Battery assembly and battery pack

Abstract

The present invention provides a battery assembly and a battery pack wherein the battery assembly comprises: a plurality of cylindrical batteries, each cylindrical battery comprising a circumferential surface and an end surface; the plate surfaces of the second cold plates are perpendicular to the plate surface of the first cold plate, the second cold plates are arranged on the two sides of the first cold plate, the large surface of the first cold plate is opposite to the end surface of the cylindrical battery and exchanges heat with the end surface of the cylindrical battery, and the large surfaces of the second cold plates are opposite to the circumferential surface of the cylindrical battery and exchanges heat with the circumferential surface of the cylindrical battery; a first medium runner is arranged in the first cold plate, and a second medium runner is arranged in the second cold plate; the liquid collecting pipe is used for communicating the second medium flow channels of the two second cold plates; and the liquid inlet and the liquid outlet are formed in the two second cold plates correspondingly and used for liquid feeding and liquid discharging of the two second cold plates. The first cold plate cools the end face of the cylindrical battery, and the second cold plate cools the peripheral surface of the cylindrical battery, so that uniform heat dissipation of the cylindrical battery is ensured.

Description

[0001] This application is a divisional application of the invention patent application with publication number CN118899587A. The application date of the original application is: 2024.10.09; the application number is: 202411398933.0; the name of the invention is: "Battery Assembly and Battery Pack". Technical Field

[0002] The present invention relates to the technical field of new energy batteries, and in particular to a battery assembly and a battery pack. Background Art

[0003] The battery pack is the core component of new energy vehicles. The batteries in the battery pack include square batteries, cylindrical batteries, blade batteries, etc. For cylindrical batteries, since their circumference is an arc surface, serpentine cold plates are usually used to cool them. However, the serpentine cold plate can only cool the circumference of the cylindrical battery, but cannot provide a good heat dissipation effect on the axial direction of the cylindrical battery, so the overall heat dissipation effect of the cylindrical battery is poor. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defect of the serpentine cold plate in the prior art that the heat dissipation effect of the cylindrical battery is poor, thereby providing a battery assembly and a battery pack.

[0005] In order to solve the above problems, the present invention provides a battery assembly, including: a plurality of cylindrical batteries, the cylindrical batteries including a circumferential surface and an end surface; a first cold plate and a second cold plate, the plate surface of the second cold plate is arranged perpendicular to the plate surface of the first cold plate, and the second cold plates are arranged on both sides of the first cold plate, the large surface of the first cold plate is opposite to the end surface of the cylindrical battery and is arranged for heat exchange, the large surface of the second cold plate is opposite to the circumferential surface of the cylindrical battery and is arranged for heat exchange, the plurality of cylindrical batteries on one surface of the second cold plate form a cylindrical battery group, a first medium flow channel is arranged in the first cold plate, and a second medium flow channel is arranged in the second cold plate; a collecting pipe, used for connecting the second medium flow channels of the two second cold plates; a liquid inlet and a liquid outlet, respectively arranged on the two second cold plates, for liquid inlet and liquid outlet of the two second cold plates.

[0006] The present invention has the following advantages:

[0007] In the technical solution of the present invention, the battery assembly uses a combination of a first cold plate and a second cold plate to cool the cylindrical battery. The first cold plate cools the end face of the cylindrical battery, and the second cold plate cools the circumferential surface of the cylindrical battery, thereby ensuring the heat dissipation of the cylindrical battery in the axial and radial directions and reducing the uneven heat exchange of the cylindrical battery. Therefore, the technical solution of the present invention solves the defect of the poor heat dissipation effect of the serpentine cold plate on the cylindrical battery in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0009] Figure 1 A schematic structural diagram of a battery assembly of the present invention is shown;

[0010] Figure 2 Shows Figure 1 A schematic diagram of a bottom view of a first cold plate and a second cold plate of a battery assembly;

[0011] Figure 3 Shows Figure 1 A schematic diagram of the structure of the high voltage jumper row of the middle battery assembly;

[0012] Figure 4 Shows Figure 1 A schematic structural diagram of a second medium flow channel of a second cold plate of a battery assembly;

[0013] Figure 5 Shows Figure 4 A magnified schematic diagram of the middle branch channel;

[0014] Figure 6 Shows Figure 1 A schematic diagram of a first medium flow channel of a first cold plate of a battery assembly;

[0015] Figure 7 Shows Figure 1 Schematic diagram of the side structure of the first cold plate of the battery assembly.

