Cooling device, connecting assembly of battery pack, battery pack and vehicle

Abstract

The utility model relates to a cooling device, a connecting assembly of a battery pack, the battery pack and a vehicle, the cooling device comprises two current collectors arranged side by side and a plurality of harmonica-shaped tubes arranged side by side at intervals, and two ends of each harmonica-shaped tube are respectively communicated with the two current collectors; one side surface of the harmonica-shaped tube forms a cell binding surface, and one side surface, opposite to the cell binding surface, of the harmonica-shaped tube is provided with a busbar fixing structure. The cooling device can simplify the mounting operation of the battery pack and improve the mounting efficiency of the battery pack while ensuring that the battery cell is effectively cooled to improve the safety.

Description

Technical Field

[0001] This application relates to the field of battery pack equipment technology, specifically to a cooling device, a battery pack connection component, a battery pack, and a vehicle. Background Technology

[0002] Lithium-ion batteries have become the mainstream power batteries for vehicles in the current new energy industry, boasting advantages such as high energy density and long cycle life. However, when power batteries experience over-discharge, overcharge, overheating, or other internal quality issues, there is a risk of thermal runaway. To address battery thermal runaway and its propagation, "thermal insulation" materials are typically used between cells to prevent heat transfer from the runaway cell to adjacent cells, thereby achieving a "non-propagation" protective effect.

[0003] Furthermore, since the battery pack contains multiple cells, and the terminals of each cell are electrically connected through busbars, the number of busbars is relatively large, and installing them one by one takes a long time, resulting in low production efficiency.

[0004] Therefore, how to ensure effective cooling of the battery cells to improve safety while simplifying the installation operation of the battery pack and improving the installation efficiency of the battery pack is a technical problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0005] The purpose of this application is to provide a cooling device, a battery pack connection component, a battery pack, and a vehicle that can effectively cool the battery cells to improve safety while simplifying the installation operation of the battery pack and improving the installation efficiency of the battery pack.

[0006] To solve the above-mentioned technical problems, this application provides a cooling device, including two parallel current collectors and multiple harmonica tubes arranged in parallel at intervals, with each end of the harmonica tube connected to the two current collectors respectively; one side surface of the harmonica tube forms a battery cell bonding surface, and the side surface of the harmonica tube opposite to the battery cell bonding surface is provided with a busbar fixing structure.

[0007] Optionally, the surface of the harmonica tube opposite to the contact surface of the battery cell is further provided with a sampling unit fixing structure.

[0008] Optionally, the bus fixing structure includes an insulating protrusion fixed to the harmonica tube, the insulating protrusion forming the bus fixing structure and / or the sampling unit fixing structure.

[0009] Optionally, the harmonica tube is a plastic tube, and the insulating protrusion is a heat-riveted post integrally formed with the harmonica tube.

[0010] This application also provides a battery pack connection assembly, including multiple busbars and a cooling device as described above. The busbars are provided with fixing parts, and the fixing parts correspond one-to-one with the busbar fixing structure and are fixed.

[0011] Optionally, the busbar further includes a pole connection portion, which is fixed to or integrally formed with the fixing portion, and a bending section is provided between the fixing portion and the pole connection portion.

[0012] Optionally, the fixing part is provided with a fixing hole, and the busbar fixing structure passes through the fixing hole and is riveted to the fixing part.

[0013] Optionally, it further includes a sampling unit electrically connected to the corresponding busbar, and the sampling unit fixing structure of the cooling device is fixed to the sampling unit.

[0014] Optionally, the sampling unit is provided with a connecting ear, the connecting ear is provided with a connecting hole, and the sampling unit fixing structure passes through the connecting hole and is riveted to the connecting ear.

[0015] This application also provides a battery pack, including a plurality of battery cells and a connection assembly of the battery pack as described above. The battery cells are arranged in parallel, and the top cover of each battery cell is provided with a terminal post. The terminals of each battery cell are electrically connected to each other through the busbar. The battery cell contact surface of the harmonica tube of the cooling device is in contact with the top cover.

[0016] Optionally, the top cover is provided with an explosion-proof valve, and the projection of the harmonica tube on the top cover is located between the explosion-proof valve and the pole.

[0017] Optionally, the distance between the projection of the harmonica tube onto the top cover and the explosion-proof valve is no greater than 30mm.

