JP7625796B2 - Power storage device - Google Patents

Description

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

Conventionally, energy storage devices equipped with multiple energy storage elements are known. For example, Patent Document 1 discloses a power supply device equipped with a battery block in which multiple rectangular secondary battery cells are connected in series, and a cooling plate that is in thermally conductive contact with a first surface that constitutes the outer surface of the battery block to cool it. In this power supply device, the cooling plate is a metal plate, and a refrigerant can be circulated inside to cool the battery block by heat exchange.

JP 2013-229182 A

In an energy storage device having multiple energy storage elements, it is important to release (cool) the heat generated by the multiple energy storage elements inside the exterior body from the viewpoint of suppressing deterioration of the multiple energy storage elements. In order to address this problem, if a structure is adopted in which a cooling plate is used to cool the multiple energy storage elements, as in Patent Document 1, a metal member (cooling plate) is placed in contact with the multiple energy storage elements. In this case, a problem arises as to how to prevent or suppress conduction between the multiple energy storage elements and the cooling plate when an excessive impact is given due to a collision accident or the like. To address this problem, for example, it is possible to reduce the possibility of conduction by placing a relatively thick insulating member between the multiple energy storage elements and the cooling plate. However, on the other hand, the insulating member reduces the cooling efficiency, and the advantage of using a cooling plate is lost. Of course, if a mechanism is adopted to circulate a refrigerant through the cooling plate, it is possible to obtain a sufficient cooling effect for the multiple energy storage elements, but in this case, another problem arises in that the cooling system for the energy storage device becomes complicated or large.

The present invention was made by the inventors of the present application by focusing on the above-mentioned problem, and aims to provide an energy storage device having multiple energy storage elements and having improved reliability.

To achieve the above object, an energy storage device according to one aspect of the present invention includes a plurality of energy storage elements, and an exterior body that houses the plurality of energy storage elements and has external electrode terminals on its outer surface that are electrically connected to the plurality of energy storage elements, the exterior body having an outer member disposed on the outside of a wall that separates the interior and exterior of the exterior body, and a penetrating member that penetrates the wall and is connected to the outer member.

According to this configuration, a penetrating member that penetrates the wall portion is disposed in the exterior body, and an outer member is connected to the penetrating member. This allows heat trapped inside the exterior body to be efficiently released to the outside via the penetrating member and the outer member. As a result, deterioration of the energy storage element due to heat is suppressed. In addition, for example, static electricity generated in the exterior body made mainly of resin during installation of the energy storage device can be released to the conductive outer member. This suppresses damage to the energy storage element due to static electricity. In this way, the energy storage device according to this aspect is an energy storage device with improved reliability.

The outer member may be a plate-shaped member that abuts against the installation surface on which the power storage device is installed.

With this configuration, the outer member can dissipate heat over a relatively wide surface area. Also, a relatively large amount of static electricity can be released from the exterior body to the outer member. Therefore, deterioration or damage to the energy storage element is more reliably suppressed.

The outer member may have a flat plate portion that contacts the installation surface and a connection portion that is fixed to the flat plate portion and connected to the penetrating member.

According to this configuration, for example, a relatively thin metal plate can be used as the flat plate portion, and the connection portion having holes suitable for connecting to the penetrating member can be fabricated as a separate member from the flat plate portion. Therefore, for example, the flat plate portion and the connection portion can be fabricated from different materials. In other words, the degree of freedom in terms of the materials used to fabricate the outer member is improved. As a result, it is possible to obtain an outer member with a configuration that easily performs functions such as heat dissipation depending on, for example, the size or shape of the exterior body.

The penetrating member may be a bolt that screws into a female threaded portion of the outer member.

With this configuration, the penetrating member and the outer member can be made from commonly available parts or materials. This makes it possible to improve the reliability of the energy storage device while suppressing increases in manufacturing efficiency or manufacturing costs.

A gap may be formed between a part of the outer member that is different from the part connected to the penetrating member and the outer surface of the wall portion of the exterior body that faces the outer member.

With this configuration, heat conducted to the outer member through the penetrating member is less likely to be conducted to the wall portion of the exterior body facing the outer member. In other words, heat that has escaped from the exterior body to the outer member is less likely to return to the exterior body. In addition, the gap between the outer member and the wall portion of the exterior body becomes a flow path for fluids such as air that exchange heat with the outer member, thereby improving heat dissipation efficiency.

