Energy storage element unit

Abstract

To provide a power storage element unit which prevents inside a storage box from being visible.SOLUTION: A power storage element unit includes a storage box having a plurality of wall parts, and a plurality of power storage element modules stored in the storage box. The plurality of wall parts includes a first wall part, and a second wall part connected to the first wall part. The first wall part includes a first resin plate having a resin plate body part, and a connection part extending in a direction crossing the resin plate body part from the edge part of the resin plate body part. The second wall part includes a second resin plate non-parallel to the resin plate body part. At least a part of the connection part overlaps a part of the second resin plate in the thickness direction of the second resin plate.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present disclosure relates to an energy storage element unit. [Background technology]

[0002] For example, an energy storage element unit having a plurality of energy storage element modules is known, as disclosed in Patent Document 1. The energy storage element unit includes a plurality of energy storage element modules and a storage box for storing the energy storage element modules. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-5027 Summary of the Invention [Problem to be solved by the invention]

[0004] There have been cases where a storage box for an energy storage element unit is required to be constructed from multiple components. When the storage box for an energy storage element unit is constructed from multiple components, there has been a demand for an energy storage element unit in which the interior of the storage box cannot be seen through gaps between the multiple components, from the perspective of improving the aesthetic appearance of the energy storage element unit.

[0005] The present disclosure has been made in consideration of the above circumstances, and aims to provide an energy storage element unit in which the inside of a storage box cannot be seen. [Means for solving the problem]

[0006] The energy storage element unit according to the present disclosure comprises: a storage box having a plurality of walls; a plurality of energy storage element modules housed in the housing box, the plurality of wall portions include a first wall portion and a second wall portion connected to the first wall portion, the first wall portion includes a first resin plate having a resin plate main body portion and a connection portion extending from an edge portion of the resin plate main body portion in a direction intersecting the resin plate main body portion, the second wall portion includes a second resin plate that is not parallel to the resin plate main body portion, At least a portion of the connection portion overlaps a portion of the second resin plate in the thickness direction of the second resin plate.

[0007] In the energy storage element unit according to the present disclosure, the first wall portion is composed of a first laminate including the first resin plate and a first metal plate overlapping the resin plate main body portion, the second wall portion is formed of a second laminate including the second resin plate and a second metal plate overlapping the second resin plate, The second wall portion may be connected to the first wall portion by fixing the positional relationship between the first metal plate and the second metal plate.

[0008] In the energy storage element unit according to the present disclosure, the connecting portion has a thin plate connecting portion at an edge portion thereof, the thin plate connecting portion having a thickness smaller than the thickness of the resin plate main body portion, the second resin plate has a thin plate portion at an edge portion thereof, the thin plate portion having a thickness smaller than the maximum thickness of the second resin plate; At least a portion of the thin plate connecting portion overlaps at least a portion of the thin plate portion in the thickness direction of the second resin plate, In a direction perpendicular to the thickness direction of the second resin plate, the thin plate connecting portion may face a part of the second resin plate, and the thin plate portion may face a part of the connecting portion.

[0009] In the energy storage element unit according to the present disclosure, At least a portion of the connection portion may overlap a portion of the second resin plate from the outside of the storage box.

[0010] In the energy storage element unit according to the present disclosure, The second resin plate may be spaced apart from the first resin plate in a direction perpendicular to the resin plate main body.

[0011] In the energy storage element unit according to the present disclosure, the plurality of wall portions include a bottom wall portion, an upper wall portion facing the bottom wall portion, and a plurality of side wall portions connected to the bottom wall portion and the upper wall portion; One of the side wall portions may form the first wall portion, and another of the side wall portions may form the second wall portion.

[0012] In the energy storage element unit according to the present disclosure, the bottom wall portion has a pair of long sides and a pair of short sides extending in a direction intersecting the pair of long sides, the plurality of side wall portions include a pair of first side wall portions connected to the pair of long sides of the bottom wall portion and a pair of second side wall portions connected to the pair of short sides of the bottom wall portion, each of the pair of first side wall portions constitutes the first wall portion including the first resin plate, and each of the pair of second side wall portions constitutes the second wall portion including the second resin plate; the first resin plate of the pair of first side wall portions has a pair of the connection portions extending from edge portions on both sides of the resin plate main body portion in the direction in which the pair of long sides extend, At least a portion of each of the pair of connecting portions may overlap a portion of the second resin plate from outside the storage box.

[0013] In the energy storage element unit according to the present disclosure, The storage box further includes a decorative panel that covers one of the side wall portions, The decorative panel has a plurality of decorative wall portions including at least a first decorative wall portion and a second decorative wall portion, the first decorative wall portion has a decorative wall portion main body portion and a decorative connecting portion extending from an edge portion of the decorative wall portion main body portion in a direction intersecting the decorative wall portion main body portion, the second decorative wall portion is non-parallel to the decorative wall portion main body portion, At least a portion of the decorative connecting portion may overlap a portion of the second decorative wall portion in a thickness direction of the second decorative wall portion. [Effects of the Invention]

[0014] According to the present disclosure, it is possible to provide an energy storage element unit in which the inside of the storage box cannot be seen. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a diagram for explaining one embodiment, and is a perspective view showing an energy storage element unit. [Figure 2] FIG. 2 is a perspective view showing the inside of the energy storage element unit of FIG. [Figure 3] 3 is a perspective view showing a first side wall portion of the storage box of the energy storage element unit of FIG. 1. FIG. [Figure 4] 4 is a perspective view showing an upper wall portion of the storage box of the energy storage element unit of FIG. [Figure 5] 5 is a perspective view showing a storage box for the energy storage element unit of FIG. 1. FIG. [Figure 6] 6 is a perspective view showing the resin plate of the first side wall portion of FIG. [Figure 7] 7 is a partial cross-sectional view showing a part of the cross section of the first side wall portion taken along line AA in FIG. [Figure 8] 8 is a side view showing a resin plate and a metal plate included in a laminate that constitutes the first side wall portion of FIG. [Figure 9] 9 is a partial cross-sectional view showing a part of the first resin plate of the first wall portion and the second resin plate of the second wall portion taken along the line BB in FIG. [Figure 10] 10 is a partial cross-sectional view showing a part of the first resin plate of the first wall portion and the second resin plate of the second wall portion taken along the line BB in FIG. [Figure 11] FIG. 11 is a diagram for explaining the effects of the features of the first resin plate and the second resin plate. [Figure 12] FIG. 12 is a diagram for explaining the effects of the features of the first resin plate and the second resin plate. [Figure 13] 13 is a perspective view showing the resin plate of the upper wall portion of FIG. [Figure 14]14 is a perspective view showing the metal plate of the upper wall portion of FIG. [Figure 15] 15 is a partial cross-sectional view showing a part of the cross section of the first decorative wall portion and the second decorative wall portion taken along line CC in FIG. [Figure 16] 16 is a perspective view showing an energy storage element module assembly and an energy storage element module arranged in a storage box for the energy storage element unit of FIG. [Figure 17] 17 is a perspective view showing an energy storage element module included in the energy storage element module assembly of FIG. 16. FIG. [Figure 18] 18 is a perspective view showing a plurality of stacked cells included in the energy storage element module of FIG. [Figure 19] FIG. 19 is a perspective view showing one cell shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, an example of an embodiment of an energy storage element unit according to the present disclosure will be described in detail with reference to FIGS.

[0017] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. Note that in the drawings accompanying this specification, the scale and aspect ratios have been appropriately changed and exaggerated from those of the actual objects for the sake of ease of illustration and understanding.

[0018] 1 to 19 are diagrams illustrating an embodiment of the present disclosure. Of these, Fig. 1 is a perspective view showing an energy storage element unit 10, and Fig. 2 is a perspective view showing the interior of the energy storage element unit 10. Note that Fig. 2 shows the energy storage element unit 10 in a state where an upper wall portion 13b and a decorative panel 19, which will be described later, have been removed. Also, in Fig. 2, a resin plate 91 is omitted from the illustration of a side wall portion 13c, which will be described later.

[0019] To clarify the directional relationships between the drawings, some drawings use arrows to indicate the first direction DA, the second direction DB, and the third direction DC, which are common to the drawings. The tip of the arrow corresponds to one side SA1, SB1, or SC1 of each direction DA, DB, or DC. Arrows pointing toward the front of the drawing in a direction perpendicular to the paper surface are indicated by a symbol with an X in a circle, as shown in FIG. 8 . Arrows pointing toward the back of the drawing in a direction perpendicular to the paper surface are indicated by a symbol with a dot in a circle, as shown in FIG. 9 . Furthermore, in the drawings showing components (e.g., the energy storage element module assembly 15 and the energy storage element module 20) stored in the storage box 11, the directions and orientations of the components stored in the storage box 11 are shown. Similarly, in the drawings showing components (e.g., the cells 30 and the case 18, described later) included in the energy storage element module 20, the directions and orientations of the components assembled in the energy storage element module 20 stored in the storage box 11 are shown.

[0020] In the illustrated example, the first direction DA, the second direction DB, and the third direction DC are perpendicular to one another. The first direction DA is parallel to the vertical direction. One side SA1 in the first direction DA is the lower side in the vertical direction, and the other side opposite to the one side in the first direction DA is the upper side in the vertical direction.

[0021] The energy storage element unit 10 is used as a secondary battery unit that can be charged and discharged. The illustrated energy storage element unit 10 is applied to buildings such as homes and public facilities, and is electrically connected to the building's wiring to function as a power source for electrical devices installed within the building.

[0022] 1 and 2, the energy storage element unit 10 includes a storage box 11 and a plurality of energy storage element modules 20 stored in the storage box 11. The energy storage element unit 10 shown in FIGS. 1 and 2 further includes a control module 14 stored in the storage box 11.

[0023] First, the storage box 11 will be described. The storage box 11 has a plurality of wall portions 13. The wall portions 13 form an arrangement space for the control module 14 and the energy storage element modules 20. In the example shown in Fig. 2, the storage box 11 further has a frame portion 12 that connects adjacent wall portions 12 to each other. The wall portions 13 close off the arrangement space for the control module 14 and the energy storage element modules 20.

