WO2022158552A1

WO2022158552A1 - Power storage device

Info

Publication number: WO2022158552A1
Application number: PCT/JP2022/002105
Authority: WO
Inventors: 一弥岡部; 良一奥山
Original assignee: 株式会社Ｇｓユアサ
Priority date: 2021-01-25
Filing date: 2022-01-21
Publication date: 2022-07-28
Also published as: JPWO2022158552A1

Abstract

This power storage device is equipped with: an outer body; a plurality of power storage elements which are arranged in a second direction perpendicular to a first direction in an orientation in which the gas discharge valve of each faces the first direction; and a gas diffusion member. The gas diffusion member is a metal plate-shaped member positioned so as to face the gas discharge valves of the plurality of power storage elements. The gas diffusion member is positioned: in a location between the plurality of power storage elements and a lid, which is another member positioned in a location facing the plurality of power storage elements in the first direction; and in a location which is separated from each of the plurality of power storage elements and from the lid. The gas diffusion member is formed in a shape and size which permit the passage of a gas in the first direction both to the side of the gas diffusion member in the second direction and to the side of the gas diffusion member in a third direction which intersects the first and second directions.

Description

power storage device

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

Patent Document 1 discloses a battery pack (power storage device) that includes a battery stack having a plurality of cells (power storage elements) and a case (enclosure) that houses the battery stack. In this power storage device, each power storage element has a gas discharge valve configured to discharge internal gas to the outside when the internal pressure increases. A metal plate member is attached to the inner surface of the upper case, which is the lid member of the exterior body, by means of fasteners such as bolts, at a position overlapping each gas discharge valve in a plan view. This prevents the high-temperature gas that is vigorously discharged from the gas discharge valve from hitting the lid directly.

JP 2019-197622 A

In the above-described conventional power storage device, for example, the heat of the gas is easily transmitted to the resin lid via the metal plate. may occur. When a portion of the exterior body is weakened or melted, gas may flow out from an unexpected position of the exterior body, or the exterior body may be destroyed due to the internal pressure of the gas. In other words, the state of the power storage device may further deteriorate.

SUMMARY OF THE INVENTION The present invention was made by the inventors of the present invention by newly paying attention to the above problem, and an object of the present invention is to provide a power storage device capable of suppressing further deterioration of the state when an unsafe event occurs. and

A power storage device according to an aspect of the present invention includes: an exterior body; and a metal plate-like gas diffusion member arranged to face the gas discharge valves of the plurality of storage elements, wherein the gas diffusion member extends in the first direction. A position between another member arranged at a position facing the plurality of power storage elements and the plurality of power storage elements and a position spaced apart from each of the plurality of power storage elements and the other member and the passage of gas in the first direction on both sides of the gas diffusion member in the second direction and in a third direction crossing the first direction and the second direction. It is shaped and sized to allow

According to the power storage device of the present invention, it is possible to suppress further deterioration of the state when an unsafe event occurs.

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 showing a schematic configuration of the power storage device according to the embodiment. FIG. 3 is an exploded perspective view showing an overview of the configuration of the storage device according to the embodiment. FIG. 4 is a perspective view showing the configuration of the gas diffusion member and its surroundings according to the embodiment. FIG. 5 is a first cross-sectional view of the power storage device according to the embodiment. FIG. 6 is a second cross-sectional view of the power storage device according to the embodiment. FIG. 7 is a cross-sectional view of a power storage device according to Modification 1 of the embodiment. FIG. 8 is a cross-sectional view of a power storage device according to Modification 2 of the embodiment. FIG. 9 is a cross-sectional view of a power storage device according to Modification 3 of the embodiment.

According to this configuration, for example, when one electric storage element opens, the gas ejected from the gas discharge valve collides with the gas diffusion member to disperse the pressure and lower the temperature. In addition, the gas diffusion member is arranged apart from other members (such as the lid of the exterior body) arranged on the first direction side of the plurality of power storage elements. Therefore, the heat of the gas diffusion member made of metal with high thermal conductivity is less likely to be transmitted to the other member. Therefore, the heat of the gas reduces the possibility that other members made of resin or the like will be weakened or melted. Further, the gas ejected in the first direction and colliding with the gas diffusion member detours from at least both the second direction side and the third direction side of the gas diffusion member, It can spread in space on the direction side. Thereby, for example, the internal space of the exterior body can be widely used to diffuse the gas, and as a result, the pressure and temperature of the gas can be rapidly lowered. As described above, according to the power storage device of this aspect, it is possible to suppress further deterioration of the state when an unsafe event occurs.

The gas diffusion member may be formed with a plurality of through holes penetrating in the first direction.

According to this configuration, part of the gas that has collided with the gas diffusion member can penetrate the gas diffusion member. That is, since the flow direction of the gas that collides with the gas diffusion member increases, the pressure of the gas is efficiently dispersed, and the temperature of the gas is also efficiently lowered.

