Energy storage device

Abstract

To provide a power storage device that protects a power storage element included therein from external impact, while suppressing an increase in size and weight of the power storage device.SOLUTION: A power storage device 1 includes a plurality of power storage elements 100 and reinforcing members 50. The plurality of power storage elements 100 are arranged side by side in a first direction (Y-axis direction). The reinforcing member 50 includes: a first plate portion 53 that is arranged between two adjacent power storage elements 100 among the plurality of power storage elements 100; and a second plate portion 54 that intersects with the first plate portion 53. The first plate portion 53 and the second plate portion 54 are connected to each other at a connection portion 51 that extends in a second direction (X-axis direction) orthogonal to the Y-axis direction. The width of at least one of the first plate portion 53 and the second plate portion 54 in the X-axis direction is larger than the width of at least one of the two power storage elements 100 in the X-axis direction.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a power storage device including a plurality of power storage elements.

Background Art

[0002] Patent Document 1 discloses a battery module including a battery assembly, a partition wall located between the battery assemblies, an end plate surrounding the battery assembly and the partition wall in a sandwich structure, and a base plate located below the battery assembly, the partition wall, and the end plate. In this battery module, the partition wall is provided in parallel with the battery assemblies and protrudes from the regions between the battery assemblies and is exposed from the battery assemblies.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Generally, battery cells (energy storage elements) are susceptible to crushing when subjected to a large external impact. In the conventional battery module (energy storage device) described above, it is believed that the partition walls (reinforcement members) exposed from the battery assembly prevent the direct transmission of external force to the battery assembly when an external force is applied from a direction perpendicular to the arrangement direction of the partition walls (the direction in which the multiple energy storage elements are arranged). However, the inventors of this invention have found that in the structure of the conventional battery module (energy storage device) described above, the battery cells (energy storage elements) may not be adequately protected from impact depending on the thickness of the partition walls (reinforcement members). To enhance the protection of the energy storage elements, it is necessary to increase the bending rigidity of the reinforcement members. To increase the bending rigidity of the reinforcement members, it is conceivable to increase the thickness of the reinforcement members in the direction perpendicular to the direction in which the impact is applied. However, increasing the thickness of the reinforcement members increases the external size of the energy storage device and increases its weight. Furthermore, if the external size of the energy storage device is not to be increased, it may be difficult to place thick reinforcement members. Therefore, the inventors of this application have diligently studied how to protect the energy storage elements of an energy storage device from external shocks while suppressing an increase in size and weight of the energy storage device. [Means for solving the problem]

[0005] An energy storage device according to one aspect of the present invention is an energy storage device comprising a plurality of energy storage elements and a reinforcing member, wherein the plurality of energy storage elements are arranged in a first direction, and the reinforcing member has a first plate portion arranged between two adjacent energy storage elements among the plurality of energy storage elements and a second plate portion intersecting the first plate portion, the first plate portion and the second plate portion are connected at a connecting portion extending in a second direction perpendicular to the first direction, and the width of at least one of the first plate portion and the second plate portion in the second direction is greater than the width of at least one of the two energy storage elements in the second direction. [Effects of the Invention]

[0006] According to the present invention, it is possible to protect the energy storage elements of an energy storage device from external shocks while suppressing an increase in the size and weight of the energy storage device. [Brief explanation of the drawing]

[0007] [Figure 1] This is a perspective view showing the external appearance of the energy storage device according to the embodiment. [Figure 2] This is an exploded perspective view of the energy storage device according to the embodiment. [Figure 3] This is a side view showing an example of the arrangement positions and orientations of multiple reinforcing members in an energy storage element unit according to an embodiment. [Figure 4] This is an enlarged view of the boundary between the reinforcing member and the container of the energy storage element according to the embodiment. [Figure 5] This is a perspective view of the energy storage element and reinforcing member according to the embodiment. [Figure 6] This is a front view of the energy storage element and reinforcing member according to the embodiment. [Figure 7] This is a side view showing a part of the reinforcing member according to a modified example 1 of the embodiment. [Figure 8] This is a side view showing a reinforcing member according to a modified example 2 of the embodiment. [Modes for carrying out the invention]

[0008] An energy storage device according to one aspect of the present invention is an energy storage device comprising a plurality of energy storage elements and a reinforcing member, wherein the plurality of energy storage elements are arranged in a first direction, and the reinforcing member has a first plate portion arranged between two adjacent energy storage elements among the plurality of energy storage elements and a second plate portion intersecting the first plate portion, the first plate portion and the second plate portion are connected at a connecting portion extending in a second direction perpendicular to the first direction, and the width of at least one of the first plate portion and the second plate portion in the second direction is greater than the width of at least one of the two energy storage elements in the second direction.

[0009] As described above, the inventors of the present invention have diligently studied how to protect the energy storage elements from external impacts while suppressing an increase in the size and weight of the energy storage device. Specifically, the inventors of the present invention have studied how to increase the bending rigidity of the reinforcing members by devising the shape of the reinforcing members, and have devised the energy storage device according to the above embodiment.

[0010] In this configuration, the reinforcing member has a first plate portion and a second plate portion that extend in directions intersecting each other and are connected to each other at a connection portion, with the first plate portion positioned between two adjacent energy storage elements among a plurality of energy storage elements arranged in a first direction. In the second direction, which is the direction in which the connection portion extends and is perpendicular to the first direction, the width of at least one of the first plate portion and the second plate portion is greater than the width of the energy storage element. Therefore, when an impact is applied from the second direction, the reinforcing member receives at least a portion of the impact. As a result, when an impact is applied from the second direction, the reinforcing member can protect the energy storage element from the impact.

[0011] Generally, restraining members or casings of a power storage device are positioned to the side of the power storage element in the second direction, or structures of the vehicle on which the power storage device is mounted or the facility where the power storage device is installed are positioned to the side of the power storage element in the second direction. Therefore, even if an impact is applied from the second direction and the reinforcing member or power storage element moves in the second direction, the structure positioned to the side of the power storage element in the second direction can stop the movement of the reinforcing member or power storage element in the second direction. For this reason, if the width of at least one of the first plate portion and the second plate portion is greater than the width of the power storage element in the second direction, the reinforcing member can protect the power storage element from impact when an impact is applied from the second direction.