[0024] The multiple wall portions 13 include a first wall portion 13d and a second wall portion 13e connected to the first wall portion 13d. The first wall portion 13d and the second wall portion 13e are connected to each other without any wall portion 13 other than the first wall portion 13d and the second wall portion 13e interposed therebetween. Any two wall portions 13 included in the multiple wall portions 13 that are connected to each other without any other wall portion 13 interposed therebetween can be considered as the first wall portion 13d and the second wall portion 13e.

[0025] In this embodiment, the multiple walls 13 of the storage box 11 include a bottom wall 13a, an upper wall 13b facing the bottom wall 13a, and multiple side walls 13c connected to the bottom wall 13a and the upper wall 13b. In the example shown in Fig. 1, the storage box 11 has a substantially rectangular parallelepiped shape and has the bottom wall 13a, the upper wall 13b, and four side walls 13c as the walls 13. In this case, one of the multiple side walls 13c can serve as a first wall 13d, and another of the multiple side walls 13c can serve as a second wall 13e.

[0026] The bottom wall portion 13a has a pair of long sides 131 and a pair of short sides 132 extending in a direction intersecting the pair of long sides 131. In this embodiment, the bottom wall portion 13a is a substantially rectangular, plate-like wall portion 13 located on one side SA1 in the first direction DA. The top wall portion 13b is a substantially rectangular, plate-like wall portion 13 facing the bottom wall portion 13a in the first direction DA. The bottom wall portion 13a and the top wall portion 13b each have a pair of long sides 131 extending in the third direction DC and a pair of short sides 132 extending in a second direction DB perpendicular to the third direction DC. The four side wall portions 13c are each a substantially rectangular, plate-like wall portion 13 connected to an edge portion located on one side of the bottom wall portion 13a and an edge portion located on one side of the top wall portion 13b.

[0027] In the present embodiment, the side walls 13c include a pair of first side walls 13c1 connected to a pair of long sides 131 of the bottom wall 13a and a pair of second side walls 13c2 connected to a pair of short sides 132 of the bottom wall 13a. The first side walls 13c1 are connected to the long sides 131 of the bottom wall 13a without any other wall 13 therebetween. The second side walls 13c2 are connected to the short sides 132 of the bottom wall 13a without any other wall 13 therebetween. In the example shown in FIGS. 1 and 2, the pair of first side walls 13c1 are a pair of side walls 13c facing each other in the second direction DB and parallel to the direction in which the long sides 131 of the bottom wall 13a extend (third direction DC). The pair of second side walls 13c2 are a pair of side walls 13c that face each other in the third direction DC and are parallel to the direction in which the short side 132 of the bottom wall 13a extends (the second direction DB). In this case, at least one of the pair of first side walls 13c1 may form the first wall 13d, and at least one of the pair of second side walls 13c2 may form the first wall 13d. Also, at least one of the pair of first side walls 13c1 may form the first wall 13d, and at least one of the pair of second side walls 13c2 may form the first wall 13d.

[0028] In this embodiment, as an example of a storage element unit 10 in which multiple wall portions 13 include first wall portions 13d and second wall portions 13e, a storage element unit 10 in which each of a pair of first side wall portions 13c1 forms a first wall portion 13d and each of a pair of second side wall portions 13c2 forms a second wall portion 13e is described.

[0029] 2, each of the multiple wall portions 13 is an independent member that is generally plate-shaped overall. The edges of each of the multiple wall portions 13 are connected to the edges of adjacent other wall portions 13 directly or via frame portions 12, which will be described later. The connections between the edges of the multiple wall portions 13 form a storage box 11 that has a storage space for storing multiple energy storage element modules 20.

[0030] The structure of the wall portion 13 will be described. First, the structure of the side wall portion 13c will be described as an example of the structure of the wall portion 13. The description of the structure of the side wall portion 13c can also be applied to the bottom wall portion 13a and the top wall portion 13b unless inconsistent. FIG. 3 is a perspective view showing one of the side wall portions 13c as viewed from inside the storage box 11. FIG. 3 shows the first side wall portion 13c1 of the pair of first side wall portions 13c1, which is located opposite one side SB1 in the second direction DB, as viewed from inside the storage box 11 (the opposite side from one side SB1 in the second direction DB). FIG. 4 is a perspective view showing the top wall portion 13b as viewed from inside the storage box 11 (one side SA1 in the first direction DA). 5 is a diagram showing the wall portions 13 of the storage box 11, excluding one of the upper wall portion 13b and the first side wall portion 13c1 (the first side wall portion 13c1 located on the opposite side from the one side SB1 in the second direction DB), and the frame portion 12 connecting the wall portions 13. Note that in FIG. 5, the resin plate 91 for the side wall portion 13c is not shown.

[0031] At least one of the multiple wall portions 13 is formed from a laminate 90 including a resin plate 91 and a metal plate 92. As long as at least one of the multiple wall portions 13 is formed from a laminate 90 including a resin plate 91 and a metal plate 92, the structure of the other wall portions 13 is not particularly limited. Each of the other wall portions 13 may be formed from a single layer or a laminate including either a resin plate 91 or a metal plate 92, which will be described later, or may be formed from a laminate including a resin plate 91 and a metal plate 92. That is, each of the other wall portions 13 may be a single layer including a resin plate 91, a single layer including a metal plate 92, or a laminate including a resin plate 91 and a metal plate 92. From the viewpoint of ensuring the strength of the storage box 11, it is preferable that each of the multiple wall portions 13 includes a metal plate 92.

[0032] In this embodiment, at least a plurality of side wall portions 13c of the plurality of wall portions 13 are formed from a laminate 90. That is, all of the plurality of side wall portions 13c included in the plurality of wall portions 13 are formed from a laminate 90 including a resin plate 91 and a metal plate 92. In this embodiment, the top wall portion 13b and the four side wall portions 13c are laminates 90 including a resin plate 91 and a metal plate 92. In this embodiment, the bottom wall portion 13a is a laminate including two metal plates 92. Note that, unless inconsistent, descriptions in this specification regarding the resin plate 91 constituting the laminate 90 including the resin plate 91 and the metal plate 92 also apply to the resin plate 91 in a single layer or a laminate that includes the resin plate 91 but does not include the metal plate 92. Furthermore, unless inconsistent, descriptions in this specification regarding the metal plate 92 constituting the laminate 90 including the resin plate 91 and the metal plate 92 also apply to the metal plate 92 in a single layer or a laminate that includes the metal plate 92 but does not include the resin plate 91.

[0033] The structure of the wall 13, which is a laminate 90 made up of a resin plate 91 and a metal plate 92, will be described in more detail using the first side wall 13c1 shown in Fig. 3 as an example. In the example shown in Fig. 3, the side wall 13c is a laminate 90 made up of a resin plate 91 and a metal plate 92 that is located more inward of the resin plate 91 in the storage box 11.

[0034] Fig. 6 is a perspective view showing a resin plate 91 included in the side wall portion 13c shown in Fig. 3. In the example shown in Fig. 6, the resin plate 91 included in the side wall portion 13c has a substantially plate-like shape.

[0035] As described above, in the present embodiment, each of the pair of first side wall portions 13c1 forms the first wall portion 13d, and each of the pair of second side wall portions 13c2 forms the second wall portion 13e. In particular, each of the pair of first side wall portions 13c1 forms the first wall portion 13d including the first resin plate 911, and each of the pair of second side wall portions 13c2 forms the second wall portion 13e including the second resin plate 912.

[0036] The first wall portion 13d includes, as the resin plate 91, a first resin plate 911 having a resin plate main body portion 911a and a connection portion 911b extending from an edge portion of the resin plate main body portion 911a in a direction intersecting the resin plate main body portion 911a. In the example shown in FIGS. 3 and 6, the first wall portion 13d has a first metal plate 921 as the metal plate 92. The first wall portion 13d is also formed of a first laminate 901 that is the laminate 90. In the example shown in FIGS. 3 and 6, the first wall portion 13d is formed of the first laminate 901 that includes the first resin plate 911 and the first metal plate 921 that overlaps the resin plate main body portion 911a.

[0037] The second wall portion 13e includes, as the resin plate 91, a second resin plate 912 that is not parallel to the resin plate main body portion 911a of the first wall portion 13d. In this embodiment, the second resin plate 912 is perpendicular to the resin plate main body portion 911a. In this embodiment, the second resin plate 912 is parallel to the connecting portion 911b. In this embodiment, the second resin plate 912 is a substantially rectangular plate-like member that is parallel to the first direction DA and the second direction DB. In this embodiment, the second wall portion 13e includes a second metal plate 922 as the metal plate 92. The second wall portion 13e is also formed of a second laminate 902 that is the laminate 90. In this embodiment, the second wall portion 13e is formed of a second laminate 902 that includes the second resin plate 912 and a second metal plate 922 that overlaps the second resin plate 912.

[0038] In the example shown in Fig. 6, a resin plate 91 included in the side wall portion 13c is provided with screw holes 95 (described later) used to fasten the resin plate 91 and the metal plate 92. The screw holes 95 are provided in a resin plate main body 911a of a first resin plate 911. In the example shown in Fig. 6, a protrusion 95a extending toward the inside of the storage box 11 is provided on a surface of the resin plate 91 located on the inside of the storage box 11. The screw holes 95 are provided in the protrusion 95a. The screw holes 95 do not penetrate the resin plate 91.

[0039] The resin plate 91 may be provided with ribs 93 protruding from the resin plate 91, as in the resin plate 91 of the side wall portion 13c shown in Fig. 6. The ribs 93 are provided, for example, on at least one of the resin plates 91 of the multiple wall portions 13 of the storage box 11. The ribs 93 are also provided on the resin plate 91 so as to protrude toward the inside or outside of the storage box 11. In the example shown in Fig. 6, the ribs 93 are provided so as to protrude toward the inside of the storage box 11. As an example, all of the resin plates 91 included in the multiple wall portions 13 of the storage box 11 are provided with ribs 93 facing inward.

[0040] 6, the ribs 93 have a lattice shape having portions extending in the first direction DA and portions extending in a direction perpendicular to the first direction DA. In addition, as an example, the ribs 93 are made of a resin material and are provided integrally with the resin plate 91.

[0041] By providing ribs 93 on resin plate 91, the strength of resin plate 91 can be improved, and the strength of storage box 11 and therefore energy storage element unit 10 can be improved.

