TWI788418B - Battery pack and method for manufactaring battery pack - Google Patents

Abstract

A battery pack of this invention includes a plurality of battery cells and a flexible printed wiring board. Each of the battery cells includes a plate-shaped terminal extending from the inside of an outer packaging 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 has a plate-shaped flying lead portion, at least a part of which is connected with a lamination structure of the flexible printed wiring board. The terminal and the flying lead portion are joined face to face.

Description

Battery pack and battery pack manufacturing method

The invention relates to a battery pack and a manufacturing method of the battery pack.

In recent years, batteries have been used in various applications. In particular, large-capacity batteries are used in power supplies for electric vehicles and power storage.

When using a battery with a single cell, the voltage of the battery may be lower than the voltage required by the machine. In this case, it is necessary to connect a plurality of batteries in series to increase the supply voltage to a desired voltage. In addition, there may be cases where the electric quantity required by the equipment cannot be sufficiently supplied by a single battery. In this case, it is necessary to connect a plurality of batteries in parallel to increase the amount of supplied electricity to a desired amount. Therefore, a battery case or a battery pack is provided in which a plurality of batteries are connected in series or in parallel, and electric power is supplied to the device from the battery case or battery pack.

There is known a method of manufacturing a battery pack by joining terminals of two adjacent single cells (for example, refer to Patent Document 1). In this forming method, when making a complicated battery pack combining series connection and parallel connection, new wires must be provided, which increases the manufacturing cost. situation. Moreover, the installation of detection lines for detecting the voltage of each single battery is relatively complicated, which increases the manufacturing cost.

There is known a method of manufacturing a battery pack in which a plurality of single cells are connected via a flexible printed wiring board (FPC) (for example, refer to Patent Document 2). By using FPC, cells can be connected in a complex manner. Also, the detection line can be provided on the FPC, and the manufacturing cost can be reduced.

[Prior Art Literature] [Patent Document]

Patent Document 1: Japanese Patent Laid-Open No. 2013-239293

Patent Document 2: Japanese Patent No. 6115265

In the conventional manufacturing method of a battery pack in which a plurality of single cells are connected by FPC, since the connection part of the FPC and the terminals of the single cells are connected by soldering, the joint strength is insufficient, and the structure of the battery pack is limited, etc. question.

The present invention was made in view of the above circumstances, and provides a battery pack which has sufficient bonding strength, is easy to design, and can be manufactured with reduced manufacturing costs.

The present invention provides a battery pack comprising a plurality of battery cells and a flexible printed wiring board, wherein each battery cell has a plate-shaped terminal protruding from the inside of the exterior body toward the outside; the aforementioned complex Several battery cells are connected in series or in parallel through the flexible printed wiring board; lead) portion; and surfaces of the aforementioned terminal and the aforementioned flying lead portion are bonded to each other.

The flexible printed wiring board included in the battery pack of the present invention includes a plate-shaped flying lead portion at least partially connected to the laminated structure of the flexible printed wiring board. The flying wire part has a laminated structure in which one end is fixed to a flexible printed wiring board, and the other end is movable. Therefore, the flying lead portion can be bent such that the plate-shaped terminal protruding from the inside of the battery unit exterior to the outside overlaps with the flying lead portion. Therefore, the terminals of the battery unit and the flying leads can be overlapped and joined by ultrasonic welding, resistance welding, laser welding, etc., thereby obtaining sufficient joint strength and reducing manufacturing costs. In addition, the flying lead portion can be bent back to its original position after the terminal of the battery unit is joined to the flying lead portion, so that the design of the battery pack can be easily performed.

2. 2a to 2l‧‧‧battery unit

3‧‧‧Flexible printed wiring board

4‧‧‧positive terminal

5‧‧‧Negative terminal

6. 6a to 6j‧‧‧flying wire part

7‧‧‧positive electrode

8‧‧‧Negative electrode

9‧‧‧Separator

10. 10a to 10e‧‧‧layer structure

11. 11a to 11j‧‧‧junction

12. 12a to 12e‧‧‧electrode assembly

15‧‧‧Electrolyte

16, 16a, 16b‧‧‧external body

18‧‧‧Positive electrode collector sheet

19‧‧‧positive active material layer

22‧‧‧Negative current collector

23‧‧‧Negative active material layer

25‧‧‧Positive extension part

26‧‧‧Negative extension part

30‧‧‧Positive bending part

31‧‧‧Negative bending part

35‧‧‧Shell

36, 36a, 36b‧‧‧partition wall

37‧‧‧cover

38‧‧‧Control Department

40‧‧‧power line

41‧‧‧Voltage detection line (battery status detection line)

42, 42a, 42b‧‧‧connection terminal

43‧‧‧connector

44‧‧‧Insulating film

45, 45a to 45j‧‧‧opening

46‧‧‧Positive side clamp

47‧‧‧Negative side clamp

48‧‧‧Base film

49‧‧‧Cover film

51‧‧‧Positive electrode side sealing part

52‧‧‧Negative side sealing part

54‧‧‧The head of the adapter

60‧‧‧Battery Pack

Fig. 1 is a schematic perspective view of a battery pack according to an embodiment of the present invention.

Fig. 2 is a schematic perspective view of the battery pack along the dotted line A-A in Fig. 1.

Figure 3(a) is a schematic enlarged view of the battery pack in the range B surrounded by the dotted line in Figure 2, and Figure 3(b) is a schematic enlarged view of the battery pack in the range C surrounded by the dotted line in Figure 2 picture.

Fig. 4 is a schematic expanded view of a flexible printed wiring board included in a battery pack according to an embodiment of the present invention.

Fig. 5 is an explanatory diagram of a method of manufacturing a battery pack according to an embodiment of the present invention.

Fig. 6 is a schematic sectional view of a battery pack according to an embodiment of the present invention.

Fig. 7 is an explanatory diagram of a method of manufacturing a battery pack according to an embodiment of the present invention.

The present invention provides a battery pack comprising a plurality of battery units and a flexible printed wiring board; wherein, each battery unit has a plate-shaped terminal protruding from the inside of the exterior body toward the outside; the plurality of battery units is a The flexible printed wiring board is connected in series or in parallel; the flexible printed wiring board has at least a part of a plate-shaped flying lead part connected to the laminated structure of the flexible printed wiring board; and the terminal and the aforementioned The faces of the flying lead portions are joined to each other.

