JP7484178B2 - Power storage device - Google Patents

Description

The present invention relates to an energy storage device having multiple energy storage elements.

Conventionally, there is known a storage device configured to reinforce multiple storage elements with a reinforcing member. For example, Patent Document 1 discloses a battery pack (storage device) that includes a multi-cell having multiple bare cells (storage elements) and reinforcing tape (reinforcing member) attached to each of the wide side surfaces of the multi-cell.

JP 2009-259778 A

In the above-mentioned conventional energy storage devices, the reinforcing member may not be able to adequately protect the multiple energy storage elements. In other words, the reinforcing member disclosed in the above-mentioned Patent Document 1 is a flat, thin plastic tape, and therefore may not adequately protect the multiple energy storage elements when an external impact is applied. For this reason, in a configuration in which multiple energy storage elements are reinforced with a reinforcing member, it is desirable to improve the protection of the multiple energy storage elements by the reinforcing member.

The present invention was made by the inventors with a new focus on the above problem, and aims to provide an energy storage device that can improve the protection of multiple energy storage elements.

In order to achieve the above object, the energy storage device according to one embodiment of the present invention comprises two energy storage elements having an electrode body in which plates are stacked in a stacking direction, a first energy storage element and a second energy storage element arranged in an arrangement direction intersecting the stacking direction, and a reinforcing member arranged in the stacking direction of the first energy storage element and the second energy storage element, the reinforcing member having a convex portion that protrudes in the stacking direction and extends in the arrangement direction.

According to this, in the energy storage device, the first and second storage elements are arranged in an arrangement direction intersecting with the stacking direction of the electrode plates of the electrode body, and the reinforcing member has a convex portion that protrudes in the stacking direction and extends in the arrangement direction. Here, when the first and second storage elements are arranged in an arrangement direction intersecting with the stacking direction of the electrode plates of the electrode body, the length of the energy storage device in the arrangement direction increases, which may weaken the strength of the energy storage device in the arrangement direction. For this reason, a reinforcing member is arranged in the stacking direction of the first and second storage elements, and a convex portion that protrudes in the stacking direction and extends in the arrangement direction is provided on the reinforcing member. This makes it possible to improve the strength of the reinforcing member in the arrangement direction, thereby improving the protection of the first and second storage elements in the arrangement direction.

The reinforcing member may be formed such that at least one of the first storage element and the second storage element does not protrude from the reinforcing member in the arrangement direction.

As a result, the reinforcing member is formed so that at least one of the first and second storage elements does not protrude in the arrangement direction, so that when an external impact or the like is applied in the arrangement direction, the reinforcing member receives the force of the impact or the like. This can further improve the strength of the first and second storage elements in the arrangement direction, thereby further improving the protection of the first and second storage elements in the arrangement direction.

The convex portion may be formed such that at least one of the first storage element and the second storage element does not protrude from the convex portion in the arrangement direction.

According to this, the convex portion of the reinforcing member is formed so that at least one of the first storage element and the second storage element 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 where the convex portion is formed and reinforced receives the force of the impact or the like. This can further improve the strength of the first storage element and the second storage element in the arrangement direction, and therefore can further improve the protection of the first storage element and the second storage element in the arrangement direction.

The energy storage device may further include an electrical device arranged in the arrangement direction of the first energy storage element and the second energy storage element, and the reinforcing member may be formed so that the electrical device does not protrude from the reinforcing member in the arrangement direction.

As a result, the reinforcing member is formed so that the electrical equipment does not protrude in the arrangement direction, so that when an external impact or the like is applied to the electrical equipment in the arrangement direction, the reinforcing member receives the force of the impact or the like. This makes it possible to protect the electrical equipment from the force of the impact or the like in the arrangement direction.

The energy storage device may further include a pair of restraining bodies that sandwich the first energy storage element and the second energy storage element together in the stacking direction, and the reinforcing member may be fixed to at least one of the pair of restraining bodies.

With this, the reinforcing member is fixed to at least one of a pair of restraining bodies that collectively sandwich the first and second storage elements, so that the reinforcing member can be fixed to the first and second storage elements. This makes it possible to prevent the reinforcing member from shifting relative to the first and second storage elements, so that the first and second storage elements can be more reliably protected.

The pair of restraining bodies may also be connected between the first storage element and the second storage element.

According to this, in order to more firmly restrain the first and second storage elements, a pair of restraining bodies are connected between the first and second storage elements. However, in this case, the gap between the first and second storage elements becomes larger, weakening the strength of the first and second storage elements in the arrangement direction. For this reason, it is highly effective to form a convex portion on the reinforcing member to improve the strength in the arrangement direction and improve the protection of the first and second storage elements in the arrangement direction.

The present invention can be realized not only as an electricity storage device, but also as a reinforcing member.

The energy storage device of the present invention can improve the protection of multiple energy storage elements.

1 is a perspective view showing an external appearance of a power storage device according to an embodiment; 2 is a perspective view showing the inside of an exterior body with a main body and a lid separated in an energy storage device according to an embodiment; FIG. FIG. 2 is an exploded perspective view illustrating each component of the electricity storage unit according to the embodiment. FIG. 2 is an exploded perspective view showing each component of the energy storage element according to the embodiment. 4 is a cross-sectional view showing the configuration of the electricity storage unit according to the embodiment together with a reinforcing member. FIG. 4 is a cross-sectional view showing the configuration of the electricity storage unit according to the embodiment together with a reinforcing member and an exterior body. FIG. 4 is a cross-sectional view showing the configuration of the electricity storage unit according to the embodiment together with other members. FIG. FIG. 13 is a perspective view showing a configuration of an electricity storage device according to a modified example of the embodiment. 13 is an exploded perspective view showing components inside an exterior body of an energy storage device according to a modified example of an embodiment. FIG. FIG. 13 is a perspective view showing a configuration of a reinforcing member according to a modified example of the embodiment.

The following describes an energy storage device according to an embodiment of the present invention (including its variations) with reference to the drawings. Note that the embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, component placement and connection forms, 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. Furthermore, the dimensions and other details are not strictly shown in each figure. Furthermore, the same reference numerals are used in each figure to identify identical or similar components.

In the following description and drawings, the longitudinal direction of the exterior body of the energy storage device, the extension direction of the reinforcing member and its protrusion, the arrangement direction of the first and second energy storage elements, the arrangement direction of the energy storage elements and the electrical equipment, the extension direction of the restraining body, the opposing direction of the short side surfaces of the container of the energy storage elements, or the arrangement direction of a pair of electrode terminals in one energy storage element are defined as the X-axis direction. The arrangement direction of the protrusions of the reinforcing member, or the arrangement direction of the main body and the lid of the container of the energy storage element are defined as the Y-axis direction. The arrangement direction of the main body and the lid of the exterior body, the arrangement direction of the pair of restraining bodies, the arrangement 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 are defined as the Z-axis direction. These X-axis, Y-axis, and Z-axis directions are mutually intersecting (orthogonal in this embodiment). Note that, depending on the mode of use, it is possible that the Z-axis direction is not the up-down direction, but for convenience of explanation, the Z-axis direction will be described as the up-down direction below.