[0012] Furthermore, since the connecting portion between the first plate portion and the second plate portion extends in the second direction, even when the first plate portion and the second plate portion are formed of a relatively thin plate material, a relatively high bending rigidity (the difficulty of bending in the direction orthogonal to the second direction, hereinafter also simply referred to as "rigidity") can be obtained. Thereby, even when the first plate portion and the second plate portion are formed of a relatively thin plate material, the power storage element can be protected against impacts from the second direction. Therefore, it is possible to protect the power storage element from external impacts while suppressing an increase in the size and weight of the power storage device.

[0013] The widths of both the first plate portion and the second plate portion in the second direction may be larger than the width of the at least one power storage element in the second direction.

[0014] According to this configuration, since the power storage element can be protected by both the first plate portion and the second plate portion, the power storage element can be more reliably protected against impacts from the second direction.

[0015] The width of the connecting portion in the second direction may be larger than the width of the at least one power storage element in the second direction.

[0016] According to this configuration, at least one end of the connecting portion is arranged to protrude in the second direction from the power storage element adjacent to the reinforcing member. Thereby, when an impact is applied from the second direction, it becomes difficult for the first plate portion and the second plate portion to buckle on the one end side. Therefore, the power storage element can be more reliably protected against impacts from the second direction.

[0017] The at least one power storage element has a first end portion where electrode terminals are arranged, the reinforcing member is made of metal, and the second plate portion may be arranged to face a second end portion which is an end portion on the opposite side of the at least one power storage element from the first end portion.

[0018] According to this configuration, since the reinforcing member is formed of a metal having higher rigidity than resin or the like, the rigidity of the reinforcing member can be further increased. Therefore, it is possible to more reliably protect the power storage element when an impact is applied from the second direction. Further, the second plate portion is disposed along the second end portion of the power storage element adjacent to the reinforcing member, which is opposite to the first end portion where the electrode terminal is disposed. Even when the reinforcing member is formed of a metal, since the second plate portion is disposed at a position relatively far from the electrode terminal, the occurrence of a short circuit due to the second plate portion is suppressed. Thereby, while suppressing the occurrence of a short circuit, it is possible to more reliably protect the power storage element against an impact from the second direction.

[0019] The at least one power storage element may have a first end portion where an electrode terminal is disposed, the reinforcing member may be made of metal, and the first plate portion may extend along the at least one power storage element from the connecting portion toward the first end portion and may have a shape that does not overlap with the electrode terminal when viewed from the first direction.

[0020] According to this configuration, since the reinforcing member is formed of a metal having higher rigidity than resin or the like, the rigidity of the reinforcing member can be further increased. Therefore, it is possible to more reliably protect the power storage element when an impact is applied from the second direction. Further, since the first plate portion has a shape that does not overlap with the electrode terminal when viewed from the first direction, even when the reinforcing member is formed of a metal, the occurrence of a short circuit due to the first plate portion is suppressed. Thereby, while suppressing the occurrence of a short circuit, it is possible to more reliably protect the power storage element against an impact from the second direction.

[0021] The second plate portion may be formed to have a length that exceeds the at least one power storage element in the first direction.

[0022] With this configuration, the length of the second plate in the first direction becomes relatively long, further increasing the rigidity of the reinforcing member against forces in the second direction. Therefore, the energy storage element can be more reliably protected against impacts from the second direction. Note that the length of the second plate in the first direction does not include the length of the connection part in the first direction (the thickness of the first plate in the first direction).

[0023] The following description of an energy storage device according to an embodiment (including its modifications) of the present invention will be made with reference to the drawings. The embodiments described below are all general or specific examples. The numerical values, shapes, materials, components, arrangement and connection configurations of components, manufacturing processes, and the order of manufacturing processes shown in the following embodiments are examples and are not intended to limit the present invention. Dimensions and other specifications are not strictly illustrated in each figure. Furthermore, the same or similar components are denoted by the same reference numerals in each figure. Note that the names of each component (each constituent member) in this embodiment are those specific to this embodiment and may differ from the names of each component (each constituent member) in the background art.

[0024] In the following description and drawings, the short direction of the casing of the energy storage device, or the direction in which the short sides of the energy storage elements face each other, is defined as the X-axis direction. The long direction of the casing of the energy storage device, or the direction in which the multiple energy storage elements are aligned, is defined as the Y-axis direction. The direction in which the main body and lid of the casing of the energy storage device are aligned, or the vertical direction, is defined as the Z-axis direction. These X-axis, Y-axis, and Z-axis directions intersect (orthogonal in this embodiment) with each other. Depending on the usage, the Z-axis direction may not be the vertical direction, but for the sake of explanation, the Z-axis direction will be described as the vertical direction below.

[0025] In the following explanation, for example, the "X-axis positive direction" refers to the direction of the X-axis arrow, and the "X-axis negative direction" refers to the opposite direction. The same applies to the Y-axis and Z-axis directions. When simply referred to as "X-axis direction," it means either the bidirectional or unidirectional direction parallel to the X-axis. The same applies to the terminology related to the Y-axis and Z-axis.

[0026] Expressions indicating relative direction or orientation, such as parallel and orthogonal, include cases where the direction or orientation is not strictly accurate. Two directions being orthogonal includes not only the state where the two directions are perfectly orthogonal, but also the state where they are deviated by 10° or less from the perfectly orthogonal state. Two directions being parallel includes not only the state where the two directions are perfectly parallel, but also the state where they are deviated by 10° or less from the perfectly parallel state. Furthermore, simply saying "in the X-axis direction" means either bidirectional or unidirectional direction parallel to the X-axis. The same applies to the terminology for the Y-axis and Z-axis. In the following explanation, "insulation" means "electrical insulation."

[0027] (Embodiment) [1. General explanation of energy storage devices] First, the general configuration of the energy storage device 1 in this embodiment will be described. Figure 1 is a perspective view showing the external appearance of the energy storage device 1 according to this embodiment. Figure 2 is an exploded perspective view of the energy storage device 1 according to this embodiment. In addition to the components shown in Figures 2 and later, busbars, electrical equipment, cables, etc., can be housed inside the outer casing 10. However, the illustration and description of these components will be omitted as appropriate.

