Battery assembly and vehicle

Abstract

Provided is a technical feature for improving safety of a battery assembly. Also provided is a battery assembly comprising a cell stack and a housing that accommodates the cell stack. In the cell stack, a plurality of cells are arranged between a pair of bus bar housings that extend along the horizontal direction. Each cell is provided with two or more electrode tabs that protrude toward one of the pair of bus bar housings, and two or more tabs that protrude toward the other of the pair of bus bar housings. The housing is provided with a pair of side walls that are disposed respectively facing the pair of bus bar housings and are each provided with a refrigerant flow path therein, and a bottom plate that supports the cell stack and is provided with a gas discharge path.

Description

Battery assembly and vehicle

[0001] Exemplary embodiments of the present disclosure relate to a battery assembly and a vehicle.

[0002] Patent Document 1 discloses a battery pack. The battery pack includes a plurality of battery modules, each including a battery cell stack in which a plurality of battery cells are stacked, a pack frame that houses the battery modules, HV lines connected to terminal bus bars of the battery modules, LV lines connected to a sensing assembly of the battery modules, and pack refrigerant pipes that supply refrigerant to the battery modules. The terminal bus bars are connected to the battery cells. The sensing assembly measures the temperature and voltage of the battery cells. The HV and LV lines are located above the pack refrigerant pipes.

[0003] JP 2024-45691 A

[0004] The present disclosure provides techniques for improving the safety of battery assemblies.

[0005] In one exemplary embodiment of the present disclosure, there is provided a battery assembly including: a cell stack in which a plurality of cells are arranged between a pair of bus bar housings extending along a horizontal direction, each cell having two or more electrode tabs protruding toward one of the pair of bus bar housings and two or more tabs protruding toward the other of the pair of bus bar housings; and a housing that accommodates the cell stack, the housing being arranged opposite the pair of bus bar housings, and including a pair of side walls that have coolant flow paths therein, and a bottom plate that supports the cell stack and has a gas discharge path.

[0006] According to one exemplary embodiment of the present disclosure, a technique for improving the safety of a battery assembly can be provided.

[0007] 1 is a perspective view illustrating an example of the configuration of a battery assembly 1. FIG. 2 is an exploded perspective view illustrating an example of the configuration of a cell stack 2. FIG. 3 is a perspective view illustrating an example of the configuration of a cell laminate 20. FIG. 4 is a perspective view illustrating an example of the configuration of a cell 200. FIG. 5 is a perspective view illustrating an example of the configuration of a housing 3. FIG. 6 is an exploded perspective view illustrating an example of the configuration of a housing 3. FIG. 7 is a cross-sectional view of a main part of the battery assembly 1. FIG. 8 is a perspective view of a main part illustrating the flow of a refrigerant FL. FIG. 9 is a plan view illustrating the flow of a refrigerant FL. FIG. 10 is a schematic diagram illustrating an example of a vehicle M equipped with the battery assembly 1.

[0008] Hereinafter, each embodiment of the present disclosure will be described.

[0009] In one exemplary embodiment, there is provided a battery assembly including: a cell stack in which a plurality of cells are arranged between a pair of bus bar housings extending horizontally, each cell having two or more electrode tabs protruding toward one of the pair of bus bar housings and two or more tabs protruding toward the other of the pair of bus bar housings; and a housing that accommodates the cell stack, the housing being arranged opposite the pair of bus bar housings, and including a pair of side walls having a coolant flow path therein, and a bottom plate that supports the cell stack and has a gas discharge path.

[0010] In one exemplary embodiment, the gas discharge path includes a gas inlet provided on the inner surface of the bottom plate, and a gas flow path that communicates with the gas inlet, passes through the inside of the bottom plate, and communicates with the outside of the housing.

[0011] In one exemplary embodiment, the gas inlet is located below the electrode tab.

[0012] In one exemplary embodiment, a plurality of gas inlets are provided along the horizontal direction.

[0013] In one exemplary embodiment, the gas supply device further includes a shielding member that shields the space between the electrode tab and the gas inlet from above and below.

[0014] In one exemplary embodiment, the shielding members are configured to rupture or melt open as pressure or temperature increases within the cell stack.

[0015] In one exemplary embodiment, the shielding member is a thin plate made of resin.

[0016] In one exemplary embodiment, the cell stack further includes a gas control plate, which is configured to partially cover the bus bar housing so as to guide gas generated inside the cell stack to the gas inlet.

