JP2019053948A - Battery pack, and method of manufacturing the same - Google Patents

Abstract

To provide a battery pack capable of being manufactured at reduced cost of manufacture.SOLUTION: A battery pack comprises a plurality of battery cells, and a flexible printed wiring board. Each battery cell has a plate-like terminal extending from the inside of an outer package to the exterior. The plurality of battery cells are connected with each other in series or in parallel by the flexible printed wiring board. The flexible printed wiring board comprises a plate-like flying lead part at least partially connected with a lamination structure of the flexible printed wiring board. A surface of the terminal and a surface of the flying lead part are bonded with each other.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an assembled battery and a method for manufacturing the assembled battery.

In recent years, batteries have been used in various applications, and particularly large capacity batteries have been used in applications such as electric vehicle power supplies and power storage.
When the battery is used as a single battery, the voltage of the battery may be lower than the voltage required by the device. In such a case, it is necessary to connect a plurality of batteries in series and increase the supply voltage to a desired voltage. In addition, the unit cell may not be able to sufficiently supply the amount of power required by the device. In such a case, it is necessary to connect a plurality of batteries in parallel and increase the amount of supplied power to a desired amount. For this reason, the battery box and assembled battery which connected the some battery in series or in parallel are provided, and electric power is supplied to an apparatus from these.

A method of manufacturing an assembled battery by joining terminals of two adjacent unit cells is known (see, for example, Patent Document 1). In such a formation method, when producing a complicated assembled battery in which series connection and parallel connection are combined, it is necessary to provide a new conductor, which may increase the manufacturing cost. Moreover, it becomes complicated to attach a detection line for detecting the voltage of each unit cell, which increases the manufacturing cost.
A method of manufacturing an assembled battery in which a plurality of single cells are connected by a flexible printed wiring board (FPC) is known (for example, see Patent Document 2). By using the FPC, it becomes possible to connect the cells in a complicated manner. Further, the detection line can be provided in the FPC, and the manufacturing cost can be reduced.

JP 2013-239293 A Patent No. 6115265

In the conventional assembled battery manufacturing method in which a plurality of unit cells are connected by FPC, the connecting portion of the FPC and the terminal of the unit cell are connected by soldering. There are problems such as being restricted.
The present invention has been made in view of such circumstances, and provides an assembled battery that has sufficient joint strength, is easy to design an assembled battery, and can be manufactured at a reduced manufacturing cost.

  The present invention includes a plurality of battery cells and a flexible printed wiring board, each battery cell includes a plate-like terminal extending from the inside of the exterior body to the outside, and the plurality of battery cells include the flexible printed circuit. The flexible printed wiring board is connected in series or in parallel by a wiring board, and the flexible printed wiring board includes a plate-like flying lead portion at least partially connected to the laminated structure of the flexible printed wiring board, and the terminal and the flying lead portion are Provided is an assembled battery characterized in that the surfaces are joined to each other.

  The flexible printed wiring board included in the assembled battery of the present invention includes a plate-like flying lead portion that is at least partially connected to the laminated structure of the flexible printed wiring board. This flying lead portion has a structure in which one end is fixed to the laminated structure of the flexible printed wiring board and the other end can move. For this reason, it is possible to bend a flying lead part so that the plate-shaped terminal extended from the inside of the exterior body of a battery cell and the flying lead part may overlap. For this reason, the battery cell terminal and the flying lead part can be overlapped with each other and joined by ultrasonic welding, resistance welding, laser welding, etc., and sufficient joining strength can be obtained, and the manufacturing cost can be obtained. Can be reduced. In addition, after joining the battery cell terminal and the flying lead part, the flying lead part can be bent back to the original position, and the design of the assembled battery can be facilitated.

It is a schematic perspective view of the assembled battery of one Embodiment of this invention. It is a schematic perspective view of the assembled battery in broken line AA of FIG. (A) is a schematic enlarged view of the assembled battery in the range B enclosed by the broken line of FIG. 2, (b) is a schematic enlarged view of the assembled battery in the range C enclosed by the broken line of FIG. It is a general | schematic expanded view of the flexible printed wiring board contained in the assembled battery of one Embodiment of this invention. It is explanatory drawing of the manufacturing method of the assembled battery of one Embodiment of this invention. It is a schematic sectional drawing of the assembled battery of one Embodiment of this invention. It is explanatory drawing of the manufacturing method of the assembled battery of one Embodiment of this invention.

  The assembled battery of the present invention includes a plurality of battery cells and a flexible printed wiring board, each battery cell includes a plate-like terminal extending from the inside of the exterior body to the outside, and the plurality of battery cells include: The flexible printed wiring board is connected in series or in parallel by the flexible printed wiring board, and the flexible printed wiring board includes a plate-like flying lead portion at least partially connected to the laminated structure of the flexible printed wiring board, and the terminal and the flying The lead portion is characterized in that the surfaces are joined to each other.

The flexible printed wiring board preferably has an opening, and the flying lead portion is preferably provided in the opening. As a result, the assembled lead can be reduced in size without the flying lead portion protruding outside from the flexible printed wiring board.
This opening is preferably formed in the plane excluding the end of the flexible printed wiring board. As a result, the assembled battery can be reduced in size.
The flexible printed wiring board preferably has a power line and a battery state detection line, and the flying lead portion is preferably a part of the power line. Thereby, the arrangement of the battery cells in the assembled battery is facilitated, and the assembled battery can be reduced in size.
It is preferable that the power line and the battery state detection line are connected inside the flexible printed wiring board. Thereby, the arrangement of the battery cells in the assembled battery is facilitated, and the assembled battery can be reduced in size.
The power line is preferably a metal plate having a thickness of 100 μm or more and 300 μm or less. As a result, a relatively large current can flow through the power line, and the output of the assembled battery can be increased.

Each battery cell has a flat plate shape, and the plurality of battery cells are preferably stacked in the thickness direction of the battery cell. As a result, the assembled battery can be reduced in size.
The battery cell includes an electrode assembly in an outer package, and the electrode assembly is formed by stacking at least one positive electrode, at least one negative electrode, and at least one separator, and a positive electrode current collecting sheet is overlapped from the stacked structure. A positive electrode extension portion extended from the laminated structure, and a negative electrode extension portion from which the negative electrode current collector sheet overlapped and extended from the laminated structure, an end portion of the laminated structure, and a joint portion of the terminal and the flying lead portion, It is preferable that the terminal or the exterior body is bent between the two. As a result, the assembled battery can be reduced in size.
The assembled battery of the present invention preferably includes a plurality of battery groups, and each battery group preferably has a structure in which a plurality of battery cells are stacked in the thickness direction, and a plurality of battery cells included in each battery group Are preferably connected in series or in parallel by the flexible printed wiring board, and the plurality of battery groups are preferably connected by the same flexible printed wiring board. As a result, a plurality of battery cells can be divided and arranged in several groups, which facilitates the design of the assembled battery.
Two adjacent battery groups include a first portion of a flexible printed wiring board to which a plurality of battery cells included in the first battery group are connected, and a flexible printed wiring board to which a plurality of battery cells included in the second battery group are connected. It is preferable that the second portion is disposed so as to face the second portion, and an insulating partition wall is preferably provided between the first portion and the second portion of the flexible printed wiring board. This can prevent a short circuit from occurring between adjacent battery groups.

