Power storage device

Abstract

A power storage device (10) comprises two power storage elements (230), each having an electrode body (230f) with a pole plate stacked in a stacking direction (Z-axis direction) and a metal container (230a) that contains the electrode body (230f), wherein the power storage device (10) comprises: a first power storage element (231) and a second power storage element (232) that are arranged in an arrangement direction (X-axis direction) intersecting the stacking direction; and a first retainer (210) and a second retainer (220) that are directly joined to each other to form a pair of retainers holding both the first power storage element (231) and the second power storage element (232) between the pair of retainers in the stacking direction.

Description

[Technical Field]

[0001] The present invention relates to an energy storage device including a plurality of energy storage elements. [Background technology]

[0002] Conventionally, there has been known a power storage device that includes a plurality of power storage elements and a pair of restraining bodies that sandwich the plurality of power storage elements in a direction intersecting the arrangement direction of the power storage elements. Patent Document 1 discloses a battery module (power storage device) in which a pair of end plates (restraining bodies) are arranged at ends of a plurality of battery cells (power storage elements) in a direction intersecting the arrangement direction, and the end plates are connected to each other by restraining plates and restraining bands. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-97983 Summary of the Invention [Problem to be solved by the invention]

[0004] When suppressing swelling of a plurality of energy storage elements by sandwiching the energy storage elements between a pair of restraining bodies in a direction intersecting the arrangement direction of the elements, a configuration that can easily suppress swelling of the energy storage elements is desired.

[0005] An object of the present invention is to provide an energy storage device that can easily suppress swelling of a plurality of energy storage elements. [Means for solving the problem]

[0006] An energy storage device according to one embodiment of the present invention comprises two energy storage elements, each having an electrode body in which electrode plates are stacked in a stacking direction and a metal container in which the electrode body is housed, the first energy storage element and the second energy storage element being arranged in an arrangement direction that intersects the stacking direction, and a pair of restraint bodies that sandwich the first energy storage element and the second energy storage element together in the stacking direction and are directly joined to each other.

[0007] The present invention can be realized not only as an electricity storage device but also as a pair of restraining bodies. [Effects of the Invention]

[0008] According to the electricity storage device of the present invention, swelling of the plurality of electricity storage elements can be easily suppressed. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing the appearance of a power storage device according to an embodiment. [Figure 2] FIG. 2 is a perspective view showing the inside of the exterior body with the main body and the lid of the exterior body separated in the electricity storage device according to the embodiment. [Figure 3] FIG. 3 is an exploded perspective view illustrating the components of the electricity storage unit according to the embodiment. [Figure 4] FIG. 4 is an exploded perspective view showing the components of the energy storage device according to the embodiment. [Figure 5] FIG. 5 is a cross-sectional view showing the configuration of the electricity storage unit according to the embodiment together with a reinforcing member. [Figure 6] FIG. 6 is a cross-sectional view showing the configuration of the electricity storage unit according to the embodiment together with the reinforcing member and the exterior body. [Figure 7] FIG. 7 is a cross-sectional view showing the configuration of the electricity storage unit according to the embodiment together with other members. DETAILED DESCRIPTION OF THE INVENTION

[0010] In the conventional energy storage device, a pair of restraining bodies sandwich the plurality of energy storage elements in a direction intersecting the arrangement direction, thereby suppressing swelling of the plurality of energy storage elements. However, the conventional energy storage device requires components (restraining plates and restraining bands) to connect the pair of restraining bodies, making the configuration complicated. Thus, when sandwiching the plurality of energy storage elements in a direction intersecting the arrangement direction to suppress swelling of the plurality of energy storage elements, a configuration that can easily suppress swelling of the plurality of energy storage elements is desired.

[0011] The present invention was made by the present inventors by focusing on the above-mentioned problem, and has an object to provide an electricity storage device that can easily suppress swelling of a plurality of electricity storage elements.

[0012] In order to achieve the above-mentioned object, an energy storage device according to one embodiment of the present invention comprises two energy storage elements, each having an electrode body in which electrode plates are stacked in a stacking direction and a metal container in which the electrode body is housed, the first energy storage element and the second energy storage element being arranged in an arrangement direction that intersects with the stacking direction, and a pair of restraint bodies that sandwich the first energy storage element and the second energy storage element together in the stacking direction and are directly joined to each other.

[0013] According to this, in the energy storage device, the first and second energy storage elements have metal containers and are arranged in an arrangement direction intersecting the stacking direction of the electrode plates of the electrode assembly, and the pair of constraint bodies are directly joined to collectively sandwich the first and second energy storage elements in the stacking direction. By collectively sandwiching the first and second energy storage elements with the pair of constraint bodies in this way, the configuration can be simplified. The pair of constraint bodies are directly joined to firmly sandwich the first and second energy storage elements with the pair of constraint bodies. This reduces the number of joints, reducing the risk of loosening of the joints, and also reduces the number of parts, simplifying the configuration. In this way, in a configuration in which multiple energy storage elements (the first and second energy storage elements) are sandwiched with the pair of constraint bodies in a direction intersecting the arrangement direction, swelling of the multiple energy storage elements can be easily suppressed.

[0014] The pair of constraint bodies may be directly joined to each other at positions sandwiching the first and second energy storage elements in the arrangement direction.

[0015] According to this, the pair of restraining bodies are directly joined at positions sandwiching the first and second storage elements in the arrangement direction of the first and second storage elements, so that the first and second storage elements can be easily sandwiched together, thereby easily suppressing swelling of the multiple storage elements (the first and second storage elements) by the pair of restraining bodies.

[0016] The pair of constraint bodies may be directly joined between the first and second storage elements.

[0017] According to this, the pair of constraint bodies are directly joined between the first and second storage elements, so that the first and second storage elements can be easily and more firmly sandwiched, respectively, and thus the pair of constraint bodies can easily suppress swelling of the multiple storage elements (the first and second storage elements).

[0018] At least one of the pair of restraining bodies may have a convex portion that protrudes toward the other of the pair of restraining bodies, is positioned between the first storage element and the second storage element, and is directly joined to the other of the pair of restraining bodies between the first storage element and the second storage element.

[0019] According to this, by forming a convex portion on at least one of the pair of constraint bodies and joining it to the other, the pair of constraint bodies can be directly joined between the first and second storage elements with a simple configuration, which makes it possible to easily suppress swelling of the multiple storage elements (the first and second storage elements).

[0020] Furthermore, the battery may include a third storage element arranged in a position sandwiching the second storage element between the first storage element and the third storage element in the arrangement direction, and the pair of restraint bodies may be directly joined between the second storage element and the third storage element.

[0021] According to this, the pair of restraining bodies are also directly joined between the second and third energy storage elements, so that the first, second, and third energy storage elements can be easily and more firmly sandwiched, respectively, and thus the pair of restraining bodies can easily suppress swelling of the multiple energy storage elements (the first, second, and third energy storage elements).

[0022] The energy storage device may include a plurality of the first energy storage elements arranged in the stacking direction and a plurality of the second energy storage elements arranged in the stacking direction, and the pair of restraining bodies may be configured to sandwich the plurality of first energy storage elements and the plurality of second energy storage elements together in the stacking direction.

[0023] According to this, in a configuration in which a plurality of first storage elements and a plurality of second storage elements are arranged in the stacking direction, the pair of constraint bodies collectively sandwich the plurality of first storage elements and the plurality of second storage elements in the stacking direction, which makes it possible to easily collectively sandwich the plurality of first storage elements and the plurality of second storage elements by the pair of constraint bodies, and thus makes it possible to easily suppress swelling of the plurality of first storage elements and the plurality of second storage elements.

[0024] The energy storage device may further include an exterior body that houses the first energy storage element and the second energy storage element, and at least one of the pair of constraint bodies may be fixed to the exterior body.

[0025] According to this, at least one of the pair of restraining bodies is fixed to the exterior body, so that the first and second storage elements can be easily fixed to the exterior body, and therefore, even if vibrations or shocks are applied to the energy storage device, movement of the first and second storage elements within the exterior body can be easily suppressed.

[0026] Another aspect of the present invention provides an energy storage device comprising two energy storage elements having an electrode body in which electrode plates are stacked in a stacking direction, the first energy storage element and the second energy storage element being arranged in an arrangement direction that intersects the stacking direction, a pair of restraint bodies that sandwich the first energy storage element and the second energy storage element together in the stacking direction, the pair of restraint bodies being joined to each other, and an outer casing that houses the first energy storage element and the second energy storage element, and at least one of the pair of restraint bodies is fixed to the outer casing.

