Power storage device

Abstract

To provide a power storage device that can be assembled efficiently.SOLUTION: A power storage device includes a power storage unit 10 including a plurality of power storage elements 100, a wiring board 400c disposed in a first direction of the power storage unit 10, and a total terminal 140A corresponding to terminals of the power storage elements 100 at end parts of the electric connection paths of the power storage elements 100. The wiring board 400c includes a base body 401c with flexibility, and a first bus bar 410c electrically connected to the total terminal 140A. The base body 401c includes a first insulating layer 450 and a second insulating layer. The first bus bar 410c is at least partially disposed between the first insulating layer 450 and the second insulating layer in the first direction and faces at least two power storage elements 100 among the plurality of power storage elements 100 in the first direction.SELECTED DRAWING: Figure 10

Description

Technical Field

[0001] The present invention relates to a power storage device.

Background Art

[0002] Patent Document 1 discloses a power supply device including a battery assembly in which a plurality of batteries are arranged in parallel and a bus bar module device. The bus bar module device has a flexible substrate. The flexible substrate is attached to the battery assembly so as to connect a plurality of batteries in series by electrically connecting the positive electrode of one adjacent battery and the negative electrode of the other battery in the battery assembly. A positive power supply cable is connected to the positive electrode of the battery located at the leftmost end of the battery assembly using a nut. A negative power supply cable is connected to the negative electrode of the battery located at the rightmost end of the battery assembly using a nut.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above conventional power supply device, the positive power supply cable is connected to the positive electrode of the battery located at the leftmost end of the battery assembly using a nut as a member separate from the flexible substrate, and extends toward the rightmost end of the battery assembly. Therefore, problems such as how to determine or maintain the position or posture of the positive power supply cable are likely to occur. This can be a factor that complicates the assembly of the power supply device.

[0005] The present invention has been made by the inventors of the present application newly focusing on the above problems, and an object thereof is to provide a power storage device that can be assembled efficiently.

Means for Solving the Problems

[0006] A power storage device according to one aspect of the present invention includes a power storage unit including a plurality of power storage elements, and a wiring board disposed in a first direction of the power storage unit. The power storage unit includes a total terminal that is a terminal of a power storage element at an end in an electrical connection path of the plurality of power storage elements. The wiring board includes a flexible base and a first bus bar electrically connected to the total terminal. The base includes a first insulating layer and a second insulating layer. The first bus bar is disposed at least partially between the first insulating layer and the second insulating layer in the first direction, and faces at least two of the plurality of power storage elements in the first direction.

Effects of the Invention

[0007] According to the present invention, a power storage device that can be efficiently assembled can be provided.

Brief Description of the Drawings

[0008]

Figure 1

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Figure 10

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Mode for Carrying Out the Invention

[0009] (1) A power storage device according to one aspect of the present invention includes a power storage unit including a plurality of power storage elements, and a wiring board disposed in a first direction of the power storage unit. The power storage unit includes a total terminal that is a terminal of an end power storage element in an electrical connection path of the plurality of power storage elements. The wiring board includes a flexible substrate and a first bus bar electrically connected to the total terminal. The substrate includes a first insulating layer and a second insulating layer. The first bus bar is disposed at least partially between the first insulating layer and the second insulating layer in the first direction, and faces at least two of the plurality of power storage elements in the first direction.

[0010] According to the power storage device according to one aspect of the present invention, a first bus bar connected to the total terminal and formed in a size facing at least two power storage elements in the first direction is integrally provided on the wiring board. Therefore, by disposing the wiring board in a predetermined direction with respect to the power storage unit, the first bus bar is also disposed in the same predetermined direction with respect to the power storage unit. Therefore, the power storage device according to this aspect is a power storage device that can be efficiently assembled.

[0011] (2) In the power storage device described in (1) above, the wiring board may further include a detection line for detecting the state of at least one of the plurality of power storage elements, and the detection line may be disposed between the first insulating layer and the second insulating layer.

[0012] According to the power storage device described in the above (2), a detection line for detecting the state of at least one power storage element is provided on the wiring board together with the first bus bar. Therefore, by arranging the wiring board in a predetermined direction with respect to a plurality of power storage elements, both the detection line and the first bus bar are arranged in the same predetermined direction with respect to the plurality of power storage elements.

[0013] (3) In the power storage device described in the above (2), the base body may further include a third insulating layer, and the third insulating layer may be disposed between at least a part of the first bus bar and the detection line.

[0014] According to the power storage device described in the above (3), the two members (the first bus bar and the detection line) disposed between the first insulating layer and the second insulating layer can be more reliably insulated.

[0015] (4) In the power storage device described in the above (2) or (3), when viewed from the first direction, at least a part of the portion of the first bus bar disposed between the first insulating layer and the second insulating layer may overlap the detection line.

[0016] According to the power storage device described in the above (4), at least a part of the portion of the first bus bar disposed between the first insulating layer and the second insulating layer is arranged to overlap the detection line in the first direction. Therefore, an increase in the width of the wiring board in the direction orthogonal to the first direction is suppressed. That is, an increase in the size of the wiring board when viewed from the first direction, which can be treated as one component, is suppressed.

[0017] (5) In the power storage device described in the above (2) or (3), the plurality of power storage elements are arranged side by side in a second direction orthogonal to the first direction, and when viewed from the first direction, the detection line may be arranged side by side with the first bus bar in a third direction orthogonal to the first direction and the second direction.

[0018] According to the energy storage device described in (5) above, when viewed from the first direction, the detection line is arranged side by side with the first bus bar in the third direction. Thereby, an increase in the width (thickness) of the wiring board in the first direction is suppressed.

[0019] (6) In the energy storage device according to any one of (1) to (5) above, the plurality of energy storage elements are arranged side by side in a second direction orthogonal to the first direction, and include a first energy storage element at one end on one side in the second direction and a second energy storage element at the other end on the other side in the second direction. The base body and the first bus bar may be opposed to the plurality of energy storage elements in the first direction continuously from the first energy storage element to the second energy storage element when viewed from the first direction.

[0020] According to the energy storage device described in (6) above, the base body and the first bus bar included in the wiring board are formed in a size opposed in the first direction over the entire or substantially the entire area of the energy storage unit in the arrangement direction (second direction) of the energy storage elements. Therefore, even if the flexible base body is long in the second direction, substantially the entire longitudinal direction thereof is reinforced by the first bus bar. Thereby, the energy storage device can be assembled more efficiently.

[0021] (7) In the energy storage device according to any one of (1) to (6) above, the wiring board further includes a second bus bar that electrically connects two adjacent energy storage elements among the plurality of energy storage elements, and the second bus bar may be arranged between the first insulating layer and the second insulating layer.