[0028] The energy storage device 1 is a device that can charge electricity from an external source and discharge electricity to the outside, and in this embodiment, it has a substantially rectangular parallelepiped shape. The energy storage device 1 is, for example, a battery module (battery pack) used for power storage or power supply purposes. Specifically, the energy storage device 1 is used as a battery for driving or starting the engine of mobile vehicles such as automobiles, motorcycles, watercraft, ships, snowmobiles, agricultural machinery, construction machinery, or railway vehicles for electric railways. Examples of automobiles include electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and fossil fuel (gasoline, diesel, liquefied natural gas, etc.) vehicles. Examples of railway vehicles for electric railways include electric trains, monorails, linear motor cars, and hybrid trains equipped with both diesel engines and electric motors. The energy storage device 1 can also be used as a stationary battery for household or commercial use.

[0029] As shown in Figures 1 and 2, the energy storage device 1 comprises an outer casing 10 and an energy storage element unit 101 housed within the outer casing 10. The outer casing 10 is a box-shaped (approximately rectangular parallelepiped) container (module case) that constitutes the housing of the energy storage device 1. In other words, the outer casing 10 is positioned outside the energy storage element unit 101, fixing the energy storage element unit 101 in a predetermined position and protecting it from impacts and the like. The exterior body 10 is formed from insulating materials such as polycarbonate (PC), polypropylene (PP), polyethylene (PE), polystyrene (PS), polyphenylene sulfide resin (PPS), polyphenylene ether (PPE (including modified PPE)), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyether ether ketone (PEEK), tetrafluoroethylene perfluoroalkyl vinyl ether (PFA), polytetrafluoroethylene (PTFE), polyethersulfone (PES), polyamide (PA), ABS resin, or composite materials thereof, or from metal with an insulating coating.

[0030] The exterior body 10 comprises an exterior body 12 that constitutes the main body of the exterior body 10, and a cover 11. The exterior body 12 is a bottomed rectangular cylindrical housing with an opening 12a formed on the Z-axis positive side. The cover 11 is a rectangular member that closes the opening 12a of the exterior body 12. The cover 11 is joined to the exterior body 12 by adhesive, heat sealing, ultrasonic welding, or fastening with bolts and nuts. The cover 11 is provided with, for example, an exhaust pipe (not shown), and when gas is discharged from the gas discharge section 105 of the energy storage element 100, the gas inside the exterior body 10 is discharged to the outside of the exterior body 10 via the exhaust pipe. The joint between the exterior body 12 and the cover 11 has relatively high airtightness because it is formed by adhesive or heat sealing as described above. Therefore, when gas is discharged from the energy storage element 100, gas leakage from the joint is suppressed. The cover 11 is provided with a pair of external terminals 19, which are a pair of module terminals (total terminals) on the positive and negative sides. The energy storage device 1 charges with electricity from the outside and discharges electricity to the outside through this pair of external terminals 19. The external terminals 19 are formed of a conductive metal material such as aluminum, aluminum alloy, copper, or copper alloy.

[0031] The energy storage element unit 101 is a group of energy storage elements 100 having multiple energy storage elements 100 and reinforcing members 50. The energy storage element unit 101 according to this embodiment consists of eight energy storage elements 100, and the eight energy storage elements 100 are arranged in the Y-axis direction with their long sides 110a facing the Y-axis direction. The Y-axis direction is an example of the first direction. In this embodiment, as shown in Figure 2, four reinforcing members 50 are arranged for eight energy storage elements 100. Specifically, one reinforcing member 50 is arranged for every two energy storage elements 100. The reinforcing member 50 is a plate-shaped member made of a metal material such as aluminum alloy or iron, and is arranged along the energy storage elements 100 to reinforce them. The reinforcing member 50 has a first plate portion 53 and a second plate portion 54, and the first plate portion 53 is arranged between two energy storage elements 100. The configuration of the reinforcing member 50 and its surroundings will be described later with reference to Figures 3 to 6.

[0032] The eight energy storage elements 100 of the energy storage element unit 101 are connected, for example, in series by a plurality of busbars (not shown). The electrical connection configuration of the eight energy storage elements 100 is not limited to this and can be any configuration. For example, four groups of energy storage elements 100, each consisting of two energy storage elements 100 connected in parallel, may be formed, and these four groups of energy storage elements 100 may be connected in series using a plurality of busbars.

[0033] The energy storage element 100 is a secondary battery (single cell) capable of charging and discharging electricity, and more specifically, a non-aqueous electrolyte secondary battery such as a lithium-ion secondary battery. As shown in Figure 2, the energy storage element 100 comprises a flat rectangular parallelepiped (square) shaped container 110, and inside the container 110 are electrodes, a current collector, and an electrolyte (not shown). As the electrodes, for example, a wound-type electrode is used, which is formed by winding together layers of electrodes with a separator sandwiched between a positive electrode plate and a negative electrode plate. Examples of electrodes for the energy storage element 100 include a wound-type electrode, a stacked electrode formed by stacking multiple flat electrode plates, and a bellows-type electrode formed by folding electrode plates in a bellows-like manner. As for the electrolyte contained in the container 110, there are no particular restrictions on the type as long as it does not impair the performance of the energy storage element 100, and various types can be selected. The energy storage element 100 is not limited to a non-aqueous electrolyte secondary battery, but may be a secondary battery other than a non-aqueous electrolyte secondary battery, or a capacitor. The energy storage element 100 may not be a secondary battery, but a primary battery that allows the user to use the stored electricity without charging. The energy storage element 100 may be a pouch-type energy storage element. The energy storage element 100 may be a battery using a solid electrolyte. The shape of the energy storage element 100 is not limited to the above-mentioned prismatic shape, but may be other polygonal prism shapes, cylindrical shapes, elliptical prism shapes, oblong cylindrical shapes, etc.

[0034] As shown in Figure 2, the container 110 has a pair of long sides 110a facing each other in the Y-axis direction and a pair of short sides 110b facing each other in the X-axis direction, and a pair of electrode terminals 120 are arranged at the first end 110c. In this embodiment, a gas discharge section 105 is further provided at the first end 110c. Specifically, the pair of electrode terminals 120 and the gas discharge section 105 are provided on the lid plate located at the first end 110c of the container 110. The energy storage element 100 is housed in the outer casing 10 with its first end 110c facing upward (in the positive Z-axis direction). When the energy storage element 100 is housed in the outer casing 10, the second end 110d of the energy storage element 100 (container 110), opposite to the first end 110c, faces the bottom surface of the outer casing body 12.

