JP2022123356A - power storage device - Google Patents

Abstract

To provide a power storage device which can prevent damage to power storage elements.SOLUTION: A power storage device 10 comprises: a plurality of power storage elements 200 each of which has a container body 220, and a lid 230 for closing the container body 220 and welded to the container body 220; a pair of end plates 400 which sandwich, in a predetermined direction, the plurality of power storage elements 200 aligned in the predetermined direction; and coupling parts which are provided to extend along the predetermined direction and are coupled to the pair of end plates. In at least one of the pair of end plates, a portion which overlaps a welding part 260 between the container body 220 and the lid 230 when viewed in the predetermined direction (an X-axis direction) serves as a first protrusion 438 protruding to the side opposite to the power storage elements 200.SELECTED DRAWING: Figure 9

Description

The present invention relates to a power storage device.

2. Description of the Related Art Conventionally, a power storage device is known in which a plurality of power storage elements such as lithium ion batteries are housed in a pair of divided exterior bodies, and connecting surfaces of the pair of exterior bodies are thermally welded together. In such a power storage device, a pair of flat plate-shaped end plates arranged at positions sandwiching a plurality of power storage elements are also housed in the exterior body (see, for example, Patent Document 1).

JP 2019-79599 A

A power storage device has a characteristic of gradually expanding with charging and discharging. Therefore, if the expansion of the plurality of storage elements progresses, the storage elements may be damaged.

An object of the present invention is to provide a power storage device capable of suppressing damage to power storage elements.

To achieve the above object, a power storage device according to one aspect of the present invention provides a plurality of power storage elements each having a container body and a lid body that closes the container body and is welded to the container body, and arranged in a predetermined direction. a pair of end plates sandwiching a plurality of storage elements in a predetermined direction; and a connecting portion extending in the predetermined direction and connected to the pair of end plates, wherein at least one of the pair of end plates is , the portion overlapping the welded portion between the container body and the lid when viewed in a predetermined direction is a first projecting portion projecting toward the side opposite to the electric storage element.

According to this, since at least one of the end plates is provided with the first projecting portion, the rigidity of the end plate itself can be increased. As a result, expansion of the storage element 200 is suppressed by the end plate 400, so damage to the storage element 200 caused by the expansion can be suppressed. In particular, in the electric storage element, the welded portion between the container body and the lid is more fragile than other portions, and thus the welded portion is likely to be damaged when the electric storage element expands. For this reason, in this aspect, in at least one of the end plates, the portion that overlaps the welded portion of the storage element is the first projecting portion. As a result, even if the welded portion of the storage element tends to swell, the expansion of the welded portion can be suppressed by the first protruding portion of the end plate. Therefore, damage to the storage element can be suppressed.

Here, when the first protrusion protrudes toward the storage element, the first protrusion may hit the welded portion of the storage element if the end plate is deformed by an external impact, for example. As described above, since the welded portion is a fragile portion, it is easily damaged when hit by the first projecting portion compared to other portions. In this aspect, since the first projecting portion projects toward the side opposite to the storage element, even if the end plate is deformed, the first projecting portion is less likely to come into contact with the welded portion of the storage element. Therefore, even when the end plate is deformed, damage to the electric storage element can be suppressed.

At least one of the end plates may have a first plate having a first protrusion, and a second plate disposed between the first plate and the plurality of power storage elements and overlapping the first plate. .

According to this, since the first plate and the second plate are overlapped end plates, the rigidity of the end plates themselves can be increased. Therefore, expansion of the power storage element can be suppressed more reliably, and damage to the power storage element can be further suppressed.

The first plate has a plurality of recesses recessed in a direction opposite to the first protrusions, and at least one protrusion between adjacent recesses and protruding in the same direction as the first protrusions, and the second plate may have flat plate portions that abut on all of the plurality of recesses.

According to this, since the first plate has an uneven structure including a plurality of recesses and at least one protrusion, the rigidity of the first plate can be further increased. This makes it possible to increase the rigidity of the end plate itself. On the other hand, the second plate has flat plate portions that abut on all of the plurality of recesses of the first plate. For example, when the first plate receives an impact from the outside, stress is transmitted from each recess to the flat plate portion, but since the flat plate portion is in contact with all of the plurality of recesses, the stress can be dispersed. Therefore, application of a large stress to the storage element can be suppressed. By these things, the damage of an electrical storage element can be suppressed more.

The second plate may have a second protrusion projecting in the same direction as the first protrusion and extending in a direction intersecting the predetermined direction.

According to this, since the second plate is provided with the second projecting portion, the rigidity of the second plate itself can be increased. This increases the rigidity of the end plate itself. Therefore, expansion of the power storage element can be suppressed more reliably, and damage to the power storage element can be further suppressed.

The first projecting portion may extend continuously over the entire length of one edge of the first plate.

According to this, since the first projecting portion continuously extends over the entire length of one edge of the first plate, the rigidity of the first plate itself can be increased. This increases the rigidity of the end plate itself. Therefore, expansion of the power storage element can be suppressed more reliably, and damage to the power storage element can be further suppressed.

According to the power storage device of the present invention, damage to the power storage element can be suppressed.

1 is a perspective view showing an appearance of a power storage device according to an embodiment; FIG. FIG. 2 is an exploded perspective view showing each component when the power storage device according to the embodiment is exploded; FIG. 3 is an exploded perspective view showing each component when the power storage device according to the embodiment is further exploded; 1 is a perspective view showing a configuration of an electric storage element according to an embodiment; FIG. 3 is an exploded perspective view showing the configuration of the end plate according to the embodiment; FIG. 3 is an exploded perspective view showing the configuration of the end plate according to the embodiment; FIG. It is a top view showing the second plate concerning an embodiment. 4 is a perspective view showing the configuration of an end spacer according to the embodiment; FIG. FIG. 4 is a cross-sectional view showing the positional relationship between end plates, end spacers, and surrounding members according to the embodiment; FIG. 11 is a plan view showing an end spacer according to a modification; FIG. 11 is a partial cross-sectional view showing an engagement structure between an end spacer and an exterior body according to a modification; It is a perspective view which shows the end spacer which concerns on a modification.

Hereinafter, power storage devices according to embodiments of the present invention (including modifications thereof) will be described with reference to the drawings. It should be noted that the embodiments described below are all comprehensive or specific examples. Numerical values, shapes, materials, components, arrangement positions and connection forms of components, manufacturing processes, order of manufacturing processes, and the like shown in the following embodiments are examples, and are not intended to limit the present invention. In each drawing, dimensions and the like are not strictly illustrated. In each figure, the same reference numerals are given to the same or similar components.

In the following description and drawings, the direction in which a plurality of energy storage elements are arranged, the direction in which the long sides of the container of the energy storage elements face each other, the direction in which the energy storage elements and the intermediate spacers are arranged, the direction in which the pair of end plates are arranged, and the direction in which the pair of end spacers are arranged The alignment direction is defined as the X-axis direction. The Y-axis direction is defined as the direction in which a pair of electrode terminals (positive electrode side and negative electrode side) in one energy storage element are aligned, the direction in which the short sides of the container of the energy storage element face each other, or the direction in which a pair of side plates are aligned. The Z-axis direction is defined as the alignment direction of the exterior body and the exterior body cover of the power storage device, the alignment direction of the container body and the container lid of the power storage element, the alignment direction of the power storage element and the bus bar, or the vertical direction. do. These X-axis direction, Y-axis direction, and Z-axis direction are directions that cross each other (perpendicularly in this embodiment). Although the Z-axis direction may not be the vertical direction depending on the mode of use, the Z-axis direction will be described below for convenience of explanation.