[0022] According to the energy storage device described in (7) above, the wiring board is provided with a first bus bar and a second bus bar. That is, at least the first bus bar and the second bus bar are incorporated in the wiring board which is a single component. Thereby, the energy storage device can be assembled more efficiently.

[0023] Hereinafter, a power storage device according to an embodiment (including its modified examples) of the present invention will be described with reference to the drawings. Each of the embodiments described below shows comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement positions and connection forms of the components, manufacturing processes, order of manufacturing processes, etc. shown in the following embodiments are merely examples and are not intended to limit the present invention. In each figure, dimensions and the like are not strictly illustrated. In each figure, the same or similar components are denoted by the same reference numerals.

[0024] In the following description and drawings, the arrangement direction of a pair of terminals of one power storage element, the opposing direction of the short side surfaces of the container of the power storage element, or the short-side direction of the power storage unit is defined as the X-axis direction. The arrangement direction of a plurality of power storage elements, the opposing direction of the long side surfaces of the container of the power storage element, or the longitudinal direction of the power storage unit is defined as the Y-axis direction. The arrangement direction of the power storage element and the first bus bar, the arrangement direction of the main body and the lid of the container of the power storage element, or the vertical direction is defined as the Z-axis direction. These X-axis direction, Y-axis direction, and Z-axis direction are directions that intersect (orthogonal in this embodiment) with each other. Although it is conceivable that the Z-axis direction may not be the vertical direction depending on the usage mode, hereinafter, for the sake of convenience of explanation, the Z-axis direction will be described as the vertical direction.

[0025] In the following description, the X-axis plus direction indicates the arrow direction of the X-axis, and the X-axis minus direction indicates the direction opposite to the X-axis plus direction. When simply referring to the X-axis direction, it indicates both directions of the X-axis plus direction and the X-axis minus direction or either one of the directions. Expressions indicating relative directions or postures such as parallel and orthogonal include cases where they are not strictly in that direction or posture. For example, when two directions are parallel, it means not only that the two directions are completely parallel but also that they are substantially parallel, that is, including a difference of, for example, about several percent. Furthermore, in the following description, when expressing "insulation", it means "electrical insulation". A material having insulation properties is preferably formed from a material with a volume resistivity of 1×10 10 Ωm or more.

[0026] [1. General Description of the Power Storage Device 1] First, a general description of the power storage device 1 in the present embodiment will be given. FIG. 1 is a perspective view showing the appearance of the power storage device 1 according to the embodiment. FIG. 2 is a first exploded perspective view of the power storage device 1 according to the embodiment. In FIG. 2, the cover member 520 and the control unit 20 are shown separated from the power storage unit 10. FIG. 3 is a second exploded perspective view of the power storage device 1 according to the embodiment. In FIG. 3, the illustration of the control unit 20 shown in FIGS. 1 and 2 is omitted. FIG. 4 is a perspective view showing the appearance of the power storage element 100 according to the embodiment.

[0027] The power storage device 1 is a device that can charge electricity from the outside and discharge electricity to the outside. The power storage device 1 is, for example, a battery module (battery pack) used for power storage applications or power supply applications. Specifically, the power storage device 1 is used, for example, as a battery for driving a moving body such as an automobile, a motorcycle, a watercraft, a ship, a snowmobile, an agricultural machine, a construction machine, an automatic guided vehicle (AGV), or a railway vehicle for electric railways, or for engine starting. Examples of the above-mentioned automobiles include electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and fossil fuel (gasoline, light oil, liquefied natural gas, etc.) automobiles. Examples of the above-mentioned railway vehicles for electric railways include trains, monorails, linear motor cars, and hybrid trains equipped with both a diesel engine and an electric motor. Further, the power storage device 1 can also be used as a stationary battery for home or business use.

[0028] As shown in FIG. 1, the power storage device 1 includes a power storage unit 10, a control unit 20, and a wiring board 400. The power storage unit 10 has a substantially rectangular parallelepiped shape that is long in the Y-axis direction. The control unit 20 is a device that can monitor the state of the power storage element 100 included in the power storage unit 10 and control the power storage element 100, and has a control circuit board and the like inside. It is not essential for the power storage device 1 to include the control unit 20. The state of the power storage element 100 included in the power storage unit 10 may be monitored and the power storage element 100 may be controlled by a device external to the power storage device 1.

[0029] As shown in FIG. 2, the power storage unit 10 includes a plurality of power storage elements 100 and a plurality of spacers 200. The power storage unit 10 is provided in the power storage device 1 while being supported by a support 500. As shown in FIGS. 2 and 3, a wiring board 400 arranged in the positive Z-axis direction of the power storage unit 10 is connected to the power storage unit 10. The positive Z-axis direction is an example of a first direction. The control unit 20, and cables 710 and 720 (see FIG. 1) not shown in FIG. 2 are electrically connected to the power storage unit 10.

[0030] The power storage element 100 is a secondary battery (single cell), and more specifically, a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. The power storage element 100 has a flat rectangular parallelepiped shape (rectangular), and in the present embodiment, 14 power storage elements 100 are arranged side by side in the Y-axis direction. The Y-axis direction is an example of a second direction.

[0031] Specifically, as shown in FIG. 4, the energy storage element 100 includes a container 110 and a pair of terminals 140. Inside the container 110, an electrode body, a pair of current collectors, an electrolytic solution (non-aqueous electrolyte), etc. are accommodated, but their illustration is omitted. The type of the electrolytic solution is not particularly limited as long as it does not impair the performance of the energy storage element 100, and various types can be selected. The energy storage element 100 includes an insulating gasket that insulates and seals between the container 110, the terminals 140, and the current collectors, but this illustration is also omitted. In addition to the above components, the energy storage element 100 may have a spacer disposed on the side or below the electrode body, and an insulating film that wraps the electrode body, etc. An insulating film (such as a shrink tube) that covers the outer surface of the container 110 may be disposed around the container 110.

[0032] The container 110 is a rectangular parallelepiped (angular or box-shaped) case having a container body 120 with an opening formed therein and a lid portion 130 that closes the opening of the container body 120. The lid portion 130 is provided with a gas discharge valve 131, a liquid injection portion (not shown) for injecting the electrolytic solution into the container 110, etc.

[0033] The material of the container 110 (the container body 120 and the lid portion 130) is not particularly limited, and can be, for example, a weldable (joinable) metal such as stainless steel, aluminum, aluminum alloy, iron, or plated steel sheet, but a resin can also be used. After the electrode body and the like are accommodated inside the container body 120, the container body 120 and the lid portion 130 are joined by welding or the like, whereby the inside of the container 110 is sealed. The container 110 has a pair of long side surfaces 111, a pair of short side surfaces 112, and a bottom surface 113. In the present embodiment, a plurality of energy storage elements 100 are arranged side by side in the Y-axis direction in a posture where the short side surface 112 is oriented in the X-axis direction and the pair of terminals 140 is oriented in the +Z-axis direction (see FIG. 2). The X-axis direction is an example of the third direction.

