Battery cell heat insulation plate and battery pack

Abstract

The utility model relates to the technical field of power batteries, and particularly discloses a battery cell heat insulation plate and a battery pack. In the first aspect, the utility model provides the battery cell heat insulation plate, the battery cell heat insulation plate is used for heat insulation among a plurality of battery cells, each battery cell is provided with a main side surface, each main side surface comprises a central region and a peripheral region, and the battery cell heat insulation plate is attached between two adjacent battery cells and is at least positioned in the central region of the main side surface of each battery cell. The battery cell heat insulation plates can effectively prevent heat from spreading in the arrangement direction of the battery cells, and dangers such as fire breakout of the battery are avoided. On the second aspect, the utility model further provides a battery pack, the battery pack comprises a plurality of battery cells and the battery cell heat insulation plates in the first aspect, and the battery cell heat insulation plates are arranged between every two adjacent battery cells. And the battery pack in the second aspect comprises the battery cell heat insulation plate in the first aspect, so that the battery pack in the second aspect has all the beneficial effects of the battery cell heat insulation plate in the first aspect.

Description

Technical Field

[0001] The present application relates to the technical field of power batteries, and in particular to a battery cell heat insulation board and a battery pack. Background Art

[0002] With the popularization of new energy electric vehicles, the number of fires in electric vehicles is increasing, and the thermal safety of power batteries is receiving more and more attention.

[0003] After a battery cell in the battery pack experiences thermal runaway, the heat will quickly transfer to the adjacent battery cells, causing them to also experience thermal runaway. Eventually, the heat will spread along the direction of the battery cell arrangement, causing the power battery pack to catch fire. Summary of the invention

[0004] In view of this, the present application provides a battery cell heat insulation plate and a battery pack to solve the technical problem that after a battery cell in the battery pack has thermal runaway, the heat spreads along the battery cell arrangement direction, causing the battery pack to catch fire.

[0005] In the first aspect, the present application provides a battery cell insulation board for heat insulation between multiple battery cells. The battery cell has a main side surface, which includes a central area and a surrounding area. The battery cell insulation board is attached between two adjacent battery cells and is at least located in the central area of ​​the main side surface of the battery cell.

[0006] In some embodiments, the battery cell thermal insulation board includes an aerogel layer.

[0007] In some embodiments, the battery cell heat insulation board is laid on the main side of the battery cell, and the thickness of the battery cell heat insulation board in the central area is greater than the thickness of the battery cell heat insulation board in the surrounding area.

[0008] In some embodiments, the thickness of the battery cell heat insulation board gradually decreases from the central area to the surrounding areas.

[0009] In some embodiments, the battery cell thermal insulation board includes an aerogel layer located in a central area and an elastic thermal insulation layer located in a surrounding area.

[0010] In some embodiments, the elastic insulation layer includes foam and / or plastic foam particles.

[0011] In some embodiments, the battery core insulation board further includes a transition layer between the aerogel layer and the elastic insulation layer, and the transition layer includes at least one of a secondary insulation layer, a heat absorption layer, and a heat conductive layer.

[0012] In some embodiments, the battery cell insulation board further includes a hollow surface coating having a plurality of cavities of different shapes, and the aerogel layer, the elastic insulation layer and the transition layer are respectively disposed in the cavities.

[0013] In some embodiments, the surface coating includes a base film and a surface film that are interlocked with each other; one of the base film and the surface film is provided with a groove protruding outward, and the other has a plane, and a cavity is formed between the groove and the plane; or, both the surface film and the base film are provided with corresponding grooves, and a cavity is formed between the grooves of the two.

[0014] In a second aspect, the present application further provides a battery pack, comprising a plurality of battery cells and the battery cell heat insulation board of the first aspect, wherein a battery cell heat insulation board is provided between every two adjacent battery cells.

