Battery module and battery pack

Abstract

The utility model discloses a battery module and a battery pack, and relates to the technical field of new energy. The battery module comprises a box body, a support and a plurality of battery cells, the box body is internally provided with a containing cavity, the support is internally provided with a containing cavity used for containing dielectric fluid, the support is provided with a mounting cavity, the mounting cavity is communicated with the containing cavity, the plurality of battery cells are contained in the mounting cavity, so that the support and the battery cells jointly form a battery cell whole, and the battery cell whole is contained in the containing cavity. And polystyrene foam is filled between the whole battery cell and the accommodating cavity. According to the battery module and the battery pack, the dielectric fluid can be sealed through the polystyrene foam, the volume expansion of the dielectric fluid due to heating can be buffered, and a good and uniform cooling effect is achieved, so that the problem of thermal runaway risk caused by improvement of the charging rate of a lithium battery in the prior art can be solved, and the service life of the lithium battery is prolonged. And the safety performance of the product is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of new energy, and particularly to a battery module and a battery pack. Background Art

[0002] With the development of the new energy industry, more and more vehicles begin to use lithium batteries as the power source. Compared with the traditional fuel system, although lithium batteries have cost advantages in the use process, there are also defects such as long charging time and insufficient cruising range, which are technical problems that need to be solved urgently in the current industry.

[0003] To solve the above problems, many manufacturers continuously increase the charging rate of lithium batteries to shorten the charging time. This method will cause the temperature of the battery cells to rise rapidly during charging. If there is no reasonable thermal management system involved, it is easy to cause thermal runaway, thus bringing certain potential safety hazards.

[0004] Currently, the immersion cooling scheme is adopted. By immersing the battery module in a non-conductive dielectric fluid, the cooling effect can be improved. However, the dielectric fluid will expand in volume during heating, generating a large pressure on the battery module. When the pressure reaches the design limit, it will cause serious damage to the battery module. In addition, the immersion cooling scheme also has the risk of liquid leakage, which is likely to cause product scrapping. Summary of the Utility Model

[0005] The purpose of the utility model is to provide a battery module and a battery pack. The foaming glue can not only seal the dielectric fluid, but also buffer the volume expansion of the dielectric fluid during heating, having a good and uniform cooling effect, so as to solve the problem of the risk of thermal runaway in the existing technology due to the increase of the charging rate of lithium batteries and improve the safety performance of the product.

[0006] The embodiments of the utility model are implemented as follows:

[0007] In the first aspect of the embodiments of the utility model, a battery module is provided, which includes a box body, a bracket and a plurality of battery cells. The box body has an accommodation cavity, the bracket has an accommodation cavity for accommodating a dielectric fluid, an installation cavity is arranged on the bracket, the installation cavity is communicated with the accommodation cavity, and the plurality of battery cells are accommodated in the installation cavity so that the bracket and the battery cells jointly form an overall battery cell. The overall battery cell is accommodated in the accommodation cavity, and foaming glue is filled between the overall battery cell and the accommodation cavity. This battery module can not only seal the dielectric fluid by the foaming glue, but also buffer the volume expansion of the dielectric fluid during heating, having a good and uniform cooling effect, so as to solve the problem of the risk of thermal runaway in the existing technology due to the increase of the charging rate of lithium batteries and improve the safety performance of the product.

[0008] Optionally, a liquid injection hole is provided at the top of the bracket, and the liquid injection hole is used for the dielectric fluid to pass through and flow into the accommodation cavity.

[0009] Optionally, the number of the installation cavities is multiple, and the multiple installation cavities are divided into at least two rows, and the installation cavities in each row are arranged staggeredly.

[0010] Optionally, a first positioning portion is provided at the bottom of the box body, and a second positioning portion is correspondingly provided at the bottom of the bracket. The second positioning portion is positioned and installed with the first positioning portion so that the bracket is positioned and installed in the box body.

[0011] Optionally, an opening is provided on the bracket to communicate the inside and the outside of the accommodation cavity through the opening, and the edge of the opening and the outer edge of the battery cell are hermetically connected by the foaming glue.

