JP7804500B2 - Energy storage element unit - Google Patents

Description

This disclosure relates to an energy storage element unit.

For example, as disclosed in Patent Document 1, a storage element unit having multiple storage element modules is known. The storage element unit includes multiple storage element modules and a storage box for storing the storage element modules.

Japanese Patent Application Laid-Open No. 2017-5027

There are cases where a storage box for an energy storage element unit needs to be constructed from multiple components. When a storage box for an energy storage element unit is constructed from multiple components, there is a need for an energy storage element unit in which the interior of the storage box cannot be seen through the gaps between the multiple components, in order to improve the aesthetic appearance of the energy storage element unit.

This disclosure has been made in consideration of these circumstances, and aims to provide an energy storage element unit that prevents the interior of the storage box from being seen.

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.

In the energy storage element unit according to the present disclosure,
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 may be connected to the first wall portion by fixing the positional relationship between the first metal plate and the second metal plate.

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 connection 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.

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.

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 body.

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 plurality of side wall portions may form the first wall portion, and another of the plurality of side wall portions may form the second wall portion.

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 a 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.

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.

This disclosure makes it possible to provide an energy storage element unit in which the inside of the storage box cannot be seen.

FIG. 1 is a perspective view showing an energy storage element unit for explaining an embodiment of the present invention. FIG. 2 is a perspective view showing the inside of the energy storage element unit of FIG. 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. 4 is a perspective view showing an upper wall portion of the storage box of the energy storage element unit of FIG. 1. FIG. FIG. 5 is a perspective view showing a storage box for the energy storage element unit of FIG. 6 is a perspective view showing the resin plate of the first side wall portion of FIG. 3. FIG. 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. FIG. 8 is a side view showing the resin plate and the metal plate included in the laminate that constitutes the first side wall portion of FIG. 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. 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. FIG. 11 is a diagram for explaining the effects of the features of the first resin plate and the second resin plate. FIG. 12 is a diagram for explaining the effects of the features of the first resin plate and the second resin plate. FIG. 13 is a perspective view showing the resin plate of the upper wall portion of FIG. FIG. 14 is a perspective view showing the metal plate of the upper wall portion of FIG. 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. 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. 1. FIG. 17 is a perspective view showing an energy storage element module included in the energy storage element module assembly of FIG. 16. FIG. FIG. 18 is a perspective view showing a plurality of stacked cells included in the energy storage element module of FIG. 17. FIG. FIG. 19 is a perspective view showing one cell shown in FIG.

Below, an example of an embodiment of an energy storage element unit according to the present disclosure will be described in detail with reference to Figures 1 to 19.

An embodiment of the present disclosure will be described below with reference to specific examples shown in the drawings. Note that in the drawings accompanying this specification, the scale and aspect ratios have been appropriately altered and exaggerated from their actual sizes for ease of illustration and understanding.

Figures 1 to 19 are diagrams illustrating one embodiment of the present disclosure. Of these, Figure 1 is a perspective view showing the energy storage element unit 10, and Figure 2 is a perspective view showing the interior of the energy storage element unit 10. Note that Figure 2 shows the energy storage element unit 10 with the upper wall portion 13b and decorative panel 19, which will be described later, removed. Also, in Figure 2, the resin plate 91 is omitted from the side wall portion 13c, which will be described later.

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 all the drawings. The tips of the arrows represent one side SA1, SB1, and SC1 of each direction DA, DB, and DC. Arrows pointing toward the front of the drawing in a direction perpendicular to the plane of the drawing are indicated by a symbol with an X in a circle, as shown in FIG. 8, for example. Arrows pointing toward the back of the drawing in a direction perpendicular to the plane of the drawing are indicated by a symbol with a dot in a circle, as shown in FIG. 9, for example. Furthermore, in drawings showing components stored in the storage box 11 (e.g., the energy storage element module assembly 15 and the energy storage element module 20), the directions and orientations of the components stored in the storage box 11 are shown. Similarly, in drawings showing components included in the energy storage element module 20 (e.g., the cell 30 and case 18, described below), the directions and orientations of the components installed in the energy storage element module 20 stored in the storage box 11 are shown.

In the illustrated example, the first direction DA, second direction DB, and 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.

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.

As shown in Figures 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 Figures 1 and 2 further includes a control module 14 stored in the storage box 11.

