Battery

Abstract

The utility model provides a battery, including a box, a battery module, and a heat insulation layer. The box has an installation cavity, a support beam is arranged in the box, a gap is set between the support beam and the bottom surface of the installation cavity, the battery module is arranged in the installation cavity and supported on the support beam, a gap is set between the battery module and the inner wall of the installation cavity, the battery module includes a shell and a plurality of batteries located in the shell; the heat insulation layer is arranged at least one of the outer surface of the battery module, between the shell and the battery, and between the battery cells. The utility model solves the problem of more serious thermal runaway caused by battery heat spread in the prior art.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a battery. Background Art

[0002] The power battery pack system for new energy vehicles usually contains multiple battery modules, and the battery module contains multiple battery cells. After mechanical abuse, electrical abuse, and thermal abuse, the battery cells will experience uncontrollable thermal runaway. The heat spread between the battery cells will cause more battery cells to thermal runaway. This phenomenon is particularly prominent for soft-pack battery cells without an active liquid cooling system. Therefore, the thermal protection design of the battery pack is particularly important. The current passive protection design for thermal runaway of battery packs usually uses thermal insulation materials between the battery cells to delay the spread of heat between batteries. However, due to the space gap between the battery cells and the lack of sealing of the module, open flames will occur after the thermal runaway of the battery cells, which will aggravate the heat spread. In addition, some thermal insulation materials are brittle and easy to lose powder, affecting the performance. Utility Model Content

[0003] The main purpose of the utility model is to provide a battery to solve the problem of more serious thermal runaway caused by thermal spread of the battery in the prior art.

[0004] In order to achieve the above-mentioned purpose, the utility model provides a battery, including a box body, a battery cell module, and a thermal insulation layer. The box body has an installation cavity, a support beam is arranged in the box body, a gap is set between the support beam and the bottom surface of the installation cavity, the battery cell module is arranged in the installation cavity and supported on the support beam, a gap is set between the battery cell module and the inner wall of the installation cavity, the battery cell module includes a shell and a plurality of battery cells located in the shell; a thermal insulation layer is arranged on at least one of the outer surface of the battery cell module, between the shell and the battery cell, and between the battery cells.

[0005] Furthermore, the distance between the support beam and the bottom surface of the installation cavity is greater than or equal to 2 mm.

[0006] Furthermore, the thermal insulation layer includes a first thermal insulation layer, the first thermal insulation layer is located on the outer surface of the battery cell module, and all outer surfaces of the battery cell module are covered with the first thermal insulation layer.

[0007] Furthermore, the first thermal insulation layer is a foam potting adhesive layer; and / or the thickness of the first thermal insulation layer is greater than or equal to 2 mm.

[0008] Furthermore, the thermal insulation layer includes a second thermal insulation layer, the battery core has a first side surface and a second side surface adjacent to each other, the area of ​​the first side surface is larger than that of the second side surface, and the second thermal insulation layer is located between the first side surface of the battery core and the shell.

[0009] Furthermore, the second thermal insulation layer is an aramid silica fireproof thermal insulation layer; and / or the thickness of the second thermal insulation layer is greater than or equal to 1 mm.

[0010] Furthermore, the thermal insulation layer also includes a third thermal insulation layer, the battery cell has an adjacent first side surface and a second side surface, the area of ​​the first side surface is larger than the second side surface, the first side surfaces of two adjacent battery cells are overlapped, and the third thermal insulation layer is located between the first side surfaces of the two adjacent battery cells.

[0011] Furthermore, the third insulation layer is a foam layer or an aramid silica fireproof insulation layer.

[0012] Furthermore, the battery cells are arranged in groups to form a sub-module, the battery cell module includes a plurality of sub-modules, the thermal insulation layer includes a fourth thermal insulation layer, and the fourth thermal insulation layer is located between two adjacent sub-modules.

