Battery pack and electric equipment

Abstract

The utility model relates to a battery pack and electric equipment. The battery pack comprises a battery module, the battery module comprises a plurality of battery cells arranged along a first direction, and each battery cell comprises a tab area and a non-tab area; the cold plate is arranged below the battery module, a runner is arranged in the cold plate, the cold plate comprises a first plate and a second plate which are oppositely arranged, the first plate is adjacent to the battery module, the second plate comprises a flat plate part and a sunken part, and the sunken part is opposite to the non-tab area; and the protective layer is arranged below the cold plate, and at least part of the protective layer is located in the sunken part. The bottom protection performance of the battery pack is improved while the heat management requirement of the battery pack is met and the Z-direction size of the battery pack is not increased.

Description

Technical Field

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

[0002] The battery pack is the power source of new energy vehicles. It has multiple cells inside. Since different parts of the cells generate different amounts of heat during the charging and discharging process, the temperatures in different areas of the battery pack are different, which affects the performance and life of the battery pack. This is especially true for blade cells. At the same time, the bottom protection of the battery pack is also an important measure to ensure the safety of the battery pack. However, the current trend of battery packs is to have smaller and smaller Z-direction dimensions. For example, increasing the ball striking space at the bottom of the battery pack or increasing the thickness of the bottom protective layer will inevitably affect the Z-direction dimensions of the battery pack. In addition, the static thermal insulation performance of the battery pack also has an important impact on the performance of the battery pack. Since the cells are located in different positions in the battery pack, they are affected differently by the external ambient temperature, which puts different requirements on the thermal insulation performance of different areas of the battery pack.

[0003] Therefore, how to balance the thermal management of the battery pack under charging and discharging and static insulation conditions to improve the temperature uniformity and thermal insulation performance of the battery pack, as well as improve the bottom protection performance of the battery pack, is an urgent problem to be solved. Utility Model Content

[0004] The present application provides a battery pack and an electrical device to solve or at least improve the problems in the above-mentioned background technology.

[0005] On the one hand, the present application provides a battery pack, comprising: a battery module, the battery module comprising a plurality of battery cells arranged along a first direction, the battery cells comprising a tab region and a non-tab region; a cold plate, the cold plate being arranged below the battery module, a flow channel being provided in the cold plate, and the cold plate comprising a first plate and a second plate arranged opposite to each other, the first plate being adjacent to the battery module, the second plate comprising a flat portion and a recessed portion, wherein the recessed portion is arranged opposite to the non-tab region; a protective layer, the protective layer being arranged below the cold plate, and at least a portion of the protective layer being located in the recessed portion.

[0006] Since the main heating area of ​​the battery cell is in the lug area, and the non-lug area generates less heat, the heat dissipation demand is also smaller. The present application sets a recessed portion on the second plate of the cold plate, and the recessed portion is opposite to the non-lug area. Therefore, the setting of the recessed portion has less impact on the overall thermal management of the battery cell. The protective layer is set at the bottom of the cold plate and at least partially located in the recessed portion. The setting of the recessed portion provides more safety and protection space at the bottom of the cold plate, that is, at the recessed portion, additional space is provided for setting the protective layer, while not affecting the Z-direction size of the battery pack. Therefore, while meeting the thermal management requirements of the battery pack and not increasing the Z-direction size of the battery pack, the bottom protection performance of the battery pack is improved.

[0007] Furthermore, the battery cell is a blade battery cell, and the tab area is located at the first end and the second end of the battery cell.

[0008] Furthermore, the cold plate is made by an extrusion process, a plurality of partition ribs are arranged between the first plate and the second plate, and the flow channel is formed between adjacent partition ribs.

[0009] Furthermore, the recessed portion includes a first inclined surface and a second inclined surface; the first inclined surface and the second inclined surface intersect at the first plate, or the first inclined surface and the second inclined surface intersect at an end of the partition rib.

[0010] Furthermore, along the direction from the two ends of the battery core to the middle of the battery core, the width of the flow channel in the flat plate portion gradually increases.

[0011] Furthermore, the battery pack also includes a frame and a beam arranged in the frame, and the beam extends along the first direction; the first end of the battery cell is close to the frame, and the second end of the battery cell is close to the beam; in the second direction, the flat plate portion close to the frame has a size L1, and the flat plate portion close to the beam has a size L2, satisfying L1>L2, wherein the second direction is perpendicular to the first direction.

