Power storage device

Abstract

To provide a power storage device capable of suppressing the spread of adverse effects when a gas exhaust valve of a power storage element opens.SOLUTION: A power storage device includes a first storage element 100A and a second storage element 100B arranged in a first direction, and a flow path forming member 350, the first storage element includes a first gas exhaust valve 131A in a second direction perpendicular to the first direction, the second storage element has a second gas exhaust 131B in the second direction, the flow path forming member faces the first gas exhaust valve and the second gas exhaust valve in the second direction, forms a gas flow path extending in the first direction, and has an outlet 358 for discharging gas to the outside, and in the first direction, the distance between a first position P1 which is the position of the first gas exhaust valve and the outlet is shorter than the distance between a second position P2 which is the position of the second gas exhaust valve and the outlet.SELECTED DRAWING: Figure 6

Description

[Technical field]

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

[0002] Patent Document 1 discloses a power supply device equipped with an exhaust duct. In this power supply device, an exhaust duct is connected to the upper surface of a battery block in which multiple battery cells are stacked, so that the inlet opening is connected to the opening of the gas exhaust valve of each battery cell, and a rupture line is provided in the rupture membrane of the gas exhaust valve, and when the rupture membrane is ruptured and the gas exhaust valve is open, the ruptured and separated rupture edge is positioned above the lower edge of the exhaust duct, and exhaust gas is guided to the exhaust duct. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-77932 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the exhaust duct of the conventional power supply device, the cross section of the internal space in the portion of the exhaust duct located above the battery block is constant in the direction in which the exhaust duct extends. Therefore, gas exhausted from a battery cell located far from the gas outlet in the exhaust duct may be difficult to exhaust from the outlet. As a result, the gas inside the exhaust duct may adversely affect other components such as other battery cells.

[0005] The present invention was made by the inventor of the present application by focusing on the above-mentioned problem, and aims to provide an energy storage device that can suppress the spread of adverse effects when the gas exhaust valve of the storage element is opened. [Means for solving the problem]

[0006] An energy storage device according to one embodiment of the present invention comprises a first storage element and a second storage element arranged in a first direction, and a flow path forming member, wherein the first storage element is provided with a first gas exhaust valve in a second direction perpendicular to the first direction, and the second storage element is provided with a second gas exhaust valve in the second direction, the flow path forming member faces the first gas exhaust valve and the second gas exhaust valve in the second direction, forms a gas flow path extending in the first direction, and has an outlet for discharging the gas to the outside, wherein in the first direction, a distance between a first position which is the location of the first gas exhaust valve and the outlet is shorter than a distance between a second position which is the location of the second gas exhaust valve and the outlet, and when a width of the gas flow path in the flow path forming member in a third direction perpendicular to the first direction and the second direction is defined as a flow path width, a first width which is the flow path width at the first position is larger than a second width which is the flow path width at the second position.

[0007] An energy storage device according to one embodiment of the present invention comprises a first storage element and a second storage element arranged in a first direction, and a flow path forming member, wherein the first storage element is provided with a first gas exhaust valve in a second direction perpendicular to the first direction, and the second storage element is provided with a second gas exhaust valve in the second direction, the flow path forming member faces the first gas exhaust valve and the second gas exhaust valve in the second direction, forms a gas flow path extending in the first direction, and has an outlet for discharging the gas to the outside, wherein in the first direction, a distance between a first position which is the location of the first gas exhaust valve and the outlet is shorter than a distance between a second position which is the location of the second gas exhaust valve and the outlet, and in the flow path within the flow path forming member, a first cross-sectional area which is a cross-sectional area at the first position is larger than a second cross-sectional area which is a cross-sectional area at the second position, and an outlet cross-sectional area which is a cross-sectional area at the outlet is larger than the first cross-sectional area, and the cross-sectional area is an area of ​​a cross section of the gas flow path perpendicular to the first direction. Effect of the Invention

[0008] According to the electricity storage device of the present invention, it is possible to suppress the spread of adverse effects caused when the gas release valve of the electricity storage element is opened. [Brief description of the drawings]

[0009] [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 of the electricity storage device according to the embodiment. [Diagram 3] FIG. 3 is a perspective view showing an external appearance of an energy storage device according to an embodiment. [Figure 4] FIG. 4 is a perspective view showing an end portion where a gas outlet is provided in the electricity storage device according to the embodiment. [Diagram 5] FIG. 5 is an exploded perspective view showing the structure of a plurality of energy storage elements and a flow path forming member according to the embodiment. [Figure 6] FIG. 6 is a plan view illustrating a schematic structure of a plurality of energy storage elements and a flow path forming member according to the embodiment. [Figure 7] FIG. 7 is a front view of a flow path forming member according to the embodiment. [Figure 8] FIG. 8 is a first cross-sectional view of a flow passage forming member according to an embodiment. [Figure 9] FIG. 9 is a second cross-sectional view of the flow passage forming member according to the embodiment. [Figure 10] FIG. 10 is a cross-sectional view of a flow path forming member according to an embodiment. [Figure 11] FIG. 11 is a cross-sectional view of a flow path forming member according to the first modified example of the embodiment. [Figure 12] FIG. 12 is a plan view illustrating a schematic structure of a plurality of energy storage elements and a flow path forming member according to a second modification of the embodiment. [Figure 13] FIG. 13 is a plan view illustrating a structure of a plurality of energy storage elements and a flow path forming member according to a third modification of the embodiment. [Figure 14] FIG. 14 is a plan view illustrating a schematic structure of a plurality of energy storage elements and a flow path forming member according to a fourth modification of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] (1) An energy storage device according to one aspect of the present invention comprises a first storage element and a second storage element aligned in a first direction, and a flow path forming member, wherein the first storage element is provided with a first gas exhaust valve in a second direction perpendicular to the first direction, and the second storage element is provided with a second gas exhaust valve in the second direction, the flow path forming member faces the first gas exhaust valve and the second gas exhaust valve in the second direction, forms a gas flow path extending in the first direction, and has an outlet for discharging the gas to the outside, wherein in the first direction, a distance between a first position which is a location of the first gas exhaust valve and the outlet is shorter than a distance between a second position which is a location of the second gas exhaust valve and the outlet, and when a width of the gas flow path in the flow path forming member in a third direction perpendicular to the first direction and the second direction is defined as a flow path width, a first width which is the flow path width at the first position is larger than a second width which is the flow path width at the second position.

[0011] According to the energy storage device described in (1) above, in the gas flow path formed by the flow path forming member, the first width at a position close to the outlet (first position) is larger than the second width at a position far from the outlet (second position). This makes it easier for gas to be discharged from the outlet of the flow path forming member when the gas is discharged from the second gas exhaust valve arranged at the second position. As a result, the gas is less likely to adversely affect other members (such as the first energy storage element) included in the energy storage device. In this way, the energy storage device according to this aspect can suppress the spread of adverse effects when the gas exhaust valve of the energy storage element is opened.

[0012] (2) In the electricity storage device described above in (1), the flow path width may increase from the second position toward the first position.

[0013] According to the electric storage device described in (2) above, the flow path forming member is formed so that the flow path width gradually increases from the second position to the first position. Therefore, gas stagnation is less likely to occur than when the flow path forming member is formed with a portion where the flow path width changes suddenly halfway in the first direction. This allows the gas inside the flow path forming member to be discharged from the outlet more efficiently.

[0014] (3) In the electricity storage device according to (1) or (2) above, a width of the gas flow path in the second direction may be constant in the first direction.

