A lithium battery pack structure with high efficiency heat dissipation

Abstract

The present invention discloses a lithium battery pack structure with high efficiency in heat dissipation, and relates to the field of battery technology, which includes a structural frame, on which through holes matching the diameter of the battery core are distributed; a liquid cooling gap is formed between each column of a plurality of battery cores, and the liquid cooling structure includes a positioning plate and an intermediate liquid cooling tube, one side of the positioning plate is used to contact the negative electrode of the battery core, and the side of the positioning plate facing the negative electrode of the battery core is provided with an intermediate positioning groove along the direction of the liquid cooling gap, one end of two adjacent intermediate positioning grooves is connected by an arc groove bypassing the battery core, and an intermediate positioning groove and two connected arc grooves form an S groove, and the intermediate liquid cooling tube is arranged along the continuous S groove and extends into the liquid cooling gap; the intermediate liquid cooling tube is divided into a long tube matching the intermediate positioning groove and an end tube matching the arc groove, and the adjacent long tubes and end tubes are detachably connected; the positioning plate includes a main board provided with an intermediate positioning groove and a block board provided with an arc groove. The present application has the effect of reducing the use and maintenance costs while ensuring the heat dissipation performance of the battery pack.

Description

Technical Field

[0001] The present application relates to the technical field of storage batteries, and in particular to a lithium battery pack structure with high efficiency in heat dissipation. Background Art

[0002] As the energy storage unit of new energy vehicles, the performance and safety of lithium batteries play an important role in automobile safety. During the operation of lithium battery packs, heat is generated due to internal chemical reactions. If the heat continues to accumulate and cannot be quickly dissipated, it will affect the performance of the battery pack on the one hand, and cause safety hazards such as overheating and spontaneous combustion on the other hand. Therefore, heat dissipation design is required for lithium battery packs.

[0003] At present, common heat dissipation methods include air cooling and liquid cooling. Air cooling is to let air pass through the gaps between the battery cells to take away the heat, while liquid cooling is to send the heat to the liquid cooling structure through the heat conducting sheet and take away the heat through the circulation of the coolant. For the sake of heat dissipation efficiency and other considerations, battery packs are often equipped with liquid cooling systems. However, the maintenance requirements of liquid cooling systems are relatively high and require regular maintenance. In addition, it is difficult to find regional defects in the battery pack and it is difficult to repair. In most cases, it is recommended to replace the battery pack, resulting in excessive vehicle use costs. Therefore, this application proposes a new technical solution. Summary of the invention

[0004] In order to reduce the use and maintenance costs while ensuring the heat dissipation performance of the battery pack, the present application provides a lithium battery pack structure with efficient heat dissipation.

[0005] The present application provides a lithium battery pack structure with high efficiency in heat dissipation, which adopts the following technical solutions:

[0006] A lithium battery pack structure with high heat dissipation efficiency, comprising a liquid cooling structure and a plurality of cells distributed in an array, and also comprising a structural frame connected to an upper / lower shell of the battery pack, wherein the structural frame is provided with through holes matching the diameter of the cells, and the cells pass through the through holes;

[0007] A liquid cooling gap is formed between each row of the plurality of battery cells, the liquid cooling structure comprises a positioning plate and an intermediate liquid cooling tube, one side of the positioning plate is used to contact the negative electrode of the battery cell, and the side of the positioning plate facing the negative electrode of the battery cell is provided with an intermediate positioning groove along the direction of the liquid cooling gap, one end of two adjacent intermediate positioning grooves is connected by an arc groove bypassing the battery cell, one intermediate positioning groove and two connected arc grooves form an S groove, and the intermediate liquid cooling tube is arranged along the continuous S groove and extends into the liquid cooling gap;

[0008] The intermediate liquid cooling tube is divided into a long tube matching the intermediate positioning groove and an end tube matching the arc groove, and the adjacent long tubes and end tubes are detachably connected; the positioning plate includes a main plate provided with an intermediate positioning groove and a block plate provided with an arc groove, and the main plate and the block plate are detachably connected;

[0009] A heat-conducting silicone gasket is arranged between the intermediate liquid cooling tube and the battery core, and the heat-conducting silicone gasket is divided into a plurality of sub-units along the interface between the long tube and the end tube.

[0010] Optionally, the main board has a hollow structure and is provided with at least two liquid inlet ports and at least two liquid outlet ports, one of the liquid inlet ports is used to connect to the long tube located at the initial section of the intermediate liquid cooling tube, and one of the liquid outlet ports is used to connect to the long tube located at the end section of the intermediate liquid cooling tube; the main board is also provided with at least one air inlet port and one air outlet port.