[0018] Optionally, the distance between the harmonica tube and the explosion-proof valve along the height direction of the battery cell is no more than 20mm.

[0019] This application also provides a vehicle including the battery pack described above.

[0020] The cooling device, battery pack connection assembly, battery pack, and vehicle provided in this application have the following technical advantages compared to the prior art:

[0021] During installation, the busbars are first fixed to the busbar fixing structure, so that the cooling device and the busbars are fixed to form the connection assembly of the battery pack. The cells are then arranged side by side to form the cell assembly. The connection assembly of the battery pack is then assembled with the cell assembly, so that the cell contact surface of the cooling device's harmonica tube is in contact with the top cover of the corresponding cell, and each busbar is in contact with the corresponding terminal. Finally, the busbars and the corresponding terminals are electrically connected by welding.

[0022] This configuration, compared to connecting each busbar to its corresponding terminal post one by one, facilitates rapid positioning of each busbar, simplifies assembly operations, and effectively improves the overall assembly efficiency of the battery pack. Furthermore, in this application, the cooling device for cooling the battery cells is assembled with the busbars, eliminating the need for a separate fixing structure for securing the busbars. This achieves effective cooling of the battery cells while simplifying the overall structure, reducing overall weight, and effectively improving the assembly efficiency of the battery pack.

[0023] Furthermore, since each harmonica tube is attached to the top cover of the battery cell for top-level cooling, and considering the existing height space at the top cover due to components like the terminals and busbars, attaching the harmonica to the cell top cover does not increase the overall height of the battery pack. This effectively reduces the overall volume of the battery pack, increases its energy density, and reduces installation space requirements. Moreover, compared to cooling cells via liquid cooling plates, using harmonica tubes allows for targeted cooling of the area near the terminals. This simplifies the overall structure and reduces the overall weight of the cooling device while ensuring effective cooling. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of the battery pack connection assembly and cell assembly in the installed state according to the embodiments of this application;

[0025] Figure 2 This is a partial structural diagram of the battery pack's connection components and cell components in their installed state;

[0026] Figure 3 This is a schematic diagram of the cooling device and battery cell assembly in the installed state;

[0027] Figure 4 yes Figure 3 Schematic diagram of the intermediate cooling device;

[0028] Figure 5 yes Figure 3 A schematic diagram of the structure of a battery cell assembly;

[0029] Figure 6 This is a schematic diagram of the battery cell structure;

[0030] Figure 7 This is a schematic diagram of the battery cell structure;

[0031] Figure 8 It is a cross-sectional view of the battery cell and cooling device in the installed state;

[0032] Figure 9 This is a schematic diagram of the structure between the busbar, harmonica tube, and poles in the installed state.

[0033] Appendix Figures 1-9 The reference numerals in the attached figures are explained as follows:

[0034] 1 Cooling device, 11 Current collector, 12 Harmonica tube, 13 Battery cell bonding surface, 14 Insulation protrusion, 15 Cooling channel, 16 Partition.

[0035] 2. Busbar, 21. Fixing part, 22. Pole post connection part, 23. Bend section;

[0036] 3 sampling units, 31 connectors;

[0037] 4 cells, 41 top cover, 42 housing, 43 explosion-proof valve, 44 pole;

[0038] 5. Thermal conductive layer. Detailed Implementation

[0039] To enable those skilled in the art to better understand the technical solutions of this application, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] This application provides a cooling device, a battery pack connection assembly, a battery pack, and a vehicle, wherein the vehicle includes a battery pack for supplying power to the vehicle, such as... Figure 1 and Figure 2 As shown, the battery pack includes a connecting assembly and multiple battery cells 4. The multiple battery cells 4 are arranged in parallel to form a battery cell assembly. The connecting assembly of the battery pack includes multiple busbars 2, a sampling unit 3, and a cooling device 1. In the installed state, the busbars 2 are connected between the terminals 44 of the battery cells 4. The sampling unit 3 is connected to the busbars 2 and is used to collect information from the battery cells 4. The cooling device 1 is used to cool the battery cells 4 to ensure the safety of the battery cells 4 during charging and discharging.

