JP2019212412A - Lamination electrode plate group, secondary battery, and manufacturing method of secondary battery - Google Patents

Abstract

To provide a lamination electrode plate group capable of restraining occurrence of positional deviation between the electrode plates during production.SOLUTION: A lamination electrode plate group is an electrode plate group laminating a positive electrode plate 21 and a negative electrode plate 22 while sandwiching a separator 23. The lamination electrode plate group comprises lead parts 214, 224 of an electrode plate group 20, where only the tip of the positive electrode plate 21 is placed in the lamination direction, or only the tip of the negative electrode plate 22 is placed, and collector foil parts 30 provided in the lead parts 214, 224 and connected with a collector plate 14 extending in the direction of the lead parts 214, 224, where the tip portions placed in the lead parts 214, 224 are collected in the lamination direction, and joined.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a laminated electrode plate group of a secondary battery, a secondary battery having the electrode plate group, and a method for manufacturing the secondary battery.

  A lithium ion secondary battery, which is one of non-aqueous electrolyte secondary batteries, has a high energy density and a high capacity, and is therefore used as a power source for driving an electric vehicle (EV), a hybrid vehicle (HV), etc. It has been. A lithium ion secondary battery has a positive electrode plate group in which electrode mixture layers are provided on both surfaces of an electrode core body and an electrode plate group in which a negative electrode plate is wound or stacked with a separator interposed therebetween. An aluminum alloy foil or a copper foil for secondary battery electrodes is used for the electrode core. A current collector plate connected to an external electrode terminal is connected to an end portion of the electrode plate to a lead portion made of an electrode core (see, for example, Patent Document 1).

  For example, in the secondary battery described in Patent Document 1, the edge of at least one electrode plate of a belt-like positive and negative electrode plate is protruded from the edge of the other electrode plate, and is wound or stacked via a separator. The protruding end edge of the power generation element (electrode plate group) and the current collector are laser welded.

Japanese Patent Laid-Open No. 10-106536

  In the electrode plate group in which the positive electrode plate and the negative electrode plate are wound with the separator interposed therebetween, the positive electrode plate and the negative electrode plate are fixed with a relatively strong binding force, so that the relative position between the positive electrode plate and the negative electrode plate is shifted. The risk of occurrence is small.

  On the other hand, the electrode plate group in which the positive electrode plate and the negative electrode plate are stacked with the separator interposed therebetween is merely stacked in a state where there is almost no binding force between the positive electrode plate, the negative electrode plate, and the separator. Therefore, until the positive electrode plate or the negative electrode plate is welded to the current collector, the position between the electrode plates may be shifted from the position when the electrodes are stacked due to external force such as vibration during manufacturing.

  The present invention has been made in view of such circumstances, and its purpose is to provide a laminated electrode plate group capable of suppressing the occurrence of misalignment between the electrode plates during manufacturing, and the electrode plate group. It is to provide a secondary battery having the same and a method for manufacturing the secondary battery.

  A laminated electrode plate group that solves the above problems is a laminated electrode plate group that is an electrode plate group obtained by laminating a positive electrode plate and a negative electrode plate with a separator interposed therebetween, and is a terminal portion of the electrode plate group, Only the edge portion of the positive electrode plate is disposed with respect to the stacked direction, or the terminal portion where only the edge portion of the negative electrode plate is disposed, and the terminal provided in the terminal portion and the terminal The current collecting part is connected to a current collecting part extending in a direction along the part, the edge parts arranged in the terminal part are gathered in the stacked direction, and the gathered edge parts And the foil collection part to which the part is joined.

  A secondary battery that solves the above-described problem is a secondary battery that includes a group of electrode plates in which a positive electrode plate and a negative electrode plate are stacked with a separator interposed therebetween, and the electrode plate group includes the stacked electrode plate group described above. Thus, at least a portion of the foil collecting portion of the electrode plate group and the current collecting portion connected to the external terminal are welded.

  A method of manufacturing a secondary battery that solves the above problem is a method of manufacturing a secondary battery having an electrode plate group in which a positive electrode plate and a negative electrode plate are stacked with a separator interposed therebetween, and is a terminal portion of the electrode plate group. The terminal portion in which only the positive electrode plate is disposed with respect to the stacked direction, or each edge portion of the terminal portion in which only the edge portion of the negative electrode plate is disposed in the stacked direction. A collecting edge portion collecting step, a foil collecting portion forming step for joining the collected terminal portions to form a foil collecting portion, an abutting step for bringing a current collecting portion into contact with the foil collecting portion, A welding step of welding a contact portion between the foil collecting portion and the current collecting portion, and an accommodating step of accommodating the electrode plate group in which the current collecting portion is welded to the foil collecting portion in a case of the secondary battery; Is provided.

  The positional deviation of the electrode plates of the stacked electrode plate group that is stacked in layers of the positive electrode plate, the separator, the negative electrode plate, and the separator may deteriorate the battery characteristics. One cause of such misalignment is that an external force such as vibration is applied after lamination during manufacturing. In this respect, according to such a configuration or method, the stacked electrode plate group is joined to the edge portion before the current collecting portion is fixed, thereby forming the foil collecting portion. Since the plates or the negative electrode plates are connected to each other, it is possible to suppress the occurrence of misalignment between the electrode plates constituting the electrode plate group during manufacturing.

  Moreover, although the end edge part of each electrode plate is a metal thin film with low rigidity, it tends to cause unintended deformation, but by using the foil collecting part, rigidity is increased and unintended deformation is suppressed. Moreover, it becomes easy to connect a foil collection part and a current collection part by improving rigidity.

  Moreover, since it is preferable that the current collecting part is connected to all the edge parts, since all the edge parts are previously joined as the foil collecting part, the current collecting part can be connected to the edge part. It is easy, and the conductivity between each electrode plate and the current collector is reliably ensured.

  As a preferred configuration, the terminal portion has a proximal end portion that is an end portion close to the external terminal in the longitudinal direction, and a distal end that is an end portion separated from the external terminal, and the foil collecting portion It is provided at least at a part between the base end and a position close to the base end by a predetermined length from the tip.

  As a preferred method, in the foil collection portion forming step, a predetermined value is determined from a base end portion that is an end portion close to the upper side of the case with respect to a longitudinal direction of the terminal portion and a tip end that is an end portion close to the lower side of the case The foil collecting portion is formed at least at a part between the base end portion and the position close to the base end portion.

