WO2022196479A1

WO2022196479A1 - Power storage device

Info

Publication number: WO2022196479A1
Application number: PCT/JP2022/010200
Authority: WO
Inventors: 修牛嶌
Original assignee: 株式会社Ｇｓユアサ
Priority date: 2021-03-17
Filing date: 2022-03-09
Publication date: 2022-09-22

Abstract

This power storage device comprises a power storage element, an outer casing having an outer casing main body that accommodates the power storage element and a lid body that covers an opening in the outer casing main body, and an auxiliary member. The auxiliary member is arranged along a peripheral edge part (opening peripheral edge part) of the opening in the outer casing main body, and is secured to the opening peripheral edge part. The auxiliary member has a first joint that is a portion bonded to the lid body.

Description

power storage device

The present invention relates to a power storage device that includes a power storage element and an exterior body that accommodates the power storage element.

Patent Document 1 discloses a battery pack that includes a plurality of battery cells (power storage elements) and a housing that accommodates the plurality of power storage elements. In this battery pack, the upper opening of the housing is covered with a top cover, and the top cover is coupled to the housing with a plurality of bolts.

JP 2011-249309 A

Conventionally, an exterior body having an exterior body and a lid covering an opening of the exterior body, and a power storage device including a power storage element housed in the exterior body has a joint portion between the exterior body and the lid. may be required to be airtight. Specifically, when the gas discharge valve of the storage element opens (valve is opened) as the internal pressure of the storage element rises, and gas is discharged from the storage element, there is a problem with the joint between the exterior main body and the lid. gas may leak from unexpected locations in the enclosure. Therefore, it is important to form a highly reliable joining portion between the exterior body and the lid. Regarding this point, when the housing (exterior body) and the upper cover (lid) are fastened with bolts as in the above-described conventional battery pack, the exterior body and lid can be firmly coupled. However, in this case, for example, it is necessary to provide a hole through which the bolt penetrates or a screw hole to be screwed with the bolt at the peripheral edge of the opening of the exterior main body (opening peripheral edge). Therefore, for example, it is necessary to increase the thickness of the side wall portion forming the opening peripheral portion. This causes, for example, an increase in the size of the exterior body.

The present invention was made by the inventors of the present invention by focusing on the above problem, and the reliability of the joint between the main body of the exterior body and the lid is improved while suppressing the increase in the size of the exterior body. An object of the present invention is to provide a power storage device.

An electricity storage device according to an aspect of the present invention includes: an electricity storage element; an exterior body that houses the energy storage element; and an auxiliary member arranged along the peripheral edge of the lid and fixed to the peripheral edge, wherein the auxiliary member has a first joint portion that is a portion joined to the lid body.

According to the present invention, it is an object of the present invention to provide a power storage device in which the reliability of the joint portion between the main body of the exterior body and the lid body is improved while suppressing an increase in the size of the exterior body.

FIG. 1 is a perspective view showing the appearance of a power storage device according to an embodiment. FIG. 2 is an exploded perspective view of the power storage device according to the embodiment. FIG. 3 is a perspective view showing the appearance of the storage device according to the embodiment. FIG. 4 is an exploded perspective view showing a structural relationship among an auxiliary member, an exterior main body, and a busbar holder according to the embodiment. FIG. 5 is a partially enlarged view showing a state in which an auxiliary member is fixed to the exterior body according to the embodiment. FIG. 6 is a cross-sectional view simply showing a joint portion of an auxiliary member, an exterior main body, and a lid according to the embodiment. FIG. 7 is an exploded perspective view showing the structural relationship between the auxiliary member and the storage element unit according to the embodiment.

According to this configuration, since the auxiliary member is arranged along the peripheral edge of the opening of the exterior main body, even if the thickness of the peripheral edge is relatively thin, the cover body can be opened via the auxiliary member. can be fixed to the exterior body. In other words, the auxiliary member reinforces the peripheral edge of the opening, and at least at the first joint portion, it is possible to increase the joint area between the lid and the exterior main body via the auxiliary member. As a result, deformation of the peripheral portion can be suppressed without increasing the thickness of the peripheral portion, and the opening of the exterior main body and the lid can be tightly joined. Therefore, when the storage element opens and the internal pressure of the exterior body suddenly increases, the occurrence of a situation in which gas leaks from the joint portion between the lid body and the exterior body is suppressed. As described above, according to the power storage device according to this aspect, it is possible to improve the reliability of the joint portion between the main body of the exterior body and the lid while suppressing an increase in the size of the exterior body.

