JP2022119485A - power storage device - Google Patents

Abstract

To provide a power storage device, having an outer package, which has improved reliability enabled by a simple configuration.SOLUTION: A power storage device 1 comprises an outer package 10 which houses a power storage element 20. The outer package 10 comprises: a lid 11; and a cover member 130 which is fitted on the lid 11 so as to close an upper surface opening 11a provided on the lid 11. The lid 11 has a first wall 141 which is erected along a fitting direction for fitting the cover member 130 onto the lid 11. The cover member 130 has a second wall 131 which is erected along the fitting direction, and the second wall 131 faces the first wall 141. The first wall 141 and the second wall 131 are fixed to each other via an adhesive 180 in such a manner that a first protrusion 133, which is provided on one of the first wall 141 and the second wall 131 so as to protrude toward the other one of them, is in contact with the other wall in a protruding direction.SELECTED DRAWING: Figure 7

Description

The present invention relates to a power storage device having an exterior body.

Patent Literature 1 discloses a power storage device including an exterior body. The exterior body has a first exterior body, which is an exterior body main body, and a second exterior body, which is a lid disposed above the first exterior body. It is closed by the exterior body. The second exterior body has a second peripheral edge portion facing from the outside to the first peripheral edge portion forming the opening of the first exterior body. The first peripheral edge portion is formed with a first protrusion that projects toward the second peripheral edge portion, and the second peripheral edge portion is formed with a second projection that projects toward the first peripheral edge portion. The upper end surface of the first peripheral edge portion and the second exterior body are adhered with an adhesive in a state where the first protrusion and the second protrusion are engaged in the vertical direction.

JP 2014-154381 A

An exterior body of a power storage device generally includes a member (first member) having an opening, such as an exterior body and a lid, and a member (second member) that closes the opening. For example, when an adhesive is used to join these two members, as in the above-described conventional power storage device, the second member is pushed back by the adhesive until the adhesive hardens, resulting in an airtight joint. may not be sufficiently flexible or watertight. In other words, a situation may arise in which the reliability of the power storage device is impaired. Therefore, for example, an operation or a jig for pressing one member toward the other member is required until the adhesive is solidified. Therefore, for example, as in the above-described conventional power storage device, two members that are joined with an adhesive are provided with projections or the like that engage with each other. This eliminates the need for an operation or a jig for pressing one member toward the other member until the adhesive is solidified. However, due to the size or shape of at least one of the two members, it may be difficult or practically impossible to provide structures such as protrusions that engage each other. In this case, for example, problems such as complication of the structure or manufacturing process of the power storage device and difficulty in ensuring reliability arise.

The present invention has been made by the inventors of the present invention by newly paying attention to the above problem, and aims to provide a power storage device having an exterior body, which has a simple configuration and improved reliability. aim.

A power storage device according to an aspect of the present invention is a power storage device that includes an exterior body that houses a power storage element, wherein the exterior body is configured to cover a first member and an opening provided in the first member. a second member attached to the first member, wherein the first member is disposed on the periphery of the opening and erected along the direction in which the second member is attached to the first member; The second member has a second wall portion erected along the mounting direction, the second wall portion facing the first wall portion, and the first The wall portion and the second wall portion are arranged in a state in which a first protrusion projecting from one of the first wall portion and the second wall portion toward the other is in contact with the other in the projecting direction. , are fixed to each other via an adhesive.

According to this configuration, when the first member is combined with the second member, the pressing force exerted by the first convex portion of one of the first wall portion and the second wall portion on the other (the pressure between the first convex portion and the other The second member can be temporarily fixed to the first member by the frictional force between the two. That is, the second member is maintained in a state in which it is difficult for the adhesive to push back. Furthermore, while the second member is temporarily fixed to the first member, the adhesive applied or filled between the first wall portion and the second wall portion is solidified, so that the second member is fixed to the first member. It is permanently fixed to the member. As a result, the gap between the opening of the first member and the second member closing the opening is more reliably filled with the adhesive. In addition, since the first convex portion exists between the mutually facing surfaces of the first wall portion and the second wall portion, a space that accommodates a sufficient amount of adhesive for fixing the second member to the first member. can be ensured between the first wall and the second wall. Therefore, the first member and the second member can be firmly joined, and the airtightness or watertightness at the peripheral edge of the opening of the first member can be ensured more reliably. Thus, the power storage device according to this aspect is a power storage device with a simple configuration and improved reliability.

one of the first wall portion and the second wall portion is a wall portion forming an inner surface of a groove provided in the first member or the second member having the one; The other of the second wall portions is inserted into the groove, and the first convex portion abuts on the first wall portion or the second wall portion located in the projecting direction of the first convex portion. It may be assumed that the groove is fitted in the state in which the groove is closed.

According to this configuration, the wall portion (the first wall portion or the second wall portion) of the other of the first member and the second member fits into the groove provided in one of the first member and the second member. , a relatively strong fixing force can be obtained when the first member is temporarily fixed to the second member. As a result, the first member can be permanently fixed to the second member with higher accuracy or more certainty.

The power storage device further has a second protrusion projecting from a surface opposite to the first protrusion on the first wall or the second wall provided with the first protrusion. , The second protrusion may be in contact with the inner side surface of the groove located in the projecting direction of the second protrusion.

According to this configuration, since the first protrusion and the second protrusion abut against the inner side surfaces of the groove that face each other, the fixing force is stronger when the first member is temporarily fixed to the second member. is obtained. As a result, the first member can be permanently fixed to the second member with higher accuracy or more certainty.

The second convex portion does not overlap the first convex portion when seen through from the thickness direction of the first wall portion or the second wall portion on which the first convex portion and the second convex portion are provided. It may be arranged at a position.

According to this configuration, for example, when the first protrusion and the second protrusion are provided on the second wall, the first protrusion and the second protrusion are offset in the extending direction of the second wall. are placed in the same position. Therefore, when the first convex portion and the second convex portion receive a pressing force from the mutually opposing inner side surfaces of the groove, the reaction force based on the elastic force due to the bending of the second wall portion in the thickness direction is applied to the first member. Acts as a fixing force for the second member. As a result, a stronger fixing force can be obtained, whereby the first member can be fixed to the second member more accurately or more reliably.