[0012] Furthermore, the angle between the first inclined surface and the plane where the first plate is located is A1, and the angle between the second inclined surface and the plane where the first plate is located is A2, satisfying A1 <A2。

[0013] Furthermore, the protective layer includes a first protective part and a second protective part; in the second direction, the first protective part is located on both sides of the second protective part; wherein the thermal insulation performance of the first protective part is better than that of the second protective part.

[0014] Furthermore, the first protection part is a vacuum insulation panel, and / or the material of the second protection part is microporous foamed polypropylene.

[0015] Furthermore, the battery pack also includes a frame and a beam arranged in the frame, and the beam extends along the first direction; the first end of the battery cell is close to the frame, and the second end of the battery cell is close to the beam; wherein, in the second direction, the first protective portion close to the frame has a size D1, and the first protective portion close to the beam has a size D2, satisfying D1>D2.

[0016] In addition, the present application also provides an electrical device, which includes the battery pack as described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the battery pack of an embodiment of the present application (the box body is omitted).

[0018] Figure 2 It is a structural cross-sectional view of the battery pack of an embodiment of the present application.

[0019] Figure 3 It is a partial structural cross-sectional view of the battery pack of an embodiment of the present application, showing half of the battery pack.

[0020] Figure 4 Schematic diagram of the structure of the cold plate of the embodiment of the present application. DETAILED DESCRIPTION

[0021] Many specific details are described in the following description to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific implementation disclosed below.

[0022] In the description of the present invention, it should be understood that descriptions involving orientation, such as up, down, front, back, left, right, inside, outside, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0023] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0024] In the description of the present invention, reference to terms such as "one embodiment", "some embodiments", "illustrative embodiment", "example", "specific example", or "some implementation methods" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present invention.

[0025] See also Figures 1 to 3 , provides a battery pack, including: a battery module 100, a cold plate 200, a protective layer 300 and a box 400 ( Figure 1 not shown).

[0026] Specifically, the battery module 100 includes a plurality of battery cells 110 arranged along a first direction X. Figure 3 , the battery cell 110 includes a tab area 111 and a non-tab area 112. It can be understood that the tab area refers to the area where the positive tab or the negative tab is located. In the present embodiment, the battery cell 110 is a blade battery cell, and the tab area 111 is located at the first end and the second end of the battery cell 110. In other words, the positive tab and the negative tab are located at the two ends of the battery cell, respectively. In some other embodiments, the positive tab and the negative tab may be located at the same end of the battery cell, that is, there is a tab area only at one end of the battery cell. The positive tab or the negative tab serves as an output pole and is a concentrated heat generation area during the operation of the battery pack. Therefore, the temperature of the tab area is relatively high, while the temperature of the non-tab area is relatively low.

[0027] The cold plate 200 is disposed below the battery module 100, and a flow channel 201 is disposed in the cold plate 200; the cold plate 200 is used to exchange heat with the battery cell 110 of the battery module 100, thereby cooling or heating the battery cell 110 according to specific working conditions, thereby ensuring that the battery cell operates at a suitable temperature. For example, a thermal conductive adhesive layer 500 is disposed between the cold plate 200 and the battery module 100. Figure 3 and Figure 4 The cold plate 200 includes a first plate 210 and a second plate 220 that are arranged opposite to each other, the first plate 210 is adjacent to the battery module 100, and the second plate 220 includes a flat portion 221 and a recessed portion 222, wherein the recessed portion 222 is opposite to the non-pole lug area 112. It should be noted that the recessed portion 222 is opposite to the non-pole lug area 112, which means that in the second direction Y, the range of the non-pole lug area 112 covers the recessed portion 222, or the size of the non-pole lug area 112 is substantially equal to the size of the recessed portion 222 and they are arranged opposite to each other. In the present embodiment, the range of the non-pole lug area 112 covers the recessed portion 222. Exemplarily, the recessed portion 222 is formed by the second plate 220 being recessed in the direction of the first plate 210. It can be understood that in the present embodiment, Figure 3The lug area 111 and the non-lug area 112 shown in the figure are schematic representations. For example, each lug area 111 occupies 5% to 20% of the total length of the battery cell, while the non-lug area 112 occupies 60% to 90% of the total length of the battery cell. The recessed portion 222 occupies a portion of the width of the cold plate 200. For example, in the second direction Y, the width of the recessed portion 222 occupies 20% to 60% of the width of the cold plate.

