JP2018010850A - Power storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage device in which a tab group can be easily insulated from a case.SOLUTION: A secondary battery comprises: a first insulation cover 81 arranged on one end side of a lamination direction in an electrode assembly 12; and a second insulation cover 91 arranged on the other end side of the lamination direction in the electrode assembly 12. The first insulation cover 81 and the second insulation cover 91 respectively comprise: wall insulation parts 82 and 92 which insulate between an electrode joint and a lid member 15 at respective poles; tab insulation parts 83 and 93 which insulate between a tab group 36 and a case member facing the tab group 36; and locking claws 86f and 95 for locking to the edge of the electrode joint.SELECTED DRAWING: Figure 7

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 insulated and a tab having a shape in which a part of one side of the electrode protrudes. 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 electrode terminals having a base projecting from the lid member toward the electrode assembly, and the tab group having the same polarity, joined to the lid member and the end surface of the electrode assembly facing the lid member The stacking direction in the electrode assembly when the stacking direction is a pair of conductive members disposed between, a holder that insulates the lid member and the base of the electrode terminal, and the stacking direction of the electrodes Placed on one end side of 1 insulating cover and a second insulating cover disposed on the other end side in the stacking direction of the electrode assembly, wherein the first insulating cover and the second insulating cover are a pair of the A wall insulating part that insulates the conductive member and the lid member; a tab insulating part that insulates the tab group and a portion of the case member facing the tab group in the stacking direction; and an edge of the conductive member And a locking claw that locks to the portion.

  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 wall insulating portion of the first insulating cover is inserted between the lid member and the pair of conductive members from one end side in the stacking direction, and the second insulating cover When the wall insulating part is inserted between the lid member and the pair of conductive members from the other end side in the stacking direction, the pair of insulating covers are assembled to the lid terminal assembly. And it can restrict | limit that both insulation covers move in the direction away from each other along the lamination direction in an electrode assembly by the latching of the latching claw with respect to a conductive member.

  In the power storage device, the lid member and the conductive member are insulated by the wall insulating portions of the both insulating covers, and both ends of the tab group in the stacking direction and the case member are insulated by the tab insulating portion. Therefore, even in a power storage device manufactured by attaching an insulating cover after assembling the lid terminal assembly, the tab group can be insulated from the case member, and can be insulated without increasing the steps for the insulation.

In the power storage device, at least one of the first insulating cover and the second insulating cover may include a holder locking claw that locks the holder.
According to this, for example, the current interrupting mechanism may be integrated with the terminal connection part of the conductive member on the negative electrode side. In this case, in order to insulate the base part including the current interruption mechanism and the lid member, the holder is manufactured with a dimension along the stacking direction larger than that of the conductive member. For this reason, when the insulating cover is mounted on the lid terminal assembly, the holder locking claw is locked to the holder, and the mounting of the insulating cover becomes smooth. And it can control that both insulation covers move in the direction which separates along the lamination direction by the latching claw with respect to a conductive member, and the holder latching claw with respect to a holder.

  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 electrode terminals having a base projecting from the lid member toward the electrode assembly, and the tab group having the same polarity, joined to the lid member and the end surface of the electrode assembly facing the lid member The stacking direction in the electrode assembly when the stacking direction is a pair of conductive members disposed between, a holder that insulates the lid member and the base of the electrode terminal, and the stacking direction of the electrodes Placed on one end side of A first insulating cover; and a second insulating cover disposed on the other end side in the stacking direction of the electrode assembly, wherein the first insulating cover and the second insulating cover are a pair of A wall insulating portion that insulates the conductive member and the lid member; a tab insulating portion that insulates the tab group and a portion of the case member facing the tab group in the stacking direction; and the holder. A gist is to provide a holder locking claw to be stopped.

  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 wall insulating portion of the first insulating cover is inserted between the lid member and the pair of conductive members from one end side in the stacking direction, and the second insulating cover When the wall insulating part is inserted between the lid member and the pair of conductive members from the other end side in the stacking direction, the pair of insulating covers are assembled to the lid terminal assembly. And it can restrict | limit 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 holder latching claw with respect to a holder.

  In the power storage device, the lid member and the conductive member are insulated by the wall insulating portions of the both insulating covers, and both ends of the tab group in the stacking direction and the case member are insulated by the tab insulating portion. Therefore, even in a power storage device manufactured by attaching an insulating cover after assembling the lid terminal assembly, the tab group can be insulated from the case member from both sides in the stacking direction 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 end surface of the conductive member facing the parallel direction is the front end surface, the first insulating cover and the second insulating cover Any one of the insulating covers includes a first contact surface that contacts the distal end surface of the conductive member, a second contact surface that is parallel to the first contact surface, and a second contact surface that is orthogonal to the second contact surface. And the other insulating cover may include a locking projection having two surfaces that contact the second contact surface and the third contact surface.

  According to this, the first contact surface of one insulating cover is in contact with the tip surface of the conductive member, and the second contact surface parallel to the first contact surface is on the engaging protrusion of the other insulating cover. Abut. By abutting on both abutting surfaces, it is possible to restrict one insulating cover from moving in the juxtaposed direction. Further, the third contact surface of the restricting portion comes into contact with the locking projection. Therefore, the locking projection is in contact with the second contact surface and the third contact surface that are orthogonal to each other in the restricting portion. Since the conductive member is fixed to the lid member, one insulating cover whose movement is restricted by the contact with the conductive member and the other insulating cover are brought into contact with each other, so that both the insulating covers are rotated. Can be regulated.

