Power storage device

Abstract

To provide a power storage device which enables improvement of vibration resistance and impact resistance of power storage element units respectively including power storage elements.SOLUTION: A power storage device 10 includes: a plurality of power storage element units 200 respectively including power storage elements; and a case which houses the power storage element units. The case includes three or more wall members 320, 330 formed by separate bodies. At least two of the three or more wall members sandwich the power storage element units in a predetermined direction and contact with the power storage element units in the predetermined direction.SELECTED DRAWING: Figure 7

Description

Technical Field

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

Background Art

[0002] Patent Document 1 discloses a power supply system in which a plurality of battery modules each including a plurality of single cells are stacked and arranged with a spacer interposed between the battery modules.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the power supply system disclosed in Patent Document 1, a plurality of battery modules are fixed with spacers, but a configuration that can further improve the vibration resistance or shock resistance of the plurality of battery modules against external vibration, impact, etc. is desirable.

[0005] The present invention has been made by the inventors of the present application newly focusing on the above problems, and an object thereof is to provide a power storage device capable of improving the vibration resistance or shock resistance of a plurality of power storage element units each including a plurality of power storage elements.

Means for Solving the Problems

[0006] A power storage device according to an aspect of the present invention includes a plurality of power storage element units each including a plurality of power storage elements, and a case that houses the plurality of power storage element units, the case including three or more wall members configured separately, and at least two of the three or more wall members sandwich the plurality of power storage element units in a predetermined direction and contact the plurality of power storage element units in the predetermined direction.

Advantages of the Invention

[0007] According to the power storage device of the present invention, the vibration resistance or shock resistance of a plurality of power storage element units each including a plurality of power storage elements can be improved.

Brief Description of the Drawings

[0008]

Figure 1

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Embodiments for Carrying Out the Invention

[0009] (1) A power storage device according to one aspect of the present invention includes a plurality of power storage element units each including a plurality of power storage elements, and a case that houses the plurality of power storage element units. The case includes three or more wall members configured separately, and at least two of the three or more wall members sandwich the plurality of power storage element units in a predetermined direction and contact the plurality of power storage element units in the predetermined direction.

[0010] According to this, in the power storage device, at least two of the three or more wall members included in the case sandwich the plurality of power storage element units in a predetermined direction and contact the plurality of power storage element units in the predetermined direction. Thereby, the two wall members of the case can sandwich and hold the plurality of power storage element units in the predetermined direction, so that the movement of the plurality of power storage element units in the case can be suppressed. Therefore, the vibration resistance or shock resistance of the plurality of power storage element units each including a plurality of power storage elements can be improved.

[0011] (2) In the power storage device according to (1) above, each of the plurality of power storage element units includes an external terminal protruding in the predetermined direction and a protruding portion protruding in the predetermined direction more than the external terminal, and the two wall members may sandwich the plurality of power storage element units at the position of the protruding portion.

[0012] According to this, each of the plurality of power storage element units includes a protruding portion protruding in a predetermined direction more than the external terminal, so that even if the two wall members sandwich the plurality of power storage element units at the position of the protruding portion, the protruding portion contacts the wall member. It is desirable that no stress other than the connection structure is applied to the external terminal, which is an electrical connection portion. By the protruding portion contacting the wall member, the power storage element unit can be sandwiched without the external terminal and the wall member contacting each other at the portion where the external terminal is disposed.

[0013] (3) In the power storage device according to the above (1) or (2), the three or more wall members may further sandwich the plurality of power storage element units in a direction intersecting the predetermined direction and contact the plurality of power storage element units in that direction.

[0014] According to this, since the plurality of power storage element units can be sandwiched and held by the wall members of the case in two directions, the movement of the plurality of power storage element units in the case can be further suppressed.

[0015] (4) In the power storage device according to any one of the above (1) to (3), at least one of the three or more wall members may integrally include two walls facing different directions.

[0016] According to this, since the wall member of the case integrally includes two walls, the number of components of the members constituting the case can be reduced. Since the connection portions between the wall members can be reduced, the connection work between the wall members can be reduced, and space saving at the connection portions can also be achieved.

[0017] (5) The power storage device according to any one of the above (1) to (4) may further include an elastic member disposed between at least one of the two wall members and the plurality of power storage element units, and the two wall members may contact the plurality of power storage element units in the predetermined direction via the elastic member.

[0018] According to this, when the two wall members of the case contact the plurality of power storage element units in the predetermined direction via the elastic member, the elastic force of the elastic member can sandwich and hold the plurality of power storage element units in a state where the two wall members compress them. Thereby, the movement of the plurality of power storage element units in the case can be further suppressed.

[0019] (6) In the power storage device according to any one of (1) to (5) above, among two adjacent wall members provided by the three or more wall members, one of the wall members includes a main body portion, and an opposing portion that bends from the main body portion and faces the other wall member, and the opposing portion may be joined to the other wall member.

[0020] According to this, by joining the opposing portion that bends from the main body portion of one wall member of the case and faces the other wall member to the other wall member, one wall member and the other wall member can be easily joined.

[0021] (7) In the power storage device according to (6) above, the other wall member may be disposed outside the case rather than the opposing portion.

[0022] According to this, since the other wall member is disposed outside the case rather than the opposing portion, when joining the other wall member and the opposing portion, the other wall member approaches the opposing portion from the outside and is joined to the opposing portion. As a result, the other wall member approaches the power storage element unit toward the inside of the case, and it is easy to press the other wall member toward the power storage element unit.

[0023] (8) In the power storage device according to (6) or (7) above, the other wall member may include a thin portion having a small thickness, and the opposing portion may be joined to the thin portion.

[0024] According to this, by joining the opposing portion of one wall member to the thin portion of the other wall member, it is possible to suppress an increase in the thickness of the joined portion, so that space can be saved (the dimensions of the case can be reduced).

[0025] (9) In the power storage device according to any one of (6) to (8) above, the other wall member may have a shape that protrudes toward the plurality of power storage element units.

[0026] According to this, it is easy to bring the other wall member into contact with the plurality of power storage element units.

[0027] Hereinafter, with reference to the drawings, a power storage device according to an embodiment (including its modifications) of the present invention will be described. Each of the embodiments described below shows comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement positions and connection forms of the components, manufacturing processes, order of manufacturing processes, etc. shown in the following embodiments are examples and are not intended to limit the present invention. In each figure, the dimensions and the like are not strictly illustrated. In each figure, the same or similar components are denoted by the same reference numerals.

[0028] In the following description and drawings, the opposing direction of a pair of short side walls of the inner case of the power storage device, the first alignment direction of a plurality of power storage element units, the alignment direction of the main body and the lid of the container of the power storage element, or the protruding direction of the terminal of the power storage element is defined as the X-axis direction. The opposing direction of a pair of long side walls of the inner case of the power storage device, the protruding direction of the external terminal of the power storage element unit, the opposing direction of the short side surfaces of the container of the power storage element, or the alignment direction of a pair of terminals provided in the power storage element is defined as the Y-axis direction. The opposing direction between the upper wall and the bottom wall of the inner case, the second alignment direction of a plurality of power storage element units, the alignment direction between the power storage element unit (power storage unit) and the electrical component, the alignment direction of a pair of external terminals provided in the power storage element unit, the opposing direction of the long side surfaces of the container of the power storage element, or the vertical direction is defined as the Z-axis direction. These X-axis direction, Y-axis direction and Z-axis direction are directions that intersect (orthogonal in this embodiment) with each other.

[0029] In the following description, the positive X-axis direction indicates the direction of the arrow on the X-axis, and the negative X-axis direction indicates the direction opposite to the positive X-axis direction. When simply referring to the X-axis direction, it indicates both directions of the positive X-axis direction and the negative X-axis direction or either one of them. The same applies to the Y-axis direction and the Z-axis direction. Hereinafter, the Z-axis direction may also be referred to as the first direction, the X-axis direction may also be referred to as the second direction, and the Y-axis direction may also be referred to as the third direction. Expressions indicating relative directions or postures such as parallel and orthogonal include cases where they are not strictly in that direction or posture. For example, when two directions are parallel, it means not only that the two directions are completely parallel but also that they are substantially parallel, that is, including a difference of, for example, about several percent. In the following description, when expressing "insulation", it means "electrical insulation". A material having insulation properties is preferably formed from a material having a volume resistivity of 1×10 10 Ωm or more.

[0030] (Embodiment) [1 General description of the power storage device 10] First, a general description of the power storage device 10 in the present embodiment will be given. FIG. 1 is a perspective view showing the appearance of the power storage device 10 according to the present embodiment. FIG. 2 is a perspective view showing a state in which the lid member 140 and the first fixing member 700 are removed from the power storage device 10 according to the present embodiment. FIG. 3 is a perspective view showing the internal configuration of the outer case 100 of the power storage device 10 according to the present embodiment. In FIG. 3, a state in which the power storage unit 20, the elastic member 800, and the gasket 900 are taken out from the inside of the outer case 100 is shown. In FIG. 3, the lid member 140 and the first fixing member 700 shown in FIG. 2 are not shown. FIG. 4 is an exploded perspective view and a cross-sectional view showing the configuration of the outer case 100 included in the power storage device 10 according to the present embodiment. FIG. 4(a) is an exploded perspective view showing each component when the outer case 100 is disassembled. FIG. 4(b) is a cross-sectional view showing the configuration when the end portion of the outer case 100 in the negative Z-axis direction (the portion including the intermediate member 130) is cut by a plane parallel to the YZ plane. In FIG. 4, the lid member 140 included in the outer case 100 shown in FIG. 2 is not shown. FIG. 5 is an exploded perspective view showing the configuration of the power storage unit 20 included in the power storage device 10 according to the present embodiment. For convenience of explanation, in FIG. 1, a state in which the case lid 150 is removed from the case body 110 of the outer case 100 is shown, and the case lid 150 is not shown from FIG. 2 onwards.

[0031] The power storage device 10 is a device that can charge electricity from the outside and discharge electricity to the outside. In this embodiment, it has a substantially rectangular parallelepiped shape. A rectangular parallelepiped is a hexahedron composed of all rectangular or square faces. The power storage device 10 is used for power storage applications or power supply applications, etc. The power storage device 10 is used as a battery for driving a moving body such as a forklift, construction machinery, agricultural machinery, automatic guided vehicle (AGV), automobile, motorcycle, watercraft, ship, snowmobile, or a railway vehicle for electric railways, or for engine starting, etc. Examples of the above-mentioned automobiles include electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and fossil fuel (gasoline, light oil, liquefied natural gas, etc.) automobiles. Examples of the above-mentioned railway vehicles for electric railways include trains, monorails, linear motor cars, and hybrid trains equipped with both a diesel engine and an electric motor. The power storage device 10 can also be used as a stationary battery for household or business use, etc.

[0032] As shown in FIGS. 1 to 3, etc., the power storage device 10 includes an outer case 100, a power storage unit 20, a first fixing member 700, an elastic member 800, and a gasket 900. As shown in FIGS. 1 to 4, the outer case 100 includes a case body 110, a weight 120, an intermediate member 130, a lid member 140, and a case lid 150. As shown in FIGS. 3 and 5, etc., the power storage unit 20 includes a power storage unit body 30 composed of a plurality of power storage element units 200, etc., an inner case 300, an elastic member 400, a connector 500, electrical components 510, a cover 600, a control wiring member 514, and main circuit wiring members such as a first wiring member 515 and a second wiring member 516 (see FIGS. 7 and 8).

[0033] [1.1 Explanation of the outer case 100] The outer case 100 is a rectangular parallelepiped-shaped (box-shaped) container (outer box) that constitutes the outer case (outer packaging body, housing, outer shell) of the power storage device 10. The outer case 100 is arranged outside the power storage unit 20, the first fixing member 700, the elastic member 800, the gasket 900, etc., houses the power storage unit 20, etc., fixes the power storage unit 20, etc. at a predetermined position, and protects it from impacts and the like. Hereinafter, the case body 110, the weight 120, the intermediate member 130, the lid member 140, and the case lid body 150 included in the outer case 100 will be described in detail.

