Battery cell shell, battery cell and immersed battery pack

Abstract

The utility model discloses a battery cell shell, a battery cell and an immersed battery pack. The battery cell shell comprises a square shell body, and a plurality of cooling liquid flow channels for circulating cooling liquid communicating the shell top surface with the shell bottom surface are formed in the large surface of the shell side surface of the square shell body. According to the battery cell shell disclosed by the utility model, the plurality of cooling liquid flow channels for communicating the shell top surface with the shell bottom surface are arranged in the large surface of the shell side surface of the square shell body, so that the cooling liquid can flow through the shell side surface through the cooling liquid flow channels, and the large surface of the battery cell can be cooled; after the battery cells are stacked to form the battery cell package, heat dissipation of the side faces of the battery cells is not affected under tight contact of the battery cells, and the problems that in a traditional immersion type liquid cooling scheme, due to direct stacking, the large faces of the battery cells cannot make contact with liquid, heat exchange cannot be achieved, and the immersion type cooling efficiency is reduced are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of battery cores, and in particular to a battery core shell, a battery core and an immersion battery pack. Background Art

[0002] In new energy batteries, thermal management is an important component. Most battery thermal management methods need to rely on external thermal management system components, such as liquid-cooled direct cooling plates. At present, some solutions are to modify the battery shell, add partitions to the outside of the battery shell to form a coolant flow channel, and open the top to let the coolant in. However, the provided coolant flow channel has a single shape, is closed on the outside, and has a large flow resistance to the coolant inside. In addition, the provided coolant flow channel is divided into a vertical arrangement. When the battery cell expands, the coolant flow channel position will be raised, which cannot effectively inhibit expansion and deformation. In addition, the large surface of the battery cell in the traditional immersion liquid cooling solution cannot contact the liquid due to direct stacking, and heat exchange cannot be achieved, which reduces the immersion efficiency. Setting up cooling components for the large surface of the battery cell separately is costly and occupies a large volume. Utility Model Content

[0003] The purpose of the utility model is to overcome the shortcomings and defects of the prior art and to provide a battery cell shell, a battery cell and an immersion battery pack. The battery cell shell can realize immersion cooling of a large surface of the battery cell, and can absorb and suppress the expansion of the battery cell in the large surface stacking structure of the battery cell. The cooling of the immersion system used is simpler and can be adapted to the solution of lying down the battery cells.

[0004] The first aspect of the utility model provides a battery cell shell, comprising a square shell body, wherein a large surface of the shell side of the square shell body has a plurality of coolant flow channels for circulating coolant connecting the shell top surface and the shell bottom surface.

[0005] Optionally, the coolant channel and the side surface of the shell are an integrally formed extruded structure.

[0006] Optionally, the shell top surface, the shell bottom surface and the shell side surface are welded together.

[0007] Optionally, the plurality of coolant flow channels are separated by a plurality of oblique ribs and arranged in a line, and the cross section is trapezoidal; two adjacent coolant flow channels share one oblique rib.

[0008] Optionally, the thickness of the coolant flow channel is consistent or inconsistent.

[0009] Optionally, the thickness of the coolant channel is 2-5 mm.

[0010] Optionally, the cross-sectional sizes of the coolant channels are the same or different.

[0011] A second aspect of the present invention provides a battery cell, comprising the battery cell casing described in the first aspect of the present invention.

[0012] A third aspect of the present invention provides an immersion battery pack, comprising a battery box and a plurality of battery cells stacked in the battery box, wherein the battery cells are the battery cells described in the second aspect of the present invention.

[0013] Optionally, the battery cells are stacked with large surfaces in contact, and a large surface on one side of the stack is placed on the inner bottom surface of the battery case; or, the inner bottom surface of the battery case has a plurality of separated grooves formed by longitudinal beams, the battery cells are stacked with large surfaces in contact, and cooling liquid channels are formed between the bottom surfaces of the plurality of battery cells and the grooves.

[0014] The battery cell shell of the utility model has a plurality of cooling liquid flow channels for circulating the cooling liquid connecting the shell top surface and the shell bottom surface inside the large surface of the shell side of the square shell body. In this way, the cooling liquid can flow through the shell side through the cooling liquid flow channels, so that the large surface of the battery cell can be cooled. After the battery cells are stacked into a battery cell pack, the heat dissipation on the side of the battery cell can be not affected when the battery cells are in close contact with each other. This solves the problem in the traditional immersion liquid cooling solution that the large surface of the battery cell cannot contact the liquid due to direct stacking, and heat exchange cannot be achieved, thereby reducing the immersion cooling efficiency.