[0015] According to the energy storage device described in (3) above, the flow path forming member can be formed in a flat shape in which the size of the flow path forming member in the second direction does not change substantially in the first direction. This suppresses a decrease in the energy density of the energy storage device caused by the inclusion of the flow path forming member. Alternatively, it becomes easier to install other members on the opposite side in the second direction to the first and second energy storage elements and at a position where there is no flow path forming member.

[0016] (4) In the power storage device according to (1) or (2) above, a width of the gas flow path in the second direction may increase from the second position toward the first position.

[0017] According to the electricity storage device described above in (4), the ratio of the cross-sectional area of ​​the gas flow path at the first position to the cross-sectional area of ​​the gas flow path at the second position can be set to a relatively large value.

[0018] (5) In the energy storage device described in any one of (1) to (4) above, the flow path forming member may have an opposing wall portion facing the first energy storage element and the second energy storage element in the second direction, the opposing wall portion having a first opening and a second opening, the first opening being positioned opposite the first gas exhaust valve, and the second opening being positioned opposite the first gas exhaust valve.

[0019] According to the energy storage device described in (5) above, regardless of whether gas is discharged from the first gas exhaust valve or the second gas exhaust valve, the gas can be efficiently guided into the flow path forming member via the first opening or the second opening.

[0020] (6) An energy storage device according to one embodiment of the present invention comprises a first storage element and a second storage element aligned in a first direction, and a flow path forming member, wherein the first storage element comprises a first gas exhaust valve in a second direction perpendicular to the first direction, and the second storage element comprises a second gas exhaust valve in the second direction, the flow path forming member faces the first gas exhaust valve and the second gas exhaust valve in the second direction, forms a gas flow path extending in the first direction, and comprises an outlet for discharging the gas to the outside, wherein in the first direction, a distance between a first position where the first gas exhaust valve is located and the outlet is shorter than a distance between a second position where the second gas exhaust valve is located and the outlet, and in the gas flow path within the flow path forming member, a first cross-sectional area which is a cross-sectional area at the first position is larger than a second cross-sectional area which is a cross-sectional area at the second position, and an outlet cross-sectional area which is a cross-sectional area at the outlet is larger than the first cross-sectional area, and the cross-sectional area is an area of ​​a cross section of the gas flow path perpendicular to the first direction.

[0021] According to the electricity storage device described in (6) above, in the gas flow path formed by the flow path forming member, the first cross-sectional area at a position (first position) close to the outlet is larger than the second cross-sectional area at a position (second position) far from the outlet. Furthermore, the outlet cross-sectional area, which is the cross-sectional area at the outlet, is larger than the first cross-sectional area. This improves the ease of gas being discharged from the outlet of the flow path forming member when gas is discharged from the second gas discharge valve arranged at the second position. As a result, the gas is less likely to adversely affect other members (such as the first electricity storage element) included in the electricity storage device. In this way, according to the electricity storage device of this aspect, it is possible to suppress the spread of adverse effects when the gas discharge valve of the electricity storage element is opened.

[0022] (7) In the electricity storage device described above in (6), the outlet cross-sectional area may be a maximum cross-sectional area of ​​a flow path of the gas.

[0023] According to the electricity storage device described in (7) above, the ease with which gas can be discharged from the outlet of the flow path forming member is further improved.

[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, the arrangement and connection of the components, manufacturing processes, and the order of the manufacturing processes 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. In each drawing, the same or similar components are given the same reference numerals.

[0025] In the following description and drawings, the arrangement direction of a pair of terminals of one energy storage element, the direction in which the short sides of the container of the energy storage element face each other, or the short side direction of the exterior body is defined as the X-axis direction. The arrangement direction of multiple energy storage elements, the direction in which the long sides of the container of the energy storage elements face each other, or the longitudinal direction of the exterior body is defined as the Y-axis direction. The arrangement direction of the energy storage elements and the bus bars, the arrangement direction of the main body and the lid of the container of the energy storage element, or the up-down direction is defined as the Z-axis direction. The X-axis direction, Y-axis direction, and 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. When simply referring to the X-axis direction, it refers to both or either of the positive and negative X-axis directions. Expressions indicating relative directions or attitudes, such as parallel and perpendicular, also include cases where the directions or attitudes are not strictly speaking the same. For example, two directions being parallel not only means that the two directions are completely parallel, but also means that the directions are substantially parallel, that is, that there is a difference of, for example, about a few percent. Furthermore, in the following description, when the word "insulation" is used, it means "electrical insulation". An insulating material has a volume resistivity of 1×10 10 It is preferable that the material used is one having a resistance of Ωm or higher.

[0027] [1. General Description of Power Storage Device 1] First, an overall description of an energy storage device 1 according to the present embodiment will be given. Fig. 1 is a perspective view showing the external appearance of an energy storage device 1 according to an embodiment. Fig. 2 is an exploded perspective view of an energy storage device 1 according to an embodiment. Fig. 3 is a perspective view showing the external appearance of an energy storage element 100 according to an embodiment.

[0028] The power storage device 1 is a device that can charge electricity from an external source and discharge electricity to the outside. The power storage device 1 is, for example, a battery module (battery pack) used for power storage or power supply. Specifically, the power storage device 1 is 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, an automatic guided vehicle (AGV: Automatic Guided Vehicle), or a railway vehicle for an electric railway. Examples of the above-mentioned automobiles include electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and fossil fuel (gasoline, diesel, liquefied natural gas, etc.) vehicles. Examples of the above-mentioned railway vehicles for an electric railway include electric trains, monorails, linear motor cars, and hybrid trains equipped with both a diesel engine and an electric motor. The power storage device 1 can also be used as a stationary battery for home or business use.

[0029] As shown in FIG. 1, 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 has a generally rectangular parallelepiped shape that is elongated in the Y-axis direction. The board unit 20 is a device that can monitor the state of the energy storage elements 100 included in the energy storage unit 10 and control the energy storage elements 100, and has a circuit board or the like therein. The energy storage device 1 does not necessarily have to include the board unit 20. The state of the energy storage elements 100 included in the energy storage unit 10 and the control of the energy storage elements 100 may be performed by a device external to the energy storage device 1.

[0030] 2, the energy storage unit 10 includes a plurality of energy storage elements 100, a plurality of spacers 200, a bus bar frame 320, a plurality of bus bars 400, a support body 500, and a flow path forming member 350. The energy storage unit 10 includes cables 410 and 420 (see FIG. 1) which are not shown in FIG. 2.

[0031] The energy 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 energy storage element 100 has a flattened rectangular parallelepiped shape (square shape), and in this embodiment, 14 energy storage elements 100 are arranged side by side in the Y-axis direction. The Y-axis direction is an example of a first direction.

[0032] Specifically, as shown in FIG. 3, the energy storage element 100 includes a container 110 and a pair of terminals 140. An electrode body, a pair of current collectors, and an electrolytic solution (non-aqueous electrolyte) are contained inside the container 110, but these are not shown in the figure. 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 and the terminals 140 and the current collectors, but this is also not shown in the figure. In addition to the above-mentioned components, the energy storage element 100 may include a spacer disposed on the side or below the electrode body, an insulating film that wraps the electrode body, and the like. An insulating film (shrink tube, etc.) that covers the outer surface of the container 110 may be disposed around the container 110.

