JP2017091723A - Method of manufacturing electricity storage device, and electricity storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing an electricity storage device capable of improving material yield, and an electricity storage device.SOLUTION: A plurality of conductive members 51 are produced by punching a sheet of a plate material 60. In plan view of the plate material 60, a first conductive member 51A and a second conductive member 51B are punched from the plate material 60 while a connection piece 53 of the second conductive member 51B is complimented to a blank portion R of the first conductive member 51A.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a method for manufacturing a power storage device including a conductive member in which a tab group and an electrode terminal are electrically connected, and a power storage device.

  Vehicles such as EVs (Electric Vehicles) and PHVs (Plug in Hybrid Vehicles) are equipped with secondary batteries as power storage devices that store the power supplied to the driving 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.

  The electrode assembly includes, for example, a stacked electrode assembly in which separators are interposed between a plurality of positive electrodes and a plurality of negative electrodes, or between a belt-like positive electrode and a belt-like negative electrode. There is a wound-type electrode assembly wound with a strip-shaped separator interposed therebetween.

  For example, the battery described in Patent Document 1 includes a case containing a wound electrode assembly and a non-aqueous electrolyte, and a negative electrode terminal is surrounded by a gasket at the center of the lid of the case. Is provided. In the battery, the portion other than the portion where the negative electrode terminal of the case is provided is the positive electrode. Further, an insulator is provided along the back surface of the lid, and a current collector as a conductive member is accommodated in the recess of the insulator. A tab having a shape protruding toward the electrode assembly is suspended from the current collector, and a negative REIT connected to the negative electrode of the electrode assembly is connected to the tab.

JP 2009-193787 A

  By the way, the conductive member (the current collector in Patent Document 1) may be manufactured by punching a metal plate as a material. In this case, the material generated by reducing the end material generated when the conductive member is manufactured is used. It is preferable to improve the yield.

  An object of the present invention is to provide a method of manufacturing a power storage device that can improve the material yield, and a power storage device.

  A method of manufacturing a power storage device for solving the above problems includes an electrode assembly in which electrodes having tabs protruding from one side are stacked, a tab group configured by stacking the tabs, and the electrode set A case that accommodates a solid body and the tab group, an electrode terminal that is fixed to the wall portion of the case and receives electricity from the electrode assembly, and a metal plate that electrically connects the tab group and the electrode terminal. An electrical storage device manufacturing method comprising: a conductive member, wherein the conductive member is a fixed piece in a position overlapping the wall portion; and a connection piece continuous to the fixed piece and joined to the tab group The direction in which the fixed piece and the connecting piece are arranged is defined as the continuous direction of the conductive member, and the direction perpendicular to the continuous direction is along the surface direction of the fixed piece. Width direction, one side in the continuous direction, the width Assuming a rectangular virtual surface extending in the direction perpendicular to the one side, the conductive member has an edge of the fixed piece along an edge of the virtual surface, and at least one of the connection pieces. The portion protrudes in the continuous direction from the width of the fixed piece and fits in the virtual surface, and has a blank portion where the metal plate does not exist on the virtual surface, and the conductive member is a single piece of metal. A plurality of punched plate materials are manufactured, and in the plan view of the plate material, the conductive piece is supplemented to the blank portion, and the conductive pieces are arranged in a state where the fixed piece and the connection piece of the different conductive member are aligned. The gist is that the member is punched from the plate.

  According to this, when punching out a plurality of conductive members from a plate material, a connection piece of another conductive member is complemented to a portion that becomes a blank portion of one conductive member. For this reason, in the plate material, a portion that becomes a blank portion of one conductive member can also be a material for manufacturing a connecting piece of another conductive member, and the material that is a portion that becomes a blank portion is discarded as it is. Yield can be improved.

Moreover, about the manufacturing method of an electrical storage apparatus, the said some electrically conductive member is pierce | punched in the state in which the edge part extended in the said connection direction becomes flush with the said conductive members arranged in the said connection direction.
According to this, when the edges of the plurality of conductive members are flush with each other, it is not necessary to complicate the shape of the die for punching the plate material, and it is easy to punch the conductive members.

Moreover, about the manufacturing method of an electrical storage apparatus, the width | variety of the said connection piece is a half of the width | variety of the said fixed piece.
According to this, in the state where the two conductive members are arranged in the connecting direction and the connection piece of another conductive member is complemented in the blank portion, the width of the connection pieces in the two conductive members can be made the same. The conductive member having the same shape can be manufactured by punching.

Moreover, about the manufacturing method of an electrical storage apparatus, the shape which protruded from the said virtual surface along the said width direction may be sufficient as the said connection piece.
According to this, the width | variety of a connection piece can be ensured and a connection piece can be bent from the bending line which follows a connection direction. Then, by bending the connection piece, the connection piece can be projected from the fixed piece, and the tab group can be easily joined to the connection piece. In particular, it becomes a shape suitable for resistance welding performed by sandwiching the connecting piece and the tab group with the electrode rod.