The flexible printed wiring board preferably has an opening, and the flying lead part is preferably disposed in the opening. Thereby, the flying lead part does not protrude outside from the flexible printed wiring board, and the miniaturization of the battery pack can be realized.

The opening is preferably formed in the surface of the flexible printed wiring board other than the end portion. Thereby, the battery pack can be miniaturized.

The flexible printed wiring board has a power line and a battery state detection line, and the flying lead is preferably a part of the power line. With this configuration, the arrangement of the battery cells in the battery pack becomes easy, and the battery pack can be miniaturized.

The power line and the battery state detection line are preferably connected inside the flexible printed wiring board. With this configuration, the arrangement of the battery cells in the battery pack becomes easy, and the battery pack can be miniaturized.

The power line is preferably a metal plate having a thickness of not less than 100 μm and not more than 300 μm. With this configuration, a relatively large current can flow through the power line, and the output of the battery pack can be increased.

Each battery unit preferably has a flat plate shape, and a plurality of battery units are preferably stacked in the thickness direction of the aforementioned battery unit. With this configuration, the battery pack can be downsized.

The battery unit is equipped with an electrode assembly in the outer casing. The electrode assembly system has: a laminated structure with at least one positive electrode, at least one negative electrode, and at least one separator; The one protruding from the laminated structure; and the negative electrode extension part, which is formed by overlapping the negative electrode current collector and protruding from the laminated structure; between the end of the laminated structure and the joint between the terminal and the flying lead , Bending with terminals or outer body. With this configuration, the battery pack can be downsized.

The battery pack of the present invention preferably has a plurality of battery groups, each battery group has a structure formed by stacking a plurality of battery cells in the thickness direction, and the plurality of battery cells included in each battery group can be obtained by the aforementioned Flexible printed wiring boards are connected in series or in parallel, and multiple battery groups are connected through the same flexible printed wiring boards. With this configuration, since a plurality of battery cells can be arranged in several groups, it is easy to design the battery pack.

The two adjacent battery groups are preferably: two adjacent battery groups It is the first part of the flexible printed wiring board connected to the plurality of battery cells included in the first battery group, and the second part of the flexible printed wiring board connected to the plurality of battery cells included in the second battery group The parts are arranged so as to face each other, and an insulating partition wall is preferably provided between the first part and the second part of the flexible printed wiring board. With this configuration, it is possible to prevent a short circuit between adjacent battery groups.

The present invention provides a method for manufacturing a battery pack, preferably including: bending at least a part of the plate-shaped flying lead part connected to the laminated structure of the flexible printed wiring board; The step of overlapping and joining the plate-shaped terminal protruding from the inside to the outside with the flying lead part; and the step of bending the flying lead part back.

Furthermore, the step of bending back the flying lead portion is a step performed along with the bending of the aforementioned terminal or the aforementioned outer casing.

Hereinafter, one embodiment of the present invention will be described using the drawings. The configurations shown in the drawings or the following descriptions are examples, and the scope of the present invention is not limited to the contents shown in the drawings or the following descriptions.

Figs. 1 to 7 are diagrams related to the battery pack of this embodiment, and the details are the same as those described in the above diagrams.

The battery pack 60 of this embodiment is provided with a plurality of battery cells 2 and a flexible printed wiring board 3, and each battery cell 2 is provided with plate-shaped terminals 4 and 5 protruding from the inside of the exterior body 16 to the outside, and a plurality of The battery cells 2 are connected in series or in parallel by a flexible printed wiring board 3. The flexible printed wiring board 3 is provided with a plate-like flying lead portion 6 connected to at least a part of the laminated structure of the flexible printed wiring board 3. Terminals 4, 5 and flying lead part 6 face to face This is joined.

The manufacturing method of the battery pack 60 of this embodiment includes: bending at least a part of the plate-shaped flying lead portion 6 connected to the laminated structure of the flexible printed wiring board 3; 16. The step of joining the plate-shaped terminals 4 and 5 protruding from the inside to the outside with the flying lead part 6; and the step of bending the flying lead part 6 back.

The battery pack 60 may also include battery groups stacked in the thickness direction of a plurality of battery cells. For example, in the battery pack 60 shown in FIG. 1 and FIG. 2, five battery cells 2a to 2e are stacked.

In addition, the battery pack 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 also be arranged. For example, in the battery pack 60 shown in FIGS. A third battery group in which two battery cells 2 are stacked is stacked.

The battery pack 60 may also include a casing 35 for accommodating a plurality of battery units 2 . The material of the housing 35 can be made of insulating materials such as plastics. Furthermore, the case 35 may have a partition wall 36 disposed between the first battery group in which the plurality of battery cells 2 are stacked and the second battery group in which the plurality of battery cells 2 are stacked. With this configuration, a short circuit between two adjacent battery cells 2 can be suppressed.

The battery unit 2 included in the battery pack 60 of this embodiment is preferably a sealed battery. A sealed battery is a battery with a closed structure that blocks the electrolyte from the outside air and does not leak during storage or discharge. The battery unit 2 can also be a secondary battery, or a non-aqueous electrolyte secondary battery. pool. 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. Moreover, the shape of the battery unit 2 can be cylindrical or plate-shaped, preferably a plate-shaped battery. The plate-shaped battery may be a thin battery such as a square battery having an exterior such as metal or resin, or a pouch type battery having an exterior such as a laminate film. Furthermore, as for the shape of the terminal, it is preferable that the plate-shaped terminal protrudes from the inside of the exterior body to the outside. Terminal refers to positive terminal 4 or negative terminal 5.

For example, the shape of the battery unit 2 can be made into a flat cuboid. In this case, the battery cell 2 may have wider upper and lower surfaces and four sides around it. On the inner sides of the two opposite sides among the four sides, the positive electrode extension part 25 and the negative electrode extension part 26 are respectively provided.

The exterior body 16 is a container for accommodating the electrode assembly 12 and the electrolyte 15 . The material of the exterior body 16 is, for example, a laminated film or the like. The exterior body 16 can be provided so as to form a closed space inside for housing the electrode assembly 12 and the electrolyte 15 . When the material of the exterior body 16 is a laminated film, the battery unit 2 is a pouch type battery. In this case, the exterior body 16 may have a welded portion in which a laminated film is laminated on its peripheral edge and welded. In addition, it is also possible to provide the peripheral portion of the exterior body 16 with: a positive side sealing portion 51 with a laminated film on both sides of the positive terminal 4; and a negative side sealing portion with a laminated film on both sides of the negative terminal 5. 52. Thus, by arranging the positive terminal 4 and the negative terminal 5, the terminals 4 and 5 protrude from the inside of the exterior body 16 to the outside. A laminated film is, for example, one in which a resin film is laminated on both surfaces of a metal film. Lamination Film Thickness The degree can be set to, for example, 50 to 200 μm.