[0013] Furthermore, the battery cell has a first side surface and a second side surface that are adjacent, the area of ​​the first side surface is larger than that of the second side surface, the first side surfaces of two adjacent battery cells are stacked to form a sub-module, the second side surfaces of the battery cells of two adjacent sub-modules are arranged relatively to each other, and the fourth thermal insulation layer is located between the second side surfaces of the battery cells of two adjacent sub-modules; and / or, the fourth thermal insulation layer is an aramid silica fireproof thermal insulation layer; and / or, the thickness of the fourth thermal insulation layer is greater than or equal to 3 mm.

[0014] By applying the technical solution of the utility model, a support beam is arranged in the box body so that there is a gap between the bottom surface of the battery cell module and the box body, and the gaps at the side and top surfaces are coordinated to reduce the heat transfer rate and delay the occurrence of thermal runaway. Specifically, on the one hand, the battery cell module is placed on the support beam at the bottom surface of the installation cavity. Since there is a gap between the support beam and the bottom surface of the installation cavity, the support beam raises the battery cell module so that there is a gap between the bottom surface of the battery cell module and the box body. At the same time, the gaps at the side and top surfaces are coordinated to greatly increase the thermal resistance on the heat transfer path as a whole, thereby reducing the heat transfer rate of heat transfer through the box body after the battery cell module has thermal runaway. On the other hand, arranging a thermal insulation layer on the outer surface of the battery cell module, between the shell of the battery cell module and the battery cell in the shell, and between the battery cells can increase the thermal resistance on the heat transfer path, thereby reducing the heat transfer rate of heat transfer to adjacent battery cells or battery cell modules after thermal runaway of the battery cell. The provision of the above-mentioned support beams and thermal insulation layers greatly reduces the temperature rise rate of the battery module and adjacent battery cells, delays the occurrence of thermal runaway, controls the generation of open flames, ensures the safety of battery use, and extends the service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings constituting part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

[0016] Figure 1 A schematic diagram of the structure of a battery of the utility model is shown;

[0017] Figure 2 A schematic diagram of the structure inside the sub-module is shown.

[0018] The above drawings include the following reference numerals:

[0019] 10. Box body; 11. Support beam; 20. Battery cell module; 21. Sub-module; 22. Shell; 31. First thermal insulation layer; 32. Second thermal insulation layer; 33. Third thermal insulation layer; 34. Fourth thermal insulation layer. DETAILED DESCRIPTION

[0020] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present utility model will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0021] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs.

[0022] In the present invention, unless otherwise specified, the directional words used, such as "up, down, top, bottom", usually refer to the directions shown in the drawings, or to the components themselves in the vertical, perpendicular or gravity directions; similarly, for ease of understanding and description, "inside and outside" refer to the inside and outside relative to the outline of each component itself, but the above-mentioned directional words are not used to limit the present invention.

[0023] In order to solve the problem of more serious thermal runaway caused by thermal propagation of batteries in the prior art, the utility model provides a battery.

[0024] like Figure 1 , Figure 2 A battery shown includes a box body 10, a battery cell module 20, and a thermal insulation layer. The box body 10 has an installation cavity. A support beam 11 is arranged in the box body 10. A gap is set between the support beam 11 and the bottom surface of the installation cavity. The battery cell module 20 is arranged in the installation cavity and supported on the support beam 11. A gap is set between the battery cell module 20 and the inner wall of the installation cavity. The battery cell module 20 includes a shell 22 and a plurality of battery cells located in the shell 22; a thermal insulation layer is arranged on at least one of the outer surface of the battery cell module 20, between the shell 22 and the battery cell, and between the battery cells.