A power storage device for solving the above problems includes an electrode assembly in which electrodes having tabs protruding from one side are stacked, a tab group formed by stacking the tabs, and the electrode assembly. And a case for housing the tab group, an electrode terminal fixed to the wall portion of the case, for transmitting and receiving electricity to and from the electrode assembly, and a conductive metal plate electrically connecting the tab group and the electrode terminal. And the conductive member has a fixed piece that is in a position overlapping the wall portion, and a connection piece that is continuous with the fixed piece and to which the tab group is joined. The direction in which the fixed piece and the connection piece are arranged is the continuous direction of the conductive member, the direction along the surface direction of the fixed piece, and the direction orthogonal to the continuous direction is the width direction of the conductive member, One side in the continuous direction and the one in the width direction. Assuming a rectangular virtual surface extending on the other side orthogonal to the conductive member, the conductive member has an edge of the fixed piece along the edge of the virtual surface, and at least a part of the connection piece is the fixed piece. It fits in the imaginary surface in a shape protruding in the continuous direction from within the width of, and has a blank portion where the metal plate does not exist in the imaginary surface,
The gist of the conductive member is a shape that can complement the connecting piece of another conductive member in the blank portion in plan view.

  According to this, when punching out a plurality of conductive members from a plate material, a shape in which a connecting piece of another conductive member is complemented to a portion that becomes a blank portion of one conductive member. For this reason, in the plate material, a portion that becomes a blank portion of one conductive member can also be a material for manufacturing a connecting piece of another conductive member, and the material that is a portion that becomes a blank portion is discarded as it is. Yield can be improved.

  According to the present invention, the material yield can be improved.

The disassembled perspective view which shows the secondary battery of 1st Embodiment. The perspective view which shows the external appearance of the secondary battery of 1st Embodiment. The disassembled perspective view which shows the component of an electrode assembly. The fragmentary sectional view which shows joining to a tab group, an electrically-conductive member, an auxiliary terminal, and an external terminal. The fragmentary sectional view which shows the joining state of a tab group and an electrically-conductive member. (A) is a perspective view which shows the state which integrated the auxiliary terminal and the external terminal in the cover member, (b) is a perspective view which shows the state which integrated the electrically-conductive member in the cover member. (A) is a top view of an electroconductive member, (b) is a top view which shows arrangement | positioning of the electroconductive member in a metal plate. The fragmentary sectional side view which shows the laser welding of the connection piece in a tab group and a cover terminal assembly. (A) is a top view of an electroconductive member, (b) is a top view which shows arrangement | positioning of the electroconductive member in a metal plate. The perspective view which shows the state which integrated the electrically-conductive member with the cover member. The fragmentary sectional view which shows the joining state of a tab group and an electrically-conductive member. The fragmentary sectional side view which shows the resistance welding of the connection piece in a tab group and a lid terminal assembly. (A) And (b) is a top view which shows another example of an electrically-conductive member.

(First embodiment)
Hereinafter, a first embodiment in which a method for manufacturing a power storage device is embodied as a method for manufacturing a secondary battery and a power storage device is embodied as a secondary battery will be described with reference to FIGS.

  As shown in FIG. 1 or 2, the secondary battery 10 as a power storage device includes a case 11, and the case 11 accommodates an electrode assembly 12 and a positive and negative electrode tab group 36. The case 11 includes a square box-shaped case member 14 and a lid member 15 as a rectangular flat plate-like wall portion that closes the opening 14 a of the case member 14. In addition, the secondary battery 10 of this embodiment is a lithium ion battery. A positive electrode terminal 16 and a negative electrode terminal 17 are electrically connected to the electrode assembly 12 as electrode terminals for transferring electricity to and from the electrode assembly 12.

  As shown in FIG. 3, 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. The positive electrode 21 has a positive metal foil (aluminum foil in this embodiment) 22 and a positive electrode active material layer 23 formed by applying a positive electrode active material on both surfaces thereof. The negative electrode 31 includes a negative electrode metal foil (copper foil in the present embodiment) 32 and a negative electrode active material layer 33 configured by applying a negative electrode active material on both surfaces thereof. The electrode assembly 12 is a layered type in which a separator 24 is interposed between a plurality of positive electrodes 21 and a plurality of negative electrodes 31 to interpose them.

  The positive electrode 21 has a positive electrode uncoated portion 22 b that is not coated with a positive electrode active material along one side 22 a of the positive metal foil 22. The positive electrode 21 has a tab 25 having a shape protruding from a part of one side 22a. The negative electrode 31 has a negative electrode uncoated portion 33 b that is not coated with a negative electrode active material along one side 32 a of the negative electrode metal foil 32. The negative electrode 31 has a tab 35 having a shape protruding from a part of one side 32a.

  As shown in FIG. 1, the plurality of positive electrode tabs 25 and the plurality of negative electrode tabs 35 are such that the positive electrode tab 25 and the negative electrode tab 35 do not overlap in a state where the positive electrode 21 and the negative electrode 31 are stacked. It is provided at each position. The electrode assembly 12 has a tab-side end face 12b formed by gathering together one side 22a of the positive electrode 21, one side 32a 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 L. 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 L.