The first protrusion may be elongated in the mounting direction.

According to this configuration, the first convex portion is provided on the first wall portion or the second wall portion as a rib elongated in the mounting direction, for example. Therefore, it acts as a fixing force of the second member to the first member while suppressing the dynamic friction between the first convex portion and the first wall portion or the second wall portion when the second member is attached to the first member. It is possible to secure the pressing force of the first convex portion to the first wall portion or the second wall portion.

ADVANTAGE OF THE INVENTION According to this invention, it is an electrical storage apparatus which is an electrical storage apparatus provided with an exterior body, and can provide an electrical storage apparatus with a simple structure and improved reliability.

1 is a perspective view showing an appearance of a power storage device according to Embodiment 1; FIG. 1 is an exploded perspective view of a power storage device according to Embodiment 1; FIG. 2 is a perspective view showing the configuration of the ventilation chamber and its surroundings according to Embodiment 1. FIG. 4 is an enlarged perspective view showing the structural relationship between the lid body and the cover member according to Embodiment 1. FIG. 4 is a perspective view showing the appearance of the cover member according to Embodiment 1; FIG. 6 is a perspective view showing the appearance of the cover member when viewed from an angle different from that of FIG. 5; FIG. FIG. 4 is a cross-sectional view showing a joint portion between a lid body and a cover member according to Embodiment 1; FIG. 4 is a perspective cross-sectional view showing a joint portion between a lid body and a cover member according to Embodiment 1; FIG. 10 is a perspective view showing a configuration outline of a power storage device according to Embodiment 2; FIG. 11 is a perspective cross-sectional view of a lid according to Embodiment 2; FIG. 11 is a perspective cross-sectional view of the lid when viewed from an angle different from that of FIG. 10; FIG. 11 is a perspective cross-sectional view showing a joint portion between an exterior body and a lid according to Embodiment 2;

Power storage devices according to embodiments of the present invention will be described below with reference to the drawings. It should be noted that the embodiments described below are all comprehensive 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. Also, in each drawing, dimensions and the like are not strictly illustrated. Furthermore, 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 and the direction in which the plurality of power storage elements are arranged in the first embodiment are defined as the X-axis direction. The lateral direction of the exterior body of the power storage device, which is the direction in which the plurality of power storage elements are arranged in the second embodiment, is defined as the Y-axis direction. The direction in which the main body of the exterior body and the lid body of the power storage device 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). 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.

Further, in the following description, for example, the positive direction of the X-axis indicates the direction of the arrow of the X-axis, and the negative direction of the X-axis indicates the opposite direction to the positive direction of the X-axis. The same applies to the Y-axis direction and the Z-axis direction. Further, simply referring 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 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)
[1-1. General description of power storage device]
First, a general description of the power storage device 1 according to the first embodiment will be given with reference to FIGS. 1 to 3. FIG. FIG. 1 is a perspective view showing the appearance of a power storage device 1 according to Embodiment 1. FIG. FIG. 2 is an exploded perspective view of power storage device 1 according to the first embodiment. FIG. 3 is a perspective view showing the configuration of the ventilation chamber 100 and its surroundings according to the first embodiment.

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 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. 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 a power storage element 20 and an exterior body 10 that accommodates the power storage element 20 . In the present embodiment, exterior body 10 accommodates eight power storage elements 20 . Note that the number of power storage elements 20 included in power storage device 1 is not limited to eight. The power storage device 1 may include one or more power storage elements 20 . In the present embodiment, one storage element unit 24 is composed of eight storage elements 20 arranged in the X-axis direction. The storage element unit 24 may have a spacer, an insulating film, and the like (not shown).

The exterior body 10 has an exterior body body 12 that accommodates the electric storage element unit 24 and a lid body 11 that closes an opening (body opening 15 ) of the exterior body body 12 . A busbar plate 17 is arranged above the power storage element unit 24 inside the exterior body 10 . A plurality of busbars 33 are held on the busbar plate 17 . A connection unit 80 including a control circuit and the like is arranged between the busbar plate 17 and the lid 11 .

The exterior body 10 is a substantially rectangular parallelepiped (box-shaped) container (module case) that constitutes the outer shell of the power storage device 1 . That is, the exterior body 10 is a member that fixes the power storage element unit 24, the bus bar plate 17, and the like 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), ABS resin, or , an insulating member such as a composite material thereof, or a metal coated with an insulating coating.

The exterior body 12 of the exterior body 10 is a bottomed rectangular cylindrical housing in which a body opening 15 for accommodating the power storage element unit 24 is formed. The lid 11 is a rectangular member that closes the body opening 15 of the exterior body 12 , and has a positive electrode-side external terminal 91 and a negative electrode-side external terminal 92 . The external terminals 91 and 92 are electrically connected to the plurality of power storage elements 20 via the connection unit 80 and the bus bar 33, and the power storage device 1 receives electricity from the outside via the external terminals 91 and 92. Charges and discharges electricity to the outside. The external terminals 91 and 92 are made of a conductive member made of metal such as aluminum or aluminum alloy.

The storage element 20 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 20 has a flat rectangular parallelepiped (rectangular) shape, and in the present embodiment, eight energy storage elements 20 are arranged in the X-axis direction as described above.

Note that the storage element 20 is not limited to a non-aqueous electrolyte secondary battery, and may be a secondary battery other than a non-aqueous electrolyte secondary battery, or may be a capacitor. The power storage element 20 may be a primary battery that can use stored electricity without being charged by the user, instead of a secondary battery. The storage element 20 may be a pouch-type storage element. Moreover, the shape of the electric storage element 20 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, the storage element 20 includes a container 21 made of metal. The container 21 is a rectangular case having a pair of long sides 21a facing each other and a pair of short sides 21b facing each other. The container 21 accommodates an electrode assembly, a current collector, an electrolytic solution, and the like. In the present embodiment, each of the plurality of power storage elements 20 is arranged in a row in the X-axis direction with the long side 21a facing the X-axis direction (the short side 21b is parallel to the X-axis direction).