[0011] Optionally, a notch is formed at one side of the end of the long tube facing the positioning plate, and a lap portion extends outward from the inner edge of the port of the end tube, and the lap portion is inserted into the end of the long tube through the notch.

[0012] Optionally, it further includes a temperature sensor, an air pump and a controller, wherein the detection end of the temperature sensor is built-in or contacts the intermediate liquid cooling tube, the air outlet port of the air pump is connected to the air inlet port on the mainboard, and the liquid inlet port, liquid outlet port, air inlet port and air outlet port on the mainboard for connecting the long tube are respectively provided with solenoid valves, the controller is electrically connected to the temperature sensor, the air pump and the solenoid valve, and the controller is configured as follows:

[0013] Get the temperature detection value output by the temperature sensor;

[0014] Determine whether the temperature detection value meets the liquid inlet conditions. If so, open the solenoid valve and air pump of the liquid outlet port and the air inlet port of the mainboard.

[0015] Optionally, the controller is electrically connected to a hydraulic sensor, a detection end of the hydraulic sensor extends into the intermediate liquid cooling pipe, and the controller is configured as follows:

[0016] Get the pressure detection value of the hydraulic sensor;

[0017] Determine whether the pressure detection value meets the air pump stop condition, and if so, close the solenoid valves of the air pump and the air inlet port of the mainboard;

[0018] If the current vehicle behavior data meets the preset self-test conditions, the change parameters of the pressure detection value are monitored after the air pump stops working, and a liquid cooling abnormality prompt message is output when the change parameters exceed the threshold.

[0019] Optionally, a pressure relief valve connected to the inner cavity is installed on the main board.

[0020] Optionally, the positioning plate is a heat-insulating structure at least in the portion not contacted by the intermediate liquid cooling tube.

[0021] Optionally, a filling body formed by thermally conductive silicone is filled between the thermally conductive silicone gasket and the battery core and the intermediate liquid level tube, and a baffle surrounding the intermediate liquid cooling tube is provided on the positioning plate.

[0022] To summarize, the present application includes the following beneficial technical effects: when local repairs are required, the staff can first separate the main board and the block board, then remove the main board or the block board to expose the inside, and then remove the liquid cooling pipe section that needs to be disassembled for replacement; since the entire battery cell area no longer needs to be disassembled and assembled after the application of this structure, and the liquid cooling mechanism is retained, the overall replacement of the battery pack can be reduced while ensuring the heat dissipation performance of the battery pack, thereby reducing the cost of use and maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a partial exploded schematic diagram of the present application;

[0024] Figure 2 yes Figure 1 Schematic diagram of the local structure;

[0025] Figure 3 yes Figure 1 A magnified schematic diagram of part A;

[0026] Figure 4 It is a schematic diagram of the control structure of this application.

[0027] Explanation of the reference numerals in the accompanying drawings: 1. battery cell; 2. structural frame; 3. positioning plate; 31. main board; 311. positioning groove; 32. block plate; 321. arc groove; 4. intermediate liquid cooling tube; 41. long tube; 42. end tube; 51. temperature sensor; 52. solenoid valve; 53. hydraulic sensor; 54. pressure relief valve; 6. air pump; 7. controller. DETAILED DESCRIPTION

[0028] The following is combined with Figure 1-4 This application is described in further detail.

[0029] The embodiment of the present application discloses a lithium battery pack structure with efficient heat dissipation.

[0030] Reference Figure 1 and Figure 2 The lithium battery pack structure with efficient heat dissipation includes a liquid cooling structure and multiple battery cells 1 distributed in an array. It can be understood that the electric vehicle battery pack is not limited to the above two structures, but also includes the upper / lower shell in the battery pack, the battery control system, the circulation pump group, etc. The present embodiment aims to improve the liquid cooling structure of the battery cell (indirect) contact, so this part is mainly explained, and the others are not repeated.

[0031] Since the purpose of this application is to make it easier to repair the battery pack after it is hit by a small stone or other object, causing damage to the local liquid cooling tube and the battery cell, and it is necessary to disassemble the structure near the battery cell, a structural frame 2 is also provided for overall stability to prevent the battery cell 1 from being randomly displaced during the process. The structural frame 2 is in the form of a plate in this embodiment, and is fixed to the bolt columns formed on the upper / lower shell of the battery pack by bolts; a through hole matching the diameter of the battery cell is provided on the structural frame 2, and the installed battery cell 1 passes through the through hole.

[0032] The plurality of cells 1 are arranged in an array, and the gaps between the columns are defined as slightly larger and are called liquid cooling gaps, so that the liquid cooling tubes can pass through them to accelerate heat dissipation. The liquid cooling structure includes a positioning plate 3 and an intermediate liquid cooling tube 4. The positioning plate 3 is parallel to the structural frame 2 and one side is used to contact the negative electrode of the cell. The intermediate liquid cooling tube 4 passes through the liquid cooling gap and is fixed by the positioning plate 3.