  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 toward one end side in the stacking direction L of the electrode assembly 12, It is configured by stacking. Further, the secondary battery 10 has a negative electrode tab group 36 protruding from the tab side end face 12 b, and the tab group 36 brings all the negative electrode tabs 35 close to one end side in the stacking direction L of the electrode assembly 12. Collected and stacked. In the secondary battery 10, the inner surface of the lid member 15 faces each tab group 36 accommodated in the case 11 and the tab side end surface 12 b of the electrode assembly 12. In the electrode assembly 12, a direction along the tab-side end surface 12 b and in which the positive electrode tab 25 (tab group 36) and the negative electrode tab 35 (tab group 36) are arranged is referred to as a parallel direction X. A direction connecting the inner surface of the lid member 15 and the tab side end surface 12b of the electrode assembly 12 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 the positive electrode terminal 16 is joined to the positive electrode tab group 36. The positive electrode conductive member 51 is made of an aluminum plate. Further, a negative electrode conductive member 51 for electrically connecting the electrode assembly 12 and the negative electrode terminal 17 is joined to the negative electrode tab group 36. The negative electrode conductive member 51 is made of a copper plate.

  Next, the joint structure of the positive electrode tab group 36 and the conductive member 51 and the negative electrode tab group 36 and the conductive member 51 will be described in detail with reference to FIG. In FIG. 5, the bonding structure of the negative electrode tab group 36 and the conductive member 51 is illustrated, but this bonding structure is the same as the bonding structure of the positive electrode tab group 36 and the conductive member 51. The joint structure between the tab group 36 and the conductive member 51 is omitted. In the following description, if the negative electrode is read as the positive electrode, the bonding structure of the positive electrode tab group 36 and the positive electrode conductive member 51 is described.

  As shown in FIG. 5, in the negative electrode tab group 36, the tab 35 positioned at one end in the stacking direction L of the electrode assembly 12 is referred to as a first tab 351. In the negative electrode tab group 36, the tab 35 positioned at the other end in the stacking direction L of the electrode assembly 12 is referred to as a second tab 352. In this case, in the negative electrode tab group 36, the tabs 35 are gathered on one end side in the stacking direction so that the second tab 352 approaches the first tab 351. As a result, the tabs 35 that were independent at the stacking stage are collected on the first tab 351 side. Then, the negative electrode tab group 36 and the conductive member 51 are joined together by performing laser welding in a state where the conductive member 51 is in contact with the first tab 351 and forming a conduction portion W, and are electrically connected. (Conducting).

  In the present embodiment, the tabs 35 are formed in the same size. Therefore, in the stacking direction L of the electrode assembly 12, the tab 35 that is gathered as the negative electrode tab group 36 is shorter as the tab 35 has a longer separation distance from the first tab 351. For this reason, the conduction | electrical_connection part W for making all the tabs 35 conduct is provided according to the superposition | polymerization area | region with the other tab 35 in the 1st tab 351. FIG.

The conductive member 51 includes a fixed piece 52 that overlaps the cover member 15 in the facing direction Z when viewed from the side-by-side direction X, and a connection piece 53 that is connected to the fixed piece 52.
Here, the conductive member 51 before being connected to the negative electrode tab group 36 will be described.

  As shown in FIG. 6B or FIG. 7A, the fixing piece 52 included in the conductive member 51 has a rectangular plate shape. The conductive member 51 is fixed to the inner surface of the lid member 15 via an inner insulating cover 55 described later, and is assembled to the lid member 15. In addition, the conductive member 51 has an insertion hole 52a in the fixed piece 52, and an auxiliary terminal 61 described later can be inserted into the insertion hole 52a.

  The conductive member 51 has a connection piece 53 that is continuous with the fixed piece 52. In the conductive member 51, a direction in which the fixed piece 52 and the connection piece 53 are continuous is defined as a continuous direction. A direction along the surface direction of the fixed piece 52 and perpendicular to the continuous direction is defined as a width direction, and a dimension of the fixed piece 52 along the width direction is defined as a width W1. The connection piece 53 has a shape protruding from a part within the width W1 of the fixed piece 52 in the connecting direction. When the dimension of the connecting piece 53 along the width direction is a width W2, the width W2 of the connecting piece 53 is half of the width W1 of the fixed piece 52.

  As shown to Fig.7 (a), the fixed piece 52 of the electrically-conductive member 51 has the 1st fixed piece edge part 52b in one of a pair of edge parts extended in a connection direction, and a 2nd fixed piece in the other. It has an edge 52c. Further, the fixed piece 52 includes a third fixed piece edge 52d that connects the first fixed piece edge portion 52b and the second fixed piece edge portion 52c, and a fourth fixed piece edge opposite to the third fixed piece edge portion 52d. It has a part 52e. Therefore, the connection piece 53 has a shape protruding in the connecting direction from the fourth fixed piece edge portion 52e.

  In addition, the connection piece 53 of the conductive member 51 has a first connection piece edge 53a on one of a pair of edges extending in the connecting direction, and a second connection piece edge 53b on the other. Furthermore, the connection piece 53 has the 3rd connection piece edge part 53c which connects the 1st connection piece edge part 53a and the 2nd connection piece edge part 53b.

  In the conductive member 51, the first fixed piece edge portion 52b and the first connection piece edge portion 53a are located on the same straight line. On the other hand, the second fixed piece edge 52c and the second connection piece edge 53b are arranged in a stepped manner, and the second connection piece edge 53b is a first connection piece edge more than the second fixed piece edge 52c. The position is close to the portion 53a.

