JP7669654B2 - Power storage device - Google Patents

Description

The present invention relates to an energy storage device that includes an energy storage unit having a plurality of energy storage elements and an exterior body that houses the plurality of energy storage elements.

Conventionally, a widely known energy storage device includes an energy storage unit having multiple energy storage elements and an exterior body that houses the multiple energy storage elements, and the energy storage unit is supported from below by a support member. For example, Patent Document 1 discloses a battery module (energy storage device) in which a configuration (energy storage unit) in which multiple secondary batteries (energy storage elements) are housed in a case (exterior body) is supported from below by a base plate (support member).

JP 2015-141765 A

In the above-mentioned conventional energy storage device, the support member is disposed in contact with the energy storage unit, so that if the energy storage element in the energy storage unit overheats, the heat may be transferred to other surrounding energy storage elements via the support member, which may cause a thermal chain reaction of the energy storage elements. For example, in the energy storage device disclosed in the above-mentioned Patent Document 1, the support member (base plate) is provided with a number of fins extending in the width direction of the energy storage unit, and the energy storage unit is placed and supported on these fins. Therefore, if the energy storage element in the energy storage unit overheats, the exterior body that houses the energy storage element melts, and heat is transferred to other surrounding energy storage elements via the fins, which may cause a thermal chain reaction of the energy storage elements.

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 that can suppress the occurrence of thermal chain reaction in the energy storage elements.

To achieve the above object, a power storage device according to one embodiment of the present invention includes a power storage unit having a plurality of power storage elements arranged in a first direction and an exterior body that houses the plurality of power storage elements, and a support member that is arranged in a second direction intersecting the first direction of the power storage unit and supports the power storage unit from below, the support member having a first support portion that is arranged spaced apart from an end of the power storage unit in a third direction intersecting the first direction and the second direction.

According to this, the energy storage device includes a support member that supports the energy storage unit from below in the second direction of the energy storage unit having a plurality of energy storage elements and an exterior body arranged in the first direction, and the support member has a first support portion that is arranged at a distance from the end of the energy storage unit in the third direction. Here, the inventor of the present application found that if the first support portion abuts against the end of the energy storage unit in the third direction, when the energy storage element overheats, the end of the exterior body in the third direction melts, and the melting of the exterior body may spread in the first direction via the first support portion that abuts against the end. When the heat of melting the exterior body spreads in the first direction (the arrangement direction of the plurality of energy storage elements), the heat is transmitted to other surrounding energy storage elements, and there is a risk of a thermal chain reaction of the energy storage elements occurring. For this reason, the first support portion of the support member is arranged at a distance from the end of the energy storage unit in the third direction. As a result, even if the energy storage element overheats and the end of the energy storage unit's exterior body in the third direction melts, the melting of the exterior body is prevented from spreading in the first direction, preventing a thermal chain reaction from occurring in the energy storage element.

The support member may further have a plate-shaped portion that faces the power storage unit in the second direction of the power storage unit and is spaced apart from the power storage unit.

According to this, by arranging the plate-shaped portion in the support member in the second direction of the energy storage unit while being spaced apart from the energy storage unit, even if the energy storage element overheats and the exterior body melts, the melting of the exterior body is prevented from spreading in the first direction. In other words, if the plate-shaped portion abuts against a location where the exterior body has melted, there is a risk that the melting of the exterior body will spread in the first direction, but because the plate-shaped portion is arranged spaced apart from the exterior body, the melting of the exterior body is prevented from spreading in the first direction. This prevents the heat from the melting of the exterior body from being transferred to other energy storage elements, thereby preventing a thermal chain reaction of the energy storage elements.

The first support portion may be arranged to extend from one end to the other end of the storage unit in the first direction.

By having the first support portion of the support member extend from one end to the other end of the energy storage unit in the first direction, the energy storage unit can be stably supported while preventing thermal chain reactions of the energy storage elements.

The storage unit may have an elongated shape in the first direction, and the support member may further have a second support portion that supports an end portion of the storage unit in the first direction.

By having the energy storage unit have a long shape in the first direction, it is possible to prevent melting of the exterior body from spreading in the longitudinal direction of the energy storage unit. Furthermore, by having the support member have a second support portion that supports the end portion of the energy storage unit in the longitudinal direction (first direction), it is possible to stably support the energy storage unit. As a result, it is possible to stably support the energy storage unit while preventing the occurrence of thermal chain reaction of the energy storage elements.

The exterior body may be made of resin.

According to this, because the exterior body of the energy storage unit is made of resin, the exterior body is likely to melt when the energy storage element overheats, and therefore, in the conventional configuration, thermal chain reaction of the energy storage element is likely to occur. In contrast, the configuration of the present invention prevents the melting of the exterior body from spreading even if the exterior body melts, and therefore, it is possible to prevent thermal chain reaction of the energy storage element even when the exterior body is made of resin.

The present invention can be realized not only as such an electricity storage device, but also as a support member.

The energy storage device of the present invention can prevent thermal chain reactions from occurring in the energy storage elements.

