Power storage device

Abstract

An electrical storage device (1) is provided with: a plurality of electrical storage elements (11) arrayed in a position such that gas discharge valves (111) are oriented in the same direction; a plurality of busbars (13) electrically connected to the plurality of electrical storage elements (11); and a busbar frame (12) (busbar holding member) which is disposed over the plurality of electrical storage elements (11) and holds the plurality of busbars (13). The busbar frame (12) is provided with: a first holding portion (71) disposed over the plurality of electrical storage elements (11) on one side of the gas discharge valves (111); a second holding portion (72) disposed over the plurality of electrical storage elements (11) on the other side of the gas discharge valves (111); and a linking portion (731) which is disposed between at least a pair of electrical storage elements (11) adjacent to each other among the plurality of electrical storage elements (11), and which links the first holding portion (71) and the second holding portion (72). An upper-end surface (bottom surface (733)) of a part of the linking portion (731) is disposed under or flush with an upper surface (11e) of a container (11a).

Description

[Technical field]

[0001] The present invention relates to an electricity storage device. [Background technology]

[0002] Conventionally, in an energy storage device including a plurality of energy storage elements, a bus bar (bus bar 16) for connecting electrode terminals of each energy storage element is held by a bus bar holding member (bus bar holder 6) (see Patent Document 1). The bus bar holding member on one side in the cell width direction and the bus bar holding member on the other side may be connected by a plurality of connecting portions (ribs 39). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2017 / 006763 Summary of the Invention [Problem to be solved by the invention]

[0004] The multiple connectors consume space within the energy storage device. In some cases, a gas path is provided above the gas exhaust valve of each energy storage element. In this case, the multiple connectors are exposed to the high-temperature gas passing through the path, and may melt or burn.

[0005] An object of the present invention is to suppress the effect of gas on the inside of the electricity storage device while improving the space efficiency within the electricity storage device. [Means for solving the problem]

[0006] According to one embodiment of the present invention, there is provided an energy storage device comprising: a plurality of energy storage elements, each having a gas exhaust valve, arranged with the gas exhaust valves facing in the same direction; a plurality of bus bars electrically connected to the plurality of energy storage elements; and a bus bar holding member arranged on the plurality of energy storage elements and holding the plurality of bus bars, wherein the energy storage elements comprise a main body portion having a gas exhaust valve on an upper surface thereof, and a pair of electrode terminals arranged on an upper surface of the main body portion, and the bus bar holding member comprises a first holding portion arranged on one side of the gas exhaust valve on the plurality of energy storage elements, a second holding portion arranged on the other side of the gas exhaust valve on the plurality of energy storage elements, and a connecting portion arranged between at least a pair of adjacent energy storage elements among the plurality of energy storage elements and connecting the first holding portion and the second holding portion, and an upper end surface of a portion of the connecting portion is arranged below an upper surface of the main body portion or is flush with the upper surface of the main body portion. Effect of the Invention

[0007] According to the electricity storage device of the present invention, it is possible to suppress the effect of gas on the inside of the electricity storage device while improving the space efficiency inside the electricity storage device. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing the appearance of a power storage device according to an embodiment. [Diagram 2] FIG. 2 is an exploded perspective view illustrating each component of the electricity storage unit according to the embodiment. [Diagram 3] FIG. 3 is an exploded perspective view showing a schematic configuration of an exhaust section and a bus bar frame according to the embodiment. [Figure 4] FIG. 4 is a top view showing a schematic configuration of a bus bar frame according to an embodiment. [Diagram 5] FIG. 5 is an explanatory diagram showing the positional relationship between the connecting portion and the energy storage element according to the embodiment. [Figure 6] FIG. 6 is a cross-sectional view showing the positional relationship between a connecting portion and an exhaust portion according to the embodiment. [Figure 7] FIG. 7 is a top view showing a schematic configuration of a guide portion according to the embodiment. [Figure 8]FIG. 8 is a perspective view showing a schematic configuration of a detection line holding unit according to the embodiment. [Figure 9] FIG. 9 is a cross-sectional view showing a schematic configuration of a detection line holding unit according to the embodiment. [Figure 10] FIG. 10 is a cross-sectional view showing a schematic configuration of a detection line holding unit according to the first modification. [Figure 11] FIG. 11 is a perspective view of the bus bar frame according to the second modification, showing the vicinity of the guide portion. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The reality is that the presence of multiple connectors consumes space within the energy storage device. In some cases, a gas path is provided above the gas exhaust valve of each energy storage element. In this case, the multiple connectors are exposed to the high-temperature gas passing through the path, and there is a risk that they will melt or burn.

[0010] An object of the present invention is to suppress the effect of gas on the inside of the electricity storage device while improving the space efficiency within the electricity storage device.

[0011] According to one embodiment of the present invention, there is provided an energy storage device comprising: a plurality of energy storage elements, each having a gas exhaust valve, arranged with the gas exhaust valves facing in the same direction; a plurality of bus bars electrically connected to the plurality of energy storage elements; and a bus bar holding member arranged on the plurality of energy storage elements and holding the plurality of bus bars, wherein the energy storage elements comprise a main body portion having a gas exhaust valve on an upper surface thereof, and a pair of electrode terminals arranged on an upper surface of the main body portion, and the bus bar holding member comprises a first holding portion arranged on one side of the gas exhaust valve on the plurality of energy storage elements, a second holding portion arranged on the other side of the gas exhaust valve on the plurality of energy storage elements, and a connecting portion arranged between at least a pair of adjacent energy storage elements among the plurality of energy storage elements and connecting the first holding portion and the second holding portion, and an upper end surface of a portion of the connecting portion is arranged below an upper surface of the main body portion or is flush with the upper surface of the main body portion.

[0012] According to this, since the connecting portion is disposed between at least a pair of adjacent energy storage elements, the gas exhaust valve of each energy storage element is exposed. This makes it possible to suppress the connection portion from being affected by the gas exhausted from the gas exhaust valve. Since the upper end surface of a portion of the connecting portion is disposed below or flush with the upper surface of the main body portion of the energy storage element, it is possible to secure space directly above that portion. This makes it possible to increase the space efficiency within the energy storage device. As a result, it is possible to suppress the effect of gas on the connection portion while increasing the space efficiency within the energy storage device.

[0013] The coupling portion may be disposed between each of the adjacent pairs of storage elements.

[0014] According to this, since a connecting portion is disposed between each of the adjacent pairs of energy storage elements, the first holding portion and the second holding portion are connected by the multiple connecting portions. This can increase the rigidity of the busbar holding member. Since the upper end surface of a portion of each connecting portion is located below or flush with the upper surface of the main body of the energy storage element, it is possible to secure space directly above the portion of each connecting portion. Therefore, it is possible to further increase the space efficiency within the energy storage device.

[0015] The power storage device may include an exhaust member that is disposed on the connecting portion of the bus bar holding member and that forms an exhaust path for the gas exhausted from the gas exhaust valve.

[0016] According to this, since the exhaust member is disposed on the connecting portion, the exhaust member can protect the connecting portion from the gas, and therefore the influence of the gas on the connecting portion can be further suppressed.

[0017] Since the exhaust member is placed on the connecting part with the space secured directly above, the exhaust member, i.e. the exhaust path, can be made as large as possible. This allows smooth exhaust of gas. This makes it possible to prevent the inside of the exhaust member from becoming too hot.

[0018] The connecting portion may have a recess that forms part of an upper end surface of the connecting portion, and the exhaust member may be disposed within the recess.

[0019] According to this, the connecting portion is provided with a recess having an upper end surface that is lower than or flush with the upper surface of the energy storage element, and the exhaust member is disposed in this recess, so that a part of the exhaust member can be disposed close to the upper surface of the energy storage element. This allows the exhaust member, i.e., the exhaust path, to be formed larger, enabling smooth exhaust of gas. Therefore, the temperature rise inside the exhaust member can be further suppressed.

[0020] Since a portion of the exhaust member is disposed within the recess of the connecting portion, the exhaust member can be positioned by the recess.

[0021] The energy storage device includes a plurality of detection lines for detecting the respective states of a plurality of energy storage elements, the plurality of detection lines including a first detection line and a second detection line, the first holding portion including a first detection line path which is a path of at least one first detection line among the plurality of detection lines, and the second holding portion including a second detection line path which is a path of at least one second detection line other than the first detection line among the plurality of detection lines, and the first detection line and the second detection line may avoid a space between the first holding portion and the second holding portion.

[0022] According to this, the first detection line, when disposed in the first detection line path, avoids the gap between the first retaining portion and the second retaining portion. Meanwhile, the second detection line, when disposed in the second detection line path, avoids the gap between the first retaining portion and the second retaining portion. In this way, since the first detection line and the second detection line avoid the gap between the first retaining portion and the second retaining portion, it is possible to secure more space between the first retaining portion and the second retaining portion, i.e., the space directly above the connecting portion.