[0035] A container 110 having such a configuration can be sealed inside by welding the container body and lid plate together after the electrode body and other components are placed inside the container body. The material of the container 110 is not particularly limited, but it is preferably a weldable metal such as stainless steel, aluminum, aluminum alloy, iron, or plated steel sheet.

[0036] The electrode terminals 120 are terminal members that are electrically connected to the electrode body housed in the container 110, and are provided protruding from the first end 110c. One of the pair of electrode terminals 120 is electrically connected to the positive electrode of the electrode body, and the other of the pair of electrode terminals 120 is electrically connected to the negative electrode of the electrode body. The electrode terminals 120 are made of a conductive material such as aluminum, aluminum alloy, copper, or copper alloy.

[0037] In the energy storage device 1 configured in this way, the energy storage element unit 101 having multiple energy storage elements 100 has multiple reinforcing members 50. The reinforcing members 50 have the function of protecting one or more energy storage elements 100 from external impacts, etc. The configuration of the reinforcing members 50 and their surroundings will be described below with reference to Figures 3 to 6, in addition to Figure 2 above.

[0038] [2. Reinforcement members and their surrounding structure] Figure 3 is a side view showing an example of the arrangement and orientation of multiple reinforcing members 50 in the energy storage element unit 101 according to the embodiment. In Figure 3, in order to distinguish the four reinforcing members 50, the four reinforcing members 50 are represented as reinforcing members 50A to 50D. Furthermore, in order to distinguish the two energy storage elements 100 located on both sides of reinforcing member 50A, the two energy storage elements 100 are represented as energy storage elements 100a and 100b. Figure 4 is an enlarged view of the boundary between the reinforcing member 50 and the container 110 of the energy storage element 100 according to the embodiment. Figure 5 is a perspective view of the energy storage element 100 and reinforcing member 50 according to the embodiment. Figure 6 is a front view of the energy storage element 100 and reinforcing member 50 according to the embodiment (viewed from the side where the energy storage element 100 is arranged).

[0039] As described above, the reinforcing member 50 according to this embodiment is a member formed of a metal material such as aluminum alloy or iron, and as shown in Figures 3, 5, and 6, it has a first plate portion 53 and a second plate portion 54 that intersect each other. The first plate portion 53 and the second plate portion 54 are connected at a connecting portion 51, and the angle between the first plate portion 53 and the second plate portion 54 is 90°. In this embodiment, the reinforcing member 50 having a connecting portion 51 which is the bent portion, and a first plate portion 53 and a second plate portion 54 which are perpendicular to each other, is manufactured by bending a single metal plate by 90°. By bending a single metal plate, the reinforcing member 50 having a first plate portion 53 and a second plate portion 54 that intersect each other can be easily formed. It should be noted that it is not essential to manufacture the reinforcing member 50 by bending in this way; for example, the reinforcing member 50 may also be manufactured by connecting the first plate portion 53 and the second plate portion 54, which are separate parts, by welding or the like. In other words, the connecting portion 51 of the reinforcing member 50, which is the part that forms the bent shape, does not need to be formed by actually bending a plate-shaped member. The reinforcing member 50 is arranged such that the first plate portion 53 is along the long side surface 110a of the energy storage element 100, and the second plate portion 54 is along the second end portion 110d of the energy storage element 100. In this state, the connecting portion 51 of the reinforcing member 50 extends in the X-axis direction, which is perpendicular to the direction in which the plurality of energy storage elements 100 are aligned (Y-axis direction). In this embodiment, the X-axis direction is an example of a second direction.

[0040] In the energy storage element unit 101 according to this embodiment, four reinforcing members 50 configured as described above are arranged for eight energy storage elements 100. In the example shown in Figure 3, one reinforcing member 50 is arranged for every two consecutive energy storage elements 100. More specifically, in Figure 3, the reinforcing members 50A, 50B, 50C, and 50D are arranged from left to right. Reinforcing members 50A and 50B are positioned with their second plate portion 54 facing left, while reinforcing members 50C and 50D are positioned with their second plate portion 54 facing right. As a result, the first plate portions 53 of reinforcing members 50B and 50C are adjacent to each other.

[0041] In this embodiment, each of the four reinforcing members 50 is made of metal and is arranged along the metal container 110 of the energy storage element 100. Therefore, as shown in Figure 4, an insulating member 150 is placed between the reinforcing member 50 and the container 110 of the energy storage element 100. The insulating member 150 is made of an insulating material such as PC, PP, or PE, which can be used as the material for the exterior body 10 described above. The insulating member 150 may be fixed to at least one of the reinforcing member 50 and the container 110. For example, the insulating member 150 may be realized by a resin coated on the surface of the reinforcing member 50. For example, the insulating member 150 may be realized by an insulating film wrapped around the container 110. During the manufacturing (assembly) of the energy storage device 1, an insulating member 150 separate from the reinforcing member 50 and the container 110 may be placed between the reinforcing member 50 and the container 110. The insulating member 150 may be realized by a plurality of laminated materials. An insulating member 150 does not necessarily have to be placed between the reinforcing member 50 and the container 110 of the energy storage element 100.

[0042] In the energy storage element unit 101, the reinforcing member 50, positioned and oriented as described above, is formed to extend beyond the energy storage element 100. Specifically, as shown in Figures 5 and 6, the maximum width of the reinforcing member 50 in the direction in which the connecting portion 51 extends (X-axis direction) is greater than the maximum width of the energy storage element 100 in the X-axis direction. Therefore, when viewed from a direction perpendicular to the X-axis direction, the reinforcing member 50 has a portion that extends beyond the energy storage element 100 (a protruding portion). Furthermore, since the connecting portion 51, which is a bent portion, extends in the X-axis direction, the reinforcing member 50 has the characteristic of being difficult to bend in the direction perpendicular to the X-axis direction (high bending rigidity) when subjected to an impact from the X-axis direction.