  Regarding the power storage device, in the insulating cover, if a direction along the juxtaposed direction of the pair of conductive members is a longitudinal direction, one of the first insulating cover and the second insulating cover is: A locking claw that includes terminal insulating portions interposed between each base portion and the electrode assembly at both ends in the longitudinal direction, and locks the edge of the conductive member on the inner side along the longitudinal direction from each terminal insulating portion. The other insulating cover may be on the inner side along the longitudinal direction than the locking claw included in the one insulating cover.

Thereby, the position of the latching claw of the 1st insulating cover and the latching claw of the 2nd insulating cover can be shifted in the longitudinal direction, and both the latching claws can be locked to the conductive member without overlapping. .
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 electrode terminals having a base projecting from the lid member toward the electrode assembly, and the tab group having the same polarity, joined to the lid member and the end surface of the electrode assembly facing the lid member A pair of conductive members disposed between the first insulating cover disposed on one end side of the electrode assembly in the stacking direction when the stacking direction of the electrodes is a stacking direction; The stacking direction in a solid A second insulating cover disposed on the other end side, wherein the first insulating cover and the second insulating cover include a wall insulating portion that insulates the pair of the conductive member and the lid member, A tab insulating portion that insulates the tab group and a portion of the case member facing the tab group in the stacking direction, and one of the first insulating cover and the second insulating cover. The insulating cover is provided on a surface intersecting the inner surface of the wall insulating portion and includes a locking surface that intersects the stacking direction, and the other insulating cover has a locking claw that locks the locking surface. The gist is to provide.

  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 wall insulating portion of the first insulating cover is inserted between the lid member and the pair of conductive members from one end side in the stacking direction, and the second insulating cover When the wall insulating part is inserted between the lid member and the pair of conductive members from the other end side in the stacking direction, the pair of insulating covers are assembled to the lid terminal assembly. Then, by the locking of the locking claw and the locking surface, it is possible to restrict the movement of both insulating covers in the direction away from each other along the stacking direction of the electrode assembly.

  In the power storage device, the lid member and the conductive member are insulated by the wall insulating portions of the both insulating covers, and both ends of the tab group in the stacking direction and the case member are insulated by the tab insulating portion. Therefore, even in a power storage device manufactured by attaching an insulating cover after assembling the lid terminal assembly, the tab group can be insulated from the case member from both sides in the stacking direction without increasing the number of steps for the insulation. Can be insulated.

  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 1st Embodiment. The perspective view which shows the secondary battery of 1st Embodiment. The perspective view which shows the state which assembled | attached the 1st insulating cover and the 2nd insulating cover. (A) is the sectional view on the 4a-4a line of FIG. 2, (b) is the sectional view on the 4b-4b line of FIG. The perspective view which shows a cover terminal assembly. The figure 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. 8 is a cross-sectional view taken along line 8-8 in FIG. 2. The perspective view which shows the state which assembled | attached the 1st insulating cover and 2nd insulating cover of 2nd Embodiment. The disassembled perspective view which shows a 1st insulating cover and a 2nd insulating cover. The fragmentary sectional view which shows the state which assembled | attached the 1st insulating cover and the 2nd insulating cover. (A) is a fragmentary sectional view which shows before attaching a 1st insulating cover and a 2nd insulating cover, (b) is a fragmentary sectional view which shows the state which the protrusion part for latching elastically deforms by a guide surface. The top view which shows another example. The top view which shows another example.

(First embodiment)
Hereinafter, a first 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, 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 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. 8, the secondary battery 10 includes a first insulating cover 81 mounted from one end side in the stacking direction and a first mounting cover mounted from the other end side in the stacking direction with respect to both electrode joints 51a and 52a. Two insulating covers 91. Here, 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, is along the outer surface of each insulating cover 81, 91 and is orthogonal to the longitudinal direction. The direction to do is the short direction.

  The first insulating cover 81 includes a wall insulating portion 82. The wall insulating portion 82 of the first insulating cover 81 is interposed between the electrode joint portions 51a and 52a and the lid member 15 and insulates both. The first insulating cover 81 includes a tab insulating portion 83 having a shape protruding from one long edge portion of the wall insulating portion 82 toward the electrode assembly 12.

  The first insulating cover 81 is disposed on one end side in the stacking direction of the electrode assembly 12. The wall insulating portion 82 of the first insulating cover 81 is supported on one end side in the stacking direction of the electrode joint portions 51a and 52a. The wall insulating part 82 insulates the half of the short sides of the electrode bonding parts 51 a and 52 a and the lid member 15. The tab insulating portion 83 of the first insulating cover 81 covers one end side of the tab group 36 in the stacking direction from the outside. The tab insulating portion 83 is interposed between one end of the tab group 36 in the stacking direction and a portion of the case member 14 facing the one end in the stacking direction, and insulates the tab group 36 and the case member 14.

  As shown in FIG. 1 or FIG. 3, the first insulating cover 81 includes a connecting portion 84 that is integral with both end portions in the longitudinal direction of the wall insulating portion 82 and at one end portion in the short-side direction. A positive electrode insulating part 85 as a terminal insulating part is connected to the connecting part 84 at one end in the longitudinal direction, and a negative electrode insulating part 86 as a terminal insulating part is connected to the connecting part 84 at the other end in the longitudinal direction. In the first insulating cover 81, the connecting portion 84 separates the wall insulating portion 82, the positive electrode insulating portion 85, and the negative electrode insulating portion 86 in the facing direction Z in a side view along the longitudinal direction.

