Cooling device and battery pack

Abstract

The utility model discloses a cooling device and a battery pack, under the driving of external pressure, an external fluid medium can enter a first collecting pipe or a second collecting pipe and then enter a heat exchange pipe and a spraying pipe, the fluid medium entering the heat exchange pipe can dissipate heat and cool over-current elements such as a post terminal and a busbar below the fluid medium, and when a battery cell is in thermal runaway, the fluid medium can be cooled by the spraying pipe. When the battery cell explosion-proof valve is used, eruption substances erupted from the battery cell explosion-proof valve can melt through the side wall of the spraying pipe located above the eruption substances, liquid in the spraying pipe can be sprayed to the position of the explosion-proof valve, and external liquid can continuously enter the spraying pipe under the driving of external pressure, so that continuous spraying and cooling of the battery cell are realized; therefore, heat spreading caused by accumulation of eruptions can be avoided, and the purpose of quickly cooling the battery cell is achieved.

Description

Technical Field

[0001] The present application relates to the field of batteries, and in particular to a cooling device and a battery pack. Background Art

[0002] Currently, a battery pack is usually composed of multiple battery cells, each of which has a shell, an electrode group, a positive electrode column and a negative electrode column. The electrode group is encapsulated inside the shell, and the electrode group is electrically connected to an external bus through two electrode columns. The bus is used to realize series and parallel connection between the battery cells to form a battery pack.

[0003] During fast charging, the battery pack draws high currents, and the Joule heat generated by current-carrying components like the cell poles and busbars increases exponentially. If the heat from these components can't be removed quickly, it will be transferred to the cell windings, causing rapid heating and exceeding the current limit. This also increases the risk of thermal runaway. To mitigate this risk, liquid cooling devices are currently being added to the cell poles and busbars to improve cooling efficiency. When thermal runaway occurs, the liquid cooling channels are destroyed, allowing coolant to flow to the cell and cool it.

[0004] How to maximize the cooling efficiency of battery cells when they experience thermal runaway is an important issue of concern to those skilled in the art. Utility Model Content

[0005] The purpose of the present application is to provide a cooling device with relatively high cooling efficiency for battery cells. Another purpose of the present application is to provide a battery pack having the above cooling device.

[0006] The present application provides a cooling device, comprising:

[0007] a first manifold and a second manifold, both of which have a liquid collecting cavity;

[0008] At least one connecting pipe unit, each connecting pipe unit including a spray pipe and two heat exchange pipes, one end of each heat exchange pipe being connected to the liquid collecting cavity of the first header, and the other end of each heat exchange pipe being connected to the liquid collecting cavity of the second header;

[0009] The spray pipe is located between the two heat exchange tubes, and at least one end of the spray pipe is communicated with the liquid collecting cavity of the first header or the liquid collecting cavity of the second header.

[0010] Driven by external pressure, the external fluid medium can enter the first manifold or the second manifold, and then enter the heat exchange tube and the spray tube. The fluid medium entering the heat exchange tube can dissipate heat and cool the current components below it, such as the pole and bus bar. When the battery cell is thermally out of control, the ejection material ejected from the battery cell explosion-proof valve can melt through the side wall of the spray tube above it, and the liquid in the spray tube can be sprayed to the explosion-proof valve position. Driven by external pressure, the external liquid can continuously enter the spray tube to achieve continuous spraying and cooling of the battery cell, which can avoid the accumulation of ejection material and cause heat spread, and achieve the purpose of rapid cooling of the battery cell.

[0011] In one example, the first end of the spray pipe is connected to the liquid collecting chamber of the first collecting pipe, and the second end of the spray pipe is configured as a closed end.

[0012] In one example, at least one damping channel is further included, wherein the first end of the spray pipe is connected to the liquid collecting chamber of the first collecting pipe, and the second end of the spray pipe is connected to the liquid collecting chamber of the second collecting pipe through the damping channel, and the sum of the flow areas of all the damping channels is smaller than the flow area of ​​the opening at any end of the heat exchange tube.