[0025] In this embodiment, a support beam 11 is arranged in the box body 10, so that there is a gap between the bottom surface of the battery cell module 20 and the box body 10, and the gaps at the side and top surfaces thereof are matched, so as to reduce the heat transfer speed and delay the occurrence of thermal runaway. Specifically, on the one hand, the battery cell module 20 is placed on the support beam 11 at the bottom surface of the installation cavity. Since there is a gap between the support beam 11 and the bottom surface of the installation cavity, the support beam 11 raises the battery cell module 20, so that the bottom surface of the battery cell module 20 is close to the box body. There is a gap between the support beams 10, and the gaps on the side and top surfaces can significantly increase the thermal resistance on the heat transfer path as a whole, thereby reducing the heat transfer rate of the battery module 20 through the box after thermal runaway. On the other hand, the thermal insulation layer is provided on the outer surface of the battery module 20, between the shell 22 of the battery module 20 and the battery cells in the shell 22, and between the battery cells, which can increase the thermal resistance on the heat transfer path, thereby reducing the heat transfer rate of the battery cell to the adjacent battery cell or the battery module 20 after thermal runaway. The setting of the support beam 11 and the thermal insulation layer greatly reduces the temperature rise rate of the battery module 20 and the adjacent battery cells, delays the occurrence of thermal runaway, controls the generation of open flames, ensures the safety of battery use, and prolongs the service life.

[0026] like Figure 1 As shown, the battery cell module 20, the support beam 11, and the bottom surface of the installation cavity are arranged from top to bottom. In this embodiment, the distance between the support beam 11 and the bottom surface of the installation cavity is greater than or equal to 2 mm, so that the distance between the battery cell module 20 arranged in the installation cavity and the bottom surface of the installation cavity is greater than or equal to 2 mm, thereby greatly increasing the thermal resistance on the heat transfer path at the bottom of the battery cell module 20, reducing the heat transfer rate of the thermal runaway battery cell module 20 through the bottom of the box 10, and reducing the temperature rise rate of other parts of the battery cell module 20, while also helping to ensure the miniaturization of the battery. When the distance between the support beam 11 and the bottom surface of the installation cavity is less than 2 mm, it is easy to reduce the distance between the support beam 11 and the bottom surface of the installation cavity due to the deformation of the box 10 and the battery cell module 20, thereby reducing the gap between the battery cell module 20 and the bottom surface of the installation cavity or even disappearing, so that the gap between the support beam 11 and the bottom surface of the installation cavity loses the function of increasing the thermal resistance.

[0027] It should be noted that although the preferred numerical values ​​given in this embodiment only provide lower limits, the upper limits can be set accordingly based on actual processing and manufacturing factors, such as the size of the battery, the heating condition of the battery cell, etc.

[0028] In this embodiment, a heat insulation layer is provided on the outer surface of the battery module 20, between the shell 22 and the battery cell, and between the battery cells, so as to reduce the heat spread between the battery cells, between the battery cells and the shell 22, and between the battery cells and the box 10 as a whole. Based on this, four types of heat insulation layers are provided in this embodiment to cover the above positions. Of course, the specific setting positions can be adjusted as needed, and the heat insulation layer can be provided only at some of the above positions, or other positions for providing the heat insulation layer can be added.

[0029] The battery cell of this embodiment adopts a rectangular block-shaped battery cell, which includes a top surface, a bottom surface and a side surface, wherein the side surface includes two first side surfaces and two second side surfaces, and the area of ​​the first side surface is larger than the second side surface, and the first side surfaces of at least some of the battery cells are in contact with each other, thereby forming a horizontal stacking situation. According to the above stacking method, the battery cells can be divided into multiple groups, for example, the first side surfaces of some of the battery cells are stacked to form a sub-module 21, and the other part of the battery cells are also stacked in this way to form another sub-module 21. In this way, the battery cell module 20 as a whole includes multiple sub-modules 21, and the adjacent two sub-modules 21 may not be stacked according to the first side surface. In this embodiment, two sub-modules 21 are set as an example, and the second side surfaces between the two sub-modules 21 are arranged relative to each other, so that the second side surfaces of the battery cells of the two adjacent sub-modules 21 are arranged relative to each other. The aforementioned battery cells include both two battery cells in a sub-module 21 and battery cells between two sub-modules 21. Of course, the specific configuration of the battery cell module 20 is not limited to the configuration described above in this embodiment, and other structural forms may be adopted as needed. Although the structure of the battery cell module 20 is adjusted, the location of the thermal insulation layer still includes being set between the battery cells.

