Energy storage device

Abstract

An energy storage device comprises: an energy storage unit; an end plate arranged in a first direction of the energy storage unit; and a side plate extending in the first direction and connected to the end plate, wherein the end plate and / or the side plate has a projecting section in at least one corner section in which the first direction and a second direction orthogonal to the first direction intersect; and the projecting section is configured such that a space open on one side of the energy storage device is created by the end plate and / or the side plate deforming into an outwardly projecting shape.

Description

Technical field

[0001] The present invention relates to an energy storage device. State of the art

[0002] Patent literature 1 discloses a battery module comprising a plurality of battery cells, a pair of end plates, and a pair of retaining elements. The multiple battery cells are aligned in one direction, and a pair of end plates is arranged accordingly at both ends of the battery cells. Furthermore, the pair of retaining elements is arranged such that it sandwich-like encloses the multiple battery cells and the pair of end plates in a direction orthogonal to the direction in which the multiple battery cells are aligned. Both ends of the two retaining elements are connected to the two end plates. Thus, the multiple battery cells are fixed in place using the two end plates and the two retaining elements. List of cited writings Patent literature

[0003] Patent Literature 1: Unexamined Japanese Patent Application Disclosure No. 2020-57520 Disclosure of the invention Problems to be solved by the invention

[0004] In the conventional battery module described above, the battery cells swell due to charging and discharging, exerting a force on the end plates or retaining elements. To prevent damage to these elements from this force, one possible measure is to increase their stiffness. However, simply increasing stiffness can increase the cost of the end plates or retaining elements, or it can increase the mass of the battery module. Therefore, it is necessary to absorb the force acting on the end plates or retaining elements.

[0005] The present invention was conceived by the inventor of the present invention by innovative consideration of the above-mentioned problems, and one objective of the present invention is to provide an energy storage device that is able to absorb a force acting on an end plate or a side plate when an energy storage device swells. Means to solve the problems

[0006] An energy storage device according to one aspect of the present invention comprises: an energy storage device; an end plate arranged in a first direction of the energy storage device; and a side plate extending in the first direction and connected to the end plate, wherein a projecting section is provided in the end plate and / or the side plate in at least one corner section in which the first direction and a second direction orthogonal to the first direction intersect, and the projecting section is configured such that a space open on one side of the energy storage device is created by the end plate and / or the side plate deforming into an outwardly projecting shape. Effect of the invention

[0007] According to the energy storage device of the present invention, it is possible to absorb the force acting on the end plate or the side plate when the energy storage device swells. Brief description of the drawings [ Fig. 1] Fig. Figure 1 is a perspective view illustrating the construction of an energy storage device (in a state where an external body is removed) according to one embodiment. [ Fig. 2] Fig. Figure 2 is a top view showing an assembly of the energy storage device (in a state where the outer body is removed) according to the embodiment. [ Fig. 3] Fig. Figure 3 is a perspective view showing the construction of an end plate according to the embodiment. [ Fig. 4] Fig. Figure 4 is a perspective view showing the construction of a side plate according to the embodiment. [ Fig. 5] Fig. Figure 5 is a perspective view showing an assembly of the energy storage device (in a state where the outer body is mounted) according to the embodiment. [ Fig. 6] Fig. Figure 6 is a cross-sectional view showing an assembly of the energy storage device (in a state in which the outer body is mounted) according to the embodiment. [ Fig. 7] Fig. Figure 7 is a cross-sectional view showing the behavior of an end plate when the energy storage device has swollen according to the embodiment. [ Fig. 8] Fig. Figure 8 is a schematic view showing simulation results of the stress distributions when a force is applied to an end plate of a comparison example and the end plate according to the embodiment. [ Fig. 9] Fig. Figure 9 is a cross-sectional view illustrating the construction of an end plate and a side plate according to modification example 1 of the embodiment. [ Fig. 10] Fig. Figure 10 is a cross-sectional view illustrating the construction of an end plate and a side plate according to modification example 2 of the embodiment. [ Fig. 11] Fig. Figure 11 is a cross-sectional view showing the construction of an end plate and a side plate according to modification example 3 of the embodiment. [ Fig. 12] Fig. Figure 12 is a cross-sectional view showing the construction of an end plate and a side plate according to modification example 4 of the embodiment. [ Fig. 13] Fig. Figure 13 is a cross-sectional view showing the construction of an end plate and a side plate according to modification example 5 of the embodiment. Description of embodiments (1) An energy storage device according to one aspect of the present invention comprises: an energy storage device; an end plate arranged in a first direction of the energy storage device; and a side plate extending in the first direction and connected to the end plate, wherein the end plate and / or the side plate has a projecting section in at least one corner section where the first direction and a second direction orthogonal to the first direction intersect, and the projecting section is configured such that a space open on one side of the energy storage device is created by deforming the end plate and / or the side plate into an outwardly projecting shape.

