Battery pack and vehicle

Abstract

The utility model relates to a battery pack and a vehicle. The battery pack includes: a case; the box cover is connected with the box body; the battery module is arranged in the box body; the cold plate is arranged below the battery module and is used for exchanging heat with the battery module; the bottom plate is arranged below the cold plate and is connected with the box body; the heat preservation box further comprises a first heat preservation part and a second heat preservation part, the first heat preservation part is arranged between the battery module and the box cover and is opposite to the corner area or the edge area of the battery module, and the second heat preservation part is arranged between the cold plate and the bottom plate and is opposite to the corner area or the edge area of the battery module. The influence of factors such as battery pack installation, the cold plate and the box body frame on heat dissipation is comprehensively considered, the heat preservation performance and the temperature uniformity of the whole pack are improved, the performance of the battery pack is improved, and the cycle life of the battery pack is prolonged.

Description

Technical Field

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

[0002] Currently, electric vehicles are becoming increasingly popular. A battery pack is provided in an electric vehicle, and a plurality of battery cells are provided in the battery pack to provide power for the vehicle.

[0003] The heat preservation performance and temperature uniformity of the battery pack are crucial for the performance and life of the battery pack. For electric vehicles, the discharge capacity decreases and the power performance decreases in a low-temperature environment, which will cause the overall vehicle endurance and power performance to decrease.

[0004] Therefore, how to improve the heat preservation performance and temperature uniformity of the battery pack is an urgent problem to be solved. Summary of the Utility Model

[0005] The present application provides a battery pack and a vehicle to solve or at least improve the problems in the above background art.

[0006] On the one hand, the present application provides a battery pack, including: a box body; a box cover connected to the box body; a battery module disposed in the box body; a cold plate disposed below the battery module for heat exchange with the battery module; a bottom plate disposed below the cold plate and connected to the box body; a first heat preservation member disposed between the battery module and the box cover and oppositely disposed with respect to a corner region or an edge region of the battery module; and a second heat preservation member disposed between the cold plate and the bottom plate and oppositely disposed with respect to a corner region or an edge region of the battery module.

[0007] In this way, through the first heat preservation member and the second heat preservation member oppositely disposed with respect to the corner region and the edge region of the battery module, the heat dissipation speed of the battery cells at the edge or corner upward and downward is respectively slowed down, thereby improving the heat preservation performance of the battery pack and realizing the temperature uniformity of the whole pack. Compared with only disposing a heat preservation member above the battery module or only at the edge or corner below the battery module, heat preservation members are disposed on both the upward and downward heat transfer paths, comprehensively considering the influence of factors such as the installation of the battery pack, the cold plate, and the box body frame on heat dissipation, greatly improving the heat preservation performance and temperature uniformity of the whole pack, and improving the performance and cycle life of the battery pack.

[0008] Further, the first heat preservation member is fixed to the box cover, and a gap is provided between the first heat preservation member and the surface of the battery module.

[0009] Further, the first heat-insulating member is rectangular in shape and is disposed opposite to the four corner regions of the battery module; alternatively, the first heat-insulating member is annular in shape and is disposed opposite to the edge region of the battery module.

[0010] Further, the first heat-insulating member is a vacuum insulation panel.

[0011] Further, the second heat-insulating member is attached to the cold plate.

[0012] Further, the second heat-insulating member is rectangular in shape and is disposed opposite to the four corner regions of the battery module; alternatively, the second heat-insulating member is annular in shape and is disposed opposite to the edge region of the battery module.

[0013] Further, the second heat-insulating member is selected from one of vacuum insulation panels, insulating cotton, and aerogel.

[0014] In a specific embodiment, the first heat-insulating member is rectangular in shape and is disposed opposite to the four corner regions of the battery module; the second heat-insulating member is annular in shape and is disposed opposite to the edge region of the battery module; both the first heat-insulating member and the second heat-insulating member are vacuum insulation panels; wherein, the area of the corner region disposed opposite to the first heat-insulating member is S1, and the area of the edge region disposed opposite to the second heat-insulating member is S2, and S1 / S2 satisfies [1 / 3, 1].

[0015] On the other hand, the present application further provides a vehicle, which includes the battery pack according to any one of the above technical solutions.

[0016] Further, the vehicle is a battery-swapping vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural diagram of the battery pack according to an embodiment of the present application.

[0018] Figure 2 is a schematic structural diagram of the battery pack according to an embodiment of the present application installed on a vehicle chassis.

