Power storage panel

Abstract

We provide a power storage panel with a configuration that can improve safety. [Solution] The power storage panel 10 comprises a power storage device 200 equipped with power storage elements, a housing 100 for housing the power storage device, an inert liquid 300 disposed in the space S1 within the housing where the power storage device is housed, and a shielding member 400 disposed in the inert liquid and along the surface of the inert liquid, which blocks the gas discharge path so that gas from the power storage elements can be discharged.

Description

Technical Field

[0001] The present invention relates to a power storage panel.

Background Art

[0002] Patent Document 1 discloses a power storage device having a battery module, a cooling liquid for cooling the battery module, a battery housing container for housing the cooling liquid and the battery module, and a gas discharge pipe for discharging the gas inside the battery housing case to the outside of the vehicle compartment when gas is generated from the battery module.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the power storage device disclosed in Patent Document 1 above, when gas is generated from the battery module, the gas inside the battery housing case is discharged through the gas discharge pipe. In this configuration, there is a possibility that high-temperature gas is discharged from the battery housing case through the gas discharge pipe, but a configuration that can suppress the discharge of high-temperature gas and improve safety is desired.

[0005] The present invention has been made by the inventors of the present application newly paying attention to the above problems, and an object thereof is to provide a power storage panel that can improve safety.

Means for Solving the Problems

[0006] A power storage panel according to one aspect of the present invention comprises a power storage device equipped with power storage elements, a housing for housing the power storage device, an inert liquid disposed in the space within the housing in which the power storage device is housed, and a shielding member disposed in the inert liquid and along the surface of the inert liquid, which obstructs the gas discharge path so as to allow gas from the power storage elements to be discharged. [Effects of the Invention]

[0007] The power storage panel according to the present invention can improve safety. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a perspective view showing the configuration of a power storage panel according to an embodiment. [Figure 2] Figure 2 is a cross-sectional view showing the internal configuration of the housing of the power storage panel according to the embodiment. [Figure 3] Figure 3 is a perspective view showing the configuration of the energy storage device included in the energy storage panel according to the embodiment. [Figure 4] Figure 4 is a perspective view showing the configuration of the energy storage elements in the energy storage device according to the embodiment. [Figure 5] Figure 5 is a cross-sectional view showing a configuration in a power storage panel according to an embodiment in which a shielding member blocks the gas discharge path from the power storage element. [Figure 6] Figure 6 is a cross-sectional view showing the internal configuration of the housing of a power storage panel according to a modified example 1 of the embodiment. [Figure 7] Figure 7 is a cross-sectional view showing the internal configuration of the housing of a power storage panel according to a modified example 2 of the embodiment. [Modes for carrying out the invention]

[0009] (1) A power storage panel according to one aspect of the present invention comprises a power storage device equipped with a power storage element, a housing for housing the power storage device, an inert liquid disposed in the space within the housing in which the power storage device is housed, and a shielding member disposed in the inert liquid and along the surface of the inert liquid, which obstructs the gas discharge path so as to allow gas from the power storage element to be discharged.

[0010] According to one aspect of the present invention, an inert liquid is placed in the space within the enclosure where the energy storage device is housed, and a shielding member is placed in the inert liquid and along the surface of the inert liquid to block the gas discharge path from the energy storage element. In other words, in the energy storage panel, the energy storage device and the inert liquid are placed in the enclosure, and the energy storage device is cooled by the inert liquid. In this configuration, when gas is discharged from the energy storage element of the energy storage device, the discharge path from which the gas is discharged to the surface of the inert liquid is blocked by the shielding member. As a result, the gas discharge path becomes longer, and the gas, whose temperature has decreased as it travels along the discharge path, is discharged from the surface of the inert liquid. Therefore, the energy storage panel can suppress the discharge of high-temperature gas, thereby improving safety.

[0011] (2) The power storage panel described in (1) above may be equipped with a plurality of power storage devices, and the shielding member may extend across the plurality of power storage devices.

[0012] According to the power storage panel described in (2) above, the shielding member extends across multiple power storage devices, so that the gas discharge path can be lengthened regardless of which of the multiple power storage devices the gas is discharged from.

[0013] (3) In the power storage panel described in (1) or (2) above, a gap may be formed between the shielding member and the housing.

[0014] According to the power storage panel described in (3) above, a gap is formed between the shielding member and the housing, allowing the gas whose temperature has been lowered by the shielding member to be discharged through the gap between the shielding member and the housing.