[0027] According to this, in the energy storage device, the first and second energy storage elements are arranged in an arrangement direction intersecting the stacking direction of the electrode plates of the electrode assembly, and a pair of constraint bodies sandwich the first and second energy storage elements together in the stacking direction, with at least one of the constraint bodies being fixed to the exterior body. By sandwiching the first and second energy storage elements together with the pair of constraint bodies in this way, the configuration can be simplified. Because at least one of the pair of constraint bodies is fixed to the exterior body, movement of the first and second energy storage elements within the exterior body can be easily suppressed even if vibration, impact, or the like is applied to the energy storage device. In this way, in a configuration in which multiple energy storage elements (the first and second energy storage elements) are sandwiched between the pair of constraint bodies in a direction intersecting the arrangement direction, movement of the multiple energy storage elements within the exterior body and swelling of the multiple energy storage elements can be easily suppressed.

[0028] At least one of the pair of restraining bodies may be fixed to the exterior body between the first energy storage element and the second energy storage element.

[0029] According to this, at least one of the pair of restraining bodies is fixed to the exterior body between the first and second energy storage elements, so that the first and second energy storage elements can be fixed to the exterior body in a balanced manner, thereby further suppressing movement of the first and second energy storage elements within the exterior body even when vibrations or shocks are applied to the energy storage device.

[0030] Hereinafter, with reference to the drawings, a description will be given of an energy storage device according to an embodiment of the present invention (including its modified examples). The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, component placement and connection configurations, manufacturing processes, and the order of manufacturing processes shown in the following embodiments are merely examples and are not intended to limit the present invention. In each drawing, dimensions and the like are not strictly illustrated. In each drawing, the same or similar components are designated by the same reference numerals.

[0031] In the following description and drawings, the X-axis direction is defined as the longitudinal direction of the exterior body of the energy storage device, the extension direction of the reinforcing member and its protrusions, the arrangement direction of multiple energy storage elements such as the first energy storage element and the second energy storage element, the alignment direction of the energy storage element and the electrical device, the extension direction of the restraining body, the opposing direction of the short side surfaces of the container of the energy storage element, or the alignment direction of a pair of electrode terminals of one energy storage element. The Y-axis direction is defined as the alignment direction of the protrusions of the reinforcing member or the alignment direction of the main body and the lid of the container of the energy storage element. The Z-axis direction is defined as the alignment direction of the main body and the lid of the exterior body, the alignment direction of the pair of restraining bodies, the alignment direction of the energy storage element, the restraining body, and the reinforcing member, the opposing direction of the long side surfaces of the container of the energy storage element, the stacking direction of the electrode plates of the electrode body of the energy storage element, or the up-down direction. The X-axis direction, Y-axis direction, and Z-axis direction intersect each other (orthogonal in this embodiment). Depending on the usage mode, the Z-axis direction may not be the up-down direction; however, for convenience of explanation, the Z-axis direction will be described below as the up-down direction.

[0032] In the following description, the positive X-axis direction refers to the direction of the X-axis arrow, and the negative X-axis direction refers to the direction opposite to the positive X-axis direction. The same applies to the Y-axis and Z-axis. Expressions indicating relative directions or attitudes, such as parallel and perpendicular, also include cases where the direction or attitude is not strictly that. "Two directions are perpendicular" does not only mean that the two directions are completely perpendicular, but also means that the directions are substantially perpendicular, i.e., there is a difference of about a few percent.

[0033] (Embodiment) [1 General Description of the Power Storage Device 10] First, a schematic configuration of an energy storage device 10 according to the present embodiment will be described. Fig. 1 is a perspective view showing the appearance of the energy storage device 10 according to the present embodiment. Fig. 2 is a perspective view showing the inside of the exterior body 100 of the energy storage device 10 according to the present embodiment, with the main body and the lid of the exterior body 100 separated.

[0034] The power storage device 10 is a device that can charge with electricity from an external source and discharge electricity to the outside, and in this embodiment has a substantially rectangular parallelepiped shape. The power storage device 10 is a battery module (battery assembly) used for power storage, power supply, or the like. Specifically, the power storage device 10 is used as a battery for driving or starting the engine of a mobile object such as an automobile, motorcycle, personal watercraft, ship, snowmobile, agricultural machinery, construction machinery, or electric railway vehicle. Examples of the automobile include an electric vehicle (EV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), and a gasoline-powered automobile. Examples of the electric railway vehicle include a train, a monorail, and a linear motor car. The power storage device 10 can also be used as a stationary battery for home use or a power generator, etc.

[0035] 1 and 2, the energy storage device 10 includes an exterior body 100, an energy storage unit 200 housed in the exterior body 100, a heat insulating sheet 300, and a reinforcing member 400. The energy storage unit 200 also includes a bus bar and the like that electrically connects the energy storage unit 200 to an external terminal 130 (described later), but these are not shown in the drawings and are not described in detail.

[0036] The exterior body 100 is a box-shaped (approximately rectangular parallelepiped) container (module case) that constitutes the exterior body of the energy storage device 10. In other words, the exterior body 100 is disposed outside the energy storage unit 200, the heat insulating sheet 300, the reinforcing member 400, etc., and secures the energy storage unit 200, etc. in predetermined positions to protect them from impacts and the like. The exterior body 100 is formed from an insulating material such as polycarbonate (PC), polypropylene (PP), polyethylene (PE), polystyrene (PS), polyphenylene sulfide resin (PPS), polyphenylene ether (PPE (including modified PPE)), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyether ether ketone (PEEK), tetrafluoroethylene-perfluoroalkyl vinyl ether (PFA), polytetrafluoroethylene (PTFE), polyethersulfone (PES), ABS resin, or a composite material thereof, or a metal with an insulating coating. The exterior body 100 thereby prevents the power storage unit 200 and the like from coming into contact with external metal members, etc. The exterior body 100 may be formed of a conductive member such as a metal as long as the electrical insulation of the power storage unit 200 and the like is maintained.

[0037] The exterior body 100 has an exterior body main body 110 that constitutes the main body of the exterior body 100, and an exterior body lid 120 that constitutes the lid of the exterior body 100. The exterior body main body 110 is a rectangular cylindrical housing with a bottom and an opening formed on the positive side of the Z axis. The exterior body lid 120 is a flat rectangular lid that is disposed in the positive direction of the Z axis of the exterior body main body 110 and is connected to the exterior body main body 110 to close the opening of the exterior body main body 110. The exterior body main body 110 and the exterior body lid 120 may be made of the same material or may be made of different materials.

[0038] Exterior body main body 110 has a body-side connecting portion 111 and an exterior body fastening portion 112, and exterior body lid body 120 has a lid-side connecting portion 121. Body-side connecting portion 111 and lid-side connecting portion 121 are connected (joined) to each other and are portions that connect (join) exterior body main body 110 and exterior body lid body 120 (see FIG. 7). In this embodiment, a plurality of body-side connecting portions 111 are arranged side by side at approximately equal intervals on the outer periphery of exterior body main body 110, and a plurality of lid-side connecting portions 121 are arranged side by side at positions corresponding to the body-side connecting portions 111 on the outer periphery of exterior body lid body 120.

[0039] The lid side connection part 121 is a bolt part, and the body side connection part 111 is a nut part into which the bolt part is screwed. In other words, the lid side connection part 121 has a through hole and a bolt to be inserted into the through hole, and the body side connection part 111 has a recess and a nut (insert nut) placed in the recess (see FIG. 7). The body side connection part 111 may be a bolt part, and the lid side connection part 121 may be a nut part into which the bolt part is screwed. Other methods may be used to connect (join) the exterior body main body 110 and the exterior body lid 120, such as adhesive bonding, heat sealing, ultrasonic welding, welding, or crimping.

[0040] The exterior body fixing portion 112 is a portion to which the power storage unit 200 is fixed. That is, at least one of a pair of constraint bodies (first constraint body 210 and second constraint body 220) of the power storage unit 200 is connected (joined) to the exterior body fixing portion 112, thereby fixing at least one of the pair of constraint bodies to the exterior body 100. In the present embodiment, a first constraint body fixing portion 218 of the first constraint body 210, which will be described later, is connected (joined) to the exterior body fixing portion 112, thereby fixing the first constraint body 210 (power storage unit 200) to the exterior body main body 110 (see FIGS. 6 and 7 ).

[0041] Specifically, a plurality of exterior body fastening parts 112 are arranged side by side at approximately equal intervals around the periphery of the internal space of exterior body main body 110. A plurality of first restraint body fastening parts 218 are arranged side by side at positions corresponding to exterior body fastening parts 112 of first restraint body 210 (see FIG. 3). The arrangement positions and number of exterior body fastening parts 112 and first restraint body fastening parts 218 are not particularly limited.

[0042] First restraint body fixing portion 218 is a bolt portion, and exterior body fixing portion 112 is a nut portion into which the bolt portion screws. In other words, first restraint body fixing portion 218 has a through hole and a bolt to be inserted into the through hole, and exterior body fixing portion 112 has a recess and a nut (insert nut) placed in the recess (see FIG. 7). Exterior body fixing portion 112 may be a bolt portion, and first restraint body fixing portion 218 may be a nut portion into which the bolt portion screws. Other methods may be used to fix first restraint body 210 (power storage unit 200) to exterior body main body 110, such as welding, crimping, adhesive bonding, or welding.