[0015] Beneficial effects:

[0016] In the first aspect, the battery cell heat insulation board is attached between two adjacent battery cells and is at least located in the central area of ​​the main side of the battery cell, effectively blocking the spread of heat in the direction of battery cell arrangement and avoiding dangers such as battery fire.

[0017] The battery pack of the second aspect includes the battery cell heat insulation board of the first aspect, so the battery pack of the second aspect has all the beneficial effects of the battery cell heat insulation board of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the specific implementation methods of the present application 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 application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work. Description of the drawings:

[0020] Figure 1 This is an axonometric view of the battery core heat insulation board described in the embodiment of the present application;

[0021] Figure 2 This is a front view of the battery core heat insulation board described in an embodiment of the present application;

[0022] Figure 3 A side view of a first structure of a battery core heat insulation board according to an embodiment of the present application;

[0023] Figure 4 A side view of the second structure of the battery core heat insulation board described in the embodiment of the present application;

[0024] Figure 5 This is a schematic diagram of the partial structure of the battery pack described in an embodiment of the present application.

[0025] Description of reference numerals:

[0026] 100, battery cell heat insulation board; 200, battery cell;

[0027] 110, aerogel layer; 120, transition layer; 130, elastic thermal insulation layer; 140, surface coating;

[0028] 141. Surface film; 142. Bottom film; 143. Groove. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of this application.

[0030] In order to deepen the understanding of this application solution, it is necessary to elaborate on the technical issues in detail in combination with relevant technologies. The specific contents are as follows:

[0031] With the popularity of new energy electric vehicles, the number of electric vehicle fires is increasing, and the thermal safety of power batteries is receiving more and more attention. After a battery cell in the battery pack thermally runs away, the heat will quickly transfer to the adjacent battery cells, causing the adjacent battery cells to also thermally run away, and eventually the heat will spread along the direction of the battery cell arrangement, causing the battery pack of the power battery to catch fire.

[0032] Furthermore, in order to reduce the probability of power battery fire, one way is to replace some ternary lithium-ion cells with lithium iron phosphate cells, which are safer and have a lower probability of thermal runaway than ternary lithium-ion cells, causing more and more battery manufacturers to increase the production of lithium iron phosphate cells. Although lithium iron phosphate is cheaper and safer, its energy density is not as good as that of ternary lithium-ion cells. At the same time, under the current trend of high voltage platform and high rate charge and discharge, ternary lithium-ion cells are still a battery solution that cannot be completely replaced, which also means that protective measures for ternary lithium-ion cells are essential.

[0033] However, the best thermal barrier material for ternary lithium-ion batteries on the market is aerogel material, which is relatively expensive and has poor compressibility. How to reduce the cost of ternary lithium-ion batteries while ensuring the safety of the ternary lithium-ion battery system is an urgent problem that needs to be solved in the industry.

[0034] Moreover, it should be noted that the thermal insulation effect of the aerogel thermal insulation material after formation in a certain area can be regarded as uniform and indifferent, which is different from the actual working condition of the lithium battery, that is, during the actual charging and discharging process of the lithium battery, the temperature in the central area of ​​the main side of the battery cell is high, and the temperature in the surrounding area is relatively low. Therefore, it is not necessary to cover the entire main side of the battery cell with aerogel material.

[0035] In order to alleviate the above technical problems, the present application provides a battery cell heat insulation board and a battery pack. Figures 1 to 5 The embodiments of the present application are described in detail.

[0036] First, refer to Figure 5 The present application provides a battery cell insulation board 100 for heat insulation between multiple battery cells 200. The battery cell 200 has a main side surface, and the main side surface includes a central area and a surrounding area. The battery cell insulation board 100 is attached between two adjacent battery cells 200 and is at least located in the central area of ​​the main side surface of the battery cell 200.

[0037] Specifically, the cell heat insulation board 100 is attached between two adjacent cells 200 and is at least located in the central area of ​​the main side of the cell 200, effectively blocking the spread of heat in the arrangement direction of the cell 200 to avoid the danger of battery fire. Moreover, when the cell heat insulation board 100 is only located in the central area of ​​the main side of the cell 200, it can also save materials while meeting the effective insulation requirements.