[0016] Description of reference numerals:

[0017] 10. Cylindrical battery; 20. First cold plate; 21. First medium flow channel; 211. Inflow channel; 212. Outflow channel; 30. Second cold plate; 31. Arc-shaped recess; 32. Second medium flow channel; 321. Branch channel; 40. Liquid collecting pipe; 50. Liquid inlet; 60. Liquid outlet; 70. High-pressure jumper row. DETAILED DESCRIPTION

[0018] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0020] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0022] like Figures 1 to 7 As shown, an embodiment of a battery assembly according to the present application includes a plurality of cylindrical batteries 10, a first cold plate 20, a second cold plate 30, a liquid collecting pipe 40, a liquid inlet 50 and a liquid outlet 60. Among them, the cylindrical battery 10 includes a circumferential surface and an end surface. The plate surface of the second cold plate 30 is arranged perpendicular to the plate surface of the first cold plate 20, and a second cold plate 30 is arranged on both sides of the first cold plate 20. The cylindrical battery 10 is arranged on the second cold plate 30, the large surface of the first cold plate 20 is opposite to the end surface of the cylindrical battery and is arranged for heat exchange, the large surface of the second cold plate 30 is opposite to the circumferential surface of the cylindrical battery and is arranged for heat exchange, and the multiple cylindrical batteries 10 on one surface of the second cold plate 30 form a cylindrical battery pack.

[0023] Further, a first medium flow channel 21 is provided in the first cold plate 20, and a second medium flow channel 32 is provided in the second cold plate 30. The collecting pipe 40 is used to connect the second medium flow channels 32 of the two second cold plates 30, and the collecting pipe 40 is located at one end in the length direction of the second cold plate 30. The liquid inlet 50 and the liquid outlet 60 are respectively provided on the two second cold plates 30, and the collecting pipe 40 is located at one end in the length direction of the second cold plate 30, and the liquid inlet 50 and the liquid outlet 60 are located at the other end in the length direction of the second cold plate 30.

[0024] Further, the ratio of the length of the second cold plate 30 perpendicular to the axial direction of the cylindrical battery 10 to the width of the second cold plate 30 parallel to the axis of the cylindrical battery 10 is in the range of 4 to 23.

[0025] In the technical solution of this embodiment, the battery assembly cools the cylindrical battery 10 by combining the first cold plate 20 and the second cold plate 30. Among them, the first cold plate 20 cools the end face of the cylindrical battery 10, and the second cold plate 30 cools the circumferential surface of the cylindrical battery 10, thereby ensuring the heat dissipation of the cylindrical battery 10 in the axial direction and the radial direction. By optimizing the relationship between the length and width of the second cold plate 30, the temperature difference of the heat exchange medium at the liquid inlet 50 and the liquid outlet 60 can be reduced, thereby ensuring the heat exchange effect on the two second cold plates 30 and reducing the uneven heat exchange of the cylindrical battery 10. Therefore, the technical solution of this embodiment solves the defect that the serpentine cold plate in the prior art has a poor heat dissipation effect on cylindrical batteries.

[0026] like Figure 1 As shown, Figure 1 Two battery assemblies are shown, and the two battery assemblies are arranged in parallel. Figure 1 Those skilled in the art can understand that the cylindrical battery 10 is placed on the battery assembly on the right, and in order to better show the specific structure of the first cold plate 20 and the second cold plate 30, the cylindrical battery 10 is not placed on the battery assembly on the left.

[0027] In this embodiment, the cylindrical battery 10 has a cylindrical structure, including a circumferential surface and two end surfaces, and the shape of the cylindrical battery 10 is circular.

[0028] like Figure 2 As shown, the first cold plate 20 and the second cold plate 30 are both thin plate structures, that is, both have large surfaces. The first cold plate 20 is arranged in a vertical direction, that is, the large surface of the first cold plate 20 faces the horizontal direction, and the first cold plate 20 has a height and a length. The second cold plate 30 is arranged in a horizontal direction, that is, the large surface of the second cold plate 30 faces the vertical direction, and the second cold plate 30 has a length direction and a width direction. The second cold plates 30 are arranged on both sides of the first cold plate 20, so one first cold plate 20 and two second cold plates 30 form a structure similar to a "cross". That is, the plate surface of the first cold plate 20 and the plate surface of the second cold plate 30 are arranged vertically.