The power storage device further includes a busbar holder that holds a busbar disposed on the first direction side of the plurality of power storage elements and electrically connected to the plurality of power storage elements, wherein the busbar holder supports the gas diffusion. It is also possible to have a supporting portion that supports the member while being separated from the plurality of power storage elements and the other member.

According to this configuration, the gas diffusion member can be supported by the busbar holder required for holding the busbar, etc., so there is no need to newly provide a dedicated member for arranging the gas diffusion member at a predetermined position.

The exterior body has an exterior body body that houses the plurality of power storage elements, and a lid body that closes an opening of the exterior body body. It is also possible to have a supporting portion that supports the device in a suspended manner while being spaced apart from the other member.

According to this configuration, the gas diffusion member can be supported by the lid of the exterior body, so there is no need to newly provide a dedicated member for arranging the gas diffusion member at a predetermined position.

The exterior body has an exhaust port for discharging the gas inside the exterior body to the outside, and the gas diffusion member is located between the gas exhaust valve and the exhaust port in the first direction. It may be arranged at a position.

According to this configuration, the gas ejected from the gas discharge valve in the first direction and diffused by the gas diffusion member is discharged from the opening located on the first direction side of the gas diffusion member to the outside of the exterior body. discharged to That is, the gas ejected from at least one gas exhaust valve and having its pressure (flow velocity) and temperature lowered by the gas diffusion member is efficiently exhausted to the outside of the exterior body.

Power storage devices according to embodiments (including modifications) of the present invention 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 of constituent elements, connection forms, 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 the following description and drawings, the direction in which a plurality of power storage elements are arranged, the direction in which the long sides of the container of the power storage elements face each other, or the thickness direction of the container is defined as the X-axis direction (except for Modification 3). The direction in which the electrode terminals of one storage element are arranged or the direction in which the short sides of the container of the storage element face each other is defined as the Y-axis direction (excluding Modifications 2 and 3). The direction in which the exterior main body and the lid are arranged in the exterior of the power storage device, 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 intersect each other (hereinafter, orthogonally in the 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 embodiments, expressions indicating relative directions or orientations such as parallel and orthogonal may be used, but strictly speaking, these expressions also include cases where the directions or orientations are not the same. 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 In the following description, for example, the positive direction of the X-axis indicates the arrow direction of the X-axis, and the negative direction of the X-axis indicates the direction opposite to the positive direction of the X-axis. The same applies to the Y-axis direction and the Z-axis direction. Furthermore, 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.

(Embodiment)
[1. General description of power storage device]
First, a general description of a power storage device 1 according to an embodiment will be given with reference to FIGS. 1 and 2. FIG. 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 showing a schematic configuration of the power storage device 1 according to the embodiment. FIG. 3 is an exploded perspective view showing a schematic configuration of the storage device 20 according to the 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. For example, the power storage device 1 is 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. Electric trains, monorails, and maglev trains are exemplified as railway vehicles for the electric railway. Moreover, the power storage device 1 can also be used as a stationary battery or the like for home use or business use.

As shown in FIGS. 1 and 2 , the power storage device 1 includes a plurality of power storage elements 20 and an exterior body 10 that accommodates the plurality of power storage elements 20 . In the present embodiment, exterior body 10 accommodates eight power storage elements 20 . 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 two or more power storage elements 20 . In this embodiment, one storage element unit 28 is configured by a plurality of storage elements 20 arranged in the X-axis direction. The storage element unit 28 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 power storage element unit 28 and a lid body 11 that closes an opening of the exterior body body 12 (body opening 15). Inside the exterior body 10 , a busbar holder 17 is arranged between the storage element unit 28 accommodated in the exterior body main body 12 and the lid body 11 . A plurality of busbars 33 are held in the busbar holder 17 . Between the busbar holder 17 and the lid body 11, electrical devices such as a control circuit and a relay, electric wires, and the like may be arranged, but illustrations and descriptions thereof are omitted.

The exterior body 10 is a rectangular (box-shaped) container (module case) that constitutes the outer shell of the power storage device 1 . In other words, the exterior body 10 is a member that fixes the electric storage element unit 28, the busbar holder 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 lid 11 of the exterior body 10 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 busbars 33, and the power storage device 1 is charged with electricity from the outside via the

external terminals

91 and 92, and Discharge 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 exterior body 12 included in the exterior body 10 is a bottomed rectangular cylindrical housing in which a body opening 15 for accommodating the power storage element unit 28 is formed. The exterior body main body 12 has a pair of wall portions 14 facing each other in the X-axis direction and a pair of wall portions 13 facing each other in the Y-axis direction. A body opening 15 is formed by the upper ends of these four walls. The main body opening 15 and the lid 11 are joined without a gap by, for example, heat welding, bonding with an adhesive, or fastening with a gasket interposed.

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. . The storage element 20 may be a secondary battery other than a non-aqueous electrolyte secondary battery, or may be a capacitor. The storage element 20 may be a primary battery that allows the stored electricity to be used without being charged by the user. The storage element 20 may be a battery using a solid electrolyte. The storage element 20 may be a pouch-type storage element.