The power storage device further includes an insulating member separate from the auxiliary member and arranged between the power storage element and the lid, wherein the insulating member is arranged in contact with the auxiliary member. You can say yes.

According to this configuration, one of the insulating member such as the busbar holder or the inner lid and the auxiliary member functions as a member that reinforces or regulates the other. In other words, the insulating member can function as a member that suppresses deformation of the peripheral portion of the opening of the exterior main body via the auxiliary member. Furthermore, the auxiliary member can function as a member that regulates the position of the insulating member. This contributes to improving the safety of the power storage device.

The auxiliary member may have a connecting portion connected to the insulating member.

According to this configuration, the insulating member and the auxiliary member are mechanically connected at the connecting portion, so that the coupling strength between these members is improved. As a result, one of the insulating member and the auxiliary member can more reliably reinforce the other of the insulating member and the auxiliary member.

The exterior body main body has, at a position adjacent to the first joint portion, a second joint portion, which is a portion where a peripheral edge end face, which is an end face of the peripheral edge portion facing the lid body, and the lid body are joined. , may be

According to this configuration, the joining portion between the exterior main body and the lid has a double structure of the first junction and the second junction, so the joint strength between the exterior body and the lid is improved. Therefore, the durability of the exterior body against internal pressure and external impact is improved, and as a result, the reliability of the joint between the body of the exterior body and the lid body is further improved.

The auxiliary member may be arranged along the peripheral inner surface, which is the surface on the inner side of the exterior body, in the peripheral portion.

According to this configuration, since the auxiliary member is arranged inside the exterior body, the auxiliary member is protected from the exterior body. This suppresses deterioration of the auxiliary member. In other words, the deterioration of the joint portion between the exterior main body and the lid using the auxiliary member is also suppressed. Furthermore, it is possible to attach the auxiliary member to the inside of the exterior body after housing the power storage element and the like in the exterior body (retrofitting). Therefore, it is possible to join the cover body and the exterior body using the auxiliary member without reducing the size and number of the electric storage elements accommodated in the exterior body. That is, it is possible to improve the reliability of the joint portion between the exterior main body and the lid without impairing the performance of the power storage device.

Power storage devices according to embodiments of the present invention (including modifications thereof) will be described below with reference to the drawings. All of the embodiments described below are generic or specific examples. Numerical values, shapes, materials, constituent elements, arrangement positions and connection forms of constituent elements, 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 longitudinal direction of the exterior body of the power storage device, the direction in which a plurality of power storage elements are arranged, or the facing direction of the long side of the container of the power storage elements is defined as the X-axis direction. A Y-axis direction is defined as the lateral direction of the exterior body of the power storage device, the facing direction of the short side surfaces of the container of the power storage element, or the direction in which a pair of electrode terminals are arranged in one power storage element. The direction in which the main body and lid of the exterior body of the power storage device are aligned, the direction in which the busbar holders and power storage element units are aligned, or the vertical direction is defined as the Z-axis direction. These X-axis direction, Y-axis direction, and Z-axis direction are directions that cross each other (perpendicularly in this embodiment). Depending on the mode of use, the Z-axis direction may not be the vertical direction, but for convenience of explanation, the Z-axis direction will be described below as the vertical direction.

In the following description, the positive direction of the X-axis indicates the direction of the arrow on 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. A simple reference to the "X-axis direction" means either or both directions parallel to the X-axis. The same applies to terms relating to the Y-axis and Z-axis.

Furthermore, expressions that indicate relative directions or postures, such as parallel and orthogonal, include cases where they are not strictly that direction or posture. For example, two directions are parallel means not only that the two directions are completely parallel, but also substantially parallel, i.e., including a difference of about several percent also means

(Embodiment)
[1. General description of power storage device]
First, a schematic configuration of a power storage device 1 according to an embodiment will be described. FIG. 1 is a perspective view showing the appearance of a power storage device 1 according to an embodiment. FIG. 2 is an exploded perspective view of the power storage device 1 according to the embodiment. FIG. 3 is a perspective view showing the appearance of the storage device 100 according to the embodiment. Inside the exterior body 10, in addition to the members shown in FIG. 2 and subsequent drawings, electrical devices such as relays and control devices, and wiring connected to the electrical devices are accommodated. Illustrations and descriptions are omitted as appropriate.

