Battery assembly and cooling plate using the battery assembly

Abstract

To provide a battery assembly capable of performing cooling of a battery cell with high performance while having smaller variation than a conventional art.SOLUTION: A battery assembly 1 comprises a cooling plate 30 for cooling a battery cell 10. The cooling plate 30 contains a first plate 31 and a second plate 32 that are oppositely arranged so as to be separated each other. In an internal space 30a, a plurality of fins 40 arranged so as to be nearly parallel to a shaft core 11 so as to be integrally stood from the first plate 31 or a second plate 32 is provided. An inter-fin flow path 50 in which a coolant circulates is formed to between the adjacent fins 40. A one end side 51 and the other end side 52 of the inter-fin flow path 50 are connected to coolant yields 61 and 62. Outer surfaces 31a and 32a of the first plate 31 or a second plate 32 that are integrated with each fin are contacted to a side surface 12 of a battery cell while curving at least one part along a side surface 20a of a battery cell column.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a battery assembly and a cooling plate for use in the battery assembly. [Background technology]

[0002] Batteries installed in vehicles (hereafter referred to as "cells") are not only the power source for driving electronic devices such as gauges, lighting, air conditioning, and ECUs (Electronic Control Units), but also the power source for driving motors in EVs (Electric Vehicles), which have become widespread in recent years. Batteries and their peripheral circuits (around the battery) are repeatedly charged and discharged with a large current, making them more susceptible to heat generation than ever before.

[0003] Operating the battery for long periods of time at high temperatures can lead to problems such as battery deterioration, motor coil burnout, and battery fire. This issue is not limited to vehicles, but also poses similar challenges to batteries and their peripheral circuits used in general mobile objects such as drones and aircraft.

[0004] In response to this issue, recently, technologies have been proposed in which the battery itself is cooled while it is operated, driven, or otherwise functioning (for example, see Non-Patent Documents 1 and 2).

[0005] Fig. 11 is a diagram for explaining a battery assembly 900 described in Non-Patent Document 1. Fig. 11(a) is a perspective view showing a plate 930a in a state before being curved. The plate 930a is in the form of an assembly of a plurality of hollow rectangular cylinders, and has an overall flat plate shape. Each hollow portion separated by partition walls 940 is utilized as a refrigerant flow path 950 for flowing a refrigerant RF.

[0006] 11(b) is a perspective view of the battery assembly 900. The cooling plate 930 is formed by appropriately curving the flat plate 930a described above into a shape that meanders along the longitudinal direction (x direction). The longitudinal direction of the cooling plate 930 extends in a meandering manner along the battery cell row 20 made up of cylindrical battery cells 10. The cooling plate 930 is in contact with the side surfaces of each battery cell 10.

[0007] Each refrigerant flow path 950 of the cooling plate 930 also extends in a serpentine manner along the longitudinal direction of the cooling plate 930. In the figure, the flow of the refrigerant RF is indicated by a schematic addition using thick arrows. The refrigerant RF is introduced from the upstream side indicated by RFin on the left side of the figure, flows inside each refrigerant flow path 950 in a wavy manner in a direction perpendicular to the axis of the battery cell 10, and is reassembled on the right side of the figure before being discharged from the downstream side indicated by RFout.

[0008] In the battery assembly 900, the cooling plate 930 is in contact with the side surfaces of the battery cells 10, and the coolant RF flows through the coolant flow paths 950 inside the cooling plate 930, making it possible to cool the battery cells 10. [Prior art documents] [Patent documents]

[0009] [Non-Patent Document 1] BorgWarner website (for the exhibition held at Pacifico Yokohama), "We are your partner in electrification - High Voltage Battery Cooling-Intercell eCooler", [online], [Retrieved July 8, 2023], Internet (URL: https: / / technologies.borgwarner.com / jsae-yokohama / ) [Non-Patent Document 2] Article from Automotive Media "Response." supervised by IID Co., Ltd., "BorgWarner to unveil battery cooling plate for the first time... promoting electrification technology at the 2023 Automotive Technology Expo," [Retrieved July 8, 2023], Internet (URL: https: / / response.jp / article / img / 2023 / 05 / 22 / 371245 / 1889116.html) Summary of the Invention [Problem to be solved by the invention]

[0010] However, in the conventional battery assembly 900 , the partition walls 940 and the coolant flow paths 950 extend along the longitudinal direction of the cooling plate 930 at a right angle to the axis of the battery cells 10 .

[0011] Because the refrigerant RF flows in a long horizontal path along the longitudinal direction, the refrigerant RF picks up heat at various points, and the downstream side becomes hotter than the upstream side. For this reason, the refrigerant RF flowing on the downstream side cannot pick up as much heat. Therefore, there is a problem in that some of the battery cells 10 on the downstream side cannot be sufficiently cooled.

[0012] In addition, because there is a difference in cooling efficiency between the upstream and downstream sides of the refrigerant RF as described above, there is also a difference in the temperature maintained for the battery cells between the upstream and downstream sides (the temperature of the downstream battery cell 10 is likely to be considerably higher than that of the upstream battery cell.) In addition, because the upstream battery cell 10 and the downstream battery cell are repeatedly charged and discharged under different temperature conditions, there is also a difference in the battery characteristics and lifespan.

[0013] Furthermore, the coolant flow passage 950 extends in a wavy, meandering manner over a long distance in the longitudinal direction, and thus has a large flow resistance. Generally, pressure is applied to the coolant RF from the outside using a pump or the like to make the coolant RF flow, but in the conventional cooling plate 930, the flow resistance of the coolant flow passage 950 is large and the pressure loss is also large, so a pump with a considerably large delivery capacity is required to make the coolant RF flow as desired. This requires a lot of energy to be consumed, and as a result, the battery cells 10 cannot be cooled efficiently.