[0017] In one exemplary embodiment, the cell stack further comprises a thermally conductive insulating sheet between the gas control plate and the bus bar housing.

[0018] In one exemplary embodiment, the cross section of the gas flow passage is generally triangular.

[0019] In one exemplary embodiment, each cell includes a sealed container that houses the electrode stack, and the sealed container is a substantially rectangular bag having a pair of short sides and a pair of long sides.

[0020] In one exemplary embodiment, the cells are arranged in a cell stack such that the direction in which a pair of short sides of the sealed container extend is vertically up and down.

[0021] In one exemplary embodiment, the polarity of the electrode tabs extending from the top half of one short side of the sealed container is different from the polarity of the electrode tabs extending from the top half of the other short side of the sealed container.

[0022] In one exemplary embodiment, a battery assembly is provided that includes: a cell stack in which a plurality of cells are arranged between a pair of bus bar housings extending horizontally, each cell having two or more electrode tabs protruding toward one of the pair of bus bar housings and two or more electrode tabs protruding toward the other of the pair of bus bar housings; and a housing that accommodates the cell stack and has a gas exhaust channel in its bottom plate.

[0023] In one exemplary embodiment, a vehicle is provided that includes a battery assembly, a motor powered by the battery assembly, and an exhaust system configured to direct gases from a gas exhaust passage to an exterior of the vehicle.

[0024] Hereinafter, each embodiment of the present disclosure will be described in detail with reference to the drawings. In each drawing, the same or similar elements are denoted by the same reference numerals, and redundant description will be omitted. The dimensional ratios in the drawings do not represent actual ratios, and the actual ratios are not limited to the illustrated ratios. In each drawing, the x-axis and y-axis may be horizontal, the z-axis may be vertical, and the positive direction of the z-axis may be referred to as "upper" or "upward," and the negative direction of the z-axis may be referred to as "lower" or "downward."

[0025] [Overall Configuration of Battery Assembly 1] Figure 1 is a perspective view illustrating an example of the configuration of a battery assembly 1 according to one embodiment. The battery assembly 1 includes a cell stack 2 and a housing 3 configured to house the cell stack 2. The cell stack 2 may be detachably housed in the housing 3 via a restraining holder or the like. The housing 3 includes side walls 30 that surround the side surfaces of the cell stack 2 and a bottom plate 31 that supports the underside of the cell stack 2.

[0026] In one embodiment, the housing 3 may be configured to accommodate a plurality of cell stacks 2. In this case, the housing 3 may include a plurality of bus bars 4 that electrically connect the cell stacks 2 together. The bus bars 4 may be made of a conductive material such as copper, aluminum, nickel, or an alloy thereof. The arrangement of the bus bars 4 and the connections between the bus bars 4 can be set as appropriate, thereby defining the electrical connection relationship (series, parallel) of the cell stacks 2. In the example shown in FIG. 1 , six cell stacks 2 are connected in series. The plurality of cell stacks 2 may be arranged in an array along a horizontal plane (xy plane).

[0027] [Configuration of Cell Stack 2] An example of the configuration of the cell stack 2 will be described with reference to Figures 2 to 4. Here, Figure 2 is an exploded perspective view for explaining an example of the configuration of the cell stack 2. Figure 3 is a perspective view for explaining an example of the configuration of the cell stack 20. Figure 4 is a perspective view showing an example of the configuration of the cell 200.

[0028] As shown in FIG. 2, the cell stack 2 may include a cell laminate 20, a compression pad 21, a pair of bus bar housings 22 (22A, 22B), a pair of thermally conductive sheets 23 (23A, 23B), a pair of gas control plates 24 (24A, 24B), an insulating sheet 25, and a cell stack housing 26.

[0029] <Cell Stack 20> As shown in Fig. 3, the cell stack 20 is configured to include a plurality of cells 200. The cells 200 are stacked in the horizontal direction (the x-axis direction in Fig. 3). The cells 200 may be pouch-type cells (also referred to as "pouch cells").

[0030] As shown in FIG. 4 , the cell 200 includes a sealed container 201 and electrode tabs 202 to 205 extending from the sealed container 201. The electrode tabs are sometimes referred to as "leads." An electrode stack (not shown) is housed inside the sealed container 201. The electrode stack may be constructed by stacking multiple sets (e.g., 10 to 50 sets) of positive electrodes, separators, and negative electrodes. In one embodiment, the electrode stack is a lithium secondary battery. The electrode stack may be housed in the sealed container 201 together with an electrolyte. The electrolyte may be a solution that fills the sealed container 201, may be impregnated into the separator of the electrode stack, or may be held in a polymer to form a polymer electrolyte or a gel electrolyte. The electrode tabs 202 to 205 are electrically connected to either the positive electrode current collector or the negative electrode current collector of the electrode stack.