In the following description, for example, the positive direction of the X-axis indicates the arrow direction of the X-axis, and the negative direction of the X-axis indicates the direction opposite to the positive direction of the X-axis. The same applies to the Y-axis direction and the Z-axis direction. Furthermore, expressions indicating relative directions or orientations such as parallel and orthogonal include cases where they are not strictly the directions or orientations. For example, two directions are orthogonal, not only means that the two directions are completely orthogonal, but also substantially orthogonal, that is, for example, a difference of about several percent It is also meant to include

(Embodiment)
[1 General description of power storage device]
First, a general description of power storage device 10 in the present embodiment will be given. FIG. 1 is a perspective view showing the appearance of a power storage device 10 according to an embodiment. FIG. 2 is an exploded perspective view showing each component when power storage device 10 according to the embodiment is exploded. FIG. 3 is an exploded perspective view showing each component when power storage device 10 according to the embodiment is further exploded. Note that FIG. 3 is an exploded perspective view showing components of power storage device 10 other than exterior body 100 and bus bar 700 in an exploded manner.

Power storage device 10 is a device capable of charging electricity from the outside and discharging electricity to the outside, and has a substantially rectangular parallelepiped shape in the present embodiment. For example, the power storage device 10 is a battery module (assembled battery) used for power storage or power supply. Specifically, the power storage device 10 is, for example, an automobile, a motorcycle, a watercraft, a ship, a snowmobile, an agricultural machine, a construction machine, or a rolling stock for an electric railway. It is used as a battery etc. Examples of such vehicles include electric vehicles (EV), hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (PHEV), and gasoline vehicles. Examples of railway vehicles for the electric railway include electric trains, monorails, linear motor cars, and hybrid trains having both diesel engines and electric motors. Moreover, the power storage device 10 can also be used as a stationary battery or the like for home use or business use.

As shown in FIG. 1 , power storage device 10 includes exterior body 100 . As shown in FIGS. 2 and 3, inside the exterior body 100 are a plurality of storage elements 200, a plurality of intermediate spacers 300 (310 to 340), a pair of end plates 400 (410, 420), a pair of side Plates 500 (501, 502), a bottom plate 600, a plurality of bus bars 700, a pair of end spacers 800 (810, 820), etc. are accommodated. In addition to the components described above, the power storage device 10 includes a busbar holder 900 (see FIG. 10) on which the busbar 700 is mounted, a circuit board for monitoring the state of charge and discharge of the power storage element 200, a fuse, a relay, and a connector. , and an exhaust unit for exhausting the gas discharged from the storage element 200 to the outside of the exterior body 100, or the like.

The exterior body 100 is a box-shaped (substantially rectangular parallelepiped) container (module case) that constitutes a housing (outer shell) of the power storage device 10 . The exterior body 100 is arranged outside the plurality of power storage elements 200, the plurality of intermediate spacers 300, the pair of end plates 400, the pair of side plates 500, the bottom plate 600, the plurality of bus bars 700, and the like. The power storage element 200 and the like are fixed at a predetermined position and protected from impact or the like. The exterior body 100 is made of, for example, polycarbonate (PC), polypropylene (PP), polyethylene (PE), polystyrene (PS), polyphenylene sulfide resin (PPS), polyphenylene ether (PPE (including modified PPE)), polyethylene terephthalate ( PET), polybutylene terephthalate (PBT), polyetheretherketone (PEEK), tetrafluoroethylene-perfluoroalkyl vinyl ether (PFA), polytetrafluoroethylene (PTFE), polyethersulfone (PES), ABS resin, or , an insulating member such as a composite material thereof, or a metal coated with an insulating coating. The exterior body 100 thereby prevents the power storage element 200 and the like from coming into contact with an external metal member or the like. Note that the exterior body 100 may be made of a conductive material such as metal as long as the electrical insulation of the power storage element 200 and the like is maintained.

The exterior body 100 has an exterior body main body 110 that constitutes the main body of the exterior body 100 and an exterior body lid 120 that constitutes the lid of the exterior body 100 . The exterior body main body 110 is a bottomed rectangular cylindrical housing (casing) with an opening formed on the top, and accommodates the power storage element 200 and the like. The exterior cover 120 is a flat rectangular member that closes the opening of the exterior main body 110 . The exterior body lid 120 is joined to the exterior body main body 110 by an adhesive, heat sealing, ultrasonic welding, or the like. A pair of external terminals 121 (on the positive electrode side and the negative electrode side) are provided on the outer cover body 120 . Power storage device 10 charges electricity from the outside and discharges electricity to the outside through the pair of external terminals 121 .

The storage element 200 is a secondary battery (single battery) capable of charging and discharging electricity, and more specifically, a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. . Energy storage element 200 has a flat rectangular parallelepiped shape (square shape), and in the present embodiment, eight energy storage elements 200 are arranged side by side in the X-axis direction (predetermined direction). Note that the size and shape of the power storage element 200, the number of power storage elements 200 to be arranged, and the like are not limited, and for example, only one power storage element 200 may be arranged. The storage element 200 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 power storage element 200 may be a primary battery that can use stored electricity without being charged by the user, instead of a secondary battery. The storage element 200 may be a battery using a solid electrolyte. The storage element 200 may be a pouch-type storage element. A detailed description of the configuration of the storage element 200 will be given later.

Bus bar 700 is a flat and rectangular member connected to power storage element 200 . The bus bar 700 is arranged above the plurality of storage elements 200 and connected (joined) to the electrode terminals 240 (see FIGS. 2 and 4, etc.) of the plurality of storage elements 200 and the external terminals 121 . In other words, the bus bar 700 connects the electrode terminals 240 of the plurality of storage elements 200 to each other and connects the electrode terminals 240 of the storage elements 200 at the ends to the external terminals 121 .

In the present embodiment, bus bar 700 and electrode terminal 240 or external terminal 121 are connected (joined) by welding, but may be connected (joined) by bolting or the like. The bus bar 700 is made of, for example, a conductive member made of metal such as aluminum, aluminum alloy, copper, copper alloy, nickel, or a combination thereof, or a conductive member other than metal. In the present embodiment, bus bar 700 connects two power storage elements 200 in parallel to form four power storage element groups, and connects the four power storage element groups in series. The connection form of the bus bar 700 is not particularly limited, and the plurality of power storage elements 200 may be arranged in any combination to be connected in series or connected in parallel.

Intermediate spacer 300 is a plate-like and rectangular member arranged to the side of power storage element 200 (X-axis plus direction or X-axis minus direction) to electrically insulate power storage element 200 from other members. The intermediate spacer 300 also has a function of holding the power storage element 200 and positioning the power storage element 200 . Among the plurality of intermediate spacers 300, the intermediate spacers 300 arranged between the power storage elements 200 (power storage element group) are also referred to as intermediate spacers 310 to 330. The intermediate spacer 300 arranged between and is also called an intermediate spacer 340 . That is, the plurality of power storage elements 200 and the plurality of intermediate spacers 300 (intermediate spacers 310 to 340) are arranged side by side in the X-axis direction.