[0014] The present invention has been made in view of the above circumstances, and has an object to provide a battery assembly that can cool battery cells more efficiently with less variation than conventional battery assemblies, and to provide a cooling plate for use in such a battery assembly. [Means for solving the problem]

[0015] According to one aspect of the present invention, a battery assembly is provided that includes a plurality of battery cells, each of which is cylindrical and arranged with their axes generally parallel to one another, and a cooling plate that contacts the sides of the battery cells to cool the battery cells. The cooling plate includes a first plate and a second plate disposed facing each other with a space therebetween. A plurality of fins are provided in the space between the first plate and the second plate, standing integrally from the first plate or the second plate, and arranged such that their longitudinal direction is substantially parallel to the axis of the battery cells. Inter-fin flow paths through which a coolant flows are formed between adjacent fins. A coolant reservoir is provided at each of one end and the other end of the inter-fin flow path, and each of the one end and the other end of the inter-fin flow path is connected to the coolant reservoir. The outer surface of the first plate or the second plate, which is integral with the fins, is in contact with the side surface of the battery cells, with at least a portion of the outer surface curving along the side surface of the battery cell row.

[0016] Here, a "battery cell row" is defined as a row of multiple battery cells arranged side by side with their axes generally parallel to each other. "Side by side" may mean that the battery cells are in contact with each other (adjacent), slightly spaced apart, or side by side with a separate member between them.

[0017] According to another aspect, there is provided a cooling plate for cooling a battery cell row in which a plurality of columnar battery cells are arranged. The cooling plate includes a first plate and a second plate disposed facing each other with a space therebetween. A plurality of fins are provided in the space between the first plate and the second plate, standing integrally from the first plate or the second plate, and arranged such that their longitudinal direction is substantially parallel to the axis of the battery cells. Inter-fin flow paths through which a coolant flows are formed between adjacent fins. A coolant reservoir is provided at each of one end and the other end of the inter-fin flow path, and each of the one end and the other end of the inter-fin flow path is connected to the coolant reservoir. The cooling plate is configured such that the outer surface of the first plate or the second plate, which is integral with the fins, contacts the side surface of the battery cells while at least a portion of the outer surface curves along the side surface of the battery cell row. Effect of the Invention

[0018] According to the present invention, it is possible to provide a battery assembly that can cool battery cells with less variation and with higher efficiency than in the past, and a cooling plate that can be used in the battery assembly having such effects. [Brief description of the drawings]

[0019] [Figure 1] 1A to 1C are diagrams shown for explaining a battery assembly 1 according to a first embodiment. [Diagram 2] FIG. 2 is an exploded view showing the configuration of the battery assembly 1. [Diagram 3] 4 is a perspective view for explaining the engagement relationship between a first plate 31 of a cooling plate 30 and a refrigerant introduction pipe 71. FIG. [Figure 4]2 is a diagram shown for explaining the flow of refrigerant RF in a battery assembly 1. FIG. [Diagram 5] 1A to 1C are diagrams shown to explain an example of a manufacturing method for a flexible heat sink. [Figure 6] FIG. 11 is a diagram shown for explaining a battery assembly 2 according to a second embodiment. [Figure 7] 13 is a cross-sectional view for explaining the assembly structure of a cooling plate 30B / 30. FIG. [Figure 8] FIG. 11 is a perspective view shown for explaining a battery assembly 3 according to a third embodiment. [Figure 9] FIG. 13 is a diagram for explaining a cooling plate 30A' of a first modified example. [Figure 10] 13A to 13C are views shown for explaining battery assemblies 5 to 7 according to modified examples 2 to 4. [Figure 11] FIG. 1 is a diagram for explaining a conventional battery assembly 900 described in Non-Patent Document 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] The battery assembly and the cooling plate used in the battery assembly according to the present invention will be described below with reference to the drawings. Note that the explanations of the symbols common to each drawing can be used in the explanations of the other drawings, so the explanations in the other drawings will be omitted. Each drawing is a schematic diagram showing an example, and does not necessarily strictly reflect the actual dimensions, ratios, etc.

[0021] [Embodiment 1] 1. Configuration of the battery assembly 1 and cooling plate 30 (30A) according to embodiment 1 First, an overview of the battery assembly 1 will be given, followed by a description of the battery cells 10, and then a detailed description of the cooling plates 30 will be given individually.

[0022] Fig. 1 is a diagram for explaining a battery assembly 1 according to embodiment 1. Fig. 1(a) is a perspective view of the battery assembly 1, Fig. 1(b) is a cross-sectional view of a main part of the battery assembly 1 taken along imaginary plane PL1 in Fig. 1(a) and viewed along arrow A, and Fig. 1(c) is an enlarged cross-sectional view of a main part of the battery assembly 1 taken along dashed line B in Fig. 1(b). Fig. 2 is an exploded view showing the configuration of the battery assembly 1.

[0023] (1) Overview of Battery Assembly 1 As shown in FIG. 1(a), the battery assembly 1 includes at least a plurality of battery cells 10 arranged with their axes 11 substantially parallel to one another, and a cooling plate 30 that contacts the side surfaces 12 of the battery cells 10 to cool the battery cells 10.

[0024] (2) 10 battery cells The battery cell 10 is columnar, having a top surface (no reference number), a bottom surface (no reference number), and side surfaces 12. In the example of the first embodiment, the battery cell 10 is in the shape of a right circular cylinder (cylindrical). The battery cell 10 may be any type of battery, but is preferably a secondary battery that can be charged and discharged. Since secondary batteries pass not only a discharge current but also a charge current, they tend to generate heat, and the present invention can be applied in a more preferable form.