[0031] In one embodiment, the positive and / or negative electrode current collectors of the electrode stack may be formed by sandwiching a resin layer between a pair of conductive layers. Such resin layers may be formed of sheet-like or fibrous resins. The resin may be, for example, at least one of polyolefin resins such as polyethylene terephthalate, polyethylene, or polypropylene, or thermoplastic resins such as polystyrene, polyvinyl chloride, or polyamide. When the current collector includes a resin layer, the resin layer may melt in the event of abnormal heat generation due to overcharge or high temperature, damaging the electrode to which the current collector is connected and interrupting short-circuit current within the battery. This may suppress a sudden temperature rise within the cell and prevent the cell from catching fire. In one embodiment, when the electrode stack includes multiple positive electrode current collectors and multiple negative electrode current collectors, at least one of the multiple positive electrode current collectors and the multiple negative electrode current collectors may be a current collector including a resin layer. At least one of the multiple positive electrode current collectors and the multiple negative electrode current collectors may be formed solely of a conductive material without including a resin layer.

[0032] 4, the sealed container 201 may be a substantially rectangular bag having a pair of long sides and a pair of short sides. The ratio (L / W) of the length W (mm) of the short side to the length L (mm) of the long side of the sealed container 201 may be 1.5<L / W<10.0, 2.0<L / W<5.0, or 2.5<L / W<5.0.

[0033] The sealed container 201 may be formed, for example, by overlapping a pair of sheet members and sealing them around their peripheries. The sealed container 201 may be formed, for example, by folding a single sheet member and sealing its periphery. In this case, the folded portion may form one of the long sides of the sealed container. The sheet member may be formed from multiple layers. For example, the sheet member may be formed by covering both sides of a thin metal sheet with a resin film. The sheet member may be, for example, an aluminum laminate film.

[0034] In one embodiment, two electrode tabs 202 and 203 are drawn out, one above the other, from one short side of the sealed container 201. Two electrode tabs 204 and 205 are drawn out, one above the other, from the other short side of the sealed container 201. An insulating material 206 such as a sealant film may be interposed between each of the electrode tabs 202 to 205 and the sealed portion of the sealed container 201. In one embodiment, three or more electrode tabs may be drawn out from one or both short sides of the sealed container 201.

[0035] In one embodiment, the polarities of the electrode tabs extending from the same short side may be different. For example, the polarities of electrode tab 202 and electrode tab 203 may be different. Also, the polarities of electrode tab 204 and electrode tab 205 may be different.

[0036] In one embodiment, the polarity of the electrode tabs extending from the upper half (or lower half) of one short side of the sealed container 201 may be different from the polarity of the electrode tabs extending from the upper half (or lower half) of the other short side. For example, the polarities of the electrode tabs 202 and 204 may be different. Also, the polarities of the electrode tabs 203 and 205 may be different.

[0037] In one embodiment, the polarity of the electrode tab extending from the upper half (or lower half) of one short side of the sealed container 201 may be the same as the polarity of the electrode tab extending from the upper half (or lower half) of the other short side. For example, the polarities of the electrode tabs 202 and 204 may be the same. Also, the polarities of the electrode tabs 203 and 205 may be the same.

[0038] In one example, electrode tabs 202 and 205 are electrode tabs for a negative electrode, and electrode tabs 203 and 204 are electrode tabs for a positive electrode. In another example, electrode tabs 203 and 204 are electrode tabs for a negative electrode, and electrode tabs 202 and 205 are electrode tabs for a positive electrode. In another example, electrode tabs 202 and 204 are electrode tabs for a negative electrode, and electrode tabs 203 and 205 are electrode tabs for a positive electrode. In another example, electrode tabs 202 and 204 are electrode tabs for a positive electrode, and electrode tabs 203 and 205 are electrode tabs for a negative electrode.

[0039] In one embodiment, the electrode tab for the positive electrode may be made of at least one material selected from the group consisting of aluminum, titanium, stainless steel, nickel, and alloys thereof. In one embodiment, the electrode tab for the negative electrode may be made of at least one material selected from the group consisting of copper, nickel, titanium, iron, metals that do not react with lithium, and alloys thereof, and stainless steel (SUS).