[0013] In one example, a slot is provided on the outer peripheral wall of the second collecting pipe, the slot having a slot bottom wall opposite to the slot opening, the second end of the spray pipe is supported inside the slot, and the damping channel passes through the slot bottom wall.

[0014] In one example, at least one first partition is provided inside the liquid collecting chamber of the second collecting pipe, and the first partition divides the liquid collecting chamber of the second collecting pipe into at least two relatively independent liquid separation chambers. One of the spray pipes can be connected to the two liquid separation chambers on both sides of the first partition at the same time through the damping channel.

[0015] In one example, the number of the connecting pipe units is at least N, which are arranged axially along the first collecting pipe. The first collecting pipe has a second partition inside to divide the liquid collecting cavity of the first collecting pipe into N relatively independent sub-cavities, and the heat exchange tube and the spray pipe in one of the connecting pipe units are connected to the same sub-cavity; wherein N is an integer greater than or equal to 2; the second collecting pipe is provided with a liquid inlet and a liquid outlet, the liquid inlet is used to connect to an external pressure pipeline, and the liquid outlet is used to connect to an external reflux pipeline.

[0016] In one example, the heat exchange tube has a heat exchange contact surface. Along the extension direction of the spray pipe, the spray pipe includes two end pipe sections and an intermediate pipe section connected between the two end pipe sections. The intermediate pipe section arches from the center line of the end pipe section toward the side away from the heat exchange contact surface.

[0017] In one example, the highest position of each intermediate pipe segment and the highest position of each heat exchange tube are on the same horizontal plane;

[0018] Alternatively, the highest position of each intermediate pipe section is lower than the highest position of each heat exchange tube.

[0019] In one example, the heat exchange tube has a heat exchange contact surface, and the spray pipe includes a first side wall and a second side wall opposite to each other, the first side wall and the heat exchange contact surface are located on the same side of the cooling device, and the wall thickness of the second side wall is greater than the wall thickness of the first side wall;

[0020] Alternatively or alternatively, the spray pipe is made of plastic.

[0021] In addition, an embodiment of the present application also provides a battery pack, comprising at least one row of battery cell groups, each of the battery cell groups having a plurality of battery cells arranged along a stacking direction, and also comprising at least one of the above-mentioned cooling devices, the heat exchange tubes being located above the same column of poles of the battery cell groups, and the spray pipes being located above the explosion-proof valve.

[0022] In one example, the distance from the spray pipe to the explosion-proof valve is greater than or equal to 8 mm.

[0023] The battery pack in the embodiment of the present application has the above-mentioned cooling device, so both also have the above-mentioned technical effects of the cooling device. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic structural diagram of the assembly of a cooling device and a battery cell group in one embodiment of the present application;

[0025] Figure 2 for Figure 1 a side view of the cooling device shown;

[0026] Figure 3 for Figure 2 AA cross-sectional view of the structure shown;

[0027] Figure 4 for Figure 1 a top view of the structure shown;

[0028] Figure 5 for Figure 4 BB section view of the structure shown;

[0029] Figure 6 for Figure 4 CC cross-sectional view of the structure shown.

[0030] in, Figures 1 to 6 The one-to-one correspondence between the reference numerals and component names is as follows:

[0031] 1 cooling device;

[0032] 2 battery cell group; 21 first battery cell; 22 second battery cell; 23 third battery cell;

[0033] 11 A heat exchange tube; 111 heat exchange contact surface; 12 B heat exchange tube; 1201 end tube section; 1202 transition tube section; 1203 intermediate tube section; 13 C heat exchange tube; 14 D heat exchange tube; 15 E heat exchange tube; 16 F heat exchange tube; 17 second manifold; 1701 first liquid outlet; 1702 liquid inlet; 1703 second liquid outlet; 1704 first partition plate; 1706 first liquid separation chamber; 1707 second liquid separation chamber; 1708 third liquid separation chamber; 1709 damping channel; 18 first manifold; 1801 first sub-chamber; 1802 second partition plate; 1803 second sub-chamber;

[0034] 31 first busbar; 32 second busbar; 2101 pole one; 2201 pole two; 2102 explosion-proof valve; S space. DETAILED DESCRIPTION

