Battery assembly and vehicle

Abstract

The present invention provides technology which improves the electrical characteristics and safety of a battery assembly. The present invention relates to a battery assembly comprising: pair of bus bar housings provided with bus bars disposed in two stages along the vertical direction and extending in the horizontal direction; and a cell stack in which a plurality of cells are disposed between the pair of bus bar housings, wherein each cell is provided with two electrode tabs that protrude toward one of the pair of bus bar housings and two tabs that protrude toward the other of the pair of bus bar housings.

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 electrical characteristics and safety of battery assemblies.

[0005] In one exemplary embodiment of the present disclosure, there is provided a battery assembly including: a pair of bus bar housings including bus bars extending horizontally and arranged in two tiers vertically; and a cell stack in which a plurality of cells are arranged between the pair of bus bar housings, each cell including two electrode tabs protruding toward one of the pair of bus bar housings and two tabs protruding toward the other of the pair of bus bar housings.

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

[0007] FIG. 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 bus bar housing 22. FIG. 4 is a perspective view illustrating an example of the configuration of a cell stack 20. FIG. 5 is a perspective view illustrating an example of the configuration of a cell 200. FIG. 6 is an exploded perspective view illustrating an example of the configuration of a housing 3. FIG. 7 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 comprising: a pair of bus bar housings each having bus bars extending horizontally and arranged in two tiers vertically; and a cell stack in which a plurality of cells are arranged between the pair of bus bar housings, each cell having two electrode tabs protruding toward one of the pair of bus bar housings and two tabs protruding toward the other of the pair of bus bar housings.

[0010] 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.

[0011] 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.

[0012] 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.

[0013] In one exemplary embodiment, the bus bars arranged in two stages are arranged so as not to overlap each other in the vertical direction.

[0014] In one exemplary embodiment, the bus bars arranged in two stages are alternately arranged along the horizontal direction.

[0015] In one exemplary embodiment, a pair of bus bar housings have terminals at both horizontal ends.

[0016] In one exemplary embodiment, the electrode stack includes a current collector having a resin layer and a pair of conductive layers provided on both sides of the resin layer.

[0017] In one exemplary embodiment, a vehicle is provided that includes at least one battery assembly and a motor powered by the battery assembly.

[0018] In one exemplary embodiment, the direction of travel of the vehicle and the stacking direction of the plurality of cell stacks in the at least one battery assembly are substantially perpendicular to each other.

[0019] 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."

[0020] [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.

[0021] 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).

[0022] [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 2A is an exploded perspective view for explaining an example of the configuration of the cell stack 2. Figure 2B is a perspective view for explaining an example of the configuration of the bus bar housing 22. 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.

[0023] As shown in FIG. 2A, 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.

[0024] <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").

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] In one embodiment, two electrode tabs 202 and 203 are drawn out vertically from one short side of the sealed container 201. Two electrode tabs 204 and 205 are drawn out vertically 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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).

[0035] <Compression Pad 21> Returning to FIG. 2A , the description 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. 2A ). The compression pads 21 can be, for example, polyurethane foam, silicone foam, or acrylic foam. The compression pads 21 can function as a cushioning material to protect the cells 200 from impact and vibration. The compression pads 21 can also 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.

[0036] <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.

[0037] The busbar housing 22 accommodates multiple busbars 220. The busbar housing 22 is made of an insulating material such as resin. The busbars 220 may be made of a conductive material such as copper, aluminum, nickel, or an alloy thereof. Electrode tabs (see "202 to 205" in FIG. 4) protruding from the cells 200 are connected to the busbars 220 by welding, for example. The number and polarity of the electrode tabs connected to each busbar 220 can be set as appropriate, thereby defining the electrical connection relationship (series or parallel) between the cells 200. The busbars 220 provided at the ends of the busbar housing 22 are also referred to as terminals 221 and can be connected to busbars 4 (see FIG. 1). The busbars 4 electrically connect the cell stacks 2 to each other.