The exterior body 16 preferably has a bag-like structure in which a laminated film is formed. With this configuration, the exterior body 16 can also be folded when the positive electrode bent portion 30 or the negative electrode bent portion 31 is formed, and the battery unit 2 can be easily reduced in size.

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 part in which the positive electrode 7, the negative electrode 8, and the separator 9 are overlapped. In addition, the electrode assembly 12 has: a positive electrode extension part 25 formed by overlapping the positive electrode current collector sheet 18 and protruding from the laminated structure 10; Negative extension part 26 .

The electrode assembly 12 may also have a stacked structure in which a plurality of positive electrodes 7 , a plurality of negative electrodes 8 and separators 9 are stacked. In this case, the laminated structure 10 is a portion in which the plurality of positive electrodes 7 and the plurality of negative electrodes 8 alternately overlap each other via the separator 9 . In the case where the electrode assembly 12 has a stacked structure, the electrode assembly 12 has a structure in which separators 9 are interposed between the sheet-shaped positive electrode 7 and the sheet-shaped negative electrode 8 to be stacked alternately. In addition, each positive electrode 7 formed by lamination is a respective positive electrode, and each negative electrode 8 formed by lamination is a respective negative electrode. In addition, the plurality of positive electrodes 7 included in the electrode assembly 12 may have substantially the same shape, and the plurality of negative electrodes 8 included in the electrode assembly 12 may have substantially the same shape. For example, the electrode assembly 12 can include: one separator 9 in zigzag shape; Moreover, it is also possible to arrange different electrodes between the positive electrode 7 and the negative electrode 8, respectively. The same separator9. In addition, the number of laminated layers of the positive electrode 7 or the negative electrode 8 included in the electrode assembly 12 can be appropriately designed according to the required battery capacity. In addition, the battery cell 2 may have a plurality of electrode assemblies 12 .

In addition, the electrode assembly 12 may have a wound structure in which the positive electrode 7, the negative electrode 8, and the separator 9 are stacked and wound. At this time, the laminated structure 10 is a portion where the positive electrode 7, the negative electrode 8, and the separator 9 overlap from the winding axis toward the outer periphery. In addition, 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 arranged on the positive electrode current collector sheet 18 . The positive electrode 7 may have a square or rectangular sheet shape. The positive electrode 7 can be produced by, for example, forming a positive electrode active material layer 19 on both surfaces of a square positive electrode current collector sheet 18 . The positive electrode 7 may have a connection portion (positive electrode collector sheet 18) connected to the positive electrode side clamp (clip) 46 or the positive electrode terminal 4. The positive electrode active material layer 19 is formed thereon. In addition, the connecting portion may be provided by forming an ear portion on one end of the positive electrode current collector sheet 18 and not forming the positive electrode active material layer 19 on the ear portion. This connecting portion protrudes from the laminated structure 10 of the electrode assembly 12 to constitute the positive electrode protruding portion 25 .

The positive electrode current collector sheet 18 is not particularly limited as long as it has electrical conductivity and may have the positive electrode active material layer 19 on the surface, and is, for example, a metal foil. Aluminum foil is preferred. The thickness of the positive electrode 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 collector sheet 18 by adding a conductive agent, a binder, etc. to the positive electrode active material, and by coating or the like. The positive electrode active material is, for example, a lithium-transfer metal composite oxide capable of reversibly storing and releasing lithium ions. Specifically, LiCoO ₂ , LiNiO ₂ , LiNi _x Co _1-x O ₂ (x=0.01 to 0.99), LiMnO ₂ , LiMn ₂ O ₄ , LiCo _x Mny _{Ni z} O ₂ (x +y+z=1) or olivine-type LiFePO ₄ , Li _x Fe _1-y M _y PO ₄ (only 0.05≦x≦1.2, 0≦y≦0.8, and M is Mn, Cr, Co, Cu, At least one or more of Ni, V, Mo, Ti, Zn, Al, Ga, Mg, B, Nb) and the like are used alone or in combination.

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 may have a square or rectangular sheet shape. The negative electrode 8 can be produced by, for example, forming the negative electrode active material layer 23 on both surfaces of a square negative electrode current collector sheet 22 . The negative electrode 8 may have a connection portion (negative electrode collector sheet 22) connected to the negative electrode side clamp 47 or the negative electrode terminal 5, and the connection portion may be formed on both sides of the negative electrode collector sheet 22 that is not at the end of the negative electrode 8. The active material layer 23 is provided. Furthermore, the connecting portion may be provided by forming an ear portion on one end of the negative electrode current collector sheet 22 and not forming the negative electrode active material layer 23 on the ear portion. This connecting portion protrudes from the laminated structure 10 of the electrode assembly 12 to form a negative electrode protruding portion 26 .

The negative electrode current collector sheet 22 is not particularly limited as long as it has electrical conductivity and may have the negative electrode active material layer 23 on the surface, and is, for example, a metal foil. Aluminum foil is preferred. The thickness of the negative electrode 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, etc. to the negative electrode active material, and by coating or the like. As the negative electrode active material, graphite, partially graphitized carbon, hard carbon, soft carbon, LiTiO ₄ , Sn alloy, etc. can be used alone or in combination for a lithium ion secondary battery.

The positive electrode extension part 25 is a portion where only the positive electrode current collector sheet 18 protrudes from the laminated structure 10 , and the positive electrode active material layer 19 is not formed on the positive electrode current collector sheet 18 in the positive electrode extension part 25 . Furthermore, the positive electrode current collector tab 18 is superimposed on the positive electrode extension portion 25 . The part protruding from the laminated structure 10 may also be the edge end of the positive electrode current collector 18, or may be provided on the ear of the positive electrode current collector 18, or may be a wire installed thereon. In addition, the positive electrode extension part 25 may also be a part protruding from the side of the laminated structure 10 of the positive electrode current collector sheet 18, may also be provided on the ear of the positive electrode current collector sheet 18, or may be a wire installed thereon.