[0033] The container 110 is a rectangular parallelepiped (rectangular 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 exhaust valve 131 that opens to release pressure when the pressure inside the container 110 increases excessively, and a liquid injection portion (not shown) for injecting an electrolyte into the container 110, and the like.

[0034] The material of the container 110 (container body 120 and lid 130) is not particularly limited, and may be, for example, a weldable (joinable) metal such as stainless steel, aluminum, aluminum alloy, iron, or plated steel sheet, but resin may also be used. After the electrode body and the like are accommodated inside the container body 120, the container body 120 and the lid 130 are joined by welding or the like to seal the inside of the container 110. The container 110 has a pair of long side surfaces 111, a pair of short side surfaces 112, and a bottom surface 113. In this embodiment, the multiple storage elements 100 are arranged side by side in the Y-axis direction with the short side surfaces 112 facing the X-axis direction and the gas exhaust valve 131 facing the Z-axis positive direction (see FIG. 2). The Z-axis direction is an example of a second direction, and the X-axis direction is an example of a third direction.

[0035] The pair of terminals 140 are terminal members (positive electrode terminal and negative electrode terminal) of the energy storage element 100 arranged on 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. The terminals 140 are formed of aluminum, an aluminum alloy, copper, a copper alloy, or the like.

[0036] The electrode body is an electricity storage element (power generation element) formed by laminating a positive electrode plate, a negative electrode plate, and a separator. The positive electrode plate is an electrode plate (electrode plate) in which a positive electrode active material layer is formed on the surface of a positive electrode current collector foil, which is a metal foil. The negative electrode plate is an electrode plate (electrode plate) in which a negative electrode active material layer is formed on the surface of a negative electrode current collector foil, which is a metal foil. For the positive electrode current collector foil, aluminum or an aluminum alloy or the like is used. For the negative electrode current collector foil, copper or a copper alloy or the like is used. The positive electrode active material layer includes a positive electrode active material, a binder, a conductive material, and the like. The negative electrode active material layer includes 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 used as long as it is a material capable of absorbing and releasing charge transport ions. For the separator, a microporous sheet or nonwoven fabric made of resin can be used. The electrode body may be in any form, such as a wound type electrode body formed by winding electrode plates (positive and negative electrode plates), a laminated type (stack type) electrode body formed by stacking multiple flat electrode plates, or a bellows type electrode body in which electrode plates are folded in a bellows shape.

[0037] The energy storage device 1 may include a plurality of energy storage elements 100, and there are no limitations on the size, shape, number of the energy storage elements 100 arranged, etc. The energy storage elements 100 are not limited to nonaqueous electrolyte secondary batteries, and may be secondary batteries other than nonaqueous electrolyte secondary batteries, or may be capacitors. The energy storage elements 100 may not be secondary batteries, but may be primary batteries that can use stored electricity without the user having to charge them.

[0038] The spacer 200 is a flat rectangular member arranged alongside the energy storage elements 100 in the Y-axis direction, and heats and / or insulates the energy storage elements 100 from other members. In this embodiment, the spacer 200 is arranged at both ends of a row of the energy storage elements 100 consisting of a plurality of the energy storage elements 100, and between two adjacent energy storage elements 100 in the row of the energy storage elements 100. The spacer 200 is formed of an insulating member such as any resin material that can be used for the bus bar frame 320 described below. It is not essential that the spacer 200 is arranged between the two energy storage elements 100. For example, when an insulating member such as an insulating film is attached to the container 110 of the energy storage elements 100, the spacer 200 does not need to be arranged between the two energy storage elements 100.

[0039] The energy storage elements 100 and the spacers 200 arranged in the Y-axis direction are disposed between the bus bar frame 320 and the tray 310 in the Z-axis direction. The bus bar frame 320 and the tray 310 are both long members in the Y-axis direction. Each of the bus bars 400 is disposed in a bus bar opening 321 (see FIG. 2) of the bus bar frame 320, and is connected to the terminals 140 of the two energy storage elements 100 adjacent in the Y-axis direction. The tray 310 is a box-shaped member having a shallow depth in the Z-axis direction. The energy storage elements 100 and the spacers 200 are alternately arranged on the tray 310 as shown in FIG. 2. More specifically, the tray 310 has a plurality of partitions 315 inserted between the lower ends of the two energy storage elements 100 adjacent in the Y-axis direction as shown in FIG. 2. The movement of each of the energy storage elements 100 in the Y-axis direction is restricted by at least one partition 315. This suppresses misalignment in the Y-axis direction between the gas release valves 131 of the energy storage elements 100 and the openings 362 of the flow path formation member 350. The configuration of the flow path formation member 350 and its periphery will be described in detail later.

[0040] The bus bar frame 320 and the tray 310 are formed of an electrically insulating material (insulating material). Specifically, the bus bar frame 320 and the tray 310 are formed of an insulating material 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 a metal with an insulating coating. The tray 310 and the bus bar frame 320 may be formed of the same material or different materials.

[0041] The bus bar 400 is a rectangular plate-like member disposed on the plurality of energy storage elements 100 and electrically connects the terminals 140 of the plurality of energy storage elements 100 to each other. In the present embodiment, the bus bar 400 and the terminals 140 are connected by bolt fastening, but may be connected by welding or the like. The bus bar 400 is formed of a conductive member made of metal such as aluminum, aluminum alloy, copper, copper alloy, nickel, or a combination thereof, or a conductive member other than metal. In the present embodiment, each of the plurality of bus bars 400 connects the terminals 140 of the energy storage elements 100 adjacent to each other in the Y-axis direction. In this way, 14 energy storage elements 100 are connected in series. The connection mode of the energy storage elements 100 is not limited to the above, and any combination of series connection and parallel connection may be used.

[0042] One terminal 140 of each of the energy storage elements 100 located at both ends in the Y-axis direction among the multiple energy storage elements 100 is connected to a cable 410 (see FIG. 1), and the other terminal 140 is connected to a cable 420 (see FIG. 1). This allows the energy storage device 1 to be charged with electricity from the outside and to discharge electricity to the outside via the cables 410 and 420.

[0043] The support body 500 is a member that supports and protects (reinforces) a plurality of energy storage elements 100, etc. The support body 500 is formed of a metal member such as stainless steel, aluminum, an aluminum alloy, iron, or a galvanized steel plate. The support body 500 has a support body main body 510 and a cover member 520. The support body 510 and the cover member 520 may be formed of members made of the same material or different materials.

[0044] The support body 510 is a member that supports, from below (the negative Z-axis direction) the tray 310 on which the multiple energy storage elements 100 are placed, and has a bottom 511 and connection parts 512 and 513. The bottom 511 is a flat, rectangular part that constitutes the bottom of the energy storage unit 10, is parallel to the XY plane, and extends in the Y-axis direction, and is disposed in the negative Z-axis direction of the tray 310.

[0045] Cover member 520 is a member disposed above bus bar frame 320 (positive direction of the Z axis), and has top surface portion 520a and connection portions 522 and 523. Top surface portion 520a is a flat rectangular portion that constitutes the upper surface portion (outer lid) of power storage unit 10, parallel to the XY plane and extending in the Y axis direction. Cover member 520 is disposed in the positive direction of the Z axis of bus bar frame 320. Connection portion 522 is connected to connection portion 512 of support body 510. Connection portion 523 is connected to connection portion 513 of support body 510.