In the following description, for example, the positive X-axis direction refers to the direction of the X-axis arrow, and the negative X-axis direction refers to the opposite direction to the positive X-axis direction. The same applies to the Y-axis and Z-axis directions. Furthermore, expressions indicating relative directions or attitudes, such as parallel and perpendicular, also include cases where the directions or attitudes are not strictly speaking the same. For example, saying 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, that is, there is a difference of, for example, a few percent.

(Embodiment)
[1 General Description of 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 external 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 in the energy storage device 10 according to the present embodiment, with the main body and the lid of the exterior body 100 separated.

The power storage device 10 is a device that can charge electricity from the outside and discharge electricity to the outside, and in this embodiment, has a substantially rectangular parallelepiped shape. For example, the power storage device 10 is a battery module (battery pack) used for power storage or power source applications. Specifically, the power storage device 10 is used as a battery for driving or starting the engine of a moving body such as an automobile, motorcycle, watercraft, ship, snowmobile, agricultural machinery, construction machinery, or railroad vehicle for electric railway. Examples of the above-mentioned automobiles include electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and gasoline-powered automobiles. Examples of the above-mentioned railroad vehicles for electric railways include trains, monorails, and linear motor cars. The power storage device 10 can also be used as a stationary battery for home use or for power generation.

As shown in Figures 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 that electrically connects the energy storage unit 200 to an external terminal 130 (described below), but illustrations and detailed descriptions are omitted.

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 arranged outside the energy storage unit 200, the heat insulating sheet 300, the reinforcing member 400, etc., and fixes the energy storage unit 200, etc. at a predetermined position to protect them from impacts, etc. The exterior body 100 is formed of, for example, an insulating material such as polycarbonate (PC), polypropylene (PP), polyethylene (PE), polystyrene (PS), polyphenylene sulfide resin (PPS), polyphenylene ether (PPE (including modified PPE)), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyether ether ketone (PEEK), tetrafluoroethylene perfluoroalkyl vinyl ether (PFA), polytetrafluoroethylene (PTFE), polyether sulfone (PES), ABS resin, or a composite material thereof, or a metal with an insulating coating. This allows the exterior body 100 to prevent the energy storage unit 200 and other components from coming into contact with external metal components and the like. Note that the exterior body 100 may be made of a conductive material such as metal as long as the electrical insulation of the energy storage unit 200 and other components is maintained.

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 body 120 that constitutes the lid body 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 Z-axis positive side. The exterior body lid body 120 is a flat rectangular lid that is arranged in the Z-axis positive direction of the exterior body main body 110 and is connected to the exterior body main body 110 to cover the opening of the exterior body main body 110. Note that the exterior body main body 110 and the exterior body lid body 120 may be formed of members made of the same material or different materials.

The exterior body main body 110 has a body side connection part 111 and an exterior body fixing part 112, and the exterior body lid body 120 has a lid body side connection part 121. The body side connection part 111 and the lid body side connection part 121 are connected (joined) to each other and are parts that connect (join) the exterior body main body 110 and the exterior body lid body 120 (see FIG. 7). In this embodiment, multiple body side connection parts 111 are arranged in a row at approximately equal intervals on the outer periphery of the exterior body main body 110, and multiple lid body side connection parts 121 are arranged in a row at positions corresponding to the body side connection parts 111 on the outer periphery of the exterior body lid body 120.

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 screws. That is, for example, the lid side connection part 121 has a through hole and a bolt 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). Note that 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 screws. The method of connecting (joining) the exterior body 110 and the exterior body lid 120 may be other methods, such as adhesion, heat sealing, ultrasonic welding, welding, crimping, etc.

The exterior body fixing portion 112 is a portion to which the energy storage unit 200 is fixed. In other words, at least one of a pair of restraining bodies (first restraining body 210 and second restraining body 220) of the energy storage unit 200 is connected (joined) to the exterior body fixing portion 112, thereby fixing at least one of the pair of restraining bodies to the exterior body 100. In this embodiment, a first restraining body fixing portion 218 of the first restraining body 210 described later is connected (joined) to the exterior body fixing portion 112, thereby fixing the first restraining body 210 (energy storage unit 200) to the exterior body main body 110 (see Figures 6 and 7).

Specifically, multiple exterior body fixing parts 112 are arranged in a row at approximately equal intervals around the periphery of the internal space of the exterior body main body 110. In addition, multiple first restraint body fixing parts 218 are arranged in a row at positions corresponding to the exterior body fixing parts 112 of the first restraint body 210 (see FIG. 3). Note that the arrangement positions and number of the exterior body fixing parts 112 and the first restraint body fixing parts 218 are not particularly limited.

The first restraint fixing portion 218 is a bolt portion, and the exterior body fixing portion 112 is a nut portion into which the bolt portion screws. That is, for example, the first restraint fixing portion 218 has a through hole and a bolt inserted into the through hole, and the exterior body fixing portion 112 has a recess and a nut (insert nut) placed in the recess (see FIG. 7). Note that the exterior body fixing portion 112 may be a bolt portion, and the first restraint fixing portion 218 may be a nut portion into which the bolt portion screws. The method of fixing the first restraint 210 (energy storage unit 200) to the exterior body main body 110 may be another method, such as welding, crimping, adhesion, or welding.

In addition, 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 storage elements 230 of the storage unit 200 via a bus bar or the like (not shown), and the 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 of a conductive metal member such as aluminum, an aluminum alloy, copper, or a copper alloy.

In the energy storage unit 200, the multiple energy storage elements 230 are stacked in the Z-axis direction in a horizontally placed (laying on their side) 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 multiple 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 restraining bodies, a first restraining body 210 and a second restraining body 220. A more detailed explanation of the configuration of the energy storage unit 200 will be given later.

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, for example, a damping material made by collecting and bonding mica pieces.

The reinforcing member 400 is a plate-shaped member that is disposed between the exterior cover 120 and the energy storage unit 200, i.e., in the positive Z-axis direction of the energy storage unit 200, and reinforces the energy storage unit 200. The reinforcing member 400 has an elongated shape in the X-axis direction corresponding to the energy storage unit 200 when viewed from the Z-axis direction.

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 long protrusions (protruding ribs) 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 side of the Z axis is recessed in the positive direction of the Z axis and the surface of the reinforcing member 400 on the positive side of the Z axis protrudes in the positive direction of the Z axis. In other words, the reinforcing member 400 has a corrugated plate-like shape formed by folding a plate-shaped member multiple times in the positive and negative directions of the Z axis. Note that the reinforcing member protrusions 410 and 420 can also be said to be recesses because the surface of the reinforcing member 400 on the negative side of the Z axis is recessed in the positive direction of the Z axis.

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

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

The reinforcing member fixing portion 430 is a portion that is fixed to the energy storage unit 200. In other words, the reinforcing member fixing portion 430 is connected (joined) to at least one of a pair of restraining bodies (first restraining body 210 and second restraining body 220) that the energy storage unit 200 has, thereby fixing the reinforcing member 400 to at least one of the pair of restraining bodies. In this embodiment, the reinforcing member fixing portion 430 is connected (joined) to the second restraining body fixing portion 226 of the second restraining body 220 described below, thereby fixing the reinforcing member 400 to the second restraining body 220 (energy storage unit 200) (see Figures 5 and 7).