[0038] More specifically, the battery cell insulation board 100 can be physically provided only in the central area of ​​the main side of the battery cell 200, or it can cover the entire main side of the battery cell 200, both of which can play an effective role in heat insulation and flame retardancy. The above schemes are all within the protection scope of this application.

[0039] In some embodiments, the battery cell thermal insulation board 100 includes an aerogel layer 110 .

[0040] Specifically, in this solution, the composition structure of the battery cell insulation board 100 is optimized, and the aerogel layer 110 can have a very good flame retardant effect; and the aerogel has a low density and will not increase the weight of the battery pack too much.

[0041] It should be noted that aerogel refers to a nanoscale porous solid material formed by using the sol-gel method, in which a certain drying method is used to replace the liquid phase in the gel with gas. It is currently the solid with the lowest density in the world.

[0042] In some embodiments, the battery cell heat insulation board 100 is laid on the main side of the battery cell 200, and the thickness of the battery cell heat insulation board 100 in the central area is greater than the thickness of the battery cell heat insulation board 100 in the surrounding area.

[0043] Specifically, this scheme is a first embodiment of the battery cell heat insulation board 100. The battery cell heat insulation board 100 is laid on the main side of the battery cell 200, and the thickness of the battery cell heat insulation board 100 in the central area is greater than the thickness of the battery cell heat insulation board 100 in the surrounding area. The battery cell heat insulation board 100 can flame retard the central area of ​​the battery cell 200 with a higher temperature by increasing the thickness, and flame retard the surrounding areas with a relatively low temperature by reducing the thickness. While ensuring a good thermal insulation and flame retardant effect, it can also save materials.

[0044] Moreover, the smaller thickness of the battery cell heat insulation board 100 in the surrounding area is also conducive to the exhaust of the battery cell 200 to the outside, thereby providing an exhaust space for the battery cell 200.

[0045] In particular, in this solution, the battery cell heat insulation board 100 is preferably made entirely of aerogel.

[0046] In some embodiments, the thickness of the battery cell thermal insulation board 100 gradually decreases from the central area to the surrounding areas.

[0047] Specifically, this solution is a further preferred setting of the structure of the first embodiment of the battery cell heat insulation board 100. The thickness of the battery cell heat insulation board 100 gradually decreases from the central area to the surrounding areas, so that the surface of the battery cell heat insulation board 100 is smoother.

[0048] In addition, the battery cell insulation board 100 can also be set to have a thickness that decreases stepwise from the central area to the surrounding areas, which can also achieve the purpose of the thickness of the battery cell insulation board 100 corresponding to the temperature changes in different areas of the main side of the battery cell 200. The above scheme also falls within the protection scope of this application.

[0049] In some embodiments, reference Figure 2 The battery cell insulation board 100 includes an aerogel layer 110 located in the central area and an elastic insulation layer 130 located in the surrounding area.

[0050] Specifically, this solution is a specific implementation of the second embodiment of the battery cell heat insulation board 100. The battery cell heat insulation board 100 has different temperatures according to different areas of the main side of the battery cell 200, so different materials are set in different areas to reduce material costs.

[0051] In addition, the battery cell heat insulation board 100 is provided with an elastic heat insulation layer 130 in the surrounding area, which is beneficial for the battery cell 200 to exhaust and breathe and avoid blockage.

[0052] It should be noted that although aerogel has good thermal insulation and flame retardant effects, it is relatively expensive. Moreover, since aerogel is mainly composed of felt and aerogel powder, its compressibility is also poor.

[0053] In some embodiments, the elastic insulation layer 130 includes foam and / or plastic foam particles.

[0054] Specifically, this solution is a better choice for the elastic insulation layer 130. Foam or plastic foam particles can be set in the surrounding areas, or foam and plastic foam particles can be set on different edges of the surrounding areas respectively. The above solutions all fall within the protection scope of this application.