[0029] Combination Figure 2 It can be seen that the cross section of the second cold plate 30 is wavy, that is, a plurality of spaced arc-shaped recesses 31 are formed on the upper and lower surfaces of the second cold plate 30 , and the arc-shaped recesses 31 extend along the length direction of the first cold plate 20 .

[0030] from Figure 1It can be seen that the cylindrical battery 10 lies on the second cold plate 30, and the axis of the cylindrical battery 10 extends along the width direction of the second cold plate 30, that is, the peripheral surface heat exchange of the cylindrical battery 10 is set on the arc-shaped recessed portion 31. The end surface of the cylindrical battery 10 is heat exchanged with the large surface of the first cold plate 20. That is, the first cold plate 20 exchanges heat with the end surface of the cylindrical battery 10, and the second cold plate 30 exchanges heat with the peripheral surface of the cylindrical battery 10.

[0031] It should be noted that the above-mentioned “the large surface of the first cold plate 20 is opposite to the end surface of the cylindrical battery and is arranged for heat exchange” means that the end surface of the cylindrical battery can exchange heat with the large surface of the first cold plate 20, including direct or indirect contact between the end surface of the cylindrical battery and the large surface of the first cold plate 20. In this embodiment, the end surface of the cylindrical battery is attached to the large surface of the first cold plate 20 by an adhesive (indirect contact).

[0032] It should be noted that the above-mentioned “the large surface of the second cold plate 30 is opposite to the peripheral surface of the cylindrical battery and is arranged for heat exchange” means that the peripheral surface of the cylindrical battery can exchange heat with the large surface of the second cold plate 30, including direct or indirect contact between the peripheral surface of the cylindrical battery and the large surface of the second cold plate 30. In this embodiment, the peripheral surface of the cylindrical battery is attached to the large surface of the second cold plate 30 by an adhesive (indirect contact).

[0033] Further, one of the two second cold plates 30 is provided with a liquid inlet 50, and the other is provided with a liquid outlet 60, and the liquid inlet 50 and the liquid outlet 60 are both located on one side of the second cold plate 30, that is, Figure 1 The liquid collecting pipe 40 is arranged on the other side opposite to the second cold plate 30, that is, Figure 1 The collecting pipe 40 is a long strip structure, which covers the outer sides of the ends of the two second cold plates 30. A flow channel is arranged in the collecting pipe 40, and the collecting pipe 40 can connect the second medium flow channels 32 of the two second cold plates 30.

[0034] Therefore, the flow pattern of the heat exchange medium in the two second cold plates 30 is: liquid inlet 50-second medium flow channel 32 of one second cold plate 30-liquid collector 40-second medium flow channel 32 of the other second cold plate 30-liquid outlet 60. Those skilled in the art can understand that the flow direction of the heat exchange medium is generally a "U"-shaped path.

[0035] Furthermore, the flow direction of the heat exchange medium is relatively long, and the heat exchange medium continuously exchanges heat with the cylindrical battery 10 when the heat exchange medium flows, so the heat exchange capacity of the heat exchange medium near the liquid inlet 50 is better than the heat exchange capacity of the heat exchange medium near the liquid outlet 60. Taking the cooling of the cylindrical battery 10 by the coolant as an example, the temperature of the heat exchange medium near the liquid inlet 50 is lower than the temperature of the heat exchange medium near the liquid outlet 60, which may lead to uneven heat exchange of multiple cylindrical batteries 10, and the above structure needs to be further optimized.

[0036] Specifically, the length of the second cold plate 30 cannot be too long. If the length of the second cold plate 30 is too long, the flow distance of the heat exchange medium will increase, and the upstream and downstream temperature difference of the heat exchange medium will increase, further aggravating the uneven heat exchange of multiple cylindrical batteries 10.

[0037] Furthermore, the width of the second cold plate 30 cannot be too small, and the width of the second cold plate 30 determines the flow area and flow rate of the heat exchange medium in the second medium flow channel 32 .