The present invention provides a power storage device with improved reliability.

1 is a perspective view showing an external appearance of a power storage device according to an embodiment; FIG. 2 is an exploded perspective view showing each component of the electricity storage device according to the embodiment. FIG. 2 is a perspective view showing the inside of an exterior body according to an embodiment. 1 is a perspective view of a power storage device according to an embodiment when viewed obliquely from below. 4 is a cross-sectional view of a fixing point of an outer member in an exterior body according to an embodiment. FIG. FIG. 13 is a perspective view showing a configuration of an electricity storage device according to a modified example of the embodiment. 13 is a diagram showing a cross-sectional shape of an outer member according to a modified example of the embodiment. FIG.

The following describes an energy storage device according to an embodiment of the present invention (including its modified examples) with reference to the drawings. Note that the embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, component placement positions, and connection forms shown in the following embodiments are merely examples and are not intended to limit the present invention.

In the following description and drawings, the Y-axis direction is defined as the arrangement direction of multiple energy storage elements, the direction in which the long sides of the energy storage element container face each other, or the thickness direction of the container. The X-axis direction is defined as the arrangement direction of the electrode terminals of one energy storage element, or the direction in which the short sides of the energy storage element container face each other. The Z-axis direction is defined as the arrangement direction of the main body and the lid in the exterior body of the energy storage device, the longitudinal direction of the short side, or the up-down direction. The X-axis direction, Y-axis direction, and Z-axis direction intersect with each other (orthogonal in the following embodiments and their modifications). Depending on the mode of use, the Z-axis direction may not be the up-down direction, but for convenience of explanation, the following description will be given assuming that the Z-axis direction is the up-down direction.

In addition, in the following embodiments and claims, expressions indicating relative directions or attitudes, such as parallel and perpendicular, may be used, but these expressions may not strictly refer to those directions or attitudes. For example, two directions being parallel does not only mean that the two directions are completely parallel, but also means that the directions are substantially parallel, that is, that there is a difference of, for example, a few percent.

In the following description, for example, the positive side in the X-axis direction refers to the side in the direction of the arrow on the X-axis, and the negative side in the X-axis direction refers to the side opposite to the positive side in the X-axis direction. The same applies to the Y-axis and Z-axis directions.

(Embodiment)
[1. General Description of the Power Storage Device]
First, an overall description of a power storage device 1 according to an embodiment will be given with reference to Fig. 1 and Fig. 2. Fig. 1 is a perspective view showing the external appearance of the power storage device 1 according to an embodiment. Fig. 2 is an exploded perspective view showing each component of the power storage device 1 according to the embodiment when disassembled.

The power storage device 1 is a device that can charge electricity from an external source and discharge electricity to the outside. Specifically, the power storage device 1 is used as a battery for driving or starting the engine of a moving object such as an automobile, a motorcycle, a watercraft, a snowmobile, an agricultural machine, a construction machine, or a rolling stock for an electric railway. Examples of the above-mentioned automobiles include electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and gasoline-powered automobiles. Examples of the above-mentioned rolling stock for an electric railway include electric trains, monorails, and linear motor cars. The power storage device 1 is also used as a stationary battery for home use or for power generation, etc.

As shown in Figures 1 and 2, the energy storage device 1 includes a plurality of energy storage elements 20 and an exterior body 10 that houses the plurality of energy storage elements 20. In this embodiment, four energy storage elements 20 arranged in the Y-axis direction are housed in the exterior body 10, and these four energy storage elements 20 form one energy storage element unit 25. Note that the number of energy storage elements 20 included in the energy storage device 1 is not limited to four. The energy storage device 1 may include a plurality of energy storage elements 20.

The exterior body 10 has an exterior body main body 30 that houses the energy storage element unit 25, and a lid body 11 that closes the opening of the exterior body main body 30 when the energy storage element unit 25 is housed therein. Between the energy storage element unit 25 and the lid body 11 are arranged a bus bar that electrically connects two or more energy storage elements 20, a bus bar plate that holds the multiple bus bars, and a control circuit that is arranged between the bus bar plate and the lid body 11, but these are not shown in the figure.