In the present embodiment, the storage element 20 includes a flat rectangular parallelepiped (square) metal container 21 . The container 21 has a rectangular shape having a pair of long side surfaces 21a facing each other, a pair of short side surfaces 21b facing each other, and a terminal arrangement surface 21c connected to upper ends of the pair of long side surfaces 21a and the pair of short side surfaces 21b. is the case. Specifically, as shown in FIG. 3, the container 21 has a container body 25 and a cover plate 24 that closes the opening of the container body 25. 21a and a pair of short sides 21b are formed. The upper surface of the cover plate 24 forms a terminal arrangement surface 21c. The container main body 25 accommodates an electrode body 26, current collectors 27 on the positive electrode side and the negative electrode side, and an electrolytic solution (not shown). 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).

The electrode body 26 in the present embodiment is a wound electrode body formed by winding electrode plates (a positive electrode plate and a negative electrode plate) with separators interposed therebetween. Both ends of the electrode body 26 in the winding axis direction (Y-axis direction) are joined to leg portions of the current collector 27 . The electrode body provided in the storage element 20 is not limited to the wound type. For example, the storage element 20 is provided with a laminated electrode body in which flat plate-shaped electrode plates are laminated, or an electrode body having a structure in which long strip-shaped electrode plates are laminated in a bellows shape by repeating mountain folds and valley folds. may be When electric storage element 20 includes a wound electrode body, the posture of the electrode body does not need to be such that the winding axis direction is parallel to the Y-axis direction (the direction in which the pair of short side surfaces 21b face each other). For example, the electrode body may be provided on the storage element 20 in a posture in which the winding axis direction is parallel to the Z-axis direction (longitudinal direction of the short side surface 21b).

Metal electrode terminals 22 (a positive electrode terminal and a negative electrode terminal) electrically connected to the electrode body 26 inside the container body 25 via the current collector 27 are arranged on the terminal arrangement surface 21c of the cover plate 24. ing. The electrode terminal 22 is fixed to the cover plate 24 via a resin gasket (not shown), for example. A lid plate 24 of the container 21 is further provided with a gas discharge valve 23 for discharging the gas inside the container 21 to the outside. For example, when the internal pressure of the container 21 rises due to the vaporization of the electrolytic solution inside the container 21, the gas discharge valve 23 is opened (opened) to discharge the gas inside the container 21 to the outside of the container 21. It has the function to More specifically, when the gas exhaust valve 23 receives internal pressure and is broken, deformed, or the like, an opening (exhaust port) is formed in the cover plate 24 at the position of the gas exhaust valve 23, and the gas is discharged from this exhaust port. be done. Therefore, the formation of an exhaust port due to breakage of the gas exhaust valve 23 is expressed as, for example, "the gas exhaust valve 23 (or the storage element 20) opens". Further, the discharge of gas from this exhaust port is expressed as, for example, "gas is discharged from the gas discharge valve 23 (or the storage element 20)".

In the present embodiment, the gas discharge valve 23 of each of the plurality of power storage elements 20 is oriented in the Z-axis plus direction, which is an example of the first direction. The X-axis direction, which is the direction in which the plurality of storage elements 20 are arranged, is an example of a second direction that intersects the first direction, and the Y-axis direction is an example of a third direction that intersects the first direction and the second direction. be.

Other members (not shown) such as insulating sheets and spacers may be arranged inside the container 21 . In the present embodiment, the rectangular parallelepiped (square) power storage element 20 is illustrated, but the shape of the power storage element 20 is not limited to the rectangular parallelepiped shape, and may be a polygonal prism shape or the like other than the rectangular parallelepiped shape. .

The busbar 33 is a rectangular plate-shaped member that is placed on at least two storage elements 20 while being held by the busbar holder 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, and may be formed of, for example, a metal such as aluminum, an aluminum alloy, copper, a copper alloy, a combination thereof, or a conductive member other than metal. In the present embodiment, five bus bars 33 are used to connect the energy storage elements 20 two by two in parallel to form four groups of energy storage elements 20, and the four groups of energy storage elements 20 are connected in series. Connected. The manner of electrical connection of the eight storage elements 20 is not particularly limited, and for example, all the eight storage elements 20 may be connected in series.

The busbar holder 17 is a resin member that holds the busbar 33 . As the resin material for forming the busbar holder 17, PC, PP, PE, PS, PPS, or the like is adopted as in the exterior body 10. FIG. In this embodiment, the busbar holder 17 also serves to support the gas diffusion member 50, which will be described later. The busbar holder 17 is provided with a plurality of busbar openings 17 a that hold the plurality of busbars 33 and expose a portion of each of the plurality of busbars 33 toward the plurality of power storage elements 20 .

The busbar holder 17 is further provided with an elongated exhaust opening 18 in the direction in which the plurality of storage elements 20 are arranged. The exhaust opening 18 is arranged in the power storage element unit 28 at a position facing the plurality of gas exhaust valves 23 arranged in the alignment direction. The gas discharged from these gas discharge valves 23 can pass through the busbar holder 17 in the Z-axis plus direction via the discharge opening 18 .

