Electricity storage device

Abstract

A power storage device (1) is provided with a power storage unit (10) having a spacer (200a) having a spacer main body (210), and a first power storage element (101) disposed on one side of the spacer main body (210) in a first direction. The spacer main body has: a first surface (214) facing the first power storage element (101); and a second surface (215) located in a second direction intersecting the first direction of the first surface and disposed at a position recessed from the first surface. The power storage unit (10) has a first opening (opening 22) that connects a first space (space 215a) between the second surface (215) and the first power storage element (101) and an external space (S) that is a space located outside the power storage unit (10) in the second direction, and the spacer (200a) has a first wall (wall 223) that protrudes from the spacer body (210) toward one side in the first direction, and that is provided with a second wall (wall 223) that protrudes from the second surface (215) toward the other side in the first direction. The second electrode faces the first power storage element (101) in the second direction.

Description

Technical Field

[0001] The present invention relates to a power storage device having a power storage element and a spacer. Background Art

[0002] Conventionally, a power storage device having a power storage element and a spacer has been widely known. For example, Patent Document 1 discloses a battery pack (power storage device) including a battery module formed by laminating battery cells (power storage elements) with a spacer therebetween, and a ventilation duct is provided between the laminated battery cells by the spacer.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2008-277085 Summary of the Invention

[0006] Problems to be Solved by the Invention

[0007] In a power storage device, during manufacturing, there is a case where an assembly operation is performed by holding a short side surface of a power storage element with a jig. However, in this case, it is impossible to arrange other members on the short side surface of the power storage element, and thus it may be impossible to insulate the short side surface of the power storage element. In view of this, a method of holding the power storage element by inserting a jig between the power storage element and the spacer to perform an assembly operation is considered. For example, in the power storage device disclosed in Patent Document 1 above, a jig can be inserted into the ventilation duct between the power storage element and the spacer. However, in this power storage device, in order to form the ventilation duct, a plurality of ridges are provided on the spacer, and the ridges are required to suppress the expansion of the power storage element, so it may be impossible to effectively suppress the expansion of the power storage element. In this power storage device, since the short side surface of the power storage element is exposed from the air passage holes of the binding band, it may be impossible to sufficiently insulate the power storage element. Thus, in the conventional power storage device, it is difficult to balance the improvement of workability during manufacturing and the maintenance of performance.

[0008] The present invention has been completed by the inventors of the present application by re-focusing on the above problems, and an object thereof is to provide a power storage device capable of improving workability during manufacturing and maintaining performance.

[0009] Means for Solving the Problems

[0010] One embodiment of the energy storage device of the present invention includes an energy storage unit having a spacer with a spacer body and a first energy storage element disposed on one side of the spacer body in a first direction. The spacer body has a first surface facing the first energy storage element and a second surface located in a second direction intersecting the first direction with respect to the first surface and disposed at a position recessed from the first surface. The energy storage unit has a first opening connecting a first space between the second surface and the first energy storage element to an external space outside the energy storage unit in the second direction. The spacer has a first wall portion protruding from the spacer body toward the one side in the first direction and facing the first energy storage element in the second direction.

[0011] Advantages of the Invention

[0012] According to the energy storage device of the present invention, it is possible to improve workability during manufacturing and maintain performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a perspective view showing the structure of the energy storage device of the embodiment.

[0014] Figure 2 It is an exploded perspective view showing the energy storage element and the spacer included in the energy storage unit of the energy storage device of the embodiment.

[0015] Figure 3 It is a perspective view showing the structure of the energy storage element of the embodiment.

[0016] Figure 4 It is a perspective view and a front view showing the structure of the spacer of the embodiment.

[0017] Figure 5 It is a perspective view and a rear view showing the structure of the spacer of the embodiment.

[0018] Figure 6 It is a perspective view showing the structure of the spacer wall portions of the first spacer, the second spacer, and the third spacer of the embodiment.

[0019] Figure 7 It is a perspective view showing the structure in a state where the first spacer, the second spacer, and the third spacer of the embodiment are arranged relative to the energy storage element.

[0020] Figure 8 It is a side view showing the structure in a state where the first spacer, the second spacer, and the third spacer of the embodiment are arranged relative to the energy storage element. DETAILED DESCRIPTION OF THE INVENTION

[0021] (1) A power storage device according to one embodiment of the present invention includes a power storage unit having: a spacer having a spacer body, and a first power storage element disposed on one side of the spacer body in a first direction. The spacer body has: a first surface facing the first power storage element; and a second surface located in a second direction intersecting the first direction of the first surface and disposed at a position recessed from the first surface. The power storage unit has a first opening that connects a first space between the second surface and the first power storage element to a space outside the power storage unit in the second direction of the power storage unit, that is, an external space. The spacer has a first wall portion that protrudes from the spacer body toward the one side in the first direction and faces the first power storage element in the second direction.

[0022] Thus, in the power storage device, the spacer body of the spacer has a second surface that is recessed from the first surface and is located in the second direction of the first surface facing the first power storage element. The power storage unit has a first opening that connects the first space between the second surface and the first power storage element to the external space of the power storage unit. In this way, in addition to the first surface facing the first power storage element, the spacer body also has a second surface that is recessed from the first surface and is located in the second direction of the first surface, so that the expansion of the first power storage element can be suppressed by the first surface, and the first space is formed by the second surface. By having the first opening that connects the first space (the internal space of the power storage unit) to the external space of the power storage unit, the power storage unit can insert a jig into the first space through the first opening to hold the first power storage element, and thus the workability during manufacturing can be improved. Further, since the spacer has the first wall portion that faces the first power storage element in the second direction, insulation of the first power storage element in the second direction can be achieved by the first wall portion. Thus, in the power storage device, improvement of workability during manufacturing and performance retention can be achieved.

[0023] (2) In the power storage device described in the above (1), the area of the first surface may be larger than the area of the second surface.

[0024] Thus, in the spacer, since the area of the first surface is larger than the area of the second surface, even when the second surface that forms the first space by recessing the spacer body is provided, the expansion of the first power storage element can be suppressed by the first surface.

[0025] (3) In the power storage device described in the above (1) or (2), the spacer body may further have a third surface disposed at a position recessed from the first surface, and the second surface may be disposed at a position recessed from the third surface.

[0026] Accordingly, in the spacer, the third surface is provided at a position recessed from the first surface by the spacer main body, and the second surface is disposed at a position recessed from the third surface. Thus, the first surface protrudes more than the third surface, and the second surface is disposed at a position recessed from the third surface. Accordingly, since the first surface that protrudes from the third surface and suppresses the swelling of the first power storage element can be disposed, and the second surface that is recessed from the third surface to form the first space can be disposed, the first surface and the second surface can be formed in a desired shape at a desired position.

[0027] (4) In the power storage device according to any one of (1) to (3) above, the spacer may further include a second wall portion that protrudes from the position of the first opening portion of the spacer main body toward the other side in the first direction.

[0028] Accordingly, by providing the spacer with the second wall portion, insulation in the second direction of other power storage elements disposed on the other side in the first direction of the spacer main body can be achieved using the second wall portion.

[0029] (5) In the power storage device according to any one of (1) to (4) above, when viewed from the second direction, the first wall portion may be disposed at a position overlapping the end edge on the one side in the first direction of the first power storage element.

[0030] Accordingly, by disposing the end edge (top end) on the one side in the first direction of the first wall portion of the spacer at a position overlapping the first power storage element when viewed from the second direction, a structure is formed in which the first wall portion does not protrude from the first power storage element. Therefore, it is possible to prevent the first wall portion from becoming an obstacle when the jig is inserted into the one side in the first direction of the first power storage element.

[0031] (6) In the power storage device according to any one of (1) to (5) above, the power storage unit may further include: a second power storage element disposed on the other side in the first direction of the spacer main body; and a second opening portion disposed at a position different from the first opening portion on the other side in the first direction of the first wall portion, connecting a second space between the spacer main body and the second power storage element to the external space; the second space may be a flow path for a fluid flowing between the spacer main body and the second power storage element.

[0032] Accordingly, the power storage unit has a second opening portion that connects a second space (the internal space of the power storage unit) between the spacer main body of the spacer and the second power storage element to the external space of the power storage unit, and the second space is a flow path for a fluid flowing between the spacer main body and the second power storage element. Accordingly, as the second space, using the flow path of the fluid flowing between the spacer main body and the second power storage element, the jig is inserted into this flow path (second space) from the second opening portion, so that the second power storage element can be held with a simple structure.

[0033] Hereinafter, a power storage device according to an embodiment (including its modified examples) of the present invention will be described with reference to the accompanying drawings. The embodiments described below are all general examples or specific examples. The numerical values, shapes, materials, structural members, arrangement positions of the structural members, connection methods, manufacturing processes, order of manufacturing processes, etc. shown in the following embodiments are merely examples and are not intended to limit the present invention. In each drawing, the dimensions, etc. are not strictly the dimensions shown. In each drawing, the same or similar structural members are denoted by the same reference numerals.

[0034] In the following description and drawings, the arrangement direction of a pair of terminals of the power storage element, the facing direction of a pair of short side surfaces in the container of the power storage element, or the arrangement direction of the power storage units is defined as the X-axis direction. The facing direction of a pair of long side surfaces in the container of the power storage element, the thickness direction (flat direction) of the container of the power storage element, the arrangement direction of a plurality of power storage elements or a plurality of spacers included in the power storage unit, or the arrangement direction of the power storage elements and the spacers included in the power storage unit is defined as the Y-axis direction. The protruding direction of the terminals of the power storage element, the arrangement direction of the container main body and the container lid portion of the power storage element, the arrangement direction of the housing main body and the lid of the housing, the facing direction of the opening and the bottom wall of the housing main body, or the up-down 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 the present embodiment) with each other. Depending on the usage mode, there may be a case where the Z-axis direction is not the up-down direction, but hereinafter, for convenience of explanation, the Z-axis direction will be described as the up-down direction.

[0035] In the following description, the positive X-axis direction indicates the arrow direction of the X-axis, and the negative X-axis direction indicates the direction opposite to the positive X-axis direction. When simply referred to as the X-axis direction, it means both the positive and negative X-axis directions or either one of the directions. When referring to one side and the other side in the X-axis direction, it means one and the other of the positive and negative X-axis directions. The same applies to the Y-axis direction and the Z-axis direction. Hereinafter, the Y-axis direction will also be referred to as the first direction, the X-axis direction will be referred to as the second direction, and the Z-axis direction will be referred to as the third direction. That is, the first direction, the second direction, and the third direction are directions that intersect (orthogonal in the present embodiment) with each other. Expressions indicating relative directions or postures such as parallel and orthogonal, strictly speaking, also include cases where they are not exactly that direction or posture. For example, two directions being parallel means not only that the two directions are completely parallel but also that they are substantially parallel, that is, it includes, for example, a difference of a few percent. In the following description, when expressed as "insulated", it means "electrically insulated".

[0036] (Embodiment)

[0037] [Description of the power storage device 1]

[0038] First, the schematic structure of the power storage device 1 of the present embodiment will be described. Figure 1 is a perspective view showing the structure of the power storage device 1 of the present embodiment. In Figure 1 it shows the state where the lid 320 is removed from the housing main body 310 of the housing 300 in the power storage device 1. Thus, in Figure 1 it shows two power storage units 10 arranged inside the housing 300. Figure 2 is an exploded perspective view showing the power storage element 100 and the spacer 200 included in the power storage unit 10 of the power storage device 1 of the present embodiment. Figure 2 It shows the structural members included in the disassembled power storage unit 10, and shows two of the power storage elements 100 and three spacers 200 (spacers 200a) among them. In Figure 1 the spacer 200a has a portion protruding upward, but in Figure 2 for ease of explanation, the illustration of the portion of the spacer 200a protruding upward is omitted. Figure 4 The same applies hereinafter.