[0015] In addition, since the large surface of the side surface of the square shell body has multiple coolant flow channels for circulating the coolant that connects the top surface of the shell with the bottom surface of the shell, it is a hollow structure. When the battery cell expands in a cycle, the hollow structure formed by the coolant flow channels can suppress and absorb part of the expansion deformation. In this way, there is no need to add additional buffer devices between the stacked battery cells, which is relatively cost-effective.

[0016] In particular, the coolant flow channel is a trapezoidal structure, which can provide higher compressive strength in the direction parallel to the coolant flow channel and can be compressed to a certain extent in the vertical direction of the coolant flow channel. Its structural function is similar to that of a honeycomb panel, but it has stronger compression resistance in the vertical direction than a hexagonal honeycomb panel.

[0017] The immersion-type battery pack of the utility model adopts the battery cell with the coolant flow channel on the inner surface of the shell of the utility model, so that the sides of the stacked battery cells can be effectively cooled, and the problem in the traditional immersion-type liquid cooling scheme that the large surfaces of the battery cells cannot contact the liquid due to direct stacking and heat exchange cannot be achieved, thereby reducing the immersion cooling efficiency, is solved. The immersion system cooling is easier to implement, and there is no need to design too many coolant flow channels inside the battery cell pack. The coolant flows to the cooling channels on the sides of the battery cell outer shell to cool the large surfaces of the battery cells efficiently. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a first schematic diagram of a battery cell according to an embodiment of the utility model.

[0019] Figure 2 This is a second schematic diagram of a battery cell according to an embodiment of the present utility model.

[0020] Figure 3 for Figure 2 Part A / Figure 3 A partial enlarged view of the coolant flow channel in part B.

[0021] Figure 4 It is a schematic diagram of the battery cells of the present invention stacked in a row.

[0022] Figure 5 for Figure 4 A partial enlarged view of part C.

[0023] Figure 6 It is a schematic diagram of the arrangement of cells in an immersed battery pack according to the first embodiment of the utility model.

[0024] Figure 7 for Figure 6 A schematic diagram of a battery pack with one side panel removed is shown.

[0025] Figure 8 for Figure 6 A schematic cross-sectional view of a battery pack is shown.

[0026] Fig. 9 It is a schematic diagram of the arrangement of cells in an immersed battery pack according to the second embodiment of the utility model.

[0027] Fig.10 for Fig. 9 The schematic diagram of the battery pack shown is with one side panel removed.

[0028] Fig.11 for Fig.10 A partial enlarged view of the battery cell stacking arrangement. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0030] like Figure 1 , 2 As shown, Figure 1 , 2Two schematic diagrams of the battery cell 5 of the embodiment of the utility model are shown. The battery cell shell of the embodiment of the utility model is a square shell, which is composed of a shell side surface 1, a shell top surface 2, and a shell bottom surface 3; the shell side surface 1 includes a dense coolant flow channel 11. The coolant flow channel 11 can realize that the coolant flows through the shell side through the coolant flow channel, so that the large surface of the battery cell can be cooled, and after the battery cells are stacked into a battery cell package, the heat dissipation of the battery cell side can be not affected under the close contact of the battery cells, which solves the problem that in the traditional immersion liquid cooling solution, the large surface of the battery cell cannot contact the liquid due to direct stacking, and heat exchange cannot be realized, which reduces the efficiency of immersion cooling.

[0031] Since flow channels are arranged on the sides of the shell, in the large-surface stacking structure of the battery cells, when the battery cells expand during a cycle, the hollow structure in the middle of the large surface of the battery cells formed by the inherent flow channels of the battery cell shell can suppress and absorb part of the expansion deformation; there is no need to add additional buffer devices in the middle of the battery cells.

[0032] In a preferred embodiment, the coolant flow channel 11 and the shell side 1 are an integrally formed extruded structure, and the shell top surface 2, the shell bottom surface 3 and the shell side 1 are independently formed and then connected by welding. The thickness of the coolant flow channel is 2-5 mm, and the thickness and cross-section can be the same or different, preferably the same thickness and the same cross-section size.

[0033] In a preferred embodiment, the plurality of cooling liquid flow channels are separated and arranged in a line by a plurality of oblique ribs, and the cross section thereof is a trapezoid, such as Figure 3 As shown; two adjacent coolant channels share one oblique rib. Due to the use of the coolant channel 11 with a trapezoidal cross section, in the stacked battery cells, a higher compressive strength can be provided in the direction parallel to the coolant channel, and a certain degree of compression can be achieved in the vertical direction of the coolant channel. Its structural function is similar to that of a honeycomb panel, but it has a stronger compression resistance in the vertical direction than a hexagonal honeycomb panel. Figure 4 , 5 shown.