[0038] The ratio of the length to the width of the second cold plate 30 cannot be too small. If the ratio is too small, the length of the second cold plate 30 will be too short. At this time, if the first cold plate 20 is set as small as possible, the arrangement direction of the cylindrical batteries 10 needs to be set perpendicular to the length direction of the battery pack, which will increase the number of high-voltage adapters between the cylindrical battery packs, which is not conducive to ensuring the reliability of the battery pack.

[0039] Optionally, a ratio of the length to the width of the second cold plate 30 is in the range of 4-23.

[0040] For example, the ratio of the length to the width of the second cold plate 30 may be selected as 4, 10, 15, 20 or 23.

[0041] Further preferably, the ratio of the length to the width of the second cold plate 30 is in the range of 4.5 to 11.4.

[0042] For example, the ratio of the length to the width of the second cold plate 30 may be selected to be 4.5, 5, 10, 11 or 11.4.

[0043] like Figure 3 As shown, in the technical solution of this embodiment, the battery assembly also includes a high-voltage jumper bar 70, which is used to connect different cylindrical battery packs or to lead out the electrical energy of the cylindrical battery pack. The high-voltage jumper bar 70 is arranged on the other side of the second cold plate 30 opposite to the liquid inlet 50 and the liquid outlet 60.

[0044] That is, the high-pressure crossover bank 70 is disposed on one side of the second cold plate 30 where the header 40 is disposed.

[0045] In this embodiment, the water circuit and the electric circuit are separated to ensure the safe use of the battery assembly.

[0046] In the technical solution of this embodiment, the ratio of the width of the first medium flow channel 21 to the width of the collecting pipe 40 is in the range of 0.0003 to 8.

[0047] Specifically, if the width of the second medium flow channel 32 is too large relative to the width of the collecting tube 40, it means that the width of the second medium flow channel 32 is large and the width of the collecting tube 40 is small, so the flow resistance of the heat exchange medium at the position of the collecting tube 40 is large, which increases the degree of turbulence. The increase in the degree of turbulence is not conducive to the uniform temperature of the heat exchange medium at the liquid inlet 50 and the liquid outlet 60. If the width of the second medium flow channel 32 is too small relative to the width of the collecting tube 40, it means that the width of the second medium flow channel 32 is small and the width of the collecting tube 40 is large, and the small width of the second medium flow channel 32 is also not conducive to reducing the flow resistance of the heat exchange medium.

[0048] Optionally, the ratio of the width of the second medium flow channel 32 to the width of the collecting pipe 40 may be selected as 0.0003, 0.001, 0.01, 0.1, 1, 5 or 8.

[0049] Further preferably, the ratio of the width of the second medium flow channel 32 to the width of the collecting pipe 40 is in the range of 0.025 to 1.

[0050] Optionally, the ratio of the width of the second medium flow channel 32 to the width of the collecting pipe 40 may be selected as 0.03, 0.04, 0.1, 0.5, 0.7, 0.9 or 1.

[0051] In the present embodiment, the width of the collecting pipe 40 is in the range of 3 mm to 70 mm.

[0052] Optionally, the width of the collecting tube 40 may be selected to be 3 mm, 5 mm, 10 mm, 20 mm, 40 mm, 60 mm or 70 mm, etc.

[0053] like Figure 2 As shown, in the technical solution of this embodiment, the width of the second cold plate 30 parallel to the axis of the cylindrical battery 10 is in the range of 70 mm to 131 mm.

[0054] Optionally, the width of the second cold plate 30 parallel to the axis of the cylindrical battery 10 may be 70 mm, 80 mm, 90 mm, 100 mm, 110 mm, 120 mm, 130 mm or 131 mm.

[0055] Further preferably, the width of the second cold plate 30 parallel to the axis of the cylindrical battery 10 is in the range of 90 mm to 121 mm.

[0056] Optionally, the width of the second cold plate 30 parallel to the axis of the cylindrical battery 10 may be 90 mm, 100 mm, 110 mm, 120 mm or 121 mm.

[0057] like Figure 4 and Figure 5 As shown, in the technical solution of this embodiment, the widths of the two second cold plates 30 parallel to the axis of the cylindrical battery 10 are the same, and the second medium flow channel 32 includes a plurality of branch channels 321.

[0058] Specifically, the branch channel 321 extends along the length direction of the second cold plate 30 , and a plurality of branch channels 321 are arranged in parallel along the width direction of the second cold plate 30 .

