JP6447015B2 - Power storage device and method for manufacturing power storage device - Google Patents

Description

  The present invention relates to a power storage device and a method for manufacturing the power storage device.

  Conventionally, vehicles such as EVs (Electric Vehicles) and PHVs (Plug in Hybrid Vehicles) have been mounted with lithium-ion secondary batteries or nickel-hydrogen secondary batteries as power storage devices that store power supplied to electric motors and the like. . In such a power storage device, as described in Patent Document 1, for example, conductive members are caulked and connected electrically by rivets.

  As shown in FIG. 9, in Patent Document 1, the diameter of the tip 73 a of the rivet member 73, which has a substantially round bar shape (cylindrical shape), is passed through a metal plate 72 that closes the opening 71 of the battery can 70. By deforming the rivet member 73 so as to increase, the tip end portion 73a of the rivet member 73 and the electrode lead-out member 74 disposed outside the metal plate 72 are electrically connected.

JP 2001-291506 A

  However, in Patent Document 1, since a gap S is generated between the distal end portion 73 a of the deformed rivet member 73 and the electrode lead-out member 74, the electrical resistance at the joint between the rivet member 73 and the electrode lead-out member 74. Can be high.

  The present invention has been made paying attention to the problems existing in the above-described conventional technology, and an object of the present invention is to provide a power storage device and a power storage that can be easily joined and can suppress an increase in electrical resistance at the joint. It is to provide a method for manufacturing an apparatus.

  A power storage device that solves the above-described problem is a power storage device that includes an electrode assembly housed in a case and an electrolyte, and the power storage device projects at least partially outside the case and is connected to the electrode assembly. An electrode terminal for transmitting and receiving electricity, a conductive member electrically connecting the electrode assembly and the electrode terminal and having a through hole, and a rod-shaped body portion inserted through the through hole, A first flange portion provided at a first end portion of both end portions of the body portion, and a second end portion opposite to the first end portion of both end portions of the body portion are provided by being deformed. A conductive rivet member that electrically connects the conductive member and the electrode assembly, and the body portion has an outer surface, and the second flange portion on the outer surface. A first connecting surface that is connected to the end of the side, and the front The second flange portion includes a contact surface that contacts the conductive member among both end surfaces in a direction in which the body portion extends, and a second continuous surface that is connected to an end portion on the body portion side of the contact surface. The gist is that the first continuous surface and the second continuous surface are in contact with each other or close to each other.

  According to this, the rivet member and the conductive member can be easily joined by deforming the second end portion of both end portions of the body portion and providing the second flange portion. Then, when the second flange portion is provided by deforming the second end portion by bringing the first continuous surface of the body portion and the second continuous surface of the second flange portion into contact or in proximity, the second flange portion is provided. It is easy to enlarge the contact surface between the portion and the conductive member. Therefore, it can suppress that the electrical resistance in the junction part of an electroconductive member and a rivet member becomes high.

  In the power storage device, it is preferable that the first continuous surface and the second continuous surface are annular surfaces surrounding a center line of the body portion. According to this, since the first continuous surface and the second continuous surface are annular surrounding the center line of the trunk portion, the contact surface between the second flange portion and the conductive member is formed over the entire circumference of the trunk portion. Easy to enlarge.

  In the power storage device, it is preferable that the first continuous surface and the second continuous surface are in surface contact. According to this, since the first connecting surface and the second connecting surface are in surface contact, when the second end portion is deformed to provide the second flange portion, the second flange portion and the conductive member The contact surface with can be made even easier.

  In the power storage device, the conductive member and the second flange portion are disposed outside the case, the conductive member is a plate-like member, and the conductive member is connected to the rivet member. It is preferable that it is connected with the said electrode terminal on the opposite side.