[0043] External terminals 130, which are a pair of module terminals (general terminals) on the positive side and negative side, are arranged on the end of the exterior cover 120 on the positive side of the X-axis. The external terminals 130 are electrically connected to the energy storage elements 230 of the energy storage unit 200 via a bus bar or the like (not shown), and the energy storage device 10 charges with electricity from the outside and discharges electricity to the outside via the external terminals 130. The external terminals 130 are formed from a conductive member made of metal such as aluminum, an aluminum alloy, copper, or a copper alloy.

[0044] In the energy storage unit 200, a plurality of energy storage elements 230 are stacked flat in the Z-axis direction in a horizontally placed (sideways) state and arranged in the X-axis direction, and further, the electrical equipment 240 is also arranged in the X-axis direction, so that the energy storage unit 200 has a shape that is flat in the Z-axis direction and elongated in the X-axis direction. Specifically, the energy storage unit 200 has a configuration in which the plurality of energy storage elements 230 arranged in the Z-axis direction and the X-axis direction are sandwiched in the Z-axis direction by a pair of constraint bodies, a first constraint body 210 and a second constraint body 220. A more detailed description of the configuration of the energy storage unit 200 will be given later.

[0045] The heat insulating sheet 300 is a heat insulating sheet member that is disposed between the exterior body 110 and the power storage unit 200 and insulates against heat emitted from the power storage unit 200. The heat insulating sheet 300 has an elongated shape in the X-axis direction corresponding to the power storage unit 200 when viewed from the Z-axis direction. The heat insulating sheet 300 may be made of any material that has heat insulating properties, such as a damping material made by collecting and bonding mica pieces.

[0046] Reinforcing member 400 is a plate-like member that is disposed between exterior body cover 120 and power storage unit 200, that is, in the positive Z-axis direction of power storage unit 200, and reinforces power storage unit 200. Reinforcing member 400 has an elongated shape in the X-axis direction corresponding to power storage unit 200 when viewed from the Z-axis direction.

[0047] The reinforcing member 400 has reinforcing member protrusions 410 and 420 and a reinforcing member fixing portion 430. The reinforcing member protrusions 410 and 420 are elongated protrusions (protruding ridges) that protrude in the positive direction of the Z axis and extend in the X axis direction. Specifically, the reinforcing member protrusions 410 and 420 are bulging portions in which the surface of the reinforcing member 400 on the negative Z axis side is recessed in the positive Z axis direction and the surface of the reinforcing member 400 on the positive Z axis side protrudes in the positive Z axis direction. In other words, the reinforcing member 400 has a corrugated plate-like shape formed by bending a plate-like member multiple times in the positive and negative Z axis directions. The reinforcing member protrusions 410 and 420 can also be considered recesses because the surface of the reinforcing member 400 on the negative Z axis side is recessed in the positive Z axis direction.

[0048] In this embodiment, the reinforcing member 400 has two reinforcing member protrusions 410 arranged on the negative Y-axis side and the center in the Y-axis direction, and one reinforcing member protrusion 420 arranged on the positive Y-axis side. The reinforcing member protrusions 410 are formed to extend continuously in a straight line from the edge of the reinforcing member 400 on the negative X-axis side to the end on the positive X-axis side. In other words, the reinforcing member protrusions 410 are open at both ends of the reinforcing member 400 in the X-axis direction. The reinforcing member protrusions 420 are formed to extend continuously in a straight line from the edge of the reinforcing member 400 on the negative X-axis side to the end on the positive X-axis side, but do not extend to the edge on the positive X-axis side. In other words, the end of the reinforcing member 400 on the negative X-axis side of the reinforcing member 400 on the positive X-axis side is open and the end on the positive X-axis side is closed. In this way, by not allowing the ends of the reinforcing member 400 on the positive X-axis side and the positive Y-axis side to protrude in the positive Z-axis direction, a bus bar (not shown) connected to the external terminal 130 can be arranged.

[0049] Depending on the arrangement position of the bus bar, reinforcing member protrusion 420 may extend to the edge of reinforcing member 400 on the positive side in the X-axis direction, or reinforcing member protrusion 410 may not extend to the edge of reinforcing member 400 on the positive side in the X-axis direction. Reinforcing member protrusions 410 and 420 may not extend to the edge of reinforcing member 400 on the negative side in the X-axis direction. In this embodiment, reinforcing member protrusions 410 and 420 have a trapezoidal shape when viewed in the X-axis direction, but may have any shape when viewed in the X-axis direction, such as a polygonal shape other than a trapezoid, such as a rectangular or triangular shape, a semicircular shape, a semi-elliptical shape, or a semi-oval shape.

[0050] The reinforcing member fixing portion 430 is a portion fixed to the energy storage unit 200. That is, the reinforcing member fixing portion 430 is connected (joined) to at least one of a pair of constraint bodies (first constraint body 210 and second constraint body 220) of the energy storage unit 200, thereby fixing the reinforcing member 400 to at least one of the pair of constraint bodies. In the present embodiment, the reinforcing member fixing portion 430 is connected (joined) to a second constraint body fixing portion 226 of the second constraint body 220, which will be described later, thereby fixing the reinforcing member 400 to the second constraint body 220 (the energy storage unit 200) (see FIGS. 5 and 7).

[0051] Specifically, a plurality of reinforcing member fixing portions 430 are arranged side by side at approximately equal intervals in the X-axis direction between the two reinforcing member protrusions 410 and between the reinforcing member protrusions 410 and 420. A plurality of second restraint body fixing portions 226 are arranged side by side at positions corresponding to the reinforcing member fixing portions 430 of the second restraint body 220. The arrangement positions and number of the reinforcing member fixing portions 430 and the second restraint body fixing portions 226 are not particularly limited.

[0052] The second restraint body fixing portion 226 is a bolt portion, and the reinforcing member fixing portion 430 is a nut portion into which the bolt portion screws. In other words, the second restraint body fixing portion 226 has a male thread portion with a thread formed on a columnar portion, and the reinforcing member fixing portion 430 has a through hole and a nut placed on the through hole (see FIG. 7). The reinforcing member fixing portion 430 may be a bolt portion, and the second restraint body fixing portion 226 may be a nut portion into which the bolt portion screws. Other methods may be used to fix the reinforcing member 400 to the second restraint body 220 (electricity storage unit 200), such as welding, crimping, adhesive bonding, or welding.

[0053] [2. Description of the Configuration of the Power Storage Unit 200] Next, the configuration of the energy storage unit 200 will be described in detail. Fig. 3 is an exploded perspective view showing each component of the energy storage unit 200 according to this embodiment. Fig. 4 is an exploded perspective view showing each component of the energy storage element 230 according to this embodiment. Specifically, Fig. 4 shows an exploded view of each part of the energy storage element 230 shown in Fig. 3 in a vertically placed (standing) state.

[0054] FIG. 5 is a cross-sectional view showing the configuration of the energy storage unit 200 according to the present embodiment together with the reinforcing member 400. Specifically, FIG. 5 shows the configuration when the reinforcing member 400 is fixed to the energy storage unit 200 and the reinforcing member 400 is cut along a plane parallel to the XZ plane at the position of line VV shown in FIG. 1 . FIG. 6 is a cross-sectional view showing the configuration of the energy storage unit 200 according to the present embodiment together with the reinforcing member 400 and the exterior body main body 110. Specifically, FIG. 6 shows the configuration when the energy storage unit 200 is fixed to the exterior body main body 110 and the reinforcing member 400 is fixed to the energy storage unit 200 and the reinforcing member 400 is cut along a plane parallel to the XZ plane at the position of line VI-VI shown in FIG. 1 . FIG. 7 is a cross-sectional view showing the configuration of the energy storage unit 200 according to the present embodiment together with other members. Specifically, FIG. 7 shows the configuration when the energy storage device 10 shown in FIG. 1 is cut along a plane parallel to the YZ plane passing through line VII-VII.

[0055] 3, the energy storage unit 200 includes a pair of constraint bodies, a first constraint body 210 and a second constraint body 220, an energy storage element 230, an electric device 240, and a spacer 250. The energy storage unit 200 also includes a bus bar or the like that electrically connects the energy storage elements 230 to each other, but illustration and detailed description thereof will be omitted.