Specifically, a plurality of reinforcing member fixing portions 430 are arranged in a line at approximately equal intervals in the X-axis direction between the two reinforcing member convex portions 410 and between the reinforcing member convex portions 410 and 420. A plurality of second restraining body fixing portions 226 are arranged in a line at positions corresponding to the reinforcing member fixing portions 430 of the second restraining body 220. Note that the arrangement positions and the number of the reinforcing member fixing portions 430 and the second restraining body fixing portions 226 are not particularly limited.

The second restraint fixing portion 226 is a bolt portion, and the reinforcing member fixing portion 430 is a nut portion into which the bolt portion screws. That is, for example, the second restraint fixing portion 226 has a male thread portion with a thread formed in 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). Note that the reinforcing member fixing portion 430 may be a bolt portion, and the second restraint fixing portion 226 may be a nut portion into which the bolt portion screws. The method of fixing the reinforcing member 400 to the second restraint 220 (energy storage unit 200) may be other methods, such as welding, crimping, adhesion, or welding.

[2. Description of the Configuration of the Energy 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 the present embodiment. Fig. 4 is an exploded perspective view showing each component of the energy storage element 230 according to the present 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.

Fig. 5 is a cross-sectional view showing the configuration of the energy storage unit 200 according to this embodiment together with the reinforcing member 400. Specifically, Fig. 5 shows the configuration when the state in which the reinforcing member 400 is fixed to the energy storage unit 200 is cut along a plane parallel to the XZ plane at the position of the line V-V shown in Fig. 1. Fig. 6 is a cross-sectional view showing the configuration of the energy storage unit 200 according to this embodiment together with the reinforcing member 400 and the exterior body 110. Specifically, Fig. 6 shows the configuration when the state in which the energy storage unit 200 is fixed to the exterior body 110 and the reinforcing member 400 is fixed to the energy storage unit 200 is cut along a plane parallel to the XZ plane at the position of the 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 this 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 the line VII-VII.

As shown in FIG. 3, the energy storage unit 200 has a pair of restraining bodies, a first restraining body 210 and a second restraining body 220, an energy storage element 230, an electrical device 240, and a spacer 250. The energy storage unit 200 also has bus bars and the like that electrically connect the energy storage elements 230 to each other, but illustrations and detailed descriptions are omitted.

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

The number of the storage elements 230 is not particularly limited as long as a plurality of storage elements 230 are arranged in the X-axis direction. Any number of storage elements 230 may be stacked (flat) in the Z-axis direction, or any number of storage elements 230 may be arranged in the X-axis direction. The shape of the storage element 230 is not limited to the above-mentioned square shape, and may be other polygonal prism shapes, cylindrical shapes, elliptical prism shapes, oblong prism shapes, etc. The storage element 230 is not limited to a non-aqueous electrolyte secondary battery, and may be a secondary battery other than a non-aqueous electrolyte secondary battery, or may be a capacitor. The storage element 230 may not be a secondary battery, but may be a primary battery that can use stored electricity without the user having to charge it. Furthermore, the storage element 230 may be a battery using a solid electrolyte. The storage element 230 may be a laminated storage element.

Here, 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, so the following describes the configuration of one storage element 230.

As shown in FIG. 4, the 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 also contains a pair of lower gaskets 230d (positive and negative), a pair of collectors 230e (positive and negative), and an electrode body 230f. An electrolyte (non-aqueous electrolyte) is enclosed inside the container 230a, but is not shown. There is no particular limit to the type of electrolyte as long as it does not impair the performance of the storage element 230, and various electrolytes can be selected. In addition to the above components, spacers arranged on the sides or above the electrode body 230f, or an insulating film that wraps the electrode body 230f, etc. may be arranged.

As shown within the dashed line in FIG. 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, in the following description, the current collector 230e and the electrode body 230f are used, 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.

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 is structured so that the inside can be sealed by welding the container body 230a1 and the container lid 230a2 together after the electrode body 230f and other components are accommodated inside the container body 230a1. The materials of 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.

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. In other words, 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 extending in the X-axis direction on the negative Y-axis side of the container body 230a1.

The electrode body 230f is an electricity storage element (power generation element) formed by stacking a positive electrode plate, a negative electrode plate, and a separator. The positive electrode plate is a positive electrode active material layer formed 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 a negative electrode active material layer formed 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 material used for the positive electrode active material layer and the negative electrode active material layer, any suitable known material can be used as long as it is capable of absorbing and releasing lithium ions.

The electrode body 230f is a laminated (stacked) electrode body formed by stacking multiple flat positive electrode plates and multiple flat negative electrode plates. In contrast, the electrode body 230h is a wound (vertically wound) electrode body formed by winding the plates (positive and negative electrode plates) around a winding axis extending in the X-axis direction. The electrode body of the storage element 230 is not limited to the above-mentioned type of electrode body, and may be any type of electrode body, 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 plates are folded in a bellows shape.

Here, the electrode plates (positive and negative plates) of the electrode body 230f are stacked in the Z-axis direction, so the Z-axis direction is also called the stacking direction. In other words, the electrode body 230f is formed by stacking the electrode plates in the stacking direction. In addition, the electrode body 230h has a pair of curved parts 230j arranged in the Y-axis direction by winding the electrode plates, and a pair of flat parts 230i arranged in the Z-axis direction and connecting the pair of curved parts 230j, and the stacking direction is the stacking direction of the electrode plates in the flat parts 230i. In addition, the direction in which the flat surface of the flat parts 230i faces, or the opposing direction of the pair of flat parts 230i, can also be defined as the stacking direction. Therefore, it can be said that the two first storage elements 231 are aligned in the stacking direction, and the two second storage elements 232 are also aligned in the stacking direction. The same applies to the third storage element 233 and the fourth storage element 234. The X-axis direction in which the first storage element 231 and the second storage element 232 are arranged is also called the arrangement direction. In other words, the first storage element 231 and the second storage element 232 are arranged in an arrangement direction that intersects with the stacking direction.

The electrode terminal 230b is a terminal (positive electrode terminal and negative electrode terminal) of the storage element 230 arranged in the container lid portion 230a2, and is electrically connected to the positive electrode plate and the negative electrode plate of the electrode body 230f via the collector 230e. The electrode terminal 230b is formed of a conductive member such as a metal such as aluminum, an aluminum alloy, copper, or a copper alloy. The collector 230e is a conductive member (positive electrode collector and negative electrode collector) electrically connected to the electrode terminal 230b and the electrode body 230f. The 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 arranged between the container lid portion 230a2 and the electrode terminal 230b and the collector 230e. The upper gasket 230c and the lower gasket 230d are formed of, for example, an insulating member similar to the exterior body 100.