[0034] The pair of terminals 140 are the terminal members (positive electrode terminal and negative electrode terminal) of the power storage element 100 disposed in the lid portion 130. One of the pair of terminals 140 is electrically connected to the positive electrode of the electrode body via a current collector, and the other of the pair of terminals 140 is electrically connected to the negative electrode of the electrode body via a current collector. More specifically, as shown in FIG. 4, each of the pair of terminals 140 includes a flat plate-shaped terminal body 142 and a shaft portion 141 protruding in the +Z-axis direction from the terminal body 142. The shaft portion 141 is a shaft body having a thread formed on its outer peripheral surface. A nut 800 (see FIG. 2) having a screw hole corresponding to the thread is coupled to the shaft portion 141. That is, in the present embodiment, the first bus bar 410 or the second bus bar 420 is connected to the terminal 140 by the nut 800 coupled to the shaft portion 141. The terminal 140 is formed of aluminum, an aluminum alloy, copper, a copper alloy, or the like.

[0035] The electrode body is a power storage element (power generation element) formed by laminating a positive electrode plate, a negative electrode plate, and a separator. The positive electrode plate is a plate (electrode plate) having a positive electrode active material layer formed on the surface of a positive electrode current collector foil which is a metal foil. The negative electrode plate is a plate (electrode plate) having a negative electrode active material layer formed on the surface of a negative electrode current collector foil which is a metal foil. Aluminum or an aluminum alloy, etc. is used for the positive electrode current collector foil. Copper or a copper alloy, etc. is used for the negative electrode current collector foil. The positive electrode active material layer contains a positive electrode active material, a binder, a conductive material, and the like. The negative electrode active material layer contains a negative electrode active material, a binder, a thickener, and the like. As the positive electrode active material and the negative electrode active material, any known material can be appropriately used as long as it is a material capable of occluding and releasing lithium ions. As the separator, a microporous sheet or nonwoven fabric made of resin can be used. The electrode body may be any form of electrode body, such as a wound-type electrode body formed by winding electrode plates (positive electrode plate and negative electrode plate), a laminated-type (stack-type) electrode body formed by laminating a plurality of flat plate-shaped electrode plates, or a bellows-type electrode body formed by folding an electrode plate in a bellows shape.

[0036] The power storage device 1 only needs to include a plurality of power storage elements 100, and there are no particular limitations on the number of the power storage elements 100, as well as the size and shape of the power storage elements 100. The power storage element 100 is not limited to a non-aqueous electrolyte secondary battery, and may be a secondary battery other than a non-aqueous electrolyte secondary battery. The power storage element 100 may be a capacitor. The power storage element 100 may be a primary battery.

[0037] The spacer 200 is a flat and rectangular member that is arranged side by side with the power storage element 100 in the Y-axis direction and insulates and / or thermally insulates the power storage element 100 from other members. In the present embodiment, the spacer 200 is arranged between two adjacent power storage elements 100 among the plurality of power storage elements 100. The spacer 200 is formed of a member having insulation properties, such as any resin material that can be used for the tray 310 described later. It is not essential that the spacer 200 be arranged between the two power storage elements 100. For example, when an insulating member such as an insulating film is attached to the container 110 of the power storage element 100, the spacer 200 may not be arranged between the two power storage elements 100. The power storage unit 10 may further include a spacer 200 arranged outside the plurality of power storage elements 100 in the Y-axis direction.

[0038] In this embodiment, the plurality (specifically, 14) of power storage elements 100 included in the power storage unit 10 are arranged in the Y-axis direction and are connected in series by a plurality of second bus bars 420 included in the wiring board 400. Among these plurality of power storage elements 100, when the power storage elements 100 at both ends in the Y-axis direction are defined as the first power storage element 100A and the second power storage element 100B (see FIG. 2), each of the first power storage element 100A and the second power storage element 100B is a power storage element 100 at the end in the electrical connection path of the plurality of power storage elements 100. More specifically, the positive terminal 140 of the first power storage element 100A is the positive main terminal (main terminal 140A) of the power storage unit 10, and the negative terminal 140 of the second power storage element 100B is the negative main terminal (main terminal 140B) of the power storage unit 10. The main terminal 140A is electrically connected to the cable 710 (see FIG. 1) via the first bus bar 410 included in the wiring board 400. The main terminal 140B is electrically connected to the cable 720 (see FIG. 1). Thereby, the power storage device 1 can charge electricity from the outside and discharge electricity to the outside via the cables 710 and 720.

[0039] The tray 310 is a box-shaped member with a shallow depth in the Z-axis direction. On the tray 310, a plurality of power storage elements 100 and a plurality of spacers 200 are arranged as shown in FIG. 3. More specifically, as shown in FIG. 3, the tray 310 has a plurality of partition portions 315 that are inserted between the lower ends of two adjacent power storage elements 100 in the Y-axis direction. Each of the plurality of power storage elements 100 has its movement in the Y-axis direction restricted by at least one partition portion 315.

[0040] The tray 310 is formed of a material having electrical insulation properties (insulating material). Specifically, the tray 310 is made of an insulating member such as polycarbonate (PC), polypropylene (PP), polyethylene (PE), polystyrene (PS), polyphenylene sulfide resin (PPS), polyphenylene ether (PPE (including modified PPE)), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyether ether ketone (PEEK), tetrafluoroethylene·perfluoroalkyl vinyl ether (PFA), polytetrafluoroethylene (PTFE), polyether sulfone (PES), polyamide (PA), ABS resin, or a composite material thereof, or is formed of a metal with insulating coating or the like.

[0041] The wiring board 400 is a flat member disposed in the +Z axis direction of the power storage unit 10. In the present embodiment, as shown in FIGS. 2 and 3, the wiring boards 400 are disposed at both ends in the +Z axis direction and the X axis direction of the power storage unit 10. Each of these two wiring boards 400 includes a flexible base 401, a second bus bar 420, and a detection line 610. The wiring board 400 in the +X axis direction among the two wiring boards 400 further includes a first bus bar 410. The first bus bar 410 is a bus bar connected to the main terminal 140A of the power storage unit 10, and the second bus bar 420 is a bus bar connecting two adjacent power storage elements 100 in the Y axis direction. The detection line 610 is a wiring for detecting the state of one or more power storage elements 100. In the present embodiment, the detection line 610 is realized by a metal layer (metal foil) provided in a flexible printed circuit board (hereinafter referred to as an FPC (Flexible Printed Circuit) board) 600. The detection line 610 is electrically connected to the control unit 20. The information detected using the detection line 610 is used for control of the power storage element 100 by the control unit 20 and the like. Details of the configuration of the wiring board 400 will be described later with reference to FIGS. 5 to 7.