[0040] <Compression Pad 21> Returning to FIG. 2 , the explanation continues. As shown in the figure, the compression pads 21 can be arranged on both sides of the cell stack 20 in the stacking direction (the x-axis direction in the example of FIG. 2 ). The compression pads 21 can be, for example, polyurethane foam, silicone foam, or acrylic foam. The compression pads 21 can function as a buffer material to protect the cells 200 from impact and vibration. The compression pads 21 can function to mitigate expansion and contraction of the cells 200 associated with charging and discharging, and to maintain a uniform internal pressure in the cell stack 20. In one embodiment, the compression pads 21 can also be arranged between the cells 200 of the cell stack 20. In this case, the compression pads 21 can function to delay or prevent a thermal chain reaction between the cells 200. For example, if a cell 200 in the cell stack 20 ignites, the compression pads 21 can prevent the heat caused by the ignition from being transmitted to other adjacent cells 200.

[0041] <Busbar Housing 22> The pair of busbar housings 22 includes a first busbar housing 22A and a second busbar housing 22B. The first busbar housing 22A and the second busbar housing 22B are arranged to sandwich the cell stack 20 on the side (y-axis direction) from which the electrode tabs of the cell stack 20 protrude. Electrode tabs 202 and 203 of the cells 200 protrude toward the first busbar housing 22A. Electrode tabs 204 and 205 of the cells 200 protrude toward the second busbar housing 22B. In the following description, when there is no need to distinguish between the first busbar housing 22A and the second busbar housing 22B, they are simply referred to as "busbar housings 22." The same applies to the other "pairs" of configurations of the cell stack 2.

[0042] The bus bar housing 22 accommodates multiple bus bars 220. The bus bar housing 22 is made of an insulating material such as resin. The bus bars 220 may be made of a conductive material such as copper, aluminum, nickel, or an alloy thereof. Electrode tabs (see "201-204" in FIG. 2B) protruding from the cells 200 are connected to the bus bars 220 by welding, for example. The number and polarity of the electrode tabs connected to each bus bar 220 can be set as appropriate, thereby defining the electrical connection relationship (series or parallel) between the cells 200. The bus bars 220 provided at the ends of the bus bar housing 22 are also called terminals and can be connected to bus bars 4 (see FIG. 1). The bus bars 4 electrically connect the cell stacks 2 to each other.

[0043] <Thermal Conductive Sheet 23> The pair of thermally conductive sheets 23 includes a first thermally conductive sheet 23A and a second thermally conductive sheet 23B. The first thermally conductive sheet 23A is disposed on the outer side of the first bus bar housing 22A (the side opposite the surface facing the cell stack 20) ​​so as to cover the bus bar 220. The second thermally conductive sheet 23B is disposed on the outer side of the second bus bar housing 22B (the side opposite the surface facing the cell stack 20) ​​so as to cover the bus bar 220. The thermally conductive sheet 23 may be formed, for example, by sandwiching a sheet of silicone between resin films (e.g., PET film). The thermally conductive sheet 23 is thermally conductive and insulating, ensuring heat transfer between the bus bar housing 22 and the gas control plate 24 while electrically insulating the bus bar 220 and the gas control plate 24. The thermally conductive sheet 23 may contribute to improving the cooling efficiency of the battery assembly 1.

[0044] <Gas Control Plates 24> The pair of gas control plates 24 includes a first gas control plate 24A and a second gas control plate 24B. The first gas control plate 24A is disposed opposite the first bus bar housing 22A via the first thermally conductive sheet 23A. The second gas control plate 24B is disposed opposite the second bus bar housing 22B via the second thermally conductive sheet 23B. The gas control plate 24 is configured to cover at least the side surface (the surface on which the bus bar 220 is provided) and the top surface of the bus bar housing 22. The gas control plate 24 may be made of a material with excellent thermal conductivity and flame resistance. The gas control plate 24 may be configured, for example, by bending a metal plate made of aluminum, nickel, copper, or the like into a generally L-shape.

[0045] The gas control plate 24 can function to guide gas discharged from the cell stack 20 downward in the cell stack 2. For example, if the internal temperature rises in some of the cells 200 constituting the cell stack 20 due to an abnormality such as a short circuit, gas may leak from the cell 200. The gas control plate 24 suppresses or prevents such gas from flowing upward or to the sides of the cell stack 2, and guides it downward in the cell stack 2 (to a gas inlet 330 provided in the bottom plate 31 of the housing 3, which will be described later).