[0015] (4) In the power storage device according to any one of (1) to (3) above, the shielding member may be provided with a through hole in the central portion.

[0016] According to the power storage device described in (4) above, since the shielding member has a through hole in the central portion, the gas whose temperature has been lowered by the shielding member can be discharged from the through hole of the shielding member.

[0017] (5) In the power storage device according to any one of (1) to (4) above, the shielding member may be provided with an inclined surface on the upper surface.

[0018] According to the power storage device described in (5) above, since the shielding member has an inclined surface on the upper surface, even when the inert liquid is ejected onto the shielding member, the inclined surface can level the inert liquid on the shielding member.

[0019] Hereinafter, with reference to the drawings, a power storage device according to an embodiment (including a modified example thereof) of the present invention will be described. Each of the embodiments described below shows comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement positions and connection forms of the components, manufacturing processes, order of manufacturing processes, etc. shown in the following embodiments are examples and are not intended to limit the present invention. In each figure, dimensions and the like are not precisely illustrated. In each figure, the same or similar components are denoted by the same reference numerals.

[0020] In the following description and drawings, the width direction of the power storage panel enclosure, the opposing directions of the two side walls of the enclosure, the arrangement direction of multiple power storage devices on the enclosure's shelves, the short-side direction of the power storage devices, the arrangement direction of a pair of terminals (positive and negative) in a single power storage element, or the opposing directions of the short sides of the containers of the power storage elements are defined as the X-axis direction. The depth direction of the power storage panel enclosure, the opposing directions of the front and rear walls of the enclosure, the longitudinal direction of the power storage devices, the arrangement direction of multiple power storage elements in a power storage device, or the opposing directions of the long sides of the containers of the power storage elements are defined as the Y-axis direction. The height direction of the power storage panel enclosure, the direction in which the bottom wall of the enclosure faces, the arrangement direction of multiple shelves in the enclosure, the arrangement direction of the body and lid of the power storage element container, the arrangement direction of the first and second spaces inside the enclosure, the arrangement direction of multiple power storage devices and shielding members, or the up and down direction are defined as the Z-axis direction. These X-axis, Y-axis, and Z-axis directions intersect (orthogonal in this embodiment) with each other.

[0021] In the following explanation, the X-axis positive direction refers to the direction of the X-axis arrow, and the X-axis negative direction refers to the direction opposite to the X-axis positive direction. When simply referred to as the X-axis direction, it refers to either the X-axis positive direction or the X-axis negative direction, or either direction. Unless otherwise specified, the center and ends of a member in the X-axis direction refer to the parts located in the center and ends when the member is divided into three parts in the X-axis direction. The same applies to the Y-axis and Z-axis directions. Expressions indicating relative directions or orientations, such as parallel and orthogonal, include cases where they are not strictly those directions or orientations. When two directions are parallel (or orthogonal), it means not only that the two directions are perfectly parallel (or orthogonal), but also that they are substantially parallel (or orthogonal), i.e., that they include a difference of, for example, a few percent. In the following explanation, when "insulation" is used, it means "electrical insulation". The volume resistivity of an insulating material is 1 × 10⁻⁶ 6 Preferably, it is Ωm or higher, 1 × 10 7 Ωm or greater is more preferable, 1 × 10 10 A value of Ωm or higher is even more preferable.

[0022] (Embodiment) [1. Explanation of the power storage panel 10] The configuration of the power storage panel 10 in this embodiment will now be described. Figure 1 is a perspective view showing the configuration of the power storage panel 10 according to this embodiment. In Figure 1, the internal configuration of the housing 100 of the power storage panel 10 is shown by dashed lines. Figure 2 is a cross-sectional view showing the internal configuration of the housing 100 of the power storage panel 10 according to this embodiment. Figure 2 shows a cross-section of the power storage panel 10 shown in Figure 1 when it is cut by a plane passing through line II-II and parallel to the XZ plane.

[0023] The power storage panel 10 is equipment that charges and discharges electricity and supplies power to an external power load. The power storage panel 10 is a stationary battery used for commercial or household purposes, and is used for power storage or power supply purposes. The power storage panel 10 is a stationary electrical panel (power storage device panel, power storage element panel, battery panel) that stores various types of power, such as power from the commercial power grid, power generated by generators, wind power generation or solar power generation, and regenerative power from railway systems, and supplies power stably to external equipment. The power storage panel 10 can also be installed on large mobile vehicles such as ships or railway vehicles for electric railways, and can be used as a battery for driving or starting the engine of such large mobile vehicles. Examples of railway vehicles for electric railways include electric trains, monorails, linear motor cars, and hybrid trains equipped with both diesel engines and electric motors.