In the case where the electrode assembly 12 has a stacked structure, the positive electrode extension portion 25 is a portion where the positive electrode collector sheet 18 protrudes from each positive electrode 7 included in the laminated structure 10 in an overlapping manner. In the positive electrode extension part 25, the negative electrode 8 and the separator 9 are not disposed between the overlapping positive electrode current collecting sheets 18, so the overlapping positive electrode current collecting sheets 18 can be bundled with the positive electrode side clamp 46, and the positive electrode current collecting sheets 18 can be bundled through the positive electrode extending part. The output part 25 electrically connects each positive electrode 7 included in the laminated structure 10 and the positive electrode side clamp 46 .

In the case where the electrode assembly 12 has a wound structure, the positive electrode extension portion 25 is a portion where the positive electrode current collector sheet 18 protrudes from the positive electrode 7 included in the spiral laminated structure 10 in an overlapping manner. In the positive electrode extension part 25, the negative electrode 8 and the separator 9 are not disposed between the overlapping positive electrode current collector sheets 18, because This enables the stacked positive electrode current collectors 18 to be collected by the positive electrode side clamp 46 , and the positive electrode 7 included in the laminated structure 10 is electrically connected to the positive electrode side clamp 46 through the positive electrode extension 25 .

Furthermore, in the case where the positive electrode side jig 46 is not provided, the overlapping positive electrode current collector tab 18 included in the positive electrode extension portion 25 is joined to the positive electrode terminal 4 . For example, ultrasonic welding may be performed by overlapping the positive electrode terminal 4 and the positive electrode current collector sheet 18 .

The negative electrode extension part 26 is only the part where the negative electrode current collector sheet 22 protrudes from the laminated structure 10 , and the negative electrode active material layer 23 is not formed on the negative electrode current collector sheet 22 in the negative electrode extension part 26 . Furthermore, the negative electrode current collector tab 22 is superimposed on the negative electrode extension portion 26 . The part protruding from the laminated structure 10 may also be the edge end of the negative electrode collector sheet 22, or may be provided on the ear of the negative electrode collector sheet 22, or may be a wire installed thereon. In addition, the negative electrode extension part 26 may also be the part protruding from the side of the laminated structure 10 from the negative electrode current collector sheet 22, or may be provided on the ear of the negative electrode current collector sheet 22, or may be a wire installed thereon. The side surface on which the negative electrode extension part 26 is provided may be the side opposite to the side surface on which the positive electrode extension part 25 is provided.

In the case where the electrode assembly 12 has a stacked structure, the negative electrode extension portion 26 is a portion where the negative electrode current collector tab 22 protrudes from the respective negative electrodes 8 included in the laminated structure 10 in an overlapping manner. In the negative electrode extension part 26, the positive electrode 7 and the separator 9 are not disposed between the overlapping negative electrode current collector sheets 22, so the overlapping negative electrode current collector sheets 22 can be bundled with the negative electrode side clamp 47, and the negative electrode current collector sheets 22 can be bundled through the negative electrode extension. The output part 26 electrically connects the negative electrode 8 included in the laminated structure 10 and the negative electrode side clamp 47 .

In the case where the electrode assembly 12 has a wound structure, the negative electrode extension portion 26 is a portion where the negative electrode current collector sheet 22 protrudes from the negative electrode 8 included in the spiral laminated structure 10 in an overlapping manner. In the negative electrode extension part 26, the positive electrode 7 and the separator 9 are not arranged between the overlapping negative electrode current collecting sheets 22, so the overlapping negative electrode current collecting sheets 22 can be bundled with the negative electrode side clamp 47, and pass through the negative electrode extending part 26. The output part 26 electrically connects the negative electrode 8 included in the laminated structure 10 and the negative electrode side clamp 47 .

Furthermore, in the case where the negative-electrode-side jig 47 is not provided, the overlapping negative-electrode current collector tab 22 included in the negative-electrode extension portion 26 is bonded to the negative-electrode terminal 5 . For example, ultrasonic welding may be performed by superimposing the negative electrode terminal 5 on the negative electrode current collector sheet 22 .

The separator 9 is in the form of a sheet, and is arranged between the positive electrode 7 and the negative electrode 8 . The separator 9 can prevent short-circuit current from flowing between the positive electrode 7 and the negative electrode 8. It is not particularly limited if it is permeable to the electrolyte, and can be, for example, a microporous film of polyolefin or polyethylene.

The electrolyte 15 may use carbonates, lactones, ethers, esters, etc. as solvents, or two or more types of these solvents may be mixed and used. Among these solvents, it is particularly preferable to use a mixture of a cyclic carbonate and a chain carbonate. The electrolyte 15 is dissolving lithium salt solutes 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 ) in non-aqueous A solution made of a solvent. Moreover, VC (vinylene carbonate, vinylene carbonate), PS (propane sultone, propane sultone), VEC (vinylethyl carbonate, vinyl ethyl carbonate), PRS (propene sultone, propene sultone) can also be used as needed. Esters), FEC (fluoroethylene carbonate, ethyl fluorocarbonate), flame retardant and other additives are formulated individually or mixed.

The positive electrode-side jig 46 is provided to overlap and hold the bundle of the positive electrode current collector sheet 18 on the portion where the positive electrode active material layer 19 is not provided (connecting portion, positive electrode extension portion 25 ). In addition, the negative electrode side jig 47 is provided to overlap and clamp the bundle of the negative electrode current collector sheet 22 on the part where the negative electrode active material layer 23 is not provided (connecting portion, negative electrode extension portion 26 ).

The positive-side jig 46 or the negative-side jig 47 can also be integrated with the superimposed and clamped positive current collector sheet 18 or negative electrode current collector sheet 22 by ultrasonic welding. For example, the positive electrode side jig 46 or the negative electrode side jig 47 can be integrated with the superimposed and sandwiched positive electrode current collector sheet 18 or negative electrode current collector sheet 22 by ultrasonic welding.

The positive-side jig 46 or the negative-side jig 47 is made of a conductive material. With this configuration, the battery cell 2 can be charged and discharged through the positive electrode side jig 46 or the negative electrode side jig 47 . In the case where the positive electrode side jig 46 and the negative electrode side jig 47 are formed of a metal plate, the thickness of the metal plate can be made, for example, 100 μm to 500 μm.