[0030] In this embodiment, the thermal insulation layer includes a first thermal insulation layer 31, which is located on the outer surface of the battery cell module 20, and all outer surfaces of the battery cell module 20 are covered with the first thermal insulation layer 31, so that the battery cell module 20 and the box body 10 are isolated by the first thermal insulation layer 31. In this way, the first thermal insulation layer 31 can not only increase the thermal resistance of the module surface and delay the heat spread of the battery cell module 20 to the outside, but also the first thermal insulation layer 31 can isolate the battery cell module 20 from oxygen in the air, seal the battery cell module 20, control the generation of open flames, and thus reduce the severity of thermal runaway.

[0031] In this embodiment, the first thermal insulation layer 31 is a foam potting glue layer. The foam potting glue is formed by mixing components A and B and has the characteristics of low density, UL94-V0 flame retardancy, and low thermal conductivity. The thickness of the first thermal insulation layer 31 is greater than or equal to 2 mm. On the one hand, after the battery module 20 is placed in the box 10, the foam potting glue is covered on the surface of the module. Preferably, the tooling positioning ensures that the thickness after foaming is 3 mm, ensuring that the battery module 20 is completely isolated from oxygen in the air and increasing the thermal resistance. On the other hand, the thickness of the first thermal insulation layer 31 corresponds to the gap between the battery module 20 and the bottom surface of the installation cavity, filling the gap, and further increasing the thermal resistance on the heat transfer path at the bottom of the battery module 20.

[0032] In this embodiment, the heat insulation layer includes a second heat insulation layer 32, and the second heat insulation layer 32 is located between the first side surface of the battery core and the shell 22. Figure 2 As shown, a second thermal insulation layer 32 is arranged between the inner side of the shell 22 on both sides of the battery cell module 20 and the battery cell to increase the thermal resistance between the battery cell and the shell 22 of the battery cell module 20, thereby slowing down the heat transfer rate of the thermal runaway battery cell module 20 to the outside through the shell 22, thereby delaying the heat spread.

[0033] In this embodiment, the second thermal insulation layer 32 is an aramid silica fireproof thermal insulation layer. The material of the aramid silica fireproof thermal insulation layer is a new type of composite material. The film material is aramid. The aramid material solves the problems of brittleness and powdering of traditional thermal insulation materials such as aerogel. The aramid material has a lower limiting oxygen index and is more flame retardant, which solves the problem of flammability of other composite materials. The physical and chemical packaging process is used to avoid the use of resin additives, which solves the problem of increased thermal conductivity of chemical composite silica materials. The thermal conductivity is ≤0.025w / mk, which can greatly reduce the heat conduction from the thermal runaway module to the outside of the shell 22; preferably, the thickness of the second thermal insulation layer 32 is greater than or equal to 1mm, which can improve the thermal resistance without occupying too much space in the battery. Further preferably, the thickness of the second thermal insulation layer 32 is 1mm.

[0034] In this embodiment, the heat insulation layer further includes a third heat insulation layer 33, which is located between the first side surfaces of two adjacent battery cells, more specifically, between the first side surfaces of two adjacent battery cells in the same sub-module 21. Figure 2 As shown, inside the battery cell module 20, each battery cell is placed crosswise with the third insulation layer 33, and the third insulation layer 33 is arranged between two adjacent battery cells to increase the thermal resistance between the battery cells in the battery cell module 20 and slow down the heat transfer rate.