The power storage device 1 is a device that can charge electricity from the outside and discharge electricity to the outside, and has a substantially rectangular parallelepiped shape in the present embodiment. The power storage device 1 is, for example, a battery module (assembled battery) used for power storage or power supply. Specifically, the power storage device 1 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 the vehicles include electric vehicles (EV), hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (PHEV), and fossil fuel (gasoline, light oil, liquefied natural gas, etc.) 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. The power storage device 1 can also be used as a stationary battery or the like for home or business use.

As shown in FIGS. 1 and 2 , the power storage device 1 includes an exterior body 10 , a power storage element unit 101 housed in the exterior body 10 , and a busbar holder 30 . The exterior body 10 is a box-shaped (substantially rectangular parallelepiped) container (module case) that constitutes the housing of the power storage device 1 . The exterior body 10 is arranged outside the power storage element unit 101 and the busbar holder 30, fixes them at predetermined positions, and protects them from impacts and the like. The exterior body 10 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), polyamide (PA) , ABS resin, or an insulating member such as a composite material thereof, or a metal coated with an insulating coating. The exterior body 10 thereby avoids contact of the electric storage element unit 101 and the like with external metal members and the like. The exterior body 10 may be made of a conductive member such as metal as long as the electrical insulation between the exterior body 10 and the power storage element unit 101 or the like is maintained.

The exterior body 10 has an exterior body main body 12 and a lid body 11 . The exterior body main body 12 is a bottomed rectangular cylindrical housing having an opening 12a formed in the positive direction of the Z axis, and accommodates the electric storage element unit 101 and the like. The lid 11 is a rectangular member that closes the opening 12 a of the exterior main body 12 . The lid body 11 is joined to the exterior body main body 12 by an adhesive, heat sealing, ultrasonic welding, laser welding, or the like. In the present embodiment, power storage device 1 includes auxiliary member 50 for good bonding between lid body 11 and exterior body main body 12 . The auxiliary member 50 is a member that is fixed to the exterior body main body 12 and joined to the lid body 11 by adhesion or welding. In the present embodiment, auxiliary member 50 also has a mechanical connection relationship with busbar holder 30, which is an example of an insulating member. The configuration of the auxiliary member 50 and its surroundings will be described later with reference to FIGS. 4 to 7. FIG.

A pair of external terminals 19 that are a pair of module terminals on the positive electrode side and the negative electrode side are arranged on the lid 11 . The power storage device 1 charges electricity from the outside and discharges electricity to the outside through the pair of external terminals 19 . The external terminal 19 is made of a conductive member made of metal such as aluminum, aluminum alloy, copper, or copper alloy. The lid 11 is further provided with an exhaust pipe 15 for guiding the gas generated inside the exterior 10 to the outside of the exterior 10 . For example, when the valve of one storage element 100 is opened and gas is discharged, the gas is designed to be sent from the inside of the exterior body 10 to the outside through the exhaust pipe 15 . When power storage device 1 is mounted in an automobile or the like, gas hose (not shown) may be connected to exhaust pipe 15 . As a result, the gas discharged from the power storage element 100 is guided to a predetermined position so that the gas does not affect other members around the power storage element 100 and the human body.

The storage element unit 101 has storage elements 100 and spacers 130 . Specifically, the power storage element unit 101 has eight power storage elements 100 and a total of eight spacers 130 arranged on both sides so as to sandwich two adjacent power storage elements 100 .

The power storage element 100 is a secondary battery (single battery) capable of charging and discharging electricity, specifically a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. As shown in FIG. 3 , the storage element 100 has a flat rectangular parallelepiped (rectangular) container 110 and a pair of (positive electrode side and negative electrode side) electrode terminals 120 fixed to the container 110 . Inside the container 110, an electrode assembly, a current collector, an electrolytic solution, and the like (not shown) are accommodated. An example of the electrode body of the storage element 100 is a wound electrode body formed by winding a positive electrode plate and a negative electrode plate with a separator sandwiched between them in layers. In addition, the storage element 100 may be provided with a laminated (stacked) electrode body formed by stacking a plurality of flat plate-shaped electrode plates, or a bellows-shaped electrode body formed by folding the electrode plates into a bellows shape. good.