The positive terminal 4 is a member that is electrically connected to the positive electrode 7 inside the exterior body 16 and functions as a terminal on the positive side of the battery cell 2 . The portion of the positive electrode terminal 4 located inside the exterior body 16 can be joined to the positive electrode side jig 46 or the positive electrode extension part 25 . The positive electrode terminal 4 can be joined to the positive electrode side jig 46 by superposing the positive electrode terminal 4 on the positive electrode side jig 46 and performing ultrasonic welding. The positive terminal 4 can be a metal plate. In addition, in the case where the materials of the positive electrode current collector sheet 18 and the positive electrode side holder 46 are aluminum, the positive electrode terminal 4 The system can be aluminum plate. The thickness of the positive terminal 4 can be made, for example, from 100 μm to 500 μm.

The positive electrode terminal 4 and the exterior body 16 can be formed with the positive electrode side sealing portion 51 where the exterior body 16 is connected to the positive electrode terminal 4 . The positive electrode side sealing part 51 forms the peripheral part of the outer casing 16 together with the welded part and the negative electrode side sealing part 52. The peripheral part is formed and arranged inside the outer casing 16 where the electrode assembly 12, the electrolyte 15, the positive electrode side jig 46 and The airtight space of the clamp 47 on the negative electrode side. Furthermore, by providing the positive-side sealing portion 51 , a part of the positive terminal 4 can be positioned inside the exterior body 16 , and another part of the positive terminal 4 can be positioned outside the exterior body 16 . Therefore, the positive electrode terminal 4 protrudes from the inside of the exterior body 16 toward the outside. The positive-side sealing portion 51 may be formed by bonding the positive terminal 4 and the exterior body 16 through an adhesive layer, or may be formed by welding the exterior body 16 to the positive terminal 4 .

The portion of the positive terminal 4 outside the exterior body 16 is joined to the flying lead portion 6 of the flexible printed wiring board 3 . Therefore, the electrode assembly 12 disposed in the closed space inside the exterior body 16 and the flexible printed wiring board 3 can be electrically connected through the positive terminal 4 , and the battery unit 2 can be charged and discharged through the positive terminal 4 .

The shape of the positive terminal 4 can be, for example, a plate shape or a strip shape. In this case, one end of the positive terminal 4 can be engaged with the positive side clip 46 or the positive extension part 25 , and the other end of the positive terminal 4 can be engaged with the flying lead part 6 . Also, a positive electrode side sealing portion 51 may be provided therebetween.

The negative electrode terminal 5 is a member that is electrically connected to the negative electrode 8 inside the exterior body 16 and serves as a terminal on the negative electrode side of the battery cell 2 . negative electrode The part of the terminal 5 located inside the exterior body 16 can be engaged with the negative electrode side clamp 47 or the negative electrode extension part 26 . The negative electrode terminal 5 can be bonded to the negative electrode side jig 47 by ultrasonically welding the negative electrode terminal 5 and the negative electrode side jig 47 . The negative terminal 5 can be a metal plate. Furthermore, in the case where the material of the negative electrode current collector sheet 22 and the negative electrode side clamp 47 is copper, the negative electrode terminal 5 can be a copper plate. The thickness of the negative terminal 5 can be set to, for example, 100 μm to 500 μm.

The negative electrode terminal 5 and the outer casing 16 may be formed with the negative electrode side sealing portion 52 where the negative electrode terminal 5 is connected to the outer casing 16 . The negative electrode side sealing part 52 forms the peripheral part of the outer casing 16 together with the welded part and the positive electrode side sealing part 51. The peripheral part is formed inside the outer casing 16 to arrange the electrode assembly 12, the electrolyte 15, the positive electrode side jig 46 and A closed space of the negative electrode side jig 47 . Furthermore, by providing the negative electrode side sealing portion 52 , a part of the negative electrode terminal 5 can be positioned inside the exterior body 16 , and another part of the negative electrode terminal 5 can be positioned outside the exterior body 16 . Therefore, the negative electrode terminal 5 protrudes from the inside of the exterior body 16 toward the outside. The negative electrode side sealing portion 52 may be formed by bonding the negative electrode terminal 5 and the exterior body 16 through an adhesive layer, or may be formed by welding the exterior body 16 to the negative electrode terminal 5 .

The portion of the negative terminal 5 located outside the exterior body 16 is joined to the flying lead portion 6 of the flexible printed wiring board 3 . Therefore, the electrode assembly 12 disposed in the closed space inside the exterior body 16 and the flexible printed wiring board 3 can be electrically connected through the negative terminal 5 , and the battery unit 2 can be charged and discharged through the negative terminal 5 .

The shape of the negative terminal 5 can be made into, for example, a strip shape. in this case Next, one end of the negative electrode terminal 5 can be engaged with the negative electrode side clamp 47 or the negative electrode extension part 26 , and the other end of the negative electrode terminal 5 can be engaged with the flying lead part 6 . Also, a negative electrode side sealing portion 52 may be provided therebetween.

The positive electrode extension 25 (positive electrode current collector tab 18 ) may have a positive electrode bent portion 30 formed by overlapping and bending the positive electrode current collector tab 18 . In addition, the negative electrode extension part 26 (the negative electrode current collector sheet 22 ) may have the negative electrode bent part 31 formed by overlapping and bending the negative electrode current collector sheet 22 . By providing the positive electrode bending part 30 and the negative electrode bending part 31, the part of the positive electrode current collector sheet 18 where the positive electrode active material layer 19 is not formed (the positive electrode extension part 25) and the part where the negative electrode current collector sheet 22 is not formed The portion with the negative electrode active material layer 23 (the negative electrode extension portion 26 ) is folded so that the battery cell 2 can be miniaturized.

The positive electrode bending part 30 is not particularly limited as long as it is a bending part provided from the end of the laminated structure 10 to the joint part 11 of the positive electrode terminal 4 and the flying lead part 6, but it can also be arranged so as to gather along the electrodes. The positive electrode terminal 4 is disposed on the side surface of the laminated structure 10 of the body 12 on which the positive electrode extension portion 25 is provided. In addition, the positive electrode bending portion 30 can also be provided so that the positive electrode terminal 4 and the flexible printed wiring board 3 overlap each other. Furthermore, the positive electrode bending portion 30 can also be provided so that the positive electrode terminal 4 is arranged along the flexible printed wiring board 3 . By providing the positive electrode bent portion 30 in this way, the space between the laminated structure 10 and the flexible printed wiring board 3 can be narrowed, and the battery pack 60 can be miniaturized.