[0034] The case body 110 is a box-shaped member that constitutes the main body of the outer case 100. The case body 110 is a bottomed rectangular cylindrical container in which a rectangular opening 100a is formed in the positive Z-axis direction. The case lid body 150 is a flat plate-shaped member that constitutes the lid of the outer case 100. The case lid body 150 is connected (joined) to the case body 110 and closes the opening 100a of the case body 110. The case lid body 150 is not limited to a flat plate shape as long as it can close the opening 100a, and may be a bottomed rectangular cylindrical shape or any other shape. The case body 110 and the case lid body 150 are metal cases formed of metal members such as steel plates, plated steel plates, iron, aluminum, aluminum alloys, and stainless steel. The case body 110 or the case lid body 150 may be formed of an insulating member such as any resin material that can be used for the terminal cover 260 of the power storage element unit 200 described later.

[0035] The case body 110 includes outer case side walls 111, which are a pair of flat plate-shaped and rectangular long side walls, on both sides in the Y-axis direction, and outer case side walls 112, which are a pair of flat plate-shaped and rectangular short side walls, on both sides in the X-axis direction. The case body 110 includes an outer case bottom wall 113, which is a flat plate-shaped and rectangular bottom wall, in the negative Z-axis direction. Thereby, an opening 100a is formed on the side opposite to the outer case bottom wall 113 of the case body 110. That is, the outer case 100 has an opening 100a on the side opposite to the outer case bottom wall 113.

[0036] The outer case side wall 111 is a wall that faces (is orthogonal to) in the Y-axis direction and is disposed at the end of the case body 110 in the Y-axis direction. The outer case side wall 112 is a wall that faces (is orthogonal to) in the X-axis direction and is disposed at the end of the case body 110 in the X-axis direction. The outer case bottom wall 113 is a wall that faces (is orthogonal to) in the Z-axis direction and is disposed at the end of the case body 110 in the minus Z-axis direction. Depending on the configuration (number, size, shape, etc.) of the contents of the outer case 100, etc., the case body 110 (outer case side walls 111, 112, outer case bottom wall 113) may have any shape. In this case, the outer case side wall 111 may be a short side wall and the outer case side wall 112 may be a long side wall.

[0037] At least one of the outer case side walls 111, 112 and the outer case bottom wall 113 is formed with a through portion which is an opening (through hole, through aperture) that penetrates the wall. In the present embodiment, a through portion 111a that penetrates the outer case side wall 111 in the Y-axis direction is formed in the outer case side wall 111. Further, a plurality of through portions 111a are formed in at least one of the outer case side walls 111, 112 and the outer case bottom wall 113. In the present embodiment, through portions 111a are formed in each of the pair of outer case side walls 111. That is, two through portions 111a are formed in the two opposing outer case side walls 111 provided in the outer case 100. The through portion 111a is a rectangular opening formed at the end of the outer case side wall 111 in the minus Z-axis direction and extending in the X-axis direction when viewed from the Y-axis direction.

[0038] A connector opening 112a is formed in the outer case side wall 112 in the plus X-axis direction. The connector opening 112a is a rectangular through hole disposed at the end of the outer case side wall 112 in the plus X-axis direction in the plus Z-axis direction, and the connector 500 penetrates therethrough.

[0039] The outer case 100 is further formed with openings 111b and 112b. That is, the openings 111b are formed in each of the pair of outer case side walls 111, and the openings 112b are formed in each of the pair of outer case side walls 112. The openings 111b and 112b are circular through-holes provided at the Z-axis plus direction ends of the outer case side walls 111 and 112. By means of the openings 111b and 112b, liquids such as water or condensed water that enter the outer case 100 are discharged to the outside of the outer case 100.

[0040] The weight 120 is a weight disposed inside the case body 110. The weight 120 is a weight (counterweight) for adjusting the weight of the power storage device 10. The weight of the weight 120 is appropriately determined as the weight required for adjusting the weight of the power storage device 10. The total weight of all the weights 120 provided in the power storage device 10 is preferably 1 / 5 or more, more preferably 1 / 4 or more, and even more preferably 1 / 3 or more of the total weight of the power storage device 10. The material of the weight 120 is not particularly limited, and it can be formed of any metal member such as a steel plate, a plated steel plate, iron, aluminum, an aluminum alloy, or stainless steel that can be used for the case body 110.

[0041] As shown in FIG. 4, the weight 120 includes a pair of flat plate-shaped and rectangular weights 121 parallel to the XZ plane on both sides in the Y-axis direction, and a pair of flat plate-shaped and rectangular weights 122 parallel to the YZ plane on both sides in the X-axis direction. The weight 120 further includes a rectangular ring-shaped connecting member 123 and an auxiliary member 124 in the Z-axis plus direction of the pair of weights 121 and the pair of weights 122, as viewed from the Z-axis direction.

[0042] The weight 121 is arranged to face and contact the outer case side wall 111 of the case body 110. The weight 121 is joined (fixed) to the outer case side wall 111 by welding (such as spot welding) or the like. In the present embodiment, a pair of weights 121 are joined (fixed) to the inner surfaces of the pair of outer case side walls 111. The weight 122 is arranged to face and contact the outer case side wall 112 of the case body 110. The weight 122 is joined (fixed) to the outer case side wall 112 by welding (such as spot welding) or the like. In the present embodiment, a pair of weights 122 are joined (fixed) to the inner surfaces of the pair of outer case side walls 112. The weights 121 and 122 may be joined (fixed) to the outer case side walls 111 and 112 by adhesion with an adhesive or double-sided tape, welding, bolt connection, caulking joint, or the like. The weight 121 is shorter than the weight 122 in the Z-axis direction. The Z-axis plus direction ends of the weight 121 and the weight 122 are arranged at the same position in the Z-axis direction. Thereby, a space is formed between the weight 121 in the Z-axis minus direction and the pair of weights 122, and the intermediate member 130 is arranged in this space.

[0043] The connecting member 123 and the auxiliary member 124 are members to which the partition wall 340 of the inner case 300 described later is fixed (see FIG. 7 etc.). That is, the connecting member 123 is a member that connects the outer case 100 and the upper wall (partition wall 340) of the inner case 300. A plurality of fixing portions 123a and 124a for fixing the power storage unit 20 (partition wall 340) are provided on the connecting member 123 and the auxiliary member 124. The connecting member 123 is joined (fixed) to the pair of weights 121 and the pair of weights 122 by welding or the like, and the auxiliary member 124 is joined (fixed) to the connecting member 123 by welding or the like. In the present embodiment, the connecting member 123 is divided into four members corresponding to each of the pair of weights 121 and the pair of weights 122, but it may be divided into any number of members or may be formed of one member. The same applies to the auxiliary member 124. The auxiliary member 124 is formed to be thinner in the Z-axis direction than the connecting member 123. The auxiliary member 124 is arranged along the gasket 900 and has a function of restricting the thickness of the gasket 900 in the Z-axis direction so as not to excessively crush the gasket 900. The auxiliary member 124 has approximately the same thickness as the gasket 900 and is thinner than the thickness of the gasket 900 before being crushed.

[0044] The intermediate member 130 is a member to which the first fixing member 700 is fixed. By fixing the intermediate member 130 to the case body 110, the first fixing member 700 is fixed to the case body 110. Specifically, the intermediate member 130 is arranged surrounded by one weight 121, the pair of weights 122, and the outer case bottom wall 113, and is fixed to the case body 110 by being joined (fixed) to at least one of these by welding or the like. At least a part (in the present embodiment, the whole of the intermediate member 130) of the intermediate member 130 is arranged in the through-hole 111a of the outer case side wall 111 when viewed from the Y-axis direction. In the present embodiment, a pair of intermediate members 130 are arranged on both sides of the outer case 100 in the Y-axis direction.

[0045] As shown in FIG. 4, the intermediate member 130 includes an intermediate member main body 131, an auxiliary member 132, and a gasket 133. The intermediate member main body 131 includes a rectangular annular frame body 131a that is long in the X-axis direction when viewed from the Y-axis direction, and a column portion 131b that is disposed at the central portion of the frame body 131a in the X-axis direction and extends in the Z-axis direction. The column portion 131b has a function of reinforcing the central portion of the frame body 131a in the X-axis direction and suppressing deformation of the frame body 131a. A plurality of fixing portions 131c for fixing the lid member 140 are provided on the frame body 131a and the column portion 131b. A plurality of fixing portions 131d for fixing the first fixing member 700 are provided on the frame body 131a.

[0046] Similar to the intermediate member main body 131, the auxiliary member 132 includes a rectangular annular frame body 132a that is long in the X-axis direction when viewed from the Y-axis direction, and a column portion 132b that is disposed at the central portion of the frame body 132a in the X-axis direction and extends in the Z-axis direction. A plurality of fixing portions 132c for fixing the lid member 140 are provided on the frame body 132a and the column portion 132b. The auxiliary member 132 is formed to be thinner in the Y-axis direction than the intermediate member main body 131, and is joined (fixed) to the intermediate member main body 131 by welding or the like. The gasket 133 is a rectangular annular gasket that is disposed on the intermediate member main body 131 along the outer periphery of the auxiliary member 132 and is long in the X-axis direction when viewed from the Y-axis direction. That is, the auxiliary member 132 is a member for increasing the bulk of the intermediate member main body 131. The gasket 133 is disposed in a step portion (groove portion) formed on the intermediate member main body 131 and on the outer periphery of the auxiliary member 132. The auxiliary member 132 is disposed along the gasket 133 and has a function of restricting the thickness of the gasket 133 in the Y-axis direction so as not to excessively crush the gasket 133.

[0047] The materials of the intermediate member body 131 and the auxiliary member 132 are not particularly limited, and they can be formed of any metal member such as a steel plate, a plated steel plate, iron, aluminum, an aluminum alloy, stainless steel, etc., that can be used for the case body 110. The material of the gasket 133 is also not particularly limited, and it can be formed of rubber such as natural rubber (NR), nitrile rubber (NBR), silicone rubber (Si), styrene butadiene rubber (SBR), chloroprene rubber (CR), butyl rubber (IIR), ethylene propylene rubber (EPDM), urethane rubber (U), fluororubber, etc., or a member having elasticity such as sponge, or any resin material that can be used for the terminal cover 260 of the power storage element unit 200 described later.

[0048] The lid member 140 is a member that closes the through-hole 111a of the outer case side wall 111 of the case body 110. The lid member 140 is fixed to the outer case side wall 111 by being attached to the intermediate member 130 to close the through-hole 111a. In the present embodiment, a pair of lid members 140 are arranged on both sides in the Y-axis direction of the outer case 100, and the through-holes 111a of the pair of outer case side walls 111 are closed by the pair of lid members 140. As shown in FIG. 2 and the like, the lid member 140 is a flat plate-shaped and rectangular member that is long in the X-axis direction parallel to the XZ plane, and has a plurality of fixing portions 141 on its outer peripheral portion. The fixing portion 141 is a member that attaches (fixes) the lid member 140 to the intermediate member 130 by being fixed to the intermediate member 130. In the present embodiment, the fixing portion 141 is a bolt having a male screw portion, passes through the fixing portion 132c of the auxiliary member 132, and is coupled to the female screw portion formed in the fixing portion 131c of the intermediate member body 131.

[0049] As described above, the outer case 100 is a rectangular parallelepiped, and a rectangular parallelepiped is a hexahedron. The outer case 100 is composed of six wall portions, and the wall portions constituting the outer case 100 are walls including at least one surface of the hexahedron. That is, the wall portions of the outer case 100 are formed by the outer case side wall 111 and the lid member 140. The outer case side wall 111 where the lid member 140 is not arranged and the through-hole 111a is formed may be defined as the wall portion of the outer case 100.