The exterior body 10 is a rectangular (box-shaped) container (module case) that constitutes the outer shell of the energy storage device 1. In other words, the exterior body 10 is a member that fixes the energy storage element unit 25 and the like in a predetermined position and protects them from impacts and the like. The exterior body 10 is formed from an insulating member such as polycarbonate (PC), polypropylene (PP), polyethylene (PE), polystyrene (PS), polyphenylene sulfide resin (PPS), polyphenylene ether (PPE (including modified PPE)), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyether ether ketone (PEEK), tetrafluoroethylene perfluoroalkyl vinyl ether (PFA), polytetrafluoroethylene (PTFE), polyether sulfone (PES), ABS resin, or a composite material thereof.

The exterior body 30 of the exterior body 10 is a container composed of multiple walls formed from the insulating material described above, and electrically insulates the energy storage element unit 25 and the like from the outside. The multiple walls include a pair of side walls 31 facing each other in the X-axis direction, a pair of side walls 31 facing each other in the Y-axis direction, and a bottom wall 32 located on the negative side in the Z-axis direction. These four side walls 31 and one bottom wall 32 are integrated to form the exterior body 30, which is a box-shaped container.

The lid 11 of the exterior body 10 is a rectangular member that closes the opening of the exterior body main body 30, and is fixed to the exterior body main body 30 by a predetermined method such as welding or adhesion. The upper wall portion 12, which is a part of the lid 11, functions as a wall portion that separates the inside and outside of the exterior body 10, just like the four side wall portions 31 and one bottom wall portion 32 of the exterior body main body 30. A positive external electrode terminal 91 and a negative external electrode terminal 92 are arranged on the outer surface of the lid 11. The external electrode terminals 91 and 92 are electrically connected to the energy storage element unit 25 via a bus bar or the like, and the energy storage device 1 charges with electricity from the outside and discharges electricity to the outside through these external electrode terminals 91 and 92. The external electrode terminals 91 and 92 are formed of a conductive member made of metal, such as aluminum or an aluminum alloy.

The energy storage element 20 is a secondary battery (single cell) that can charge and discharge electricity, and more specifically, is a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. The energy storage element 20 has a flattened rectangular parallelepiped (corneral) shape, and has a pair of opposing long sides 21a and a pair of opposing short sides 21b. In this embodiment, the four energy storage elements 20 are arranged in the Y-axis direction with the long sides 21a facing in the Y-axis direction.

The storage element 20 is not limited to a non-aqueous electrolyte secondary battery, and may be a secondary battery other than a non-aqueous electrolyte secondary battery, or may be a capacitor. The storage element 20 may also be a primary battery that allows the user to use stored electricity without having to charge it. The storage element 20 may also be a battery that uses a solid electrolyte.

Specifically, the energy storage element 20 includes a metal container 21, and a pair of metal electrode terminals 22 (positive and negative terminals) are provided on the lid of the container 21. The pair of electrode terminals 22 (positive and negative terminals) are arranged to protrude from the lid of the container 21 toward the lid body 11 (upward, i.e., toward the positive side in the Z-axis direction). Inside the container 21, electrodes (also called energy storage elements or power generation elements) and current collectors (positive and negative current collectors) are arranged, and an electrolyte (non-aqueous electrolyte) is enclosed, but detailed description will be omitted.

The four storage elements 20 included in the storage element unit 25 are connected in series, for example, by three bus bars (not shown). The bus bars are conductive members made of metal, such as copper, copper alloy, aluminum, aluminum alloy, etc. There are no particular limitations on the manner of electrical connection of the four storage elements 20, and for example, two sets of storage element groups may be formed by connecting two storage elements 20 in parallel, and the two sets of storage element groups may be connected in series.

In the energy storage device 1 configured in this manner, an outer member 40 is disposed on the outside of the exterior body 10. The outer member 40 is a member formed of a material having higher thermal conductivity and electrical conductivity than the resin forming the exterior body 10, and has the function of discharging or removing heat and static electricity. Specifically, the outer member 40 is formed of a metal plate such as iron, aluminum, or an aluminum alloy. In this embodiment, as shown in FIG. 2, the outer member 40 is disposed along the bottom wall portion 32 of the exterior body 10, and is fixed to the exterior body 10 by four penetrating members 80. Details of the outer member 40 according to the embodiment will be described below with reference to FIGS. 3 to 5.