[0039] The power storage device 1 is a device that can be charged with electricity from the outside and can discharge electricity to the outside. The power storage device 1 is used for power storage or power sources, etc. The power storage device 1 is used as a battery for driving or starting an engine of a moving body such as an automobile, a motorcycle, a personal watercraft, a ship, a snowmobile, an agricultural machine, a construction machine, or a railway vehicle for electric railways. As the above-mentioned automobile, an electric vehicle (EV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), and a fossil fuel (gasoline, diesel, liquefied natural gas, etc.) vehicle can be exemplified. As the above-mentioned railway vehicle for electric railways, a tram, a monorail, a maglev train, and a hybrid tram having both a diesel engine and an electric motor can be exemplified. The power storage device 1 can also be used as a battery for fixed installation used in a home or business, etc.

[0040] As Figure 1 shown, the power storage device 1 has a power storage unit 10 and a housing 300 that houses the power storage unit 10. The power storage device 1 also has external terminals (a positive external terminal and a negative external terminal) for electrically connecting to an external device, etc., but illustrations and descriptions of these are omitted. In addition to having the above-mentioned structural members, the power storage device 1 may also have electrical devices such as a circuit board and a relay for monitoring or controlling the charging state and discharging state, etc. of the power storage unit 10.

[0041] The power storage unit 10 is a battery module (battery pack) having a plurality of power storage elements 100. The power storage unit 10 has a substantially rectangular parallelepiped shape that is long in the Y-axis direction by alternately arranging a plurality of power storage elements 100 and spacers 200 in the Y-axis direction (first direction). In the present embodiment, two power storage units 10 arranged in the X-axis direction are accommodated inside the housing 300. The power storage unit 10 has a plurality of power storage elements 100 and a plurality of spacers 200 (200a, 200b, 200c). The power storage unit 10 also has bus bars for connecting the power storage elements 100 in series or in parallel, a bus bar holder for holding the bus bars, and bus bars for connecting the power storage elements 100 and external terminals, but illustration of these is omitted. The bus bars can connect all the power storage elements 100 in series, or can connect any one of the power storage elements 100 in parallel and then connect them in series, or can connect all the power storage elements 100 in parallel. The power storage unit 10 is a non-constrained type of module that does not have a constraining member (end plates, side plates, etc.) for constraining a plurality of power storage elements 100 and spacers 200 in the Y-axis direction.

[0042] The power storage element 100 is a secondary battery (single cell) that can be charged and discharged, and more specifically, is a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. The power storage element 100 has a rectangular parallelepiped shape (square, rectangular) that is flat in the Y-axis direction. In the present embodiment, a plurality of power storage elements 100 are arranged and configured in the Y-axis direction, but the number of the arranged power storage elements 100 is not particularly limited, and can be one, or several tens, or more. The size and shape of the power storage element 100 are not particularly limited, but can also be a long cylindrical shape, an elliptical cylindrical shape, a cylindrical shape, a polygonal prism shape other than a rectangular parallelepiped shape, etc. The power storage element 100 is not limited to a non-aqueous electrolyte secondary battery, and can be a secondary battery other than a non-aqueous electrolyte secondary battery, or can be a capacitor. The power storage element 100 can be a primary battery in which a user can use the stored power without charging. The power storage element 100 can be a battery using a solid electrolyte. The power storage element 100 can also be a pouch type power storage element.

[0043] The spacer 200 is arranged in the Y-axis direction in alignment with the power storage element 100, and is a flat member in the Y-axis direction that insulates and / or thermally insulates the power storage element 100 and other components. The spacer 200 is arranged in the positive or negative Y-axis direction of the power storage element 100, and is an insulating plate or a heat insulating plate that insulates and / or thermally insulates the power storage elements 100 from each other or the power storage element 100 and the housing 300. The spacer 200 holds the power storage element 100 by having wall portions on both sides in the X-axis direction and both sides in the Z-axis direction of the power storage element 100, and has the function of a holder for positioning the power storage element 100. A flow path for a coolant (fluid such as air) is formed in the spacer 200, and it also has the function of cooling the power storage element 100.

[0044] The spacer 200 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, or a member having heat insulating properties such as mica.

[0045] Hereinafter, the spacer 200 arranged at the central position in the Y-axis direction of the power storage unit 10 (between the two power storage elements 100 at the central position) is also referred to as the spacer 200b. The spacer 200 arranged at both ends in the Y-axis direction of the power storage unit 10 (between the power storage element 100 at the end and the housing 300) is also referred to as the spacer 200c. The spacer 200 arranged between the spacer 200b and the spacer 200c (between the two power storage elements 100 other than the central position) is also referred to as the spacer 200a. The spacer 200 (spacers 200a, 200b, 200c) and the power storage element 100 are alternately arranged. Figure 2 The structure in which the power storage element 100 and the spacer 200a are alternately arranged is shown, but the spacer 200a, together with the spacers 200b and 200c, is alternately arranged with the power storage element 100.

[0046] Specifically, as Figure 2As shown, the spacer 200a is an intermediate spacer (intermediate retainer) that has wall portions on both sides in the X-axis direction and both sides in the Z-axis direction of two power storage elements 100 disposed on both sides in the Y-axis direction of the spacer 200a and holds the two power storage elements 100. Similarly, the spacer 200b is a center plate (center spacer or center retainer) that has wall portions on both sides in the X-axis direction and both sides in the Z-axis direction of two power storage elements 100 disposed on both sides in the Y-axis direction of the spacer 200b and holds the two power storage elements 100. The spacer 200b has a function of improving the rigidity of the power storage unit 10 that is long in the Y-axis direction. The spacer 200c is an end spacer (end retainer) that has wall portions on both sides in the X-axis direction and both sides in the Z-axis direction of one power storage element 100 disposed on one side in the Y-axis direction of the spacer 200c and holds the one power storage element 100.

[0047] That is, the power storage element 100 located at the central portion in the Y-axis direction of the power storage unit 10 is held by the spacer 200a and the spacer 200b. The power storage element 100 located at the end portion in the Y-axis direction of the power storage unit 10 is held by the spacer 200a and the spacer 200c. The other power storage elements 100 are held by two spacers 200a. All the spacers 200 (spacers 200a, 200b, 200c) may be formed of members of the same material or members of different materials.

[0048] The housing 300 is a container in a substantially rectangular parallelepiped shape (box shape) that constitutes the exterior body (outer shell) of the power storage device 1. The housing 300 is disposed outside the power storage unit 10, fixes the power storage unit 10 at a specified position, and protects it from impacts and the like. The housing 300 is a metal housing formed of a member made of metal such as aluminum, aluminum alloy, stainless steel, iron, or electroplated steel sheet. In the present embodiment, the housing 300 is formed by die casting of aluminum (aluminum die casting).

[0049] As Figure 1As shown, the housing 300 has a housing body 310 that forms the main body of the housing 300 and a lid body 320 that forms the lid of the housing 300. The housing body 310 is a housing (frame) having an opening 310a formed on the positive Z-axis direction (one side of the third direction), and houses the power storage unit 10 (the power storage element 100 and the spacers 200 (spacers 200a, 200b, 200c)). The lid body 320 is a flat rectangular member that closes the opening 310a of the housing body 310. Two rectangular openings 310a are formed on the housing body 310 and arranged along the X-axis direction. After the power storage unit 10 is inserted through each opening 310a, the housing body 310 and the lid body 320 are joined by screw fixing with bolts or the like, welding, bonding, etc. Thus, the housing 300 has a structure in which the interior is sealed. In this way, the housing 300 (housing body 310) has housing wall portions 311 on the positive X-axis direction (one side of the second direction intersecting the first direction) and the negative X-axis direction (the other side of the second direction) of the power storage unit 10. The housing wall portion 311 is a flat plate-shaped wall portion that faces the power storage unit 10 in the X-axis direction, is parallel to the YZ plane, and extends in the Y-axis direction. A terminal block for external terminals (a positive external terminal and a negative external terminal) can be installed on the housing body 310 or the lid body 320, and the external terminals are arranged on the terminal block.

[0050] Next, the structures of the power storage element 100 and the spacer 200a will be described in detail.

[0051] [1.1 Description of the power storage element 100]

[0052] Figure 3 is a perspective view showing the structure of the power storage element 100 of the present embodiment. Figure 3 Enlargedly shows Figure 2 the power storage element 100 shown. Since all of the plural power storage elements 100 included in the power storage unit 10 have the same structure, Figure 3 one power storage element 100 is shown in

[0053] As Figure 3As shown, the electricity storage element 100 has a container 110 and a pair of (positive and negative) terminals 140. Inside the container 110, an electrode body, a pair of (positive and negative) current collectors, and an electrolytic solution (non-aqueous electrolyte) are accommodated. Sealing gaskets are disposed between the terminals 140 and the current collectors and the container 110, but their illustrations are omitted. As this electrolytic solution, as long as the performance of the electricity storage element 100 is not impaired, there is no particular limitation on its type, and various electrolytic solutions can be selected. As long as the sealing gasket has insulating properties, it can be formed of any material. In addition to the above-described structural members, the electricity storage element 100 may further have a spacer disposed on the side of the electrode body, an insulating film that wraps the electrode body, etc., and an insulating film (such as a shrink tube) that covers the outer surface of the container 110.

[0054] The container 110 is a rectangular parallelepiped-shaped (square or box-shaped) housing having a container body 120 formed with an opening and a container lid portion 130 that closes the opening of the container body 120. The container body 120 is a rectangular cylindrical member having a bottom that constitutes the main body portion of the container 110, and an opening is formed on the positive Z-axis side. The container lid portion 130 is a rectangular plate-like member that is long in the X-axis direction and constitutes the lid portion of the container 110, and is disposed on the positive Z-axis direction of the container body 120. A gas discharge valve 131 that opens the pressure when the pressure inside the container 110 rises excessively, and a liquid injection portion (not shown) for injecting an electrolytic solution into the inside of the container 110, etc. are provided on the container lid portion 130. The material of the container 110 (the container body 120 and the container lid portion 130) is not particularly limited, and can be a weldable (joinable) metal such as stainless steel, aluminum, aluminum alloy, iron, electroplated steel sheet, etc., or a resin can also be used.

[0055] The container 110 is hermetically sealed (sealed) inside by joining the container body 120 and the container lid portion 130 by welding or the like after accommodating the electrode body, etc. inside the container body 120. The container 110 has a pair of long side surfaces 111 on the side surfaces on both sides in the Y-axis direction, a pair of short side surfaces 112 on the side surfaces on both sides in the X-axis direction, and a bottom surface 113 on the negative Z-axis side. The long side surface 111 is a rectangular planar portion that forms the long side surface of the container 110, and is disposed facing the adjacent spacer 200 in the Y-axis direction. The long side surface 111 is adjacent to the short side surface 112 and the bottom surface 113, and has a larger area than the short side surface 112. The short side surface 112 is a rectangular planar portion that forms the short side surface of the container 110, and is disposed facing the wall portion of the spacer 200 and the housing 300 in the X-axis direction. The short side surface 112 is adjacent to the long side surface 111 and the bottom surface 113, and has a smaller area than the long side surface 111. The bottom surface 113 is a rectangular planar portion that forms the bottom surface of the container 110, and is disposed facing the wall portion of the spacer 200 and the bottom wall of the housing 300 in the Z-axis direction. The bottom surface 113 is disposed adjacent to the long side surface 111 and the short side surface 112.