The power storage element 100 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 device 100 may be a primary battery that can use stored electricity without being charged by the user, instead of a secondary battery. The storage element 100 may be a battery using a solid electrolyte. The storage element 100 may be a pouch-type storage element. The shape of the electric storage element 100 is not limited to the rectangular shape described above, and may be other shapes such as a polygonal columnar shape, a cylindrical shape, an elliptical columnar shape, and an oval columnar shape.

In this embodiment, as shown in FIG. 3, the container 110 has a pair of long side surfaces 110a, a pair of short side surfaces 110b, and a terminal arrangement surface 110c. The terminal arrangement surface 110c is a surface on which the positive and negative electrode terminals 120 are arranged. In this embodiment, a gas exhaust valve 105 is further arranged on the terminal arrangement surface 110c. When the internal pressure of the container 110 rises excessively, the gas discharge valve 105 is a part that receives the internal pressure and opens (opens the valve), thereby discharging the gas inside the container 110 to the outside.

In the power storage element unit 101, each of the plurality of power storage elements 100 is arranged in a posture in which the long side surfaces 110a are oriented in the alignment direction (X-axis direction). In the plurality of power storage elements 100 arranged in this way, spacers 130 are arranged on both sides of a set of power storage elements 100 composed of two power storage elements 100 adjacent to each other. That is, in the present embodiment, four power storage element 100 groups each including a pair of spacers 130 and two power storage elements 100 sandwiched between the pair of spacers 130 are arranged in the X-axis direction. The spacer 130 is made of an electrically insulating resin such as PC, PP, or PE, like the exterior body 10 . In the present embodiment, two power storage elements 100 included in one power storage element 100 group are connected in parallel by bus bar 60 . Therefore, even if the container 110 of the two storage elements 100 is a conductive member such as metal and the spacer 130 having electrical insulation is not arranged between the two storage elements 100, the Problems such as short circuits between the two storage elements 100 are unlikely to occur. The storage element unit 101 may be restrained in the direction in which the plurality of storage elements 100 are arranged by a restraining member (not shown). In this case, even if the end plate of the restraining member is made of metal, spacer 130 electrically insulates the end plate from power storage element 100 adjacent to the end plate.

The busbar holder 30 is a flat rectangular insulating member arranged to face the terminal arrangement surface 110c of the power storage element 100 and holds a plurality of busbars 60 and electrical equipment (not shown). The busbar holder 30 is made of, for example, any electrically insulating resin material or the like that can be used for the exterior body 10 described above. The busbar holder 30 abuts on the terminal arrangement surface 110c of the plurality of power storage elements 100 and is fixed to the exterior body 10, thereby restricting the upward movement (Z-axis positive direction) of the plurality of power storage elements 100. It also functions as a regulating member.

The busbar 60 arranged in the busbar holder 30 is positioned with respect to the electrode terminal 120 to be joined, and in that state is joined to the electrode terminal 120 by, for example, laser welding. In the present embodiment, of the eight power storage elements 100 included in power storage element unit 101 , two adjacent power storage elements 100 are connected in parallel by bus bar 60 . As a result, four sets of parallel-connected energy storage elements 100 are formed, and spacers 130 are arranged on both sides of the two parallel-connected energy storage elements 100 as described above. The mode of electrical connection of eight power storage elements 100 by busbars 60 is not limited to this, and all eight power storage elements 100 may be connected in series by a plurality of busbars 60 . The number of storage elements 100 included in storage element unit 101 is not limited to eight. The number of storage elements 100 included in the storage element unit 101 may be one or more.

In the power storage device 1 configured as described above, the auxiliary member 50 is used for joining the exterior body main body 12 and the lid body 11 as described above. The configuration of the auxiliary member 50 and its surroundings will be described in detail below with reference to FIGS. 4 to 7. FIG.