[0035] In response to the problem of high-temperature thermal runaway cooling of battery cells mentioned in the background art, the inventors of this application have conducted extensive research and found that the following methods are currently used for spraying thermal runaway battery cells: First, a liquid cooling plate is only set above the pole of the battery cell. When the battery cell is operating normally, the liquid cooling plate cools the pole and other current-passing components. When the battery cell is in thermal runaway, the liquid cooling plate is destroyed, and the cooling medium in the liquid cooling plate sprays the battery cell. In this method, the liquid cooling plate mainly sprays to the position of the lower pole, and cannot quickly cool down the position of the explosion-proof valve where the temperature is relatively high, and the cooling efficiency is relatively low. Second, a spray device is added on the basis of the first method. The spray pipe of the spray device is located above the explosion-proof valve. When the battery cell is in thermal runaway, the spray device sprays the explosion-proof valve. This method of spraying device increases the complexity of the thermal management system, bringing additional weight and cost.

[0036] Therefore, how to provide a device with high cooling efficiency and simple structure for battery cells when the battery cells are in thermal runaway is a technical problem that needs to be solved by those skilled in the art.

[0037] This application describes the technical solution and technical effects using the example of a battery cell in upright position, where the tabs and explosion-proof valves of each battery cell are located at the top of the battery cell. Furthermore, this application describes the technical solution and technical effects using the cooling device applied to a battery pack as an example. Of course, this does not exclude the possibility that the cooling device of this application can be applied to other environments to achieve the same or equivalent technical effects as those of this application.

[0038] Please refer to Figures 1 to 6 , Figure 1 This is a schematic structural diagram of the assembly of a cooling device and a battery cell group in one embodiment of the present application; Figure 2 for Figure 1a side view of the cooling device shown; Figure 3 for Figure 2 AA cross-sectional view of the structure shown; Figure 4 for Figure 1 a top view of the structure shown; Figure 5 for Figure 4 BB section view of the structure shown; Figure 6 for Figure 4 CC cross-sectional view of the structure shown.

[0039] The embodiment of the present application provides a battery pack, the battery pack includes a box ( Figure 1 (not shown) and several cells located inside the box, the cells are stacked along the x direction to form a column of cell groups 2, which can be referred to Figure 4 understand, Figure 4 Only three cells in a row of cell groups 2 are shown: the first cell 21, the second cell 22 and the third cell 23, but the number is not limited to three. The box body can have one row of cell groups 2, or at least two rows of cell groups 2 can be arranged along the y direction. Figure 1 Two rows of battery cell groups 2 are shown in FIG. A battery cell has a positive pole and a negative pole, and the poles of all the battery cells are connected in series or / and in parallel according to the rules through a bus bar to form a power supply. Please refer to Figure 5 It is understood that the first electrode 2101 of the first battery cell 21 and the second electrode 2201 of the second battery cell 22 are electrically connected via the second busbar 32, wherein the first electrode 2101 and the second electrode 2201 can be a positive electrode and a negative electrode, respectively. The positive and negative electrodes can be made of a single component material, such as copper, aluminum, or other materials with good electrical conductivity, or a composite material composed of different components, such as a composite material formed of copper, aluminum, or other materials with good electrical conductivity, as long as good electrical conductivity is achieved.

[0040] In this embodiment, a battery cell includes a housing and an electrode assembly enclosed within the housing. The housing has an opening at the top, and an upper cover is positioned over the opening. Typically, the upper cover is installed over the opening after the electrode assembly is installed within the housing. For the safety of the battery cell, an explosion-proof valve 2102 is provided on the upper cover.

[0041] The battery pack in the embodiment of the present application also includes a cooling device 1, which is installed on the top of each battery cell group 2 to form a whole. In the embodiment of the present application, the cooling device 1 includes a first collector 18, a second collector 17 and at least one connecting tube unit. The first collector 18 and the second collector 17 can have roughly the same shape, and rectangular tubes with rectangular cross-sections can be used, that is, the first collector 18 and the second collector 17 are both flat tubes. This can reduce the overall height of the cooling device 1. Of course, in some embodiments, the cross-sections of the first collector 18 and the second collector 17 can also be other shapes, such as circular tubes, which have relatively small fluid resistance. The first collector 18 and the second collector 17 can also adopt different shapes, depending on the specific product.