[0008] In the energy storage device according to one embodiment of the present invention, the end plate and / or the side plate have a projecting section that is deformed into an outwardly projecting shape. Therefore, when the energy storage device expands in the first direction during charging and discharging, a force acting on the end plate or the side plate can be absorbed by the projecting section. That is, the force acting on the end plate or the side plate can be absorbed by the deformation of the projecting section.

[0009] (2) In the energy storage device described in (1) above, the foregoing section may be located on the end plate.

[0010] According to the energy storage device described in (2) above, the preceding section, being located on the end plate arranged in the first direction of the energy storage device, will be further slightly deformed when the energy storage device swells in the first direction. That is to say, a force acting on the end plate can be absorbed.

[0011] In the energy storage device described in (2) above, the thickness of the end plate in the first direction can be greater than the thickness of the side plate in the second direction.

[0012] According to the energy storage device described in (3) above, the thickness of the end plate in the first direction is greater than the thickness of the side plate in the second direction. Therefore, if the energy storage device expands in the first direction, excessive deformation of the aforementioned section can be prevented. Furthermore, since the thickness of the side plate in the second direction is less than the thickness of the end plate in the first direction, an increase in the mass of the energy storage device can be suppressed.

[0013] (4) In the energy storage device described in (1) above, the foregoing section may be located on the side plate.

[0014] According to the energy storage device described in (4) above, the preceding section, being located on the side plate extending in the first direction, will be further slightly deformed when the energy storage device swells in the first direction. That is to say, a force acting on the side plate can be absorbed.

[0015] (5) In the energy storage device described in (1) to (4), a cross-section of the preceding section taken parallel to the first direction and to the second direction may have an arc shape.

[0016] According to the energy storage device described in (5) above, it is possible to suppress a local concentration of the force acting on the preceding section, since the cross-section of the preceding section is arc-shaped.

[0017] (6) In the energy storage device described in any of points (1) to (5) above, the energy storage device may have an outer body in which the energy storage device, the end plate and the side plate are housed, and a gap may be formed between a surface of the outer body opposite the end plate and the end plate.

[0018] According to the energy storage device described in (6) above, a gap is formed between the outer body and the end plate. This feature prevents a load acting on the deformed outer body from acting directly on the end plate when the outer body is deformed by an external impact. This prevents damage to the energy storage device. If the energy storage device expands in the first direction, this gap can be used to accommodate the expansion. This prevents damage to the outer body. At the same time, the outer body can limit the expansion of the energy storage device, preventing it from expanding excessively. <1. Design of an energy storage device 8>

[0019] An embodiment of an energy storage device 8 according to the present invention is described below with reference to the drawings. A numerical value, a shape, a material, a component, an arrangement position, and a connection form of the components, and the like, which are specified in the following embodiment and the modification examples, are merely examples and are not intended to limit the present invention. The drawings are schematic representations, and dimensions and the like are not necessarily shown precisely. Identical or similar components in the drawings are designated with the same reference numerals.

[0020] In the following description and drawings, the embodiment is described in accordance with the following for the sake of clarity. Fig. The directions indicated in points 1 to 4 are described. However, these directions are only specified for the sake of clarity and do not limit the present invention.

[0021] Expressions that specify relative directions or positions, such as parallel and orthogonal, also encompass cases where the directions or positions are not strictly parallel or orthogonal. Two mutually orthogonal directions do not only mean that the two directions are completely orthogonal to each other, but also that the two directions are essentially orthogonal to each other, so that even two directions intersecting at an angle deviating from 90 degrees fall within the scope. In the following description, the term "insulation / insulating" refers to "electrical insulation." A material with insulating properties should preferably be made of a material with a specific volume resistivity of 1 × 10⁻⁶. 6 Ωm or more, preferably 1 × 10 7 Ωm or more, preferably 1 × 10 10 Ωm or more must be formed. <2. Overview of the energy storage device 8>