1 is a perspective view showing a configuration of an electricity storage device according to an embodiment; FIG. 2 is a perspective view showing a configuration of an electricity storage unit according to the embodiment. FIG. 2 is a perspective view showing a configuration of an energy storage element according to an embodiment. FIG. 2 is a perspective view showing a configuration of a support member according to the embodiment. 5 is a perspective view showing a positional relationship between a support member and an electricity storage unit according to the embodiment. FIG. 13 is a perspective view showing a configuration of a support member according to a first modified example of the embodiment and a positional relationship between the support member and an electricity storage unit. FIG. 13 is a perspective view showing a configuration of a support member according to a second modification of the embodiment and a positional relationship between the support member and an electricity storage unit. FIG. 13 is a perspective view showing a configuration of a support member according to a third modification of the embodiment, and a positional relationship between the support member and an electricity storage unit. FIG.

The following describes an energy storage device according to an embodiment of the present invention (including its variations) 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 and connection forms, manufacturing processes, and the order of manufacturing processes shown in the following embodiments are merely examples and are not intended to limit the present invention. Each figure is a schematic diagram, and dimensions are not necessarily strictly depicted. In each figure, the same or similar components are given the same reference numerals.

In the following explanation and drawings, the width direction of the rack, the arrangement direction of the storage units on the support members (shelf boards) of the rack, the facing direction of the long sides of the storage units, or the facing direction of the short sides of the storage elements are defined as the X-axis direction. The depth direction of the rack, the facing direction of the short sides of the storage units (longitudinal direction of the storage units), the arrangement direction of the storage elements in one storage unit, or the facing direction of the long sides of the storage elements are defined as the Y-axis direction. The height direction of the rack, the arrangement direction of the storage units sandwiching the support members, the arrangement direction of the storage units and the support members, or the up-down direction are defined as the Z-axis direction. These X-axis, Y-axis, and Z-axis directions intersect each other (orthogonal in this embodiment).

In the following description, for example, the positive X-axis direction refers to the direction of the X-axis arrow, and the negative X-axis direction refers to the opposite direction to the positive X-axis direction. The same applies to the Y-axis and Z-axis directions. Hereinafter, the Y-axis direction may also be called the first direction, the Z-axis direction (or the negative Z-axis direction) may also be called the second direction, and the X-axis direction may also be called the third direction. Expressions indicating relative directions or attitudes, such as parallel and orthogonal, may also include cases where the direction or attitude is not strictly speaking the same. For example, saying that two directions are orthogonal does not only mean that the two directions are completely orthogonal, but also means that the two directions are substantially orthogonal, that is, there is a difference of, for example, about a few percent.

(Embodiment)
[1 General Description of Power Storage Device 10]
First, a general description of the energy storage device 10 according to the present embodiment will be given. Fig. 1 is a perspective view showing the configuration of the energy storage device 10 according to the present embodiment. In Fig. 1, a part of a rack 200 of the energy storage device 10 is seen through, and a part of the inside of the rack 200 is shown by a dashed line. Fig. 2 is a perspective view showing the configuration of the energy storage unit 100 according to the present embodiment. In Fig. 2, an exterior body 120 of the energy storage unit 100 is seen through, and the inside of the exterior body 120 is shown by a dashed line.

The power storage device 10 is a device that can charge electricity from the outside and discharge electricity to the outside, and in this embodiment, has a rectangular parallelepiped shape. The power storage device 10 is used for power storage purposes or power source purposes. Specifically, the power storage device 10 is used as a stationary battery or the like used in home or industrial power storage facilities. In this embodiment, the power storage device 10 is a stationary storage battery panel that stores power generated by wind power generation, solar power generation, etc., and stably supplies power to external facilities. The power storage device 10 can also be used as a battery for driving or starting an engine of a moving body such as an automobile, motorcycle, watercraft, ship, snowmobile, agricultural machinery, construction machinery, or a railway vehicle 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 railway vehicles for electric railways include electric trains, monorails, linear motor cars, and hybrid trains equipped with both a diesel engine and an electric motor.

As shown in FIG. 1, the energy storage device 10 includes an energy storage unit 100 and a rack 200 that houses the energy storage unit 100. In this embodiment, three energy storage units 100 are arranged in the X-axis direction in the rack 200, and are arranged in four tiers in the Z-axis direction.

The energy storage unit 100 is a battery module (battery assembly) having a rectangular parallelepiped shape that is elongated in the Y-axis direction (first direction). As shown in FIG. 2, the energy storage unit 100 has a plurality of energy storage elements 110 arranged in the Y-axis direction (first direction), and an exterior body 120 that houses the plurality of energy storage elements 110. The number of energy storage elements 110 in the energy storage unit 100 is not particularly limited, but for example, 16 energy storage elements 110 are arranged in the Y-axis direction and housed in the exterior body 120. In addition to these configurations, the energy storage unit 100 also has bus bars and the like that connect the electrode terminals of the plurality of energy storage elements 110, but these are not shown in the figures and detailed description is also omitted. The energy storage unit 100 may also include spacers arranged between the energy storage elements 110, restraining members (end plates, side plates, etc.) that restrain the energy storage elements 110, a bus bar frame that positions the bus bars, and electrical equipment such as circuit boards and relays for monitoring the charging and discharging states of the energy storage elements 110, but these are not shown or described here.