[0056] [2.1 Description of the configuration of the energy storage element 230] First, the configuration of the energy storage element 230 will be described in detail. The energy storage element 230 is a secondary battery (single cell) that can charge and discharge electricity, and more specifically, is a nonaqueous electrolyte secondary battery such as a lithium-ion secondary battery. The energy storage element 230 has a flat rectangular parallelepiped (rectangular) shape, and in this embodiment, eight energy storage elements 230 are placed horizontally (laying on their sides) (with the long sides of the energy storage elements 230 facing the Z-axis direction) and arranged in the Z-axis and X-axis directions. Specifically, two first energy storage elements 231 are stacked (flat) in the Z-axis direction, two second energy storage elements 232 are stacked (flat) in the Z-axis direction, two third energy storage elements 233 are stacked (flat) in the Z-axis direction, and two fourth energy storage elements 234 are stacked (flat) in the Z-axis direction. Two first storage elements 231, two second storage elements 232, two third storage elements 233, and two fourth storage elements 234 are arranged side by side in the X-axis direction from the negative X-axis direction to the positive X-axis direction.

[0057] The number of the energy storage elements 230 is not particularly limited as long as a plurality of the energy storage elements 230 are arranged in the X-axis direction, and any number of the energy storage elements 230 may be stacked (flatly stacked) in the Z-axis direction, or any number of the energy storage elements 230 may be arranged in a plurality of rows in the X-axis direction. The shape of the energy storage elements 230 is not limited to the above-mentioned rectangular shape, and may be other shapes such as a polygonal prism, a cylindrical shape, an elliptical cylindrical shape, or an oblong cylindrical shape. The energy storage elements 230 are not limited to non-aqueous electrolyte secondary batteries, and may be secondary batteries other than non-aqueous electrolyte secondary batteries, or may be capacitors. The energy storage elements 230 may not be secondary batteries, but may be primary batteries that can use stored electricity without the user having to charge them.

[0058] Since the eight storage elements 230 (two first storage elements 231, two second storage elements 232, two third storage elements 233, and two fourth storage elements 234) all have the same configuration, the following will explain the configuration of one storage element 230.

[0059] As shown in FIG. 4, the energy storage element 230 includes a container 230a, a pair of electrode terminals 230b (positive and negative), and a pair of upper gaskets 230c (positive and negative). The container 230a contains a pair of lower gaskets 230d (positive and negative), a pair of current collectors 230e (positive and negative), and an electrode assembly 230f. An electrolyte (non-aqueous electrolyte) is enclosed within the container 230a, but this is not shown. The electrolyte may be of any type, and various types may be selected, as long as it does not impair the performance of the energy storage element 230. In addition to the above components, spacers may be disposed on the sides or above the electrode assembly 230f, or an insulating film may be disposed to encase the electrode assembly 230f.

[0060] 4, the energy storage element 230 may have a current collector 230g and an electrode body 230h instead of the current collector 230e and the electrode body 230f. Therefore, the following description will be given using the current collector 230e and the electrode body 230f, but unless otherwise specified, the current collector 230e and the electrode body 230f in the following description can be rephrased as the current collector 230g and the electrode body 230h.

[0061] The container 230a is a rectangular parallelepiped (square or box-shaped) case having a container body 230a1 with an opening and a container lid 230a2 that closes the opening of the container body 230a1. With this configuration, the container 230a can be sealed by, for example, welding the container body 230a1 and the container lid 230a2 together after the electrode assembly 230f and other components are housed inside the container body 230a1. The materials for the container body 230a1 and the container lid 230a2 are not particularly limited, but are preferably weldable metals such as stainless steel, aluminum, aluminum alloy, iron, and plated steel sheet. In other words, in this embodiment, the container 230a is a metal container.

[0062] The container body 230a1 is a rectangular cylindrical member with a bottom that constitutes the main body of the container 230a, and has an opening on the negative Y-axis side. That is, the container body 230a1 has a pair of rectangular, flat, long side portions on both sides in the Z-axis direction, a pair of rectangular, flat, short side portions on both sides in the X-axis direction, and a rectangular, flat, bottom portion on the positive Y-axis side. The container lid 230a2 is a rectangular, plate-like member that constitutes the lid of the container 230a, and is disposed on the negative Y-axis side of the container body 230a1, extending in the X-axis direction.

[0063] The electrode body 230f is an electricity storage element (power generation element) formed by laminating a positive electrode plate, a negative electrode plate, and a separator. The positive electrode plate is formed by forming a positive electrode active material layer on a positive electrode substrate layer, which is a current collector foil made of a metal such as aluminum or an aluminum alloy. The negative electrode plate is formed by forming a negative electrode active material layer on a negative electrode substrate layer, which is a current collector foil made of a metal such as copper or a copper alloy. As the active materials 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 capable of absorbing and releasing lithium ions.

[0064] The electrode body 230f is a laminated (stacked) electrode body formed by stacking a plurality of flat positive electrode plates and a plurality of flat negative electrode plates. In contrast, the electrode body 230h is a wound (vertically wound) electrode body formed by winding the electrode plates (positive and negative electrode plates) around a winding axis extending in the X-axis direction. The electrode body of the energy storage element 230 is not limited to the above-mentioned types of electrode body, and may be an electrode body of any shape, such as a wound (horizontally wound) electrode body formed by winding the positive and negative electrode plates around a winding axis extending in the Y-axis direction, or a bellows-shaped electrode body in which the electrode plates are folded in a bellows shape.

[0065] The electrode plates (positive and negative electrode plates) of the electrode body 230f are stacked in the Z-axis direction, and therefore the Z-axis direction is also referred to as the stacking direction. That is, the electrode body 230f is formed by stacking the electrode plates in the stacking direction. The electrode body 230h has a pair of curved portions 230j aligned in the Y-axis direction and a pair of flat portions 230i aligned in the Z-axis direction and connecting the pair of curved portions 230j by winding the electrode plates. The stacking direction is the stacking direction of the electrode plates in the flat portions 230i. The direction in which the flat surfaces of the flat portions 230i face or the direction in which the pair of flat portions 230i face each other can also be defined as the stacking direction. Therefore, the two first energy storage elements 231 can be said to be aligned in the stacking direction, and the two second energy storage elements 232 can also be said to be aligned in the stacking direction. The same applies to the third energy storage element 233 and the fourth energy storage element 234.

[0066] The X-axis direction in which the first storage element 231, the second storage element 232, etc. are arranged is also referred to as the arrangement direction. That is, the first storage element 231, the second storage element 232, etc. are arranged in an arrangement direction that intersects with the stacking direction. The first storage element 231 and the second storage element 232 are arranged in positions adjacent to each other in the arrangement direction. The third storage element 233 is arranged in a position where the second storage element 232 is sandwiched between the first storage element 231 and the fourth storage element 234 in the arrangement direction. In other words, the first storage element 231, the second storage element 232, the third storage element 233, and the fourth storage element 234 are arranged side by side in this order in the arrangement direction.

[0067] The electrode terminals 230b are terminals (positive and negative terminals) of the energy storage element 230 disposed in the container lid portion 230a2, and are electrically connected to the positive and negative electrode plates of the electrode body 230f via the current collector 230e. The electrode terminals 230b are formed of a conductive material such as a metal, such as aluminum, an aluminum alloy, copper, or a copper alloy. The current collector 230e is a conductive member (positive and negative current collector) electrically connected to the electrode terminal 230b and the electrode body 230f. The current collector 230e is formed of aluminum, an aluminum alloy, copper, a copper alloy, or the like. The upper gasket 230c and the lower gasket 230d are flat, electrically insulating sealing members disposed between the container lid portion 230a2 and the electrode terminal 230b and the current collector 230e. The upper gasket 230c and the lower gasket 230d are formed of the same insulating material as the exterior body 100.

[0068] [2.2 Description of the configuration of the spacer 250 and the electrical device 240] The spacer 250 is a rectangular, flat spacer disposed adjacent to the energy storage element 230. Specifically, the spacer 250 is disposed facing the long side surface of the container 230a of the energy storage element 230, in the positive Z-axis direction or the negative Z-axis direction of the energy storage element 230. In this embodiment, the spacers 250 are disposed so as to sandwich the energy storage element 230 in the Z-axis direction, thereby electrically insulating the energy storage element 230 from the adjacent energy storage element 230, the first constraint 210, or the second constraint 220. The spacer 250 is formed of an insulating material similar to the exterior body 100, or a insulating material similar to the heat insulating sheet 300. Instead of or in addition to the spacer 250, an insulating sheet may be disposed on the side surface of the container 230a of the energy storage element 230.

[0069] The electric device 240 is an electric product arranged in the X-axis direction (arrangement direction) of the plurality of storage elements 230, such as the first storage element 231 and the second storage element 232. Specifically, the electric device 240 is arranged in the positive X-axis direction of the storage element 230 (the lower fourth storage element 234) that is furthest in the positive X-axis direction and in the negative Z-axis direction among the plurality of storage elements 230. The electric device 240 has electric components such as a circuit board that monitors the charge or discharge state of the storage elements 230 and controls the charge and discharge of the storage elements 230, a fuse, a relay, a semiconductor switch such as a field effect transistor (FET), a shunt resistor, a thermistor, and a connector.

