Spacers and battery modules for battery stacks

Abstract

To provide a spacer for battery stacks that can improve heat exchange efficiency. [Solution] The spacer 10 for the battery stack 20 is interposed between two adjacent single cells and has a plate-shaped spacer body 11 having a first side surface 10A facing the first single cell 2A and a second side surface 10B facing the second single cell 2B. The first side surface is provided with a first contact portion 11A, defining a plurality of first flow paths 31 between it and the first single cell 2A. The second side surface is provided with a second contact portion 11B, defining a plurality of second flow paths 32 between it and the second single cell 2B. A plurality of communication holes 12 provided through the spacer body 11 connect adjacent first flow paths 31 and second flow paths 32.

Description

Technical Field

[0001] The present invention relates to a spacer used for a battery laminate and a battery module using the same.

Background Art

[0002] In a battery module including a battery laminate in which a plurality of single cells are laminated, a configuration is known in which a spacer is provided between single cells arranged in parallel with each other and a ventilation path is provided. The spacer is shaped to have, for example, ribs or bent portions that contact the wide main surface of a square single cell in order to hold the space between two adjacent single cells and prevent contact due to expansion or vibration of the single cells. At this time, the space partitioned by the ribs or bent portions serves as a flow path through which cooling air circulates, and adjacent single cells can be cooled.

[0003] For example, Patent Document 1 discloses a configuration in a power storage device including a cooling path between a plurality of single cells, in which a plurality of ribs are formed to protrude on one surface of a plate-like partition member having connecting portions vertically, and a cooling path is defined between the partition member and one single cell. The other surface of the partition member is configured as a flat surface that contacts the other single cell in a plane. The cooling path is configured such that a refrigerant is introduced from the outside through a supply path formed in the case.

[0004] Further, Patent Document 2 discloses a configuration in a battery module in which battery cells and frame members are alternately laminated, and the frame member has an inner portion configured as an elastic member made of a soft resin on the inner peripheral side of a hard resin outer frame portion at least in a partial range. A plurality of linear or dot-like flow path forming ribs are integrally formed on one or both surfaces of the inner portion to form a refrigerant flow path between the inner portion and the battery cell. Furthermore, Patent Document 3 discloses a battery module in which a plurality of prismatic spacer members are arranged substantially parallel to each other on a wide surface of a battery to serve as a spacer for maintaining a ventilation gap in a case.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2014-110191 [Patent Document 2] Japanese Patent Publication No. 2020-043005 [Patent Document 3] International Publication No. 2017 / 154076 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, in the conventional configuration described above, it cannot necessarily be said that the refrigerant flowing through the refrigerant channel efficiently exchanges heat with the individual cells, and there is room for improvement.

[0007] This invention was made in view of the above background, and provides a spacer for a battery stack that can improve heat exchange efficiency, and a battery module using the same. [Means for solving the problem]

[0008] One aspect of the present invention is, A battery stack spacer used in a battery stack comprising multiple single cells arranged parallel to each other, A plate-shaped spacer body is interposed between two adjacent single cells and has a first side facing the side of the first single cell, which is one of the two single cells, and a second side facing the side of the second single cell, which is the other of the two single cells. A plurality of first contact portions are provided on the first side surface, protruding so as to be able to contact the first single cell, and defining a plurality of first flow channels parallel to each other between the first side surface and the first single cell, A plurality of second contact portions are provided on the second side surface, protruding so as to be able to contact the second single cell, and defining a plurality of parallel second flow paths between the second side surface and the second single cell, The battery stack spacer comprises a plurality of communication holes that penetrate the main body of the spacer and connect adjacent first and second flow channels.

[0009] Furthermore, other embodiments of the present invention include: In a battery module comprising a battery stack in which multiple single cells and multiple spacers are arranged alternately, A battery module is provided in which some or all of the multiple spacers are battery stack spacers as described in one embodiment. [Effects of the Invention]

[0010] The spacer for the battery stack according to the above embodiment is configured such that a plurality of first contact portions protruding from the first side surface of the spacer body abut against the first cell to define a plurality of first flow paths, and a plurality of second contact portions protruding from the second side surface abut against the second cell to define a plurality of second flow paths. The spacer body is provided with a plurality of communication holes that connect adjacent first and second flow paths, and turbulence is easily generated as fluid flows through the communication holes. In addition, the uneven distribution of fluid flowing through the first and second flow paths is reduced. As a result, the fluid can more easily come into contact with the surfaces of the first and second cell bodies, promoting heat exchange and enabling efficient cooling.

[0011] In the other embodiment of the battery module described above, by applying the battery stack spacer described above, the fluid flow between the individual cells constituting the battery stack can be controlled to improve the heat exchange efficiency between the fluid and the individual cells.