[0056] The terminal 140 is an electrode terminal (positive terminal and negative terminal) of the storage element 100 disposed on the container cover 130. Specifically, the terminal 140 is disposed in a state of protruding from the upper surface (terminal configuration surface) of the container cover 130 in the positive direction of the Z axis. The terminal 140 is electrically connected to the positive electrode plate and the negative electrode plate of the electrode body via the collector. That is, the terminal 140 is a metal member for conducting the power stored in the electrode body to the external space of the storage element 100 and for conducting the power into the internal space of the storage element 100 in order to store the power in the electrode body. The terminal 140 is formed of aluminum, aluminum alloy, copper, copper alloy, etc.

[0057] The electrode body is a storage element (power generation element) formed by stacking a positive electrode plate, a negative electrode plate and a separator. The positive electrode plate is obtained by forming a positive electrode active material layer on a collector foil, i.e., a positive electrode substrate layer, which is made of a metal such as aluminum or an aluminum alloy. The negative electrode plate is obtained by forming a negative electrode active material layer on a collector foil, i.e., a negative electrode substrate layer, which is made of a metal such as copper or a copper alloy. As the active material used in the positive electrode active material layer and the negative electrode active material layer, any known material can be used as long as it is a material that can absorb / release lithium ions. The separator can use a microporous sheet or non-woven fabric made of a resin. In the present embodiment, the electrode body is formed by stacking the electrode plates (positive electrode plates and negative electrode plates) along the Y-axis direction. The electrode body can be of any form: a wound electrode body formed by winding electrode plates (positive electrode plates and negative electrode plates), a stacked electrode body formed by stacking a plurality of flat electrode plates, or a corrugated electrode body in which electrode plates are folded into a corrugated shape.

[0058] The current collector is a conductive current collecting member (positive current collector and negative current collector) that electrically and mechanically connects the terminal 140 and the electrode body. The positive current collector is formed of aluminum or an aluminum alloy, etc., similarly to the positive electrode substrate layer of the positive electrode plate of the electrode body, and the negative current collector is formed of copper or a copper alloy, etc., similarly to the negative electrode substrate layer of the negative electrode plate of the electrode body.

[0059] [1.2 Description of spacer 200a]

[0060] Next, the structure of the spacer 200 a will be described in detail. Figure 4 2 is a perspective view and a front view showing the structure of the spacer 200a of this embodiment. Specifically, Figure 4 (a) is an enlarged representation Figure 2 A perspective view of spacer 200a is shown. Figure 4 (b) indicates that the Figure 4 (a) is a front view of the structure of the spacer 200a at the end portion in the positive direction of the X axis. Figure 5FIG. 0 is a perspective view and a rear view showing the structure of the spacer 200a of the present embodiment. Specifically, Figure 5 FIG. (a) of Figure 4 is a perspective view showing the structure of the opposite side of the spacer 200a shown in FIG. (a) of Figure 5 FIG. (b) of Figure 5 is a rear view showing the structure when observing the end portion in the negative X-axis direction of the spacer 200a shown in FIG. (a) of Figure 4 and Figure 5 All of the plurality of spacers 200a included in the power storage unit 10 have the same structure. Therefore, one spacer 200a is shown in

[0061] As Figure 4 and Figure 5 shown, both end portions of the spacer 200a in the X-axis direction have the same shape. That is, the spacer 200a has a shape symmetric with respect to the plane passing through the central position and parallel to the YZ plane. The spacer 200a includes a spacer main body 210 and spacer wall portions 220 to 250.

[0062] The spacer main body 210 is a flat and rectangular portion constituting the main body of the spacer 200a, and is arranged parallel to the XZ plane. In the present embodiment, the spacer main body 210 faces the long side surface 111 in the Y-axis direction and is arranged in contact with the long side surface 111 so as to cover the entire surface of the long side surface 111 of the container 110 of the power storage element 100 in the positive Y-axis direction or the negative Y-axis direction of the power storage element 100.

[0063] As Figure 4 shown, spaces 211a to 211d are formed on the surface in the negative Y-axis direction of the spacer main body 210. When the spacer 200a and the power storage element 100 arranged in the negative Y-axis direction of the spacer 200a (spacer main body 210) are assembled, the spaces 211a to 211d are spaces arranged between the spacer main body 210 and the power storage element 100. The spaces 211a to 211d are flow paths for a fluid flowing between the spacer main body 210 and the power storage element 100. The fluid flowing in the spaces 211a to 211d is a gas such as air or a fluid (coolant) for cooling the power storage element 100 such as a liquid. At the time of manufacturing (during the assembly operation), when holding the power storage element 100, the spaces 211a to 211d are also used as spaces into which jigs are inserted.

[0064] In the present embodiment, the spaces 211a to 211d are spaces within an L-shaped groove portion formed by a plurality of ribs bent in an L shape on the surface of the spacer body 210 in the negative Y-axis direction, and are bent in an L shape along the spacer body 210. Specifically, a recess 212 recessed in the positive Y-axis direction is formed on the surface of the spacer body 210 in the negative Y-axis direction. The recess 212 is a large rectangular recess when viewed from the Y-axis direction, occupying a large part of the surface of the spacer body 210 in the negative Y-axis direction. A plurality of ribs are provided in the recess 212, and the spaces 211a to 211d are formed.

[0065] The space 211a is a space that extends from the central portion in the X-axis direction at the negative Z-axis end of the spacer body 210 in the positive Z-axis direction and bends in the X-axis direction, so as to extend in the X-axis direction. Specifically, the two spaces 211a arranged in the X-axis direction extend in the positive Z-axis direction and bend to both sides in the X-axis direction, so as to extend to both sides in the X-axis direction. In the present embodiment, each space 211a is divided into two spaces after bending in the X-axis direction, and the two spaces merge at the X-axis end of the spacer body 210.

[0066] The space 211b is a space that extends from the outside in the X-axis direction of the space 211a at the negative Z-axis end of the spacer body 210 in the positive Z-axis direction and bends in the X-axis direction so as to extend in the X-axis direction. Specifically, the two spaces 211b extend in the positive Z-axis direction from positions sandwiching the two spaces 211a at the negative Z-axis end of the spacer body 210 and bend to both sides in the X-axis direction so as to extend to both sides in the X-axis direction. In the present embodiment, each space 211b is divided into two spaces after bending in the X-axis direction, and the two spaces merge at the X-axis end of the spacer body 210.

[0067] The space 211c is a space that extends from the outside in the X-axis direction of the space 211b at the negative Z-axis end of the spacer body 210 in the positive Z-axis direction and bends in the X-axis direction so as to extend in the X-axis direction. Specifically, the two spaces 211c extend in the positive Z-axis direction from positions sandwiching the two spaces 211b at the negative Z-axis end of the spacer body 210 and bend to both sides in the X-axis direction so as to extend to both sides in the X-axis direction. The space 211d is a space that extends from the outside in the X-axis direction of the space 211c at the negative Z-axis end of the spacer body 210 in the X-axis direction. Specifically, the two spaces 211d extend to both sides in the X-axis direction from positions sandwiching the two spaces 211c at the negative Z-axis end of the spacer body 210.

[0068] As Figure 5 shown, the spacer body 210 has a first surface 214, a second surface 215, and a third surface 216 provided on the surface in the positive Y-axis direction.

[0069] The first surface 214 is a large planar (flat surface) that is rectangular when viewed from the Y-axis direction and occupies most of the area of the surface in the positive Y-axis direction of the spacer body 210. The area of the first surface 214 is larger than that of the second surface 215 and also larger than that of the third surface 216. The first surface 214 is disposed facing the power storage element 100 in the positive Y-axis direction of the spacer 200a (spacer body 210). The first surface 214 faces the long side surface 111 in the Y-axis direction and is disposed in a state of contacting the long side surface 111 so as to cover most of the area of the long side surface 111 of the container 110 of the power storage element 100. The first surface 214 is disposed at a position protruding in the positive Y-axis direction from the third surface 216. Thus, the first surface 214 is disposed at a position protruding in the positive Y-axis direction compared to the second surface 215 and the third surface 216. The first surface 214 is disposed on the back side of the above-described concave portion 212 of the spacer body 210 (a position overlapping the concave portion 212 when viewed from the Y-axis direction). That is, the first surface 214 is provided by the surface in the positive Y-axis direction of the spacer body 210 protruding in the positive Y-axis direction, so that the surface in the negative Y-axis direction of the spacer body 210 is recessed in the positive Y-axis direction to form the concave portion 212.

[0070] The third surface 216 is disposed at a position recessed in the negative Y-axis direction compared to the first surface 214 among the surfaces in the positive Y-axis direction of the spacer body 210. The third surface 216 is a planar (flat surface) disposed at a position recessed in the negative Y-axis direction from the first surface 214 so as to surround the periphery of the first surface 214. The third surface 216 is a four-sided annular surface disposed on the outer periphery of the spacer body 210 when viewed from the Y-axis direction, surrounding the entire circumference of both sides in the X-axis direction and both sides in the Z-axis direction of the first surface 214.

[0071] The second surface 215 is located in the X-axis direction of the first surface 214 (the second direction intersecting the first direction) and is disposed at a position recessed in the negative Y-axis direction compared to the first surface 214. Specifically, the second surface 215 is disposed at a position recessed in the negative Y-axis direction compared to the third surface 216. The second surface 215 is a surface disposed at a position recessed in the negative Y-axis direction from the third surface 216 at the X-axis direction end of the third surface 216. The size and shape of the second surface 215 are not particularly limited, but in the present embodiment, the area of the second surface 215 is smaller than that of the third surface 216. The second surface 215 has: a planar (flat surface) that is long in the Z-axis direction and recessed in the negative Y-axis direction from the third surface 216, and a curved surface that is curved more in the negative Y-axis direction as it goes toward the outer side in the X-axis direction (the X-axis direction edge of the spacer body 210). In the present embodiment, two second surfaces 215 arranged in the Z-axis direction are formed on both sides in the X-axis direction of the spacer body 210, respectively.

[0072] The second surface 215 is disposed at a position corresponding to the wall portions 232 and 233 described later. Specifically, the second surface 215 is formed by recessing the Y-axis positive direction surface of the roots of the wall portions 232 and 233 (the connection portions with the spacer body 210) toward the Y-axis negative direction. Thus, as Figure 4 shown, by the Y-axis negative direction surface of the roots of the wall portions 232 and 233 protruding toward the Y-axis negative direction, a protruding portion 213 is formed. Four protruding portions 213 are formed at positions corresponding to the roots of the wall portions 232 and 233 on the Y-axis negative direction surface of the spacer body 210. The protruding portion 213 has a shape in which the Y-axis negative direction surface follows the shape of the second surface 215 (a shape having a plane long in the Z-axis direction and a curved surface that curves more toward the Y-axis negative direction as it goes toward the outer side in the X-axis direction).

[0073] Since the second surface 215 is disposed at a position recessed from the third surface 216 toward the Y-axis negative direction, a space 215a is formed at the position of the second surface 215. When the spacer 200a and the power storage element 100 disposed in the Y-axis positive direction of the spacer 200a (spacer body 210) are assembled, the space 215a is a space disposed between the second surface 215 and the power storage element 100. The space 215a is a space into which a jig is inserted when holding the power storage element 100 during manufacturing (assembly operation). The space 215a is not a flow path for fluid flowing between the spacer body 210 and the power storage element 100 like the spaces 211a to 211d.