First, the storage box 11 will be described. The storage box 11 has multiple 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 Figure 2, the storage box 11 further has a frame portion 12 that connects adjacent wall portions 12. The wall portions 13 close off the arrangement space for the control module 14 and the energy storage element modules 20.

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 intervening wall portions 13 other than the first wall portion 13d and the second wall portion 13e. Any two wall portions 13 included in the multiple wall portions 13 that are connected to each other without any intervening wall portions 13 can be considered to be the first wall portion 13d and the second wall portion 13e.

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 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, upper wall 13b, and four side walls 13c as the walls 13. In this case, one of the multiple side walls 13c can form the first wall 13d, and another of the multiple side walls 13c can form the second wall 13e.

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 generally rectangular, plate-shaped wall portion 13 located on one side SA1 in the first direction DA. The top wall portion 13b is a generally rectangular, plate-shaped 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 generally rectangular, plate-shaped wall portions 13 that are 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, respectively.

In this embodiment, the multiple side wall portions 13c include a pair of first side wall portions 13c1 connected to a pair of long sides 131 of the bottom wall portion 13a, and a pair of second side wall portions 13c2 connected to a pair of short sides 132 of the bottom wall portion 13a. The first side wall portion 13c1 is connected to the long side 131 of the bottom wall portion 13a without passing through another wall portion 13. The second side wall portion 13c2 is connected to the short side 132 of the bottom wall portion 13a without passing through another wall portion 13. In the example shown in Figures 1 and 2, the pair of first side wall portions 13c1 are a pair of side wall portions 13c that face each other in the second direction DB and are parallel to the direction in which the long sides 131 of the bottom wall portion 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. Alternatively, 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.

In this embodiment, as an example of an energy storage element unit 10 in which the multiple wall portions 13 include first wall portions 13d and second wall portions 13e, an energy 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 will be described.

In the example shown in FIG. 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 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.

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. Figure 3 is a perspective view showing one of the side wall portions 13c as viewed from inside the storage box 11. Figure 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). Figure 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). Figure 5 shows the wall portions 13 of the storage box 11, excluding the top wall portion 13b and one of the first side wall portions 13c1 (the first side wall portion 13c1 located on the opposite side from one side SB1 in the second direction DB), and the frame portion 12 connecting the wall portions 13 to each other. Note that in Figure 5, the resin plate 91 for the side wall portion 13c is not shown.

At least one of the multiple wall portions 13 is composed of 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 composed of 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 composed of a single layer or a laminate including either a resin plate 91 or a metal plate 92, as described below, or may be composed of 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 perspective 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.

In this embodiment, at least several of the side wall portions 13c of the multiple wall portions 13 are composed of a laminate 90. That is, all of the multiple side wall portions 13c included in the multiple wall portions 13 are composed of 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 herein regarding the resin plate 91 constituting the laminate 90 including a resin plate 91 and a metal plate 92 also apply to the resin plate 91 in a single layer or laminate that includes the resin plate 91 but does not include the metal plate 92. Furthermore, unless inconsistent, descriptions herein regarding the metal plate 92 constituting the laminate 90 including a resin plate 91 and a metal plate 92 also apply to the metal plate 92 in a single layer or laminate that includes the metal plate 92 but does not include the resin plate 91.

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

Figure 6 is a perspective view showing the resin plate 91 included in the side wall portion 13c shown in Figure 3. In the example shown in Figure 6, the resin plate 91 included in the side wall portion 13c has a generally plate-like shape.

As described above, in this 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.

The first wall portion 13d includes a first resin plate 911 as the resin plate 91, which has a resin plate main body portion 911a and a connection portion 911b extending from the 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 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 composed of a first laminate 901, which is the laminate 90. In the example shown in Figures 3 and 6, the first wall portion 13d is composed of a first laminate 901 including the first resin plate 911 and the first metal plate 921 overlapping the resin plate main body portion 911a.

The second wall portion 13e includes a second resin plate 912 as the resin plate 91 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-shaped 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 composed of a second laminate 902 that is the laminate 90. In this embodiment, the second wall portion 13e is composed 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.

In the example shown in FIG. 6, the resin plate 91 included in the side wall portion 13c has screw holes 95 (described below) that are used to fasten the resin plate 91 to the metal plate 92. The screw holes 95 are provided in the resin plate main body portion 911a of the 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 the surface of the resin plate 91 that is 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.

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 Figure 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 Figure 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 inward-facing ribs 93.