[0012] As described above, the present invention provides a spacer for a battery stack that can improve heat exchange efficiency, and a battery module using the same. [Brief explanation of the drawing]

[0013] [Figure 1] A perspective view showing an example configuration of a battery stack spacer and a battery module using the same in Embodiment 1. [Figure 2] A partially enlarged view showing the main structure of the battery stack constituting the battery module in Embodiment 1. [Figure 3]Perspective view showing the overall configuration of the battery module in Embodiment 1. [Figure 4] Schematic diagram showing the overall configuration of the battery module and the fluid flow in Embodiment 1. [Figure 5] Schematic diagram showing the fluid flow around the spacer, which is the main part of the battery laminate, in Embodiment 1. [Figure 6] Perspective view showing a configuration example of the spacer, which is the main part of the battery module, and a schematic diagram showing the fluid flow around the spacer in Comparative Form 1. [Figure 7] Perspective view showing a configuration example of the flow path formed by sandwiching the spacer of the battery module in Embodiment 1. [Figure 8] Perspective view showing another configuration example of the flow path formed by sandwiching the spacer of the battery module in Embodiment 1. [Figure 9] Perspective view showing another example of the spacer for the battery laminate in Embodiment 1. [Figure 10] Perspective view showing another example of the spacer for the battery laminate in Embodiment 1. [Figure 11] Perspective view showing a configuration example of the spacer for the battery laminate in Embodiment 2. [Figure 12] Perspective view showing a configuration example of the spacer for the battery laminate and the battery module using the same in Embodiment 3. [Figure 13] Schematic diagram showing the overall configuration of the battery module and the fluid flow in Embodiment 3. [Figure 14] Schematic diagram showing the fluid flow around the spacer, which is the main part of the battery laminate, in Embodiment 4. [Figure 15] Enlarged perspective view of the main part showing a configuration example of the communication hole provided in the spacer for the battery laminate and its cross-sectional view taken along the line A - A in Embodiment 4. [Figure 16] Enlarged perspective view of the main part showing a configuration example of the communication hole provided in the spacer for the battery laminate and its cross-sectional view taken along the line A - A in Embodiment 4.

Mode for Carrying Out the Invention

[0014] Embodiments relating to spacers for battery stacks and battery modules will be described. Spacers for battery stacks are used in battery stacks that have multiple individual cells arranged parallel to each other. A battery stack is constructed by alternately stacking multiple rectangular individual cells and multiple spacers. An individual cell is the smallest unit of a battery that makes up a battery stack, and is also called a single cell or storage battery.

[0015] In a battery stack, the spacer comprises a plate-shaped spacer body interposed between two adjacent single cells. The spacer body has a first side facing the side of one of the two single cells, the first single cell, and a second side facing the side of the other single cell, the second single cell. The first side is provided with a plurality of first contact portions that protrude so as to be able to contact the first single cell. This defines a plurality of parallel first flow channels between the first side and the first single cell. Similarly, the second side is provided with a plurality of second contact portions that protrude so as to be able to contact the second single cell. This defines a plurality of parallel second flow channels between the second side and the second single cell.

[0016] The spacer body is provided with multiple communication holes that penetrate through it at multiple points. This allows adjacent first and second flow channels to communicate, enabling the flow of a heat exchange medium fluid, promoting turbulence, which increases the opportunity for contact with the surface of the first or second cell, and allowing for efficient heat exchange. The heat exchange medium fluid is, for example, a cooling gas, in which case the first and second flow channels function as ventilation passages.

[0017] For example, the spacer body may have multiple first inclined surfaces and multiple second inclined surfaces that are inclined in opposite directions relative to the arrangement direction of the multiple single cells. In this case, the multiple first inclined surfaces and the multiple second inclined surfaces can be arranged alternately via a first contact portion or a second contact portion. This makes it possible to form first and second flow channels having a maximum width equal to the width between the single cells, while supporting adjacent single cells with the first and second contact portions, thereby facilitating fluid flow.

[0018] Furthermore, the spacer body can be configured such that communication holes are provided in some or all of the multiple first inclined surfaces and the multiple second inclined surfaces. In this case, by appropriately arranging the multiple communication holes, the flow in the first and second flow channels formed on both sides of the spacer body can be controlled, and adjacent cells can be cooled evenly.

[0019] Communication holes can also be provided at multiple locations on the first or second inclined surface located between adjacent first and second flow paths, along the flow direction of the heat exchange medium flowing through the first and second flow paths. In this case as well, the communication holes may be provided on a part of the first or second inclined surface, or they may be provided throughout the entire surface. By appropriately arranging multiple communication holes, the heat exchange medium can be brought into even contact with adjacent cells, thereby improving cooling performance.

[0020] Furthermore, the spacer body can be configured to include vertical wall portions projecting inward into the first or second flow path at the peripheral edge downstream of the communication hole in the flow direction of the heat exchange medium. In this case, the vertical wall portions facilitate the passage of the heat exchange medium through the communication hole, and by appropriately arranging the vertical wall portions for multiple communication holes provided in the spacer body, it becomes easier to control the flow of the heat exchange medium.

[0021] Such battery stack spacers are suitably used in battery modules that comprise a battery stack in which multiple individual cells and multiple spacers are arranged alternately. By using some or all of the multiple spacers as spacers provided with the aforementioned communication holes, the flow of the heat exchange medium circulating inside can be appropriately controlled, thereby achieving uniform heating of the entire battery stack and improving heat exchange efficiency while keeping costs down.

[0022] Preferably, the battery module may further include an introduction path for introducing a heat exchange medium into the battery stack from the outside. When the battery stack is composed of multiple battery stack spacers, the opening area of ​​the total number of communication holes in the introduction path for the heat exchange medium can be configured to be larger closer to the inlet. This suppresses uneven distribution of the amount of heat exchange medium introduced and allows for even distribution to the battery stack, even when the number of stacks is large.

[0023] (Embodiment 1) Next, a specific example of the configuration of a battery stack spacer and a battery module using the same will be described with reference to the drawings. The battery module of this form has the basic configuration shown in Figure 1 and can be used as an energy storage device or power supply device for mobile devices such as electric vehicles, or as a stationary type for household or industrial use, as well as a power supply source for various devices. In the drawings shown from Figure 1 onward, components with the same reference numerals represent the same or equivalent components, and their explanations have been omitted as appropriate.