[0050] [1.2 Description of the power storage unit 20] Next, the power storage unit main body 30, inner case 300, elastic member 400, connector 500, electrical component 510, and cover 600 included in the power storage unit 20 will be described in detail.

[0051] As shown in FIG. 5 and FIG. 7 described later, the power storage unit main body 30 includes a power storage element unit group 31, a first bus bar 41, a second bus bar 42, a first conductive member 513, and electrical components (such as electrical component 511) that form part of the current path of the main circuit of the power storage unit main body 30. Specifically, the power storage unit main body 30 includes a plurality of power storage element unit groups 31 arranged in the X-axis direction (the second direction intersecting the first direction). In the present embodiment, six power storage element unit groups 31 are arranged side by side in the X-axis direction. Each of the plurality of power storage element unit groups 31 includes a plurality of power storage element units 200 arranged in the Z-axis direction (the first direction) and a third bus bar 43 that electrically connects the plurality of power storage element units 200. In the present embodiment, in each power storage element unit group 31, two power storage element units 200 are arranged side by side in the Z-axis direction. The number of power storage element unit groups 31 included in the power storage unit main body 30 and the number of power storage element units 200 included in the power storage element unit group 31 are not particularly limited, and any number of power storage element unit groups 31 may be arranged in the X-axis direction, and any number of power storage element units 200 may be arranged in the Z-axis direction. A plurality of power storage element units 200 (a plurality of power storage element unit groups 31) may be arranged in the Y-axis direction. The power storage unit main body 30 may include only one power storage element unit group 31. In the present embodiment, the plurality of power storage element units 200 included in the power storage element unit group 31 are connected in series, and the plurality of power storage element unit groups 31 are connected in parallel, but any of the power storage element units 200 may be connected in series or in parallel. A detailed description of the configuration of the power storage element unit 200 will be described later.

[0052] In this embodiment, two adjacent power storage element units 200 are in direct or indirect surface contact with each other. That is, the power storage element units 200 arranged in the X-axis direction are in surface contact in the X-axis direction, or are in surface contact in the X-axis direction on both sides of the member between the power storage element units 200. Examples of the member between the power storage element units 200 include an elastic member 421 or a member similar to the elastic member 420 described later. The power storage element units 200 arranged in the Z-axis direction are in surface contact in the Z-axis direction, or are in surface contact in the Z-axis direction on both sides of the member between the power storage element units 200. Examples of the member between the power storage element units 200 include a member similar to the elastic member 440 described later.

[0053] The inner case 300 is a substantially rectangular parallelepiped-shaped (box-shaped) container (inner box) that constitutes the inner case (housing) of the power storage device 10. The inner case 300 is disposed inside the outer case 100 (inside the outer case 100), houses and holds a plurality of power storage element units 200 (power storage unit main bodies 30), and protects them from impacts and the like. The inner case 300 is a metal case formed of a metal member such as a steel plate, a plated steel plate, iron, aluminum, an aluminum alloy, or stainless steel. In this embodiment, the inner case 300 is formed of a member of the same material as the outer case 100, but may be formed of a member of a different material from the outer case 100. The inner case 300 may be formed of an insulating member such as any resin material that can be used for the terminal cover 260 of the power storage element unit 200 described later.

[0054] The inner case 300 includes a pair of first wall members 310 that constitute a pair of long side walls of the inner case 300, a second wall member 320 that constitutes one short side wall, a third wall member 330 that constitutes the other short side wall and the bottom wall, and a partition wall 340 that constitutes the upper wall. In the present embodiment, the pair of first wall members 310, the second wall member 320, the third wall member 330, and the partition wall 340 are all configured separately. The third wall member 330 integrally includes a side wall 331 and a bottom wall 332 which are two walls facing different directions (X-axis direction and Z-axis direction). That is, the inner case 300 includes five wall members configured separately from each other. The inner case 300 may include four or three wall members in which any one of the wall members is integrated and configured separately. That is, the inner case 300 includes three or more wall members configured separately, and at least one of the three or more wall members (the third wall member 330) integrally includes two walls facing different directions. The side wall 331 and the bottom wall 332 of the third wall member 330 may be configured separately, and the inner case 300 may include six wall members configured separately.

[0055] The pair of first wall members 310 are flat plate-shaped and rectangular walls parallel to the XZ plane, which are arranged on both sides in the Y-axis direction of the power storage unit main body 30. The pair of first wall members 310 are joined (fixed) to the second wall member 320, the third wall member 330, and the partition wall 340 by means of bolting or the like. Each first wall member 310 is provided with a plurality of fixing portions 310b for fixing to the second wall member 320, a plurality of fixing portions 310c for fixing to the side wall 331 of the third wall member 330, and a plurality of fixing portions 310d for fixing to the bottom wall 332 of the third wall member 330. The fixing portion 310d is a bolt having a male screw portion and a hole into which the bolt is inserted, passes through a hole formed in a bottom wall facing portion 332d (described later) of the bottom wall 332, and is coupled to a female screw portion formed in the fixing portion 332a (see FIG. 10). The bolt of the fixing portion 310d is a separate bolt (fixing member), and the first wall member 310 includes the separate bolt (fixing member). Further, the first wall member 310 is provided with a plurality of fixing portions 310a for fixing the first fixing member 700.

[0056] The second wall member 320 is a flat plate-shaped and rectangular wall parallel to the YZ plane, which is arranged in the positive X-axis direction of the power storage unit main body 30. The second wall member 320 is joined (fixed) to the pair of first wall members 310, the bottom wall 332 and the partition wall 340 of the third wall member 330 by means of bolting or the like. The second wall member 320 is provided with a plurality of fixing portions 320a for fixing to the pair of first wall members 310, a plurality of fixing portions 320b for fixing to the bottom wall 332, and a plurality of fixing portions 320c for fixing to the partition wall 340. The fixing portion 320a is a bolt having a male screw portion and a hole into which the bolt is inserted, and is coupled to a female screw portion formed in the fixing portion 310b of the first wall member 310. The bolt of the fixing portion 320a is a separate bolt (fixing member), and the second wall member 320 includes the separate bolt (fixing member).

[0057] The side wall 331 of the third wall member 330 is a flat plate-shaped and rectangular wall parallel to the YZ plane, which is arranged in the negative X-axis direction of the power storage unit main body 30. The side wall 331 is joined (fixed) to the pair of first wall members 310 and the partition wall 340 by means of bolting or the like. The side wall 331 is provided with a plurality of fixing portions 331a for fixing to the pair of first wall members 310 and a plurality of fixing portions 331b for fixing to the partition wall 340. The fixing portion 331a is a bolt having a male screw portion and a hole into which the bolt is inserted, and is coupled to a female screw portion formed in the fixing portion 310c of the first wall member 310. The bolt of the fixing portion 331a is a separate bolt (fixing member), and the side wall 331 of the third wall member 330 includes the separate bolt (fixing member).

[0058] The bottom wall 332 of the third wall member 330 is a flat and rectangular wall parallel to the XY plane, which is arranged in the negative Z-axis direction of the power storage unit main body 30. The bottom wall 332 is joined (fixed) to the pair of first wall members 310 and second wall members 320 by means of bolting or the like. The bottom wall 332 is provided with a plurality of fixing portions 332a for fixing to the pair of first wall members 310 and a plurality of fixing portions 332b for fixing to the second wall member 320. The fixing portion 332b is a bolt having a male screw portion and a hole into which the bolt is inserted, passes through the hole (the hole formed in the second thin wall portion 320f) provided in the fixing portion 320b of the second wall member 320, and is coupled to the female screw portion formed in a separate nut provided in the fixing portion 320b. The bolt of the fixing portion 332b is a bolt integrally formed with the bottom wall 332 of the third wall member 330, and the bottom wall 332 of the third wall member 330 includes the integrally formed bolt.

[0059] The partition wall 340 is a flat and rectangular wall parallel to the XY plane, which is arranged in the positive Z-axis direction of the power storage unit main body 30. The partition wall 340 is joined (fixed) to the pair of first wall members 310, second wall members 320, and the side wall 331 of the third wall member 330 by means of bolting or the like. The partition wall 340 is provided with a plurality of fixing portions 342 for fixing to the pair of first wall members 310, second wall members 320, and side wall 331. The fixing portion 342 is a bolt having a male screw portion and a hole into which the bolt is inserted, and is coupled to the female screw portions formed in the fixing portion 310e of the first wall member 310, the fixing portion 320c of the second wall member 320, and the fixing portion 331b of the side wall 331. The bolt of the fixing portion 342 is a separate bolt (fixing member), and the partition wall 340 includes the separate bolt (fixing member).

[0060] The partition wall 340 is further provided with a plurality of second fixing members 341 for fixing to the outer case 100, a plurality of openings 343 through which a first conductive member 513 described later penetrates, and a plurality of openings 344 through which a control wiring member 514 described later penetrates. The main circuit wiring member (second wiring member 516) penetrates the opening 343 at the X-axis plus direction end. The plurality of second fixing members 341 are arranged at predetermined intervals over the entire circumference of the outer peripheral portion of the partition wall 340. The plurality of openings 343 are arranged at predetermined intervals from one end to the other end in the X-axis direction at the Y-axis minus direction end of the partition wall 340. The plurality of openings 344 are arranged at predetermined intervals from one end to the other end in the X-axis direction at the Y-axis plus direction end of the partition wall 340.

[0061] The second fixing member 341 is a member for attaching (fixing) the partition wall 340 to the outer case 100 by being fixed to the weight 120 of the outer case 100. In the present embodiment, the second fixing member 341 is a bolt having a male screw portion, penetrates the fixing portion 124a of the auxiliary member 124 of the weight 120, and is coupled to the female screw portion formed in the fixing portion 123a of the connecting member 123. Thereby, when the partition wall 340 is fixed to the weight 120, the power storage unit 20 is fixed to the outer case 100. Since the partition wall 340 is disposed at a position closer to the opening 100a than the outer case bottom wall 113 of the outer case 100, the second fixing member 341 fixes the power storage unit 20 and the outer case 100 at a position closer to the opening 100a than the outer case bottom wall 113.

[0062] When the partition wall 340 is fixed to the weight 120, the space inside the outer case 100 is partitioned vertically. Thus, the partition wall 340 also serves to partition the space inside the outer case 100. That is, the space inside the outer case 100 is partitioned by the partition wall 340 which is a part of the inner case 300.

[0063] The pair of first wall members 310, second wall members 320, third wall members 330, and partition wall 340 may be joined by welding, adhesion, or the like. The pair of first wall members 310, second wall members 320, third wall members 330, and partition wall 340 may all be formed of members of the same material, or any of them may be formed of members of different materials. Depending on the size, shape, etc. of the power storage unit main body 30, the pair of first wall members 310, second wall members 320, third wall members 330, and partition wall 340 may have any shape. In this case, the pair of first wall members 310 may be short side walls, and the side walls 331 of the second wall members 320 and third wall members 330 may be long side walls.

[0064] The elastic member 400 is a member disposed between at least one of the two wall members sandwiching the plurality of power storage element units 200 provided in the inner case 300 and the plurality of power storage element units 200. The elastic member 400 is a sheet-like elastic member having functions such as tolerance absorption, vibration suppression, or anti-slip. The elastic member 400 can be formed of an elastic member or the like among those that can be used for the gasket 133 described above. In the present embodiment, the elastic member 400 is disposed between each of the two wall members sandwiching the power storage unit main body 30 and the power storage unit main body 30 in three directions of the X-axis direction, Y-axis direction, and Z-axis direction.

[0065] Specifically, an elastic member 410 is disposed between the pair of first wall members 310 and the power storage unit main body 30 (such as the protruding portion 221 of the power storage element unit 200 described later). An elastic member 420 is disposed between the second wall member 320 and the power storage unit main body 30. Further, an elastic member 421 is disposed at a recessed position on the surface of the power storage element unit 200 in the positive X-axis direction. An elastic member 430 is disposed between the side wall 331 of the third wall member 330 and the power storage unit main body 30. An elastic member 440 is disposed between the bottom wall 332 of the third wall member 330 and the power storage unit main body 30. An elastic member 450 is disposed between the partition wall 340 and the power storage unit main body 30.