[0042] The support body 500 is a member that supports and protects (reinforces) a plurality of power storage elements 100 and the like. The support body 500 is formed of a metal member such as a stainless steel, aluminum, aluminum alloy, iron, or zinc-plated steel plate. The support body 500 has a support body main body 510 and a cover member 520. The support body main body 510 and the cover member 520 may be formed of members of the same material or members of different materials.

[0043] The support body main body 510 is a member that supports a tray 310 on which a power storage unit 10 including a plurality of power storage elements 100 is placed from below (in the negative Z-axis direction), and has a bottom portion 511, and connection portions 512 and 513. The bottom portion 511 is disposed in the negative Z-axis direction of the tray 310. The cover member 520 is a member disposed in the positive Z-axis direction of the wiring board 400, and has a top surface portion 520a, and connection portions 522 and 523. The connection portion 522 is connected to the connection portion 512 of the support body main body 510. The connection portion 523 is connected to the connection portion 513 of the support body main body 510.

[0044] Among the two wiring boards 400 included in the power storage device 1 according to the present embodiment, the wiring board 400 in the positive X-axis direction includes the first bus bar 410 connected to the total terminal 140A as described above. Hereinafter, paying attention to the wiring board 400 in the positive X-axis direction among the two wiring boards 400, the wiring board 400 will be described in detail with reference to FIGS. 5 to 7. The wiring board 400 in the negative X-axis direction among the two wiring boards 400 is common to the wiring board 400 in the positive X-axis direction in that it includes a base body 401, a second bus bar 420, and a detection line 610. Therefore, a detailed description of the wiring board 400 in the negative X-axis direction will be omitted. Hereinafter, when referring to the "wiring board 400", it refers to the wiring board 400 in the positive X-axis direction among the two wiring boards 400.

[0045] [Regarding the configuration of the wiring board 400] FIG. 5 is an exploded perspective view of a wiring board 400 according to an embodiment. In FIG. 5, two of the plurality of power storage elements 100 included in the power storage unit 10 are illustrated, and illustration of the spacer 200 is omitted. In FIG. 5, a pattern is provided in the range of the bus bar main body portion 415 which is a part of the first bus bar 410. FIG. 6 is a cross-sectional view of the wiring board 400 according to the embodiment. In FIG. 6, an example of a cross-section of the wiring board 400 in the XZ plane passing through line VI-VI of FIG. 5 is simply illustrated. FIG. 7 is a cross-sectional view of an FPC board 600 including a detection line 610 according to the embodiment. In FIG. 7, a part of a cross-section orthogonal to the Y-axis direction of the FPC board 600 is simply illustrated.

[0046] As shown in FIGS. 5 to 7, the wiring board 400 includes a flexible base 401, a first bus bar 410, and a plurality of second bus bars 420. The base 401 includes a first insulating layer 450 and a second insulating layer 460. At least a part of the first bus bar 410 is disposed between the first insulating layer 450 and the second insulating layer 460. Each of the first insulating layer 450 and the second insulating layer 460 is a sheet-like member formed of an insulating resin such as PET, PP, PE, or PS. The thickness of each of the first insulating layer 450 and the second insulating layer 460 is, for example, 10 μm or more and 1000 μm or less, preferably 50 μm or more and 500 μm or less. Preferably, the thickness of the second insulating layer 460 is equal to or greater than the thickness of the first insulating layer 450.

[0047] The first bus bar 410 is electrically connected to the common terminal 140A and faces at least two power storage elements 100 in the Z-axis direction. In the present embodiment, the first bus bar 410 faces the 14 power storage elements 100 included in the power storage unit 10 in the Z-axis direction. More specifically, the first bus bar 410 includes a first connection portion 411 connected to the common terminal 140A of the power storage unit 10, a second connection portion 413 connected to the cable 720 (see FIG. 1), and a bus bar main body portion 415 that is a portion between the first connection portion 411 and the second connection portion 413. A common terminal hole 412 into which the shaft portion 141 (see FIG. 4) of the common terminal 140A is inserted is formed in the first connection portion 411. The bus bar main body portion 415 is disposed between the first insulating layer 450 and the second insulating layer 460. The first connection portion 411 and the second connection portion 413 protrude from the base body 401 when viewed from the +Z-axis direction (plan view).

[0048] The wiring board 400 according to the present embodiment further includes a detection line 610 for detecting the state of one or more power storage elements 100. Specifically, an FPC board 600 including the detection line 610 is disposed between the first insulating layer 450 and the second insulating layer 460. In the present embodiment, the detection line 610 is disposed at a position overlapping at least a part of the bus bar main body portion 415 of the first bus bar 410 when viewed from the +Z-axis direction. Briefly speaking, the bus bar main body portion 415 of the first bus bar 410 is disposed above (in the +Z-axis direction) the FPC board 600 including the detection line 610. The first insulating layer 450 includes a bus bar cover portion 458 that covers the bus bar main body portion 415 from the +Z-axis direction.

[0049] As shown in FIG. 7, the FPC substrate 600 includes a base film 611, a detection line 610 disposed along the base film 611, and a coverlay 612 covering the detection line 610. The base film 611 is a thin film formed of an insulating material such as polyimide. The detection line 610 is, for example, a metal foil (such as a copper foil) adhered to the surface in the thickness direction of the base film 611 via an adhesive layer (not shown). In the present embodiment, the FPC substrate 600 includes a plurality of detection lines 610 extending in the Y-axis direction. The coverlay 612 is a thin film formed of an insulating material such as polyimide, similar to the base film 611. In this case, the coverlay 612 is adhered to the base film 611 and the detection line 610 via an adhesive layer (not shown), for example. The coverlay 612 may be formed by applying an ink-like insulating material to the surface of the base film 611 where the detection line 610 is disposed.

[0050] In the present embodiment, the base body 401 further includes a third insulating layer 470, and the third insulating layer 470 is disposed between the first bus bar 410 and the detection line 610. That is, in the present embodiment, as shown in FIGS. 5 and 6, the first bus bar 410 is disposed between the first insulating layer 450 and the third insulating layer 470, and the FPC substrate 600 including the detection line 610 is disposed between the second insulating layer 460 and the third insulating layer 470. The third insulating layer 470 is a sheet-like (film-like) member formed of an insulating resin, similar to the first insulating layer 450 and the second insulating layer 460. The thickness of the third insulating layer 470 is, for example, 10 μm or more and 1000 μm or less, and preferably 20 μm or more and 100 μm or less. There is no particular limitation on the method of connecting the third insulating layer 470 to each of the first insulating layer 450 and the second insulating layer 460. As the connection method, pressure bonding by pressure and heating, or adhesion using an adhesive, etc. can be adopted. When the first insulating layer 450 and the second insulating layer 460 have a directly connected portion, the connection method at the portion can also be pressure bonding or adhesion, etc.