[0024] [Battery stack 20] In Figure 1, the battery stack 20 includes a plurality of rectangular single cells 2 and a plurality of plate-shaped spacers 10, and is configured as part of the battery module 1. The plurality of single cells 2 and the plurality of spacers 10 are arranged alternately such that a spacer 10 is interposed between two adjacent single cells 2, and a flow path 3 (first flow path 31, second flow path 32) through which cooling gas flows is defined between one or the other of the two single cells 2 and the spacer 10.

[0025] The individual cells 2 used in the battery stack 20 are rechargeable secondary batteries, and can be appropriately selected from, for example, lithium-ion batteries, nickel-metal hydride batteries, nickel-cadmium batteries, etc., depending on the application. In the X direction, which is the stacking direction, a pair of end plates 4 (41, 42) are arranged at both ends of the battery stack 20 as retaining plates.

[0026] [Spacer 10] As shown in an enlarged view in Figure 1, the spacer 10 of this embodiment has a spacer body 11 that is formed entirely in a corrugated shape. The spacer body 11 has one surface in the X direction (i.e., the plate thickness direction) designated as a first side surface 10A and the other surface designated as a second side surface 10B. Multiple first contact portions 11A are provided at multiple locations on the first side surface 10A, and multiple second contact portions 11B are provided at multiple locations on the second side surface 10B. The first contact portions 11A and the second contact portions 11B are the highest points of the plate surface that protrude alternately in a corrugated shape on the side of the first side surface 10A or the side of the second side surface 10B, and are linear convex portions that are parallel to each other when viewed from the X direction.

[0027] Hereafter, the direction perpendicular to the X direction, and the vertical direction in Figure 1, will be referred to as the Y direction. Furthermore, the direction perpendicular to both the X and Y directions will be referred to as the Z direction. Note that the notations "up" and "down" are for convenience only, and the direction that is the vertical direction in the arrangement of the battery stack 20 shown in Figure 1 does not necessarily have to coincide with the actual vertical direction in which it is arranged.

[0028] [Spacer body 11] The corrugated shape of the spacer body 11 is not necessarily limited, but here it is a zigzag shape formed by combining a first inclined surface 12A and a second inclined surface 12B, which are flat plate-shaped regions of a predetermined width. That is, the first inclined surface 12A and the second inclined surface 12B are inclined to opposite sides with respect to the Y direction. Multiple first inclined surface 12A are inclined to the same side with respect to the Y direction. Multiple second inclined surface 12B are inclined to the same side with respect to the Y direction. The first inclined surface 12A and the second inclined surface 12B are identical in shape and are inclined at predetermined angles in different directions with respect to the wide main surface of adjacent cell 2. Multiple first inclined surface 12A and multiple second inclined surface 12B are arranged alternately in the Y direction. As a result, the connection between the first inclined surface portion 12A and the second inclined surface portion 12B forms bent portions that alternately protrude in a triangular roof shape toward one or the other side of the two adjacent single cells 2, and the tops of the bent portions aligned in the Y direction become the first contact portion 11A or the second contact portion 11B.

[0029] [Communication hole 12] In this embodiment, each of the multiple first inclined surfaces 12A and multiple second inclined surfaces 12B forming the spacer body 11 is provided with multiple communication holes 12 that penetrate the flat plate surface. The shape of the communication holes 12 is not particularly limited, but for example, they can be round. Multiple communication holes 12 are provided along the corresponding first inclined surfaces 12A or second inclined surfaces 12B, and they connect adjacent first flow channels 31 and second flow channels 32. Details regarding the shape and arrangement of the communication holes 12 will be described later.

[0030] [First channel 31 and second channel 32] As shown in Figure 2, specifically, when two adjacent single cells 2 are designated as the first single cell 2A and the second single cell 2B, a plurality of parallel first contact portions 11A protrude so as to be able to contact the side surface of the first single cell 2A. Similarly, a plurality of parallel second contact portions 11B protrude so as to be able to contact the side surface of the second single cell 2B. The direction in which the first contact portions 11A and the second contact portions 11B are aligned is the same as the direction in which the first inclined surface portion 12A and the second inclined surface portion 12B are aligned (i.e., the Y direction).

[0031] As a result, on the side of the first cell 2A, multiple parallel first flow channels 31 are formed, surrounded by the first inclined surface portion 12A and the second inclined surface portion 12B, and separated by the first contact portion 11A. Similarly, on the side of the second cell 2B, multiple parallel second flow channels 32 are formed, surrounded by the first inclined surface portion 12A and the second inclined surface portion 12B, and separated by the second contact portion 11B. The direction of fluid flow in the first flow channels 31 and the second flow channels 32 is parallel to the longitudinal direction of the first inclined surface portion 12A or the second inclined surface portion 12B, and is perpendicular to the X and Y directions (i.e., the Z direction).

[0032] The multiple first channels 31 and multiple second channels 32 are channels with a roughly triangular cross-section, with openings at both ends in the direction of flow, and are configured so that cooling gas flows from one opening to the other. In addition, multiple communication holes 12 that connect the first channels 31 and the second channels 32 are formed by penetrating the first inclined surface portion 12A or the second inclined surface portion 12B. Here, the cooling gas is cooling air, which can be introduced from the outside as cooling air F. As a result, the cooling air F passing through the first channels 31 and the second channels 32 can circulate through the first channels 31 and the second channels 32 via the communication holes 12, promoting heat exchange with the adjacent first cell 2A and second cell 2B, and contributing to improved cooling efficiency.