[0070] [2.3 Explanation of the configuration of the first restraint body 210 and the second restraint body 220] Next, the configuration of the first restraint body 210 and the second restraint body 220 will be described in detail. The first restraint body 210 and the second restraint body 220 are a pair of restraint bodies that collectively sandwich a plurality of energy storage elements 230, such as the first energy storage element 231 and the second energy storage element 232, in the Z-axis direction (the stacking direction). That is, the first restraint body 210 and the second restraint body 220 collectively sandwich a plurality of first energy storage elements 231 and a plurality of second energy storage elements 232, in the Z-axis direction (the stacking direction). As a result, the first restraint body 210 and the second restraint body 220 collectively restrain the plurality of energy storage elements 230 in the Z-axis direction (collectively applying a restraining force in the Z-axis direction to the plurality of energy storage elements 230). The first restraint body 210 and the second restraint body 220 are formed of metal members such as stainless steel, aluminum, aluminum alloy, iron, and plated steel plate, but may also be formed of insulating members such as highly rigid resin.

[0071] That is, the first constraint body 210 and the second constraint body 220 are each an integral body (integrally molded product) formed by bending a single plate-like member or the like, and are directly joined to each other to collectively sandwich the plurality of energy storage elements 230. Specifically, the first constraint body 210 and the second constraint body 220 are directly joined in the X-axis direction (the arrangement direction) at a position where the plurality of energy storage elements 230, such as the first energy storage element 231 and the second energy storage element 232, are sandwiched between them. The first constraint body 210 and the second constraint body 220 are connected between the energy storage elements 230 adjacent in the X-axis direction, such as the first energy storage element 231 and the second energy storage element 232. In this embodiment, the first constraint body 210 and the second constraint body 220 are directly joined between the energy storage elements 230 adjacent in the X-axis direction, such as between the first energy storage element 231 and the second energy storage element 232 and between the second energy storage element 232 and the third energy storage element 233. These will be explained in detail below.

[0072] The first restraint body 210 is a plate-shaped member that is arranged in the negative Z-axis direction of the plurality of energy storage elements 230, the plurality of spacers 250, and the electric equipment 240, and that places the energy storage elements 230, etc. on it. The first restraint body 210 has four energy storage element placement sections 211, four first restraint body protrusions 212, and an electric equipment placement section 213. The second restraint body 220 is a plate-shaped member that is arranged in the positive Z-axis direction of the plurality of energy storage elements 230 and the plurality of spacers 250, and that presses (compresses) the energy storage elements 230, etc. The second restraint body 220 has four energy storage element restraint sections 221 and five second restraint body protrusions 222.

[0073] The energy storage element arrangement portion 211 of the first constraint body 210 is a rectangular, plate-like portion parallel to the XY plane, on which the energy storage elements 230 are arranged (placed) via spacers 250. Four energy storage element arrangement portions 211 are arranged side by side in the X-axis direction, corresponding to the four energy storage elements 230 arranged in the X-axis direction. In this embodiment, the energy storage element arrangement portions 211 are arranged so as to cover the entire side surface (long side surface) of the container 230a of the energy storage element 230 on the negative Z-axis direction side (see FIG. 2).

[0074] The energy storage element restraining portion 221 of the second restraining body 220 is a rectangular, plate-like portion parallel to the XY plane that sandwiches and restrains the multiple energy storage elements 230 and multiple spacers 250 aligned in the Z-axis direction between the energy storage element arrangement portion 211 and the second restraining body 220. Four energy storage element restraining portions 221 are aligned in the X-axis direction corresponding to the four energy storage element arrangement portions 211 aligned in the X-axis direction. In this embodiment, the energy storage element restraining portion 221 is arranged so as to cover the entire side surface (long side surface) of the container 230a of the energy storage element 230 on the positive side of the Z-axis (see FIG. 2).

[0075] The first restraint body protrusions 212 of the first restraint body 210 are protrusions (protruding ridges) that protrude in a bulging manner in the positive Z-axis direction from the energy storage element arrangement section 211 and extend in the Y-axis direction. Four first restraint body protrusions 212 are arranged between adjacent energy storage element arrangement sections 211 and in the negative X-axis direction of the energy storage element arrangement section 211 on the negative X-axis side. The electric device arrangement section 213 is a rectangular, plate-like section parallel to the XY plane on which the electric device 240 is arranged (placed). The electric device arrangement section 213 is arranged in a position that protrudes in the positive Z-axis direction (one step up) from the positive X-axis side end of the energy storage element arrangement section 211 on the positive X-axis side.

[0076] The second restraint body protrusions 222 of the second restraint body 220 are protrusions (protruding ridges) that protrude in a bulging manner in the negative Z-axis direction from the energy storage element restraint portion 221 and extend in the Y-axis direction. Five second restraint body protrusions 222 are arranged between adjacent energy storage element restraint portions 221, in the negative X-axis direction of the energy storage element restraint portion 221 on the negative X-axis side, and in the positive X-axis direction of the energy storage element restraint portion 221 on the positive X-axis side. In other words, the five second restraint body protrusions 222 are arranged in positions facing the four first restraint body protrusions 212 and the end of the electrical device arrangement portion 213 on the negative X-axis direction side. The second restraint body protrusions 222 are formed so that the protrusion amount in the negative Z-axis direction is greater than the protrusion amount in the positive Z-axis direction of the first restraint body protrusions 212.

[0077] The four first constraint body protrusions 212 and the electric device arrangement section 213 are provided with first constraint body connection portions 217. Specifically, two first constraint body connection portions 217 are provided at both ends in the Y axis direction of each of the first constraint body protrusions 212 and the end on the X axis negative direction side of the electric device arrangement section 213. The five second constraint body protrusions 222 are provided with second constraint body connection portions 227. Specifically, two second constraint body connection portions 227 are provided at each of the second constraint body protrusions 222 at positions corresponding to the first constraint body connection portions 217 at both ends in the Y axis direction.

[0078] 5 and 7 , the first constraint body protrusion 212 protrudes toward the second constraint body protrusion 222 of the second constraint body 220, is disposed between the first power storage element 231 and the second power storage element 232, or the like, and is directly joined to the second constraint body protrusion 222 of the second constraint body 220, or the like, between the first power storage element 231 and the second power storage element 232. The second constraint body protrusion 222 protrudes toward the first constraint body protrusion 212 of the first constraint body 210, is disposed between the first power storage element 231 and the second power storage element 232, or the like, and is directly joined to the first constraint body protrusion 212 of the first constraint body 210, or the like, between the first power storage element 231 and the second power storage element 232. With the first constraint body protrusions 212 and the second constraint body protrusions 222 in contact (the first constraint body 210 and the second constraint body 220 in contact), the first constraint body connecting portions 217 and the second constraint body connecting portions 227 are joined. In this manner, the first constraint body 210 and the second constraint body 220 (the first constraint body protrusions 212 and the second constraint body protrusions 222) are directly joined in the X-axis direction at positions sandwiching the multiple energy storage elements 230 and between adjacent energy storage elements 230.

[0079] The direct joining of the first constraint body 210 and the second constraint body 220 does not necessarily mean that they are joined in an abutting state, but refers to a state in which they are joined without a member that transmits force between them. In other words, even if the first constraint body 210 and the second constraint body 220 are joined in a state in which an accessory such as a gasket or a washer is sandwiched between the first constraint body 210 and the second constraint body 220, this is included in the concept of the first constraint body 210 and the second constraint body 220 being directly joined.

[0080] Specifically, the second restraint body connection portion 227 is a bolt portion, and the first restraint body connection portion 217 is a nut portion into which the bolt portion is threaded. In other words, the second restraint body connection portion 227 has a through hole and a bolt to be inserted into the through hole, and the first restraint body connection portion 217 has a through hole and a nut disposed below the through hole (see FIG. 7). The first restraint body connection portion 217 may be a bolt portion, and the second restraint body connection portion 227 may be a nut portion into which the bolt portion is threaded. Other methods may be used to connect (join) the second restraint body 220 to the first restraint body 210, such as welding, crimping, adhesive bonding, or welding. The arrangement positions and numbers of the first restraint body connection portion 217 and the second restraint body connection portion 227 are not particularly limited.

[0081] The above-mentioned first restraint body fixing portions 218 are provided on the four first restraint body protrusions 212 and the electric device arrangement portion 213 of the first restraint body 210. Specifically, two first restraint body fixing portions 218 are provided on the first restraint body protrusions 212 and the end portion of the electric device arrangement portion 213 on the negative X-axis direction side, respectively, on the outer side in the Y-axis direction of the two first restraint body connecting portions 217 (see FIG. 7 ).