[0025] (3) Battery cell columns 20, 21, and 22 A plurality of battery cells 10 are arranged to form a battery cell string 20 . A "battery cell row 20" refers to an assembly of multiple battery cells 10 arranged next to each other. The battery assembly 1 has multiple battery cell rows 21, 22. In the example shown in the figure, a first battery cell row 21 and a second battery cell row 22 are configured, and the battery cell rows 21, 22 are arranged so that their longitudinal directions are parallel to each other. Each of the battery cell strings 20 (21, 22) has a side surface 20a (21a, 22a). The "side surface 20a (21a, 22a) of the battery cell string" refers to the side surface when the entire battery cell string is viewed as a single assembly. Part of the side surface 20a (21a, 22a) of the battery cell string includes part of the side surface 12 of each battery cell 10.

[0026] (4) Cooling plate 30 The cooling plate 30 is a plate that cools the battery cells 10. The cooling plate 30 may be made of a metal including aluminum, for example. The cooling plate 30 has at least a partially curved shape to follow the shape of the side surface of the battery cell row 20 (21, 22). The cooling plate 30 of the first embodiment has a partially curved shape that undulates along the longitudinal direction (x direction). At least one of the two main surfaces of the cooling plate 30 is in contact with the side surface 20a (21a, 22a) of the battery cell row. The length (height) of the cooling plate 30 in the z direction is slightly shorter than the height in the z direction of the battery cells 10. It is preferable that the length (width) of the cooling plate 30 in the x direction is slightly longer than the width of the battery cell row 20 that is the cooling target.

[0027] 1(b), the cooling plate 30 includes a first plate 31 and a second plate 32 that are disposed facing each other with a space between them. An internal space 30a is defined between the first plate 31 and the second plate 32. A part of a series of flow paths (without reference numbers; details will be described later) that allow the refrigerant RF to flow is provided in the internal space 30a. The cooling plate 30 allows the refrigerant RF to flow through the flow paths provided in the internal space 30a, and transfers heat received by the cooling plate 30 from the battery cells 10 to the refrigerant RF.

[0028] The refrigerant RF is a fluid for cooling objects (fins 40, cooling plate 30, and ultimately battery cells 10). Examples of the refrigerant RF include liquids such as water, water containing special components, and gases such as air, but there are no particular limitations and any refrigerant may be used as long as it meets the objectives of the present invention.

[0029] As described above, the battery assembly 1 according to the first embodiment has multiple battery cell rows 21, 22. When the multiple battery cells 10 are viewed as an entire block, cooling plates are arranged to cover the outer surface of the entire block (see, of the three cooling plates 30 shown in Fig. 1(a) , the cooling plate 30 on the front side of the first battery cell row 21 and the cooling plate 30 on the rear side of the second battery cell row 22). In addition, a cooling plate 30 may be disposed between the first battery cell row 21 and the second battery cell row 22. In this case, the cooling plate 30 is configured so that the first plate 31 contacts the first battery cell row 21 and the second plate 32 contacts the second battery cell row 22.

[0030] (4-1) Fin 40 As shown in Fig. 1(c), a plurality of fins 40 are provided in a space (internal space 30a) sandwiched between the first plate 31 and the second plate 32. The fins 40 are integrally provided upright from the first plate 31 or the second plate 32. The fins 40 may be provided upright from the first plate 31 or may be provided upright from the second plate 32. In the example of Fig. 1 etc., the fins 40 are provided upright from the first plate 31. Note that the second plate 32 of the first embodiment does not have the fins 40 and is simply a curved flat plate. Here, "integrally erected" means that the first plate 31 or the second plate 32 which becomes the base portion 45 of the fin and the fin 40 are formed integrally and continuously.

[0031] The fin base 45 supports the multiple fins 40 near the base ends of the fins 40. The fin base 45 also conducts heat from its rear surface (the outer surface 31a of the first plate 31) to the fins 40. The fins 40 dissipate the heat conducted from the base 45 to the refrigerant RF passing through inter-fin flow paths 50 (described later).

[0032] Focusing on each individual fin 40, the fin 40 has a flat plate shape. The base end of the fin 40 is connected to the base 45, and the tip of the fin 40 protrudes upward to form a long protrusion extending along the longitudinal direction of the fin 40 (z direction). The fins 40 are arranged so that their longitudinal direction is approximately parallel to the axis 11 of the battery cell 10. Because each fin 40 is approximately parallel to the axis 11, when multiple fins 40 are compared with each other, the longitudinal directions of each fin 40 are parallel to one another (see also Figures 1(b), 2, 4, etc.).

[0033] (4-2) Fin-to-fin flow passage 50 In the cooling plate 30, inter-fin channels 50 through which the refrigerant RF flows are formed between adjacent fins 40. In cross-sectional view, the inter-fin channels 50 are surrounded by the side surfaces (no reference numerals) of the fins 40, a base portion 53 formed by the inner wall of the first plate 31 that is integral with the fins 40, and the inner wall (no reference numerals) of the second plate 32 (see Figs. 1(c), 2, 4(b), etc.). When the cooling plate 30 is viewed from a direction substantially perpendicular to the main surfaces (the outer surface 31a of the first plate 31 and the outer surface 32a of the second plate 32) (when viewed along the y direction), the inter-fin channels 50 extend linearly in a direction substantially parallel to the axis 11 of the battery cells 10.

[0034] (4-3) Refrigerant reservoir 61, 62 The upstream coolant reservoir 61 is a place where the coolant RF is temporarily buffered before it moves to the inter-fin flow paths 50. The downstream coolant reservoir 62 is a place where the coolant RF discharged from the inter-fin flow paths 50 is temporarily buffered.

[0035] 2, the refrigerant reservoirs 61, 62 are provided respectively at one end side 51 and the other end side 52 in the longitudinal direction of the inter-fin flow passage 50. The refrigerant reservoirs 61, 62 are connected respectively to the one end side 51 and the other end side 52 of the inter-fin flow passage 50 so that the refrigerant RF flows continuously (also see FIG. 4 described later).