The intermediate spacers 310 to 330 are spacers (intermediate spacers) arranged between two adjacent power storage elements 200 to electrically insulate between the two power storage elements 200 . Intermediate spacer 310 is disposed between intermediate spacers 320 and 330 and is thicker and more rigid than intermediate spacers 320 and 330 . The intermediate spacer 310 is made of a metal member such as aluminum, aluminum alloy, iron, stainless steel, plated steel plate, or the like. The material of the intermediate spacer 310 is not particularly limited, and may be formed of an insulating member having high rigidity, or may be subjected to an insulating treatment. The intermediate spacers 320 and 330 are formed of, for example, an electrically insulating member such as any resin material that can be used for the exterior body 100, or a heat insulating member such as a damper material. .

Intermediate spacer 340 is arranged between power storage element 200 at the end and end plate 400 (410, 420) to electrically connect between power storage element 200 at the end and end plate 400 (410, 420). It is an insulating spacer. The intermediate spacer 340 is formed of, for example, an electrically insulating member such as any resin material that can be used for the exterior body 100, or a heat insulating member such as a damper material.

The end plate 400, the side plate 500, and the bottom plate 600 are restraining members that externally press (restrain) the power storage elements 200 in the direction in which the plurality of power storage elements 200 are arranged (X-axis direction). In other words, the end plates 400, the side plates 500, and the bottom plate 600 sandwich the plurality of power storage elements 200 from both sides in the alignment direction, so that each power storage element 200 included in the plurality of power storage elements 200 is positioned in the alignment direction. apply pressure (restraint) from both sides of the

The end plate 400, the side plate 500, and the bottom plate 600 are made of metal members such as aluminum, aluminum alloy, iron, stainless steel, and plated steel plate. The materials of the end plate 400, the side plate 500, and the bottom plate 600 are not particularly limited. good.

Specifically, the end plates 400 are arranged on both sides of the plurality of energy storage elements 200 and the plurality of intermediate spacers 300 (310 to 340) in the X-axis direction, and the plurality of energy storage elements 200 and the like are arranged in the alignment direction (X It is a plate-like member (sandwiching member) that sandwiches and holds from both sides in the axial direction. Of the pair of end plates 400 , the end plate 400 on the positive side of the X axis is also called an end plate 410 , and the end plate 400 on the negative side of the X axis is also called an end plate 420 . That is, the pair of end plates 410 and 420 are arranged at positions sandwiching the plurality of power storage elements 200 and the plurality of intermediate spacers 300 in the X-axis direction (predetermined direction) to sandwich them. Details of the end plate 400 will be described later.

Both ends of the side plate 500 and the bottom plate 600 are attached to a pair of end plates 400 (410, 420). 340). That is, the side plate 500 and the bottom plate 600 are connecting portions that extend in the X-axis direction so as to straddle the plurality of power storage elements 200 and the plurality of intermediate spacers 300 and are connected to the pair of end plates 400 . In the present embodiment, a case where a pair of end plate 400 and bottom plate 600 are provided as an example of the connecting portion is illustrated, but only one of the pair of end plate 400 and bottom plate 600 may be provided. The side plate 500 and the bottom plate 600 are connected to the pair of end plates 400 to give a restraining force to the plurality of power storage elements 200 and the like in the alignment direction (X-axis direction).

In this embodiment, a pair of side plates 500 are arranged on both sides of the plurality of storage elements 200 and the plurality of intermediate spacers 300 (310 to 340) in the Y-axis direction. In the present embodiment, the pair of side plates 500 are arranged closer to the Z-axis plus direction on both sides of the plurality of power storage elements 200 and the like in the Y-axis direction. Each of the pair of side plates 500 is attached to the ends of the pair of end plates 400 in the Y-axis direction at both ends in the X-axis direction. As a result, the pair of side plates 500 and the pair of end plates 400 sandwich and constrain the plurality of power storage elements 200 and the like from both sides in the X-axis direction and both sides in the Y-axis direction.

Specifically, the side plate 500 has a shape in which both ends in the X-axis direction are bent toward the storage element 200 side. Both ends of the side plate 500 are connected (joined) to the end plates 400 (410, 420) by a plurality of (two in this embodiment) connecting members 500a arranged in the Z-axis direction. In the present embodiment, connection member 500a is a bolt, and is fastened by screwing with nut 450 (see FIG. 6) of end plate 400. As shown in FIG. Here, of the pair of side plates 500 , the side plate 500 on the positive side of the Y axis is also called side plate 501 , and the side plate 500 on the negative side of the Y axis is also called side plate 502 .

Similarly, the bottom plate 600 is arranged in the negative Z-axis direction of the plurality of power storage elements 200 and the plurality of intermediate spacers 300 (310 to 340). The bottom plate 600 is attached to the ends of the pair of end plates 400 in the negative Z-axis direction at both ends in the X-axis direction. Specifically, bottom plate 600 has a shape in which both ends in the X-axis direction are bent toward power storage element 200 . Both ends of the bottom plate 600 are connected (joined) to the end plates 400 (410, 420) by a plurality of (two in this embodiment) connecting members 600a arranged in the Y-axis direction. In the present embodiment, connection member 600a is a bolt and is fastened by screwing with nut 450 (see FIG. 6) of end plate 400. As shown in FIG. Thereby, the bottom plate 600 restrains the plurality of power storage elements 200 and the plurality of intermediate spacers 300 together with the pair of end plates 400 from the Z-axis negative direction side.

In addition, a plurality of drawn portions 510 and 610 are formed at the bent corners of the side plate 500 and the bottom plate 600 to increase strength. Each of the drawn portions 510 and 610 is formed by drawing so as to be convex toward the inside of the corner.

The pair of end spacers 800 are plate-like members arranged at positions sandwiching the pair of end plates 400 in the X-axis direction (predetermined direction). Specifically, the pair of end spacers 800 are arranged at positions sandwiching the connected end plate 400, side plate 500, and bottom plate 600 in the X-axis direction. Here, of the pair of end spacers 800 , the end spacer 800 on the X-axis plus direction side is also called an end spacer 810 , and the end spacer 800 on the X-axis minus direction side is also called an end spacer 820 . Each end spacer 800 has a function of positioning each end plate 400 , each side plate 500 , the bottom plate 600 , the plurality of power storage elements 200 and the plurality of intermediate spacers 300 inside the exterior body 110 . The end spacer 800 is formed of, for example, an electrically insulating member such as any resin material that can be used for the exterior body 100 or a heat insulating member such as a damper material. Details of the end spacer 800 will be described later.

[2 Description of storage element]
Next, the configuration of the storage element 200 will be described in detail. FIG. 4 is a perspective view showing the configuration of the storage device 200 according to the embodiment. Specifically, FIG. 4 shows an enlarged appearance of one power storage element 200 out of the plurality of power storage elements 200 shown in FIG. Since all of the plurality of power storage elements 200 have the same configuration, the configuration of one power storage element 200 will be described in detail below.