In the power storage device 1 according to the present embodiment, a gas diffusion member 50 for diffusing the gas ejected from the gas discharge valves 23 when the gas discharge valves 23 are opened is provided at a position facing the plurality of gas discharge valves 23 . are placed. Specifically, in the present embodiment, a plurality of support portions 19 are arranged around the exhaust opening 18 in the busbar holder 17, and the gas diffusion member 50 is supported by the plurality of support portions 19. there is Thereby, the gas diffusion member 50 is arranged at a position separated from both the storage element unit 28 and the lid 11 in the Z-axis direction. That is, the gas traveling in the positive direction of the Z axis through the exhaust opening 18 is diffused in various directions by the gas diffusion member 50 disposed ahead. After that, the gas is discharged to the outside of the exterior body 10 through the exhaust pipe 120 provided in the lid body 11 . This prevents the state of the power storage device 1 from further deteriorating when the power storage element 20 opens due to some kind of abnormality. The configuration of the gas diffusion member 50 and its surroundings according to the embodiment will be described below with reference to FIGS. 4 to 6. FIG.

[2. Configuration of Gas Diffusion Member and its Periphery]
FIG. 4 is a perspective view showing the configuration of the gas diffusion member 50 and its surroundings according to the embodiment. In FIG. 4, only the lid 11, the gas diffusion member 50, and the electric storage element unit 28 are illustrated, and each of them is illustrated separated in the Z-axis direction. Each of the hollow arrows and dotted arrows illustrated in FIG. 4 and subsequent figures schematically indicates the flow of the gas. FIG. 5 is a first cross-sectional view of power storage device 1 according to the embodiment, and FIG. 6 is a second cross-sectional view of power storage device 1 according to the embodiment. FIG. 5 simply illustrates a cross section of the power storage device 1 in the YZ plane passing through the IV-IV line in FIG. FIG. 6 simply illustrates a cross section of the power storage device 1 on the XZ plane passing through the VV line in FIG. 5 and 6 show the external shape of the storage element 20 when viewed from the X-axis direction or the Y-axis direction, and the approximate existence range of the gas discharge valve 23 is represented by a hatched rectangle. ing.

As shown in FIGS. 4 to 6, the power storage device 1 according to the present embodiment includes a gas diffusion member 50 at a position facing the power storage element unit 28 having a plurality of power storage elements 20 . The gas diffusion members 50 are plate-shaped members made of metal, and are arranged side by side in the X-axis direction when viewed from the Z-axis positive direction (planar view) with the thickness direction facing the power storage element unit 28 . It is arranged at a position covering the plurality of gas discharge valves 23 . Metals forming the gas diffusion member 50 include iron, stainless steel, aluminum, and aluminum alloys. Therefore, the gas diffusion member 50 is not melted by the high-temperature (for example, about 400°) gas ejected from the gas discharge valve 23 when the valve is opened.

More specifically, the size and shape of the gas diffusion member 50 in plan view cover the plurality of gas discharge valves 23 and cover the storage element units 28 in the X-axis direction and the Y-axis direction. It has a size and shape that partially exposes. In the present embodiment, the gas diffusion member 50 is a rectangular member in plan view, but the shape in plan view may be a polygonal shape other than a rectangle, an elliptical shape, an oval shape, or the like. The position of the gas diffusion member 50 in the Z-axis direction is, as shown in FIGS. It is a position spaced apart from both. In other words, spaces in which the gas can move are formed in the vertical direction (Z-axis direction) and sideways (directions parallel to the XY plane) of the gas diffusion member 50 . That is, when the Z-axis plus direction, the X-axis direction, and the Y-axis direction are expressed in this order as a first direction, a second direction, and a third direction, the basic The configuration is described as follows.

The power storage device 1 is housed in the exterior body 10 and the exterior body 10, each of which faces the first direction (Z-axis plus direction) with the gas discharge valve 23 facing in the second direction (X and a gas diffusion member 50 . The gas diffusion member 50 is a plate-like member made of metal arranged to face the gas discharge valves 23 of the plurality of power storage elements 20 . The gas diffusion member 50 is positioned between the plurality of storage elements 20 and the lid 11 , which is another member arranged at a position facing the plurality of storage elements 20 in the first direction, and is located between the plurality of storage elements 20 . 20 and lid body 11, respectively. The gas diffusion member 50 extends in the first direction both on the side of the gas diffusion member 50 in the second direction and on the side in the third direction (Y-axis direction) intersecting the first direction and the second direction. It is shaped and sized to allow the passage of gas.