[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 in the positive Z-axis direction or negative Z-axis direction of the energy storage element 230, facing the long side surface of the container 230a 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, and electrically insulate the energy storage element 230 from the adjacent energy storage element 230, the first restraining body 210, or the second restraining body 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 the spacer 250, 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.

The electrical device 240 is an electrical device arranged in the X-axis direction (arrangement direction) of the multiple storage elements 230, such as the first storage element 231 and the second storage element 232. Specifically, the electrical device 240 is arranged in the X-axis positive direction of the storage element 230 (the lower fourth storage element 234) that is furthest in the X-axis positive direction and the Z-axis negative direction among the multiple storage elements 230. The electrical device 240 has electrical components such as a circuit board that monitors the charge and discharge states of the storage elements 230 and controls the charging and discharging of the storage elements 230, fuses, relays, semiconductor switches such as FETs (Field Effect Transistors), shunt resistors, thermistors, and connectors.

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

That is, the first restraint body 210 and the second restraint body 220 are each an integral body (integrally molded product) formed by bending a single plate-like member, etc., and are directly joined to each other to collectively sandwich a plurality of storage elements 230. Specifically, the first restraint body 210 and the second restraint body 220 are directly joined in the X-axis direction (arrangement direction) at a position where the first storage element 231, the second storage element 232, and other storage elements 230 are sandwiched. In addition, the first restraint body 210 and the second restraint body 220 are connected between the storage elements 230 adjacent in the X-axis direction, such as the first storage element 231 and the second storage element 232. In this embodiment, the first restraint body 210 and the second restraint body 220 are directly joined between the storage elements 230 adjacent in the X-axis direction, such as between the first storage element 231 and the second storage element 232. These will be specifically described below.

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

The energy storage element placement section 211 of the first restraint body 210 is a rectangular, plate-like section parallel to the XY plane on which the energy storage element 230 is placed (placed) via the spacer 250. The four energy storage element placement sections 211 are arranged side by side in the X-axis direction in correspondence with the four energy storage elements 230 arranged in the X-axis direction. In this embodiment, the energy storage element placement sections 211 are arranged so as to cover the entire surface of the 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).

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 arranged in the Z-axis direction between the energy storage element arrangement portion 211. Four energy storage element restraining portions 221 are arranged in a line in the X-axis direction corresponding to the four energy storage element arrangement portions 211 arranged in the X-axis direction. In this embodiment, the energy storage element restraining portion 221 is arranged so as to cover the entire surface of the 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).

The first restraining body protrusion 212 of the first restraining body 210 is a protrusion (protruding ridge) that protrudes in a bulging manner in the Z-axis positive direction from the energy storage element arrangement section 211 and extends in the Y-axis direction. Four first restraining body protrusions 212 are arranged between adjacent energy storage element arrangement sections 211 and in the X-axis negative direction of the energy storage element arrangement section 211 on the X-axis negative 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 at a position protruding in the Z-axis positive direction (one step up) from the X-axis positive side end of the energy storage element arrangement section 211 on the X-axis positive side.

The second restraint body protrusion 222 of the second restraint body 220 is a protrusion (protruding ridge) that protrudes in a bulging manner from the energy storage element restraint portion 221 in the negative Z-axis direction and extends 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.

Furthermore, the four first constraint body protrusions 212 and the electrical device arrangement section 213 are provided with first constraint body connection parts 217. Specifically, two first constraint body connection parts 217 are provided at both ends in the Y axis direction of each of the first constraint body protrusions 212 and the X-axis negative direction end of the electrical device arrangement section 213. Furthermore, the five second constraint body protrusions 222 are provided with second constraint body connection parts 227. Specifically, two second constraint body connection parts 227 are provided at positions corresponding to the first constraint body connection parts 217 at both ends in the Y axis direction of each of the second constraint body protrusions 222.

The second constraint body connection portion 227 is then connected (joined) to the first constraint body connection portion 217, thereby fixing the second constraint body 220 to the first constraint body 210. Specifically, as shown in FIG. 5 and FIG. 7, the first constraint body connection portion 217 and the second constraint body connection portion 227 are joined in a state in which the first constraint body convex portion 212 and the second constraint body convex portion 222 are in contact (the first constraint body 210 and the second constraint body 220 are in contact). In this way, the first constraint body 210 and the second constraint body 220 (the first constraint body convex portion 212 and the second constraint body convex portion 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.

Here, the direct joining of the first constraint body 210 and the second constraint body 220 does not mean that they are joined in abutting contact with each other, but means that they are joined without any member that mediates force between them. In other words, even if the first constraint body 210 and the second constraint body 220 are joined with an accessory such as a gasket or washer sandwiched between them, this is included in the concept of the first constraint body 210 and the second constraint body 220 being directly joined.

Specifically, the second restraint body connection part 227 is a bolt part, and the first restraint body connection part 217 is a nut part into which the bolt part is screwed. That is, for example, the second restraint body connection part 227 has a through hole and a bolt inserted into the through hole, and the first restraint body connection part 217 has a through hole and a nut arranged below the through hole (see FIG. 7). Note that the first restraint body connection part 217 may be a bolt part, and the second restraint body connection part 227 may be a nut part into which the bolt part is screwed. In addition, the method of connecting (joining) the second restraint body 220 to the first restraint body 210 may be another method, such as welding, crimping, adhesion, or welding. In addition, the arrangement positions and the number of the first restraint body connection part 217 and the second restraint body connection part 227 are not particularly limited.

The four first constraint body protrusions 212 and the electrical device arrangement section 213 of the first constraint body 210 are provided with the above-mentioned first constraint body fixing sections 218. Specifically, two first constraint body fixing sections 218 are provided on the Y-axis outer side of the two first constraint body connection sections 217 at each of the first constraint body protrusions 212 and the X-axis negative direction end of the electrical device arrangement section 213 (see FIG. 7).

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 in the X-axis direction where the first storage element 230 is sandwiched between the first storage element 231 and the second storage element 232, and between adjacent storage elements 230. In this manner, the first restraint body 210 is fixed to the exterior body 100 at a position in the X-axis direction where the first storage element 231 and the second storage element 232, and other storage elements 230 are sandwiched between the first storage element 231 and the second storage element 232, and other storage elements 230 adjacent to each other in the X-axis direction.

In addition, the four storage element restraint portions 221 of the second restraint body 220 are provided with the above-mentioned second restraint body fixing portion 226. Specifically, in each of the storage element restraint 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 portion 226 is a portion to which the reinforcing member 400 is fixed, and is a cylindrical bolt portion protruding in the Z-axis positive direction from the storage element restraint portion 221. In other words, as shown in FIG. 5, the reinforcing member fixing portion 430 of the reinforcing member 400 is connected (joined) to the second restraint body fixing portion 226, thereby fixing the reinforcing member 400 to the second restraint body 220. As a result, the reinforcing member 400 is arranged in the Z-axis positive direction (the stacking direction) of the multiple storage elements 230 such as the first storage element 231 and the second storage element 232. Additionally, the reinforcing member protrusions 410 and 420 protrude in the positive Z-axis direction (the stacking direction) and extend in the X-axis direction (the arrangement direction).