[0036] It is preferable that the portions of first plate 31 (the plate to which fins 40 belong) corresponding to coolant reservoirs 61, 62 are formed to have the same thickness as base portions 45 of fins 40 or slightly thinner than the thickness of base portions 45. The cooling plate 30 also has an edge spacer 35. The edge spacer 35 is disposed between the opposing first and second plates 31, 32 at the peripheral portions of the first and second plates 31, 32, and is joined and sealed to the first and second plates 31, 32 by brazing or the like. As a result, a space capable of accommodating a considerable amount of fluid is formed inside the peripheral portion of the cooling plate 30 so as to extend in the longitudinal direction, and this space is used as the refrigerant reservoirs 61, 62.

[0037] Here, the width (width in the z direction) of the refrigerant reservoirs 61, 62 is constant. However, the present invention is not limited to this configuration, and for example, the width of the upstream refrigerant reservoir 61 may be different between a position close to a refrigerant inlet 61a (described later) and a position far from the refrigerant inlet 61a. By appropriately changing the width in this manner, it is also possible to appropriately change the way the refrigerant RF flows.

[0038] (4-4) The plate to which the fin 40 belongs is brought into contact with the battery cell 10 In the battery assembly 1 according to the first embodiment, the outer surface 31a, 32a of the first plate 31 or the second plate 32 integrated with the fin 40 contacts the side surface 12 of the battery cell 10 while at least a portion of the plate is curved along the side surface 20a of the battery cell row 20. In the example of the first embodiment, the outer surface 31a of the first plate 31 integrated with the fin 40 contacts the side surface 12 of the battery cell 10, as shown in Fig. 1(c) for example.

[0039] Note that the "contact" in "in contact with the side surface of the battery cell" and "the outer surface of the first plate or second plate integrated with the fin...is in contact with the side surface of the battery cell" includes cases where the first plate 31 or second plate 32 is in direct contact with the battery cell 10, as well as cases where it is in indirect contact with the battery cell 10 via, for example, molded resin. In this case, the above-mentioned resin mold, for example, can be included as a component of the first plate 31 or second plate 32.

[0040] To sum up, the cooling plate 30 according to the first embodiment has the following configuration. The cooling plate 30 according to the first embodiment is a plate for cooling a battery cell row 20 in which a plurality of columnar battery cells 10 are arranged. In this battery cell row 20, a plurality of battery cells 10 are arranged adjacent to each other with their respective axes 11 being approximately parallel to each other. The cooling plate 30 includes a first plate 31 and a second plate 32 that are arranged facing each other with a space between them. In a space (internal space 30a) sandwiched between the first plate 31 and the second plate 32, a plurality of fins 40 are provided that are integrally erected from the first plate 31 or the second plate 32 and that are arranged such that their longitudinal direction is approximately parallel to the axes 11 of the battery cells 10. Between adjacent fins 40, an inter-fin flow path 50 through which a refrigerant RF flows is formed, and refrigerant reservoirs 61, 62 are provided at one end side 51 and the other end side 52 of the inter-fin flow path 50, respectively, and the one end side 51 and the other end side 52 of the inter-fin flow path 50 are connected to the refrigerant reservoirs 61, 62. The cooling plate 30 is configured such that the outer surfaces 31a, 32a of the first plate 31 or the second plate 32, which are integral with the fins 40, contact the side surface 12 of the battery cell 10 while at least a portion of the outer surfaces 31a, 32a are curved along the side surface 20a of the battery cell row 20.

[0041] (5) A series of flow paths through which the refrigerant RF flows FIG. 3 is a perspective view showing an engagement relationship between the first plate 31 of the cooling plate 30 and the refrigerant introduction pipe 71. As shown in FIG. The first plate 31, which has a structure corresponding to the refrigerant reservoir 61, is provided with a through hole 31b for inserting the refrigerant introduction pipe 71 as shown in FIG. 3, and further, a part of the inner wall of the through hole 31b is cut out to form a refrigerant introduction port 61a. Meanwhile, the refrigerant introduction pipe 71 has a slit 71a formed in a part of the cylindrical side surface. When the refrigerant introduction pipe 71 is inserted into the through hole 31b (see also FIG. 1(a)), the slit 71a is positioned at the refrigerant introduction port 61a provided at the position of the notch of the through hole 31b. As a result, the refrigerant RFin introduced into the refrigerant introduction pipe 71 flows from the slit 71a through the refrigerant introduction port 61a into the refrigerant reservoir 61.

[0042] 4, the upstream coolant reservoir 61 extends in the x direction so as to intersect with the z direction in which the inter-fin flow paths 50 extend. This allows the coolant RF that flows into the upstream coolant reservoir 61 to flow evenly to each of the inter-fin flow paths 50 arranged in sequence in the x direction.

[0043] The downstream coolant reservoir 62 also extends in the x direction, and is capable of equally receiving and buffering the heated coolant RF that has passed through each of the inter-fin flow paths 50 .

[0044] Further, a through hole 31c is also provided on the downstream side, and a part of the inner wall of the through hole 31c is cut out to form a refrigerant discharge port 62a. The refrigerant RF accumulated in the refrigerant reservoir 62 can flow from the refrigerant discharge port 62a through a slit (not shown) of the refrigerant discharge pipe 72 to the refrigerant discharge pipe 72.

[0045] However, in the internal space 30a of the cooling plate 30, a series of flow paths is formed, passing through the refrigerant inlet 61a, the refrigerant reservoir 61 on one end side of the fin, the flow paths 50 between the fins, the refrigerant reservoir 62 on the other end side of the fin, and the refrigerant outlet 62a.

[0046] (6) Type A cooling plate 30A For reference, the fins 40 in the first embodiment are configured to stand on the first plate 31, and the cooling plate 30 is configured such that the multiple fins 40 belong only to the first plate 31 and not to the second plate 32 (see Figs. 1 and 2, etc.). This type of cooling plate is referred to as "Type A cooling plate 30A."