[0074] The spacer wall portion 220 is a portion protruding from the X-axis direction end portion of the spacer body 210 toward the Y-axis positive direction, and has wall portions 221 to 225. The wall portions 221 to 225 are respectively disposed at different positions in the Z-axis direction and are arranged in the Z-axis direction toward the Z-axis negative direction in this order, and are a plurality of plate-like wall portions parallel to the YZ plane. The spacer wall portion 220 (wall portions 221 to 225) is disposed facing the short side surface 112 of the container 110 of the power storage element 100 located in the Y-axis positive direction of the spacer body 210 in the X-axis direction. The spacer wall portion 220 (wall portions 221 to 225) is disposed facing the housing wall portion 311 of the housing 300 (housing body 310) (refer to Figure 1 ). The spacer wall portion 220 (wall portions 221 to 225) is disposed separately (with a gap) from the housing wall portion 311. In the present embodiment, two spacer wall portions 220 (two sets of wall portions 221 to 225) are disposed at both ends in the X-axis direction of the spacer body 210.

[0075] The spacer wall portion 230 is a portion that protrudes from the X-axis direction end of the spacer main body 210 toward the negative Y-axis direction, and has wall portions 231 to 234. The wall portions 231 to 234 are respectively arranged at different positions in the Z-axis direction and are arranged in the Z-axis direction toward the negative Z-axis direction in this order, and are a plurality of plate-like wall portions parallel to the YZ plane. The spacer wall portion 230 (wall portions 231 to 234) is arranged facing the short side surface 112 of the container 110 of the power storage element 100 located in the negative Y-axis direction of the spacer main body 210 in the X-axis direction. The spacer wall portion 230 (wall portions 231 to 234) is arranged facing the case wall portion 311 (refer to Figure 1 ) of the case 300 (case main body 310). The spacer wall portion 230 (wall portions 231 to 234) is arranged separately (with a gap) from the case wall portion 311. In the present embodiment, two spacer wall portions 230 (two sets of wall portions 231 to 234) are arranged at both ends in the X-axis direction of the spacer main body 210.

[0076] The spacer wall portion 240 is a plate-like portion that protrudes from the positive Z-axis direction end of the spacer main body 210 toward both sides in the Y-axis direction, and is arranged parallel to the XY plane. The spacer wall portion 240 is arranged facing the container lid portion 130 of the container 110 of the power storage element 100 located on both sides in the Y-axis direction of the spacer main body 210 in the Z-axis direction. The spacer wall portion 250 is a plate-like portion that protrudes from the negative Z-axis direction end of the spacer main body 210 toward both sides in the Y-axis direction, and is arranged parallel to the XY plane. The spacer wall portion 250 is arranged facing the bottom surface 113 of the container 110 of the power storage element 100 located on both sides in the Y-axis direction of the spacer main body 210 in the Z-axis direction.

[0077] In this way, the spacer wall portions 220 to 250 are arranged so as to cover both sides in the X-axis direction and both sides in the Z-axis direction of the power storage element 100. Thereby, the spacer 200a holds the power storage element 100.

[0078] Hereinafter, Figures 6 - 8 will also be used to further describe in detail the structures of the spacer wall portion 220 (wall portions 221 to 225) and the spacer wall portion 230 (wall portions 231 to 234). In this description, hereinafter, as Figure 2 shown, the central spacer 200a among the three spacers 200a arranged in the Y-axis direction is also referred to as the first spacer 201. The spacer 200a located in the positive Y-axis direction of the first spacer 201 is also referred to as the second spacer 202. The spacer 200a located in the negative Y-axis direction of the first spacer 201 is also referred to as the third spacer 203. The first spacer 201, the second spacer 202, and the third spacer 203 have the same structure.

[0079] The power storage element 100 disposed between the first spacer 201 and the second spacer 202 is also referred to as the first power storage element 101. The power storage element 100 disposed between the first spacer 201 and the third spacer 203 is also referred to as the second power storage element 102. That is, the power storage element 100 disposed in the positive Y-axis direction (one side of the first direction) of the spacer main body 210 of the first spacer 201 is also referred to as the first power storage element 101. The power storage element 100 disposed in the negative Y-axis direction (the other side of the first direction) of the spacer main body 210 of the first spacer 201 is also referred to as the second power storage element 102. The first power storage element 101 and the second power storage element 102 have the same structure. In this way, the second spacer 202, the first power storage element 101, the first spacer 201, the second power storage element 102, and the third spacer 203 are arranged in sequence from the positive Y-axis direction.

[0080] [Description of the spacer wall portions 220 and 230 of 1.3]

[0081] Figure 6 It is a perspective view showing the structure of the spacer wall portions 220 and 230 of the first spacer 201, the second spacer 202, and the third spacer 203 of the present embodiment. Figure 6 It shows the structure of the positive X-axis end portions of the first spacer 201, the second spacer 202, and the third spacer 203 arranged in the Y-axis direction. Figure 7 It is a perspective view showing the structure in a state where the first spacer 201, the second spacer 202, and the third spacer 203 of the present embodiment are arranged relative to the power storage element 100. Figure 7 It shows a state where the first power storage element 101 and the second power storage element 102 are disposed between the first spacer 201, the second spacer 202, and the third spacer 203 respectively. Figure 8 It is a side view showing the structure in a state where the first spacer 201, the second spacer 202, and the third spacer 203 of the present embodiment are arranged relative to the power storage element 100. Figure 8 It shows when viewed from the positive X-axis direction Figure 7 of the structure.

[0082] The X-axis positive direction ends and X-axis negative direction ends of the first spacer 201, the second spacer 202, and the third spacer 203 have the same structure. Therefore, the structure of the X-axis positive direction ends of the first spacer 201, the second spacer 202, and the third spacer 203 will be described in detail below, and the description of the structure of the X-axis negative direction ends will be omitted. That is, the structure of the X-axis negative direction ends of the first spacer 201, the second spacer 202, and the third spacer 203 is obtained by replacing "X-axis negative direction" with "X-axis positive direction" and "X-axis positive direction" with "X-axis negative direction" in the description of the structure of the X-axis positive direction ends described later.

[0083] As Figures 6 - 8 shown, the first spacer 201, the second spacer 202, and the third spacer 203 each have spacer wall portions 220 and 230. The spacer wall portions 220 and 230 of the first spacer 201 are also referred to as the first spacer wall portions 220A and 230A. The spacer wall portions 220 and 230 of the second spacer 202 are also referred to as the second spacer wall portions 220B and 230B. The spacer wall portions 220 and 230 of the third spacer 203 are also referred to as the third spacer wall portions 220C and 230C. The first spacer wall portion 220A protrudes in the positive Y-axis direction toward the second spacer 202, and the first spacer wall portion 230A protrudes in the negative Y-axis direction toward the third spacer 203. The second spacer wall portion 230B protrudes in the negative Y-axis direction toward the first spacer 201. The third spacer wall portion 220C protrudes in the positive Y-axis direction toward the first spacer 201. The first spacer wall portion 220A, the second spacer wall portion 220B, and the third spacer wall portion 220C each have wall portions 221 to 225. The first spacer wall portion 230A, the second spacer wall portion 230B, and the third spacer wall portion 230C each have wall portions 231 to 234.

[0084] [1.3.1 Explanation of Each Wall Portion of the Spacer Wall Portions 220 and 230]

[0085] The wall portion 221 is a flat plate-shaped wall that protrudes in the positive Y-axis direction from the positive Z-axis end of the X-axis positive direction end of the spacer body 210 and is parallel to the YZ plane. The wall portion 231 is a flat plate-shaped wall that protrudes in the negative Y-axis direction from the positive Z-axis end of the X-axis positive direction end of the spacer body 210 and is parallel to the YZ plane. The wall portion 221 is in the X-axis direction with the power storage element 100 located in the positive Y-axis direction of the spacer body 210 and the case wall portion 311 of the case 300 (case main body 310) (refer to Figure 1)Face each other. The wall portion 231 faces the power storage element 100 in the negative Y-axis direction of the spacer body 210 and the housing wall portion 311 in the X-axis direction. In the first spacer 201, the wall portion 221 of the first spacer wall portion 220A faces the first power storage element 101 in the X-axis direction, and the wall portion 231 of the first spacer wall portion 230A faces the second power storage element 102 in the X-axis direction. The same applies to the second spacer 202 and the third spacer 203.

[0086] The wall portion 221 and the wall portion 231 are arranged at different positions in the X-axis direction and at least partially arranged at the same position in the Z-axis direction. Specifically, the wall portion 221 is arranged closer to the positive X-axis direction than the wall portion 231 and is arranged at substantially the same position as the wall portion 231 in the Z-axis direction. Thus, the wall portion 221 of the first spacer wall portion 220A is arranged in the positive X-axis direction of the wall portion 231 of the second spacer wall portion 230B and overlaps with this wall portion 231 in the X-axis direction. The same applies to the wall portion 221 of the third spacer wall portion 220C and the wall portion 231 of the first spacer wall portion 230A.

[0087] The wall portion 225 is a flat plate-shaped wall protruding in the positive Y-axis direction from the negative Z-axis end of the positive X-axis end of the spacer body 210 and parallel to the YZ plane. The wall portion 234 is a flat plate-shaped wall protruding in the negative Y-axis direction from the negative Z-axis end of the positive X-axis end of the spacer body 210 and parallel to the YZ plane. The wall portion 225 faces the power storage element 100 in the positive Y-axis direction of the spacer body 210 and the housing wall portion 311 in the X-axis direction. The wall portion 234 faces the power storage element 100 in the negative Y-axis direction of the spacer body 210 and the housing wall portion 311 in the X-axis direction. On the first spacer 201, the wall portion 225 of the first spacer wall portion 220A faces the first power storage element 101 in the X-axis direction, and the wall portion 234 of the first spacer wall portion 230A faces the second power storage element 102 in the X-axis direction. The same applies to the second spacer 202 and the third spacer 203.

[0088] The wall portion 225 and the wall portion 234 are arranged at different positions in the X-axis direction and at least partially arranged at the same position in the Z-axis direction. Specifically, the wall portion 225 is arranged closer to the positive X-axis direction than the wall portion 234 and is arranged at substantially the same position as the wall portion 234 in the Z-axis direction. Thus, the wall portion 225 of the first spacer wall portion 220A is arranged in the positive X-axis direction of the wall portion 234 of the second spacer wall portion 230B and overlaps with this wall portion 234 in the X-axis direction. The same applies to the wall portion 225 of the third spacer wall portion 220C and the wall portion 234 of the first spacer wall portion 230A.

[0089] The wall portion 222 is a flat plate-shaped wall parallel to the YZ plane that protrudes in the positive Y-axis direction from a position further in the negative Z-axis direction than the wall portion 221 at the positive X-axis end of the spacer body 210. In the present embodiment, the wall portion 222 is connected (continuously connected) to the wall portion 221, but may also be arranged separately from the wall portion 221. The wall portion 222 faces the power storage element 100 and the housing wall portion 311 located in the positive Y-axis direction of the spacer body 210 in the X-axis direction. In the first spacer 201, the wall portion 222 of the first spacer wall portion 220A faces the first power storage element 101 in the X-axis direction, and in the third spacer 203, the wall portion 222 of the third spacer wall portion 220C faces the second power storage element 102 in the X-axis direction. The same applies to the second spacer 202.