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 from the reinforcing member 400 in the X-axis direction (the arrangement direction). In other words, the reinforcing member 400 is formed so that it extends at least to the X-axis edge of at least one of the first storage element 231 and the second storage element 232 in the X-axis direction. In other words, at least a portion of the reinforcing member 400 overlaps with the X-axis edge of at least one of the first storage element 231 and the second storage element 232 when viewed from the Z-axis direction.

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

More specifically, the reinforcing member 400 is formed so that the electrical equipment 240 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 that it extends at least to the edge of the electrical equipment 240 in the X-axis direction in the X-axis direction. In other words, at least a portion of the reinforcing member 400 overlaps with the edge of the electrical equipment 240 in the X-axis direction when viewed from the Z-axis direction.

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

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 be approximately the same length as the first restraining body 210 in the Y-axis direction as well. Therefore, the reinforcing member 400 protrudes further than all of the storage elements 230 and electrical equipment 240 on both sides in the Y-axis direction. As a result, the multiple storage elements 230 and electrical equipment 240 are protected by the first restraining 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 restraining body 210 in the Y-axis direction.

Furthermore, similar to the reinforcing member 400, the reinforcing member protrusions 410 and 420 are formed so that at least one of the first storage element 231 and the second 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 edge of at least one of the first storage element 231 and the second storage element 232 in the X-axis direction. In other words, at least a portion of the reinforcing member protrusions 410 and 420 overlaps with the X-axis edge of at least one of the first storage element 231 and the second storage element 232 when viewed from the Z-axis direction.

The reinforcing member protrusion 410 is formed so that the electrical 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 at least to the edge of the electrical device 240 in the X-axis direction in the X-axis direction. In other words, at least a portion of the reinforcing member protrusion 410 overlaps with the edge of the electrical device 240 in the X-axis direction when viewed from the Z-axis direction.

In this 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 storage elements 230 and the electrical equipment 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 storage elements 230 on both sides in the X-axis direction. In this embodiment, the reinforcing member protrusion 420 does not protrude beyond the electrical equipment 240, but may be configured to protrude beyond the electrical equipment 240.

[3. Description of Effects]
As described above, according to the energy storage device 10 according to the embodiment of the present invention, 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) intersecting with the stacking direction (Z-axis direction) of the electrode plates of the electrode body 230f. The reinforcing member 400 has the reinforcing member protrusions 410 and 420 that protrude in the stacking direction and extend in the arrangement direction. Here, 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 intersecting with the stacking direction of the electrode plates of the electrode body 230f, the length of the energy storage device 10 in the arrangement direction becomes long, which may weaken the strength of the energy storage device 10 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 the reinforcing member protrusions 410 and 420 that protrude in the stacking direction and extend in the arrangement direction. This improves the strength of the reinforcing member 400 in the arrangement direction, thereby improving protection of the storage elements 230, such as the first storage element 231 and the second storage element 232, in the arrangement direction.

The reinforcing member 400 can also 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. In particular, the reinforcing member 400 is a corrugated plate and can absorb forces in the stacking direction, improving protection of the first storage element 231 and the second storage element 232 in the stacking direction.

In addition, since the reinforcing member 400 is a metallic (conductive) member, it can dissipate heat generated from the storage elements 230, such as the first storage element 231 and the second storage element 232. In particular, since the reinforcing member 400 is a corrugated plate and a space is formed on the storage element 230 side, the air heated by the heat moves through the space, thereby dissipating heat. In addition, since the reinforcing member 400 is a corrugated plate, it can be easily manufactured and can also be made lightweight.

In addition, 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, so that when an external impact or the like is applied in the arrangement direction, the reinforcing member 400 receives the force of the impact or the like. This can further improve 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.

The reinforcing member protrusions 410 and 420 are 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. 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 receives 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.

In addition, since the reinforcing member 400 is formed so that the electrical equipment 240 does not protrude in the arrangement direction, when an external impact or the like is applied to the electrical equipment 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 electrical equipment 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 electrical equipment 240 does not protrude in the arrangement direction, so that the protection of the electrical equipment 240 can be further improved in the same manner as above.

The reinforcing member 400 can also protect the reinforcing member 400 side of the electrical device 240 in the stacking direction. In particular, the reinforcing member 400 is a corrugated plate and can absorb forces in the stacking direction, improving protection of the electrical device 240 in the stacking direction.

In addition, since the reinforcing member 400 is fixed to at least one of a pair of restraining bodies that collectively hold the storage elements 230, such as the first storage element 231 and the second storage element 232, the reinforcing member 400 can be fixed to the storage elements 230, such as the first storage element 231 and the second storage element 232. This makes it possible to prevent the reinforcing member 400 from shifting relative to the storage elements 230, such as the first storage element 231 and the second storage element 232, so that the storage elements 230, such as the first storage element 231 and the second storage element 232, can be more reliably protected.

In addition, in order to more firmly restrain the first storage element 231 and the second storage element 232, a pair of restraining bodies are connected between the first storage element 231 and the second storage element 232. However, in this case, the gap between the first storage element 231 and the second storage element 232 becomes larger, and the strength in the arrangement direction of the first storage element 231 and the second storage element 232 becomes weaker. 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 improve 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.

The storage elements 230, such as the first storage element 231 and the second 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 the electrode body 230f. A pair of restraining bodies (the first restraining body 210 and the second restraining body 220) are directly joined together to sandwich the storage elements 230, such as the first storage element 231 and the second storage element 232, together in the stacking direction.

Here, the storage elements 230 such as the first storage element 231 and the second storage element 232 swell in the stacking direction of the electrode plates of the electrode body 230f. For this reason, when the storage elements 230 such as the first storage element 231 and the second storage element 232 are arranged in an arrangement direction intersecting with the stacking direction, it is necessary to suppress the swelling 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. For this reason, 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.

In addition, the storage elements 230, such as the first storage element 231 and the second storage element 232, have a metal container 230a to prevent swelling, but even if the container 230a is made of metal, it will still swell, so it is necessary to firmly clamp the storage element 230 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 the joints loosening. For this reason, the pair of restraining bodies are joined directly. This reduces the number of joints, reducing the risk of the joints loosening, and also simplifies the configuration by reducing the number of parts.

In this manner, in a configuration in which multiple storage elements 230 (such as the first storage element 231 and the second storage element 232) are sandwiched between a pair of restraining bodies in a direction intersecting the arrangement direction, it is possible to easily suppress the swelling of the multiple storage elements 230.

In addition, since the pair of restraining bodies are directly joined in the arrangement direction at a position that sandwiches the storage elements 230, such as the first storage element 231 and the second storage element 232, the storage elements 230, such as the first storage element 231 and the second storage element 232, can be easily sandwiched together. This makes it possible to easily suppress swelling of the multiple storage elements 230 (the first storage element 231 and the second storage element 232, etc.) by the pair of restraining bodies.

In addition, since the pair of restraining bodies are directly joined between the first storage element 231 and the second storage element 232, the first storage element 231 and the second storage element 232 can be clamped simply and more firmly. This makes it possible to easily suppress swelling of the multiple storage elements 230 (the first storage element 231 and the second storage element 232) by the pair of restraining bodies. The same applies to the third storage element 233 and the fourth storage element 234.