The negative electrode bending part 30 is not particularly limited as long as it is a bending part provided from the end of the laminated structure 10 to the joint part 11 between the negative electrode terminal 5 and the flying lead part 6, but it can also be arranged so as to gather along the electrodes. Negative electrode terminals are arranged on the side of the laminated structure 10 of the body 12 provided with the negative electrode extension portion 26 5. Furthermore, the negative electrode bending portion 31 can also be provided so that the negative electrode terminal 5 overlaps with the flexible printed wiring board 3 . Furthermore, the negative electrode bending portion 31 can also be provided so that the negative electrode terminal 5 is arranged along the flexible printed wiring board 3 . By providing the negative electrode bending portion 31 in this way, the space between the laminated structure 10 and the flexible printed wiring board 3 can be narrowed, and the battery pack 60 can be miniaturized.

When the battery pack 60 has a battery group in which a plurality of battery cells 2 are stacked, the positive electrode extension 25 or the negative electrode extension 26 of each battery cell 2 can be positioned on the first side surface of the battery group, and each A plurality of battery cells 2 are stacked so that the positive electrode extension part 25 or the negative electrode extension part 26 of the battery cell 2 is located on the second side surface of the battery group. In addition, the flexible printed wiring board 3 can also be arranged along the first side surface and the second side surface of the battery group. With this configuration, the positive terminal 4 and the negative terminal 5 of each battery cell 2 and the flying lead portion 6 of the flexible printed wiring board 3 can be easily joined.

The battery pack 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 units 2 through the flexible printed wiring board 3, the plurality of battery units 2 included in the battery pack 60 can be arranged in various arrangements, and the shape of the battery pack 60 can be adapted to various spaces.

The flexible printed wiring board 3 is a substrate in which a metal layer on which a wiring pattern is formed is provided on a thin and flexible insulating base film 48 (insulating film 44 ). The flexible printed wiring board 3 can be a single-sided FPC with a metal layer on one side of the base film 48, or a double-sided FPC with a metal layer on both sides of the base film 48, or a A multi-layer FPC with a base film 48 superimposed on it. The flexible printed wiring board 3 can be expanded in the way of Figure 4 set up.

Electronic components or connectors 43 may be mounted on the flexible printed wiring board 3 . Furthermore, the flexible printed wiring board 3 may have a structure (laminated structure) in which a metal layer is sandwiched between the base film 48 and the cover film 49 . The 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 . In addition, the metal layer may also be the connection terminals 42a and 42b belonging to the ends of the power line 40 . The insulating film 44 (base film 48 and cover film 49 ) is, for example, a polyimide film. Moreover, the material of the metal layer is, for example, copper, aluminum or silver. The thickness of the metal layer is, for example, not less than 100 μm and not more than 300 μm. 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 . In the case of using a metal layer as the electric force line 40, it is preferable that the metal layer has a relatively thick thickness. By using a thicker metal plate for the metal layer, a larger current can be passed through the power line 40 . Furthermore, since the flying lead portion 6 has a thick plate shape, the flying lead portion 6 , the positive terminal 4 or the negative terminal 5 can be easily joined.

In addition, the thickness of the base film 48 or the cover film 49 is, for example, not less than 10 μm and not more than 60 μm. Furthermore, 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 formed in the wiring of the flexible printed wiring board 3 through which the discharge current and the charging current of the battery cell 2 flow. The power line 40 may have a pattern that can connect the plurality of battery cells 2 included in the battery pack 60 in series or in parallel. And, the power line 40 It can be provided so that the positive terminal 4 or the negative terminal 5 of at least two battery cells 2 included in the battery pack 60 can be connected. In addition, the power line 40 has a larger width than the voltage detection line 41 because a large current flows therethrough. 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 metal surface is exposed by removing the insulating film 44 on the upper surface and the lower surface of the metal layer, so the upper surface and the lower surface of the flying lead portion 6 are conductive. The metal layer of the flying lead part 6 can also be subjected to 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 electric force 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 . Therefore, the flying lead portion 6 can be bent at its base. When the battery pack is manufactured, when the flexible printed wiring board 3 is bent or folded back, the internal wiring may be damaged, but when only the flying lead portion 6 is bent, it is not a metal plate because it is a metal plate. Risk of injury.

The flying wire part 6 can be disposed in the opening 45 provided on the flexible printed wiring board 3 . The opening 45 is preferably provided at a position where it does not protrude from the surface of the flexible printed wiring board 3 , and is more preferably provided at a position other than an end portion within the surface of the flexible printed wiring board.

Moreover, the flying lead portion 6 may also have a cantilever structure.

The flying lead part 6 and the positive terminal 4 of the battery unit 2 or The negative terminals 5 are overlapped and bonded to form a bonded portion 11 . Therefore, the power line 40 of the flexible printed wiring board 3 and the battery unit 2 can be electrically connected through the flying lead portion 6, and a plurality of battery units 2 included in the battery pack 60 can be connected in series or in parallel through the power line 40. connect. Furthermore, the flying lead part 6 can be made into a plate shape with a width of 5 mm to 20 mm. With this configuration, the flying lead portion 6 can be easily overlapped and bonded to the positive terminal 4 or the negative terminal 5 . The method for forming the junction portion 11 will be described later.

The flexible printed wiring board 3 may have a plurality of flying lead parts 6 . The plurality of flying lead parts 6 are connected to the positive terminal 4 and the negative terminal 5 of the plurality of battery cells 2 included in the battery pack 60 respectively.

The power line 40 may have connection terminals 42a, 42b. The connection terminals 42 a and 42 b are external connection terminals of a plurality of battery cells 2 connected in series or in parallel via the flexible printed wiring board 3 . The connection terminals 42 a and 42 b may also be connected to the control unit 38 . With this configuration, the charge and discharge of the battery pack 60 can be controlled by the control unit 38 . The control unit 38 may include a fuse or a relay. With this configuration, when the control unit 38 detects overcharge or overdischarge of the battery unit 2, the electrical connection between the external connection terminal of the battery pack 60 and the battery can be cut off, and the safety of the battery pack 60 can be improved. . The connection between the connection terminal 42 and the control unit 38 is not particularly limited, but it can also be fixed by screws, for example.