In the power storage device 1 configured as described above, for example, when one power storage element 20 is opened, the gas ejected from the gas discharge valve 23 of the power storage element 20 collides with the gas diffusion member 50 to disperse the pressure. and its temperature drops. In addition, the gas diffusion member 50 is arranged apart from other members (cover 11 in the present embodiment) arranged on the first direction side of the plurality of power storage elements 20 . Therefore, the heat of the gas diffusion member 50 made of metal with high thermal conductivity is less likely to be transmitted to the lid body 11 . Therefore, the heat of the gas reduces the possibility that the strength of the lid 11 made of resin or the like is reduced or melted. Furthermore, the gas ejected in the first direction and colliding with the gas diffusion member 50 detours from at least the sides of the gas diffusion member 50 (both sides of the second direction and the third direction), and the gas diffuses. It can spread in the space on the first direction side of the member 50 . That is, the gas diffusion member 50 is not arranged so as to partition (partition) the space inside the exterior body 10 . The gas diffusion member 50 is formed in a shape and size that forms a space serving as a gas flow path on its side so that the gas that collides with the gas diffusion member 50 spreads over the gas diffusion member 50 . Thereby, for example, the internal space of the exterior body 10 can be widely used to diffuse the gas, and as a result, the pressure and temperature of the gas can be rapidly lowered. As described above, according to power storage device 1 of the present embodiment, it is possible to suppress further deterioration of the state when an unsafe event occurs.

The distance between the storage element 20 (more specifically, the gas discharge valve 23) and the gas diffusion member 50 in the first direction is set to suppress interference between the gas discharge valve 23 and the gas diffusion member 50 when the valve is open. , is preferably larger than half of the maximum outer dimension of the gas discharge valve 23 in plan view (the radius in the case of a circle). More preferably, the distance is larger than the maximum outer dimension (diameter in the case of a circle) of the gas exhaust valve 23 .

The distance between the gas diffusion member 50 and another member (lid 11) in the first direction is preferably, for example, 1 mm or more in order to suppress heat conduction from the gas diffusion member 50 to the lid 11. More preferably, it is 5 mm or more.

When a temperature sensor (for example, a thermistor) for monitoring the state of the power storage device 1 is arranged in the power storage device 1 , the temperature sensor may be arranged in contact with the gas diffusion member 50 . As a result, the gas diffusion member 50, which is made of metal and has high thermal conductivity, can be used to quickly detect a temperature rise when the valve is opened. The arrangement position of the gas diffusion member 50 is preferably the central portion of the gas diffusion member 50 in plan view. As a result, for example, with one temperature sensor, it is possible to quickly detect a temperature rise in a wide range of one or more storage elements 20 when the valves are opened. This is advantageous, for example, in simplifying the configuration of the power storage device 1 or reducing the manufacturing cost of the power storage device 1 .

The gas diffusion member 50 according to the present embodiment is configured so that part of the gas that collides with the gas diffusion member 50 penetrates in the collision direction. Specifically, the gas diffusion member 50 is formed with a plurality of through holes 51 penetrating in the first direction. That is, as shown in FIGS. 4 to 6, the plate-like gas diffusion member 50 has a plurality of through-holes 51 penetrating in its thickness direction.

As a result, part of the gas that has collided with the gas diffusion member 50 can pass through the gas diffusion member 50 . As a result, the flow direction of the gas that collides with the gas diffusion member 50 increases. Specifically, as shown in FIGS. 4 to 6, the gas that has collided with the gas diffusion member 50 not only detours around the side of the gas diffusion member 50 and crosses the gas diffusion member 50, but also passes through the gas diffusion member 50 in the collision direction. The gas diffusion member 50 can be crossed by penetrating the diffusion member 50 . Since the gas diffusion member 50 is spaced apart from the lid 11 which is another member located directly above it, the gas that has passed over the gas diffusion member 50 is at least transmitted through the gas diffusion member 50 and the lid 11 . diffuse in the space between Therefore, the pressure of the gas ejected from the gas discharge valve 23 of the electric storage element 20 is efficiently dispersed, and the temperature of the gas is also efficiently lowered. Therefore, the possibility that the lid 11 is deformed or damaged by the heat or pressure of the gas is reduced. The plurality of through-holes 51 allow the gas diffusion member 50 to release pressure from the gas ejected from the gas discharge valve 23 , thereby suppressing deformation or damage of the gas diffusion member 50 due to the pressure of the gas. Therefore, for example, a relatively thin (low-rigidity) metal plate can be used as the base material of the gas diffusion member 50 , thereby reducing the weight of the power storage device 1 .

The shape and size of the through hole 51 are not limited to a specific shape and size. Each of the plurality of through-holes 51 may be, for example, a circular hole with an inner diameter of about 1 to 5 mm, or a hole of any shape with a maximum inner dimension of 1 mm or less. The shape and size of the plurality of through holes 51 may not be uniform, and at least one of the shape and size may be random. The gas diffusion member 50 having a plurality of through-holes 51 does not need to be a plate-like metal plate with a plurality of through-holes 51 arranged in a matrix as shown in FIGS. For example, a plate-shaped metal net or steel wool may be employed as the gas diffusion member 50 having a plurality of through-holes 51 .