[0047] (7) Refrigerant RF flows from bottom to top The battery assembly 1 is preferably arranged so that the axis 11 of the battery cells 10 is roughly aligned with the vertical direction g, and the refrigerant RF flows in each inter-fin flow passage 50 from one end side 51 located below the inter-fin flow passage 50 to the other end side 52 located above. That is, it is preferable to arrange the refrigerant RF so that it flows from bottom to top, as shown in Fig. 4. The "vertical direction g" refers to the direction of gravitational acceleration.

[0048] Fig. 4 is a diagram for explaining the flow of refrigerant RF in the battery assembly 1 (details will be described later). Fig. 4(a) corresponds to Fig. 11(b) and is a diagram that shows a schematic diagram of the flow of refrigerant RF with thick arrows. Note that the second plate 32, battery cells 10, battery cell rows 20, refrigerant inlet pipes 71, refrigerant outlet pipes 72, etc. are omitted. Fig. 4(b) is an enlarged perspective view of a main portion of the area surrounded by dashed line C in Fig. 4(a).

[0049] (8) 30A cooling plate with flexible heat sink The fins 40 used in the type A cooling plate 30A and the first plate 31 (or the second plate 32) to which the fins 40 belong are preferably applied using a so-called flexible heat sink (flexible HS). The flexible HS is constructed as follows. The fins 40 are made of a metal plate, and the surface of the metal plate is scraped away with the blade of a cutting tool to form a plurality of plate-like fins 40 that are integral with a base 45 of the metal plate (details will be described later with reference to FIG. 5). Furthermore, the base 45 of the first plate 31 or the second plate 32 that is integral with the fins 40 can be curved in a direction perpendicular to the longitudinal direction of the fins 40. The thickness of the base 45 of the flexible HS is set to a value that allows elastic deformation to the extent that the functions and effects of embodiment 1 are achieved, and that allows the strength to be sufficient to maintain functionality.

[0050] 2. Manufacturing method of flexible HS used for cooling plate 30A of type A 5 is a diagram for explaining an example of a method for manufacturing a flexible HS used as the fin 40 and the first plate 31 (or the second plate 32) to which the fin 40 belongs. The flexible HS can be manufactured by an appropriate method. For example, it can be manufactured by the following method.

[0051] First, a metal plate 100 is prepared (see FIG. 5(a)). As the material for the metal plate, for example, an aluminum material such as pure aluminum (A1050), a copper material, or the like can be used.

[0052] Next, the through holes 31b and 31c are formed by drilling, while the plate thickness is reduced in the region (low height region 120) where the refrigerant reservoirs 61 and 62 and the edge spacer 35 are to be disposed by pressing, cutting, etc. As a result, the rib 110 is relatively formed (see FIG. 5(b)).

[0053] Next, a fin forming process is performed. In the fin forming process, as shown in Fig. 5(c), the blade portion 210 of the cutting tool 200 is brought into contact with the rib 110 and slid from the upper right to the lower left of the drawing, and the rib 110 is scraped up by skiving to form the fin 40 integrally with the base portion 45. Regarding the method of manufacturing such fin 40, for example, the description of the fin manufacturing technology described in JP 2014-212290 A by the same applicant can be cited as a detailed description of the fin forming process in this specification.

[0054] By carrying out the above steps, a flexible HS (corresponding to the first plate 31 in FIG. 2) shown in Fig. 5(d) can be obtained. Note that the first plate 31B, the second plate 32B and the fins 40 associated therewith in the second embodiment described below can also be obtained by the above-mentioned manufacturing method for the flexible HS.

[0055] 3. Effects of the battery assembly 1 and the cooling plate 30 (30A) according to the first embodiment Returning to FIG. 4 (and also referring to other drawings as appropriate), the operation and effects of the battery assembly 1 and the cooling plate 30 (30A) according to the first embodiment will be described below, focusing on the flow of the refrigerant RF.

[0056] (1) In the battery assembly 1 according to the first embodiment, "a plurality of fins 40 are provided, each arranged such that its longitudinal direction is substantially parallel to the axis 11 of the battery cell 10, and an inter-fin flow passage 50 through which the refrigerant RF flows is formed between adjacent fins 40." "Refrigerant reservoirs 61, 62 are provided at one end side 51 and the other end side 52 of the inter-fin flow passage 50, respectively, and the one end side and the other end side of the inter-fin flow passage 50 are connected to the refrigerant reservoirs 61, 62."

[0057] Due to this configuration, as shown in FIG. 4, the refrigerant RF first spreads evenly laterally within the upstream refrigerant reservoir 61, straddling each of the battery cells 10, while its temperature has not yet risen, then flows into the inter-fin flow paths 50 from the inlets (one end side 51) of each inter-fin flow path 50, and as it flows through each inter-fin flow path 50, it absorbs heat from the fins 40 on the left and right walls and the base 45 of the base portion 53 (see FIG. 1(c)), then is discharged from the outlets (other end side 52) of each inter-fin flow path 50 into the downstream refrigerant reservoir 62, and is further discharged from the refrigerant discharge port 62a.

[0058] Of the series of flow paths for the refrigerant RF, the section that passes over the outer surfaces of the battery cells 10 and contributes substantially to cooling the battery cells 10 is the section of the inter-fin flow paths 50, and the path therebetween is relatively short, at most the height (length) of the battery cells 10. Therefore, there is no problem that the temperature of the refrigerant RF becomes high downstream and the battery cells 10 corresponding to the downstream cannot be sufficiently cooled, as occurs with the long path of the refrigerant flow path 950 (see FIG. 11) in the conventional battery assembly 900.

[0059] In the first embodiment, the coolant RF that spreads evenly throughout the coolant reservoir 61 before its temperature has increased enters each of the inter-fin flow paths 50. Furthermore, in the conventional battery assembly 900, the coolant flow path 950 spans multiple battery cells, but in the battery assembly 1 according to the first embodiment, one inter-fin flow path 50 runs only along one battery cell 10. It can be said that each battery cell 10 has its own group of fins 40 and group of inter-fin flow paths 50. Therefore, each battery cell 10 can equally benefit from the cooling, and there is no variation in cooling efficiency between many battery cells 10 arranged horizontally. Furthermore, each battery cell 10 can be charged and discharged under approximately the same temperature conditions, which reduces variation in battery characteristics and lifespan.