[0046] The cell stack 2 may be accommodated in the housing 3 such that the gas control plate 24 abuts against the side wall 30 of the housing 3. This may improve the cooling efficiency of the battery assembly 1. In one embodiment, a thermally conductive paste may be applied to the surface of the gas control plate 24 (the surface facing the side wall 30 of the housing) to increase adhesion between the gas control plate 24 and the side wall 30. This may improve the cooling efficiency of the battery assembly 1.

[0047] <Insulating Sheet 25> The insulating sheet 25 is provided to cover the cell stack 20. The insulating sheet 25 may be made of one or more resin sheets. The insulating sheet 25 may be made of, for example, polypropylene, polycarbonate, polyethylene, polyamide, polyethylene terephthalate, ABS, carbon reinforced plastic (CFRP), or a composite material thereof. The insulating sheet 25 may be disposed on a surface of the cell stack 20 other than the surface on which the bus bar housing 22 is provided. The insulating sheet 25 may be bonded to the cell stack 20 with an adhesive such as urethane or epoxy.

[0048] <Cell stack housing 26> The cell stack housing 26 is a housing made of, for example, metal that houses the cell stack 20. The cell stack housing 26 is configured to cover at least the lower surface of the cell stack 20 and both sides of the cell stack 20 in the stacking direction (x-axis direction). The cell stack housing 26 is configured to be in close contact with both sides of the cell stack 20 in the stacking direction and to apply pressure to the cell stack 20. In other words, the cell stack 20 is pressurized in the stacking direction by the cell stack housing 26 and is housed within the cell stack housing 26.

[0049] [Configuration of Housing 3] An example of the configuration of the housing 3 will be described with reference to Figures 5 and 6. Figure 5 is a perspective view for explaining the example of the configuration of the housing 3. Figure 6 is an exploded perspective view for explaining the example of the configuration of the housing 3.

[0050] 5 and 6 , the housing 3 includes a side wall 30 and a bottom plate 31 disposed below the side wall 30. The housing 3 is configured to protect the cell stack 2 from external impacts and the like. The housing 3 is also configured to release heat generated in the cell stack 2 to the outside. The housing 3 may be made of a material that has high rigidity and thermal conductivity. For example, the housing 3 may be made of a metal material such as aluminum.

[0051] The housing 3 may be configured to accommodate a plurality of cell stacks 2 aligned along a horizontal plane (xy plane). In this case, the side walls 30 may be arranged in a grid pattern in a plan view (when the housing 3 is viewed from the positive direction of the z axis) so as to separate the space in which the plurality of cell stacks 2 are arranged. For example, as shown in FIG. 6 , the side walls 30 may be configured such that first to fourth side wall portions 301 to 304 extending along the x axis direction and fifth to seventh side wall portions 305 to 307 extending along the y axis direction are arranged in a grid pattern. The side walls define an accommodation space for accommodating the cell stacks 2.

[0052] For example, the storage space SP1 is defined by a space partitioned by the first side wall portion 301 and the second side wall portion 302, and the fifth side wall portion 305 and the sixth side wall portion 306. The distance between each side wall portion is set according to the shape of the cell stack 2 to be stored. For example, the distances between the first side wall portion 301 to the fourth side wall portion 304 can be set so that the cell stack 2 abuts against these side wall portions.

[0053] The side wall 30 has a refrigerant flow path 32 (see FIGS. 7 to 9 ) through which a refrigerant FL flows to cool the cell stack 2. The refrigerant FL may be a liquid refrigerant (e.g., water, water-glycol liquid, oil, etc.) or a gaseous refrigerant (e.g., an air conditioner refrigerant such as HFO-1234yf or HFC-134a). A first side wall portion 301 of the side wall 30 is provided with a refrigerant inlet 308 for introducing the refrigerant into the refrigerant flow path 32 and a refrigerant outlet 309 for discharging the refrigerant from the refrigerant flow path 32. An example of the configuration of the refrigerant flow path 32 will be described later with reference to FIGS. 7 to 9 .

[0054] The bottom plate 31 can be configured as a plate-like body that covers from below the space defined by the side wall 30. The bottom plate 31 includes a gas exhaust path 33 for exhausting gas from the cell stack 2. An example of the configuration of the gas exhaust path 33 will be described later with reference to FIGS.