[0042] Next, the metal plate 92 will be described. The metal plate 92 has a flat main body portion 92a. The metal plate 92 may have, in addition to the main body portion 92a, a portion that connects the main body portion 92a to the resin plate 91. The metal plate 92 may not have a portion that connects the main body portion 92a to the resin plate 91, and the main body portion 92a may be directly connected to the resin plate 91. In this embodiment, the metal plate 92 included in the side wall portion 13c does not have a portion that connects the main body portion 92a to the resin plate 91. In the laminate 90 that constitutes the side wall portion 13c, the main body portion 92a of the metal plate 92 is connected to the resin plate 91. As an example, in this embodiment, the main body portion 92a of the metal plate 92 included in the side wall portion 13c contacts a rib 93 of the resin plate 91. Furthermore, in the example shown in FIG. 3, the metal plate 92 included in the side wall portion 13c has a through hole 94, which will be described later and is used to fix the resin plate 91 and the metal plate 92 together. The through-hole 94 is provided in the main body 92 a of the metal plate 92 .

[0043] FIG. 7 is a diagram showing a portion of a cross section of the wall portion 13 taken along line AA in FIG. 3. As shown in FIGS. 3 and 7, a resin plate 91 and a metal plate 92 included in a laminate 90 are fixed to each other using a screw 96. The screw 96 has a head 96b and a shaft 96a extending from the head 96b. In this case, one of a plurality of through holes 94 through which the shaft 96a of the screw 96 is passed or one of a plurality of screw holes 95 into which the shaft 96a passed through the plurality of through holes 94 is screwed is provided in the resin plate 91. The other of the plurality of through holes 94 or the plurality of screw holes 95 is provided in the metal plate 92. That is, the other of the plurality of through holes 94 or the plurality of screw holes 95, which is different from the one provided in the resin plate 91, is provided in the metal plate 92.

[0044] 3 and 6, a plurality of screw holes 95 are formed in the resin plate 91, and a plurality of through holes 94 are formed in the metal plate 92. In particular, in the first side wall 13c1 constituting the first wall 13d shown in FIGS. 3 and 6, the screw holes 95 are formed in the resin plate main body 911a of the first resin plate 911, as described above. In addition, in the second side wall 13c2 constituting the second wall 13e in this embodiment, the screw holes 95 are formed in the second resin plate 912. In addition, in both the first side wall 13c1 constituting the first wall 13d and the second side wall 13c2 constituting the second wall 13e, the through holes 94 are formed in the main body 92a of the metal plate 92.

[0045] The resin plate 91 and the metal plate 92 can be fixed to each other by overlapping the through hole 94 and the screw hole 95 and screwing the shank 96a of the screw 96 through the through hole 94 into the screw hole 95. The number of the through holes 94 and the number of the screw holes 95 are not particularly limited as long as the resin plate 91 and the metal plate 92 can be fixed to each other. As an example, the number of the through holes 94 provided in the resin plate 91 or the metal plate 92 of one wall portion 13 is 9 to 12. Furthermore, the number of the screw holes 95 provided in the resin plate 91 or the metal plate 92 of one wall portion 13 is 9 to 12. In FIGS. 3 and 6, nine screw holes 95 are provided in the resin plate 91. Furthermore, in FIGS. 3 and 6, nine screw holes 95 are provided in the metal plate 92.

[0046] 8 is a side view showing the resin plate 91 and the metal plate 92 included in the laminate 90 constituting the first side wall portion 13c1 shown in FIG. 3 as viewed from the inside of the storage box 11 (the side opposite to the one side SB1 in the second direction DB). The dimensional ratio between the size of the through hole 94 and the size of the metal plate 92 in FIG. 8 has been changed from the actual dimensional ratio for the sake of convenience in illustration and ease of understanding. In FIG. 8, holes and protrusions other than the through hole 94 provided in the resin plate 91 and the metal plate 92 shown in FIGS. 3 and 6 are omitted from illustration.

[0047] In the example shown in FIG. 8, the multiple through holes 94 include one reference through hole 94a and multiple wide through holes 94b. In FIG. 8, the reference through hole 94a has a circular cross section. Each of the multiple wide through holes 94b has a width greater than the diameter d1 of the reference through hole 94a in the direction in which the wide through hole 94b and the reference through hole 94a are aligned. For example, the wide through hole 94b and the reference through hole 94a denoted by reference symbol A1 in FIG. 8 are aligned in the first direction DA. The width d2 of the wide through hole 94b denoted by reference symbol A1 in the second direction DB in which the wide through hole 94b and the reference through hole 94a are aligned is greater than the diameter d1 of the reference through hole 94a. 8, the wide through hole 94b and the reference through hole 94a are aligned in a direction DD that is non-parallel to any of the first direction DA, the second direction DB, and the third direction DC. The width d3 of the wide through hole 94b, which is aligned in the direction DD, is greater than the diameter d1 of the reference through hole 94a. Although not shown, if the cross section of the reference through hole 94a is not circular, the diameter d1 of the reference through hole 94a may be defined as the maximum width of the reference through hole 94a.

[0048] In this embodiment, the reference through hole 94a fixes the position of the shank 96a that is inserted through the reference through hole 94a. The reference through hole 94a fixes the relative position of the shank 96a that is inserted through the reference through hole 94a with respect to the reference through hole 94a. As an example, the diameter d1 of the reference through hole 94a is equal to the maximum width of the shank 96a in a direction perpendicular to the axial direction of the screw 96. In this case, when the shank 96a is inserted through the reference through hole 94a, the shank 96a comes into contact with the metal plate 92 within the reference through hole 94a, thereby fixing the relative position of the shank 96a with respect to the reference through hole 94a. Although not shown, the reference through hole 94a may have a portion through which the shank 96a of the screw 96 is inserted and a portion that engages with at least a portion of the head 96b of the screw 96. In this case, the part of the reference through-hole 94a and at least a part of the head 96b of the screw 96 are engaged with each other, so that the position of the shaft 96a relative to the reference through-hole 94a can be fixed.

[0049] As an example, the wall 13 formed of the laminate 90 has a pair of first sides 13f extending in a first extension direction and a pair of second sides 13g extending in a second extension direction perpendicular to the first extension direction. In the example shown in Fig. 8, the first side wall 13c1, which is the wall 13 formed of the laminate 90, has a pair of first sides 13f extending in the third direction DC as the first extension direction and a pair of second sides 13g extending in the first direction DA as the second extension direction.

[0050] Here, the multiple wide through holes 94b include a first wide through hole 94c, a second wide through hole 94d, and a third wide through hole 94e. The first wide through hole 94c and the reference through hole 94a are aligned in the first extension direction. The second wide through hole 94d and the reference through hole 94a are aligned in the second extension direction. The third wide through hole 94e and the reference through hole 94a are positioned differently in the first extension direction and the second extension direction. In other words, the third wide through hole 94e does not correspond to either the first wide through hole 94c or the second wide through hole 94d. In the example shown in FIG. 8, two first wide through holes 94c are provided aligned with the reference through hole 94a in the third direction DC. Furthermore, two second wide through holes 94d are provided aligned with the reference through hole 94a in the first direction DA. Furthermore, four third wide through-holes 94e are provided at positions different from the reference through-holes 94a in the third direction DC and the first direction DA.

[0051] The first wide through hole 94c has a width in the first stretching direction that is larger than the diameter d1 of the reference through hole 94a. In other words, the width d4 of the first wide through hole 94c in the first stretching direction shown in Fig. 8 is larger than the diameter d1 of the reference through hole 94a. In Fig. 8, the width d4 of the first wide through hole 94c in the first stretching direction is larger than the width of the first wide through hole 94c in the second stretching direction. In Fig. 8, the first wide through hole 94c has a rounded rectangular shape that extends in the first stretching direction.

[0052] The second wide through hole 94d has a width in the second stretching direction that is larger than the diameter d1 of the reference through hole 94a. In other words, the width d5 ​​of the second wide through hole 94d in the second stretching direction shown in Fig. 8 is larger than the diameter d1 of the reference through hole 94a. In Fig. 8, the width d5 ​​of the second wide through hole 94d in the second stretching direction is larger than the width of the second wide through hole 94d in the second stretching direction. In Fig. 8, the second wide through hole 94d has a rounded rectangular shape that extends in the second stretching direction.

[0053] The third wide through hole 94e has a diameter larger than the diameter d1 of the reference through hole 94a. In other words, the diameter d6 of the third wide through hole 94e shown in FIG. 8 is larger than the diameter d1 of the reference through hole 94a. In FIG. 8, the third wide through hole 94e has a circular cross section. Although not shown, if the cross section of the third wide through hole 94e is not circular, the diameter d6 of the third wide through hole 94e may be defined as the maximum width of the third wide through hole 94e.

[0054] In the present embodiment, the reference through hole 94a is provided in a position in the side wall portion 13c closer to the top wall portion 13b than to the bottom wall portion 13a. In the example shown in Fig. 8, the reference through hole 94a provided in the main body portion 92a of the metal plate 92 of the first side wall portion 13c1 is provided in a position closer to the long side 131 of the top wall portion 13b than to the long side 131 of the bottom wall portion 13a. Although not shown, the reference through hole 94a provided in the main body portion 92a of the metal plate 92 of the second side wall portion 13c2 is provided in a position closer to the short side 132 of the top wall portion 13b than to the short side 132 of the bottom wall portion 13a.

[0055] The effect of the above-described features of the through holes 94 in this embodiment will be described. As described above, in this embodiment, at least one of the plurality of wall portions 13 is configured from a laminate 90 including a resin plate 91 and a metal plate 92. The resin plate 91 is provided with either a plurality of through holes 94 through which shanks 96a of screws 96 are passed or a plurality of screw holes 95 into which the shanks 96a passed through the plurality of through holes 94 are screwed. The metal plate 92 is provided with the other of the plurality of through holes 94 or the plurality of screw holes 95. The through holes 94 and the screw holes 95 are overlapped, and the shanks 96a of the screws 96 are screwed into the screw holes 95 through the through holes 94, thereby fixing the resin plate 91 and the metal plate 92 to each other, thereby forming the laminate 90.

[0056] Generally, the resin constituting the resin plate 91 and the metal constituting the metal plate 92 have different coefficients of thermal expansion. In particular, the resin constituting the resin plate 91 has a higher coefficient of thermal expansion than the metal constituting the metal plate 92. For this reason, when the wall portion 13 is heated by heat generated by the energy storage element modules 20 housed inside the storage box, it is thought that the resin plate 91 will thermally expand by an amount greater than the amount of thermal expansion of the metal plate 92.