The present invention includes a step of bending a plate-like flying lead portion at least partially connected to a laminated structure of a flexible printed wiring board, a plate-like terminal and a flying lead extending from the inside to the outside of a battery cell exterior body Provided is a method of manufacturing an assembled battery including a step of overlapping and joining a portion and a step of bending back a flying lead portion.
Moreover, it is preferable that the step of bending back the flying lead portion is a step involving bending of the terminal or the exterior body.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The configurations shown in the drawings and the following description are merely examples, and the scope of the present invention is not limited to those shown in the drawings and the following description.

FIGS. 1-7 is drawing regarding the assembled battery of this embodiment, and the detail is the same as that of description of the above-mentioned drawing.
The assembled battery 60 of this embodiment includes a plurality of battery cells 2 and a flexible printed wiring board 3, and each battery cell 2 has plate-like terminals 4, 5 extending from the inside of the exterior body 16 to the outside. The plurality of battery cells 2 are connected in series or in parallel by a flexible printed wiring board 3, and the flexible printed wiring board 3 is at least partially connected to a laminated structure of the flexible printed wiring board 3. A portion 6 is provided, and the surfaces of the terminals 4 and 5 and the flying lead portion 6 are bonded to each other.
The manufacturing method of the assembled battery 60 of this embodiment includes a step of bending the plate-like flying lead portion 6 at least partially connected to the laminated structure of the flexible printed wiring board 3, and the inside of the outer package 16 of the battery cell 2. It includes a step of overlapping and joining the plate-like terminals 4 and 5 and the flying lead portion 6 extending outward, and a step of bending back the flying lead portion 6.

The assembled battery 60 may include a battery group that is stacked in the thickness direction of a plurality of battery cells. For example, in the assembled battery 60 shown in FIGS. 1 and 2, five battery cells 2 a to 2 e are stacked.
Moreover, the assembled battery 60 may have a plurality of battery groups in which a plurality of battery cells 2 are stacked, and the plurality of battery groups may be arranged. For example, in the assembled battery 60 shown in FIGS. 7B to 7D, a first battery group in which five battery cells 2 are stacked, a second battery group in which five battery cells 2 are stacked, and 2 A third battery group in which two battery cells 2 are stacked is arranged.
The assembled battery 60 may include a housing 35 that houses a plurality of battery cells 2. The material of the housing 35 can be an insulating material such as plastic. Moreover, the housing | casing 35 may have the partition 36 arrange | positioned between the 1st battery group in which the some battery cell 2 was laminated | stacked, and the 2nd battery group in which the some battery cell 2 was laminated | stacked. . As a result, it is possible to suppress a short circuit between two adjacent battery cells 2.

  The battery cell 2 included in the assembled battery 60 of the present embodiment is preferably a sealed battery. A sealed battery is a battery having a sealed structure in which an electrolyte is blocked from outside air and does not leak during storage or discharge. The battery cell 2 may be a secondary battery or a non-aqueous electrolyte secondary battery. The battery cell 2 is, for example, a lithium ion battery, a sodium ion battery, a lead storage battery, a nickel / hydrogen battery, a nickel / cadmium battery, or the like. The shape of the battery cell 2 may be cylindrical or plate-like, but a plate-like battery is preferable. The plate-like battery may be a thin battery such as a prismatic battery having an exterior such as a metal or a resin, or a pouch-type battery having an exterior such as a laminate film. Moreover, as a terminal shape, what extended the plate-shaped terminal from the inside of an exterior body to the exterior is preferable. The terminal is the positive terminal 4 or the negative terminal 5.

  For example, the shape of the battery cell 2 can be a flat rectangular parallelepiped. In this case, the battery cell 2 can have an upper surface and a lower surface which are wider surfaces, and can have four side surfaces around it. The positive electrode extending portion 25 and the negative electrode extending portion 26 can be provided on the inner side of two opposing side surfaces among the four side surfaces.

The exterior body 16 is a container that accommodates the electrode assembly 12 and the electrolyte 15. The material of the exterior body 16 is, for example, a laminate film. The outer package 16 can be provided so as to form a sealed space in which the electrode assembly 12 and the electrolyte 15 are accommodated. When the material of the exterior body 16 is a laminate film, the battery cell 2 is a pouch-type battery. In this case, the exterior body 16 can have a welded portion in which a laminate film is stacked and welded to the peripheral edge portion. Moreover, the positive electrode side sealing part 51 which adhere | attached the laminate film on both surfaces of the positive electrode terminal 4 and the negative electrode side sealing part 52 which adhere | attached the laminate film on both surfaces of the negative electrode terminal 5 are provided in the peripheral part of the exterior body 16. Can do. By arranging the positive electrode terminal 4 and the negative electrode terminal 5 in this manner, the terminals 4 and 5 are extended from the inside of the exterior body 16 to the outside. The laminate film is obtained by, for example, laminating a resin film on both surfaces of a metal film. The thickness of the laminate film can be set to, for example, 50 to 200 μm.
The outer package 16 preferably has a structure in which a laminate film is formed in a bag shape. Thereby, when forming the positive electrode bent part 30 or the negative electrode bent part 31, the exterior body 16 can also be folded and the battery cell 2 can be reduced in size easily.