  According to such a configuration or method, at least a part between the proximal end portion of the terminal portion of the electrode plate group and the position close to the proximal end portion by a predetermined length from the distal end is closed by the foil collecting portion. However, the part where the foil collecting part is not provided is open. By opening the distal end side of the terminal portion, the electrolytic solution is easily supplied to the electrode plate group from the opened distal end side. In particular, by providing the tip side to be the lower side where the electrolytic solution stays, the permeability of the electrolytic solution to the electrode plate group having the foil collecting portion can be maintained in a high state.

As a preferable configuration, in the foil collecting portion, the two edge portions facing each other in the stacked direction are interface-bonded to each other.
According to such a structure, since it joins, without changing the shape of an edge part, the fracture | rupture of metal foil is suppressed. That is, it is possible to reduce the risk that the foil shape cannot be maintained by melting the surroundings by melting, or the foil thickness may be uneven and easy to break. Reliability is improved.

As a preferable configuration, in the electrode plate group, the end edge portion of one of the end portions is made of an aluminum alloy foil, and the end edge portion of the other end portion is made of a copper foil.
According to such a configuration, in the lithium ion secondary battery, it is possible to suppress the occurrence of positional deviation between the electrode plates constituting the electrode plate group at the time of manufacture.

  As a preferred configuration, in the foil collecting portion, the protruding portion of the terminal portion is cut and aligned at a predetermined position in the protruding direction, and the predetermined position is the same as that of the stacked direction. This is the position where the terminal part is stacked.

  As a preferred method, prior to the accommodating step, the protruding portion of the terminal portion is a predetermined position in the protruding direction, and the predetermined position where all the terminal portions are stacked in the stacked direction. A cutting step of cutting and aligning.

According to such a configuration or method, it is possible to reduce the size of the secondary battery and increase the capacity of the secondary battery by setting the protruding length of the foil collecting portion to the minimum necessary length.
As a preferred configuration, the foil collecting portion is sandwiched between slits provided in the current collecting portion from the stacked direction.

  As a preferred configuration, the current collecting part has a slit for sandwiching the foil collecting part in the laminated direction, and at least a part of the foil collecting part sandwiched by the slit is welded to the current collecting part. Yes.

  As a preferred method, in the foil collecting portion forming step, the two edge portions facing each other in the stacked direction are interfaced with each other, and in the contacting step, the foil collecting portion is arranged in the longitudinal direction of the current collecting portion. The current collecting part is brought into contact with the foil collecting part by being sandwiched by a slit extended to the at least part of the foil collecting part along the slit of the current collecting part in the welding step. Weld the current collector.

  According to such a configuration or method, since the foil collecting portion can be sandwiched in the slit of the current collecting portion, the conductivity between the current collecting portion and the foil collecting portion can be secured. Further, the foil collecting portion has higher rigidity than the single terminal portion by gathering the terminal portions. For this reason, while being able to pinch a foil collection part in a current collection part, attachment to the foil collection part of a current collection part becomes easy. Further, since the heat collecting capacity of the foil collecting part is increased, it is easy to control the energy applied for welding. Therefore, for example, it is possible to suppress the possibility that the laser penetrates the foil collecting portion in laser welding.

  A secondary battery that solves the above problem is a secondary battery that has a plurality of electrode plate groups in which a positive electrode plate and a negative electrode plate are stacked with a separator interposed therebetween, and the electrode plate group is the stacked electrode plate described above At least a part of the current collecting part connected to the external terminal and the foil collecting part of the plurality of electrode plate groups is welded.

  As a preferred method, prior to the abutting step, the electrode plate group laminating step of laminating a plurality of the electrode plate groups is provided, and in the abutting step, each foil collecting portion of the plurality of electrode plate groups is connected to the current collecting portion. The current collecting part is brought into contact with the foil collecting part by being sandwiched in each of a plurality of slits extending in the longitudinal direction.

  According to such a configuration or method, the foil collecting portions of the plurality of electrode plate groups are welded to the current collecting portion. Therefore, it is easy to configure a secondary battery having a plurality of electrode plate groups.

  According to the present invention, it is possible to suppress the occurrence of misalignment between electrode plates during manufacturing.

Schematic which shows the structure about 1st Embodiment of a secondary battery. The schematic diagram which shows the cross-section of the electrode group of the embodiment. The schematic diagram which shows the structure of the electrode group of the same embodiment, and a current collection board. The top view which shows a lead part in the embodiment. The top view which shows a lead part in the embodiment. The flowchart which shows the procedure which assembles a secondary battery in the same embodiment. The schematic diagram which shows the structure of the electrode group about 2nd Embodiment of a secondary battery. The front view which shows the structure of a current collecting plate in the embodiment. The flowchart which shows the procedure which assembles a secondary battery in the same embodiment. Schematic which shows the structure about other embodiment of a secondary battery.

(First embodiment)
A first embodiment of a laminated electrode plate group, a secondary battery, and a method for manufacturing a secondary battery will be described with reference to FIGS. In the present embodiment, the secondary battery is a lithium ion secondary battery.

  The secondary battery of this embodiment comprises an assembled battery by connecting two or more with a bus bar. The assembled battery is mounted on an electric vehicle or a hybrid vehicle, and supplies power to an electric motor or the like. The secondary battery is a sealed battery whose outer shape is a rectangular parallelepiped shape.

  As shown in FIG. 1, the secondary battery 10 includes a rectangular parallelepiped battery case 11 having an opening on the upper side, a lid body 12 that seals the battery case 11, and an electrode body that is accommodated in the battery case 11. Electrode plate group 20 and a liquid nonaqueous electrolyte 27 injected into the battery case 11. The battery case 11 and the lid 12 are made of a metal such as an aluminum alloy. The secondary battery 10 has a sealed battery case by attaching a lid 12 to the battery case 11. In addition, the secondary battery 10 includes two external terminals 13 used for charging and discharging power on the lid 12.

