JP6394908B2 - Power storage device and power storage device module - Google Patents

Description

  The present invention relates to a power storage device and a power storage device module.

  Conventionally, power storage devices for storing electric power used in electrical components are mounted on vehicles such as electric vehicles and hybrid vehicles. As such a power storage device, for example, a lithium ion secondary battery or a nickel hydride secondary battery is known. These secondary batteries include a positive electrode terminal and a negative electrode terminal as terminals for transmitting and receiving electricity to and from the electrode assembly housed in the case.

  For example, Patent Document 1 discloses that the conductive member and the external terminal plate are electrically connected while being fixed by caulking that deforms a part of the conductive member electrically connected to the electrode assembly. Has been. For this reason, it is easy to fix the conductive member and the external terminal plate.

JP 2012-38529 A

  By the way, modularization is performed by electrically connecting terminals of different secondary batteries using a metal bus bar. In order to reduce the number of parts, it is conceivable to omit the external terminal plate as a separate member by welding the bus bar and the caulked portion of the conductive member. However, when the melting point of the metal forming the bus bar is different from the melting point of the metal forming the conductive member, welding is difficult.

  This invention was made paying attention to the problem which exists in the prior art mentioned above. An object of the present invention is to provide a power storage device and a power storage device module capable of easily connecting a bus bar and a terminal portion.

  A power storage device that solves the above-described problem includes an electrode assembly, a case that accommodates the electrode assembly, and a terminal unit that transmits and receives electricity to and from the electrode assembly. A second terminal penetrating the wall of the case and made of a first metal, and a portion welded to the bus bar outside the case and having a melting point different from that of the first metal. A second terminal portion made of metal, wherein the first terminal portion is disposed outside the case, and is disposed inside the case, and the first portion. A second part sandwiching the wall of the case between the first terminal part and the second terminal part of the first part of the first terminal part sandwiching the wall of the case The point is that it is exposed in a different part.

  According to this configuration, the bus bar and the terminal portion can be easily welded by selecting a metal that can be welded to the bus bar as the second metal constituting the second terminal portion. Accordingly, the bus bar and the terminal portion can be easily connected.

  In the power storage device, it is preferable that the first terminal portion and the second terminal portion are friction-welded. According to this structure, even if the melting point of the 1st metal which comprises the 1st terminal part and the melting point of the 2nd metal which comprises the 2nd terminal part are separated, both terminal parts can be joined. Therefore, the types of metals that can be selected as the second metal can be increased.

  In the power storage device, the terminal portion is a negative electrode terminal portion, and the first metal is copper, gold, aluminum, magnesium, tungsten, cobalt, zinc, nickel, iron, platinum, tin, indium, titanium, It is preferably a single metal selected from the group consisting of ruthenium, tantalum, and molybdenum, or an alloy containing a metal selected from the group as a main component.

According to this configuration, the bus bar and the terminal portion can be easily connected even if these single metals or alloys containing these metals as main components are used in the terminal portion for the negative electrode.
About the said electrical storage apparatus, it is provided so that it may continue with the said 2nd site | part, and when the internal pressure of the said case reaches | attains the predetermined pressure, the electrically conductive path | route between the said electrode assembly and the said 2nd terminal part will be interrupted | blocked The first terminal portion includes a through hole that opens to the first portion and the second portion, and the first terminal portion includes the first terminal portion. It is preferable to extend along a direction penetrating the wall of the case, and the current interrupting device faces an opening of the through hole in the second portion.

According to this configuration, since the current interrupting device faces the opening of the through hole penetrating the terminal portion, maintenance of the current interrupting device can be easily performed through the through hole.
About the said electrical storage apparatus, it is preferable that the junction part of a said 1st terminal part and a said 2nd terminal part is not exposed to the inside of the said through-hole. According to this structure, it is suppressed that the foreign material from a junction part reaches | attains an electric current interruption apparatus. Therefore, inhibiting the function of the current interrupt device is suppressed.

  A power storage device module that solves the above-described problem includes a plurality of power storage devices and a bus bar for electrically connecting the power storage devices, and the power storage device is the power storage device described above, The gist is that each of the power storage devices is welded to the second terminal portion among the terminal portions.

  According to this configuration, the bus bar and the terminal portion can be easily welded by selecting a metal that can be welded to the bus bar as the second metal constituting the second terminal portion. Accordingly, the bus bar and the terminal portion can be easily connected. As a result, the manufacture of the power storage device module is simplified.