According to this, in the exterior of a case, it can join more simply by deform | transforming the 2nd edge part of a trunk | drum and providing a 2nd flange part.
Regarding the power storage device, the power storage device is preferably a secondary battery. According to this, as a secondary battery, while being able to join simply, it can suppress that the electrical resistance in a junction part becomes high.

  In addition, a method for manufacturing a power storage device that solves the above problem includes a conductive member having a through hole, a rod-shaped body, and a first flange provided at a first end of both ends of the body. In the method of manufacturing a power storage device including a joining step of joining a conductive rivet member having a portion, the barrel portion is an annular cutout cut out from an outer surface so as to surround a center line of the barrel portion. A cutout portion, the cutout portion being connected to an outer surface on the first end side with respect to the cutout portion; and the first cutout portion than the cutout portion. A second connecting surface that is connected to the outer surface of the second end opposite to the end, and in the joining step, the body is inserted into the through hole. The second end portion of the barrel portion is the notch portion so that the first continuous surface and the second continuous surface are close to or in contact with each other. It is deformed to bend outward and gist providing a second flange portion.

  According to this, a 2nd flange part can be provided by deform | transforming the 2nd end part in the trunk | drum of a rivet member, and a conductive member and a rivet member can be joined simply. At this time, when the second flange portion is provided by deforming the second end portion by bringing the first continuous surface and the second continuous surface of the notch portion of the body portion close to or in contact with each other, the second flange portion is provided. It is easy to enlarge the contact surface between the portion and the conductive member. Therefore, it can suppress that the electrical resistance in the junction part of an electroconductive member and a rivet member becomes high.

  ADVANTAGE OF THE INVENTION According to this invention, while being able to join simply, it can suppress that the electrical resistance in a junction part becomes high.

The exploded perspective view of a secondary battery. The perspective view of a secondary battery. The exploded perspective view of an electrode assembly. (A) is the 1-1 sectional view taken on the line shown in FIG. 2, (b) is the elements on larger scale of (a). (A) And (c) is sectional drawing of a secondary battery, (b) is the elements on larger scale of (a). Sectional drawing of the secondary battery in another embodiment. (A) And (b) is sectional drawing of the connection member in another embodiment. Sectional drawing of the secondary battery in another embodiment. Sectional drawing of the conventional secondary battery.

Hereinafter, an embodiment of the secondary battery will be described.
As shown in FIGS. 1 and 2, in the present embodiment, the secondary battery 10 as the power storage device is a lithium ion secondary battery, and is a square battery whose appearance is square. The secondary battery 10 includes a case 11 and an electrode assembly 12 accommodated in the case 11. The case 11 includes a bottomed square cylindrical case body 13 having an opening 14 and a square plate-like lid 15 that closes the opening 14. The case main body 13 and the lid 15 are made of metal such as stainless steel or aluminum.

  The lid 15 has two through holes 15a penetrating in the thickness direction. The lid 15 has two rectangular parallelepiped projecting portions 15b that project toward the outside of the case 11 at positions close to the respective through holes 15a. The case 11 contains an electrolytic solution as an electrolyte (not shown).

  As shown in FIG. 3, the electrode assembly 12 includes a positive electrode 16 as an electrode, a negative electrode 17 as an electrode, and a porous separator 18 that insulates between the electrodes 16 and 17. The electrode assembly 12 has a stacked structure in which positive electrodes 16 and negative electrodes 17 are alternately stacked with a separator 18 interposed therebetween. In the following description, the stacking direction of the electrodes 16 and 17 in the electrode assembly 12 is simply referred to as “stacking direction D1”.

  The positive electrode 16 includes a positive electrode metal foil 19 such as aluminum, a positive electrode active material layer 20 covering the positive electrode metal foil 19, and a positive electrode collection protruding from the edge 16 a of the positive electrode metal foil 19 in the surface direction of the positive electrode metal foil 19. And an electric tab 21. The positive electrode active material layer 20 is provided by applying a positive electrode active material on both surfaces of the positive electrode metal foil 19. The positive electrode current collecting tab 21 is an uncoated portion of the positive electrode metal foil 19 where no positive electrode active material is applied.