In the example shown in Figure 6, the ribs 93 have a lattice-like shape with portions extending in the first direction DA and portions extending in a direction perpendicular to the first direction DA. Also, as an example, the ribs 93 are made of a resin material that is integral with the resin plate 91.

By providing the resin plate 91 with ribs 93, the strength of the resin plate 91 can be improved, thereby improving the strength of the storage box 11 and, in turn, the energy storage element unit 10.

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 connecting the main body portion 92a to the resin plate 91. Alternatively, the metal plate 92 may not have a portion connecting 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 connecting 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 the 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, described below, that is used to fasten the resin plate 91 and the metal plate 92 together. The through-hole 94 is provided in the main body portion 92a of the metal plate 92.

Figure 7 is a diagram showing a portion of the cross section of the wall portion 13 taken along line A-A in Figure 3. As shown in Figures 3 and 7, the resin plate 91 and metal plate 92 included in the laminate 90 are fixed to each other using screws 96. The screws 96 have a head 96b and a shaft 96a extending from the head 96b. In this case, the resin plate 91 is provided with one of a plurality of through holes 94 through which the shafts 96a of the screws 96 are passed, or one of a plurality of screw holes 95 into which the shafts 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. That is, the other of the plurality of through holes 94 or the plurality of screw holes 95 that is different from the one provided in the resin plate 91 is provided in the metal plate 92.

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

By overlapping the through holes 94 and the screw holes 95 and screwing the shanks 96a of the screws 96 through the through holes 94 and into the screw holes 95, the resin plate 91 and the metal plate 92 can be fixed to each other. The number of through holes 94 and the number of screw holes 95 are not particularly limited, as long as they can fix the resin plate 91 and the metal plate 92 to each other. As an example, the number of through holes 94 provided in the resin plate 91 or the metal plate 92 of one wall portion 13 is 9 to 12. The number of screw holes 95 provided in the resin plate 91 or the metal plate 92 of one wall portion 13 is 9 to 12. In Figures 3 and 6, nine screw holes 95 are provided in the resin plate 91. In Figures 3 and 6, nine screw holes 95 are provided in the metal plate 92.

Figure 8 is a side view showing the resin plate 91 and metal plate 92 included in the laminate 90 constituting the first side wall portion 13c1 shown in Figure 3, as viewed from the inside of the storage box 11 (the side opposite 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 Figure 8 has been changed from the actual dimensional ratio for the sake of ease of illustration and understanding. In Figure 8, holes and protrusions other than the through hole 94 provided in the resin plate 91 and the metal plate 92, which are shown in Figures 3 and 6, have been omitted.

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. Furthermore, 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. Furthermore, the wide through hole 94b and the reference through hole 94a, designated by the symbol A2 in FIG. 8, 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 designated by the symbol A2 in the direction DD 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. 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.

In this embodiment, the reference through hole 94a fixes the position of the shank 96a passed through it. The reference through hole 94a fixes the relative position of the shank 96a passed through it 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 passed 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 passed and a portion that engages with at least a portion of the head 96b of the screw 96. In this case, the relative position of the shaft portion 96a with respect to the reference through-hole 94a can be fixed by engaging that portion of the reference through-hole 94a with at least a portion of the head 96b of the screw 96.

As an example, the wall portion 13 formed from 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 Figure 8, the first side wall portion 13c1, which is the wall portion 13 formed from 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.

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 aligned with the reference through holes 94a in the third direction DC. Furthermore, two second wide through holes 94d are aligned with the reference through holes 94a in the first direction DA. In addition, four third wide through holes 94e are provided, which are positioned differently in the third direction DC and the first direction DA from the reference through holes 94a.

The first wide through hole 94c has a width in the first extension 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 extension 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 extension direction is larger than the width of the first wide through hole 94c in the second extension direction. In FIG. 8, the first wide through hole 94c has a rounded rectangular shape that extends in the first extension direction.

The second wide through hole 94d has a width in the second extension 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 extension 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 extension direction is larger than the width of the second wide through hole 94d in the second extension direction. In FIG. 8, the second wide through hole 94d has a rounded rectangular shape that extends in the second extension direction.

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.

In this embodiment, the reference through hole 94a in the side wall portion 13c is located 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 in the main body portion 92a of the metal plate 92 of the first side wall portion 13c1 is located closer to the long side 131 of the top wall portion 13b than to the long side 131 of the bottom wall portion 13a. Furthermore, although not shown, the reference through hole 94a in the main body portion 92a of the metal plate 92 of the second side wall portion 13c2 is located closer to the short side 132 of the top wall portion 13b than to the short side 132 of the bottom wall portion 13a.