[0023] Since the first detection line and the second detection line are arranged between the first holding portion and the second holding portion, i.e., away from the gas exhaust valve, the first detection line and the second detection line are less likely to be exposed to gas exhausted from the gas exhaust valve.

[0024] Hereinafter, a description will be given of an energy storage device according to an embodiment (including modified examples) of the present invention with reference to the drawings. The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement positions and connection forms of the components shown in the following embodiments are merely examples and are not intended to limit the present invention. In each drawing, the dimensions are not strictly shown.

[0025] In the following description and drawings, the X-axis direction is defined as the arrangement direction of a pair of electrode terminals (positive and negative) in one energy storage element, the opposing direction of the short side surfaces of the container of the energy storage element, or the opposing direction of the long side surfaces of the exterior body of the energy storage unit. The Y-axis direction is defined as the arrangement direction of a plurality of energy storage elements, the opposing direction of the long side surfaces of the container of the energy storage element, the opposing direction of the short side surfaces of the exterior body of the energy storage unit, and the arrangement direction of the energy storage unit and the substrate unit. The Z-axis direction is defined as the arrangement direction of the exterior body support body and the exterior body cover of the energy storage unit, the arrangement direction of the energy storage element and the bus bar, the arrangement direction of the container body and the cover of the energy storage element, or the up-down direction. The X-axis direction, the Y-axis direction, and the Z-axis direction intersect with each other (orthogonal in this embodiment). Depending on the mode of use, the Z-axis direction may not be the up-down direction, but for convenience of explanation, the following description will be given assuming that the Z-axis direction is the up-down direction.

[0026] In the following description, the positive X-axis direction refers to the direction of the X-axis arrow, and the negative X-axis direction refers to the opposite direction to the positive X-axis direction. The same applies to the Y-axis direction and the Z-axis direction. Hereinafter, the Y-axis direction may also be called the first direction, the X-axis direction may also be called the second direction, and the Z-axis direction may also be called the third direction. Expressions indicating relative directions or attitudes, such as parallel and perpendicular, may also include cases where the directions or attitudes are not strictly those. Two directions being perpendicular to each other not only means that the two directions are completely perpendicular to each other, but also means that the two directions are substantially perpendicular to each other, that is, includes a difference of about a few percent.

[0027] (Embodiment) [1 Explanation of the configuration of the energy storage device] First, the configuration of an energy storage device 1 according to the present embodiment will be described. Fig. 1 is a perspective view showing the appearance of an energy storage device 1 according to the embodiment. Fig. 2 is an exploded perspective view showing each component when an energy storage unit 10 according to the embodiment is disassembled.

[0028] The power storage device 1 is a device that can be charged with electricity from the outside and discharge electricity to the outside, and in this embodiment, has a substantially rectangular parallelepiped shape. The power storage device 1 is used for power storage or power source applications. Specifically, the power storage device 1 is used as a stationary battery for home use or power generation. The power storage device 1 can be used as a battery for driving or starting an engine of a moving body such as an automobile, a motorcycle, a watercraft, a ship, a snowmobile, an agricultural machine, a construction machine, or a railway vehicle for an electric railway. Examples of the automobile include an electric vehicle (EV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), and a gasoline vehicle. Examples of the railway vehicle for the electric railway include a train, a monorail, and a linear motor car.

[0029] As shown in these figures, the energy storage device 1 includes an energy storage unit 10 and a board unit 20 attached to the energy storage unit 10. The energy storage unit 10 is a battery module (battery assembly) having a generally rectangular parallelepiped shape that is elongated in the Y-axis direction. Specifically, the energy storage unit 10 includes a plurality of energy storage elements 11, a bus bar frame 12, an exhaust section 50, a plurality of bus bars 13, and an exterior body 18 that contains these and is made up of an exterior body main body 14, an exterior body support 15, and an exterior body lid 17. A cable 30 is connected to the energy storage unit 10. The energy storage unit 10 may include restraining members (end plates, side plates, etc.) that restrain the plurality of energy storage elements 11.

[0030] The energy storage element 11 is a secondary battery (single cell) capable of charging and discharging electricity, and more specifically, a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. The energy storage element 11 has a flat rectangular parallelepiped shape (square shape), and in this embodiment, 16 energy storage elements 11 are arranged in the Y-axis direction. The shape, arrangement position, number, etc. of the energy storage elements 11 are not particularly limited. The energy storage element 11 is not limited to a non-aqueous electrolyte secondary battery, and may be a secondary battery other than a non-aqueous electrolyte secondary battery, or may be a capacitor. The energy storage element 11 may not be a secondary battery, but may be a primary battery that can use stored electricity without the user having to charge it. The energy storage element 11 may be a battery using a solid electrolyte. The energy storage element 11 may be a laminate type energy storage element.

[0031] Specifically, the energy storage element 11 includes a metallic container 11a forming a main body, and a lid of the container 11a is provided with a positive electrode terminal 11b and a negative electrode terminal 11c, which are metallic electrode terminals. That is, the positive electrode terminal 11b and the negative electrode terminal 11c are provided on the upper surface of the main body. A gas exhaust valve 111 (see FIG. 4) that exhausts gas and releases pressure when the pressure inside the container 11a rises is provided between the positive electrode terminal 11b and the negative electrode terminal 11c on the lid of the container 11a. The multiple energy storage elements 11 are arranged in such a manner that the respective gas exhaust valves 111 face the same direction (the positive direction of the Z axis). A flat spacer 11d having thermal insulation properties is disposed between adjacent energy storage elements 11. A liquid injection part for injecting an electrolyte may be provided on the lid of the container 11a. Inside the container 11a, an electrode body (also called an electricity storage element or a power generation element), current collectors (positive electrode current collector and negative electrode current collector), etc. are arranged, and an electrolyte solution (non-aqueous electrolyte) etc. is sealed inside, but detailed description thereof will be omitted.

[0032] The positive electrode terminal 11b and the negative electrode terminal 11c protrude upward (in the positive direction of the Z axis) from the lid of the container 11a. The outermost positive electrode terminals 11b and the negative electrode terminals 11c of the multiple energy storage elements 11 are connected to the cable 30, so that the energy storage device 1 can be charged with electricity from the outside and discharged to the outside.

[0033] The cable 30 is an electric wire (also referred to as a power cable, electric power cable, power line, or power line) through which a current (also referred to as a charge / discharge current or main current) for charging and discharging the energy storage device 1 (energy storage elements 11) flows, and has a positive power cable 31 at the positive electrode and a negative power cable 32 at the negative electrode. That is, the positive power cable 31 of the cable 30 is connected to the positive terminal 11b of the energy storage element 11 at the end in the positive direction of the Y axis among the multiple energy storage elements 11, and the negative power cable 32 of the cable 30 is connected to the negative terminal 11c of the energy storage element 11 at the end in the negative direction of the Y axis.

[0034] The busbar frame 12 is a flat rectangular member capable of electrically insulating the busbars 13 from other members and regulating the position of the busbars 13. The busbar frame 12 is formed of an insulating material similar to that of the board accommodating portion 100 of the board unit 20 described later, such as polycarbonate (PC), polypropylene (PP), or polyethylene (PE). Specifically, the busbar frame 12 is placed above the multiple energy storage elements 11 and positioned relative to the multiple energy storage elements 11. The multiple busbars 13 are placed and positioned on the busbar frame 12. As a result, each busbar 13 is positioned relative to the multiple energy storage elements 11 and joined to the positive electrode terminals 11b and negative electrode terminals 11c of the multiple energy storage elements 11. The busbar frame 12 also has a function of reinforcing the exterior body main body 14 as an inner lid of the exterior body 18. The busbar frame 12 will be described in detail later.

[0035] Exhaust section 50 is disposed on bus bar frame 12, and constitutes an exhaust path 59 (see FIG. 6) for gas exhausted from gas exhaust valves 111 of each energy storage element 11. One end of exhaust section 50 in the positive Y-axis direction is exhaust port section 51 through which gas is exhausted, and protrudes from one end of exterior body 18 in the positive Y-axis direction. Details of exhaust section 50 will be described later.

[0036] Each bus bar 13 is disposed on the plurality of energy storage elements 11 (on the bus bar frame 12) and is a rectangular plate-like member that electrically connects electrode terminals of the plurality of energy storage elements 11 to each other. The bus bar 13 is formed of a metal such as aluminum, an aluminum alloy, copper, a copper alloy, or stainless steel. In this embodiment, the bus bar 13 connects the positive electrode terminal 11b and the negative electrode terminal 11c of adjacent energy storage elements 11 to connect 16 energy storage elements 11 in series. The plurality of bus bars 13 are divided into a first bus bar group 131 arranged along the Y axis direction in the positive direction of the X axis (one side), and a second bus bar group 132 arranged along the Y axis direction in the negative direction of the X axis (the other side). The manner of connection of the energy storage elements 11 is not limited to the above, and any combination of series connection and parallel connection may be used.