The storage element 110 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 storage element 110 has a flat rectangular parallelepiped shape (corner). The shape of the storage element 110 is not limited to a rectangular parallelepiped shape, and may be a polygonal column shape, a cylindrical shape, an oblong cylindrical shape, or the like other than a rectangular parallelepiped shape. The storage element 110 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 110 may not be a secondary battery, but may be a primary battery that can use stored electricity without the user having to charge it. The storage element 110 may be a pouch-type storage element. A detailed description of the configuration of the storage element 110 will be given later.

The exterior body 120 is a box-shaped (rectangular parallelepiped) container (module case) that is elongated in the Y-axis direction and constitutes the exterior body of the energy storage unit 100. The exterior body 120 is disposed outside the multiple energy storage elements 110, fixes the multiple energy storage elements 110 in predetermined positions, and protects them from impacts and the like. There are no particular limitations on the material of the exterior body 120, but in this embodiment, the exterior body 120 is formed from a material that melts (burns) due to heat, specifically, resin. For example, the exterior body 120 is formed of an insulating resin material 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 120 thereby prevents the multiple energy storage elements 110 from coming into contact with external metal members, etc.

The exterior body 120 has an exterior body main body 121 constituting the main body of the exterior body 120, and an exterior body lid 122 constituting the lid of the exterior body 120. The exterior body main body 121 is a bottomed rectangular cylindrical housing (housing) with an opening formed therein, and houses the energy storage element 110 and the like. The exterior body main body 121 is a bottomed rectangular cylindrical housing (housing) with an opening formed in the Z-axis positive direction, and houses the energy storage element 110 and the like. That is, the exterior body main body 121 has a pair of opposing rectangular and flat long side walls on both sides in the X-axis direction, a pair of opposing rectangular and flat short side walls on both sides in the Y-axis direction, and a rectangular and flat bottom wall on the Z-axis negative direction side. The exterior body lid 122 is a flat rectangular member extending in the Y-axis direction that closes the opening of the exterior body main body 121. The exterior cover 122 is engaged or fitted with the exterior body 121 and joined by adhesive, heat sealing, ultrasonic welding, or the like. The exterior body 120 is provided with external terminals (positive external terminal and negative external terminal) for charging with electricity from the outside and discharging electricity to the outside, but these are not shown in the figure.

The rack 200 is a rectangular parallelepiped (box-shaped) container (shelf) and includes a rack body 210 that stores multiple power storage units 100, and a support member 220 that supports the multiple power storage units 100. The rack 200 (rack body 210 and support member 220) is formed of metal such as stainless steel, aluminum, aluminum alloy, iron, plated steel sheet, etc. The rack 200 may be formed of any resin that can be used for the exterior body 120 described above, but the rack body 210 is preferably formed of a material with high strength, and the support member 220 is preferably formed of a material with high strength and heat resistance.

The rack main body 210 has an opening on the surface (front) on the negative Y-axis side. In other words, the rack main body 210 has two side surfaces 211, a top surface 212, a bottom surface 213, a back surface 214, and a partition 215. The rack main body 210 may have a cover member (door) that closes the opening on the surface (front) on the negative Y-axis side in an openable/closable manner (openable/closable).

The two side sections 211 are flat, rectangular wall sections arranged on both sides of the rack body section 210 in the X-axis direction. The top section 212 is a flat, rectangular wall section arranged on the Z-axis positive side of the rack body section 210. The bottom section 213 is a flat, rectangular wall section arranged on the Z-axis negative side of the rack body section 210. The rear section 214 is a flat, rectangular wall section arranged on the Y-axis positive side of the rack body section 210. The rear section 214 may be a cover member (door) that closes the opening of the surface (rear surface) of the rack body section 210 on the Y-axis positive side in an openable/closable manner (openable/closable). The partition section 215 is a flat, rectangular wall section that separates the storage space 230 in which the power storage unit 100 is accommodated from the storage space 240 in which equipment other than the power storage unit 100, such as a control device, is accommodated.

The support member 220 is a flat rectangular shelf plate arranged in the negative Z-axis direction (second direction intersecting with the first direction) of the energy storage unit 100 and supporting the energy storage unit 100 from below (negative Z-axis direction). In this embodiment, a plurality (four) of support members 220 parallel to the XY plane are arranged in the Z-axis direction to divide the space inside the rack body 210. As a result, four storage spaces 230 arranged in the Z-axis direction are formed inside the rack body 210. The storage space 230 is a rectangular parallelepiped space in which one or more energy storage units 100 (three energy storage units 100 in this embodiment) are accommodated. In other words, the rack 200 has four storage spaces 230, and three energy storage units 100 are accommodated in each of the four storage spaces 230. In other words, three energy storage units 100 are placed on the four support members 220. A detailed explanation of the configuration of the support member 220 will be given later.

[2. Description of the Configuration of Energy Storage Element 110]
Next, the configuration of the energy storage element 110 will be described in detail. Since all of the energy storage elements 110 included in the energy storage unit 100 have the same configuration, the configuration of one energy storage element 110 will be described in detail below. Fig. 3 is a perspective view showing the configuration of the energy storage element 110 according to this embodiment.