[0051] Each of the plurality of second bus bars 420 included in the wiring substrate 400 is disposed between a first insulating layer 450 and a second insulating layer 460 in the substrate 401. More specifically, each of the plurality of second bus bars 420 is disposed between a second insulating layer 460 and a third insulating layer 470, as shown in FIGS. 5 and 6. As shown in FIG. 5, the second bus bar 420 includes two terminal connection portions 421 connected to the terminals 140 of two adjacent power storage elements 100, and a connection portion 425 connecting the two terminal connection portions 421. Each of the two terminal connection portions 421 is formed with a terminal hole 422 into which a shaft portion 141 (see FIG. 4) of the terminal 140 located at a position facing in the Z-axis direction is inserted. By coupling a nut 800 to the shaft portion 141 inserted into the terminal hole 422, the terminal 140 and the second bus bar 420 are connected.

[0052] Specifically, as shown in FIG. 5, the first insulating layer 450 includes a plurality of upper openings 452, and the third insulating layer 470 includes a plurality of upper openings 472. At least a part of the terminal connection portion 421 of the second bus bar 420 disposed below (in the negative Z-axis direction) the third insulating layer 470 is exposed above (in the positive Z-axis direction) the wiring substrate 400 through the upper openings 452 and 472. As a result, the nut 800 disposed in the upper openings 452 and 472 contacts the second bus bar 420. As a result, the terminal 140 to which the nut 800 is coupled is connected to the second bus bar 420. The second insulating layer 460 includes a plurality of lower openings 462. Each of the plurality of second bus bars 420 contacts a terminal body 142 (see FIG. 4) of the terminal 140 located in the negative Z-axis direction of the lower opening 462 through the lower opening 462 corresponding to the second bus bar 420.

[0053] The first insulating layer 450 further includes an insertion portion 455 provided between two upper openings 452 corresponding to one second bus bar 420. The third insulating layer 470 further includes an insertion portion 475 at a position overlapping the insertion portion 455 in the Z-axis direction. The connection portion 425 protruding in the positive Z-axis direction in the second bus bar 420 is inserted into the insertion portions 455 and 475.

[0054] As shown in FIG. 5, the wiring board 400 according to this embodiment further includes a first connection terminal 430 connected to the main terminal 140A of the power storage unit 10 and a second connection terminal 440 connected to the main terminal 140B of the power storage unit 10. The first connection terminal 430 is a detection terminal for detecting the voltage of the first power storage element 100A, and the second connection terminal 440 is a detection terminal for detecting the voltage of the second power storage element 100B. At least a part of each of the first connection terminal 430 and the second connection terminal 440 is disposed between the second insulating layer 460 and the third insulating layer 470, similar to the second bus bar 420. A terminal hole 431 into which the shaft portion 141 of the main terminal 140A is inserted is formed in the first connection terminal 430. By coupling the nut 800 to the shaft portion 141 inserted into the terminal hole 431, the main terminal 140A and the first connection terminal 430 are connected. More specifically, as shown in FIG. 5, the first connection terminal 430 and the first connection portion 411 of the first bus bar 410 are overlapped. In this state, the nut 800 is coupled to the shaft portion 141 that penetrates the terminal hole 431 and the main terminal hole 412. Thereby, the main terminal 140A, the first connection terminal 430, and the first bus bar 410 are connected. A terminal hole 441 into which the shaft portion 141 of the main terminal 140B is inserted is formed in the second connection terminal 440. By coupling the nut 800 to the shaft portion 141 inserted into the terminal hole 441, the main terminal 140B and the second connection terminal 440 are connected.

[0055] More specifically, as shown in FIG. 5, the first insulating layer 450 includes a first notch 453 provided at an end in the +Y-axis direction and a second notch 454 provided at an end in the -Y-axis direction. The third insulating layer 470 includes a first notch 473 provided at an end in the +Y-axis direction and a second notch 474 provided at an end in the -Y-axis direction. The second insulating layer 460 includes a first notch 463 provided at an end in the +Y-axis direction and a second notch 464 provided at an end in the -Y-axis direction. The nut 800 coupled to the common terminal 140A is at least partially disposed inside the first notch 453 and contacts the first connection portion 411 of the first bus bar 410 when viewed from the +Z-axis direction. The first connection portion 411 contacts the first connection terminal 430 through the first notch 473. The first connection terminal 430 contacts the terminal body 142 (see FIG. 4) of the common terminal 140A through the first notch 463. As a result, the common terminal 140A to which the nut 800 is coupled is connected to the first connection portion 411 and the first connection terminal 430.

[0056] The nut 800 coupled to the common terminal 140B is at least partially disposed inside the second notches 454 and 474 and contacts the second connection terminal 440 when viewed from the +Z-axis direction. The second connection terminal 440 contacts the terminal body 142 (see FIG. 4) of the common terminal 140B through the second notch 464. As a result, the common terminal 140B to which the nut 800 is coupled is connected to the second connection terminal 440.

[0057] A connection piece 480 made of, for example, copper is connected to each of the plurality of second bus bars 420, the first connection terminal 430, and the second connection terminal 440 by welding or the like. One connection piece 480 is connected to one detection line 610 of the FPC substrate 600 by laser welding or the like. Thereby, the potentials of each of the plurality of second bus bars 420, the first connection terminal 430, and the second connection terminal 440 are detected by the control unit 20 via the plurality of detection lines 610 provided in the FPC substrate 600. As a result, the control unit 20 can detect the voltage of each of the plurality of power storage elements 100 provided in the power storage unit 10. As a method of connecting the connection piece 480 and the detection line 610, soldering, resistance welding, caulking, or the like may be employed.

[0058] The first insulating layer 450 and the third insulating layer 470 are provided with openings for performing the connection work between the connection piece 480 and the second bus bar 420 or the like. Specifically, as shown in FIGS. 5 and 6, the first insulating layer 450 includes a plurality of connection openings 459, and the third insulating layer 470 includes a plurality of connection openings 479. The connection openings 459 and 479 are arranged side by side in the Z-axis direction, and a part of the connection piece 480 located in the minus Z-axis direction of the connection openings 459 and 479 is exposed. For example, as shown in FIG. 6, the connection openings 459 and 479 expose the upper surface of a part of the connection piece 480. The said part of the connection piece 480 is a part that overlaps with the second bus bar 420 in the Z-axis direction. Thereby, the work (such as welding) of connecting the connection piece 480 and the second bus bar 420 can be performed through the connection openings 459 and 479.