As shown in FIG. 4 , the storage element 200 includes a container 210 , a pair of electrode terminals 240 (positive electrode side and negative electrode side), and an upper gasket 250 . In addition, a lower gasket, an electrode body, a pair of current collectors (on the positive electrode side and the negative electrode side), an electrolytic solution (non-aqueous electrolyte), and the like are accommodated inside the container 210, but these are not shown in the drawing. omitted. As the electrolytic solution, the type is not particularly limited as long as it does not impair the performance of the electric storage element 200, and various kinds can be selected.

In addition to the components described above, the electric storage element 200 may include spacers disposed on the side or below the electrode body, an insulating film that wraps the electrode body and the like, and the like. Furthermore, an insulating film (shrink tube or the like) covering the outer surface of the container 210 may be arranged around the container 210 . The material of the insulating film is not particularly limited as long as it can ensure the insulation required for the electric storage element 200. Examples include insulating resins such as PC, PP, PE, PPS, PET, PBT, and ABS resins. Epoxy resin, Kapton, Teflon (registered trademark), silicone, polyisoprene, and polyvinyl chloride can be exemplified.

The container 210 is a rectangular parallelepiped (square or box-shaped) case having a container body 220 with an opening and a lid 230 closing the opening of the container body 220 . The container main body 220 is a rectangular cylindrical member having a bottom that constitutes the main body of the container 210, and has an opening formed in the positive direction of the Z axis. The lid body 230 is a rectangular plate-like member that constitutes the lid portion of the container 210 , and is arranged to extend in the Y-axis direction on the Z-axis plus direction side of the container body 220 . The lid 230 includes a gas discharge valve 231 that releases the pressure inside the container 210 when the pressure rises excessively, and a liquid injection part (not shown) for injecting an electrolytic solution into the container 210. ) etc. are provided. The material of the container 210 (the container body 220 and the lid 230) is not particularly limited, and can be, for example, a weldable (bondable) metal such as stainless steel, aluminum, aluminum alloy, iron, or plated steel plate. can also be used.

The container 210 has a structure in which the inside is hermetically sealed by joining the container body 220 and the lid 230 by welding or the like after housing the electrode body and the like inside the container body 220 . At the boundary between the container body 220 and the lid body 230, a jointed portion by welding is referred to as a welded portion 260 (see FIG. 9). The welded portion 260 is formed continuously along the entire perimeter of the boundary of the lid 230 of the container body 220 .

The container 210 has a pair of long side surfaces 211 on both side surfaces in the X-axis direction, a pair of short side surfaces 212 on both side surfaces in the Y-axis direction, and a bottom surface 213 on the Z-axis negative direction side. The long side 211 is a rectangular planar portion that forms the long side of the container 210 . Long side 211 adjoins short side 212 and bottom 213 . The short side surface 212 is a rectangular planar portion that forms the short side surface of the container 210 and is arranged to face the side plate 500 in the Y-axis direction. The bottom surface 213 is a rectangular planar portion that forms the bottom surface of the container 210 , faces the bottom plate 600 in the Z-axis direction, and is arranged adjacent to the long side surface 211 and the short side surface 212 .

The electrode terminal 240 is a terminal member (a positive electrode terminal and a negative electrode terminal) of the storage element 200 arranged in the lid 230, and is electrically connected to the positive electrode plate and the negative electrode plate of the electrode body via a current collector. there is In other words, the electrode terminal 240 is made of metal for leading electricity stored in the electrode body to the external space of the storage element 200 and for introducing electricity into the internal space of the storage element 200 to store the electricity in the electrode body. It is a member made of The electrode terminal 240 is made of aluminum, aluminum alloy, copper, copper alloy, or the like.

The electrode assembly is a power storage element (power generation element) formed by laminating a positive electrode plate, a negative electrode plate, and a separator. The positive electrode plate is formed by forming a positive electrode active material layer on a positive electrode substrate layer, which is a collector foil made of a metal such as aluminum or an aluminum alloy. The negative electrode plate is formed by forming a negative electrode active material layer on a negative electrode substrate layer, which is a collector foil made of a metal such as copper or a copper alloy. As the active material used for the positive electrode active material layer and the negative electrode active material layer, any known material can be appropriately used as long as it can intercalate and deintercalate lithium ions. A microporous sheet made of resin, a non-woven fabric, or the like can be used as the separator. In the present embodiment, the electrode body is formed by stacking electrode plates (a positive electrode plate and a negative electrode plate) in the X-axis direction. The electrode body includes a wound electrode body formed by winding electrode plates (a positive electrode plate and a negative electrode plate), and a laminated type (stacked) electrode body formed by stacking a plurality of flat plate-shaped electrode plates. or a bellows-shaped electrode body in which an electrode plate is folded into a bellows shape.

The current collectors are conductive members (a positive electrode current collector and a negative electrode current collector) that are electrically connected to the electrode terminal 240 and the electrode body. The positive electrode current collector is made of aluminum, an aluminum alloy, or the like, like the positive electrode substrate layer of the positive electrode plate, and the negative electrode current collector is made of copper, a copper alloy, or the like, like the negative electrode substrate layer of the negative electrode plate. It is

The upper gasket 250 is a gasket that is arranged between the lid 230 and the electrode terminal 240 to insulate and seal between the lid 230 and the electrode terminal 240 . The lower gasket is a gasket that is placed between the lid 230 and the current collector to insulate and seal between the lid 230 and the current collector. The upper gasket 250 and the lower gasket may be made of any material that has electrical insulation.

[3 Explanation of end plate]
Next, the configuration of the end plate 400 (410, 420) will be described in detail. Note that the end plate 410 and the end plate 420 have the same configuration. Therefore, the configuration of the end plate 410 will be mainly described below, and the configuration of the end plate 420 will conform to the configuration of the end plate 410, and detailed description thereof will be omitted. Specifically, end plate 420 has the same configuration as end plate 410 rotated 180 degrees around the Z-axis.

5 and 6 are exploded perspective views showing the configuration of the end plate 410 according to the embodiment. Specifically, FIG. 5 is an exploded perspective view of the end plate 410 viewed from the positive direction of the X-axis, and FIG. 6 is an exploded perspective view of the end plate 410 viewed from the negative direction of the X-axis.

As shown in FIGS. 5 and 6, the end plate 410 has a first plate 430 and a second plate 440, which are joined and integrated by welding, for example.

The first plate 430 is a corrugated sheet metal laminated on the main surface of the second plate 440 in the positive X-axis direction. Specifically, the first plate 430 has a plurality of concave portions 431 and a plurality of convex portions 432, and each concave portion 431 and each convex portion 432 are repeatedly arranged in the Z-axis direction. When the first plate 430 is viewed as a whole, each concave portion 431 is a portion recessed in the negative direction of the X axis, and each convex portion 432 is a portion protruding in the positive direction of the X axis. In this embodiment, four concave portions 431 and three convex portions 432 are provided, but the number of concave portions 431 and convex portions 432 to be provided is arbitrary.