Furthermore, the connection terminals 42a and 42b may be connected to external wiring. The metal layers of the connection terminals 42a and 42b may also be subjected to surface treatment such as metal plating. Here, although a part of the power line 40 is described as the connection terminal 42, it is also possible to mount a flexible printed wiring board 3 to connect to the power line. 40, and the power line 40 is connected to the control unit 38 or external wiring through the connector.

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 formed in the wiring of the flexible printed wiring board 3 . The voltage detection line 41 may have a pattern capable of detecting a voltage between terminals of each battery cell 2 included in the battery pack 60 . In addition, the voltage detection line 41 can be connected to the electric power line 40 so that the voltage between the terminals of each battery cell 2 can be detected by the control part 38. As shown in FIG. Furthermore, by forming the electric power line 40 and the voltage detection line 41 other than the flying lead portion 6 inside the flexible printed wiring board 3, false contact or false detection can be prevented. Moreover, the voltage detection line 41 is provided to electrically connect the power line 40 electrically connected to at least two battery units 2 and the control unit 38 . In addition, since a relatively small current flows through the voltage detection line 41 , it has a narrower width than the power line 40 .

The flexible printed wiring board 3 may have a connector 43 connected to the voltage detection line 41 . The connector 43 is connectable to the control unit 38 . With this configuration, the terminal voltage of each battery cell 2 included in the battery pack 60 can be detected through 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, although the voltage detection line is taken as an example as the battery state detection line 41 , the detection line can also be used to detect other battery states such as current detection or temperature detection.

In the battery pack 60, a plurality of battery cells 2 are stacked. In the case of a battery group, it can be arranged along the first side of the battery group with the positive terminal 4 or negative terminal 5 of each battery unit 2 facing up and down, and the positive terminal 4 or negative terminal 5 of each battery unit 2 facing The flexible printed wiring board 3 is arranged on the second side of the battery group arranged in the vertical direction, and a plurality of flying lead parts 6 can be connected to the positive terminal 4 or the negative terminal 5 arranged in the vertical direction. In this case, the plurality of flying lead portions 6 are arranged vertically corresponding to the positive terminal 4 or the negative terminal 5 arranged vertically, and are joined to the positive terminal 4 or the negative terminal 5 in the joint portion 11 . Furthermore, one bent flexible printed wiring board 3 may be arranged along the first side surface and the second side surface of the battery group. With this configuration, 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 battery pack 60 may have a structure in which a plurality of battery groups of such a plurality of battery cells 2 and the flexible printed wiring board 3 are connected. 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. In addition, 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 can be connected with the positive electrode extension part 2 of the battery cell 2 included in the other battery group. A plurality of battery groups are arranged in such a way that the outlet portion 25 or the negative electrode extension portion 26 faces each other. In this case, two flexible printed wiring boards 3 arranged between two adjacent battery groups may face each other. At this time, since the flying lead parts 6 are also arranged facing each other, an insulating partition wall 36 can be provided between the facing flexible printed wiring boards 3 . Thereby, even in the case where the battery pack 60 has a structure in which a plurality of battery groups are arranged, the All the battery cells 2 included in the battery pack 60 can be connected by one bent flexible printed wiring board 3 . With this configuration, 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 a battery pack 60 including the battery cells 2a to 2e shown in FIG. 1 and FIG. 2, one flexible printed wiring board 3 to be bent is along the first side and the second side of the battery pack. In configuration, 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 sides. Furthermore, the positive terminals 4a to 4e or the negative terminals 5a to 5e are joined to the flying lead parts 6a to 6j to form the joint parts 11a to 11j.

Furthermore, in the case of a battery pack 60 including battery cells 2a to 2l shown in (c) and (d) of FIG. The side surfaces of the first battery group of the units 2a and 2b, the side surfaces of the second battery group on which the battery cells 2c to 2g are stacked, and the side surfaces of the third battery group on which the battery cells 2h to 2l are stacked are arranged, and the battery unit 2a To 2l to be connected in series or in parallel.

The manufacturing method of the battery pack 60 includes: bending the flying lead part 6 having a cantilever structure of the flexible printed wiring board 3; 6 a step of overlapping and bonding; and a step of bending the battery unit 2 and bending the flying lead portion 6 back.

Here, a method of manufacturing the battery pack 60 shown in FIGS. 1 to 3 will be described.

First, the flexible printed wiring board 3 of the expanded view in Fig. 4 is prepared. As shown in Fig. 5(a) and (b), the flying lead portion 6 included in the flexible printed wiring board 3 is bent. In the step of bending the flying lead portion 6, as shown in the flexible printed wiring board 3 included in the battery pack 60 in FIG. The opposite side is bent. With this configuration, as shown in FIG. 5( b ), the opening 45 in which the flying lead portion 6 is provided becomes wider.

Next, a plurality of pouch-type battery cells 2a to 2e are stacked on the flexible printed wiring board 3, as shown in Fig. 5(c) and Fig. 6, the positive terminal 4 and the negative terminal 5 of the battery cell 2 are Insert it into the opening 45 and make the bent flying lead part 6 overlap the positive terminal 4 or the negative terminal 5 .

Next, as shown in Fig. 5 (d), the head 54 of the adapter or welder (in the case of ultrasonic welding, an ultrasonic horn (horn) and anvil (anvil)) is used to clamp the The overlapping flying lead portion 6 and the positive terminal 4 or the negative terminal 5 are welded to the flying lead portion 6 and the positive terminal 4 or the negative terminal 5 to form a bonding portion 11 . As a bonder or a welder, for example, an ultrasonic welder, a resistance welder, or the like can be utilized. Furthermore, the flying lead portion 6 and the positive terminal 4 or the negative terminal 5 may be bonded by laser welding or crimping. In addition, soldering, brazing, caulking, and the like may be used for joining. In this manner, by bending the flying lead portion 6, the flying lead portion 6 can be easily overlapped with the positive terminal 4 or the negative electrode terminal, and the bonding operation becomes easy. In this embodiment, it is possible to secure a space for sandwiching the overlapped flying lead portion 6 and the positive terminal 4 or the negative terminal 5 by the head portion 54 . And, since the main The main surface is connected to the main surface of the positive terminal 4 or the main surface of the negative terminal 5, so that more stable bonding can be performed.