[0059] The width of the second medium flow channel 32 mentioned above refers to the width of one branch channel 321. When the widths of the plurality of branch channels 321 are different, the width of the second medium flow channel 32 refers to the width of the branch channel 321 with the smallest width among the plurality of branch channels 321.

[0060] In the technical solution of this embodiment, the number of branch channels 321 of the second cold plate 30 connected to the liquid outlet 60 is less than the number of branch channels 321 of the second cold plate 30 connected to the liquid inlet 50 .

[0061] Specifically, when the widths of the two second cold plates 30 are the same, the fewer the number of branch channels 321, the greater the flow rate of the heat exchange medium, and the stronger the convective heat exchange capacity of the heat exchange medium. Therefore, the number of branch channels 321 of the second cold plate 30 connected to the liquid outlet 60 is smaller than the number of branch channels 321 of the second cold plate 30 connected to the liquid inlet 50, so that the convective heat exchange capacity of the heat exchange medium located at the liquid outlet 60 is greater than the convective heat exchange capacity of the heat exchange medium located at the liquid inlet 50 of the inlet plate, thereby compensating for the insufficient heat exchange after the heat exchange medium flows a certain distance, and making the temperature of each cylindrical battery 10 in the battery pack more balanced.

[0062] In the technical solution of this embodiment, the ratio of the number of branch channels 321 of the second cold plate 30 connected to the liquid outlet 60 to the number of branch channels 321 of the second cold plate 30 connected to the liquid inlet 50 is in the range of 0.026 to 1.

[0063] Optionally, the ratio can be selected as 0.026, 0.03, 0.05, 0.1, 0.5 or 1.

[0064] Further preferably, the ratio of the number of branch channels 321 of the second cold plate 30 connected to the liquid outlet 60 to the number of branch channels 321 of the second cold plate 30 connected to the liquid inlet 50 is in the range of 0.5 to 0.8.

[0065] Alternatively, the ratio may be selected as 0.5, 0.6, 0.7, or 0.8.

[0066] like Figure 6 As shown, in the technical solution of this embodiment, the first medium flow channel 21 includes an inlet flow channel 211 and an outlet flow channel 212, and the inlet flow channel and the outlet flow channel divide the large surface of the first cold plate into a first area S1 and a second area S2, and the projection of the second cold plate 30 on the large surface of the first cold plate 20 is located in the first area S1.

[0067] Specifically, the inflow channel 211 and the outflow channel 212 also include a plurality of branch channels, and the branch channels are arranged in parallel along the length direction of the first cold plate 20 .

[0068] In this embodiment, a liquid inlet and a liquid outlet are also provided on the side of the first cold plate 20, and the liquid inlet and the liquid outlet are located on the same side of the first cold plate 20 as the liquid inlet 50 and the liquid outlet 60 of the second cold plate 30, and the liquid inlet and the liquid outlet of the first cold plate 20 are arranged along the height direction of the first cold plate 20. The liquid inlet of the first cold plate 20 is connected to the inflow channel 211, and the liquid outlet of the first cold plate 20 is connected to the outflow channel 212, and the inflow channel 211 and the outflow channel 212 are connected on the other side of the first cold plate 20 (that is, the side where the collecting pipe 40 is provided).

[0069] Further, the aforementioned inflow channel 211 means that the heat exchange medium enters the inflow channel 211 from the liquid inlet, and flows along the inflow channel 211 in a direction away from the liquid inlet and the liquid outlet of the first cold plate 20. The aforementioned outflow channel 212 means that the heat exchange medium can flow from the outflow channel 212 to the liquid outlet and be discharged, and flows along the outflow channel 212 in a direction toward the liquid inlet and the liquid outlet of the first cold plate 20.

[0070] That is, the flow paths of the heat exchange medium in the inflow channel 211 and the outflow channel 212 are approximately "U"-shaped tracks.

[0071] from Figure 7 It can be seen that the first cold plate 20 has a large surface corresponding to the inflow channel 211, forming a first area S1, that is, Figure 7 The large surface of the first cold plate 20 corresponding to the outflow channel 212 forms a second area S2, that is, Figure 7 The area below the dotted line.