In addition, in a configuration in which a plurality of first storage elements 231 and second storage elements 232 are arranged in the stacking direction, a pair of restraining bodies clamp the plurality of first storage elements 231 and the plurality of second storage elements 232 together in the stacking direction. This allows the plurality of first storage elements 231 and the plurality of second storage elements 232 to be easily clamped together by the pair of restraining bodies, making it possible to easily suppress swelling of the plurality of first storage elements 231 and the plurality of second storage elements 232. The same applies to the third storage element 233 and the fourth storage element 234.

In addition, since at least one of the pair of restraining bodies is fixed to the exterior body 100, the storage elements 230, such as the first storage element 231 and the second storage element 232, can be easily fixed to the exterior body 100. This makes it possible to easily prevent the storage elements 230, such as the first storage element 231 and the second storage element 232, from moving within the exterior body 100 even if vibrations, impacts, etc. are applied to the storage device 10.

In addition, 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, impacts, etc. are applied to the storage device 10. The same applies to the third storage element 233 and the fourth storage element 234.

[4. Description of Modifications]
Next, a modified example of the above embodiment will be described. FIG. 8 is a perspective view showing the configuration of the energy storage device 20 according to the modified example of the present embodiment. Specifically, FIG. 8 is a perspective view showing the inside of the exterior body 100 with the exterior body cover 120 removed from the energy storage device 20. FIG. 9 is an exploded perspective view showing each component inside the exterior body 100 of the energy storage device 20 according to the modified example of the present embodiment. FIG. 9 is a view corresponding to FIG. 3. FIG. 10 is a perspective view showing the configuration of a reinforcing member 510 according to the modified example of the present embodiment. Specifically, FIG. 10(a) is a view of the reinforcing member 510 when viewed obliquely from above, and FIG. 10(b) is a view of the reinforcing member 510 when viewed obliquely from below.

As shown in Figures 8 to 10, the energy storage device 20 in this modified example includes a first constraint 500 and a second constraint 600 instead of the exterior body main body 110, heat insulating sheet 300, reinforcing member 400, first constraint 210, and second constraint 220 included in the energy storage device 10 in the above embodiment. In other words, in this modified example, the first constraint 500 combines the functions of the exterior body main body 110, reinforcing member 400, and first constraint 210 in the above embodiment. The other configurations are the same as those in the above embodiment, so detailed explanations will be omitted.

In this modified example, the first restraint 500 is a flat rectangular member on which the energy storage element 230 and the electrical device 240 are placed and fixed. The exterior body cover 120 is a bottomed rectangular tubular member that is arranged in the Z-axis positive direction of the first restraint 500 and is connected to the first restraint 500 to cover the energy storage element 230 and the electrical device 240. That is, an opening is formed in the exterior body cover 120 on the Z-axis negative direction side, and the first restraint 500 is arranged to close the opening of the exterior body cover 120. Specifically, the first restraint 500 has a body side connection portion 501, and the body side connection portion 501 is connected (joined) to the cover side connection portion 121 of the exterior body cover 120, thereby connecting (joining) the first restraint 500 and the exterior body cover 120. The method for connecting (joining) the body side connection part 501 and the lid side connection part 121 is the same as in the above embodiment, so a detailed description will be omitted. The first restraint body 500 and the exterior body lid body 120 are made of the same material as the first restraint body 210 and the exterior body lid body 120 in the above embodiment.

The first restraint body 500 has a reinforcing member 510 and two connecting members 520 arranged at both ends of the reinforcing member 510 in the positive Z-axis direction and the Y-axis direction.

The reinforcing member 510 is a plate-like member that constitutes the main body of the first restraining body 500, and is disposed so as to protrude from all the energy storage elements 230 and the electrical equipment 240 on both sides in the X-axis direction and on both sides in the Y-axis direction. The reinforcing member 510 has a reinforcing member protrusion 511. The reinforcing member protrusion 511 is a long protrusion (protruding stripe portion) that protrudes in the negative Z-axis direction (the stacking direction) and extends in the X-axis direction (the arrangement direction). Specifically, the reinforcing member protrusion 511 is a bulging portion in which the surface of the reinforcing member 510 on the positive Z-axis side is recessed in the negative Z-axis direction and the surface of the reinforcing member 510 on the negative Z-axis side protrudes in the negative Z-axis direction. In this modified example, four reinforcing member protrusions 511 are disposed side by side in the Y-axis direction.

In addition, the reinforcing member protrusion 511 is formed so that at least one of the first storage element 231 and the second storage element 232 does not protrude from the reinforcing member protrusion 511 in the X-axis direction (arrangement direction). In other words, the reinforcing member protrusion 511 is formed so that it extends at least to the edge in the X-axis direction of at least one of the first storage element 231 and the second storage element 232 in the X-axis direction. In other words, at least a portion of the reinforcing member protrusion 511 overlaps with the edge in the X-axis direction of at least one of the first storage element 231 and the second storage element 232 when viewed from the Z-axis direction. In addition, the reinforcing member protrusion 511 is formed so that the electrical device 240 does not protrude from the reinforcing member protrusion 511 in the X-axis direction (arrangement direction). In other words, the reinforcing member protrusion 511 is formed so that it extends at least to the edge in the X-axis direction of the electrical device 240 in the X-axis direction. In other words, at least a portion of the reinforcing member protrusion 511 overlaps with the edge of the electrical device 240 in the X-axis direction when viewed from the Z-axis direction. In this modified example, the reinforcing member protrusion 511 protrudes beyond all of the energy storage elements 230 and electrical device 240 on both sides in the X-axis direction.

In this way, the reinforcing member 510 is configured to be reinforced in the X-axis direction by the reinforcing member protrusion 511. Note that the reinforcing member protrusion 511 does not extend to the edge of the reinforcing member 510 in the X-axis direction, but may extend to the edge of the reinforcing member 510 in the X-axis direction. In other words, the reinforcing member 510 may have a shape like a corrugated sheet. In this modified example, the reinforcing member protrusion 511 has a trapezoidal or triangular shape when viewed from the X-axis direction, but may have any shape when viewed from the X-axis direction, such as a trapezoidal shape such as a rectangle or a polygonal shape other than a triangular shape, a semicircular shape, a semi-elliptical shape, a semi-oval shape, or the like. Note that the reinforcing member protrusion 511 can also be called a recess because the surface of the reinforcing member 510 on the positive Z-axis side is recessed in the negative Z-axis direction.

The connection member 520 is an L-shaped member extending in the X-axis direction when viewed from the X-axis direction, and is placed and fixed on the reinforcing member 510 (the surface on the Z-axis positive side of the reinforcing member protrusion 511). Two connection members 520 are arranged at positions sandwiching the energy storage element 230 in the Y-axis direction. The connection members 520 are fixed to the reinforcing member 510 by welding, for example, but may be fixed to the reinforcing member 510 by a method other than welding, such as screwing, adhesive bonding, crimping, or welding.