[0035] Optionally, the third thermal insulation layer 33 can be a foam layer or an aramid silica fireproof thermal insulation layer, both of which can improve thermal resistance and slow down the heat transfer rate. Preferably, the third thermal insulation layer 33 uses an aramid silica fireproof thermal insulation layer, which has a better effect of reducing the heat spread rate than the foam layer.

[0036] The thermal insulation layer of this embodiment also includes a fourth thermal insulation layer 34, which is located between two adjacent sub-modules 21, so that the thermal resistance between the sub-modules 21 is increased, which can greatly reduce the heat conduction from the thermal runaway sub-module 21 to the adjacent sub-module 21, and delay the heat spread between the sub-modules 21. Based on the specific structure of the aforementioned battery cell module 20, the fourth thermal insulation layer 34 is located between the second side surfaces of the battery cells of two adjacent sub-modules 21, and is attached between the two adjacent sub-modules 21 through the adhesive backing, forming a structure in which the sub-module 21, the fourth thermal insulation layer 34, and another adjacent sub-module 21 are arranged in sequence, so that the two adjacent sub-modules 21 are completely isolated by the fourth thermal insulation layer 34, and the heat spread between the sub-modules 21 is delayed.

[0037] It should be noted that, based on the arrangement of multiple sub-modules 21, for example, the shell 22 of the battery module 20 can adopt an integral structure, that is, a larger shell 22 is uniformly arranged on the outside of some or all sub-modules 21, or a structure in which multiple shells are arranged can be adopted, that is, there are multiple shells 22, and a sub-shell is arranged on the outside of the battery cell of each sub-module 21 to shield the battery cell in the same sub-module 21. This embodiment adopts this arrangement. At this time, the fourth thermal insulation layer 34 is not actually in direct contact with the battery cells of two adjacent sub-modules 21, but is located between the shells of the two sub-modules 21 and directly in contact with the shell. Of course, the above two arrangements can also be arranged at the same time, that is, the sub-module 21 has a separate shell, and at the same time, a large shell is arranged on the outside of all sub-modules 21.

[0038] Preferably, the fourth insulation layer 34 is an aramid silica fireproof insulation layer, and the thickness of the fourth insulation layer 34 is preferably greater than or equal to 3 mm, which can greatly reduce the heat conduction from the thermal runaway sub-module 21 to the adjacent sub-module 21. Further preferably, the thickness of the fourth insulation layer 34 is 3 mm.

[0039] In this embodiment, an explosion-proof vent valve is further provided on the box body 10 to further ensure the safety of the battery and avoid accidents such as explosion.

[0040] The overall structure of the battery in this embodiment is as follows: a plurality of sub-modules 21 are placed in the box 10, and the sub-modules 21 are placed on the support beam 11, and a gap is left between the support beam 11 and the bottom surface of the box 10. In the horizontal direction, the sub-module 21 and the fourth insulation layer 34 are cross-arranged in the installation cavity of the box 10, and the exposed surface of the sub-module 21 and the outer surface of the battery module 20 are all covered with the first insulation layer 31. Inside the sub-module 21, each battery cell is cross-arranged with the third insulation layer 33, and a second insulation layer 32 is arranged between the battery cell and the shell 22 of the sub-module 21. In this embodiment, The structural design and the use of new aramid silica fireproof insulation materials and foam potting glue increase the thermal resistance between battery cells, control the generation of open flames, and solve the problems of high brittleness, easy powdering, and high thermal conductivity of insulation materials after composite with other materials. Combined with the use of explosion-proof air valves, it is used to discharge high-temperature gases in the box during thermal runaway, thereby avoiding structural failure of the box 10 due to the high pressure in the box. This battery can achieve thermal runaway of a sub-module 21 between the battery cell modules 20 without active liquid cooling of the battery pack system, and the time for the heat to spread to the adjacent sub-module 21 for thermal runaway is greater than 30 minutes.