[0019] Figure 3 is a schematic diagram of the relative position of the first heat-insulating member and the battery module in an embodiment of the present application.

[0020] Figure 4 is a schematic diagram of the relative position of the first heat-insulating member and the battery module in another embodiment of the present application.

[0021] Figure 5 is a schematic diagram of the relative position of the second heat-insulating member and the battery module in an embodiment of the present application (the cold plate is omitted). DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] In the following description, many specific details are set forth in order to provide a thorough understanding of the present utility model. However, the present utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the connotation of the present utility model. Therefore, the present utility model is not limited by the specific implementations disclosed below.

[0023] In the description of the present utility model, it should be understood that with respect to the orientation description, such as the orientation or positional relationship indicated by up, down, front, back, left, right, inside, outside, etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application 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 should not be construed as a limitation to the present utility model.

[0024] In the description of the present utility model, unless otherwise clearly defined, terms such as setting, installation, connection, etc. should be understood in a broad sense, and those skilled in the relevant technical field can reasonably determine the specific meanings of the above terms in the present utility model in combination with the specific content of the technical solution.

[0025] In the description of the present utility model, the description with reference to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some implementation manners", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model.

[0026] See Figure 1 , the present application provides a battery pack, including: a box body 1, a battery module 2, a box cover 3, a cold plate 4, and a bottom plate 5.

[0027] Specifically, the box body 1 is a frame structure. Exemplarily, it is a rectangular or approximately rectangular structure. Optionally, the box body 1 may further include internal cross beams or longitudinal beams.

[0028] The battery module 2 is disposed inside the box body 1. The battery module 2 includes a plurality of stacked and arranged battery cells. Exemplarily, the battery cells are square shell battery cells. Of course, the battery cells can also be blade battery cells, cylindrical battery cells, or soft package battery cells. In addition, it can be understood that the battery module 2 may further include end plates, side plates, etc., which are not specifically limited herein. It should be noted that the battery module 2 herein refers to the collection of battery cells disposed in the box body. When specifically setting it, since cross beams and longitudinal beams can be selectively disposed in the box body, the battery module 2 can be composed of a plurality of small battery modules.

[0029] The lid 3 is arranged above the battery module 2 and connected to the box body 1. Exemplarily, there is a certain gap between the lid 3 and the upper surface of the battery module 2, so as to provide an exhaust space for thermal runaway of the battery cells. When a battery cell undergoes thermal runaway, the thermal runaway gas sprays out from the explosion-proof valve on the upper cover of the battery cell, enters this exhaust space, and finally discharges out of the battery pack through the explosion-proof valve on the box body.

[0030] The cold plate 4 is arranged below the battery module 2 and exchanges heat with the battery module 2. A thermal conductive adhesive can be arranged between the cold plate 4 and the battery module 2. A flow channel is arranged inside the cold plate 4 for the heat exchange medium to flow, which is used to exchange heat with the battery cells of the battery module 2 to heat or cool the battery cells.

[0031] The bottom plate 5 is arranged below the cold plate 4 and connected to the box body 1. Exemplarily, there is a certain gap between the bottom plate 5 and the lower surface of the cold plate 4, which is used to provide a bottom impact space.

[0032] More importantly, the inventors found in the research that, also referring to Figure 2 , there is a receiving cavity for the battery pack on the chassis 500 of the vehicle. When the battery pack is installed in the receiving cavity, the lid 3 of the battery pack fits well with the inner wall of the receiving cavity, and there is only a very small gap, usually only a gap within 7 mm. Therefore, it is difficult for the air above the lid 3 to circulate. However, there is a certain gap between the edge of the lid 3 and the frame of the box body 1 and the inner wall of the receiving cavity. Therefore, these positions are directly facing the external environment, and the air is relatively easy to flow, resulting in faster heat dissipation. Therefore, the above design results in better heat preservation effect in the middle area of the battery pack lid, but poorer heat preservation effect in the edge area, causing the battery cells in the edge area of the battery module, especially the battery cells in the corner area, to dissipate heat faster. Another heat transfer path of the battery cells in the battery pack is through the cold plate below the battery module and the box body frame. Since the cold plate and the frame are usually made of metal materials, the heat conduction is faster. The battery cells located at the edge of the battery module, especially in the corner, are closer to the box body frame. Therefore, the battery cells in these areas are prone to heat exchange with the external environment through the cold plate and the frame. Therefore, the temperature of the battery cells in these areas is lower than the temperature of the battery cells in the middle area of the battery module. Considering the heat transfer paths of the battery module upward and downward, the heat dissipation of the edge battery cells in the battery pack will be faster than that of the middle battery cells in the battery pack, thus resulting in a decrease in the overall heat preservation performance of the battery pack and affecting the overall temperature uniformity of the battery pack, which has an impact on the battery pack's endurance and lifespan. This is particularly obvious for battery-swapping vehicles. Due to the requirement of frequent disassembly of the battery pack for battery-swapping vehicles, a fixed sealed heat preservation structure cannot be set between the receiving cavity on the vehicle and the battery pack lid.