As shown in FIG. 3, the energy storage element 110 includes a container 111 and a pair of electrode terminals 114 (positive and negative terminals). Inside the container 111, an electrode body, a current collector (positive and negative current collectors), and an electrolyte (non-aqueous electrolyte) are contained, but these are not shown. There is no particular limit to the type of electrolyte as long as it does not impair the performance of the energy storage element 110, and various types can be selected. Between the container 111 (container lid 113 described below) and the electrode terminal 114, and between the container 111 (container lid 113) and the current collector, gaskets and the like are arranged to improve insulation and airtightness, but these are also not shown. A spacer may be arranged on the side of the current collector, or an insulating sheet covering the outer surface of the container 111 may be arranged.

The container 111 is a rectangular parallelepiped (angular) container having a container body 112 with an opening formed therein and a container lid 113 that closes the opening of the container body 112. The material of the container 111 is not particularly limited, but is preferably a weldable metal such as stainless steel, aluminum, aluminum alloy, iron, or plated steel sheet.

The container body 112 is a rectangular cylindrical member with a bottom that constitutes the main body of the container 111. The container body 112 has a pair of opposing rectangular and planar long side portions on both sides in the Y-axis direction, a pair of opposing rectangular and planar short side portions on both sides in the X-axis direction, and a rectangular and planar bottom portion on the negative Z-axis direction. The container lid 113 is a flat and rectangular member that constitutes the lid of the container 111, and is arranged in the positive Z-axis direction of the container body 112, extending in the X-axis direction. The container lid 113 is provided with a gas exhaust valve 115 that releases pressure when the pressure inside the container 111 increases. The container 111 (e.g., the container lid 113) may also be provided with a liquid injection portion for injecting electrolyte into the container 111.

The electrode terminals 114 are terminals (positive and negative terminals) of the energy storage element 110 that are disposed on the container lid 113 of the container 111, and are electrically connected to the positive and negative plates of the electrode body via a current collector. In other words, the electrode terminals 114 are metal members that conduct electricity stored in the electrode body to the external space of the energy storage element 110, and also introduce electricity into the internal space of the energy storage element 110 to store electricity in the electrode body. The electrode terminals 114 are formed of aluminum, an aluminum alloy, copper, a copper alloy, or the like.

The electrode body is a storage element (power generating element) formed by stacking a positive electrode plate, a negative electrode plate, and a separator. The positive electrode plate of the electrode body is a positive electrode active material layer formed on a positive electrode substrate layer, which is a current collector foil made of a metal such as aluminum or an aluminum alloy. The negative electrode plate is a negative electrode active material layer formed on a negative electrode substrate layer, which is a current collector foil made of a metal such as copper or a copper alloy. As the positive electrode active material used in the positive electrode active material layer and the negative electrode active material used in the negative electrode active material layer, any suitable known material can be used as long as it can absorb and release lithium ions. The separator is a microporous sheet, and any suitable known material such as resin can be used. The electrode body may be a stack-type electrode body formed by stacking multiple flat electrode plates (positive electrode plates and negative electrode plates), a bellows-type electrode body in which the electrode plates are folded in a bellows shape, or a wound-type electrode body formed by winding the electrode plates.

The current collectors are conductive members (positive and negative current collectors) that are electrically connected to the electrode terminal 114 and the electrode body. The positive current collector is made of aluminum or an aluminum alloy, similar to the positive electrode substrate layer of the positive electrode plate, and the negative current collector is made of copper or a copper alloy, similar to the negative electrode substrate layer of the negative electrode plate.

[3. Description of the Configuration of Support Member 220]
Next, the configuration of the support member 220 will be described in detail. Fig. 4 is a perspective view showing the configuration of the support member 220 according to this embodiment. Since all the support members 220 of the rack 200 have the same configuration, Fig. 4 shows the configuration of one support member 220. Fig. 5 is a perspective view showing the positional relationship between the support member 220 according to this embodiment and the energy storage unit 100. Specifically, Fig. 5 shows a state in which the energy storage unit 100 is placed on the support member 220 at a portion on the positive side of the X-axis of the support member 220.

The support member 220 is a member that supports multiple (three in this embodiment) energy storage units 100 from below, and as shown in Figures 4 and 5, has a plate-shaped portion 221, a first support portion 222, and a second support portion 223.

The plate-shaped portion 221 is a flat rectangular portion parallel to the XY plane, and is arranged in the negative Z-axis direction (second direction) of the energy storage unit 100, facing the energy storage unit 100 and spaced apart from the energy storage unit 100. Specifically, the plate-shaped portion 221 is arranged in the Z-axis direction next to the multiple (three) energy storage units 100 at a distance. The plate-shaped portion 221 is also arranged to extend in the X-axis direction across the multiple energy storage units 100, and to extend in the Y-axis direction from one end (one edge) to the other end (the other edge) of the multiple energy storage units 100 in the Y-axis direction. As a result, the plate-shaped portion 221 is arranged to cover the entire multiple energy storage units 100 when viewed from the negative Z-axis direction (second direction).