[0041] Specifically, such as Figure 3 and Figure 4As shown, the cooling device 1 includes two current collectors 11 and multiple harmonica tubes 12. The two current collectors 11 are arranged side by side with a gap between them, and the multiple harmonica tubes 12 are arranged side by side between the two current collectors 11. Both ends of each harmonica tube 12 are connected to the two current collectors 11 respectively. Coolant flows inside the cooling device 1, and one side surface of the harmonica tube 12 forms a battery cell bonding surface 13. Figure 5 and Figure 6 As shown, the battery cell 4 includes a top cover 41 and a housing 42. The top of the housing 42 is open, and the top cover 41 is fitted over the top of the housing 42. The top cover 41 is provided with a terminal post 44 and an explosion-proof valve 43. In the installed state, as shown... Figure 3 As shown, the cell bonding surface 13 can be bonded to the top cover 41 of the cell 4, and the coolant flowing in the cooling device 1 can exchange heat with the cell 4 from the top, thereby cooling the cell 4 and ensuring safety.

[0042] The harmonica tube 12 has a busbar fixing structure on the side opposite to the cell contact surface 13. This busbar fixing structure is used to fix the busbar 2. Specifically, the busbar 2 is provided with a fixing part 21, and the busbar fixing structure can be fixed to the fixing part 21 to achieve the fixation between the busbar 2 and the harmonica tube 12. In terms of installation, the busbar 2 and the busbar fixing structure can be fixed first, so that the cooling device 1 and the busbar 2 are fixed to form the connection assembly of the battery pack. The cells 4 are arranged side by side to form the cell assembly. Then, the connection assembly of the battery pack is assembled with the cell assembly, so that the cell contact surface 13 of the harmonica tube 12 of the cooling device 1 is attached to the top cover 41 of the corresponding cell 4, and each busbar 2 is in contact with the corresponding terminal 44. Then, the busbar 2 and the corresponding terminal 44 are electrically connected by welding.

[0043] This configuration, compared to connecting each busbar 2 to its corresponding terminal post 44 one by one, facilitates rapid positioning of each busbar 2, simplifies assembly operations, and effectively improves the overall assembly efficiency of the battery pack. Furthermore, in this embodiment, the cooling device 1 used to cool the battery cell 4 is assembled with the busbar 2, eliminating the need for a separate fixing structure for securing the busbar 2. This achieves effective cooling of the battery cell 4 while simplifying the overall structure, reducing overall weight, and effectively improving the assembly efficiency of the battery pack.

[0044] Furthermore, since each harmonica tube 12 is attached to the top cover 41 of the battery cell 4 to cool the battery cell 4 from the top, and due to the placement of components such as the terminal post 44 and busbar 2, the top cover 41 of the battery cell 4 already has a certain height space in the vertical direction. Therefore, setting the harmonica tube 12 to be attached to the top cover 41 of the battery cell 4 does not increase the overall height of the battery pack, thus effectively reducing the overall volume of the battery pack and increasing the energy density of the battery pack while reducing installation space requirements. Moreover, compared to the solution of cooling the battery cell 4 by attaching it to a liquid cooling plate, cooling the battery cell through the harmonica tube 12 allows for focused cooling of the area near the terminal post 44. While ensuring effective cooling of the battery cell 4, it also simplifies the overall structure of the cooling device and effectively reduces its overall weight.

[0045] Furthermore, such as Figure 1 and Figure 2 As shown, the battery pack connection assembly also includes a sampling unit 3, which is electrically connected to the busbar 2 and is used to collect signals such as voltage and temperature of each cell 4. The surface of the harmonica tube 12 of the cooling device 1 away from the cell contact surface 13 is also provided with a sampling unit fixing structure for fixing to the sampling unit 3. This sampling unit fixing structure has a similar function to the busbar fixing structure described above, and is used to fix it to the sampling unit 3 during assembly. Specifically, the sampling unit 3 is provided with a connecting ear 31, which is fixed to the sampling unit fixing structure.