[0022] Fig. Figure 1 is a perspective view illustrating the construction of an energy storage device 8 (in a state in which an external body 7 is removed) according to the present embodiment. Fig. Figure 2 is a top view showing an assembly of the energy storage device 8 (in a state where the outer body 7 is removed) according to the present embodiment. As shown in Fig. 1 and Fig. As shown in Figure 2, the energy storage device 8 comprises: several energy storage devices 1 oriented in a forward-backward direction (a first direction); end plates 2 arranged accordingly at both ends of the several energy storage devices 1 in the forward-backward direction; and side plates 3 enclosing the several energy storage devices 1 from both sides in a left-right direction (a second direction) that is orthogonal to the forward-backward direction. Furthermore, a first spacer 4 or a second spacer 5 is located on a front or rear surface of the energy storage device 1. Each element is described below. <3. Energy storage device 1>

[0023] The energy storage device 1 comprises a primary battery, a secondary battery, a capacitor, or the like. In the present embodiment, the energy storage device 1, which consists of a rechargeable and dischargeable secondary battery with a non-aqueous electrolyte, is described as an example. More precisely, the energy storage device 1 is a lithium-ion secondary battery that utilizes electron transfer, which occurs through the transfer of lithium ions. The energy storage device 1 has a flat, rectangular parallelepiped shape (square shape, angular configuration), the length of which is long in the up-down and left-right directions and short in the forward-backward direction. In the present embodiment, several (four) energy storage devices 1 are aligned and arranged in the forward-backward direction.The number of energy storage devices 1 to be arranged is not particularly limited. The number of energy storage devices 1 can be one. The size and shape of the energy storage device 1 are also not particularly limited, and the energy storage device 1 does not have to be long in the left-right direction and flat in the forward-backward direction. The energy storage device 1 does not necessarily have to have a rectangular parallelepiped shape, but can also have a long column shape, an elliptical column shape, a column shape, or any other polygonal prism shape other than the rectangular parallelepiped shape, etc. The energy storage device 1 is not limited to the secondary battery with a non-aqueous electrolyte and can be a secondary battery other than the secondary battery with a non-aqueous electrolyte. The energy storage device 1 can be a battery that uses a solid electrolyte.The energy storage device 1 can be a bag-shaped energy storage device.

[0024] The energy storage device 1 comprises: an electrode body (not shown); a housing 11 in which the electrode body is accommodated together with an electrolyte solution (not shown); and two terminals 12 arranged as a pair, at least part of which is exposed on an outer surface of the housing 11. The terminals 12 are provided on a surface of the housing 11 in the upward-downward direction (a third direction) that is orthogonal to the forward-backward direction and the left-right direction.

[0025] The housing 11 comprises: a housing body with an opening on its top surface in the upward-downward direction; and a plate-shaped cover body that closes the opening of the housing body. The terminals 12 are located near both ends of the cover body in the left-right direction. The housing 11 has a flat rectangular parallelepiped shape (square shape, angular configuration), the length of which is long in the upward-downward and left-right directions and short in the forward-backward direction. The housings 11 are oriented in the forward-backward direction such that their surfaces face each other in the forward-backward direction. <4. Spacers 4 and 5>

[0026] The first spacer 4 is a plate-shaped structure located between two adjacent energy storage devices 1 and is made of a material with insulating properties. The first spacer 4 serves to insulate between the two adjacent energy storage devices 1 and to protect the energy storage devices 1 from external influences and the like. The second spacer 5 is a plate-shaped structure located on one side (front) of the energy storage device 1 that is oriented at one end (front end) of the multiple energy storage devices 1 in the forward-backward direction, and on the other side (rear) of the energy storage device 1 that is oriented at the other end (rear end) of the same in the forward-backward direction. The second spacer 5 is also made of a material with insulating properties.The second spacer 5 has the function of isolating between the energy storage device 1 and the end plate 2 described later, and of protecting the energy storage device 1 from external influences and the like. <5. End plate 2>

[0027] Fig. Figure 3 is a perspective view illustrating the assembly of the end plate 2 according to the present embodiment. As shown in Fig. As shown in Figure 2, the end plate 2 is located on one (front) side of the energy storage device 1, which is arranged at one end section (front end) in the forward-backward direction, and on the other (rear) side of the energy storage device 1, which is arranged at the other end section (rear end) in the forward-backward direction. In the present embodiment, two end plates 2 are used as a pair. However, since the end plates 2 have symmetrical shapes in the forward-backward direction, the end plate 2 that is in contact with the energy storage device 1 located at one end section (front end) in the forward-backward direction is referred to as... Fig. 3 described. It should be noted that the second spacer 5 described above is located between the energy storage device 1 and the end plate 2 to insulate between the two.