In this embodiment, the power storage device 1 includes a busbar holder 17 that holds a busbar 33 that is arranged on the first direction side of the plurality of power storage elements 20 and electrically connected to the plurality of power storage elements 20 . The busbar holder 17 has a support portion 19 that supports the gas diffusion member 50 while being separated from the plurality of power storage elements 20 and the lid body 11 . More specifically, the busbar holder 17 has four support portions 19 distributed around the exhaust opening 18, and these four support portions 19 support the gas diffusion member 50 at four points. Support.

According to this configuration, since the gas diffusion member 50 can be supported by the busbar holder 17 required for holding the busbar 33, etc., a dedicated member for arranging the gas diffusion member 50 at a predetermined position is newly provided. No need. The member having the support portion 19 that supports the gas diffusion member 50 while being separated from the gas discharge valve 23 and the lid body 11 is not limited to the busbar holder 17 . For example, the support 19 may be provided in a tray or case that holds electrical equipment such as control circuits and relays. Further, for example, each of one or more rod-shaped (or string-shaped) members that connect the inner surface of the exterior main body 12 and the gas diffusion member 50 in the lateral direction (direction parallel to the XY plane) is the gas diffusion member 50. may be adopted as a support portion that supports the gas discharge valve 23 and the lid body 11 in a state of being spaced apart from each other. In other words, the supporting portion that supports the gas diffusion member 50 may be implemented by a member dedicated to supporting the gas diffusion member 50 .

In the present embodiment, the exterior body 10 has an exhaust port 121 for discharging the gas inside the exterior body 10 to the outside. The gas diffusion member 50 is arranged at a position between the gas exhaust valve 23 and the exhaust port 121 in the first direction. Specifically, as shown in FIGS. 5 and 6 , a discharge port 121 is provided inside the cover 11 of the exterior body 10 . The exhaust port 121 is formed at a position communicating with an exhaust pipe 120 protruding from the outer surface of the lid 11 . That is, the gas that has flowed into the exhaust port 121 from the interior of the exterior body 10 passes through the exhaust pipe 120 and is discharged to the exterior of the exterior body 10 .

According to this configuration, the gas ejected in the first direction from the gas discharge valve 23 and diffused by the gas diffusion member 50 is discharged from the discharge port 121 positioned further in the first direction than the gas diffusion member 50, It is discharged to the outside of the exterior body 10 . That is, the gas ejected from at least one gas exhaust valve 23 and having its pressure (flow velocity) and temperature lowered by the gas diffusion member 50 is efficiently exhausted to the outside of the exterior body 10 .

The power storage device 1 according to the embodiment of the present invention has been described above. good. Therefore, various modifications of the gas diffusion member 50 and its peripheral configuration will be described with reference to FIGS. 7 to 9, focusing on differences from the above embodiment.

[3-1. Modification 1]
FIG. 7 is a cross-sectional view of a power storage device 1a according to Modification 1 of the embodiment. Supplementary matters such as the position of the cross section in FIG. 7 and the simplified illustration of the cross section conform to FIG. 5 described above. This also applies to FIGS. 8 and 9, which will be described later.

As shown in FIG. 7, the power storage device 1a according to this modification includes a gas diffusion member 50 made of metal and having a plate shape. The gas diffusion member 50 is arranged at a position between the lid body 11a and the plurality of power storage elements 20 and separated from the plurality of power storage elements 20 and the lid body 11a. These configurations are common to the power storage device 1 according to the embodiment. The power storage device 1a according to this modification differs from the power storage device 1 according to the embodiment in that the gas diffusion member 50 is supported by the support portion 19a provided on the lid 11a.

That is, in this modified example, the exterior body 10a has an exterior body main body 12a that accommodates a plurality of power storage elements 20 and a lid body 11a that closes the main body opening 15 . The lid body 11a has a support portion 19a that supports the gas diffusion member 50 in a suspended manner while being separated from the plurality of storage elements 20 and the lid body 11a, which is another member.

According to this configuration, the gas diffusion member 50 can be supported by the lid 11a of the exterior body 10, so there is no need to newly provide a dedicated member for arranging the gas diffusion member 50 at a predetermined position.

When the lid body 11a supports the gas diffusion member 50, it is not essential to support the gas diffusion member 50 in a suspended manner. For example, each of one or more rod-shaped (or string-shaped) members connecting the inner surface of the lid 11a and the gas diffusion member 50 in the lateral direction separates the gas diffusion member 50 from the gas discharge valve 23 and the lid 11a. You may employ|adopt as a support part which supports in the state which carried out.

[3-2. Modification 2]
FIG. 8 is a cross-sectional view of a power storage device 1b according to Modification 2 of the embodiment. As shown in FIG. 8, a power storage device 1b according to this modification includes a power storage element unit 28 having a plurality of power storage elements 20 arranged in the X-axis direction, and an exterior body 10b that accommodates the power storage element unit 28. . The exterior body 10b has an exterior body main body 12b and a lid body 11b. In the power storage device 1b configured in this manner, the plurality of power storage elements 20 and the wall portion 13b (of the exterior main body 12b), which is another member, are positioned facing the gas discharge valves 23 of the power storage elements 20. A plate-shaped gas diffusion member 50 made of metal is arranged between the wall portion 13b). The gas diffusion member 50 is arranged at a position separated from each of the plurality of power storage elements 20 and the wall portion 13b. Spaces in which gas can move are formed in the vertical direction (Z-axis direction) and sideways (directions parallel to the XY plane) of the gas diffusion member 50 .