[0024] As shown in Figures 1 and 2, the power storage panel 10 has a rectangular parallelepiped shape. The power storage panel 10 comprises a housing 100, power storage devices 200, an inert liquid 300, and a shielding member 400. In this embodiment, within the housing 100, a plurality (six) of power storage devices 200 are arranged in the X-axis direction and in multiple rows in the Z-axis direction. The number of power storage devices 200 arranged in the X-axis direction and the number of rows in the Z-axis direction are not particularly limited. In addition to these components, the power storage panel 10 also includes wires or busbars for connecting the plurality of power storage devices 200, but these are not shown in the illustration and detailed explanation is omitted. The plurality of power storage devices 200 may all be connected in series, a combination of series and parallel connections, or all be connected in parallel. The power storage panel 10 may also include a power converter, copper bars, circuit breakers, and other electrical equipment (electrical components).

[0025] [1.1 Description of the enclosure 100 and the inert liquid 300] First, the configuration of the housing 100 and the inert liquid 300 housed within the housing 100 will be described in detail. The housing 100 is a rectangular parallelepiped (box-shaped) housing (shelf, rack). The housing 100 houses the energy storage device 200, the inert liquid 300, and the shielding member 400 inside. The housing 100 is made of metal such as stainless steel, aluminum, aluminum alloy, iron, or plated steel sheet. The housing 100 may be made of a material other than metal (such as resin), but it is preferable that it be made of a material with high strength, heat resistance, and flame retardancy. The housing 100 comprises side walls 110 and 120, a front wall 130, a rear wall 140, a bottom wall 150, and a shelf 160.

[0026] The side walls 110 and 120, the front wall 130, the rear wall 140, and the bottom wall 150 are flat, rectangular wall sections that cover five surfaces of the housing 100 other than the top surface. Specifically, the side wall 110 is the wall of the housing 100 in the positive X-axis direction, the side wall 120 is the wall of the housing 100 in the negative X-axis direction, the front wall 130 is the wall of the housing 100 in the negative Y-axis direction, the rear wall 140 is the wall of the housing 100 in the positive Y-axis direction, and the bottom wall 150 is the wall of the housing 100 in the negative Z-axis direction.

[0027] In this configuration, the housing 100 has an internal space formed by the side walls 110 and 120, the front wall 130, the rear wall 140, and the bottom wall 150, which is divided into a first space S1 and a second space S2. The first space S1 and the second space S2 are two spaces aligned in the vertical direction (Z-axis direction).

[0028] The first space S1 is located below the second space S2 within the housing 100 (in the negative Z-axis direction) and occupies most of the internal space of the housing 100. The first space S1 is a rectangular parallelepiped-shaped space within the internal space of the housing 100 other than the second space S2. The first space S1 is the space within the housing 100 that houses the energy storage device 200, the inert liquid 300, and the shielding member 400. In other words, the inert liquid 300 is housed in the first space S1, and multiple energy storage devices 200 and shielding members 400 are housed within the inert liquid 300. To put it another way, the space within the internal space of the housing 100 where the inert liquid 300 is located is the first space S1, and the energy storage devices 200 and shielding members 400 are housed within the first space S1 where the inert liquid 300 is located. In this embodiment, the entire energy storage device 200 and shielding member 400 are immersed in the inert liquid 300 in a liquid immersion cooling configuration.

[0029] The inert liquid 300 is placed in the first space S1, which is the space within the housing 100 in which the energy storage device 200 is housed, and is a cooling medium (cooling liquid) that cools the energy storage device 200 (the energy storage element 220 described later) by immersing it in the liquid. The inert liquid 300 is a chemically inert, insulating liquid. As the inert liquid 300, any known oil (insulating oil) such as mineral oil or chemically synthesized oil (fluorine-based or silicone-based) can be used as appropriate. It is preferable to use a liquid as the inert liquid 300 that has a flash point of 250°C or higher and does not fall under the category of hazardous materials under the Fire Service Act. For cooling the inert liquid 300 itself, a single-phase cooling method can be adopted in which the inert liquid 300 is removed and heat is exchanged elsewhere, but a two-phase cooling method that utilizes the endothermic reaction in the phase change from liquid to gas may also be adopted.