[0042] Similarly, each heat exchange tube and each spray pipe can also be a rectangular tube with a rectangular cross-section, that is, both the heat exchange tube and the spray pipe are flat tubes. Of course, each heat exchange tube and each spray pipe can also have other shapes. In addition, the interior of each heat exchange tube and each spray pipe can be further divided into multiple flow channels, each of which extends along the x-direction. Of course, each heat exchange tube and each spray pipe can also have a single flow channel.

[0043] In the embodiment of the present application, both the first manifold 18 and the second manifold 17 have a liquid collecting cavity.

[0044] The connecting pipe unit in the embodiment of the present application includes a spray pipe and two heat exchange tubes. One end of each heat exchange tube is connected to the liquid collecting cavity of the first header 18, and the other end is connected to the liquid collecting cavity of the second header 17, so that the fluid medium can flow between the first header 18 and the second header 17. The main function of the heat exchange tube is to exchange heat between the liquid in the heat exchange tube and the flow-through components (electrodes and busbars) of the battery cell.

[0045] The spray pipe is located between the two heat exchange tubes. At least one end of the spray pipe is connected to the liquid collection cavity of the first header 18 or the liquid collection cavity of the second header 17. In other words, the spray pipe can be connected to the liquid collection cavity of either the first header 18 or the second header 17 at only one end, while the other end is not connected to the liquid collection cavity of the other. Of course, both ends of the spray pipe can also be connected to the first header 18 and the second header 17 respectively. The specific connection method of the spray pipe will be described in detail later.

[0046] The material requirements for the spray pipe are: when a battery cell experiences thermal runaway, the spray pipe can be melted through by the ejected material, forming a spray opening from which the liquid inside can be ejected. For spray pipes used in battery pack environments, the melt-through temperature of the spray pipe material can be roughly between 150°C and 700°C.

[0047] When the cooling device 1 is installed in the battery pack, one connecting tube unit corresponds to one cell group 2, and two heat exchange tubes are located above the two columns of the cell group 2: one heat exchange tube is located above the positive column of the cell group 2, and the other heat exchange tube is located above the negative column of the cell group 2. The spray pipe is located above the explosion-proof valve 2102 of the cell group 2.

[0048] Driven by external pressure, the external fluid medium can enter the first manifold 18 or the second manifold 17, and then enter the heat exchange tube and the spray tube. The fluid medium entering the heat exchange tube can dissipate heat and cool the current-passing components such as the pole and bus below it. When the battery cell is thermally out of control, the ejecta ejected from the battery cell explosion-proof valve 2102 can melt through the side wall of the spray tube above it, and the liquid in the spray tube can be sprayed to the position of the explosion-proof valve 2102. Driven by external pressure, the external liquid can continuously enter the spray tube to achieve continuous spraying and cooling of the battery cell. This can avoid the accumulation of ejecta and cause heat spread, and achieve the purpose of quickly cooling the battery cell.

[0049] In the embodiment of the present application, the first end of the spray pipe is connected to the liquid collecting chamber of the first manifold 18, and the second end of the spray pipe is configured as a closed end. When the battery pack is in a normal state, once the spray pipe is filled with liquid, the liquid in the manifold will no longer enter the spray pipe. The liquid in the spray pipe hardly flows, which does not interfere with the liquid flow distribution. The liquid in the manifold will only circulate inside the heat exchange tube, which is more efficient for heating or cooling the pole. Only when the battery cell thermal runaway melts through, driven by external pressure, will the external liquid continuously enter the spray pipe through the manifold to spray the runaway battery cell.