[2. Outer member and its surrounding structure]
Fig. 3 is a perspective view showing the inside of the exterior body 10 according to the embodiment. In Fig. 3, the exterior body main body 30 is cut along the YZ plane passing through the line III-III in Fig. 2, the energy storage device 1 is illustrated in a state in which the energy storage element unit 25 is lifted up, and the illustration of the lid 11 is omitted. Fig. 4 is a perspective view of the energy storage device 1 according to the embodiment as viewed obliquely from below. In Fig. 4, the outer member 40 is removed from the bottom wall portion 32 of the exterior body 10.

Figure 5 is a cross-sectional view of a fixing location of the outer member 40 in the exterior body 10 according to the embodiment. In Figure 5, a cross section of a portion of the energy storage device 1 in the YZ plane passing through the V-V line in Figure 3 is shown, and the mounting portion 33 on which the energy storage element 20 is placed is omitted.

As shown in Figures 3 to 5, the energy storage device 1 includes an outer member 40 arranged along the wall of the exterior body 10. In this embodiment, the outer member 40 is arranged along the outer surface 32a of the bottom wall portion 32 of the exterior body 10.

Specifically, as shown in Figs. 4 and 5, the bottom wall 32 of the exterior body 30 has four through holes 32b penetrating the bottom wall 32, and a penetrating member 80 is disposed in each of the four through holes 32b. The penetrating member 80 according to this embodiment is a bolt, and has a shaft 81 which is a male screw, and a head 82 whose outer diameter is larger than that of the shaft 81. The penetrating member 80 is a member that thermally connects the internal space 10a of the exterior body 10 and the outer member 40, and fixes the outer member 40 to the exterior body 10. The penetrating member 80 also functions as a member that forms a conductive path that releases static electricity carried by the exterior body 10 to the outer member 40. The penetrating member 80 having such a function is formed of a metal such as iron, aluminum, or stainless steel.

Specifically, the outer member 40 has four mounting holes 41 at positions corresponding to the four through holes 32b, and the shaft portion 81 of the through member 80 is screwed into each of the four mounting holes 41. This fixes the outer member 40 to the exterior body 10. The energy storage device 1 equipped with the outer member 40 is installed on the installation surface 200 (see FIG. 5) with the outer member 40 facing the installation surface 200. The mounting holes 41 are an example of a female screw portion that the outer member 40 has.

More specifically, a gasket 85 is fitted into each of the four through holes 32b, and when the shaft portion 81 of the penetrating member 80 is screwed into the mounting hole 41 of the outer member 40, the head portion 82 of the penetrating member 80 compresses the gasket 85 in the axial direction. As a result, airtightness is maintained in the through hole 32b. Furthermore, the head portion 82 of the penetrating member 80 and the gasket 85 exposed inside the exterior body 10 may be covered and hardened with an adhesive or the like. This further improves the airtightness in the through hole 32b of the exterior body 10. In the embodiment, the mounting hole 41 is a bottomless hole that penetrates the outer member 40, but the mounting hole 41 may be a bottomed hole that does not penetrate the outer member 40.

3, the bottom wall 32 of the exterior body 10 has a mounting portion 33 on which the energy storage element unit 25 is placed. The mounting portion 33 is provided as a portion protruding toward the inside of the exterior body 10 on the bottom wall 32, and a recess 33a corresponding to the shape and size of the mounting portion 33 is formed on the outer surface 32a of the bottom wall 32. By placing the energy storage element unit 25 on the mounting portion 33 provided in the center of the bottom wall 32 in a top view, interference between the heads 82 of the penetrating members 80 arranged at the four corners of the bottom wall 32 and the energy storage element unit 25 is avoided. In other words, each of the four penetrating members 80 can be arranged at a position overlapping with the energy storage element unit 25 in a top view, and the metal penetrating members 80 and the energy storage element unit 25 can be separated. A number of ribs 35 are arranged inside the recess 33a formed on the back side of the mounting portion 33, thereby improving the mechanical strength of the mounting portion 33. As a result, the energy storage element unit 25 fixed to the mounting portion 33 can be stably and reliably supported. There are no particular limitations on the method for fixing the energy storage element unit 25 to the mounting portion 33, but for example, the bottom surface of the energy storage element unit 25 is adhered to the mounting portion 33 with an adhesive.