[0055] <Refrigerant Flow Channel 32> An example of the configuration of the refrigerant flow channel 32 will be described with reference to Figures 7 to 9. Figure 7 is a cross-sectional view of a main portion of the battery assembly 1. Figure 8 is a perspective view of a main portion for explaining the flow of the refrigerant FL. Figure 9 is a plan view (view of the housing 3 from the positive direction of the z-axis) for explaining the flow of the refrigerant FL. Note that in Figures 8 and 9, the arrows indicate the direction in which the refrigerant FL flows through the refrigerant flow channel 32.

[0056] 7 to 9, the refrigerant flow paths 32 are provided at least in the side walls (hereinafter also referred to as "cooling side walls"; in the illustrated example, these are the first side wall portion 301 to the fourth side wall portion 304) that face the gas control plate 24 of the cell stack 2. The refrigerant FL flowing through the cooling side walls can cool each cell 200 of the cell stack 20 via the gas control plate 24 and the like.

[0057] The refrigerant flow path 32 may form two or more flow paths in the cooling side wall. In the example shown in Fig. 7, the refrigerant flow path 32 includes an upper flow path 32A and a lower flow path 32B in the cooling side wall. The upper flow path 32A and the lower flow path 32B may be disposed in positions facing the electrode tabs 202, 203 protruding from each cell 200 of the cell stack 2. Because the electrode tabs can become very hot, disposing the refrigerant flow path in a position close to the electrode tabs can improve the cooling efficiency of the cell stack 2.

[0058] 8 and 9 , the coolant flow path 32 may be provided in a side wall connecting adjacent cooling side walls (hereinafter also referred to as a “connecting side wall”; in the illustrated example, this is the sixth side wall portion 306). Note that the coolant flow path 32 may be provided in the fifth side wall portion 305 and / or the seventh side wall portion 307.

[0059] 8 and 9 , the coolant FL introduced from the coolant inlet 308 flows through two upper and lower flow paths in the first side wall 301 (cooling side wall), turning back from bottom to top. Next, the coolant FL passes through a coolant flow path in the sixth side wall 306 (connecting side wall) and flows through two upper and lower flow paths in the second side wall 302 (cooling side wall), from top to bottom. This cools the cell stack 2 accommodated in the accommodation space SP1. In the same manner, the coolant FL flowing through the coolant flow paths sequentially cools each cell stack 2 and is discharged from the coolant inlet 308.

[0060] 5 to 7, an example of the configuration of the gas exhaust path 33 will be described. The gas exhaust path 33 includes a gas inlet 330 and a gas flow path 331.

[0061] 5 and 6, the gas inlet 330 is provided on the inner surface of the bottom plate 31 (the surface facing the cell stack 2). A plurality of gas inlets 330 may be provided. The plurality of gas inlets 330 may be provided in rows along the stacking direction (x-axis direction) of the cell stack 20 of the cell stack 2. For example, as shown in FIG. 6, for one storage space SP1, a first row L1 consisting of a plurality of gas inlets 330 and a second row L2 consisting of a plurality of gas inlets 330 may be configured. The first row L1 and the second row L2 are parallel to each other.

[0062] 7 , each gas inlet 330 constituting the first row L1 may be provided below the electrode tabs 202 and 203. Similarly, each gas inlet 330 constituting the second row L2 may be provided below the electrode tabs 204 and 205. Gas from the cells 200 tends to leak out from the short sides of the sealed container 201 where the electrode tabs are arranged, and is guided below the cell stack 20 by the gas control plate 24. By providing the gas inlet 330 below the electrode tabs 204 and 205, the gas from the cells 200 can be efficiently introduced into the gas inlet.

[0063] In one embodiment, a shielding member may be provided in a space SP2 (see FIG. 7 ) between the electrode tab and the gas inlet 330 disposed below the electrode tab. The shielding member is configured to shield the space SP2 from above and below. The shielding member may be configured to break or melt with an increase in pressure or temperature within the cell stack 2. In this case, the cell stack 2 is isolated from the gas inlet 330 until the shielding member breaks or melts. This can improve the airtightness of the cell stack 2. The shielding member may be, for example, a thin plate made of resin. Examples of resins include polypropylene, polycarbonate, polyethylene, polyamide, polyethylene terephthalate, ABS, carbon reinforced plastic (CFRP), and composite materials thereof.

[0064] 5 and 6, a plurality of gas flow paths 331 may be provided. The plurality of gas flow paths 331 may be configured such that the cross-sectional shape of adjacent gas flow paths 331 is an upside-down triangle. In this case, the cross-sectional shape of the bottom plate 31 has a truss structure. This makes it possible to ensure the strength of the bottom plate 31 even when a plurality of gas flow paths 331 are provided inside the bottom plate 31.