[0033] An intermediate positioning groove 311 is provided on one side of the positioning plate 3 facing the negative electrode of the battery cell along the direction of the liquid cooling gap. One end of two adjacent intermediate positioning grooves 311 is connected by an arc groove 321 that bypasses the battery cell 1. One intermediate positioning groove 311 and two connected arc grooves 321 form an S groove. The intermediate liquid cooling tube 4 is arranged along the continuous S groove and extends into the liquid cooling gap.

[0034] It should be noted that the liquid cooling tube in the attached figure has been widened for clarity. In order to save space in the battery pack, it is better for the liquid cooling tube to be a flat thin plate.

[0035] The intermediate liquid cooling tube 4 is divided into a long tube 41 matching the intermediate positioning groove 311 and an end tube 42 matching the arc groove 321, and the adjacent long tubes 41 and end tubes 42 are detachably connected; the positioning plate 3 includes a main board 31 provided with an intermediate positioning groove and a block board 32 provided with an arc groove. The main board 31 and the block board 32 are detachably connected, such as: glued or bolted. A thermally conductive silicone gasket is sandwiched between the intermediate liquid cooling tube 4 and the battery cell 1, and the thermally conductive silicone gasket is divided into multiple sub-units along the interface between the long tube 41 and the end tube 42.

[0036] According to the above arrangement, when local repairs are required, the staff can first separate the main board 31 and the block board 32, then remove the main board 31 or the block board 32 to expose the inner side, and then remove and replace the liquid cooling pipe section that needs to be removed; since the entire battery cell area no longer needs to be disassembled and assembled after the application of this structure, and the liquid cooling mechanism is retained, the overall replacement of the battery pack can be reduced while ensuring the heat dissipation performance of the battery pack, thereby reducing the cost of use and maintenance.

[0037] In this embodiment, in addition to using a thermally conductive silicone gasket to allow the battery cell 1 and the intermediate liquid cooling tube 4 to fully contact and conduct heat, a filling body formed by thermally conductive silicone (mud) is filled between the thermally conductive silicone gasket and the battery cell 1 and the intermediate liquid cooling tube 4, that is, the gap around the gap battery cell 1 is reduced to enhance the thermal conductivity effect.

[0038] The positioning plate 3 is at the bottom and the structural frame 2 is at the top; in order to prevent the thermal conductive silica gel (mud) from overflowing and polluting the environment inside the battery pack during filling, especially during secondary filling during later maintenance, a (thin) baffle (not shown in the figure) arranged around the intermediate liquid cooling tube 4 is fixed to the positioning plate 3 by bolts.

[0039] The position setting of the positioning plate 3 and the structural frame 2 is not only for the convenience of setting the above-mentioned baffle, but also for cooperating with other structural designs, which is explained in another embodiment of the present application.

[0040] Reference Figure 3 In one embodiment of the present application, in order to facilitate the installation and disassembly of the long tube 41 and the end tube 42, a notch is formed at the end of the long tube 41 facing the positioning plate 3, and a lap portion extends outward from the inner edge of the port of the end tube 42, and the lap portion is inserted into the end of the long tube 41 through the notch.

[0041] To enhance the sealing performance, a sealing ring may be provided on the overlapped part or sealant may be applied.

[0042] Reference Figure 1 and Figure 2 In another embodiment of the present application, the main board 31 is a hollow structure and is provided with at least two liquid inlet ports and at least two liquid outlet ports. This embodiment takes two as an example. One liquid inlet port is formed in the positioning groove 311 and is inserted by the tube head formed on the long tube 41 located at the initial section of the intermediate liquid cooling tube 4. A sealing ring is arranged on the outer surface of the tube head to increase the sealing effect; the other liquid inlet port is exposed to the outside and is used to connect the liquid outlet pipe of the liquid cooling circulation pump group. Another tube head is formed on one liquid outlet port and is used to connect the long tube 41 located at the end section of the intermediate liquid cooling tube 4. There are at least one air inlet port and one air outlet port at both ends of the main board 31.

[0043] According to the above arrangement, in one usage mode, the structure is inverted, so that the coolant can be stored in the main board 31. When in use, air is inflated into the main board 31 to squeeze out the liquid into the intermediate liquid cooling tube 4. This method can reduce the probability of coolant leakage from the joints of the intermediate liquid cooling tubes 4; after all, when it is hot, the metal expansion and the sealing ring can strengthen the seal of the joint, but the sealing is weakened when the temperature is too low (one reason for the leakage of antifreeze in some vehicles); in another usage mode, the liquid-cooled coolant is stored independently, and the air-cooled cycle is selected when the ambient temperature is low, and the coolant enters the liquid-cooled cycle when the ambient temperature is high; in this method, each port should have an electric valve for easy control. This method can extend the service life of the liquid cooling system, and the heat dissipation is relatively good. After all, the main defect of air cooling is poor heat dissipation when the ambient temperature is high.