[2. Configuration of Auxiliary Member and its Periphery]
FIG. 4 is an exploded perspective view showing the structural relationship among the auxiliary member 50, the exterior main body 12, and the busbar holder 30 according to the embodiment. In FIG. 4, illustration of other members such as the storage element unit 101 and the bus bar 60 is omitted. FIG. 5 is a partially enlarged view showing a state in which the auxiliary member 50 is fixed to the exterior body main body 12 according to the embodiment. FIG. 6 is a cross-sectional view simply showing a joint portion of the auxiliary member 50, the exterior body main body 12, and the lid body 11 according to the embodiment. In FIG. 6, a part of the VI-VI line cross section in FIG. 5 is simply illustrated. FIG. 7 is an exploded perspective view showing the structural relationship between the auxiliary member 50 and the storage element unit 101 according to the embodiment.

As shown in FIGS. 4 and 5, the auxiliary member 50 according to the present embodiment is fixed to the peripheral edge portion (opening peripheral edge portion 13) of the opening 12a of the exterior body 12, and is connected to the busbar holder 30. be. Specifically, the elongated auxiliary member 50 along the extending direction of the opening peripheral portion 13 is arranged along the inner peripheral edge surface 13 a of the opening peripheral portion 13 , which is the surface on the inner side of the exterior body 10 . there is In FIG. 4, the dotted area represents the approximate area of the peripheral inner surface 13a. The peripheral inner surface 13a and the auxiliary member 50 are joined by laser welding, heat welding, ultrasonic welding, adhesion with an adhesive, or a combination thereof. Thereby, the auxiliary member 50 is fixed at the position shown in FIG. More specifically, for example, after the power storage element unit 101 (see FIG. 2) having a plurality of power storage elements 100 is housed in the exterior body 12, the auxiliary member 50 is joined to the peripheral inner surface 13a of the exterior body 12. be done. After that, the busbar holder 30 is arranged above the storage element unit 101 . At this time, the busbar holder 30 is in a state in which the busbar 60 is arranged in each of the plurality of busbar openings 30a (see FIG. 4). Bus bar holder 30 arranged above power storage element unit 101 is connected to auxiliary member 50 by screw 59 . After that, each of the plurality of bus bars 60 is joined to the electrode terminal 120 immediately below. After that, the auxiliary member 50 and the lid body 11 are joined together. In the present embodiment, along with the auxiliary member 50 , the opening peripheral portion 13 of the exterior body main body 12 is also joined to the lid body 11 .

An upper end surface 53a of the auxiliary member 50 shown in FIG. Specifically, as shown in FIG. 6, the auxiliary member 50 and the lid 11 are joined while the upper end surface 53a of the auxiliary member 50 and the inner surface of the lid 11 are in contact with each other. 53 are formed. For this joining, various welding or bonding methods are employed, as in the case of joining the auxiliary member 50 and the exterior body main body 12 .

As described above, in the present embodiment, the power storage device 1 includes the power storage element 100, the exterior body 12 that accommodates the power storage element 100, and the exterior body 10 that includes the lid 11 that closes the opening 12a of the exterior body 12. and an auxiliary member 50. The auxiliary member 50 is arranged along the peripheral edge portion (opening peripheral edge portion 13 ) of the opening 12 a of the exterior body 12 and is fixed to the opening peripheral edge portion 13 . The auxiliary member 50 has a first joint portion 53 that is a portion joined to the lid body 11 .

According to this configuration, since the auxiliary member 50 is arranged along the opening peripheral portion 13 of the exterior main body 12, even if the opening peripheral portion 13 is relatively thin, the auxiliary member 50 can be The lid body 11 can be fixed to the exterior body main body 12 through the holes. That is, the auxiliary member 50 reinforces the opening peripheral portion 13 , and at least at the first joint portion 53 , it is possible to increase the joint area between the lid body 11 and the exterior main body 12 via the auxiliary member 50 . As a result, deformation of the opening peripheral portion 13 can be suppressed without increasing the thickness of the opening peripheral portion 13, and the opening portion 12a of the exterior main body 12 and the lid 11 can be tightly joined. . Therefore, when the electric storage element 100 is opened and the internal pressure of the exterior body 10 rises sharply, the occurrence of a situation in which gas leaks from the joint portion between the lid body 11 and the exterior body 10 is suppressed. . As described above, according to the power storage device 1 according to this aspect, it is possible to improve the reliability of the joint portion between the exterior body 12 and the lid 11 while suppressing an increase in the size of the exterior body 10 .