[0012] Optionally, openings are provided at both the top and the bottom of the bracket, the installation cavity penetrates along the height direction of the bracket, and both ends of the battery cell are exposed outside the installation cavity through the openings.

[0013] Optionally, the dielectric fluid is fluorinated liquid or mineral oil, and the mineral oil is hydrocarbon oil or silicone oil.

[0014] Optionally, the material of the bracket is plastic, and the thickness of the bracket is between 1 mm and 2 mm.

[0015] Optionally, the battery cell is a cylindrical battery cell.

[0016] In the second aspect of the embodiment of the present invention, a battery pack is provided, including the above-mentioned battery module. The foaming glue can not only seal the dielectric fluid for the battery module, but also play a buffering role in the volume expansion of the dielectric fluid due to heat, and has a good and uniform cooling effect, thereby being able to solve the problem that the lithium battery in the prior art has a risk of thermal runaway due to the increase of the charging rate, and improving the safety performance of the product.

[0017] The beneficial effects of the embodiment of the present invention include:

[0018] The battery module includes a box body, a bracket, and multiple battery cells. The box body has a receiving cavity, and the bracket has a receiving cavity for accommodating a dielectric fluid. An installation cavity is provided on the bracket, and the installation cavity communicates with the receiving cavity. The multiple battery cells are accommodated in the installation cavity so that the bracket and the battery cells together form an integral battery cell unit. The integral battery cell unit is accommodated in the receiving cavity, and a foaming agent is filled between the integral battery cell unit and the receiving cavity. Compared with the immersion cooling solution in the prior art, where the battery module is directly immersed in the dielectric fluid in the battery pack box body, there are problems such as easy leakage and expansion of the dielectric fluid. In the battery module provided in this application, the box body serves as the installation and support foundation for the integral battery cell unit formed by the bracket and the battery cells. The bracket not only plays the role of installing and supporting the battery cells but also serves as the container for the dielectric fluid, enabling the dielectric fluid to surround the outer periphery of the battery cells in the receiving cavity and directly exchange heat with the battery cells. On this basis, a foaming agent is filled between the integral battery cell unit and the receiving cavity to seal the gaps between the battery cells and the bracket, the bracket and the box body, and the battery cells and the box body. Thus, the foaming agent can not only seal the dielectric fluid but also buffer the volume expansion of the dielectric fluid when heated, achieving a good, uniform, and safe cooling effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0020] Figure 1 One of the structural schematic diagrams of the battery module provided by the embodiment of the present invention;

[0021] Figure 2 Another structural schematic diagram of the battery module provided by the embodiment of the present invention;

[0022] Figure 3 Another structural schematic diagram of the battery module provided by the embodiment of the present invention;

[0023] Figure 4 Another structural schematic diagram of the battery module provided by the embodiment of the present invention.

[0024] Reference numerals: 100 - battery module; 10 - box body; 11 - receiving cavity; 12 - first positioning portion; 20 - bracket; 21 - installation cavity; 22 - opening; 23 - liquid injection hole; 24 - second positioning portion; 30 - battery cell. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. The components of the embodiments of the present utility model usually described and illustrated in the drawings here can be arranged and designed in various different configurations.

[0026] Therefore, the following detailed description of the embodiments of the present utility model provided in the drawings is not intended to limit the scope of the claimed present utility model, but merely represents selected embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without making creative efforts fall within the protection scope of the present utility model.

[0027] It should be noted that similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0028] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the utility model product is usually placed during use. It is only for the convenience of describing the present utility model 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 construed as a limitation of the present utility model. In addition, the terms "first", "second", "third", etc. are only used for descriptive distinction and cannot be construed as indicating or implying relative importance.