A bottom wall 433 of each recess 431 is a flat plate portion parallel to the YZ plane and arranged at the same position in the X-axis direction. Also, the top wall 434 of each convex portion 432 is a flat plate portion parallel to the YZ plane and arranged at the same position in the X-axis direction. An upper wall 435 of each projection 432 is a wall that connects the top wall 434 of the projection 432 and the bottom wall 433 of the recess 431 directly above the projection 432 . A lower wall 436 of each protrusion 432 is a wall that connects the top wall 434 of the protrusion 432 and the bottom wall 433 of the recess 431 directly below the protrusion 432 . That is, the upper wall 435 of each protrusion 432 is also the lower wall of the recess 431 directly above it, and the lower wall 436 of each protrusion 432 is the upper wall of the recess 431 directly below it. Due to such a shape, each convex portion 432 has a space formed therein.

Here, among the plurality of protrusions 432, the uppermost protrusion 432a, the intermediate protrusion 432b, and the lowermost protrusion 432c. The convex portion 432a is formed wider at both ends in the Y-axis direction than at the central portion. Specifically, in plan view (viewed in the X-axis direction), the lower edge of the ceiling wall 434a of the projection 432a is formed in a substantially linear shape, whereas the upper edge of the ceiling wall 434a is formed in the center in the Y-axis direction. It is formed in a stepped shape so that the portion is at a low level and both ends are at a high level. For this reason, the upper side wall 435 of the convex portion 432a is formed in a stepped shape, and the lower side wall 436 is formed in a straight line.

On the other hand, the convex portions 432b and 432c are each formed to have a substantially uniform width over the entire length in the Y-axis direction. Therefore, the upper side wall 435 and the lower side wall 436 of the projections 432b and 432c are formed linearly.

A pair of through holes 437 are provided in each of the ceiling walls 434a, 434b and 434c. Specifically, the through holes 437 are arranged at both ends of the ceiling walls 434a, 434b, and 434c in the Y-axis direction and penetrate in the X-axis direction. A pair of nuts 450 are fixed to the surfaces of the ceiling walls 434a, 434b and 434c in the negative direction of the X axis. Each nut 450 is fixed to each ceiling wall 434 a , 434 b and 434 c by welding or the like so that the screw hole communicates with each through hole 437 .

Here, the side plate 500 is fastened to the through holes 437 and the nuts 450 of the ceiling walls 434a and 434b via connecting members 500a. A bottom plate 600 is fastened to the through hole 437 of the top wall 434c and the nut 450 via a connecting member 600a. Thus, the nut 450 and the connecting member 500a are an example of a fastening portion that fastens the end plate 410 and the side plate 500 together. Similarly, the nut 450 and the connecting member 600a are an example of a fastening portion that fastens the end plate 410 and the bottom plate 600 together. That is, the nut 450 that is part of the fastening portion is arranged in the space inside each projection 432 . In addition, in this embodiment, although the case where the fastening part is a screw type was illustrated, it may be a riveting type fastening part. Even if it is a riveted fastening portion, it is sufficient that one end of the rivet is arranged in the space inside each convex portion 432 .

A first projecting portion 438 projecting in the positive direction of the X-axis is provided on the upper edge of the recessed portion 431 positioned most upward among the plurality of recessed portions 431 . The first projecting portion 438 extends continuously in the Y-axis direction over the entire length of the upper edge, which is one edge of the first plate 430 .

In addition, although the case where the lower end portion of the concave portion 431 located at the lowest position does not protrude is illustrated in the present embodiment, the lower end portion may protrude in the positive direction of the X axis.

The second plate 440 is disposed between the first plate 430 and the plurality of power storage elements 200 and is a substantially flat sheet metal that overlaps the first plate 430 . Specifically, the second plate 440 is arranged between the intermediate spacer 340 in the positive direction of the X-axis and the first plate 430 and directly overlaps them.

The second plate 440 has a flat plate portion 441 and a pair of second projecting portions 442 . The flat plate portion 441 is a flat plate-like portion having a rectangular shape in plan view, and is in contact with the bottom walls 433 of all the concave portions 431 of the first plate 430 . That is, the flat plate portion 441 is in surface contact with the bottom walls 433 of all the recesses 431 . The flat plate portion 441 is spaced apart from the top walls 434a, 434b, and 434c of all the convex portions 432, and covers the space inside each convex portion 432 from the negative direction of the X axis. A portion of the flat plate portion 441 that covers the space inside each convex portion 432 is referred to as a wall portion 445 . In FIG. 5, the wall portion 445 is an area surrounded by a dashed line. As shown in FIG. 5, the wall portions 445 are provided on the flat plate portion 441 in a number corresponding to the number of the convex portions 432 provided. It can also be said that the plurality of walls 445 are formed in a flat plate shape as a whole.

The pair of second projecting portions 442 are portions projecting in the positive direction of the X-axis from both ends of the flat plate portion 441 in the Y-axis direction. Each second projecting portion 442 extends along the Z-axis direction. Thus, the second projecting portion 442 projects in the same direction as the first projecting portion 438 and extends in a direction crossing the predetermined direction (X-axis direction).

Specifically, each second projecting portion 442 extends in the Z-axis direction from the upper end portion of the flat plate portion 441 to a position corresponding to the side plate 500 . A plurality of notch-like relief portions 443 are formed at the tip of each of the second projecting portions 442 to release the constricted portion 510 provided on the side plate 500 . Since each narrowed portion 510 of each side plate 500 is accommodated in each relief portion 443 , each narrowed portion 510 is less likely to interfere with each second projecting portion 442 .

A plurality of narrowed portions 444 for increasing the strength are provided at the corners formed by the respective second projecting portions 442 and the flat plate portion 441 . Each drawn portion 444 is formed by drawing so as to be convex toward the inside of the corner.

As described above, in the end plate 410, the first plate 430 is provided with the projection 432 having a space inside. It deforms while crushing and absorbs the impact.

Furthermore, in the end plate 410, the second plate 440 is provided with the wall portion 445 that covers the space between the convex portion 432 and the plurality of power storage elements 200. Therefore, even if the convex portion 432 is crushed, the wall portion 445 serves as a barrier to prevent the convex portion 432 from reaching the storage element 200 . As a result, it is possible to suppress the power storage element 200 from being damaged when receiving an impact from the outside.

In particular, in the present embodiment, since a part of the fastening portion (connecting members 500a and 600a) is housed in the space of the convex portion 432, the fastening portion receives an impact from the outside, for example, and the power storage element 200 is damaged. Even if the power storage element 200 is pressed toward the power storage element 200 , the wall portion 445 acts as a barrier to prevent the fastening portion from reaching the power storage element 200 . As a result, damage to the power storage element 200 caused by the fastening portion can be suppressed when receiving an impact from the outside.

Furthermore, in the present embodiment, since the first plate 430 has a plurality of protrusions 432 , recesses 431 are formed between a pair of adjacent protrusions 432 . That is, since the first plate 430 has the uneven structure, the rigidity of the first plate 430 can be further increased. This makes it possible to increase the rigidity of the end plate 410 itself.

Moreover, the flat plate portion 441 of the second plate 440 has a plurality of wall portions 445 that are flat as a whole and are in contact with the plurality of concave portions 431 of the first plate 430 . For example, when the first plate 430 receives an impact from the outside, stress is transmitted from the plurality of recesses 431 to the flat plate portion 441, but since the flat plate portion 441 is in contact with the plurality of recesses 431, the stress can be dispersed. can be done. Therefore, it is possible to suppress the application of a large stress to the storage element 200, and to further suppress damage to the storage element 200. FIG.