The electrode assembly 12 has a laminated structure 10 in which at least one positive electrode 7, at least one negative electrode 8, and at least one separator 9 are stacked. The laminated structure 10 is a portion where the positive electrode 7, the negative electrode 8, and the separator 9 overlap. Further, the electrode assembly 12 includes a positive electrode extension portion 25 that extends from the laminated structure 10 with the positive electrode current collector sheet 18 overlapped, and a negative electrode extension portion 26 that extends from the laminated structure 10 with the negative electrode current collector sheet 22 extended. And have.
The electrode assembly 12 may have a stacked structure in which a plurality of positive electrodes 7, a plurality of negative electrodes 8, and a separator 9 are stacked. In this case, the laminated structure 10 is a portion in which a plurality of positive electrodes 7 and a plurality of negative electrodes 8 are alternately stacked via separators 9. When the electrode assembly 12 has a stack structure, the electrode assembly 12 has a structure in which sheet-like positive electrodes 7 and sheet-like negative electrodes 8 are alternately stacked with a separator 9 interposed therebetween. Moreover, each stacked positive electrode 7 is a separate positive electrode, and each stacked negative electrode 8 is a separate negative electrode. The plurality of positive electrodes 7 included in the electrode assembly 12 can have substantially the same shape, and the plurality of negative electrodes 8 included in the electrode assembly 12 can have substantially the same shape. For example, the electrode assembly 12 includes one separator 9 that is folded in a zigzag manner, and positive electrodes 7 and negative electrodes 8 that are arranged in the valleys of the separator 9 and are alternately arranged via the separators 9. it can. Separate separators 9 may be arranged between the positive electrode 7 and the negative electrode 8. Note that the number of stacked positive electrodes 7 or negative electrodes 8 included in the electrode assembly 12 can be appropriately designed according to the required battery capacity. Further, the battery cell 2 may have a plurality of electrode assemblies 12.
Further, the electrode assembly 12 may have a winding structure in which the positive electrode 7, the negative electrode 8, and the separator 9 are overlapped and wound. In this case, the laminated structure 10 is a portion where the positive electrode 7, the negative electrode 8, and the separator 9 overlap from the winding shaft toward the outer periphery. The electrode assembly 12 may have a flat wound structure.

  The positive electrode 7 includes a positive electrode current collector sheet 18 and a positive electrode active material layer 19 provided on the positive electrode current collector sheet 18. The positive electrode 7 can have a square or rectangular sheet shape. The positive electrode 7 can be produced, for example, by forming a positive electrode active material layer 19 on both surfaces of a square positive electrode current collector sheet 18. The positive electrode 7 can have a connecting portion (positive electrode current collecting sheet 18) connected to the positive electrode side clip 46 or the positive electrode terminal 4, and this connecting portion is provided on both surfaces of the positive electrode current collecting sheet 18 at the end of the positive electrode 7. It can be provided by not forming the positive electrode active material layer 19. Further, it is also possible to provide a connection portion by forming an ear portion at one end portion of the positive electrode current collector sheet 18 and not forming the positive electrode active material layer 19 at the ear portion. This connecting portion extends from the laminated structure 10 of the electrode assembly 12 and constitutes a positive electrode extending portion 25.

The positive electrode current collector sheet 18 is not particularly limited as long as it has electrical conductivity and can be provided with the positive electrode active material layer 19 on the surface. For example, it is a metal foil. Aluminum foil is preferable. The thickness of the positive electrode current collector sheet 18 is, for example, 10 μm to 40 μm.
The positive electrode active material layer 19 can be formed on the positive electrode current collector sheet 18 by adding a conductive agent, a binder, or the like to the positive electrode active material and applying the coating method. The positive electrode active material is, for example, a lithium transition metal composite oxide capable of reversibly occluding and releasing lithium ions. Specifically, the positive electrode active _{material, LiCoO 2, LiNiO 2, LiNi} x Co 1-x O 2 (x = 0.01~0.99), LiMnO 2, LiMn 2 O 4, LiCo x Mn y Ni z O ₂ (x + y + z = 1) or olivine type LiFePO ₄ or Li _x Fe _{1- y My} PO ₄ (where 0.05 ≦ x ≦ 1.2, 0 ≦ y ≦ 0.8, where M is Mn , Cr, Co, Cu, Ni, V, Mo, Ti, Zn, Al, Ga, Mg, B, and Nb) may be used singly or in combination. it can.

  The negative electrode 8 includes a negative electrode current collector sheet 22 and a negative electrode active material layer 23 provided on the negative electrode current collector sheet 22. The negative electrode 8 can have a square or rectangular sheet shape. The negative electrode 8 can be produced, for example, by forming the negative electrode active material layer 23 on both surfaces of the square negative electrode current collector sheet 22. The negative electrode 8 can have a connection part (negative electrode current collector sheet 22) connected to the negative electrode side clip 47 or the negative electrode terminal 5, and this connection part is formed on both surfaces of the negative electrode current collector sheet 22 at the end of the negative electrode 8. It can be provided by not forming the negative electrode active material layer 23. Further, it is also possible to provide a connection portion by forming an ear portion at one end portion of the negative electrode current collector sheet 22 and not forming the negative electrode active material layer 23 at the ear portion. This connecting portion extends from the laminated structure 10 of the electrode assembly 12 and constitutes the negative electrode extending portion 26.

Although it will not specifically limit if the negative electrode current collection sheet 22 has electrical conductivity and can provide the negative electrode active material layer 23 on the surface, For example, it is metal foil. Copper foil is preferred. The thickness of the negative electrode current collector sheet 22 is, for example, 10 μm to 40 μm.
The negative electrode active material layer 23 can be formed on the negative electrode current collector sheet 22 by adding a conductive agent, a binder, or the like to the negative electrode active material, and applying a coating method or the like. As the negative electrode active material, for example, in the case of a lithium ion secondary battery, graphite, partially graphitized carbon, hard carbon, soft carbon, LiTiO ₄ , Sn alloy, or the like can be used singly or in combination.

  The positive electrode extension portion 25 is a portion in which only the positive electrode current collector sheet 18 extends from the laminated structure 10. In the positive electrode extension portion 25, the positive electrode active material layer 19 is formed on the positive electrode current collector sheet 18. Absent. In the positive electrode extension portion 25, the positive electrode current collector sheet 18 overlaps. The portion extending from the laminated structure 10 may be an edge portion of the positive current collector sheet 18, an ear provided on the positive current collector sheet 18, or an attached lead or the like. Further, the positive electrode extension portion 25 may be a portion where the positive electrode current collector sheet 18 extends from the side surface of the laminated structure 10, or may be an ear provided on the positive electrode current collector sheet 18. A lead or the like may be used.