[0041] It should be noted that the specific material types of the above-mentioned thermal insulation layers in this embodiment are not limited to the above-mentioned material layers in this embodiment, and they can be adjusted accordingly as needed. Other material layers can also be used to form the thermal insulation layers, as long as the thermal insulation and flame retardant effects can be achieved.

[0042] It should be noted that, the multiple in the above embodiments refers to at least two.

[0043] From the above description, it can be seen that the above embodiments of the utility model achieve the following technical effects:

[0044] 1. Solve the problem of battery heat spread leading to more serious thermal runaway in the prior art;

[0045] 2. A support beam is set inside the box to create a gap between the battery module and the box, thereby reducing the heat transfer rate and delaying the occurrence of thermal runaway;

[0046] 3. The first thermal insulation layer isolates the battery cell module from oxygen in the air, controls the generation of open flames, and thus reduces the severity of thermal runaway.

[0047] Obviously, the embodiments described above are only some embodiments of the utility model, not all embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the utility model.

[0048] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0049] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0050] The above description is only the preferred embodiment of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A battery, characterized in that: include: A box body, the box body having an installation cavity, a support beam is arranged in the box body, and a gap is arranged between the support beam and the bottom surface of the installation cavity; A battery cell module, the battery cell module is arranged in the installation cavity and supported on the support beam, a gap is arranged between the battery cell module and an inner wall of the installation cavity, and the battery cell module includes a shell and a plurality of battery cells located in the shell; The heat insulation layer is provided at least one of the outer surface of the battery cell module, between the shell and the battery cell, and between the battery cells.

2. The battery according to claim 1, characterized in that The distance between the support beam and the bottom surface of the installation cavity is greater than or equal to 2 mm.

3. The battery according to claim 1, characterized in that The thermal insulation layer includes a first thermal insulation layer, the first thermal insulation layer is located on the outer surface of the battery cell module, and all outer surfaces of the battery cell module are covered with the first thermal insulation layer.

4. The battery according to claim 3, characterized in that The first thermal insulation layer is a foam potting adhesive layer; and / or the thickness of the first thermal insulation layer is greater than or equal to 2 mm.

5. The battery according to claim 1, characterized in that The thermal insulation layer includes a second thermal insulation layer, the battery core has a first side surface and a second side surface adjacent to each other, the area of ​​the first side surface is larger than the area of ​​the second side surface, and the second thermal insulation layer is located between the first side surface of the battery core and the shell.

6. The battery according to claim 5, characterized in that The second thermal insulation layer is an aramid silica fireproof thermal insulation layer; And / or, the thickness of the second thermal insulation layer is greater than or equal to 1 mm.

7. The battery according to claim 1, characterized in that The thermal insulation layer also includes a third thermal insulation layer. The battery cell has a first side surface and a second side surface that are adjacent to each other. The area of ​​the first side surface is larger than that of the second side surface. The first side surfaces of two adjacent battery cells are overlapped, and the third thermal insulation layer is located between the first side surfaces of the two adjacent battery cells.

8. The battery according to claim 7, characterized in that The third heat-insulating layer is a foam layer or an aramid silica fireproof heat-insulating layer.

9. The battery according to claim 1, characterized in that The battery cells are arranged in groups to form sub-modules, the battery cell module includes a plurality of sub-modules, the thermal insulation layer includes a fourth thermal insulation layer, and the fourth thermal insulation layer is located between two adjacent sub-modules.

10. The battery according to claim 9, characterized in that The battery cell has a first side surface and a second side surface that are adjacent, the area of ​​the first side surface is larger than that of the second side surface, the first side surfaces of two adjacent battery cells are stacked to form the sub-module, the second side surfaces of the battery cells of two adjacent sub-modules are arranged opposite to each other, and the fourth thermal insulation layer is located between the second side surfaces of the battery cells of two adjacent sub-modules; and / or the fourth thermal insulation layer is an aramid silica fireproof thermal insulation layer; and / or the thickness of the fourth thermal insulation layer is greater than or equal to 3 mm.

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