[0082] As described above, the first restraint body fixing portion 218 is a portion fixed to the exterior body main body 110 of the exterior body 100. That is, as shown in FIG. 6 , the first restraint body fixing portion 218 is fixed to the exterior body fixing portion 112 of the exterior body main body 110 at a position where it sandwiches multiple energy storage elements 230 in the X-axis direction and between adjacent energy storage elements 230. In this way, the first restraint body 210 is fixed to the exterior body 100 at a position where it sandwiches multiple energy storage elements 230, such as the first energy storage element 231 and the second energy storage element 232, in the X-axis direction. The first restraint body 210 is fixed to the exterior body 100 between adjacent energy storage elements 230 in the X-axis direction, such as between the first energy storage element 231 and the second energy storage element 232.

[0083] The four energy storage element restraining portions 221 of the second restraint body 220 are provided with the above-described second restraint body fixing portions 226. Specifically, in each of the energy storage element restraining portions 221, two second restraint body fixing portions 226 are arranged side by side in the Y-axis direction at the center in the X-axis direction. As described above, the second restraint body fixing portions 226 are portions to which the reinforcing member 400 is fixed, and are cylindrical bolt portions protruding in the positive direction of the Z-axis from the energy storage element restraining portion 221. That is, as shown in FIG. 5 , the reinforcing member 400 is fixed to the second restraint body 220 by connecting (joining) the reinforcing member fixing portions 430 of the reinforcing member 400 to the second restraint body fixing portions 226. As a result, the reinforcing member 400 is arranged in the positive direction of the Z-axis (the stacking direction) of the multiple energy storage elements 230, such as the first energy storage element 231 and the second energy storage element 232. The reinforcing member protrusions 410 and 420 are portions that protrude in the positive Z-axis direction (the stacking direction) and extend in the X-axis direction (the arrangement direction).

[0084] The reinforcing member 400 is formed so that at least one of the first power storage element 231 and the second power storage element 232 does not protrude from the reinforcing member 400 in the X-axis direction (the arrangement direction). In other words, the reinforcing member 400 is formed so as to extend in the X-axis direction at least to the edge in the X-axis direction of at least one of the first power storage element 231 and the second power storage element 232. In other words, at least a portion of the reinforcing member 400 overlaps with the edge in the X-axis direction of at least one of the first power storage element 231 and the second power storage element 232 when viewed from the Z-axis direction.

[0085] In the present embodiment, reinforcing member 400 is formed so that neither first storage element 231 nor second storage element 232 protrudes from reinforcing member 400 in the X-axis direction. Specifically, reinforcing member 400 is formed so that none of storage elements 230 protrudes from reinforcing member 400 in the X-axis direction. In other words, reinforcing member 400 is formed to have a length in the X-axis direction that is the same as or longer than the length from the edge of first storage element 231 on the negative X-axis direction side to the edge of fourth storage element 234 on the positive X-axis direction side.

[0086] More specifically, the reinforcing member 400 is formed so that the electric device 240 does not protrude from the reinforcing member 400 in the X-axis direction (the arrangement direction). That is, the reinforcing member 400 is formed so as to extend in the X-axis direction at least to the edge of the electric device 240 in the X-axis direction. In other words, at least a portion of the reinforcing member 400 overlaps with the edge of the electric device 240 in the X-axis direction when viewed from the Z-axis direction.

[0087] In this embodiment, the reinforcing member 400 is formed to have approximately the same length as the first restraint body 210 in the X-axis direction. As a result, the reinforcing member 400 protrudes further than all of the energy storage elements 230 and the electric device 240 on both sides in the X-axis direction. In this manner, the multiple energy storage elements 230 are protected by the first restraint body 210 on the negative Z-axis direction side, and are protected by the second restraint body 220 and the reinforcing member 400 on the positive Z-axis direction side. The electric device 240 is protected by the first restraint body 210 on the negative Z-axis direction side, and is protected by the reinforcing member 400 on the positive Z-axis direction side. The reinforcing member 400 may be longer or slightly shorter than the first restraint body 210 in the X-axis direction.

[0088] The length of the reinforcing member 400 in the Y-axis direction is not particularly limited, but in this embodiment, the reinforcing member 400 is formed to have approximately the same length as the first constraint body 210 in the Y-axis direction as well. Therefore, the reinforcing member 400 protrudes further than all of the energy storage elements 230 and electrical devices 240 on both sides in the Y-axis direction. As a result, the multiple energy storage elements 230 and electrical devices 240 are protected by the first constraint body 210 on the negative Z-axis direction side and by the reinforcing member 400 on the positive Z-axis direction side in the Y-axis direction as well. The reinforcing member 400 may be longer or shorter than the first constraint body 210 in the Y-axis direction.

[0089] Similar to the reinforcing member 400, the reinforcing member protrusions 410 and 420 are formed so that at least one of the first power storage element 231 and the second power storage element 232 does not protrude from the reinforcing member protrusions 410 and 420 in the X-axis direction (the arrangement direction). In other words, the reinforcing member protrusions 410 and 420 are formed so as to extend at least to the X-axis direction edge of at least one of the first power storage element 231 and the second power storage element 232. In other words, at least a portion of the reinforcing member protrusions 410 and 420 overlaps with the X-axis direction edge of at least one of the first power storage element 231 and the second power storage element 232 when viewed from the Z-axis direction.

[0090] The reinforcing member protrusion 410 is formed so that the electric device 240 does not protrude from the reinforcing member protrusion 410 in the X-axis direction (the arrangement direction). In other words, the reinforcing member protrusion 410 is formed so as to extend in the X-axis direction at least to the edge of the electric device 240 in the X-axis direction. In other words, at least a portion of the reinforcing member protrusion 410 overlaps with the edge of the electric device 240 in the X-axis direction when viewed from the Z-axis direction.

[0091] In the present embodiment, the reinforcing member protrusion 410 is formed over the entire length of the reinforcing member 400 in the X-axis direction, and therefore, like the reinforcing member 400, protrudes beyond all of the energy storage elements 230 and the electric device 240 on both sides in the X-axis direction. The reinforcing member protrusion 420 has a shorter length in the X-axis direction than the reinforcing member protrusion 410, but protrudes beyond all of the energy storage elements 230 on both sides in the X-axis direction. In the present embodiment, the reinforcing member protrusion 420 does not protrude beyond the electric device 240, but may be configured to protrude beyond the electric device 240.

[0092] [3 Explanation of effects] As described above, in energy storage device 10 according to the embodiment of the present invention, energy storage elements 230 such as first energy storage element 231 and second energy storage element 232 have metal containers 230a, and are arranged in an arrangement direction (X-axis direction) that intersects with the stacking direction (Z-axis direction) of the electrode plates of electrode body 230f. A pair of constraint bodies (first constraint body 210 and second constraint body 220) are directly joined to collectively sandwich energy storage elements 230 such as first energy storage element 231 and second energy storage element 232 in the stacking direction.

[0093] The storage elements 230, such as the first storage element 231 and the second storage element 232, expand in the stacking direction of the electrode plates of the electrode body 230f. Therefore, when the storage elements 230, such as the first storage element 231 and the second storage element 232, are arranged in an arrangement direction that intersects with the stacking direction, it is necessary to suppress expansion of all of the storage elements 230, such as the first storage element 231 and the second storage element 232. However, if the first storage element 231 and the second storage element 232 are individually sandwiched between restraining bodies, the configuration becomes complicated. Therefore, the configuration can be simplified by collectively sandwiching the storage elements 230, such as the first storage element 231 and the second storage element 232, between a pair of restraining bodies.

[0094] The energy storage elements 230, such as the first energy storage element 231 and the second energy storage element 232, have metal containers 230a to prevent swelling. However, even if the containers 230a are made of metal, swelling still occurs, so the energy storage elements 230 must be firmly sandwiched between a pair of restraining bodies. However, if the pair of restraining bodies are joined via other members, the number of joints increases, increasing the risk of loosening of the joints. For this reason, the pair of restraining bodies are directly joined. This reduces the number of joints, reducing the risk of loosening of the joints, and also simplifies the configuration by reducing the number of parts.

[0095] In this manner, in a configuration in which a plurality of energy storage elements 230 (first energy storage elements 231, second energy storage elements 232, etc.) are sandwiched between a pair of restraining bodies in a direction intersecting the arrangement direction, swelling of the plurality of energy storage elements 230 can be easily suppressed.

[0096] The pair of restraining bodies are directly joined in the arrangement direction at positions that sandwich the storage elements 230, such as the first storage element 231 and the second storage element 232, and therefore can easily sandwich the storage elements 230, such as the first storage element 231 and the second storage element 232, all together. This makes it possible to easily suppress swelling of the multiple storage elements 230 (such as the first storage element 231 and the second storage element 232) using the pair of restraining bodies.