[0065] 7, the gas flow path 331 communicates with the gas inlet 330 and passes through the inside of the bottom plate 31 to communicate with the outside of the housing 3. As a result, the gas introduced into the gas inlet 330 passes through the gas flow path 331 inside the bottom plate 31 and is discharged from the housing 3. Note that in the example shown in FIG. 7, the gas flow path 331 is provided along the y-axis direction, but the direction in which the gas flow path 331 extends is not limited to this.

[0066] As described above, the battery assembly 1 can efficiently cool the cell stack 2 and can efficiently discharge gas discharged from the cell stack 2 to the outside. This can improve the safety of the battery assembly 1.

[0067] [Vehicle M Equipped with Battery Assembly 1] Figure 10 is a schematic diagram showing an example of a vehicle M equipped with a battery assembly 1. The vehicle M is an electric vehicle. The vehicle M includes the battery assembly 1 disposed on, for example, the floor of the vehicle body, a motor MT driven by power from the battery assembly 1, a PCU that controls the operation of both, and an exhaust system VS. The exhaust system VS is connected to a gas exhaust passage 33 of the housing 3 of the battery assembly 1 and is configured to exhaust gas from the battery assembly 1 to the outside of the vehicle M.

[0068] In one embodiment, the battery assembly 1 can be applied not only to electric vehicles, but also to vehicles such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (P-HEVs), electric motorcycles, and electric bicycles, as well as various mobile objects (drones, robots, power tools, ships, airplanes, etc.) and stationary systems.

[0069] [Additional Notes] The embodiments of the present disclosure further include the following aspects.

[0070] (Supplementary Note 1) A battery assembly comprising: a cell stack in which a plurality of cells are arranged between a pair of bus bar housings extending along a horizontal direction, each cell having two or more electrode tabs protruding toward one of the pair of bus bar housings and two or more tabs protruding toward the other of the pair of bus bar housings; and a housing that accommodates the cell stack, the housing comprising: a pair of side walls that are arranged opposite the pair of bus bar housings, respectively, and have a refrigerant flow path therein; and a bottom plate that supports the cell stack and has a gas discharge path.

[0071] (Supplementary Note 2) The battery assembly according to Supplementary Note 1, wherein the gas exhaust path includes a gas inlet provided on an inner surface of the bottom plate, and a gas flow path that communicates with the gas inlet, passes through the inside of the bottom plate, and communicates with the outside of the housing.

[0072] (Supplementary Note 3) The battery assembly according to Supplementary Note 2, wherein the gas inlet is provided below the electrode tab.

[0073] (Supplementary Note 4) The battery assembly according to Supplementary Note 2 or Supplementary Note 3, wherein the gas inlet port is provided in plurality along the horizontal direction.

[0074] (Supplementary Note 5) The battery assembly according to any one of Supplementary Note 2 to Supplementary Note 4, further comprising a shielding member that shields a space between the electrode tab and the gas inlet from above and below.

[0075] (Supplementary Note 6) The battery assembly according to Supplementary Note 5, wherein the shielding member is configured to break or melt with an increase in pressure or temperature within the cell stack.

[0076] (Supplementary Note 7) The battery assembly according to Supplementary Note 5 or Supplementary Note 6, wherein the shielding member is a thin plate made of resin.

[0077] (Supplementary Note 8) The battery assembly according to any one of Supplementary Note 2 to Supplementary Note 7, wherein the cell stack further includes a gas control plate, the gas control plate being configured to partially cover the bus bar housing so as to guide gas generated inside the cell stack to the gas inlet.

[0078] (Supplementary Note 9) The battery assembly according to Supplementary Note 8, wherein the cell stack further includes a thermally conductive insulating sheet between the gas control plate and the bus bar housing.

[0079] (Supplementary Note 10) The battery assembly according to any one of Supplementary Note 2 to Supplementary Note 9, wherein a cross section of the gas flow path is substantially triangular.

[0080] (Supplementary Note 11) The battery assembly according to any one of Supplementary Note 1 to Supplementary Note 10, wherein each of the cells includes a sealed container that houses an electrode stack, and the sealed container is a substantially rectangular bag having a pair of short sides and a pair of long sides.

[0081] (Supplementary Note 12) The battery assembly according to Supplementary Note 11, wherein each of the cells is arranged in the cell stack such that a pair of short sides of the sealed container extend in a vertical direction.