In this embodiment, as shown in FIG. 5, the exterior body 30 has an outer edge 36 provided on the outer periphery of the bottom wall 32, and the outer member 40 is disposed inside the outer edge 36. That is, the outer member 40 according to this embodiment is disposed on the exterior body 10 in a state where it does not protrude from the exterior body 10 when viewed from the arrangement direction (Z-axis direction) of the outer member 40 and the bottom wall 32. In other words, the outer member 40 is provided in a manner that suppresses an increase in the overall size of the exterior body 10. Therefore, for example, if the exterior body 10 is formed to a size that conforms to some standard, the outer member 40 can be contained within that size.

Thus, the energy storage device 1 according to this embodiment includes a plurality of energy storage elements 20, and an exterior body 10 that houses the plurality of energy storage elements 20 therein and has external electrode terminals 91 and 92 on its outer surface that are electrically connected to the plurality of energy storage elements 20. The exterior body 10 has an outer member 40 that is disposed on the outside of a bottom wall portion 32, which is a wall portion that separates the inside and outside of the exterior body 10, and a penetrating member 80 that penetrates the bottom wall portion 32 and is connected to the outer member 40.

According to this configuration, the penetrating member 80 penetrating the bottom wall portion 32 is disposed in the exterior body 10, and the outer member 40 is connected to the penetrating member 80. As a result, the heat generated from the energy storage element 20 and the like and trapped inside the exterior body 10 can be efficiently released to the outside through the penetrating member 80 and the outer member 40. As a result, deterioration of the energy storage element 20 due to heat is suppressed. In addition, for example, when the energy storage device 1 is installed on the installation surface 200 (see FIG. 5), static electricity may be generated in the exterior body 10 due to the outer edge portion 36 of the exterior body 10 rubbing against the installation surface 200. Even in this case, the static electricity generated in the exterior body 10 can be released to the conductive outer member 40. As a result, damage to the energy storage element 20 caused by static electricity is suppressed. In this way, the energy storage device 1 according to this embodiment is an energy storage device with improved reliability. In this embodiment, the outer member 40 and the exterior body 10 are connected by four penetrating members 80, but the number of penetrating members 80 is not limited to four. The energy storage device 1 may include at least one penetrating member 80. For example, five or more penetrating members 80 may be arranged side by side along the periphery of the outer member 40. In addition, the outer member 40 may be fixed to the exterior body 10 by a claw provided on the wall of the exterior body 10 and one penetrating member 80. Even in this case, the outer member 40 and the exterior body 10 are thermally and electrically connected by one penetrating member 80.

In addition, in this embodiment, the outer member 40 is made of a metal such as iron or aluminum, and the installation surface 200 that faces and contacts the outer member 40 is, for example, a metal fixed part of a vehicle such as an automobile. Therefore, compared to the case where a member made of a material with lower thermal conductivity than metal, such as a resin member, is placed at the position of the outer member 40, the heat dissipation (cooling) effect for the heat of the energy storage device 1 is high.

In addition, in this embodiment, the outer member 40 is a plate-shaped member that abuts against the installation surface 200 on which the energy storage device 1 is installed, as shown in Figures 4 and 5.

With this configuration, the outer member 40 can dissipate heat over a relatively wide surface area. In addition, a relatively large amount of static electricity can be released from the exterior body 10 to the outer member 40. Therefore, deterioration or damage to the energy storage element 20 is more reliably suppressed.

In this embodiment, the penetrating member 80 is a bolt that screws into the mounting hole 41, which is a female threaded portion of the outer member 40.

With this configuration, the penetrating member 80 and the outer member 40 can be realized using parts or materials that are generally available and easy to obtain. Therefore, the reliability of the energy storage device 1 can be improved while suppressing increases in manufacturing efficiency or manufacturing costs.

An example of the penetrating member 80 other than a bolt is a rivet that connects the inside and outside of the exterior body 10 and fixes the outer member 40. A sealing bolt with a sealing member such as an O-ring on the seat surface (shaft side surface) of the head may be used as the penetrating member. This further improves the airtightness of the through hole 32b of the exterior body 10. A ring-shaped metal member may be placed in place of the gasket 85 placed in the through hole 32b. For example, when a ring-shaped metal member is embedded in the bottom wall portion 32 by insert molding, the central hole of the metal member functions as the through hole 32b. In this case, in order to ensure or improve the airtightness between the metal member and the penetrating member 80 which is a bolt, a resin washer or an O-ring may be used, or a sealing bolt may be used as the penetrating member 80. In this way, by forming the through hole 32b part from metal, for example, the tightening torque of the penetrating member 80 which is a bolt can be increased, and as a result, the bonding force between the exterior body 10 and the outer member 40 can be improved. Also, for example, a penetrating member 80 (bolt) inserted into a mounting hole 41 of the outer member 40 may be screwed into a female thread provided in the bottom wall portion 32 of the exterior body 10. In this case, a recess for accommodating the head 82 of the penetrating member 80 may be provided on the underside of the outer member 40 so that the head 82 does not protrude from the underside of the outer member 40 (the surface facing the installation surface 200).