[0033] [Battery Module 1] As shown in Figure 3, the battery module 1 can be configured such that a battery stack 20, in which a predetermined number of single cells 2 are stacked with spacers 10 in between, is housed in a case C which is part of a pair of end plates 41 and 42, and a ventilation duct D is placed on the side of the case C. The pair of end plates 41 and 42 are fastened together by a binding member (not shown) or the like, so as to sandwich the battery stack 20 from both sides and maintain the contact state between two adjacent single cells 2 and the spacer 10 between them.

[0034] The spacer 10 is provided with a pair of locking portions 13 and 14 that are attached to both ends of the spacer body 11 in the Y direction. The locking portions 13 and 14 have, for example, a roughly T-shaped cross-section, and a flat plate-like surface extending in the X direction abuts against the end faces (upper or lower end faces in Figure 3) of the single cell 2 located on both sides in the X direction. As a result, the single cell 2 is positioned and held between the locking portions 13 and 14, and the first contact portion 11A or the second contact portion 11B abuts against the main surface of the single cell 2, forming the first flow path 31 or the second flow path 32, and determining the distance between two adjacent single cells 2.

[0035] In this configuration, the pair of locking portions 13 and 14 are formed with a width in the X direction that is wider than the maximum width of the spacer body portion 11 (distance between the single cells 2), and are configured to be able to abut against the end faces of adjacent single cells 2 in the Y direction. The width of the pair of locking portions 13 and 14 is set according to the space on the top or bottom side (top or bottom side in Figures 2 and 3), and here the locking portion 14 on the bottom side is formed to be wider. However, this is not limited to this configuration, and the locking portions 13 and 14 may have the same shape or different shapes.

[0036] [2 single batteries] Each cell 2 is configured as a secondary battery, with electrodes housed in a battery container and filled with electrolyte. The top surface of the battery container is equipped with positive and negative electrode terminals 21 and 22 spaced apart from each other. Multiple cell 2s are stacked in the X direction via spacers 10 so that the wide surfaces of the flat rectangular parallelepiped battery containers face each other. They can be electrically connected in series by connecting the electrode terminals 21 and 22 to each other using electrode plates (not shown). In this example, a battery stack 20 is constructed using six cell 2s and five spacers 10, but the number of stacked cell 2s is arbitrary and can be changed as appropriate according to the desired battery capacity, etc.

[0037] The battery container may be made by molding a metal material such as stainless steel or aluminum into a container shape, and the surface of the battery container may be coated with an insulating resin material. The spacer 10 is made by molding an insulating resin material into a predetermined shape, and can be made using, for example, polypropylene (PP), polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), polycarbonate (PC), etc. The resin material can be appropriately selected according to the heat resistance, rigidity, etc. required for the application.

[0038] The case C of the battery module 1 can be configured to include a pair of end plates 41 and 42, a side plate 5 connected to it, and a base plate 6. The side plates 5 are positioned on both sides of the battery stack 20 in the Z direction and, as shown in Figure 4, have openings 51 opposite each spacer 10, with an opening size corresponding to the gap between individual cells (not shown in Figure 3). A ventilation duct D is positioned on the outside of the side plate 5, and cooling air can be blown through the opening 51 to the first flow path 31 and the second flow path 32 formed on both sides of the spacer 10.

[0039] In Figure 3, the bottom surface of the battery stack 20 is supported by the base plate 6. A cooling structure can also be created in which pipes or the like that form a flow path for a cooling liquid (e.g., water) are placed in contact with the bottom surface of the base plate 6, thereby cooling the battery stack 20 through the base plate 6. Alternatively, the base plate 6 can be made hollow, with a cooling liquid flow path provided inside. Of course, a cooling structure without a cooling liquid flow path, having only a first flow path 31 and a second flow path for cooling air F, is also acceptable.

[0040] In this case, as shown in Figure 4, one of the pair of ducts D (D1, D2) is designated as the first duct D1, which serves as the introduction path, with one end serving as the inlet D11. Cooling air F from the outside can be forcibly introduced into the corresponding spacer 10 through multiple openings 51 in the side plate 5. The cooling air F that has passed through the spacer 10 is discharged to the outside via the second duct D2, which serves as the outlet. A fan or blower (not shown) or other ventilation device can also be placed on the inlet side of the first duct D1. Alternatively, an exhaust device may be placed on the outlet side of the second duct D2.

[0041] The cooling air F flows from the first duct D1 through the opening 51 into the first flow path 31 and the second flow path 32 (not shown in Figure 4) formed inside the spacer 10, and flows out through the opposite opening 51 into the second duct D2, while coming into contact with the surface of the main surface of the first cell 2A or the second cell 2B facing the flow path. Here, as schematically shown in Figure 5, the first flow path 31 and the second flow path 32 are connected through a plurality of communication holes 12 provided in the spacer 10, allowing the cooling air F to flow through.

[0042] As a result, flows are generated within the flow path 3 that pass through the communication hole 12 from the first flow path 31 to the second flow path 32, and flows that pass through the communication hole 12 from the second flow path 32 to the first flow path 31, making it easier for turbulence to occur around the communication hole 12. Then, the turbulence of the cooling air flow F increases the flow that goes directly toward the surface of the first cell 2A or the second cell 2B, or the flow that passes near the surface, promoting heat exchange with the cell 2 and improving cooling efficiency.