[0059] As described above, the power storage device 1 according to the present embodiment includes a power storage unit 10 including a plurality of power storage elements 100, and a wiring board 400 disposed in the +Z-axis direction of the power storage unit 10. The power storage unit 10 includes a total terminal 140A which is a terminal 140 of the power storage element 100 at the end in the electrical connection path of the plurality of power storage elements 100. The wiring board 400 includes a flexible base 401 and a first bus bar 410 electrically connected to the total terminal 140A. The base 401 includes a first insulating layer 450 and a second insulating layer 460. The first bus bar 410 is at least partially disposed between the first insulating layer 450 and the second insulating layer 460 in the Z-axis direction, and faces at least two of the plurality of power storage elements 100 in the Z-axis direction.

[0060] Thus, in the present embodiment, the first bus bar 410 connected to the total terminal 140A and formed in a size facing at least two power storage elements 100 in the Z-axis direction is integrally provided on the wiring board 400. Therefore, by arranging the wiring board 400 in a predetermined direction with respect to the plurality of power storage elements 100 (power storage unit 10), the first bus bar 410 is also arranged in the same predetermined direction with respect to the power storage unit 10. Therefore, the power storage device 1 according to the present embodiment is a power storage device that can be assembled efficiently.

[0061] In the present embodiment, the wiring board 400 further includes a detection line 610 for detecting the state of at least one of the plurality of power storage elements 100. The detection line 610 is disposed between the first insulating layer 450 and the second insulating layer 460.

[0062] Thus, since the detection line 610 is provided on the wiring board 400 together with the first bus bar 410, by arranging the wiring board 400 in a predetermined direction with respect to the power storage unit 10, both the detection line 610 and the first bus bar 410 are arranged in the same predetermined direction with respect to the power storage unit 10.

[0063] In this embodiment, the detection line 610 is realized by a metal layer included in the FPC substrate 600 disposed between the first insulating layer 450 and the second insulating layer 460. Therefore, the detection line 610 is covered at least by the first insulating layer 450 and the second insulating layer 460 included in the base body 401, and is further covered by the base film 611 and the coverlay 612 included in the FPC substrate 600. That is, the detection line 610 is more reliably insulated from other members outside the wiring substrate 400.

[0064] The detection line 610 does not necessarily have to be a metal layer included in the FPC substrate 600. The detection line 610 may be, for example, a wire covered with an insulator, or may be a conductive member such as a wire or a metal layer not covered with an insulator. In any case, since the detection line 610 is covered at least by the first insulating layer 450 and the second insulating layer 460, the insulation of the detection line 610 from other members outside the wiring substrate 400 is ensured.

[0065] In this embodiment, the detection line 610 is used for detecting the voltage of the power storage element 100, but the type of information detected using the detection line 610 is not particularly limited. For example, by connecting the detection line 610 to a thermistor disposed at an end portion or a central portion in the Y-axis direction of the power storage unit 10, the detection line 610 may be used for detecting the temperature of the power storage unit 10 at the position where the thermistor is disposed. The wiring substrate 400 may be provided with a detection line 610 used for detecting the voltage of the power storage element 100 and a detection line 610 used for detecting the temperature of the power storage unit 10.

[0066] In this embodiment, the base body 401 further includes a third insulating layer 470. The third insulating layer 470 is disposed between at least a part of the first bus bar 410 (the part disposed between the first insulating layer 450 and the second insulating layer 460) and the detection line 610.

[0067] According to this configuration, the two members (the first bus bar 410 and the detection line 610) disposed between the first insulating layer 450 and the second insulating layer 460 can be more reliably insulated.

[0068] In the present embodiment, when viewed from the +Z axis direction, at least a part of the portion of the first bus bar 410 disposed between the first insulating layer 450 and the second insulating layer 460 overlaps with the detection line 610.

[0069] Thus, in the wiring board 400 according to the present embodiment, at least a part of the portion (bus bar main body portion 415) of the first bus bar 410 disposed between the first insulating layer 450 and the second insulating layer 460 is arranged so as to overlap with the detection line 610 in the Z-axis direction. Therefore, for example, an increase in the width of the wiring board 400 in the direction orthogonal to the Z-axis direction is suppressed. That is, an increase in the size of the wiring board 400 when viewed from the +Z axis direction, which can be treated as one component, is suppressed. In the present embodiment, at least a part of the bus bar main body portion 415, which is elongated in the Y-axis direction, and one or more detection lines 610 are arranged side by side in the Z-axis direction. Thereby, an increase in the width of the wiring board 400 in the X-axis direction is suppressed.

[0070] In the present embodiment, as shown in FIGS. 2 and 3, the plurality of power storage elements 100 are arranged side by side in the Y-axis direction orthogonal to the Z-axis direction. The plurality of power storage elements 100 include a first power storage element 100A at one end in the Y-axis direction and a second power storage element 100B at the other end in the Y-axis direction. The base 401 and the first bus bar 410 face the plurality of power storage elements 100 continuously in the Z-axis direction from the first power storage element 100A to the second power storage element 100B when viewed from the +Z axis direction.

[0071] Thus, the base 401 and the first bus bar 410 included in the wiring board 400 are formed in sizes that face each other in the Z-axis direction over the entire or almost the entire area of the power storage unit 10 in the arrangement direction (Y-axis direction) of the power storage elements 100. That is, when viewed from the +Z axis direction, the base 401 and the first bus bar 410 are arranged so as to cross the power storage unit 10 in the Y-axis direction. Therefore, even if the flexible base 401 is elongated in the Y-axis direction, almost the entire longitudinal direction thereof is reinforced by the first bus bar 410. Thereby, the power storage device 1 can be assembled more efficiently.

[0072] In this embodiment, the wiring board 400 further includes a second bus bar 420 that electrically connects two adjacent power storage elements 100 among the plurality of power storage elements 100. The second bus bar 420 is disposed between the first insulating layer 450 and the second insulating layer 460.

[0073] That is, in this embodiment, the wiring board 400 is also provided with a second bus bar 420 that connects two power storage elements 100 in addition to the first bus bar 410 connected to the main terminal 140A. Thereby, the power storage device 1 can be assembled more efficiently.

[0074] More specifically, as shown in FIGS. 5 and 6, the second bus bar 420 is disposed between the second insulating layer 460 and the third insulating layer 470, and the first bus bar 410 is disposed between the first insulating layer 450 and the third insulating layer 470. Thereby, the first bus bar 410 and the second bus bar 420 are more surely insulated from each other.