The effect of the above-described features of the through holes 94 in this embodiment will now be described. As described above, in this embodiment, at least one of the multiple wall portions 13 is composed of 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 the shanks 96a of screws 96 are passed or a plurality of screw holes 95 into which the shanks 96a passed through the multiple through holes 94 are screwed. The metal plate 92 is provided with the other of the multiple through holes 94 or the multiple screw holes 95. By overlapping the through holes 94 and the screw holes 95 and screwing the shanks 96a of the screws 96 through the through holes 94 into the screw holes 95, the resin plate 91 and the metal plate 92 can be fixed to each other to form the laminate 90.

In general, the resin that makes up the resin plate 91 and the metal that makes up the metal plate 92 have different coefficients of thermal expansion. In particular, the resin that makes up the resin plate 91 has a greater coefficient of thermal expansion than the metal that makes up 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.

Let us now consider a hypothetical case in which, when the resin plate 91 and the metal plate 92 are fixed together using the screws 96, there is no room for the shafts 96a passed through each of the through holes 94 to shift within the through holes 94, and the relative positions of the shafts 96a to each of 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 to each of the through holes 94 are fixed.

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 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 cracking of the thermally expanded resin plate 91.

In addition, in this embodiment, the reference through-hole 94a fixes the position of the shaft 96a that is passed through the reference through-hole 94a. This makes it possible to determine the position from which the resin plate 91 expands due to thermal expansion (the position where the multiple arrows marked with symbol A3 in Figure 8 intersect when extended) at the position of the reference through-hole 94a.

In this embodiment, 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 of the pair of first sides 13f. The second wide through hole 94d and the reference through hole 94a are aligned in the second extension direction of the pair of second sides 13g. 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 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 are easier to form by processing the resin plate 91 or the metal plate 92 than 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).

In particular, in this embodiment, the width d4 of the first wide through hole 94c in the first stretch direction is larger than the width of the first wide through hole 94c in the second stretch direction. This makes it easier for the shaft portion 96a passed through the first wide through hole 94c to shift in the first stretch direction than in the second stretch direction within the first wide through hole 94c. Furthermore, the width d5 of the second wide through hole 94d in the second stretch direction is larger than the width of the second wide through hole 94d in the second stretch direction. This makes it easier for the shaft portion 96a passed through the second wide through hole 94d to shift in the second stretch direction than in the first stretch direction within 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, thereby suppressing distortion of the resin plate 91.

Furthermore, in this embodiment, at least a plurality of the side wall portions 13c of the plurality of wall portions 13 are constructed from a laminate 90. This makes it possible to suppress distortion of the resin plate 91 in the side wall portions 13c while constructing the plurality of side wall portions 13c from a laminate 90 including a resin plate 91 and a metal plate 92.

Furthermore, in the side wall portion 13c of this embodiment, the reference through hole 94a is located closer to the top wall portion 13b than to the bottom wall portion 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 each wide through hole 94b and the reference through hole 94a are aligned. Therefore, the shaft portion 96a passed through the reference through hole 94a has less room for misalignment than the shaft portion 96a passed through the wide through hole 94b. In particular, in the wall portion 13 shown in FIG. 8, the shaft portion 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 96a that passes through the reference through hole 94a. By locating the reference through hole 94a in a position closer to the top 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 top wall portion 13b than to the bottom wall portion 13a. This allows the resin plate 91 to be supported by the metal plate 92 more stably due to the action of gravity than if the resin plate 91 were supported by the metal plate 92 in a position closer to the bottom wall portion 13a than to the top wall portion 13b.

Furthermore, in the wall portion 13 shown in Figures 3 and 6, a plurality of screw holes 95 are provided in the resin plate 91, and a plurality of through holes 94 are provided in the metal plate 92. This feature provides the following effect. In the wall portion 13 of this embodiment, which is composed of a laminate 90 including a resin plate 91 and a metal plate 92, the resin plate 91 covers the metal plate 92 from the outside of the storage box 11. Here, by providing 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 portion 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, improving the aesthetic appearance of the energy storage element unit 10.

Next, we will explain how multiple wall portions 13 are connected to each other. In this embodiment, adjacent wall portions 12 are connected to each other via a frame portion 12, which will be described later. As an example of how multiple wall portions 13 are connected to each other, we will explain how the first side wall portion 13c1, which forms the first wall portion 13d, and the second side wall portion 13c2, which forms the second wall portion 13e, are connected.