  The electrode plate group 20 is formed by alternately stacking positive plates 21 and negative plates 22 in the stacking direction (direction perpendicular to the paper surface in FIG. 1) with the separators 23 sandwiched therebetween. In the present embodiment, the electrode plate group 20 constitutes a stacked electrode plate group by stacking the positive electrode plate 21, the negative electrode plate 22, and the separator 23 while being maintained in a planar shape. The electrode group 20 includes a positive electrode lead portion 214 as a terminal portion protruding from one end side in the longitudinal direction (left side in FIG. 1) and a negative electrode on the other end side in the longitudinal direction (right side in FIG. 1). The plate 22 has a negative lead portion 224 as a terminal portion protruding. In the lead portion 214 of the positive electrode, in a portion where only the positive electrode plate 21 is arranged in the longitudinal direction of the electrode plate group 20, a tip portion 211C (see FIG. 2) as an edge portion of the positive electrode plate 21 is gathered in the stacking direction. ing. Further, the positive electrode lead part 214 is welded along the short direction of the electrode plate group 20 to the foil collecting part 30 which is an assembled part, as a current collecting part 14 connected to the external terminal 13. Has been. In the lead portion 224 of the negative electrode, in a portion where only the negative electrode plate 22 is arranged in the longitudinal direction of the electrode plate group 20, a tip portion 221C (see FIG. 2) as an end edge portion of the negative electrode plate 22 is gathered in the stacking direction. ing. Further, the current collector plate 14 connected to the external terminal 13 is welded along the short direction of the electrode plate group 20 to the foil collecting portion 30 which is a gathered portion of the negative lead portion 224.

  The separator 23 is a nonwoven fabric made of polypropylene or the like for holding the nonaqueous electrolyte 27 between the positive electrode plate 21 and the negative electrode plate 22. Further, as the separator 23, a porous polymer film such as a porous polyethylene film, a porous polyolefin film, and a porous polyvinyl chloride film, or a lithium ion or ion conductive polymer electrolyte film is used alone or in combination. You can also

(Nonaqueous electrolyte)
The nonaqueous electrolyte 27 is a composition in which a supporting salt is contained in a nonaqueous solvent. Here, as the non-aqueous solvent, one or two selected from the group consisting of propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), and the like. More than one type of material can be used. The supporting salts include LiPF ₆ , LiBF ₄ , LiClO ₄ , LiAsF ₆ , LiCF ₃ SO ₃ , LiC ₄ F ₉ SO ₃ , LiN (CF ₃ SO ₂ ) ₂ , LiC (CF ₃ SO ₂ ) ₃ , LiI 1 type, or 2 or more types of lithium compounds (lithium salt) selected from these etc. can be used.

(Positive electrode plate)
Referring to FIG. 2, positive electrode plate 21 has positive electrode mixtures 212 and 213 on first surface 211 </ b> A and second surface 211 </ b> B of positive electrode substrate 211 as an aluminum alloy foil for a secondary battery positive electrode that is an electrode core, respectively. It has been applied. The positive electrode base material 211 of the positive electrode plate 21 is a thin film (foil) made of an aluminum alloy as a conductive material made of a metal having good conductivity. In addition, let the part to which the positive mix 212,213 of the positive electrode plate 21 is uncoated be the front-end | tip part 211C.

The positive electrode mixture 212 and 213 has a positive electrode active material. In addition to the transition metal element (that is, at least one of Ni, Co, and Mn), the positive electrode active material can additionally contain one or more elements. Additional elements include Group 1 (alkali metals such as sodium), Group 2 (alkaline earth metals such as magnesium and calcium), Group 4 (transition metals such as titanium and zirconium), Group 6 (chromium). , Transition metals such as tungsten), and any element belonging to Group 8 (transition metals such as iron). In addition, the additional element may include any element belonging to Group 13 (metal such as boron or aluminum which is a metalloid element) and Group 17 (halogen such as fluorine) of the periodic table. it can. Preferably, the positive electrode active material is “LiNiCoMnO ₂ -based positive electrode active material”. The “LiNiCoMnO ₂ positive electrode active material” means a composite oxide containing Li, Ni, Co, and Mn, and may further contain a metal element different from Li, Ni, Co, and Mn.

  Moreover, the positive electrode mixtures 212 and 213 may contain a conductive material. As the conductive material, for example, carbon black such as acetylene black (AB) and ketjen black, and graphite (graphite) can be used.

  The positive electrode plate 21 is formed by, for example, kneading a positive electrode active material, a conductive material, a solvent, and a binder (binder). It is produced by applying to and drying. Here, as the solvent, for example, an NMP (N-methyl-2-pyrrolidone) solution can be used. As the binder, for example, polyvinylidene fluoride (PVdF), styrene butadiene rubber (SBR), polytetrafluoroethylene (PTFE), carboxymethyl cellulose (CMC), or the like can be used. In the present embodiment, the electrode slurry is adjusted so that the ratio of the solid matter is 40% or more and 70% or less.

(Negative electrode plate)
Next, as for the negative electrode plate 22, the negative electrode mixtures 222 and 223 are apply | coated to the 1st surface 221A and 2nd surface 221B of the negative electrode base material 221 as current collection foil which is an electrode core, respectively. The negative electrode base material 221 of the negative electrode plate 22 can use the same components as those of a conventional secondary battery. For example, a conductive material made of a metal with good conductivity is preferably used as the base material. For example, as the negative electrode substrate 221, a thin film (foil) made of copper, nickel, or an alloy thereof can be used. A portion of the negative electrode plate 22 where the negative electrode mixture 222, 223 is not applied is defined as a tip portion 221C.

  The negative electrode mixture 222, 223 has a negative electrode active material. The negative electrode active material is a material capable of inserting and extracting lithium, and for example, a powdery carbon material made of graphite or the like can be used. The negative electrode plate 22 kneads a negative electrode active material, a solvent, and a binder in the same manner as the positive electrode plate 21, and applies an electrode slurry that includes the negative electrode mixture 222 after the kneading to the negative electrode base material 221. And dried. In this embodiment, the binder includes carboxymethyl cellulose (CMC) having a sodium salt.

(Current collector)
As shown in FIG. 3, the lid body 12 is provided with a positive external terminal 13 and a negative external terminal 13 on the outer surface side, and a positive current collector plate 14 and a negative current collector plate 14 on the inner surface side. Is provided. Since the positive current collector plate 14 and the negative current collector plate 14 have the same structure, the positive current collector plate 14 will be described in detail here, and the description of the negative current collector plate 14 is omitted. To do.

  The positive collector plate 14 is a plate-like member made of a conductor, and is orthogonal to the fixed portion 14D (see FIG. 1) fixed to the inner surface of the lid 12 and the fixed portion 14D (see FIG. 1). And an extending portion 140 that extends in the direction in which it extends. The fixing portion 14 </ b> D (see FIG. 1) is mechanically fixed to the lid body 12 by a conductor penetrating the lid body 12 and is electrically and mechanically connected and fixed to the external terminal 13.