[0046] The energy storage device 1 according to this embodiment further includes a flow path forming member 350 as shown in FIG. 2. When gas is discharged from one or more energy storage elements 100, the gas passes through the inside of the flow path forming member 350 and is discharged to the outside of the energy storage device 1. Specifically, the gas that has flowed into the inside of the flow path forming member 350 is discharged to the outside of the flow path forming member 350 from a gas discharge port 358, which is an outlet provided at an end of the flow path forming member 350 in the positive direction of the Y axis. The flow path forming member 350 is a cylindrical member that includes a space therein that forms a gas flow path extending in the Y axis direction. The gas discharge port 358 opens in the positive direction of the Y axis at the end of the flow path forming member 350 in the positive direction of the Y axis. As a result, the gas inside the flow path forming member 350 is discharged to the outside of the flow path forming member 350 from the gas discharge port 358. The gas exhaust port 358 is disposed at a position in the positive direction of the Y axis relative to the gas exhaust valve 131 of the energy storage element 100 that is disposed at the end in the positive direction of the Y axis among the plurality of energy storage elements 100. The gas exhaust port 358 may be disposed in the positive direction of the Y axis relative to the energy storage unit 10. The gas exhausted from the gas exhaust port 358 (see FIG. 2) is guided to a predetermined location, for example, via a gas hose or the like (not shown). Hereinafter, the configuration of the flow path formation member 350 and its periphery according to the embodiment will be described in detail with further reference to FIGS. 4 to 9.

[0047] [2. Configuration of flow path forming member 350 and its surroundings] FIG. 4 is a perspective view showing an end portion where a gas discharge port 358 is provided in the energy storage device 1 according to the embodiment. FIG. 5 is an exploded perspective view showing the structure of a plurality of energy storage elements 100 and a flow path forming member 350 according to the embodiment. In FIG. 5, some of the plurality of energy storage elements 100 are omitted, and a first member 360 and a second member 370 are shown separated in the Z-axis direction. In FIG. 5, other members such as the spacer 200 and the bus bar frame 320 are omitted. FIG. 6 is a plan view showing a schematic structure of a plurality of energy storage elements 100 and a flow path forming member 350 according to the embodiment. In FIG. 6, only two openings 362 (362A and 362B) out of a plurality of openings 362 provided in the flow path forming member 350 are shown. This also applies to FIGS. 12 to 14 described later.

[0048] FIG. 7 is a diagram (front view) of the flow path forming member 350 according to the embodiment when viewed from the Y-axis positive direction. FIG. 8 is a first cross-sectional view of the flow path forming member 350 according to the embodiment, and FIG. 9 is a second cross-sectional view of the flow path forming member 350 according to the embodiment. In FIG. 8, a cross section taken along line VIII-VIII in FIG. 5 is simply illustrated. In FIG. 9, a cross section taken along line IX-IX in FIG. 5 is simply illustrated. FIG. 10 is a cross-sectional view of the flow path forming member 350 according to the embodiment. In FIG. 10, a cross section taken along line XX in FIG. 5 is simply illustrated. The cross section taken along line XX is a cross section of the electricity storage unit 10 cut along a plane that passes through the center position of the flow path forming member 350 in the X-axis direction and is parallel to the YZ plane. In FIGS. 8 to 10, the approximate arrangement range of the gas exhaust valve 131 provided in the electricity storage element 100 is represented by a patterned rectangle.

[0049] As shown in Figures 4 to 10, the flow path forming member 350 of this embodiment is a member that forms a flow path 390 for gas discharged from the energy storage element 100, and is also called, for example, a "duct" or an "exhaust duct."

[0050] In this embodiment, as shown in FIG. 2 and FIG. 5, the flow path forming member 350 has a first member 360 and a second member 370 aligned in the up-down direction (Z-axis direction). The first member 360 and the second member 370 are overlapped in the Z-axis direction to form a gas flow path 390 extending in the Y-axis direction between the first member 360 and the second member 370. The flow path forming member 350 has an end wall portion 359 that blocks the gas flow path 390 at an end portion on the opposite side (Y-axis minus direction) from the gas exhaust port 358. As shown in FIG. 5, the end wall portion 359 has a first end wall portion 369 and a second end wall portion 379 aligned in the Y-axis direction. The first end wall portion 369 is provided at an end portion of the first member 360 in the Y-axis minus direction. The second end wall portion 379 is provided at an end portion of the second member 370 in the Y-axis minus direction. In this way, the end of the internal space of flow path forming member 350 in the negative Y-axis direction is blocked by end wall portion 359. As a result, gas inside flow path forming member 350 is discharged from gas exhaust port 358 provided at the end in the positive Y-axis direction. In the positive Y-axis direction, gas flow path 390 is formed at least up to gas exhaust port 358.

[0051] The first member 360 is an elongated member in the Y-axis direction, and has openings 362 at positions facing the gas exhaust valves 131 of the energy storage elements 100. Specifically, the first member 360 includes an opposing wall portion 361 facing the energy storage elements 100 in the Z-axis direction. The opposing wall portion 361 has openings 362 formed at positions facing the gas exhaust valves 131. When gas is exhausted from the gas exhaust valve 131, the gas can flow into the flow path forming member 350 through the openings 362 positioned in the Z-axis plus direction of the gas exhaust valve 131. The first member 360 is formed of, for example, resin. Examples of the resin material forming the first member 360 include any of the resin materials usable for the bus bar frame 320 described above.

[0052] The second member 370, which is located at a position where the gas flowing in from the opening 362 of the first member 360 collides with, is formed of a metal such as a galvanized steel plate. This suppresses damage to the second member 370 due to the pressure and heat of the gas. The second member 370 is fixed to the cover member 520 by, for example, a plurality of screws 529. In this case, the cover member 520 is placed on the first member 360 from above in a state where the first member 360 is disposed in the central portion of the bus bar frame 320 in the X-axis direction. This causes the second member 370 to be inserted into the first member 360 from the positive direction of the Z-axis, and as a result, the flow path forming member 350 consisting of the first member 360 and the second member 370 is configured.

[0053] More specifically, as shown in Figs. 7 to 10, the second member 370 has an upper wall portion 371 at a position facing the facing wall portion 361 of the first member 360 in the Z-axis direction. The second member 370 further has side wall portions 375 arranged on both sides of the upper wall portion 371 in the short side direction (X-axis direction). The facing wall portions 361 of the first member 360 are arranged in the negative Z-axis direction of a space surrounded by the upper wall portion 371 and the pair of side wall portions 375. As a result, a gas flow path 390 extending in the Y-axis direction is formed inside the flow path forming member 350.

[0054] In this embodiment, as shown in FIG. 6, the flow path width W, which is the width of the gas flow path 390 in the X-axis direction, is larger at a position closer to the gas exhaust port 358 than at a position farther from the gas exhaust port 358.

[0055] For example, focusing on two of the multiple energy storage elements 100, one is designated as a first energy storage element 100A and the other is designated as a second energy storage element 100B in order to distinguish between the two energy storage elements 100 (see FIGS. 5 and 6). In this embodiment, the first energy storage element 100A, the second energy storage element 100B, and three energy storage elements 100 arranged between the first energy storage element 100A and the second energy storage element 100B are aligned in the Y-axis direction. Specifically, in the Y-axis direction, the first energy storage element 100A is arranged at a position closer to the gas discharge port 358 than the second energy storage element 100B. Therefore, the first gas discharge valve 131A, which is the gas discharge valve 131 provided in the first energy storage element 100A, is arranged at a position closer to the gas discharge port 358 than the second gas discharge valve 131B, which is the gas discharge valve 131 provided in the second energy storage element 100B. In other words, in the present embodiment, first energy storage element 100A is located between second energy storage element 100B and gas exhaust port 358 in the Y-axis direction.