[0043] On the other hand, as shown in Figure 6 as comparative configuration 1, in a configuration where no communication holes 12 are formed in the spacer 100, when the cooling air F flows from the first duct D1 into the first flow path 31 or the second flow path 32 at a constant flow velocity, it continues to flow towards the second duct D2 and passes through the flow path. In other words, the flow of the cooling air F in each flow path 3 becomes laminar. In this case, the flow near the surface of the first cell 2A or the second cell 2B (i.e., the flow shown by the dashed line in Figure 8) does not contribute much to heat exchange. As a result, the heat from the cell 2 is not sufficiently transferred to the cooling air F, and the cooling efficiency tends to decrease.

[0044] In contrast, as in this embodiment, the spacer 10 is provided with communication holes 12, which makes it easier for the cooling air F in each flow path 3 to become turbulent, and thus makes it easier to improve the cooling efficiency of the single cell 2 as described above.

[0045] Furthermore, in this embodiment, the cooling air F flows evenly through the connecting hole 12 to the adjacent first channel 31 and second channel 32, enabling even heat dissipation from the two adjacent single cells 2. In other words, as in the comparative embodiment 1 (Figure 6) described above, if the spacer 100 is not provided with a connecting hole, the cooling air distributed to the first channel 31 and the second channel 32 does not undergo redistribution of flow rates from the upstream end to the downstream end, which can result in a difference in flow rates between the first channel 31 and the second channel 32.

[0046] In contrast, as in this embodiment, the spacer 10 is provided with a communication hole 12. For example, even if there is an imbalance in the flow rate of the cooling air F flowing in at the upstream end, the flow rate is redistributed at the communication hole 12 in the middle of the flow path. As a result, the difference in flow rate between the first flow path 31 and the second flow path 32 is suppressed, and the cooling efficiency of the battery module 1 is improved overall.

[0047] Thus, according to this embodiment, the cooling performance can be improved by providing the spacer 10 with communication holes 12 that connect the first flow path 31 and the second flow path 32. In this case, the shape and arrangement of the communication holes 12 are arbitrary and can be appropriately set according to the configuration of the battery module 1 to obtain the desired cooling efficiency.

[0048] In this embodiment (see Figure 1), the spacer body 11 has multiple circular communication holes 12 arranged almost entirely over its surface. Specifically, except for both ends in the Y direction, multiple communication holes 12 of the same shape are arranged in the Z direction on each of the multiple first inclined surfaces 12A and multiple second inclined surfaces 12B that form the spacer body 11, and the first flow path 31 and the second flow path 32 adjacent in the Y direction are in communication with each other through the multiple communication holes 12. Note that the shape of the communication holes 12 is not limited to circular holes, but may also be elongated holes, rectangular holes with rounded corners, or elongated slits.

[0049] At this time (see Figure 5), the flow rate passing through the communication hole 12 changes depending on the size (opening area) of the communication hole 12, and affects the turbulence generated near the communication hole 12 and the flow downstream. Therefore, by appropriately setting the shape and number of communication holes 12 and arranging them appropriately, the flow of cooling air F from the first duct D1 to the second duct D2 can be passed through the communication hole 12 in a balanced manner through the first flow path 31 and the second flow path 32, thereby cooling adjacent cells in a balanced manner.

[0050] (modified version) As shown in the schematic configuration in Figures 7 and 8, the flow directions of the first channel 31 and the second channel 32 in the spacer 10 are not particularly limited and may be either of the two directions orthogonal to the stacking direction (X direction) of the battery stack 20. Specifically, in the battery stack 20 shown in Figure 1 above, as shown in Figure 7, the first channel 31 and the second channel 32 are arranged alternately along the vertical direction (Y direction) in the figure, and the flow direction of the cooling air F is in the Z direction orthogonal to that, i.e., the horizontal direction shown in the figure (indicated by arrows in the figure).

[0051] Alternatively, as shown in Figure 8, the first inclined surface portion 12A and the second inclined surface portion 12B may be arranged alternately in the Z direction such that the vertical direction shown in the figure is the longitudinal direction of the flow path 3. In this case, the cooling air F introduced from the bottom side will flow toward the top side where the electrode terminals 21 and 22 of the single cell 2 are located. For example, in the battery module 1 shown in Figure 3 above, a duct D can be provided in contact with the base plate 6 on the bottom side to introduce the cooling air F to the bottom side of the case C. In this case as well, the cooling air F can flow through the communication holes 12 arranged in the first inclined surface portion 12A and the second inclined surface portion 12B.

[0052] Furthermore, as shown in the schematic configuration in Figures 9 and 10, the shape of the spacer 10 is not limited to a corrugated sheet shape made up of flat plates as shown in Figure 1 above, but may be a different shape. For example, as shown in Figure 9, the first inclined surface portion 12A and the second inclined surface portion 12B that constitute the spacer body portion 11 may have a shape that includes a curved surface portion. Here, the first inclined surface portion 12A and the second inclined surface portion 12B are arranged alternately such that the tops including the first contact portion 11A or the second contact portion 11B alternately protrude in a mountain shape in the X direction. Even in this case, the spacer 10 as a whole is corrugated sheet shape because the first inclined surface portion 12A and the second inclined surface portion 12B are arranged alternately via the first contact portion 11A or the second contact portion 11B.