Further, in the present embodiment, as shown in FIGS. 2 and 5, the auxiliary member 50 is in contact with the busbar holder 30, which is an example of an insulating member. That is, power storage device 1 includes bus bar holder 30 that is separate from auxiliary member 50 and that is arranged between power storage element 100 and lid body 11 . The busbar holder 30 is arranged in contact with the auxiliary member 50 .

According to this configuration, one of the busbar holder 30 and the auxiliary member 50 functions as a member that reinforces or regulates the other. In other words, the busbar holder 30 can function as a member that suppresses deformation of the peripheral portion of the opening 12 a of the exterior body 12 via the auxiliary member 50 . Furthermore, the auxiliary member 50 can function as a member that regulates the position of the busbar holder 30 . This contributes to improving the safety of the power storage device 1 .

Specifically, in this embodiment, the auxiliary member 50 has connecting

portions

55 and 56 that are connected to the busbar holder 30 . The connecting portion 55 according to the embodiment is a portion having a through hole through which a screw 59 passes, as shown in FIG. In the busbar holder 30, a screw hole 35 is formed at a position corresponding to the connecting portion 55, and a screw 59 inserted through the connecting portion 55 and the screw hole 35 is screwed with a nut (not shown), thereby tightening the connecting portion. 55 is fastened to the busbar holder 30 . The connecting portions 55 are provided at both ends of the auxiliary member 50 in the longitudinal direction, and therefore the auxiliary member 50 is fastened to the busbar holders 30 at both ends in the longitudinal direction. The auxiliary member 50 further has two connecting portions 56 between the connecting portions 55 at both ends in the longitudinal direction. As shown in FIGS. 4 and 5, the connecting portion 56 is a projection that is inserted into the coupling hole 36 provided in the busbar holder 30 and crimped by heat. In addition, FIG. 5 shows a state before the connecting portion 56 is crimped by heat.

According to this configuration, the busbar holder 30 and the auxiliary member 50 are mechanically connected at the

coupling portions

55 and 56, so that the coupling force between these members is improved. As a result, one of the busbar holder 30 and the auxiliary member 50 can reinforce the other of the busbar holder 30 and the auxiliary member 50 more reliably. In the present embodiment, the auxiliary member 50 is elongated in the extending direction of the opening peripheral edge portion 13 of the exterior main body 12, and the connecting

portions

55 or 56 are provided at a plurality of locations including both ends in the longitudinal direction. It is Therefore, the elongated auxiliary member 50 is supported in a balanced manner in the longitudinal direction by both the opening peripheral portion 13 of the exterior body 12 and the busbar holders 30 located on both sides of the auxiliary member 50 in the thickness direction.

As described above, in the present embodiment, the auxiliary member 50 is connected to the busbar holder 30 , so that the busbar holder 30 is fixed to the exterior body 10 via the auxiliary member 50 . The busbar holder 30 may have a portion directly connected to the exterior body 12 . The busbar holder 30 may be directly fixed to the plurality of power storage elements 100 by being adhered to the terminal arrangement surfaces 110c of the plurality of power storage elements 100 with an adhesive.

Furthermore, in the present embodiment, a direct joint portion between the exterior main body 12 and the lid body 11 is provided adjacent to the joint portion (first joint portion 53) between the auxiliary member 50 and the lid body 11. there is That is, as shown in FIGS. 5 and 6 , the exterior main body 12 has a peripheral edge surface 14a, which is an end surface of the opening peripheral edge portion 13 facing the lid body 11, and the lid body 11 at a position adjacent to the first joint portion 53. It has a second joint portion 14 which is a portion where and are joined.

According to this configuration, the joint portion between the exterior body main body 12 and the lid body 11 has a double structure of the first joint portion 53 and the second joint portion 14, so that the exterior body body 12 and the lid body 11 are joined together. Improves strength. Therefore, the durability of the exterior body 10 against internal pressure and external impact is improved, and as a result, the reliability of the joint portion between the exterior body body 12 and the lid body 11 is further improved.

In the present embodiment, the auxiliary member 50 is arranged along the peripheral inner surface 13a, which is the surface on the inner side of the exterior body 10, in the opening peripheral edge portion 13 of the exterior body main body 12. As shown in FIG.