The first support portion 222 is a flat rectangular portion parallel to the YZ plane that protrudes from the plate portion 221 in the positive direction of the Z axis and extends in the Y axis direction from one end to the other end of the plate portion 221. In this embodiment, three first support portions 222 are arranged on both sides and the center of the plate portion 221 in the X axis direction corresponding to the three power storage units 100. The first support portion 222 may be joined to the plate portion 221 (and the second support portion 223) by welding, fitting, engaging, bolting, bonding, welding, etc., or may be formed integrally with the plate portion 221 (and the second support portion 223) by casting, forging, pressing, etc.

Each first support portion 222 is disposed in the center of the energy storage unit 100 in the X-axis direction and extends from one end to the other end in the Y-axis direction (first direction) of the energy storage unit 100. The first support portion 222 is disposed in the negative Z-axis direction of the energy storage unit 100, and supports the energy storage unit 100 by placing it in contact with the surface of the energy storage unit 100 in the negative Z-axis direction (the bottom wall portion of the exterior body 120). The surface (upper surface) of the first support portion 222 in the positive Z-axis direction is formed as a flat surface (horizontal surface), and the energy storage unit 100 is placed and supported in contact with the flat surface.

In this way, the first support portion 222 is disposed apart from the end portion in the X-axis direction of the energy storage unit 100 (a third direction intersecting the first and second directions). In other words, the first support portion 222 is disposed at a position that does not overlap with the end portion in the X-axis direction of the energy storage unit 100 when viewed from the Z-axis direction. The end portion in the X-axis direction is, for example, a region located at the end portion when the width in the X-axis direction of the energy storage unit 100 (exterior body 120) is divided into thirds. It is more preferable that the end portion in the X-axis direction is a region located at the end portion when the width in the X-axis direction of the energy storage unit 100 (exterior body 120) is divided into fifths, and even more preferable that the end portion in the X-axis direction is a region located at the end portion when the width in the X-axis direction of the energy storage unit 100 (exterior body 120) is divided into ten equal parts.

The second support portion 223 is a flat, rectangular portion parallel to the XZ plane that protrudes from the plate portion 221 in the positive direction of the Z axis and extends in the X axis direction from one end (one edge) of the plate portion 221 in the X axis direction to the other end (the other edge). Specifically, two second support portions 223 that protrude in the positive direction of the Z axis from both edges of the plate portion 221 in the Y axis direction are arranged at both ends of the plate portion 221 in the Y axis direction. The two second support portions 223 are arranged at positions that sandwich the three first support portions 222 in the Y axis direction and are connected to both ends of the three first support portions 222.

In this embodiment, the second support portion 223 is connected to the plate-shaped portion 221 and is formed integrally with the plate-shaped portion 221 (integrally formed). For example, the plate-shaped portion 221 and the second support portion 223 can be formed by bending the end of a single flat plate-shaped member. The second support portion 223 may be integrally formed with the plate-shaped portion 221 (and the first support portion 222) by casting, forging, press processing, or the like. The second support portion 223 may be formed separately from the plate-shaped portion 221 and joined to the plate-shaped portion 221 (and the first support portion 222) by welding, fitting, engagement, bolting, adhesion, welding, or the like.

The second support portion 223 supports the end portion of the energy storage unit 100 in the Y-axis direction (first direction). That is, at both ends of the multiple (three) energy storage units 100 in the Y-axis direction, two second support portions 223 are arranged extending in the X-axis direction across the multiple energy storage units 100, and support both ends of the multiple energy storage units 100 in the Y-axis direction. The second support portion 223 is arranged in the negative Z-axis direction of the energy storage unit 100, and supports the energy storage unit 100 by placing it in contact with the surface of the energy storage unit 100 in the negative Z-axis direction (the bottom wall portion of the exterior body 120). The surface (upper surface) of the second support portion 223 in the positive Z-axis direction is formed as a flat surface (horizontal surface), and the energy storage unit 100 is placed and supported in contact with the flat surface.

In this way, the two second support parts 223 are arranged at positions overlapping both end parts (both end edges) of the energy storage unit 100 in the Y axis direction when viewed from the Z axis direction. Since the first support part 222 is arranged between the two second support parts 223, the first support part 222 supports a part of the energy storage unit 100 different from the end part in the Y axis direction when viewed from the Z axis direction. In other words, the first support part 222 abuts against a part of the energy storage unit 100 (exterior body 120) different from the edge in the Y axis direction and supports the part different from the edge.

[4. Description of Effects]
As described above, the energy storage device 10 according to the embodiment of the present invention includes a support member 220 that supports the energy storage unit 100 from below in the second direction (negative Z-axis direction) of the energy storage unit 100 having a plurality of energy storage elements 110 and an exterior body 120 arranged in the first direction (Y-axis direction). The support member 220 has a first support portion 222 that is disposed apart from an end portion of the energy storage unit 100 in the third direction (X-axis direction). Here, the inventors of the present application have found that if the first support portion 222 is in contact with an end portion of the energy storage unit 100 in the third direction, when the energy storage elements 110 overheat, the end portion of the exterior body 120 in the third direction may melt, and the melting of the exterior body 120 may spread in the first direction via the first support portion 222 that is in contact with the end portion. When the heat of melting of the exterior body 120 spreads in the first direction (the arrangement direction of the multiple energy storage elements 110), the heat is transferred to the other surrounding energy storage elements 110, which may cause a thermal chain reaction of the energy storage elements 110. For this reason, the first support portion 222 of the support member 220 is disposed away from the end portion in the third direction of the energy storage unit 100. As a result, even if the energy storage element 110 overheats and the end portion in the third direction of the exterior body 120 of the energy storage unit 100 melts, the melting of the exterior body 120 is prevented from spreading in the first direction, and therefore, the occurrence of a thermal chain reaction of the energy storage elements 110 can be prevented.