  According to the present invention, the bus bar and the terminal portion can be easily connected.

The perspective view which shows a part of secondary battery module. The perspective view which shows the secondary battery which fractured | ruptured one part. The perspective view which shows the secondary battery disassembled partially. Sectional drawing when it assumes that it cut | disconnected by the 4-4 line shown in FIG. Sectional drawing when it assumes that it cut | disconnected by the 5-5 line shown in FIG. Sectional drawing of the secondary battery in another embodiment.

Hereinafter, an embodiment of a power storage device and a power storage device module will be described.
As shown in FIG. 1, the secondary battery module 10 as a power storage device module includes a plurality of secondary batteries 11 as power storage devices. The plurality of secondary batteries 11 are flat rectangular lithium ion secondary batteries.

  The secondary battery module 10 includes a plurality of bus bars 12 for electrically connecting the secondary batteries 11 to each other. The bus bar 12 is a rectangular plate member. The bus bar 12 is made of, for example, aluminum or an alloy mainly composed of aluminum.

  The secondary battery module 10 may include a restraining device that applies restraint weight to the plurality of secondary batteries 11. The secondary battery module 10 may include a case that houses a plurality of secondary batteries 11. The secondary battery module 10 may include a control device that controls charging / discharging of the plurality of secondary batteries 11.

The plurality of secondary batteries 11 are configured as follows.
As shown in FIGS. 2 and 3, each of the plurality of secondary batteries 11 includes a case 14. The case 14 includes a square cylindrical case main body 17 having an opening 17a, and a square plate-like lid 18 that closes the opening 17a. The lid 18 is welded to the case body 17 over the entire edge thereof.

  The lid 18 is one of the walls of the case 14. The case body 17 and the lid 18 are made of, for example, aluminum or an alloy mainly composed of aluminum. The lid 18 includes two through holes 18a and 18b that penetrate the lid 18 in the thickness direction.

  Each of the plurality of secondary batteries 11 includes an electrode assembly 20. The electrode assembly 20 is accommodated in the case 14. The electrode assembly 20 includes a plurality of positive electrodes 21, a plurality of negative electrodes 22, and a plurality of separators 23. The electrode assembly 20 has a stacked structure in which the positive electrode 21 and the negative electrode 22 are alternately stacked in layers with a separator 23 interposed therebetween. In the following description, the “stacking direction” indicates the direction in which the electrodes 21 and 22 overlap in the electrode assembly 20. The separator 23 is a sheet formed from a porous insulating material.

  The plurality of positive electrodes 21 have a rectangular sheet shape. The positive electrode 21 includes a metal foil, an active material layer covering at least a part of the metal foil, and a tab protruding from the edge of the metal foil along the surface direction of the metal foil. .

  The metal foil of the positive electrode 21 is made of, for example, aluminum or an alloy containing aluminum as a main component. The active material layer of the positive electrode 21 contains an active material for the positive electrode. The tab of the positive electrode 21 is a part of the metal foil and is not covered with the active material layer.

  The plurality of negative electrodes 22 have a rectangular sheet shape. The negative electrode 22 includes a metal foil, an active material layer covering at least a part of the metal foil, and a tab protruding from the edge of the metal foil along the surface direction of the metal foil. .

  The metal foil of the negative electrode 22 is made of, for example, copper or an alloy containing copper as a main component. The active material layer of the negative electrode 22 contains a negative electrode active material and the like. The tab of the negative electrode 22 is a part of the metal foil and is not covered with the active material layer.

  The electrode assembly 20 includes a positive electrode tab group 24 protruding from the edge portion 20a. The positive electrode tab group 24 has a structure in which tabs of a plurality of positive electrode electrodes 21 are stacked in layers. The electrode assembly 20 includes a negative electrode tab group 25 protruding from the edge 20a. The negative electrode tab group 25 has a structure in which tabs of a plurality of negative electrode 22 are stacked in layers.

Each of the plurality of secondary batteries 11 includes a negative electrode terminal portion 30 as a terminal portion for transferring electricity to and from the electrode assembly 20. The negative terminal portion 30 is fixed to the lid 18.
As shown in FIGS. 3 and 4, the negative electrode terminal portion 30 includes a conductive member 31. The conductive member 31 is a rectangular plate member. The conductive member 31 is made of copper as the first metal or an alloy containing copper as a main component.