  Assuming that a straight line extending the second fixed piece edge 52c in the connecting direction is a first virtual line L1, and a straight line extending the third connection piece edge 53c in the width direction is a second virtual line L2, the conductive member 51 is The shape fits in the rectangular virtual surface M. One side of the virtual surface M is the first fixed piece edge portion 52b and the first connection piece edge portion 53a, the second fixed piece edge portion 52c, and the first virtual line L1 extending in the connecting direction. The other side orthogonal to one side is a third fixed piece edge portion 52d extending in the width direction, a third connection piece edge portion 53c, and a second imaginary line L2.

  The planar view shape of the conductive member 51 is such that the edge of the fixed piece 52 is accommodated along the edge of the virtual surface M, and the connection piece 53 is also within the virtual surface M. Moreover, in the planar view shape of the conductive member 51, the conductive member 51 includes a blank portion R in which no metal plate exists in the virtual plane M. The blank portion R is a region surrounded by the first virtual line L1, the second virtual line L2, the fourth fixed piece edge 52e, and the second connection piece edge 53b. Further, the connection piece 53 and the blank portion R are point-symmetric in the virtual plane M excluding the fixed piece 52. The area of the blank portion R is the same as the area of the connection piece 53.

  As shown in FIG. 7B, the conductive member 51 has a shape that can form a rectangle when the two conductive members 51A and 51B are arranged in the connecting direction. This is because the connection piece 53 and the blank portion R are point-symmetric in the virtual plane M excluding the fixed piece 52, so that the connection pieces 53 of the conductive members 51A and 51B can be accommodated in the blank portion R of each other. by.

  That is, the connection piece 53 of the second conductive member 51B is arranged in the blank portion R of the first conductive member 51A, and the connection piece 53 of the first conductive member 51A is arranged in the blank portion R of the second conductive member 51B. To do. Then, the second connection piece edge 53b of the first conductive member 51A and the second connection piece edge 53b of the second conductive member 51B are brought into contact with each other, and the fourth fixed piece of the first conductive member 51A is contacted. The edge 52e and the third connection piece edge 53c of the second conductive member 51B are brought into contact with each other. Then, the first fixed piece edge portion 52b and the first connection piece edge portion 53a of the first conductive member 51A and the second fixed piece edge portion 52c of the second conductive member 51B are positioned on the same straight line. Become one. In addition, the second fixed piece edge 52c of the first conductive member 51A and the first connection piece edge 53a and the first fixed piece edge 52b of the second conductive member 51B are located on the same straight line. Become one. Therefore, a rectangle is completed by the combination of the two conductive members 51A and 51B.

Next, the inner insulating cover 55 provided in the secondary battery 10 will be described.
As shown in FIG. 1, the secondary battery 10 includes an inner insulating cover 55 in the case 11, and the inner insulating cover 55 is interposed between the negative electrode conductive member 51 and the positive electrode conductive member 51 and the lid member 15. Intervene. The inner insulating cover 55 has through holes 56 at both ends in the direction in which the long sides extend.

  The secondary battery 10 includes a positive terminal 16 and a negative terminal 17 that are fixed to the lid member 15. Each of the positive electrode terminal 16 and the negative electrode terminal 17 includes an auxiliary terminal 61 fixed to the lid member 15 via the above-described inner insulating cover 55 and an outer insulating member 57 described later. The positive auxiliary terminal 61 is made of aluminum, and the negative auxiliary terminal 61 is made of copper. The auxiliary terminal 61 includes a prismatic pedestal portion 61a, a first caulking portion 61b that protrudes from one surface of the pedestal portion 61a, and a second caulking portion 61c that protrudes from the other surface of the pedestal portion 61a. .

  In the secondary battery 10, the auxiliary terminal 61 is insulated from the lid member 15 by the outer insulating member 57. The outer insulating member 57 has a cylindrical shape, and has a pedestal support portion 57a on one end side in the axial direction. The pedestal support portion 57a has an auxiliary terminal recess 57b having a shape into which the pedestal portion 61a is fitted. The outer insulating member 57 has a cylindrical shaft portion 57c having a smaller diameter than the pedestal support portion 57a and inserted into the terminal insertion hole 15b of the lid member 15.

  Next, the structure of the positive terminal 16 and the negative terminal 17 will be described. FIG. 4 illustrates the structure of the negative electrode terminal 17, but the structure of the positive electrode terminal 16 is the same as that of the negative electrode terminal 17. In the description of the negative electrode terminal 17, the positive electrode terminal 16 can be described by replacing the negative electrode with the positive electrode.

  As shown in FIG. 4, in the outer insulating member 57, the pedestal support portion 57 a is disposed on the outer surface of the lid member 15, and the shaft portion 57 c is fitted into the terminal insertion hole 15 b of the lid member 15. The shaft portion 57 c is inserted through the through hole 56 of the inner insulating cover 55.