[0033] Based on this, the battery pack of the present application further includes a first heat-insulating member 100 disposed between the battery module 2 and the box cover 3 and opposite to the corner area or the edge area of the battery module 2; and a second heat-insulating member 200 disposed between the cold plate 4 and the bottom plate 5 and opposite to the corner area or the edge area of the battery module 2.

[0034] Thus, through the first heat-insulating member and the second heat-insulating member disposed opposite to the corner area and the edge area of the battery module, the heat dissipation speed of the battery cells at the edge or corner upward and downward is respectively slowed down, thereby improving the heat preservation performance of the battery pack and realizing the temperature uniformity of the whole pack. Compared with only setting heat-insulating members at the edge or corner above or below the battery module, the present application sets heat-insulating members on both the upward and downward heat transfer paths, comprehensively considering the influence of factors such as battery pack installation, cold plate, and box body frame on heat dissipation, greatly improving the heat preservation performance and temperature uniformity of the whole pack, and improving the performance and cycle life of the battery pack.

[0035] It can be understood that the heat-insulating member being disposed opposite to the corner area means that the projection of the heat-insulating member on the battery module covers or falls within the corner area of the battery module. The area of the heat-insulating member can be the same as the area of the corner area, or slightly larger or slightly smaller than the area of the corner area. Similarly, the heat-insulating member being disposed opposite to the edge area means that the projection of the heat-insulating member on the battery module covers or falls within the edge area of the battery module. The area of the heat-insulating member can be the same as the area of the edge area, or slightly larger or slightly smaller than the area of the edge area, and all of these fall within the protection scope of the present application.

[0036] In some specific embodiments, the area of the heat-insulating member is set to be the same as or slightly larger than the area of the corner area, or the area of the heat-insulating member is set to be the same as or slightly larger than the area of the edge area to improve the heat insulation effect.

[0037] In this embodiment, referring to Figure 3 , the battery module 2 is rectangular as a whole, and the shape of the first heat-insulating member 100 is also rectangular and disposed opposite to the four corner areas of the battery module 2. In other words, there are four independently distributed first heat-insulating members 100, corresponding one by one to the four corner areas of the battery module 2.

[0038] Exemplarily, continue to refer to Figure 3, it shows that the first heat insulation member 100 in the shape of a rectangle exactly covers the corner area. Among them, the corner area has a size L1 in the first direction and a size W1 in the second direction, the battery module 2 has a size L in the first direction and a size W in the second direction, and the ranges of L1 / L are [1 / 6, 1 / 3], and the ranges of W1 / W are [1 / 8, 1 / 4]. The above ratios enable the area of the battery cell area covered by the first heat insulation member 100 to meet the design requirements of heat preservation and temperature uniformity of the battery pack, and make full use of the heat preservation performance of the first heat insulation member, saving material costs. In a specific embodiment, L1 / L is 1 / 5 and W1 / W is 1 / 6. In addition, the first heat insulation member in the shape of a rectangle reduces the processing cost and is convenient for pasting.

[0039] Of course, it can be understood that in some other embodiments, the corner area of the battery module 2 can also be a sector with a central angle of 90°, or an "L" shape or other shapes, which are not specifically limited herein and do not depart from the essence of the present application.

[0040] In another embodiment, referring to Figure 4 , the edge area of the battery module 2 is annular, and the shape of the first heat insulation member 100 is also annular and is disposed opposite to the edge area of the battery module 2. It can be understood that the shape of the first heat insulation member 100 is annular, and the annular shape can be a continuous annular shape or an intermittent annular shape. For example, for the convenience of pasting, the first heat insulation member 100 can be composed of multiple heat insulation members to form an overall annular shape, and there can be a certain interval between the multiple heat insulation members, and it does not depart from the essence of the present application.