Thus, the power storage device 1b according to this modification has a configuration common to that of the power storage device 1 according to the embodiment. The power storage device 1b according to the present modification differs from the power storage device 1 according to the embodiment in that each of the plurality of power storage elements 20 is arranged with the gas discharge valve 23 directed in the positive direction of the Y axis. different. More specifically, the plurality of power storage elements 20 are arranged in the X-axis direction with the gas discharge valve 23 directed in the Y-axis plus direction and the long side surface 21a directed in the X-axis direction.

When the positive Y-axis direction, the X-axis direction, and the Z-axis direction of the power storage device 1b having the above configuration are expressed in this order as the first direction, the second direction, and the third direction, the description of the configuration is as follows. This is common with the description of the configuration of the power storage device 1 according to the embodiment. That is, the power storage device 1b is housed in the exterior body 10b and the exterior body 10b, each of which has a posture in which the gas discharge valve 23 is directed in the first direction (Y-axis plus direction), and in the second direction intersecting the first direction. It includes a plurality of power storage elements 20 arranged in the (X-axis direction) and a gas diffusion member 50 . The gas diffusion member 50 is positioned between the plurality of storage elements 20 and the wall portion 13b arranged at a position facing the plurality of storage elements 20 in the first direction, and is located between the plurality of storage elements 20 and the wall portion 13b. are arranged at positions separated from each other. The gas diffusion member 50 extends in the first direction both on the side of the gas diffusion member 50 in the second direction and on the side in the third direction (Z-axis direction) intersecting the first direction and the second direction. It is shaped and sized to allow the passage of gas.

According to this configuration, in the power storage device 1b according to the present modification, the pressure and temperature of the gas ejected from the gas discharge valve 23 can be quickly reduced by the gas diffusion member 50, as in the power storage device 1 according to the embodiment. can be done. This suppresses deterioration in strength, melting, or the like of the exterior body 10b. Therefore, according to the power storage device 1b, it is possible to suppress further deterioration of the state when an unsafe event occurs.

[3-3. Modification 3]
FIG. 9 is a cross-sectional view of a power storage device 1c according to Modification 3 of the embodiment. As shown in FIG. 9, a power storage device 1c according to this modification includes a power storage element unit 28 having a plurality of power storage elements 20 arranged in the Z-axis direction, and an exterior body 10c that accommodates the power storage element unit 28. . The exterior body 10c has an exterior body main body 12c and a lid body 11c. In the power storage device 1c configured in this manner, the plurality of power storage elements 20 and the wall portion 13c (of the exterior main body 12c), which is another member, are located opposite the gas discharge valves 23 of the power storage elements 20. A plate-like gas diffusion member 50 made of metal is arranged between the wall portion 13c). The gas diffusion member 50 is arranged at a position separated from each of the plurality of power storage elements 20 and the wall portion 13c. Spaces in which gas can move are formed in the vertical direction (Z-axis direction) and sideways (directions parallel to the XY plane) of the gas diffusion member 50 .

Thus, the power storage device 1c according to this modification has a configuration common to that of the power storage device 1 according to the embodiment. The power storage device 1c according to the present modification differs from the power storage device 1 according to the embodiment in that each of the plurality of power storage elements 20 is arranged with the gas discharge valve 23 directed in the positive direction of the Y axis. different. More specifically, the plurality of power storage elements 20 are arranged in the Z-axis direction with the gas discharge valve 23 directed in the Y-axis positive direction and the short side surface 21b directed in the X-axis direction. That is, in this modified example, the plurality of power storage elements 20 are stacked vertically.

When the positive Y-axis direction, Z-axis direction, and X-axis direction of the power storage device 1c having the above configuration are expressed in this order as the first direction, the second direction, and the third direction, the description of the configuration is as follows. This is common with the description of the configuration of the power storage device 1 according to the embodiment. That is, the power storage device 1c is housed in the exterior body 10c and the exterior body 10c, each of which is in a posture in which the gas discharge valve 23 is directed in the first direction (Y-axis plus direction), and in the second direction intersecting the first direction. It includes a plurality of power storage elements 20 arranged in the (Z-axis direction) and a gas diffusion member 50 . The gas diffusion member 50 is positioned between the plurality of storage elements 20 and the wall portion 13b arranged at a position facing the plurality of storage elements 20 in the first direction, and is located between the plurality of storage elements 20 and the wall portion 13b. are arranged at positions separated from each other. The gas diffusion member 50 extends in the first direction both on the side of the gas diffusion member 50 in the second direction and on the side in the third direction (X-axis direction) intersecting the first direction and the second direction. It is shaped and sized to allow the passage of gas.