[0057] Here, consider a case where, when the resin plate 91 and the metal plate 92 are fixed with the screws 96, there is no room for the shafts 96a passed through the through holes 94 to shift inside the through holes 94, and the relative positions of the shafts 96a with respect to the through holes 94 are fixed. In this case, when the wall portion 13 is heated and the resin plate 91 thermally expands, distortion may occur in the thermally expanded resin plate 91 because the relative positions of the shafts 96a with respect to the through holes 94 are fixed.

[0058] In contrast, in this embodiment, the multiple through holes 94 include one reference through hole 94a and multiple wide through holes 94b. Each of the multiple wide through holes 94b has a width greater than the diameter d1 of the reference through hole 94a in the direction in which the wide through hole 94b and the reference through hole 94a are aligned. In this case, the shaft 96a inserted through each wide through hole 94b is allowed to shift within the wide through hole 94b through which the shaft 96a is inserted in the direction in which the wide through hole 94b and the reference through hole 94a are aligned. Therefore, when the resin plate 91 thermally expands from the reference through hole 94a along the directions of the multiple radial arrows labeled A3 in FIG. 8 , the shaft 96a is allowed to shift within the wide through hole 94b in response to the thermal expansion. This prevents distortion of the thermally expanded resin plate 91. This effectively prevents plastic deformation and cracks from occurring in the thermally expanded resin plate 91.

[0059] In the present embodiment, the reference through hole 94a fixes the position of the shaft 96a that is passed through the reference through hole 94a, thereby making it possible to determine the position that serves as the starting point for expansion of the resin plate 91 due to thermal expansion (the position where the multiple arrows denoted by reference symbol A3 in FIG. 8 intersect when they are extended) at the position of the reference through hole 94a.

[0060] In this embodiment, the plurality of wide through holes 94b include a first wide through hole 94c, a second wide through hole 94d, and a third wide through hole 94e. The first wide through hole 94c and the reference through hole 94a are aligned in a first extension direction in which the pair of first sides 13f extend. The second wide through hole 94d and the reference through hole 94a are aligned in a second extension direction in which the pair of second sides 13g extend. The third wide through hole 94e and the reference through hole 94a are positioned at different positions in the first extension direction and the second extension direction. The first wide through hole 94c has a width greater than the diameter d1 of the reference through hole 94a in the first extension direction. The second wide through hole 94d has a width greater than the diameter d1 of the reference through hole 94a in the second extension direction. The third wide through hole 94e has a diameter greater than the diameter d1 of the reference through hole 94a. By designing the wide through holes 94b in this manner, the wide through holes 94b can be formed into a shape that can be easily formed by processing the resin plate 91 or the metal plate 92. For example, as shown in Fig. 8, the wide through holes 94b can be formed by forming a first wide through hole 94c extending in the direction in which the first side 13f extends (first extension direction), a second wide through hole 94d extending in the direction in which the second side 13g extends (second extension direction), and a third wide through hole 94e having a circular cross section, thereby producing a metal plate 92 provided with the wide through holes 94b. These wide through holes 94b shown in Fig. 8 can be easily formed by processing the resin plate 91 or the metal plate 92, compared to through holes 94 extending in a direction different from the direction in which the first side 13f extends (first extension direction) and the direction in which the second side 13g extends (second extension direction).

[0061] In particular, in this embodiment, the width d4 of the first wide through hole 94c in the first stretching direction is larger than the width of the first wide through hole 94c in the second stretching direction. This makes it easier for the shaft 96a passed through the first wide through hole 94c to deviate in the first stretching direction than in the second stretching direction inside the first wide through hole 94c. Furthermore, the width d5 ​​of the second wide through hole 94d in the second stretching direction is larger than the width of the second wide through hole 94d in the second stretching direction. This makes it easier for the shaft 96a passed through the second wide through hole 94d to deviate in the second stretching direction than in the first stretching direction inside the second wide through hole 94d. As described above, the first wide through hole 94c and the second wide through hole 94d in this embodiment guide the direction of displacement of the shaft 96a passed through the first wide through hole 94c in the first extension direction, and guide the direction of displacement of the shaft 96a passed through the second wide through hole 94d in the second extension direction, thereby guiding the direction in which the resin plate 91 expands due to thermal expansion. This allows the resin plate 91 to expand uniformly when thermally expanding, and can suppress distortion of the resin plate 91.

[0062] In the present embodiment, at least a plurality of side wall portions 13c of the plurality of wall portions 13 are formed from the laminate 90. This makes it possible to form the plurality of side wall portions 13c from the laminate 90 including the resin plate 91 and the metal plate 92, while suppressing distortion of the resin plate 91 in the side wall portions 13c.

[0063] Furthermore, in the side wall 13c of this embodiment, the reference through hole 94a is located closer to the top wall 13b than to the bottom wall 13a. This feature provides the following advantages. As described above, each of the wide through holes 94b has a width greater than the diameter d1 of the reference through hole 94a in the direction in which the wide through holes 94b and the reference through hole 94a are aligned. Therefore, the shaft 96a passed through the reference through hole 94a has less room for misalignment than the shaft 96a passed through the wide through hole 94b. In particular, in the wall 13 shown in FIG. 8, the shaft 96a passed through the reference through hole 94a has less room for misalignment in the up-down direction than the second wide through hole 94d and the third wide through hole 94e, whose widths in the up-down direction (first direction DA) are greater than the diameter d1 of the reference through hole 94a. As a result, the resin plate 91 is supported by the metal plate 92 at the position of the reference through hole 94a via the shaft portion 96a passed through the reference through hole 94a. Here, by providing the reference through hole 94a at a position closer to the upper wall portion 13b than to the bottom wall portion 13a, the position at which the resin plate 91 is supported by the metal plate 92 can be closer to the upper wall portion 13b than to the bottom wall portion 13a. As a result, the resin plate 91 can be more stably supported by the metal plate 92 due to the action of gravity than when the resin plate 91 is supported by the metal plate 92 at a position closer to the bottom wall portion 13a than to the upper wall portion 13b.

[0064] 3 and 6, a plurality of screw holes 95 are formed in the resin plate 91, and a plurality of through holes 94 are formed in the metal plate 92. This feature provides the following effect. In the wall 13 of the present embodiment, which is constituted by a laminate 90 including the resin plate 91 and the metal plate 92, the resin plate 91 covers the metal plate 92 from the outside of the storage box 11. Here, by forming a plurality of screw holes 95 in the resin plate 91 and a plurality of through holes 94 in the metal plate 92, the side of the wall 13 on which the heads 96b of the screws 96 are exposed can be made to face the inside of the storage box 11. This prevents the heads 96b of the screws 96 from being exposed to the outside of the storage box 11, thereby improving the aesthetic appearance of the energy storage element unit 10.

[0065] Next, a description will be given of a mode in which the plurality of wall portions 13 are connected to one another. In this embodiment, adjacent wall portions 12 are connected to one another via a frame portion 12, which will be described later. As an example of a mode in which the plurality of wall portions 13 are connected to one another, a mode in which a first side wall portion 13c1 constituting the first wall portion 13d and a second side wall portion 13c2 constituting the second wall portion 13e are connected will be described.

[0066] In the present embodiment, the positional relationship between the first metal plate 921 of the first wall portion 13d and the second metal plate 922 of the second wall portion 13e is fixed, thereby connecting the second wall portion 13e to the first wall portion 13d. In the present embodiment, the positional relationship between the first metal plate 921 and the second metal plate 922 is fixed, thereby connecting the first wall portion 13d and the second wall portion 13e to each other via the frame portion 12.

[0067] The first metal plate 921 and the second metal plate 922 may be fixed to the frame portion 12 by being directly connected to the frame portion 12, or may be fixed to the frame portion 12 by being connected to the frame portion 12 via a connecting member (not shown). In the example shown in FIG. 3 , a connecting through hole 92h is formed in the first metal plate 921. In this case, the first metal plate 921 can be fixed to the frame portion 12 by fastening a screw, rivet, or the like, which is passed through the connecting through hole 92h, to a connecting member and then fastening the connecting member to the frame portion 12. Although not shown, the second metal plate 922 may also be formed with a connecting through hole 92h, similar to the first metal plate 921. In this case, the second metal plate 922 can be fixed to the frame portion 12 by fastening a screw, rivet, or the like, which is passed through the connecting through hole 92h, to a connecting member and then fastening the connecting member to the frame portion 12, similar to the first metal plate 921.

[0068] 3 and 6, a resin plate 91 such as a first resin plate 911 and a second resin plate 912 may have an insertion protrusion 91c at a position where it does not overlap with a metal plate 92. Furthermore, as shown in Fig. 5, the frame portion 12 may have a frame through-hole 12c. In this case, when a metal plate 92 such as a first metal plate 921 and a second metal plate 922 is fixed to the frame portion 12, the insertion protrusion 91c can be inserted into the frame through-hole 12c, thereby more stably supporting the wall portion 13 such as the first wall portion 13d and the second wall portion 13e on the frame portion 12.

[0069] By fixing the positional relationship between the first metal plate 921 and the second metal plate 922, the positional relationship between the first resin plate 911, which together with the first metal plate 921 constitutes the first laminate 901, and the second resin plate 912, which together with the second metal plate 922 constitutes the second laminate 902, is fixed.

[0070] Fig. 9 is a diagram illustrating a portion of the periphery of an edge portion of a first resin plate 911 and an edge portion of a second resin plate 912 in a cross section of the first wall portion 13d and the second wall portion 13e taken along line BB in Fig. 1. In particular, Fig. 9 illustrates a portion of the periphery of an edge portion of a first side wall portion 13c1, of a pair of first side wall portions 13c1 constituting the first wall portion 13d, located on the opposite side from one side SB1 in the second direction DB, and an edge portion of a second side wall portion 13c2, of a pair of second side wall portions 13c2 constituting the second wall portion 13e, located on the opposite side from one side SB1 in the third direction DC.