[0028] The protective layer 300 is disposed below the cold plate 200, and at least a portion of the protective layer 300 is located in the recessed portion 222. The protective layer 300 is used to resist and absorb the bottom impact of the battery pack. Exemplarily, a portion of the protective layer 300 is filled in the recessed portion 222. In a specific embodiment, at the recessed portion 222, the protective layer 300 has a shape that matches the recessed portion 222.

[0029] In addition, the battery pack case 400 includes a bottom guard plate 430 to seal the bottom of the battery pack. In other words, the protective layer 300 is disposed between the cold plate 200 and the bottom guard plate 430 .

[0030] In this way, since the main heating area of ​​the battery cell 110 is in the tab area 111, and the non-tab area 112 generates less heat, the heat dissipation demand is also small. The present application sets a recessed portion 222 on the second plate 220 of the cold plate 200, and the recessed portion 222 is opposite to the non-tab area 112. Therefore, the setting of the recessed portion 222 has little effect on the overall thermal management of the battery cell. The protective layer 300 is set at the bottom of the cold plate 200 and is at least partially located in the recessed portion 222. The setting of the recessed portion provides more safety and protection space at the bottom of the cold plate, that is, at the recessed portion 222, additional space is provided for setting the protective layer 300, and the Z-direction dimension of the battery pack is not affected. Therefore, while meeting the thermal management requirements of the battery pack and not increasing the Z-direction dimension of the battery pack, the bottom protection performance of the battery pack is improved.

[0031] See also Figure 3 and Figure 4 In this embodiment, the cold plate 200 is made by an extrusion process, and a plurality of ribs 230 are arranged between the first plate 210 and the second plate 220, and a flow channel 201 is formed between adjacent ribs 230. For example, a plurality of flow channels 201 are arranged in parallel. In addition, the battery pack further includes a liquid inlet and a liquid outlet, and the heat exchange medium enters the flow channel of the cold plate from the liquid inlet, performs heat exchange with the battery cell, and flows out from the liquid outlet.

[0032] Exemplarily, the recessed portion 222 includes a first inclined surface 2221 and a second inclined surface 2222, and the first inclined surface 2221 and the second inclined surface 2222 intersect at the first plate 210. In some other embodiments, the first inclined surface 2221 and the second inclined surface 2222 intersect at the end of the partition rib 230, that is, the partition rib at the intersection has a smaller height, which does not deviate from the essence of the present application.

[0033] Since the heat level of the tab area at the end of the blade cell is greater than that of the non-tab area in the middle, the tab area at the end of the cell is a high-temperature area during the operation of the cell, and the heat level gradually decreases from the two ends of the cell to the middle of the cell. Therefore, in order to improve the temperature uniformity of the cell, in this embodiment, the width of the flow channel 201 in the flat portion 221 gradually increases from the two ends of the cell 110 to the middle. It can be understood that there are multiple flow channels 201 within the range of the cold plate flat portion 221, that is, the closer to the end, the denser the flow channels, so the higher the heat exchange efficiency, so the setting of the above-mentioned flow channels corresponds to the temperature distribution of the cell, that is, the corresponding heat exchange efficiency is set according to the temperature of different areas of the cell, so that different areas of the entire cell have basically the same temperature, thereby improving the temperature uniformity of the battery pack, and improving the performance and life of the battery pack.

[0034] In a specific embodiment of the present application, see Figure 1 to Figure 2 , the battery pack box 400 also includes a frame 410 and a beam 420 disposed in the frame 410, the beam 420 extending along the first direction X; the first end of the battery cell 110 is close to the frame 410, and the second end of the battery cell 110 is close to the beam 420. In other words, the battery pack box 400 is divided into two accommodating chambers in the second direction Y by the beam 420 for accommodating the battery module 100. Of course, in some other embodiments, the box may also include a beam extending along the second direction Y, so as to separate the box into a plurality of accommodating chambers, which does not deviate from the essence of the present application.