  Therefore, in the side view along the longitudinal direction, the wall insulating part 82 and the positive electrode insulating part 85 are separated from each other in the facing direction Z, and the wall insulating part 82 and the negative electrode insulating part 86 are separated from each other in the facing direction Z. The wall insulating portion 82 includes an inner surface 82a on a surface facing the electrode bonding portions 51a and 52a.

  The positive electrode 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 positive electrode 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 positive electrode insulating portion 85 includes a ridge portion 85c at a portion along three sides.

  In the side view along the longitudinal direction, the wall insulating portion 82 and the protruding portion 85c are in a position facing the facing direction Z. Therefore, the first insulating cover 81 includes a positive electrode-side gap 85d between the wall insulating part 82 and the positive electrode insulating part 85 that are opposed in a side view.

  As shown in FIG. 4B, the positive electrode side gap 85 d opens at the other end of the first insulating cover 81 in the short direction. The dimension of the positive electrode side gap 85d along the facing direction Z is larger than the thickness of the terminal connection part 51b of the positive electrode conductive member 51, and the positive terminal connection part 51b is inserted into the positive electrode side gap 85d. The wall insulating portion 82 of the first insulating cover 81 is supported by the terminal connecting portion 51b, and the wall insulating portion 82 is sandwiched between the terminal connecting portion 51b and the lid member 15.

  The first insulating cover 81 includes a holder locking claw 85 f that protrudes from the protruding portion 85 c of the positive electrode insulating portion 85. The holder locking claw 85f of the positive electrode insulating portion 85 protrudes from the protruding portion 85c from the positive electrode insulating portion 85 toward the wall insulating portion 82 in a side view. The dimension between the coupling part 84 along the short direction of the first insulating cover 81 and the opposing surface of the holder locking claw 85f is longer than the dimension of the terminal connection part 51b along the short direction. And in the state which the terminal connection part 51b entered in 85 d of positive electrode side gaps, while the connection part 84 contact | abuts to one edge part among a pair of edge parts along the transversal direction of the holder 40, the other edge part The holder latching claw 85f is latched.

  As shown in FIG. 1, the negative electrode insulating portion 86 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 86 is substantially the same as the size in plan view of the base 63 of the negative electrode lead terminal 61 and the current interrupt mechanism 80, and the entire current interrupt mechanism 80 can be covered from the electrode assembly 12 side. The negative electrode insulating portion 86 includes a ridge portion 86c along three sides.

  The first insulating cover 81 includes a negative electrode side gap 86e between the wall insulating part 82 and the negative electrode insulating part 86 facing each other in a side view. The first insulating cover 81 includes a negative electrode side gap 86e between the wall insulating portion 82 and the protrusion 86c in the facing direction Z. The negative electrode side gap 86e is formed in the short direction of the first insulating cover 81. Open to the other end. The dimension of the negative electrode side gap 86e 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 86e.

As shown in FIG. 4A, the wall insulating portion 82 is supported by the electrode bonding portion 52a, and the wall insulating portion 82 is sandwiched between the electrode bonding portion 52a and the lid member 15 along the facing direction Z. Yes.
In the negative electrode insulating portion 86, the connecting portion 84 is located at one end portion of the protruding portion 86 c among the both end portions along the short direction of the first insulating cover 81, and the locking claw 86 f is present at the other end portion. The locking claw 86f of the negative electrode insulating portion 86 protrudes from the protrusion 86c from the negative electrode insulating portion 86 toward the wall insulating portion 82 in a side view. The dimension between the opposing surface of the connection part 84 and the latching claw 86f along the short direction of the 1st insulating cover 81 is slightly longer than the dimension along the short direction of the electrode junction part 52a. In a state where the electrode joint portion 52a enters the negative electrode side gap 86e, the connecting portion 84 abuts on one of the edges of the electrode joint portion 52a facing the short direction of the first insulating cover 81, and the other The locking claw 86f is locked to the edge of the.

  As shown in FIG. 3 or 5, the first insulating cover 81 includes a locking protrusion 87 that protrudes from the inner surface of the tab insulating part 83 in the short direction. The locking protrusion 87 has a rectangular shape when viewed from the outer surface of the lid member 15.

  As shown in FIG. 7 or FIG. 8, the second insulating cover 91 includes a wall insulating portion 92 that is interposed between the electrode joint portions 51a and 52a and the lid member 15 and insulates them. The second insulating cover 91 includes a tab insulating portion 93 having a shape protruding from one long edge portion of the wall insulating portion 92 toward the electrode assembly 12.

  The second insulating cover 91 is disposed on the other end side of the electrode assembly 12 in the stacking direction. The wall insulating portion 92 of the second insulating cover 91 is supported on the other end side in the stacking direction of the electrode joint portions 51a and 52a. The wall insulating portion 92 insulates the cover member 15 from the half of the electrode joint portions 51a, 52a in the short direction. Therefore, almost the entire surface of the electrode bonding portions 51 a and 52 a is covered with the wall insulating portions 82 and 92.