According to this configuration, in the power storage device 1c according to the present modification, the gas diffusion member 50 quickly reduces the pressure and temperature of the gas ejected from the gas discharge valve 23, as in the power storage device 1 according to the embodiment. be able to. This suppresses deterioration in strength, melting, or the like of the exterior body 10c. Therefore, according to the power storage device 1c, it is possible to suppress further deterioration of the state when an unsafe event occurs.

[4. Other Modifications]
The power storage device according to the present invention has been described above based on the embodiment and its modification. However, the present invention is not limited to the above embodiments and modifications. As long as they do not deviate from the spirit 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, other members arranged in the first direction, which is the direction in which the gas discharge valve 23 is directed with respect to the electric storage element 20 , need not be part of the exterior body 10 . For example, when a control device or an electric device such as a relay, or a tray or the like for holding the electric device is arranged at a position facing the gas discharge valve 23 in the first direction, another member, such as a tray or an electric device, is arranged. and the storage element 20, the gas diffusion member 50 is arranged. As a result, even when the gas is ejected from the gas discharge valve 23, the gas is diffused and spread by the gas diffusion member 50, so that the temperature and pressure of the gas are rapidly lowered, thereby allowing the tray or the electric device to cool down. etc. are protected. That is, when a member formed of a material (resin or the like) having a lower melting point than the gas diffusion member 50 is arranged as another member, the gas diffusion member 50 is arranged apart from the other member. , the other member can be protected from the gas while obtaining the effect of lowering the pressure and temperature of the gas by the gas diffusion member 50 . That is, for example, in the structures shown in FIGS. 4 to 6, even if an electrical device is placed between the gas diffusion member 50 and the lid 11, the electrical device can be , from the gas ejected from the gas discharge valve 23 . Furthermore, the gas diffusion member 50 can widely utilize the internal space of the exterior body 10 to diffuse the gas, and as a result, the pressure and temperature of the gas are efficiently lowered.

The gas diffusion member 50 does not need to have a shape and size that collectively cover the plurality of gas discharge valves 23 in plan view. For example, a separate gas diffusion member may be arranged for each of the plurality of gas discharge valves 23 . Even in this case, if spaces through which the gas can pass are formed in the upper, lower, left, and right sides of the gas diffusion member, the internal space of the exterior body 10 can be widely used to diffuse the gas.

The gas diffusion member 50 does not need to be supported by a member other than the electric storage element 20, such as the busbar holder 17, and may be supported by the electric storage element 20. For example, by fixing one or more legs extending from the gas diffusion member 50 toward the storage element unit 28 to the terminal arrangement surface 21c (see FIG. 3) of the one or more storage elements 20 with an adhesive or the like. , the gas diffusion member 50 may be arranged with respect to the electric storage element unit 28 . As described above, when an individual gas diffusion member is arranged for each of the multiple gas discharge valves 23, each of the multiple storage elements 20 may support the gas diffusion member corresponding to the storage element 20. .

A form constructed by arbitrarily combining the plurality of components described above is also included within the scope of the present invention. For example, various supplementary matters regarding power storage device 1 according to the above-described embodiment may be applied to any one of power storage devices 1a to 1c according to modified examples 1 to 3.

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, 1a, 1b, 1c

power storage device

10, 10a, 10b,

10c exterior body

13, 13b, 13c, 14 wall portion 17 busbar holder 18

exhaust opening

19, 19a support portion 20 power storage element 21 container 23 gas discharge valve 24 Lid plate 25 Container main body 33 Bus bar 50 Gas diffusion member 51 Through hole 121 Outlet

Claims

an exterior body;
a plurality of power storage elements housed in the exterior body and arranged in a second direction intersecting with the first direction, each with a gas discharge valve facing the first direction;
a metal plate-shaped gas diffusion member disposed facing the gas discharge valves of the plurality of storage elements,
The gas diffusion member is
A position between the plurality of energy storage elements and another member disposed at a position facing the plurality of energy storage elements in the first direction, and between each of the plurality of energy storage elements and the other member are spaced apart, and
Both sides of the gas diffusion member in the second direction and sides in a third direction intersecting the first direction and the second direction allow passage of gas in the first direction. formed in shape and size,
storage device.
The gas diffusion member is formed with a plurality of through holes penetrating in the first direction,
The power storage device according to claim 1 .
further comprising a busbar holder that holds a busbar that is arranged on the first direction side of the plurality of power storage elements and electrically connected to the plurality of power storage elements,
The busbar holder has a support portion that supports the gas diffusion member while being separated from the plurality of power storage elements and the other members.
The power storage device according to claim 1 or 2.
The exterior body has an exterior body body that accommodates the plurality of power storage elements, and a lid body that closes an opening of the exterior body body,
The lid has a supporting portion that supports the gas diffusion member in a suspended manner while being separated from the plurality of power storage elements and the other members.
The power storage device according to claim 1 or 2.
The exterior body has a discharge port for discharging the gas inside the exterior body to the outside,
The gas diffusion member is arranged at a position between the gas discharge valve and the discharge port in the first direction,
The power storage device according to any one of claims 1 to 4.