When the electrode assembly 12 has a stack type structure, the positive electrode extension part 25 is a part extended so that the positive electrode current collection sheet 18 may overlap from each positive electrode 7 included in the laminated structure 10. In the positive electrode extension portion 25, the negative electrode 8 and the separator 9 are not disposed between the overlapping positive electrode current collecting sheets 18, so that the overlapping positive electrode current collecting sheets 18 can be bundled by the positive electrode side clip 46, and a laminated structure 10 and the positive electrode side clip 46 can be electrically connected via the positive electrode extension portion 25.
When the electrode assembly 12 has a winding structure, the positive electrode extension portion 25 is a portion extended from the positive electrode 7 included in the spiral laminated structure 10 so that the positive electrode current collector sheet 18 overlaps. In the positive electrode extension portion 25, the negative electrode 8 and the separator 9 are not disposed between the overlapping positive electrode current collecting sheets 18, so that the overlapping positive electrode current collecting sheets 18 can be bundled by the positive electrode side clip 46, and a laminated structure 10 and the positive electrode side clip 46 can be electrically connected via the positive electrode extension portion 25.
Further, the overlapping positive electrode current collector sheet 18 included in the positive electrode extension portion 25 may be bonded to the positive electrode terminal 4 without providing the positive electrode side clip 46. For example, the positive electrode terminal 4 and the positive electrode current collector sheet 18 can be superposed and ultrasonically welded.

  The negative electrode extension portion 26 is a portion in which only the negative electrode current collector sheet 22 extends from the laminated structure 10. In the negative electrode extension portion 26, the negative electrode active material layer 23 is formed on the negative electrode current collector sheet 22. Absent. Further, in the negative electrode extension portion 26, the negative electrode current collector sheet 22 is overlapped. The portion extending from the laminated structure 10 may be an edge portion of the negative electrode current collector sheet 22, an ear provided on the negative electrode current collector sheet 22, or an attached lead or the like. Further, the negative electrode extension portion 26 may be a portion where the negative electrode current collector sheet 22 extends from the side surface of the laminated structure 10, or may be an ear provided on the positive electrode current collector sheet 18. A lead or the like may be used. The side surface on which the negative electrode extension portion 26 is provided may be a side surface opposite to the side surface on which the positive electrode extension portion 25 is provided.

When the electrode assembly 12 has a stack type structure, the negative electrode extension part 26 is a part extended from each negative electrode 8 included in the laminated structure 10 so that the negative electrode current collector sheet 22 overlaps. In the negative electrode extension portion 26, the positive electrode 7 and the separator 9 are not disposed between the overlapping negative electrode current collecting sheets 22, so that the overlapping negative electrode current collecting sheets 22 can be bundled by the negative electrode side clip 47, and a laminated structure 10 and the negative electrode side clip 47 can be electrically connected via the negative electrode extension 26.
When the electrode assembly 12 has a winding structure, the negative electrode extending portion 26 is a portion extended from the negative electrode 8 included in the spiral laminated structure 10 so that the negative electrode current collecting sheet 22 overlaps. In the negative electrode extension portion 26, the positive electrode 7 and the separator 9 are not disposed between the overlapping negative electrode current collecting sheets 22, so that the overlapping negative electrode current collecting sheets 22 can be bundled by the negative electrode side clip 47, and a laminated structure 10 and the negative electrode side clip 47 can be electrically connected via the negative electrode extension 26.
Alternatively, the negative electrode current collector sheet 22 included in the negative electrode extension 26 may be joined to the negative electrode terminal 5 without providing the negative electrode side clip 47. For example, the negative electrode terminal 5 and the negative electrode current collector sheet 22 can be superposed and ultrasonically welded.

  The separator 9 has a sheet shape and is disposed between the positive electrode 7 and the negative electrode 8. The separator 9 is not particularly limited as long as it can prevent a short-circuit current from flowing between the positive electrode 7 and the negative electrode 8 and can permeate the electrolyte. For example, the separator 9 is a microporous film of polyolefin or polyethylene. be able to.

The electrolyte 15 can use carbonates, lactones, ethers, esters, and the like as a solvent, and can also be used by mixing two or more of these solvents. Among these, it is particularly preferable to use a mixture of a cyclic carbonate and a chain carbonate. The electrolyte 15 is made of, for example, a lithium salt solute such as LiCF ₃ SO ₃ , LiAsF ₆ , LiClO ₄ , LiBF ₄ , LiPF ₆ , LiBOB, LiN (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ SO ₂ ). It is a solution dissolved in an aqueous solvent. In addition, one or more additives such as VC (vinylene carbonate), PS (propane sultone), VEC (vinyl ethyl carbonate), PRS (propene sultone), FEC (fluoroethylene carbonate), flame retardant, etc. may be used as necessary. You may mix and mix | blend.

The positive electrode side clip 46 is provided so as to overlap and bundle the portions (connection portion, positive electrode extension portion 25) of the positive electrode current collector sheet 18 where the positive electrode active material layer 19 is not provided. Moreover, the negative electrode side clip 47 is provided so that the part (connection part, negative electrode extension part 26) in which the negative electrode active material layer 23 of the negative electrode current collection sheet 22 is not provided may be piled up and bundled.
The positive electrode side clip 46 or the negative electrode side clip 47 may be ultrasonically welded and integrated together with the positive electrode current collector sheet 18 or the negative electrode current collector sheet 22 sandwiched therebetween. For example, the positive electrode side clip 46 or the negative electrode side clip 47 can be integrated with the positive electrode current collector sheet 18 or the negative electrode current collector sheet 22 that are overlapped by ultrasonic welding.

  The positive side clip 46 or the negative side clip 47 is made of a conductive material. Thus, the battery cell 2 can be charged / discharged via the positive side clip 46 or the negative side clip 47. When the positive side clip 46 and the negative side clip 47 are made of a metal plate, the thickness of the metal plate can be, for example, 100 μm to 500 μm.

  The positive electrode terminal 4 is a member that is electrically connected to the positive electrode 7 inside the exterior body 16 and serves as a positive electrode side terminal of the battery cell 2. A portion of the positive electrode terminal 4 located inside the outer package 16 can be joined to the positive clip 46 or the positive electrode extension 25. The positive electrode terminal 4 can be joined to the positive electrode side clip 46 by superposing the positive electrode terminal 4 and the positive electrode side clip 46 and performing ultrasonic welding. The positive electrode terminal 4 can be a metal plate. Moreover, when the material of the positive electrode current collector sheet 18 and the positive electrode side clip 46 is aluminum, the positive electrode terminal 4 can be an aluminum plate. The thickness of the positive electrode terminal 4 can be set to 100 μm to 500 μm, for example.