  In a state where the pedestal portion 61a of the auxiliary terminal 61 is fitted in the auxiliary terminal recess 57b, the first caulking portion 61b is electrically conductive in a state of passing through the shaft portion 57c of the outer insulating member 57 and the insertion hole 52a of the conductive member 51. The auxiliary terminal 61 is fixed to the lid member 15 by being caulked by the member 51. The auxiliary terminal 61 is electrically connected to the negative electrode 31 of the electrode assembly 12 through a connection by caulking between the first caulking portion 61 b and the conductive member 51, and via the outer insulating member 57 and the inner insulating cover 55. The lid member 15 is clamped and fixed in an insulated state with respect to the lid member 15.

  The lid member 15 includes anti-rotation portions 15a on both ends in the direction in which the long side extends and outside the terminal insertion hole 15b. The anti-rotation portion 15a is a convex portion in which the metal plate of the lid member 15 is projected outward in a square shape by pressing. And in each rotation prevention part 15a, the external terminal 66 is arrange | positioned through the terminal insulating material 59 of the substantially covered square cylinder shape. The external terminal 66 is made of metal. The external terminal 66 has a rectangular box shape, and includes a base portion 66a into which the anti-rotation portion 15a is inserted via a terminal insulating material 59, and a pole column portion 66b protruding from the base portion 66a. The male column portion 66c is provided on the outer peripheral surface of the pole column portion 66b. The external terminal 66 and the lid member 15 are insulated from each other by the terminal insulating material 59.

  The secondary battery 10 has a rectangular flat connecting conductor 54. The connecting conductor 54 has a caulking portion insertion hole 54a at one end in the extending direction of the long side, and a pole column insertion hole 54b at the other end in the extending direction of the long side. The connecting conductor 54 has the pole column portion 66b of the external terminal 66 inserted into the pole column insertion hole 54b from the lid member 15 side, and the second crimp portion 61c of the auxiliary terminal 61 is covered with the crimp portion insertion hole 54a. It is inserted from the member 15 side. The second caulking portion 61 c is caulked outside the connection conductor 54. Therefore, although the connection conductor 54 is connected and fixed to the auxiliary terminal 61, the external terminal 66 has only the pole column part 66 b inserted through the pole column part insertion hole 54 b. Further, the connection conductor 54 is in contact with the base portion 66a of the external terminal 66 and is conductive.

  In the secondary battery 10, the positive external terminal 66 is electrically connected to the positive electrode tab group 36 of the positive electrode 21 through the connection conductor 54, the auxiliary terminal 61, and the conductive member 51. Therefore, the positive electrode terminal 16 is electrically connected at one end in the direction in which the long side of the conductive member 51 extends, and the positive electrode tab group 36 is electrically connected at the other end in the direction in which the long side of the conductive member 51 extends. It is connected. For this reason, the positive electrode terminal 16 can exchange electricity with the electrode assembly 12 via the conductive member 51.

  The negative external terminal 66 is electrically connected to the tab group 36 of the negative electrode 31 through the connection conductor 54, the auxiliary terminal 61, and the conductive member 51. Therefore, the negative electrode terminal 17 is electrically connected at one end of the conductive member 51 in the extending direction of the long side, and the negative electrode tab group 36 is electrically connected at the other end of the conductive member 51 in the extending direction of the long side. It is connected. Therefore, the negative electrode terminal 17 can exchange electricity with the electrode assembly 12 via the conductive member 51.

  6 (a) or 6 (b), the inner insulating cover 55, the conductive member 51, the connection conductor 54, the terminal insulating material 59, and the auxiliary terminal 61 are connected to the lid member 15. The lid terminal assembly 18 is configured by integrally assembling the external terminal 66. In the lid terminal assembly 18, the fixing piece 52 of the conductive member 51 is in a state of facing the inner surface of the lid member 15. Further, in the lid terminal assembly 18, the connection piece 53 protrudes from the inner surface in a state orthogonal to the inner surface of the lid member 15.

Next, the manufacturing method of the conductive member 51 among the manufacturing methods of the secondary battery 10 is demonstrated with an effect | action.
The conductive member 51 is manufactured by punching a single plate material. For example, a case where two conductive members 51 are manufactured from one plate material 60 will be described.

  As shown in FIG. 7B, the first conductive member 51A and the second conductive member 51B are punched from the plate member 60 in a state of being rectangular in plan view. In this case, the second connection piece edge 53b of the first conductive member 51A and the second connection piece edge 53b of the second conductive member 51B are along, and the fourth fixed piece edge of the first conductive member 51A is provided. The plate member 60 is punched in a state where the portion 52e and the third connection piece edge portion 53c of the second conductive member 51B are along.

  In addition, the first fixed piece edge 52b and the first connection piece edge 53a of the first conductive member 51A and the second fixed piece edge 52c of the second conductive member 51B are located on the same straight line, The plate member 60 is in a state where the second fixed piece edge portion 52c of the first conductive member 51A and the first connection piece edge portion 53a and the first fixed piece edge portion 52b of the second conductive member 51B are located on the same straight line. Punched out. In the punching, the plate member 60 is punched so that the surplus portion 60a exists around the two conductive members 51A and 51B combined in a rectangular shape.