[0090] The wall portion 224 is a flat plate-shaped wall parallel to the YZ plane that protrudes in the positive Y-axis direction from a position further in the positive Z-axis direction than the wall portion 225 at the positive X-axis end of the spacer body 210. In the present embodiment, the wall portion 224 is connected (continuously connected) to the wall portion 225, but may also be arranged separately from the wall portion 225. The wall portion 224 faces the power storage element 100 and the housing wall portion 311 located in the positive Y-axis direction of the spacer body 210 in the X-axis direction. In the first spacer 201, the wall portion 224 of the first spacer wall portion 220A faces the first power storage element 101 in the X-axis direction, and in the third spacer 203, the wall portion 224 of the third spacer wall portion 220C faces the second power storage element 102 in the X-axis direction. The same applies to the second spacer 202.

[0091] The wall portion 223 is a flat plate-shaped wall parallel to the YZ plane that protrudes in the positive Y-axis direction from the central portion in the Z-axis direction at the positive X-axis end of the spacer body 210. The wall portion 223 faces the power storage element 100 and the housing wall portion 311 located in the positive Y-axis direction of the spacer body 210 in the X-axis direction. In the first spacer 201, the wall portion 223 of the first spacer wall portion 220A faces the first power storage element 101 in the X-axis direction, and in the third spacer 203, the wall portion 223 of the third spacer wall portion 220C faces the second power storage element 102 in the X-axis direction. The same applies to the second spacer 202.

[0092] The wall portion 232 is a flat plate-shaped wall parallel to the YZ plane that protrudes in the negative Y-axis direction from a position that is more in the negative Z-axis direction than the wall portion 222 and more in the positive Z-axis direction than the wall portion 223 at the positive X-axis end of the spacer body 210. The wall portion 232 faces the power storage element 100 and the housing wall portion 311 located in the negative Y-axis direction of the spacer body 210 in the X-axis direction. In the first spacer 201, the wall portion 232 of the first spacer wall portion 230A faces the second power storage element 102 in the X-axis direction, and in the second spacer 202, the wall portion 232 of the second spacer wall portion 230B faces the first power storage element 101 in the X-axis direction. The same applies to the third spacer 203.

[0093] The wall portion 232 and the wall portions 222 and 223 are arranged at different positions in the X-axis direction and at least partially arranged at the same position in the Z-axis direction. Specifically, the wall portion 232 is arranged more in the positive X-axis direction than the wall portion 222, and the positive Z-axis end of the wall portion 232 is arranged at the same position in the Z-axis direction as the negative Z-axis end of the wall portion 222. The wall portion 232 is arranged more in the negative X-axis direction than the wall portion 223, and the negative Z-axis end of the wall portion 232 is arranged at the same position in the Z-axis direction as the positive Z-axis end of the wall portion 223. Thus, the wall portion 232 of the first spacer wall portion 230A is arranged in the positive X-axis direction of the wall portion 222 of the third spacer wall portion 220C and in the negative X-axis direction of the wall portion 223 of the third spacer wall portion 220C, and at least partially overlaps with the wall portions 222 and 223 in the X-axis direction. The same applies to the wall portion 232 of the second spacer wall portion 230B and the wall portions 222 and 223 of the first spacer wall portion 220A.

[0094] The wall portion 233 is a flat plate-shaped wall parallel to the YZ plane that protrudes in the negative Y-axis direction from a position that is more in the negative Z-axis direction than the wall portion 223 and more in the positive Z-axis direction than the wall portion 224 at the positive X-axis end of the spacer body 210. The wall portion 233 faces the power storage element 100 and the housing wall portion 311 located in the negative Y-axis direction of the spacer body 210 in the X-axis direction. In the first spacer 201, the wall portion 233 of the first spacer wall portion 230A faces the second power storage element 102 in the X-axis direction, and in the second spacer 202, the wall portion 233 of the second spacer wall portion 230B faces the first power storage element 101 in the X-axis direction. The same applies to the third spacer 203.

[0095] The wall portion 233 and the wall portions 223 and 224 are arranged at different positions in the X-axis direction and at least a part of them is arranged at the same position in the Z-axis direction. Specifically, the wall portion 233 is arranged on the negative X-axis side relative to the wall portion 223, and the positive Z-axis end portion of the wall portion 233 is arranged at the same position as the negative Z-axis end portion of the wall portion 223 in the Z-axis direction. The wall portion 233 is arranged on the positive X-axis side relative to the wall portion 224, and the negative Z-axis end portion of the wall portion 233 is arranged at the same position as the positive Z-axis end portion of the wall portion 224 in the Z-axis direction. Thus, the wall portion 233 of the first spacer wall portion 230A is arranged on the negative X-axis side of the wall portion 223 of the third spacer wall portion 220C and on the positive X-axis side of the wall portion 224 of the third spacer wall portion 220C, and at least a part of it overlaps with the wall portions 223 and 224 in the X-axis direction. The same applies to the wall portion 233 of the second spacer wall portion 230B and the wall portions 223 and 224 of the first spacer wall portion 220A.

[0096] The length of the wall portion 223 in the Z-axis direction is longer than that of the wall portions 232 and 233. In the present embodiment, the wall portions 222 and 224 have the same length as the wall portions 232 and 233 in the Z-axis direction, but they may also be longer than the wall portions 232 and 233. The lengths of the wall portions 232 and 233 in the Z-axis direction are the same, but they may also be different. The lengths of the wall portions 221, 225, 231, and 234 in the Z-axis direction are not particularly limited.

[0097] The wall portion 223 is arranged at a position closer to the negative Z-axis side than the wall portions 221 and 222 and closer to the positive Z-axis side than the wall portions 224 and 225. Thus, the wall portion 223 is arranged closer to the center position of the power storage element 100 than the wall portions 221, 222, 224, and 225 in the Z-axis direction. The wall portion 223 is arranged closer to the terminal 140 of the power storage element 100 than the wall portions 224 and 225. The wall portions 221 and 222 are arranged closer to the terminal 140 of the power storage element 100 than the wall portions 223 to 225.

[0098] When viewed from the X-axis direction, the wall portions 222 to 224 are arranged at positions where the edge in the positive Y-axis direction overlaps with the power storage element 100 in the positive Y-axis direction of the spacer main body 210. That is, the wall portions 222 to 224 are arranged in such a manner that they do not protrude in the positive Y-axis direction from the surface (long side surface 111) in the positive Y-axis direction of the power storage element 100. Specifically, the length of the wall portions 222 to 224 in the Y-axis direction is shorter than the thickness of the power storage element 100 in the Y-axis direction (the width of the short side surface 112 in the Y-axis direction). The length of the wall portions 221 and 225 in the Y-axis direction is not particularly limited. Similarly, when viewed from the X-axis direction, the wall portions 232 and 233 are arranged at positions where the edge in the negative Y-axis direction overlaps with the power storage element 100 in the negative Y-axis direction of the spacer main body 210. That is, the wall portions 232 and 233 are arranged in such a manner that they do not protrude in the negative Y-axis direction from the surface (long side surface 111) in the negative Y-axis direction of the power storage element 100. Specifically, the length of the wall portions 232 and 233 in the Y-axis direction is shorter than the thickness of the power storage element 100 in the Y-axis direction (the width of the short side surface 112 in the Y-axis direction). The length of the wall portions 231 and 234 in the Y-axis direction is not particularly limited.

[0099] [1.3.2 Description of the convex portions and reinforcing ribs of the spacer wall portions 220 and 230]

[0100] The wall portion 221 has a convex portion 221a that protrudes toward the housing wall portion 311. The convex portion 221a is a convex portion (rib) having a substantially cylindrical shape that protrudes in the positive X-axis direction, and the end portion (root) in the negative X-axis direction has a conical shape with a diameter that increases toward the negative X-axis direction in order to ensure strength and the like. The convex portion 221a is arranged at the end portion in the negative Y-axis direction and the central portion in the Z-axis direction of the wall portion 221. When viewed from the X-axis direction, the convex portion 221a is arranged at a position that does not overlap with the spacer main body 210. The convex portion 221a is arranged separately (with a gap) from the housing wall portion 311.

[0101] The wall portion 223 has a convex portion 223a that protrudes toward the housing wall portion 311. The convex portion 223a is a convex portion (rib) having a substantially rectangular parallelepiped shape that protrudes in the positive X-axis direction, and the end portion (root) in the negative X-axis direction has a frustum of a pyramid shape with a diameter that increases toward the negative X-axis direction in order to ensure strength and the like. The convex portion 223a is arranged at the end portion in the positive Y-axis direction and the central portion in the Z-axis direction of the wall portion 223. When viewed from the X-axis direction, the convex portion 223a is arranged at a position that does not overlap with the spacer main body 210. The convex portion 223a is arranged separately (with a gap) from the housing wall portion 311.

[0102] The wall portion 225 has a convex portion 225a that protrudes toward the housing wall portion 311. The convex portion 225a is a convex portion (rib) in the shape of a substantially rectangular parallelepiped that protrudes in the positive X-axis direction, and has a frustum shape with a diameter that increases toward the negative X-axis direction at the end (root) in the negative X-axis direction in order to ensure strength and the like. The convex portion 225a is disposed at the end in the positive Y-axis direction and the end in the negative Z-axis direction of the wall portion 225. When viewed from the X-axis direction, the convex portion 225a is disposed at a position that does not overlap with the spacer body 210. The convex portion 225a is disposed separately (with a gap) from the housing wall portion 311.

[0103] When viewed from the X-axis direction, the size of the convex portion 223a is smaller than that of the convex portion 225a. Specifically, the area of the convex portion 223a (or the minimum cross-sectional area in the YZ plane) when viewed from the X-axis direction is smaller than the area of the convex portion 225a. When viewed from the X-axis direction, the size of the convex portion 221a is smaller than the sizes of the convex portions 223a and 225a. Specifically, the area of the convex portion 221a (or the minimum cross-sectional area in the YZ plane) when viewed from the X-axis direction is smaller than the areas of the convex portions 223a and 225a.

[0104] The top end of the convex portion 223a is disposed more toward the positive X-axis direction than the top end of the convex portion 225a (see Figure 4 and Figure 5 ). That is, the convex portion 223a is disposed so as to protrude more toward the positive X-axis direction than the convex portion 225a. In the present embodiment, the protruding amount of the convex portion 223a is the same as or smaller than the protruding amount of the convex portion 225a, but since the wall portion 223 is disposed more toward the positive X-axis direction than the wall portion 225, the top end of the convex portion 223a is disposed more toward the positive X-axis direction than the top end of the convex portion 225a. The protruding amount of the convex portion 223a may also be larger than the protruding amount of the convex portion 225a. The top end of the convex portion 221a is disposed more toward the positive X-axis direction than the top ends of the convex portions 223a and 225a (see Figure 4 and Figure 5 ). That is, the convex portion 221a is disposed so as to protrude more toward the positive X-axis direction than the convex portions 223a and 225a. In the present embodiment, since the wall portion 221 is disposed at the same position as the wall portion 225 in the X-axis direction, the protruding amount of the convex portion 221a is larger than the protruding amount of the convex portion 225a. Since the wall portion 221 is disposed more toward the negative X-axis direction than the wall portion 223, the protruding amount of the convex portion 221a is larger than the protruding amount of the convex portion 223a.