[0072] As described above, the flow path of the heat exchange medium in the first cold plate 20 is also roughly in a "U"-shaped structure. As described above, in the first cold plate 20, there is also a situation where the heat exchange capacity of the heat exchange medium in the inflow channel 211 is higher than the heat exchange capacity of the heat exchange medium in the outflow channel 212.

[0073] Therefore, if the second cold plate 30 is disposed at the junction of the first area S1 and the second area S2 of the large surface of the first cold plate 20, the cylindrical battery 10 located above the second cold plate 30 can only contact the heat exchange medium with high heat exchange capacity, while the cylindrical battery 10 located below the second cold plate 30 can only contact the heat exchange medium with low heat exchange capacity, resulting in uneven temperatures of the cylindrical batteries 10 on the upper and lower sides of the second cold plate 30.

[0074] Therefore, in the technical solution of this embodiment, the projection of the second cold plate 30 on the large surface of the first cold plate 20 is located in the first area S1, so that the cylindrical battery 10 located above the second cold plate 30 can contact the heat exchange medium with high heat exchange capacity, and the cylindrical battery 10 located below the second cold plate 30 can contact part of the heat exchange medium with high heat exchange capacity, so that the temperature of each cylindrical battery 10 in the battery pack is more balanced.

[0075] Optionally, the distance between the lower edge of the projection of the second cold plate 30 on the large surface of the first cold plate 20 and the boundary between the first area S1 and the second area S2 is in the range of 0.05 mm to 0.5 mm.

[0076] For example, the distance may be 0.05 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm or 0.5 mm.

[0077] Further preferably, the distance between the lower edge of the projection of the second cold plate 30 on the large surface of the first cold plate 20 and the boundary between the first area S1 and the second area S2 is in the range of 0.1 mm to 0.3 mm.

[0078] For example, the distance may be 0.1 mm, 0.2 mm or 0.3 mm.

[0079] Optionally, the total cross-sectional area of ​​the inflow channel 211 is greater than the total cross-sectional area of ​​the outflow channel 212 .

[0080] from Figure 7 It can be seen that along the height direction of the first cold plate 20, the height of the region S1 is slightly greater than the height of the region S2, so the total cross-sectional area of ​​the inflow channel 211 (the sum of the cross-sectional areas of each branch channel) is greater than the total cross-sectional area of ​​the outflow channel 212 (the sum of the cross-sectional areas of each branch channel). This allows the cylindrical battery 10 located above the second cold plate 30 to contact the heat exchange medium with high heat exchange capacity in the inflow channel 211, and the cylindrical battery 10 located below the second cold plate 30 to contact part of the heat exchange medium with high heat exchange capacity in the inflow channel 211, thereby making the temperature of each cylindrical battery 10 in the battery pack more balanced.

[0081] In the technical solution of this embodiment, on one side of the first cold plate 20, the surface area of ​​the large surface of the first cold plate 20, the surface area of ​​the large surface of the second cold plate 30, and the size of the cylindrical battery 10 satisfy the following relationship:

[0082] (A / (B*n)) / (C / (D*n)) is in the range of 0.013 to 14.8,

[0083] Among them, A is the surface area of ​​the large surface of the first cold plate 20, B is the end surface area of ​​the cylindrical battery 10, C is the surface area of ​​the large surface of the second cold plate 30, D is the circumferential area of ​​the cylindrical battery 10, and n is the number of cylindrical batteries 10 on one side of the first cold plate 20.

[0084] The numerator (A / (B*n)) represents the area of ​​the first cold plate 20 for axial cooling shared by each cylindrical battery 10, and the denominator (C / (D*n) represents the area of ​​the second cold plate 30 for radial cooling shared by each cylindrical battery 10.

[0085] Considering that the axial heat transfer efficiency and radial heat transfer efficiency of the cylindrical battery 10 are different, in order to balance the two, the above ratio should be within a reasonable range.

[0086] Optionally, the above ratio may be 0.013, 0.02, 0.1, 1, 5, 10, 14 or 14.8.

[0087] More preferably, the above ratio is in the range of 0.8 to 4.

[0088] For example, the above ratio may be 0.8, 1, 2, 3 or 4.

[0089] The present application also provides a battery pack, including a box and a battery assembly arranged in the box, the battery assembly is the above-mentioned battery assembly, the box includes a bottom plate, a first cold plate is arranged perpendicular to the bottom plate, and a second cold plate is arranged parallel to the bottom plate.