[0037] A detection line 13a is connected to the bus bar 13 or the electrode terminal of the energy storage element 11. The detection line 13a is a cable for detecting the state of each energy storage element 11. The detection line 13a is an electric wire (also called a communication cable, control cable, communication line, or control line) for measuring the voltage or temperature of the energy storage element 11 or for voltage balancing between the energy storage elements 11. A thermistor (not shown) for measuring the temperature of the energy storage element 11 is disposed on the bus bar 13 or the electrode terminal of the energy storage element 11, but a description thereof will be omitted. A connector 13b is connected to an end of the detection line 13a in the negative Y-axis direction. The connector 13b is a connector connected to a board 200 of the board unit 20 described later. That is, the detection line 13a transmits information such as the voltage and temperature of the energy storage element 11 to the board 200 of the board unit 20 via the connector 13b. The detection line 13a also has the function of discharging the storage element 11 with a higher voltage under the control of the substrate 200, thereby balancing the voltages between the storage elements 11.

[0038] The exterior body 18 is a rectangular (box-shaped) container (module case) that constitutes the exterior body of the energy storage unit 10. In other words, the exterior body 18 is disposed outside the energy storage elements 11, etc., and fixes the energy storage elements 11, etc. at predetermined positions to protect them from impacts and the like. The exterior body 18 has an exterior body main body 14 that constitutes the main body of the exterior body 18, an exterior body support 15 that supports the exterior body main body 14, and an exterior body lid 17 that constitutes the lid (outer lid) of the exterior body 18.

[0039] The exterior body 14 is a rectangular cylindrical housing with a bottom and an opening formed therein. The exterior body 14 is made of an insulating material such as PC, PP, or PE, similar to the board accommodating portion 100 of the board unit 20 described later.

[0040] The exterior body support 15 and the exterior body lid 17 are members that protect (reinforce) the exterior body main body 14. The exterior body support 15 and the exterior body lid 17 are formed of metal members such as stainless steel, aluminum, aluminum alloy, iron, plated steel plate, etc. The exterior body support 15 and the exterior body lid 17 may be formed of members made of the same material or different materials.

[0041] The exterior body support 15 is a member that supports the exterior body main body 14 from below (Z-axis negative direction), and has a bottom 15a, a board unit attachment part 16, and connection parts 15b and 15c. The bottom 15a is a flat, rectangular part that constitutes the bottom of the energy storage device 1 and is parallel to the XY plane and extends in the Y-axis direction, and is disposed below the exterior body main body 14. The board unit attachment part 16 is a flat, rectangular part that stands in the Z-axis positive direction from the end of the bottom 15a in the Y-axis negative direction, and the board unit 20 is attached to it. The connection part 15b is a part that is disposed at the end of the board unit attachment part 16 in the Z-axis positive direction, protrudes in the Y-axis negative direction, and is connected to the exterior body cover 17. The connection part 15c is a part that stands in the Z-axis positive direction from the end of the bottom 15a in the Y-axis positive direction, protrudes in the Y-axis positive direction, and is connected to the exterior body cover 17.

[0042] The exterior body cover 17 is a member disposed so as to cover the opening of the exterior body main body 14, and has a top surface portion 17a and connection portions 17b and 17c. The top surface portion 17a is a flat, rectangular portion that is parallel to the XY plane and extends in the Y-axis direction, constituting the upper surface portion of the power storage device 1, and is disposed above the exterior body main body 14. The connection portion 17b is disposed at the end of the top surface portion 17a in the negative Y-axis direction, protrudes in the negative Y-axis direction, and is connected to the connection portion 15b of the exterior body support body 15. The connection portion 17c is a portion that extends in the negative Z-axis direction from the end of the top surface portion 17a in the positive Y-axis direction, protrudes in the positive Y-axis direction, and is connected to the connection portion 15c of the exterior body support body 15. In this way, the exterior body support 15 and the exterior body cover 17 are configured to sandwich the exterior body main body 14 from above and below, and are fixed by connecting the connection portions 15b and 15c to the connection portions 17b and 17c with screws or the like.

[0043] The board unit 20 is a device capable of monitoring the state of the energy storage element 11 included in the energy storage unit 10 and controlling the energy storage element 11. In the present embodiment, the board unit 20 is a flat rectangular member attached to an end of the energy storage unit 10 in the longitudinal direction, i.e., to a side surface of the energy storage unit 10 in the negative Y-axis direction. Specifically, the board unit 20 is rotatably attached to a board unit attachment portion 16 provided on an exterior body support 15 included in an exterior body 18 of the energy storage unit 10.

[0044] [2. Exhaust section and busbar frame configuration] FIG. 3 is an exploded perspective view showing a schematic configuration of the exhaust unit 50 and the bus bar frame 12 according to the embodiment.

[0045] 3, the exhaust section 50 has an exhaust member 60 and a cover member 65. The exhaust member 60 is disposed directly above the gas exhaust valves 111 of the energy storage elements 11. The exhaust member 60 is formed in a U-shape with an open upper portion when viewed in the Y-axis direction, and is a resin member that is elongated in the Y-axis direction. A plurality of holes 61 are formed in the bottom of the exhaust member 60 to expose the gas exhaust valves 111 of the energy storage elements 11.

[0046] The exhaust member 60 may be formed from a resin having higher heat resistance than the bus bar frame 12. If the bus bar frame 12 is formed from PP, the exhaust member 60 may be formed from polyphenylene sulfide (PPS), which has higher heat resistance than PP. When the bus bar frame and the exhaust member are integrally molded from a single resin, the entirety of the exhaust member 60 needs to be molded from a resin having high heat resistance. However, in this embodiment, only the exhaust member 60, which is separate from the bus bar frame 12, needs to be formed from a resin having high heat resistance, so that the amount of resin used can be reduced.

[0047] The cover member 65 is disposed above the exhaust member 60 and closes the open portion of the exhaust member 60. Specifically, the cover member 65 is formed in a U-shape with an open lower side when viewed in the Y-axis direction, and is a member that is long in the Y-axis direction. The cover member 65 is made of metal and has higher heat dissipation properties than the exhaust member 60. One end of the cover member 65 in the Y-axis positive direction is open at the lower side and at the tip end while protruding from the exhaust member 60. Meanwhile, the other end of the cover member 65 is closed, preventing the discharge of gas. The cover member 65, when housed in the exhaust member 60, constitutes a gas exhaust path 59 together with the exhaust member 60. Gas is discharged from the open portion at one end of the cover member 65 described above. That is, one end of the cover member 65 is the exhaust port portion 51 through which gas is discharged. The exhaust port portion 51 protrudes outward from the end of the busbar frame 12 in the Y-axis positive direction. Therefore, the gas discharged from the gas discharge valve 111 of each energy storage element 11 enters the exhaust path 59 formed by the exhaust member 60 and the cover member 65 through the hole 61 of the exhaust member 60. The gas then passes through the exhaust path 59 and is discharged to the outside of the energy storage unit 10 through the exhaust port 51 located outside the bus bar frame 12.

[0048] Next, the bus bar frame 12 will be described in detail. Fig. 4 is a top view showing a schematic configuration of the bus bar frame 12 according to the embodiment. Fig. 4 also shows the energy storage elements 11, the bus bars 13, the positive power cable 31, the negative power cable 32, and a plurality of detection lines 13a.

[0049] 3 and 4, the busbar frame 12 is an example of a busbar holding member that is disposed on the multiple energy storage elements 11 and holds the multiple busbars 13. Specifically, the busbar frame 12 has a first holding portion 71, a second holding portion 72, and a connecting portion 73. Of the multiple detection wires 13a, the multiple detection wires 13a held by the first holding portion 71 are referred to as first detection wires 13a1. Of the multiple detection wires 13a, the multiple detection wires 13a held by the second holding portion 72 are referred to as second detection wires 13a2.

[0050] The first holding portion 71 is a portion of the busbar frame 12 in the positive direction along the X-axis (one side), and holds the first busbar group 131 and the positive power cable 31. The first holding portion 71 also holds the electrode terminals (positive electrode terminals 11b or negative electrode terminals 11c) in the positive direction along the X-axis of each energy storage element 11, or a plurality of first detection wires 13a1 connected to the busbars 13 included in the first busbar group 131.