[0066] With this configuration, the pair of first wall members 310 sandwich the power storage unit main body 30 in a state of compressing it in the Y-axis direction. The side walls 331 of the second wall member 320 and the third wall member 330 sandwich the power storage unit main body 30 in a state of compressing it in the X-axis direction. The bottom wall 332 and the partition wall 340 of the third wall member 330 sandwich the power storage unit main body 30 in a state of compressing it in the Z-axis direction.

[0067] The connector 500 is a connector that electrically connects the power storage element unit 200 in the power storage unit main body 30 and the wiring outside the power storage device 10 (for example, the wiring of an external charger not shown). The connector 500 is electrically connected to the power storage element unit 200 via a main circuit wiring member described later. The connector 500 is also connected to the electronic components (electronic circuits) provided in the electrical component 510 via a control wiring different from the control wiring member 514. The connector 500 is disposed on the partition wall 340, and the end portion in the positive X-axis direction protrudes from the connector opening 112a of the outer case 100 (see FIGS. 1, 3, etc.). That is, at least a part of the connector 500 is disposed inside the outer case 100. The connector 500 may not protrude from the connector opening 112a, and all the connectors 500 may be disposed inside the outer case 100.

[0068] The electrical component 510 is an electrical component that is electrically connected to the power storage element unit 200 in the power storage unit main body 30. The electrical component 510 is disposed on the partition wall 340. The electrical component 510 includes electronic components such as a circuit board, a relay (magnetic contactor), a fuse, and a current sensor (Hall sensor) for monitoring or controlling the state (voltage, temperature, charge / discharge state, etc.) of the power storage element unit 200, and wiring.

[0069] Cover 600 is a cover member that covers the electrical component 510. Cover 600 is disposed on the partition wall 340 so as to cover the electrical component 510 on the partition wall 340. Cover 600 also covers the fixing portion 342, the opening 343, and the opening 344 of the partition wall 340 (see FIG. 3). That is, within the range covered by cover 600, the electrical component 510, and the fixing portion 342, the opening 343, and the opening 344 of the partition wall 340 are disposed. The gap between cover 600 and partition wall 340 is filled by caulking or welding or the like, and waterproofing treatment is performed. Thereby, in a state where partition wall 340 vertically partitions the space within outer case 100, power storage unit main body 30 is waterproofed, and electrical components 510 and the like are waterproofed.

[0070] Cover 600 is a box-shaped member and includes a wire holding portion 610 on the side surface in the positive X-axis direction. Wire holding portion 610 is a member that allows a wire to be inserted and held. The side surface of cover 600 and wire holding portion 610 face connector 500. In each wire holding portion 610, a main circuit wiring member for the positive and negative electrodes for charging, a control wiring member (not shown), and the like are inserted and held. One end of the wire for charging is connected to connector 500, and the other end is connected to the main circuit wiring member within cover 600. Wire holding portion 610 has waterproof properties and prevents water from entering into cover 600. Wire holding portion 610 also holds a wire for discharging (not shown). Wire holding portion 610 may hold a wire for both charging and discharging.

[0071] [1.3 Description of the First Fixing Member 700] Next, the first fixing member 700 will be described in detail.

[0072] The first fixing member 700 is a member that is housed in the outer case 100 and fixes the power storage unit 20 and the outer case 100. The first fixing member 700 is fixed to the first wall member 310 of the inner case 300 of the power storage unit 20 and the intermediate member 130 of the outer case 100. Thereby, the first fixing member 700 is disposed at a position facing the through portion 111a of the outer case side wall 111 of the outer case 100 (a position where at least a part of the first fixing member 700 is exposed from the through portion 111a). In the present embodiment, a plurality of first fixing members 700 are disposed corresponding to the plurality of through portions 111a of the outer case 100. Specifically, two first fixing members 700 are disposed corresponding to the two through portions 111a formed in the pair of outer case side walls 111 of the case main body 110.

[0073] As shown in FIG. 2, the first fixing member 700 includes two fixing member main bodies 710 arranged in the X-axis direction, and a plurality of reinforcing portions 720 provided on the two fixing member main bodies 710. The two fixing member main bodies 710 are disposed on both sides in the X-axis direction of the column portion 131b of the intermediate member main body 131 of the intermediate member 130. Each fixing member main body 710 is a plate-like member that is L-shaped when viewed from the X-axis direction and extends in the X-axis direction. The reinforcing portion 720 is a triangular and plate-like reinforcing rib when viewed from the X-axis direction.

[0074] Each fixing member main body 710 includes a plurality of fixing portions 711 for fixing to the outer case 100 and a plurality of fixing portions 712 for fixing to the power storage unit 20. The fixing portion 711 is disposed on a flat plate-like portion parallel to the XY plane at the end portion in the minus Z-axis direction of the fixing member main body 710. The fixing portion 711 is a bolt having a male screw portion, and is coupled to a female screw portion formed in the fixing portion 131d of the intermediate member main body 131 of the intermediate member 130. The fixing portion 712 is disposed on a flat plate-like portion parallel to the XZ plane at the end portion in the plus Y-axis direction of the fixing member main body 710. The fixing portion 712 is a bolt having a male screw portion, and is coupled to a female screw portion formed in the fixing portion 310a of the first wall member 310 of the inner case 300. The reinforcing portion 720 is disposed at a position adjacent in the X-axis direction to each of the fixing portion 711 and the fixing portion 712 having the same position in the X-axis direction.

[0075] [1.4 Description of Elastic Member 800 and Gasket 900] Next, the elastic member 800 and the gasket 900 will be described in detail.

[0076] The elastic member 800 is a member disposed between the power storage unit 20 and the outer case bottom wall 113 of the outer case 100. Similar to the elastic member 400, the elastic member 800 is a sheet-like elastic member having functions such as tolerance absorption, vibration suppression, or anti-slip. The elastic member 800 can be formed of any member that can be used for the elastic member 400.

[0077] The gasket 900 is a member disposed between the partition wall 340 of the inner case 300 of the power storage unit 20 and the outer case 100. The gasket 900 is a rectangular annular member disposed along the outer peripheral portion outside the second fixing member 341 on the partition wall 340. Specifically, the gasket 900 is disposed between the partition wall 340 and the weight 120. In the present embodiment, the gasket 900 is divided into four members corresponding to each of the pair of weights 121 and the pair of weights 122, but it may be divided into any number of members or may be formed of one member. The gasket 900 can be formed of any member that can be used for the gasket 133 of the intermediate member 130.

[0078] [2 Description of Power Storage Element Unit 200] Next, the configuration of the energy storage element unit 200 will be described in detail. FIG. 6 is a perspective view showing the configuration of the energy storage element unit 200 according to the present embodiment. FIG. 6(a) shows an enlarged view of one energy storage element unit 200 shown in FIG. 5, and the energy storage element 210 and the external terminals 250 located inside are shown by broken lines. FIG. 6(b) is a perspective view showing the end portion of the energy storage element unit 200 in the +Y-axis direction when the energy storage element unit 200 shown in FIG. 6(a) is viewed from the opposite side (+Y-axis direction). Since the plurality of energy storage element units 200 included in the energy storage device 10 (energy storage unit 20, energy storage unit main body 30) all have the same configuration, FIG. 6 shows one energy storage element unit 200, and hereinafter, the configuration of one energy storage element unit 200 will be described in detail.

[0079] The energy storage element unit 200 is a substantially rectangular parallelepiped battery module (battery pack) that can charge electricity from the outside and discharge electricity to the outside. As shown in FIG. 6, the energy storage element unit 200 includes a plurality of energy storage elements 210, a pair of end plates 220, a pair of side plates 230, an exterior member 240, a pair (positive and negative) of external terminals 250, and a pair (positive and negative) of terminal covers 260. In addition to the above configuration, the energy storage element unit 200 also includes a spacer disposed between the energy storage elements 210, a bus bar that connects the terminals 212 of the plurality of energy storage elements 210, and a bus bar frame that positions the bus bar, etc., but illustration and detailed description thereof are omitted.

[0080] In the present embodiment, the depth direction (front-rear direction) of the energy storage element unit 200 is along the Y-axis direction (third direction). The surface of the side plate 230 in the -Y-axis direction in the -Y-axis direction and the surface of the exterior member 240 in the -Y-axis direction are referred to as the front surface of the energy storage element unit 200. The surface of the side plate 230 in the +Y-axis direction in the +Y-axis direction and the surface of the exterior member 240 in the +Y-axis direction are referred to as the rear surface of the energy storage element unit 200. The pair of external terminals 250 are disposed on the front surface of the energy storage element unit 200.

[0081] The energy storage element 210 is a secondary battery (single cell) that can charge and discharge electricity. More specifically, it is a non-aqueous electrolyte secondary battery such as a lithium-ion secondary battery. In the present embodiment, a plurality of energy storage elements 210 are arranged side by side in the Y-axis direction and the Z-axis direction, but the arrangement direction and number of the energy storage elements 210 are not particularly limited. In the present embodiment, the energy storage element 210 has a rectangular parallelepiped shape (square shape) that is flat in the Z-axis direction, but the shape of the energy storage element 210 is not limited to the rectangular parallelepiped shape, and may be a polygonal prism shape, a cylindrical shape, an elliptical cylinder shape, an elliptical cylinder shape, etc. other than the rectangular parallelepiped shape. The energy storage element 210 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 210 may be a primary battery instead of a secondary battery. The energy storage element 210 may be a battery using a solid electrolyte. The energy storage element 210 may be a pouch-type energy storage element.

[0082] The energy storage element 210 includes a container 211 and terminals 212 which are a pair of (positive and negative) electrode terminals. Inside the container 211, an electrode body, a pair of (positive and negative) current collectors, an electrolytic solution (non-aqueous electrolyte), etc. are accommodated, but their illustration and detailed description are omitted. The container 211 includes a container body having an opening formed therein and a lid portion that closes the opening of the container body, and the terminals 212 are arranged in a state of protruding in the negative X-axis direction from the lid portion. The terminals 212 are electrically connected to the positive and negative electrode plates of the electrode body via a conductive current collector. The electrode body is an energy storage element (power generation element) formed by laminating a positive electrode plate, a negative electrode plate, and a separator.

[0083] A pair of end plates 220 and a pair of side plates 230 are restraining members that sandwich a plurality of power storage elements 210 from both sides in the Z-axis direction, thereby compressing (restraining) each power storage element 210 from both sides in the Z-axis direction. The restraining member is composed of a first restraining member (end plate 220) and a second restraining member (side plate 230). In other words, a pair of end plates 220 and a pair of side plates 230 are holding members that hold a plurality of power storage elements 210. The holding member is composed of a first holding member (end plate 220) and a second holding member (side plate 230). The end plates 220 and the side plates 230 are formed of metal members such as steel or stainless steel from the viewpoint of ensuring strength, etc., but their materials are not particularly limited, and they may be formed of highly strong insulating members, or the metal members may be subjected to an insulation treatment.

[0084] A pair of end plates 220 are plate-shaped and rectangular members that are arranged on both sides of a plurality of power storage elements 210 in the Z-axis direction and sandwich and hold the plurality of power storage elements 210 from both sides in the Z-axis direction. The end plate 220 may be a flat block-shaped member or the like instead of a plate shape. The end plate 220 includes a protruding portion 221 that protrudes in the minus Y-axis direction and a protruding portion 222 that protrudes in the plus Y-axis direction. Concave portions 221a are formed on both sides in the X-axis direction of the protruding portion 221, and concave portions 222a are formed on both sides in the X-axis direction of the protruding portion 222. The end face (front end face) in the minus Y-axis direction of the protruding portion 221 has a front end face 221c that is a flat surface, and the end face (front end face) in the plus Y-axis direction of the protruding portion 222 has a front end face 222c that is a flat surface. In the present embodiment, both of the pair of end plates 220 include protruding portions 221 and concave portions 221a and protruding portions 222 and concave portions 222a having the same configuration.