[0097] The pair of restraining bodies are directly joined between the first energy storage element 231 and the second energy storage element 232, and therefore can easily and more firmly sandwich each of the first energy storage element 231 and the second energy storage element 232. This makes it possible to easily suppress swelling of the multiple energy storage elements 230 (the first energy storage element 231 and the second energy storage element 232) by the pair of restraining bodies. The same applies to the third energy storage element 233 and the fourth energy storage element 234.

[0098] By forming a convex portion (first constraining body convex portion 212, second constraining body convex portion 222) on at least one of the pair of constraining bodies and joining it to the other, the pair of constraining bodies can be directly joined between the first storage element 231 and the second storage element 232 with a simple configuration. This makes it possible to easily suppress swelling of the multiple storage elements 230 (first storage element 231 and second storage element 232).

[0099] The pair of restraining bodies are also directly joined between the second energy storage element 232 and the third energy storage element 233, and therefore can easily and more firmly clamp each of the first energy storage element 231, the second energy storage element 232, and the third energy storage element 233. As a result, the pair of restraining bodies can easily suppress swelling of the multiple energy storage elements 230 (the first energy storage element 231, the second energy storage element 232, and the third energy storage element 233).

[0100] In a configuration in which a plurality of first energy storage elements 231 and a plurality of second energy storage elements 232 are arranged in the stacking direction, a pair of restraining bodies sandwiches the plurality of first energy storage elements 231 and the plurality of second energy storage elements 232 together in the stacking direction. This allows the plurality of first energy storage elements 231 and the plurality of second energy storage elements 232 to be easily sandwiched together by the pair of restraining bodies, thereby easily suppressing swelling of the plurality of first energy storage elements 231 and the plurality of second energy storage elements 232. The same applies to the third energy storage element 233 and the fourth energy storage element 234.

[0101] At least one of the pair of restraining bodies is fixed to the exterior body 100, and therefore, the energy storage elements 230, such as the first energy storage element 231 and the second energy storage element 232, can be easily fixed to the exterior body 100. This makes it possible to easily prevent the energy storage elements 230, such as the first energy storage element 231 and the second energy storage element 232, from moving within the exterior body 100 even if vibrations, shocks, or the like are applied to the energy storage device 10.

[0102] At least one of the pair of restraining bodies is fixed to the exterior body 100 between the first storage element 231 and the second storage element 232, so that the first storage element 231 and the second storage element 232 can be fixed in a balanced manner to the exterior body 100. This makes it possible to further suppress movement of the first storage element 231 and the second storage element 232 within the exterior body 100 even if vibrations or shocks are applied to the energy storage device 10. The same applies to the third storage element 233 and the fourth storage element 234.

[0103] The energy storage elements 230, such as the first energy storage element 231 and the second energy storage element 232, are arranged in an arrangement direction (X-axis direction) that intersects with the stacking direction (Z-axis direction) of the electrode plates of the electrode body 230f, and the reinforcing member 400 has reinforcing member protrusions 410 and 420 that protrude in the stacking direction and extend in the arrangement direction. When the energy storage elements 230, such as the first energy storage element 231 and the second energy storage element 232, are arranged in an arrangement direction that intersects with the stacking direction of the electrode plates of the electrode body 230f, the length in the arrangement direction increases, which may weaken the strength in the arrangement direction. For this reason, the reinforcing member 400 is arranged in the stacking direction of the energy storage elements 230, such as the first energy storage element 231 and the second energy storage element 232, and the reinforcing member 400 is provided with reinforcing member protrusions 410 and 420 that protrude in the stacking direction and extend in the arrangement direction. This improves the strength of reinforcing member 400 in the arrangement direction, thereby improving protection of storage elements 230 such as first storage element 231 and second storage element 232 in the arrangement direction.

[0104] The reinforcing member 400 can protect the reinforcing member 400 side of the storage elements 230, such as the first storage element 231 and the second storage element 232, in the stacking direction as well. In particular, the reinforcing member 400 is a corrugated plate and can absorb forces in the stacking direction, thereby improving protection of the first storage element 231 and the second storage element 232 in the stacking direction as well.

[0105] Because reinforcing member 400 is a metal (conductive) member, it can dissipate heat generated from power storage elements 230, such as first power storage element 231 and second power storage element 232. In particular, because reinforcing member 400 is a corrugated plate and has spaces formed on the power storage element 230 side, air heated by the heat moves through the spaces, thereby dissipating heat. Because reinforcing member 400 is a corrugated plate, it can be easily manufactured and can also be made lightweight.

[0106] The reinforcing member 400 is formed so that at least one of the first storage element 231 and the second storage element 232 does not protrude in the arrangement direction, and therefore, when an external impact or the like is applied in the arrangement direction, the reinforcing member 400 bears the force of the impact or the like. This further improves the strength of the first storage element 231 and the second storage element 232 in the arrangement direction, thereby further improving the protection of the first storage element 231 and the second storage element 232 in the arrangement direction. The same applies to the third storage element 233 and the fourth storage element 234.

[0107] The reinforcing member protrusions 410 and 420 are formed so that at least one of the first energy storage element 231 and the second energy storage element 232 does not protrude in the arrangement direction. Therefore, when an external impact or the like is applied in the arrangement direction, the portion of the reinforcing member 400 that is reinforced by the reinforcing member protrusions 410 and 420 bears the force of the impact or the like. This further improves the strength of the first energy storage element 231 and the second energy storage element 232 in the arrangement direction, thereby further improving the protection of the first energy storage element 231 and the second energy storage element 232 in the arrangement direction. The same applies to the third energy storage element 233 and the fourth energy storage element 234.

[0108] The reinforcing member 400 is formed so that the electric device 240 does not protrude in the arrangement direction, and therefore, when an external impact or the like is applied to the electric device 240 in the arrangement direction, the reinforcing member 400 receives the force of the impact or the like. This makes it possible to protect the electric device 240 from the force of the impact or the like in the arrangement direction. The reinforcing member protrusions 410 and 420 are also formed so that the electric device 240 does not protrude in the arrangement direction, and therefore, similarly to the above, it is possible to further improve the protection of the electric device 240.

[0109] The reinforcing member 400 can protect the reinforcing member 400 side of the electric device 240 in the stacking direction as well. In particular, the reinforcing member 400 is a corrugated plate and can absorb forces in the stacking direction, thereby improving protection of the electric device 240 in the stacking direction as well.

[0110] The reinforcing member 400 is fixed to at least one of a pair of restraining bodies that collectively sandwich the energy storage elements 230, such as the first energy storage element 231 and the second energy storage element 232, and therefore the reinforcing member 400 can be fixed to the energy storage elements 230, such as the first energy storage element 231 and the second energy storage element 232. This makes it possible to prevent the reinforcing member 400 from shifting relative to the energy storage elements 230, such as the first energy storage element 231 and the second energy storage element 232, and therefore allows the energy storage elements 230, such as the first energy storage element 231 and the second energy storage element 232, to be protected more reliably.

[0111] In order to more firmly restrain the first energy storage element 231 and the second energy storage element 232, a pair of restraining bodies are connected between the first energy storage element 231 and the second energy storage element 232. However, in this case, the gap between the first energy storage element 231 and the second energy storage element 232 becomes larger, weakening the strength of the first energy storage element 231 and the second energy storage element 232 in the arrangement direction. For this reason, it is highly effective to form reinforcing member protrusions 410 and 420 on the reinforcing member 400 to improve the strength in the arrangement direction and thereby improve protection of the first energy storage element 231 and the second energy storage element 232 in the arrangement direction. The same applies to the third energy storage element 233 and the fourth energy storage element 234.

[0112] [4 Explanation of Variations] Although the energy storage device 10 according to the embodiment of the present invention has been described above, the present invention is not limited to this embodiment. In other words, the embodiment disclosed herein is illustrative in all respects and is not restrictive, and the scope of the present invention includes all modifications within the meaning and scope of the claims.

[0113] In the above embodiment, the first constraint body 210 and the second constraint body 220 are joined in the X-axis direction at positions where the plurality of storage elements 230 are sandwiched between them and between adjacent storage elements 230. However, the first constraint body 210 and the second constraint body 220 may be joined at any positions, and may not be joined at one or both of the positions where the plurality of storage elements 230 are sandwiched between them, or may not be joined between adjacent storage elements 230.

[0114] In the above embodiment, the first constraint body 210 and the second constraint body 220 are configured as separate bodies. However, the first constraint body 210 and the second constraint body 220 may be an integral body connected at one end in the X-axis direction or one end in the Y-axis direction. In other words, the first constraint body 210 and the second constraint body 220 may be formed by bending a single plate-like member, and the unconnected ends may be joined together.

[0115] In the above embodiment, the energy storage device 10 includes a plurality of first energy storage elements 231 and a plurality of second energy storage elements 232, etc., aligned in the Z-axis direction, and the first constraint body 210 and the second constraint body 220 sandwich these together in the Z-axis direction. However, the energy storage device 10 may include only one first energy storage element 231 and one second energy storage element 232, etc., in the Z-axis direction, and the first constraint body 210 and the second constraint body 220 may sandwich this one first energy storage element 231 and one second energy storage element 232, etc., together.