A cover plate 21 c of the container 21 is provided with metal electrode terminals 22 (a positive electrode terminal and a negative electrode terminal) electrically connected to the electrode body inside the container 21 . The electrode terminal 22 is arranged to protrude from the cover plate 21c of the container 21 toward the busbar plate 17 (upward, that is, in the positive Z-axis direction). The cover plate 21c of the container 21 is further provided with a gas discharge valve 23 for discharging internal gas to the outside when the internal pressure of the container 21 is excessively increased. In the present embodiment, as shown in FIG. 2, each of the plurality of power storage elements 20 is arranged with the gas exhaust valve 23 directed in the positive direction of the Z axis.

The busbar 33 is a rectangular plate-shaped member that is arranged on at least two storage elements 20 while being held by the busbar plate 17 and electrically connects the electrode terminals 22 of the at least two storage elements 20 . be. The material of the bus bar 33 is not particularly limited. For example, it may be made of a metal such as aluminum, an aluminum alloy, copper, a copper alloy, or stainless steel, a combination thereof, or a conductive member other than metal. In the present embodiment, five bus bars 33 are used to connect two energy storage elements 20 in parallel to form four energy storage element groups, and the four energy storage element groups are connected in series. ing. Moreover, the manner of electrical connection of the eight power storage elements 20 is not particularly limited, and all the eight power storage elements 20 may be connected in series by seven bus bars.

The connection unit 80 is a unit having a plurality of bus bars, control boards, etc., and electrically connects the storage element unit 24 and the external terminals 91 and 92 . The control board of the connection unit 80 has a plurality of electrical components, and these electrical components form a detection circuit for detecting the state of each storage element 20, a control circuit for controlling charging and discharging, and the like. there is In this embodiment, connection unit 80 is fixed to busbar plate 17 .

The busbar plate 17 is a member made of resin that holds the busbars 33 . More specifically, the busbar plate 17 is a member that holds a plurality of busbars 33, connection units 80, and other wirings (not shown) and can regulate the positions of these members. In addition, the busbar plate 17 is provided with a plurality of busbar openings 17 a that expose a part of each of the plurality of busbars 33 to the side of the plurality of power storage elements 20 .

A path forming portion 19 extending in the X-axis direction and projecting in the positive Z-axis direction is provided in the center of the busbar plate 17 in the Y-axis direction along the arrangement of the gas discharge valves 23 of the plurality of power storage elements 20 . . The path forming portion 19 covers all the gas discharge valves 23 from the Z-axis plus direction side. The path forming portion 19 forms an exhaust path for the gas discharged from the power storage element 20 along the X-axis direction. A path outlet 18 is provided at the longitudinal end of the path forming portion 19 as shown in FIG. The gas discharged from the power storage element 20 preferentially passes through the path outlet 18 and is discharged to the outside of the exterior body 10 via the exhaust pipe 120 . The busbar plate 17 configured in this manner is fixed to the exterior body main body 12 of the exterior body 10 by a predetermined method such as adhesion or heat welding.

The lid body 11 further has a ventilation chamber 100 through which gas moving from one of the inside and the outside of the exterior body 10 to the other passes, and an exhaust pipe 120 connected to the ventilation chamber 100 . For example, the gas inside the exterior body 10 reaches the inside of the ventilation chamber 100 through the exhaust port provided in the ventilation chamber 100, and then passes through the exhaust pipe 120 communicating with the ventilation chamber 100 to the exterior body 10. released to the outside of the As shown in FIG. 3, the lid 11 has a top opening 11a that exposes the ventilation chamber 100. As shown in FIGS. 1 to 3, the top opening 11a is closed by a cover member . It's leaking. In the present embodiment, lid body 11 is an example of a first member, and upper surface opening 11a is an example of an opening provided in the first member. Furthermore, the cover member 130 is an example of a second member. Specifically, the second wall portion 131 of the cover member 130 is inserted into the groove 140 extending along the periphery of the upper opening 11a (see FIG. 3), and the second wall portion 131 and the inner surface of the groove 140 are joined by an adhesive. The joint portion between the first member and the second member, that is, the joint portion between the lid body 11 and the cover member 130 will be described later with reference to FIGS. 4 to 8. FIG.

As shown in FIG. 3, the ventilation chamber 100 includes a cylindrical body 101 whose tip opening is closed by a valve member 115 and a ventilation waterproof membrane 119 that closes the ventilation holes 118 . The cylinder 101 is a member that forms a through hole that communicates the inside of the ventilation chamber 100 with the inside of the exterior body 10 (the portion other than the ventilation chamber 100). It is blocked by In this embodiment, the valve member 115 is a cap-like member made of a highly heat-resistant elastic material such as silicone rubber, and covers the tip of the cylindrical body 101 . In this state, the valve member 115 is in close contact with the cylinder 101 due to the elastic force (restoring force) of the valve member 115 made of an elastic material. That is, the valve member 115 is in a closed state that closes the opening of the cylindrical body 101 . When the valve member 115 is in the closed state, for example, when gas is discharged from one or more power storage elements 20, the internal pressure of the exterior body 10 rises and exceeds a predetermined value, causing the valve member 115 to close. At least a portion of the opening of 101 is opened, thereby transitioning from the closed state to the open state. As a result, the gas flows into the ventilation chamber 100 through the opening of the cylinder 101 . The gas that has flowed into ventilation chamber 100 is discharged to the outside of power storage device 1 through exhaust pipe 120 that communicates with ventilation chamber 100 . Since the cover member 130 is arranged at a position facing the valve member 115 , the upward movement of the valve member 115 is restricted by the cover member 130 .