[0085] The protruding portion 221 is a rectangular portion extending in the X-axis direction that protrudes in the negative Y-axis direction from the substantially central portion in the X-axis direction at the negative Y-axis direction end of the end plate 220. The protruding portion 221 is provided with a fixing portion 221b such as a bolt for fixing the end plate 220 to the side plate 230. The protruding portion 221 protrudes in a predetermined direction (negative Y-axis direction) from the external terminal 250. The protruding portion 222 is a rectangular portion extending in the X-axis direction that protrudes in the positive Y-axis direction from the substantially central portion in the X-axis direction at the positive Y-axis direction end of the end plate 220. The protruding portion 222 is provided with a fixing portion 222b such as a bolt for fixing the end plate 220 to the side plate 230.

[0086] The pair of side plates 230 are plate-shaped and rectangular members arranged on both sides in the Y-axis direction of the plurality of power storage elements 210. The side plates 230 have both ends in the Z-axis direction attached to the ends in the Y-axis direction of the pair of end plates 220, and by connecting the pair of end plates 220, the plurality of power storage elements 210 are restrained. The side plates 230 extend in the Z-axis direction so as to straddle the plurality of power storage elements 210, and apply a restraining force in the Z-axis direction to the plurality of power storage elements 210. The side plates 230 may be long rod-shaped members or the like instead of plate-shaped.

[0087] The exterior member 240 is a member that covers the X-axis minus direction of a plurality of power storage elements 210 and the like, and protects the plurality of power storage elements 210 and the like from external impacts and the like. In the present embodiment, the exterior member 240 is a metal member, but it may also be a resin member. At the Z-axis plus direction end portion in the Y-axis plus direction end portion of the exterior member 240, an opening 241 through which a control wiring member 514 (see FIG. 8) including wiring for monitoring or controlling the state (voltage, temperature, charge / discharge state, etc.) of the power storage element 210 passes is formed. The opening 241 is disposed on the rear surface, which is on the opposite side of the front surface of the power storage element unit 200 in the Y-axis direction (third direction). The exterior member 240 is attached and fixed to a pair of end plates 220 and a pair of side plates 230. At both ends in the Z-axis direction of the exterior member 240, recesses 242 extending in the Y-axis direction are formed, and fixing portions 243 with the pair of end plates 220 are disposed in the recesses 242. Thereby, it is suppressed that the fixing portion 243 protrudes from the outer surface (end surface in the X-axis minus direction) of the exterior member 240. In the present embodiment, the fixing portion 243 does not protrude from the outer surface (end surface in the X-axis minus direction) of the exterior member 240.

[0088] The external terminal 250 is an external terminal that is electrically connected to the terminal 212 of the power storage element 210, charges electricity from the outside, and discharges electricity to the outside. The external terminal 250 is a terminal member different from the terminal 212 of the power storage element 210. The external terminal 250 is formed of a metal conductive member such as aluminum, aluminum alloy, copper, copper alloy, nickel, or a combination thereof, or a conductive member other than metal. In the present embodiment, a pair (positive electrode and negative electrode) of external terminals 250 arranged in the Z-axis direction are disposed at the X-axis minus direction end portion and both ends in the Z-axis direction in the Y-axis minus direction end portion of the power storage element unit 200. The external terminal 250 protrudes in a predetermined direction (Y-axis minus direction) from the main body portion (portion where the power storage element 210 is disposed) of the power storage element unit 200. Specifically, the external terminal 250 protrudes in the Y-axis minus direction from the Y-axis minus direction surface of the side plate 230 in the Y-axis minus direction and the Y-axis minus direction surface of the exterior member 240.

[0089] The terminal cover 260 is a cover member for the external terminal 250, which is arranged to cover the external terminal 250 and insulate and protect the external terminal 250. An opening (not shown) through which a conductive member such as a bus bar connected to the external terminal 250 passes is formed in the terminal cover 260. The terminal cover 260 is formed of an insulating member such as polycarbonate (PC), polypropylene (PP), polyethylene (PE), polystyrene (PS), polyphenylene sulfide resin (PPS), polyphenylene ether (PPE (including modified PPE)), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyether ether ketone (PEEK), tetrafluoroethylene·perfluoroalkyl vinyl ether (PFA), polytetrafluoroethylene (PTFE), polyethersulfone (PES), polyamide (PA), ABS resin, or a composite material thereof. The terminal cover 260 may be formed of metal or the like with an insulating coating. The terminal cover 260 thereby protects the external terminal 250 and avoids the external terminal 250 from contacting an external metal member or the like.

[0090] [Explanation of the positional relationship of the components included in the power storage device 10] Next, the positional relationship of the components included in the power storage device 10 will be described in detail. FIG. 7 is a cross-sectional view showing the positional relationship of the components included in the power storage device 10 according to the present embodiment. In FIG. 7, the power storage device 10 is cut along a plane parallel to the XZ plane located between the elastic member 410 in the negative Y-axis direction and the power storage unit main body 30, and the configuration when viewed from the negative Y-axis direction is shown. FIG. 8 is a top view showing the positional relationship of the components included in the power storage device 10 according to the present embodiment. FIG. 8 shows the configuration when viewed from the positive Z-axis direction after removing members other than the first bus bar 41 and the electrical component 511 (partition wall 340, other electrical components 510, cover 600, etc.) among the members located in the positive Z-axis direction relative to the power storage unit main body 30 from the power storage device 10.

[0091] As shown in FIG. 7, the side walls 331 of the second wall member 320 and the third wall member 330 of the inner case 300 sandwich the plurality of power storage element units 200 in the X-axis direction and contact the plurality of power storage element units 200 in the X-axis direction (indirectly through elastic members 420, 430, etc.). The bottom wall 332 and the partition wall 340 of the third wall member 330 sandwich the plurality of power storage element units 200 in the Z-axis direction and contact the plurality of power storage element units 200 in the Z-axis direction (indirectly through elastic members 440, 450). As shown in FIG. 8, the pair of first wall members 310 sandwich the plurality of power storage element units 200 in the Y-axis direction and contact the plurality of power storage element units 200 in the Y-axis direction (indirectly through the elastic member 410).

[0092] The pair of first wall members 310, which are two wall members provided in the inner case 300, sandwich the plurality of power storage element units 200 at the position of the protruding portion 221 of the end plate 220. That is, as described above, in the power storage element unit 200, the protruding portion 221 of the end plate 220 protrudes in the negative Y-axis direction from the external terminal 250. Further, the protruding portion 221 protrudes in the negative Y-axis direction from the terminal cover 260 (see FIG. 12). In the negative Y-axis direction of the protruding portion 221, the first wall member 310 is disposed, and the protruding portion 221 contacts the first wall member 310 in the Y-axis direction (indirectly through the elastic member 410). That is, the external terminal 250 and the terminal cover 260 are disposed at a distance from the first wall member 310 without contacting the first wall member 310.

[0093] Similarly, a pair of first wall members 310, which are two wall members, sandwich a plurality of power storage element units 200 at the position of the protruding portions 222 of the end plate 220. That is, in the +Y-axis direction of the protruding portion 222 protruding in the +Y-axis direction, the other first wall member 310 is arranged, and the protruding portion 222 contacts the first wall member 310 in the Y-axis direction (indirectly contacts via the other elastic member 410). In this way, the pair of first wall members 310 sandwich the plurality of power storage element units 200 in the Y-axis direction at the positions of the protruding portions 221 and 222 in the Z-axis direction. The tip surface 221c, which is a flat surface, of the protruding portion 221 is in surface contact with one of the first wall members 310, and the tip surface 222c, which is a flat surface, of the protruding portion 222 is in surface contact with the other first wall member 310.

[0094] With such a configuration, a recess in which two recesses 221a are connected is formed between two external terminals 250 provided in two adjacent power storage element units 200 in the Z-axis direction. A bus bar or wiring or the like connected to the external terminal 250 passes through the recess 221a. That is, the recess 221a is formed in a size through which the bus bar or wiring or the like can pass.

[0095] As described above, the power storage unit main body 30 includes six power storage element unit groups 31 arranged in the X-axis direction (second direction), and each of the plurality of power storage element unit groups 31 includes two power storage element units 200 arranged in the Z-axis direction (first direction). As shown in FIG. 6, each of the plurality of power storage element units 200 includes a pair of external terminals 250 arranged in the Z-axis direction (first direction). As shown in FIG. 7, in each power storage element unit group 31, by making the arrangement direction (stacking direction) of the power storage element units 200 included in the power storage element unit group 31 and the arrangement direction of the pair of external terminals 250 of the power storage element units 200 the same direction (Z-axis direction), four external terminals 250 are arranged in the Z-axis direction. In the power storage unit main body 30, the power storage element unit groups 31 are arranged in the direction (X-axis direction) intersecting the direction in which the pair of external terminals 250 are arranged, so that the external terminals 250 included in each of the six power storage element unit groups 31 are arranged in the X-axis direction. More specifically, the external terminals 250 of the same potential in each power storage element unit group 31 are arranged in the X-axis direction at the same position in the Z-axis direction.

[0096] The plurality of power storage element unit groups 31 are connected in parallel. Specifically, the power storage unit main body 30 further includes a first bus bar 41 and a second bus bar 42 which are a pair of bus bars 40. The pair of bus bars 40 (the first bus bar 41 and the second bus bar 42) extend in the X-axis direction (second direction) and connect the plurality of power storage element unit groups 31 in parallel. The plurality of power storage element units 200 included in each of the plurality of power storage element unit groups 31 are connected in series. Specifically, the power storage element unit group 31 further includes a third bus bar 43. The third bus bar 43 extends in the Z-axis direction and connects the plurality of power storage element units 200 in series. The third bus bar 43 passes through the recess 221a of the end plate 220 of the two power storage element units 200. The first bus bar 41, the second bus bar 42, and the third bus bar 43 are formed of a metal conductive member such as aluminum, aluminum alloy, copper, copper alloy, nickel, or a combination thereof, or a conductive member other than metal. Since the first bus bar 41, the second bus bar 42, and the third bus bar 43 are plate-like members, the connection work is easier than that of a cable (electric wire) or the like.

[0097] In this embodiment, the first bus bar 41 is connected to each power storage element unit group 31 via the first conductive member 513. That is, the power storage unit 20 includes the first conductive members 513 connected to each of the plurality of power storage element unit groups 31. The first conductive member 513 is connected to the external terminal 250 at the plus Z-axis direction end among the external terminals 250 of the power storage element unit 200 included in each power storage element unit group 31. Further, each first conductive member 513 is electrically connected to the first bus bar 41. Specifically, the first conductive member 513 is connected to the first bus bar 41 via the electrical component 511. More specifically, the first conductive member 513 passes through the recess 221a of the power storage element unit 200 located in the plus Z-axis direction of the external terminal 250 from the external terminal 250, penetrates the opening 343 of the partition wall 340, and is connected to the electrical component 511. In this way, the first conductive member 513 electrically connects the power storage element unit 200 and the electrical component 511. Thereby, the first conductive member 513 is connected to the first bus bar 41 connected to the electrical component 511. In this embodiment, the first conductive member 513 is a cable (electric wire), but may also be a conductive member such as a bus bar. The electrical component 511 is a magnetic contactor (electromagnetic contactor, MC), but may also be a fuse or the like. When the first conductive member 513 passes through the electrical component 512, the current flowing through the first conductive member 513 is measured. The electrical component 512 is a Hall sensor.

[0098] With such a configuration, as shown in FIG. 8, the first bus bar 41 is arranged at a position in the plus Z-axis direction of the plurality of power storage element unit groups 31 and overlapping the plurality of power storage element unit groups 31 when viewed from the Z-axis direction. In this way, the plurality of power storage element unit groups 31 are connected in parallel by the bus bar 40 (first bus bar 41) arranged at a position in the Z-axis direction (first direction) of the plurality of power storage element unit groups 31 and overlapping the plurality of power storage element unit groups 31 when viewed from the Z-axis direction (first direction).