The tab insulating portion 93 of the second insulating cover 91 covers the other end side in the stacking direction of the tab group 36 from the outside, and insulates the other end of the tab group 36 from the case 11 facing the other end in the stacking direction. .
As shown in FIG. 3 or FIG. 7, the second insulating cover 91 includes projecting pieces 94 that project in the lateral direction from both longitudinal ends of the tab insulating portion 93. The second insulating cover 91 includes a locking claw 95 at the protruding end of each protruding piece 94. The locking claw 95 of the second insulating cover 91 protrudes from the protruding piece 94 toward the wall insulating portion 92 in a side view. The dimension between the opposing surfaces of the tab insulating portion 93 and the locking claw 95 along the short direction of the second insulating cover 91 is slightly longer than the dimension along the short direction of the electrode joint portions 51a and 52a.

  As shown in FIG. 6, in a state where the second insulating cover 91 is supported on the other end side in the stacking direction of the electrode joint portions 51a and 52a, the locking claw 95 is engaged with one edge portion of the electrode joint portions 51a and 52a. It has stopped.

  The second insulating cover 91 includes a restricting portion 97 that protrudes from the inner surface of the tab insulating portion 93 in the short direction. The restricting portion 97 has a first contact surface 97 a that extends linearly in the short direction of the second insulating cover 91 when viewed from the outer surface of the lid member 15. The first contact surface 97 a 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.

  The restricting portion 97 includes a second contact surface 97b parallel to the first contact surface 97a and a third contact surface 97c that is continuous with and orthogonal to the second contact surface 97b. Therefore, when viewed from the outer surface of the lid member 15, the second contact surface 97b and the third contact surface 97c of the restricting portion 97 are connected in an L shape.

  Of the side surfaces of the locking projection 87 of the first insulating cover 81, the third contact surface 97c of the restricting portion 97 is in contact with the side surface facing in the short direction. In addition, the second contact surface 97 b is in contact with the side surface of the locking projection 87 near the negative electrode conductive member 52. Therefore, the restricting portion 97 is in contact with the locking protrusion 87 on two sides.

  In the restricting portion 97, the tip end surface 52c of the negative electrode conductive member 52 is in contact with the first contact surface 97a, and the locking protrusion 87 is in contact with the second contact surface 97b. Further, the locking projection 87 is also in contact with the third contact surface 97 c of the restricting portion 97. These abutments restrict the rotation of the first insulating cover 81 and the second insulating cover 91.

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, 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, as shown in FIG. 7, 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 wall insulating portion 82 of the first insulating cover 81 is inserted between the lid member 15 and the electrode bonding portions 51a and 52a, and the electrode bonding of the positive electrode conductive member 51 to the positive electrode side gap 85d. The first insulating cover 81 is slid and moved so that the electrode joining portion 52a of the negative electrode conductive member 52 is inserted into the negative electrode side gap 86e.

  Then, on the positive electrode side, the holder locking claw 85 f of the positive electrode insulating portion 85 is locked to the edge portion of the holder 40. In the negative electrode insulating portion 86, the locking claw 86f of the negative electrode insulating portion 86 is locked to the edge portion of the terminal connection portion 52b.

  As a result, the first insulating cover 81 is assembled integrally with 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 wall insulating portion 82. . At the same time, one end surface of the tab group 36 in the stacking direction is insulated from the side wall of the case 11 by the tab insulating portion 83.

  In addition, the positive electrode insulation portion 85 insulates the crimped portion of the positive electrode lead terminal 60 from the electrode assembly 12 side, and the negative electrode insulation portion 86 insulates the negative electrode lead terminal 61 including the current interruption mechanism 80 from the electrode assembly 12 side. Become.

  Next, the second insulating cover 91 is slid from the other end side in the stacking direction so that the wall insulating portion 92 of the second insulating cover 91 is inserted between the lid member 15 and the electrode joint portions 51a and 52a. .

  As shown in FIG. 6, the locking claw 95 is locked to the edge of the electrode joint portion 51 a of the positive electrode conductive member 51 on the positive electrode side. Also on the negative electrode side, the locking claw 95 is locked to the edge of the electrode joint portion 52 a of the negative electrode conductive member 52. Further, the restricting portion 97 of the second insulating cover 91 has a first contact surface 97a that contacts the tip end surface 52c of the negative electrode conductive member 52, and the second contact surface 97b that engages the first insulating cover 81. The protrusion 87 is in contact. Further, the locking protrusion 87 of the first insulating cover 81 is also in contact with the second contact surface 97 b of the restricting portion 97 of the second insulating cover 91. These abutments restrict the rotation of the first insulating cover 81 and the second insulating cover 91.

  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.

  For this reason, in the secondary battery 10, with respect to the tab group 36 protruding from the tab side end surface 12 b of the electrode assembly 12, one end side in the stacking direction is insulated from the case member 14 by the tab insulating portion 83 of the first insulating cover 81. The other end side in the stacking direction can be insulated from the case member 14 by the tab insulating portion 93 of the second insulating cover 91. Therefore, even in the secondary battery 10 manufactured by attaching the insulating covers 81 and 91 to the lid terminal assembly 20, the tab group 36 can be easily insulated from the case 11 from both sides in the stacking direction. Therefore, it is possible to insulate the tab group 36 from the case member 14 simply by mounting the insulating covers 81 and 91, which are existing configurations for insulating the conductive members 51 and 52 and the lid member 15, and increase the number of steps for the insulation. You do n’t have to.

  (2) The first insulating cover 81 includes a locking claw 86f that is locked to the electrode joint portion 52a of the negative electrode conductive member 52, and the second insulating cover 91 is locked to the electrode joint portions 51a and 52a of both electrodes. A locking claw 95 is provided. The conductive members 51 and 52 are assembled to the lid terminal assembly 20 and are fixed to the lid member 15. When the locking claws 86f and 95 are locked to the fixed conductive members 51 and 52, the movement of the insulating covers 81 and 91 in the direction opposite to the insertion direction can be restricted.