[0082] (Supplementary Note 13) The battery assembly according to Supplementary Note 12, wherein the polarity of the electrode tab drawn out from the upper half of one short side of the sealed container is different from the polarity of the electrode tab drawn out from the upper half of the other short side of the sealed container.

[0083] (Supplementary Note 14) A battery assembly comprising: a cell stack in which a plurality of cells are arranged between a pair of bus bar housings extending along a horizontal direction, each cell having two or more electrode tabs protruding toward one of the pair of bus bar housings and two or more electrode tabs protruding toward the other of the pair of bus bar housings; and a housing that accommodates the cell stack and has a gas exhaust channel in its bottom plate.

[0084] (Supplementary Note 15) A vehicle comprising: a battery assembly according to any one of Supplementary Note 1 to Supplementary Note 14; a motor powered by the battery assembly; and an exhaust system configured to direct gas from the gas exhaust path to the outside of the vehicle.

[0085] The above embodiments are described for the purpose of explanation and are not intended to limit the scope of the present disclosure. Various modifications can be made to the above embodiments without departing from the scope and spirit of the present disclosure. For example, some components in one embodiment can be added to other embodiments. Also, some components in one embodiment can be replaced with corresponding components in other embodiments.

[0086] REFERENCE SIGNS LIST 1 battery assembly, 2 cell stack, 20 cell stack, 200 cell, 201 sealed container, 202 to 205 electrode tabs, 21 compression pad, 22 bus bar housing, 23 thermally conductive sheet, 24 gas control plate, 25 insulating sheet, 26 cell stack housing, 3 housing, 30 side wall, 31 bottom plate, 32 refrigerant flow path, 33 gas exhaust path, 330 gas inlet, 331 gas flow path, 4 bus bar, M vehicle

Claims

1. A battery assembly comprising: a cell stack in which a plurality of cells are arranged between a pair of bus bar housings extending horizontally, each cell having two or more electrode tabs protruding toward one of the pair of bus bar housings and two or more tabs protruding toward the other of the pair of bus bar housings; and a housing that accommodates the cell stack, the housing comprising: a pair of side walls that are arranged opposite the pair of bus bar housings and have coolant flow paths therein; and a bottom plate that supports the cell stack and has a gas discharge path.

2. The battery assembly according to claim 1, wherein the gas discharge path comprises a gas inlet provided on the inner surface of the bottom plate, and a gas flow path that communicates with the gas inlet, passes through the inside of the bottom plate, and communicates with the outside of the housing.

3. The battery assembly according to claim 2, wherein the gas inlet is provided below the electrode tab.

4. The battery assembly according to claim 3, wherein a plurality of the gas inlets are provided along the horizontal direction.

5. The battery assembly according to claim 3, further comprising a shielding member for shielding a space between the electrode tab and the gas inlet from above and below.

6. The battery assembly according to claim 5, wherein the shielding member is configured to break or melt as the pressure or temperature inside the cell stack increases.

7. The battery assembly according to claim 6, wherein the shielding member is a thin plate made of resin.

8. The battery assembly according to claim 2, wherein the cell stack further comprises a gas control plate, the gas control plate being configured to partially cover the bus bar housing so as to guide gas generated inside the cell stack to the gas inlet.

9. The battery assembly of claim 8, wherein the cell stack further comprises a thermally conductive insulating sheet between the gas control plate and the bus bar housing.

10. The battery assembly of claim 2, wherein the cross section of the gas flow passage is generally triangular.

11. The battery assembly according to claim 1, wherein each of the cells includes a sealed container that houses an electrode stack, and the sealed container is a substantially rectangular bag having a pair of short sides and a pair of long sides.

12. The battery assembly according to claim 11, wherein each of the cells is arranged in the cell stack so that the direction in which a pair of short sides of the sealed container extend is vertically up and down.

13. The battery assembly according to claim 12, wherein the polarity of the electrode tab drawn from the upper half of one short side of the sealed container is different from the polarity of the electrode tab drawn from the upper half of the other short side of the sealed container.

14. A battery assembly comprising: a cell stack in which a plurality of cells are arranged between a pair of bus bar housings extending horizontally, each cell having two or more electrode tabs protruding toward one of the pair of bus bar housings and two or more electrode tabs protruding toward the other of the pair of bus bar housings; and a housing that houses the cell stack and has a gas exhaust channel in its bottom plate.

15. A vehicle comprising: a battery assembly according to claim 1; a motor powered by said battery assembly; and an exhaust system configured to direct gas from said gas exhaust passage to the outside of said vehicle.

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