In the support member 220, by arranging the plate-shaped portion 221 in the second direction of the energy storage unit 100 while being spaced apart from the energy storage unit 100, even if the energy storage element 110 overheats and the exterior body 120 melts, the melting of the exterior body 120 is prevented from spreading in the first direction. In other words, if the plate-shaped portion 221 abuts against the melted portion of the exterior body 120, there is a risk that the melting of the exterior body 120 will spread in the first direction, but since the plate-shaped portion 221 is arranged spaced apart from the exterior body 120, the melting of the exterior body 120 is prevented from spreading in the first direction. This prevents the heat of melting of the exterior body 120 from being transferred to other energy storage elements 110, and thus prevents the occurrence of a thermal chain reaction of the energy storage elements 110. In addition, even if the molten material of the exterior body 120 falls from the exterior body 120, it remains on the plate-shaped portion 221, which prevents the heat chain reaction from spreading to other energy storage units 100 below the energy storage unit 100.

The first support portion 222 of the support member 220 extends from one end to the other end in the first direction of the energy storage unit 100, thereby stably supporting the energy storage unit 100 while preventing thermal chain reaction of the energy storage elements 110.

By arranging the first support portion 222 in a position that does not overlap with the end portion of the energy storage unit 100 in the third direction when viewed from the second direction, even if the end portion of the exterior body 120 in the third direction melts, the molten material is prevented from falling onto the first support portion 222. This prevents the melting of the exterior body 120 from spreading in the first direction, thereby preventing a thermal chain reaction from occurring in the energy storage element 110.

The first support portion 222 supports the energy storage unit 100 except for the end portion in the first direction. In other words, by disposing another support portion (second support portion 223) that supports the end portion in the third direction at the end portion in the first direction of the energy storage unit 100, the energy storage unit 100 can be stably supported.

By having the energy storage unit 100 have a long shape in the first direction, it is possible to prevent the melting of the exterior body 120 from spreading in the longitudinal direction of the energy storage unit 100. Furthermore, by having the support member 220 have the second support portion 223 that supports the end portion of the energy storage unit 100 in the longitudinal direction (first direction), it is possible to stably support the energy storage unit 100. As a result, it is possible to stably support the energy storage unit 100 while preventing the occurrence of thermal chain reaction of the energy storage elements 110.

Because the exterior body 120 of the energy storage unit 100 is made of resin, the exterior body 120 is likely to melt when the energy storage element 110 overheats, and therefore, in the conventional configuration, thermal chain reaction of the energy storage element 110 is likely to occur. In contrast, the configuration of the present embodiment prevents the melting of the exterior body 120 from spreading even if the exterior body 120 melts, and therefore, it is possible to prevent thermal chain reaction of the energy storage element 110 from occurring even when the exterior body 120 is made of resin.

[5. Description of Modifications]
(Variation 1)
Next, a first modification of the above embodiment will be described. Fig. 6 is a perspective view showing the configuration of a support member 220a according to the first modification of the present embodiment, and the positional relationship between the support member 220a and the energy storage unit 100. Specifically, Fig. 6 corresponds to Fig. 5.

As shown in FIG. 6, the support member 220a in this modified example has a first support portion 222a instead of the first support portion 222 of the support member 220 in the above embodiment. The rest of the configuration is the same as in the above embodiment, so detailed description is omitted.

The first support portion 222a is a cylindrical portion that protrudes in the positive direction of the Z axis from the center of the plate-shaped portion 221 in the Y axis direction. In this modification, three first support portions 222a are arranged at the center of the X axis direction and the center of the Y axis direction of the energy storage unit 100 corresponding to the three energy storage units 100. The first support portion 222a may be joined to the plate-shaped portion 221 by welding, fitting, engagement, bolting, adhesion, welding, etc., or may be formed integrally with the plate-shaped portion 221 by casting, forging, pressing, etc.

Each first support portion 222a is disposed at the center in the X-axis direction and the Y-axis direction of the energy storage unit 100 in the negative Z-axis direction, and supports the energy storage unit 100 by placing it in contact with the surface of the energy storage unit 100 in the negative Z-axis direction (the bottom wall of the exterior body 120). The surface (upper surface) of the first support portion 222a in the positive Z-axis direction is formed as a flat surface (horizontal surface), and the energy storage unit 100 is placed and supported in contact with the flat surface. In this way, the first support portion 222a is disposed away from the end of the energy storage unit 100 in the X-axis direction (third direction).