  (3) The holder locking claw 85 f of the first insulating cover 81 is locked to the holder 40 of the positive terminal structure 16. The holder 40 is fixed to the lid member 15 by the connecting shaft portion 60a of the positive electrode lead terminal 60 and the caulking portion. When the holder locking claw 85f is locked to the fixed holder 40, the movement of the first insulating cover 81 in the direction opposite to the insertion direction can be restricted.

  (4) The second insulating cover 91 includes a restricting portion 97. The first contact surface 97 a of the restricting portion 97 contacts the tip surface 52 c of the negative electrode conductive member 52, and the second contact surface 97 b parallel to the first contact surface 97 a locks the first insulating cover 81. Abuts against the protrusion 87. The movement of the second insulating cover 91 in the juxtaposed direction X can be restricted by the abutment with both abutment surfaces 97a, 97b. In addition, the third contact surface 97 c of the restricting portion 97 contacts the locking protrusion 87 of the first insulating cover 81. Therefore, in the restricting portion 97, the locking projection 87 is in contact with the second contact surface 97b and the third contact surface 97c which are orthogonal to each other. The rotation of the second insulating cover 91 can be restricted by contact with the two surfaces.

  (5) The first insulating cover 81 has a holder locking claw 85f in the positive electrode insulating portion 85 and a locking claw 86f in the negative electrode insulating portion 86. One locking claw 95 of the second insulating cover 91 is disposed on the inner side of the holder locking claw 85f existing in the positive electrode insulating portion 85, and the other locking claw 95 is locked on the negative electrode insulating portion 86. It is arrange | positioned inside the nail | claw 86f. For this reason, the latching claws 85f and 86f of the first insulating cover 81 and the latching claws 95 of the second insulating cover 91 do not overlap with each other, and the holder 40 and the conductive members 51 and 52 can be latched. it can.

(Second Embodiment)
Next, a second embodiment in which the power storage device is embodied as a secondary battery will be described with reference to FIGS. In the second embodiment, detailed description of the same parts as those in the first embodiment is omitted.

  As shown in FIG. 9 or FIG. 10, the first insulating cover 81 includes a convex portion 82 c at the center in the longitudinal direction of the wall insulating portion 82. The convex portion 82 c has a shape protruding from both end portions in the longitudinal direction of the wall insulating portion 82. The first insulating cover 81 includes a reinforcing rib 100 near the negative electrode insulating portion 86 in the longitudinal direction of the wall insulating portion 82. The wall insulating portion 82 includes an outer surface 82b on the surface facing the inner surface 15d of the lid member 15, and includes an inner surface 82a on the surface facing the electrode bonding portions 51a and 52a. In the wall insulating portion 82, the direction connecting the inner surface 82a and the outer surface 82b with the shortest distance is the thickness direction, and the dimension in the thickness direction is the thickness.

  The thickness of the reinforcing rib 100 is larger than the thickness of the portion without the reinforcing rib 100 in the wall insulating portion 82. The reinforcing rib 100 has a base end portion 100 a at an end portion connected to the tab insulating portion 83, and a distal end portion 100 b at an end portion connected to the edge of the wall insulating portion 82.

  The first insulating cover 81 includes a liquid injection hole 101. The liquid injection hole 101 is closer to the base end portion 100 a of the reinforcing rib 100. The liquid injection hole 101 passes through the reinforcing rib 100 along the thickness direction of the wall insulating portion 82. The liquid injection hole 101 is disposed at a position corresponding to a liquid injection port (not shown) of the lid member 15. Then, in order to inject the electrolyte into the case 11, when injected into the injection port of the lid member 15, the electrolyte passes through the injection hole 101 of the first insulating cover 81 and enters the electrode assembly 12. Poured.

  The first insulating cover 81 includes a locking recess 102 in the reinforcing rib 100. The locking recess 102 is closer to the tip end 100 b of the reinforcing rib 100 than the liquid injection hole 101. The locking recess 102 has a shape that is recessed in the thickness direction from the reinforcing rib 100 on the inner surface 82 a side of the wall insulating portion 82.

  The first insulating cover 81 includes a first locking claw 103 on the reinforcing rib 100. The first locking claw 103 is also a portion of the reinforcing rib 100 that is closer to the distal end portion 100 b than the locking recess 102. The first locking claw 103 has a shape in which the thickness gradually increases from the distal end portion 100b of the reinforcing rib 100 toward the proximal end portion 100a. The 1st latching claw 103 equips the surface inclined toward the base end part 100a from the front-end | tip part 100b of the reinforcement rib 100 with the guide surface 103b.

  The first locking claw 103 includes a locking surface 103 a on the surface connected to the locking recess 102. The locking surface 103 a is also a surface near the tip end portion 100 b of the reinforcing rib 100 among the surfaces that define the locking recess 102. The locking surface 103a is a surface that is orthogonal to (intersects) the inner surface 82a of the wall insulating portion 82 and is also a surface that is orthogonal to the stacking direction. The locking surface 103a may be an inclined surface that is not perpendicular to the inner surface 82a of the wall insulating portion 82.