The above describes the energy storage device 1 according to the embodiment, but the configuration of the outer member arranged in the exterior body 10 may be different from the configuration shown in Figures 2 to 5. Therefore, below, an energy storage device including an outer member having a different configuration from the above embodiment will be described as a modified example, focusing on the differences from the above embodiment.

(Modification)
Fig. 6 is a perspective view showing a configuration of an energy storage device 1a according to a modified example of the embodiment. In Fig. 6, an outer member 140 included in the energy storage device 1a is shown removed from an exterior body 10, and the energy storage element unit 25 (plurality of energy storage elements 20) and the cover body 11 are omitted. Fig. 7 is a diagram showing a cross-sectional shape of the outer member 140 according to a modified example of the embodiment. Fig. 7 shows a cross section of a portion of the energy storage device 1a in an XZ plane passing through line VII-VII in Fig. 6.

The energy storage device 1a according to this modification includes an exterior body 10 that houses multiple energy storage elements 20 therein and has external electrode terminals 91 and 92 on its outer surface. The exterior body 10 has an outer member 140 that is disposed on the outside of a bottom wall portion 32 that is a wall portion that separates the inside and outside of the exterior body 10, and a penetrating member 80 that penetrates the bottom wall portion 32 and is connected to the outer member 140. In this configuration, the energy storage device 1a according to this modification and the energy storage device 1 according to the embodiment are common.

In this modified example, as shown in Figs. 6 and 7, the outer member 140 has a flat plate portion 142 that abuts against the installation surface 200, and a connection portion 143 that is fixed to the flat plate portion 142 and connected to the penetrating member 80. The flat plate portion 142 and the connection portion 143 are joined by, for example, welding.

According to this configuration, for example, a relatively thin metal plate is used as the flat plate portion 142, and the connection portion 143 having the mounting hole 141 suitable for connection with the penetrating member 80 can be manufactured as a separate member from the flat plate portion 142. Therefore, for example, the flat plate portion 142 and the connection portion 143 can be manufactured from different materials. Also, for example, as shown in FIG. 7, since the tip of the shaft portion 81 of the penetrating member 80 can be protruded downward from the connection portion 143, it is also possible to form the connection portion 143 from a relatively thin plate material. In other words, the entire outer member 140 can be formed from a relatively thin plate material. It is also possible to manufacture multiple types of outer members having different sizes or shapes of flat plate portions with the connection portion 143 as a common part. Therefore, the outer member 140 according to this modified example is a member that can improve the reliability of the power storage device 1a and has a high degree of freedom in terms of the materials used for manufacturing.

The connecting portion 143 may be formed so that the portion of the mounting hole 141 that is connected to the penetrating member 80 is thicker than the other portions. Specifically, the connecting portion 143 may have a nut welded to a bent plate-like connecting portion body, thereby providing the mounting hole 141 that is connected to the penetrating member 80. This improves the bonding strength between the connecting portion 143 and the penetrating member 80 compared to when the mounting hole 141 is provided in the relatively thin connecting portion body itself.

In addition, in this modified example, a gap is formed between a part of the outer member 140 that is different from the part connected to the penetrating member 80 and the outer surface 32a of the bottom wall portion 32 of the exterior body 10 that faces the outer member 140.

More specifically, in the outer member 140, as shown in FIG. 7, the connection portion 143 that is connected to the penetrating member 80 has a bent shape that separates the mounting hole 141 from the flat portion 142. This allows the outer member 140 to be fixed to the exterior body 10 with the flat portion 142 floating above the outer surface 32a of the bottom wall portion 32. As a result, a clear gap is formed between the flat portion 142 and the outer surface 32a of the bottom wall portion 32.