[0035] Continue to see Figure 3, although the tab area 111 of the battery cell 110 has a higher temperature than the non-tab area 112, due to the arrangement of the battery cells and their location in the box, the area close to the frame 410 is more affected by the ambient temperature. Therefore, in this embodiment, further, in the second direction Y, the flat plate portion 221 close to the frame 410 has a size L1, and the flat plate portion 221 close to the beam 420 has a size L2, satisfying L1>L2. That is to say, in addition to the gradual increase in the width of the flow channel 201 in the flat plate portion 221 from the two ends of the battery cell 110 to the middle, it is further arranged that the flat plate portion close to the frame 410 has a larger width than the flat plate portion close to the beam 420, so that there are more flow channels 201 in the flat plate portion close to the frame 410 to provide a stronger heat exchange performance to the area, thereby offsetting the influence of the ambient temperature on the thermal management, and thus the temperature uniformity of the battery pack can be further improved. Exemplarily, L1 accounts for 35% of the entire cold plate width, and L2 accounts for 25% of the entire cold plate width.

[0036] In addition, see Figure 3 and Figure 4 , the first inclined surface 2221 close to the battery pack frame 410 has a larger area than the second inclined surface 2222 close to the battery pack beam 420. Therefore, the flow channel formed by the first inclined surface 2221, the first plate 210 and the partition rib 230 has a larger heat exchange area than the flow channel formed by the second inclined surface 2222, the first plate 210 and the partition rib 230, thereby providing better thermal management to further improve temperature uniformity. In other words, the angle between the first inclined surface 2221 and the plane where the first plate 210 is located is A1, and the angle between the second inclined surface 2222 and the plane where the first plate 210 is located is A2, satisfying A1 <A2。

[0037] Continue to see Figure 2 and Figure 3, the protective layer 300 includes a first protective portion 310 and a second protective portion 320. In the second direction Y, the first protective portion 310 is located on both sides of the second protective portion 320, that is, the first protective portion 310 is located at both ends of the protective layer 300, and the second protective portion 320 is located in the middle of the protective layer 300. Exemplarily, a part of the second protective portion 320 is located in the recessed portion 222 and has a shape that matches the recessed portion 222. Among them, the thermal insulation performance of the first protective portion 310 is better than that of the second protective portion 320. In this way, when the battery pack is in a low-temperature static environment, since the two ends of the battery cell are closer to the box 400 than the middle of the battery cell, that is, the two ends of the battery cell are respectively close to the frame 410 and the beam 420, the two ends of the battery cell are more likely to dissipate heat to the outside through the box, so the temperature at the two ends of the battery cell will be lower than the temperature in the middle of the battery cell, resulting in a temperature difference in the entire battery pack. If the battery pack is allowed to work at this time, it will greatly affect the performance and service life of the battery cell. Therefore, in the present embodiment, the thermal insulation performance of the first protective part 310 is set to be better than the thermal insulation performance of the second protective part 320, so as to address the problem of low temperature caused by heat dissipation at both ends of the battery cell. The thermal insulation performance is provided at both ends of the battery cell, so that the degree of heat dissipation of the battery cell as a whole is basically the same, thereby reducing the temperature difference of the entire battery pack.

[0038] Exemplarily, the first protection part 310 is a vacuum insulation panel (VIP panel for short), which provides excellent thermal insulation performance while providing protection; the material of the second protection part 320 is microcellular polypropylene foam (MPP for short), which provides excellent energy absorption and impact resistance performance while providing thermal insulation.

[0039] Furthermore, since the influence of the ambient temperature on the battery cell area near the frame 410 is greater than that near the beam 420, the battery cell area near the frame 410 has a lower temperature in a low-temperature static environment. Therefore, in this embodiment, in the second direction Y, the first protective portion 310 near the frame 410 has a size D1, and the first protective portion 310 near the beam 420 has a size D2, satisfying D1>D2, thereby further enhancing the thermal insulation performance of the area near the frame 410, and further reducing the temperature difference, so that the temperature of the entire battery pack is basically the same. Exemplarily, D1 accounts for 30% of the width of the entire protective layer, and D2 accounts for 20% of the width of the entire protective layer.