The connecting member 520 is provided with a plurality of first constraint body connection parts 521 arranged in the X-axis direction. The first constraint body connection parts 521 are connected (joined) to the second constraint body connection parts 611 of the second constraint body 600, thereby fixing the second constraint body 600 to the first constraint body 500. In this modified example, a total of eight first constraint body connection parts 521 are provided in one connecting member 520, corresponding to the two second constraint body connection parts 611 of each of the four members, the first member 601 to the fourth member 604 of the second constraint body 600. The first constraint body connection parts 521 are bolt parts, and the second constraint body connection parts 611 are nut parts into which the bolt parts are screwed. The positions and numbers of the first constraint body connection parts 521 and the second constraint body connection parts 611 are not particularly limited, and the method of fixing the second constraint body 600 to the first constraint body 500 is also not particularly limited.

The second restraining body 600 is a member that is joined (directly joined) to the first restraining body 500 and sandwiches the storage elements 230, such as the multiple first storage elements 231 and the multiple second storage elements 232, in the Z-axis direction with the first restraining body 500. The second restraining body 600 is formed of a metal member or the like similar to the first restraining body 500. The second restraining body 600 has a first member 601, a second member 602, a third member 603, and a fourth member 604. The first members 601 to the fourth member 604 are each separate members and are arranged at a distance from each other. The first member 601 is directly joined to the first restraining body 500 in the Y-axis direction (a cross direction that crosses the stacking direction and the arrangement direction) at a position where the first storage element 231 is sandwiched, and the first restraining body 500 sandwiches the first storage element 231. The same applies to the second member 602, etc.

In this way, the first restraint body 500 is arranged extending in the X-axis direction so as to straddle the first storage element 231, the second storage element 232, the third storage element 233, and the fourth storage element 234. The second restraint body 600 has individual members that restrain each of the first storage element 231, the second storage element 232, the third storage element 233, and the fourth storage element 234 with the first restraint body 500.

As described above, the energy storage device according to this modification can achieve the same effects as the above embodiment. In particular, in this modification, the first restraint body 500 having the reinforcing member 510 serves the functions of the exterior body main body 110, the reinforcing member 400, and the first restraint body 210 in the above embodiment, thereby simplifying the configuration.

The first storage element 231 is sandwiched between the first restraint 500 and the first member 601 of the second restraint 600, and the second storage element 232 is sandwiched between the first restraint 500 and the second member 602 of the second restraint 600. This allows the first storage element 231 and the second storage element 232 to be handled as a single unit by the first restraint 500, and the swelling of the first storage element 231 and the second storage element 232 can be individually suppressed. Therefore, even if the swelling amount of the first storage element 231 is large, for example, it is possible to suppress the influence on the suppression of the swelling of the second storage element 232, and therefore the swelling of the first storage element 231 and the second storage element 232 can be effectively suppressed. The same applies to the third storage element 233 and the fourth storage element 234.

In addition, when the first restraining body 500 and the first member 601 are joined between the first storage element 231 and the second storage element 232, the gap between the first storage element 231 and the second storage element 232 becomes large. Therefore, the first restraining body 500 and the first member 601 are joined at a position sandwiching the first storage element 231 in the intersecting direction (Y-axis direction) intersecting the stacking direction and the arrangement direction. This makes it possible to reduce the gap between the first storage element 231 and the second storage element 232 (the gap in the arrangement direction), thereby enabling space saving and strength improvement in the arrangement direction. In this way, it is possible to effectively suppress the swelling of the multiple storage elements 230 while achieving space saving and strength improvement. The same applies to the joining of the first restraining body 500 to other members such as the second member 602.

In the above modified example, the exterior body 100 has the exterior body cover 120 as a bottomed rectangular tubular member with an opening formed on the negative Z-axis side, and the first restraint body 500 as a flat rectangular member that covers the opening of the exterior body cover 120. However, the first restraint body 500 may be a bottomed rectangular tubular member with an opening formed on the positive Z-axis side, and the exterior body cover 120 may be a flat rectangular cover that covers the opening of the first restraint body 500, or may have any other shape.

In the above modified example, the first restraint body 500 is arranged in the negative Z-axis direction of the energy storage element 230, and the second restraint body 600 is arranged in the positive Z-axis direction of the energy storage element 230, and they are joined to each other. However, the first restraint body 500 may be arranged in the positive Z-axis direction of the energy storage element 230, and the second restraint body 600 may be arranged in the negative Z-axis direction of the energy storage element 230, and they may be joined to each other. In other words, the energy storage device 20 may have a configuration in which the top and bottom are reversed.

In the above modification, the reinforcing member 510 and the connecting member 520 in the first restraining body 500 are separate members. However, the reinforcing member 510 and the connecting member 520 may be formed integrally.

In addition, in the above modified example, the first restraining body 500 is part of the exterior body 100. However, the first restraining body 500 may be a separate member from the exterior body 100. In this case, the energy storage device 20 may not include the exterior body 100. Alternatively, the energy storage device 20 may not include the exterior body cover 120 in the configuration of the above modified example.

(Other Modifications)
Although the embodiment of the present invention and the modified examples thereof have been described above, the present invention is not limited to these embodiments and the modified examples. In other words, the embodiment and the modified examples disclosed herein are illustrative and not restrictive in all respects, and the scope of the present invention is defined by the claims, and includes all modifications within the meaning and scope equivalent to the claims.

For example, 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. Also, in the above modified example, the reinforcing member 510 is arranged in the negative direction of the Z axis of the energy storage element 230. However, in addition to the reinforcing member 510, another reinforcing member may be arranged in the positive direction of the Z axis of the energy storage element 230.

In the above embodiment, the reinforcing member 400 protrudes from all the storage elements 230 and the electrical equipment 240 on both sides in the X-axis direction and both sides in the Y-axis direction. However, the storage elements 230 or the electrical equipment 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 storage elements 230 and the electrical equipment 240 can be protected compared to the case where the reinforcing member 400 is not arranged. Furthermore, at least the storage elements 230 that do not protrude from the reinforcing member 400 can be protected. The same applies to the reinforcing member 510 in the above modified example. That is, the reinforcing member 510 may be formed so that at least one of the first storage element 231 and the second storage element 232 does not protrude from the reinforcing member 510, or the electrical equipment 240 does not protrude from the reinforcing member 510, for example, in either the X-axis direction or the Y-axis direction. The same applies to the reinforcing member protrusions 410 and 420 in the above embodiment and the reinforcing member protrusion 511 in the above modified example.

In the above embodiment, the reinforcing member protrusions 410 and 420 are bulging protrusions that extend continuously in a straight line in the X-axis direction. However, the reinforcing member protrusions 410 and 420 may be protrusions in which the surface of the reinforcing member 400 on the negative Z-axis side does not recess 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. Alternatively, the reinforcing member protrusions 410 and 420 may be protrusions that protrude in the negative Z-axis direction. The reinforcing member protrusions 410 and 420 may be multiple protrusions that are intermittently formed in the X-axis direction, or may be protrusions that extend in a curved manner in the X-axis direction rather than extending in a straight line in the X-axis direction. Furthermore, the reinforcing member protrusions 410 and 420 may be protrusions that extend in a direction inclined from the X-axis direction to the Y-axis direction. The same applies to the reinforcing member protrusions 511 in the above modified example.