  The extending contact portion 140 extends from the fixing portion 14 </ b> D fixed to the lid body 12 toward the bottom surface of the battery case 11. The extending contact portion 140 has such a length that the tip end 14 </ b> A is disposed at a position before reaching the bottom surface of the battery case 11. In other words, the extending contact portion 140 is disposed at a position where the tip end 14 </ b> A is separated from the bottom surface of the battery case 11 by a predetermined distance.

  The extended contact portion 140 has its surface directed in a direction orthogonal to the longitudinal direction of the electrode plate group 20. Thereby, when connecting the extension part 140 to the electrode plate group 20, the length required in the longitudinal direction of the electrode plate group 20 may be about the thickness of the extension part 140. As a result, the secondary battery 10 can be downsized or the secondary battery 10 can be increased in capacity.

  In the extended contact portion 140, a slit 141 is extended in the longitudinal direction, which is a direction from the distal end 14A toward the fixed portion 14D. The slit 141 penetrates the current collector plate 14 in the thickness direction of the current collector plate 14. The extending contact portion 140 includes a first extending piece 142 and a second extending piece 143 that are divided by the slit 141 on both sides of the slit 141.

  The extended contact portion 140 has a slit 141 opened at the distal end 14A, and has an end point of the slit 141 at the proximal end portion 14C on the fixed portion side. That is, when viewed from the fixed portion 14D side, the slit 141 branches between the first extending piece 142 and the second extending piece 143 that are branched at the base end portion 14C and disposed substantially parallel to the distal end 14A. Is provided. The first extending piece 142 and the second extending piece 143 are tapered at the tip 14A, and the tip 14A is expanded so as to widen the width of the slit 141. The extending contact portion 140 has a sandwiching portion 14B following the tip end 14A in the longitudinal direction. The sandwiching portion 14B has a narrow slit 141 and pressurizes the foil collecting portion 30 of the positive lead portion 214 sandwiched between the slit 141 between the first extending piece 142 and the second extending piece 143. In this way, it can be restrained. Further, the extending contact portion 140 has a base end portion 14C on the fixed portion side of the sandwiching portion 14B. The base end portion 14C has a wider slit 141 than the sandwiching portion 14B, and the positive lead portion 214 is not pressurized between the first extending piece 142 and the second extending piece 143. , Arranged in an unconstrained state.

(Foil collection part)
The positive electrode lead portion 214, the negative electrode lead portion 224, and the foil collecting portion 30 formed from the positive electrode lead portion 214 and the negative electrode lead portion 224 will be described with reference to FIGS. Since the positive lead portion 214 and the negative lead portion 224 have the same structure, the positive lead portion 214 will be described in detail and the negative lead portion 224 will not be described.

  As shown in FIG. 2, the positive electrode lead portion 214 is a tip portion 211 </ b> C of the positive electrode base material 211, and is configured between a position P <b> 1 and a position P <b> 3 of the end portion of the separator 23. More specifically, the electrode plate group 20 includes a positive electrode plate 21, a negative electrode plate 22, and a separator 23 stacked between the longitudinal center of the electrode plate group 20 and a substantially position P3, and a positive electrode between the position P3 and the position P2. The plate 21 and the separator 23 are laminated, and only the positive electrode plate 21 is laminated between the position P2 and the position P1. Further, the positive electrode mixtures 212 and 213 of the positive electrode plate 21 are provided between the center in the longitudinal direction of the electrode plate group 20 and the approximate position P3. Therefore, the tip end portion 211C of the positive electrode plate 21 between the vicinity of the position P3 and the position P1 is composed of only the positive electrode base material 211.

  As shown in FIG. 3, the lead portion 214 of the positive electrode has the short direction of the electrode plate group 20 as a long direction, and the direction protruding from the electrode plate group 20 along the long direction of the electrode plate group 20 is short. The direction.

  The lead portion 214 of the positive electrode has an upper end portion 214a on the upper side, a lower end portion 214b on the lower side, and a central portion 214c between the upper end portion 214a and the lower end portion 214b in the longitudinal direction.

  4 shows the upper surface of the electrode plate group 20, but for the sake of illustration, only the positive electrode substrate 211 of the positive electrode plate 21 is shown, and the negative electrode plate 22 and the separator 23 are not shown. That is, in the electrode plate group 20, the positive electrode plate 21, the negative electrode plate 22, and the separator 23 are stacked from the center in the longitudinal direction to the position P3, and the positive electrode plate 21 and the separator 23 are stacked from the position P3 to the position P2. Only the positive electrode base material 211 is laminated from P2 to position P1. The lead part 214 does not face at least the negative electrode plate 22 and the separator 23. The lead portion 214 can bend the positive electrode base material 211 in the stacking direction between the position P3 and the position P1 where the negative electrode plate 22 is not disposed.

  Between the position P3 and the position P1, the laminated positive electrode base materials 211 are aligned and arranged at intervals in the lamination direction. At this time, the positive electrode plate 21 is laminated so that the position P1 of the end side of the positive electrode base material 211 that is the tip portion of the positive electrode plate 21 is aligned at the same position in the lamination direction.

  As shown in FIG. 5, in the lead part 214, the front end portions 211 </ b> C of the plurality of positive electrode base materials 211 are folded and assembled in the stacking direction so as to contact the front end portions 211 </ b> C of the adjacent positive electrode base materials 211. For example, the positive electrode base material 211 is bent so that the position P1 of the tip portion 211C of the positive electrode base material 211 is gathered at the center CH with respect to the stacking direction of the electrode plate group 20. At this time, the curved portion K3 of the positive electrode base material 211 that is separated from the center CH of the electrode plate group 20 in the stacking direction becomes longer, and the curved portion K3 of the positive electrode base material 211 in the center CH of the electrode plate group 20 becomes shorter. Therefore, when gathered at the center CH, the position P1 of the tip portion 211C of each positive electrode base material 211 is such that the center CH protrudes in the longitudinal direction of the electrode plate group 20 with respect to the stacking direction and the distance from the center CH increases. A stepped portion K1 that is shortened stepwise is formed.

  The tip portions 211C are gathered at the center and the curved portion K3 is provided, so that the mechanical strength (rigidity) of the lead portion 214 is increased compared to the case where the lead portion 214 is linear. For this reason, it is easy to attach the current collector plate 14 to the lead portion 214.

  In addition, all the tip portions 211C are stacked between the stepped portion K1 and the curved portion K3 where the tip portions 211C are gathered, and the stacked portion K2 whose rigidity is increased by the restraining force generated by the mutual contact of the tip portions 211C. Is formed. The laminated portion K2 may be bonded and restrained to further increase the rigidity of the lead portion 214. In this embodiment, the foil collection part 30 is comprised from the lamination | stacking part K2 and the front-end | tip part 31. As shown in FIG.