The positive electrode terminal 4 and the outer package 16 can form a positive electrode side sealing portion 51 in which the outer package 16 is bonded to the positive electrode terminal 4. The positive electrode side sealing part 51 forms a peripheral part of the outer package 16 together with the welded part and the negative electrode side sealing part 52, and this peripheral part is inside the outer package 16, the electrode assembly 12, the electrolyte 15, and the positive electrode side. A sealed space in which the clip 46 and the negative electrode side clip 47 are arranged is formed. Further, by providing the positive electrode side sealing portion 51, a part of the positive electrode terminal 4 can be located inside the exterior body 16, and another part of the positive electrode terminal 4 can be located outside the exterior body 16. Accordingly, the positive electrode terminal 4 extends from the inside of the exterior body 16 to the outside. The positive electrode side sealing portion 51 may be formed by bonding the positive electrode terminal 4 and the outer package 16 through an adhesive layer, or may be formed by welding the outer package 16 to the positive electrode terminal 4.
A portion of the positive electrode terminal 4 located outside the exterior body 16 is joined to the flying lead portion 6 of the flexible printed wiring board 3. For this reason, the electrode assembly 12 and the flexible printed wiring board 3 arranged in the sealed space inside the exterior body 16 can be electrically connected via the positive electrode terminal 4, and the battery cell 2 via the positive electrode terminal 4. Can be charged and discharged.
The shape of the positive electrode terminal 4 can be, for example, a plate shape or a belt shape. In this case, one end of the positive terminal 4 can be joined to the positive clip 46 or the positive extension 25, and the other end of the positive terminal 4 can be joined to the flying lead 6. And the positive electrode side sealing part 51 can be provided in the meantime.

  The negative electrode terminal 5 is a member that is electrically connected to the negative electrode 8 inside the outer package 16 and serves as a terminal on the negative electrode side of the battery cell 2. A portion of the negative electrode terminal 5 located inside the exterior body 16 can be joined to the negative electrode side clip 47 or the negative electrode extension portion 26. The negative electrode terminal 5 can be joined to the negative electrode side clip 47 by superposing the negative electrode terminal 5 and the negative electrode side clip 47 and ultrasonically welding them. The negative electrode terminal 5 can be a metal plate. Moreover, when the material of the negative electrode current collector sheet 22 and the negative electrode side clip 47 is copper, the negative electrode terminal 5 can be a copper plate. The thickness of the negative electrode terminal 5 can be set to 100 μm to 500 μm, for example.

The negative electrode terminal 5 and the outer package 16 can form a negative electrode side sealing portion 52 in which the outer package 16 is bonded to the negative electrode terminal 5. The negative electrode side sealing part 52 forms a peripheral part of the outer package 16 together with the welded part and the positive electrode side sealing part 51, and this peripheral part is inside the outer package 16, the electrode assembly 12, the electrolyte 15, and the positive electrode side. A sealed space in which the clip 46 and the negative electrode side clip 47 are arranged is formed. Further, by providing the negative electrode side sealing portion 52, a part of the negative electrode terminal 5 can be located inside the exterior body 16, and another part of the negative electrode terminal 5 can be located outside the exterior body 16. Accordingly, the negative electrode terminal 5 extends from the inside of the exterior body 16 to the outside. The negative electrode side sealing portion 52 may be formed by bonding the negative electrode terminal 5 and the outer package 16 through an adhesive layer, or may be formed by welding the outer package 16 to the negative electrode terminal 5.
The portion of the negative electrode terminal 5 located outside the exterior body 16 is joined to the flying lead portion 6 of the flexible printed wiring board 3. For this reason, the electrode assembly 12 and the flexible printed wiring board 3 disposed in the sealed space inside the exterior body 16 can be electrically connected via the negative electrode terminal 5, and the battery cell 2 is connected via the negative electrode terminal 5. Can be charged and discharged.
The shape of the negative electrode terminal 5 can be, for example, a belt shape. In this case, one end of the negative electrode terminal 5 can be bonded to the negative electrode clip 47 or the negative electrode extension portion 26, and the other end of the negative electrode terminal 5 can be bonded to the flying lead portion 6. And the negative electrode side sealing part 52 can be provided in the meantime.

  The positive electrode extension part 25 (positive electrode current collector sheet 18) can have a positive electrode bent part 30 formed by overlapping and bending the positive electrode current collector sheet 18. Moreover, the negative electrode extension part 26 (negative electrode current collection sheet | seat 22) can have the negative electrode bending part 31 formed by overlapping and bending the negative electrode current collection sheet | seat 22. As shown in FIG. By providing the positive electrode bent portion 30 and the negative electrode bent portion 31, the portion of the positive electrode current collector sheet 18 where the positive electrode active material layer 19 is not formed (the positive electrode extension portion 25) and the negative electrode active material layer 23 of the negative electrode current collector sheet 22. Thus, the portion (negative electrode extension portion 26) where no is formed can be folded, and the battery cell 2 can be reduced in size.

  The positive electrode bent portion 30 is not particularly limited as long as it is a bent portion provided between the end portion of the laminated structure 10 and the joint portion 11 of the positive electrode terminal 4 and the flying lead portion 6. The positive electrode terminal 4 can be provided along the side surface of the structure 10 where the positive electrode extension 25 is provided. Moreover, the positive electrode bending part 30 can be provided so that the positive electrode terminal 4 and the flexible printed wiring board 3 may overlap. Moreover, the positive electrode bending part 30 can be provided so that the positive electrode terminal 4 may be arrange | positioned along the flexible printed wiring board 3. FIG. Thus, by providing the positive electrode bending part 30, the space between the laminated structure 10 and the flexible printed wiring board 3 can be narrowed, and the assembled battery 60 can be reduced in size.

  The negative electrode bent portion 30 is not particularly limited as long as it is a bent portion provided between the end portion of the laminated structure 10 and the joint portion 11 of the negative electrode terminal 5 and the flying lead portion 6. The negative electrode terminal 5 can be provided along the side surface of the structure 10 where the negative electrode extension 26 is provided. Moreover, the negative electrode bending part 31 can be provided so that the negative electrode terminal 5 and the flexible printed wiring board 3 may overlap. Further, the negative electrode bent portion 31 can be provided so that the negative electrode terminal 5 is disposed along the flexible printed wiring board 3. Thus, by providing the negative electrode bending part 31, the space between the laminated structure 10 and the flexible printed wiring board 3 can be narrowed, and the assembled battery 60 can be reduced in size.

  When the assembled battery 60 has a battery group in which a plurality of battery cells 2 are stacked, the positive electrode extension portion 25 or the negative electrode extension portion 26 of each battery cell 2 is located on the first side surface side of the battery group, and each battery cell 2 A plurality of battery cells 2 can be stacked such that the positive electrode extension portion 25 or the negative electrode extension portion 26 is positioned on the second side surface side of the battery group. Moreover, the flexible printed wiring board 3 can be arrange | positioned so that the 1st side surface and 2nd side surface of a battery group may be followed. Thereby, the positive electrode terminal 4 and the negative electrode terminal 5 of each battery cell 2 and the flying lead part 6 of the flexible printed wiring board 3 can be easily joined.