[0029] In addition, terms such as "horizontal" and "vertical" do not mean that the components are required to be absolutely horizontal or hanging, but can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0030] In the description of the present utility model, it should also be noted that unless otherwise clearly specified and defined, the terms "set", "installed", "connected", "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 directly connected, or indirectly connected through an intermediate medium, and can be the connection inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0031] Please refer toFigures 1 to 4 , an embodiment of the present application provides a battery module 100, which includes a box body 10, a bracket 20, and a plurality of battery cells 30. The box body 10 has a receiving cavity 11, and the bracket 20 has a receiving cavity for receiving a dielectric fluid. An installation cavity 21 is provided on the bracket 20, and the installation cavity 21 communicates with the receiving cavity. A plurality of battery cells 30 are accommodated in the installation cavity 21, so that the bracket 20 and the battery cells 30 together form an overall battery cell 30. The overall battery cell 30 is accommodated in the receiving cavity 11, and a foaming adhesive is filled between the overall battery cell 30 and the receiving cavity 11. The battery module 100 can not only seal the dielectric fluid through the foaming adhesive, but also buffer the volume expansion of the dielectric fluid when heated, and has a good and uniform cooling effect, thereby being able to solve the problem of the risk of thermal runaway in existing lithium batteries due to the increase in the charging rate and improving the safety performance of the product.

[0032] It should be noted that, as Figure 1 and Figure 2 shown, the battery module 100 includes a box body 10, a bracket 20, and a plurality of battery cells 30, so as to form the battery module 100 through the series-parallel connection between the plurality of battery cells 30; at the same time, an installation cavity 21 is provided on the bracket 20 to use the bracket 20 as the installation and support basis for the plurality of battery cells 30, so that the plurality of battery cells 30 can be accommodated in the installation cavity 21, and further the bracket 20 and the battery cells 30 can together form an overall battery cell 30; and, a receiving cavity 11 is provided in the box body 10 to use the box body 10 as the installation and support basis for the overall battery cell 30, so that the overall battery cell 30 can be accommodated in the receiving cavity 11. Regarding the implementation method of the series-parallel connection between the plurality of battery cells 30, the electrical connection between two adjacent battery cells 30 can be realized through busbars, etc. Those skilled in the art should be able to make reasonable selections and designs according to the actual situation, and no specific limitations are made here.

[0033] In order to dissipate the heat generated when the plurality of battery cells 30 work, the present application adopts an immersion cooling scheme. Specifically, as Figures 2 to 4 shown, a receiving cavity is provided in the bracket 20, and the receiving cavity is used to receive a coolant (such as a non-conductive dielectric fluid). The installation cavity 21 communicates with the receiving cavity, so that the dielectric fluid originally located in the receiving cavity can flow to the installation cavity 21, so that the dielectric fluid can surround the outer periphery of the battery cells 30 located in the receiving cavity. Through the direct contact between the dielectric fluid and the battery cells 30, the heat generated when the battery cells 30 work can be taken away, and further the battery cells 30 can be cooled down. It should be noted that regarding the positional relationship between the battery cells 30 and the bracket 20, it should be ensured that the terminal posts located at the top of the battery cells 30 protrude outside the installation cavity 21, so as to ensure that the series-parallel connection operation between the plurality of battery cells 30 will not be affected by the dielectric fluid.

[0034] On this basis, in order to improve the sealing performance of the immersion cooling solution and avoid the leakage of the dielectric fluid, a foaming agent (not shown in the figure) is filled between the entire battery cell 30 and the accommodation cavity 11, so that the battery cell 30 and the bracket 20 can be hermetically connected through the foaming agent, thereby ensuring that the dielectric fluid is always sealed in the accommodation cavity and the installation cavity 21. Moreover, the foaming agent can also fill the gaps between the bracket 20 and the box body 10, and between the battery cell 30 and the box body 10, thereby preventing the bracket 20 from shaking relative to the box body 10. Additionally, when the dielectric fluid in the bracket 20 expands due to heat, the foaming agent can play a buffering role by virtue of its own characteristics.