[0046] In other words, during battery pack assembly, the cooling device 1 is first fixed to the busbar 2 via a busbar fixing structure, and then fixed to the sampling unit 3 via a sampling unit fixing structure. Simultaneously, the sampling unit 3 is electrically connected to the corresponding busbar 2 by welding. At this point, the cooling device 1, busbar 2, and sampling unit 3 form the connecting components of the battery pack. The individual battery cells 4 are then arranged sequentially to form the following configuration: Figure 7 After assembling the battery cell assembly as shown, the battery pack connecting assembly is assembled with the battery cell assembly, so that the battery cell contact surface 13 of the harmonica tube 12 is in contact with the top cover 41 of the battery cell 4, and the busbar 2 is in contact with the corresponding terminal 44 of the battery cell 4. The busbar 2 and the corresponding terminal 44 are then electrically connected by welding. This setup further simplifies the overall assembly operation of the battery pack and effectively improves the overall assembly efficiency.

[0047] Specifically, in this embodiment, the specific structures of the bus fixing structure and the sampling unit fixing structure are not limited. Taking the bus fixing structure as an example, the bus fixing structure can be set as an adhesive layer, and the bus 2 and the harmonica tube 12 can be bonded and fixed through the adhesive layer, which can simplify the overall structure. In this embodiment, an insulating protrusion 14 is provided on the side of the harmonica tube 12 away from the battery cell bonding surface 13. The insulating protrusion 14 can form the above-mentioned bus fixing structure. Similarly, the above-mentioned sampling unit fixing structure can also be formed by the insulating protrusion 14 fixed on the surface of the harmonica tube 12. Alternatively, the same insulating protrusion 14 can be fixed to both the bus 2 and the sampling unit 3. Figure 2 As shown, the partially insulating protrusion 14 is fixed only to the busbar 2, and the partially insulating protrusion 14 is fixed to both the busbar 2 and the sampling unit 3.

[0048] The insulating protrusion 14 is made of insulating material to prevent short circuits when fixed to the busbar 2. Specifically, the insulating protrusion 14 can be a plastic post or an insulating ceramic post, etc., whichever is appropriate for the actual situation.

[0049] In this embodiment, both the harmonica tube 12 and the current collector 11 are plastic tubing, the insulating protrusion 14 is a plastic column, and the harmonica tube 12 and the insulating protrusion 14 are integrally formed. This configuration simplifies the molding process of the cooling device 1 and effectively reduces costs.

[0050] Specifically, the harmonica tube 12, current collector 11, and insulating protrusion 14 can be made of PPA (Polyphthalamide) or PPO (Polyphenylene Oxide), with a melting point not exceeding 400℃, ensuring that the high-temperature substance ejected by the explosion-proof valve 43 can melt the side wall of the harmonica tube 12. The thermal conductivity is greater than or equal to 0.5 W / m·K, guaranteeing thermal conductivity. In other words, under normal conditions, coolant flows inside the cooling device 1, cooling the battery cell 4 by contacting its top cover 41. In the event of thermal runaway, the side wall of the harmonica tube 12 melts, forming a spray device that sprays coolant onto the thermally runaway battery cell 4, quickly and promptly cooling it and preventing heat spread.

[0051] Preferably, the wall thickness of the harmonica tube 12 is set within the range of 0.1mm-2mm. Of course, the wall thickness of the harmonica tube 12 can also be set to 0.05mm, 2.5mm, 3mm, etc. Setting the wall thickness of the harmonica tube 12 within the range of 0.1mm-2mm, such as 0.1mm, 0.5mm, 1mm, 1.5mm, 2mm, etc., can ensure structural strength while avoiding the impact of excessive wall thickness of the harmonica tube 12 on heat exchange performance.

[0052] The busbar 2 includes a terminal connection portion 22 and a fixing portion 21. The terminal connection portion 22 is used to weld and fix to the terminal 44 to achieve electrical connection, and the fixing portion 21 is used to fix to the busbar fixing structure. In this embodiment, the terminal connection portion 22 and the fixing portion 21 are configured as an integrally formed structure, and a bending section 23 is also provided between the terminal connection portion 22 and the fixing portion 21. The setting of the bending section 23 enables the fixing portion 21 to be fixed to the busbar fixing structure of the cooling device 1, while also ensuring that the terminal connection portion 22 can be connected to the terminal 44. That is to say, even if the height of the busbar fixing structure and the surface of the terminal 44 are different, an effective electrical connection between the terminal connection portion 22 and the terminal 44 can be guaranteed. The specific structure and size of the bending section 23 can be designed according to the actual situation.