The assembled battery 60 includes a flexible printed wiring board (FPC) 3 that connects a plurality of battery cells 2 in series or in parallel. By connecting the plurality of battery cells 2 by the flexible printed wiring board 3, it becomes possible to arrange the plurality of battery cells 2 included in the assembled battery 60 in various arrangements, and the shape of the assembled battery 60 can be changed to various spaces. It becomes possible to adapt to.
The flexible printed wiring board 3 is a substrate provided with a metal layer having a wiring pattern formed on a thin and soft insulating base film 48 (insulating film 44). The flexible printed wiring board 3 may be a single-sided FPC in which a metal layer is provided on one side of the base film 48, or may be a double-sided FPC in which a metal layer is provided on both sides of the base film 48, A multilayer FPC in which the base film 48 is stacked may be used. The flexible printed wiring board 3 can be provided, for example, as shown in a development view of FIG.

Electronic components and connectors 43 may be mounted on the flexible printed wiring board 3. The flexible printed wiring board 3 can have a structure (laminated structure) in which a metal layer is sandwiched between the base film 48 and the cover film 49. This metal layer becomes the power line 40 including the flying lead portion 6 and the battery state detection line, here, the voltage detection line 41. Further, this metal layer may serve as connection terminals 42 a and 42 b that are ends of the power line 40. The insulating film 44 (base film 48 and cover film 49) is, for example, a polyimide film. The material of the metal layer is, for example, copper, aluminum, or silver. The thickness of the metal layer is, for example, 100 μm or more and 300 μm or less. A wiring pattern is formed on this metal layer, and includes a power line 40 and a voltage detection line (battery state detection line) 41. When a metal layer is used as the power line 40, it is preferable that the metal layer has a relatively thick thickness. By using a relatively thick metal plate for the metal layer, a relatively large current can be passed through the power line 40. Moreover, since the flying lead part 6 also has a relatively thick plate shape, the flying lead part 6 and the positive electrode terminal 4 or the negative electrode terminal 5 can be easily joined.
Moreover, the thickness of the base film 48 or the cover film 49 is 10 micrometers or more and 60 micrometers or less, for example. Further, an adhesive layer may or may not be provided between the metal layer and the base film 48 or between the metal layer and the cover film 49.

The power line 40 is a wiring through which the discharging current and the charging current of the battery cell 2 flow among the wirings formed on the flexible printed wiring board 3. The power line 40 can have a pattern that allows a plurality of battery cells 2 included in the assembled battery 60 to be connected in series or in parallel. The power line 40 can be provided so as to connect the positive terminal 4 or the negative terminal 5 of at least two battery cells 2 included in the assembled battery 60. The power line 40 has a wider width than the voltage detection line 41 because a relatively large current flows. The width of the metal plate (metal layer) of the power line 40 is preferably 5 mm to 20 mm.
The power line 40 has a flying lead portion 6. In the flying lead portion 6, the insulating film 44 on the upper surface and the lower surface of the metal layer is removed, and the metal surface is exposed. Therefore, the upper surface and the lower surface of the flying lead portion 6 have conductivity. The metal layer of the flying lead portion 6 may be subjected to a surface treatment such as metal plating. The flying lead portion 6 has a structure in which at least a part is connected to the laminated structure of the flexible printed wiring board 3. That is, one end of the flying lead portion 6 is connected to the power line 40 between the base film 48 and the cover film 49, and is fixed to the base film 48 and the cover film 49. The other end of the flying lead portion 6 is not fixed to the base film 48 and the cover film 49. For this reason, it is possible to bend the flying lead part 6 at the base. When the assembled battery is manufactured, if the flexible printed wiring board 3 is bent or folded back, the internal wiring may be damaged, but if only the flying lead portion 6 is bent, it is a metal plate. There is no fear.
The flying lead portion 6 can be provided in the opening 45 provided in the flexible printed wiring board 3. The opening 45 is preferably provided at a position that does not protrude from the surface of the flexible printed wiring board 3, and more preferably provided at a position excluding an end portion within the surface of the flexible printed wiring board.
The flying lead 6 may have a cantilever structure (cantilever structure).

The flying lead portion 6 and the positive electrode terminal 4 or the negative electrode terminal 5 of the battery cell 2 are overlapped and bonded to form a bonded portion 11. For this reason, the power line 40 of the flexible printed wiring board 3 and the battery cell 2 can be electrically connected via the flying lead part 6, and the plurality of battery cells 2 included in the assembled battery 60 are connected in series by the power line 40. Or it can be connected in parallel. Moreover, the flying lead part 6 can be made into a plate shape having a width of 5 mm to 20 mm. Thereby, the flying lead part 6 and the positive electrode terminal 4 or the negative electrode terminal 5 can be easily overlapped and joined. A method for forming the joint portion 11 will be described later.
The flexible printed wiring board 3 can have a plurality of flying lead portions 6. The plurality of flying lead portions 6 correspond to and join to the positive terminal 4 and the negative terminal 5 of the plurality of battery cells 2 included in the assembled battery 60.

The power line 40 can have connection terminals 42a and 42b. The connection terminals 42 a and 42 b are external connection terminals of the plurality of battery cells 2 connected in series or in parallel by the flexible printed wiring board 3. The connection terminals 42a and 42b may be connected to the control unit 38. As a result, charging / discharging of the assembled battery 60 can be controlled by the control unit 38. The control unit 38 can include a fuse or a relay. Accordingly, when the control unit 38 detects overcharge or overdischarge of the battery cell 2, the electrical connection between the external connection terminal of the assembled battery 60 and the battery can be disconnected, and the safety of the assembled battery 60 is ensured. Can be improved. Although there is no restriction | limiting in particular in fixation of the connection terminal 42 and the control part 38, For example, screwing can be used.
Further, the connection terminals 42a and 42b may be connected to external wiring. The metal layers of the connection terminals 42a and 42b may be subjected to a surface treatment such as metal plating. Here, a case where a part of the power line 40 is the connection terminal 42 is described, but the flexible printed wiring board 3 is mounted with a connector connected to the power line 40, and the power line 40 is connected to the control unit via this connector. 38 or an external wiring.