[0050] In another embodiment, cooling device 1 further includes at least one damping channel 1709. The first end of the spray pipe communicates with the liquid collecting chamber of the first header 18, and the second end of the spray pipe communicates with the liquid collecting chamber of the second header 17 through damping channel 1709. The total flow area of ​​all damping channels 1709 is less than the flow area of ​​any opening at either end of the heat exchange tube. Damping channel 1709 can be directly provided on the wall of the second header 17, or alternatively, a separate pipeline can be provided as damping channel 1709. Furthermore, the size of the end opening of the spray pipe can be controlled to serve as damping channel 1709.

[0051] In this embodiment, the second end of the spray pipe communicates with the liquid collection chamber of the second manifold 17 via damping channel 1709. This facilitates the removal of bubbles from the second end of the spray pipe, prevents localized air entrapment, and fully utilizes the internal space of the spray pipe to store the spray liquid. Furthermore, due to the presence of damping channel 1709, the flow rate between the spray pipe and the second manifold 17 is minimal, thus not disturbing the flow diversion of the remaining heat exchange tubes and not affecting the heating or cooling of the battery cell's current-carrying components.

[0052] In a specific implementation, a slot is provided on the outer peripheral wall of the second collecting pipe 17, and the slot has a slot bottom wall opposite to the slot opening. The second end of the spray pipe is supported inside the slot, and the damping channel 1709 runs through the slot bottom. The slot can further support the second end of the second collecting pipe 17, thereby improving the reliability of the spray pipe fixation.

[0053] The two ends of the spray pipe can adopt an open structure, and the spray pipe is closed by a slot, and it is only necessary to process the damping channel 1709 at the bottom of the slot. In this way, the spray pipe structure is relatively simple.

[0054] In a specific embodiment, the aperture range of the damping channel 1709 can be 2 mm to 5 mm. The aperture of the damping channel 1709 within this range is relatively small and the flow resistance is relatively high. When the battery cell works normally, the spray pipe has little effect on the flow of the heat exchange tube.

[0055] The heat exchange tube and the first header 18 , the heat exchange tube and the second header 17 , the spray tube and the first header 18 , and the spray tube and the first header 18 may be connected and fixed by welding.

[0056] In the embodiment of the present application, a first partition 1704 is usually provided inside the liquid collecting chamber of the second manifold 17, and a second partition 1802 is usually provided inside the liquid collecting chamber of the first manifold 18, so as to configure the cooling device 1 to form different flow channels. Among them, the first partition 1704 divides the liquid collecting chamber of the second manifold 17 into at least two relatively independent liquid separation chambers, and a spray pipe can be simultaneously connected to the two liquid separation chambers on both sides of a first partition 1704 through the damping channel 1709. In this way, different positions of the second end of the spray pipe can be connected to the liquid separation chamber through the damping channel 1709 respectively, so that bubbles can flow out smoothly. In addition, the second end of the spray pipe is connected to different liquid separation chambers, which can avoid the occurrence of excessive pressure in a certain liquid separation chamber and the inability of bubbles to flow out, and effectively avoid gas accumulation at the second end of the spray pipe.

[0057] In the embodiment of the present application, the number of connecting pipe units is at least N, and the accompanying drawings show an example where N equals 2. Arranged axially along the first manifold 18, the first manifold 18 has a second partition 1802 inside it to divide the liquid collecting cavity of the first manifold 18 into N relatively independent sub-cavities. The heat exchange tubes and spray pipes in a connecting pipe unit communicate with the same sub-cavity; N is an integer greater than or equal to 2. The second manifold 17 is provided with a liquid inlet and a liquid outlet. The liquid inlet is used to connect to an external pressure line, and the liquid outlet is used to connect to an external return line.

[0058] In this embodiment, the external liquid flows through the second header 17 and the heat exchange tube to the first header 18 and then flows to the spray pipe, which is conducive to the fluid filling the slow spray pipe.

[0059] Please combine Figure 1 and Figure 3 For further understanding, the accompanying drawings show that the cooling device 1 includes two connecting pipe units: a first unit and a second unit. The first unit includes heat exchange tube A 11, heat exchange tube B 12, and heat exchange tube C 13, where heat exchange tubes A 11 and B 12 are the aforementioned heat exchange tubes, and heat exchange tube C 13 is the aforementioned spray pipe. The second unit includes heat exchange tube D 14, heat exchange tube E 15, and heat exchange tube F 16, where heat exchange tubes D 14 and F 16 are the aforementioned heat exchange tubes, and heat exchange tube E 15 is the aforementioned spray pipe.