[0028] As in Fig. As shown in Figure 3, the end plate 2 comprises: a rectangular main body section 21; projecting sections 22 connected to both ends of the main body section 21 in the left-right direction; and side surface sections 23, each connected to the projecting sections 22, the aforementioned sections being formed in one piece. The end plate 2 is formed by bending a sheet of metal.

[0029] The main body section 21 is a rectangular structure that is in contact with the second spacer 5. The length of the main body section 21 in the upward-downward direction is shorter than that of the energy storage device 1 in the upward-downward direction, and the length of the main body section 21 in the left-right direction is also shorter than that of the energy storage device 1 in the left-right direction.

[0030] The foreground sections 22 are each connected to upper sections at both ends of the main body section 21. One upper end of the main body section 21 corresponds to one upper end of the foreground sections 22. In other words, the upper end of the main body section 21 and the upper end of the foreground sections 22 are positioned on the same straight line. As shown in Fig. As shown in Figure 2, the preceding section 22 is curved in an arc, so that it projects forward in the forward-backward direction and, when viewed from above (upward-downward direction), forwards. Thus, a space S1 is provided between a surface (a back side) of the preceding section 22, which faces the energy storage device 1, and the second spacer 5.

[0031] The side surface section 23 is a rectangular structure extending rearward in the forward-backward direction from an end section of the projecting section 22, which is located on one side opposite an end section of the projecting section 22 that is closer to the main body section 21. The length of the side surface section 23 in the upward-downward direction corresponds to the length of the projecting section 22 in the upward-downward direction. The length of the side surface section 23 in the forward-backward direction is less than the length of the energy storage device 1 in the forward-backward direction. The side surface section 23 is covered by the side plate 3 and connected to the side plate 3 by welding, gluing, bolting, or the like.

[0032] When the energy storage device 1 expands in the forward-backward direction due to charging and discharging, a central section of the surface of the energy storage device 1, oriented in the forward-backward direction, becomes the most expanded section. For this reason, the main body section 21 should preferably be positioned to be in contact with the central section of the surface of the energy storage device 1, oriented in the forward-backward direction, in order to suppress swelling of the energy storage device 1.Here, the middle section of the surface of the energy storage device 1 in the forward-backward direction refers to an area corresponding to a middle section if the surface of the energy storage device 1 in the forward-backward direction is divided into three equal sections in the upward-downward direction, and also to a middle section if the surface is divided into three equal sections in the left-right direction.

[0033] The housing 11 of the energy storage device 1 has a connecting section 13 for joining the main housing body and the cover body. The connecting section 13 is a section of the housing 11 that is weak with respect to its strength. Therefore, if the main body section 21 comes into contact with the connecting section 13 in the forward-backward direction, the connecting section 13 will bear a load from the main body section 21 and may be damaged. Therefore, the main body section 21 should preferably be positioned so that it does not come into contact with the connecting section 13 of the housing 11. <6. Side panel 3>

[0034] Fig. Figure 4 is a perspective view illustrating the construction of the side plate 3 according to the present embodiment. In the present embodiment, two side plates 3 are used. However, since the side plates 3 have shapes that are bilaterally symmetrical to each other, the side plate 3 located on the right side of the energy storage device 1 is described.

[0035] As in Fig. As shown in Figure 4, the side plate 3 is formed by bending a single sheet of metal and has a rectangular first section 31 and a second section 32 extending to the left from an upper end of the first section 31. The length of the first section 31 in the upward-downward direction is greater than that of the side surface section 23 of the end plate 2 in the upward-downward direction. When the end plate 2 and the side plate 3 are joined, the first section 31 extends upward beyond the upper end of the side surface section 23. The second section 32 is a section bent from the upper end of the first section 31 and is designed to engage with a top surface of the first spacer 4 or the second spacer 5.In the second section 32, a recess 321 or a projection 322 is formed according to the shape of the first spacer 4 or the second spacer 5, which is in contact with the second section 32. <7. Assembly of the energy storage device 8>

[0036] Fig. Figure 5 is a perspective view illustrating an assembly of the energy storage device 8 (in a state in which the outer body 7 is mounted) according to the present embodiment.