[0035] Compared with the immersion cooling solutions in the prior art, where the battery module 100 is directly immersed in the dielectric fluid in the battery pack box, there are problems such as easy leakage and expansion of the dielectric fluid. In the battery module 100 provided in this application, the box body 10 serves as the installation and support foundation for the entire battery cell 30 that can be jointly formed by the bracket 20 and the battery cell 30. The bracket 20 not only plays the role of installing and supporting the battery cell 30 but also serves as a container for the dielectric fluid, enabling the dielectric fluid to surround the outer periphery of the battery cell 30 located in the accommodation cavity and directly exchange heat with the battery cell 30. On this basis, a foaming agent is also filled between the entire battery cell 30 and the accommodation cavity 11 to seal the gaps between the battery cell 30 and the bracket 20, between the bracket 20 and the box body 10, and between the battery cell 30 and the box body 10. Thus, the foaming agent can not only seal the dielectric fluid but also buffer the volume expansion of the dielectric fluid due to heat, achieving a good, uniform, and safe cooling effect.

[0036] Optionally, as Figures 1 to 4 shown, a liquid injection hole 23 is provided at the top of the bracket 20. The liquid injection hole 23 is used for the dielectric fluid to pass through and flow into the accommodation cavity, so that the dielectric fluid provided by an external device can flow into the accommodation cavity via the liquid injection hole 23, and then flow into the installation cavity 21 through the passage between the accommodation cavity and the installation cavity 21.

[0037] Exemplarily, the number of the liquid injection holes 23 can be one to reduce the risk of leakage of the dielectric fluid through the liquid injection hole 23. It should be noted that when filling the gap between the entire battery cell 30 and the accommodation cavity 11 with the foaming agent, it is necessary to ensure that the foaming agent does not cover the liquid injection hole 23 to avoid affecting the liquid injection process of the dielectric fluid.

[0038] Optionally, as Figure 2 and Figure 3As shown, the number of installation cavities 21 can be multiple. The multiple installation cavities 21 are divided into at least two rows, and the installation cavities 21 in each row are arranged staggeredly, so that there is a gap between any two installation cavities 21, and these gaps together form an accommodation cavity. The multiple battery cells 30 are respectively accommodated in the multiple installation cavities 21, so as to ensure that the dielectric fluid located in the accommodation cavity can be distributed around the outer periphery of each battery cell 30.

[0039] Optionally, as Figures 2 to 4 shown, a first positioning portion 12 is provided at the bottom of the box body 10, and a second positioning portion 24 is correspondingly provided at the bottom of the bracket 20. The second positioning portion 24 is positioned and installed with the first positioning portion 12, so that the bracket 20 is positioned and installed in the box body 10. Exemplarily, the first positioning portion 12 is a groove, and the second positioning portion 24 is a protrusion corresponding to the groove, or the first positioning portion 12 is a protrusion, and the second positioning portion 24 is a groove corresponding to the protrusion.

[0040] Optionally, as Figure 3 and Figure 4 shown, an opening 22 is provided on the bracket 20 to communicate the inside and outside of the accommodation cavity through the opening 22, so that the battery cell 30 can be inserted into the installation cavity 21 through the opening 22. The edge of the opening 22 and the outer edge of the battery cell 30 are sealed and connected by foaming glue to fill the gap between the battery cell 30 and the bracket 20 with foaming glue.

[0041] In some embodiments, the bottom of the bracket 20 is closed. In this way, the dielectric fluid and the bottom of the battery cell 30 can be accommodated in the bracket 20; of course, in other embodiments, as Figure 3 and Figure 4 shown, openings 22 are provided at both the top and the bottom of the bracket 20, and the diameter of the opening 22 at the bottom is smaller than the diameter of the opening 22 at the top, so as to prevent the battery cell 30 from directly falling off from the bracket 20 through the opening 22 at the bottom. The installation cavity 21 penetrates along the height direction of the bracket 20, and both ends of the battery cell 30 are exposed outside the installation cavity 21 through the openings 22. At this time, special attention needs to be paid to filling the gap between the edge of the opening 22 at the bottom of the bracket 20 and the outer edge of the battery cell 30.