  The second insulating cover 91 includes a concave portion 92c in the longitudinal center portion of the wall insulating portion 92. The concave portion 92c is recessed toward the tab insulating portion 93 rather than the longitudinal central portion of the wall insulating portion 92. It is. The wall insulating portion 92 includes an outer surface 92b on the surface facing the inner surface 15d of the lid member 15, and includes an inner surface 92a on the surface facing the electrode bonding portions 51a and 52a. The second insulating cover 91 includes a locking protruding portion 105 that protrudes in a bar shape in the same direction as the protruding direction of the wall insulating portion 92 from the tab insulating portion 93.

  The locking protrusion 105 includes an inner surface 105 a parallel to the inner surface 92 a of the wall insulating portion 92. The second insulating cover 91 includes an inclined surface 105 b in the locking protrusion 105. The inclined surface 105b is inclined so as to gradually approach the inner surface 105a from the tab insulating portion 93 toward the protruding end portion of the locking protruding portion 105.

  The second insulating cover 91 includes a second locking claw 106 at the protruding end of the locking protrusion 105. The second locking claw 106 has a shape protruding from the inclined surface 105 b of the locking protrusion 105. The second locking claw 106 includes a locking surface 106a connected to the inclined surface 105b. The locking surface 106 a can be locked to the locking surface 103 a of the first insulating cover 81. The locking surface 106a is a surface that is orthogonal (intersects) with the inner surface 92a of the wall insulating portion 92 and is also a surface that is orthogonal to the stacking direction. The locking surface 106a may be an inclined surface that is not perpendicular to the inner surface 92a of the wall insulating portion 92.

  In the second embodiment, both the first insulating cover 81 and the second insulating cover 91 include the locking claws 103 and 106, and both of the locking surfaces 103 a and the locking claws 103 and 106 are locked. 106a.

Next, the manufacturing method of the secondary battery 10 will be described together with the operation.
In the state in which the lid terminal assembly 20 and the electrode assembly 12 are integrated, as shown in FIG. 12A, from the other end side in the stacking direction, the lid member 15 and electrode joint portions 51a and 52a (not shown) The wall insulating part 92 of the second insulating cover 91 is inserted therebetween, and the second insulating cover 91 is integrated with the lid member 15. In this state, the locking projection 105 is inserted between the positive and negative tab groups 36, and the second locking claw 106 protrudes toward the inner surface 15 d of the lid member 15. The locking surface 106a is orthogonal to the inner surface 92a of the wall insulating portion 92 and also orthogonal to the stacking direction. Therefore, in this embodiment, the 2nd insulating cover 91 provided with the latching surface 106a turns into one insulating cover.

  Next, as shown in FIG. 12B, from the one end in the stacking direction, the wall insulating portion 82 of the first insulating cover 81 is inserted between the lid member 15 and the electrode joint portions 51a and 52a. The first insulating cover 81 is slid to move the first insulating cover 81 closer to the second insulating cover 91. At this time, the reinforcing rib 100 is inserted into a position facing the locking projection 105 of the second insulating cover 91 in the stacking direction. Then, the guide surface 103 b of the first locking claw 103 comes into sliding contact with the second locking claw 106 and is elastically deformed so that the locking projection 105 is separated from the lid member 15.

  Then, when the locking recess 102 faces the second locking claw 106, the sliding contact of the second locking claw 106 with the guide surface 103b is released, and the locking projection 105 returns to the original shape, and the locking The second locking claw 106 enters the recess 102.

  Then, as shown in FIG. 11, the locking surface 103 a of the first locking claw 103 can be locked to the locking surface 106 a of the second locking claw 106. At the same time, the locking surface 106 a of the second locking claw 106 can be locked to the locking surface 103 a of the first locking claw 103. In the present embodiment, the first insulating cover 81 is the other insulating cover having a locking claw.

As shown in FIG. 9, the convex portion 82c of the first insulating cover 81 enters the concave portion 92c of the second insulating cover 91, and the wall insulating portions 82 and 92 are assembled in a flat plate shape.
Thereafter, as in the first embodiment, the electrode assembly 12 is inserted into the case member 14 through 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.

  As shown in FIG. 11, in the assembled secondary battery 10, the tab group 36 protruding from the tab side end surface 12 b of the electrode assembly 12 has one end side in the stacking direction of the tab insulating portion of the first insulating cover 81. 83, and can be insulated from the case member 14 (not shown). Similarly, the other end side of the tab group 36 in the stacking direction is covered by the tab insulating portion 93 of the second insulating cover 91 and can be insulated from the case member 14 (not shown).

  The movement of the first insulating cover 81 and the second insulating cover 91 in the insertion direction is restricted by the contact of the tab insulating portions 83 and 93 with the tab group 36. Due to the locking of the first locking claw 103 and the second locking claw 106 in this movement restricted state, the movement of the insulating covers 81 and 91 in the direction opposite to the insertion direction is restricted, and the first insulating cover 81 And separation of the second insulating cover 91 are restricted.

Therefore, according to the second embodiment, in addition to the effects described in the first embodiment, the following effects can be obtained.
(6) The first locking claws 103 of the first insulating cover 81 and the second locking claws 106 of the second insulating cover 91 are respectively disposed between the positive and negative tab groups 36. Accordingly, the space in the case 11 is disposed in a relatively wide space sandwiched between the positive and negative tab groups 36. Therefore, even if the insulating covers 81 and 91 are installed by inserting the wall insulating portions 82 and 92 between the lid member 15 and the electrode joint portions 51 a and 52 a, the first locking claws 103 and the second locking claws 106. The first insulating cover 81 and the second insulating cover 91 are easily integrated. In addition, the locking state of the first locking claw 103 and the second locking claw 106 can be made favorable, and separation of the first insulating cover 81 and the second insulating cover 91 can be suitably controlled.