[0037] A method for assembling the energy storage device 8 is described. First, several energy storage devices 1 are aligned longitudinally. The first spacer 4 is located between two adjacent energy storage devices 1. Next, the second spacer 5 and the end plate 2 are arranged on one (front) side of the energy storage device 1, which is oriented at one end section (front end) in the forward-backward direction, and on the other (rear) side of the energy storage device 1, which is oriented at the other end section (rear end) in the forward-backward direction.A pair of side plates 3 is then positioned to enclose the multiple energy storage devices 1, the first spacers 4, the second spacers 5, and a pair of end plates 2 in a left-right direction, and the pair of side plates 3 is attached to the pair of end plates 2. That is, the second section 32 of the side plate 3 engages with the top of the first spacer 4 or the second spacer 5, and furthermore, a front end and a rear end of the side plate 3 are connected to the respective side surface sections 23 of the pair of end plates 2 by welding, gluing, screwing, or the like.

[0038] The multiple energy storage devices 1, the first spacers 4, the second spacers 5, the pair of end plates 2, and the pair of side plates 3 are then housed in the outer body 7. The outer body 7 has a rectangular, parallelepiped-shaped main body 71 with an opening at its top and a cover body 72 that closes the opening of the main body 71. An external connection 721 is provided on the cover body 72. The multiple energy storage devices 1, the first spacers 4, the second spacers 5, the pair of end plates 2, and the pair of side plates 3 are inserted into the main body 71, and then the opening of the main body 71 is closed by the cover body 72. The terminals 12 of the multiple energy storage devices 1 are also connected to each other by a busbar (not shown).Furthermore, the terminals 12 are electrically connected to the external terminals 721 of the cover body 72 via the busbar.

[0039] Fig. Figure 6 is a cross-sectional view illustrating the assembly of the energy storage device 8 (in a state where the outer body 7 is mounted) according to the present embodiment. As shown in Fig. As shown in Figure 6, when the energy storage device 8 has the outer body 7, a space S2 is provided between the main body section 21 of the end plate 2 and a side wall of the main body 71. Fig. For the sake of simplicity, the first spacer 4 and the second spacer 5 have been omitted in Figure 6.

[0040] The thickness of the end plate 2 in the forward-backward direction should preferably be greater than that of the side plate 3 in the left-right direction. This prevents excessive deformation of the aforementioned section 22 when the energy storage device 1 expands in the forward-backward direction. Furthermore, since the thickness of the side plate 3 in the left-right direction is less than the thickness of the end plate 2 in the forward-backward direction, an increase in the mass of the energy storage device 8 can be suppressed. If the aforementioned section 22 is deformed to such an extent that it undergoes plastic deformation, a binding force necessary to hold the energy storage device 1 in place will not be generated, and the performance of the energy storage device 1 may deteriorate.Since the foregoing section 22 is provided on the end plate 2, which has a greater thickness than the side plate 3, the maximum stress acting on the end plate 2 can be reduced without adversely affecting the performance of the energy storage device 1.

[0041] It is sufficient if the thickness of the end plate 2 in the forward-backward direction is greater than the thickness of the side plate 3 in the left-right direction. It is sufficient if the thickness of one of the two end plates 2 is greater than the thickness of one of the two side plates 3. <8. Properties>

[0042] Fig. Figure 7 is a cross-sectional view showing the behavior of the end plate 2 when the energy storage device 8 has swollen according to the present embodiment.

[0043] The energy storage device 8 described above offers the following advantages.

[0044] If the energy storage device 1 is damaged due to charging and discharging in the Fig. When the end plate 2 is swollen in the forward-backward direction shown in Figure 7, a force acting on the end plate 2 can be absorbed by the protruding section 22. Although a force acts on the end plate 2 at this point, causing it to expand outwards, a portion of this force can be transferred to the protruding section 22 due to its design. That is, the protruding section 22 can deform in such a way that the space S1 within the protruding section 22 is increased in conjunction with the deformation of the end plate 2. Therefore, it is possible to suppress the local concentration of the force acting on the end plate 2 and distribute the force. Consequently, the maximum load acting on the end plate 2 can be reduced, and it becomes possible to implement a design in which the stiffness required for the end plate 2 is reduced.As an alternative to the measure mentioned above, it is possible to increase the stiffness of the end plate 2. In particular, the elastic modulus of the material of the end plate 2 can be increased, or the thickness of the end plate 2 can be increased. In this case, disadvantages arise such as increased costs for the end plate 2 and an increased mass of the energy storage device 8. The energy storage device 8 of the present embodiment can reduce the maximum load acting on the end plate 2 while simultaneously suppressing the disadvantages described above. It should be noted that in . Fig. 7. The dimensions of the energy storage device 1 are exaggerated for the sake of simplicity. Furthermore, the first spacer 4 and the second spacer 5 have been omitted.