[0030] The second space S2 is a space located above the first space S1 (in the positive Z-axis direction) within the housing 100. The second space S2 is a rectangular parallelepiped-shaped space that is flattened in the Z-axis direction and located at the end of the internal space of the housing 100 in the positive Z-axis direction. Since the inert liquid 300 is located in the first space S1, the second space S2 is a space located above the inert liquid 300 within the housing 100. In other words, the second space S2 is the space within the internal space of the housing 100 where the inert liquid 300 is not located.

[0031] The shelf plate 160 is a flat, rectangular wall that partitions the internal space (first space S1) of the housing 100. Multiple shelf plates 160 are arranged in the Z-axis direction within the first space S1, partitioning the first space S1 in the Z-axis direction. The shelf plate 160 has an opening (not shown) through which the inert liquid 300 can pass. The shape of the shelf plate 160 is not particularly limited and may be a narrow plate-shaped or rod-shaped member such as a beam. Each energy storage device 200 is placed inside the housing 100 within the space partitioned by the multiple shelf plates 160, supported by each shelf plate 160, etc. On each shelf plate 160, multiple energy storage devices 200 are arranged in the X-axis direction. In this way, the multiple energy storage devices 200 are arranged adjacent to each other in the X-axis and Z-axis directions. Although Figures 1 and 2 do not show the shelf 160 and the energy storage device 200 in the space below the housing 100, the shelf 160 and the energy storage device 200 may be placed in the space below the housing 100, or the energy storage device 200 may be placed on the bottom wall 150.

[0032] Electrical equipment such as circuit boards for controlling each energy storage device 200 may be placed inside the housing 100 (first space S1 or second space S2). The electrical equipment may be placed in the upper part of the housing 100 (upper part of the first space S1 or second space S2), and the wiring connected to the electrical equipment may be routed out through an opening in the upper part of the housing 100.

[0033] [1.2 Description of the Energy Storage Device 200] Next, the configuration of the energy storage device 200 will be described in detail. Figure 3 is a perspective view showing the configuration of the energy storage device 200 provided in the energy storage panel 10 according to this embodiment. In Figure 3, the internal configuration of the outer casing 210 of the energy storage device 200 is shown by dashed lines, with a transparent view of the outer casing 210. Since all of the multiple energy storage devices 200 provided in the energy storage panel 10 have the same configuration, Figure 3 shows one energy storage device 200. Figure 4 is a perspective view showing the configuration of the energy storage element 220 provided in the energy storage device 200 according to this embodiment. Since all of the multiple energy storage elements 220 provided in the energy storage device 200 have the same configuration, Figure 4 shows one energy storage element 220.

[0034] The energy storage device 200 is a battery module (battery pack) that is elongated in the Y-axis direction and has a roughly rectangular parallelepiped shape. As shown in Figure 3, the energy storage device 200 comprises an outer casing 210 and a plurality of energy storage elements 220. In this embodiment, the plurality of energy storage elements 220 are arranged in line in the Y-axis direction, but the direction of arrangement and the number of energy storage elements 220 are not particularly limited, and only one energy storage element 220 may be arranged. In addition to these components, the energy storage device 200 also comprises busbars for connecting the terminals of the plurality of energy storage elements 220, a gas exhaust path and exhaust port (exhaust pipe) for exhausting gas discharged from the energy storage elements 220, and a pair of external terminals (positive and negative electrodes) (or cables equivalent to external terminals) for connecting to the outside, but these are not shown in the illustration and their detailed explanation is omitted. The energy storage device 200 may also include spacers placed between the energy storage elements 220, restraining members (end plates, side plates, etc.) that constrain the energy storage elements 220, a busbar frame for positioning the busbars, and electrical equipment such as a circuit board for monitoring and controlling the charging and discharging states of the energy storage elements 220, but these are not shown or described.

[0035] The outer casing 210 is a box-shaped (rectangular parallelepiped) container (module case) that is elongated in the Y-axis direction and forms the outer shell of the energy storage device 200. The outer casing 210 houses a plurality of energy storage elements 220 and fixes the plurality of energy storage elements 220 in predetermined positions, protecting them from impacts and the like. The outer casing 210 is made of an insulating material such as resin to prevent the energy storage elements 220 from coming into contact with external metal members, etc. The outer casing 210 may be made of a conductive material such as metal, as long as the insulating properties of the energy storage elements 220 are maintained.