The foil collecting portion 30 includes a collecting portion 32 to which the current collecting plate 14 is connected in the lead portion 214 and a tip portion 31 after being cut and aligned.
As shown in FIG. 3, the foil collecting portion 30 is joined between the upper end portion 214a and the lower end portion 214b. In addition, the foil collection part 30 should just be provided in at least one part between the upper end part 214a and the lower end part 214b of the lead part 214. FIG. That is, the joining of the foil collecting part 30 may be continuous between the upper end part 214a and the lower end part 214b, or may be performed at predetermined intervals. Bonding is preferably interfacial bonding by ultrasonic bonding because the positive electrode base material 211 that is a thin film may be melted.

(Cut)
By the way, the stepped portion K1 is a portion where all the tip portions 211C are not stacked and is a portion that does not affect the battery performance. Therefore, the cutting is performed at the position P4 which is the shortest stepped portion K1 or a position inside thereof. Cutting is performed with a Thomson mold, an ultrasonic cutter, a mold, or the like. Thereby, the foil collection part 30 is provided with the collection part 32 and the front-end | tip part 31 formed from the lead part 214 cut and aligned in the lamination direction in the position P4. Since the longitudinal direction of the electrode plate group 20 can be shortened by cutting the stepped portion K1, the secondary battery 10 can be downsized or the secondary battery 10 can be increased in capacity.

(Method for manufacturing secondary battery)
With reference to FIG. 6, the procedure about the manufacturing method of a secondary battery is demonstrated based on a flowchart.

  When the manufacturing method of the secondary battery is started, a stacking process is performed in which the positive electrode plate 21, the negative electrode plate 22, and the separator 23 are stacked while maintaining a planar shape (step S10). For example, in the laminating step, the positive plates 21 and the negative plates 22 accommodated in the bag-like separator 23 are alternately laminated.

Next, a terminal portion assembly step for collecting the tip portion 211C of the positive electrode plate 21 and the tip portion 221C of the negative electrode plate 22 is performed (step S11).
Further, a foil collecting part forming step is performed in which the tip part 211C of the assembled positive electrode plate 21 and the tip part 221C of the negative electrode plate 22 are joined by interfacial bonding to form the foil collecting part 30 (step S12).

  When the foil collecting portion 30 is formed, an end cutting step for cutting the stepped portion K1 of the positive lead portion 214 and the negative lead portion 224 is performed (step S13). Thereby, an unnecessary part is removed from the foil collecting part 30, and the collecting part 32 to which the current collector plate 14 is connected and the tip part 31 after being cut and arranged are provided.

  If an unnecessary part is removed from the foil collection part 30, the current collection board contact process in which the current collection board 14 is attached to the foil collection part 30 will be performed (step S14). If it demonstrates with reference to FIG. 3, the foil collection part 30 of the electrode group 20 will be inserted | pinched by the slit 141 formed in the current collection board 14 by the slide. First, the lid body 12 is disposed with the tip end 14 </ b> A of the current collector plate 14 facing the upper end portion 214 a of the electrode plate group 20. Next, the lid body 12 is relatively moved so that the lid body 12 and the electrode plate group 20 approach each other, and the foil collecting portion 30 formed at the upper end portion 214 a of the lead portion 214 at the tip end 14 </ b> A of the current collector plate 14. Plug in. Furthermore, by moving the electrode plate group 20 and the lid 12 relatively close to each other, the tip end 14A of the current collector plate 14 is moved to the central portion 214c of the foil collecting portion 30, and subsequently moved to the vicinity of the lower end portion 214b. Let Accordingly, the sandwiching portion 14B moves the foil collecting portion 30 from the upper end portion 214a to the central portion 214c. Since the sandwiching portion 14B has a narrow width of the slit 141, the sandwiching foil portion 30 sandwiched between the slits 141 is sandwiched between the first extending piece 142 and the second extending piece 143 and pressurized. to bound. Further, the base end portion 14C of the slit 141 is disposed at the upper end portion 214a. Since the base end portion 14C has a wider slit 141 than the sandwiching portion 14B and does not pressurize the foil collection portion 30 and is in an unconstrained state, stress or the like is applied to the upper end portion 214a of the foil collection portion 30. Is suppressed.

  When the current collecting plate 14 is attached to the foil collecting portion 30, a welding process is performed in which the sandwiched portion 14B of the slit 141 of the current collecting plate 14 is welded to the collecting portion 32 of the foil collecting portion 30 (step S15). In the welding process, the current collector plate 14 is welded to the foil collector 30 by laser welding. By sandwiching the foil collection part 30 in the slit 141 of the current collection board 14, the electrical conductivity of the current collection board 14 and the foil collection part 30 is ensured. Moreover, since the foil collection part 30 has high rigidity compared with the front-end | tip part 211C single-piece | unit by gathering each front-end | tip part 211C, while being able to pinch the foil collection part 30 in the current collecting plate 14, foil collection | recovery Attachment of the current collector plate 14 to the portion 30 is facilitated. In order to exhibit this effect, it is particularly preferable that the foil collecting portion 30 includes the upper end portion 214a. Moreover, since the heat collection capacity | capacitance part 30 becomes large, control of the energy added for welding becomes easy. For example, at least a part of the foil collecting portion 30 and the current collecting plate 14 is welded by laser welding or the like, but since the foil collecting portion 30 plays a role of suppressing laser penetration, the laser is inside the electrode plate group 20. It is possible to suppress reaching up to. In order to exhibit this effect, it is preferable that the foil collection part 30 is provided in the location where a laser is irradiated in a welding process.

  When the attachment of the current collector plate 14 fixed to the lid body 12 to the electrode plate group 20 is completed, an accommodating step of accommodating the electrode plate group 20 to which the lid body 12 is attached into the battery case 11 from the opening is executed. (Step S16).

  Then, the lid body 12 is aligned with the opening of the battery case 11, and a case sealing process is performed in which the lid body 12 is welded to the battery case 11 to seal the battery case 11 (step S17).

  When the battery case 11 is sealed, a liquid injection process for injecting the nonaqueous electrolyte 27 into the battery case 11 is performed (step S18). The liquid injection is performed from the liquid injection port of the lid body 12. Then, the nonaqueous electrolyte 27 permeates the separator 23 of the electrode plate group 20, thereby completing the production of the secondary battery.