[0045] Fig. Figure 8 shows an overview of the result of a simulation carried out by the inventor of the present invention with regard to the above point. Fig. Figure 8 is a schematic representation showing the simulation results of the load distributions when a force is applied to an end plate 20 of a comparative example and to the end plate 2 according to the present embodiment. Figure (a) of Fig. Figure 8 shows a model (comparative example) in which the end plate 20, which has no protruding section and has a main body section 201 and a side surface section 202, is used, and the side plate 3 is connected to the end plate 20. Figure (b) in Fig. Figure 8 shows a model in which the side plate 3 is connected to the end plate 2 according to the present embodiment.

[0046] These models were used, and a force in the direction of an arrow was applied to end plates 2 and 20. Here, in the model shown in Figure (a), Fig. 8 a load or stress acting on a connected section between the main body section 201 and the side surface section 202 in the end plate 20 is greatest. Meanwhile, in the model of Figure (b) of Fig. 8 a load acting on the preceding section 22 of the end plate 2 was greatest. In addition, in the Fig. In model 8 (b), the area S in which the load has its maximum value is longer than in the area shown in Fig. 8 shown in model (a). That is, it was found that the load acting on end plate 2 is distributed more efficiently than the load acting on end plate 20. Furthermore, the maximum load on the model shown in (b) was Fig. 8. Acting load approximately 20% lower than that on the model of representation (a) in Fig. 8 effective maximum load.

[0047] The thickness of the end plate 2 in the forward-backward direction is greater than the thickness of the side plate 3 in the left-right direction. Therefore, when the energy storage device 1 expands in the forward-backward direction, excessive deformation of the aforementioned section 22 can be prevented. Furthermore, since the thickness of the side plate 3 in the left-right direction is less than the thickness of the end plate 2 in the forward-backward direction, an increase in the mass of the energy storage device 8 can be suppressed. If the aforementioned section 22 is deformed to such an extent that it undergoes plastic deformation, a binding force required to hold the energy storage device 1 in place will not be generated, and the performance of the energy storage device 1 may deteriorate.Since the foregoing section 22 is provided on the end plate 2, which has a greater thickness than the side plate 3, the maximum load acting on the end plate 2 can be reduced without adversely affecting the performance of the energy storage device 1.

[0048] Since the cross-section of the preceding section 22 is arc-shaped, it is possible to suppress a local concentration of the force acting on the preceding section 22.

[0049] As in Fig. As shown in Figure 6, when the energy storage device 8 has the outer body 7, the space S2 is located between the side wall 71 of the outer body 7 and the main body section 21 of the end plate 2. This feature prevents a load acting on the deformed outer body 7 from acting directly on the end plate 2 if the outer body 7 is deformed by an external impact. This prevents damage to the energy storage device 1. Furthermore, the presence of space S2 allows it to serve as a receiving or compensation space for expansion when the energy storage device 1 expands longitudinally. This also prevents damage to the outer body 7. Meanwhile, the side wall 71 of the outer body 7 limits the swelling of the energy storage device 1, preventing excessive swelling. <9. Modification Examples>

[0050] The energy storage device 8 according to the embodiment of the present invention is described above. However, the present invention is not limited to the embodiment described above, and various modifications can be made without departing from the basic concept of the present invention. It should be noted that the following modification examples can be combined with the embodiment described above and that the modification examples can optionally be combined with one another.