  The negative electrode 17 protrudes in the surface direction of the negative electrode metal foil 22 from the negative electrode metal foil 22 such as copper, the negative electrode active material layer 23 covering the negative electrode metal foil 22, and the edge 17 a of the negative electrode metal foil 22. And a negative electrode current collecting tab 24. The negative electrode active material layer 23 is provided by applying a negative electrode active material on both surfaces of the negative electrode metal foil 22. The negative electrode current collecting tab 24 is an uncoated portion of the negative electrode metal foil 22 where no negative electrode active material is applied. The negative electrode active material layer 23 has a size capable of covering the entire surface of the positive electrode active material layer 20 when viewed from the stacking direction D1 in the electrode assembly 12.

  As shown in FIG. 1, the electrode assembly 12 has a positive electrode current collection tab group 25 that protrudes from an opposing surface 12 a that faces the lid 15 and in which a plurality of positive electrode current collection tabs 21 are stacked in layers. In the electrode assembly 12, the positive electrode current collecting tab group 25 is provided by laminating the positive electrode 16 so that the positive electrode current collecting tabs 21 are arranged in a line along the lamination direction D1. The electrode assembly 12 has a negative electrode current collecting tab group 26 that protrudes from the facing surface 12a and in which a plurality of negative electrode current collecting tabs 24 are stacked in layers. In the electrode assembly 12, the negative electrode current collecting tab group 26 is provided by laminating the negative electrode 17 so that the negative electrode current collecting tabs 24 are arranged in a line along the lamination direction D1.

  Further, the secondary battery 10 is joined to the positive electrode current collecting tab group 25 and has a positive electrode connecting member 27 which is a conductive substantially square plate member. The positive electrode connection member 27 is made of, for example, aluminum or aluminum alloy. The secondary battery 10 is electrically connected to a positive electrode connection member 27, and has a positive electrode terminal 29 that exchanges electricity with the electrode assembly 12. In other words, the positive connection member 27 electrically connects the positive current collecting tab group 25 and the positive electrode terminal 29.

  Further, the secondary battery 10 is joined to the negative electrode current collecting tab group 26 and has a negative electrode connecting member 27 which is a conductive substantially square plate member. The connecting member 27 for the negative electrode is made of copper or a copper alloy. The secondary battery 10 is electrically connected to a negative electrode connection member 27, and has a negative electrode terminal 29 that exchanges electricity with the electrode assembly 12. That is, the negative electrode connecting member 27 electrically connects the negative electrode current collecting tab group 26 and the negative electrode terminal 29.

  Hereinafter, a connection structure between the connection member 27 and the electrode terminal 29 will be described with reference to FIGS. 1, 2, and 4 </ b> A and 4 </ b> B. In the present embodiment, since the connection structure between the connection member 27 and the electrode terminal 29 is substantially the same for the positive electrode and the negative electrode, the connection structure for the positive electrode will be described in detail, and the connection structure for the negative electrode will be described. The description will be simplified.

  The electrode terminal 29 includes a rectangular box-shaped fixing portion 31 having an opening on the lid 15 side, and a solid round bar-shaped (columnar) terminal portion 32 protruding from the fixing portion 31. The electrode terminal 29 is fixed to the lid 15 by inserting the fixing portion 31 into the protruding portion 15b with the terminal insulating member 33 that insulates the lid 15 and the electrode terminal 29 interposed therebetween. ing. That is, the electrode terminal 29 protrudes outside the case 11. The terminal portion 32 is provided with a male screw 32a. In the following description, the protruding direction of each terminal portion 32 is simply indicated as “projecting direction D2”. In the following description, a direction orthogonal to the stacking direction D1 and the protruding direction D2 is simply referred to as “width direction D3”.