[0056] That is, in the Y-axis direction, if the position of the first gas exhaust valve 131A is the first position P1, the position of the second gas exhaust valve 131B is the second position P2, and the position of the gas exhaust port 358 is the outlet position P0, the positional relationship between them can be explained as follows. In the Y-axis direction, the first position P1 is closer to the outlet position P0 than the second position P2. That is, in the Y-axis direction, the distance La between the first position P1 and the gas exhaust port 358 is shorter than the distance Lb between the second position P2 and the gas exhaust port 358. In this embodiment, as shown in FIGS. 6 to 9, the first width W1, which is the flow path width W at the first position P1, is larger than the second width W2, which is the flow path width W at the second position P2.

[0057] In this embodiment, the position of the gas release valve 131 in the Y-axis direction is defined as the center position of the gas release valve 131 in the Y-axis direction as shown in Fig. 6 (see Fig. 6). However, the position of the gas release valve 131 in the Y-axis direction may be defined uniformly for a plurality of energy storage elements 100, and may be defined by the position of the edge of the gas release valve 131 in the positive Y-axis direction or the position of the edge of the gas release valve 131 in the negative Y-axis direction.

[0058] The first position P1 and the second position P2 shown in FIG. 5, FIG. 6, and FIG. 10 are examples. The first position P1 and the second position P2 are not limited to the positions shown in FIG. 5, FIG. 6, and FIG. 10. The first position P1 is the position of one gas exhaust valve 131 among the multiple gas exhaust valves 131 arranged in the Y-axis direction. The second position P2 is the position of one gas exhaust valve 131 different from the first position P1 among the multiple gas exhaust valves 131 arranged in the Y-axis direction, and the second position P2 may be farther from the outlet position P0, which is the position of the gas exhaust port 358, than the first position P1. For example, the first position P1 may be the position of the gas exhaust valve 131 provided in the storage element 100 at the end in the positive direction of the Y-axis among the multiple storage elements 100. In this case, the second position P2 may be the position of any gas exhaust valve 131 of the storage element 100 located in the negative direction of the Y-axis than the storage element 100 at the end in the positive direction of the Y-axis among the multiple storage elements 100. The second position P2 may be the position of any of the gas release valves 131 provided in the thirteen energy storage elements 100 excluding the energy storage element 100 at the end in the positive direction of the Y axis.

[0059] Thus, in the present embodiment, in the gas flow path 390 formed by the flow path forming member 350, the first width W1, which is the flow path width at the first position P1, which is a position close to the gas exhaust port 358, is larger than the second width W2, which is the flow path width at the second position P2, which is a position far from the gas exhaust port 358. As a result, when gas is exhausted from the second gas exhaust valve 131B arranged at the second position P2, the gas is more likely to flow in the first width W1, which is the flow path width wider than the second width W2, and the gas is more likely to be exhausted from the gas exhaust port 358. As a result, the gas is less likely to adversely affect other members such as the first energy storage element 100A included in the energy storage device 1. Thus, according to the energy storage device 1 according to the present embodiment, it is possible to suppress the spread of adverse effects caused by the gas when the gas exhaust valve 131 of the energy storage element 100 is opened.

[0060] Further, in this embodiment, as shown in Figs. 6 to 9, the outlet width W0, which is the flow path width W at the gas exhaust port 358, is larger than the first width W1 at the first position P1. That is, the second width W2, the first width W1, and the outlet width W0 increase in this order. This improves the ease of exhausting gas from the gas exhaust port 358, even for gas exhausted from the first gas exhaust valve 131A, which is located closer to the gas exhaust port 358 than the second gas exhaust valve 131B. In this embodiment, the outlet width W0 is the maximum flow path width W. This more reliably improves the ease of exhausting gas from the inside of the flow path forming member 350 from the gas exhaust port 358.

[0061] In this embodiment, the flow path width W is the width of the gas flow path 390 in the X-axis direction. Therefore, in this embodiment, the gas flow path 390 can be ensured to have a width in the X-axis direction. This makes it possible to suppress an increase in the size of the power storage device 1 in the Z-axis direction caused by providing the flow path formation member 350. For example, even if the size of the flow path formation member 350 is changed so that the second width W2 is larger, the change is unlikely to affect the size of the power storage device 1 in the Z-axis direction.

[0062] More specifically, in this embodiment, as shown in Figures 5 and 6, the flow path width W of the gas flow path 390 increases from the second position P2 toward the first position P1. That is, the flow path formation member 350 is formed so that the flow path width W gradually increases from the second position P2 toward the first position P1. Therefore, gas stagnation is less likely to occur than when the flow path formation member 350 is formed with a portion where the flow path width W changes suddenly midway in the Y-axis direction. This allows the gas inside the flow path formation member 350 to be more efficiently discharged from the gas outlet 358 to the outside of the flow path formation member 350.

[0063] 10, in the gas flow path 390 according to this embodiment, the flow path vertical width H, which is the width in the Z-axis direction of the gas flow path 390, is constant in the Y-axis direction. That is, in the gas flow path 390, the flow path width W, which is the width in the X-axis direction, varies depending on the position in the Y-axis direction, while the flow path vertical width H, which is the width in the Z-axis direction (length in the Z-axis direction), is constant at any position in the Y-axis direction. "The flow path vertical width H being constant in the Y-axis direction" includes a ratio of the minimum value to the maximum value of the flow path vertical width H in the Y-axis direction being 90% or more, and more preferably, a ratio of the minimum value to the maximum value being 95% or more.

[0064] According to this configuration, the flow path forming member 350 can be made flat such that the size of the flow path forming member 350 in the Z axis direction remains almost constant at any position in the Y axis direction (see FIG. 10). In this embodiment, the surfaces facing the Z axis direction, such as the upper wall portion 371 of the flow path forming member 350, can be made flat. This suppresses a decrease in the energy density of the power storage device 1 caused by the inclusion of the flow path forming member 350, or makes it easier to place other members in the positive direction of the Z axis than the flow path forming member 350, for example.

[0065] In this embodiment, the upper wall portion 371 of the second member 370, which is the top surface of the flow path forming member 350, has a flat shape that follows the surface of the opposing wall portion 361 located between the gas flow path 390 and the multiple energy storage elements 100 in the Z-axis direction. Therefore, by fixing the second member 370 to the cover member 520, a wide area of ​​the surface of the upper wall portion 371 in the positive direction of the Z-axis can be brought into contact with the surface of the cover member 520 in the negative direction of the Z-axis shown in FIG. 5. Therefore, a space is unlikely to be generated between the flow path forming member 350 and the cover member 520. This suppresses a decrease in the energy density of the energy storage device 1, and / or makes the fixation of the second member 370, which is one member that forms the gas flow path 390, and the cover member 520 more stable.

[0066] In this embodiment, the first member 360 included in the flow path formation member 350 has an opposing wall portion 361 located between the gas flow path 390 and the multiple energy storage elements 100. As shown in Fig. 5, the opposing wall portion 361 has multiple openings 362, and each gas exhaust valve 131 of the multiple gas exhaust valves 131 and each opening 362 of the multiple openings 362 are paired and opposed to each other in the Z axis direction. If, among the multiple openings 362, the opening 362 facing the first gas exhaust valve 131A is referred to as a first opening 362A and the opening 362 facing the second gas exhaust valve 131B is referred to as a second opening 362B, the flow path formation member 350 will be described, for example, as follows.