[0036] The energy storage element 220 is a secondary battery (single cell) capable of charging and discharging electricity, and more specifically, a non-aqueous electrolyte secondary battery such as a lithium-ion secondary battery. In this embodiment, the energy storage element 220 has a flattened rectangular parallelepiped shape (square), but the shape of the energy storage element 220 is not limited to a rectangular parallelepiped shape, and may be a polygonal prism shape, cylindrical shape, oblong cylindrical shape, elliptical prism shape, etc. The energy storage element 220 may be a secondary battery other than a non-aqueous electrolyte secondary battery, or it may be a capacitor. The energy storage element 220 may be a primary battery. The energy storage element 220 may be a battery using a solid electrolyte. The energy storage element 220 may be a pouch-type energy storage element.

[0037] As shown in Figure 4, the energy storage element 220 comprises a container 221 and a pair of terminals 222 (positive and negative electrodes). Inside the container 221 are electrodes, a pair of current collectors (positive and negative electrodes), and an electrolyte (non-aqueous electrolyte), but these are not shown in the illustration. There are no particular restrictions on the type of electrolyte as long as it does not impair the performance of the energy storage element 220, and various types can be selected. Gaskets and the like are placed between the container 221, the terminals 222, and the current collectors to improve insulation and airtightness, but these are also not shown in the illustration.

[0038] The container 221 is a rectangular (square) container, and the container lid 221b closes the opening of the container body 221a in the positive Z-axis direction. The material of the container 221 (container body 221a and container lid 221b) is not particularly limited, but it is preferably a weldable metal such as stainless steel, aluminum, aluminum alloy, iron, or plated steel sheet.

[0039] Between a pair of terminals 222 on the container lid 221b of the container 221, a gas discharge valve 221c is positioned to release gas from inside the container 221 and relieve pressure if the pressure inside the container 221 rises excessively. If the energy storage element 220 is a non-aqueous electrolyte energy storage element, the energy storage element 220 generates flammable gas. In other words, if an abnormality such as an internal short circuit occurs in the energy storage element 220 due to factors such as the application of external stress to the energy storage element 220 or the inclusion of foreign matter inside the energy storage element 220, the energy storage element 220 may generate flammable gas. For this reason, the gas (vent gas) discharged from the gas discharge valve 221c of the energy storage element 220 contains flammable gas.

[0040] Terminal 222 is an electrode terminal (positive electrode terminal and negative electrode terminal) electrically connected to the positive electrode plate and negative electrode plate of the electrode body via a current collector, and is formed of a metal (conductive) material such as aluminum, aluminum alloy, copper, or copper alloy. The electrode body is an energy storage element (power generation element) formed by laminating a positive electrode plate, a negative electrode plate, and a separator. The positive electrode plate has a positive electrode active material layer formed on a current collector foil made of a metal such as aluminum or an aluminum alloy. The negative electrode plate has a negative electrode active material layer formed on a current collector foil made of a metal such as copper or a copper alloy. As for the active material used in the positive electrode active material layer and the negative electrode active material layer, any known material can be used as long as it is capable of intercalating and releasing charge transport ions. The current collector is a conductive member (positive electrode current collector and negative electrode current collector) electrically connected to terminal 222 and the electrode body. The positive electrode current collector is made of aluminum or an aluminum alloy, similar to the current collector foil of the positive electrode plate, while the negative electrode current collector is made of copper or a copper alloy, similar to the current collector foil of the negative electrode plate.

[0041] [1.3 Description of shielding member 400] Next, the configuration of the shielding member 400 will be described in detail, with reference to Figures 1 and 2, and also to Figure 5. Figure 5 is a cross-sectional view showing the configuration in the power storage panel 10 according to this embodiment in which the shielding member 400 blocks the gas discharge path from the power storage element 220. Figure 5 is a diagram of Figure 2 with the gas discharge paths F1 to F4 from the power storage element 220 added.

[0042] As shown in Figures 1 and 2, the shielding member 400 is a flat, rectangular member parallel to the XY plane, positioned in the inert liquid 300 and along the liquid surface 301 of the inert liquid 300. The shielding member 400 is fixed to the housing 100. The shielding member 400 is fixed to the housing 100 by being connected to the housing 100 via a connecting part (not shown). The means for fixing the shielding member 400 to the housing 100 are not particularly limited, and if the position of the shielding member 400 can be maintained without fixing the shielding member 400 to the housing 100, the shielding member 400 does not need to be fixed to the housing 100.

[0043] Specifically, the shielding member 400 is positioned entirely within the inert liquid 300 and near the liquid surface 301 of the inert liquid 300. The shielding member 400 extends across multiple energy storage devices 200. In this embodiment, the shielding member 400 extends in the X-axis direction across all energy storage devices 200 aligned in the X-axis direction. The shielding member 400 is positioned between the liquid surface 301 of the inert liquid 300 and the multiple energy storage devices 200, and the distance between the shielding member 400 and the liquid surface 301 is smaller than the distance between the shielding member 400 and the energy storage devices 200.