  The secondary battery 10 has a terminal plate 42 as a conductive member having conductivity. The positive terminal plate 42 is made of, for example, aluminum or aluminum alloy. The negative terminal plate 42 is made of, for example, copper or copper alloy. The terminal plate 42 is a substantially square plate-like member extending along the width direction D3 outside the case 11, and is a first through-hole as a through-hole penetrating in the thickness direction (corresponding to the D2 direction). 42a and a second through hole 42b through which the terminal portion 32 is inserted.

  The connecting member 27 includes a solid round bar-shaped (columnar) body 35 inserted into the through-hole 15 a of the lid 15 and the first through-hole 42 a of the terminal plate 42, and both end portions of the body 35. The first flange portion 36 provided at the first end portion disposed inside the case 11 is included. The first flange portion 36 is a quadrangular plate-like member extending along the width direction D3, and the positive electrode current collecting tab group 25 is formed at the first end portion of both end portions of the first flange portion 36 in the width direction D3. It is joined.

  Further, the body portion 35 extends from the surface facing the lid 15 along the protruding direction D2 at the second end portion on the opposite side to the first end portion of the both end portions of the first flange portion 36. The body portion 35 has an outer peripheral surface 35a as an outer surface, and a first continuous surface 35b that is connected to the end portion on the protruding direction D2 side of the outer peripheral surface 35a (see FIG. 4B). Show). The first continuous surface 35b has an outer peripheral surface shape of a truncated cone whose diameter decreases from the lid 15 side toward the protruding direction D2. That is, the first continuous surface 35 b is an annular surface that surrounds the center line CL of the body portion 35.

  Further, the connection member 27 has a second flange portion 37 provided at a second end portion disposed outside the case 11 on the opposite side to the first end portion of the both end portions of the body portion 35. The second flange portion 37 is substantially disc-shaped when viewed from the protruding direction D2, and has a substantially conical recess 37a at the center. Moreover, the 2nd flange part 37 has the cyclic | annular protrusion part 37b which protrudes in the protrusion direction D2 so that it may become concentric with the hollow 37a.

Of the two end surfaces of the second flange portion 37 in the protruding direction D2, the surface on the terminal plate 42 side is a contact surface 37c that is in contact with the terminal plate 42 as a whole. Moreover, the 2nd flange part 37 has the 2nd connection surface 37d provided in a line by the edge part by the side of the trunk | drum 35 in the contact surface 37c (shown in FIG.4 (b)). The second continuous surface 37d is in the shape of an outer peripheral surface of a truncated cone whose diameter increases from the lid 15 side toward the protruding direction D2. That is, the second continuous surface 37 d is an annular surface that surrounds the center line CL of the body portion 35.

  In this embodiment, the front-end | tip part of the 1st continuous connection surface 35b in the trunk | drum 35 and the front-end | tip part of the 2nd continuous connection surface 37d in the 2nd flange part 37 are connected over the perimeter. In the present embodiment, at least a part (all in the present embodiment) of the first continuous surface 35b and the second continuous surface 37d are in contact with each other.

  As will be described later, the second flange portion 37 of the present embodiment is provided by deforming (plastically deforming) the second end portion of the body portion 35. In the following description, the second end portion of the body portion 35 is deformed (plastically deformed) to form the second flange portion 37, so that the connection member 27 and the other member are simply joined by “rivet joining”. ". FIG. 1 shows the connection member 27 in a state before the second end portion of the body portion 35 is deformed. As described above, the connection member 27 of the present embodiment corresponds to a rivet member.

  The secondary battery 10 is disposed between the first flange portion 36 and the lid 15, and has a square plate-shaped first insulating member 38 that insulates the connecting member 27 and the lid 15. The first insulating member 38 has a through hole 38a that penetrates in the thickness direction and through which the body portion 35 is inserted. In addition, the secondary battery 10 includes an insulating O-ring 39 that is inserted into the through hole 38 a in a state where the body portion 35 is inserted.