[0071] As shown in Figures 3, 6, and 9 and described above, the first resin plate 911 has a resin plate main body portion 911a and a connecting portion 911b extending from an edge of the resin plate main body portion 911a in a direction intersecting the resin plate main body portion 911a. In the example shown in Figures 3, 6, and 9, the connecting portion 911b extends in a direction perpendicular to the resin plate main body portion 911a (second direction DB). In the example shown in Figures 3 and 6, the resin plate main body portion 911a is a generally rectangular plate-like portion parallel to the first direction DA and the third direction DC. The connecting portion 911b extends in a direction parallel to the first direction DA and the second direction DB.

[0072] In the example shown in FIG. 9, the edge of the connecting portion 911b and the edge of the second resin plate 912 face each other in a direction (second direction DB) perpendicular to the resin plate main body portion 911a. Here, the edge of the connecting portion 911b and the edge of the second resin plate 912 are not directly joined to each other. In the example shown in FIG. 9, the positional relationship between the first metal plate 921 and the second metal plate 922 is fixed, thereby fixing the positional relationship between the first resin plate 911 and the second resin plate 912, and maintaining the positional relationship between the edge of the connecting portion 911b and the edge of the second resin plate 912. Because the edge of the connecting portion 911b and the edge of the second resin plate 912 are not directly joined to each other, when the edge of the connecting portion 911b and the edge of the second resin plate 912 are in contact with each other, the edge of the connecting portion 911b and the edge of the second resin plate 912 are allowed to be misaligned with each other. Therefore, when the resin plate 91 thermally expands and the edge of the connection portion 911b comes into contact with the edge of the second resin plate 912, a misalignment occurs between the edges, reducing the force pressing against each other between the edge of the connection portion 911b and the edge of the second resin plate 912. This makes it possible to prevent the resin plate 91 from being distorted by the force pressing against each other between the edge of the connection portion 911b and the edge of the second resin plate 912 when the wall portion 13 is heated and the resin plate 91 thermally expands.

[0073] 9, the second resin plate 912 is spaced apart from the first resin plate 911 in a direction (second direction DB) perpendicular to the resin plate main body 911a. This can prevent the edge of the connecting portion 911b from coming into contact with the edge of the second resin plate 912 when the resin plate 91 thermally expands. Even if the edge of the connecting portion 911b comes into contact with the edge of the second resin plate 912, the force with which the edge of the connecting portion 911b and the edge of the second resin plate 912 press against each other can be more effectively reduced. This can effectively prevent distortion of the resin plate 91 caused by the edge of the connecting portion 911b and the edge of the second resin plate 912 pressing against each other when the resin plate 91 thermally expands.

[0074] In particular, in the present embodiment, the reference through hole 94a and the wide through hole 94b described above allow the resin plate 91 to expand due to thermal expansion. In this case, it is possible to prevent the edge of the connection portion 911b, which has expanded due to thermal expansion, from coming into contact with the edge of the second resin plate 912. Furthermore, even if the edge of the connection portion 911b, which has expanded due to thermal expansion, comes into contact with the edge of the second resin plate 912, it is possible to reduce the force that presses the edge of the connection portion 911b and the edge of the second resin plate 912 against each other.

[0075] Here, at least a portion of the connecting portion 911b overlaps a portion of the second resin plate 912 in the thickness direction of the second resin plate 912. In the example shown in FIG. 9, a portion of the connecting portion 911b overlaps a portion of the second resin plate 912 in the third direction DC, which is the thickness direction of the second resin plate 912. In the example shown in FIG. 3, the connecting portion 911b extends in a direction (first direction DA) in which the edge of the resin plate main body 911a in which the connecting portion 911b is provided extends. The connecting portion 911b extends over the entire range in which the edge of the resin plate main body 911a in which the connecting portion 911b is provided extends. The edge of the second resin plate 912 that overlaps the connecting portion 911b extends in the direction (first direction DA) in which the connecting portion 911b extends. A portion of the connecting portion 911b overlaps the edge portion of the second resin plate 912 over the entire range in which the edge portion extends.

[0076] 9, the connecting portion 911b has a thin plate connecting portion 911c at its edge portion, the thin plate connecting portion 911c having a thickness t2 that is smaller than the thickness t1 of the resin plate main body portion 911a. The second resin plate 912 has a thin plate portion 912a at its edge portion, the thin plate portion 912a having a thickness t4 that is smaller than the maximum thickness t3 of the second resin plate 912. At least a portion of the thin plate connecting portion 911c overlaps at least a portion of the thin plate portion 912a in the thickness direction (third direction DC) of the second resin plate 912. In the direction perpendicular to the thickness direction of the second resin plate 912, the thin plate connecting portion 911c faces a portion of the second resin plate 912, and the thin plate portion 912a faces a portion of the connecting portion 911b. In the example shown in FIG. 9, in the thickness direction (second direction DB) of the resin plate main body 911a, the thin plate connecting portion 911c faces a part of the second resin plate 912, and the thin plate portion 912a faces a part of the connecting portion 911b.

[0077] 9, the thin plate connecting portion 911c extends in the direction (first direction DA) that the connecting portion 911b extends over the entire range over which the connecting portion 911b extends. Furthermore, the thin plate portion 912a extends in the direction (first direction DA) that the edge portion of the second resin plate 912 on which the thin plate portion 912a is provided extends over the entire range over which the edge portion extends. Furthermore, a portion of the thin plate connecting portion 911c overlaps the thin plate portion 912a over the entire range over which the thin plate portion 912a extends.

[0078] At least a portion of the connecting portion 911b may overlap a portion of the second resin plate 912 from the outside of the storage box 11, or may overlap a portion of the second resin plate 912 from the inside of the storage box 11. In the example shown in Fig. 9, a portion of the connecting portion 911b overlaps a portion of the second resin plate 912 from the outside of the storage box 11. In the example shown in Fig. 9, a portion of the thin plate connecting portion 911c overlaps a portion of the thin plate portion 912a from the outside of the storage box 11.

[0079] As described above, in this embodiment, each of the pair of first side walls 13c1 forms a first wall 13d including a first resin plate 911, and each of the pair of second side walls 13c2 forms a second wall 13e including a second resin plate 912. FIG. 10 is a cross-sectional view of the first resin plate 911 included in each of the pair of first side walls 13c1 and the second resin plate 912 included in each of the pair of second side walls 13c2 according to this embodiment, taken along line BB in FIG. 1. The dimensional ratios of elements included in the first resin plate 911 and the second resin plate 912 in FIG. 10 have been changed from their actual dimensional ratios for ease of illustration and understanding. Elements other than the first resin plate 911 and the second resin plate 912, such as the metal plate 92 and the rib 93 provided on the resin plate 91, are omitted from FIG. 10.

[0080] 10, the first resin plate 911 of the pair of first side wall portions 13c1 has, as connecting portions 911b, a pair of connecting portions 911b extending from both edge portions of the resin plate main body portion 911a in the direction in which the pair of long sides 131 of the bottom wall portion 13a extend (third direction DC). Also, at least a portion of each of the pair of connecting portions 911b overlaps a portion of the second resin plate 912 from the outside of the storage box 11.

[0081] The effects of the features of the first resin plate 911 and the second resin plate 912 in this embodiment will be described. As described above, there are cases where it is required to prevent the first resin plate 911 and the second resin plate 912 from being directly joined together, for example, to prevent the resin plate 91 from being distorted when the resin plate 91 thermally expands. In particular, there are cases where it is required to prevent the edge of the connection portion 911b and the edge of the second resin plate 912 from being directly joined together. In particular, there are cases where it is required to separate the second resin plate 912 from the first resin plate 911 in a direction perpendicular to the resin plate main body portion 911a (second direction DB). Here, in this embodiment, at least a portion of the connection portion 911b overlaps a portion of the second resin plate 912 in the thickness direction of the second resin plate 912. This prevents the interior of the storage box 11 from being seen between the edge of the connection portion 911b and the edge of the second resin plate 912 when a user of the energy storage element unit 10 views the storage box 11 from outside the storage box 11 in the portion where the connection portion 911b overlaps the second resin plate 912. This prevents the interior of the storage box 11 from being seen between the edge of the connection portion 911b and the edge of the second resin plate 912 even when the first resin plate 911 and the second resin plate 912 are not directly joined, particularly when the edge of the connection portion 911b and the edge of the second resin plate 912 are not directly joined to each other. This improves the aesthetic appearance of the energy storage element unit 10. This also prevents foreign matter from entering the interior of the storage box 11 between the edge of the connection portion 911b and the edge of the second resin plate 912.

[0082] In this embodiment, at least a portion of the thin plate connecting portion 911c overlaps at least a portion of the thin plate portion 912a in the thickness direction (third direction DC) of the second resin plate 912. In a direction perpendicular to the thickness direction of the second resin plate 912, the thin plate connecting portion 911c faces a portion of the second resin plate 912, and the thin plate portion 912a faces a portion of the connecting portion 911b. This allows at least a portion of the connecting portion 911b to overlap a portion of the second resin plate 912, while reducing the thickness t5 of the storage box 11 at the portion where the connecting portion 911b and the second resin plate 912 overlap, as shown in FIG. 9 . In particular, the thickness t5 of the storage box 11 at the portion where the connecting portion 911b and the second resin plate 912 overlap can be made equal to or smaller than the thickness t1 of the resin plate main body portion 911a and equal to or smaller than the maximum thickness t3 of the second resin plate 912.

[0083] In this embodiment, at least a portion of the connection portion 911b overlaps a portion of the second resin plate 912 from the outside of the storage box 11. The effect of this feature will be described with reference to Fig. 11. Fig. 11 is a diagram for explaining the effect of the feature of the first resin plate 911 and the second resin plate 912 of this embodiment.

[0084] FIG. 11 corresponds to a cross-sectional view of the first resin plate 911 and the second resin plate 912, which have a different configuration from the first resin plate 911 and the second resin plate 912 shown in FIG. 11 differs from the first resin plate 911 and the second resin plate 912 shown in FIG. 10 only in that a portion of the connection portion 911b overlaps a portion of the second resin plate 912 from the inside of the storage box 11. The dimensional ratios of the elements included in the first resin plate 911 and the second resin plate 912 in FIG. 11 have been changed from the actual dimensional ratios for the sake of convenience and ease of understanding. Elements other than the first resin plate 911 and the second resin plate 912, such as the metal plate 92 and the rib 93 provided on the resin plate 91, are not shown in FIG. Note that the energy storage element unit 10 having the first resin plate 911 and the second resin plate 912 shown in FIG. 11 may also be included in the scope of the energy storage element unit 10 of the present invention.