[0051] The first holding portion 71 is disposed in the positive direction of the X-axis relative to the gas exhaust valves 111 of each energy storage element 11. The first holding portion 71 has a first outer wall portion 711 that surrounds the outer periphery of the first holding portion 71, and a first surrounding wall 712 that surrounds each bus bar 13 together with the first outer wall portion 711.

[0052] A pair of first notches 711a and 711b are formed at the end in the negative Y-axis direction of the first outer wall portion 711. The positive power cable 31 and the multiple first detection lines 13a1 are arranged to pass through the first notch 711a of the pair of first notches 711a and 711b. The negative power cable 32 is arranged to pass through the other first notch 711b.

[0053] The first surrounding wall 712 is disposed in the positive direction of the X-axis within the first outer wall portion 711, and is provided long in the Y-axis direction. The end portion of the first surrounding wall 712 in the positive direction of the Y-axis is disposed between the energy storage element 11 at the end portion in the positive direction of the Y-axis and the adjacent energy storage element 11. The end portion of the first surrounding wall 712 in the negative direction of the Y-axis extends to the vicinity of the first notch 711a of the first outer wall portion 711.

[0054] Within first surrounding wall 712, there are provided a plurality of first partition walls 713 arranged between each bus bar 13, and a plurality of first partition portions 714 arranged between each energy storage element 11. First partition wall 713 has a flat plate shape parallel to the XZ plane, and its upper end surface is flush with the upper end surface of first outer wall portion 711. First partition portion 714 is a portion that is elongated in the X-axis direction, and is lower in height than first partition wall 713. Each bus bar 13 is arranged to straddle a corresponding first partition portion 714.

[0055] Within the first outer wall portion 711, a region on the negative side of the X-axis from the first surrounding wall 712 is a first cable path portion 715 that penetrates along the Y-axis direction. The first cable path portion 715 is disposed between the gas exhaust valves 111 of each energy storage element 11 and each bus bar 13 included in the first bus bar group 131. In this manner, the first cable path portion 715 is disposed inward in the X-axis direction from the first bus bar group 131 within the bus bar frame 12.

[0056] The positive power cable 31 and the multiple first detection wires 13a1 are arranged in the first cable path portion 715. The first cable path portion 715 forms a path for the positive power cable 31 and the multiple first detection wires 13a1. In other words, the first cable path portion 715 can also be called a first detection wire path, which is a path for the multiple first detection wires 13a1. The multiple first detection wires 13a1 and the positive power cable 31 are arranged in the first cable path portion 715, thereby avoiding the area between the first holding portion 71 and the second holding portion 72, i.e., above the connecting portion 73.

[0057] In the first cable path section 715, the positive power cable 31 and the multiple first detection wires 13a1 are each disposed in a position generally along the Y-axis direction. The first cable path section 715 has a guide section 80 that guides one end of the positive power cable 31. The first cable path section 715 has multiple detection wire holding sections 90 that hold the first detection wires 13a1. The guide section 80 and the detection wire holding sections 90 will be described in detail later.

[0058] The second holding portion 72 is a portion in the negative X-axis direction (the other side) of the busbar frame 12. The second holding portion 72 holds the second busbar group 132 and the electrode terminals (positive electrode terminals 11b or negative electrode terminals 11c) in the negative X-axis direction of each energy storage element 11, or a plurality of second detection wires 13a2 connected to the busbars 13 included in the second busbar group 132.

[0059] The second holding portion 72 is disposed in the negative X-axis direction relative to the gas exhaust valves 111 of each energy storage element 11. The second holding portion 72 has a second outer wall portion 721 that surrounds the outer periphery of the second holding portion 72, and a second surrounding wall 722 that, together with the second outer wall portion 721, surrounds each bus bar 13.

[0060] A second cutout 721a is formed at an end portion in the negative Y-axis direction of the second outer wall portion 721. A plurality of second detection lines 13a2 are arranged to pass through the second cutout 721a.

[0061] The second surrounding wall 722 is disposed in the negative X-axis direction within the second outer wall portion 721, and is provided long in the Y-axis direction. The end of the second surrounding wall 722 in the positive Y-axis direction is continuous with the end of the second outer wall portion 721 in the positive Y-axis direction. The end of the second surrounding wall 722 in the negative Y-axis direction extends to the vicinity of the second notch 721a of the second outer wall portion 721.

[0062] In the region of second surrounding wall 722 in the negative direction of the X-axis, a plurality of second partition walls 723 arranged between bus bars 13 and a plurality of second partition portions 724 arranged between energy storage elements 11 are provided. Second partition wall 723 has a flat plate shape parallel to the XZ plane, and its upper end surface is flush with the upper end surface of second outer wall portion 721. Second partition portion 724 is a portion that is elongated in the X-axis direction and is lower in height than second partition wall 723. Each bus bar 13 is arranged to straddle a corresponding second partition portion 724.

[0063] Within second outer wall portion 721, a region on the positive side of the X-axis from second surrounding wall 722 is a second cable path portion 725 that penetrates along the Y-axis direction. Second cable path portion 725 is disposed between gas exhaust valve 111 of each energy storage element 11 and each bus bar 13 included in second bus bar group 132. In this manner, second cable path portion 725 is disposed inward in the X-axis direction from second bus bar group 132 within bus bar frame 12.

[0064] A plurality of second detection lines 13a2 are arranged in the second cable path portion 725. The second cable path portion 725 can be said to be a second detection line path that is a path of the plurality of second detection lines 13a2. The plurality of second detection lines 13a2 are arranged in the second cable path portion 725, thereby avoiding a space between the first holding portion 71 and the second holding portion 72, i.e., above the connecting portion 73.

[0065] In the second cable path section 725, each of the multiple second detection lines 13a2 is disposed in a posture generally along the Y-axis direction. In the second cable path section 725, multiple detection line locking portions 99 that lock the second detection lines 13a2 are provided. The multiple detection line locking portions 99 are arranged along the Y-axis direction. The detection line locking portions 99 are long protrusions in the X-axis direction, and a space through which the second detection lines 13a2 pass in the Y-axis direction is formed below the detection line locking portions 99. The second detection lines 13a2 pass through the space, so that the detection line locking portions 99 suppress the second detection lines 13a2 from floating. The multiple detection line locking portions 99 all have the same shape, but the number of second detection lines 13a2 that they lock is different. Specifically, as shown in FIG. 4, the detection line locking portion 99 farthest from the second notch 721a, that is, the detection line locking portion 99 arranged furthest in the Y-axis positive direction, holds one second detection line 13a2. Further toward the negative Y-axis direction, the number of second detection lines 13a2 locked by each detection line locking portion 99 can be increased by one. In a location where the number of second detection lines 13a2 is large, one detection line locking portion 99 may or may not hold all of the second detection lines 13a2.

[0066] As shown in FIG. 3 and FIG. 4, the connecting portion 73 is a portion that connects the first holding portion 71 and the second holding portion 72. Specifically, the connecting portion 73 has a plurality of connecting portions 731 that are long in the X-axis direction and have one end connected to the first holding portion 71 and the other end connected to the second holding portion 72. The plurality of connecting portions 731 are arranged at predetermined intervals in the Y-axis direction. Among the plurality of connecting portions 731, the connecting portion 731 at the end in the negative Y-axis direction is arranged outside the energy storage element 11 at the end in the negative Y-axis direction. The connecting portion 731 at the end in the positive Y-axis direction is arranged outside the energy storage element 11 at the end in the positive Y-axis direction. The other connecting portions 731 are arranged between a pair of adjacent energy storage elements 11. In this manner, the plurality of connecting portions 731 are arranged at positions retreated from the gas exhaust valves 111 of the energy storage elements 11. In other words, gas release valve 111 of each energy storage element 11 is exposed from a plurality of connecting portions 731 when viewed from above.

[0067] [3 Connecting part] Fig. 5 is an explanatory diagram showing the positional relationship between the coupling portion 731 according to the embodiment and the energy storage element 11. Specifically, Fig. 5 is a cross-sectional view including the line VV in Fig. 4. In Fig. 5, the energy storage element 11 is shown in a plan view, and the coupling portion 731 is shown in a cross-sectional view. Fig. 6 is a cross-sectional view showing the positional relationship between the coupling portion 731 according to the embodiment and the exhaust unit 50. Specifically, Fig. 6 is a cross-sectional view taken along the XZ plane at the position of the coupling portion 731.

[0068] As shown in Fig. 5 and Fig. 6, a recess 732 is formed in the center of the upper surface of the connecting portion 731 in the X-axis direction. A bottom surface 733 of the recess 732 constitutes a partial upper end surface of the connecting portion 731, and is formed in a planar shape parallel to the XY plane. The bottom surface 733 of the recess 732 is disposed below the upper surface 11e of the container 11a (main body) of the energy storage element 11 (see Fig. 5). It is sufficient that the partial upper end surface of the connecting portion 731 is disposed below the upper end (the portion located most positive in the Z-axis direction) of the container 11a of the energy storage element 11. The partial upper end surface of the connecting portion 731 may be disposed flush with the upper surface of the container 11a.