The ventilation hole 118 provided in the ventilation chamber 100 is a hole for exchanging gas between the inside and the outside of the exterior body 10 at normal times. Specifically, the vent hole 118 is closed by a breathable waterproof membrane 119 that has a function of allowing gas to pass through but not liquid. Specifically, the air-permeable waterproof membrane 119 is a membrane made of a waterproof and moisture-permeable material having waterproofness and breathability (moisture permeability) such as Gore-Tex (registered trademark) and TEMISH (registered trademark). be. As a result, for example, when there is a difference between the internal pressure and the external pressure of the exterior body 10 due to a change in the environmental temperature of the power storage device 1 during normal operation, gas is exchanged via the breathable waterproof membrane 119. A pressure balance is achieved between the inside and outside of the exterior body 10 .

It is not essential that the valve member 115 and the ventilation waterproof membrane 119 are arranged in the ventilation chamber 100 . For example, vent chamber 100 may not have barrel 101 and valve member 115 . In this case, the air-permeable waterproof film 119 is broken or deformed due to a sudden increase in the internal pressure of the exterior body 10 , thereby allowing the gas inside the exterior body 10 to flow into the ventilation chamber 100 . In other words, the air-permeable waterproof membrane 119 can be provided with an emergency pressure release function and a normal pressure balancing function.

As described above, when the gas discharge valves 23 of one or more storage elements 20 are opened (opened), the high-temperature and high-pressure gas discharged from the gas discharge valves 23 flows into the ventilation chamber 100 . . This gas is sent to a predetermined position away from power storage device 1 via exhaust pipe 120 communicating with ventilation chamber 100 and a gas hose connected to exhaust pipe 120 . However, if there is a gap between the cover member 130 that forms the top surface of the ventilation chamber 100 and the lid 11, or if the gap is caused by the pressure of the gas, the gas may leak from an unexpected position. It will leak out, and this will be a factor in the occurrence of unsafe events. Therefore, the joint portion between cover member 130 and lid body 11 is an important portion from the viewpoint of reliability of power storage device 1 . On the other hand, adopting a complicated structure for the joint portion, adopting a joining method that requires complicated work, and the like are difficult to adopt from the viewpoint of time- or economical manufacturing efficiency of the power storage device 1. .

Therefore, in the present embodiment, a simple structure and a structure for joining lid body 11 and cover member 130 more reliably are adopted. Details of the joint portion between lid body 11 and cover member 130 according to the present embodiment will be described below with reference to FIGS. 4 to 8. FIG.

[1-2. Regarding the junction between the lid and the cover member]
FIG. 4 is an enlarged perspective view showing the structural relationship between lid body 11 and cover member 130 according to the first embodiment. FIG. 5 is a perspective view showing the appearance of cover member 130 according to the first embodiment. FIG. 6 is a perspective view showing the appearance of the cover member 130 when viewed from an angle different from that of FIG. FIG. 7 is a cross-sectional view showing a joint portion between lid body 11 and cover member 130 according to the first embodiment. FIG. 7 shows a cross section of the joint on the YZ plane passing through line VII-VII in FIG. In addition, FIG. 7 illustrates a rough arrangement range of the adhesive 180 in the groove 140, and the illustration of the adhesive 180 itself is omitted. FIG. 8 is a perspective cross-sectional view showing a joint portion between cover member 130 and lid body 11 according to Embodiment 1. As shown in FIG. The position of the cross section in FIG. 8 is the same as the position of the cross section shown in FIG.

As shown in FIG. 3 and FIGS. 4 to 6, the cover member 130 is a member that is attached to the lid body 11 from above. The lid 11 has a first wall portion 141 provided on the periphery of the upper opening portion 11a. Specifically, as shown in FIG. 7, the first wall portion 141 is a wall portion that forms an inner side surface 141a of the groove 140 formed along the peripheral edge of the upper opening portion 11a. The cover member 130 has a second wall portion 131 that fits into the groove 140 . The first wall portion 141 of the lid 11 and the second wall portion 131 of the cover member 130 are both erected along the mounting direction of the cover member 130 with respect to the lid 11 (Z-axis minus direction). As shown in FIG. 7 , the first wall portion 141 and the second wall portion 131 are arranged in positions and postures facing each other when the cover member 130 is attached to the lid body 11 .

The cover member 130 and the lid body 11 configured in this way are joined with an adhesive 180 as shown in FIGS. For example, the adhesive 180 is poured into the groove 140 of the lid 11, and the second wall portion 131 of the cover member 130 is inserted into the groove 140 of the lid 11 from above. After that, the cover member 130 and the lid body 11 are joined by solidifying the adhesive 180 . Until the adhesive 180 hardens, the adhesive 180 exerts an upward force on the cover member 130 . Therefore, cover member 130 and lid body 11 according to the present embodiment have a configuration for suppressing pushback of cover member 130 by adhesive 180 .

Specifically, when viewed from the positive direction of the Z-axis (planar view, the same shall apply hereinafter), the cover member 130 extends from a rectangular portion 130a located in the negative direction of the Y-axis to an elongated protruding portion 130b extending in the positive direction of the Y-axis. has a protruding shape. The rectangular portion 130a is a relatively wide portion of the cover member 130, and has a U-shaped engaging portion 139 projecting toward the lid 11, as shown in FIGS. The engagement portion 139 is hooked on a projection 149 (see FIG. 3) provided on the lid 11, thereby restricting the movement of the cover member 130 in the direction away from the lid 11 (Z-axis plus direction). .

On the other hand, the projecting portion 130b of the cover member 130 is elongated in the Y-axis direction and narrow in the X-axis direction. Therefore, it is necessary to suppress the lifting (pushing back) of the tip portion of the protruding portion 130b in the positive direction of the Y axis for more reliable joining of the cover member 130 to the lid 11 as a whole. However, the tip of the projecting portion 130b is a small portion in plan view. Therefore, providing an engaging structure such as the engaging portion 139 and the projection 149 at the tip and the portion of the lid body 11 corresponding to the tip would complicate the manufacturing process or increase the manufacturing cost. leads to another problem of

Therefore, in the present embodiment, a first convex portion 133 is provided on the second wall portion 131 of the cover member 130, as shown in FIG. 5, for example. The first convex portion 133 abuts on the first wall portion 141 of the lid 11 when the cover member 130 is attached to the lid 11 . Specifically, both the cover member 130 and the lid body 11 are made of resin such as PC, PP, or PE as described above, and when the second wall portion 131 is inserted into the groove 140, For example, as shown in FIGS. 7 and 8 , the first convex portion 133 is in a state where the tip in the projecting direction is crushed by the first wall portion 141 . As a result, at least a frictional force that resists the pushing-back force of the adhesive 180 until the adhesive 180 is solidified is generated between the first convex portion 133 and the first wall portion 141 . As a result, the adhesive 180 is solidified while the cover member 130 is stopped at the proper position with respect to the lid 11 , and as a result, the cover member 130 and the lid 11 are appropriately bonded.