As described above, according to the present embodiment, the following effects can be obtained.
(1) Since the stacked electrode plate group 20 forms the foil collecting portion 30 by joining the tip portions 211C and 221C before the current collector plate 14 is fixed, the positive electrode plate 21 or the negative electrode plate 22 are connected to each other, and it is possible to suppress the occurrence of positional deviation between the electrode plates constituting the electrode plate group 20 at the time of manufacture.

  In addition, the tip portions 211C and 221C of the respective electrode plates are metal thin films having low rigidity, so that unintended deformation is likely to occur. However, by using the foil collecting section 30, the rigidity is increased and unintended deformation is suppressed. Moreover, it becomes easy to connect the foil collection part 30 and the current collecting plate 14 by improving rigidity.

  Further, the current collector plate 14 is preferably connected to all the tip portions 211C and 221C. Since all the tip portions 211C and 221C are bonded in advance as the foil collector portion 30, the current collector plate 14 is connected to the tip portion. It is easy to connect to the portions 211C and 221C, and the conductivity between each electrode plate and the current collector plate 14 is reliably ensured.

  (2) Since the joining is performed without changing the shape of the tip portions 211C and 221C by interfacial joining, breakage of the metal foil is suppressed. In other words, it is possible to reduce the risk that the foil shape cannot be maintained by forming a spherical shape that collects the surroundings by melting, or that the thickness of the foil becomes uneven and easily breaks. Reliability is improved.

(3) In the lithium ion secondary battery, it is possible to suppress the occurrence of misalignment between the electrode plates constituting the electrode plate group 20 at the time of manufacture.
(4) By making the protruding length of the foil collecting portion 30 the minimum necessary length, it is possible to reduce the size of the secondary battery 10 and increase the capacity of the secondary battery 10.

  (5) Since the foil collecting portion 30 can be sandwiched in the slit 141 of the current collecting plate 14, conductivity between the current collecting plate 14 and the foil collecting portion 30 can be secured. Moreover, the foil collection part 30 has high rigidity compared with the single front-end | tip part 211C, 221C because each front-end | tip part 211C, 221C gathers. For this reason, while being able to pinch the current collection part 30 in the current collection board 14, attachment to the current collection board 30 of the current collection board 14 becomes easy. Moreover, since the heat collecting capacity of the foil collecting portion 30 increases, it becomes easy to control the energy applied for welding. Therefore, for example, the possibility that the laser penetrates the foil collection part 30 in laser welding can be suppressed.

(Second Embodiment)
A second embodiment of the laminated electrode plate group, the secondary battery, and the method for manufacturing the secondary battery will be described with reference to FIGS. In addition, in this embodiment, the point which connects each foil collector part of a some electrode group to one current collector is 1st Embodiment which connects one electrode group 20 to one current collector 14. Is different.

As shown in FIG. 7, four electrode plate groups 40 are stacked.
Each electrode plate group 40 includes a positive electrode side foil collecting portion 60 at the lead portion of the positive electrode plate 21 in the longitudinal direction of the electrode plate group 40, and the negative electrode side of the lead portion of the negative electrode plate 22 in the longitudinal direction of the electrode plate group 40. A foil collecting unit 60 is provided. It is assumed that each foil collecting portion 60 has a paper surface on the upper end portion side, a back side of the paper surface on the lower end portion side, and extends from the upper end portion side to the lower end portion side.

  In the present embodiment, the four electrode plate groups 40 have substantially the same structure, and the foil collecting portions 60 are aligned with respect to the stacking direction of the electrode plate groups 40 and are spaced apart from each other by a predetermined interval. Are arranged in parallel.

  Each foil collecting portion 60 forms a collecting portion 62 in which the leading end portion of the positive electrode plate 21 or the leading end portion of the negative electrode plate 22 is assembled, a leading end portion 61 in which the stepped portions K1 are aligned, and a collecting portion 62. And a curved portion 63 whose front end portion is bent.

  The current collector plate 14 will be described with reference to FIG. Since the positive current collector plate 14 and the negative current collector plate 14 have the same structure, the current collector plate 14 will be described without distinction.

  The current collector plate 14 includes four slits 141 formed in the vertical direction. Each of the four slits 141 is for arranging the foil collecting portion 60 and has the same structure. The slit 141 includes a first extending piece 142 at the left end in FIG. 8 and a second extending piece 143 at the right end. In addition, third to fifth extending pieces 144 to 146 are provided between the first extending piece 142 and the second extending piece 143. Since the third to fifth extending pieces 144 to 146 have the same shape, the third extending piece 144 will be described in detail.

  The third extending piece 144 has the same shape as the second extending piece 143 on the right side in FIG. 8 and the same shape as the first extending piece 142 on the left side. Further, the third extending piece 144 is formed such that the width in the left-right direction orthogonal to the up-down direction can sandwich the foil collecting portion 60 of the electrode plate group 40. Similarly, the fourth and fifth extending pieces 145 and 146 have the same shape as the second extending piece 143 on the right side and the same shape as the first extending piece 142 on the left side in FIG. Have.

  Accordingly, each of the slits 141 of the current collector plate 14 has the same shape as the second extending piece 143 on the right side and the same shape as the first extending piece 142 on the left side, and the tip 14A. And a sandwiching portion 14B and a base end portion 14C.

Then, the current collector plate 14 fixed to the lid body 12 is attached to the four electrode plate groups 40 stacked.
With reference to FIG. 9, the procedure about the manufacturing method of a secondary battery is demonstrated based on a flowchart.

  When the manufacturing method of the secondary battery is started, an electrode plate group preparation step for producing a plurality of electrode plate groups is executed (step S20 in FIG. 9). In the electrode plate group preparation step, the lamination step (step S10 in FIG. 6), the terminal portion assembly step (step S11 in FIG. 6), and the foil collection portion formation step (step S12 in FIG. 6) described in the first embodiment. ) And the end cutting step (step S13 in FIG. 6), each electrode plate group 40 is produced.

  Next, an electrode plate group stacking step for stacking the prepared four electrode plate groups 40 is performed (step S21 in FIG. 9). In the electrode plate group stacking step, the four electrode plate groups 40 thus manufactured are stacked such that the foil collecting portions 60 are parallel to each other at the same position and a predetermined interval in the stacking direction. The four electrode plate groups 40 are configured such that at least one separator 23 is disposed between the electrode plate groups 40 when stacked. For example, one separator 23 may be stacked between the electrode plate groups 40, or two separators 23 may be stacked. Even if two separators 23 are sandwiched between the electrode plate groups 40, the risk of affecting the battery performance is small.