[0060] The second manifold 17 is provided with a liquid inlet 1702 and two liquid outlets, which are defined as a first liquid outlet 1701 and a second liquid outlet 1703. The liquid inlet 1702 is used to connect to an external pressure pipeline. The liquid medium in the external pressure pipeline can flow into the interior of the second manifold 17 through the liquid inlet 1702. The first liquid outlet 1701 and the second liquid outlet 1703 are both connected to an external return line.

[0061] A first partition 1704 is provided inside the liquid collecting chamber of the second collecting pipe 17, and the first partition 1704 divides the liquid collecting chamber of the second collecting pipe 17 into three relatively independent liquid separation chambers: a first liquid separation chamber 1706, a second liquid separation chamber 1707 and a third liquid separation chamber 1708, wherein the liquid inlet 1702 is located in the second liquid separation chamber 1707, the first liquid outlet 1701 is located in the first liquid separation chamber 1706, and the second liquid outlet 1703 is located in the third liquid separation chamber 1708.

[0062] A second partition 1802 is provided inside the liquid collecting chamber of the first collecting pipe 18, and the second partition 1802 divides the liquid collecting chamber of the first collecting pipe 18 into two relatively independent sub-chambers: a first sub-chamber 1801 and a second sub-chamber 1803. The A heat exchange tube 11, the B heat exchange tube 12 and the C heat exchange tube 13 in the first unit are located between the first sub-chamber 1706 and the second collecting pipe 17, and the D heat exchange tube 14, the E heat exchange tube 15 and the F heat exchange tube 16 in the second unit are located between the second sub-chamber 1707 and the second collecting pipe 17.

[0063] The two ends of heat exchange tube A 11 connect to the first sub-chamber 1801 and the first liquid-separating chamber 1706, respectively. The two ends of heat exchange tube C 13 connect to the first sub-chamber 1801 and the second liquid-separating chamber 1707, respectively. The two ends of heat exchange tube D 14 connect to the second liquid-separating chamber 1707 and the second sub-chamber 1803, respectively. The two ends of heat exchange tube F 16 connect to the third liquid-separating chamber 1708 and the second sub-chamber 1803, respectively. Heat exchange tube B 12 has one end connected to the first sub-chamber 1801 and the other end supported within slot 1710 of second manifold 17. The bottom of slot 1710 is provided with a damping hole that connects to the first liquid-separating chamber 1706. Heat exchange tube E 15 has one end connected to the second sub-chamber 1803 and the other end supported within slot 1710 of second manifold 17. The bottom 1711 of slot 1710 is provided with a damping hole that connects to the third liquid-separating chamber 1708.

[0064] When the cooling device 1 is normally heating or cooling the battery cell, the fluid flow path of the first unit is as follows: the fluid enters the second liquid separation chamber 1707 through the liquid inlet 1702, enters the first liquid separation chamber 1801 through the C heat exchange tube 13, enters the A heat exchange tube 11 from the first liquid separation chamber 1801, flows back to the first liquid separation chamber 1706, and flows from the first liquid separation chamber 1706 to the return liquid pipeline. At the same time, the fluid in the first liquid separation chamber 1801 can fill the B heat exchange tube 12 with liquid. The fluid flow path of the second unit is as follows: the fluid enters the second liquid separation chamber 1707 through the liquid inlet 1702, enters the second liquid separation chamber 1803 through the D heat exchange tube 14, enters the F heat exchange tube 16 from the second liquid separation chamber 1803, flows back to the third liquid separation chamber 1708, and flows from the third liquid separation chamber 1708 to the return liquid pipeline. At the same time, the fluid in the second liquid separation chamber 1803 can fill the E heat exchange tube 15 with liquid.