[0043] In other words, the energy storage device 1 according to this embodiment comprises a plurality of energy storage elements 100 and a reinforcing member 50. The plurality of energy storage elements 100 are arranged in a line in a first direction (Y-axis direction). The reinforcing member 50 has a first plate portion 53 positioned between two adjacent energy storage elements 100 among the plurality of energy storage elements 100, and a second plate portion 54 intersecting the first plate portion 53. The first plate portion 53 and the second plate portion 54 are connected by a connecting portion 51 extending in a second direction (X-axis direction) perpendicular to the Y-axis direction. The width of at least one of the first plate portion 53 and the second plate portion 54 in the X-axis direction is greater than the width of at least one of the two energy storage elements 100 in the X-axis direction.

[0044] Thus, the reinforcing member 50 according to this embodiment has a first plate portion 53 and a second plate portion 54 that extend in directions intersecting each other and are connected to each other by a connecting portion 51. In the X-axis direction, which is the direction in which the connecting portion 51 extends, the width of at least one of the first plate portion 53 and the second plate portion 54 is greater than the width of the energy storage element 100.

[0045] For example, focusing on the first plate portion 53 of the first plate portion 53 and the second plate portion 54, as shown in Figures 5 and 6, the width Wa of the first plate portion 53 in the X-axis direction is greater than the width Wc of the energy storage element 100 in the X-axis direction. Therefore, when an impact is applied from the X-axis direction, the reinforcing member 50 receives at least a portion of that impact. This protects the energy storage element 100 from impact when an impact is applied from the X-axis direction. The connecting portion 51, which is the part that forms the bent shape of the reinforcing member 50, extends in the X-axis direction. Therefore, even if the first plate portion 53 and the second plate portion 54 are formed from relatively thin plate material, relatively high bending rigidity (difficulty of bending when bending in a direction perpendicular to the X-axis direction) can be obtained. In particular, the reinforcing member 50 according to this embodiment has an L-shaped cross-section parallel to the YZ plane, and the L-shaped cross-section extends in the X-axis direction. A reinforcing member 50 with such a shape can be easily formed by bending a plate material. Even when the reinforcing member 50 according to this embodiment is made of a relatively thin plate material, it has relatively high bending rigidity. Therefore, even if there are constraints on the inner or outer dimensions of the outer casing 10, for example, the reinforcing member 50 can be used as a member to protect the energy storage element 100 from impact. Thus, the energy storage device 1 according to this embodiment can protect the energy storage element 100 from impacts from the X-axis direction while suppressing an increase in the size and weight of the energy storage device 1.

[0046] In this embodiment, the multiple energy storage elements 100 are of the same type (same product) and are substantially the same size. Therefore, in this embodiment, the above explanation applies when comparing the size of the reinforcing member 50 with the two energy storage elements 100 (see Figure 3) on both sides of the reinforcing member 50 in the Y-axis direction. For example, the width in the X-axis direction of at least one of the first plate portion 53 and the second plate portion 54 of the reinforcing member 50A in Figure 3 is greater than the width in the X-axis direction of the respective energy storage elements 100a and 100b. Therefore, the protective effect (reinforcing effect) of the reinforcing member 50A extends to at least both of the two energy storage elements 100 (energy storage elements 100a and 100b) arranged on both sides of the reinforcing member 50A in the Y-axis direction.

[0047] As shown in Figure 5, the reinforcing member 50 according to this embodiment does not have a portion that contacts the short side 110b of the energy storage element 100. In this embodiment, by not having a contact portion that contacts the short side 110b of the energy storage element 100, the possibility of impact from the X-axis direction being transmitted to the energy storage element 100 via the contact portion is reduced. In other words, the reinforcing member 50 according to this embodiment has high bending rigidity against force from the X-axis direction and is formed in a shape that makes it difficult to transmit impact from the X-axis direction to the energy storage element 100.

[0048] In this embodiment, as shown in Figures 5 and 6, the reinforcing member 50 has portions that protrude from the energy storage element 100 on both sides in the X-axis direction of the energy storage element 100, which is arranged along the reinforcing member 50. In other words, whether the energy storage device 1 is subjected to an impact from the positive X-axis direction or the negative X-axis direction, at least one of the two energy storage elements 100, which are arranged on both sides in the Y-axis direction with the reinforcing member 50 in between, can be more reliably protected from the impact. Specifically, when viewed from the Y-axis direction, the first plate portion 53 has portions that protrude from the energy storage element 100 on both sides in the X-axis direction of the energy storage element 100. In other words, when viewed from the Z-axis direction, the second plate portion 54 has portions that protrude from the energy storage element 100 on both sides in the X-axis direction of the energy storage element 100. This makes it possible to more reliably protect the energy storage element 100 from impacts from the X-axis direction.

[0049] In this embodiment, the width in the X-axis direction of both the first plate portion 53 and the second plate portion 54 is greater than the width in the second direction of at least one of the energy storage elements 100. That is, as shown in Figures 5 and 6, the width Wb in the X-axis direction of not only the first plate portion 53 but also the second plate portion 54 is greater than the width Wc in the X-axis direction of the energy storage element 100. In this embodiment, the width in the X-axis direction of the first plate portion 53 and the second plate portion 54 is equal. In other words, in Figures 5 and 6, Wa = Wb > Wc.

[0050] With this configuration, the energy storage element 100 can be protected by both the first plate portion 53 and the second plate portion 54. Therefore, more reliable protection of the energy storage element 100 when an impact is applied from the X-axis direction is possible.

[0051] As described above, in this embodiment, the first plate portion 53 and the second plate portion 54 have equal width in the X-axis direction. Furthermore, as shown in Figure 5, the connecting portion 51 is the portion that connects the entire X-axis direction area at the Z-axis direction end of the first plate portion 53 and the entire X-axis direction area at the Y-axis direction end of the second plate portion 54. In other words, in this embodiment, the width of the connecting portion 51 in the X-axis direction is equal to Wa and Wb in Figure 5. Therefore, in this embodiment, the width of the connecting portion 51 in the X-axis direction is greater than the width in the X-axis direction of at least one of the two energy storage elements 100 arranged on both sides of the Y-axis direction of the reinforcing member 50.

[0052] In this configuration, at least one end of the connecting portion 51, which forms the bent shape of the reinforcing member 50, is positioned to protrude in a second direction from the energy storage element adjacent to the reinforcing member. This makes it less likely for the first plate portion and the second plate portion to buckle on that end when an impact is applied from the X-axis direction. In this embodiment, the connecting portion 51 has portions that protrude from the energy storage element 100 on both sides of the energy storage element 100 in the X-axis direction when viewed from a direction perpendicular to the X-axis direction. Therefore, even if the energy storage device 1 is subjected to an impact from either the positive X-axis direction or the negative X-axis direction, more reliable protection of the energy storage element 100 is possible.