[0099] One and the other of the main circuit wiring members (the positive electrode wiring member and the negative electrode wiring member) of the positive electrode and the negative electrode, through which the currents flowing through the respective power storage element unit groups 31 are integrated, are connected to the first bus bar 41 and the second bus bar 42. In the present embodiment, the first wiring member 515, which is the main circuit wiring member (positive electrode wiring member) of the positive electrode, is connected to the first bus bar 41. The second wiring member 516, which is the main circuit wiring member (negative electrode wiring member) of the negative electrode, is connected to the second bus bar 42. The positive electrode wiring member and the negative electrode wiring member are each composed of a plurality of wiring members, penetrate through the wire holding portion 610 provided in the cover 600, and are connected to the connector 500. The wire holding portion 610 is configured to be able to seal between the wire holding portion 610 and the main circuit wiring member and between the wire holding portion 610 and the cover 600. The wire holding portion 610 is a cable ground, but may also have a structure that fills gaps with caulking or the like.

[0100] As shown in FIG. 8, the power storage unit 20 further includes a control wiring member 514 for controlling at least one power storage element unit 200 among the plurality of power storage element units 200. The control wiring member 514 is derived from the rear surface of the power storage element unit 200, which is located on the opposite side of a pair of external terminals 250 of the plurality of power storage element units 200 in the Y-axis direction (the third direction intersecting the first direction and the second direction). In the present embodiment, the control wiring member 514 is provided with harness connectors (not shown) at both ends and is connected to the mating harness connector inside the opening 241 on the rear surface of the power storage element unit 200. Thereby, in each power storage element unit 200, the control wiring member 514 is derived from the opening 241 formed at the Y-axis positive direction end of the exterior member 240. The control wiring member 514 derived from the opening 241 is connected to the connector 500 through the electronic components (electronic circuits) and wiring etc. provided in the electrical component 510 (such as by the wiring penetrating the cover 600). In the present embodiment, the control wiring member 514 is a cable (wire) including various wirings such as wiring for monitoring or controlling the state (voltage, temperature, charge and discharge state, etc.) of the power storage element 210, wiring for controlling the electrical component 510, and wiring for communication, but may also be a conductive member such as a bus bar.

[0101] As shown in FIG. 7, the partition wall 340 divides the space inside the outer case 100 into a first space S1 and a second space S2 arranged in the Z-axis direction. The power storage element unit 200 (power storage unit main body 30) is disposed in the first space S1. At least a part of the connector 500 is disposed in the second space S2. Further, in the second space S2, an electrical component 510 and a cover 600 covering the electrical component 510 are disposed.

[0102] [Description of the connection configuration of each wall member of the inner case 300] Next, the connection configuration of each wall member (a pair of first wall members 310, second wall member 320, third wall member 330, and partition wall 340) constituting the inner case 300 will be described in detail. FIG. 9 is a perspective view showing the appearance of the inner case 300 according to the present embodiment. FIG. 10 is a cross-sectional view showing the configuration of the inner case 300 according to the present embodiment. FIG. 10 shows a cross-section of a pair of first wall members 310, third wall members 330, and partition wall 340 by cutting the inner case 300 shown in FIG. 9 with a plane parallel to the YZ plane passing through the X-X line. FIG. 11 is a cross-sectional view and a cross-sectional perspective view showing the configuration of the inner case 300 according to the present embodiment. FIG. 11(a) is a cross-sectional view showing a cross-section of the second wall member 320, third wall member 330, and partition wall 340 by cutting the inner case 300 shown in FIG. 9 with a plane parallel to the XZ plane passing through the XI-XI line. In FIG. 11(a), since the inner wall facing portion 311c in the positive X-axis direction is hidden by the second inner wall 322 and cannot be seen, in FIG. 11(b), this inner wall facing portion 311c is shown by a cross-sectional perspective view. In FIG. 11(b), the illustration of the bolts of the fixing portion 320a is omitted. In FIG. 10, an enlarged view of both end portions in the Z-axis direction at the positive Y-axis direction end portion of the inner case 300 is shown within the broken line frame, and in FIG. 11, since it is a figure similar to the figure within the broken line frame in FIG. 10, the enlarged view is omitted. FIG. 12 is a cross-sectional view showing the configuration in a state where the power storage element unit 200 is accommodated in the inner case 300 according to the present embodiment. FIG. 12 shows a state where the power storage element unit 200 is accommodated in the inner case 300 shown in FIG. 10, and for convenience of explanation, the illustration of the elastic members 400 (410, 440, 450) is omitted.

[0103] As described above, the inner case 300 is a rectangular parallelepiped, and a rectangular parallelepiped is a hexahedron. The inner case 300 is composed of six wall portions, and the wall portions constituting the inner case 300 are walls including at least one face of the hexahedron. As will be described later, each wall portion includes a main body portion, and the main body portion is a portion including one face of the hexahedron. The wall portion may be composed of a main body portion and a peripheral portion. The peripheral portion is, for example, an opposing portion described later.

[0104] In the inner case 300, a pair of first wall members 310 are arranged in the minus X-axis direction of the second wall member 320, and the plus X-axis direction ends of the pair of first wall members 310 and both ends in the Y-axis direction of the second wall member 320 are joined (fixed) in the X-axis direction. A pair of first wall members 310 are arranged in the plus X-axis direction of the side wall 331 provided in the third wall member 330, and the minus X-axis direction ends of the pair of first wall members 310 and both ends in the Y-axis direction of the side wall 331 are joined (fixed) in the X-axis direction. A pair of first wall members 310 are arranged outside the bottom wall 332 provided in the third wall member 330 in the minus Z-axis direction, and the minus Z-axis direction ends of the pair of first wall members 310 and both ends in the Y-axis direction of the bottom wall 332 are joined (fixed) in the Y-axis direction. A pair of first wall members 310 are arranged in the minus Z-axis direction of the partition wall 340, and both ends in the Y-axis direction of the partition wall 340 are joined (fixed) in the Z-axis direction.

[0105] The second wall member 320 is arranged in the plus X-axis direction of the bottom wall 332 of the third wall member 330, and the minus Z-axis direction end of the second wall member 320 and the plus X-axis direction end of the bottom wall 332 are joined (fixed) in the X-axis direction. The second wall member 320 is arranged in the minus Z-axis direction of the partition wall 340, and the plus X-axis direction end of the partition wall 340 and the second wall member 320 are joined (fixed) in the Z-axis direction. The side wall 331 of the third wall member 330 is arranged in the minus Z-axis direction of the partition wall 340, and the minus X-axis direction end of the partition wall 340 and the side wall 331 are joined (fixed) in the Z-axis direction.

[0106] As shown in FIGS. 10 and 11, each of the pair of first wall members 310 includes a first inner wall 311, a first outer wall 312, and first reinforcing members 313 and 314. The first inner wall 311 includes an inner wall main body portion 311a, an inner wall facing portion 311b, and a pair of inner wall facing portions 311c. The inner wall main body portion 311a is a flat plate-shaped and rectangular portion parallel to the XZ plane. The inner wall facing portion 311b bends outward in the Y-axis direction from the end portion of the inner wall main body portion 311a in the positive Z-axis direction, and is a flat plate-shaped and long portion extending in the X-axis direction parallel to the XY plane, and faces the partition wall 340 in the Z-axis direction. The outer side in the Y-axis direction is the direction away from the center position of the inner case 300 in the Y-axis direction. The same applies hereinafter. The same applies to other directions. The pair of inner wall facing portions 311c bend inward in the Y-axis direction from both end portions of the inner wall main body portion 311a in the X-axis direction, and are flat plate-shaped and long portions extending in the Z-axis direction parallel to the YZ plane, and face the side walls 331 of the second wall member 320 and the third wall member 330 in the X-axis direction. The inner side in the Y-axis direction is the direction approaching the center position of the inner case 300 in the Y-axis direction. The same applies hereinafter. The same applies to other directions.

[0107] The first outer wall 312 is a flat plate-shaped and rectangular member parallel to the XZ plane, and is joined to the outer surface of the inner wall main body portion 311a in the Y-axis direction by welding or the like with the end portion in the negative Z-axis direction protruding from the inner wall main body portion 311a in the negative Z-axis direction. The first reinforcing member 313 is a flat plate-shaped and long member extending in the X-axis direction parallel to the XY plane, and is joined to the surface of the inner wall facing portion 311b in the negative Z-axis direction by welding or the like. The first reinforcing member 314 is a flat plate-shaped and long member extending in the Z-axis direction parallel to the YZ plane, and is joined to the inner surface of the inner wall facing portion 311c in the X-axis direction by welding or the like. Two first reinforcing members 314 arranged in the Z-axis direction are disposed with respect to one inner wall facing portion 311c. Thus, the first wall member 310 is configured with a laminated structure of a plurality of plate-shaped members. By configuring the first wall member 310 by stacking a plurality of plate-shaped members, thickness adjustment or bending processing or the like in a necessary range in the first wall member 310 becomes easy.

[0108] The inner wall body portion 311a and the first outer wall 312 constitute the first main body portion 310f which is the main body portion of the first wall member 310. The inner wall facing portion 311b and the first reinforcing member 313 constitute the first facing portion 310g which is the portion of the first wall member 310 facing another wall member (partition wall 340). The inner wall facing portion 311c and the first reinforcing member 314 constitute the first facing portion 310h which is the portion of the first wall member 310 facing another wall member (third wall member 330). The portion of the first outer wall 312 protruding in the negative Z-axis direction from the inner wall body portion 311a constitutes the first thin-walled portion 310i which is the thin-walled portion of the first wall member 310. The first main body portion 310f is a thick-walled portion thicker than the first thin-walled portion 310i. That is, the first wall member 310 has a shape in which the first main body portion 310f protrudes from the first thin-walled portion 310i toward the plurality of power storage element units 200. Thus, each of the pair of first wall members 310 includes the first main body portion 310f, the first facing portions 310g and 310h, and the first thin-walled portion 310i.

[0109] The second wall member 320 includes a second outer wall 321, a second inner wall 322, and a second reinforcing member 323. The second outer wall 321 includes an outer wall body portion 321a and an outer wall facing portion 321b. The outer wall body portion 321a is a flat plate-shaped and rectangular portion parallel to the YZ plane, and the end portion in the negative Z-axis direction protrudes in the negative Z-axis direction from the second inner wall 322. The outer wall facing portion 321b bends outward in the X-axis direction from the end portion in the positive Z-axis direction of the outer wall body portion 321a, and is a flat plate-shaped and long-sized portion extending in the Y-axis direction parallel to the XY plane, and faces the partition wall 340 in the Z-axis direction. The second inner wall 322 is a flat plate-shaped and rectangular member parallel to the YZ plane, and is joined to the inner surface in the X-axis direction of the outer wall body portion 321a by welding or the like. The second reinforcing member 323 is a flat plate-shaped and long-sized member extending in the Y-axis direction parallel to the XY plane, and is joined to the surface in the negative Z-axis direction of the outer wall facing portion 321b by welding or the like. Thus, the second wall member 320 is configured with a laminated structure of a plurality of plate-shaped members. By configuring the second wall member 320 by stacking a plurality of plate-shaped members, thickness adjustment or bending processing or the like within the necessary range in the second wall member 320 becomes easy.

[0110] The outer wall main body portion 321a and the second inner wall 322 constitute the second main body portion 320d which is the main body portion of the second wall member 320. The outer wall facing portion 321b and the second reinforcing member 323 constitute the second facing portion 320e which is the portion of the second wall member 320 facing another wall member (partition wall 340). The portion of the outer wall main body portion 321a protruding in the minus Z-axis direction from the second inner wall 322 constitutes the second thin portion 320f which is the portion of the second wall member 320 having a small thickness. The second main body portion 320d is a thick portion having a greater thickness than the second thin portion 320f. That is, the second wall member 320 has a shape in which the second main body portion 320d protrudes from the second thin portion 320f toward the plurality of power storage element units 200. Thus, the second wall member 320 includes the second main body portion 320d, the second facing portion 320e, and the second thin portion 320f.