[0116] In the above embodiment, first constraint body 210 and second constraint body 220 have convex portions (first constraint body convex portion 212 and second constraint body convex portion 222) that protrude toward the other, and these convex portions are joined to each other. However, one of first constraint body 210 and second constraint body 220 may have a convex portion that protrudes away from the other, and they may be joined at the convex portion, or they may be joined at a flat portion without having a convex portion. In other words, it is sufficient that at least one of the pair of constraint bodies (first constraint body 210 and second constraint body 220) has a convex portion that protrudes toward the other, is disposed between first power storage element 231 and second power storage element 232, and is directly joined to the other between first power storage element 231 and second power storage element 232.

[0117] In the above embodiment, the first restraint 210 is fixed to the exterior body main body 110 of the exterior body 100. However, the first restraint 210 may be fixed to the exterior body lid body 120. Instead of or in addition to the first restraint 210, the second restraint 220 may be fixed to the exterior body main body 110 or the exterior body lid body 120. In other words, it is sufficient that at least one of the first restraint 210 and the second restraint 220 is fixed to at least one of the exterior body main body 110 and the exterior body lid body 120. Neither the first restraint 210 nor the second restraint 220 needs to be fixed to either the exterior body main body 110 or the exterior body lid body 120.

[0118] In the above embodiment, the first constraint 210 is fixed to the exterior body 100 at a position in the X-axis direction where the first constraint 210 sandwiches the multiple energy storage elements 230 and between adjacent energy storage elements 230. However, the first constraint 210 may be fixed to the exterior body 100 at any position, and may not be fixed to the exterior body 100 at one or both of the positions where the first constraint 210 sandwiches the multiple energy storage elements 230, or may not be fixed to the exterior body 100 between adjacent energy storage elements 230. Instead of or in addition to the first constraint 210, a second constraint 220 may be fixed to the exterior body 100.

[0119] In a configuration in which at least one of first constraint body 210 and second constraint body 220 is fixed to exterior body 100, energy storage element 230 does not need to have metal container 230a, and a pouch-type energy storage element can be used as energy storage element 230. In this case, first constraint body 210 and second constraint body 220 do not need to be directly joined, and a separate member may be disposed between first constraint body 210 and second constraint body 220.

[0120] In the above embodiment, the reinforcing member 400 is arranged in the positive direction of the Z axis of the energy storage unit 200. However, the reinforcing member 400 may be arranged in the negative direction of the Z axis of the energy storage unit 200, or two reinforcing members 400 may be arranged on both sides of the energy storage unit 200 in the Z axis direction.

[0121] In the above embodiment, the reinforcing member 400 is fixed to the second constraint body 220. However, the reinforcing member 400 may be fixed to the first constraint body 210. The reinforcing member 400 does not have to be fixed to either the first constraint body 210 or the second constraint body 220.

[0122] In the above embodiment, the reinforcing member 400 protrudes beyond all of the energy storage elements 230 and the electric devices 240 on both sides in the X-axis direction and both sides in the Y-axis direction. However, the energy storage elements 230 or the electric devices 240 may protrude slightly from the reinforcing member 400 in either the X-axis direction or the Y-axis direction. Even in this case, the energy storage elements 230 and the electric devices 240 can be better protected than when the reinforcing member 400 is not provided. At least the energy storage elements 230 that do not protrude from the reinforcing member 400 can be protected. Similarly, for the reinforcing member protrusions 410 and 420, the energy storage elements 230 or the electric devices 240 may protrude slightly from the reinforcing member 400 in the X-axis direction.

[0123] In the above embodiment, the reinforcing member protrusions 410, 420 are bulging protrusions extending continuously and linearly in the X-axis direction. However, the reinforcing member protrusions 410, 420 may be protrusions in which the surface of the reinforcing member 400 on the negative Z-axis side is not recessed in the positive Z-axis direction, and the surface of the reinforcing member 400 on the positive Z-axis side protrudes in the positive Z-axis direction. The reinforcing member protrusions 410, 420 may also be protrusions protruding in the negative Z-axis direction. The reinforcing member protrusions 410, 420 may be multiple protrusions formed intermittently in the X-axis direction, or may be protrusions that extend in a curved manner in the X-axis direction rather than extending linearly in the X-axis direction. The reinforcing member protrusions 410, 420 may also be protrusions that extend in a direction inclined from the X-axis direction to the Y-axis direction.

[0124] The power storage device 10 does not necessarily have to include all of the above-mentioned components. The power storage device 10 does not necessarily have to include the heat insulating sheet 300, the electrical device 240, the spacer 250, or the like.

[0125] Any combination of the components included in the above-described embodiments and their modifications is also included within the scope of the present invention.

[0126] The present invention can be realized not only as the power storage device 10, but also as a pair of restraining bodies (first restraining body 210 and second restraining body 220). [Industrial Applicability]

[0127] The present invention can be applied to an electricity storage device including an electricity storage element such as a lithium ion secondary battery. [Explanation of symbols]

[0128] 10. Energy storage device 100 exterior body 110 Exterior body 112 Exterior body fixing part 200 Energy Storage Unit 210 First restraint body 211 Storage element arrangement section 212 First restraint body convex part 213 Electrical Equipment Layout Section 217 First restraint body connection part 218 First restraint body fixing part 220 Second restraint body 221 Storage element restraint section 222 Second restraint convex part 226 Second restraint body fixing part 227 Second restraint body connection part 230 Energy storage element 230a container 230f, 230h electrode body 231 First storage element 232 Second storage element 233 Third storage element 234 Fourth storage element 240 Electrical Equipment 400 Reinforcement member 410, 420 Reinforcing member convex portion 430 Reinforcement member fixing part

Claims

1. two electric storage elements each including an electrode assembly in which electrode plates are stacked in a stacking direction and a metal container in which the electrode assembly is housed, the first electric storage element and the second electric storage element being arranged in an arrangement direction intersecting the stacking direction; a pair of constraint bodies that collectively sandwich the first energy storage element and the second energy storage element in the stacking direction, the pair of constraint bodies being joined to each other in the stacking direction without a member that transmits force being disposed between the pair of constraint bodies, The pair of constraint bodies are joined at positions sandwiching the first and second power storage elements in the arrangement direction. Energy storage device.

2. two electric storage elements each including an electrode assembly in which electrode plates are stacked in a stacking direction and a metal container in which the electrode assembly is housed, the first electric storage element and the second electric storage element being arranged in an arrangement direction intersecting the stacking direction; a pair of constraint bodies that collectively sandwich the first energy storage element and the second energy storage element in the stacking direction, the pair of constraint bodies being joined to each other without a member that transmits force being disposed between the pair of constraint bodies; The pair of restraining bodies are joined between the first storage element and the second storage element. Energy storage device.

3. At least one of the pair of constraint bodies has a protrusion that protrudes toward the other of the pair of constraint bodies, is disposed between the first power storage element and the second power storage element, and is joined to the other of the pair of constraint bodies between the first power storage element and the second power storage element. The power storage device according to claim 2 .

4. further comprising a third storage element disposed at a position where the second storage element is sandwiched between the first storage element and the third storage element in the arrangement direction, The pair of restraining bodies are joined between the second power storage element and the third power storage element. The electricity storage device according to claim 2 or 3.

5. the energy storage device includes a plurality of the first energy storage elements arranged in the stacking direction and a plurality of the second energy storage elements arranged in the stacking direction, The pair of restraining bodies collectively sandwich the plurality of first energy storage elements and the plurality of second energy storage elements in the stacking direction. The electricity storage device according to any one of claims 1 to 4.

6. two electric storage elements each including an electrode assembly in which electrode plates are stacked in a stacking direction and a metal container in which the electrode assembly is housed, the first electric storage element and the second electric storage element being arranged in an arrangement direction intersecting the stacking direction; a pair of constraint bodies that collectively sandwich the first energy storage element and the second energy storage element in the stacking direction, the pair of constraint bodies being joined to each other without a member that transmits force being disposed between the pair of constraint bodies; an exterior body that houses the first storage element and the second storage element, At least one of the pair of restraining bodies is fixed to the exterior body. Energy storage device.

7. two electric storage elements each having an electrode body in which electrode plates are stacked in a stacking direction, the first electric storage element and the second electric storage element being arranged in an arrangement direction intersecting the stacking direction; a pair of restraining bodies that collectively sandwich the first energy storage element and the second energy storage element in the stacking direction and are joined to each other; an exterior body that houses the first storage element and the second storage element, At least one of the pair of restraining bodies is fixed to the exterior body between the first storage element and the second storage element. Energy storage device.

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