[0060] From the above, it can be seen that the battery assembly 1 according to the first embodiment has smaller variations than conventional ones and can cool the battery cells 10 with high efficiency.

[0061] (2) In the cooling plate 30 of the first embodiment, "multiple fins 40 are provided, each arranged such that its longitudinal direction is approximately parallel to the axis 11 of the battery cell 10, and inter-fin flow paths 50 through which the refrigerant RF flows are formed between adjacent fins 40." In this case, since the fins 40 are parallel to each other, the inter-fin flow paths 50 are like a straight tunnel when viewed in the direction in which the refrigerant RF travels. Because the inter-fin flow paths 50 are straight tunnels, the flow resistance of the inter-fin flow paths 50 is reduced, and the refrigerant RF can flow very smoothly through the inter-fin flow paths 50.

[0062] Therefore, even when pressure is applied to the refrigerant RF from the outside to make it flow, the pressure loss due to flow resistance is small according to the cooling plate 30 of embodiment 1, so that the pumping capacity can be met with a low-power pump. Energy required to operate the pump can also be saved, resulting in efficient cooling of the battery cells 10. In view of the above, the battery assembly 1 according to the first embodiment is capable of cooling the battery cells 10 more efficiently than conventional battery assembly.

[0063] (3) In the battery assembly 1 according to embodiment 1, "the outer surface of the first plate 31 or the second plate 32 integrated with the fin 40 contacts the side surface 12 of the battery cell 10 while at least a portion of the outer surface curves along the side surface of the battery cell row 20." In other words, the plate integrated with the fin 40 (the first plate 31 or the second plate 32) contacts the battery cell 10.

[0064] As a result, seamless thermal conduction can be achieved from the surface of the battery cell 10 through the outer surface 31a, 32a of the first plate 31 or the second plate 32, the fin base 45, and the fin 40, allowing heat from the battery cell 10 to be dissipated efficiently.

[0065] (4) In the battery assembly 1 of embodiment 1, the fins 40 are arranged to stand upright from the first plate 31, and the cooling plate 30 is configured as a “Type A cooling plate 30A” in which the multiple fins 40 belong only to the first plate 31 and not to the second plate 32.

[0066] According to this type A cooling plate 30A, a simple plate having no fins 40 can be used as the second plate 32 that faces the first plate 31, and as a result, the battery assembly 1 is cost-effective and has excellent mass-producibility.

[0067] (5) In the first embodiment, "the battery assembly 1 is placed upright with the axis 11 of the battery cell 10 roughly aligned with the vertical direction g...the battery assembly 1 is arranged so that the refrigerant RF flows in each inter-fin flow passage 50 from one end side 51 located below the inter-fin flow passage 50 to the other end side 52 located above." In other words, the battery assembly 1 is arranged so that the refrigerant RF flows from bottom to top, as shown in FIG. 4.

[0068] With this configuration, particularly when the refrigerant RF first begins to flow, fresh refrigerant RF that has not yet absorbed heat from the battery can be distributed evenly across the entire width of the upstream refrigerant reservoir 61 (lower refrigerant reservoir 61) under the influence of gravity.

[0069] (6) The battery assembly 1 has multiple battery cell rows 20 (21, 22), and a cooling plate 30 is disposed between a first battery cell row 21 and a second battery cell row 22, such that a first plate 31 of the cooling plate 30 contacts the first battery cell row 21 and a second plate 32 contacts the second battery cell row 22.

[0070] In this way, by arranging the cooling plate 30 not only on the outer surface of the battery cell block (no reference number) (cluster of battery cells) but also on the inside of the battery cell block (between the first battery cell row 21 and the second battery cell row 22), it is possible to increase the contact area with the battery cell rows 20, 21, and 22 for cooling. By arranging the cooling plate 30 on the inside of the battery cell block, where heat is particularly likely to build up, it is possible to further promote cooling of the battery cell rows 20, 21, and 22.

[0071] (7) As described above, flexible HS is used for the fins 40 and the first plate 31 or the second plate 32 to which the fins 40 belong. In particular, the fins 40 are made of a metal plate 100, and the surface of the metal plate 100 is scraped away with the blade 210 of the cutting tool 200 to form a plurality of plate-like fins 40 that are integrally formed and stand up with the base 45 of the metal plate 100. This results in a cooling plate 30 that is highly suitable for mass production.

[0072] In addition, "the first plate 31 or the second plate 32, which is formed integrally with the fins 40, is configured so that its base 45 can be bent," making it a flexible heat sink, so to speak. For this reason, it is easily deformed to fit the curved surface of the battery cell 10, and because it is formed integrally, it is easy to handle, making it possible to provide a cooling plate 30 with excellent mass-producibility.

[0073] (8) The functions and effects described thus far can be achieved not only by the battery assembly 1 but also by the cooling plate 30 .

[0074] [Embodiment 2] FIG. 6 is a diagram for explaining a battery assembly 2 according to the second embodiment. FIG. 6(a) is a diagram corresponding to FIG. 1(a) and is a perspective view of the battery assembly 2. FIG. 6(b) is a diagram corresponding to FIG. 1(c) and is an enlarged cross-sectional view of a main part in which the area surrounded by the dashed lines D1, D2, and D3 in FIG. 6(a) is enlarged. Note that the cross sections of the dashed lines D1, D2, and D3 have substantially the same structure, so FIG. 6(b) shows only one diagram. FIG. 7 is a cross-sectional view for explaining the assembly structure of the cooling plate 30B / 30.