  The conductive member 31 includes a first end portion 31a and a second end portion 31b opposite to the first end portion 31a. The first end portion 31 a of the conductive member 31 is welded to the negative electrode tab group 25. That is, the conductive member 31 and the electrode assembly 20 are electrically connected.

  The conductive member 31 includes a concave portion 31c that is recessed in a flat conical shape at a portion of the second end portion 31b that faces the electrode assembly 20. The conductive member 31 includes an annular fragile portion 31d at the center of the recess 31c. The fragile portion 31d is fragile because it is provided with an annular groove, for example, so that it is thinner than other portions.

  A portion surrounded by the fragile portion 31d is a separation portion 31e separated from the conductive member 31 when the fragile portion 31d is broken. Further, the conductive member 31 includes through holes 31f and 31f penetrating in the thickness direction of the conductive member 31 at both edges in the stacking direction. The through holes 31f and 31f of this embodiment are each slit-like extending along the edge of the conductive member 31.

  The negative terminal portion 30 includes a thin metal diaphragm 32 that covers the concave portion 31 c of the conductive member 31. The diaphragm 32 is made of, for example, copper or an alloy containing copper as a main component. The diaphragm 32 is welded to the conductive member 31 over the entire edge thereof.

  The diaphragm 32 is a flat conical member protruding toward the electrode assembly 20. The diaphragm 32 includes a columnar convex portion 32 a at the center of the surface facing the conductive member 31. When it is assumed that the projection is performed on a plane perpendicular to the penetration direction of the through hole 18a, the projection area of the convex portion 32a is smaller than the projection area of the separation portion 31e, and the whole overlaps with the projection region of the separation portion 31e. Yes.

  The negative terminal portion 30 includes a thin metal conductive plate 33 on the opposite side of the diaphragm 32 with the conductive member 31 interposed therebetween. The conductive plate 33 is made of, for example, copper or an alloy containing copper as a main component. The conductive plate 33 is a flat conical member that protrudes toward the conductive member 31. The leading end portion 33 a of the conductive plate 33 is welded to the separation portion 31 e in the conductive member 31. That is, the conductive plate 33 is electrically connected to the conductive member 31.

  The negative terminal portion 30 includes a metal support member 34 for supporting the conductive plate 33. The support member 34 is made of, for example, copper or an alloy containing copper as a main component. The support member 34 includes an annular plate-shaped first wall 34 a and a cylindrical second wall 34 b extending from the peripheral edge of the first wall 34 a toward the electrode assembly 20.

  The support member 34 includes a through hole 34c that penetrates the first wall 34a in the thickness direction at the center of the first wall 34a. The conductive plate 33 described above is welded to the first wall 34a over the entire edge thereof. That is, the conductive plate 33 is electrically connected to the support member 34.

  The negative electrode terminal portion 30 includes an O-ring 35 as a gasket. The O-ring 35 is made of an insulating material. The O-ring 35 seals between the leading end portion of the second wall 34 b and the conductive member 31. The O-ring 35 insulates between the conductive member 31 and the support member 34.

  The negative terminal portion 30 includes a holding member 36 for integrating the conductive member 31, the support member 34, and the O-ring 35. The holding member 36 is made of an insulating material. The holding member 36 includes a square plate-shaped first wall 36a. The first wall 36 a is sandwiched between the support member 34 and the lid 18. That is, the first wall 36 a insulates the support member 34 and the lid 18.

  The holding member 36 includes square plate-like second walls 36b and 36b extending toward the conductive member 31 from both edges in the stacking direction of the electrode assembly 20 among the edges of the first wall 36a. ing. The distal ends of the second walls 36b and 36b are fixed to the conductive member 31 by caulking that is deformed while being inserted through the through holes 31f and 31f in the conductive member 31, respectively.

  The negative electrode terminal portion 30 includes a first insulating member 37 made of an insulating material. The first insulating member 37 is a substantially cylindrical member. The first insulating member 37 is provided so as to be connected to a cylindrical first wall 37a inserted through the through hole 18a of the lid 18 and an end portion inside the case 14 of both end portions of the first wall 37a. An annular plate-shaped second wall 37b.

  Further, the negative terminal portion 30 includes a second insulating member 38 made of an insulating material. The second insulating member 38 is an annular plate member. The second insulating member 38 is disposed outside the case 14 so as to surround the through hole 18a.