[0038] In the bus bar housing 22, the bus bars 220 are arranged in two tiers along the vertical direction (z-axis direction), including an upper vertical bus bar 220a and a lower vertical bus bar 220b. The upper vertical electrode tab (electrode tab 202 or 204 in FIG. 4 ) is connected to the upper vertical bus bar 220a, and the lower vertical electrode tab (electrode tab 203 or 205 in FIG. 4 ) is connected to the lower vertical bus bar 220b. This creates two current paths: an upper current path formed via bus bar 220a and a lower current path formed via bus bar 220b, allowing for efficient current extraction. In one embodiment, an insulating member 222 is disposed between the two tiers of bus bars. This prevents short-circuiting between the two current paths. The insulating member 222 may be made of the same insulating material, such as resin, that forms the bus bar housing 22.

[0039] 2B , in one embodiment, a horizontal gap 223 exists between the bus bar 220 and the bus bar housing 22. Electrode tabs protruding from the cells 200 are inserted into this gap 223 and welded to connect the electrode tabs to the bus bar 220. Inserting multiple electrode tabs of the same polarity into the same gap 223 allows multiple cells 200 to be connected in parallel. For example, by inserting multiple positive electrode tabs into the gaps 223 on one side of the gaps 223 on both sides of the bus bar 220 and inserting multiple negative electrode tabs into the gaps 223 on the other side, a cell group made up of multiple cells 200 connected in parallel can be connected in series.

[0040] In one embodiment, in a plan view of the bus bar housing 22 viewed from the vertical direction, the bus bars 220a and the bus bars 220b do not overlap each other. Furthermore, in one embodiment, in a plan view of the bus bar housing 22 viewed from the vertical direction, the bus bars 220b are arranged between adjacent bus bars 220a. Furthermore, in one embodiment, the bus bars 220a and the bus bars 220b arranged in two tiers are arranged alternately along the horizontal direction (the x-axis direction in FIGS. 2A and 3 ). Arranging the bus bars 220 in two tiers in this manner further prevents the bus bars 220a and the bus bars 220b from coming into contact with each other and shorting out.

[0041] In a plan view of the bus bar housing 22 viewed from the vertical direction, when a bus bar 220 b is disposed between adjacent bus bars 220 a, and cell groups each consisting of a plurality of cells 200 connected in parallel are connected in series via the bus bars 220, the polarity of the electrode tabs drawn from the upper half (or lower half) of one short side of the sealed container 201 is different from the polarity of the electrode tabs drawn from the upper half (or lower half) of the other short side, and the polarities of the electrode tabs drawn from the same short side are also different from each other. For example, the electrode tabs 202 and 205 can be negative electrodes, and the electrode tabs 203 and 204 can be positive electrodes.

[0042] The bus bars 220 do not all have to be arranged in two rows along the vertical direction. For example, the terminals 221 of the bus bars 220 provided at the ends of the bus bar housing 22 may be provided in a single row so as to penetrate the bus bar housing 22 in the vertical direction in order to extract the lower current formed through the bus bar 220 b and transmit it to the bus bar 4. In one embodiment, the terminals 221 at one end of the bus bar housing 22 are provided in a single row so as to penetrate the bus bar housing 22 in the vertical direction, and the terminals 221 at the other end are provided in a row on the upper side in the extension direction of the bus bar housing 22.

[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 downwards 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 those cells 200. The gas control plate 24 suppresses or prevents such gas from flowing upwards or to the sides of the cell stack 2, and guides it downwards in the cell stack 2 (to a gas discharge path 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 Fig. 5. Fig. 5 is an exploded perspective view for explaining the example of the configuration of the housing 3.

[0050] <Side Walls 30 and Bottom Plate 31> As shown in Fig. 5, the housing 3 includes side walls 30 and a bottom plate 31 disposed below the side walls 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. 5 , 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 through which a refrigerant flows to cool the cell stack 2. The refrigerant may be a liquid refrigerant (e.g., water, water-glycol liquid, oil, etc.) or a gaseous refrigerant (e.g., a refrigerant for air conditioners 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 and a refrigerant outlet 309 for discharging the refrigerant from the refrigerant flow path.

[0054] The bottom plate 31 may be configured as a plate-like body that covers from below the space defined by the side wall 30. In one embodiment, the bottom plate 31 may include a gas exhaust path 330 for exhausting gas from the cell stack 2.

[0055] As described above, the battery assembly 1 can extract current efficiently and has a high level of safety.