[0075] The battery assembly 2 according to the second embodiment basically has the same configuration as the battery assembly 1 according to the first embodiment, but differs from the battery assembly 1 according to the first embodiment in the configuration of the cooling plate. That is, as shown in Fig. 6, the cooling plate 30B used in the battery assembly 2 has fins 40 standing on both the first plate 31B and the second plate 32B.

[0076] Specifically, the cooling plate 30B is configured as shown in FIG. In the cooling plate 30B, the fins 40 -1 The first plate 31B is provided with a fin 40. -2 is also erected from the second plate 32B. The cooling plate 30B includes a plurality of fins 40 belonging to the first plate 31B. -1 and a plurality of fins 40 belonging to the second plate 32B. -2 The first plate 31B and the second plate 32B are arranged facing each other so that the fins 40 and 41 are not in contact with each other (see FIG. 7(b) in particular). In this specification, such a cooling plate 30B is referred to as a "cooling plate 30B of type B." In addition, in order to obtain the same fin pitch P as the cooling plate 30A of type A, the fins 40 on the first plate 31B are arranged so that the fins 40 and 41 are not in contact with each other (see FIG. 7(b) in particular). -1 The pitch of the fins 40 in the second plate 32B is set to 2P, which is twice the pitch of P. -2 The pitch is 2P.

[0077] According to the cooling plate 30B of type B, the heat from the outer surface 31a of the first plate 31B and the heat from the outer surface 32a of the second plate 32B are radiated through the fins 40 belonging to each plate. -1 ,40 -2 Since heat can be dissipated from the refrigerant to the RF refrigerant, the cooling efficiency can be further improved.

[0078] The cooling plate 30B of type B can also employ the flexible HS described in embodiment 1. In other respects, the technical features described in embodiment 1 can also be applied to the cooling plate 30B of embodiment 2.

[0079] Except for the cooling plate, the battery assembly 2 according to the second embodiment has a basically similar configuration to the battery assembly 1 according to the first embodiment. Therefore, the battery assembly 2 according to the second embodiment has the same effects as those of the battery assembly 1 according to the first embodiment.

[0080] [Embodiment 3] FIG. 8 is a perspective view shown for explaining a battery assembly 3 according to the third embodiment. The battery assembly 3 of embodiment 3 basically has a similar configuration to the battery assembly 1 of embodiment 1 and the battery assembly 2 of embodiment 2, but differs from the battery assembly 1 of embodiment 1 and the battery assembly 2 of embodiment 2 in the configuration of the cooling plate.

[0081] As shown in FIG. 8, in the battery assembly 3, a type A cooling plate 30A and a type B cooling plate 30B are used depending on the location.

[0082] Specifically, the battery assembly 3 includes a type A cooling plate 30A and a type B cooling plate 30B. The type B cooling plate 30B is disposed between the first battery cell row 21 and the second battery cell row 22, and is configured such that a first plate 31B (see FIG. 7) of the type B cooling plate 30B contacts the first battery cell row 21 and a second plate 32B (see FIG. 7) contacts the second battery cell row 22. Meanwhile, the type A cooling plate 30A is disposed on one of the side surfaces of the battery cell row 20 that is not sandwiched between the multiple battery cell rows 20. In the figure, the type A cooling plate 30A is disposed on the -y direction side of the first battery cell row 21 and the +y direction side of the second battery cell row 22.

[0083] In this way, on the one hand, the outside of the battery cell block (no reference number) is in contact with the group of battery cells 10 via a Type A cooling plate 30A that is highly suitable for mass production, while on the other hand, on the inside of the battery cell block, both the first plate 31B and the second plate 32B are provided with fins 40. -1 ,40 -2 The battery assembly 3 according to the third embodiment is configured so that a Type B cooling plate 30B having a cooling plate portion 30A contacts the group of battery cells 10. Therefore, with the battery assembly 3 according to the third embodiment, by providing an optimal cooling plate according to location, it is possible to improve cooling efficiency while ensuring economy.

[0084] Except for the cooling plate, the battery assembly 3 according to embodiment 3 has a basically similar configuration to the battery assembly 1 according to embodiment 1 and the battery assembly 2 according to embodiment 2. Therefore, the battery assembly 3 according to embodiment 3 has the same effects as those of the battery assembly 1 according to embodiment 1 and the battery assembly 2 according to embodiment 2.

[0085] Although the present invention has been described based on the above embodiment, the present invention is not limited to the above embodiment. It can be embodied in various forms without departing from the spirit of the present invention, and for example, the following modifications are also possible.

[0086] (1) The flexible HS described above as applicable to each embodiment is not limited to the form shown in FIG. 5(d). For example, the flexible HS may be in the form shown by reference numeral 31' in FIG. 9 (Modification 1). FIG. 9 is a diagram for explaining the cooling plate 30A' of Modification 1, and the parts at the bottom of the figure are the flexible HS of Modification 1. In the flexible HS of Modification 1, the edge spacer 35' is also formed integrally with the first plate 31' in advance. The groove 31g is also used as the coolant reservoir 61, 62 as it is. If the flexible HS is processed as shown in FIG. 9 in the process of drilling, pressing, cutting, etc. corresponding to FIG. 5(b), the cooling plate 30A' can be manufactured with higher productivity and at lower cost than the case where the edge spacer 35' and the coolant reservoir 61, 62 are separately provided.

[0087] (2) In each embodiment, an example has been described in which there are multiple battery cell strings 20, but in the present invention, there may be only one battery cell string 20. In addition, the present invention is also applicable to a group of battery cells 10 (which may also be called a battery cell block) that does not necessarily form a string.