In this 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 this 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.

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, the first metal plate 921 has a connecting through-hole 92h. In this case, the first metal plate 921 can be fixed to the frame portion 12 by fastening a screw, rivet, etc., 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 have 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, similar to the first metal plate 921, by fastening a screw, rivet, etc., passed through the connecting through-hole 92h to a connecting member and then fastening the connecting member to the frame portion 12.

As shown in Figures 3 and 6, resin plates 91 such as the first resin plate 911 and the second resin plate 912 may have insertion protrusions 91c at positions that do not overlap with the metal plates 92. Furthermore, as shown in Figure 5, the frame portion 12 may have frame through-holes 12c. In this case, when metal plates 92 such as the first metal plate 921 and the second metal plate 922 are fixed to the frame portion 12, the insertion protrusions 91c can be inserted into the frame through-holes 12c, thereby more stably supporting the wall portions 13 such as the first wall portion 13d and the second wall portion 13e on the frame portion 12.

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 also fixed.

Figure 9 is a diagram showing a portion of the periphery of the edge of the first resin plate 911 and the edge of the second resin plate 912 in the cross section of the first wall portion 13d and the second wall portion 13e taken along line B-B in Figure 1. In particular, Figure 9 shows a portion of the periphery of the edge of the first side wall portion 13c1, of the pair of first side wall portions 13c1 that form the first wall portion 13d, located on the opposite side from one side SB1 in the second direction DB, and the edge of the second side wall portion 13c2, of the pair of second side wall portions 13c2 that form the second wall portion 13e, located on the opposite side from one side SB1 in the third direction DC.

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 that extends from the 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-shaped portion that is parallel to the first direction DA and the third direction DC. The connecting portion 911b is parallel to the first direction DA and the second direction DB.

In the example shown in Figure 9, the edge of the connection portion 911b and the edge of the second resin plate 912 face each other in a direction perpendicular to the resin plate main body portion 911a (second direction DB). Here, the edge of the connection portion 911b and the edge of the second resin plate 912 are not directly joined to each other. In the example shown in Figure 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 connection 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 bonded to each other, when the edge of the connecting portion 911b and the edge of the second resin plate 912 are in contact, the edge of the connecting portion 911b and the edge of the second resin plate 912 are allowed to shift relative to each other. Therefore, when the resin plate 91 thermally expands and the edge of the connecting portion 911b and the edge of the second resin plate 912 come into contact, a shift occurs between the edges, reducing the force pressing against each other between the edge of the connecting portion 911b and the edge of the second resin plate 912. This prevents distortion of the resin plate 91 caused by the force pressing against each other between the edge of the connecting 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.

In the example shown in FIG. 9 , the second resin plate 912 is spaced apart from the first resin plate 911 in a direction perpendicular to the resin plate main body 911a (second direction DB). This prevents contact between the edge of the connection portion 911b and the edge of the second resin plate 912 when the resin plate 91 thermally expands. Even if the edge of the connection portion 911b and the edge of the second resin plate 912 come into contact, the force exerted by the edge of the connection portion 911b and the edge of the second resin plate 912 pressing against each other can be more effectively reduced. This effectively prevents distortion of the resin plate 91 caused by the edge of the connection portion 911b and the edge of the second resin plate 912 pressing against each other when the resin plate 91 thermally expands.

In particular, in this embodiment, the resin plate 91 is allowed to expand due to thermal expansion due to the action of the reference through hole 94a and wide through hole 94b described above. In this case, contact between the edge of the connection portion 911b, which has expanded due to thermal expansion, and the edge of the second resin plate 912 can be suppressed. 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, the force pressing against each other between the edge of the connection portion 911b and the edge of the second resin plate 912 can be reduced.

Here, 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. In the example shown in FIG. 9, a portion of the connection 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 connection portion 911b extends in the direction (first direction DA) in which the edge portion of the resin plate main body 911a in which the connection portion 911b is provided extends. The connection portion 911b extends over the entire range in which the edge portion of the resin plate main body 911a in which the connection portion 911b is provided extends. The edge portion of the second resin plate 912 that overlaps the connection portion 911b extends in the direction (first direction DA) in which the connection portion 911b extends. A portion of the connecting portion 911b overlaps the edge of the second resin plate 912 over the entire extension range of the edge that the connecting portion 911b overlaps.