[0069] As shown in FIG. 6, the lower end of the exhaust member 60 is disposed in the recess 732. More specifically, a convex portion 62 that protrudes downward is formed in a portion of the lower surface of the exhaust member 60 that corresponds to the connecting portion 731. The convex portion 62 is accommodated in the recess 732 of the connecting portion 731. The convex portion 62 is disposed in the recess 732, so that the exhaust member 60 is positioned relative to the bus bar frame 12. The strength of the exhaust member 60 is increased by thickening the portion where the convex portion 62 is present. It is also possible to thicken the exhaust member 60 by bulging the inner bottom surface of the exhaust member 60, but in this case, the exhaust path 59 may be narrowed, which may hinder smooth exhaust (see the two-dot chain line L5 in FIG. 6). In this embodiment, the convex portion 62 is provided on the lower surface of the exhaust member 60, so that the exhaust path 59 is prevented from being narrowed while a portion of the exhaust member 60 is thickened. In particular, in this embodiment, since the recess 732 is provided in the connecting portion 731, the protrusion 62 can be made to protrude further into the recess 732, thereby making it possible to increase the thickness.

[0070] In this manner, bottom surface 733 (upper end surface) of recess 732, which is part of connecting portion 731, is disposed below upper surface 11e of container 11a of energy storage element 11, so that space directly above that portion can be secured and part of exhaust member 60 can be made thicker. In other words, the space efficiency within energy storage device 1 is improved. When prioritizing improvement of the strength of exhaust member 60, the inner bottom surface of exhaust member 60 may be bulged.

[0071] [4 Guide section] Next, a detailed description will be given of the guide section 80. Fig. 7 is a top view showing a schematic configuration of the guide section 80 according to the embodiment.

[0072] As shown in Fig. 7, the guide portion 80 is a portion that guides one end of the positive power cable 31 in a position inclined with respect to the Y-axis direction within the first cable path portion 715. A general-purpose round terminal 311 is attached to one end of the positive power cable 31. This round terminal 311 is screwed with a nut 312 together with the connection terminal 19 of the detection wire 13a to the positive terminal 11b of the energy storage element 11 at the end in the positive direction of the Y-axis among the multiple energy storage elements 11. The guide portion 80 supports one end of the positive power cable 31 from the side, thereby guiding the one end in a position inclined with respect to the Y-axis direction.

[0073] Assume that one end of the positive power cable 31 is disposed in a position perpendicular to the Y-axis direction, that is, that one end of the positive power cable 31 is disposed in a position along the X-axis direction. The positive power cable 31 is thicker and less likely to bend than the detection wire 13a, so if the one end is disposed in a position perpendicular to the Y-axis direction via the round terminal 311, it may protrude to the connecting part 73 side as shown by the dashed line L2 in FIG. 7. To allow this, the first holding part 71 must be made larger in the negative X-axis direction, but in that case, the exhaust part 50 must be made smaller. In other words, the exhaust path 59 may be narrowed, which may reduce the exhaust performance.

[0074] In the present embodiment, the guide portion 80 guides one end of the positive power cable 31 in a position inclined with respect to the Y-axis direction, so that it is not necessary to sharply bend the positive power cable 31. This makes it possible to accommodate the positive power cable 31 in the first cable path portion 715 without making the first holding portion 71 larger.

[0075] Specifically, the guide portion 80 is provided at the end of the first surrounding wall 712 in the positive direction of the Y axis. The end of the first surrounding wall 712 in the positive direction of the Y axis has a flat first wall 718 parallel to the XZ plane and a flat second wall 719 parallel to the YZ plane. The guide portion 80 is disposed between the first wall 718 and the second wall 719, and is a portion that connects the first wall 718 and the second wall 719. The guide portion 80 can also be said to be a corner portion provided at the end of the first surrounding wall 712 in the positive direction of the Y axis. The guide portion 80 is disposed between the energy storage element 11 disposed at the end of the first surrounding wall 712 in the positive direction of the Y axis among the multiple energy storage elements 11 and the bus bar 13 disposed at the end of the first bus bar group 131 in the positive direction of the Y axis, and functions as a barrier. In the unlikely event that one end of the positive power cable 31 becomes detached from the storage element 11, or during connection or removal work, the guide portion 80 can prevent the one end of the positive power cable 31 from touching the bus bar 13.

[0076] The guide portion 80 is a flat wall, and its planar outer surface 81 supports one end of the positive power cable 31 from the side. This allows one end of the positive power cable 31 to be supported in a straight line. The acute angle α formed by the outer surface 81 of the guide portion 80 and the Y-axis direction is less than 45 degrees. In other words, the one end of the positive power cable 31 guided by the guide portion 80 is also disposed at approximately the same angle with respect to the Y-axis direction. This allows the moment acting on the connection portion between the one end of the positive power cable 31 and the energy storage element 11 when the other end of the positive power cable 31 is pulled in the negative Y-axis direction to be reduced.

[0077] The first cable path section 715 is provided with a locking piece 717 for locking the positive power cable 31 at a location on the negative Y-axis side of the guide section 80. Specifically, the locking piece 717 is disposed on an extension line (dashed line L3) of the guide section 80. The locking piece 717 locks the boundary portion between a portion of the positive power cable 31 along the Y-axis direction and an inclined portion. When the other end of the positive power cable 31 is pulled in the negative Y-axis direction, the locking piece 717 receives part of the tension. This makes it possible to further reduce the moment acting on the connection portion between one end of the positive power cable 31 and the energy storage element 11.

[0078] [5 Detection line holding section] 4, one of the multiple detection line holding units 90 is disposed near the storage element 11 disposed at the end in the negative Y-axis direction. The remaining detection line holding units 90 are disposed near the storage element 11 in the negative Y-axis direction of a pair of storage elements 11 connected to one bus bar 13 in the first bus bar group 131. Since the detection line holding units 90 have substantially the same configuration, one detection line holding unit 90 will be described here as an example.

[0079] Fig. 8 is a perspective view showing a schematic configuration of a detection line holding section 90 according to an embodiment. Fig. 9 is a cross-sectional view showing a schematic configuration of a detection line holding section 90 according to an embodiment.

[0080] As shown in FIGS. 8 and 9, the detection line holding unit 90 holds a first detection line 13a1 connected to an energy storage element 11 in the vicinity of the detection line holding unit 90. As shown in FIG.

[0081] First, the connection terminal 19 of the first detection line 13a1 will be described. The connection terminal 19 is connected to the tip of the first detection line 13a1. The connection terminal 19 is made of sheet metal, and is formed in a stepped shape so that a base portion 191 is located higher than a tip portion 192. The base portion 191 is provided with a fixing claw 193 for fixing the tip of the first detection line 13a1. The fixing claw 193 and the base portion 191 sandwich the first detection line 13a1, thereby fixing the first detection line 13a1. The tip portion 192 of the connection terminal 19 has a hanging portion 194 that hangs down continuously from the tip of the base portion 191, and an attachment portion 195 that continues from the tip of the hanging portion 194 and extends parallel to the base portion 191. The attachment portion 195 is formed in a circular ring shape in a plan view (when viewed in the Z-axis direction), and an electrode terminal (positive electrode terminal 11b) of the energy storage element 11 is inserted into an opening of the attachment portion 195. A nut 115 is screwed to the positive electrode terminal 11b with the bus bar 13 and the mounting portion 195 passing through it. This fixes the bus bar 13 and the mounting portion 195 to the positive electrode terminal 11b. The connection terminal of the second detection line 13a2 is the same as the connection terminal 19 of the first detection line 13a1.

[0082] Next, a detailed description will be given of the detection line holding unit 90. The detection line holding unit 90 holds the first detection line 13a1 and its connection terminal 19, which are connected to the energy storage element 11 in the vicinity of the detection line holding unit 90. In the following description, of the multiple first detection lines 13a1, the first detection line 13a1 connected to the energy storage element 11 in the vicinity of the detection line holding unit 90 will be referred to as a connection target line 13b1, and the other first detection lines 13a1 different from the connection target line 13b1 will be referred to as non-target lines 13c1.

[0083] Specifically, the detection line holding portion 90 is disposed above (in the positive direction of the Z axis) the inner bottom surface of the first cable path portion 715. The detection line holding portion 90 has a first wall portion 91, a second wall portion 92, a third wall portion 93, and a spring portion 94.