[0053] The fixing part 21 is provided with fixing holes. During installation, the insulating protrusion 14 is passed through the fixing holes. The insulating protrusion 14 and the fixing holes can be fixed by snap-fit, interference fit, or threaded engagement of a nut with the insulating protrusion 14. When the insulating protrusion 14 is a plastic protrusion, it can be heat-fused and riveted after passing through the fixing holes to fix the insulating protrusion 14 to the busbar 2. This design facilitates assembly and ensures the stability of the fixation, thereby ensuring the accuracy of the positioning between the busbar 2 and the corresponding terminal 44 when assembling the battery pack connection assembly and the cell assembly. Similarly, the connecting ear 31 of the sampling unit 3 can be provided with connecting holes. The insulating protrusion 14 is passed through the connecting holes and heat-fused and riveted to achieve fixation.

[0054] In this embodiment, the harmonica tube 12 and the current collector 11 can also be made of aluminum alloy tubes, and an insulating layer can be provided on the surface of the harmonica tube 12 away from the battery cell bonding surface 13. The insulating layer is integrally formed with the aforementioned insulating protrusion 14. The insulating layer and the harmonica tube 12 can be fixed by adhesive bonding, or a fixing post can be provided on the surface of the harmonica tube 12, with the fixing post passing through the insulating layer and fixed by a fastener. When the harmonica tube 12 is made of aluminum alloy tube, the heat exchange performance of the harmonica tube 12 can be improved, ensuring the cooling effect on the battery cell 4.

[0055] like Figure 6As shown, the projection A of the harmonica tube 12 on the top cover 41 of the battery cell 4 is located between the explosion-proof valve 43 and the terminal post 44. This projection A of the harmonica tube 12 on the top cover 41 of the battery cell 4 does not overlap with the explosion-proof valve 43. Therefore, when the battery cell 4 experiences thermal runaway, the explosion-proof valve 43 is ruptured, and the high-temperature material inside is ejected without being obstructed by the harmonica tube 12, ensuring that the battery cell 4 can smoothly depressurize. Furthermore, when the high-temperature material is ejected, it can melt the sidewall of the adjacent harmonica tube 12, allowing the coolant inside the harmonica tube 12 to be ejected to the location of the explosion-proof valve 43 for rapid cooling, preventing thermal runaway of other surrounding battery cells 4 and ensuring safety.

[0056] The distance D between the projection A of the harmonica tube 12 on the top cover 41 and the explosion-proof valve 43 is no greater than 30mm. This distance D is as follows: Figure 8 As shown, the distance D between the projection A of the harmonica tube 12 on the top cover 41 and the explosion-proof valve 43 is in the range of 0-30mm. Of course, this distance D can also be set to 35mm, 40mm, etc. Setting this distance D in the range of 0-30mm, such as 0mm, 10mm, 20mm, 30mm, etc., can ensure that when the battery cell 4 experiences thermal runaway and high-temperature substances are ejected, the side wall of the harmonica tube 12 can be melted, ensuring that the coolant is ejected to achieve rapid cooling and ensure safety.

[0057] And, as Figure 3 As shown, in the installed state, the two current collectors 11 are located on both sides of the battery cell assembly. This arrangement allows the length of the harmonica tube 12 to extend to the location of all the battery cells 4 arranged in parallel, and all the busbars 2 can be fixed to the corresponding harmonica tubes 12.

[0058] like Figure 9 As shown, the battery cell bonding surface 13 of the harmonica tube 12 is bonded to the top cover of the battery cell 4 through a heat-conducting layer 5 to achieve heat conduction. This heat-conducting layer 5 can balance the tolerances between the battery cell bonding surface 13 of each harmonica tube 12 and the battery cell 4, ensuring the cooling effect of the harmonica tube 12 on the battery cell 4. A heat-conducting layer 5 is also provided on the surface of the harmonica tube 12 away from the battery cell 4. This heat-conducting layer 5 can balance the tolerances between the harmonica tube 12 and the fixing part 21 of the busbar 2, ensuring that the fixing part 21 of the busbar 2 can be fixed to the busbar fixing structure of the harmonica tube 12.