  The negative terminal portion 30 includes a rivet 40. The rivet 40 includes a rivet body 41 as a first terminal portion. The rivet body 41 is made of copper as the first metal or an alloy mainly composed of copper. The rivet body 41 is a hollow rivet having a substantially cylindrical shape as a whole.

  The rivet body 41 includes a shaft portion 41 a inserted through the through hole 18 a, the support member 34, the first insulating member 37, and the second insulating member 38. That is, the rivet body 41 passes through the lid 18 which is also the wall of the case 14 by being inserted into the through hole 18 a of the lid 18. The rivet body 41 includes a flange portion 41b provided so as to be connected to an end portion disposed outside the case 14 among both end portions of the shaft portion 41a. The flange portion 41b has a disk shape.

  The flange portion 41b includes a first surface 41e facing the lid 18 and a second surface 41f opposite to the first surface 41e. When it is assumed that the projection is performed on a plane orthogonal to the penetration direction of the through hole 18a, the projection area of the through hole of the first insulating member 37 is smaller than the projection area of the flange portion 41b, and the entire projection area of the flange portion 41b. It overlaps the projection area. The flange portion 41 b of this embodiment corresponds to a first portion that is disposed outside the case 14.

  The rivet body 41 includes a large-diameter portion 41c provided so as to be connected to an end portion disposed inside the case 14 among both end portions of the shaft portion 41a. When it is assumed that the projection is performed on a plane orthogonal to the penetration direction of the through hole 18a, the projection area of the through hole 34c of the support member 34 is smaller than the projection area of the large diameter part 41c, and the entire area is the large diameter part 41c. It overlaps the projected area.

  The large diameter portion 41 c is in close contact with the support member 34. That is, the rivet body 41 and the support member 34 are electrically connected. The large-diameter portion 41c of this embodiment is provided by deforming the tip of an unused rivet body 41 that does not include the large-diameter portion 41c.

  The flange portion 41b and the large diameter portion 41c protrude in the diametrical direction from the shaft portion 41a. Therefore, the lid 18, the support member 34, the first insulating member 37, and the second insulating member 38 are sandwiched between the flange portion 41b and the large diameter portion 41c.

  Thereby, the support member 34 is fixed to the lid 18 inside the case 14. The large diameter portion 41c of this embodiment corresponds to the second part. The first surface 41e of the flange portion 41b corresponds to a portion sandwiching the lid 18.

  A through hole 41d penetrating the rivet body 41 is open at the flange portion 41b and the large diameter portion 41c. The through hole 41 d extends along the direction in which the rivet body 41 passes through the lid 18. The rivet main body 41 includes a step portion 41g provided in the flange portion 41b so as to surround the through hole 41d.

  The rivet 40 includes a welding table 42 that is a portion welded to the bus bar 12 outside the case 14. The welding table 42 is made of aluminum as a second metal having a melting point (melting temperature) different from that of the first metal, or an alloy containing aluminum as a main component. That is, in this embodiment, the melting point of the second metal is lower than the melting point of the first metal constituting the rivet body 41. The second metal is a metal that can be welded to the bus bar 12. The welding table 42 corresponds to a second terminal portion.

  The welding table 42 is fitted into the step 41 g of the rivet body 41. The welding table 42 is friction-welded with the rivet body 41. That is, the rivet body 41 and the welding table 42 are electrically connected. In this embodiment, the joint portion 42 a between the rivet body 41 and the welding base 42 is exposed inside the through hole 41 d of the rivet body 41.

  The welding table 42 protrudes from the second surface 41 f of the rivet body 41. In other words, the welding table 42 is exposed in a portion of the flange portion 41b of the rivet body 41 that is different from the first surface 41e that is the portion sandwiching the lid 18. In the secondary battery module 10, the bus bar 12 is welded to the welding base 42 in the negative terminal portion 30. As the welding, for example, laser welding, ultrasonic welding, spot welding, or the like can be adopted.

  In the secondary battery 11 of this embodiment, the conductive path between the electrode assembly 20 and the welding table 42 is formed by the conductive member 31, the conductive plate 33, the support member 34, the rivet body 41, and the welding table 42. Yes.

  In the secondary battery 11 of this embodiment, the current interrupt device 43 is configured by the conductive member 31, the diaphragm 32, the conductive plate 33, the support member 34, the O-ring 35, and the holding member 36. The current interruption device 43 faces the opening 41h of the through hole 41d in the large diameter portion 41c.

