary battery 10, the one end side in the stacking direction of the tab group 36 of both electrodes of the electrode assembly 12 can be insulated from the case member 14 by the first tab insulating portion 83 of the first insulating cover 81. The other end side in the direction can be insulated from the case member 14 by the second tab insulating portion 93 of the second insulating cover 91. Therefore, even in the secondary battery 10 manufactured by mounting the insulating covers 81 and 91 on the lid terminal assembly 20, the tab groups 36 of both electrodes can be easily insulated from the case 11 from both ends in the stacking direction. . Therefore, it is possible to insulate the tab group 36 of both poles from the case member 14 only by attaching the insulating covers 81 and 91, and it is not necessary to increase the number of steps for the insulation.

  (2) The first insulating cover 81 includes a first locking claw 85 a that is locked to the holder 40, and the second insulating cover 91 is a second engagement that is locked to the terminal connection portion 52 b of the negative electrode conductive member 52. A pawl 96a is provided. The holder 40 and the negative electrode conductive member 52 are assembled to the lid terminal assembly 20 and are fixed to the lid member 15. When the locking claws 85a and 96a are locked to the fixed holder 40 and the negative electrode conductive member 52, the movement of the insulating covers 81 and 91 in the direction opposite to the insertion direction can be suppressed.

  (3) The first insulating cover 81 includes a contact surface 87 a that contacts the tip surface 51 c of the positive electrode conductive member 51, and the second insulating cover 91 contacts the tip surface 52 c of the negative electrode conductive member 52. A surface 97a is provided. The movement of the insulating covers 81 and 91 in the juxtaposed direction X can be suppressed by the contact between the contact surfaces 87a and 97a and the tip surfaces 51c and 52c. The movement of the insulating covers 81 and 91 in the stacking direction can be suppressed by the locking of the locking claws 85a and 96a. Therefore, the stacking direction and the juxtaposition are provided by the contact between the front end surfaces 51c and 52c of the conductive members 51 and 52 and the contact surfaces 87a and 97a of the insulating covers 81 and 91 and the locking claws 85a and 96a. The movement of the insulating covers 81 and 91 in both directions can be suppressed, and the insulating state can be maintained.

  (4) When the first insulating cover 81 is attached to the electrode assembly 12, the crimping portion of the positive electrode lead terminal 60 can be insulated from the electrode assembly 12 side by the first terminal insulating portion 85. When the second insulating cover 91 is attached to the electrode assembly 12, the current interrupt mechanism 80 including the negative electrode lead terminal 61 can be insulated from the electrode assembly 12 by the second terminal insulating portion 96. Therefore, by attaching the insulating covers 81 and 91, not only the conductive members 51 and 52 and the tab group 36 but also the lead terminals 60 and 61 can be insulated from the electrode assembly 12.

  (5) The wall insulating portions 82 and 92 of the insulating covers 81 and 91 are sized to insulate only the electrode joint portions 51 a and 52 a from the lid member 15. For example, the material costs of the insulating covers 81 and 91 can be reduced as compared with the case where the wall insulating portions 82 and 92 are sized to extend in the entire longitudinal direction of the insulating covers 81 and 91.

In addition, you may change the said embodiment as follows.
As shown in FIG. 8, the first locking claw 85 a of the first insulating cover 81 may be locked to the terminal connection portion 51 b of the positive electrode conductive member 51. Further, the second locking claw 96 a of the second insulating cover 91 may be locked to the holder 40.

O About the 1st insulating cover 81, you may provide the latching claw latched to the positive electrode conductive member 51 besides the 1st latching claw 85a latched to the holder 40. FIG.
O About the 2nd insulating cover 91, you may provide the latching claw latched to the holder 40 other than the 2nd latching claw 96a latched to the negative electrode electrically-conductive member 52. FIG.

The first terminal insulating portion 85 of the first insulating cover 81 may be omitted, and the second terminal insulating portion 96 of the second insulating cover 91 may be omitted.
The contact surface 87a of the first insulating cover 81 may not be provided, and the contact surface 97a of the second insulation cover 91 may not be provided.

  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 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) The electrode terminal is fixed to the lid member, the conductive member is joined to the base portion of the electrode terminal, the lid terminal assembly 20 is manufactured, and then the tab group is joined to the conductive member. A power storage device in which the first insulating cover and the second insulating cover are attached to the lid terminal assembly after the lid terminal assembly and the electrode assembly are integrated.

  DESCRIPTION OF SYMBOLS 10 ... Secondary battery as a power storage device, 11 ... Case, 12 ... Electrode assembly, 12b ... Tab side end face as end face, 14 ... Case member, 14a ... Opening part, 15 ... Lid member, 21 ... Positive electrode, 21a ... one side, 25, 35 ... tab, 31 ... negative electrode, 31a ... one side, 36 ... tab group, 40 ... holder, 51 ... positive electrode conductive member, 52 ... negative electrode conductive member, 51c, 52c ... tip surface, 60 ... electrode terminal As a positive electrode lead terminal, 60b, 63 ... base, 61 ... negative electrode lead terminal as an electrode terminal, 81 ... first insulating cover, 82 ... first wall insulating part, 83 ... first tab insulating part, 85 ... first Terminal insulating portion, 85a ... first locking claw, 87a, 97a ... contact surface, 91 ... second insulating cover, 92 ... second wall insulating portion, 93 ... second tab insulating portion, 96 ... second terminal insulation Part, 96a ... 2nd latching claw.

Claims (4)

An electrode assembly in which sheet-like positive and negative electrodes are alternately stacked in an insulated state;
A tab group in which tabs in a shape protruding from a part of one side of the electrode are laminated with the same polarity,
A case member containing the electrode assembly and the tab group, and a case having a lid member closing the opening of the case member;
A pair of electrode terminals having a base fixed to the lid member and projecting from the lid member toward the electrode assembly;
A pair of conductive members disposed between the lid member and an end face of the electrode assembly facing the lid member;
A holder for insulating the lid member and the base of the electrode terminal;
When the direction in which the electrodes are stacked is the stacking direction,
A first wall insulating portion that insulates one of the conductive members and the lid member, a first tab insulating portion that insulates the case member from one end side in the stacking direction of the tab group of both poles, and the one conductive member or A first insulating cover having a first locking claw for locking to the holder;
A second wall insulating portion that insulates the other conductive member from the lid member, a second tab insulating portion that insulates the case member from the other end side in the stacking direction of the tab group of both poles, and the other conductive member Or a 2nd insulation cover which has a 2nd latching claw latched to the said holder, An electrical storage apparatus provided with.   When the direction in which the pair of conductive members are arranged is a parallel direction, and the opposing surface of the conductive member facing the parallel direction is the front end surface of each conductive member, the first insulating cover is one of the conductive members. 2. The power storage device according to claim 1, further comprising: a contact surface that contacts the front end surface of the second conductive cover, wherein the second insulating cover includes a contact surface that contacts the front end surface of the other conductive member.   The first insulating cover includes a first terminal insulating portion that insulates the base joined to one conductive member from the electrode assembly, and the second insulating cover is joined to the other conductive member. The power storage device according to claim 1, further comprising a second terminal insulating portion that insulates the base from the electrode assembly.   The power storage device according to any one of claims 1 to 3, wherein the power storage device is a secondary battery.