  Therefore, the first conductive member 51A and the second conductive member 51B are manufactured by punching a single rectangle. In other words, the connection portion 53 of the second conductive member 51B is complemented to the blank portion R of the first conductive member 51A, and the connection of the first conductive member 51A to the blank portion R of the second conductive member 51B. The plate material 60 is punched with the pieces 53 complemented. Therefore, the connection piece 53 of the second conductive member 51B is disposed within the width W1 of the fixed piece 52 of the first conductive member 51A, and the fixed piece 52 and the connection piece 53 are arranged in the width direction. As a result, two conductive members 51 are manufactured from one plate member 60.

Next, a method for assembling the secondary battery 10 will be described.
First, the lid terminal assembly 18 is assembled. In the lid terminal assembly 18, the fixing piece 52 and the connection piece 53 of the conductive member 51 are in a state of facing the inner surface of the lid member 15.

  Next, as shown in FIG. 8, the lid terminal assembly 18 and the electrode assembly 12 are integrated by joining the conductive members 51 and the tabs 25 and 35 of each electrode. In the conductive member 51, a plurality of tabs 25, 35 are laser welded to the connection piece 53 in a state where the first tab 351 is in contact with each other, thereby forming a conduction portion W that electrically connects all the tabs 25, 35 and the connection piece 53. To do.

Next, after the electrode assembly 12 is inserted into the case member 14 and the lid member 15 is joined to the open end of the electrode assembly 12, the case 11 is formed and the secondary battery 10 is formed.
According to the above embodiment, the following effects can be obtained.

  (1) The plurality of conductive members 51 are manufactured by punching one plate member 60, and the plate member 60 has a shape in which the blank portion R of one conductive member 51 is complemented by the connection piece 53 of another conductive member 51. Is punched out. Then, the two conductive members 51 are punched in a state where a single rectangle is formed in combination. Therefore, for example, the material yield can be improved as compared with the case where the blank portion R of one conductive member 51 is not complemented and the portion corresponding to the blank portion R is discarded as the end material.

  (2) The conductive member 51 is manufactured by punching the plate member 60 so that the combined shape of the two conductive members 51 is a rectangle. For this reason, even if the two conductive members 51 are combined, it does not become a stepped shape, the end material of the plate member 60 can be reduced, and the shape of the die for punching can be simplified.

  (3) The connection piece 53 exists within the width W1 of the fixed piece 52, and the width W2 of the connection piece 53 is half of the width W1 of the fixed piece 52. Therefore, the two conductive members 51 can be punched in the same shape.

(Second Embodiment)
Next, a second embodiment in which the method for manufacturing the power storage device is embodied as a method for manufacturing a secondary battery and 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 or overlapping portions as those in the first embodiment is omitted.
As shown in FIG. 9A, in the second embodiment, the conductive member 71 before being bent has an insertion hole 72a in the fixed piece 72, and the auxiliary terminal 61 can be inserted into the insertion hole 72a. is there. In addition, the conductive member 71 has a connection piece 73, and the connection piece 73 has a shape protruding from a part within the width of the fixed piece 72 in the connecting direction. The width W1 of the fixed piece 72 and the width W2 of the connection piece 73 are the same.

  The fixed piece 72 of the conductive member 71 has a first fixed piece edge 72b on one of a pair of edges extending in the connecting direction, and a second fixed piece edge 72c on the other. Furthermore, the fixed piece 72 has a fourth fixed piece edge on the opposite side of the third fixed piece edge portion 72d that connects the first fixed piece edge portion 72b and the second fixed piece edge portion 72c, and the third fixed piece edge portion 72d. It has a portion 72e. Therefore, the connection piece 73 has a shape protruding in the connecting direction from the fourth fixed piece edge portion 72 e of the fixed piece 72.

  The connection piece 73 of the conductive member 71 has a first connection piece edge 73a on one of a pair of edges extending in the connecting direction, and a second connection piece edge 73b on the other. Furthermore, the connection piece 73 includes a third connection piece edge 73c that connects the first connection piece edge 73a and the second connection piece edge 73b, and a fourth connection piece edge on the opposite side of the third connection piece edge 73c. It has part 73d. The dimensions of the fourth fixed piece edge portion 72e of the fixed piece 72 and the dimensions of the fourth connection piece edge portion 73d of the connection piece 73 are the same.

  A straight line obtained by extending the second fixed piece edge 72c in the connecting direction is referred to as a first virtual line L1, and a straight line obtained by extending the third connection piece edge 73c in the width direction is referred to as a second virtual line L2. Further, a straight line obtained by extending the first fixed one edge portion 72b in the connecting direction is defined as a third imaginary line L3. The conductive member 71 has a shape that a part of the conductive member 71 fits in the rectangular virtual surface M. One side of the imaginary plane M is a first fixed piece edge 72b and a third imaginary line L3 extending in the connecting direction, and a second fixed piece edge 72c and the first imaginary line L1, and the other side of the imaginary plane M is The third fixed piece edge 72d extending in the width direction, the third connection piece edge 73c, and the second imaginary line L2.