[0075] As described above, the power storage device 1 according to the embodiment has been described mainly with respect to the wiring board 400 and its surrounding configuration. However, the wiring board 400 in the power storage device 1 may be different from the configuration shown in FIGS. 2, 3, 5, and 6. Therefore, hereinafter, a modification example of the wiring board 400 will be described mainly with respect to the differences from the above embodiment.

[0076] [3-1. Modification Example 1] FIG. 8 is a cross-sectional view of a wiring board 400a according to Modification Example 1 of the embodiment. In FIG. 8, a cross-section parallel to the XZ plane of the wiring board 400a is simply illustrated. As shown in FIG. 8, a third insulating layer 470 is not provided in a substrate 401a included in the wiring board 400a according to this modification example. In this regard, the wiring board 400a is different from the wiring board 400 according to the embodiment. Even in this case, since the detection line 610 is provided in the wiring board 400a as a metal layer of the FPC board 600, an insulating layer (for example, a coverlay 612, see FIG. 7) included in the FPC board 600 is disposed between the detection line 610 and the first bus bar 410. Therefore, as shown in FIG. 8, even when at least a part of the first bus bar 410 and the detection line 610 are arranged side by side in the Z-axis direction, it is possible to insulate the first bus bar 410 and the detection line 610. However, from the viewpoint of more reliably insulating the first bus bar 410 and the detection line 610, it is preferable that a third insulating layer 470 is disposed between the first bus bar 410 and the detection line 610.

[0077] [3-2. Modification Example 2] FIG. 9 is a cross-sectional view of a wiring board 400b according to Modification Example 2 of the embodiment. In FIG. 9, a cross-section parallel to the XZ plane of the wiring board 400b is simply illustrated. In the wiring board 400b according to this modification example, when viewed from the +Z axis direction, the detection line 610 is arranged side by side with the first bus bar 410 in the X-axis direction. In this regard, it is different from the wiring board 400 according to the embodiment.

[0078] Thus, in this modification example, since the detection line 610 is arranged side by side with the first bus bar 410 in the X-axis direction, as shown in FIG. 9, the detection line 610 can be prevented from overlapping the first bus bar 410 in the Z-axis direction. Thereby, an increase in the width (thickness) of the wiring board 400b in the Z-axis direction is suppressed.

[0079] The substrate 401b included in the wiring board 400b according to this modification example may not include the third insulating layer 470, similar to the substrate 401a according to the above modification example 1. When the wiring board 400b does not include the third insulating layer 470, the first insulating layer 450 and the second insulating layer 460 may be connected by pressure bonding or the like between the first bus bar 410 and the detection line 610 (FPC board 600) in the X-axis direction. Thereby, the first bus bar 410 and the detection line 610 are more reliably insulated.

[0080] [3-3. Modification Example 3] FIG. 10 is a perspective view of a wiring board 400c according to Modification Example 3 of the embodiment. FIG. 11 is a perspective view of the first bus bar 410c according to Modification Example 3 of the embodiment. In FIG. 11, a pattern is provided in the range of the bus bar main body portion 415c which is a part of the first bus bar 410c.

[0081] In this modification example, substantially the entire longitudinal direction (Y-axis direction) of the first bus bar 410c included in the wiring board 400c is arranged in a posture with the thickness direction facing the X-axis direction. In this regard, it is different from the first bus bar 410 according to the embodiment. More specifically, the first bus bar 410c according to this modification example includes a first connection portion 411c connected to the main terminal 140A of the power storage unit 10, a second connection portion 413c connected to the cable 720 (see FIG. 1), and a bus bar main body portion 415c which is a portion between the first connection portion 411c and the second connection portion 413c. The bus bar main body portion 415c is covered by the first insulating layer 450 included in the substrate 401c. The first insulating layer 450 includes a bus bar cover portion 458c that covers the bus bar main body portion 415c with the thickness direction facing the X-axis direction.

[0082] The first connection portion 411c of the first bus bar 410c has a main terminal hole 412c into which the main terminal 140A is inserted and an intermediate connection portion 418c connected to the bus bar main body portion 415c. As shown in FIGS. 10 and 11, the intermediate connection portion 418c has its thickness direction oriented in the X-axis direction. The bus bar main body portion 415c extends from the intermediate connection portion 418c in the minus Y-axis direction. That is, the bus bar main body portion 415c assumes a posture with its thickness direction oriented in the X-axis direction. Therefore, for example, when other members are arranged in the minus X-axis direction of the wiring board 400c, the distance in the X-axis direction between the other member and the first bus bar 410c increases. As a result, the first bus bar 410c and the other member are more reliably insulated from each other.

[0083] In this modification, the second connection portion 413c extending from the bus bar main body portion 415c in the minus Y-axis direction also assumes a posture with its thickness direction oriented in the X-axis direction. Therefore, for example, the connection operation (connection using bolts and nuts, welding, etc.) between the cable 710 (see FIG. 1) and the second connection portion 413c is easy to perform.

[0084] [3-4. Modification 4] FIG. 12 is a perspective view of the first bus bar 410d according to Modification 4 of the embodiment. In FIG. 12, in order to show the features of the first bus bar 410d, the end portion of the first bus bar 410d in the plus Y-axis direction is enlarged and shown, and the illustration of the base body of the wiring board including the first bus bar 410d is omitted. As the base body on which the first bus bar 410d is arranged, a base body having the same shape as the base body 401c (see FIG. 10) according to the above Modification 3 is exemplified.

[0085] The first bus bar 410d according to this modification is not directly connected to the main terminal 140A, but is connected to the main terminal 140A via the third bus bar 417, and in this respect, it is different from the first bus bar 410 according to the embodiment.

[0086] In this modified example, the first bus bar 410d has its thickness direction oriented in the X-axis direction, just like the bus bar main body 415c according to the above-described modified example 3. The third bus bar 417 has a portion where a main terminal hole 419 to which the main terminal 140A is connected, and an intermediate connection portion 418d orthogonal to the said portion. For example, as shown in FIG. 12, the intermediate connection portion 418d is connected to the first bus bar 410d using a screw 810. The intermediate connection portion 418d may be connected to the first bus bar 410d by other methods such as welding.

[0087] Thus, the first bus bar 410d according to this modified example is arranged in a posture with its thickness direction oriented in the X-axis direction. Therefore, when other members are arranged in the -X-axis direction of the wiring board provided with the first bus bar 410d, the said other members and the first bus bar 410d are more reliably insulated from each other. Each of the first bus bar 410d and the intermediate connection portion 418d of the third bus bar 417 is stacked in the X-axis direction in a posture with its thickness direction oriented in the X-axis direction. Therefore, for example, the first bus bar 410d and the intermediate connection portion 418d can be easily connected using a screw 810 that penetrates in their thickness directions.