[0065] The second end of heat exchange tube B 12 may be provided with two or more damping channels 1709, which can simultaneously connect the first liquid separation chamber 1706 and the second liquid separation chamber 1707. Similarly, heat exchange tube E 15 can simultaneously connect the second liquid separation chamber 1707 and the third liquid separation chamber 1708 through the damping channel 1709.

[0066] Please refer to Figure 6 In a specific example, along the extension direction of the spray pipe, the spray pipe includes two end pipe sections 1201 and a middle pipe section 1203 connected between the two end pipe sections 1201. The middle pipe section 1203 is arched toward the side away from the explosion-proof valve 2102. Figure 5 It is understood that the heat exchange tube has a heat exchange contact surface 111 (heat exchange tube A 11 is used as an example). Heat exchange contact surface 111 is the side of the heat exchange tube facing the battery cell. Heat exchange contact surface 111 is used to contact the busbar and pole on the battery cell for heat exchange. With heat exchange contact surface 111 as a reference, the middle tube section 1203 arches from the centerline of the end tube section 1201 toward the side away from heat exchange contact surface 111.

[0067] The spray pipe has an upward arch feature, which can increase the distance from the lower edge of the spray pipe to the battery cell explosion-proof valve 2102 while sharing the collecting pipes on both sides with the heat exchange tube, so as to increase the exhaust space S.

[0068] In one embodiment, the distance from the middle section of the spray pipe to the explosion-proof valve 2102 is greater than or equal to 8 mm to ensure normal exhaust when the battery cell experiences thermal runaway.

[0069] The middle pipe section 1203 and the end pipe section 1201 can be transitionally connected through a transition pipe section 1202 , and the transition pipe section 1202 is a gradually inclined pipe section.

[0070] In one embodiment, the highest position of each intermediate pipe section 1203 and the highest position of each heat exchange tube are at the same horizontal plane;

[0071] Alternatively, the highest position of each intermediate pipe section 1203 is lower than the highest position of each heat exchange tube. In this way, the upward arch of the spray pipe will not take up additional height space in the z direction.

[0072] In this application, the spray pipe can be made of plastic material, such as nylon 12 (Polyamide12 or Nylon12, PA12), polyphenylene oxide (Polyphenylene Oxide, PPO), etc., which can be lightweight and, due to its lower melting point, is more easily affected by the ejected materials of the battery cell to melt through, thereby achieving a spraying effect.

[0073] In the embodiment of the present application, the spray pipe includes opposing first and second side walls 1204 and 1205. First side wall 1204 is the side wall facing explosion-proof valve 2102. With the heat exchange contact surface as a reference, first side wall 1204 and the heat exchange contact surface are located on the same side of the cooling device. Second side wall 1205 has a greater thickness than first side wall 1204. In a specific battery pack, the thickness of second side wall 1205 can be 0 mm to 0.2 mm greater than the thickness of first side wall 1204. Of course, the difference between the two can be any value within the aforementioned range. For example, in one embodiment, the difference in thickness can be 0.05 mm, 0.1 mm, 0.12 mm, 0.15 mm, 0.2 mm, etc. This makes the first side wall easier to penetrate by spraying, while the second side wall is less likely to be penetrated by spraying, without significantly reducing the mechanical strength of the spray pipe, thereby protecting the upper cover of the battery pack.

[0074] In the embodiment of the present application, the number of buses in the battery pack is not limited to one. Figure 5Only the first busbar 31 and the second busbar 32 are shown. The first busbar 31 is the main input or output electrical connection, connecting to external electrical components of the battery cell group 2. The first busbar 31 is 10 mm to 20 mm longer than the first collector 18 in the x-direction to provide space for screwing or welding.

[0075] The battery pack in the embodiment of the present application has the above-mentioned cooling device 1, so the battery pack also has the above-mentioned technical effects of the cooling device 1.

[0076] For other structures of the battery pack, please refer to the current technology, which will not be elaborated in this application.

[0077] In the description of the embodiments of the present application, the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0078] In the embodiments of this application, "and / or" is simply a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three situations: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this document generally indicates that the related objects are in an "or" relationship.