With this configuration, the gap between the flat plate portion 142 and the bottom wall portion 32 becomes a flow path for fluids such as air that exchange heat with the power storage device 1a, thereby improving the heat dissipation efficiency of the power storage device 1a. In addition, the gap between the flat plate portion 142 and the bottom wall portion 32 can be used as a space for bending of the flat plate portion 142 in the thickness direction (Z-axis direction). For example, when an impact is applied to the power storage device 1a from below, the flat plate portion 142 bends (deforms) so as to approach the bottom wall portion 32, thereby suppressing the transmission of the impact to the exterior body 10.

Other Embodiments
The power storage device according to the present invention has been described above based on the embodiment. However, the present invention is not limited to the above embodiment. As long as the modification does not deviate from the spirit of the present invention, various modifications conceivable by those skilled in the art to the above embodiment are also included in the scope of the present invention.

For example, the material of the outer member 40 does not have to be a metal such as iron. For example, the outer member 40 may be formed of a resin containing a conductive filler such as a metal powder. This allows the outer member 40 to perform the function of releasing or removing heat and static electricity from the exterior body 10, while also making the outer member 40 lighter. The penetrating member 80 may also be formed of a resin containing a conductive filler.

In addition, for example, the wall on which the outer member is disposed is not limited to the bottom wall 32, and the outer member may be disposed on the outside of the upper wall 12 or the side wall 31. In either case, by disposing the outer member connected to a penetrating member that penetrates the wall on the outside of the wall of the exterior body 10, it is possible to obtain the effect of dissipating heat or removing static electricity from the exterior body 10 by the outer member.

The shape of the outer member 40 does not need to be a substantially rectangular plate as shown in FIG. 4, but may be a polygonal shape other than a rectangle, or a circular shape, etc. The outer member 40 may have an opening (through hole) for fixing to the installation surface 200, for weight reduction, or for increasing the surface area. The outer member 40 does not need to have both sides in the thickness direction flat, and for example, at least one of the sides may have a bent portion or a rib formed thereon to improve strength or increase the surface area.

The various supplementary points regarding the outer member 40 described above may also be applied to the outer member 140 according to the modified example. In addition, configurations constructed by arbitrarily combining the multiple components described above are also included within the scope of the present invention.

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

REFERENCE SIGNS LIST 1, 1a Energy storage device 10 Exterior body 11 Lid body 12 Upper wall portion 20 Energy storage element 25 Energy storage element unit 30 Exterior body main body 31 Side wall portion 32 Bottom wall portion 32a Outer surface 32b Through hole 36 Outer edge portion 40, 140 Outer member 41, 141 Mounting hole 80 Penetrating member 81 Shaft portion 82 Head portion 85 Gasket 91, 92 External electrode terminal 142 Flat plate portion 143 Connection portion 200 Installation surface

Claims (4)

A power storage device,
A plurality of storage elements;
an exterior body that accommodates the plurality of energy storage elements therein and has external electrode terminals on an outer surface thereof that are electrically connected to the plurality of energy storage elements;
The exterior body includes an outer member disposed along a wall portion on the outer side of the wall portion that separates an inside and an outside of the exterior body, and a penetrating member that penetrates the wall portion and is connected to the outer member,
the outer member is a plate-like member that comes into contact with an installation surface on which the power storage device is installed,
The penetrating member and the outer member are formed of a material having higher thermal conductivity and electrical conductivity than a material forming the exterior body.
Energy storage device. A plurality of storage elements;
an exterior body that accommodates the plurality of energy storage elements therein and has external electrode terminals on an outer surface thereof that are electrically connected to the plurality of energy storage elements;
The exterior body includes an outer member disposed along a wall portion on the outer side of the wall portion that separates an inside and an outside of the exterior body, and a penetrating member that penetrates the wall portion and is connected to the outer member,
a gap is formed between a part of the outer member other than a part connected to the penetrating member and an outer surface of the wall portion of the exterior body facing the outer member,
The penetrating member and the outer member are formed of a material having higher thermal conductivity and electrical conductivity than a material forming the exterior body.
Energy storage device. The outer member has a flat plate portion that contacts the installation surface and a connection portion that is fixed to the flat plate portion and connected to the penetrating member.
The power storage device according to claim 1. The penetrating member is a bolt that screws into a female thread portion of the outer member.
The power storage device according to any one of claims 1 to 3.

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