[0055] More specifically, foam and plastic foam particles are compressible and have good resilience, and can better meet the purpose of this solution; further, silicone foam or MPP is preferred.

[0056] It should be noted that MPP in this solution refers to microcellular polypropylene foam (Microcellular Polypropylene foam), abbreviated as MPP, which specifically refers to polypropylene porous foam material with a pore size of less than 100 microns.

[0057] In particular, the elastic heat-insulating layer 130 may be disposed on four edges of the surrounding area, or may be disposed only on two opposite edges of the surrounding area, and the above solutions all fall within the protection scope of the present application.

[0058] In some embodiments, reference Figure 1 and Figure 2 The battery core insulation board 100 further includes a transition layer 120 located between the aerogel layer 110 and the elastic insulation layer 130 , and the transition layer 120 includes at least one of a secondary insulation layer, a heat absorption layer, and a heat conductive layer.

[0059] Specifically, this solution is a further preferred configuration of the second embodiment of the battery cell heat insulation board 100 , and the transition layer 120 can play at least one role of heat insulation, heat absorption, and heat conduction, further reducing heat transfer between the battery cells 200 .

[0060] More specifically, any one of the secondary insulation layer, the heat absorption layer and the heat conductive layer can be set at different positions between the aerogel layer 110 and the elastic heat insulation layer 130, or any two of them can be set, or a combination of the three can be set, and the above schemes all fall within the protection scope of the present application.

[0061] Furthermore, the secondary insulation layer can be a material with insulation effect such as aerogel, MPP, EPP, silica gel, silicone rubber, ceramic silicone rubber, etc., and the preferred insulation material is aerogel material; the heat absorption layer can be a heat absorption material with large specific heat capacity such as solid-solid PCM, solid-liquid PCM, etc., and the preferred heat absorption material can be paraffin because of its low cost; the heat conductive layer can be a metal sheet, a graphene film, a carbon nanotube film or other composite materials with added graphene / carbon nanotube materials.

[0062] It should be noted that PCM refers to phase change material (PCM), which is a material that changes its material state and provides latent heat without changing the temperature. The process of changing physical properties is called phase change process. At this time, the phase change material will absorb or release a large amount of latent heat.

[0063] In addition, the heat-conducting layer is connected to other heat dissipation structures outside the battery core 200, and is suitable for transferring heat to a location away from the battery core 200 for heat dissipation.

[0064] In some embodiments, reference Figure 1 and Figure 2 The battery cell insulation board 100 further includes a hollow surface coating 140 , which has a plurality of cavities of different shapes, and the aerogel layer 110 , the elastic insulation layer 130 and the transition layer 120 are respectively disposed in the cavities.

[0065] Specifically, the surface coating 140 proposed in the present solution connects the aerogel layer 110, the elastic heat-insulating layer 130 and the transition layer 120 as a whole, and different cavities are provided for accommodation and positioning.

[0066] More specifically, the cavity can be circular, square for easy processing, or other special shapes that conform to the actual design. Preferably, the aerogel layer 110 is an ellipse arranged in the middle, the elastic heat insulation layer 130 is four long strips arranged at the four edges, and the transition layer 120 is four long plates arranged between the middle and the four edges.

[0067] It should be noted that the surface coating 140 can be made of film materials such as aluminum-plastic film, PET film, PI film, etc., and PET film is preferably used because of its low cost.

[0068] In addition, the surface coating 140 may not be provided, but each layer structure may be separately attached between two adjacent battery cells 200, which also falls within the protection scope of the present application.

[0069] In some embodiments, reference Figure 3 and Figure 4 The surface coating 140 includes a base film 142 and a surface film 141 that are interlocked with each other; one of the base film 142 and the surface film 141 is provided with a groove 143 protruding outward, and the other has a plane, and a cavity is formed between the groove 143 and the plane; or, both the surface film 141 and the base film 142 are provided with corresponding grooves 143, and a cavity is formed between the grooves 143 of the two.