[0088] 10 is a diagram shown for explaining battery assemblies 5 to 7 according to modifications 2 to 4. Each diagram is a plan view of the battery assemblies 5 to 7 as viewed along the z-axis. For example, as shown in Figures 10(a) and 10(b), cooling plates 30A, 30B, 30A' may be arranged on the outer side surfaces of the battery cell block so as to surround the battery cell block. Also, as shown in Figure 10(c), cooling plates 30A, 30B, 30A' may be made to run along the outer and inner sides of the battery cell block in a single stroke along the side surfaces of each battery cell 10 that constitutes the battery cell block. In these modified examples, flexible HS can be more suitably used as the material that constitutes the cooling plates 30A, 30B, 30A'.

[0089] (3) In each embodiment, the battery cell 10 is described as having a cylindrical shape. However, the present invention is not limited to this. The battery cell 10 may have a prismatic shape such as a rectangular prism, a hexagonal prism, or an octagonal prism. [Explanation of symbols]

[0090] 1,2,3,5,6,7,900...battery assembly, 10...battery cell, 11...(battery cell) axis, 12...(battery cell) side, 20...battery cell row, 20a...(battery cell row) side, 21...first battery cell row, 22...second battery cell row, 30,30A,30A',30B,930...cooling plate, 30a...internal space, 31,31',31B...first plate, 31a...(first plate) outer surface, 31b,31c...through hole, 31g...groove, 32,32B...second plate, 32a...(second plate) outer surface, 35,35'...edge spacer, 40,40 -1 ,40 -2 ...fins, 45...base (of fins), 50...inter-fin flow passage, 51...one end (of inter-fin flow passage), 52...other end (of inter-fin flow passage), 53...base (of inter-fin flow passage), 61, 62...refrigerant reservoir, 61a...refrigerant inlet, 62a...refrigerant outlet, 71...refrigerant inlet pipe, 71a...slit, 72...refrigerant outlet pipe, 100...metal plate, 110...rib, 120...low height region, 200...cutting tool, 210...blade, 930a...plate, 940...partition wall, 950...refrigerant flow passage

Claims

1. A battery assembly comprising: a plurality of battery cells each having a columnar shape and arranged with their axes generally parallel to one another; and a cooling plate that contacts a side surface of the battery cells to cool the battery cells, The cooling plate includes a first plate and a second plate disposed opposite to each other and spaced apart from each other, a plurality of fins are provided in a space between the first plate and the second plate, the fins being integrally erected from the first plate or the second plate and arranged such that the longitudinal direction of the fins is substantially parallel to the axis of the battery cell; An inter-fin flow passage through which a coolant flows is formed between adjacent fins, a coolant reservoir is provided at one end side and the other end side of the inter-fin flow path, and the one end side and the other end side of the inter-fin flow path are connected to the coolant reservoir, When a plurality of the battery cells arranged adjacent to each other is defined as a battery cell string, an outer surface of the first plate or the second plate that is integral with the fin is in contact with the side surface of the battery cell while at least a portion of the outer surface is curved along the side surface of the battery cell row; A battery assembly comprising:

2. 2. The battery assembly of claim 1, The battery cell array includes a plurality of battery cell arrays, the cooling plate is disposed between the first row of battery cells and the second row of battery cells, the first plate of the cooling plate being in contact with the first row of battery cells and the second plate being in contact with the second row of battery cells; A battery assembly comprising:

3. 3. The battery assembly according to claim 1, The fin is provided upright from the first plate, The cooling plate is a "type A cooling plate" in which the fins belong only to the first plate and not to the second plate. A battery assembly comprising:

4. 3. The battery assembly according to claim 1, The fin is erected from the first plate and also erected from the second plate, The cooling plate is a "type B cooling plate" in which the first plate and the second plate are arranged opposite each other such that the plurality of fins belonging to the first plate and the plurality of fins belonging to the second plate do not contact each other. A battery assembly comprising:

5. 3. The battery assembly according to claim 2, "Type A cooling plate" in which the fins are erected from the first plate and the plurality of fins belong only to the first plate and not to the second plate; a "cooling plate of type B" in which the fins are erected from the first plate and also from the second plate, and the first plate and the second plate are arranged opposite each other such that the fins belonging to the first plate and the fins belonging to the second plate do not contact each other; the type B cooling plate is disposed between the first row of battery cells and the second row of battery cells, and is configured such that the first plate of the type B cooling plate contacts the first row of battery cells and the second plate of the type B cooling plate contacts the second row of battery cells; the type A cooling plate is disposed on a side surface of the battery cell row that is not sandwiched between a plurality of the battery cell rows, A battery assembly comprising:

6. The battery assembly according to any one of claims 1 to 5, When the battery assembly is placed upright with the axis of the battery cell roughly aligned with the vertical direction, The coolant is configured to flow in each of the inter-fin flow paths from the one end side located below the inter-fin flow paths to the other end side located above the inter-fin flow paths. A battery assembly comprising:

7. The battery assembly according to any one of claims 1 to 6, the fin is made of a metal plate, and a surface of the metal plate is scraped off with a blade of a cutting tool to form a plurality of plate-like fins integrally with a base of the metal plate, The first plate or the second plate formed integrally with the fin is configured so that the base portion can be bent. A battery assembly comprising:

8. A cooling plate for cooling a battery cell row in which a plurality of columnar battery cells are arranged, the battery cell row is a row in which a plurality of the battery cells are arranged adjacent to one another with their respective axes being substantially parallel to one another; The cooling plate includes a first plate and a second plate disposed opposite to each other and spaced apart from each other, a plurality of fins are provided in a space between the first plate and the second plate, the fins being integrally erected from the first plate or the second plate and arranged such that the longitudinal direction of the fins is substantially parallel to the axis of the battery cell; An inter-fin flow passage through which a coolant flows is formed between adjacent fins, a coolant reservoir is provided at one end side and the other end side of the inter-fin flow path, and the one end side and the other end side of the inter-fin flow path are connected to the coolant reservoir, the cooling plate is configured such that an outer surface of the first plate or the second plate, which is integrated with the fin, contacts the side surface of the battery cell while at least a portion of the outer surface curves along the side surface of the battery cell row. A cooling plate characterized by:

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