[0105] The wall portion 222 has a reinforcing rib 222a inside at the position (root) where it bends from the spacer body 210 (see Figure 5 ). The wall portion 223 has a reinforcing rib 223b inside at the position (root) where it bends from the spacer body 210 (see Figure 5)。The wall portion 224 has a reinforcing rib 224a on the inner side of the position (root) bent from the spacer body 210 (refer to Figure 5 )。The wall portion 231 has a reinforcing rib 231a on the inner side of the position (root) bent from the spacer body 210 (refer to Figure 4 )。The wall portion 234 has a reinforcing rib 234a on the inner side of the position (root) bent from the spacer body 210 (refer to Figure 4 )。

[0106] That is, reinforcing ribs 222a, 224a, 231a, and 234a are provided on the wall portions 222, 224, 231, and 234 for holding the power storage element 100. A reinforcing rib 223b is also provided on the wall portion 223 having the convex portion 223a. The wall portions 221 and 225 having the convex portions 221a and 225a are connected to the wall portions 222 and 224, so no reinforcing ribs are provided, but reinforcing ribs can also be provided on the wall portions 221 and 225. Reinforcing ribs can also be provided on the wall portions 232 and 233.

[0107] [1.3.3 Description of the openings 21 - 25]

[0108] The wall portions 222 - 224 protrude only in the positive Y-axis direction in the Y-axis direction. Therefore, as Figure 7 and Figure 8 shown, openings 21, 23, and 25 are provided in the negative Y-axis direction of the wall portions 222 - 224. The openings 21, 23, and 25 are openings formed in the power storage unit 10 at the boundary between the internal space and the external space of the power storage unit 10 for connecting the internal space and the external space of the power storage unit 10 and are formed by separating a part of the surface in the negative Y-axis direction of the spacer body 210 and a part of the power storage element 100 between the spacer body 210 and the power storage element 100 located in the negative Y-axis direction of the spacer body 210. The openings 21, 23, and 25 are arranged at different positions in the Z-axis direction.

[0109] Specifically, an opening 21 for connecting the space 211a (refer to Figure 4 ) and the external space S, which is the space outside the power storage unit 10 (refer to Figure 7 ), is formed in the negative Y-axis direction of the wall portion 222. The external space S is the space in the positive X-axis direction of the power storage unit 10 (the power storage element 100 and the spacer 200a). An opening 23 for connecting the space 211b (refer to Figure 4 ) and the external space S of the power storage unit 10 is formed in the negative Y-axis direction of the wall portion 223. An opening 25 for connecting the space 211d (refer to Figure 4)An opening 25 connected to the external space S of the power storage unit 10. The wall portion 222 protrudes in the positive Y-axis direction from the position of the opening 21 of the spacer body 210. The wall portion 223 protrudes in the positive Y-axis direction from the position of the opening 23 of the spacer body 210. The wall portion 224 protrudes in the positive Y-axis direction from the position of the opening 25 of the spacer body 210. As described above, the spaces 211a to 211d are flow paths for the fluid flowing between the spacer body 210 and the power storage element 100, and the openings 21, 23, and 25 are the outlets of this flow path. Therefore, in addition to the openings 21, 23, and 25 that form the outlets of this flow path, the power storage unit 10 also has an opening that forms the inlet of this flow path at the negative Z-axis end (see Figure 4 ).

[0110] The wall portions 232 and 233 protrude only in the negative Y-axis direction in the Y-axis direction. Therefore, as Figure 7 , Figure 8 shown, openings 22 and 24 are formed in the positive Y-axis direction of the wall portions 232 and 233. The openings 22 and 24 are openings formed in the power storage unit 10 when viewed from the X-axis direction at the boundary between the internal space and the external space of the power storage unit 10 for connecting the internal space and the external space of the power storage unit 10. The openings 22 and 24 are formed by separating a part of the positive Y-axis surface of the spacer body 210 and a part of the power storage element 100 located in the positive Y-axis direction of the spacer body 210. The openings 22 and 24 are arranged at different positions in the Z-axis direction. The openings 22 and 24 and the openings 21, 23, and 25 are all arranged at different positions in the Z-axis direction.

[0111] Specifically, an opening 22 that connects the space 215a (see Figure 5 ) to the external space S, which is the space outside the power storage unit 10, is formed in the positive Y-axis direction of the wall portion 232. An opening 24 that connects the space 215a (see Figure 5 ) to the external space S, which is the space outside the power storage unit 10, is formed in the positive Y-axis direction of the wall portion 233. The wall portion 232 protrudes in the negative Y-axis direction from the position of the opening 22 of the spacer body 210. The wall portion 233 protrudes in the negative Y-axis direction from the position of the opening 24 of the spacer body 210.

[0112] In the above structure, the wall portion 223 of the first spacer wall portion 220A of the first spacer 201 is an example of the first wall portion. That is, the wall portion 223 (first wall portion) protrudes from the spacer main body 210 in the positive Y-axis direction or the negative Y-axis direction (one side or the other side of the first direction) and faces the housing wall portion 311 in the X-axis direction (second direction). In the present embodiment, the wall portion 223 (first wall portion) protrudes from the spacer main body 210 only in the positive Y-axis direction (one side of the first direction) in the Y-axis direction (first direction). The wall portion 223 (first wall portion) does not protrude from the spacer main body 210 in the negative Y-axis direction (the other side of the first direction), but protrudes in the positive Y-axis direction (one side of the first direction) and faces the first power storage element 101 in the X-axis direction (second direction intersecting the first direction). When viewed from the X-axis direction (second direction), the wall portion 223 (first wall portion) is disposed at a position where the end edge in the positive Y-axis direction (one side of the first direction) overlaps with the first power storage element 101.

[0113] The wall portion 232 of the first spacer wall portion 230A of the first spacer 201 is an example of the second wall portion. That is, the wall portion 232 (second wall portion) protrudes from the spacer main body 210 in the negative Y-axis direction (the other side of the first direction) and faces the second power storage element 102 in the X-axis direction (second direction). The wall portion 232 (second wall portion) is disposed closer to the positive Z-axis direction (one side of the third direction intersecting the first direction and the second direction) than the wall portion 223 (first wall portion). The wall portion 223 (first wall portion) and the wall portion 232 (second wall portion) are disposed at different positions in the X-axis direction (second direction). The wall portion 223 (first wall portion) and the wall portion 232 (second wall portion) are disposed at least partially at the same position in the Z-axis direction (third direction). The length of the wall portion 223 (first wall portion) in the Z-axis direction (third direction) is longer than that of the wall portion 232 (second wall portion).

[0114] The space 215a and the opening 22 formed by the first spacer 201 are examples of the first space and the first opening. The space 211b and the opening 23 formed by the first spacer 201 are examples of the second space and the second opening. That is, the power storage unit 10 has an opening 22 (the first opening) that connects the space 215a (the first space) between the second surface 215 and the first power storage element 101 to the external space S, which is the space outside the power storage unit 10 in the X-axis direction (the second direction). The first surface 214 faces the first power storage element 101. The power storage unit 10 has an opening 23 (the second opening) that is disposed in the negative Y-axis direction (the other side of the first direction) of the wall portion 223 (the first wall portion) and at a position different from the opening 22 (the first opening), and connects the space 211b (the second space) between the spacer main body 210 and the second power storage element 102 to the external space S. The space 211b (the second space) is a flow path for the fluid flowing between the spacer main body 210 and the second power storage element 102. The wall portion 232 (the second wall portion) protrudes in the negative Y-axis direction (the other side of the first direction) from the position of the opening 22 (the first opening) of the spacer main body 210.

[0115] [Description of effects]

[0116] As described above, in the power storage device 1 according to the present embodiment, the spacer body 210 of the spacer 200a has a second surface 215 at a position recessed in the X-axis direction (second direction) of the first surface 214 facing the first power storage element 101. The power storage unit 10 has an opening 22 (first opening) that connects the space 215a (first space) between the second surface 215 and the first power storage element 101 to the external space S of the power storage unit 10. In this way, by the spacer body 210 having not only the first surface 214 facing the first power storage element 101 but also the second surface 215 at a position recessed in the X-axis direction (second direction) of the first surface 214, it is possible to suppress the expansion of the first power storage element 101 using the first surface 214 and form the space 215a (first space) by the second surface 215. Since the power storage unit 10 has an opening 22 (first opening) that connects the space 215a (first space) (the internal space of the power storage unit 10) to the external space S of the power storage unit 10, the jig is inserted into the space 215a (first space) from the opening 22 (first opening) to hold the first power storage element 101, so that the workability during manufacturing can be improved. Furthermore, the spacer 200a has a wall portion 223 (first wall portion) facing the first power storage element 101 in the X-axis direction (second direction). Therefore, the insulation in the X-axis direction (second direction) of the first power storage element 101 (improvement of high-voltage protection and insulation) can be improved using the wall portion 223 (first wall portion). By the spacer 200a having the wall portion 223 (first wall portion), it is possible to improve the vibration resistance and shock resistance of the first power storage element 101 in the X-axis direction (second direction). Thus, in the power storage device 1, it is possible to improve the workability during manufacturing and maintain the performance.

[0117] The power storage device 1 has a non-constrained type of power storage unit 10 that does not have a constraining member (such as an end plate and a side plate) that constrains the plurality of power storage elements 100 and the spacers 200. Therefore, when vibrations or impacts from the outside are applied to the power storage device 1, the power storage elements 100 and the spacers 200 are likely to move within the housing 300, and the power storage elements 100 and the spacers 200 are likely to approach the housing wall portion 311. Even if the spacers 200 are arranged separately (with a gap) from the housing wall portion 311, the spacers 200 are likely to move and come into contact with the housing wall portion 311. Therefore, the effect of improving the insulation of the power storage element 100 is more significant.

[0118] In the spacer 200a, since the area of the first surface 214 is larger than that of the second surface 215, even when the second surface 215 is provided to form the space 215a (first space) by recessing the spacer body 210, it is possible to suppress the expansion of the first power storage element 101 using the first surface 214.

[0119] In the spacer 200a, the spacer main body 210 has a third surface 216 at a position recessed more in the negative Y-axis direction than the first surface 214, and the second surface 215 is disposed at a position recessed more in the negative Y-axis direction than the third surface 216. Thus, the first surface 214 protrudes more than the third surface 216, and the second surface 215 is disposed at a position recessed more in the negative Y-axis direction than the third surface 216. Therefore, since the first surface 214 that protrudes from the third surface 216 and suppresses the swelling of the first power storage element 101 can be disposed, and the second surface 215 that is recessed from the third surface 216 to form the space 215a (first space) can be disposed, the first surface 214 and the second surface 215 can be formed in a desired shape at a desired position.

[0120] By the spacer 200a having the wall portion 232 (second wall portion), the insulation (improvement of high voltage protection and insulation) in the X-axis direction (second direction) of the other power storage element 100 (second power storage element 102) disposed on the negative Y-axis side (the other side of the first direction) of the spacer main body 210 can be achieved by the wall portion 232 (second wall portion). By the spacer 200a having the wall portion 232 (second wall portion), the improvement of the vibration resistance and shock resistance in the X-axis direction (second direction) of the other power storage element 100 (second power storage element 102) can be achieved.

[0121] By disposing the edge (top end) on the positive Y-axis side (one side of the first direction) of the wall portion 223 (first wall portion) of the spacer 200a at a position overlapping the first power storage element 101 when viewed from the X-axis direction (second direction), a structure in which the wall portion 223 (first wall portion) does not protrude from the first power storage element 101 is formed. Therefore, the case where the wall portion 223 (first wall portion) becomes an obstacle when the jig is inserted into the positive Y-axis side (one side of the first direction) of the first power storage element 101 can be suppressed.