FIG. 7 is a plan view showing the second plate 440 according to the embodiment. In FIG. 7, the outer shape of the first plate 430 is indicated by a chain double-dashed line. Here, as described above, the second plate 440 is formed in a generally flat plate shape, whereas the first plate 430 is formed in a corrugated plate shape. That is, since the second plate 440 has a smaller surface area than the first plate 430 , the second plate 440 can be made smaller than the first plate 430 . On the other hand, as shown in FIG. 7, the second plate 440 has a larger projected area than the first plate 430 when viewed in the X-axis direction. Therefore, the impact received by the first plate 430 can be dispersed over a wider range.

[4 Explanation of end spacer]
Next, the configuration of the end spacers 800 (810, 820) will be described in detail. Note that the end spacer 810 and the end spacer 820 have the same configuration. Therefore, the configuration of the end spacer 810 will be mainly described below, and the configuration of the end spacer 820 will conform to the configuration of the end spacer 810, and detailed description thereof will be omitted. Specifically, the end spacer 820 has the same configuration as the end spacer 810 rotated 180 degrees around the Z-axis.

FIG. 8 is a perspective view showing the configuration of the end spacer 810 according to the embodiment. Specifically, FIG. 8 is a perspective view of the end spacer 810 viewed from the plus direction of the X axis. The end spacers 810 are arranged along part of the outer periphery of the end plates 410 with the central portions of the end plates 410 overlapping in the X-axis direction exposed. Specifically, as shown in FIG. 8, the end spacer 810 is substantially U-shaped in plan view and is a plate-like member. are arranged along the outer periphery of the End spacer 810 has a lower edge 811 and a pair of side edges 812 . The lower edge portion 811 is a rectangular plate-like portion elongated in the Y-axis direction. The lower edge 811 is arranged at a corner formed by a wall surface forming a short side surface and a wall surface forming a bottom surface of the exterior main body 110 . A pair of through holes 813 are formed in the lower edge portion 811 to accommodate the head portions 600b of the connecting members 600a. The pair of through holes 813 are arranged with a predetermined spacing in the Y-axis direction.

Each side edge portion 812 is a rectangular plate-like portion elongated in the Z-axis direction. Each side edge portion 812 continuously extends upward from both ends of the lower edge portion 811 in the Y-axis direction. Each side edge 812 is arranged at a corner formed by a wall surface forming a long side surface and a wall surface forming a short side surface of the exterior main body 110 . Each side edge portion 812 is formed with a pair of through holes 814 in which the head portion 500b of each connecting member 500a is accommodated. A pair of through-holes 814 are arranged at a predetermined interval in the Z-axis direction.

The area surrounded by the lower edge 811 and the pair of side edges 812 exposes the central portion of the end plate 410 . The width of the region (interval between the pair of side edges 812) is at least half the width (length in the Y-axis direction) of the end spacer 810, and the height of the region is equal to the height of the end spacer 810 (Z length in the axial direction). As a result, the central portion of the end plate 410 is largely exposed, making it easier to allow deformation of the central portion.

[5 Positional relationship between end plates, end spacers and surrounding members]
Next, the positional relationship between the end plate 410, the end spacer 810, and surrounding members will be described. FIG. 9 is a cross-sectional view showing the positional relationship between the end plate 410, the end spacer 810, and surrounding members according to the embodiment. FIG. 9 shows the structure around the upper portion of the end plate 410 and the like.

As shown in FIG. 9 , the main surface of the end spacer 810 in the plus direction of the X-axis is in contact with the inner surface of the exterior main body 110 . Thus, the movement of the contents including the end spacers 810 (the plurality of power storage elements 200 , the intermediate spacers 300 , the end plates 400 , the side plates 500 and the bottom plate 600 ) in the X-axis direction is restricted by the exterior body main body 110 . Therefore, even if power storage device 10 vibrates, it is possible to make it more difficult for the contents to be displaced, and to suppress the impact on the contents. It is preferable that the contents are press-fitted into the exterior body main body 110 because the effect of suppressing the displacement of the contents is enhanced.

Also, the end spacer 810 is formed to have a uniform thickness as a whole. The thickness of the end spacer 810 is thicker than the thickness (length in the axial direction) of the head portion 500b of the connecting member 500a. As a result, the head portion 500b of the connecting member 500a does not protrude from the end spacer 810. As shown in FIG. Therefore, even if exterior body main body 110 receives an impact from the outside, end spacer 810 receives the impact, and the impact is less likely to be directly transmitted to head portion 500b of connecting member 500a. Therefore, it is possible to suppress damage to the connection member 500a. The same applies to the head portion 600b of the connecting member 600a.

In FIG. 9 , the welded portion 260 is the boundary portion between the container body 220 and the lid 230 of the storage element 200 . At least part of the welded portion 260 is contained within the thickness (the length in the Z-axis direction) of the first projecting portion 438 of the first plate 430 . Therefore, the first projecting portion 438 of the first plate 430 overlaps the welded portion 260 as viewed in the X-axis direction. Here, although the welded portion 260 is more fragile than other portions of the container 210 , the first projecting portion 438 overlaps the welded portion 260 as viewed in the X-axis direction, so expansion of the container 210 is caused. Even if the welded portion 260 also tries to swell, the expansion of the welded portion 260 can be suppressed by the first protruding portion 438 . Even if a crack occurs in the welded portion 260, since the first projecting portion 438 overlaps the welded portion 260 as viewed in the X-axis direction, the position of the container body 220 and the lid portion 230 will not be displaced from the crack. You can stop trying. In particular, in the present embodiment, intermediate spacer 340 directly overlaps welded portion 260 as viewed in the X-axis direction. can be suppressed with certainty.

[6 Explanation of effects]
As described above, the power storage device 10 according to the embodiment of the present invention includes a plurality of power storage elements 200 each having a container body 220 and a lid body 230 that closes the container body 220 and is welded to the container body 220, and a predetermined and a pair of end plates 400 sandwiching a plurality of storage elements 200 arranged in the direction of , and connecting portions extending in the predetermined direction and connected to the pair of end plates. At least one of the pair of end plates has a first protrusion that protrudes toward the side opposite to the storage element 200 at a portion that overlaps the welded portion 260 of the container body 220 and the lid 230 when viewed in a predetermined direction (X-axis direction). A portion 438 is provided.

According to this, since at least one of the end plates 400 is provided with the first projecting portion 438, the rigidity of the end plate 400 itself can be increased. As a result, expansion of the storage element 200 is suppressed by the end plate 400, so damage to the storage element 200 caused by the expansion can be suppressed. In particular, in power storage element 200, welded portion 260 between container body 220 and lid body 230 is more fragile than other portions, and welded portion 260 is easily damaged when power storage element 200 expands. Therefore, in at least one of the end plates 400 , the portion overlapping the welded portion 260 of the storage element 200 is the first projecting portion 438 . Accordingly, even if welded portion 260 of power storage element 200 tries to swell, expansion of welded portion 260 can be suppressed by first projecting portion 438 of end plate 400 . Therefore, damage to the storage element 200 can be suppressed.