  The planar shape of the conductive member 71 is such that the first fixed piece edge portion 72b and the second fixed piece edge portion 72c along the connecting direction are along the edge portion of the virtual surface M, and a part of the connection piece 73 is fixed. It is a shape that fits in the virtual plane M in a shape that protrudes in the continuous direction from the width W1 of the piece 72. In the plan view shape of the conductive member 71, the conductive member 71 includes a blank portion R in the virtual plane M where no metal plate exists. The blank portion R is a region surrounded by the first virtual line L1, the second virtual line L2, the fourth fixed piece edge portion 72e, and the second connection piece edge portion 73b. Further, the connection piece 73 and the blank portion R are translationally symmetric in the virtual plane M excluding the fixed piece 72. The area of the blank portion R is the same as the area of the connection piece 73 protruding from the third imaginary line L3.

  Therefore, as shown in FIG. 9B, the first conductive member 71A and the second conductive member 71B are arranged in the width direction, and the second conductive member 71B is connected to the blank portion R of the first conductive member 71A. A part of the piece 73 is arranged.

  Then, the second connection piece edge 73b of the first conductive member 71A and the first connection piece edge 73a of the second conductive member 71B are arranged along the fourth fixed piece edge of the first conductive member 71A. The portion 72e and the fourth connecting piece edge portion 73d of the second conductive member 51B are aligned. Then, the blank portion R of the first conductive member 71A is supplemented by a part of the connection piece 73 of the second conductive member 71B.

Next, the manufacturing method of the conductive member 71 will be described together with the operation.
The conductive member 71 is manufactured by punching a single rectangular plate 80. For example, a case where two conductive members 71A and 71B are manufactured from one plate member 80 will be described. The second connection piece edge 73b of the first conductive member 71A and the first connection piece edge 73a of the second conductive member 71B are along, and the fourth fixed piece edge 72e of the first conductive member 71A is The plate member 80 is punched out in a state where the fourth connection piece edge portion 73d of the second conductive member 71B is aligned. Therefore, when punching out the first conductive member 71A and the second conductive member 71B, the blank portion R of the first conductive member 71A is complemented by a part of the connection piece 73 of the second conductive member 71B.

  As shown in FIGS. 10 and 11, when the conductive member 71, the auxiliary terminal 61, and the external terminal 66 are fixed to the lid member 15, the connection piece 73 is fixed in a state orthogonal to the inner surface of the lid member 15. Projecting from the piece 72. The connecting piece 73 is bent from a bending line along the third virtual line L3 of the conductive member 71. In the lid terminal assembly 18, the connection piece 73 protrudes from the inner surface in a state orthogonal to the inner surface of the lid member 15.

As shown in FIG. 11, the lid terminal assembly 18 and the electrode assembly 12 are integrated by joining the conductive members 71 and the tabs 25 and 35 of each pole.
As shown in FIG. 12, the conductive member 71 and the tabs 25 and 35 are joined together with the pair of electrode rods 85 in a state where the plurality of tabs 25 and 35 and the second tab 352 are in contact with the connection piece 73. Thus, the connecting piece 73 and the plurality of tabs 25 and 35 are sandwiched and welded by resistance welding to form a conduction portion W that electrically connects all the tabs 25 and 35 and the connecting piece 73.

Therefore, according to the second embodiment, the following effects can be obtained.
(4) Even if the two conductive members 71 are arranged side by side in the width direction, the blank portion R of one conductive member 71 can be supplemented by a part of the connection piece 73 of another conductive member 71. Therefore, for example, the material yield can be improved as compared with the case where the blank portion R of the conductive member 71 is not complemented and the portion corresponding to the blank portion R is discarded as an end material.

  (5) The connection piece 73 of the conductive member 71 has a shape protruding in the width direction from the first fixed piece edge portion 72 b of the fixed piece 72, and is bent in a state orthogonal to the fixed piece 72. Then, the tabs 25 and 35 are joined to the distal end side of the connection piece 73. At this time, the connection piece 73 is orthogonal to the fixed piece 72 included in the lid terminal assembly 18. Therefore, resistance welding can be performed with the connection piece 73 and the tabs 25 and 35 sandwiched between the electrode rods 85.

In addition, you may change this embodiment as follows.
As shown in FIG. 13A, in the conductive member 71 of the second embodiment, the connection piece 73 may be stepped along the width direction. As shown in FIG. 13B, the conductive member 71 of the second embodiment may have a shape in which a portion connecting the connection piece 73 and the fixed piece 72 extends obliquely.

In each embodiment, the number of conductive members 51 and 71 punched from the plate materials 60 and 80 may be changed as appropriate.
In the first embodiment, the plate material 60 is punched out so that the surplus portion 60a exists around the two conductive members 51 combined in a rectangular shape, but the present invention is not limited to this. The plate member 60 may be punched out so that the edge portions of the two conductive members 51 combined in a rectangular shape are along the edge portion of the plate member 60.

The connection between the conductive members 51 and 71 and the electrode terminal may not be a connection via the auxiliary terminal 61, the external terminal 66, and the connection conductor 54.
For example, the electrode terminals may be directly connected to the conductive members 51 and 71.

  If the lid member 15 is made of an insulating material, the fixing pieces 52 and 72 of the conductive members 51 and 71 may be assembled by direct fixing to the lid member 15, and in this case, the inner insulating cover 55 is unnecessary. It becomes.