[0044] The shielding member 400 is provided with a through hole 410 in its central part. The through hole 410 is a circular through hole that penetrates in the Z-axis direction through the portion of the shielding member 400 that includes the center position (central part) when viewed from the Z-axis direction. The through hole 410 may be positioned at a location offset from the center position of the shielding member 400, multiple through holes 410 may be formed, and the shape and size of the through hole 410 are not particularly limited.

[0045] A gap 420 is formed between the shielding member 400 and the housing 100 (see Figure 2). The shielding member 400 is formed such that its outer edge is smaller than the inner surface of the housing 100 when viewed from the Z-axis direction. As a result, a gap 420 is formed between the outer edge of the shielding member 400 (all four sides on both the X-axis and Y-axis sides) and the inner surface of the housing 100 (the inner surfaces of the side walls 110, 120, front wall 130, and rear wall 140). The gap 420 is a rectangular annular space when viewed from the Z-axis direction, formed continuously on the outside (outer circumference) of the shielding member 400 and on the inside (inner circumference) of the housing 100. The gap 420 may be formed intermittently rather than continuously, may not be formed on any of the four sides of the outer edge of the shielding member 400, and the width of the gap 420 is not limited.

[0046] In this configuration, as shown in Figure 5, if the pressure inside the container 221 of the energy storage element 220 of the energy storage device 200 rises excessively, gas (flammable gas) is discharged into the inert liquid 300 from the gas discharge valve 221c of the energy storage element 220. Figure 5 shows the case where gas is discharged into the inert liquid 300 from the energy storage element 220 of the second energy storage device 201 from the X-axis minus end, among the multiple energy storage devices 200 arranged on the shelf plate 160 located at the Z-axis positive end. In this case, since the discharged gas has a lower specific gravity than the inert liquid 300, it tries to rise within the inert liquid 300 and exit from the first space S1 to the second space S2, but the discharge path is blocked by the shielding member 400. Therefore, the gas moves in two separate paths: a discharge path F1 directed in the X-axis positive direction and a discharge path F2 directed in the X-axis minus direction. The gas that has moved to the discharge path F1 passes through the discharge path F3 and exits into the second space S2 through the through hole 410 of the shielding member 400. The gas that has moved to the discharge path F2 passes through the discharge path F4 and exits into the second space S2 through the gap 420 between the shielding member 400 and the housing 100.

[0047] In this way, the shielding member 400 blocks the gas discharge path so that gas from the energy storage element 220 can be discharged. That is, after blocking the gas discharge path from the energy storage element 220, the shielding member 400 discharges the gas to the outside (second space S2) of the inert liquid 300 (first space S1). As a result, the distance the gas travels is longer by the length of the discharge path F1 or F2 compared to when it is not blocked by the shielding member 400. That is, the distance the gas travels through the inert liquid 300 is longer by the length of the discharge path F1 or F2 compared to when it is not blocked by the shielding member 400. The same applies when gas is discharged from an energy storage element 220 of another energy storage device 200.

[0048] [2. Explanation of Effects] As described above, according to the embodiment of the present invention, inert liquid 300 is arranged in the space (first space S1) within the housing 100 in which the energy storage device 200 is housed. A shielding member 400 is arranged within the inert liquid 300 and along the liquid surface 301 of the inert liquid 300 to block the gas discharge path from the energy storage element 220. In other words, in the energy storage panel 10, the energy storage device 200 and the inert liquid 300 are arranged within the housing 100, and the energy storage device 200 is cooled by liquid immersion cooling using the inert liquid 300. In this configuration, when gas (flammable gas) is discharged from the energy storage element 220 of the energy storage device 200, the discharge path from which the gas is discharged to the liquid surface 301 of the inert liquid 300 is blocked by the shielding member 400. As a result, the gas discharge path becomes longer, and the gas, whose temperature decreases as it travels along the discharge path, is discharged from the liquid surface 301 of the inert liquid 300. Therefore, the power storage panel 10 can suppress the discharge of high-temperature gas, thereby improving safety. Since the shielding member 400 can lengthen the gas discharge path, there is no need to increase the amount of inert liquid 300 to lengthen the gas discharge path.