  The current interrupt device 43 can interrupt the above-described conductive path when the internal pressure of the case 14 reaches a predetermined pressure. Here, the function of the current interrupt device 43 will be described. When the internal pressure of the case 14 reaches a predetermined pressure, the diaphragm 32 is inverted so as to protrude in the opposite direction to the electrode assembly 20.

  At this time, the separation portion 31e is separated from the conductive member 31 as a result of the fragile portion 31d being broken by the contact of the convex portion 32a of the diaphragm 32. Thereby, the electrical connection between the conductive member 31 and the conductive plate 33 is cut. That is, the above-described conductive path is blocked.

  Each of the plurality of secondary batteries 11 includes a positive terminal portion 50 as a terminal portion for transferring electricity to and from the electrode assembly 20. The positive terminal portion 50 is fixed to the lid 18. Unlike the negative electrode terminal unit 30, the positive electrode terminal unit 50 does not include the current interrupt device 43.

  As shown in FIGS. 3 and 5, the positive terminal portion 50 includes a conductive member 51. The conductive member 51 is a rectangular plate member. The conductive member 51 is made of, for example, aluminum or an alloy containing aluminum as a main component.

  The conductive member 51 includes a first end portion 51a and a second end portion 51b opposite to the first end portion 51a. The first end 51 a of the conductive member 51 is welded to the positive electrode tab group 24. That is, the conductive member 51 and the electrode assembly 20 are electrically connected. The conductive member 51 includes a through hole 51c penetrating in the thickness direction at the second end 51b.

  The positive terminal portion 50 includes a third insulating member 52 made of an insulating material. The third insulating member 52 includes a square plate-shaped first wall 52a. The first wall 52 a is sandwiched between the conductive member 51 and the lid 18. That is, the first wall 52 a insulates the conductive member 51 and the lid 18.

  The third insulating member 52 includes a through hole 52b penetrating in the thickness direction on the first wall 52a and a cylindrical second wall 52c surrounding the through hole 52b. The second wall 52 c is inserted through the through hole 18 b of the lid 18.

  Further, the positive terminal portion 50 includes a fourth insulating member 53 made of an insulating material. The fourth insulating member 53 is an annular plate member. The fourth insulating member 53 is disposed outside the case 14 so as to surround the through hole 18b.

  The positive terminal portion 50 includes a rivet 60. The rivet 60 is made of, for example, aluminum or an alloy mainly composed of aluminum. The rivet 60 is a solid rivet having a substantially cylindrical shape as a whole.

  The rivet 60 includes a shaft portion 60 a inserted through the through hole 18 b, the conductive member 51, the third insulating member 52, and the fourth insulating member 53. The rivet 60 passes through the lid 18 which is also the wall of the case 14 by being inserted into the through hole 18 b of the lid 18.

  The rivet 60 includes a flange portion 60b provided so as to be connected to an end portion disposed outside the case 14 among both end portions of the shaft portion 60a. The rivet 60 includes a large-diameter portion 60c provided so as to be connected to an end portion disposed inside the case 14 among both end portions of the shaft portion 60a.

  The large diameter portion 60 c is in close contact with the conductive member 51. That is, the conductive member 51 and the rivet 60 are electrically connected. The large diameter portion 60c of this embodiment is provided by deforming the tip of an unused rivet 60 that is not provided with the large diameter portion 60c.

  The flange portion 60b and the large diameter portion 60c protrude in the diameter direction from the shaft portion 60a. For this reason, the lid 18, the conductive member 51, the third insulating member 52, and the fourth insulating member 53 are sandwiched between the flange portion 60b and the large diameter portion 60c. Thus, the conductive member 51 is fixed to the lid 18 inside the case 14.

  In the secondary battery module 10, the bus bar 12 is welded to the flange portion 60 b of the rivet 60 in the positive electrode terminal portion 50. As the welding, for example, laser welding, ultrasonic welding, spot welding, or the like can be adopted.

The secondary battery module 10 can be manufactured by the following manufacturing method.
As shown in FIG. 1, the method for manufacturing the secondary battery module 10 includes a step of arranging a plurality of secondary batteries 11 along the stacking direction of the electrode assemblies 20. In this step, the plurality of secondary batteries 11 are arranged between the adjacent secondary batteries 11 so that the negative electrode terminal portion 30 and the positive electrode terminal portion 50 are adjacent to each other.