Here, when the first projecting portion 438 projects toward the storage element 200 , for example, when the end plate 400 is deformed due to external impact, the first projecting portion 438 hits the welded portion 260 of the storage element 200 . There is a risk. Since the welded portion 260 is a fragile portion as described above, it is more likely to be damaged than other portions if the first projecting portion 438 hits it. In the present embodiment, first protrusion 438 protrudes toward the opposite side of power storage element 200 , so even if end plate 400 is deformed, first protrusion 438 hits welded portion 260 of power storage element 200 . Hateful. Therefore, even when end plate 400 is deformed, damage to power storage element 200 can be suppressed.

At least one of the end plates 400 includes a first plate 430 having a first protrusion 438 and a second plate 440 that is disposed between the first plate 430 and the plurality of power storage elements 200 and overlaps the first plate 430. and

According to this, since the end plate 400 is formed by overlapping the first plate 430 and the second plate 440, the rigidity of the end plate 400 itself can be increased. Therefore, expansion of power storage element 200 can be more reliably suppressed, and damage to power storage element 200 can be further suppressed.

In addition, the first plate 430 includes a plurality of recesses 431 recessed in the opposite direction to the first protrusions 438 and at least one protrusion 432 between the adjacent recesses 431 and protruding in the same direction as the first protrusions 438. and The second plate 440 has a flat plate portion 441 that contacts all of the recesses 431 .

According to this, the first plate 430 has a concave-convex structure including a plurality of concave portions 431 and at least one convex portion 432, so that the rigidity of the first plate 430 can be further increased. This makes it possible to increase the rigidity of the end plate 400 itself. On the other hand, the second plate 440 has flat plate portions 441 that abut on all of the plurality of recesses 431 of the first plate 430 . For example, when the first plate 430 receives an impact from the outside, stress is transmitted from each concave portion 431 to the flat plate portion 441, but since the flat plate portion 441 is in contact with all of the plurality of concave portions 431, the stress is dispersed. be able to. Therefore, application of a large stress to the storage element 200 can be suppressed. By these things, the damage of the electrical storage element 200 can be suppressed more.

The second plate 440 also has a second protrusion 442 that protrudes in the same direction as the first protrusion 438 and extends in a direction intersecting the predetermined direction.

According to this, since the second projecting portion 442 is provided on the second plate 440, the rigidity of the second plate 440 itself can be increased. This increases the rigidity of the end plate 400 itself. Therefore, expansion of power storage element 200 can be more reliably suppressed, and damage to power storage element 200 can be further suppressed.

Also, the first projecting portion 438 extends continuously over the entire length of one edge of the first plate 430 .

According to this, since the first projecting portion 438 extends continuously over the entire length of one edge of the first plate 430, the rigidity of the first plate 430 itself can be increased. This increases the rigidity of the end plate 400 itself. Therefore, expansion of power storage element 200 can be more reliably suppressed, and damage to power storage element 200 can be further suppressed.

In addition, the power storage device 10 includes a plurality of power storage elements 200 arranged in a predetermined direction (X-axis direction), a pair of end plates 400 sandwiching the plurality of power storage elements 200 in a predetermined direction, and a pair of end plates 400 arranged in a predetermined direction. a connecting portion (a side plate 500 and a bottom plate 600) extending and connected to a pair of end plates 400; , a pair of end plates 400 , a connecting portion, and a pair of end spacers 800 . The end spacers 800 are arranged along a part of the outer periphery of the end plates 400 with the central portions of the end plates 400 overlapping in a predetermined direction exposed.

According to this, since the end spacer 800 exposes the central portion of the end plate 400 , it is possible to allow deformation of the end plate 400 caused by the expansion of the central portion of the storage element 200 . Therefore, the mechanical load on the expanded power storage element 200 can be suppressed.

In addition, since the end spacer 800 is arranged along a part of the outer peripheral edge of the end plate 400, the end spacer 800 is arranged to face at least one side of the inner edge of the exterior body 100 when viewed from a predetermined direction. . Since the inner edge of the exterior body 100 when viewed from a predetermined direction is the corner of the two wall surfaces of the exterior body 100, it has a higher strength than, for example, the central portion of the wall surface. In other words, it can be said that the inner edge of the exterior body 100 is a portion that is difficult to deform. Since the end spacer is received on at least one side of this inner edge, it is possible to stably restrict the movement of the contents of the package 100 .

In addition, since the end spacer 800 is received by the inner edge of the exterior body 100, which has a relatively high strength, even if the contents of the exterior body 100 move in a predetermined direction due to vibration, the exterior body 100 is less likely to be damaged. .

The exterior body 100 also includes an exterior body body 110 having an opening formed upward, and an exterior body cover 120 that covers the opening of the exterior body body 110 . The end spacer 800 is arranged along the outer peripheral edge of the end plate 400 except for the upper portion.

Here, in the exterior body 100 , the portion corresponding to the joint portion between the exterior body main body 110 and the exterior body cover 120 is a portion of the exterior body 100 that is weaker than the other portions. End spacer 800 of the present embodiment is arranged along the outer peripheral edge of end plate 400 except for the upper portion. However, the deformation is less likely to be transmitted to the joint portion between the exterior main body 110 and the exterior lid 120 . Therefore, it is possible to suppress damage to the joint portion caused by the expansion of the power storage element 200 .

Power storage device 10 also has bolts (connecting members 500 a and 600 a ) that fasten the connecting portion to end plate 400 . The end spacer 800 is formed with through holes 813 and 814 in which the bolt heads 500b and 600b are accommodated. The end spacer 800 is thicker than the bolt heads 500b and 600b.

According to this, the bolt heads 500b and 600b do not protrude from the end spacer 800 because the thickness of the end spacer 800 is thicker than the thickness of the bolt heads 500b and 600b. Therefore, even if the exterior body 100 receives an impact from the outside, the end spacer 800 receives the impact, and the impact is less likely to be directly transmitted to the bolt heads 500b and 600b. Therefore, it is possible to suppress damage to the bolt.

[7 Description of Modifications]
Although power storage device 10 according to the present embodiment has been described above, the present invention is not limited to the above embodiment. The embodiments disclosed this time are illustrative in all respects and are not restrictive, and the scope of the present invention includes all modifications within the meaning and range of equivalents to the claims. . In the following description, parts that are the same as those in the above-described embodiment are denoted by the same reference numerals, and description thereof may be omitted.

For example, in the above embodiment, the case where the end spacer 800 is not fixed to the end plate 400 is exemplified. However, end spacers 800 may be fixed to end plates 400 . Specifically, a collar may be embedded in the peripheries of the through holes 813 and 814 of the end spacer 800, and the head portions 500b and 600b of the connection members 500a and 600a may engage the collars. In this case, the collar and the connecting members 500a and 600a serve as spacer fixing portions fixed to the end plate 400. FIG.

According to this, since the end spacer 800 is provided with the spacer fixing portion fixed to the end plate 400, the integration between the end plate 400 and the end spacer 800 can be enhanced by the spacer fixing portion. . Therefore, even if power storage device 10 receives vibration, relative displacement between end plate 400 and end spacer 800 can be suppressed. Thereby, damage to each member in power storage device 10 caused by the relative displacement can be suppressed.

Note that the spacer fixing portion is not limited to the form described above as long as it is fixed to the end plate 400 . For example, an engaging structure that engages with the end plate 400 may be used as the spacer fixing portion, or a joining portion that is welded or adhered to the end plate 400 may be used as the spacer fixing portion.