[0085] 11, consider the case where the resin plate main body 911a expands due to thermal expansion. In this case, the dimension w5 of the resin plate main body 911a in the thickness direction (third direction DC) of the second resin plate 912 shown in FIG. 11 increases. This causes a part of the connecting portion 911b and a part of the second resin plate 912 to come into contact with each other in the thickness direction of the second resin plate 912 and press against each other. Therefore, the resin plate 91 may be distorted by the force of the edge of the connecting portion 911b and the edge of the second resin plate 912 pressing against each other.

[0086] In contrast, in the present embodiment, when the resin plate main body 911a expands due to thermal expansion and the dimension w5 increases, it is believed that the connecting portion 911b moves away from the second resin plate 912 in the thickness direction of the second resin plate 912. This can prevent a part of the connecting portion 911b and a part of the second resin plate 912 from contacting and pressing against each other in the thickness direction of the second resin plate 912. This can prevent the resin plate 91 from being distorted by the force generated when the edge of the connecting portion 911b and the edge of the second resin plate 912 press against each other.

[0087] In this embodiment, each of the pair of first side wall portions 13c1 forms a first wall portion 13d including a first resin plate 911, and each of the pair of second side wall portions 13c2 forms a second wall portion 13e including a second resin plate 912. The first resin plate 911 of the pair of first side wall portions 13c1 has a pair of connecting portions 911b extending from both edge portions of the resin plate main body portion 911a in the direction in which the pair of long sides 131 of the bottom wall portion 13a extend (third direction DC). At least a portion of each of the pair of connecting portions 911b overlaps a portion of the second resin plate 912 from the outside of the storage box 11. The effect of this feature will be described with reference to FIG. 12. FIG. 12 is a diagram for explaining the effect of the feature of the first resin plate 911 and the second resin plate 912 of this embodiment.

[0088] FIG. 12 corresponds to a cross-sectional view of the first resin plate 911 and the second resin plate 912, which have different configurations from those of the first resin plate 911 and the second resin plate 912 shown in FIG. 12 differ from the first resin plate 911 and the second resin plate 912 shown in FIG. 10 only in that each of the pair of first side wall portions 13c1 forms the second wall portion 13e and each of the pair of second side wall portions 13c2 forms the first wall portion 13d. The dimensional ratios of the elements included in the first resin plate 911 and the second resin plate 912 in FIG. 12 have been changed from the actual dimensional ratios for the sake of illustration and ease of understanding. In FIG. 12, elements other than the first resin plate 911 and the second resin plate 912, such as the metal plate 92 and the rib 93 provided on the resin plate 91, are not shown. Note that the energy storage element unit 10 having the first resin plate 911 and the second resin plate 912 shown in FIG. 12 may also be included in the scope of the energy storage element unit 10 of the present invention.

[0089] 10 and 12, at least a portion of each of the pair of connecting portions 911b overlaps a portion of the second resin plate 912 from the outside of the storage box 11. In this case, an edge portion of the second resin plate 912 faces a portion of the first resin plate 911 in the thickness direction of the resin plate main body 911a. Here, in the example shown in FIG. 10, each of the pair of second side wall portions 13c2 connected to the short side 132 of the bottom wall portion 13a forms the second wall portion 13e including the second resin plate 912. On the other hand, in the example shown in FIG. 12, each of the pair of first side wall portions 13c1 connected to the long side 131 of the bottom wall portion 13a forms the second wall portion 13e including the second resin plate 912. Therefore, in the example shown in FIG. 10, the dimension w6 of the second resin plate 912 in the thickness direction of the resin plate main body 911a is smaller than in the example shown in FIG. 12. 10 than in the example shown in Fig. 12. Therefore, in the example shown in Fig. 10, when the second resin plate 912 is heated and thermally expands, the increase in the dimension w6 of the second resin plate 912 is smaller than in the example shown in Fig. 12. Therefore, in the example shown in Fig. 10, when the second resin plate 912 thermally expands, the edge of the second resin plate 912 comes into contact with the first resin plate 911 in the thickness direction of the resin plate main body 911a, and the first resin plate 911 and the second resin plate 912 are more likely to be prevented from pressing against each other. As described above, in the example shown in Fig. 10, distortion of the resin plate 91 caused by the force generated when the edge of the connection portion 911b and the edge of the second resin plate 912 press against each other can be more effectively prevented.

[0090] Next, the upper wall portion 13b in this embodiment will be described. In the description of the upper wall portion 13b, descriptions common to the above-mentioned side wall portion 13c will be omitted as appropriate. Figure 13 is a perspective view showing a resin plate 91 included in the upper wall portion 13b.

[0091] In the examples shown in FIGS. 4 and 13 , the resin plate 91 included in the upper wall portion 13b does not have a portion corresponding to the connecting portion 911b that overlaps a portion of the resin plate 91 included in the wall portion 13 connected to the upper wall portion 13b. Therefore, the upper wall portion 13b shown in FIG. 4 does not form the first wall portion 13d. Furthermore, the resin plate 91 included in the upper wall portion 13b does not have a portion that overlaps the connecting portion 911b of the resin plate 91 included in the wall portion 13 connected to the upper wall portion 13b. Therefore, the upper wall portion 13b shown in FIG. 4 does not form the second wall portion 13e. Although not shown, the upper wall portion 13b may form either the first wall portion 13d or the second wall portion 13e. In this case, at least one of the multiple side wall portions 13c connected to the upper wall portion 13b forms either the first wall portion 13d or the second wall portion 13e.

[0092] FIG. 14 is a perspective view showing a metal plate 92 included in the upper wall portion 13b. The metal plate 92 included in the upper wall portion 13b shown in FIG. 14 includes a main body portion 92a and may also have a connecting portion 92d including an upright portion 92e that stands up from the main body portion 92a and a portion that connects to the resin plate 91. In the example shown in FIG. 14, the metal plate 92 has a plurality of connecting portions 92d, each including a flat upright portion 92e that is parallel to the first direction DA and the second direction DB and extends in the second direction DB. The upright portions 92e of the plurality of connecting portions 92d face each other in the third direction DC. In the example shown in FIG. 14, the metal plate 92 has two connecting portions 92d.

[0093] In the example shown in FIG. 14, the connecting portion 92d is connected to the end of the upright portion 92e on the side where the main body portion 92a is located and further includes a flat first connecting portion 92f parallel to the main body portion 92a. The connecting portion 92d is connected to the main body portion 92a at the first connecting portion 92f. The first connecting portion 92f of the connecting portion 92d and the main body portion 92a are connected by, for example, welding, riveting, or burring. In the example shown in FIG. 14, the connecting portion 92d is connected to the end of the upright portion 92e opposite the side where the main body portion 92a is located and further includes a flat second connecting portion 92g parallel to the resin plate main body portion 911a. The second connecting portion 92g of the connecting portion 92d is the portion that is connected to the resin plate 91 of the upper wall portion 13b shown in FIG.

[0094] The connecting portion 92d can be made of the same metal material as the metal material that makes up the main body 92a. The connecting portion 92d may be formed, for example, by folding a flat metal material.

[0095] When the metal plate 92 is included in the laminate 90 that forms the upper wall portion 13b together with the resin plate 91, the metal plate 92 does not need to have the connecting portion 92d. In this case, in the laminate 90 that forms the upper wall portion 13b, the resin plate main body portion 911a of the resin plate 91 and the main body portion 92a of the metal plate 92 may be in contact with each other.

[0096] 4, 13, and 14, a through hole 94 used for screwing to the metal plate 92 is provided in the resin plate 91. In the upper wall portion 13b shown in FIGS. 4, 13, and 14, a screw hole 95 used for screwing to the resin plate 91 is provided in the metal plate 92. In particular, a screw hole 95 used for screwing to the resin plate 91 is provided in the second connection portion 92g of the metal plate 92.

[0097] 4, 13, and 14, the resin plate 91 and the metal plate 92 can be fixed to each other by overlapping the through hole 94 and the screw hole 95 and screwing the shank 96a of the screw 96 through the through hole 94 and into the screw hole 95. In particular, by providing the through hole 94 in the resin plate 91 and the screw hole 95 in the metal plate 92, the shank 96a of the screw 96 can be screwed into the screw hole 95 through the through hole 94 from outside the storage box 11 with the resin plate 91 placed on top of the metal plate 92 fixed to the frame portion 12.

[0098] 3 and 8 may also be applied to the plurality of through holes 94 formed in the resin plate 91 of the upper wall portion 13b shown in Fig. 13, unless the description is inconsistent. For example, the plurality of through holes 94 formed in the resin plate 91 of the upper wall portion 13b shown in Fig. 13 may include one reference through hole 94a and a plurality of wide through holes 94b. Furthermore, the description of the plurality of screw holes 95 formed in the resin plate 91 of the side wall portion 13c shown in Fig. 6 may also be applied to the plurality of screw holes 95 formed in the metal plate 92 of the upper wall portion 13b shown in Fig. 14, unless the description is inconsistent.

[0099] Next, the bottom wall portion 13a will be described. In the example shown in Fig. 5, the bottom wall portion 13a is a laminated body made up of two metal plates 92. In the example shown in Fig. 5, the bottom wall portion 13a includes an outer metal plate 923 and an inner metal plate 924 located more inward of the storage box 11 than the outer metal plate 923 (on the opposite side to one side SA1 in the first direction DA). In the example shown in Fig. 5, the outer metal plate 923 has a flat outer metal plate main body portion 923a and a bent portion 923b bent relative to the outer metal plate main body portion 923a.

[0100] Although not shown, the bottom wall portion 13a may be made of a laminate 90 including a resin plate 91 and a metal plate 92. In this case, the description of the structure of the side wall portion 13c made of the laminate 90 including the resin plate 91 and the metal plate 92 can also be applied to the bottom wall portion 13a made of the laminate 90 including the resin plate 91 and the metal plate 92, unless there is a contradiction.