[0053] In this embodiment, the first plate portion 53 of the reinforcing member 50 is arranged along the long side surface 110a of the energy storage element 100, and the second plate portion 54 is arranged opposite to the second end portion 110d of the energy storage element 100. At least one of the two energy storage elements 100, which are arranged on both sides of the reinforcing member 50 in the Y-axis direction, has a first end portion 110c on which electrode terminals 120 are located. The reinforcing member 50 is made of metal, and the second plate portion 54 is arranged opposite to the second end portion 110d, which is the end of the at least one energy storage element 100 opposite to the first end portion 110c.

[0054] As described above, in this embodiment, the reinforcing member 50 is formed of a metal that has higher rigidity than resin, etc., so the rigidity of the reinforcing member 50 can be further increased. Therefore, the energy storage element 100 can be protected more reliably when an impact is applied from the X-axis direction. Furthermore, the second plate portion 54 is positioned along the second end 110d of the energy storage element 100, which is opposite to the first end 110c where the electrode terminals 120 are located. Even when the reinforcing member 50 is formed of metal, the second plate portion 54 is positioned relatively far from the electrode terminals 120, so the occurrence of a short circuit caused by the second plate portion 54 is suppressed. As a result, the energy storage element 100 can be protected more reliably from impacts in the X-axis direction while suppressing the occurrence of a short circuit.

[0055] The second plate portion 54 may be positioned, for example, opposite the short side 110b of the energy storage element 100. In other words, the reinforcing member 50 may be positioned such that the first plate portion 53 is along the long side 110a of the energy storage element 100, and the second plate portion 54 is along the short side 110b of the energy storage element 100. In this case, the Z-axis direction is the second direction, and the width in the Z-axis direction of at least one of the first plate portion 53 and the second plate portion 54 is greater than the width in the Z-axis direction of the energy storage element 100, so that at least a part of the reinforcing member 50 can protrude in the Z-axis direction beyond the energy storage element 100 adjacent to the reinforcing member 50. In this case, the energy storage element 100 can be protected from impacts in the Z-axis direction.

[0056] As shown in Figures 3, 5, and 6, the first plate portion 53 of the reinforcing member 50 according to this embodiment is formed in a shape that avoids electrical contact with the electrode terminals 120. Specifically, at least one of the two energy storage elements 100 arranged on both sides of the reinforcing member 50 in the Y-axis direction has a first end portion 110c on which the electrode terminals 120 are located. The reinforcing member 50 is made of metal. As shown in Figures 3, 5, and 6, the first plate portion 53 extends from the connection portion 51 toward the first end portion 110c along the at least one energy storage element 100 and has a shape that does not overlap with the electrode terminals 120 when viewed from the Y-axis direction.

[0057] As described above, in this embodiment, the reinforcing member 50 is formed of a metal that has higher rigidity than resin, etc., so the rigidity of the reinforcing member 50 can be further increased. Therefore, it becomes possible to provide more reliable protection for the energy storage element 100 when an impact is applied from the second direction. Furthermore, since the first plate portion 53 has a shape that does not overlap with the electrode terminals 120 when viewed from the Y-axis direction, even if the reinforcing member 50 is formed of metal, the occurrence of a short circuit caused by the first plate portion 53 is suppressed. As a result, the occurrence of a short circuit can be suppressed while providing more reliable protection for the energy storage element 100 from impacts in the X-axis direction.

[0058] In this embodiment, the first plate portion 53 is formed to a length (width in the Z-axis direction) that does not reach the position of the electrode terminal 120 in the Z-axis direction throughout the entire X-axis direction. However, the first plate portion 53 may be formed to a length that reaches the position of the electrode terminal 120 in the Z-axis direction in a part of the X-axis direction. In other words, the maximum length of the first plate portion 53 in the Z-axis direction may be longer than the Z-axis length of the container 110, and in this case, the end in the Z-axis positive direction may have a shape in which only the portion that overlaps with the electrode terminal 120 when viewed from the Y-axis direction is cut out.

[0059] In this embodiment, the second plate portion 54 is formed to have a length that extends beyond the Y-axis direction of at least one of the two energy storage elements 100 arranged on both sides of the reinforcing member 50 in the Y-axis direction. That is, as shown in Figure 5, if the width of the second plate portion 54 in the Y-axis direction is La and the width of the energy storage element 100 in the Y-axis direction is Lb, then La > Lb.

[0060] With this configuration, the length of the second plate portion 54 in the Y-axis direction becomes relatively long, further increasing the bending rigidity of the reinforcing member 50 against forces in the X-axis direction. Therefore, more reliable protection of the energy storage element 100 when an impact is applied from the X-axis direction becomes possible.

[0061] In this embodiment, as shown in Figure 3, the second plate portion 54 of the reinforcing member 50 is adjacent to the first plate portion 53 and faces the second end portions 110d of two energy storage elements 100: one energy storage element 100a that is adjacent to the first plate portion 53 and runs along the second plate portion 54, and the other energy storage element 100 that is adjacent to the first energy storage element 100a.

[0062] In this embodiment, the length of the second plate portion 54 in the Y-axis direction is formed such that it does not exceed the length of two or more (two in this embodiment) opposing energy storage elements 100 in the Y-axis direction. Therefore, even if there is variation in the width of the multiple energy storage elements 100 in the Y-axis direction, as shown in Figure 3, one reinforcing member 50 can be placed for every two energy storage elements 100, and two adjacent reinforcing members 50 in the Y-axis direction can be placed without interfering with each other.

[0063] The above description focuses on the configuration of the reinforcing member 50 and its surroundings in relation to the energy storage device 1 according to the embodiment. However, the reinforcing member 50 may have a configuration different from that shown in Figures 2 to 6. Therefore, the following describes some modifications of the reinforcing member 50, focusing on the differences from the above embodiment.

[0064] [3-1. Variation 1] Figure 7 is a side view showing a part of the reinforcing member 50a according to the first modified embodiment. In Figure 7, only two energy storage elements 100 and one reinforcing member 50a are shown, but the same combination is arranged in the Y-axis direction to form the energy storage element unit 101 according to this modified embodiment.