[0059] like Figure 8As shown, along the height direction of the battery cell 4, the distance H between the end face of the harmonica tube 12 facing the battery cell 4 and the explosion-proof valve 43 is in the range of 0-20mm. Of course, this distance H can also be 22mm, 25mm, 30mm, etc. Setting this distance H in the range of 0-20mm, such as 0mm, 5mm, 10mm, 15mm, 20mm, etc., makes it convenient for the harmonica tube 12 to balance the tolerance through the heat-conducting layer 5, while also ensuring that the harmonica tube 12 is closer to the battery cell 4, thereby ensuring the cooling effect on the battery cell 4.

[0060] like Figure 9 As shown, the harmonica tube 12 is provided with multiple parallel cooling channels 15. The two ends of each cooling channel 15 are connected to two current collectors 11 respectively. The harmonica tube 12 can be formed by multiple pipes arranged in parallel and fixed, or the harmonica tube 12 can be set as an integral structure. A partition 16 is set in the cavity to form a multi-cavity structure. The partition 16 is arranged along the height direction and can form a reinforcing rib in the cavity to ensure the overall structural strength of the harmonica tube 12.

[0061] Table (1) below shows the test results of thermal runaway of cell 4. Specifically, the test was conducted using different materials for the harmonica tube 12 and the distance D between the projection A of the harmonica tube 12 on the top cover 41 of cell 4 and the explosion-proof valve 43 as variables. When a single cell 4 experiences thermal runaway, the temperature of adjacent cells 4 and whether the harmonica tube 12 sprays water are shown in Table (1) below. In each test group, the wall thickness of the harmonica tube 12 is 0.5 mm, and the distance H between the harmonica tube 12 and the explosion-proof valve 43 along the height direction of cell 4 is 6.2 mm.

[0062] Table (1) Test results of thermal runaway in battery cells

[0063] experimental group Harmonica tube D (mm) Temperature of the ejector valve of the runaway battery cell (°C) Coolant leakage (L) Temperatures of the two hot surfaces of the runaway battery cell (°C) Highest temperature of adjacent cells (°C) Experimental results 1 Aluminum alloy tube 10 888.8 0 846.9 / 815.7 244.8 Thermal spread occurred within 15 minutes. 2 PPO pipe (melting point 220℃) 10 801.9 2.6 835.8 / 847.4 186.5 No heat spread 3 PPO pipe (melting point 220℃) 8 794.0 3 573.00 / 530.00 176 No heat spread 4 PPO pipe (melting point 220℃) 1 1034.4 4 764.4 / 695.7 184.1 No heat spread

[0064] Among them, the temperatures of the two hot surfaces of the runaway cell 4 refer to the temperatures of the two large surfaces of the cell 4 that experienced thermal runaway.

[0065] As can be seen from Experiment Group 1 in Table (1), when the harmonica tube 12 is made of aluminum alloy, thermal runaway of a certain battery cell will cause thermal propagation within 15 minutes. According to Experiment Groups 2-4 in Table (1), when the harmonica tube 12 is made of PPO tube, the melting point is 220℃. When the battery cell 4 experiences thermal runaway, the harmonica tube 12 can be melted by the high-temperature substance sprayed by the explosion-proof valve 43, and coolant will be sprayed out. The coolant will rapidly cool down the battery cell 4 and effectively prevent the thermal runaway from spreading, thus avoiding thermal runaway of other battery cells 4 in the vicinity. Furthermore, according to Experiment Groups 2-4, the harmonica tube 12 in The smaller the distance D between the projection A of the top cover 41 and the explosion-proof valve 43, the greater the coolant leakage. According to experimental groups 2 and 3, it can be seen that a large coolant leakage can effectively reduce the temperature of the cell 4 that has thermal runaway, and can also reduce the maximum temperature of adjacent cells 4. Furthermore, according to experimental groups 2 and 4, it can be seen that the spray valve temperature of the runaway cell 4 in experimental group 4 is higher, that is, the temperature of the high-temperature substance sprayed by the runaway cell 4 is higher. A smaller distance D results in a larger coolant leakage, which can effectively reduce the temperature of the runaway cell 4, and can also effectively prevent the maximum temperature of adjacent cells 4 from being too high, resulting in a better cooling effect.

[0066] Table (2) Test results of battery pack charging

[0067] experimental group harmonica tube Wall thickness (mm) Thermal conductivity of material (W / m·K) Fast charging conditions Maximum cell temperature (°C) Full charge time (s) 5 PPO pipe (melting point 220℃) 0.5 0.7 6C 52.5 628 6 Aluminum alloy tube 0.5 200 6C 52.5 616

[0068] Table (2) shows the test results of battery pack charging. Specifically, it shows the time required to fully charge the test battery pack with the same initial charge when different materials are used for the harmonica tube 12.