In addition, in the above embodiment, the reinforcing member 400 is fixed to the second restraint body 220. However, the reinforcing member 400 may be fixed to the first restraint body 210. Alternatively, the reinforcing member 400 may not be fixed to either the first restraint body 210 or the second restraint body 220.

In addition, in the above embodiment and its modified example, the first constraint body 210 and the second constraint body 220 are directly joined. However, the first constraint body 210 and the second constraint body 220 do not have to be directly joined, and a separate member may be disposed between the first constraint body 210 and the second constraint body 220. The same applies to the first constraint body 500 and the second constraint body 600 in the modified example.

In the above embodiment, the first restraint body 210 and the second restraint body 220 are joined in the X-axis direction at a position where the plurality of storage elements 230 are sandwiched between them and between adjacent storage elements 230. However, the first restraint body 210 and the second restraint body 220 may be joined at any position, for example, they may not be joined at one or both of the positions where the plurality of storage elements 230 are sandwiched between them, or they may not be joined between adjacent storage elements 230. In the above modified example, the first restraint body 500 and the first member 601 of the second restraint body 600 are joined at a position where the storage element 230 is sandwiched between them in the Y-axis direction. However, the first restraint body 500 and the second restraint body 600 may be joined at any position, for example, they may be joined at a position where the storage element 230 is sandwiched between them in the X-axis direction.

In addition, in the above embodiment, the energy storage device 10 includes a plurality of first storage elements 231 and a plurality of second storage elements 232, etc., arranged in the Z-axis direction, and the first restraint body 210 and the second restraint body 220 sandwich these together in the Z-axis direction. However, the energy storage device 10 may include only one first storage element 231 and one second storage element 232, etc., in the Z-axis direction, and the first restraint body 210 and the second restraint body 220 may sandwich this one first storage element 231 and one second storage element 232, etc. together. The same applies to the energy storage device 20 in the above modified example.

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, for example, with one end side in the X-axis direction or one end side in the Y-axis direction connected. 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.

In the above embodiment, the first constraint 210 and the second constraint 220 have convex portions (first constraint convex portion 212 and second constraint convex portion 222) that protrude toward the other side, and these convex portions are joined together. However, at least one of the first constraint 210 and the second constraint 220 may have a convex portion that protrudes in a direction away from the other side, and they may be joined at the convex portion, or they may not have a convex portion and may be joined at a flat portion.

In the above embodiment, the first constraint 210 is fixed to the exterior body 110 of the exterior body 100. However, the first constraint 210 may be fixed to the exterior body lid 120. Also, instead of the first constraint 210, or in addition to the first constraint 210, the second constraint 220 may be fixed to the exterior body body 110 or the exterior body lid 120. In other words, it is sufficient that at least one of the first constraint 210 and the second constraint 220 is fixed to at least one of the exterior body body 110 and the exterior body lid 120. Alternatively, both the first constraint 210 and the second constraint 220 may not be fixed to either the exterior body body 110 or the exterior body lid 120.

In the above embodiment, the first restraint body 210 is fixed to the exterior body 100 at a position in the X-axis direction where the multiple storage elements 230 are sandwiched and between adjacent storage elements 230. However, the first restraint body 210 may be fixed to the exterior body 100 at any position, and for example, the first restraint body 210 may not be fixed to the exterior body 100 at one or both of the positions where the multiple storage elements 230 are sandwiched, or may not be fixed to the exterior body 100 between adjacent storage elements 230. Also, instead of or in addition to the first restraint body 210, a second restraint body 220 may be fixed to the exterior body 100.

Furthermore, the energy storage device does not need to include all of the components described above. For example, in the above embodiment, the energy storage device 10 does not need to include the insulating sheet 300, the electrical equipment 240, or the spacer 250, etc.

In addition, configurations constructed by arbitrarily combining the components included in the above embodiments and their variations are also included within the scope of the present invention.

In addition, the present invention can be realized not only as an electricity storage device, but also as a reinforcing member.

The present invention can be applied to a storage device equipped with a storage element such as a lithium-ion secondary battery.

REFERENCE SIGNS LIST 10, 20 Energy storage device 100 Exterior body 110 Exterior body main body 112 Exterior body fixing portion 200 Energy storage unit 210, 500 First restraining body 211 Energy storage element arrangement portion 212 First restraining body protrusion portion 213 Electrical device arrangement portion 217, 521 First restraining body connecting portion 218 First restraining body fixing portion 220, 600 Second restraining body 221 Energy storage element restraining portion 222 Second restraining body protrusion portion 226 Second restraining body fixing portion 227, 611 Second restraining body connecting portion 230 Energy storage element 230a Container 230f Electrode body 231 First energy storage element 232 Second energy storage element 233 Third energy storage element 234 Fourth energy storage element 240 Electrical device 400, 510 Reinforcing member 410, 420, 511 Reinforcing member protruding portion 430 Reinforcing member fixing portion

Claims (8)

Two electric storage elements each having an electrode body in which 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 reinforcing member disposed in the stacking direction of the first energy storage element and the second energy storage element;
a pair of constraint 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;
the reinforcing member has a protrusion that protrudes in the stacking direction and extends in the arrangement direction. The power storage device according to claim 1 , wherein the reinforcing member is fixed to at least one of the pair of restraining bodies. The energy storage device according to claim 1 , wherein the pair of constraint bodies are connected between the first energy storage element and the second energy storage element. Two electric storage elements each having an electrode body in which 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 reinforcing member disposed in the stacking direction of the first energy storage element and the second energy storage element;
a restraint body that collectively sandwiches the first storage element and the second storage element between the reinforcing member and the restraint body in the stacking direction,
The reinforcing member has a protrusion protruding in the stacking direction and extending in the arrangement direction,
The restraining body includes a plurality of separate members that individually restrain the first power storage element and the second power storage element, respectively.
Energy storage device. Two electric storage elements each having an electrode body in which 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 reinforcing member disposed in the stacking direction of the first energy storage element and the second energy storage element;
An electrical device,
The reinforcing member has a protrusion protruding in the stacking direction and extending in the arrangement direction,
The reinforcing member is formed so that the electrical device does not protrude from the reinforcing member in the arrangement direction or in a direction intersecting the stacking direction and the arrangement direction.
Energy storage device. the electrical device is disposed in the arrangement direction of the first storage element and the second storage element,
The power storage device according to claim 5 , wherein the reinforcing member is formed so that the electrical device does not protrude from the reinforcing member in the arrangement direction. The energy storage device according to claim 1 , wherein the reinforcing member is formed so that at least one of the first energy storage element and the second energy storage element does not protrude from the reinforcing member in the arrangement direction. The energy storage device according to claim 1 , wherein the convex portion is formed such that at least one of the first energy storage element and the second energy storage element does not protrude from the convex portion in the arrangement direction.

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