As described above, power storage device 1 according to the present embodiment includes exterior body 10 that accommodates power storage element 20 . The exterior body 10 includes a first member (lid 11 ) and a second member (cover member 130 ) attached to the lid 11 so as to close the upper opening 11 a provided in the lid 11 . The lid body 11 has a first wall portion 141 that is disposed on the periphery of the upper opening 11 a and erected along the direction in which the cover member 130 is attached to the lid body 11 . The cover member 130 has a second wall portion 131 erected along the mounting direction and facing the first wall portion 141 . The first wall portion 141 and the second wall portion 131 are such that the first convex portion 133 that protrudes from one of the first wall portion 141 and the second wall portion 131 toward the other contacts the other in the protruding direction. They are fixed to each other via an adhesive 180 in this state. More specifically, in the present embodiment, first convex portion 133 protrudes from second wall portion 131 toward first wall portion 141 . That is, the first wall portion 141 and the second wall portion 131 are fixed to each other via the adhesive 180 in a state where the first convex portion 133 provided on the second wall portion 131 is in contact with the first wall portion 141. It is

According to this configuration, when the cover member 11 is combined with the cover member 130 , the cover member 130 is separated from the cover member 11 by the frictional force between the first convex portion 133 of the second wall portion 131 and the first wall portion 141 . can be temporarily fixed to That is, the cover member 130 is maintained in a state in which it is difficult for the adhesive 180 to push back. Furthermore, while the cover member 130 is temporarily fixed to the lid body 11, the adhesive 180 applied or filled between the first wall portion 141 and the second wall portion 131 is solidified, so that the cover member 130 is permanently fixed to the lid 11 . As a result, the gap between the upper opening 11a of the lid 11 and the cover member 130 closing the upper opening 11a is filled with the adhesive 180 . In addition, since the first convex portion 133 is present between the opposing surfaces of the first wall portion 141 and the second wall portion 131 , a sufficient amount of the adhesive 180 is applied to fix the cover member 130 to the lid body 11 . can be secured between the first wall portion 141 and the second wall portion 131 to accommodate the . Therefore, the lid 11 and the cover member 130 can be firmly joined together, and the airtightness or watertightness of the periphery of the upper opening 11a of the lid 11 can be ensured more reliably. Thus, the power storage device 1 according to this aspect is a power storage device with a simple configuration and improved reliability.

The above effect can be achieved even when the first wall portion 141 is provided with the first convex portion 133 projecting toward the second wall portion 131 . That is, even in this case, the cover member 130 is temporarily fixed to the lid body 11 by the frictional force between the first convex portion 133 and the second wall portion 131, and the adhesive 180 is removed in the temporarily fixed state. By solidifying, the lid body 11 and the cover member 130 are appropriately joined.

Further, in the present embodiment, one of the first wall portion 141 and the second wall portion 131 is a wall portion forming the inner side surface 141a of the groove 140 provided in the lid body 11 or the cover member 130 having the one. be. The other of the first wall portion 141 and the second wall portion 131 is inserted into the groove 140, and the first protrusion 133 is positioned in the projecting direction of the first protrusion 133. It fits into the groove 140 while in contact with the wall portion 131 . More specifically, in the present embodiment, as shown in FIG. 7 , first wall portion 141 is a wall portion that forms inner side surface 141 a of groove 140 provided in lid 11 . Further, the second wall portion 131 is inserted into the groove 140 and the first protrusion 133 is in contact with the first wall portion 141 located in the projecting direction of the first protrusion 133 . is mated with

According to this configuration, the second wall portion 131 of the cover member 130 fits into the groove 140 provided in the lid body 11 . Therefore, a relatively strong fixing force can be obtained when the lid body 11 is temporarily fixed to the cover member 130 . As a result, the lid body 11 can be permanently fixed to the cover member 130 more accurately or more reliably.

The above effect is exhibited even when the groove 140 is provided in the cover member 130 and the second wall portion 131 of the cover member 130 is a wall portion forming the inner side surface 141 a of the groove 140 . That is, the first wall portion 141 erected on the lid body 11 may fit into the groove 140 provided on the cover member 130 . In this case, the first wall portion 141 is such that the first convex portion 133 provided on one of the first wall portion 141 and the second wall portion 131 contacts the other of the first wall portion 141 and the second wall portion 131. In this state, it can be fitted into the groove 140 of the cover member 130 . As a result, the lid body 11 can be permanently fixed to the cover member 130 more accurately or more reliably.

In addition, in the present embodiment, as shown in FIGS. 6 and 7 , power storage device 1 further includes first convex portion 141 or second wall portion 131 in which first convex portion 133 is provided. It has a second protrusion 134 protruding from the surface opposite to 133 . The second protrusion 134 abuts on the inner side surface 142a of the groove 140 located in the projecting direction of the second protrusion 134 . As shown in FIG. 7, the inner side surface 142a is a surface formed by the first wall portion 142 facing the first wall portion 141 and facing the inner side surface 141a. That is, in the present embodiment, the groove 140 into which the second wall portion 131 is fitted is formed by the pair of first wall portions 141 and 142 arranged to face each other in the lid body 11 . Inside the groove 140 thus formed, the second protrusion 134 protrudes from the surface of the second wall portion 131 of the cover member 130 opposite to the first protrusion 133 . It abuts on the inner side surface 142 a of the groove 140 .