[0067] The flow path forming member 350 has an opposing wall portion 361 that faces the first energy storage element 100A and the second energy storage element 100B in the Z axis direction. The opposing wall portion 361 has a first opening 362A and a second opening 362B. The first opening 362A is disposed at a position facing the first gas discharge valve 131A, and the second opening 362B is disposed at a position facing the second gas discharge valve 131B.

[0068] According to this configuration, when gas is discharged from the first gas exhaust valve 131A, the gas can be efficiently guided into the inside of the flow path formation member 350 through the first opening 362A, and when gas is discharged from the second gas exhaust valve 131B, the gas can be efficiently guided into the inside of the flow path formation member 350 through the second opening 362B.

[0069] The opposing wall portion 361 has an energy storage element opposing portion 361a (see FIG. 8) that faces the first energy storage element 100A and does not face at least a portion of the first gas release valve 131A. The opposing wall portion 361 has an energy storage element opposing portion 361b (see FIG. 9) that faces the second energy storage element 100B and does not face at least a portion of the second gas release valve 131B.

[0070] With this configuration, gas flow path 390 can be separated from the space in which first energy storage element 100A and second energy storage element 100B are arranged at energy storage element facing portion 361a and energy storage element facing portion 361b of facing wall portion 361. This is advantageous in suppressing the spread of adverse effects when first gas exhaust valve 131A or second gas exhaust valve 131B is opened.

[0071] One opening 362 provided in the opposing wall portion 361 may face two or more gas exhaust valves 131 in the Z axis direction. For example, two gas exhaust valves 131 adjacent in the Y axis direction may both be disposed to face one opening 362 in the Z axis direction. In this case, seven openings 362 may be provided in the opposing wall portion 361 for 14 gas exhaust valves 131.

[0072] When the area of ​​a cross section perpendicular to the Y-axis direction in gas flow path 390 according to this embodiment is defined as the cross-sectional area S of gas flow path 390, the configuration of flow path formation member 350 in power storage device 1 is described, for example, as follows.

[0073] In the gas flow path 390 in the flow path formation member 350, a first cross-sectional area S1 (see FIG. 8) which is the cross-sectional area S at the first position P1 is larger than a second cross-sectional area S2 (see FIG. 9) which is the cross-sectional area S at the second position P2. An outlet cross-sectional area S0 (see FIG. 7) which is the cross-sectional area S at the gas discharge port 358 is larger than the first cross-sectional area S1.

[0074] According to this configuration, in the gas flow path 390 formed by the flow path forming member 350, the first cross-sectional area S1 at the first position P1, which is a position close to the gas discharge port 358, is larger than the second cross-sectional area S2 at the second position P2, which is a position far from the gas discharge port 358. Furthermore, the outlet cross-sectional area S0, which is the cross-sectional area S at the gas discharge port 358, is larger than the first cross-sectional area S1. This improves the ease of gas being discharged from the gas discharge port 358 of the flow path forming member 350 when gas is discharged from the second gas discharge valve 131B arranged at the second position P2. As a result, the gas is less likely to adversely affect other members such as the first energy storage element 100A included in the energy storage device 1. In this way, according to the energy storage device 1 according to this embodiment, it is possible to suppress the spread of adverse effects when the gas discharge valve 131 of the energy storage element 100 is opened.

[0075] More specifically, the gas discharged from the second gas discharge valve 131B flows into the flow passage forming member 350 from the second opening 362B, passes through the first position P1, and heads toward the gas discharge port 358. In this series of flows, since the first cross-sectional area S1 is larger than the second cross-sectional area S2, at least one of the temperature and pressure of the gas is more likely to decrease. Furthermore, since the outlet cross-sectional area S0 is larger than the first cross-sectional area S1, at least one of the temperature and pressure of the gas is more likely to decrease.

[0076] In this embodiment, the exit cross-sectional area S0, which is the cross-sectional area S of the gas exhaust port 358, is the maximum cross-sectional area S of the gas flow path 390. That is, in this embodiment, the exit cross-sectional area S0, which is the cross-sectional area S of the gas exhaust port 358, is the largest value among the cross-sectional areas S in the gas flow path 390.

[0077] According to this configuration, the ease of discharging the gas from the gas discharge port 358 is further improved. Therefore, for example, the energy storage element 100 closest to the gas discharge port 358 among the multiple energy storage elements 100 is less likely to be adversely affected by heat or the like due to the gas discharged from the other energy storage elements 100. As a result, malfunctions are less likely to occur in the energy storage element 100 closest to the gas discharge port 358, and the gas discharge valve 131 of the energy storage element 100 closest to the gas discharge port 358 is suppressed from opening and discharging the gas. When the gas discharge valve 131 of one of the multiple energy storage elements 100 is opened, in the gas flow path 390, the energy storage element 100 located between the opened energy storage element 100 and the gas discharge port 358 in the Y-axis direction is more likely to be adversely affected by heat or the like due to the discharged gas. However, since the outlet cross-sectional area S0 is the maximum cross-sectional area S of the gas flow path 390, the gas easily flows toward the gas exhaust port 358 in the gas flow path 390. As a result, the adverse effects of heat and the like caused by the gas are less likely to spread to the energy storage element 100 located between the opened energy storage element 100 and the gas exhaust port 358. This configuration is also expected to have the effect of suppressing the discharge of gas with high temperature and / or pressure from the gas exhaust port 358. Since the outlet cross-sectional area S0 is the maximum cross-sectional area S of the gas flow path 390, the pressure inside the flow path forming member 350 is easily reduced. As a result, when a gas hose or the like is not connected to the gas exhaust port 358, the gas is prevented from scattering far away from the gas exhaust port 358. This makes it less likely that the adverse effects of heat and the like caused by the gas will spread to devices outside the energy storage device 1.

[0078] The above describes the energy storage device 1 according to the embodiment, focusing on the configuration of the flow path formation member 350 and its surroundings. However, the flow path formation member 350 in the energy storage device 1 may have a configuration different from that shown in Fig. 2 and Figs. 4 to 10. Therefore, below, modified examples of the flow path formation member 350 will be described, focusing on the differences from the above embodiment.

[0079] [3-1. Variation 1] Fig. 11 is a cross-sectional view of a flow path formation member 350a according to the first modified example of the embodiment. The position of the cross section in Fig. 11 corresponds to the position of the cross section in Fig. 10. In Fig. 11, the approximate arrangement range of the gas release valve 131 provided in the energy storage element 100 is represented by a patterned rectangle.

[0080] As shown in FIG. 11, the energy storage device 1a according to this modification includes a flow path forming member 350a. The flow path forming member 350a forms a gas flow path 390a extending in the Y-axis direction. In the Y-axis direction, a distance La between a first position P1, which is the position of the first gas exhaust valve 131A, and the gas exhaust port 358a is shorter than a distance Lb between a second position P2, which is the position of the second gas exhaust valve 131B, and the gas exhaust port 358a. The second position P2, the first position P1, and the gas exhaust port 358a are arranged in this order in the Y-axis direction. Furthermore, although not shown in FIG. 11, regarding a flow path width W, which is the width in the X-axis direction of the gas flow path 390a, the first width W1, which is the flow path width W at the first position P1, is larger than the second width W2, which is the flow path width W at the second position P2. These configurations are common to the energy storage device 1 according to the above embodiment.