Also, the spacer fixing portion may be fixed to the busbar holder 900 . FIG. 10 is a plan view showing an end spacer 810A according to a modification. FIG. 10 illustrates a case where the spacer fixing portion 850a has a snap-fit structure.

As shown in FIG. 10, each side edge portion 812a of the end spacer 810A is provided with a pair of claw portions 851 forming a spacer fixing portion 850a at the upper end portion. The pair of claw portions 851 are elastically deformable portions and are arranged at intervals from each other. Projections 852 protruding outward are formed at the tip portions of the pair of claw portions 851 .

The busbar holder 900 has a portion that overlaps the upper end of each side edge 812a of the end spacer 810A. In the busbar holder 900, engagement holes 910 are formed at portions of each side edge 812a that face the pair of claws 851. As shown in FIG. The pair of claws 851 are locked by inserting the pair of claws 851 into the engagement hole 910 and engaging the protrusion 852 . Thereby, the spacer fixing portion 850 a is fixed to the busbar holder 900 .

As described above, the end spacer 810A is provided with the spacer fixing portion 850a fixed to the busbar holder 900. Therefore, the integration between the busbar holder 900 and the end spacer 810A can be enhanced by the spacer fixing portion 850a. can. Therefore, even if power storage device 10 receives vibration, relative displacement between busbar holder 900 and end spacer 810A can be suppressed.

Note that the spacer fixing portion fixed to the busbar holder 900 is not limited to the form described above as long as it is fixed to the busbar holder 900 . For example, a joining portion welded or adhered to the busbar holder 900 may be used as the spacer fixing portion. Moreover, both the spacer fixing portion for the busbar holder and the spacer fixing portion for the end plate may be provided in one end spacer.

Alternatively, the structure may be such that the end spacer and the inner surface of the exterior main body are engaged with each other. FIG. 11 is a partial cross-sectional view showing an engagement structure between an end spacer 810B and an exterior main body 110B according to a modification.

As shown in FIG. 11, a plurality of first ribs 111 arranged at predetermined intervals are provided on the inner surface of the exterior main body 110B facing the end spacer 810B. The plurality of first ribs 111 are portions that protrude in the X-axis direction, and are arranged at predetermined intervals in the Y-axis direction, for example. Each first rib 111 extends along the Z-axis direction.

A plurality of second ribs 881 arranged between the plurality of first ribs 111 are provided on the main surface of the end spacer 810B facing the inner surface of the exterior main body 110B. The plurality of second ribs 881 are portions that protrude in the X-axis direction, and are arranged at predetermined intervals in the Y-axis direction, for example. Each second rib 881 extends along the Z-axis direction. Since each second rib 881 is arranged between the plurality of first ribs 111 of the exterior main body 110B, the first ribs 111 and the second ribs 881 interfere with each other when the power storage device 10 vibrates. This interference can suppress the displacement of the end spacer 810B inside the exterior main body 110B. As a result, damage to each member in power storage device 10 caused by displacement of end spacer 810B can be suppressed. In addition, the number of the second ribs 881 may be one. Moreover, if the second rib 881 is fitted between the plurality of first ribs 111, it is possible to further enhance the effect of suppressing the displacement of the end spacer 810B.

Moreover, in the above-described embodiment, the end spacer 800 having a substantially U shape in a plan view is exemplified. However, the end spacer may have any shape as long as it is arranged along a part of the outer peripheral edge of the end plate 400 with the central portion of the end plate 400 exposed.

FIG. 12 is a perspective view showing the configuration of an end spacer 810C according to a modification. As shown in FIG. 12 , the end spacer 810</b>C has a beam portion 860 that connects the pair of side edge portions 812 and continuously extends from the upper portion of each side edge portion 812 . Specifically, the beam portion 860 is provided at a low position spaced apart from the upper end of each side edge portion 812 . Also in this case, the central portion of the end plate 410 is exposed in the region surrounded by the pair of side edge portions 812, the beam portion 860 and the lower edge portion 811. As shown in FIG. As another shape, an end spacer consisting of only a pair of side edges 812 may be used. In this case, the pair of side edges 812 are separate structures.

Also, in the above-described embodiment, the two-plate type end plate 400 was exemplified, but a single-plate type end plate may be used. In this case, the end plate has only one of the first plate and the second plate, and the first projecting portion may be provided on one of the plates.

Moreover, in the above embodiment, the end plate 400 in which the first plate 430 and the second plate 440 are separate members is exemplified. However, the first plate and the second plate may be continuous end plates by bending one sheet metal.

Further, in the above embodiment, the intermediate spacer 340 is interposed between the end plate 400 and the storage element 200, but the end plate and the storage element may directly overlap each other.

Forms constructed by arbitrarily combining the constituent elements included in the above embodiments and modifications thereof are also included within the scope of the present invention.

INDUSTRIAL APPLICABILITY The present invention can be applied to a power storage device having a power storage element such as a lithium ion secondary battery.

10 power storage device 100 exterior body 110, 100B exterior body main body 111 first rib 120 exterior body lid 121 external terminal 200 storage element 210 container 211 long side 212 short side 213 bottom 220 container body 230 lid 231 gas discharge valve 240 electrode terminal 250 upper gasket 260 welded portion 300, 310, 320, 330, 340 intermediate spacer 400, 410, 420 end plate 430 first plate 431 concave portion 432, 432a, 432b, 432c convex portion 433 bottom wall 434, 434a, 434b, 434c top Wall 435 Upper wall 436 Lower wall 437, 813, 814 Through hole 438 First projection 440 Second plate 441 Flat plate 442 Second projection 443 Relief 444, 510, 610 Constriction 445 Wall 450 Nuts 500, 501, 502 side plate (connecting part)
500a, 600a Connection member (bolt)
500b, 600b Head 600 Bottom plate (connecting part)
700 busbars 800, 810, 810A, 810B, 810C, 820 end spacer 811 lower edge portions 812, 812a side edge portion 850a spacer fixing portion 851 claw portion 852 projection 860 beam portion 881 second rib 900 busbar holder 910 engagement hole portion

Claims (5)

a plurality of power storage elements each having a container body and a lid body that closes the container body and is welded to the container body;
a pair of end plates sandwiching the plurality of electric storage elements arranged in a predetermined direction in the predetermined direction;
a connecting portion extending along the predetermined direction and connected to the pair of end plates;
At least one of the pair of end plates has a first projecting portion that overlaps the welded portion between the container body and the lid when viewed in the predetermined direction and projects in a direction opposite to the storage element. storage device. the at least one end plate,
a first plate having the first protrusion;
The power storage device according to claim 1, further comprising a second plate disposed between the first plate and the plurality of power storage elements and overlapping the first plate. The first plate is
a plurality of recesses recessed in a direction opposite to the first protrusion;
having at least one protrusion between adjacent recesses and protruding in the same direction as the first protrusion;
The power storage device according to claim 2, wherein the second plate has a flat plate portion that abuts on all of the plurality of recesses. The power storage device according to claim 2 or 3, wherein the second plate has a second protrusion that protrudes in the same direction as the first protrusion and extends in a direction that intersects with the predetermined direction. The power storage device according to any one of claims 2 to 4, wherein the first protrusion extends continuously over the entire length of one edge of the first plate.

Images