[0042] Optionally, the dielectric fluid is a fluorinated liquid or a mineral oil, and the mineral oil is a hydrocarbon oil or a silicone oil. Among them, the fluorinated liquid has the characteristics of insulation and non-flammability, and can well control the occurrence of fire and explosion of the battery cell 30 when the battery cell 30 undergoes thermal runaway; the mineral oil has the advantages of non-toxic, odorless, non-volatile and high flash point, and is more cost-effective. Those skilled in the art should be able to select according to the actual situation.

[0043] Optionally, the material of the bracket 20 is plastic. Regarding the specific selection of the plastic, those skilled in the art should be able to select it according to the actual situation, as long as the bracket 20 has the advantages of light weight and corrosion resistance. The thickness of the bracket 20 is between 1 mm and 2 mm, which can avoid excessively increasing the volume of the battery module 100.

[0044] Optionally, the battery cell 30 is a cylindrical battery cell 30. At this time, the opening 22 on the bracket 20 should be a circle matching the shape of the battery cell 30. As for the shape of the box body 10, it can be a cuboid or a disc shape, etc.

[0045] In summary, during the actual assembly process, the bracket 20 can be first positioned and installed in the accommodation cavity 11 of the box body 10, and then multiple battery cells 30 can be correspondingly installed in the installation cavity 21 of the bracket 20 one by one. Subsequently, the gaps between the whole battery cells 30 and the accommodation cavity 11 (including the battery cells 30 and the bracket 20, the bracket 20 and the box body 10, and the battery cells 30 and the box body 10) are filled with foaming glue. After the foaming glue is completely foamed, the gap between the upper surface of the bracket 20 and the box body 10 is filled. At this time, it should be noted that the foaming glue should not cover the liquid injection hole 23. Finally, the liquid injection hole 23 is opened for liquid injection.

[0046] The embodiment of the present application also provides a battery pack, including the above-mentioned battery module 100. Since the structure and beneficial effects of the battery module 100 have been described in detail in the foregoing embodiments, they will not be elaborated herein.

[0047] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A battery module, characterized in that: The invention comprises a box body, a bracket and a plurality of battery cells, wherein the box body has a containing cavity, the bracket has a containing cavity for containing dielectric fluid, the bracket is provided with an installation cavity, the installation cavity is communicated with the containing cavity, a plurality of battery cells are contained in the installation cavity, so that the bracket and the battery cells together form a battery cell as a whole, the battery cell as a whole is contained in the containing cavity, and foam glue is filled between the battery cell as a whole and the containing cavity.

2. The battery module according to claim 1, characterized in that: A liquid injection hole is arranged on the top of the bracket, and the liquid injection hole is used for the dielectric fluid to pass through and flow into the accommodating cavity.

3. The battery module according to claim 1, characterized in that: There are multiple installation cavities, and the multiple installation cavities are divided into at least two rows, and the installation cavities in each row are arranged in a staggered manner.

4. The battery module according to claim 1, characterized in that: The bottom of the box body is provided with a first positioning portion, and the bottom of the bracket is correspondingly provided with a second positioning portion, and the second positioning portion is positioned and installed with the first positioning portion so that the bracket is positioned and installed in the box body.

5. The battery module according to claim 1, characterized in that: The bracket is provided with an opening to communicate the inside and the outside of the accommodating cavity through the opening, and the edge of the opening and the outer edge of the battery core are sealed and connected by the foam glue.

6. The battery module according to claim 5, characterized in that: The top and the bottom of the bracket are both provided with the openings, the installation cavity penetrates along the height direction of the bracket, and the two ends of the battery cell are exposed outside the installation cavity through the openings.

7. The battery module according to claim 1, characterized in that: The dielectric fluid is fluorinated liquid or mineral oil, and the mineral oil is hydrocarbon oil or silicone oil.

8. The battery module according to claim 1, characterized in that: The material of the bracket is plastic, and the thickness of the bracket is between 1 mm and 2 mm.

9. The battery module according to claim 1, characterized in that: The battery cell is a cylindrical battery cell.

10. A battery pack, characterized in that: A battery module comprising any one of claims 1 to 9.

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