According to this configuration, the first convex portion 133 and the second convex portion 134 abut against the inner side surfaces 141a and 142a of the groove 140 facing each other. and a stronger fixing force can be obtained. As a result, the lid body 11 can be permanently fixed to the cover member 130 more accurately or more reliably. In addition, since a space filled with the adhesive 180 is secured on both sides of the second wall portion 131 in the thickness direction, the cover member 130 and the lid body 11 are joined more firmly.

The above effects are also exhibited when the first wall portion 141 erected on the lid body 11 is fitted into the groove 140 provided on the cover member 130 . That is, the first convex portion 133 may be provided on one surface of the first wall portion 141 in the thickness direction, and the second convex portion 134 may be provided on the other surface. Even in this case, the lid body 11 can be permanently fixed to the cover member 130 more accurately or more reliably.

Further, in the present embodiment, when the second convex portion 134 is seen through from the thickness direction of the first wall portion 141 or the second wall portion 131 on which the first convex portion 133 and the second convex portion 134 are provided, It is arranged at a position not overlapping with the first convex portion 133 . More specifically, in the present embodiment, as shown in FIGS. 5 and 6, the first convex portion 133 and the second convex portion 134 are provided on the second wall portion 131, and the first convex portion 133 and second convex portion 134 are arranged at positions shifted in the extending direction of second wall portion 131 .

According to this configuration, when the first convex portion 133 and the second convex portion 134 receive a pressing force from the inner side surfaces 141a and 142a of the groove 140 facing each other, the second wall portion 131 is bent in the thickness direction. An elastic force (restoring force) acts as a force for fixing the cover member 11 to the cover member 130 . As a result, a stronger fixing force can be obtained, so that the lid body 11 can be permanently fixed to the cover member 130 more accurately or more reliably.

The above effects are similarly obtained when the first wall portion 141 provided with the first protrusion 133 and the second protrusion 134 is fitted into the groove 140 provided in the cover member 130 . That is, in the first wall portion 141 , the first convex portion 133 and the second convex portion 134 may be arranged at positions shifted in the extending direction of the first wall portion 141 . In this case, when the first wall portion 141 is fitted in the groove 140 provided in the cover member 130 , the elastic force (restoring force) due to the bending of the first wall portion 141 in the thickness direction is applied to the cover member of the lid body 11 . Acts as a fixing force for 130 .

Further, in the present embodiment, the first convex portion 133 is elongated in the mounting direction of the cover member 130 with respect to the lid body 11 .

According to this configuration, as shown in FIGS. 5 and 6, the first convex portion 133 is a rib elongated in the mounting direction (minus direction of the Z-axis) as the first wall portion 141 or the second wall portion 131 ( In the present embodiment, it is provided on the second wall portion 131). Therefore, while suppressing the dynamic friction between the first convex portion 133 and the first wall portion 141 when the cover member 130 is attached to the lid body 11 , the first contact portion acting as a fixing force of the cover member 130 to the lid body 11 . The pressing force of the convex portion 133 against the first wall portion 141 can be ensured.

(Embodiment 2)
In the first embodiment, the lid 11 of the exterior body 10 is the first member, and the cover member 130 that closes the upper opening 11a of the lid 11 is the second member. explained the structural features of However, such structural features can be employed regardless of the type or function of the first and second members. Therefore, as Embodiment 2, the first member is the exterior body of the exterior body, and the second member is the cover that closes the opening of the exterior body. 9 to 12, focusing on differences from the first embodiment.

[2-1. General description of power storage device]
FIG. 9 is a perspective view showing a schematic configuration of power storage device 201 according to the second embodiment. In FIG. 9 , the lid body 230 is shown separated from the exterior body main body 212 , and the illustration of components such as the busbars, busbar plates, and control board provided in the power storage device 201 is omitted.

As shown in FIG. 9 , power storage device 201 according to the present embodiment includes exterior body 210 and power storage element 20 housed in exterior body 210 . In this embodiment, one storage element unit 224 is configured by four storage elements 20 arranged in the Y-axis direction. Specifically, each of the four power storage elements 20 is arranged in a row in the Y-axis direction with the long side surface 21a of the container 21 directed in the Y-axis direction. As in the first embodiment, there is no particular limitation on the electrical connection mode of these four storage elements 20 .

The exterior body 210 has an exterior body body 212 that accommodates the power storage element unit 224 and a lid body 230 that closes an opening (body opening 215) of the exterior body body 212 . The exterior body main body 212 and the lid body 230 are made of resin such as PC, PP, PE, or PS, like the exterior body 10 according to the first embodiment. An external terminal 291 on the positive electrode side and an external terminal 292 on the negative electrode side are arranged on the cover 230, and the external terminals 291 and 292 are accommodated in the exterior main body 212 via a bus bar or the like (not shown). It is electrically connected to the storage element unit 224 .

As described above, power storage device 201 according to the present embodiment includes exterior body 210 that accommodates a plurality of energy storage elements 20, and exterior body 210 includes exterior body main body 212 and lid body 230. This is common with the power storage device 1 according to the first embodiment. However, the structure employed in the joint portion between lid body 11 and cover member 130 in Embodiment 1 is employed in the joint portion between exterior main body 212 and lid body 230 in the present embodiment. , differs from the first embodiment in this respect. That is, in the present embodiment, the exterior main body 212 is an example of the first member, and the lid 230 that closes the opening (main body opening 215) of the exterior main body 212 is an example of the second member. A joint portion between the exterior body main body 212 and the lid body 230 according to the present embodiment will be described below.

[2-2. Regarding the junction between the main body of the exterior body and the lid body]
FIG. 10 is a perspective cross-sectional view of lid body 230 according to the second embodiment. FIG. 10 shows a part of the cross section of the lid 230 on the YZ plane passing through line XX in FIG. FIG. 11 is a perspective cross-sectional view of the lid body 230 viewed from an angle different from that of FIG. The position of the cross section in FIG. 11 is the same as the position of the cross section shown in FIG. FIG. 12 is a perspective cross-sectional view showing a joint portion between exterior body main body 212 and lid body 230 according to the second embodiment.