[0053] Alternatively, as shown in Figure 10, the spacer body 11 of the spacer 10 is not limited to a corrugated shape, but may have a shape with a rib 15 protruding from it, including a first contact portion 11A or a second contact portion 11B. Specifically, the flat spacer body 11 has a plurality of first ribs 15A on the first side surface 10A side, with the protruding end being the first contact portion 11A, forming a plurality of first flow channels 31 between it and the first cell 2A. Similarly, a plurality of second ribs 15B are provided on the second side surface 10B side, with the protruding end being the second contact portion 11B, forming a plurality of second flow channels 32 between it and the second cell 2B.

[0054] The multiple ribs 15 are elongated convex bodies with a rectangular cross-section extending in the Z direction, and are arranged parallel to each other at predetermined intervals on both sides 10A and 10B of the spacer body 11 in the Y direction. In this case, the spacer body 11 has multiple flat plate-shaped regions 12C between two adjacent ribs 15 in the Y direction. Each of the multiple regions 12C is provided with multiple communication holes 12, allowing fluid to flow between adjacent first flow channels 31 and second flow channels 32. On the first side surface 10A, the region 12C is the region between the first ribs 15A that form the first contact portion 11A, and on the second side surface 10B, the region 12C is the region between the second ribs 15B that form the second contact portion 11B.

[0055] Even in this configuration, the same effect can be obtained by providing the spacer 10 with a plurality of communication holes 12 that connect the first flow path 31 and the second flow path 32. Here, the shape of the communication holes 12 is not round but elongated as shown in the figure. Furthermore, the cross-sectional shape of the plurality of first ribs 15A or second ribs 15B is not limited to rectangular; for example, the protruding ends that become the first contact portion 11A and the second contact portion 11B may be formed in a curved or tapered shape.

[0056] In any of the configurations shown in Figures 7 to 10, the size and number of communication holes 12 provided in the spacer 10 are not particularly limited. For example, the hole diameter or length can be smaller than the plate width (short-side length) of the first inclined surface portion 12A and the second inclined surface portion 12B, and the communication holes 12 can be appropriately arranged to obtain a desired effect on the fluid flow while maintaining the formability and necessary strength of the spacer body portion 11. In this case, multiple communication holes 12 provided in different first inclined surface portions 12A (or second inclined surface portion 12B) of the same spacer body portion 11 may have different shapes or sizes, or their number may be changed. The same can be applied to multiple communication holes 12 provided in different spacer body portions 11.

[0057] According to this embodiment, the flow of cooling air F passing through the channels formed between multiple single cells 2 of the battery module 1 can be adjusted to efficiently transfer heat between adjacent single cells 2. Alternatively, the size and number of communication holes 12 can be intentionally changed for each of the multiple first channels 31 and multiple second channels 32 formed between adjacent single cells 2 to achieve a desired flow, thereby adjusting them to obtain a desired heat transfer efficiency.

[0058] (Embodiment 2) Embodiment 2 relating to a spacer for a battery stack and a battery module will be described with reference to Figure 9. The battery module 1 in this embodiment has the same basic configuration as Embodiment 1, but the configuration of the spacer 10 constituting the battery stack 20 is different. The differences from Embodiment 1 will be described below.

[0059] As shown in Figure 11, the communication holes 12 provided in the spacer 10 do not need to be arranged across the entire spacer body 11, but may be selectively arranged on at least a portion of the multiple first inclined surfaces 12A and multiple second inclined surfaces 12B. In this case, the communication holes 12 can be arranged on the first inclined surfaces 12A or second inclined surfaces 12B corresponding to the area where cooling efficiency needs to be improved, depending on temperature variations on the surface of the single cell 2 adjacent to the spacer body 11.

[0060] For example, in Figure 3 above, if a coolant flow path is provided on the bottom side of the battery module 1, the temperature of the single cell 2 tends to be higher on the side opposite the bottom. Therefore, in this case, in the Y direction, a circular communication hole 12 is formed only on a portion of the top side of the single cell 2 (for example, one first inclined surface portion 12A and the two second inclined surface portions 12B on both sides of it), while the entire Z direction is formed.

[0061] This improves the cooling efficiency of the adjacent first channel 31 and second channel 32 via the three inclined surfaces on the top side, and makes it possible to suppress cooling variations in the Y direction of the single cell 2 adjacent to the spacer 10. Note that the configuration of the spacer 10 in this embodiment is just one example, and the first inclined surface 12A and the second inclined surface 12B on which the communication holes 12 are located can be arbitrarily selected.

[0062] Alternatively, in the multiple first inclined surfaces 12A and second inclined surfaces 12B arranged in the Y direction, the flow may be adjusted such that the number of communication holes 12 decreases as you move from the top side to the bottom side of the single cell 2, or the diameter of the communication holes 12 becomes smaller.

[0063] (Embodiment 3) Embodiment 3 relating to the battery stack spacer and battery module will be described with reference to Figures 12 and 13. The battery module 1 in this embodiment has the same basic configuration as Embodiment 1, but the configuration of the multiple spacers 10 constituting the battery stack 20 is different. The differences from Embodiment 1 will be described below.

[0064] For example, as shown in Figure 3 above, in a configuration where a duct D is connected to the case C of the battery module 1, the amount of cooling air F flowing into the flow path 3 facing each of the multiple spacers 10 incorporated into the battery stack 20 changes depending on the positional relationship between the flow path 3 and the first duct D1 on the introduction side. Therefore, if the multiple spacers 10 have the same configuration, the amount of cooling air F flowing into the flow path 3 facing the spacer 10 that is closer to the inlet side of the first duct D1 tends to be greater, and is not distributed evenly throughout.