[0065] The reinforcing member 50a according to this modified example has a first plate portion 53 positioned between two adjacent energy storage elements 100 among a plurality of energy storage elements 100, and a second plate portion 54a intersecting the first plate portion 53. The first plate portion 53 and the second plate portion 54a are connected by a connecting portion 51 extending in the X-axis direction. The width of at least one of the first plate portion 53 and the second plate portion 54a in the X-axis direction is greater than the width of at least one of the two energy storage elements 100 in the X-axis direction. These configurations are common to the reinforcing member 50 according to the embodiment.

[0066] In this modified example, as shown in Figure 7, the second plate portion 54a is positioned opposite the second end portions 110d of each of the two energy storage elements 100, which are located on both sides of the first plate portion 53 in the Y-axis direction, which is different from the reinforcing member 50 in the embodiment. In other words, the reinforcing member 50a in this modified example has a T-shaped cross-section parallel to the YZ plane, and the T-shaped cross-section extends in the X-axis direction. Even in this case, the reinforcing member 50a can obtain relatively high bending rigidity. When viewed from a direction perpendicular to the X-axis direction, the reinforcing member 50a has a portion that protrudes from the energy storage elements 100 in the X-axis direction. As a result, the reinforcing member 50a can protect the energy storage elements 100 from impact when an impact is applied from the X-axis direction. In particular, in this modified example, since the second plate portion 54a is folded and overlapped, the bending rigidity of the reinforcing member 50 against force in the X-axis direction is further increased. As a result, the energy storage elements 100 can be protected more reliably from impact in the X-axis direction.

[0067] In this modified example, as shown in Figure 7, a T-shaped reinforcing member 50a is obtained by providing three bent sections on a single plate-shaped member. In other words, a reinforcing member 50a having a first plate section 53 and a second plate section 54a is manufactured from a single member. However, the reinforcing member 50a may also be manufactured by connecting the first plate section 53 and the second plate section 54a, which are separate components. For example, a T-shaped reinforcing member 50a may be manufactured by connecting a flat rectangular first plate section 53 and a flat rectangular second plate section 54a by welding, press-fitting, or crimping. The reinforcing member 50a, like the reinforcing member 50 in the embodiment, may have portions that protrude from the energy storage element 100 on both sides in the X-axis direction of the energy storage element 100.

[0068] [3-2. Variation 2] Figure 8 is a side view showing a reinforcing member 50b according to a modified example 2 of the embodiment. In Figure 8, two energy storage elements 100 and one reinforcing member 50b are shown, and the same combination is arranged in the Y-axis direction to form the energy storage element unit 101 according to this modified example.

[0069] The reinforcing member 50b according to this modified example has a pair of first plate portions 53b positioned between two adjacent energy storage elements 100 among a plurality of energy storage elements 100, and a second plate portion 54b intersecting the first plate portion 53b. In other words, the first plate portion 53b is located between the energy storage element 100 shown in Figure 8 and another adjacent energy storage element 100 in the Y-axis direction, which is not shown in Figure 8. The first plate portion 53b and the second plate portion 54b are connected by a connecting portion 51 extending in the X-axis direction. The width of at least one of the first plate portion 53b and the second plate portion 54b in the X-axis direction is greater than the width of at least one of the two energy storage elements 100 in the X-axis direction. These configurations are common to the reinforcing member 50 according to the embodiment.

[0070] In this modified example, the reinforcing member 50 differs from the embodiment in that a pair of first plate portions 53b are connected to both ends of the second plate portion 54b in the Y-axis direction. In other words, the reinforcing member 50b in this modified example has a U-shaped cross-section parallel to the YZ plane, and the U-shaped cross-section extends in the X-axis direction. Therefore, as shown in Figure 8, when the reinforcing member 50b is placed for two energy storage elements 100, the second plate portion 54b is aligned with the second end portions 110d of the two energy storage elements 100, and the pair of first plate portions 53b are positioned to sandwich the two energy storage elements 100 in the Y-axis direction. Even in this case, the reinforcing member 50b can obtain relatively high bending rigidity. When viewed from a direction perpendicular to the X-axis direction, the reinforcing member 50b has a portion that protrudes from the energy storage elements 100 in the X-axis direction. As a result, the reinforcing member 50b can protect the energy storage elements 100 from impact when an impact is applied from the X-axis direction.

[0071] In this modified example, as shown in Figure 8, a reinforcing member 50b with a U-shaped cross-section is obtained by providing two bent portions on a single plate-shaped member. In other words, a reinforcing member 50b having a pair of first plate portions 53b and second plate portions 54b is manufactured from a single member. However, the reinforcing member 50b may also be manufactured by connecting a pair of separate first plate portions 53b and second plate portions 54b. For example, the reinforcing member 50b may be manufactured by connecting a pair of flat rectangular first plate portions 53b and a flat rectangular second plate portion 54b by welding, press-fitting, or crimping. The reinforcing member 50b may have portions that protrude from the energy storage element 100 on both sides in the X-axis direction of the energy storage element 100, similar to the reinforcing member 50 in the embodiment.

[0072] [4. Other variations] Although the embodiment of the energy storage device 1 and its modified forms have been described above, the present invention is not limited to the embodiment and its modified forms. In other words, the embodiments disclosed herein are illustrative and not restrictive in all respects, and the scope of the present invention includes all modifications in the sense and scope equivalent to the claims.

[0073] The number, placement, and orientation of the reinforcing members 50 shown in Figure 3 are examples. At least one reinforcing member 50 is required for each row of energy storage elements 100, which consists of multiple energy storage elements 100. For example, if only one reinforcing member 50 is placed for each row of energy storage elements 100, that reinforcing member 50 can function as a member that protects at least two energy storage elements 100 that sandwich the first plate portion 53 of the reinforcing member 50 in the Y-axis direction. The reinforcing members 50 may be placed in a one-to-one correspondence with multiple energy storage elements 100. In this case, it is preferable that the width La of the second plate portion 54 is shorter than the width Lb of the energy storage element 100 in the Y-axis direction. This allows two adjacent reinforcing members 50 in the Y-axis direction to be placed without interfering with each other.