In the example shown in Figure 9, the connection portion 911b has a thin plate connection portion 911c at its edge, which has a thickness t2 that is smaller than the thickness t1 of the resin plate main body portion 911a. The second resin plate 912 also has a thin plate portion 912a at its edge, which has 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 connection 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 addition, in a direction perpendicular to the thickness direction of the second resin plate 912, the thin plate connection portion 911c faces a portion of the second resin plate 912, and the thin plate portion 912a faces a portion of the connection 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 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 Figure 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.

At least a portion of the connection 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 connection 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 connection portion 911c overlaps a portion of the thin plate portion 912a from the outside of the storage box 11.

As described above, 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. Figure 10 is a cross-sectional view of the first resin plate 911 included in each of the pair of first side wall portions 13c1 and the second resin plate 912 included in each of the pair of second side wall portions 13c2 according to this embodiment, taken along line B-B in Figure 1. The dimensional ratios of the elements included in the first resin plate 911 and the second resin plate 912 in Figure 10 have been changed from the 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 Figure 10.

In this embodiment, as shown in FIG. 10, the first resin plate 911 of the pair of first side wall portions 13c1 has a pair of connection portions 911b that extend from the edges on both sides 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). Furthermore, at least a portion of each of the pair of connection portions 911b overlaps a portion of the second resin plate 912 from the outside of the storage box 11.

The effects of the above-described features of the first resin plate 911 and the second resin plate 912 in this embodiment will now be described. As described above, it may be necessary 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, it may be necessary 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, it may be necessary 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 a user of the energy storage element unit 10 from viewing the storage box 11 from outside the storage box 11, in the area where the connection portion 911b overlaps the second resin plate 912, from seeing the interior of the storage box 11 between the edge of the connection portion 911b and the edge 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, 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. It 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.

In addition, 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 (see 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 less than the thickness t1 of the resin plate main body portion 911a and equal to or less than the maximum thickness t3 of the second resin plate 912.

In addition, 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 explained with reference to Figure 11. Figure 11 is a diagram for explaining the effect of the features of the first resin plate 911 and the second resin plate 912 in this embodiment.

Figure 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 Figure 10. The first resin plate 911 and the second resin plate 912 shown in Figure 11 differ from the first resin plate 911 and the second resin plate 912 shown in Figure 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 Figure 11 have been changed from the actual dimensional ratios for the sake of ease of illustration and understanding. In Figure 11, 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 the illustration. 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.

In the example shown in Figure 11, consider the case where the resin plate main body portion 911a expands due to thermal expansion. In this case, the dimension w5 of the resin plate main body portion 911a in the thickness direction (third direction DC) of the second resin plate 912 shown in Figure 11 increases. This causes a part of the connection portion 911b and a part of the second resin plate 912 to come into contact 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 connection portion 911b and the edge of the second resin plate 912 pressing against each other.

In contrast, in the present embodiment, when the resin plate main body 911a expands due to thermal expansion and the dimension w5 increases, the connection portion 911b is thought to move away from the second resin plate 912 in the thickness direction of the second resin plate 912. This can prevent a portion of the connection portion 911b and a portion of the second resin plate 912 from coming into contact 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 connection portion 911b and the edge of the second resin plate 912 press against each other.

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. The first resin plate 911 of the pair of first side walls 13c1 has a pair of connecting portions 911b extending from both edge portions of the resin plate main body 911a in the direction in which the pair of long sides 131 of the bottom wall 13a extend (third direction DC). Furthermore, 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.

Figure 12 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 Figure 10. The first resin plate 911 and the second resin plate 912 shown in Figure 12 differ from the first resin plate 911 and the second resin plate 912 shown in Figure 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 Figure 12 have been changed from the actual dimensional ratios for ease of illustration and understanding. In Figure 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 omitted from the illustration. Note that the energy storage element unit 10 having the first resin plate 911 and 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.

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, the edge 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 portion 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 portion 911a is smaller than in the example shown in FIG. 12. For this reason, the increase in the dimension w6 of the second resin plate 912 when the second resin plate 912 is heated and thermally expands is smaller in the example shown in FIG. 10 than in the example shown in FIG. 12. Therefore, in the example shown in FIG. 10, compared to the example shown in FIG. 12, 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 a result, the example shown in FIG. 10 can more effectively prevent 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.

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

In the examples shown in Figures 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 Figure 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 Figure 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.