[0111] The third wall member 330 includes an intermediate wall 333, a third outer wall 334, a third reinforcing member 335, and a third inner wall 336. The intermediate wall 333 includes an intermediate side wall main body portion 333a, an intermediate side wall facing portion 333b, an intermediate bottom wall main body portion 333c, and intermediate bottom wall facing portions 333d and 333e. The intermediate side wall main body portion 333a is a flat plate-shaped and rectangular portion parallel to the YZ plane. The intermediate side wall facing portion 333b is a long flat plate-shaped portion that bends outward in the X-axis direction from the plus Z-axis end of the intermediate side wall main body portion 333a and extends in the Y-axis direction parallel to the XY plane, and faces the partition wall 340 in the Z-axis direction. The intermediate bottom wall main body portion 333c is a flat plate-shaped and rectangular portion that bends in the plus X-axis direction from the minus Z-axis end of the intermediate side wall main body portion 333a and is parallel to the XY plane. The intermediate bottom wall facing portion 333d is a long flat plate-shaped portion that bends in the plus Z-axis direction from the plus Y-axis end of the intermediate bottom wall main body portion 333c and extends in the X-axis direction parallel to the XZ plane, and faces the first thin portion 310i in the Y-axis direction. The intermediate bottom wall facing portion 333e is a long flat plate-shaped portion that bends in the plus Z-axis direction from the plus X-axis end of the intermediate bottom wall main body portion 333c and extends in the Y-axis direction parallel to the YZ plane, and faces the second thin portion 320f in the X-axis direction.

[0112] The third outer wall 334 is a flat plate-shaped and rectangular member parallel to the YZ plane, and is joined to the outer surface of the intermediate side wall main body 333a in the X-axis direction by welding or the like. The third reinforcing member 335 is a flat plate-shaped and long member parallel to the XY plane and extending in the Y-axis direction, and is joined to the surface of the intermediate side wall opposing portion 333b in the negative Z-axis direction by welding or the like. The third inner wall 336 is a flat plate-shaped and rectangular member parallel to the XY plane, and is joined to the surface of the intermediate bottom wall main body 333c in the positive Z-axis direction by welding or the like. Thus, the third wall member 330 is configured by a laminated structure of a plurality of plate-shaped members. By configuring the third wall member 330 by stacking a plurality of plate-shaped members, thickness adjustment or bending processing or the like within a necessary range in the third wall member 330 becomes easy.

[0113] The intermediate side wall main body 333a and the third outer wall 334 constitute the side wall main body 331c which is the main body of the side wall 331. The intermediate side wall opposing portion 333b and the third reinforcing member 335 constitute the side wall opposing portion 331d which is the portion of the side wall 331 facing another wall member (partition wall 340). The intermediate bottom wall main body 333c and the third inner wall 336 constitute the bottom wall main body 332c which is the main body of the bottom wall 332. The intermediate bottom wall opposing portion 333d constitutes the bottom wall opposing portion 332d which is the portion of the bottom wall 332 facing another wall member (first wall member 310). The intermediate bottom wall opposing portion 333e constitutes the bottom wall opposing portion 332e which is the portion of the bottom wall 332 facing another wall member (second wall member 320). Thus, the side wall 331 of the third wall member 330 includes the side wall main body 331c and the side wall opposing portion 331d. The bottom wall 332 of the third wall member 330 includes the bottom wall main body 332c and the bottom wall opposing portions 332d and 332e.

[0114] In such a configuration, the first opposing portion 310g of the first wall member 310 bends from the first main body portion 310f and is arranged to face the partition wall 340 in the Z-axis direction. The first opposing portion 310g is joined to the partition wall 340 when the fixing portion 342 of the partition wall 340 is coupled to the fixing portion 310e of the first wall member 310. The second opposing portion 320e of the second wall member 320 bends from the second main body portion 320d and is arranged to face the partition wall 340 in the Z-axis direction. The second opposing portion 320e is joined to the partition wall 340 when the fixing portion 342 of the partition wall 340 is coupled to the fixing portion 320c of the second wall member 320. The side wall opposing portion 331d of the third wall member 330 bends from the side wall main body portion 331c and is arranged to face the partition wall 340 in the Z-axis direction. The side wall opposing portion 331d is joined to the partition wall 340 when the fixing portion 342 of the partition wall 340 is coupled to the fixing portion 331b of the side wall 331.

[0115] The bottom wall opposing portion 332d of the third wall member 330 bends from the bottom wall main body portion 332c and is arranged to face the first thin portion 310i of the first wall member 310 in the Y-axis direction. A nut having a female screw portion formed thereon is joined by welding or the like to the bottom wall opposing portion 332d in order to increase the portion (thread) that is coupled to the fixing portion 310d of the first wall member 310. The bottom wall opposing portion 332d is joined to the first thin portion 310i when the bolt of the fixing portion 310d is coupled to the nut. The fixing portion 332a is the hole (the hole of the bottom wall opposing portion 332d) into which the bolt of the fixing portion 310d is inserted and the nut. The bottom wall opposing portion 332e of the third wall member 330 bends from the bottom wall main body portion 332c and is arranged to face the second thin portion 320f of the second wall member 320 in the X-axis direction. A fixing portion 332b having a male screw portion is joined by welding or the like to the bottom wall opposing portion 332e so that the fixing portion 332b does not protrude in the negative X-axis direction. The bottom wall opposing portion 332e is joined to the second thin portion 320f when the fixing portion 320b of the second wall member 320 is coupled to the fixing portion 332b.

[0116] Similarly, the first opposing portion 310h of the first wall member 310 bends from the first main body portion 310f and is arranged to face the second main body portion 320d of the second wall member 320 or the side wall main body portion 331c of the third wall member 330 in the X-axis direction. The first opposing portion 310h is joined to the second main body portion 320d or the side wall main body portion 331c by the fixing portion 320a of the second wall member 320 or the fixing portion 331a of the third wall member 330 being joined to the fixing portion 310b or 310c of the first wall member 310. In the present embodiment, the portion joined to the first opposing portion 310h of the second main body portion 320d and the side wall main body portion 331c is a thin-walled portion (not shown), and the first opposing portion 310h is joined to the thin-walled portion of the second main body portion 320d or the side wall main body portion 331c.

[0117] The fixing portion 331a includes a bolt as described above, and the tip of the bolt protrudes inward of the inner case 300 (see (a) of FIG. 11). A space is formed between a pair of external terminals 250 (between a pair of terminal covers 260) in the power storage element unit 200 (see FIG. 6). As shown in FIG. 12, the fixing portion 331a located at the minus Y-axis direction end of the inner case 300 is arranged in the space between a pair of external terminals 250 (between a pair of terminal covers 260). A space is also formed in the power storage element unit 200 by a pair of protruding portions 221 or a pair of protruding portions 222. The fixing portion 331a located at the plus Y-axis direction end of the inner case 300 is arranged in the space formed by a pair of protruding portions 222. Thereby, contact between the fixing portion 331a and the power storage element unit 200 is avoided. The same applies to other fixing portions. A space is also formed in the power storage element unit 200 by the recess 221a or the recess 222a. A fixing portion (such as the fixing portion 310d) may be arranged in the space formed by the recess 221a or the recess 222a. Even if there is a member (such as the first reinforcing member 314) protruding inward of the inner case 300 other than the fixing portion, the member may be arranged in the space formed in the power storage element unit 200. In this way, the portion protruding inward of the inner case 300 is arranged in the space formed in the power storage element unit 200, thereby avoiding contact with the power storage element unit 200.

[0118] The partition wall 340 is disposed outside the inner case 300 than the first opposing portion 310g, the second opposing portion 320e, and the side wall opposing portion 331d. The first thin portion 310i of the first wall member 310 is disposed outside the inner case 300 than the bottom wall opposing portion 332d. The second thin portion 320f of the second wall member 320 is disposed outside the inner case 300 than the bottom wall opposing portion 332e. The second main body portion 320d of the second wall member 320 and the side wall main body portion 331c of the third wall member 330 are disposed outside the inner case 300 than the first opposing portion 310h.

[0119] In the above, the inner case 300 is an example of a "case". The first main body portion 310f, the second main body portion 320d, the side wall main body portion 331c, and the bottom wall main body portion 332c are examples of a "main body portion". The first opposing portions 310g, 310h, the second opposing portion 320e, the side wall opposing portion 331d, the bottom wall opposing portions 332d and 332e are examples of an "opposing portion". The first thin portion 310i and the second thin portion 320f are examples of a "thin portion". That is, among two adjacent wall members provided in three or more wall members of the case, one wall member includes a main body portion, and an opposing portion that bends from the main body portion and opposes the other wall member. The opposing portion is joined to the other wall member. The other wall member is disposed outside the inner case 300 than the opposing portion. The other wall member includes a thin portion having a small thickness, and the opposing portion is joined to the thin portion.

[0120] Furthermore, the pair of first wall member 310, second wall member 320, third wall member 330, and partition wall 340 provided in the inner case 300 are examples of a "wall member". That is, as shown in FIGS. 7 and 8 and the like, at least two of the three or more (five) wall members provided in the inner case 300 sandwich a plurality of power storage element units 200 in a predetermined direction and contact (surface contact) the plurality of power storage element units 200 in the predetermined direction.

[0121] To be sandwiched and in contact between two wall members means being directly in contact with the two wall members being sandwiched between the two wall members without passing through other members, or being indirectly in contact with the two wall members (directly in contact with other members) being sandwiched between the two wall members via other members. That is, the two wall members are in direct or indirect contact with a plurality of power storage element units 200 in a predetermined direction. In the present embodiment, the two wall members are in contact (indirectly in contact) with a plurality of power storage element units 200 in a predetermined direction via an elastic member 400. In the present embodiment, if it is defined that the wall member includes the elastic member 400 (the elastic member 400 is a part of the wall member), the two wall members will be in direct contact with a plurality of power storage element units 200 in a predetermined direction. In either definition, it can be said that the two wall members are in contact with a plurality of power storage element units 200 in a predetermined direction. The predetermined direction is the three directions of the X-axis direction, the Y-axis direction, and the Z-axis direction.

[0122] [Description of Effects] As described above, according to the power storage device 10 according to the embodiment of the present invention, at least two of the three or more wall members provided in the inner case 300 sandwich a plurality of power storage element units 200 in a predetermined direction and are in contact with the plurality of power storage element units 200 in the predetermined direction. The two wall members are two wall members including walls facing each other among a pair of first wall members 310, second wall members 320, third wall members 330, and partition walls 340. Thereby, since the two wall members of the inner case 300 can sandwich and hold a plurality of power storage element units 200 in the predetermined direction, the movement of the plurality of power storage element units within the inner case 300 can be suppressed. Therefore, the vibration resistance or shock resistance of the plurality of power storage element units 200 each including a plurality of power storage elements 210 can be improved.

[0123] By bringing the two wall members of the inner case 300 into contact with a plurality of power storage element units 200 in the predetermined direction, the width of the inner case 300 in the predetermined direction can be reduced, so that space can be saved. Since the two wall members of the inner case 300 are in contact with a plurality of power storage element units 200 in the predetermined direction, the inner case 300 and the plurality of power storage element units 200 are integrated, so that the rigidity of the power storage device 10 can be increased. Since the inner case 300 includes three or more wall members configured separately, it is easy to compress a plurality of power storage element units 200, and the plurality of power storage element units 200 can be more firmly restrained. In particular, since the wall members are joined (fixed) by screwing with bolts, the wall members can be pushed in by tightening the bolts, so that it is easy to compress a plurality of power storage element units 200. Since the inner case 300 includes three or more wall members configured separately, the power storage unit main body 30 can be easily accommodated in the inner case 300.