  The secondary battery 10 is interposed between the second flange portion 37 and the lid 15 in a state where the body portion 35 is inserted, and the second annular battery 10 that insulates the connection member 27 and the lid 15. An insulating member 40 is included. The second insulating member 40 is interposed between the outer peripheral surface 35 a of the body portion 35 and the inner peripheral surface of the through hole 15 a, thereby having an interposition portion 40 a that insulates the body portion 35 and the lid 15. .

  In the secondary battery 10, the lid 15, the first insulating member 38, the O-ring 39, the second insulating member 40, and the terminal plate 42 are sandwiched between the first flange portion 36 and the second flange portion 37, and It is in close contact with. Therefore, the connection member 27 is electrically connected to the terminal plate 42 at the second flange portion 37, thereby electrically connecting the electrode assembly 12 and the terminal plate 42. The terminal plate 42 is connected to the electrode terminal 29 on the side opposite to the side connected to the connection member 27. Further, the O-ring 39 is compressed between the lid 15, the interposition part 40 a, the first flange part 36, and the through hole 38 a, and the electrolyte solution in the case 11 and the gas that can be generated along with charging / discharging do not leak out. Is sealed.

  Next, with reference to FIG. 5, the manufacturing method of the secondary battery 10 is demonstrated centering on the joining method of the connection member 27 and the terminal board 42. FIG. In addition, since the joining method of the connection member 27 and the terminal board 42 is substantially the same in the joining method in a positive electrode, and the joining method in a negative electrode, it explains in detail about the joining method in a positive electrode, and explains the joining method in a negative electrode. To simplify.

  In the present embodiment, the manufacturing method of the secondary battery 10 includes a welding step in which the positive electrode current collecting tab group 25 and the first end portion of the first flange portion 36 in the connection member 27 are joined by welding, and the connection member 27. The second end portion of the body portion 35 is deformed to provide the second flange portion 37, and the joining step of rivet joining the connecting member 27 and the terminal plate 42 is included.

  As shown in FIGS. 5A and 5B, the connection member 27 has an annular cutout portion 50 cut out from the outer peripheral surface 35 a so as to surround the center line CL of the trunk portion 35. The notch 50 includes a first continuous surface 35 b that is continuous with the outer peripheral surface 35 a on the first end side of the body 35 with respect to the notch 50, and a second end with respect to the notch 50. The outer peripheral surface 35a on the side is provided with a second continuous surface 37d that is continuous with the outer peripheral surface 35a. That is, the notch 50 is a recess that has a triangular cross-section when cut along a virtual plane that includes the center line CL of the body 35 in the plane, and extends along the circumferential direction of the body 35.

  Further, the notch 50 is formed on both end surfaces of the terminal plate 42 in a state where the body 35 is inserted into the through hole 38a, the O-ring 39, the through hole 15a, the second insulating member 40, and the first through hole 42a. Of these, the surface opposite to the second insulating member 40 is provided so as to be located within the range from the proximal end to the distal end of the first connecting surface 35b in the protruding direction D2. In the body portion 35, the second end portion side of the notch portion 50 is a cylindrical processing portion 37 e. That is, the connection member 27 is a so-called hollow rivet member.

  In the joining step, the body of the connection member 27 is formed in the order of the through hole 38a of the first insulating member 38, the O-ring 39, the through hole 15a of the lid 15, the second insulating member 40, and the first through hole 42a of the terminal plate 42. The portion 35 is inserted and placed on the support base 60. The terminal portion 32 is inserted through the second through hole 42b of the terminal plate 42.

  Next, the caulking jig 61 for caulking the processing part 37e is brought into contact with the tip of the processing part 37e, and the caulking jig 61 is moved toward the support base 60. A concave portion having a shape corresponding to the second flange portion 37 is provided on a contact surface of the caulking jig 61 with the processing portion 37e.