  (7) The first insulating cover 81 includes a guide surface 103 b on the first locking claw 103, and the guide surface 103 b is connected to the locking surface 103 a of the locking recess 102. When the first locking claw 103 and the second locking claw 106 are locked, the second locking claw 106 can be guided toward the locking surface 103a of the locking recess 102 by the guide surface 103b. The first locking claw 103 and the second locking claw 106 can be easily locked.

  (8) In order to pour the electrolyte into the electrode assembly 12, the first insulating cover 81 includes a liquid injection hole 101. The liquid injection hole 101 is formed in the thick reinforcing rib 100 so that the poured electrolyte is poured into a position close to the electrode assembly 12. Using this reinforcing rib 100, the locking recess 102 and the first locking claw 103 were formed. Therefore, the latching recess 102 and the first latching claw 103 can be formed by using a site necessary for manufacturing the secondary battery 10.

  (9) After the second insulating cover 91 is assembled to the lid terminal assembly 20, the first insulating cover 81 is moved closer to the second insulating cover 91, and the second engagement of the second insulating cover 91 is performed. The first locking claw 103 of the first insulating cover 81 is locked to the locking claw 106. In the first insulating cover 81, the first locking claw 103 is formed on the thick reinforcing rib 100, and the second locking claw 106 is formed on the locking protruding portion 105 protruding in a rod shape. Therefore, the locking projection 105 is bent by the first locking claw 103 and the second locking claw 106 and the first locking claw 103 are easily locked.

In addition, you may change the said embodiment as follows.
As shown in FIG. 13, the first embodiment has a structure in which rotation is restricted by the locking protrusion 87 of the first insulating cover 81 and the restricting portion 97 of the second insulating cover 91. For example, one locking claw 95 of the second insulating cover 91 may be omitted. When configured in this manner, the exposed area of the electrode joint portion of the conductive member is widened on the side without the locking claw 95 (on the negative electrode conductive member 52 side in FIG. 13), and welding work between the electrode joint portion and the tab group 36 is performed. Is easier to do.

  As shown in FIG. 14, in the first embodiment, in the second insulating cover 91, the engaging claw 95 on the positive electrode conductive member 51 side of the pair of engaging claws 95 is engaged with the edge of the holder 40. The first and second insulating covers 81 and 91 may be locked to the holder 40 as holder holding claws to be stopped.

  When configured in this way, the positive electrode terminal structure 16 does not include the current interruption mechanism 80, but the holder 40 is wider than the terminal connection portion 51 b of the positive electrode conductive member 51, and the short sides of the respective insulating covers 81 and 91. It protrudes from the terminal connection part 51b along the direction. And by setting each holder latching claw to the holder 40 wider than this terminal connection part 51b, when attaching each insulating cover 81 and 91, a holder latching claw latches to the holder 40. In addition, the respective insulating covers 81 and 91 can be mounted smoothly.

Further, as shown in FIG. 14, in the first insulating cover 81, the locking claw 86 f of the negative electrode insulating portion 86 may be a holder locking claw that locks the holder 40 of the negative electrode terminal structure 17.
○ In the first insulating cover 81 of the first embodiment, the holder locking claw 85f is a locking claw that locks the negative electrode conductive member 52, and the two claws are both locking claws that lock the conductive member. Also good.

  In the first embodiment, the locking claw of the first insulating cover 81 does not protrude from the positive electrode insulating portion 85 or the negative electrode insulating portion 86 but may be provided on the protruding piece protruding from the tab insulating portion 83. Good.

  In the first embodiment, of the pair of locking claws of the first insulating cover 81, one locking claw protrudes from the positive electrode insulating portion 85 or the negative electrode insulating portion 86, and the other locking claw is tab insulating. You may be provided in the protrusion piece protruded from the part 83. FIG.

In the first embodiment, the locking protrusion 87 of the first insulating cover 81 and the restricting portion 97 of the second insulating cover 91 may be omitted.
In the first embodiment, the first insulating cover 81 is provided with a regulating portion 97 including a first contact surface 97a, a second contact surface 97b, and a third contact surface 97c, and the second insulating cover 81 91 may be provided with a locking protrusion 87 that contacts the second contact surface 97b and the third contact surface 97c.

  In the first embodiment, the conductive member with which the first contact surface 97 a of the restricting portion 97 contacts may be the tip surface of the positive electrode conductive member 51. In this case, the positions of the first contact surface 97a and the second contact surface 97b are opposite to those of the embodiment so that the first contact surface 97a faces the positive electrode conductive member 51.

  In the second embodiment, after the first insulating cover 81 is first assembled to the lid terminal assembly 20, the second insulating cover 91 is moved closer to the first insulating cover 81 and the first locking is performed. The claw 103 and the second locking claw 106 may be locked.

  In the second embodiment, of the first insulating cover 81 and the second insulating cover 91, the first insulating cover 81 is configured to include a locking claw, and the second insulating cover 91 is locked. It is good also as a structure which is provided only with a surface and is not provided with a latching claw.

  In this case, the outer surface of the tab insulating portion 93 of the second insulating cover 91 is used as a locking surface, and the first locking claw 103 is extended to extend the first engagement of the first insulating cover 81 to the outer surface of the tab insulating portion 93. The pawl 103 is locked.