[0070] Specifically, the present scheme is a further preferred setting for the surface coating 140, including two structures. The first structure is that one of the bottom film 142 and the surface film 141 is provided with a groove 143 protruding outward, and the other has a plane, and a cavity is formed between the groove 143 and the plane; the second structure is that both the surface film 141 and the bottom film 142 are provided with a corresponding groove 143, and a cavity is formed between the grooves 143 of the two. Both structures are within the protection scope of the present application.

[0071] Furthermore, the cavity thickness of the second structure is greater than that of the first structure, and the heat insulation effect is better; the battery cell insulation board 100 is generally combined with the battery cell 200 by double-sided adhesive, and the material can be placed between every two battery cells 200 or between multiple battery cells 200, and two different structural schemes are selected according to different thermal safety requirements of battery packs.

[0072] Second, refer to Figure 5 The present application also provides a battery pack, comprising a plurality of battery cells 200 and a battery cell heat insulation plate 100 of the first aspect, wherein a battery cell heat insulation plate 100 is provided between each two adjacent battery cells 200.

[0073] Specifically, the endoscope of the second aspect includes the battery cell heat insulation board 100 of the first aspect, so the battery pack of the second aspect has all the beneficial effects of the battery cell heat insulation board 100 of the first aspect.

[0074] In addition, the battery pack of the present solution also includes other components, such as a battery management system, a cooling system, etc., which will not be described one by one. Only the components related to the present solution are listed here, but it does not limit the composition of the battery pack.

[0075] Although the embodiments of the present application are described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present application, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A battery core heat insulation board, used for heat insulation between multiple battery cores, wherein the battery core has a main side surface, and the main side surface includes a central area and a surrounding area, characterized in that: The battery core heat insulation board is arranged between two adjacent battery cores and is at least located in the central area of ​​the main side surface of the battery core.

2. The battery core heat insulation board according to claim 1, characterized in that: The battery core heat insulation board includes an aerogel layer.

3. The battery core heat insulation board according to claim 2, characterized in that: The battery cell heat insulation board is laid on the main side surface of the battery cell, and the thickness of the battery cell heat insulation board in the central area is greater than the thickness of the battery cell heat insulation board in the surrounding areas.

4. The battery core heat insulation board according to claim 3, characterized in that: The thickness of the battery core heat insulation board gradually decreases from the central area to the surrounding areas.

5. The battery core heat insulation board according to claim 2, characterized in that: The battery core heat insulation board comprises an aerogel layer located in the central area and an elastic heat insulation layer located in the surrounding area.

6. The battery core heat insulation board according to claim 5, characterized in that: The elastic heat-insulating layer comprises foam and / or plastic foam particles.

7. The battery core heat insulation board according to claim 5, characterized in that: The battery core insulation board also includes a transition layer located between the aerogel layer and the elastic insulation layer, and the transition layer includes at least one of a secondary insulation layer, a heat absorption layer and a heat conductive layer.

8. The battery core heat insulation board according to claim 7, characterized in that: The battery core insulation board also includes a hollow surface coating, which has a plurality of cavities of different shapes, and the aerogel layer, the elastic insulation layer and the transition layer are respectively arranged in the cavities.

9. The battery core heat insulation board according to claim 8, characterized in that: The surface coating includes a bottom layer film and a surface layer film which are interlocked; One of the bottom layer film and the surface layer film is provided with a groove protruding outward, and the other has a plane, and the cavity is formed between the groove and the plane; Alternatively, the surface film and the bottom film are both provided with corresponding grooves, and the cavity is formed between the grooves of the two films.

10. A battery pack, characterized in that: The invention comprises a plurality of battery cells and the battery cell heat insulation board according to any one of claims 1 to 9, wherein the battery cell heat insulation board is arranged between every two adjacent battery cells.

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