Thus, in this embodiment, the auxiliary member 50 is arranged inside the exterior body 10 . Therefore, the auxiliary member 50 is protected from the exterior body 10 . This suppresses deterioration of the auxiliary member 50 . That is, the deterioration of the joint portion (first joint portion 53) between the exterior body main body 12 and the lid body 11 using the auxiliary member 50 is also suppressed. In the present embodiment, as described above, auxiliary member 50 is arranged above storage element unit 101 accommodated in exterior body 12 while being connected to busbar holder 30 by screw 59 or the like. In other words, the auxiliary member 50 can be retrofitted inside the exterior body 12 together with the busbar holder 30 . Therefore, the lid 11 and the exterior body 12 can be joined using the auxiliary member 50 without reducing the size and number of the power storage elements 100 housed in the exterior body 12 . That is, the reliability of the joint portion between the exterior main body 12 and the lid body 11 in the power storage device 1 can be improved without impairing the performance of the power storage device 1 . Furthermore, even if the thickness of the auxiliary member 50 (the width of the upper end surface 53a in FIG. 5 in the Y-axis direction) is increased, the increase in thickness does not affect the outer shape and size (outer dimensions) of the exterior body 10. don't give Therefore, by increasing the thickness of the auxiliary member 50 while maintaining the size of the exterior body 10, it is possible to improve the rigidity of the auxiliary member 50 and the joint strength at the first joint portion 53.

In this embodiment, the auxiliary member 50 has a portion that mechanically engages with the power storage element unit 101 . Specifically, as shown in FIG. 7 , the auxiliary member 50 has a body portion 51 and a plurality of restricting portions 57 projecting from the body portion 51 toward the storage element unit 101 . The restricting portion 57 is inserted between a pair of spacers 130 sandwiching the two storage elements 100 in the longitudinal direction of the auxiliary member 50 (same as the extending direction of the opening peripheral portion 13, in the present embodiment, the X-axis direction). be. Accordingly, one restricting portion 57 can restrict the movement of the pair of spacers 130 in the X-axis direction by engaging with the spacers 130 positioned on both sides in the X-axis direction. That is, one restricting portion 57 can indirectly engage with two power storage elements 100 sandwiched between the pair of spacers 130 . Thereby, the movement of the two storage elements 100 in the X-axis direction can be restricted. The restricting portion 57 may be directly engaged with the power storage element 100 . In this case, the restricting portion 57 may have a rib that contacts the long side surface 110 a of at least one storage element 100 .

In this way, auxiliary member 50 according to the present embodiment engages directly or indirectly with power storage element 100, thereby restricting movement of power storage element 100 in the extending direction of opening peripheral edge portion 13. 57.

According to this configuration, the auxiliary member 50 can restrict movement of the power storage element 100 in at least one direction. Therefore, the stability of the position of the power storage device 100 is improved when the power storage device 1 is subjected to vibration or impact, which contributes to the improvement of the safety of the power storage device 1 .

The restricting portion 57 is located between the short side surface 110 b of the power storage element 100 and the inner side surface of the exterior main body 12 . That is, it can be said that the restricting portion 57 is an insertion portion that is inserted between the power storage element 100 and the inner surface of the exterior body 10 .

According to this configuration, the insertion portion (restriction portion 57) can suppress movement of the power storage element 100 in the direction (Y-axis direction) facing the short side surface 110b. Further, the auxiliary member 50 is supported by the exterior body 10 over a relatively large area by abutting the insertion portion (regulating portion 57 ) against the inner side surface of the exterior body 10 . That is, since the auxiliary member 50 has the insertion portion (regulating portion 57), it is possible to improve the positional stability of the power storage element 100 and the auxiliary member 50 in the exterior body 12. Contribute to improving the safety of 1.

[3. Modification]
Although the power storage device 1 according to the embodiment of the present invention has been described above, the present invention is not limited to this embodiment. In other words, the embodiments disclosed this time are illustrative in all respects and are not restrictive, and the scope of the present invention includes all changes within the meaning and range equivalent to the claims. included.

The auxiliary member 50 and the busbar holder 30 may be connected by a method other than fastening with screws 59 and caulking by heat. The auxiliary member 50 and the busbar holder 30 may be connected by an engaging structure using elastic deformation such as a snap fit. It is not essential that the auxiliary member 50 and the busbar holder 30 are connected, and the auxiliary member 50 and the busbar holder 30 may simply be arranged in contact with each other. They may be physically separated and arranged.