  Alternatively, the first insulating cover 81 may be one insulating cover provided with a locking surface, and the second insulating cover 91 may be the other insulating cover provided with a locking claw. In this case, the engaging claw of the second insulating cover 91 may be configured to be engaged with the outer surface of the tab insulating portion 83 of the first insulating cover 81 as the engaging surface.

  In the second embodiment, the first locking claw 103 of the first insulating cover 81 is provided at a position different from the reinforcing rib 100 in the wall insulating portion 82, and is aligned with the position of the first locking claw 103. The second locking claw 106 (locking protrusion 105) of the second insulating cover 91 may be provided.

  If the first locking claw 103 of the first insulating cover 81 and the second locking claw 106 of the second insulating cover 91 can be locked, the wall insulating portion 82 of the first insulating cover 81 and the second The shape of the wall insulating portion 92 of the insulating cover 91 may be changed as appropriate.

  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.

  DESCRIPTION OF SYMBOLS 10 ... Secondary battery, 11 ... Case, 12 ... Electrode assembly, 12b ... Tab side end surface as end surface, 14 ... Case member, 15 ... Cover member, 21 ... Positive electrode, 25, 35 ... Tab, 31 ... Negative electrode , 36 ... tab group, 40 ... holder, 51 ... positive electrode conductive member, 52 ... negative electrode conductive member, 52c ... tip surface, 60 ... positive electrode lead terminal as electrode terminal, 61 ... negative electrode lead terminal as electrode terminal, 60b, 63 ... Base part, 81 ... First insulating cover, 82, 92 ... Wall insulating part, 83, 93 ... Tab insulating part, 85 ... Positive electrode insulating part as terminal insulating part, 86 ... Negative electrode insulating part as terminal insulating part, 86f 95 ... Locking claw, 85f ... Holder locking claw, 87 ... Locking protrusion, 91 ... Second insulating cover, 97a ... First contact surface, 97b ... Second contact surface, 97c ... Third contact Contact surface, 103 ... first locking claw, 103a, 106a ... engagement Surface, 106 ... the second engagement claw.

Claims (7)

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 joined to the tab group of the same polarity and disposed between the lid member and an end surface of the electrode assembly facing the lid member;
A holder for insulating the lid member and the base of the electrode terminal;
When the stacking direction of the electrodes is the stacking direction, a first insulating cover disposed on one end side in the stacking direction of the electrode assembly;
A second insulating cover disposed on the other end side in the stacking direction of the electrode assembly,
The first insulating cover and the second insulating cover include a wall insulating portion that insulates a pair of the conductive member and the lid member,
In the laminating direction, a tab insulating portion that insulates the tab group and a portion of the case member facing the tab group;
A power storage device comprising: a locking claw that locks to an edge of the conductive member.   The power storage device according to claim 1, wherein at least one of the first insulating cover and the second insulating cover includes a holder locking claw that locks the holder. 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 joined to the tab group of the same polarity and disposed between the lid member and an end surface of the electrode assembly facing the lid member;
A holder for insulating the lid member and the base of the electrode terminal;
When the stacking direction of the electrodes is the stacking direction, a first insulating cover disposed on one end side in the stacking direction of the electrode assembly;
A second insulating cover disposed on the other end side in the stacking direction of the electrode assembly,
The first insulating cover and the second insulating cover include a wall insulating portion that insulates a pair of the conductive member and the lid member,
In the laminating direction, a tab insulating portion that insulates the tab group and a portion of the case member facing the tab group;
A power storage device comprising: a holder locking claw for locking to the holder.   When a direction in which the pair of conductive members are arranged is a parallel direction, and an end surface of the conductive member facing the parallel direction is a tip surface, one of the first insulating cover and the second insulating cover The insulating cover has a first contact surface that contacts the tip surface of the conductive member, a second contact surface that is parallel to the first contact surface, and a third contact surface that is orthogonal to the second contact surface. And the other insulating cover includes a locking projection having two surfaces that contact the second contact surface and the third contact surface. The power storage device described.   In the first insulating cover and the second insulating cover, when the direction along the juxtaposed direction in which the pair of conductive members are arranged is a longitudinal direction, any of the first insulating cover and the second insulating cover One of them is provided with a terminal insulating portion interposed between each base portion and the electrode assembly at both ends in the longitudinal direction, and is locked to the edge portion of the conductive member on the inner side along the longitudinal direction than each terminal insulating portion. 3. The power storage device according to claim 1, further comprising a locking claw, wherein the other insulating cover is located on an inner side along a longitudinal direction than a locking claw included in the one insulating cover. 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 joined to the tab group of the same polarity and disposed between the lid member and an end surface of the electrode assembly facing the lid member;
When the stacking direction of the electrodes is the stacking direction, a first insulating cover disposed on one end side in the stacking direction of the electrode assembly;
A second insulating cover disposed on the other end side in the stacking direction of the electrode assembly,
The first insulating cover and the second insulating cover include a wall insulating portion that insulates a pair of the conductive member and the lid member,
In the laminating direction, including the tab group and a tab insulating portion that insulates the portion of the case member that faces the tab group,
One insulating cover of the first insulating cover and the second insulating cover is provided on a surface intersecting the inner surface of the wall insulating portion and has a locking surface intersecting the stacking direction, The insulating cover includes an engaging claw that engages with the engaging surface.   The power storage device according to any one of claims 1 to 6, wherein the power storage device is a secondary battery.

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