[0084] The first wall portion 91 is a portion that supports the base portion 191 of the connection terminal 19 from below. The first wall portion 91 is a flat portion that is disposed above the inner bottom surface of the first cable path portion 715 and parallel to the inner bottom surface. An opening 715a is formed in the inner bottom surface of the first cable path portion 715 at a portion that faces the first wall portion 91. Since the inner bottom surface of the first cable path portion 715 and the first wall portion 91 are spaced apart in the up-down direction, the multiple asymmetric lines 13c1 are disposed in a space formed by the inner bottom surface and the first wall portion 91. At this time, the multiple asymmetric lines 13c1 are bridged over the opening 715a. On the other hand, the connection terminal 19 of the connection target line 13b1 is held above the multiple asymmetric lines 13c1 by being disposed on the first wall portion 91. That is, in a plan view (as viewed in the Z-axis direction), the connection terminal 19 and at least one of the multiple asymmetric lines 13c1 are disposed so as to overlap each other. The space formed by the inner bottom surface of the first cable path portion 715 and the first wall portion 91 needs to be large enough to allow at least one asymmetric wire 13c1 to overlap the connection terminal 19 of the connection target wire 13b1 in a plan view.

[0085] A pair of restricting protrusions 911 are provided on the upper surface of first wall portion 91 and are arranged to sandwich base portion 191 of connection terminal 19 in the Y-axis direction. Connection terminal 19 is positioned in the Y-axis direction by sandwiching base portion 191 between the pair of restricting protrusions 911. Downwardly extending portion 194 of connection terminal 19 abuts against the end face of first wall portion 91 facing energy storage element 11 (end face in the positive direction of the X-axis). This positions connection terminal 19 in the X-axis direction.

[0086] The second wall portion 92 is a flat plate-shaped portion provided below the first wall portion 91 and at a position sandwiching the first wall portion 91 in the Y-axis direction. The second wall portion 92 is also a part of the first surrounding wall 712. The second wall portion 92 is disposed at a position corresponding to the end of the first wall portion 91 in the X-axis positive direction. The second wall portion 92 is disposed between the hanging portion 194 of the connection terminal 19 and the asymmetric line 13c1. This allows the second wall portion 92 to function as a barrier, thereby suppressing interference between the asymmetric line 13c1 and the connection terminal 19. During assembly, the asymmetric line 13c1 can be reliably disposed at a position overlapping the connection terminal 19 in a plan view by sliding it along the inner bottom surface of the first cable path portion 715 and abutting against the second wall portion 92.

[0087] The third wall portion 93 is erected on the upper surface of the first wall portion 91 at an end portion in the positive direction of the Y axis and an end portion in the negative direction of the X axis. That is, the third wall portion 93 is disposed between the positive power cable 31 and the connection terminal 19. The third wall portion 93 serves as a barrier, thereby preventing interference between the positive power cable 31 and the connection terminal 19.

[0088] The spring portion 94 is a portion that restricts the connection terminal 19. Specifically, the spring portion 94 has a pair of leaf springs 941. The pair of leaf springs 941 are disposed above the first wall portion 91 and face each other at a predetermined interval in the Y-axis direction. Each of the pair of leaf springs 941 is a rod-shaped body hanging down from the upper end of the detection line holding portion 90. Each of the pair of leaf springs 941 is inclined so as to approach the other leaf spring 941 as it goes downward. That is, the interval in the Y-axis direction between the pair of leaf springs 941 is narrowest at the lower end and widest at the upper end. During assembly, when the base 191 of the connection terminal 19 is disposed between the pair of leaf springs 941 and lowered along the pair of leaf springs 941, the pair of leaf springs 941 elastically deform to allow the connection terminal 19 to lower. When the base 191 of the connection terminal 19 passes the lower ends of the pair of leaf springs 941, the pair of leaf springs 941 return to their original shape. At this time, the lower ends of the pair of leaf springs 941 are positioned directly above the base 191 of the connection terminal 19. In other words, the pair of leaf springs 941 hold the base 191 of the connection terminal 19. As a result, the pair of leaf springs 941 restrict the upward movement of the connection terminal 19, and the connection terminal 19 is positioned in the up-down direction.

[0089] Although the multiple detection line holding parts 90 are all the same shape, the number of asymmetric lines 13c1 arranged in the space formed by the inner bottom surface of the first cable path part 715 and the first wall part 91 is different. Specifically, as shown in FIG. 4, the detection line holding part 90 farthest from the first notch 711a, that is, the detection line holding part 90 arranged furthest in the Y-axis positive direction, does not have asymmetric lines 13c1 arranged in the space. The number of asymmetric lines 13c1 arranged in the space can be increased by one as it moves toward the Y-axis negative direction. In a place where the number of asymmetric lines 13c1 is large, all of the asymmetric lines 13c1 may or may not be arranged in the space of one detection line holding part 90.

[0090] [6 Explanation of Effects] As described above, the energy storage device 1 according to this embodiment includes a plurality of energy storage elements 11, each having a gas release valve 111, and arranged with the gas release valves 111 facing the same direction, a plurality of bus bars 13 electrically connected to the plurality of energy storage elements 11, and a bus bar frame 12 (bus bar holding member) arranged on the plurality of energy storage elements 11 and holding the plurality of bus bars 13. The energy storage elements 11 include a container 11a (main body) having the gas release valve 111 on its upper surface, and a pair of electrode terminals (positive terminal 11b and and a negative terminal 11c), the busbar frame 12 comprises a first retaining portion 71 arranged on one side of the gas exhaust valve 111 on the multiple storage elements 11, a second retaining portion 72 arranged on the other side of the gas exhaust valve 111 on the multiple storage elements 11, and a connecting portion 731 arranged between at least a pair of adjacent storage elements 11 among the multiple storage elements 11 and connecting the first retaining portion 71 and the second retaining portion 72, and a portion of an upper end surface (bottom surface 733) of the connecting portion 731 is arranged below or flush with an upper surface 11e of the container 11a.

[0091] According to this, since the connecting portion 731 is disposed between at least a pair of adjacent energy storage elements 11, the gas exhaust valve 111 of each energy storage element 11 is exposed. This makes it possible to suppress the connection portion 731 from being affected by the gas exhausted from the gas exhaust valve 111. Since the bottom surface 733 of the connection portion 731 is disposed below or flush with the upper surface 11e of the container 11a of the energy storage element 11, it is possible to ensure space directly above that portion. This makes it possible to improve the space efficiency within the energy storage device 1. As a result, it is possible to suppress the effect of gas on the connection portion 731 while improving the space efficiency within the energy storage device 1.

[0092] The coupling portions 731 are disposed between each of the adjacent pairs of energy storage elements 11.

[0093] According to this, since the connecting portions 731 are disposed between each of the adjacent pairs of energy storage elements 11, the first holding portion 71 and the second holding portion 72 are connected by the connecting portions 731. This can increase the rigidity of the bus bar frame 12. Since the bottom surface 733 of each connecting portion 731 is also located below or flush with the upper surface 11e of the container 11a of the energy storage element 11, it is possible to secure space directly above the connecting portion 731. Therefore, the space efficiency within the energy storage device 1 can be further improved.

[0094] The power storage device 1 includes an exhaust member 60 that is disposed on the connecting portion 731 of the bus bar frame 12 and that forms an exhaust path 59 for the gas exhausted from the gas exhaust valve 111.

[0095] According to this, since the exhaust member 60 is disposed on the connecting portion 731, the exhaust member 60 can protect the connecting portion 731 from the gas. Therefore, the effect of the gas on the connecting portion 731 can be further suppressed.

[0096] The connecting portion 731 has a recess 732 forming the upper end surface of the portion, and the exhaust member 60 is disposed within the recess 732.

[0097] According to this, the connecting portion 731 is provided with a recess 732 that forms an upper end surface (bottom surface 733) that is lower than or flush with the upper surface 11e of the container 11a of the energy storage element 11, and the exhaust member 60 is disposed in this recess 732, so that a part of the exhaust member 60 can be disposed close to the upper surface of the container 11a of the energy storage element 11. This allows the exhaust member 60, i.e., the exhaust path 59, to be formed larger, enabling smooth exhaust of gas. Therefore, the inside of the exhaust member 60 can be further prevented from becoming hot.

[0098] Since a portion of the exhaust member 60 is disposed within the recess 732 of the connecting portion 731, the exhaust member 60 can be positioned by the recess 732.

[0099] The energy storage device 1 has a plurality of detection lines 13a for detecting the respective states of the plurality of energy storage elements 11, the first holding portion 71 has a first cable path portion 715 (first detection line path) which is the path of at least one first detection line 13a1 among the plurality of detection lines 13a, and the second holding portion 72 has a second cable path portion 725 (second detection line path) which is the path of a second detection line 13a2 other than the at least one first detection line 13a1 among the plurality of detection lines 13a, and the first detection line 13a1 and the second detection line 13a2 avoid the space between the first holding portion 71 and the second holding portion 72.