  Then, as shown in FIG. 5 (c), as the caulking jig 61 moves, the processed portion 37 e is deformed (plastically deformed) so as to expand the diameter along the concave portion of the caulking jig 61. A flange portion 37 is provided at the second end portion of the body portion 35. At this time, since the notch 50 is provided in the trunk portion 35, the processed portion 37 e is deformed so as to be bent outward from the notch portion 50 in the diameter direction of the trunk portion 35. For this reason, the terminal plate 42 is formed at the base end portion of the second flange portion 37 as the first connecting surface 35b and the second connecting surface 37d constituting the notch 50 come into contact with each other. The occurrence of a gap between the two is suppressed. And the outer peripheral surface 35a in the process part 37e is in surface contact with the terminal board 42 as the contact surface 37c.

  If the notch 50 is not provided in the body portion 35, a gap may be formed between the base end portion of the second flange portion 37 and the terminal plate 42 due to the deformation of the processed portion 37e. is there. On the other hand, in this embodiment, such a problem is suitably solved by providing the notch part 50 in the trunk | drum 35 previously.

  Further, as described above, the notch portion 50 has a surface on the opposite side to the second insulating member 40 of both end surfaces of the terminal plate 42 in the protruding direction D2 from the proximal end of the first connecting surface 35b. It is provided so that it may be located in the range. Therefore, in the present embodiment, the second flange portion is formed by deforming the processed portion 37e until the first continuous surface 35b and the second continuous surface 37d constituting the notch 50 come into contact with each other. Each member can be strongly clamped between 37 (contact surface 37c) and the first flange portion 36.

Therefore, according to the present embodiment, the following effects can be obtained.
(1) The connecting member 27 and the terminal plate 42 can be simply joined by providing the second flange portion 37 by deforming the second end portion of the both end portions of the body portion 35. And it is easy to enlarge the area of the contact surface 37c in the 2nd flange part 37 by making the 1st continuous connection surface 35b of the trunk | drum 35 and the 2nd continuous connection surface 37d of the 2nd flange part 37 contact. Therefore, it is possible to suppress an increase in electrical resistance at the joint between the terminal plate 42 and the connection member 27.

  (2) Since the first continuous surface 35b and the second continuous surface 37d are annular surrounding the center line CL of the body portion 35, the second flange portion 37 and the terminal plate 42 are formed over the entire periphery of the body portion 35. The contact surface 37c can be easily enlarged.

  (3) Since the first connecting surface 35b and the second connecting surface 37d are in surface contact with each other, when the second flange portion 37 is provided by deforming the second end portion, The contact surface 37c with the terminal plate 42 can be further increased easily.

(4) Outside the case 11, the second flange portion 37 is provided by deforming the processed portion 37 e of the second end portion of the body portion 35, so that the joining can be performed more easily.
(5) The secondary battery 10 can be simply joined, and the electrical resistance at the joined portion can be suppressed from increasing.

  (6) The 2nd flange part 37 can be provided by deform | transforming the 2nd end part in the trunk | drum 35 of the connection member 27, and the terminal board 42 and the connection member 27 can be joined simply. At this time, when the second flange portion 37 is provided by deforming the second end portion by bringing the first continuous surface 35b of the body portion 35 into contact with the second continuous surface 37d of the second flange portion 37. The contact surface 37c between the second flange portion 37 and the terminal plate 42 can be easily increased. Therefore, it is possible to suppress an increase in electrical resistance at the joint between the terminal plate 42 and the connection member 27.

  (7) In this embodiment, since it is possible to suppress an increase in electrical resistance (contact resistance) between the terminal plate 42 and the connection member 27, after the terminal plate 42 and the connection member 27 are rivet joined, The process of performing resistance welding or laser welding can be omitted.

  (8) The connecting member 27 has a first flange portion 36 to which the current collecting tab groups 25 and 26 are joined. Therefore, the number of parts can be reduced by combining the head as the rivet member and the member for joining the current collecting tab groups.