[0049] Since the shielding member 400 extends across multiple energy storage devices 200, the gas discharge path can be lengthened regardless of which of the multiple energy storage devices 200 discharges the gas.

[0050] Because a gap 420 is formed between the shielding member 400 and the housing 100, the gas whose temperature has been lowered by the shielding member 400 can be discharged through the gap 420 between the shielding member 400 and the housing 100.

[0051] Since the shielding member 400 has a through hole 410 in the center, the gas whose temperature has been lowered by the shielding member 400 can be discharged through the through hole 410 of the shielding member 400.

[0052] [3 Explanation of variations] Although an embodiment of the power storage panel 10 according to the present invention has been described above, the present invention is not limited to this embodiment. The embodiments disclosed herein are illustrative in all respects, and the scope of the present invention includes all modifications in the sense and scope equivalent to the claims.

[0053] (Variation 1) In the above embodiment, a gap 420 is formed between the shielding member 400 and the housing 100, and gas is discharged from the gap 420. However, a gap 420 does not need to be formed between the shielding member 400 and the housing 100. In this case, a through hole may be formed at the end of the shielding member 400, and gas may be discharged from the through hole. An example of this is described below. Figure 6 is a cross-sectional view showing the internal configuration of the housing 100 of the power storage panel 11 according to Modification 1 of this embodiment. Figure 6 corresponds to Figure 2.

[0054] As shown in Figure 6, the power storage panel 11 in this modified example is equipped with a shielding member 401 instead of the shielding member 400 provided in the power storage panel 10 in the above embodiment. No gap is formed between the shielding member 401 and the housing 100. The shielding member 401 is equipped with a through hole 421 at its end. The other configurations of this modified example are the same as in the above embodiment, so their description is omitted.

[0055] The through-hole 421 is a through-hole that penetrates the end of the shielding member 401 in the X-axis direction or the Y-axis direction in the Z-axis direction. In Figure 6, through-holes 421 are formed at both ends of the shielding member 401 in the X-axis direction, but the through-hole 421 may be formed at only one end of the shielding member 401 in the X-axis direction. If a through-hole 421 is formed at the end of the shielding member 401 in the positive X-axis direction, multiple through-holes 421 arranged in the Y-axis direction may be formed at that end. The same applies to the end of the shielding member 401 in the negative X-axis direction. Similarly, through-holes 421 may be formed at one or both ends of the shielding member 401 in the Y-axis direction. The shape and size of the through-hole 421 are not particularly limited.

[0056] In this modified example, the same effects as in the above embodiment can be achieved. In this modified example, the shielding member 401 is provided with a through hole 421 at its end, allowing the gas whose temperature has been lowered by the shielding member 401 to be discharged from the through hole 421 of the shielding member 401. In particular, in this modified example, since the shielding member 401 is in contact with the housing 100, it is easy to position the shielding member 401 relative to the housing 100, and it is easy to fix the shielding member 401 to the housing 100.

[0057] (Modification 2) In the above embodiment, the shielding member 400 is a flat plate-shaped member, but the shape of the shielding member 400 is not limited. The shielding member 400 may have recesses or protrusions formed on its upper or lower surface, or its upper or lower surface may be inclined. An example is described below. Figure 7 is a cross-sectional view showing the internal configuration of the housing 100 of the power storage panel 12 according to Modification 2 of this embodiment. Figure 7 is a diagram corresponding to Figure 2.

[0058] As shown in Figure 7, the power storage panel 12 in this modified example is equipped with a shielding member 402 instead of the shielding member 400 provided in the power storage panel 10 in the above embodiment. The shielding member 402 has an inclined surface 402a on its upper surface. The other configurations of this modified example are the same as in the above embodiment, so a description will be omitted.

[0059] The inclined surface 402a is an inclined surface formed on the Z-axis positive side of the shielding member 402. The inclined surface 402a is a surface that slopes gently in the Z-axis negative direction as it moves from the through hole 410 in the center of the shielding member 402 toward both the X-axis and Y-axis sides. In this modified example, the inclined surface 402a is continuously inclined from the through hole 410 to the gap 420. As a result, the shielding member 402 has a substantially frustoconical shape. The inclination angle of the inclined surface 402a is not particularly limited. The inclined surface 402a may be formed only on a part of the Z-axis positive side of the shielding member 402. The inclined surface 402a may have an inclined surface that slopes in the Z-axis negative direction as it moves toward the through hole 410.