[0034] An embodiment of the present invention provides a battery cell, including the battery cell shell described in the embodiment of the present invention, wherein the battery cell shell contains an electrode group and an electrolyte; the electrode group is composed of a plurality of positive and negative electrode sheets and a separator, which are stacked in the order of separator, positive electrode sheet, separator, and negative electrode sheet.

[0035] like Figure 6As shown, the embodiment of the utility model provides an immersion-cooled battery pack, in which the battery cells 5 are stacked in a positively enlarged manner, and the immersion coolant enters from the liquid inlet 41 of the battery case 4. There is no need for too many coolant flow channels to be designed inside. The coolant flows to the coolant flow channel 11 on the side of the battery cell outer shell, so that the large surface of the battery cell can be cooled; the coolant enters the system to cool all sides of the battery cell in all directions, and then flows out from the liquid outlet 42. The structure of the overall immersion cooling system is very simple, and no separate coolant flow channel design is required.

[0036] In the above-mentioned battery pack embodiment, in order to allow the coolant entering the battery box to flow smoothly, a box longitudinal beam 43 is arranged at the bottom of the battery box. Figure 7 , 8 As shown, in addition to enhancing the strength, a gap or groove 44 can be left at the bottom of the battery cell 5 so that the incoming coolant can flow from the bottom gap to the coolant channel 11 of the battery cell shell to cool the large surface of the battery cell and then flow out from the liquid outlet 42.

[0037] like Fig. 9 As shown, the utility model embodiment provides another immersion type battery pack. In this embodiment, the battery cells 5 are stacked in two layers lying down to form a stack. The immersion type coolant enters from the liquid inlet 41 and flows through the coolant flow channel 11 of each battery cell shell to cool the large surface of the battery cell. The coolant enters the system to cool all surfaces of the battery cell in all directions and then flows out from the liquid outlet 42. The overall immersion cooling is very simple and does not require a separate coolant flow channel design. In this embodiment, as Fig.10 , 11 As shown in the figure, for most battery cells, the thickness of the battery cell is twice smaller than the height of the battery cell. Therefore, laying the battery cell horizontally can also realize the formation of the immersed battery pack, thereby effectively reducing the height of the battery pack. For vehicle-mounted battery cells, the arrangement of laying the battery cell horizontally can increase the ground clearance of the vehicle and reduce the probability of collision. For energy storage systems, stacking battery packs can reduce the space occupied in the Z direction and improve the volume utilization rate.

[0038] The above shows and describes the basic principles and main features of the utility model and the advantages of the utility model. For those skilled in the art, it is obvious that the utility model is not limited to the details of the above exemplary embodiments, and the utility model can be implemented in other specific forms without departing from the spirit or basic features of the utility model; therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the utility model is limited by the attached claims rather than the above description, and it is intended to include all changes within the meaning and scope of the equivalent elements of the claims in the utility model.

[0039] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A battery cell housing, characterized in that: The invention comprises a square shell body, wherein a large surface of the shell side of the square shell body is provided with a cooling liquid flow channel which connects the shell top surface with the shell bottom surface.

2. The battery cell housing according to claim 1, characterized in that: The coolant flow channel and the side surface of the shell are an integrally formed extrusion structure.

3. The battery cell housing according to claim 1, characterized in that: The shell top surface, the shell bottom surface and the shell side surface are welded and connected.

4. The battery cell casing according to claim 1, characterized in that: The cooling liquid flow channels are separated and arranged by a plurality of oblique ribs and arranged in a line, and the cross section is a trapezoid; two adjacent cooling liquid flow channels share one oblique rib.

5. The battery cell casing according to claim 1, characterized in that: The thickness of the coolant flow channel is uniform or inconsistent.

6. The battery cell casing according to claim 1, characterized in that: The thickness of the coolant flow channel is 2-5 mm.

7. The battery cell casing according to claim 1, characterized in that: The cross-sectional sizes of the coolant flow channels are the same or different.

8. A battery cell, characterized in that: The invention comprises a battery cell shell as described in any one of claims 1 to 7.

9. An immersion battery pack, comprising a battery box and a plurality of battery cells stacked in the battery box, characterized in that: The battery cell adopts the battery cell described in claim 7.

10. The submerged battery pack according to claim 9, characterized in that: The large surfaces of the battery cells are stacked in contact, and the large surface of one side of the stack is placed on the inner bottom surface of the battery case; or, the inner bottom surface of the battery case has a plurality of separated grooves formed by longitudinal beams, the large surfaces of the battery cells are stacked in contact, and cooling liquid channels are formed between the bottom surfaces of the plurality of battery cells and the grooves.

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