[0040] At this point, the present application sets a recessed portion on the cold plate so that at least part of the protective layer is located in the recessed portion, thereby improving the bottom protection performance of the battery pack without affecting the thermal management of the battery cell and the Z-direction size of the battery pack. The cold plate flow channels are set denser closer to the battery cell tab area, i.e., the heat generation area, thereby providing stronger thermal management, so that when the battery pack is working, the temperature uniformity of the single battery cell and the entire pack is improved; and combined with the arrangement and setting position of the battery cells in the battery pack, the heat exchange performance of the cold plate area close to the battery pack frame is further made stronger than the heat exchange performance of the cold plate area close to the battery pack beam, thereby offsetting the influence of ambient temperature on the thermal management of the battery pack. In the area where the battery cell is close to the box, the thermal insulation performance of the protective layer is set to be better than that of other areas, so that when the battery pack is placed in a low-temperature static environment, the heat dissipation of the battery cell area close to the box is slowed down, thereby reducing the temperature difference of the entire battery pack; and combined with the arrangement and setting position of the battery cells in the battery pack, the size of the first protective layer close to the battery pack frame is further made larger than the size of the first protective layer close to the beam, so that the thermal insulation performance of the entire pack is consistent, further reducing the temperature difference and improving the performance and service life of the battery cells.

[0041] Finally, the present application also provides an electric device, which includes the above-mentioned battery pack. For example, the electric device is a vehicle.

[0042] It should be noted that although the utility model is disclosed as above in the form of a preferred embodiment, it is not intended to limit the utility model. Any technical personnel in this field may make possible changes and modifications without departing from the spirit and scope of the utility model. Therefore, the scope of protection of the utility model shall be based on the scope defined by the claims of the utility model.

Claims

1. A battery pack, characterized in that: include: A battery module, wherein the battery module comprises a plurality of battery cells arranged along a first direction, wherein the battery cells comprise a tab region and a non-tab region; A cold plate, the cold plate is arranged below the battery module, a flow channel is arranged in the cold plate, and the cold plate comprises a first plate and a second plate arranged opposite to each other, the first plate is adjacent to the battery module, and the second plate comprises a flat plate portion and a recessed portion, wherein the recessed portion is arranged opposite to the non-ear area; A protective layer is disposed below the cold plate, and at least a portion of the protective layer is located in the recessed portion.

2. The battery pack according to claim 1, characterized in that: The battery cell is a blade battery cell, and the tab area is located at the first end and the second end of the battery cell.

3. The battery pack according to claim 2, characterized in that: The cold plate is made by an extrusion process, a plurality of partition ribs are arranged between the first plate and the second plate, and the flow channel is formed between adjacent partition ribs.

4. The battery pack according to claim 3, characterized in that: The recessed portion includes a first inclined surface and a second inclined surface; The first inclined surface and the second inclined surface intersect at the first plate, or the first inclined surface and the second inclined surface intersect at an end of the partition rib.

5. The battery pack according to claim 4, characterized in that: Along the direction from the two ends of the battery core to the middle of the battery core, the width of the flow channel in the flat plate portion gradually increases.

6. The battery pack according to claim 5, characterized in that: The battery pack further includes a frame and a beam disposed in the frame, wherein the beam extends along the first direction; the first end of the battery cell is close to the frame, and the second end of the battery cell is close to the beam; In the second direction, the flat plate portion close to the frame has a size L1, and the flat plate portion close to the beam has a size L2, satisfying L1>L2, wherein the second direction is perpendicular to the first direction.

7. The battery pack according to claim 6, characterized in that: The angle between the first inclined surface and the plane where the first plate is located is A1, and the angle between the second inclined surface and the plane where the first plate is located is A2, satisfying A1 <A2。 8. The battery pack according to claim 2, characterized in that: The protective layer comprises a first protective portion and a second protective portion; in the second direction, the first protective portion is located on both sides of the second protective portion; Wherein, the thermal insulation performance of the first protective part is better than the thermal insulation performance of the second protective part.

9. The battery pack according to claim 8, characterized in that: The first protection part is a vacuum insulation panel, and / or the second protection part is made of microporous foamed polypropylene.

10. The battery pack according to claim 8 or 9, characterized in that: The battery pack further includes a frame and a beam disposed in the frame, wherein the beam extends along the first direction; the first end of the battery cell is close to the frame, and the second end of the battery cell is close to the beam; In the second direction, the first protection portion close to the frame has a size D1, and the first protection portion close to the beam has a size D2, satisfying D1>D2.

11. An electrical device, characterized in that: The electrical device comprises a battery pack according to any one of claims 1-10.

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