[0100] According to this, the first detection line 13a1, when disposed in the first cable path portion 715, avoids being between the first holding portion 71 and the second holding portion 72. On the other hand, the second detection line 13a2, when disposed in the second cable path portion 725, avoids being between the first holding portion 71 and the second holding portion 72. In this way, since the first detection line 13a1 and the second detection line 13a2 avoid being between the first holding portion 71 and the second holding portion 72, the space between the first holding portion 71 and the second holding portion 72, i.e., the space directly above the connecting portion 731, can be more secure.

[0101] Since the first detection line 13a1 and the second detection line 13a2 are arranged between the first holding portion 71 and the second holding portion 72, i.e., away from the gas exhaust valve 111, the first detection line 13a1 and the second detection line 13a2 are less likely to be exposed to the gas exhausted from the gas exhaust valve 111.

[0102] The energy storage device 1 of this embodiment includes a plurality of energy storage elements 11 arranged along the Y-axis direction (a predetermined direction), a plurality of bus bars 13 electrically connected to the plurality of energy storage elements 11, a bus bar frame 12 (bus bar holding member) arranged on the plurality of energy storage elements 11 and holding the plurality of bus bars 13, and a positive power cable 31 (power cable) electrically connected to one of the plurality of energy storage elements 11, the bus bar frame 12 being arranged inwardly of the plurality of bus bars 13 and having a first cable path portion 715 (cable path portion) in which the positive power cable 31 is arranged in a position along the Y-axis direction, and the first cable path portion 715 having a guide portion 80 that guides one end of the positive power cable 31 connected to one of the energy storage elements 11 into a position inclined with respect to the Y-axis direction.

[0103] According to this, by inclining one end of the positive power cable 31 with respect to the arrangement direction (Y-axis direction) of the multiple energy storage elements 11, the amount of bending of the positive power cable 31 can be reduced while ensuring installation space for the connection structure compared to the case where the end is perpendicular. In other words, a general-purpose round terminal 311 can be used. In this manner, the bus bar frame 12 is provided with a guide portion 80 that guides one end of the positive power cable 31 into a position inclined with respect to the Y-axis direction, so that one end of the positive power cable 31 can be stably held while reducing the burden on the positive power cable 31.

[0104] Each of the multiple storage elements 11 has a gas exhaust valve 111, and the gas exhaust valves 111 are arranged in a position facing the same direction, and the first cable path portion 715 is arranged between the multiple bus bars 13 and each of the gas exhaust valves 111 of the multiple storage elements 11.

[0105] According to this, since the first cable path portion 715 is disposed between the multiple bus bars 13 and the gas exhaust valves 111 of the multiple energy storage elements 11, the positive power cable 31 in the first cable path portion 715 is also disposed at a position retracted from the gas exhaust valve 111. This makes it possible to reduce exposure of the positive power cable 31 to the gas exhausted from the gas exhaust valve 111. This makes it possible to reduce the burden on the positive power cable 31 during gas exhaust.

[0106] Since the guide portion 80 is planar, one end of the positive power cable 31 can be guided in a straight line. Therefore, the burden on the positive power cable 31 can be further reduced.

[0107] The acute angle α formed by the guide portion 80 and the Y-axis direction is less than 45 degrees.

[0108] According to this, since the angle α on the acute side formed by the guide portion 80 and the Y-axis direction is less than 45 degrees, one end of the positive power cable 31 guided by the guide portion 80 is also disposed at approximately the same angle with respect to the Y-axis direction. This makes it possible to reduce the moment applied to the connection portion between one end of the positive power cable 31 and the energy storage element 11 when the other end of the positive power cable 31 is pulled. This makes it possible to stabilize the connection between one end of the positive power cable 31 and the energy storage element 11.

[0109] Guide portion 80 is disposed between one of the plurality of bus bars 13 and one energy storage element 11 .

[0110] According to this, the guide portion 80 is arranged between one of the multiple bus bars 13 and one storage element 11, so that even if one end of the positive power cable 31 happens to come off from the storage element 11, the guide portion 80 acts as a barrier to prevent interference with the bus bar 13 or other storage elements 11.

[0111] The energy storage device 1 of this embodiment includes a plurality of storage elements 11 arranged along the Y-axis direction (a predetermined direction), a plurality of bus bars 13 electrically connected to the plurality of storage elements 11, a plurality of detection wires 13a electrically connected to each of the at least two storage elements 11 to detect the state of at least two of the plurality of storage elements 11, and a bus bar frame 12 (bus bar holding member) arranged on the plurality of storage elements 11 and holding the plurality of bus bars 13 and the plurality of detection wires 13a, and the bus bar frame 12 has a detection wire holding portion 90 arranged in the vicinity of one of the at least two storage elements 11 and holding the connection terminal 19 of the connection target wire 13b1 connected to the storage element 11 above the non-target wire 13c1 connected to the other storage element 11.

[0112] According to this, since the detection line holding portion 90 holds the connection terminal 19 of the connection target line 13b1 above the asymmetric line 13c1, the connection terminal 19 and the asymmetric line 13c1 can be arranged to overlap each other when viewed from above. This makes it difficult for the connection terminal 19 and the asymmetric line 13c1 to be arranged to spread out in a plan view, thereby enabling space saving.

[0113] In particular, in the present embodiment, since the first cable path section 715 contains the multiple first detection lines 13a1 and the positive power cable 31, the space constraints are greater than those of the second cable path section 725. However, as described above, if the connection terminal 19 and the asymmetric line 13c1 can be arranged to overlap each other in a top view, the installation space for the positive power cable 31 in the first cable path section 715 can be secured.

[0114] The detection line holding portion 90 holds the connection terminal 19 at a position where the connection terminal 19 overlaps with the astigmatism line 13c1 in a plan view.

[0115] According to this, since the connection terminal 19 is disposed at a position overlapping the asymmetric line 13c1 in a plan view, the connection terminal 19 and the asymmetric line 13c1 can be disposed reliably overlapping each other, thereby making it possible to more reliably achieve space saving.

[0116] The detection line holding portion 90 has a first wall portion 91 interposed between the connection terminal 19 of the held connection target line 13b1 and the non-target line 13c1.

[0117] According to this, since the first wall portion 91 of the detection line holding portion 90 is interposed between the connection terminal 19 held by it and the asymmetric line 13c1, it is possible to prevent the connection terminal 19 from interfering with the asymmetric line 13c1. Therefore, it is possible to prevent the connection terminal 19 from damaging the asymmetric line 13c1, and to prevent the occurrence of a short circuit caused by the damage. This makes it unnecessary to provide a dedicated member for preventing a short circuit, and thus it is possible to further save space.

[0118] The detection line holding portion 90 has a spring portion 94 that regulates the connection terminal 19 .

[0119] According to this, since the detection line holding portion 90 has the spring portion 94 that restricts the connection terminal 19, the spring portion 94 can suppress the positional deviation of the connection terminal 19.

[0120] The detection line holding portion 90 has a first wall portion 91 that restricts the asymmetric line 13c1 passing below the detection line holding portion 90 from above, and a second wall portion 92 that restricts the asymmetric line 13c1 from one side.

[0121] According to this, the first wall portion 91 of the detection line holding portion 90 restricts the upward movement of the as-target line 13c1, and the second wall portion 92 restricts the lateral movement of the as-target line 13c1, thereby preventing the as-target line 13c1 from moving and interfering with the connection terminal 19.

[0122] The connection terminal 19 is formed in a stepped shape so that the base 191 is located above the tip 192 connected to the storage element 11, and the detection line holding portion 90 holds the base 191 of the connection terminal 19.

[0123] According to this, the connection terminal 19 is formed in a stepped shape, and the base 191, which is located above the tip 192 connected to the storage element 11, is held by the detection line holding portion 90, so that a space for the asymmetric line 13c1 can be easily formed below the detection line holding portion 90.

[0124] [7 Explanation of Variations] Although the storage device 1 according to the present embodiment has been described above, the present invention is not limited to the above embodiment. In other words, the embodiment disclosed herein is illustrative in all respects and is not restrictive. The scope of the present invention is defined by the claims, and includes all modifications within the meaning and scope of the claims.

[0125] In the above embodiment, the guide portion 80 is a corner portion of the first surrounding wall 712, but the guide portion may be a portion separate from the first surrounding wall 712. In this case, the shape of the guide portion can be determined without depending on the first surrounding wall 712. If the guide portion is integrated with the locking piece 717, one end of the positive power cable 31 can be supported over a wider range.

[0126] In the above embodiment, the acute angle α formed by the outer surface 81 of the guide portion 80 and the Y-axis direction is less than 45 degrees, but it may be 45 degrees or more.