  The electrode assembly may be a wound type in which a belt-like positive electrode and a belt-like negative electrode are wound around a winding axis while being insulated from each other. In the wound electrode assembly, the positive electrode has a positive electrode uncoated portion where the positive electrode active material is not applied along the long side which is one side of the positive electrode metal foil. Further, the positive electrode has a plurality of tabs having a shape protruding from a part of one side at intervals in the longitudinal direction. The negative electrode has a negative electrode uncoated portion where the negative electrode active material is not applied along the long side which is one side of the negative electrode metal foil. The negative electrode has a plurality of tabs having a shape protruding from a part of one side at intervals in the longitudinal direction.

  In the wound type electrode assembly, the positive electrode and the negative electrode are wound in an insulated state so that the tabs of the same polarity overlap each other, so that the winding axis of the electrode assembly extends in the extending direction. On one end side, the plurality of positive electrode tabs are stacked in the stacking direction of the electrode assembly, and the plurality of negative electrode tabs are stacked in the stacking direction of the electrode assembly.

The positive electrode 21 may have a positive electrode active material layer 23 on one side. Similarly, the negative electrode 31 may have a negative electrode active material layer 33 on one side.
The separator 24 may have a bag shape that accommodates the positive electrode 21 or the negative electrode 31.

In the case 11, the wall portion to which the positive electrode terminal 16 and the negative electrode terminal 17 are fixed may be a side wall or a bottom wall of the case member 14.
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.

  The power storage device is not limited to the secondary battery 10 and may be a capacitor such as an electric double layer capacitor or a lithium ion capacitor.

  L ... Stacking direction, M ... Virtual plane, R ... Blank part, 10 ... Secondary battery as power storage device, 11 ... Case, 12 ... Electrode assembly, 15 ... Lid member as wall part, 16 ... As electrode terminal Positive terminal, 17 ... Negative electrode terminal as electrode terminal, 21 ... Positive electrode as electrode, 25 ... Tab, 31 ... Negative electrode as electrode, 35 ... Tab, 36 ... Tab group, 51, 71 ... Conductive member, 51A, 71A ... first conductive member, 51B, 71B ... second conductive member, 52,72 ... fixed piece, 53,73 ... connecting piece, 60,80 ... plate material.

Claims (5)

An electrode assembly in which electrodes having tabs protruding from one side are stacked, a tab group formed by stacking the tabs, a case for housing the electrode assembly and the tab group, and a wall of the case A method of manufacturing a power storage device, comprising: an electrode terminal fixed to a portion, and an electrode terminal that exchanges electricity with the electrode assembly; and a conductive member of a metal plate that electrically connects the tab group and the electrode terminal,
The conductive member includes a fixing piece that is positioned to overlap the wall portion, and a connection piece that is continuous with the fixing piece and to which the tab group is joined, and the fixing piece and the connection piece are aligned. With the direction as the continuous direction of the conductive member, along the surface direction of the fixed piece, the direction orthogonal to the continuous direction as the width direction of the conductive member,
Assuming a rectangular virtual surface extending in one side in the continuous direction and extending in the width direction on the other side orthogonal to the one side, the conductive member has an edge of the fixed piece at an edge of the virtual surface. Along with, at least a part of the connection piece fits in the virtual surface in a shape protruding in the connecting direction from the width of the fixed piece, and has a blank portion where the metal plate does not exist in the virtual surface,
A plurality of the conductive members are manufactured by punching out a single metal plate, and in the plan view of the plate, the connection piece of another conductive member is complemented to the blank portion, and the conductive piece is separated from the fixed piece. A method of manufacturing a power storage device in which each conductive member is punched from the plate in a state where the connection pieces are arranged.   2. The method for manufacturing a power storage device according to claim 1, wherein the plurality of conductive members are punched in a state in which edges extending in the continuous direction are flush with each other in the conductive direction.   The method for manufacturing a power storage device according to claim 2, wherein a width of the connection piece is half of a width of the fixed piece.   The method for manufacturing a power storage device according to claim 1, wherein the connection piece has a shape protruding from the virtual surface along the width direction. An electrode assembly in which electrodes having tabs protruding from one side are stacked, a tab group formed by stacking the tabs, a case for housing the electrode assembly and the tab group, and a wall of the case A power storage device comprising: an electrode terminal fixed to a portion; and an electrode terminal that exchanges electricity with the electrode assembly; and a conductive member of a metal plate that electrically connects the tab group and the electrode terminal,
The conductive member includes a fixing piece that is positioned to overlap the wall portion, and a connection piece that is continuous with the fixing piece and to which the tab group is joined, and the fixing piece and the connection piece are aligned. With the direction as the continuous direction of the conductive member, along the surface direction of the fixed piece, the direction orthogonal to the continuous direction as the width direction of the conductive member,
Assuming a rectangular virtual surface extending in one side in the continuous direction and extending in the width direction on the other side orthogonal to the one side, the conductive member has an edge of the fixed piece at an edge of the virtual surface. Along with, at least a part of the connection piece fits in the virtual surface in a shape protruding in the connecting direction from the width of the fixed piece, and has a blank portion where the metal plate does not exist in the virtual surface,
The power storage device, wherein the conductive member has a shape that allows the connection piece of another conductive member to be complemented to the blank portion in a plan view.

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