  When the four electrode plate groups 40 are stacked, a current collector plate contact step for attaching the current collector plate 14 to the foil collecting portion 60 of the electrode plate group 40 is executed (step S22 in FIG. 9). The respective foil collecting portions 60 of the four electrode plate groups 40 are sandwiched between the four slits 141 formed in the current collecting plate 14 by sliding the current collecting plate 14.

  When the current collecting plates 14 are attached to the four foil collecting portions 60, a welding process is performed in which the sandwiched portions 14B of the slits 141 of the current collecting plates 14 are welded to the collecting portions 62 of the respective foil collecting portions 60 (FIG. 9 step S23). In the welding process, the current collector plates 14 are welded to the foil collecting portions 60 sandwiched between them by laser welding. In addition, the four foil collection parts 60 may be laser-welded simultaneously to the current collecting plate 14, and the four foil collection parts 60 may be laser-welded one by one.

  When the attachment of the four electrode plate groups 40 to the current collector plate 14 fixed to the lid 12 is completed, an assembly process for assembling the four electrode plate groups 40 as the secondary battery 10 is executed (step S24 in FIG. 9). . In the assembly process, two steps are performed through the housing process (step S16 in FIG. 6), the case sealing process (step S17 in FIG. 6), and the liquid injection process (step S18 in FIG. 6) described in the first embodiment. The secondary battery 10 is assembled. And the manufacture of a secondary battery is complete | finished because the nonaqueous electrolyte 27 osmose | permeates the separator 23 of the some electrode group 40. FIG.

As described above, according to this embodiment, in addition to the effects (1) to (5) described in the first embodiment, the following effects can be obtained.
(6) The foil collecting portions 60 of the plurality of electrode plate groups 40 are welded to the current collecting plate 14. Therefore, it is easy to configure a secondary battery having a plurality of electrode plate groups 40.

  (7) By providing a plurality of electrode plate groups 40, the curved portion K3 can be shortened compared to the case where these are one electrode plate group, and therefore the stepped portion K1 to be cut can be shortened. In addition, the lengths of the tip portions of the positive electrode plate 21 and the negative electrode plate 22 which are uncoated portions can be shortened.

(8) By increasing or decreasing the number of electrode plate groups 40, secondary batteries having different battery capacities can be produced.
(Other embodiments)
In addition, each said embodiment can also be implemented with the following aspects.

-In the said 2nd Embodiment, although illustrated about the case where the four electrode plate groups 40 were laminated | stacked, not only this but the electrode plate groups laminated | stacked are two, three, or five or more. There may be.
-In each above-mentioned embodiment, although illustrated about the case where foil collection part 30 had cut-off tip part 31, it is not restricted to this but the foil collection part does not need to be cut off.

  In each of the above embodiments, the foil collecting portions 30 and 60 of the lead portion 214 are illustrated as being joined between the upper end portion 214a and the lower end portion 214b. However, the present invention is not limited to this, and the foil collecting portion of the lead portion only needs to be provided at least at a part between the upper end portion and the lower end portion. For example, the position where the tip of the current collector reaches from the upper end portion It is also possible to join up to. In other words, the lead portion does not have to be provided with the foil collecting portion between the lower end portion and the end of the current collector plate.

  For example, as shown in FIG. 10, when the current collector plate 14 does not reach the lower end portion of the lead portion 214, the foil collector portion 30 is set to the vicinity of the position where the tip end 14 </ b> A of the current collector plate 14 reaches and the tip end 14 </ b> A reaches the position. The foil collecting portion 30 may not be provided from the vicinity to the lower end portion.

  That is, as shown in FIG. 5, the portion where the foil collection portion 30 is provided is closed at the end of the positive electrode base material 211 of the lead portion 214, while the portion where the foil collection portion 30 is not provided As shown in FIG. 4, the end portion of the positive electrode base material 211 of the lead portion 214 is opened. Since the leading end side from which the lead portion 214 protrudes is opened, the nonaqueous electrolyte 27 can be easily infiltrated into the electrode plate group 20 from the opened leading end side. In particular, even if the electrode plate group 20 is provided with the foil collection part 30 by not providing the foil collection part 30 in the lead part 214 disposed below the battery case 11 in which the non-aqueous electrolyte 27 stays, the nonaqueous electrolyte High permeability of 27 can be maintained.

Further, since the tip end 14A of the current collector plate 14 is inserted into the upper end portion 214a of the lead portion 214, the foil collection portion 30 is preferably formed at the upper end portion 214a.
In addition, the part in which the foil collection part 30 is provided in the lead part 214 should just be a part suitable for attachment of a current collecting plate.

  For example, in the case of so-called “end face current collection” in which the flat surface of the current collection plate is pressed against the end face of the foil collection portion 30 and welded, the rigidity of the foil collection portion 30 is increased. Can be welded by pressing with an appropriate pressing force. At this time, if the lead part 214 is composed of a plurality of thin films that are not joined, the thin film with low rigidity may be deformed or the end part may be short, so that it may not be properly welded to the current collector plate. . Therefore, the foil collection part 30 should just be provided in the part to which a collector plate is welded with a laser etc., for example, may not be provided in the upper end part 214a.

  In each of the above embodiments, the case where the current collector plate 14 and the foil collector portions 30 and 60 are laser welded has been illustrated, but the present invention is not limited thereto, and the current collector plate and the foil collector portion may be electron beam welded. However, resistance welding may be performed.

  In each of the above embodiments, the case where the lead part 214 is collected at the center CH is illustrated, but the present invention is not limited thereto, and the lead part can be formed as long as a foil collecting part to which a current collector plate can be attached can be formed. It may be collected at a position off the center.

  In each of the above embodiments, the case where the lead part 214 is collected at one place in the center CH is exemplified, but not limited to this, as long as a foil collecting part to which a current collector plate can be attached can be formed. The lead portions may be collected at a plurality of locations, and the foil collection portions may be formed at a plurality of locations.

  In each of the above embodiments, the case where the foil collecting portions 30 and 60 are provided on both sides of the electrode plate groups 20 and 40 is illustrated. However, the present invention is not limited to this, and a foil collecting portion may be provided in any one of the electrode plate groups. Also by this, the stacking deviation of the electrode plate group can be suppressed to some extent.