Next, the plurality of battery cells 2a to 2e are bent to form the positive electrode bending portion 30 and the negative electrode bending portion 31, and the plurality of flying lead portions 6a to 6j are bent back as shown in FIG. 5(e). At this time, the flexible printed wiring board 3 on the side of the battery group on which the plurality of battery cells 2a to 2e are stacked is lifted. With this configuration, the battery pack 60 shown in FIG. 6 can be transformed into the battery pack 60 shown in FIGS. 1 to 3 . With this configuration, the battery pack 60 can be downsized. Then, by connecting the connection terminals 42a, 42b and the connector 43 of the flexible printed wiring board 3 to the control unit 38, the battery pack 60 shown in FIGS. 1 and 2 can be manufactured.

In addition, in the manufacturing method of the battery pack 60 shown in FIG. 7, a plurality of pouch-type battery cells 2a to 2l are stacked on the flexible printed wiring board 3 shown in FIG. The flying lead portion 6 overlaps with the positive terminal 4 or the negative terminal 5 . Then, the flying lead part 6 is joined to the positive terminal 4 or the negative terminal 5, the plurality of battery cells 2a to 2l are bent and the plurality of flying lead parts 6 are bent back, and the flexible printed wiring board on the side of the battery group is 3 to be lifted. Then, the flexible printed wiring board 3 is bent along the dotted line D and the dotted line E in FIG. With this configuration, as shown in FIG. 7(c), the arrangement of the battery groups of the battery unit 2 can be changed. Furthermore, by making the flexible printed wiring board 3 into a bent structure, the unfolded 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. 7( d ), the flexible printed wiring board 3 and the battery unit 2 can be accommodated in the casing 35 to form the battery pack 60 . Furthermore, the casing 35 may have partition walls 36a, 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 vertical direction, but they may be stacked in a direction other than the vertical direction as long as the thickness direction of the battery cells 2 is used.

2a to 2e‧‧‧battery unit

3‧‧‧Flexible printed wiring board

6a to 6e, 6j‧‧‧flying wire part

11a to 11e, 11j‧‧‧junction

38‧‧‧Control Department

42a, 42b‧‧‧connection terminal

43‧‧‧connector

60‧‧‧Battery Pack

A-A‧‧‧dashed line

Claims (16)

A battery pack comprising a plurality of battery units and a flexible printed wiring board, wherein each battery unit has a plate-shaped battery terminal protruding from the inside of an exterior body toward the outside; Flexible printed wiring boards are connected in series or in parallel; the flexible printed wiring board has a laminated structure of at least one layer including an insulating base film; the base film has an opening in a part, and the flexible printed wiring board is A plate-shaped flying lead part whose two surfaces of the metal layer are not covered by the insulating layer is arranged in the aforementioned opening; at least a part of the aforementioned flying lead part is connected to the laminated structure of the aforementioned flexible printed wiring board; the aforementioned flying lead part has one end A laminated structure fixed to the flexible printed wiring board, and a cantilever structure whose other end is movable; and the surfaces of the battery terminals and the flying leads are bonded to each other. The battery pack according to claim 1, wherein the opening is formed in a surface of the flexible printed wiring board other than an end portion. The battery pack as described in claim 2 of the patent application, wherein the flexible printed wiring board has a power line and a battery state detection line; the flying lead part is a part of the power line. The battery pack as described in item 3 of the scope of the patent application, wherein the aforementioned power The wires and the aforementioned battery state detection wires are connected inside the aforementioned flexible printed wiring board. The battery pack according to claim 4, wherein the electric force line is a metal plate having a thickness of not less than 100 μm and not more than 300 μm. The battery pack as described in claim 1 of the patent application, wherein the flexible printed wiring board has a power line and a battery state detection line; the flying lead part is a part of the power line. The battery pack described in claim 6 of the patent application, wherein the aforementioned electric power line and the aforementioned battery state detection line are connected inside the aforementioned flexible printed wiring board. The battery pack according to claim 7, wherein the electric force line is a metal plate having a thickness of not less than 100 μm and not more than 300 μm. The battery pack described in claim 6 of the patent application, wherein the aforementioned electric power line and the aforementioned battery state detection line are connected inside the aforementioned flexible printed wiring board. The battery pack according to claim 9, wherein the electric force line is a metal plate having a thickness of not less than 100 μm and not more than 300 μm. The battery pack described in any one of the claims 1 to 10, wherein each battery unit has a flat plate shape; and a plurality of battery units are stacked in the thickness direction of the battery unit. The battery pack according to any one of the claims 1 to 10, wherein the aforementioned battery unit is equipped with an electrode assembly in the aforementioned outer casing; The aforementioned electrode assembly system is formed by overlapping at least one positive electrode, at least one negative electrode, and at least one separator. The aforementioned electrode assembly includes: a positive electrode extension part formed by extending a positive electrode collector sheet from the aforementioned electrode assembly. The aforementioned battery The terminal is a positive terminal or a negative terminal; the aforementioned positive terminal is connected to the aforementioned positive extension; the negative extension is formed by the negative current collector extending from the aforementioned electrode assembly; and the aforementioned negative terminal is connected to the The above-mentioned negative electrode extension part is joined; wherein, the above-mentioned positive electrode extension part, the above-mentioned negative electrode extension part, the above-mentioned positive electrode terminal, the aforementioned negative electrode terminal or the aforementioned outer packaging system are at the end of the aforementioned electrode assembly, and the aforementioned positive electrode terminal or the aforementioned negative electrode terminal Bending between the joints with the aforementioned flying leads. The battery pack described in any one of items 1 to 10 of the scope of the patent application has a plurality of battery groups; each battery group has a structure formed by stacking a plurality of battery cells in the thickness direction; included in A plurality of battery units in each battery group are connected in series or in parallel through the aforementioned flexible printed wiring board; a plurality of battery groups are connected through the same flexible printed wiring board. The battery pack as described in item 13 of the scope of the patent application, wherein the two adjacent battery groups are such that the first flexible printed wiring board connected to the plurality of battery units included in the first battery group part, connected to a plurality of battery cells included in the second battery group The second part of the flexible printed wiring board is disposed so as to face each other; an insulating partition wall is provided between the first part and the second part of the flexible printed wiring board. A method of manufacturing a battery pack, comprising: bending at least a part of a plate-shaped flying lead part connected to a laminated structure of a flexible printed wiring board; a step of overlapping and joining the plate-shaped battery terminal with the aforementioned flying lead portion; and a step of bending the aforementioned flying lead portion back. The method of manufacturing a battery pack as described in claim 15 of the patent application, wherein the step of bending back the flying lead is a step accompanied by bending the battery terminal or the outer casing.

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