As described above, the energy storage device according to this modified example can achieve the same effects as the above-described embodiment. In this way, the first support portion 222a only needs to be disposed away from the end portion in the X-axis direction of the energy storage unit 100, and its position and shape are not particularly limited. Note that in this modified example, the first support portion 222a may be disposed at a position shifted from the center portion in the X-axis direction and the center portion in the Y-axis direction of the energy storage unit 100, and may have a shape other than a cylindrical shape, such as a tubular shape such as an oval cylinder shape, an elliptical cylinder shape, a rectangular cylinder shape, or a cylindrical shape, or a hollow shape.

(Variation 2)
Next, a second modification of the above embodiment will be described. Fig. 7 is a perspective view showing the configuration of a support member 220b according to the second modification of the present embodiment, and the positional relationship between the support member 220b and the energy storage unit 100. Specifically, Fig. 7 is a view corresponding to Fig. 5.

As shown in FIG. 7, the support member 220b in this modified example has a first support portion 222b instead of the first support portion 222 of the support member 220 in the above embodiment. The rest of the configuration is the same as in the above embodiment, so detailed description is omitted.

The first support portion 222b is a flat, rectangular portion parallel to the XZ plane that protrudes from the center of the plate-shaped portion 221 in the Y-axis direction in the positive Z-axis direction and extends in the X-axis direction from one end (one edge) to the other end (the other edge) of the plate-shaped portion 221 in the X-axis direction. In this modified example, the first support portion 222b is arranged in the center of the Y-axis direction of the multiple (three) energy storage units 100, extending in the X-axis direction across the multiple energy storage units 100, and supports the center of the Y-axis direction of the multiple energy storage units 100. The first support portion 222b is arranged in the center of the Y-axis direction of the energy storage unit 100 in the negative Z-axis direction, and supports the energy storage unit 100 by placing it on it in a state of abutting against the surface of the energy storage unit 100 in the negative Z-axis direction (the bottom wall portion of the exterior body 120). The surface (upper surface) of the first support portion 222b in the positive direction of the Z axis is formed as a flat surface (horizontal surface), and the energy storage unit 100 is placed and supported in contact with the flat surface.

The first support portion 222b has a recess 224 recessed in the negative Z-axis direction at a position facing the end of the energy storage unit 100 in the X-axis direction. In this modified example, the recess 224 is a recess recessed in a semicircular shape when viewed from the Y-axis direction. Thus, the first support portion 222b is disposed at a position overlapping with the end of the energy storage unit 100 in the X-axis direction when viewed from the Z-axis direction, but is disposed away from the end of the energy storage unit 100 in the X-axis direction. The first support portion 222b may be joined to the plate-shaped portion 221 by welding, fitting, engagement, bolting, adhesion, welding, etc., or may be formed integrally with the plate-shaped portion 221 by casting, forging, pressing, etc.

As described above, the energy storage device according to this modification can achieve the same effects as the above embodiment. In this way, the first support portion 222b only needs to be arranged away from the end of the energy storage unit 100 in the X-axis direction, and its position and shape are not particularly limited. In this modification, the shape of the recess 224 of the first support portion 222b is not particularly limited, and may be a shape other than a semicircle, such as a semi-oval shape, a semi-ellipse shape, a rectangle shape, a triangle shape, or another polygonal shape, when viewed from the Y-axis direction. The first support portion 222b may be divided into three parts and arranged to correspond to the three energy storage units 100.

(Variation 3)
Next, a third modification of the above embodiment will be described. Fig. 8 is a perspective view showing a configuration of a support member 220c according to the third modification of the present embodiment, and a positional relationship between the support member 220c and the energy storage unit 100. Specifically, Fig. 8 corresponds to Fig. 5.

As shown in FIG. 8, the support member 220c in this modified example has a first support portion 222c instead of the first support portion 222 and the second support portion 223 of the support member 220 in the above embodiment. The rest of the configuration is the same as in the above embodiment, so detailed description will be omitted.

The first support portion 222c is an inverted U-shaped portion when viewed from the Y-axis direction, which protrudes from the plate-shaped portion 221 in the positive direction of the Z-axis and extends from one end (one edge) of the plate-shaped portion 221 in the Y-axis direction to the other end (the other edge) in the Y-axis direction. In other words, the first support portion 222c has a rectangular parallelepiped shape in which the surface facing the negative Z-axis direction of the rectangular parallelepiped prism extending in the Y-axis direction is recessed in a rectangular shape in the positive Z-axis direction. In this modification, two first support portions 222c aligned in the X-axis direction are arranged for each storage unit 100. The first support portion 222c may be joined to the plate-shaped portion 221 by welding, fitting, engagement, bolting, adhesion, welding, etc., or may be formed integrally with the plate-shaped portion 221 by casting, forging, etc.

Each of the first support parts 222c is disposed at a position avoiding the end of the energy storage unit 100 in the X-axis direction, and extends from one end to the other end of the energy storage unit 100 in the Y-axis direction (first direction). In other words, the first support parts 222c are disposed away from the end of the energy storage unit 100 in the X-axis direction (third direction). The first support parts 222c are disposed in the negative Z-axis direction of the energy storage unit 100, and support the energy storage unit 100 by placing it in contact with the surface of the energy storage unit 100 in the negative Z-axis direction (the bottom wall of the exterior body 120). The surface (upper surface) of the first support part 222c in the positive Z-axis direction is formed as a flat surface (horizontal surface), and the energy storage unit 100 is placed and supported in contact with the flat surface.