[0127] In the above embodiment, the guide portion 80 supports one end of the positive power cable 31 from the side, but the guide portion 80 may support the round terminal 311 of the positive power cable 31 from the side.

[0128] In the above embodiment, the outer surface 81 of the guide portion 80 is flat, but the outer surface of the guide portion may be a concave or convex curved surface. From the viewpoint of absorbing the tension when the other end of the positive power cable 31 is pulled, it is preferable that the outer surface of the guide portion is a convex curved surface.

[0129] In the above embodiment, the case where coupling portion 731 is disposed between all of the adjacent pairs of energy storage elements 11 has been illustrated, but it is sufficient that coupling portion is provided between at least one pair of energy storage elements.

[0130] In the above embodiment, the case where exhaust member 60 is disposed directly above connecting portion 731 has been exemplified. The member disposed directly above connecting portion 731 may be a member other than exhaust member 60. Even in this case, the upper end surface of a part of the connecting portion is disposed below or flush with upper surface 11e of container 11a of energy storage element 11, so that a larger installation space for other members can be secured.

[0131] In the above embodiment, the case where the recess 732 is provided in the connecting portion 731 has been illustrated. The connecting portion may have a uniform shape over its entire length. In this case, the entire upper surface of the connecting portion may be disposed below or flush with the upper surface 11e of the container 11a of the energy storage element 11.

[0132] In the above embodiment, the connection terminal 19 has a stepped shape, but the connection terminal 19 may have a flat plate shape.

[0133] In the above embodiment, the detection line holding portion 90 and the detection line locking portion 99 have different configurations, but the detection line locking portion 99 may have the same configuration as the detection line holding portion 90. In this case, the space efficiency in the second cable path portion 725 is improved, so that it is also possible to newly accommodate a member different from the second detection line 13a2 in the second cable path portion 725.

[0134] In the above embodiment, the case where the detection line 13a is connected to all of the multiple storage elements 11 has been exemplified. In the case of a detection line for temperature detection, the detection line may not be connected to all of the multiple storage elements. In other words, the detection line for temperature detection may be electrically connected to at least two storage elements to detect the state of at least two storage elements among the multiple storage elements. Specifically, the detection line for temperature detection may be connected only to the storage elements at both ends and the storage element at the center in the Y-axis direction. Even in this case, the detection line holding unit may be disposed near one of the at least two storage elements, and the connection terminal of the detection line connected to the storage element may be held above the other detection lines connected to the other storage elements. Even in this case, the connection terminal of the detection line connected to the storage element and the other detection lines are less likely to be arranged in a planar manner, and space can be saved.

[0135] FIG. 10 is a cross-sectional view showing a schematic configuration of the detection line holding unit 715b according to the first modification. FIG. 10 is a view corresponding to FIG. 9. As shown in FIG. 10, in the detection line holding unit 715b, the asymmetric line 13c1 is arranged below the positive power cable 31. In this manner, the asymmetric line 13c1 may be arranged below the positive power cable 31. This can suppress the floating of the asymmetric line 13c1 in the positive power cable 31. In FIG. 10, the case where all the asymmetric lines 13c1 are arranged below the positive power cable 31 is shown, but it is sufficient that at least one asymmetric line 13c1 is arranged below the positive power cable 31. It is sufficient that the remaining asymmetric lines 13c1 are arranged below the detection line holding unit 90.

[0136] FIG. 11 is a perspective view showing the vicinity of the guide portion 80 of the busbar frame 12b according to the second modification. As shown in FIG. 11, the busbar frame 12b is provided with a slope portion 89b near the guide portion 80. Specifically, the slope portion 89b is an inner bottom surface of the first cable path portion 715 and is disposed near the guide portion 80. More specifically, the slope portion 89b is disposed at a position adjacent to the outer side surface 81 of the guide portion 80. The slope portion 89b is a groove portion extending along the outer side surface 81. The positive power cable 31 is accommodated in the slope portion 89b. The bottom surface of the slope portion 89b is inclined so as to be lower toward the positive terminal 11b. That is, the thickness of the bottom of the slope portion 89b becomes thinner toward the positive terminal 11b. Since the bottom surface of the slope portion 89b is inclined in this manner, an angular portion in the slope portion 89b is less likely to come into contact with the positive power cable 31. This can prevent damage to the positive power cable 31. Since the positive power cable 31 is housed within the slope portion 89b, it can also prevent the positive power cable 31 from shifting out of position. When one end of the positive power cable 31 is housed within the slope portion 89b, it is inclined with respect to the Y-axis direction. In other words, the slope portion 89b can be said to be an example of a guide portion according to the present disclosure.

[0137] The present invention can be realized not only as an energy storage device 1, but also as a bus bar frame 12 (bus bar holding portion) that holds a plurality of bus bars.

[0138] Any combination of the components of the above-described embodiment and its modified examples is also included within the scope of the present invention. [Industrial Applicability]

[0139] The present invention can be applied to an electricity storage device including an electricity storage element such as a lithium ion secondary battery. [Explanation of symbols]

[0140] 1. Energy storage device 10 Energy storage unit 11 Energy storage element 11a Container (main body) 11b Positive terminal (electrode terminal) 11c Negative terminal (electrode terminal) 11d Spacer 11e Top side 12, 12b Busbar frame (busbar holding member) 13 Busbar 13a Detection line 13a1 First detection line 13a2 Second detection line 13b Connector 13b1 Connection target line 13c1 Non-target line (other detection line) 14 Exterior body 15 Exterior body support 15a bottom 15b, 15c, 17b, 17c Connections 16 Board unit mounting section 17 Exterior body cover 17a Top section 18 Exterior body 19 Connection terminal 20 Circuit Board Unit 30 Cable 31 Positive power cable (power cable) 32 Negative power cable 50 Exhaust section 51 Exhaust port 59 Exhaust route 60 Exhaust parts 61 Hole 62 Convex 65 Lid member 71 First holding part 72 Second holding part 73 Connecting part 80 Guide part 81 External surface 89b Slope section 90 Detection line holder 91 First wall 92 Second wall section 93 Third wall 94 Spring part 99 Detection line locking part 100 Substrate storage section 111 Gas exhaust valve 115, 312 Nut 131 First busbar group 132 Second busbar group 191 Base 192 Tip 193 Fixed claw 194 Drooping part 195 Mounting part 200 Substrates 311 Round terminal 711 First outer wall 711a, 711b, all missing 712 First Enclosure 713 First Compartment Wall 714 First Partition 715 First cable path section (cable path section, first detection line path) 715a aperture 715b Detection line holder 717 Locking piece 718 First wall 719 Second wall 721 Second outer wall section 721a Second notch 722 Second Enclosure 723 Second Compartment Wall 724 Second Partition 725 Second cable path section (second detection line path) 731 Connecting part 732 Recess 733 Bottom surface (top surface) 911 Regulating protrusion 941 Leaf spring L2 dashed line L3 dashed line L5 Dashed-double line α angle

Claims

1. A plurality of electric storage elements each having a gas exhaust valve, the gas exhaust valves being arranged in such a manner that they face in the same direction; A plurality of bus bars electrically connected to the plurality of energy storage elements; a bus bar holding member arranged on the plurality of energy storage elements and holding the plurality of bus bars, the energy storage element includes a body having the gas exhaust valve on an upper surface thereof, and a pair of electrode terminals disposed on the upper surface of the body; The bus bar holding member is a first holding portion disposed on one side of the gas release valve and on the plurality of electric storage elements; a second holding portion disposed on the other side of the gas release valve and on the plurality of electric storage elements; a connecting portion that is disposed between a pair of adjacent energy storage elements among the plurality of energy storage elements and connects the first holding portion and the second holding portion; An upper end surface of a part of the connecting portion is disposed below the upper surface of the main body portion or is disposed flush with the upper surface of the main body portion. Energy storage device.

2. The coupling portion is disposed between each of the adjacent pairs of storage elements. The power storage device according to claim 1 .

3. an exhaust member that is disposed on the connecting portion of the bus bar holding member and that forms an exhaust path for the gas exhausted from the gas exhaust valve; The power storage device according to claim 1 or 2.

4. the connecting portion has a recess that forms the upper end surface of the portion of the connecting portion, The exhaust member is disposed in the recess. The power storage device according to claim 3 .

5. a plurality of detection lines for detecting the respective states of the plurality of storage elements; the plurality of detection lines includes a first detection line and a second detection line; the first holding portion has a first detection line path which is a path of at least one first detection line among the plurality of detection lines; the second holding portion has a second detection line path which is a path of a second detection line other than the at least one first detection line among the plurality of detection lines, The first detection line and the second detection line avoid a gap between the first holding portion and the second holding portion. The power storage device according to any one of claims 1 to 4.

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