[0065] Therefore, in this embodiment, as shown in Figure 12, the arrangement of communication holes 12 in multiple spacers 10 is changed. For example, as shown in Figure 13, the spacers 10 closer to the inlet D11 of the first duct D1 (i.e., the end plate 41 side) can be arranged so that there are more communication holes 12 in the spacers 10. In other words, the spacers 10 further from the inlet D11 (i.e., the end plate 42 side) have fewer communication holes 12 than the spacers 10 closer to it.

[0066] Specifically, the spacer 10 closest to the inlet D11 can be configured such that, for example, communication holes 12 are arranged throughout, as shown in Embodiment 1 described above, and the number of communication holes 12 gradually or in stages decreases as it moves further away from the inlet D11. In this case, the arrangement of the communication holes 12 is not particularly limited, but for example, as shown in an enlarged view in Figure 12, communication holes 12 can be arranged from the upstream to the middle of the flow in the Z direction on the side relatively close to the inlet D11, and communication holes 12 can be arranged only in the upstream part of the flow on the side further away.

[0067] Here, the number of communication holes 12 of the same shape and size is increased or decreased in multiple spacers 10, but instead, the size (opening area) of the communication holes 12 can also be changed in multiple spacers 10. Alternatively, both the number and size (opening area) can be changed. In either case, it is sufficient that the total opening area of ​​the multiple communication holes 12 provided in the spacer 10 increases as it approaches the entrance portion D11.

[0068] In this case, in the flow path 3 facing the spacer 10, the presence of communication holes 12 in the upstream portion of the flow in the Z direction increases pressure loss, and the more communication holes 12 there are, the more difficult it becomes for the cooling air F to flow in. In other words, the fewer communication holes 12 there are, the easier it becomes for the cooling air F to flow into the interior of the spacer 10. Therefore, as shown in Figure 10, the cooling air F that flows into the first duct D1 reaches the side farther from the inlet D11 without significantly reducing its flow velocity or flow rate, and the cooling air F can be distributed evenly to each flow path 3.

[0069] The arrangement of communication holes 12 in the multiple spacers 10 incorporated into the battery stack 20 can be appropriately changed depending on the number of stacks in the battery stack 20 and the flow of cooling air F in the first duct D1. For example, the inlet D11 of the first duct D1 is not limited to one end of the duct extending in the X direction, but may be located in the middle. In this case, cooling air F will flow from the inlet D11 to both sides in the X direction in the first duct D1. In this case as well, a similar effect can be obtained by preferably configuring the spacers 10 to have more communication holes 12 on the upstream side of the cooling air F flow, i.e., closer to the inlet D11.

[0070] Thus, according to this embodiment, by changing the number and opening area of ​​the communication holes 12 provided in the spacer 10, the resistance balance of the flow paths 3 in each part of the battery stack 20 can be changed, and the cooling air F can be adjusted to flow evenly throughout the entire battery stack 20. In each flow path 3, the cooling air F flows through the communication holes 12, allowing adjacent individual cells 2 to be cooled efficiently. As a result, the entire battery stack 20 constituting the battery module 1 can be cooled evenly, improving the cooling performance.

[0071] (Embodiment 4) Embodiment 4 relating to the battery stack spacer and battery module will be described with reference to Figures 14 to 16. The battery module 1 in this embodiment has the same basic configuration as Embodiment 1, but the configuration of the multiple spacers 10 constituting the battery stack 20 is different. The differences from Embodiment 1 will be described below.

[0072] As schematically shown in Figure 14, in this embodiment, the spacer body 11 has a vertical wall portion 121 on the downstream peripheral edge of the communication hole 12 in the Z direction, which is the flow direction of the cooling air F. Specifically, the vertical wall portion 121 is configured to protrude from the spacer body 11 toward the flow path 3 at a position along the peripheral edge of the through hole which becomes the communication hole 12. As a result, a portion of the flow of cooling air F circulating in the first flow path 31 or the second flow path 32 collides with the vertical wall portion 121, changes direction, and makes it easier for it to pass through the communication hole 12.

[0073] Preferably, the vertical wall portions 121 protruding into the flow path 3 can be evenly distributed for the first flow path 31 and the second flow path 32 adjacent to each other with the spacer body portion 11 in between. For example, if the vertical wall portions 121 are arranged alternately to protrude towards either the first flow path 31 or the second flow path 32 for a plurality of communication holes 12 aligned in the Z direction, it becomes easier to adjust the flow rate passing through the communication holes 12. That is, when considering two communication holes 12 aligned in the Z direction, the cooling air F is more likely to pass through the upstream communication hole 12 toward one of the first flow path 31 and the second flow path 32, and the cooling air F is more likely to pass through the downstream communication hole 12 toward the other. This makes it possible to control the flow of the cooling air F in a balanced manner while suppressing flow rate bias.

[0074] Specifically, as shown in an enlarged view in Figure 15, the downstream half of the circular communication hole 12 can be formed by creating a vertical wall portion 121 that surrounds the periphery in a semicircular shape with a constant width and rises to a constant height. The formation range and shape of the vertical wall portion 121 are not particularly limited and can be changed as appropriate. Preferably, the protruding end of the vertical wall portion 121 has a rounded chamfered shape. The height of the vertical wall portion 121 is set to be sufficiently small relative to the height of the flow path 3 and the diameter of the communication hole 12, for example, within a range where the effect of guiding the flow of cooling air F can be obtained. This allows for control of the flow of cooling air F while suppressing an increase in pressure loss in the flow path 3, thereby improving cooling performance.