[0124] The wall members included in the inner case 300 sandwich a plurality of power storage element units 200 in two directions among the X-axis direction, the Y-axis direction, and the Z-axis direction, and are in contact with the plurality of power storage element units 200 in the two directions. Thereby, since the plurality of power storage element units 200 can be sandwiched and held in two directions by the wall members of the inner case 300, the movement of the plurality of power storage element units 200 in the inner case 300 can be more suppressed. Further, the wall members included in the inner case 300 sandwich a plurality of power storage element units 200 in three directions among the X-axis direction, the Y-axis direction, and the Z-axis direction, and are in contact with the plurality of power storage element units 200 in the three directions. Thereby, the vibration resistance or shock resistance of the plurality of power storage element units 200 can be further improved.

[0125] By directly or indirectly bringing into surface contact two adjacent power storage element units 200 in the X-axis direction and the Z-axis direction, vibration resistance, shock resistance, space saving, etc. can be achieved in the two directions of the X-axis direction and the Z-axis direction.

[0126] Each of the plurality of power storage element units 200 includes a protruding portion 221 that protrudes in a predetermined direction (Y-axis direction) from the external terminal 250. As a result, even when two wall members sandwich the plurality of power storage element units 200 at the position of the protruding portion 221, the protruding portion 221 contacts the wall member. It is desirable not to apply stress other than the connection structure to the external terminal 250, which is an electrical connection location. By the protruding portion 221 contacting the wall member, the power storage element units 200 can be sandwiched without the external terminal 250 and the wall member contacting each other at the portion where the external terminal 250 is disposed. By the protruding portion 221 protruding more than the external terminal 250, a space for arranging wiring or the like can be formed around the external terminal 250.

[0127] Since the wall member (third wall member 330) of the inner case 300 integrally includes two walls (side wall 331 and bottom wall 332), the number of parts of the members constituting the inner case 300 can be reduced. Since the connection locations between the wall members can be reduced, the connection work between the wall members can be reduced, and space saving at the connection portion can also be achieved. There is no step at the boundary portion between the two integrated walls (side wall 331 and bottom wall 332), and the power storage element units 200 can be arranged close to the wall, so that space saving can be achieved (the dimensions of the inner case 300 can be reduced).

[0128] When the two wall members of the inner case 300 contact the plurality of power storage element units 200 in a predetermined direction via the elastic member 400, the two wall members can sandwich and hold the plurality of power storage element units 200 in a compressed state by the elastic force of the elastic member 400. As a result, the movement of the plurality of power storage element units 200 within the inner case 300 can be further suppressed.

[0129] By joining the opposing part (such as the bottom wall opposing part 332d) that bends from the main body part (such as the bottom wall main body part 332c) of one wall member (such as the third wall member 330) of the inner case 300 to the other wall member (such as the first wall member 310), the one wall member and the other wall member can be easily joined. Specifically, it is as follows. When joining the one wall member and the other wall member, if an opposing part is not provided on the one wall member, it is necessary to increase the thickness of the main body part so that screw holes are formed or an adhesive is applied to the surface where the thickness of the main body part is visible. Increasing the thickness of the main body part may lead to an increase in the amount of member used, an increase in weight, an increase in cost, etc., and there is also a problem that it is difficult to process the screw holes. For this reason, an opposing part is provided on the one wall member, and the opposing part and the other wall member are joined. As a result, the one wall member can be made thinner, and even when forming screw holes, the screw holes can be easily processed in the opposing part, so the one wall member and the other wall member can be easily joined.

[0130] Since the other wall member (such as the first wall member 310) is arranged outside the inner case 300 compared to the opposing part (such as the bottom wall opposing part 332d), when joining the other wall member and the opposing part, the other wall member approaches the opposing part from the outside and is joined to the opposing part. As a result, the other wall member approaches the power storage element unit 200 toward the inside of the inner case 300, and it is easy to press the other wall member toward the power storage element unit 200.

[0131] By joining the opposing part (such as the bottom wall opposing part 332d) of the one wall member to the thin part (such as the first thin part 310i) of the other wall member, it is possible to suppress an increase in the thickness of the joined part, so space saving can be achieved (the dimensions of the inner case 300 can be reduced). By arranging the opposing part within the step formed by the thin part, it is possible to suppress the opposing part from protruding inward, so it becomes easier to press the other wall member (such as the first wall member 310) toward the power storage element unit 200.

[0132] Since the first opposing portion 310g of the first wall member 310 is a portion that bends from the first main body portion 310f to the outside of the inner case 300, the partition wall 340 can be stably arranged on the first wall member 310, and joining can be facilitated. The same applies to the second opposing portion 320e of the second wall member 320 and the side wall opposing portion 331d of the third wall member 330.

[0133] On the other hand, the other wall member (such as the first wall member 310) has a shape in which the first main body portion 310f protrudes from the first thin-walled portion 310i toward the plurality of power storage element units 200. For this reason, it is easy to bring the other wall member into contact with the plurality of power storage element units 200. The same applies to the second main body portion 320d of the second wall member 320.

[0134] [Description of Modification Example 6] As described above, the power storage device 10 according to the embodiment of the present invention has been described, but the present invention is not limited to this embodiment. The embodiments disclosed this time are illustrative in all respects, and the scope of the present invention includes all modifications within the meaning and scope equivalent to the claims.

[0135] In the above embodiment, the two wall members provided in the inner case 300 are configured to contact (indirectly contact) the plurality of power storage element units 200 via the elastic members 400, but they may contact (directly contact) the plurality of power storage element units 200 without passing through the elastic members 400. That is, the power storage unit 20 may not include some or all of the elastic members 400 (410, 420, 430, 440, 450).

[0136] In the above embodiment, the two wall members provided in the inner case 300 are configured to sandwich the plurality of power storage element units 200 in three directions of the X-axis direction, the Y-axis direction, and the Z-axis direction, but the present invention is not limited to this. The two wall members may sandwich the plurality of power storage element units 200 in only two directions or only one direction among the X-axis direction, the Y-axis direction, and the Z-axis direction.

[0137] In the above-described embodiment, in the inner case 300, the opposing portion (such as the bottom wall opposing portion 332d) of one wall member (such as the third wall member 330) is joined to the other wall member (such as the first wall member 310), and the other wall member is arranged outside the opposing portion. However, the present invention is not limited to this. The other wall member (such as the first wall member 310) may be arranged inside the opposing portion (such as the bottom wall opposing portion 332d), or the one wall member (such as the third wall member 330) may be joined to the other wall member without providing an opposing portion.

[0138] In the above-described embodiment, in the inner case 300, the opposing portion (such as the bottom wall opposing portion 332d) of one wall member (such as the third wall member 330) is joined to the thin-walled portion (the first thin-walled portion 310i) of the other wall member (such as the first wall member 310). However, the present invention is not limited to this. The opposing portion may not be joined to the thin-walled portion, and in this case, the other wall member (such as the first wall member 310) may not be provided with a thin-walled portion.

[0139] In the above-described embodiment, the first wall member 310 is configured by a plurality of plate-like members. However, it may be configured by a single plate-like member. The same applies to the second wall member 320 and the third wall member 330.

[0140] In the above-described embodiment, the partition wall 340 is a wall that partitions the inner space of the outer case 100. However, it may not have the function of partitioning the inner space of the outer case 100.

[0141] In the above-described embodiment, the posture (orientation) in which the power storage element unit 200 is arranged is not limited. In the power storage element unit 200, the external terminal 250 may protrude in the +Y-axis direction, or may protrude in the X-axis direction or the Z-axis direction. The pair of end plates 220 may be arranged to face each other in the X-axis direction, or may be arranged to face each other in the Y-axis direction.

[0142] In the above embodiment, in the power storage element unit 200, the end plate 220 is provided with the protruding portions 221 and 222. However, the side plate 230 may be provided with protruding portions, or other members may be provided with protruding portions.

[0143] In the above embodiment, the power storage element unit 200 may include a box body (container) constituting the exterior body instead of or in addition to the end plate 220 and the side plate 230.

[0144] In the above embodiment, the power storage device 10 is not limited to having all the configurations described above, such as not having to include the elastic member 800.

[0145] A form constructed by arbitrarily combining the above embodiment and the above modification is also included within the scope of the present invention.

Industrial Applicability

[0146] The present invention can be applied to a power storage device including a power storage element such as a secondary battery.

Explanation of Reference Numerals

[0147] 10 Power storage device 20 Power storage unit 30 Power storage unit main body 31 Power storage element unit group 40 Bus bar 43 Third bus bar 100 Outer case 110 Case main body 120, 121, 122 Weight 310a, 310b, 310c, 310d, 310e, 320a, 320b, 320c, 331a, 331b, 332a, 332b, 342 Fixing portion 130 Intermediate member 140 Cover member 200 Power storage element unit 210 Power storage element 220 End Plate 221, 222 Protrusions 221a, 222a, 242 Recesses 221c, 222c End Surfaces 230 Side Plate 250 External Terminal 260 Terminal Cover 300 Inner Case 310 First Wall Member 310f First Main Body 310g, 310h First Opposing Parts 310i First Thin-Walled Part 311 First Inner Wall 311a Inner Wall Main Body 311b Inner Wall Opposing Part 311c Inner Wall Opposing Part 312 First Outer Wall 313, 314 First Reinforcing Members 320 Second Wall Member 320d Second Main Body 320e Second Opposing Part 320f Second Thin-Walled Part 321 Second Outer Wall 321a Outer Wall Main Body 321b Outer Wall Opposing Part 322 Second Inner Wall 323 Second Reinforcing Member 330 Third Wall Member 331 Side Wall 331c Side Wall Main Body 331d Side Wall Opposing Part 332 Bottom Wall 332c Bottom Wall Main Body 332d, 332e Bottom Wall Opposing Parts 333 Intermediate Wall 333a Intermediate Side Wall Main Body 333b Intermediate Side Wall Opposing Part 333c Intermediate Bottom Wall Main Body 333d, 333e Intermediate Bottom Wall Opposing Parts 334 Third Outer Wall 335 Third Reinforcing Member 336 Third Inner Wall 340 Partition Wall 341 Second fixing member 400, 410, 420, 421, 430, 440, 450, 800 Elastic member 500 Connector 510, 511, 512 Electrical component 513 First conductive member 514 Control wiring member 600 Cover 700 First fixing member

Claims

1. a plurality of power storage element units each including a plurality of power storage elements; a case for housing the plurality of power storage element units; and the case includes three or more wall members configured separately, at least two of the three or more wall members sandwich the plurality of power storage element units in a predetermined direction and contact the plurality of power storage element units in the predetermined direction a power storage device.

2. each of the plurality of power storage element units includes an external terminal protruding in the predetermined direction and a protruding portion protruding more in the predetermined direction than the external terminal, the two wall members sandwich the plurality of power storage element units at positions of the protruding portions The power storage device according to claim 1.

3. the three or more wall members further sandwich the plurality of power storage element units in a direction intersecting the predetermined direction and contact the plurality of power storage element units in the direction The power storage device according to claim 1 or 2.

4. at least one of the three or more wall members integrally includes two walls facing different directions The power storage device according to claim 1 or 2.

5. further including an elastic member disposed between at least one of the two wall members and the plurality of power storage element units, the two wall members contact the plurality of power storage element units in the predetermined direction via the elastic member The power storage device according to claim 1 or 2.

6. one of two adjacent wall members included in the three or more wall members includes a main body portion and an opposing portion that bends from the main body portion and faces the other wall member, the opposing portion is joined to the other wall member The power storage device according to claim 1.

7. the other wall member is disposed outside the case more than the opposing portion The power storage device according to claim 6.

8. the other wall member includes a thin portion having a small thickness, the opposing portion is joined to the thin portion The power storage device according to claim 6 or 7.

9. the other wall member has a shape protruding toward the plurality of power storage element units The power storage device according to claim 6 or 7.

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