[0074] The relationship between the width La of the second plate portion 54 of the reinforcing member 50 and the width Lb of the energy storage element 100 may be La ≤ Lb or La ≥ 2 Lb.

[0075] The reinforcing member 50 may be made of a material other than metal. For example, the reinforcing member 50 may be made of fiber-reinforced plastic, which is a composite material of a resin such as epoxy resin and glass fibers or carbon fibers. In this case, the weight of the reinforcing member 50 can be reduced.

[0076] Preferably, the reinforcing member 50 is restricted from relative movement with respect to the energy storage element 100 in the X-axis direction. This makes it easier for at least a portion of the reinforcing member 50 to maintain a state where it protrudes in the X-axis direction from the energy storage element 100 adjacent to the reinforcing member 50, even when the energy storage device 1 is subjected to an impact from the X-axis direction, thereby more reliably protecting the energy storage element 100 from impacts from the X-axis direction. Restriction of the relative movement of the reinforcing member 50 with respect to the energy storage element 100 in the X-axis direction can be achieved by fixing, connecting, or contacting the reinforcing member 50 with a member arranged around the reinforcing member 50. Examples of members arranged around the reinforcing member 50 include, but are not limited to, the outer casing 10, the energy storage element 100, spacers arranged between adjacent energy storage elements 100, busbar holders that hold busbars, and restraining members arranged along the outer surface of the energy storage element unit 101. For example, the second plate portion 54 of the reinforcing member 50 may be fixed to the inner bottom surface of the outer casing body 12 with an adhesive or the like. This allows the reinforcing member 50 to also serve as a limiting member that restricts the movement of the energy storage element 100 in the Y-axis direction relative to the outer casing 10.

[0077] The length of the second plate portion 54 of the reinforcing member 50 in the Y-axis direction may be the length that faces the second end portion 110d of three or more energy storage elements 100 that are arranged continuously in the Y-axis direction. In other words, one reinforcing member 50 may be provided for three or more energy storage elements 100. In this case, since the width Wb of the second plate portion 54 in the X-axis direction is greater than the width Wc of the energy storage element 100 in the X-axis direction (see Figures 5 and 6), the reinforcing member 50 can function as a member that protects at least one of the three or more energy storage elements 100 from impact from the X-axis direction.

[0078] The shape of the outer casing 10 does not have to be a rectangular parallelepiped as shown in Figures 1 and 2. For example, an outer casing of another shape, such as a cylindrical shape, may be used as a case to house the energy storage element unit 101.

[0079] Furthermore, forms constructed by arbitrarily combining the components included in the above embodiments and their modified examples are also included within the scope of the present invention. [Industrial applicability]

[0080] This invention can be applied to energy storage devices equipped with energy storage elements such as lithium-ion secondary batteries. [Explanation of symbols]

[0081] 1. Energy storage device 10 Exterior 11 Lid 12 Main body of the exterior 12a opening 19 External terminals 50, 50a, 50A, 50b, 50B, 50C, 50D Reinforcement members 51 Connection part 53, 53b First plate section 54, 54a, 54b Second plate section 100, 100a, 100b energy storage elements 101 Energy Storage Element Unit 105 Gas discharge section 110 Container 110a long side 110b short side 110c First end 110d Second end 120 Electrode terminal 150 Insulating material

Claims

1. An energy storage device comprising multiple energy storage elements and reinforcing members, The aforementioned plurality of energy storage elements are arranged in a line in the first direction, The reinforcing member is A first plate portion is positioned between two adjacent energy storage elements among the plurality of energy storage elements, A second plate portion intersects with the first plate portion, is provided integrally with the first plate portion, and has a second plate portion that is aligned with one of the two energy storage elements, The first plate portion and the second plate portion are connected at a connecting portion extending in a second direction perpendicular to the first direction. The width of at least one of the first plate portion and the second plate portion in the second direction is greater than the width of the one energy storage element in the second direction. The connecting portion has an L-shaped cross-section that is parallel to the first direction and perpendicular to the second direction. The first plate portion is a single flat plate-shaped part. Energy storage device.

2. The width of both the first plate portion and the second plate portion in the second direction is greater than the width of one of the energy storage elements in the second direction. The energy storage device according to claim 1.

3. The width of the connection portion in the second direction is greater than the width of the one energy storage element in the second direction. The energy storage device according to claim 2.

4. The aforementioned energy storage element has a first end on which electrode terminals are arranged, The reinforcing member is made of metal. The second plate portion is positioned opposite to the second end of the one energy storage element, which is the end opposite to the first end. The energy storage device according to any one of claims 1 to 3.

5. The aforementioned energy storage element has a first end on which electrode terminals are arranged, The reinforcing member is made of metal. The first plate portion extends from the connection portion toward the first end along the one energy storage element and has a shape that does not overlap with the electrode terminal when viewed from the first direction. The energy storage device according to any one of claims 1 to 4.

6. An energy storage device comprising multiple energy storage elements and reinforcing members, The aforementioned plurality of energy storage elements are arranged in a line in the first direction, The reinforcing member is A first plate portion is positioned between two adjacent energy storage elements among the plurality of energy storage elements, A second plate portion intersects with the first plate portion and has a second plate portion that is aligned with one of the two energy storage elements, The first plate portion and the second plate portion are connected at a connecting portion extending in a second direction perpendicular to the first direction. The width of at least one of the first plate portion and the second plate portion in the second direction is greater than the width of the one energy storage element in the second direction. The second plate portion is formed to have a length exceeding that of the one energy storage element in the first direction. Energy storage device.

7. An energy storage device comprising multiple energy storage elements and reinforcing members, The aforementioned plurality of energy storage elements are arranged in a line in the first direction, The reinforcing member is A first plate portion is positioned between two adjacent energy storage elements among the plurality of energy storage elements, A second plate portion intersects with the first plate portion and has a second plate portion that is aligned with one of the two energy storage elements, The first plate portion and the second plate portion are connected at a connecting portion extending in a second direction perpendicular to the first direction. The width of at least one of the first plate portion and the second plate portion in the second direction is greater than the width of the one energy storage element in the second direction. The second plate portion has two plate-like portions and a bent portion positioned between the two plate-like portions. The two plate-like portions are connected by the bent portion and are overlapped in the thickness direction of the second plate portion. The two plate-like portions and one of the energy storage elements are aligned in the thickness direction. Energy storage device.

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