[0060] In this modified example, the same effects as in the above embodiment can be achieved. In particular, in this modified example, since the shielding member 402 has an inclined surface 402a on its upper surface, even if the inert liquid 300 is sprayed onto the shielding member 402, the inclined surface 402a can level the inert liquid 300 on the shielding member 402.

[0061] (Other variations) In the above embodiment, the shielding member 400 extends in the X-axis direction across all energy storage devices 200 arranged in the X-axis direction. However, the shielding member 400 only needs to extend across at least two energy storage devices 200. Alternatively, the shielding member 400 may not span two energy storage devices 200, but may extend within the scope of one energy storage device 200.

[0062] In the above embodiment, the shielding member 400 is positioned between the liquid surface 301 of the inert liquid 300 and the energy storage device 200, with the distance to the liquid surface 301 being smaller than the distance to the energy storage device 200. However, the distance to the liquid surface 301 may be larger than the distance to the energy storage device 200. Alternatively, a portion of the shielding member 400 may protrude from the liquid surface 301 of the inert liquid 300 in the positive Z-axis direction. In other words, at least a portion of the shielding member 400 needs to be positioned within the inert liquid 300.

[0063] In the above embodiment, the shielding member 400 is provided with a through hole 410 in the center and a gap 420 is formed between it and the housing 100, and gas is discharged from the through hole 410 and the gap 420, but it is not limited to this. The shielding member 400 may not have a through hole 410 and gas may be discharged from the gap 420, or the shielding member 400 may not have a gap 420 formed between it and the housing 100 and gas may be discharged from the through hole 410.

[0064] In the above embodiment, the shielding member 400 may be a member with many through holes, such as a wire mesh. Even in this case, the gas discharge path can be blocked compared to the case where the shielding member 400 is not provided.

[0065] In the above embodiment, one shielding member 400 is provided, but the shielding member 400 may be divided into multiple parts. That is, multiple shielding members may be arranged in the X-axis direction or the Y-axis direction. Alternatively, multiple shielding members 400 may be arranged in the Z-axis direction. In this case, multiple shielding members 400 may be provided between the liquid surface 301 of the inert liquid 300 and the energy storage device 200, or shielding members 400 may be provided between energy storage devices 200 arranged in the Z-axis direction.

[0066] In the above embodiment, the housing 100 of the power storage panel 10 is provided with multiple shelves 160, but it is not limited to this. The housing 100 may have only one shelf 160, or it may not have any shelves 160 at all, with the power storage device 200 placed on the bottom wall 150. In this case, the bottom wall 150 on which the power storage device 200 is placed can be said to be a shelf of the housing 100. In other words, the housing 100 is provided with at least a shelf on which the power storage device 200 is placed.

[0067] In the above embodiment, the inert liquid 300 may be a liquid with a flash point lower than 250°C.

[0068] In the above embodiment, it is assumed that all energy storage devices 200 provided in the energy storage panel 10 have the above configuration, but it is not necessary for any of the energy storage devices 200 to have the above configuration. In the above embodiment, it is assumed that all energy storage elements 220 provided in the energy storage device 200 have the above configuration, but it is not necessary for any of the energy storage elements 220 to have the above configuration.

[0069] Embodiments constructed by arbitrarily combining the above embodiments and modifications are also included within the scope of the present invention. [Industrial applicability]

[0070] This invention can be applied to a power storage panel or the like equipped with a power storage device. [Explanation of Symbols]

[0071] 10, 11, 12 Storage panel 100 cabinets 160 shelf board 200, 201 Energy storage devices 220 Energy Storage Elements 221 Container 221c Gas discharge valve 222 terminals 300 Inert liquid 301 Liquid level 400, 401, 402 Shielding members 402a Slope 410, 421 Through holes 420 gap F1, F2, F3, F4 Emission Routes S1 first space S2 Second space

Claims

1. A power storage device equipped with a power storage element, A housing for the aforementioned energy storage device, An inert liquid is placed in the space within the housing where the energy storage device is housed, A shielding member is positioned in the inert liquid and along the surface of the inert liquid, and blocks the gas discharge path so as to allow gas from the energy storage element to be discharged. A power storage panel equipped with the following features.

2. The aforementioned power storage panel comprises a plurality of the aforementioned power storage devices, The shielding member extends across the plurality of energy storage devices. The power storage panel according to claim 1.

3. A gap is formed between the shielding member and the housing. The power storage panel according to claim 1 or 2.

4. The shielding member has a through hole in its center. The power storage panel according to claim 1 or 2.

5. The shielding member has an inclined surface on its upper surface. The power storage panel according to claim 1 or 2.

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