As described above, the energy storage device according to this modification can achieve the same effect as the above embodiment. In particular, in this modification, the support member 220c does not have the second support portion 223 that the support member 220 in the above embodiment has, but even with this configuration, the same effect as the above embodiment can be achieved. In this modification, the shape of the first support portion 222c is not particularly limited, and the surface in the Z-axis positive direction may be concave, the other surfaces may be concave, or none of the surfaces may be concave, and the shape may be semicircular, semi-elliptical, semi-oval, triangular, or other polygonal when viewed from the Y-axis direction. The number of first support portions 222c is also not particularly limited, and three or more first support portions 222c may be arranged in the X-axis direction, or one first support portion 222c with a large width in the X-axis direction may be arranged.

(Other Modifications)
Although the power storage device according to the embodiment of the present invention (including its modified examples) has been described above, the present invention is not limited to this embodiment. The embodiment disclosed here is illustrative in all respects, and the scope of the present invention includes all modifications within the meaning and scope of the claims.

For example, in the above embodiment, the support member is arranged vertically below the energy storage unit 100 (second direction) and supports the energy storage unit 100 from below. However, the support member may be arranged in a direction slightly tilted from below the vertical direction of the energy storage unit 100 and supports the energy storage unit 100 from below. In other words, the second direction may be defined as a direction tilted from below the vertical direction.

In the above embodiment, the support member has a plate-shaped portion 221, but it does not have to have a plate-shaped portion 221.

In the above embodiment, the energy storage unit 100 has an elongated shape in the Y-axis direction, and the second support portion 223 supports the end portion of the energy storage unit 100 in the longitudinal direction. However, the energy storage unit 100 may have an elongated shape in the X-axis direction (shorter in the Y-axis direction), and the second support portion 223 may support the end portion of the energy storage unit 100 in the lateral direction. Alternatively, the energy storage unit 100 may have an elongated shape in the Z-axis direction.

In the above embodiment, the rack 200 has multiple (four) support members, but the number of support members that the rack 200 has is not particularly limited, and the rack 200 may have only one support member. Also, the support member is a member that supports multiple (three) energy storage units 100, but the number of energy storage units 100 supported by the support member is not particularly limited, and the support member may support only one energy storage unit 100. In other words, the support member may be configured to only have a first support portion, etc., that corresponds to one energy storage unit 100.

In the above embodiment, all of the support members of the rack 200 have the above configuration, but any of the support members may not have the above configuration. Also, although one support member has the above configuration for all of the energy storage units 100, any of the energy storage units 100 may not have the above configuration.

In the above embodiment, the energy storage unit 100 is placed and supported in contact with the support member. However, the energy storage unit 100 may be placed in indirect contact with the support member via an insulating member or the like, rather than in direct contact with the support member. Even in this case, if the insulating member or the like is included in the support member, or if the insulating member or the like is defined as being included in the energy storage unit 100, the energy storage unit 100 will be placed in direct contact with the support member.

Any combination of the above embodiments and modifications is also within the scope of the present invention.

The present invention can be realized not only as such an electricity storage device, but also as a support member.

The present invention can be applied to energy storage devices equipped with energy storage elements such as lithium-ion secondary batteries.

REFERENCE SIGNS LIST 10 Energy storage device 100 Energy storage unit 110 Energy storage element 111 Container 114 Electrode terminal 120 Exterior body 200 Rack 210 Rack main body 211 Side surface 212 Top surface 213 Bottom surface 214 Rear surface 215 Partition 220, 220a, 220b, 220c Support member 221 Plate-shaped portion 222, 222a, 222b, 222c First support portion 223 Second support portion 224 Recess 230, 240 Storage space

Claims (5)

an energy storage unit including a plurality of energy storage elements arranged in a first direction and an exterior body that houses the plurality of energy storage elements;
a rack that houses the power storage unit;
the rack is arranged in a second direction intersecting the first direction of the power storage unit and includes a shelf plate supporting the power storage unit from below;
The shelf board is
a first support portion disposed apart from an end portion of the electricity storage unit in a third direction intersecting the first direction and the second direction ;
a plate-shaped portion disposed in the second direction of the power storage unit, facing the power storage unit and spaced apart from the power storage unit . an energy storage unit including a plurality of energy storage elements arranged in a first direction and an exterior body that houses the plurality of energy storage elements;
a rack that houses the power storage unit;
the rack is arranged in a second direction intersecting the first direction of the power storage unit and includes a shelf plate supporting the power storage unit from below;
the shelf board has a first support portion arranged to be spaced apart from an end portion of the electricity storage unit in a third direction intersecting the first direction and the second direction,
The first support portion is disposed at a position facing a center portion of the energy storage unit in the third direction.
Energy storage device. The energy storage device according to claim 1 , wherein the first support portion is disposed so as to extend from one end to another end of the energy storage unit in the first direction. The power storage unit has an elongated shape in the first direction,
The power storage device according to claim 1 , wherein the shelf board further includes a second support portion that supports an end portion of the power storage unit in the first direction. The power storage device according to claim 1 , wherein the exterior body is made of resin.

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