  In each of the above embodiments, the case where the current collector plate 14 as a current collector is a plate-like member is illustrated, but the present invention is not limited thereto, and the current collector may be a columnar shape or the like as long as it can be connected to the foil collector. It may be a shape other than a plate shape.

  In each of the above embodiments, the case where the secondary battery 10 is a lithium ion secondary battery is exemplified, but the present invention is not limited to this, and other non-aqueous electrolyte secondary batteries, nickel-hydrogen secondary batteries, nickel cadmium batteries, etc. Alkaline secondary batteries and other secondary batteries may be used.

  The secondary battery 10 is not limited to being mounted on an electric vehicle or a hybrid vehicle, but may be mounted on a moving body such as a vehicle such as a gasoline vehicle or a diesel vehicle, a railway, a ship, or an aircraft, or a robot. It may also be used as a power source for information processing apparatuses and the like.

  DESCRIPTION OF SYMBOLS 10 ... Secondary battery, 11 ... Battery case, 12 ... Cover, 13 ... External terminal, 14 ... Current collecting plate, 14A ... Tip, 14B ... Clamping part, 14C ... Base end part, 14D ... Fixed part, 20 ... Pole Plate group, 21 ... positive electrode plate, 22 ... negative electrode plate, 23 ... separator, 27 ... non-aqueous electrolyte, 30 ... foil collecting part, 31 ... tip part, 32 ... collecting part, 40 ... electrode plate group, 60 ... foil collecting part , 61 ... tip part, 62 ... gathering part, 63 ... curved part, 140 ... extension part, 141 ... slit, 142 ... first extension piece, 143 ... second extension piece, 144 ... third extension piece, 145: Fourth extending piece, 146: Fifth extending piece, 211: Positive electrode base material, 211A: First surface, 211B: Second surface, 211C: Tip portion, 212, 213: Positive electrode mixture, 214, 224 ... Lead portion, 214a ... Upper end portion, 214b ... Lower end portion, 214c ... Central portion, 221 ... Negative electrode base , 221A ... first surface, 221B ... second surface, 221C ... tip portion, 222, 223 ... negative electrode mixture.

Claims (14)

A laminated electrode plate group that is an electrode plate group in which a positive electrode plate and a negative electrode plate are stacked with a separator interposed therebetween,
The terminal portion of the electrode plate group, wherein only the end edge portion of the positive electrode plate is disposed in the stacked direction, or only the end edge portion of the negative electrode plate is disposed. ,
A foil collecting portion connected to a current collecting portion provided in the terminal portion and extending in a direction along the terminal portion, wherein the edge portions arranged in the terminal portion are assembled in the stacked direction. And the foil collecting part to which the collected edge portions are joined together. The terminal portion has a proximal end portion which is an end portion close to the external terminal with respect to the longitudinal direction, and a distal end which is an end portion separated from the external terminal,
The stacked electrode group according to claim 1, wherein the foil collecting portion is provided at least at a part between the base end portion and a position close to the base end portion by a predetermined length from the tip end. . 3. The stacked electrode group according to claim 1, wherein the foil collecting portion has two edge portions facing each other in the stacked direction and interface-bonded to each other. The said electrode group consists of aluminum alloy foil in the said edge part of one said terminal part, and the said edge part of the other said terminal part consists of copper foil. Laminated electrode plate group. The foil collecting part is aligned at a predetermined position in the protruding direction of the protruding part of the terminal part,
The stacked electrode group according to any one of claims 1 to 4, wherein the predetermined position is a position where all the terminal portions are stacked in the stacked direction. The stacked electrode group according to any one of claims 1 to 5, wherein the foil collecting part is sandwiched between slits provided in the current collecting part from the stacked direction. A secondary battery having an electrode plate group in which a positive electrode plate and a negative electrode plate are stacked with a separator interposed therebetween,
The electrode plate group includes the laminated electrode plate group according to any one of claims 1 to 6,
A secondary battery in which at least a part of a foil collecting part of the electrode plate group and a current collecting part connected to an external terminal are welded. The current collector has a slit for sandwiching the foil collector in the stacked direction,
The secondary battery according to claim 7, wherein at least a part of the foil collecting part sandwiched between the slits is welded to the current collecting part. A secondary battery having a plurality of electrode plate groups in which a positive electrode plate and a negative electrode plate are laminated with a separator interposed therebetween,
The electrode plate group is composed of the stacked electrode plate group according to any one of claims 1 to 6,
A secondary battery in which at least a part of a foil collecting part of the plurality of electrode plate groups and a current collecting part connected to an external terminal are respectively welded. A method for producing a secondary battery having an electrode plate group in which a positive electrode plate and a negative electrode plate are laminated with a separator interposed therebetween,
Each terminal portion of the electrode plate group, in which only the positive electrode plate is arranged in the stacked direction, or only the edge portion of the negative electrode plate is arranged. An edge gathering step for gathering the edge in the stacked direction;
A foil collection part forming step of forming a foil collection part by joining the collected terminal parts,
An abutting step of bringing the current collecting part into contact with the foil collecting part;
A welding step of welding a contact portion between the foil collecting portion and the current collecting portion;
And a housing step of housing the electrode plate group in which the current collector is welded to the foil collector in a case of the secondary battery. In the foil collection portion forming step, a predetermined length from a base end portion that is an end portion close to the upper side of the case with respect to a longitudinal direction of the terminal portion and a tip end that is an end portion close to the lower side of the case. The method for manufacturing a secondary battery according to claim 10, wherein the foil collecting part is formed at least at a part between the position close to the base end part. In the foil collection portion forming step, the two edge portions facing each other in the stacked direction are interfaced with each other,
In the abutting step, the current collector is brought into contact with the foil collector by sandwiching the foil collector with a slit extending in the longitudinal direction of the current collector,
The method for manufacturing a secondary battery according to claim 10 or 11, wherein in the welding step, the current collector is welded to at least a part of the foil collector along the slit of the current collector. Prior to the accommodating step, the protruding portion of the terminal portion is a predetermined position in the protruding direction, and the cutting is performed so that all the terminal portions are stacked with respect to the stacked direction. It has a process. The manufacturing method of the secondary battery as described in any one of Claims 10-12. Prior to the contacting step, comprising a plate group lamination step of laminating a plurality of the plate group,
In the abutting step, the current collecting part is inserted into the foil collecting part by sandwiching each foil collecting part of the plurality of electrode plate groups into a plurality of slits extending in the longitudinal direction of the current collecting part. The manufacturing method of the secondary battery as described in any one of Claims 10-13.

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