[0069] As can be seen from experiments 5 and 6, under the same charging conditions, the charging time of harmonica tube 12 using PPO tube is nearly 12 seconds different from that using aluminum alloy tube, which is a small difference.

[0070] Therefore, in this embodiment, it is preferable to use plastic tubes such as PPO tubes or PPA tubes for the harmonica tube 12. Under normal operating conditions, it can play a cooling role for the battery cell 4 to ensure the fast charging performance of the battery pack. When the battery cell 4 experiences thermal runaway, the harmonica tube 12 can be melted and form a spray device to spray coolant onto the battery cell 4 that has experienced thermal runaway in a timely and rapid manner, so as to avoid the spread of heat and ensure safety.

[0071] The above are merely preferred embodiments of this application. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A cooling device, characterized in that, It includes two parallel current collectors (11) and multiple spaced parallel harmonica tubes (12), with each end of the harmonica tube (12) connected to the two current collectors (11). One side surface of the harmonica tube (12) forms a battery cell bonding surface (13), and the side surface of the harmonica tube (12) opposite to the battery cell bonding surface (13) is provided with a busbar fixing structure.

2. The cooling device according to claim 1, characterized in that, The harmonica tube (12) is also provided with a sampling unit fixing structure on the side surface opposite to the battery cell bonding surface (13).

3. The cooling device according to claim 2, characterized in that, The bus fixing structure includes an insulating protrusion (14) fixed to the harmonica tube (12), the insulating protrusion (14) forming the bus fixing structure and / or the sampling unit fixing structure.

4. The cooling device according to claim 3, characterized in that, The harmonica tube (12) is a plastic tube, and the insulating protrusion (14) is a hot-riveted post integrally formed with the harmonica tube (12).

5. A connection assembly for a battery pack, characterized in that, It includes multiple busbars (2) and a cooling device as described in any one of claims 1-4, wherein each busbar (2) is provided with a fixing part (21), and the fixing part (21) corresponds to and is fixed to the busbar fixing structure.

6. The battery pack connection assembly according to claim 5, characterized in that, The busbar (2) further includes a pole connection part (22), which is fixed or integrally formed with the fixing part (21), and a bending section (23) is provided between the fixing part (21) and the pole connection part (22).

7. The battery pack connection assembly according to claim 5, characterized in that, The fixing part (21) is provided with a fixing hole, and the busbar fixing structure passes through the fixing hole and is riveted to the fixing part (21).

8. The battery pack connection assembly according to any one of claims 5-7, characterized in that, It also includes a sampling unit (3), which is electrically connected to the corresponding busbar (2), and the sampling unit fixing structure of the cooling device is fixed to the sampling unit (3).

9. The battery pack connection assembly according to claim 8, characterized in that, The sampling unit (3) is provided with a connecting ear (31), the connecting ear (31) is provided with a connecting hole, and the sampling unit fixing structure passes through the connecting hole and is riveted and fixed to the connecting ear (31).

10. A battery pack, characterized in that, The battery pack includes multiple battery cells (4) and a connection assembly as described in any one of claims 5-9. The battery cells (4) are arranged in parallel, and the top cover (41) of each battery cell (4) is provided with a terminal post (44). The terminals (44) of each battery cell (4) are electrically connected to each other through the busbar (2). The battery cell contact surface (13) of the harmonica tube (12) of the cooling device is in contact with the top cover (41).

11. The battery pack according to claim 10, characterized in that, The top cover (41) is equipped with an explosion-proof valve (43), and the projection of the harmonica tube (12) on the top cover (41) is located between the explosion-proof valve (43) and the pole (44).

12. The battery pack according to claim 11, characterized in that, Furthermore, the distance between the projection of the harmonica tube (12) on the top cover (41) and the explosion-proof valve (43) is no greater than 30mm.

13. The battery pack according to claim 11 or 12, characterized in that, Along the height direction of the battery cell (4), the distance between the harmonica tube (12) and the explosion-proof valve (43) is no more than 20mm.

14. A vehicle, characterized in that, Includes the battery pack as described in any one of claims 10-13.

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