[0088] When the first bus bar 410d is connected to the main terminal 140A via the third bus bar 417, it is not essential for the thickness direction of the first bus bar 410d to be oriented in the X-axis direction. For example, a first bus bar 410d with its thickness direction oriented in the Z-axis direction may be connected to the main terminal 140A via the third bus bar 417.

[0089] [4. Other Modified Examples] As described above, the power storage device 1 according to the embodiment and its modified examples have been explained, but the present invention is not limited to the embodiment and its modified examples. That is, the embodiment disclosed this time is illustrative in all respects and not restrictive, and the scope of the present invention includes all modifications within the meaning and scope equivalent to the claims.

[0090] It was assumed that the main terminal 140A is the main terminal of the positive electrode of the power storage unit 10, and the main terminal 140B is the main terminal of the negative electrode of the power storage unit 10. However, the main terminal 140A may be the main terminal of the negative electrode of the power storage unit 10, and the main terminal 140B may be the main terminal of the positive electrode of the power storage unit 10.

[0091] It is not essential that two mutually separated wiring boards 400 (see FIG. 3) be arranged in the power storage unit 10. The two wiring boards 400 may be treated as one wiring board by being connected to each other. For example, by arranging a single first bus bar 410, thirteen second bus bars 420, two FPC boards 600, etc. on a substrate sized to correspond to the two wiring boards 400, one wiring board having substantially the same functions as the two wiring boards 400 may be realized.

[0092] In an example of the cross-section of the wiring board 400 shown in FIG. 6, the first insulating layer 450 protrudes in the +Z-axis direction, the second insulating layer 460 protrudes in the -Z-axis direction, and the third insulating layer 470 is flat. However, there is no particular limitation on the uneven shape formed by the unevenness in the Z-axis direction of each of the first insulating layer 450, the second insulating layer 460, and the third insulating layer 470. The uneven shape of these insulating layers may be appropriately determined according to the position in the Z-axis direction of members (such as the first bus bar 410 and the second bus bar 420) arranged between the first insulating layer 450 and the second insulating layer 460.

[0093] The power storage device 1 may not include the cables 710 and 720. For example, by the end of the first bus bar 410 protruding in the -Y-axis direction from the support 500, it may function as an external terminal (positive electrode external terminal) for connecting the power storage device 1 and an external device.

[0094] It is not essential that the first connection terminal 430 (see FIG. 5) be arranged between the first bus bar 410 and the terminal body 142 of the general terminal 140A (see FIG. 4). The general terminal 140A and the terminal body 142 may be directly overlapped in the Z-axis direction. In this case, for example, the detection line 610 for detecting the potential of the general terminal 140A may be electrically connected to the first bus bar 410.

[0095] It is not essential that a nut 800 be used for connecting the first bus bar 410 and the general terminal 140A. The first bus bar 410 and the general terminal 140A may be connected by caulking or welding. As the welding method, laser welding using a laser beam or ultrasonic welding using ultrasonic vibration may be employed. For example, in a state where the first connection portion 411 of the first bus bar 410 and the first connection terminal 430 are overlapped in the Z-axis direction with the general terminal 140A having no shaft portion 141, the general terminal 140A, the first connection portion 411, and the first connection terminal 430 may be connected by welding. For the connection between the second bus bar 420 and the terminal 140 and the connection between the second connection terminal 440 and the general terminal 140B, various methods such as welding may be employed.

[0096] The power storage device 1 does not necessarily need to be elongated in the arrangement direction (Y-axis direction) of the plurality of power storage elements 100. For example, when the number of power storage elements 100 included in the power storage device 1 is small (for example, 4 or less), the length of the power storage device 1 in the Y-axis direction may be equal to or less than the length in the X-axis direction.

[0097] The supplementary matters regarding the wiring board 400 according to the above embodiment may be applied to at least one of the wiring boards 400a etc. according to Modifications 1 to 4. A form constructed by arbitrarily combining the components included in the above embodiment and its modifications is also included in the scope of the present invention.

Industrial Applicability

[0098] The present invention can be applied to a power storage device including a power storage element such as a lithium ion secondary battery.

Explanation of Signs

[0099] 1 Power storage device 10 Power storage unit 100 Power storage element 100A First power storage element 100B Second power storage element 140 Terminal 140A Main terminal 140B Main terminal 400, 400a, 400b, 400c Wiring board 401, 401a, 401b, 401c Substrate 410, 410c, 410d First bus bar 420 Second bus bar 450 First insulating layer 460 Second insulating layer 470 Third insulating layer 600 FPC board 610 Detection line

Claims

1. A power storage unit including a plurality of power storage elements, and a wiring board disposed in a first direction of the power storage unit, wherein the power storage unit includes main terminals that are terminals of the power storage elements at ends in an electrical connection path of the plurality of power storage elements, the wiring board includes a flexible base body and a first bus bar electrically connected to the main terminals, the base body includes a first insulating layer and a second insulating layer, at least a part of the first bus bar is disposed between the first insulating layer and the second insulating layer in the first direction, and faces at least two of the plurality of power storage elements in the first direction, a power storage device.

2. The wiring board further includes a detection line for detecting a state of at least one of the plurality of power storage elements, the detection line is disposed between the first insulating layer and the second insulating layer, the power storage device according to Claim 1.

3. The base body further includes a third insulating layer, the third insulating layer is disposed between at least a part of the first bus bar and the detection line, the power storage device according to Claim 2.

4. When viewed from the first direction, at least a part of a portion of the first bus bar disposed between the first insulating layer and the second insulating layer overlaps the detection line, the power storage device according to Claim 2 or 3.

5. The plurality of power storage elements are arranged side by side in a second direction orthogonal to the first direction, when viewed from the first direction, the detection line is arranged side by side with the first bus bar in a third direction orthogonal to the first direction and the second direction, the power storage device according to Claim 2 or 3.

6. The plurality of power storage elements are arranged side by side in a second direction orthogonal to the first direction, and include a first power storage element at one end in the second direction and a second power storage element at the other end in the second direction, when viewed from the first direction, the base body and the first bus bar face the plurality of power storage elements continuously from the first power storage element to the second power storage element in the first direction, the power storage device according to any one of Claims 1 to 3.

7. The wiring board further includes a second bus bar for electrically connecting two adjacent power storage elements among the plurality of power storage elements, the second bus bar is disposed between the first insulating layer and the second insulating layer, the power storage device according to any one of Claims 1 to 3.

Images