In addition, you may change the said embodiment as follows.
As shown in FIG. 6, it is necessary that the first connecting surface 35b and the second connecting surface 37d are in contact (contact) except for the connecting portion at the tip of each connecting surface 35b, 37d. There should be no proximity.

  (Circle) As shown in FIG. 7, you may change the shape of the notch part 50. FIG. For example, the cutout portion 50 may have a trapezoidal cross section when cut along a virtual plane including the center line CL of the body portion 35 in the plane (shown in FIG. 7A). Further, for example, the cutout portion 50 may have a semicircular cross-sectional shape when cut by a virtual plane including the center line CL of the body portion 35 in the plane (shown in FIG. 7B).

  As shown in FIG. 8, the rivet joining described above can be applied to joining the connecting member 27 and the conductive member 51 different from the terminal plate 42. In this case, the second flange portion 37 is formed in the state where the barrel portion 35 is inserted into the through hole 25a of the positive electrode current collecting tab group 25 and the through hole 51a of the conductive member 51, and the processed portion 37e ( (Not shown here) may be deformed. Even in such a configuration, the contact surface 37c of the second flange portion 37 is increased by bringing the first continuous surface 35b of the body portion 35 into contact with the second continuous surface 37d of the second flange portion 37. Easy to do. Therefore, it is possible to suppress an increase in electrical resistance at the joint between the conductive member 51 and the connection member 27. In addition, the connection member 27 of this another example is a member for joining the positive electrode current collection tab group 25 and the conductive member 51. In this different example, the conductive member 51 is disposed inside the case 11. This example can also be applied to a negative electrode connection structure and bonding method.

  The electrode terminal 29 may be arranged so as to penetrate the wall (lid 15) of the case 11 so that the terminal portion 32 protrudes outside the case 11 and the fixing portion 31 protrudes inside the case 11. . That is, it is only necessary that at least a part of the electrode terminal 29 protrudes outside the case 11. In this case, the conductive member that electrically connects the electrode assembly 12 and the electrode terminal 29 is disposed inside the case 11.

The second flange portion 37 may have a contact surface 37 c with the terminal plate 42, and a part thereof may be separated from the terminal plate 42.
○ The shape of the trunk portion 35 may be changed. For example, the trunk portion 35 may be prismatic.

O The processing part 37e of the trunk | drum 35 may be a solid round bar shape (columnar shape). Further, the processed portion 37e may have a split pin shape.
O The trunk | drum 35 of the connection member 27 may be hollow round bar shape (cylindrical shape) as a whole.

  (Circle) when trying to further reduce the electrical resistance between the 2nd flange part 37 and the terminal board 42, the 2nd flange part 37 and the terminal board 42 can also be joined by resistance welding or laser welding.

  A flange portion may be provided by deforming an end portion disposed inside the case 11 among both end portions of the body portion 35 in the connection member 27. In this case, the positive electrode current collecting tab group 25 directly or indirectly with no other conductive member interposed between the flange portion provided inside the case 11 or other conductive member. May be electrically connected. This example can also be applied to a negative electrode connection structure and bonding method.

  A conductive member joined to the positive electrode current collecting tab group 25 may be joined to the first flange portion 36 of the connecting member 27. That is, the head as the rivet member does not have to be used as a member for joining the current collecting tab groups. This example can also be applied to a negative electrode connection structure and bonding method.

The electrode assembly 12 may be a wound electrode assembly that is wound and laminated in a layered manner with a strip-shaped separator interposed between the strip-shaped positive electrode and the strip-shaped negative electrode.
The number of members constituting the case 11 may be three or more, and the shape of each member may be changed. For example, the case 11 may be formed by combining a first member having an opening and a second member having an opening so that the openings face each other.

  The shape of the case 11 may be changed as appropriate in accordance with the shape of the electrode assembly 12 to be accommodated. For example, the case 11 may be cylindrical. In this case, a bottomed cylindrical case body 13 and a disk-shaped lid 15 may be used.