[0122] The power storage unit 10 has an opening 23 (second opening) that connects the space 211b (second space) (the internal space of the power storage unit 10) between the spacer main body 210 of the spacer 200a and the second power storage element 102 to the external space S of the power storage unit 10. The space 211b (second space) is a flow path for the fluid that flows between the spacer main body 210 and the second power storage element 102. Thus, as the space 211b (second space), by using the flow path of the fluid (coolant such as air) that flows between the spacer main body 210 and the second power storage element 102, the jig is inserted into this flow path (space 211b (second space)) from the opening 23 (second opening), and therefore, the second power storage element 102 can be held with a simple structure.

[0123] The spacer 200a has: a wall portion 223 (first wall portion) facing the first power storage element 101 in the X-axis direction (second direction); and a wall portion 232 (second wall portion) facing the second power storage element 102 in the X-axis direction (second direction). Thus, the insulation (improvement of high-voltage protection and insulation) of the first power storage element 101 in the X-axis direction (second direction) can be achieved by the wall portion 223 (first wall portion) of the spacer 200a. The insulation (improvement of high-voltage protection and insulation) of the second power storage element 102 in the X-axis direction (second direction) can be achieved by the wall portion 232 (second wall portion) of the spacer 200a. The power storage unit 10 has an opening 23 in the negative Y-axis direction (the other side of the first direction) of the wall portion 223 (first wall portion), connecting the space 211b between the spacer main body 210 and the second power storage element 102 to the external space S of the power storage unit 10. Thus, through the opening 23, a flow path for a fluid (coolant such as air) flowing between the space 211b (the internal space of the power storage unit 10) between the spacer main body 210 and the second power storage element 102 and the external space S of the power storage unit 10 can be ensured. Therefore, the power storage element 100 can be cooled and the insulation can be improved. In particular, as described above, since the power storage unit 10 is of a non-constrained type, the power storage element 100 and the spacer 200 are easily accessible to the housing wall portion 311. Therefore, the effect of improving the insulation of the power storage element 100 is more significant. By the spacer 200a having the wall portion 223 (first wall portion) and the wall portion 232 (second wall portion), the vibration resistance and shock resistance of the first power storage element 101 and the second power storage element 102 in the X-axis direction (second direction) can be improved.

[0124] The wall portion 223 (first wall portion) and the wall portion 232 (second wall portion) of the spacer 200a are arranged at different positions in the X-axis direction (second direction). Thus, when assembling the power storage unit 10 or the like, contact between the wall portion 223 (first wall portion) of one spacer 200a and the wall portion 232 (second wall portion) of the other spacer 200a sandwiching the power storage element 100 can be suppressed.

[0125] At least a part of the wall portion 223 (first wall portion) and the wall portion 232 (second wall portion) of the spacer 200a are arranged at the same position in the Z-axis direction (third direction). Thus, the wall portion 223 (first wall portion) of one spacer 200a and the wall portion 232 (second wall portion) of the other spacer 200a sandwiching the power storage element 100 can be overlapped. Therefore, the insulation (improvement of high-voltage protection and insulation) of the power storage element 100 in the X-axis direction (second direction) can be further achieved. The vibration resistance and shock resistance of the power storage element 100 in the X-axis direction (second direction) can be further improved.

[0126] By extending the length of the wall portion 223 (first wall portion) of the spacer 200a in the Z-axis direction (third direction), it is possible to extend the length of the opening 23 in the Z-axis direction (third direction) located on the negative Y-axis direction (the other side of the first direction) of the wall portion 223 (first wall portion). Thereby, it is possible to ensure a relatively large flow path for the fluid (coolant such as air) flowing between the space 211b and the external space S.

[0127] The spacer 200a also has a wall portion 222 facing the first power storage element 101 in the X-axis direction (second direction). Thereby, by means of the wall portion 222 of the spacer 200a, it is possible to further achieve insulation of the first power storage element 101 in the X-axis direction (second direction) (improvement of high-voltage protection and insulation). The power storage unit 10 also has an opening 21 in the negative Y-axis direction (the other side of the first direction) of the wall portion 222 that connects the space 211a between the spacer main body 210 and the second power storage element 102 to the external space S of the power storage unit 10. Thereby, through the opening 21, it is possible to ensure a flow path for the fluid (coolant such as air) flowing between the space 211a (the internal space of the power storage unit 10) between the spacer main body 210 and the second power storage element 102 and the external space S of the power storage unit 10. The spacer 200a also has a wall portion 222, thereby making it possible to further improve the vibration resistance and shock resistance of the first power storage element 101 in the X-axis direction (second direction).

[0128] By disposing the edge (top end) of the wall portion 223 (first wall portion) of the spacer 200a on the positive Y-axis direction (one side of the first direction) at a position overlapping the first power storage element 101 when viewed from the X-axis direction (second direction), a structure is formed in which the wall portion 223 (first wall portion) does not protrude from the first power storage element 101. Therefore, it is possible to prevent the wall portion 223 (first wall portion) from blocking the flow path of the fluid (coolant such as air) on the positive Y-axis direction (one side of the first direction) of the first power storage element 101.

[0129] The spacer 200a has a wall portion 223 (first wall portion) facing the housing wall portion 311 in the X-axis direction (second direction), so that the insulation between the power storage element 100 and the housing wall portion 311 can be improved by using the wall portion 223 (first wall portion). However, if the wall portion 223 (first wall portion) is in surface contact with the housing wall portion 311, there is a possibility that the creepage distance between the power storage element 100 and the housing wall portion 311 becomes smaller. Therefore, by providing a convex portion 223a protruding toward the housing wall portion 311 on the wall portion 223 (first wall portion), surface contact between the wall portion 223 (first wall portion) and the housing wall portion 311 is suppressed. Thereby, the creepage distance between the power storage element 100 and the housing wall portion 311 can be increased, and thus the insulation between the power storage element 100 and the housing wall portion 311 can be further improved. In particular, as described above, the power storage unit 10 is of a non-restrained type, so the spacer 200 is likely to move and is likely to come into contact with the housing wall portion 311. Therefore, the effect of increasing the creepage distance between the power storage element 100 and the housing wall portion 311 is more significant.

[0130] In the case where the spacer 200a does not have the wall portion 223 (first wall portion), the convex portion 223a needs to be arranged at a position overlapping the spacer main body 210 when viewed from the X-axis direction (second direction), so the area where the convex portion 223a can be arranged is narrow and it is difficult to arrange the convex portion 223a. In contrast, since the convex portion 223a is arranged on the wall portion 223 (first wall portion), the convex portion 223a can be arranged at a position that does not overlap the spacer main body 210 when viewed from the X-axis direction (second direction). Therefore, the convex portion 223a can be easily arranged on the spacer 200a.

[0131] In the spacer 200a, even if the wall portion 223 (first wall portion) protrudes from the spacer main body 210 only in the positive Y-axis direction (one side of the first direction), as long as the wall portion 223 (first wall portion) is provided, the convex portion 223a can be arranged on the wall portion 223 (first wall portion). Therefore, the convex portion 223a can be easily arranged on the spacer 200a.

[0132] The spacer 200a also has a wall portion 225 facing the housing wall portion 311 in the X-axis direction (second direction) at a position different from that of the wall portion 223 (first wall portion) in the Z-axis direction (third direction). Thereby, even at a position different from that of the wall portion 223 (first wall portion) in the Z-axis direction (third direction), the insulation between the power storage element 100 and the housing wall portion 311 can be improved by using the wall portion 225.

[0133] By disposing the wall portion 223 (first wall portion) provided with the convex portion 223a at a position closer to the center of the power storage element 100 than the wall portion 225, the creepage distance between the power storage element 100 and the housing wall portion 311 can be evenly increased by means of the convex portion 223a. By disposing the wall portion 223 (first wall portion) near the center position of the power storage element 100, tilting of the power storage unit 10 can be suppressed when the convex portion 223a contacts the housing wall portion 311, and thus deviation in the distance between the power storage unit 10 and the housing wall portion 311 can be suppressed. Thereby, the creepage distance between the power storage element 100 and the housing wall portion 311 can be evenly increased.

[0134] By providing the convex portion 225a on the wall portion 225 of the spacer 200a, surface contact between both the wall portion 223 (first wall portion) and the wall portion 225 and the housing wall portion 311 can be suppressed. Thereby, the creepage distance between the power storage element 100 and the housing wall portion 311 can be further increased.

[0135] In the power storage element 100, since various components such as bus bars, sensors, substrates, and wirings are disposed near the terminal 140, it is difficult to completely cover them with the spacer 200a, and there is a possibility of a reduction in insulation performance. On the other hand, the smaller the size of the convex portion provided on the wall portion of the spacer 200a (the size when observed from the X-axis direction (second direction)), the larger the creepage distance between the power storage element 100 and the housing wall portion 311. Therefore, the wall portion 223 (first wall portion) is disposed at a position closer to the terminal 140 of the power storage element 100 than the wall portion 225, and the size of the convex portion 223a provided on the wall portion 223 (first wall portion) when observed from the X-axis direction (second direction) is made smaller than that of the convex portion 225a. Thereby, the creepage distance between the power storage element 100 and the housing wall portion 311 at a position near the terminal 140 of the power storage element 100 where there is a possibility of a reduction in insulation performance can be increased.

[0136] In the power storage device 1, various components such as bus bars, sensors, substrates, and wirings are arranged near the opening 310a of the housing main body 310. Therefore, it is difficult to completely cover the power storage element 100 with the spacer 200a, and there is a possibility of a reduction in insulation. On the other hand, the more the convex portion provided on the wall portion of the spacer 200a protrudes, the greater the creepage distance between the power storage element 100 and the housing wall portion 311. Therefore, the wall portion 223 (first wall portion) is arranged closer to the positive Z-axis direction (one side of the third direction) than the wall portion 225, and the tip of the convex portion 223a provided on the wall portion 223 (first wall portion) is arranged closer to the positive X-axis direction (one side of the second direction) than the tip of the convex portion 225a. That is, the wall portion 223 (first wall portion) is arranged closer to the opening 310a of the housing main body 310 than the wall portion 225, and the convex portion 223a is arranged to protrude more than the convex portion 225a. Thereby, it is possible to increase the creepage distance between the power storage element 100 and the housing wall portion 311 at a position near the opening 310a of the housing main body 310 where there is a possibility of a reduction in insulation.

[0137] The convex portion 223a near the opening 310a of the housing main body 310 protrudes more than the convex portion 225a, so that when the power storage unit 10 is inserted into the housing main body 310, it is easy to insert. In particular, when the housing wall portion 311 is inclined with a draft angle or the like, by the convex portion 223a protruding more than the convex portion 225a, it is easy to insert the power storage unit 10 into the housing main body 310, and in addition, the tips of the convex portion 223a and the convex portion 225a can be arranged along the housing wall portion 311.

[0138] As described above, the effects of a part of the wall portions of the spacer 200a have been described, but the other wall portions also have the same effects. Furthermore, the effects of a part of the spacers 200a of the power storage unit 10 have been described, but the other spacers 200a also have the same effects.

[0139] [Description of 3 Modification Examples]

[0140] As described above, the power storage device 1 according to the embodiment of the present invention has been described, but the present invention is not limited to the above embodiment. The embodiment disclosed this time is illustrative in all aspects, and the scope of the present invention includes all changes within the meaning and scope equivalent to the claims.