[0041] In addition, although the temperature of the battery cells in the edge area of the battery module is relatively low, the lowest temperature usually appears on the battery cells in the corner area. Therefore, when the first heat insulation member 100 is composed of multiple heat insulation members to form an overall annular shape, the thickness of the heat insulation member at the corner can be set slightly larger than the thickness of the heat insulation member at the edge, so as to further improve the temperature uniformity.

[0042] Exemplarily, continuing to refer to Figure 4 , it shows that the annular first heat insulation member 100 exactly covers the edge area of the battery module. The ratio of the area of the annular edge area of the battery module to the area of the upper surface of the battery module is [1 / 5, 3 / 5], for example, 2 / 5.

[0043] Furthermore, the first heat insulation member 100 is fixed to the box cover 3, that is, fixed to the inner surface of the box cover 3, for example, by bonding. In this way, when the installation of the box cover 3 is completed, the installation of the first heat insulation member 100 is also completed, simplifying the installation steps and improving the assembly efficiency of the battery pack.

[0044] In addition, since there is a certain gap between the lid 3 and the battery module 2, the first heat-insulating member 100 is fixed to the inner surface of the lid 3. When it is disposed opposite to the battery cell module 2, by setting the thickness of the first heat-insulating member 100 to be slightly less than the above-mentioned gap, a certain gap can still be reserved between the first heat-insulating member 100 and the battery module 2, thereby providing an exhaust space for the thermal runaway of the battery cells in the corner area or the edge area, ensuring the safety of the battery pack. In this embodiment, the gap between the first heat-insulating member 100 and the battery module 2 is 1 mm to 3 mm, for example, 1 mm.

[0045] Based on the full utilization of the gap between the lid 3 and the battery module 2, a heat-insulating member that meets the heat-insulating performance of the battery pack needs to be provided in this very small space. In this embodiment, the first heat-insulating member 100 is selected as a vacuum insulation panel (VIP panel). The vacuum insulation panel has several times the heat-insulating performance compared to conventional aerogels or thermal insulation cotton. Therefore, even in the case of limited installation space, it can meet the heat-insulating performance requirements, which is beneficial to reducing the Z-direction size of the battery pack.

[0046] The second heat-insulating member 200 is attached to the cold plate 4. Exemplarily, the second heat-insulating member 200 is adhered to the cold plate 4.

[0047] See Figure 1 , in a specific embodiment, the shape of the second heat-insulating member 200 is rectangular and is disposed opposite to the four corner areas of the battery module 2.

[0048] In some other embodiments, see Figure 5 , the shape of the second heat-insulating member 200 is annular and is disposed opposite to the edge area of the battery module 2. It can be understood that where the shape of the second heat-insulating member 200 is annular, the annular shape can be a continuous annular shape or a discontinuous annular shape. For example, for the convenience of pasting, the second heat-insulating member 200 can be composed of multiple heat-insulating members to form an overall annular shape, and there can be a certain interval between the multiple heat-insulating members, and it does not deviate from the essence of the present application.

[0049] In addition, when the second heat-insulating member 200 is composed of multiple heat-insulating members to form an overall annular shape, the thickness of the heat-insulating member at the corner can be set to be slightly greater than the thickness of the heat-insulating member at the edge, thereby further improving the temperature uniformity.

[0050] In this embodiment, the second heat-insulating member 200 is a vacuum insulation panel to improve the heat-insulating effect. Of course, in some other embodiments, the second heat-insulating member 200 can also be selected from thermal insulation cotton, aerogel, etc.

[0051] So far, in a specific embodiment of the present application, the first thermal insulation member 100 is rectangular in shape and is disposed opposite to the four corner regions of the battery module; the second thermal insulation member 200 is annular in shape and is disposed opposite to the edge region of the battery module; both the first thermal insulation member 100 and the second thermal insulation member 200 are vacuum insulation panels.

[0052] Furthermore, in this specific embodiment, the area of the corner region on the upper surface of the battery module 2 opposite to the first thermal insulation member 100 is S1, and the area of the edge region on the lower surface of the battery module 2 opposite to the second thermal insulation member 200 is S2, satisfying that S1 / S2 is in the range of [1 / 3, 1].