[0079] This document uses specific examples to illustrate the principles and implementation methods of this application. The description of the above examples is only intended to help understand the method and core ideas of this application. It should be noted that for those skilled in the art, without departing from the principles of this application, various improvements and modifications can be made to this application, and such improvements and modifications also fall within the scope of protection of the claims of this application.

Claims

1. A cooling device, characterized in that: include: a first manifold and a second manifold, both of which have a liquid collecting cavity; At least one connecting pipe unit, each of the connecting pipe units comprising a spray pipe and two heat exchange pipes, one end of each heat exchange pipe being in communication with the liquid collecting cavity of the first header, and the other end of each heat exchange pipe being in communication with the liquid collecting cavity of the second header; The spray pipe is located between the two heat exchange tubes, and at least one end of the spray pipe is communicated with the liquid collecting cavity of the first header or the liquid collecting cavity of the second header.

2. The cooling device according to claim 1, characterized in that The first end of the spray pipe is communicated with the liquid collecting cavity of the first collecting pipe, and the second end of the spray pipe is configured as a closed end.

3. The cooling device according to claim 1, characterized in that It also includes at least one damping channel, the first end of the spray pipe is connected to the liquid collecting chamber of the first collecting pipe, and the second end of the spray pipe is connected to the liquid collecting chamber of the second collecting pipe through the damping channel, and the total flow area of ​​all the damping channels is smaller than the flow area of ​​the opening at any end of the heat exchange tube.

4. The cooling device according to claim 3, characterized in that The outer peripheral wall of the second manifold is provided with a slot having a slot bottom wall opposite to the notch. The second end of the spray pipe is supported inside the slot, and the damping channel passes through the slot bottom wall.

5. The cooling device according to claim 3 or 4, characterized in that: At least one first partition is provided inside the liquid collecting chamber of the second collecting pipe, and the first partition divides the liquid collecting chamber of the second collecting pipe into at least two relatively independent liquid separation chambers. One of the spray pipes can be connected to the two liquid separation chambers on both sides of the first partition at the same time through the damping channel.

6. The cooling device according to any one of claims 1 to 4, characterized in that: The number of the connecting pipe units is at least N, which are arranged axially along the first collecting pipe. The first collecting pipe has a second partition inside to divide the liquid collecting cavity of the first collecting pipe into N relatively independent sub-cavities, and the heat exchange tube and the spray pipe in one of the connecting pipe units are connected to the same sub-cavity; wherein N is an integer greater than or equal to 2; the second collecting pipe is provided with a liquid inlet and a liquid outlet, the liquid inlet is used to connect to an external pressure pipeline, and the liquid outlet is used to connect to an external reflux pipeline.

7. The cooling device according to any one of claims 1 to 4, characterized in that: The heat exchange tube has a heat exchange contact surface. Along the extension direction of the spray pipe, the spray pipe includes two end pipe sections and an intermediate pipe section connected between the two end pipe sections. The intermediate pipe section arches from the center line of the end pipe sections toward the side away from the heat exchange contact surface.

8. The cooling device according to claim 7, characterized in that The highest position of each intermediate pipe section and the highest position of each heat exchange tube are on the same horizontal plane; Alternatively, the highest position of each intermediate pipe section is lower than the highest position of each heat exchange tube.

9. The cooling device according to any one of claims 1 to 4, characterized in that: The heat exchange tube has a heat exchange contact surface, and the spray pipe includes a first side wall and a second side wall opposite to each other, the first side wall and the heat exchange contact surface are located on the same side of the cooling device, and the wall thickness of the second side wall is greater than that of the first side wall; Alternatively or in addition, the spray pipe is made of plastic or aluminum.

10. A battery pack comprising at least one row of battery cell groups, each of the battery cell groups comprising a plurality of battery cells arranged along a stacking direction, characterized in that: It also includes at least one cooling device according to any one of claims 1 to 9, wherein the heat exchange tubes are located above the poles in the same column of the battery cell group, and the spray pipes are located above the explosion-proof valves of the battery cells.

11. The battery pack according to claim 10, characterized in that: The distance from the spray pipe to the explosion-proof valve is greater than or equal to 8 mm.

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