As shown in FIG. 9 and FIGS. 10 to 12, the lid 230 is a member attached to the exterior main body 212 from above. As shown in FIGS. 9 and 12, the exterior main body 212 has a first wall portion 216 provided along the periphery of the main body opening 215 . The lid 230 has a second wall portion 231a, as shown in FIGS. Specifically, the second wall portion 231a is a wall portion that forms an inner side surface 241a of the groove 240 into which the first wall portion 216 of the exterior main body 212 is inserted. The first wall portion 216 of the exterior main body 212 and the second wall portion 231a of the lid 230 are both erected along the mounting direction (Z-axis direction) of one of the lid 230 and the exterior body 212 with respect to the other. ing. The first wall portion 216 and the second wall portion 231a are arranged in positions and postures facing each other when the lid body 230 is attached to the exterior body main body 212 .

The lid body 230 and the exterior body main body 212 configured in this manner are joined with an adhesive 180 as shown in FIG. 12 . For example, the adhesive 180 is poured into the groove 240 with the opening of the groove 240 facing upward by turning the cover 230 upside down. Further, the first wall portion 216 of the exterior main body 212 is inserted into the groove 240 of the lid 230 from above the groove 240 . After that, the adhesive 180 is solidified, so that the lid body 230 and the exterior body main body 212 are joined. Until the adhesive 180 is solidified, the adhesive 180 exerts an upward force on the exterior main body 212 . Therefore, lid body 230 and exterior body main body 212 according to the present embodiment are configured so as not to be pushed back by adhesive 180 .

Specifically, in the present embodiment, for example, as shown in FIG. 10, the second wall portion 231a of the lid 230 is provided with the first convex portion 233a. The first convex portion 233 a abuts on the first wall portion 216 of the exterior body main body 212 in a state where the lid 230 is attached to the exterior body body 212 . Specifically, when the first wall portion 216 is inserted into the groove 240, the first convex portion 233a is pressed against the first wall portion 216 at its tip in the projecting direction, as shown in FIG. It will be in a state where it has been applied. As a result, at least a frictional force that resists the pushing-back force of the adhesive 180 until the adhesive 180 is solidified is generated between the first convex portion 233a and the first wall portion 216 . As a result, the adhesive 180 is solidified while the exterior body main body 212 is stopped at the proper position with respect to the lid body 230 , and as a result, the lid body 230 and the exterior body body 212 are appropriately joined.

Thus, power storage device 201 according to the present embodiment includes exterior body 210 that accommodates power storage element 20 . The exterior body 210 includes a first member (the exterior body main body 212) and a second member (the lid body 230) attached to the exterior body body 212 so as to close the body opening 215 provided in the exterior body body 212. Prepare. The exterior body main body 212 has a first wall portion 216 that is disposed on the periphery of the body opening 215 and erected along the mounting direction of the lid body 230 with respect to the exterior body body 212 . The lid body 230 has a second wall portion 231 a erected along the mounting direction and facing the first wall portion 216 . The first wall portion 216 and the second wall portion 231a are such that the first convex portion 233a that protrudes from one of the first wall portion 216 and the second wall portion 231a toward the other contacts the other in the protruding direction. They are fixed to each other via an adhesive 180 in this state. More specifically, in the present embodiment, the first convex portion 233a protrudes toward the first wall portion 216 on the second wall portion 231a. That is, the first wall portion 216 and the second wall portion 231a are fixed to each other via the adhesive 180 in a state in which the first convex portion 233a provided on the second wall portion 231a is in contact with the first wall portion 216. It is

As described above, the joint portion between the exterior body main body 212 and the lid body 230 according to the present embodiment has features in common with the joint portion between the lid body 11 and the cover member 130 according to the first embodiment. . Therefore, the gap between the body opening 215 of the exterior body body 212 and the lid body 230 closing the body opening 215 is more reliably filled with the adhesive 180 . In addition, since the first convex portion 233a is present between the mutually facing surfaces of the first wall portion 216 and the second wall portion 231a, a sufficient amount of adhesive is used to fix the lid body 230 to the exterior body main body 212. 180 can be secured between the first wall portion 216 and the second wall portion 231a. Therefore, for example, airtightness or watertightness at the periphery of the body opening 215 of the exterior body body 212 can be ensured more reliably. Thus, the power storage device 201 according to this aspect is a power storage device with a simple configuration and improved reliability.

It is also conceivable to provide engagement structures such as projections 149 and engagement portions 139 (see FIGS. 3 and 5) for the exterior body main body 212 and lid body 230 according to the second embodiment. However, in this case, in order to stably temporarily fix one of the exterior body main body 212 and the lid body 230 to the other, it is necessary to arrange a plurality of sets of projections and engaging portions, and each of these must be It is necessary to engage with high precision at the regular position. Therefore, high precision is required for the positions and shapes of these projections and engaging portions. Regarding this point, in the present embodiment, by bringing the first convex portion 233a projecting toward the first wall portion 216 into contact with the first wall portion 216, one of the exterior body main body 212 and the lid body 230 is moved. temporarily fixed to the other. Therefore, such high accuracy as described above is not required for the position of the first convex portion 233a. Specifically, for example, as shown in FIG. 10, in the present embodiment, a plurality of first protrusions 233a are arranged dispersedly in the X-axis direction on the second wall portion 231a extending in the X-axis direction. ing. In this structure, even if the positions of the plurality of first protrusions 233a in the X-axis direction or the Z-axis direction are slightly deviated from the designed positions, each of the plurality of first protrusions 233a It can abut on one wall portion 216 . That is, one of the exterior body main body 212 and the lid body 230 can be stably and temporarily fixed to the other by the plurality of first protrusions 233a. That is, in the present embodiment, the temporary fixation is achieved by the frictional force in the mounting direction, not by the engagement between the exterior body main body 212 and the lid body 230 in the mounting direction. Therefore, for example, the position of the first protrusion 233a in the direction orthogonal to the projecting direction of the first protrusion 233a does not require as high precision as the engagement structure. This is advantageous from the viewpoint of efficient manufacture of power storage devices with improved reliability.