  The method for manufacturing the secondary battery module 10 includes a step of electrically connecting the negative electrode terminal portion 30 and the positive electrode terminal portion 50 between the adjacent secondary batteries 11 using the bus bar 12. In this step, the bus bar 12 is welded to the welding table 42 constituting the rivet 40 in the negative electrode terminal portion 30. As described above, since both the bus bar 12 and the welding table 42 are made of aluminum or an alloy containing aluminum as a main component, welding of both is easy.

  On the other hand, the rivet body 41 is made of copper or an alloy containing copper as a main component. The melting point of copper or copper alloy is generally around 1357K. On the other hand, the melting point of aluminum or aluminum alloy is generally around 933K. As described above, the melting point of copper or copper alloy is much higher than that of aluminum or aluminum alloy.

  For this reason, when it is going to weld the rivet main body 41 and the bus-bar 12 without providing the welding stand 42, welding of both is difficult. Such a problem can be solved by the manufacturing method of this embodiment.

  Further, the bus bar 12 is welded to the rivet 60 in the positive terminal portion 50. Since the rivet 60 of this embodiment is made of aluminum or an alloy containing aluminum as a main component, welding of both is easy.

  Moreover, the manufacturing method of the secondary battery module 10 may include a step of assembling a restraining device that applies restraint weight to the plurality of secondary batteries 11 from the stacking direction. Moreover, the manufacturing method of the secondary battery module 10 may include a step of housing a plurality of secondary batteries 11 in a case and a step of assembling a control device that controls charging / discharging of the plurality of secondary batteries 11.

Therefore, this embodiment has the following effects.
(1) By selecting a metal that can be welded to the bus bar 12 as the second metal constituting the welding table 42, the bus bar 12 and the negative electrode terminal portion 30 can be easily welded. Accordingly, the bus bar 12 and the negative terminal portion 30 can be easily connected.

  (2) The rivet body 41 and the welding table 42 are friction-welded. For this reason, even if the melting point of the 1st metal which comprises the rivet main body 41 and the melting point of the 2nd metal which comprises the welding stand 42 are large apart, both can be joined. Therefore, the types of metals that can be selected as the second metal can be increased.

  (3) Since the current interrupt device 43 faces the opening 41h of the through hole 41d that penetrates the negative electrode terminal portion 30, the current interrupt device 43 can be easily maintained through the through hole 41d. .

(4) The bus bar 12 and the negative terminal portion 30 can be easily connected. As a result, the production of the secondary battery module 10 is simplified.
The embodiment described above may be modified as follows.

  The first metal is a single metal selected from the group consisting of copper, gold, aluminum, magnesium, tungsten, cobalt, zinc, nickel, iron, platinum, tin, indium, titanium, ruthenium, tantalum, and molybdenum, or An alloy mainly containing a metal selected from the above group is preferable. According to this configuration, the bus bar 12 and the negative electrode terminal portion 30 can be easily connected to each other even if these single metals or alloys containing these metals as main components are used in the negative electrode terminal portion 30. .

(Circle) as shown in FIG. 6, the welding stand 42 does not need to protrude from the 2nd surface 41f.
(Circle) as shown in FIG. 6, the welding stand 42 does not need to face the through-hole 41d. For example, the rivet main body 41 may include an annular concave portion that surrounds the through hole 41d in the flange portion 41b. And the welding stand 42 is good to be friction-welded with the rivet main body 41 in the state fitted by this recessed part. According to this configuration, the boundary between the rivet body 41 and the welding table 42 is not exposed inside the through hole 41d. For this reason, the joint part 42a of the rivet main body 41 and the welding stand 42 can be prevented from being exposed to the through hole 41d. According to this configuration, for example, burrs or the like, it is possible to suppress foreign matter from the joint portion 42a from reaching the current interrupt device 43. Therefore, inhibiting the function of the current interrupt device 43 is suppressed.

  As shown in FIG. 6, the shape of the bus bar 12 may be changed. For example, the bus bar 12 may include a convex portion 12 b for welding to the welding table 42. In addition, the bus bar 12 may include a recess for irradiating a laser during laser welding.

(Circle) the welding stand 42 may protrude in the diameter direction rather than the flange part 41b.
The welding table 42 may be brazed with the rivet body 41. The welding table 42 may be ultrasonically welded to the rivet body 41. The welding table 42 may be fixed to the rivet body 41 by press-fitting. Moreover, the welding stand 42 may be formed in the rivet main body 41 by insert die casting.