(Circle) the secondary battery 10 may be mounted in the passenger car and industrial vehicle as a vehicle, and may be applied as a stationary electrical storage apparatus.
The secondary battery 10 is not limited to a lithium ion secondary battery, and may be another secondary battery such as a nickel hydrogen secondary battery or a nickel cadmium secondary battery.

O Not only a secondary battery, but may be embodied as a capacitor such as an electric double layer capacitor or a lithium ion capacitor.
Hereinafter, a technical idea that can be grasped from the above-described embodiment and modified examples will be added.

  (A) It is preferable that an electrode assembly is electrically connected to the rivet member.

  DESCRIPTION OF SYMBOLS 10 ... Secondary battery (electric storage apparatus), 11 ... Case, 12 ... Electrode assembly, 27 ... Connection member, 29 ... Electrode terminal, 35 ... Body part, 35a ... Outer peripheral surface (outer surface), 35b ... 1st connection surface 36 ... first flange portion, 37 ... second flange portion, 37c ... contact surface, 37d ... second connecting surface, 37e ... machined portion, 42 ... terminal plate (conductive member), 42a ... first through hole (through) Hole), 50 ... notch, 51 ... conductive member.

Claims (6)

A power storage device having an electrode assembly and an electrolyte housed in a case,
The power storage device
An electrode terminal protruding at least partially outside the case and transferring electricity to and from the electrode assembly;
A conductive member electrically connecting the electrode assembly and the electrode terminal and having a through hole;
What is the rod-shaped body portion inserted through the through-hole, the first flange portion provided at the first end portion of the both end portions of the body portion, and the first end portion of the both end portions of the body portion? A conductive rivet member having a second flange portion provided by deforming the second end portion on the opposite side, and electrically connecting the conductive member and the electrode assembly;
The trunk portion has an outer surface and a first continuous surface that is continuous with an end portion of the outer surface on the second flange portion side,
The second flange portion includes a contact surface that is in contact with the conductive member among both end surfaces in a direction in which the body portion extends, and a second continuous surface that is connected to an end portion on the body portion side of the contact surface. And
The first continuous surface and the second continuous surface are in contact with or close to each other,
The power storage device according to claim 1, wherein the first continuous surface has an outer peripheral surface of a truncated cone whose diameter decreases from the case side in a direction in which the electrode terminal protrudes . Before Stories second communication setting surface, the power storage device according to claim 1, wherein the surface of the annular surrounding the center line of the barrel.   The power storage device according to claim 1, wherein the first continuous surface and the second continuous surface are in surface contact. The conductive member and the second flange portion are disposed outside the case, and the conductive member is a plate-shaped member,
The power storage device according to any one of claims 1 to 3, wherein the conductive member is connected to the electrode terminal on a side opposite to a side connected to the rivet member.   The power storage device according to any one of claims 1 to 4, wherein the power storage device is a secondary battery. A conductive member having a through hole;
A method for manufacturing a power storage device, comprising: a joining step of joining a rod-shaped body portion and a conductive rivet member having a first flange portion provided at a first end portion of both end portions of the body portion. In
The trunk portion has an annular cutout portion cut out from an outer surface so as to surround a centerline of the trunk portion, and the notch portion is an imaginary plane including the centerline of the trunk portion in the plane. The cross-sectional shape when cut at is a triangle, a trapezoid, or a semicircle, the first continuous surface that is connected to the outer surface on the first end side than the notch, and the cutout A second connecting surface that is connected to the outer surface of the second end opposite to the first end,
In the joining step, the second end portion of the body portion is arranged so that the first connection surface and the second connection surface are close to or in contact with each other in a state where the body portion is inserted through the through hole. A method of manufacturing a power storage device, wherein the second flange portion is provided by being deformed so as to be bent outward from the notch portion.