Figure 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 Figure 14 includes a main body portion 92a and may have connecting portions 92d including upstanding portions 92e that stand up from the main body portion 92a and a portion that connects to the resin plate 91. In the example shown in Figure 14, the metal plate 92 has multiple connecting portions 92d, including flat upstanding portions 92e that are parallel to the first direction DA and the second direction DB and extend in the second direction DB. The upstanding portions 92e of the multiple connecting portions 92d face each other in the third direction DC. In the example shown in Figure 14, the metal plate 92 has two connecting portions 92d.

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 connects to the resin plate 91 of the upper wall portion 13b shown in FIG. 13.

The connecting portion 92d can be made of the same metal material as the main body portion 92a. For example, the connecting portion 92d may be formed by folding a flat metal plate.

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, the resin plate main body portion 911a of the resin plate 91 and the main body portion 92a of the metal plate 92 may come into contact with each other in the laminate 90 that forms the upper wall portion 13b.

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

In the upper wall portion 13b shown in Figures 4, 13, and 14, the through hole 94 and the screw hole 95 are overlapped, and the shank 96a of the screw 96 is threaded through the through hole 94 and into the screw hole 95, thereby fixing the resin plate 91 and the metal plate 92 to each other. 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 threaded through the through hole 94 and into the screw hole 95 from outside the storage box 11, with the resin plate 91 overlapping the metal plate 92 fixed to the frame portion 12.

The descriptions regarding the multiple through holes 94 provided in the metal plate 92 of the side wall portion 13c shown in Figures 3 and 8 can also be applied to the multiple through holes 94 provided in the resin plate 91 of the top wall portion 13b shown in Figure 13, unless contradictory. For example, the multiple through holes 94 provided in the resin plate 91 of the top wall portion 13b shown in Figure 13 may include one reference through hole 94a and multiple wide through holes 94b. Furthermore, the descriptions regarding the multiple screw holes 95 provided in the resin plate 91 of the side wall portion 13c shown in Figure 6 can also be applied to the multiple screw holes 95 provided in the metal plate 92 of the top wall portion 13b shown in Figure 14, unless contradictory.

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 composed 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 that is 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 folded portion 923b that is folded relative to the outer metal plate main body portion 923a.

Although not shown, the bottom wall portion 13a may be composed 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 composed of a laminate 90 including a resin plate 91 and a metal plate 92 can also be applied to the bottom wall portion 13a composed of a laminate 90 including a resin plate 91 and a metal plate 92, unless inconsistent.

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 L-shaped cross section frame portion 12. 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 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.

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 each of 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.

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

As shown in FIG. 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 that one side wall portion 13c and the components provided on that one side wall portion 13c.

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.

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 generally 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 generally 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 one side SB1 of the main decorative wall portion 19d 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 of the three connecting decorative wall portions 19e is located between the connecting decorative wall portion 19e and the edge of the main decorative wall portion 19d opposite side SA1 in the first direction DA, and the storage box 11. In this case, the main 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.

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 side opposite 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.

Figure 15 shows a cross section of the first decorative wall portion 19b and the second decorative wall portion 19c taken along line C-C in Figure 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 Figure 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 Figure 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 Figure 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 Figure 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. In the example shown in Figure 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 Figure 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.

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 against each other between the edge of the first decorative wall portion 19b and the edge of the second decorative wall portion 19c. This prevents distortion of the decorative wall portion 19a. This effectively prevents plastic deformation, cracks, and other problems from occurring in the thermally expanded decorative wall portion 19a.

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 that extends from the 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 Figure 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.

By at least partially overlapping the decorative connecting portion 19b2 with a portion of the second decorative wall portion 19c in the thickness direction of the second decorative wall portion 19c, the following effects are achieved. As described above, it may be necessary to avoid direct bonding between the edge of the first decorative wall portion 19b and the edge of the second decorative wall portion 19c, for example, to prevent distortion of the decorative wall portion 19a when the decorative wall portion 19a thermally expands. Here, in this embodiment, at least partially overlapping the decorative connecting portion 19b2 with a portion of the second decorative wall portion 19c in the thickness direction of the second decorative wall portion 19c. This prevents a user of the energy storage element unit 10 from viewing the decorative panel 19 from outside the energy storage element unit 10. In the area where the decorative connection portion 19b2 overlaps the second decorative wall portion 19c, the portion of the storage box 11 covered by the decorative panel 19 is prevented from being seen between the edge of the first decorative wall portion 19b and the edge 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, 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. 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.