[0081] This modification is characterized in that the gas flow path 390a has a Z-axis width (length in the Z-axis direction) that is a flow path vertical width H that increases from the second position P2 toward the first position P1.

[0082] That is, in the gas flow passage 390a according to this modification, both the flow passage width W, which is the width in the X-axis direction, and the flow passage vertical width H, which is the width in the Z-axis direction, increase as the gas flow passage 390a approaches the first position P1 from the second position P2. As a result, the first cross-sectional area Sa1, which is the cross-sectional area S of the gas flow passage 390a at the first position P1, becomes larger than the second cross-sectional area Sa2, which is the cross-sectional area S of the gas flow passage 390a at the second position P2. As a result, when gas is discharged from the second gas discharge valve 131B, the ease of gas being discharged from the gas discharge port 358a of the flow passage formation member 350a is more reliably improved. In the gas flow passage 390a, gas flows more easily at least between the second position P2 and the first position P1.

[0083] In this modification, the exit cross-sectional area Sa0, which is the cross-sectional area S of the gas flow path 390a at the gas exhaust port 358a, is larger than the first cross-sectional area Sa1. That is, in this modification, the first cross-sectional area Sa1, which is the cross-sectional area S at the first position P1, is larger than the second cross-sectional area Sa2, which is the cross-sectional area S at the second position P2. The exit cross-sectional area Sa0, which is the cross-sectional area S at the gas exhaust port 358a, is larger than the first cross-sectional area Sa1.

[0084] In this way, the cross-sectional area S of the gas flow path 390a increases from the second position P2 through the first position P1 to the gas exhaust port 358a (exit position P0), which improves the ease of gas being discharged from the gas exhaust port 358a of the flow path forming member 350a. When the second cross-sectional area Sa2 at the second position P2, the first cross-sectional area Sa1 at the first position P1, and the outlet cross-sectional area Sa0 at the outlet position P0 increase in this order, it is expected that the gas will pass through more efficiently than when the cross-sectional area S is constant in the Y-axis direction, regardless of where the second position P2 is. That is, it is expected that the gas inside the flow path forming member 350 will be quickly discharged to the outside through the gas exhaust port 358a.

[0085] As described above, in at least a portion of the Y-axis direction, the gas flow path 390a according to this modification has a flow path vertical width H, which is the width in the Z-axis direction, that increases toward the gas exhaust port 358a. When the cross-sectional area S of the gas flow path 390a satisfies the relationship: second cross-sectional area Sa2<first cross-sectional area Sa1<outlet cross-sectional area Sa0, the flow path width W, which is the width in the X-axis direction, may be constant in the Y-axis direction.

[0086] [3-2. Variation 2] Fig. 12 is a plan view showing a schematic structure of a plurality of energy storage elements 100 and a flow path forming member 350b according to the second modification of the embodiment. As shown in Fig. 12, the energy storage device 1b according to the present modification includes a flow path forming member 350b that forms a gas flow path 390b extending in the Y-axis direction. In the Y-axis direction, a distance La between a first position P1, which is the position of the first gas exhaust valve 131A, and the gas exhaust port 358b is shorter than a distance Lb between a second position P2, which is the position of the second gas exhaust valve 131B, and the gas exhaust port 358b. These configurations are common to the energy storage device 1 according to the above embodiment.

[0087] In this modification, the gas flow path 390 according to the above embodiment is different in that the flow path width W at the intermediate position Pb, which is a position between both ends of the gas flow path 390b in the Y-axis direction, is changed with respect to the flow path width W at the end of the gas flow path 390b in the negative Y-axis direction. Specifically, in FIG. 12, the intermediate position Pb is a position between the first position P1 and the second position P2 in the Y-axis direction. In the gas flow path 390b according to this modification, the flow path width W is constant from the end in the negative Y-axis direction to the intermediate position Pb, and the flow path width W becomes larger as it approaches the outlet position P0 from the intermediate position Pb. Even in this case, the first width Wb1, which is the flow path width W at the first position P1, is larger than the second width Wb2, which is the flow path width W at the second position P2. Therefore, when gas is discharged from the second gas discharge valve 131B, the ease of gas being discharged from the gas discharge port 358b of the flow path formation member 350b is improved. In this modification, the outlet width Wb0, which is the flow path width W at the gas exhaust port 358b, is the maximum flow path width W. This more reliably improves the ease with which the gas inside the flow path formation member 350b can be discharged through the gas exhaust port 358b.

[0088] The intermediate position Pb is not limited to a position between the first position P1 and the second position P2 in the Y-axis direction. The intermediate position Pb may be any position on the negative Y-axis direction from the first position P1. The intermediate position Pb may be, for example, a position on the negative Y-axis direction from the second position P2.

[0089] [3-3. Variation 3] Fig. 13 is a plan view showing a schematic structure of a plurality of energy storage elements 100 and a flow path forming member 350c according to the third modification of the embodiment. As shown in Fig. 13, the energy storage device 1c according to this modification includes a flow path forming member 350c that forms a gas flow path 390c extending in the Y-axis direction. In the Y-axis direction, a distance La between a first position P1, which is the position of the first gas exhaust valve 131A, and the gas exhaust port 358c is shorter than a distance Lb between a second position P2, which is the position of the second gas exhaust valve 131B, and the gas exhaust port 358c. These configurations are common to the energy storage device 1 according to the above embodiment.

[0090] This modification is different from the gas flow path 390 according to the above embodiment in that the flow path width W changes at each of intermediate positions Pc1 and Pc2 between both ends of the gas flow path 390c in the Y-axis direction. Specifically, in FIG. 13, the intermediate position Pc1 is a position between the first position P1 and the second position P2 in the Y-axis direction, and the intermediate position Pc2 is a position between the first position P1 and the outlet position P0 in the Y-axis direction. In the gas flow path 390c according to this modification, the flow path width W is constant from the end in the negative Y-axis direction to the intermediate position Pc1, and the flow path width W becomes larger as it approaches the intermediate position Pc2 from the intermediate position Pc1. Furthermore, the flow path width W is constant from the intermediate position Pc2 to the outlet position P0. Even in this case, the first width Wc1, which is the flow path width W at the first position P1, is larger than the second width Wc2, which is the flow path width W at the second position P2. Therefore, when gas is discharged from the second gas discharge valve 131B, the ease with which the gas is discharged from the gas discharge port 358c of the flow path formation member 350c is improved. In this modification, the outlet width Wc0, which is the flow path width W at the gas discharge port 358c, is the maximum flow path width W. This more reliably improves the ease with which the gas inside the flow path formation member 350c is discharged from the gas discharge port 358c.

[0091] The intermediate position Pc1 is not limited to a position between the first position P1 and the second position P2 in the Y-axis direction. The intermediate position Pc1 may be any position on the negative Y-axis direction from the first position P1. The intermediate position Pc1 may be, for example, a position on the negative Y-axis direction from the second position P2.

[0092] The intermediate position Pc2 is not limited to a position between the first position P1 and the exit position P0 in the Y-axis direction. The intermediate position Pc2 may be any position in the Y-axis positive direction from the intermediate position Pc1. The intermediate position Pc2 may be, for example, a position between the intermediate position Pc1 and the first position P1.