The insulating member connected to the auxiliary member 50 may be a member other than the busbar holder 30. When power storage device 1 has a resin member such as an inner lid or an electrical component tray between power storage element unit 101 and lid 11 , the resin member is connected to auxiliary member 50 . It may be used as an insulating member.

In the present embodiment, the auxiliary member 50 is arranged in a portion (a portion extending in the X-axis direction) of the peripheral portion (opening peripheral portion 13) along the direction in which the plurality of power storage elements 100 are arranged. . However, the auxiliary member 50 may be arranged in a portion along the direction (Y-axis direction) perpendicular to the direction in which the plurality of power storage elements 100 are arranged, of the peripheral portion. When the peripheral portion is rectangular with four sides when viewed from the Z-axis plus direction (plan view), the auxiliary member 50 is arranged along any selected side of the four sides. good too. The auxiliary member 50 may be arranged only on the side with the smallest thickness among the four sides. The auxiliary member 50 may be arranged along part of the peripheral edge.

The first joint portion 53 and the second joint portion 14 do not have to be arranged in parallel with the Y-axis direction. Specifically, the upper end surface 53a of the auxiliary member 50 shown in FIG. 5 and the peripheral end surface 14a of the exterior main body 12 may not be flush with each other. The positions in the height direction (Z-axis direction) of the upper end surface 53 a and the peripheral end surface 14 a may be different, and the resulting step may be used to position the lid 11 with respect to the exterior body 12 . When the upper end surface 53a and the peripheral edge surface 14a are flush with each other, it is advantageous in that the inner surface of the lid body 11 to which the upper end surface 53a and the peripheral edge surface 14a are joined may be simply flat. Furthermore, when the upper end surface 53a and the peripheral edge surface 14a are flush with each other, the thickness of the portions of the lid body 11 joined to the upper end surface 53a and the peripheral edge surface 14a becomes uniform. Therefore, when the materials of the exterior body 10 and the auxiliary member 50 are the same and the first joint portion 53 and the second joint portion 14 are formed by, for example, laser welding or ultrasonic welding, various welding conditions are set first. The joint portion 53 and the second joint portion 14 can be made common. As a result, the welding work for forming the first joint portion 53 and the second joint portion 14 is made more efficient.

When it is difficult to form the second joint portion 14 because the thickness of the opening peripheral portion 13 of the exterior main body 12 is small, or the peripheral edge surface 14a has an uneven shape, the exterior main body 12 and the lid 11 are separated from each other by It may be joined only at one joint portion 53 . In this case, as described above, by increasing the thickness of the auxiliary member 50, it is possible to improve the bonding strength at the first bonding portion 53. FIG.

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.

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

1 Power storage device 10 Exterior body 11 Lid body 12 Exterior body body 12a Opening 13 Opening peripheral edge 13a Peripheral inner surface 14 Second joint 14a Peripheral edge surface 30 Bus bar holder 35 Screw hole 36 Coupling hole 50 Auxiliary member 51 Main body 53 First joint Part 53a

Upper end surface

55, 56 Connecting part 57 Regulating part 59 Screw 100 Storage element 101 Storage element unit

Claims

a storage element;
an exterior body having an exterior body that houses the power storage element and a lid that closes an opening of the exterior body;
an auxiliary member arranged along the peripheral edge of the opening of the exterior body main body and fixed to the peripheral edge,
The auxiliary member has a first joint portion that is a portion joined to the lid,
storage device.
Furthermore, an insulating member separate from the auxiliary member is provided between the power storage element and the lid,
The insulating member is arranged in contact with the auxiliary member,
The power storage device according to claim 1 .
The auxiliary member has a connecting portion connected to the insulating member,
The power storage device according to claim 2 .
The exterior body main body has, at a position adjacent to the first joint portion, a second joint portion, which is a portion where a peripheral edge end face, which is an end face of the peripheral edge portion facing the lid body, and the lid body are joined. ,
The power storage device according to any one of claims 1 to 3.
The auxiliary member is arranged along a peripheral inner surface, which is a surface on the inner side of the exterior body, in the peripheral portion.
The power storage device according to any one of claims 1 to 4.