The voltage detection line (battery state detection line) 41 is a wiring for detecting the voltage between the positive terminal 4 and the negative terminal 5 of the battery cell 2 among the wirings formed on the flexible printed wiring board 3. The voltage detection line 41 can have a pattern that can detect the voltage between the terminals of each battery cell 2 included in the assembled battery 60. The voltage detection line 41 can be connected to the power line 40 so that the control unit 38 can detect the voltage between the terminals of each battery cell 2. Further, by forming the power line 40 and the voltage detection line 41 other than the flying lead portion 6 inside the flexible printed wiring board 3, erroneous contact and erroneous detection can be prevented. The voltage detection line 41 is provided so as to electrically connect the power line 40 that electrically connects at least two battery cells 2 and the control unit 38. Further, since only a relatively small current flows through the voltage detection line 41, the voltage detection line 41 has a narrower width than the power line 40.
The flexible printed wiring board 3 can have a connector 43 connected to the voltage detection line 41. The connector 43 can be connected to the control unit 38. This makes it possible to detect the terminal voltage of each battery cell 2 included in the assembled battery 60 via the voltage detection line 41 and the connector 43, and overcharge and overdischarge of each battery cell 2 during charging and discharging. Can be detected. The control unit 38 is, for example, a battery monitoring unit (BMU).
In this embodiment, a voltage detection line is used as an example of the battery state detection line 41. However, this detection line can be used to detect other battery states such as current detection and temperature detection.

  When the assembled battery 60 has a battery group in which a plurality of battery cells 2 are stacked, the first side surface of the battery group in which the positive electrode terminals 4 or the negative electrode terminals 5 of the battery cells 2 are arranged in the vertical direction, and the The flexible printed wiring board 3 can be disposed along the second side surface of the battery group in which the positive electrode terminals 4 or the negative electrode terminals 5 are arranged in the vertical direction, and the plurality of flying lead portions 6 are arranged in the positive electrode terminals 4 arranged in the vertical direction. Or it can provide so that it may correspond to the negative electrode terminal 5, and may join. In this case, the plurality of flying lead portions 6 are arranged in the vertical direction corresponding to the positive electrode terminals 4 or the negative electrode terminals 5 arranged in the vertical direction, and are joined to the positive electrode terminals 4 or the negative electrode terminals 5 in the joint portions 11, respectively. Moreover, the one flexible printed wiring board 3 bent can be arrange | positioned along the 1st side surface and 2nd side surface of a battery group. Thus, the voltage detection line 41 can be provided on one flexible printed wiring board 3, and the voltage detection line 41 and the control unit 38 can be connected by one connector 43.

  The assembled battery 60 can have a structure in which a plurality of such battery groups of the battery cells 2 connected to the flexible printed wiring board 3 are arranged. In this case, a plurality of battery groups can be arranged so that the flexible printed wiring board 3 is positioned between two adjacent battery groups. Moreover, the positive electrode extension part 25 or the negative electrode extension part 26 of the battery cell 2 included in one of the two adjacent battery groups, and the positive electrode extension part 25 or the negative electrode extension of the battery cell 2 included in the other battery group. A plurality of battery groups can be arranged so that the protruding portion 26 faces. In this case, the two flexible printed wiring boards 3 arranged between two adjacent battery groups may be arranged facing each other. In this case, since the flying lead part 6 is also arranged facing each other, an insulating partition 36 can be provided between the flexible printed wiring boards 3 facing each other. Thereby, even when the assembled battery 60 has a structure in which a plurality of battery groups are arranged, all the battery cells 2 included in the assembled battery 60 can be connected by the single flexible printed wiring board 3 that is bent. Thus, the voltage detection line 41 can be provided on one flexible printed wiring board 3, and the voltage detection line 41 and the control unit 38 can be connected by one connector 43.

For example, in the case of the assembled battery 60 including the battery cells 2a to 2e shown in FIGS. 1 and 2, one folded flexible printed wiring board 3 is disposed along the first side surface and the second side surface of the battery group, The flexible printed wiring board 3 has ten flying lead portions 6a to 6j corresponding to the positive terminals 4a to 4e and the negative terminals 5a to 5e on the first and second side surfaces. Further, the positive terminals 4a to 4e or the negative terminals 5a to 5e and the flying lead portions 6a to 6j are joined to form joined portions 11a to 11j.
Further, for example, in the case of the assembled battery 60 including the battery cells 2a to 2l shown in FIGS. 7C and 7D, the folded flexible printed wiring board 3 is laminated with the battery cells 2a and 2b. The battery cells 2a to 2l are disposed along the side surface of the first battery group, the side surface of the second battery group in which the battery cells 2c to 2g are stacked, and the side surface of the third battery group in which the battery cells 2h to 2l are stacked. Are connected in series or in parallel.

  The manufacturing method of the assembled battery 60 includes a step of bending the flying lead portion 6 having a cantilever structure of the flexible printed wiring board 3, one of the positive electrode terminal 4 and the negative electrode terminal 5 of the battery cell 2, and the flying lead portion 6. And a step of bending the battery cell 2 and bending the flying lead portion 6 back.

Here, the manufacturing method of the assembled battery 60 as shown to FIGS. 1-3 is demonstrated.
First, the flexible printed wiring board 3 as shown in the development view of FIG. 4 is prepared. The flying lead portion 6 included in the flexible printed wiring board 3 is bent as shown in FIGS. In the step of bending the flying lead portion 6, the flying lead portion 6 is bent to the side opposite to the battery cell 2 side of the flexible printed wiring board 3, like the flexible printed wiring board 3 included in the assembled battery 60 of FIG. 6. As a result, as shown in FIG. 5B, the opening 45 provided with the flying lead portion 6 becomes wide.

Next, a plurality of pouch-type battery cells 2a to 2e are stacked on the flexible printed wiring board 3, and the positive terminal 4 and the negative terminal 5 of the battery cell 2 are placed in the opening 45 as shown in FIGS. The flying lead portion 6 inserted and bent is overlapped with the positive electrode terminal 4 or the negative electrode terminal 5.
Next, as shown in FIG. 5 (d), the overlapping flying lead 6 and the positive terminal 4 or the negative terminal 5 are joined to a joint or welder head 54 (in the case of ultrasonic welding, an ultrasonic horn and an anvil). And the flying lead portion 6 and the positive electrode terminal 4 or the negative electrode terminal 5 are welded to form the joint portion 11. For example, an ultrasonic welder, a resistance welder, or the like can be used as the joiner or the welder. The flying lead 6 and the positive terminal 4 or the negative terminal 5 may be joined by laser welding or pressure welding. Further, they may be joined by soldering, brazing, caulking, or the like. In this way, by folding the flying lead portion 6, the flying lead portion 6 and the positive electrode terminal 4 or the negative electrode terminal 5 can be easily overlapped, and the joining work is facilitated. In this embodiment, a space for sandwiching the superimposed flying lead portion 6 and the positive electrode terminal 4 or the negative electrode terminal 5 between the head portions 54 can be secured. Moreover, since the main surface of the flying lead part 6 and the main surface of the positive electrode terminal 4 or the main surface of the negative electrode terminal 5 can be joined, stronger joining can be performed.