[0051] In the embodiment described above, the protruding section 22 is indeed provided on the end plate 2; however, the position or orientation of the protruding section is not particularly restricted, and various embodiments are possible. That is to say, the protruding section can be located near a corner section where the end plate 2 and the side plate 3 intersect. (Modification example 1)

[0052] As in Fig. As shown in Figure 9, the end plate 2 may optionally have only a flat main body section, and the side plate 3 may be provided with a projecting section 35. More precisely, the side plate 3 has a plate-shaped main body section 34, the projecting section 35 which is curved such that it projects forward in a forward-backward direction from a front end of the main body section 34, and a front surface section 36 which extends in a left-right direction from an end section of the projecting section 35 on a side opposite the main body section 34. A rear or a front of the front surface section 36 is attached to the end plate 2 by welding, bonding, bolting, or the like. Even in a mode as described above, a force acting on the side plate 3 can be absorbed by the projecting section 35 of the side plate 3.This means that since the preceding section 35 is deformed in such a way that the space S1 of the preceding section 35 is enlarged, the force acting on the side plate 3 can be absorbed. (Modification example 2)

[0053] As in Fig. As shown in Figure 10, a projecting section provided on the end plate 2 does not extend forward in the forward-backward direction, but rather in the right-left direction in which a main body section 24 extends, and is curved such that it projects laterally. Even in a mode as described above, a force acting on the end plate 2 can be absorbed by a projecting section 25. (Modification example 3)

[0054] As in Fig. As shown in Figure 11, a projecting section is provided on the side plate 3; however, this projecting section, i.e., a projecting section 38, is curved such that it projects in the left-right direction. Even in a mode such as the one described above, a force acting on the side plate 3 can be absorbed by the projecting section 38 of the side plate 3. (Modification examples 4 and 5)

[0055] In the embodiment described above, the cross-section of the preceding section 22 is indeed curved in an arc, but the preceding section 22 is not limited to this shape. As in Fig. As shown in Figure 12, a cross-section of the preceding section 22 may have a shape that projects at an acute angle. As shown in Fig.As shown in Figure 13, a cross-section of the projecting section 22 can have a rectangular shape. That is, the cross-sectional shape can have a flat surface that is substantially parallel to the main body section 21. Even if the projecting section 22 has an acute-angled or rectangular projection shape, it is deformed in such a way that the space S1 is enlarged. Therefore, it is possible to absorb the force acting on the end plate 2. However, it is advantageous for the cross-section of the projecting section 22 to have a curved shape, since the curved shape can suppress a local occurrence of the force. (Further examples)

[0056] As described above, the direction in which the preceding section 22 projects is not particularly restricted and can be determined accordingly with respect to the outer body 7. Preferably, however, the direction of the projection should be the direction in which the energy storage devices 1 are oriented.

[0057] In the embodiment described above, the protruding sections 22 are provided at four corner sections, which are bounded by the two end plates 2 and the two side plates 3. However, the locations where the protruding sections 22 are provided are not limited to those mentioned above. The protruding section 22 may optionally be provided at only two corner sections at one end in the forward-backward direction or at only two corner sections at one end in the left-right direction. Alternatively, the protruding section 22 may be provided at only one of the four corner sections.

[0058] The design of the energy storage device 1 is not particularly restricted, and a design from a known energy storage device can be adopted. Furthermore, the shapes of the first spacer 4, the second spacer 5, and the outer body 7 can be modified accordingly.

[0059] In the embodiment described above, two end plates 2 and two side plates 3 are used. The end plate 2 may optionally be provided only at one end section of the multiple energy storage devices 1. Furthermore, optionally only one side plate 3 is provided. It is also not essential that the end plate 2 and the side plate 3 are separate bodies. That is, the end plate 2 and the side plate 3 can be formed in one piece without a connecting section.

[0060] The embodiment described above is designed such that the thickness of the end plate 2 in the forward-backward direction is greater than the thickness of the side plate 3 in the left-right direction. However, this design is not strictly necessary. A design in which the thickness of the end plate 2 equals the thickness of the side plate 3, or a design in which the thickness of the end plate 2 is less than the thickness of the side plate 3, can also be used.

[0061] In the embodiment described above, the energy storage device 8 has the outer body 7. However, it is not absolutely necessary for the energy storage device 8 to have the outer body 7. That is, the multiple energy storage devices 1, the first spacers 4, the second spacers 5, the two end plates 2, and the two side plates 3 can be provided directly in a vehicle housing. Industrial applicability

[0062] The present invention can be applied to an energy storage device equipped with an energy storage device such as a lithium-ion secondary battery. Description of the reference symbols 1 Energy storage device 11 cases 12 connection 13 Connecting section 2.20 End plate 21, 201 Main body section 22 Foreground section 23, 202 side surface section 3 side panel 31 First Section 32 Second Section 36 Front surface section 321 Excerpt 322 lead 4 First spacer 5 Second spacer 7 Outer body 71 Main body 72 lid bodies 721 External connection 8 Energy storage device S1 Room S2 Room QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2020-57520

[0003]

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