The outer shape of the welding table 42 may be a polygon or an ellipse.
The rivet 40 may be a solid rivet like the rivet 60.
(Circle) the negative electrode terminal part 30 does not need to be provided with the electric current interruption apparatus 43. FIG.

The electrode assembly 20 may have a wound structure in which a belt-like positive electrode 21 and a belt-like negative electrode 22 are wound with a belt-like separator 23 interposed therebetween.
(Circle) the terminal parts 30 and 50 may be provided in the wall of the case main body 17 about the one or both.

○ The shape of the case 14 may be changed. For example, the case 14 may be a columnar type or a hexagonal column type.
The melting point of the second metal forming the bus bar 12 and the welding table 42 may be higher than the melting point of the first metal forming the rivet body 41.

  The welding table 42 may be exposed on the side surface of the flange portion 41b instead of or in addition to the second surface 41f. In other words, the exposed position of the welding table 42 can be changed as long as it can be welded to the bus bar 12.

  * The some secondary battery 11 may be provided with the terminal cover which covers the flange part 41b and the welding stand 42. FIG. That is, “the welding table 42 is exposed” in this specification may be a state in which the welding table 42 and the bus bar 12 can be welded, and the welding table 42 is not completely covered by the rivet body 41. Is intended.

The secondary battery 11 is not limited to being mounted on a vehicle, but may be a stationary battery used in a house or the like.
The secondary battery 11 may be a secondary battery of a different type from a lithium ion secondary battery, such as a nickel hydrogen secondary battery. The embodiment may be embodied as a power storage device of a different type from the secondary battery, such as an electric double layer capacitor.

  DESCRIPTION OF SYMBOLS 10 ... Secondary battery module (electric storage apparatus module), 11 ... Secondary battery (electric storage apparatus), 12 ... Bus bar, 14 ... Case, 20 ... Electrode assembly, 30 ... Negative electrode terminal part (terminal part), 41 ... Rivet main body (1st terminal part), 41b ... flange part (1st site | part), 41c ... large diameter part (2nd site | part), 41d ... through-hole, 41h ... opening part, 42 ... welding stand (2nd terminal part), 42a ... Junction part, 43 ... Current interruption device, 50 ... Positive electrode terminal part.

Claims (6)

An electrode assembly;
A case housing the electrode assembly;
A terminal portion for transmitting and receiving electricity with the electrode assembly,
The terminal portion is
A first terminal portion penetrating the wall of the case and made of a first metal;
A portion welded to the bus bar outside the case, and having a melting point different from that of the first metal, and a second terminal portion made of a second metal capable of being welded to the bus bar, and
The first terminal portion is a second part arranged outside the case and a second part arranged inside the case and sandwiching the wall of the case between the first part. A region, and
The first portion is provided with a stepped portion or a recess, and the second terminal portion is fitted in the stepped portion or the recessed portion without protruding in the diameter direction from the first portion,
The upper surface opposite to the lower surface fitted in the stepped portion or the recessed portion in the second terminal portion is not covered with the first terminal portion,
The second terminal portion is a power storage device that is exposed in a portion of the first portion of the first terminal portion that is different from a portion sandwiching the wall of the case.
  The power storage device according to claim 1, wherein the first terminal portion and the second terminal portion are friction-welded. The terminal part is a terminal part for a negative electrode,
The first metal is a single metal selected from the group consisting of copper, gold, aluminum, magnesium, tungsten, cobalt, zinc, nickel, iron, platinum, tin, indium, titanium, ruthenium, tantalum, and molybdenum, or The power storage device according to claim 1, wherein the power storage device is an alloy mainly composed of a metal selected from the group. A current interrupting device provided to be connected to the second portion, and interrupting a conductive path between the electrode assembly and the second terminal portion when an internal pressure of the case reaches a predetermined pressure; Has
The first terminal portion includes a through hole that opens to the first portion and the second portion, and the through hole has a direction in which the first terminal portion passes through the wall of the case. Extending along the
The power storage device according to any one of claims 1 to 3, wherein the current interrupt device faces an opening of the through hole in the second portion.   The power storage device according to claim 4, wherein a joint portion between the first terminal portion and the second terminal portion is not exposed inside the through hole. A plurality of power storage devices;
And a bus bar for electrically connecting power storage devices to each other,
The power storage device is the power storage device according to any one of claims 1 to 5,
The bus bar is a power storage device module welded to the second terminal portion among the terminal portions included in each power storage device.