[0141] In the above-described embodiment, the spacer walls 220 and 230 (walls 221 to 225, 231 to 234) of the spacer 200a are arranged facing the short side surface 112 of the container 110 of the power storage element 100, but they may also be arranged facing the bottom surface 113 of the container 110 or the container lid portion 130. The housing wall portion 311 facing the spacer walls 220 and 230 (walls 221 to 225, 231 to 234) is the side wall of the housing main body 310, but it may also be the bottom wall of the housing main body 310, or the side wall or the upper wall of the lid body 320, etc.

[0142] In the above-described embodiment, the wall portion 223 of the spacer 200a is taken as an example of the first wall portion, and the wall portion 232 is taken as an example of the second wall portion, but it is not limited thereto. The wall portion 223 may be taken as an example of the first wall portion, and the wall portion 233 may be taken as an example of the second wall portion. The wall portion 222 or 224 may be taken as an example of the first wall portion, and other wall portions may be taken as an example of the first wall portion.

[0143] In the above-described embodiment, the positions of the wall portions 221 to 225, 231 to 234 of the spacer 200a in the X-axis direction and the Z-axis direction are not limited to the above, and they can be arranged at various positions. The lengths of the wall portions 221 to 225, 231 to 234 in the Y-axis direction and the Z-axis direction are also not limited to the above, and they can be formed in various lengths. Any one of the wall portions 221 to 225, 231 to 234 may not be provided, or wall portions may be provided in addition to the wall portions 221 to 225, 231 to 234. For the spaces 211a to 211d, 215a and the openings 21 to 25, their sizes, shapes, arrangement positions, numbers, etc. are also not limited to the above.

[0144] In the above-described embodiment, the convex portions 221a, 223a, 225a are provided on the wall portions 221, 223, 225 of the spacer 200a, but the convex portions may not be provided on any of the wall portions 221, 223, 225. The convex portions may be provided on any of the wall portions 222, 224, 231 to 234. The arrangement positions, shapes and sizes of the convex portions provided on the wall portions are not limited to the above. From the viewpoint of ensuring strength, etc., the convex portions may extend in a part (such as half) or the whole range of the wall portion in the Y-axis direction, the Z-axis direction or the direction inclined from these directions along these directions.

[0145] In the above-described embodiment, in the spacer 200a, the top end of the convex portion 223a protrudes more than the top end of the convex portion 225a, and the top end of the convex portion 221a protrudes more than the top end of the convex portion 223a. However, it is not limited thereto. The top end of the convex portion 225a may protrude more than the top end of the convex portion 223a, and the top end of the convex portion 223a may also protrude more than the top end of the convex portion 221a. The top end positions of these convex portions are not particularly limited and are appropriately determined according to the shape of the housing 300 and the like. When the convex portion 221a faces the wall portion of the lid body 320, the top end position of the convex portion 221a is determined according to the position of the wall portion of the lid body 320, and the top end of the convex portion 221a may not protrude more than the top end of the convex portion 223a.

[0146] In the above-described embodiment, the wall portion 223 of the spacer 200a protrudes only in the positive Y-axis direction, but it may also protrude only in the negative Y-axis direction, or may protrude in both the positive Y-axis direction and the negative Y-axis direction. When the wall portion 223 protrudes in both the positive Y-axis direction and the negative Y-axis direction, a through hole serving as the opening portion 23 may be formed in the wall portion 223. However, when the wall portion 223 protrudes only in the positive Y-axis direction, a through hole may not be formed in the wall portion 223, so that the spacer 200a can be easily manufactured (the mold structure can be simplified), which is preferable. The same applies to other wall portions.

[0147] In the above-described embodiment, the spaces 211a to 211d of the spacer main body 210 provided in the spacer 200a are separated from each other by ribs, but it is not limited thereto. For example, the space 211a and the space 211b may not be separated by a rib and may communicate with each other, or some of the spaces 211a to 211d may not be separated by a rib and may communicate with each other.

[0148] In the above-described embodiment, the spaces 211a to 211d of the spacer main body 210 provided in the spacer 200a are flow paths for a fluid flowing between the spacer main body 210 and the power storage element 100, but they may not be flow paths for a fluid.

[0149] In the above-described embodiment, the spacer main body 210 of the spacer 200a has a third surface 216 at a position recessed from the first surface 214, and the second surface 215 is disposed at a position recessed from the third surface 216, but it is not limited thereto. If the second surface 215 is disposed at a position recessed from the first surface 214, the second surface 215 may also be disposed at a position protruding from the third surface 216, and the first surface 214 may also be disposed at a position recessed from the third surface 216. The spacer main body 210 may not have the third surface 216, and the second surface 215 may be disposed at a position recessed from the first surface 214. The area of the first surface 214 is larger than the areas of the second surface 215 and the third surface 216, but the area may also be smaller than either of the second surface 215 and the third surface 216.

[0150] In the above-described embodiment, on the surface of the spacer body 210 of the spacer 200a in the positive Y-axis direction, the space 215a is not a flow path for the fluid flowing between the spacer body 210 and the power storage element 100, but it may be this flow path. That is, even on the surface of the spacer body 210 in the positive Y-axis direction, spaces (flow paths) such as the spaces 211a to 211d can be formed at the position of the space 215a, similarly to the surface of the spacer body 210 in the negative Y-axis direction. With such a structure, flow paths for the fluid (coolant) to flow can be formed on both surfaces of the spacer body 210 in the Y-axis direction. Therefore, the two power storage elements 100 located on both sides of the spacer 200a in the Y-axis direction can be cooled. Furthermore, by using the two spacers 200a sandwiching one power storage element 100, both surfaces of the power storage element 100 in the Y-axis direction can be cooled. Thereby, the cooling efficiency of the power storage element 100 can be improved.

[0151] In the above-described embodiment, the spacer 200a has spacer wall portions 220 to 250, but any one of these spacer wall portions may not be provided. In this case, the spacer 200a may not be a holder for holding the power storage element 100.

[0152] In the above-described embodiment, all the spacers 200a have the above structure, but any one of the spacers 200a may not have the above structure.

[0153] In the above-described embodiment, the spacer 200b or the spacer 200c may also have the same structure as the spacer 200a. That is, any one of the plurality of spacers 200 may have the same above structure as the spacer 200a.

[0154] In the above-described embodiment, the spacers 200 (spacers 200a, 200b, and 200c) and the power storage elements 100 are alternately arranged and configured in the Y-axis direction, but it may also be a structure in which no spacer 200 is arranged. It may also be a structure in which only one spacer 200 (spacer 200a, 200b, or 200c) is arranged.

[0155] In the above-described embodiment, the housing 300 is formed of a metal member, but it may also be formed of an insulating member such as any resin material that can be used for the spacer 200. In this case, since various metal members can also be arranged inside the housing 300, it is important to improve the insulation of the power storage element 100.

[0156] In the above-described embodiment, the housing main body 310 has sufficient height in the Z-axis direction to accommodate the power storage unit 10, and the power storage unit 10 is structured such that it is hardly exposed when viewed from the XY plane, but this is not essential. The housing main body 310 may also have a height that is two-thirds or half of that of the power storage unit 10 in the Z-axis direction, accommodating the portion of the power storage unit 10 in the negative Z-axis direction and exposing the portion in the positive Z-axis direction that does not accommodate the power storage unit 10. In this case, the lid body 320 may also have a height that is one-third or half of that of the power storage unit 10 in the Z-axis direction, accommodating the portion of the power storage unit 10 in the positive Z-axis direction. In this case, as described above, the convex portion 221a of the wall portion 221 of the spacer 200a may also be configured to face the wall portion of the lid body 320.

[0157] In the above-described embodiment, the housing 300 has the housing main body 310 and the lid body 320, but it may not have the lid body 320. In the above-described embodiment, two power storage units 10 arranged in the X-axis direction are accommodated inside the housing 300, but three or more power storage units 10 arranged in the X-axis direction may be accommodated, or only one power storage unit 10 may be accommodated. A plurality of power storage units 10 arranged in the Y-axis direction may also be accommodated inside the housing 300. In the above-described embodiment, the power storage unit 10 may also have a constraining member (end plate, side plate, etc.) that constrains a plurality of power storage elements 100 and the spacer 200.

[0158] The forms constructed by arbitrarily combining the respective structural members included in the above-described embodiment and its modified examples are also included within the scope of the present invention.

[0159] Industrial Applicability

[0160] The present invention can be applied to power storage devices having power storage elements such as lithium ion secondary batteries.

[0161] Description of Reference Numerals

[0162] 1 Power storage device

[0163] 10 Power storage unit

[0164] 21, 22, 23, 24, 25 Opening

[0165] 100 Power storage element

[0166] 101 First power storage element

[0167] 102 Second power storage element

[0168] 110 Container

[0169] 111 Long side surface

[0170] 112 Short side surface

[0171] 140 terminal

[0172] 200, 200a, 200b, 200c spacers

[0173] 201 First spacer

[0174] 202 Second spacer

[0175] 203 Third spacer

[0176] 210 Spacer body

[0177] 211a, 211b, 211c, 211d, 215a spaces

[0178] 212 Recess

[0179] 213 Protrusion

[0180] 214 First surface

[0181] 215 Second surface

[0182] 216 Third surface

[0183] 220, 230, 240, 250 spacer wall parts

[0184] 220A, 230A First spacer wall part

[0185] 220B, 230B Second spacer wall part

[0186] 220C, 230C Third spacer wall part

[0187] 221, 222, 223, 224, 225, 231, 232, 233, 234 wall parts

[0188] 221a, 223a, 225a protrusions

[0189] 222a, 223b, 224a, 231a, 234a ribs

[0190] 300 Housing

[0191] 310 Housing body

[0192] 310a Opening

[0193] 311 Housing wall part

[0194] 320 Cover

Claims

1. An electricity storage device, wherein, It has a power storage unit, The power storage unit has: a spacer having a spacer body, and a first power storage element disposed on one side of the spacer body in a first direction; The spacer body has: A first surface facing the first power storage element, and A second surface located in a second direction intersecting the first direction of the first surface and disposed at a position recessed from the first surface; The power storage unit has a first opening that connects a first space between the second surface and the first power storage element to a space outside the power storage unit in the second direction, i.e., an external space; The spacer has a first wall portion that protrudes from the spacer body toward the one side in the first direction and faces the first power storage element in the second direction.

2. The electricity storage device according to claim 1, wherein, The area of the first surface is larger than the area of the second surface.

3. The electricity storage device according to claim 1 or 2, wherein, The spacer body further has a third surface disposed at a position recessed from the first surface, The second surface is disposed at a position recessed from the third surface.

4. The electricity storage device according to claim 1 or 2, wherein, The spacer further has a second wall portion that protrudes from the position of the first opening of the spacer body toward the other side in the first direction.

5. The electricity storage device according to claim 1 or 2, wherein, When viewed from the second direction, the first wall portion is disposed at a position where the end edge on the one side in the first direction overlaps with the first power storage element.

6. The electricity storage device according to claim 1 or 2, wherein, The power storage unit further has: A second power storage element disposed on the other side of the spacer body in the first direction; And A second opening disposed at a position different from the first opening on the other side of the first wall portion in the first direction, connecting a second space between the spacer body and the second power storage element to the external space; The second space is a flow path for a fluid flowing between the spacer body and the second power storage element.

Images