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

Next, the control module 14 will be described. The control module 14 has, for example, one or more of the following functions: controlling the charging and discharging of the multiple energy storage element modules 20; monitoring the charge state (e.g., charge amount) 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 charge state of the energy storage element modules 20 and the monitoring results of the presence or absence of abnormalities 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 the energy storage element modules 20 and external wiring (e.g., building wiring) of the energy storage element unit 10.

Figure 16 is a diagram showing multiple energy storage element modules 20 stored in a storage box 11. As shown in Figure 16, the energy storage element unit 10 has two energy storage element module assemblies 15. The energy storage element module assemblies 15 have multiple energy storage element modules 20 stacked in a first direction DA. The two energy storage element module assemblies 15 are arranged side by side in a second direction DB that is non-parallel to the first direction DA.

In the illustrated example, the first storage element module assembly 15A has three storage element modules 20 stacked in the first direction DA. The second storage element module assembly 15B is adjacent to the first storage element module assembly 15A from one side SB1 in the second direction DB. As shown in FIG. 2, the second storage element module assembly 15B supports the control module 14 from one side SA1 in the first direction DA. FIG. 17 shows one storage element module 20 included in the storage element module assembly 15. The multiple storage element modules 20 included in the 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 storage element modules 20 have the same configuration and preferably include at least the same components (e.g., cells 30 and cases 18 described below). In the illustrated example, the multiple storage element modules 20 have the same configuration.

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 used, and for example, they can be lithium-ion secondary batteries. Figure 18 shows the plurality of cells 30 included in one energy storage element module 20, and Figure 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.

As shown in Figures 18 and 19, the cell 30 has a flattened shape. In a plan view (observed from the first direction DA), the cell 30 has a substantially rectangular shape. The cell 30 has a short side in the second direction DB and a long side in the third direction DC. Multiple cells 30 are stacked in the 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 thicker than the thickness of the peripheral portion 31E. In the illustrated example, the cell 30 bulges out at the central portion 31C toward either side in the first direction DA. The multiple cells 30 are stacked so that the central portions 31C at least partially face each other in the first direction DA. The cell 30 shown in Figure 19 has multiple electrode plates 32 including positive and negative electrode plates, an exterior body 33 that houses the multiple 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 has a pair of tabs 35. The pair of tabs 35 function as positive and negative terminals, respectively.

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

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, for example, using 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 the 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 Figure 18, eight pairs of parallel-connected cells 30 are connected in series.

As shown in Figure 17, the energy storage element module 20 has a case 18 for storing multiple cells. The case 18 defines a storage space on its inner surface for storing multiple cells. The case 18 has a case body 40 and a cover 60. The cover 60 is detachable from the case body 40.

The case body 40 and cover 60 of each case 18 included in the energy storage element unit 10 are formed, for example, using 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.

As an example, each of the cases 18 included in the energy storage element unit 10 is made of a resin material. In a 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.

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 fixing the resin plate 91 and the metal plate 92 to each other include one reference through hole 94a and multiple wide through holes 94b. This allows the shanks 96a to be displaced within the wide through holes 94b in accordance with the thermal expansion of the resin plate 91. This prevents 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 the 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 the thermal expansion of the resin plate 91.

In addition, in the energy storage element unit 10 according to this embodiment, the storage box 11 is composed of multiple components. In particular, in the energy storage element unit 10 according to this embodiment, the storage box 11 has multiple 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 visible 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 necessary to avoid directly joining the first resin plate 911 and the second resin plate 912, for purposes such as preventing distortion of the resin plate 91 when the resin plate 91 thermally expands. Here, with the energy storage element unit 10 according to this embodiment, even if the first resin plate 911 and the second resin plate 912 are not directly joined, the interior of the storage box 11 is prevented from being visible 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.

As described above, the energy storage element unit 10 according to this embodiment prevents the resin plates 91 from warping when they thermally expand, 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.

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 content. In other words, various additions, modifications, and partial deletions are possible within the scope of the conceptual idea and spirit of the present invention, which can be derived from the content defined in the claims and their equivalents.

10 Energy storage element unit 11 Storage box 12 Frame portion 13 Wall portion 13a Bottom wall portion 13b Upper wall portion 13c Side wall portion 91 Resin plate 92 Metal plate

Claims (7)

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 by 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. 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. 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. The energy storage element unit described in any one of claims 1 to 3, wherein at least a portion of the connection portion overlaps a portion of the second resin plate from the outside of the storage box. 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. 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. 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.