Further, in the present embodiment, one of the first wall portion 216 and the second wall portion 231a is a wall portion that forms the inner side surface 241a of the groove 240 provided in the exterior main body 212 or the lid body 230 having the one. is. The other of the first wall portion 216 and the second wall portion 231a is inserted into the groove 240, and the first protrusion 233a is positioned in the projecting direction of the first protrusion 233a. It fits into the groove 240 while being in contact with the wall portion 231a. More specifically, in the present embodiment, second wall portion 231a is a wall portion that forms inner side surface 241a of groove 240 provided in lid body 230, as shown in FIG. The first wall portion 216 is inserted into the groove 240 and fitted with the groove 240 in a state in which the first protrusion 233a is in contact with the first wall portion 216 located in the projecting direction of the first protrusion 233a. are in agreement.

11, a second wall portion 231b forming an inner side surface 241b of the groove 240 is arranged at a position facing the second wall portion 231a in the lid body 230. The wall portion 231b has a first convex portion 233b projecting toward the first wall portion 216 . The second wall portion 231 b is fixed to the first wall portion 216 via the adhesive 180 while the first convex portion 233 b is in contact with the first wall portion 216 . In this embodiment, the first protrusions 233a and 233b are arranged at the same position in the extending direction of the groove 240 (the X-axis direction in FIGS. 10 to 12). In other words, the first convex portions 233a and 233b are arranged to face each other in their projecting directions, and are arranged so as to sandwich the first wall portion 216 from both sides in the thickness direction. As a result, the first wall portion 216 is temporarily fixed more reliably by the pair of first convex portions 233a and 233b, and spaces filled with the adhesive 180 are formed on both sides of the first wall portion 216 in the thickness direction. Secured. Therefore, the pushing back of the exterior body 212 by the adhesive 180 in the manufacturing process is more reliably suppressed, and the lid 230 and the exterior body 212 are joined more firmly.

Moreover, each of the first protrusions 233 a and 233 b according to the present embodiment is formed in an elongated shape in the mounting direction of the lid body 230 with respect to the exterior body main body 212 . Therefore, dynamic friction between the first convex portions 233a and 233b and the first wall portion 216 is suppressed when the lid body 230 is attached to the exterior body main body 212 .

(Other embodiments)
The power storage device according to the present invention has been described above based on the embodiment. However, the present invention is not limited to the above embodiments. As long as they do not deviate from the gist of the present invention, various modifications conceived by those skilled in the art are also included in the scope of the present invention.

For example, in Embodiments 1 and 2, one of the first member and the second member has a groove in which the wall portion of the other is inserted, and the wall portion and the other member are joined by the adhesive 180. there is However, both the first member and the second member need not have grooves. For example, in Embodiment 1, the first wall portion 142 (see FIG. 7) arranged to face the first wall portion 141 may be omitted. Even in this case, in the second wall portion 131 of the cover member 130, the first convex portion 133 protruding toward the first wall portion 141 abuts against the first wall portion 141, thereby Pushing back of the cover member 130 by 180 is suppressed. Furthermore, a space for accommodating a sufficient amount of the adhesive 180 for fixing the cover member 130 to the lid 11 can be secured between the second wall portion 131 and the first wall portion 141 .

Moreover, the first member and the second member that are joined by the joining structure illustrated in FIG. 8 or FIG. . For example, when the exterior body 12 includes a member (for example, referred to as an “inner lid”) that separates the space in which the power storage element unit 24 is accommodated from other spaces, the exterior body 12 as the first member, For example, the joining structure shown in FIG. 8 or FIG. 12 may be adopted for joining with the inner lid, which is the second member.

Moreover, the shape of the exterior body 10 does not need to be substantially rectangular parallelepiped (box-like). For example, when joining a cylindrical exterior body with one end closed to an exterior body configured by a lid that is circular in plan view and closes the circular opening, for example, as shown in FIG. 8 or FIG. Bonded structures may be employed.

In addition, the supplementary matters regarding the power storage device 1 and the exterior body 10 according to the first embodiment may be applied to the power storage device 201 and the exterior body 210 according to the second embodiment. Moreover, the form constructed by arbitrarily combining the plurality of components described above is 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.

Reference Signs List 1, 201 power storage device 10, 210 exterior body 11, 230 lid body 11a top opening 12, 212 exterior body body 15, 215 body opening 20 storage element 130 cover member 131, 231a, 231b second wall 133, 233a, 233b first protrusion 134 second protrusion 140, 240 groove 141, 142, 216 first wall 141a, 142a, 241a, 241b inner surface 180 adhesive

Claims (5)

A power storage device including an exterior body that houses a power storage element,
The exterior body includes a first member and a second member attached to the first member so as to block an opening provided in the first member,
The first member has a first wall portion arranged on the periphery of the opening and erected along the mounting direction of the second member with respect to the first member,
The second member has a second wall portion erected along the mounting direction and facing the first wall portion,
In the first wall portion and the second wall portion, a first convex portion protruding from one of the first wall portion and the second wall portion toward the other contacts the other in the protruding direction. are fixed to each other via an adhesive,
storage device. one of the first wall portion and the second wall portion is a wall portion forming an inner surface of a groove provided in the first member or the second member having the one;
The other of the first wall portion and the second wall portion is inserted into the groove, and the first protrusion is located in the projecting direction of the first protrusion or the first wall portion. It is fitted with the groove while in contact with the two wall portions,
The power storage device according to claim 1 . Further, the first wall or the second wall provided with the first protrusion has a second protrusion protruding on a surface opposite to the first protrusion,
The second protrusion is in contact with the inner surface of the groove located in the projecting direction of the second protrusion.
The power storage device according to claim 2 . The second convex portion does not overlap the first convex portion when seen through from the thickness direction of the first wall portion or the second wall portion on which the first convex portion and the second convex portion are provided. placed in position,
The power storage device according to claim 3 . The first convex portion is formed in an elongated shape in the mounting direction,
The power storage device according to any one of claims 1 to 4.

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