[0075] Alternatively, as shown in Figure 16, the vertical wall portion 121 can be shaped such that its height increases and its wall thickness increases towards the downstream side. In this case, the vertical wall portion 121 rises along the periphery of the communication hole 12 and has an inner circumferential surface 122 of different heights and an outer circumferential surface 123 consisting of a curved inclined surface that covers the periphery of the communication hole 12.

[0076] If a vertical wall portion 121 of a certain width is provided on the periphery of the communication hole 12, the cooling air F that reaches the vertical wall portion 121 will flow along the arc-shaped outer surface, making it easy for a swirling flow to occur. In contrast, if the outer surface 123 of the vertical wall portion 121 has a shape that slopes downward toward the downstream side, the swirl can be suppressed and it is easier to form a flow toward the downstream side. The vertical wall portion 121 can be integrally molded using the same resin material as the spacer body portion 11 of the spacer 10.

[0077] The shape of the vertical wall portion 121 shown in this embodiment is just one example and can be changed as appropriate depending on the shape of the communication holes 12, etc. Furthermore, the vertical wall portion 121 may be placed in all of the communication holes 12 provided in the spacer body portion 11, or in only some of them. In that case, the arrangement of the communication holes 12 provided with the vertical wall portion 121, the height of the vertical wall portion 121, etc. can be adjusted according to the flow of cooling air F in the flow path 3 to control the flow to the desired state.

[0078] Thus, according to this embodiment, by providing a vertical wall portion 121 in the communication hole 12, the flow of cooling air F passing through the communication hole 12 and the flow of cooling air F in the first flow path 31 and the second flow path 32 that communicate through the communication hole 12 can be effectively controlled, thereby improving cooling performance.

[0079] (Other embodiments) In the embodiments described above, the case in which a round-shaped communication hole 12 is provided in the corrugated spacer body portion 11 has been mainly explained, but the vertical wall portion 121 of Embodiment 4 can also be provided in other configurations. Furthermore, although the basic structure of the battery module 1 including the battery stack 20 has been shown in the embodiments above, the ventilation paths and other structures in the battery module 1 can be changed as appropriate. The battery module 1 with the above configuration can also be used as a unit module to form a battery pack containing multiple unit modules.

[0080] The present invention is not limited to the embodiments described above, and can be applied to various embodiments without departing from its spirit. Furthermore, the components shown in each of the embodiments described above can be applied to or combined with other embodiments. [Explanation of Symbols]

[0081] 1 Battery Module 10 Spacers 10A First side 10B 2nd side 11A 1st contact part 11B 2nd contact part 11 Spacer body 12 Communication hole 12A 1st slope section 12B 2nd slope section 12C area 13, 14 Locking parts 15 Ribs 15A First Rib 15B Second Rib 2 single batteries 20 Battery stack 2A Single Cell 2B Second cell 3 channels 31 First channel 32 Second channel 4, 41, 42 End plates (retaining plates) 5 Side Plates 51 Opening 6 Base plate C Case D Duct

Claims

1. A battery stack spacer used in a battery stack comprising multiple single cells arranged parallel to each other, A plate-shaped spacer body is interposed between two adjacent single cells and has a first side facing the side of the first single cell, which is one of the two single cells, and a second side facing the side of the second single cell, which is the other of the two single cells. A plurality of first contact portions are provided on the first side surface, protruding so as to be in contact with the first single cell, and defining a plurality of parallel first flow channels between the first side surface and the first single cell, A plurality of second contact portions are provided on the second side surface, protruding so as to be able to contact the second single cell, and defining a plurality of parallel second flow paths between the second side surface and the second single cell, A spacer for a battery stack, comprising a plurality of communication holes provided through the main body of the spacer, which connect adjacent first flow channels and second flow channels.

2. The spacer body has a plurality of first inclined surfaces and a plurality of second inclined surfaces that are inclined in opposite directions to the arrangement direction of the plurality of single cells, and the plurality of first inclined surfaces and the plurality of second inclined surfaces are arranged alternately via the first contact portion or the second contact portion, as described in claim 1.

3. The spacer for a battery stack according to claim 2, wherein the communication holes are provided in some or all of the plurality of first inclined surfaces and the plurality of second inclined surfaces.

4. The spacer for a battery stack according to claim 3, wherein the communication holes are provided at multiple locations on the first inclined surface or the second inclined surface, along the flow direction of the heat exchange medium flowing through the first channel and the second channel.

5. The spacer for a battery stack according to claim 4, wherein the spacer body is provided with a vertical wall portion projecting inward into the first or second flow path at the peripheral edge downstream of the communication hole in the flow direction of the heat exchange medium.

6. In a battery module in which a battery stack, in which multiple single cells and multiple spacers are arranged alternately, is held between a pair of retaining plates, A battery module in which some or all of the multiple spacers are battery stack spacers according to any one of claims 1 to 5.

7. The aforementioned battery stack is further provided with an introduction path for introducing a heat exchange medium from the outside, The aforementioned battery stack is configured to include a plurality of spacers for the battery stack, The battery module according to claim 6, wherein the multiple spacers for the battery stack are configured such that the total opening area of ​​the multiple communication holes increases as they get closer to the inlet of the heat exchange medium in the introduction path.

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