[0090] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A battery assembly, characterized in that: include: A plurality of cylindrical batteries (10), wherein the cylindrical batteries (10) include a peripheral surface and an end surface; A first cold plate (20) and a second cold plate (30), wherein a plate surface of the second cold plate (30) is arranged perpendicular to a plate surface of the first cold plate (20), and the second cold plate (30) is arranged on both sides of the first cold plate (20), a large surface of the first cold plate (20) is opposite to an end surface of the cylindrical battery and is arranged for heat exchange, a large surface of the second cold plate (30) is opposite to a peripheral surface of the cylindrical battery and is arranged for heat exchange, a plurality of cylindrical batteries (10) on a surface of the second cold plate (30) form a cylindrical battery pack, a first medium flow channel (21) is arranged in the first cold plate (20), and a second medium flow channel (32) is arranged in the second cold plate (30); A liquid collecting pipe (40) for connecting the second medium flow channels (32) of the two second cold plates (30); The liquid inlet (50) and the liquid outlet (60) are respectively arranged on the two second cold plates (30) and are used for liquid inlet and liquid outlet of the two second cold plates (30).

2. The battery assembly according to claim 1, characterized in that: The battery assembly further comprises a high-voltage jumper bar (70), the high-voltage jumper bar (70) being used to connect different cylindrical battery packs or to lead out electrical energy from the cylindrical battery packs, the high-voltage jumper bar (70) being arranged on the other side of the second cold plate (30) opposite to the liquid inlet (50) and the liquid outlet (60).

3. The battery assembly according to claim 1, characterized in that: The ratio of the width of the second medium flow channel (32) to the width of the collecting pipe (40) is in the range of 0.0003 to 8.

4. The battery assembly according to claim 1, characterized in that: The width of the second cold plate (30) parallel to the axis of the cylindrical battery (10) is in the range of 70 mm to 131 mm.

5. The battery assembly according to any one of claims 1 to 4, characterized in that: The widths of the two second cold plates (30) parallel to the axis of the cylindrical battery (10) are the same, the second medium flow channel (32) comprises a plurality of branch channels (321), and the number of the branch channels (321) of the second cold plate (30) connected to the liquid outlet (60) is less than the number of the branch channels (321) of the second cold plate (30) connected to the liquid inlet (50).

6. The battery assembly according to claim 5, characterized in that: The ratio of the number of the branch channels (321) of the second cold plate (30) connected to the liquid outlet (60) to the number of the branch channels (321) of the second cold plate (30) connected to the liquid inlet (50) is in the range of 0.026 to 1.

7. The battery assembly according to claim 5, characterized in that: The first medium flow channel (21) comprises an inlet flow channel (211) and an outlet flow channel (212), wherein the inlet flow channel and the outlet flow channel divide the large surface of the first cold plate into a first area (S1) and a second area (S2), and a projection of the second cold plate (30) on the side surface of the first cold plate (20) is located within the first area (S1).

8. The battery assembly according to claim 7, characterized in that: The distance between the lower edge of the projection of the second cold plate (30) on the large surface of the first cold plate (20) and the boundary position between the first area (S1) and the second area (S2) is in the range of 0.05 mm to 0.5 mm.

9. The battery assembly according to claim 7, characterized in that: The total cross-sectional area of ​​the inflow channel (211) is greater than the total cross-sectional area of ​​the outflow channel (212).

10. The battery assembly according to claim 7, characterized in that: On one side of the first cold plate (20), the surface area of ​​the large surface of the first cold plate (20), the surface area of ​​the large surface of the second cold plate (30), and the size of the cylindrical battery (10) satisfy the following relationship: (A / (B*n)) / (C / (D*n)) is in the range of 0.013 to 14.8, Wherein, A is the surface area of ​​the large surface of the first cold plate (20), B is the end surface area of ​​the cylindrical battery (10), C is the surface area of ​​the large surface of the second cold plate (30), D is the circumferential surface area of ​​the cylindrical battery (10), and n is the number of the cylindrical batteries (10) on one side of the first cold plate (20).

11. A battery pack, characterized in that: The invention comprises a box body and a battery assembly arranged in the box body, wherein the battery assembly is the battery assembly according to any one of claims 1 to 10, the box body comprises a bottom plate, and the second cold plate is arranged parallel to the bottom plate.

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