[0101] Next, the frame portion 12 will be described. The frame portion 12 is a member that connects adjacent wall portions 13 to each other. In FIG. 5, the frame portion 12 forms the sides of the storage box 11, which has a substantially rectangular parallelepiped shape. In the example shown in FIG. 5, one of the multiple wall portions 13 has one edge, and another wall portion 13 adjacent to the one wall portion 13 has another edge that is close to the one edge. The frame portion 12 has an L-shaped cross section, and the one edge and the other edge are connected via the frame portion 12 that also has an L-shaped cross section. In the example shown in FIG. 5, the frame portion 12 has a flat first portion 121 and a flat second portion 122 that is perpendicular to the first portion 121 and connected to the first portion 121, thereby forming an L-shaped cross section. The one edge portion is connected to one of the first portion 121 and the second portion 122, and the other edge portion is connected to the other of the first portion 121 and the second portion 122, thereby connecting adjacent wall portions 13 to each other.

[0102] In this embodiment, as shown in FIG. 5, the frame portion 12 connects the top wall portion 13b to each of the four side wall portions 13c and also connects adjacent ones of the four side wall portions 13c. In the example shown in FIG. 5, the frame portion 12 has a rectangular frame-shaped first frame portion 12a extending between the top wall portion 13b and the four side wall portions 13c, and four rod-shaped second frame portions 12b extending between adjacent ones of the four side wall portions 13c. The first frame portion 12a and the four second frame portions 12b are fixed to each other at the corners of the top wall portion 13b. In the example shown in FIG. 5, the above-mentioned frame through-holes 12c are provided in each of the first frame portion 12a and the second frame portion 12b.

[0103] 5, no frame 12 is provided between the bottom wall 13a and each of the four side walls 13c. In the example shown in Fig. 5, the outer metal plate 923 of the bottom wall 13a has a bent portion 923b, and the bottom wall 13a and each of the four side walls 13c are fixed to each other using the bent portion 923b. That is, each of the four side walls 13c is fixed to the bent portion 923b.

[0104] 1, the energy storage element unit 10 may further include a decorative panel 19 that is provided on the storage box 11 and covers one of the side wall portions 13c. The decorative panel 19 is a member that protects the one side wall portion 13c and the components provided on the one side wall portion 13c.

[0105] The decorative panel 19 has a plurality of decorative wall portions 19a including at least a first decorative wall portion 19b and a second decorative wall portion 19c. The material of the plurality of decorative wall portions 19a is a resin material. The material of the plurality of decorative wall portions 19a may be the same resin material as the material of the resin plate 91 of the wall portion 13. Any two decorative wall portions 19a included in the plurality of decorative wall portions 19a that are connected to each other without passing through another decorative wall portion 19a can be considered to be the first decorative wall portion 19b and the second decorative wall portion 19c.

[0106] In the example shown in FIG. 1 , the decorative panel 19 has multiple decorative wall portions 19a, including a main decorative wall portion 19d and multiple connecting decorative wall portions 19e. The main decorative wall portion 19d is a substantially plate-shaped decorative wall portion 19a parallel to the side wall portion 13c covered by the decorative panel 19. The connecting decorative wall portion 19e is a substantially plate-shaped decorative wall portion 19a perpendicular to the main decorative wall portion 19d, connecting the main decorative wall portion 19d and the storage box 11. In the example shown in FIG. 1 , the decorative panel 19 has three connecting decorative wall portions 19e. One of the three connecting decorative wall portions 19e is located between the edge of the main decorative wall portion 19d on one side SB1 in the second direction DB and the storage box 11. Another of the three connecting decorative wall portions 19e is located between the edge of the main decorative wall portion 19d opposite the one side SB1 in the second direction DB and the storage box 11. Another one of the three connecting decorative wall portions 19e is located between the connecting decorative wall portion 19e and the edge of the main body decorative wall portion 19d on the opposite side to one side SA1 in the first direction DA, and the storage box 11. In this case, the main body decorative wall portion 19d and one of the three connecting decorative wall portions 19e can form the first decorative wall portion 19b, and the other can form the second decorative wall portion 19c.

[0107] In this embodiment, as an example of a decorative panel 19 in which multiple decorative wall portions 19a include a first decorative wall portion 19b and a second decorative wall portion 19c, a decorative panel 19 will be described in which a connecting decorative wall portion 19e located between the edge of the main decorative wall portion 19d on the opposite side to one side SA1 in the first direction DA (the upper side in Figure 1) and the storage box 11 forms the first decorative wall portion 19b, and the main decorative wall portion 19d forms the second decorative wall portion 19c.

[0108] FIG. 15 is a cross-sectional view of the first decorative wall portion 19b and the second decorative wall portion 19c taken along line CC in FIG. 1, illustrating a portion of the periphery of the edge of the first decorative wall portion 19b and the edge of the second decorative wall portion 19c. In the example shown in FIG. 15, a decorative wall screw hole 19g is provided in the first decorative wall portion 19b. The decorative wall screw hole 19g is provided at a position away from the edge of the first decorative wall portion 19b. In the example shown in FIG. 15, the first decorative wall portion 19b has a decorative wall protrusion 19f, and the decorative wall screw hole 19g is provided in the decorative wall protrusion 19f. In addition, in the example shown in FIG. 15, the second decorative wall portion 19c has a decorative wall connecting portion 19i with a decorative wall through-hole 19h at its tip. In the example shown in FIG. 15, the decorative wall connecting portion 19i is a protruding portion extending from a position away from the edge of the second decorative wall portion 19c. 15, the positional relationship between the first decorative wall portion 19b and the second decorative wall portion 19c is fixed by overlapping the decorative wall through hole 19h and the decorative wall screw hole 19g and screwing the shank of the screw 19j through the decorative wall through hole 19h into the decorative wall screw hole 19g. Therefore, in the example shown in FIG. 15, although the positional relationship between the first decorative wall portion 19b and the second decorative wall portion 19c is fixed, the edge of the first decorative wall portion 19b and the edge of the second decorative wall portion 19c are not directly joined to each other.

[0109] Because the edge of the first decorative wall portion 19b and the edge of the second decorative wall portion 19c are not directly joined to each other, when the decorative wall portion 19a thermally expands, a misalignment occurs between the edges, reducing the force pressing the edge of the first decorative wall portion 19b and the edge of the second decorative wall portion 19c against each other. This prevents distortion of the decorative wall portion 19a. This effectively prevents plastic deformation, cracks, and the like from occurring in the thermally expanded decorative wall portion 19a.

[0110] In the example shown in FIG. 15, the first decorative wall portion 19b has a decorative wall portion main body 19b1 and a decorative connecting portion 19b2 extending from an edge of the decorative wall portion main body 19b1 in a direction intersecting the decorative wall portion main body 19b1. In the example shown in FIG. 15, the decorative connecting portion 19b2 extends in a direction perpendicular to the decorative wall portion main body 19b1 (first direction DA). The second decorative wall portion 19c is non-parallel to the decorative wall portion main body 19b1. In the example shown in FIG. 15, the second decorative wall portion 19c is perpendicular to the decorative wall portion main body 19b1. In the example shown in FIG. 15, the second decorative wall portion 19c is parallel to the second decorative wall portion 19c. At least a portion of the decorative connecting portion 19b2 overlaps a portion of the second decorative wall portion 19c in the thickness direction of the second decorative wall portion 19c. In the example shown in FIG. 15, a portion of the decorative connecting portion 19b2 overlaps a portion of the second decorative wall portion 19c in the thickness direction (third direction DC) of the second decorative wall portion 19c.

[0111] At least a portion of the decorative connecting portion 19b2 overlaps a portion of the second decorative wall portion 19c in the thickness direction of the second decorative wall portion 19c, thereby achieving the following effect. As described above, there are cases where it is required to avoid direct joining between the edge of the first decorative wall portion 19b and the edge of the second decorative wall portion 19c, for the purpose of suppressing distortion of the decorative wall portion 19a when the decorative wall portion 19a thermally expands. Here, in the present embodiment, at least a portion of the decorative connecting portion 19b2 overlaps a portion of the second decorative wall portion 19c in the thickness direction of the second decorative wall portion 19c. This prevents the portion of the storage box 11 covered by the decorative panel 19 from being seen between the edge of the first decorative wall portion 19b and the edge of the second decorative wall portion 19c when a user of the energy storage element unit 10 visually checks the decorative panel 19 from outside the energy storage element unit 10, in the portion where the decorative connecting portion 19b2 overlaps the second decorative wall portion 19c. This prevents the portion of the storage box 11 covered by the decorative panel 19 from being visible between the edge of the first decorative wall portion 19b and the edge of the second decorative wall portion 19c, even if the edge of the first decorative wall portion 19b and the edge of the second decorative wall portion 19c are not directly joined together. This improves the aesthetic appearance of the energy storage element unit 10. It also prevents foreign matter from entering between the storage box 11 and the decorative panel 19 from between the edge of the first decorative wall portion 19b and the edge of the second decorative wall portion 19c.

[0112] The above-mentioned explanations regarding the resin plate main body 911a and the connecting portion 911b of the first resin plate 911 also apply, unless contradictory, to the decorative wall main body 19b1 and the decorative connecting portion 19b2 of the first decorative wall portion 19b. Furthermore, the above-mentioned explanations regarding the portion of the second resin plate 912 with which at least a portion of the connecting portion 911b overlaps also apply, unless contradictory, to the portion of the second decorative wall portion 19c with which at least a portion of the decorative connecting portion 19b2 overlaps.

[0113] Next, the control module 14 will be described. The control module 14 has, for example, one or more of the functions of controlling the charging and discharging of the multiple energy storage element modules 20, monitoring the charging states (e.g., charge amounts) of the energy storage element modules 20, and monitoring the presence or absence of abnormalities in the energy storage element modules 20. The control module 14 may also be configured to transmit information such as the monitoring results of the charging states and the presence or absence of abnormalities of the energy storage element modules 20 to a control device installed outside the energy storage element unit 10. The control module 14 may also have a switch that switches between electrical connection and disconnection between wiring external to the energy storage element unit 10 (e.g., building wiring) and the energy storage element modules 20.

[0114] Fig. 16 is a diagram showing a state in which a plurality of storage element modules 20 are stored in a storage box 11. As shown in Fig. 16, the storage element unit 10 has two storage element module assemblies 15. The storage element module assemblies 15 have a plurality of storage element modules 20 stacked in a first direction DA. The two storage element module assemblies 15 are arranged side by side in a second direction DB that is non-parallel to the first direction DA.