[0093] [3-4. Variation 4] Fig. 14 is a plan view showing a schematic structure of a plurality of energy storage elements 100 and a flow path forming member 350d according to the fourth modified example of the embodiment. As shown in Fig. 14, an energy storage device 1d according to the present modified example includes a flow path forming member 350d that forms a gas flow path 390d extending in the Y-axis direction. In the Y-axis direction, a distance La between a first position P1, which is the position of the first gas exhaust valve 131A, and the gas exhaust port 358d is shorter than a distance Lb between a second position P2, which is the position of the second gas exhaust valve 131B, and the gas exhaust port 358d. These configurations are common to the energy storage device 1 according to the above-described embodiment.

[0094] In this modification, the flow path width W at the intermediate position Pd, which is a position between both ends of the gas flow path 390d in the Y-axis direction, changes with respect to the flow path width W at the end of the gas flow path 390d in the negative Y-axis direction, and the flow path width W is constant in both the positive and negative Y-axis directions at the intermediate position Pd. In this respect, it is different from the gas flow path 390 according to the above embodiment. Even in this case, the first width Wd1, which is the flow path width W at the first position P1, is larger than the second width Wd2, which is the flow path width W at the second position P2. Therefore, when gas is discharged from the second gas discharge valve 131B, the ease of gas being discharged from the gas discharge port 358d of the flow path formation member 350d is improved. In this modification, the outlet width Wd0, which is the flow path width W at the gas discharge port 358d, is the same (including approximately the same) as the first width Wd1. Therefore, the gas discharge port 358d is less likely to obstruct the flow of gas that passes through the first position P1 and is discharged from the gas discharge port 358d.

[0095] [4. Other Modifications] Although the energy storage device 1 according to the embodiment and its modified examples have been described above, the present invention is not limited to the embodiment and its modified examples. In other words, the embodiment disclosed herein is illustrative and not restrictive in all respects, and the scope of the present invention includes all modifications within the meaning and scope equivalent to the claims.

[0096] The flow path forming member 350 may not include the opposing wall portion 361. For example, the flow path forming member 350 may include only the second member 370, without including the first member 360. Even in this case, the gas flow path 390 extending in the Y-axis direction can be formed by the second member 370 having the upper wall portion 371 and a pair of side wall portions 375.

[0097] The number of components forming the flow path forming member 350 is not particularly limited. For example, one metallic cylindrical component may be disposed in the energy storage device 1 as the flow path forming member 350. A pair of wall portions opposing each other in the Z-axis direction and a pair of wall portions opposing each other in the X-axis direction of the flow path forming member 350 may be formed of separate components. That is, the flow path forming member 350 may be configured by a combination of four components. The shape of the cross section (cross section perpendicular to the Y-axis direction) of the flow path forming member 350 does not need to be rectangular, and may be a circle, an ellipse, or a polygonal shape other than a rectangle. One or more components forming the flow path forming member 350 may be part of the cover member 520 (see FIGS. 2 and 4).

[0098] The energy storage device 1 does not need to be elongated in the arrangement direction (Y-axis direction) of the multiple energy storage elements 100. For example, when the energy storage device 1 includes a small number of energy storage elements 100 (e.g., four or less), the length of the energy storage device 1 in the Y-axis direction may be equal to or shorter than the length of the energy storage device 1 in the X-axis direction.

[0099] The above supplementary notes regarding the energy storage device 1 according to the embodiment may be applied to at least one of the energy storage devices 1a to 1d according to the modified examples 1 to 4. Configurations constructed by arbitrarily combining the components included in the above embodiment and the modified examples are also included within the scope of the present invention. [Industrial Applicability]

[0100] 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]

[0101] 1, 1a, 1b, 1c, 1d Energy storage device 10 Energy storage unit 20 Circuit Board Unit 100 Energy storage element 100A First storage element 100B Second storage element 110 Container 111 Long side 112 short side 113 Bottom 120 Container body 130 Lid 131 Gas exhaust valve 131A First gas exhaust valve 131B Second gas exhaust valve 140 Terminals 200 Spacer 310 Tray 315 Partition 320 Busbar Frame 321 Busbar opening 350, 350a, 350b, 350c, 350d Flow path forming member 358 Gas exhaust port 359 End wall 360 First member 361 Opposing wall 361a, 361b Energy storage element opposing part 362 Opening 362A First opening 362B Second opening 369 First end wall 370 Second member 371 Upper wall section 375 Side wall 379 Second end wall 390, 390a, 390b, 390c, 390d Gas flow path 400 Busbar 410, 420 Cable 500 support 510 Support body 511 Bottom 512, 513, 522, 523 Connections 520 Cover material 520a Top section 529 Screw H Channel length La, Lb distance P0 exit position P1 first position P2 2nd position Pb, Pc1, Pc2, Pd intermediate position S cross-sectional area S0, Sa0 outlet cross-sectional area S1, Sa1 first cross-sectional area S2, Sa2 second cross section W Flow path width W0, Wb0, Wc0, Wd0 Exit width W1, Wb1, Wc1, Wd1 First width W2, Wb2, Wc2, Wd2 Second width

Claims

1. A first storage element and a second storage element arranged in a first direction; A flow path forming member, the first storage element is provided with a first gas exhaust valve in a second direction perpendicular to the first direction; the second storage element includes a second gas exhaust valve in the second direction; The flow path forming member is facing the first gas exhaust valve and the second gas exhaust valve in the second direction, forming a gas flow path extending in the first direction; and An outlet for discharging the gas to the outside is provided, In the first direction, a distance between a first position, which is a position of the first gas exhaust valve, and the outlet is shorter than a distance between a second position, which is a position of the second gas exhaust valve, and the outlet; When a width of the gas flow passage in the flow passage forming member in a third direction perpendicular to the first direction and the second direction is defined as a flow passage width, a first width which is the flow passage width at the first position is larger than a second width which is the flow passage width at the second position. Energy storage device.

2. the flow path width increases from the second position toward the first position, The power storage device according to claim 1.

3. In the first direction, the width of the gas flow path in the second direction is constant. The electricity storage device according to claim 1 or 2.

4. a width of the gas flow path in the second direction increases from the second position toward the first position; The electricity storage device according to claim 1 or 2.

5. the flow path forming member includes an opposing wall portion opposing the first energy storage element and the second energy storage element in the second direction, The opposing wall portion includes a first opening and a second opening, The first opening is disposed at a position opposite to the first gas exhaust valve, The second opening is disposed at a position opposite to the second gas exhaust valve. The electricity storage device according to claim 1 or 2.

6. A first storage element and a second storage element arranged in a first direction; A flow path forming member, the first storage element is provided with a first gas exhaust valve in a second direction perpendicular to the first direction; the second storage element includes a second gas exhaust valve in the second direction; The flow path forming member is facing the first gas exhaust valve and the second gas exhaust valve in the second direction, forming a gas flow path extending in the first direction; and An outlet for discharging the gas to the outside is provided, In the first direction, a distance between a first position, which is a position of the first gas exhaust valve, and the outlet is shorter than a distance between a second position, which is a position of the second gas exhaust valve, and the outlet; In the gas flow passage in the flow passage forming member, a first cross-sectional area which is a cross-sectional area at the first position is larger than a second cross-sectional area which is a cross-sectional area at the second position, and an outlet cross-sectional area which is a cross-sectional area at the outlet is larger than the first cross-sectional area, The cross-sectional area is a cross-sectional area of ​​the gas flow path perpendicular to the first direction. Energy storage device.

7. The outlet cross-sectional area is the maximum cross-sectional area of ​​the gas flow path. The power storage device according to claim 6.

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