[0056] [Vehicle M Including Battery Assembly 1] FIG. 6 is a schematic diagram showing an example of a vehicle M including a battery assembly 1. The vehicle M is an electric vehicle. The vehicle M includes a battery assembly 1 disposed on, for example, the floor of the vehicle body, a motor MT driven by power from the battery assembly 1, and a PCU that controls the operation of both. In the vehicle M, the motor MT rotates the tires T, causing the vehicle M to travel in a forward direction (direction F in FIG. 6 ). In one embodiment, the battery assembly 1 is disposed in the vehicle M so that the stacking direction of the multiple cell stacks in the battery assembly 1 is approximately perpendicular to the forward direction of the vehicle M. In other words, because the stacking direction of the cell stacks coincides with the width direction of the vehicle M (direction W in FIG. 6 ), no bus bars or electrode tabs of the battery assembly 1 are disposed on the side of the vehicle M. Therefore, even if another vehicle or the like collides with the side of the vehicle M, a fire is unlikely to break out in the battery assembly 1, ensuring the safety of the vehicle M.

[0057] 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.

[0058] [Additional Notes] The embodiments of the present disclosure further include the following aspects.

[0059] (Supplementary Note 1) A battery assembly comprising: a pair of bus bar housings including bus bars extending horizontally and arranged in two tiers vertically; and a cell stack in which a plurality of cells are arranged between the pair of bus bar housings, each cell including two electrode tabs protruding toward one of the pair of bus bar housings and two tabs protruding toward the other of the pair of bus bar housings.

[0060] (Supplementary Note 2) The battery assembly according to Supplementary Note 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.

[0061] (Supplementary Note 3) The battery assembly according to Supplementary Note 2, 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.

[0062] (Supplementary Note 4) The battery assembly according to Supplementary Note 2 or 3, 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.

[0063] (Supplementary Note 5) The battery assembly according to any one of Supplementary Notes 1 to 4, wherein the bus bars arranged in two stages are arranged so as not to overlap each other along the vertical direction.

[0064] (Supplementary Note 6) The battery assembly according to any one of Supplementary Notes 1 to 5, wherein the bus bars arranged in two stages are arranged alternately along the horizontal direction.

[0065] (Supplementary Note 7) The battery assembly according to any one of Supplementary Notes 1 to 6, wherein the pair of bus bar housings are provided with terminals at both ends in the horizontal direction.

[0066] (Supplementary Note 8) The battery assembly according to any one of Supplementary Notes 2 to 7, wherein the electrode stack includes a current collector having a resin layer and a pair of conductive layers provided on both sides of the resin layer.

[0067] (Supplementary Note 9) A vehicle comprising: at least one battery assembly according to any one of Supplementary Notes 1 to 8; and a motor supplied with power from the battery assembly.

[0068] (Supplementary Note 10) The vehicle according to Supplementary Note 9, wherein a traveling direction of the vehicle and a stacking direction of the plurality of cell stacks in the at least one battery assembly are substantially perpendicular to each other.

[0069] 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.

[0070] 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, 330 gas exhaust channel, 4 bus bar, M vehicle

Claims

1. A battery assembly comprising: a pair of bus bar housings each having bus bars extending horizontally and arranged in two vertical stages; and a cell stack in which a plurality of cells are arranged between the pair of bus bar housings, each cell having two electrode tabs protruding toward one of the pair of bus bar housings and two tabs protruding toward the other of the pair of bus bar housings.

2. The battery assembly according to claim 1, wherein each of the cells has 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.

3. The battery assembly according to claim 2, 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.

4. The battery assembly according to claim 3, 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.

5. The battery assembly according to claim 4, wherein the bus bars arranged in two stages are arranged so as not to overlap each other in the vertical direction.

6. The battery assembly according to claim 5, wherein the bus bars arranged in two stages are arranged alternately along the horizontal direction.

7. The battery assembly according to claim 4, wherein the pair of bus bar housings are provided with terminals at both ends in the horizontal direction.

8. The battery assembly according to claim 2, wherein the electrode stack comprises a current collector having a resin layer and a pair of conductive layers provided on both sides of the resin layer.

9. A vehicle comprising: at least one battery assembly according to claim 1; and a motor powered by said battery assembly.

10. The vehicle according to claim 9, wherein the direction of travel of the vehicle and the stacking direction of the plurality of cell stacks in the at least one battery assembly are substantially perpendicular to each other.

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