[0115] In the illustrated example, the first energy storage element module assembly 15A has three energy storage element modules 20 stacked in the first direction DA. The second energy storage element module assembly 15B is adjacent to the first energy storage element module assembly 15A from one side SB1 in the second direction DB. As shown in FIG. 2, the second energy storage element module assembly 15B supports the control module 14 from one side SA1 in the first direction DA. FIG. 17 shows one energy storage element module 20 included in the energy storage element module assembly 15. The multiple energy storage element modules 20 included in the energy storage element unit 10 may have different configurations or may have the same configuration. However, from the perspective of improving versatility, it is preferable that the multiple energy storage element modules 20 have the same configuration and include at least the same components (e.g., cells 30 and cases 18 described below). In the illustrated example, the multiple energy storage element modules 20 have the same configuration.

[0116] Each energy storage element module 20 has a plurality of cells 30 and a case 18 that houses the plurality of cells 30. The cell 30 is the smallest unit that can be used as an energy storage element. Various types of cells 30 can be employed, and for example, a lithium-ion secondary battery can be used. FIG. 18 shows the plurality of cells 30 included in one energy storage element module 20, and FIG. 19 shows one cell 30. The plurality of cells 30 included in one energy storage element module 20 may have the same configuration as each other, or may have different configurations from each other.

[0117] As shown in FIGS. 18 and 19 , the cell 30 has a flattened shape. The cell 30 has a substantially rectangular shape in a plan view (observed from the first direction DA). The cell 30 has a short side in the second direction DB and a long side in the third direction DC. The plurality of cells 30 are stacked in a stacking direction. In the illustrated example, the stacking direction of the cells 30 is parallel to the first direction DA. The cell 30 has a central portion 31C located in the center and a peripheral portion 31E surrounding the central portion 31C. The thickness of the central portion 31C is greater than the thickness of the peripheral portion 31E. In the illustrated example, the central portion 31C of the cell 30 bulges out toward either side in the first direction DA. The plurality of cells 30 are stacked such that the central portions 31C at least partially face each other in the first direction DA. 19 includes a plurality of electrode plates 32 including positive and negative electrode plates, an exterior body 33 that houses the plurality of electrode plates 32, and tabs 35 that are electrically connected to the electrode plates 32 and extend to the outside of the exterior body 33. The cell 30 includes a pair of tabs 35. The pair of tabs 35 function as a positive electrode terminal or a negative electrode terminal, respectively.

[0118] The cell 30 has a generally symmetrical configuration with respect to a reference plane that is a plane extending along the first direction DA and the third direction DC and that passes through the center in the second direction DB. The cell 30 also has a generally symmetrical configuration with respect to a reference plane that is a plane extending along the first direction DA and the second direction DB and that passes through the center in the third direction DC.

[0119] The many cells 30 included in one energy storage element module 20 are electrically connected to one another through series or parallel connections by electrically connecting their tabs 35 to one another. The tabs 35 of the many cells 30 are electrically connected to one another using, for example, electrode members (not shown). By appropriately setting the number and connection of the cells 30 in series or parallel, the output from one cell 30 can be set to a desired voltage and capacity. In the illustrated example, one energy storage element module 20 includes 16 cells 30. In particular, in the example shown in FIG. 18, eight pairs of two parallel-connected cells 30 are connected in series.

[0120] 17, the energy storage element module 20 has a case 18 for housing a plurality of cells. The case 18 defines a housing space on its inner surface for housing the plurality of cells. The case 18 has a case main body 40 and a cover 60. The cover 60 is detachable from the case main body 40.

[0121] The case body 40 and the cover 60 of each of the cases 18 included in the energy storage element unit 10 are formed using, for example, an insulating material. The cover 60 as a whole can be integrally molded from an insulating resin material. The case body 40 as a whole can be integrally molded from an insulating resin material.

[0122] As an example, each of the cases 18 included in the energy storage element unit 10 is made of a resin material. In the case 18 having a case body 40 and a cover 60 as shown in Fig. 17, the case body 40 and the cover 60 are made of a resin material. The resin material making up the case 18 is, for example, the same resin material as the material of the resin plate 91.

[0123] In the energy storage element unit 10 of this embodiment, the multiple through holes 94 through which the shanks 96a of the screws 96 are passed when the resin plate 91 and the metal plate 92 are fixed to each other include one reference through hole 94a and multiple wide through holes 94b. This allows the shanks 96a to be displaced inside the wide through holes 94b in accordance with thermal expansion of the resin plate 91. This makes it possible to prevent distortion of the thermally expanded resin plate 91. As described above, the energy storage element unit 10 of this embodiment uses resin as the material for the storage box 11, while allowing for thermal expansion of the resin. In particular, the resin plate 91 is used as part of the wall 13 of the storage box 11, while allowing for thermal expansion of the resin plate 91.

[0124] Furthermore, in the energy storage element unit 10 according to this embodiment, the storage box 11 is made up of a plurality of members. In particular, in the energy storage element unit 10 according to this embodiment, the storage box 11 includes a plurality of wall portions 13. Here, in the energy storage element unit 10 according to this embodiment, at least a portion of the connection portion 911b overlaps a portion of the second resin plate 912 in the thickness direction of the second resin plate 912. This prevents the interior of the storage box 11 from being seen between the first wall portion 13d and the second wall portion 13e, thereby improving the aesthetic appearance of the energy storage element unit 10. In particular, in the energy storage element unit 10, it may be required to avoid directly joining the first resin plate 911 and the second resin plate 912, for the purpose of preventing distortion of the resin plate 91 when the resin plate 91 thermally expands. Here, according to the energy storage element unit 10 of this embodiment, even if the first resin plate 911 and the second resin plate 912 are not directly joined, the inside of the storage box 11 is prevented from being seen between the edge of the connection portion 911b and the edge of the second resin plate 912, thereby improving the aesthetic appearance of the energy storage element unit 10.

[0125] As described above, the energy storage element unit 10 according to this embodiment can prevent the resin plate 91 from being distorted when the resin plate 91 thermally expands, while also preventing the interior of the storage box 11 from being visible through the gaps between the resin plates 91, thereby improving the aesthetic appearance of the energy storage element unit 10.

[0126] The aspects of the present invention are not limited to the above-described embodiments, but include various modifications that may be conceived by those skilled in the art, and the effects of the present invention are not limited to the above-described contents. In other words, various additions, modifications, and partial deletions are possible within the scope of the conceptual idea and spirit of the present invention that can be derived from the contents defined in the claims and their equivalents. [Explanation of symbols]

[0127] 10. Energy storage element unit 11 Storage Box 12 Frame section 13 Wall 13a Bottom wall 13b Upper wall 13c Side wall portion 91 Resin Board 92 Metal Plate

Claims

1. A storage box having a plurality of walls; a plurality of energy storage element modules housed in the housing box, the plurality of wall portions include a first wall portion and a second wall portion connected to the first wall portion, the first wall portion includes a first resin plate having a resin plate main body portion and a connection portion extending from an edge portion of the resin plate main body portion in a direction intersecting the resin plate main body portion, the second wall portion includes a second resin plate that is not parallel to the resin plate main body portion, at least a portion of the connection portion overlaps a portion of the second resin plate in a thickness direction of the second resin plate, the first wall portion is formed of a first laminate including the first resin plate and a first metal plate overlapping the resin plate main body portion, the second wall portion is formed of a second laminate including the second resin plate and a second metal plate overlapping the second resin plate, The second wall portion is connected to the first wall portion by fixing the positional relationship between the first metal plate and the second metal plate.

2. A storage box having a plurality of walls; a plurality of energy storage element modules housed in the housing box, the plurality of wall portions include a first wall portion and a second wall portion connected to the first wall portion, the first wall portion includes a first resin plate having a resin plate main body portion and a connection portion extending from an edge portion of the resin plate main body portion in a direction intersecting the resin plate main body portion, the second wall portion includes a second resin plate that is not parallel to the resin plate main body portion, at least a portion of the connection portion overlaps a portion of the second resin plate in a thickness direction of the second resin plate, The second resin plate is spaced apart from the first resin plate in a direction perpendicular to the resin plate main body.

3. the connecting portion has a thin plate connecting portion at an edge portion thereof, the thin plate connecting portion having a thickness smaller than the thickness of the resin plate main body portion, the second resin plate has a thin plate portion at an edge portion thereof, the thin plate portion having a thickness smaller than the maximum thickness of the second resin plate; At least a portion of the thin plate connection portion overlaps at least a portion of the thin plate portion in the thickness direction of the second resin plate, The energy storage element unit according to claim 1 , wherein the thin plate connecting portion faces a part of the second resin plate, and the thin plate portion faces a part of the connecting portion in a direction perpendicular to a thickness direction of the second resin plate.

4. The energy storage element unit according to claim 1 , wherein at least a portion of the connection portion overlaps a portion of the second resin plate from outside the storage box.

5. the plurality of wall portions include a bottom wall portion, an upper wall portion facing the bottom wall portion, and a plurality of side wall portions connected to the bottom wall portion and the upper wall portion; The energy storage element unit according to claim 1 , wherein one of the plurality of side wall portions forms the first wall portion, and another of the plurality of side wall portions forms the second wall portion.

6. the bottom wall portion has a pair of long sides and a pair of short sides extending in a direction intersecting the pair of long sides, the plurality of side wall portions include a pair of first side wall portions connected to the pair of long sides of the bottom wall portion and a pair of second side wall portions connected to the pair of short sides of the bottom wall portion, each of the pair of first side wall portions constitutes the first wall portion including the first resin plate, and each of the pair of second side wall portions constitutes the second wall portion including the second resin plate; the first resin plate of the pair of first side wall portions has a pair of the connection portions extending from edge portions on both sides of the resin plate main body portion in a direction in which the pair of long sides extend, The energy storage element unit according to claim 5 , wherein at least a portion of each of the pair of connecting portions overlaps a portion of the second resin plate from outside the storage box.

7. The storage box further includes a decorative panel that covers one of the side wall portions, The decorative panel has a plurality of decorative wall portions including at least a first decorative wall portion and a second decorative wall portion, the first decorative wall portion has a decorative wall portion main body portion and a decorative connecting portion extending from an edge portion of the decorative wall portion main body portion in a direction intersecting the decorative wall portion main body portion, the second decorative wall portion is non-parallel to the decorative wall portion main body portion, The energy storage element unit according to claim 5 , wherein at least a portion of the decorative connecting portion overlaps a portion of the second decorative wall portion in a thickness direction of the second decorative wall portion.

Images