[0053] In this way, in this specific embodiment, the shape of the first thermal insulation member is set to be rectangular and is disposed opposite to the four corner regions of the battery module, and the shape of the second thermal insulation member is set to be annular and is disposed opposite to the edge region of the battery module. By setting the areas of the battery cell regions thermally insulated by the first thermal insulation member and the second thermal insulation member in the above ratio, the upward heat dissipation condition and the downward heat dissipation condition of the battery pack are comprehensively considered. The upward heat transfer path is mainly affected by the installation of the battery pack. In the downward heat transfer path, the heat of the battery cells is mainly dissipated through the cold plate and the frame. Through the research of the inventor, it is found that the temperature difference between the battery cells in the four corner regions on the upper surface of the battery module and the average temperature of the battery cells in the battery pack is relatively large, and the temperature difference between the battery cells in the edge region on the lower surface of the battery module and the average temperature of the battery cells in the battery pack is relatively large, and both are greater than the temperature difference threshold required by the design. Therefore, the above design in this embodiment meets the thermal insulation requirements of the battery pack while taking into account the material cost of the thermal insulation member, makes the temperature of the entire battery pack tend to be consistent, realizes the precise control of the battery cell temperature, and optimizes the performance of the battery pack.

[0054] In addition, referring to Figure 1 , a buffer layer 6 is further provided in the space between the cold plate 4 and the bottom plate 5, and the buffer layer 6 can fill this space. In other words, a part of the buffer layer 6 is located between the second thermal insulation member 200 and the cold plate 5, and the remaining part of the buffer layer 6 is located between the cold plate 4 and the bottom plate 5. Exemplarily, the material of the buffer layer 6 is a foaming material or a honeycomb material, etc., to improve the anti-impact performance of the bottom of the battery pack.

[0055] Finally, the present application also provides a vehicle, and the vehicle includes the above battery pack.

[0056] In one embodiment, the vehicle is a battery-swappable vehicle. For a battery-swappable vehicle, in the case of frequent disassembly requirements for the battery pack, there is no fixed sealed thermal insulation structure between the accommodation cavity on the vehicle and the battery pack box cover. The design of the battery pack in the present application improves the thermal insulation performance and temperature uniformity of the battery pack, and improves the endurance of the vehicle.

[0057] It should be noted that although the present utility model is disclosed above with preferred embodiments, it is not intended to limit the present utility model. Any person skilled in the art can make possible changes and modifications without departing from the spirit and scope of the present utility model. Therefore, the protection scope of the present utility model shall be subject to the scope defined by the claims of the present utility model.

Claims

1. A battery pack, characterized in that, Comprising: A box body; A box cover, which is connected to the box body; A battery module, which is arranged inside the box body; A cold plate, which is arranged below the battery module and is used for heat exchange with the battery module; A bottom plate, which is arranged below the cold plate and is connected to the box body; A first heat insulation member, which is arranged between the battery module and the box cover and is oppositely arranged with respect to the corner area or the edge area of the battery module; A second heat insulation member, which is arranged between the cold plate and the bottom plate and is oppositely arranged with respect to the corner area or the edge area of the battery module.

2. The battery pack according to claim 1, characterized in that The first heat insulation member is fixed to the box cover, and a gap is provided between the first heat insulation member and the surface of the battery module.

3. The battery pack according to claim 2, characterized in that, The shape of the first heat insulation member is rectangular and is oppositely arranged with respect to the four corner areas of the battery module; or, the shape of the first heat insulation member is annular and is oppositely arranged with respect to the edge area of the battery module.

4. The battery pack according to claim 1, characterized in that The first heat insulation member is a vacuum insulation panel.

5. The battery pack according to any one of claims 1-4, characterized in that, The second heat insulation member is attached to the cold plate.

6. The battery pack according to claim 5, characterized in that, The shape of the second heat insulation member is rectangular and is oppositely arranged with respect to the four corner areas of the battery module; or, the shape of the second heat insulation member is annular and is oppositely arranged with respect to the edge area of the battery module.

7. The battery pack according to claim 1, characterized in that, The second heat insulation member is selected from one of a vacuum insulation panel, thermal insulation cotton and aerogel.

8. The battery pack according to claim 1, wherein The shape of the first heat insulation member is rectangular and is oppositely arranged with respect to the four corner areas of the battery module; the shape of the second heat insulation member is annular and is oppositely arranged with respect to the edge area of the battery module; both the first heat insulation member and the second heat insulation member are vacuum insulation panels; wherein, the area of the corner area oppositely arranged with respect to the first heat insulation member is S1, and the area of the edge area oppositely arranged with respect to the second heat insulation member is S2, and S1 / S2 satisfies [1 / 3, 1].

9. A vehicle, characterized in that, The vehicle includes the battery pack according to any one of claims 1-8.

10. The vehicle according to claim 9, wherein The vehicle is a vehicle with swappable batteries.

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