  Next, the plurality of battery cells 2a to 2e are bent so that the positive electrode bent portion 30 and the negative electrode bent portion 31 are formed, and the plurality of flying lead portions 6a to 6j are bent back as shown in FIG. At this time, the flexible printed wiring board 3 on the side surface of the battery group in which the plurality of battery cells 2a to 2e are stacked is pulled up. Thereby, the assembled battery 60 as shown in FIG. 6 can be transformed into the assembled battery 60 as shown in FIGS. Thereby, the assembled battery 60 can be reduced in size. Then, the assembled battery 60 as shown in FIGS. 1 and 2 can be manufactured by connecting the connection terminals 42a and 42b and the connector 43 of the flexible printed wiring board 3 to the control unit 38.

Further, in the method of manufacturing the assembled battery 60 shown in FIG. 7, a plurality of pouch-type battery cells 2a to 2l are stacked on the flexible printed wiring board 3 as shown in FIG. 6 and the positive electrode terminal 4 or the negative electrode terminal 5 are overlapped. Thereafter, the flying lead portion 6 and the positive electrode terminal 4 or the negative electrode terminal 5 are joined, the plurality of battery cells 2a to 21 are bent, the plurality of flying lead portions 6 are bent back, and the flexible printed wiring board 3 on the side surface of the battery group is pulled up. . Thereafter, the flexible printed wiring board 3 is bent along the dotted lines D and E in FIG. 7B so that the flexible printed wiring board 3 is positioned between two adjacent battery groups. As a result, the arrangement of the battery groups of the battery cells 2 can be changed as shown in FIG. Moreover, by making the flexible printed wiring board 3 into a bent structure, the development length of the flexible printed wiring board 3 can be shortened, and the manufacturing cost of the flexible printed wiring board 3 can be reduced.
Next, as shown in FIG. 7D, the assembled battery 60 can be formed by housing the flexible printed wiring board 3 and the battery cell 2 in the housing 35. Moreover, the housing | casing 35 can have the partition walls 36a and 36b located between two adjacent battery groups.

  In this embodiment, the plurality of battery cells 2 included in the battery group are stacked in the up-down direction, but can be stacked in directions other than the up-down direction as long as the thickness direction of the battery cells 2.

  2, 2a-2l: Battery cell 3: Flexible printed wiring board 4: Positive electrode terminal 5: Negative electrode terminal 6, 6a-6j: Flying lead part 7: Positive electrode 8: Negative electrode 9: Separator 10, 10a-10e: Laminate structure 11, 11a to 11j: Junction parts 12, 12a to 12e: Electrode assembly 15: Electrolyte 16, 16a, 16b: Exterior body 18: Positive electrode current collector sheet 19: Positive electrode active material layer 22: Negative electrode current collector sheet 23: Negative electrode active material layer 25: Positive electrode extension part 26: Negative electrode extension part 30: Positive electrode bending part 31: Negative electrode bending part 35: Housing 36, 36a, 36b: Bulkhead 37: Lid 38: Control part 40: Power line 41: Voltage detection line (battery (State detection line) 42, 42a, 42b: connection terminal 43: connector 44: insulating film 5,45A～45j: opening 46: the positive-side clip 47: negative electrode side clips 48: base film 49: cover film 51: positive-side sealing portion 52: negative electrode side plugs 54: splicer head portion 60: battery pack

Claims (12)

A plurality of battery cells and a flexible printed wiring board are provided,
Each battery cell includes a plate-like terminal extending from the inside of the exterior body to the outside,
The plurality of battery cells are connected in series or in parallel by the flexible printed wiring board,
The flexible printed wiring board includes a plate-like flying lead portion at least partially connected to the laminated structure of the flexible printed wiring board,
The assembled battery characterized in that surfaces of the terminal and the flying lead portion are bonded to each other. The flexible printed wiring board has an opening,
The assembled battery according to claim 1, wherein the flying lead portion is provided in the opening.   The assembled battery according to claim 2, wherein the opening is formed in a plane excluding an end portion of the flexible printed wiring board. The flexible printed wiring board has a power line and a battery state detection line,
The assembled battery according to claim 1, wherein the flying lead part is a part of the power line.   The assembled battery according to claim 4, wherein the power line and the battery state detection line are connected inside the flexible printed wiring board.   The assembled battery according to claim 4, wherein the power line is a metal plate having a thickness of 100 μm to 300 μm. Each battery cell has a flat plate shape,
The assembled battery according to claim 1, wherein the plurality of battery cells are stacked in a thickness direction of the battery cell. The battery cell includes an electrode assembly in the exterior body,
The electrode assembly includes a laminated structure in which at least one positive electrode, at least one negative electrode, and at least one separator are stacked, a positive electrode extending portion in which a positive current collector sheet extends from the laminated structure, and A negative electrode current collector sheet extending from the laminated structure, and a negative electrode extension part,
The assembled battery according to any one of claims 1 to 7, wherein the terminal or the exterior body is bent between an end portion of the laminated structure and a joint portion between the terminal and the flying lead portion. With multiple battery groups,
Each battery group has a structure in which a plurality of battery cells are stacked in the thickness direction,
A plurality of battery cells included in each battery group are connected in series or in parallel by the flexible printed wiring board,
The assembled battery according to any one of claims 1 to 8, wherein the plurality of battery groups are connected by the same flexible printed wiring board. The two adjacent battery groups include the first portion of the flexible printed wiring board to which the plurality of battery cells included in the first battery group are connected, and the flexible to which the plurality of battery cells included in the second battery group are connected. It is arranged to face the second part of the printed wiring board,
The assembled battery according to claim 9, wherein an insulating partition is provided between the first portion and the second portion of the flexible printed wiring board. A step of bending a plate-like flying lead portion at least partially connected to the laminated structure of the flexible printed wiring board;
A step of stacking and joining the plate-like terminal extending from the inside of the battery cell exterior body to the outside and the flying lead portion;
And a step of bending back the flying lead portion.   The method of manufacturing an assembled battery according to claim 11, wherein the step of bending back the flying lead portion is a step involving bending of the terminal or the exterior body.