[0044] Reference Figure 4 In another embodiment of the present application, the first method is used. Specifically, the present application further includes a temperature sensor 51, an air pump 6 and a controller 7, wherein the detection end of the temperature sensor 51 is built in or contacts the intermediate liquid cooling tube 4, the air outlet port of the air pump 6 is connected to the air inlet port on the main board 31 through a pipeline, and the main board 31 is used to connect the liquid inlet port and the liquid outlet port of the long tube 41. The connected pipelines are respectively provided with a solenoid valve 52. The controller 7 can directly adopt the vehicle controller and the battery pack control system and is electrically connected to the temperature sensor 51, the air pump 6 and the solenoid valve 52.

[0045] The controller 7 is configured as follows:

[0046] Obtaining a temperature detection value output by the temperature sensor 51;

[0047] It is determined whether the temperature detection value meets the liquid inlet condition. If so, the liquid outlet port of the main board 31, the electromagnetic valve 52 of the air inlet port and the air pump 6 are opened.

[0048] Example: When the vehicle is started and the temperature rises to 40°C, the air pump 6 is turned on to allow gas to enter the mainboard 31 to squeeze out the internal coolant, so that it enters the intermediate liquid cooling pipe 4 from the opened solenoid valve 52 to start the liquid cooling cycle to quickly dissipate heat. Under this premise, if the vehicle stops working, the solenoid valves 52 at the liquid inlet port and the gas outlet port of the mainboard 31 are opened to allow the coolant to flow back into the mainboard 31.

[0049] Furthermore, the controller 7 is electrically connected to a hydraulic sensor 53, the detection end of the hydraulic sensor 53 extends into the intermediate liquid cooling pipe 4, and the controller 7 is configured as follows:

[0050] Get the pressure detection value of the hydraulic sensor;

[0051] Determine whether the pressure detection value meets the air pump stop condition, for example: whether the set pressure when the coolant injection is completed is reached. If so, close the solenoid valve 52 of the air pump 6 and the air inlet port of the main board 31 to stop supplying air into the main board 31.

[0052] If the current vehicle behavior data meets the preset self-test conditions, for example, the vehicle is started and the ambient temperature does not exceed the preset high temperature threshold, the change parameters of the pressure detection value are monitored after the air pump 6 stops working, and a liquid cooling abnormality prompt message is output when the change parameters exceed the threshold.

[0053] It is understandable that vehicle behavior data can be obtained from the vehicle system. The principle of the above setting is: because the pumping of coolant is stopped when the pressure reaches the standard, the hydraulic pressure in the liquid cooling cycle is theoretically relatively constant; once leakage caused by pipeline damage occurs during the liquid cooling cycle, the hydraulic pressure will gradually decrease, so the change in hydraulic pressure can be used to evaluate and diagnose whether there is a liquid cooling abnormality.

[0054] For safety reasons, under the above premise, a pressure relief valve 54 connected to the inner cavity is installed for the mainboard 31 to prevent safety accidents caused by abnormal opening and closing of the air pump 6 and the solenoid valve 52.

[0055] In another embodiment of the present application, the positioning plate 3 is a heat-insulating structure at least in the portion not contacted by the intermediate liquid cooling tube 4, for example, a heat-insulating coating is applied on the surface of the positioning plate 3 or the entire structure is made of a heat-insulating material.

[0056] The above functions are: 1. To prevent the battery pack from overheating and the air thermal pressure in the mainboard 31 from being too large. The above pressure relief valve 54 is also used in consideration of this situation; 2. The battery cell 1 is in direct contact with the positioning plate 3. If the thermal conductivity is good, then when the coolant exits the intermediate liquid cooling tube 4 and enters the mainboard 31, it will be easy for the residual heat of the coolant to be continuously transferred to the battery cell 1.

[0057] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A lithium battery pack structure with high heat dissipation efficiency, comprising a liquid cooling structure and a plurality of battery cells (1) distributed in an array, characterized in that: It also comprises a structural frame (2) connected to the upper / lower shell of the battery pack, the structural frame (2) being provided with through holes matching the diameter of the battery cell (1), and the battery cell (1) passing through the through holes; A liquid cooling gap is formed between each row of the plurality of battery cells (1), the liquid cooling structure comprising a positioning plate (3) and an intermediate liquid cooling tube (4), one side of the positioning plate (3) being used to contact the negative electrode of the battery cell (1), an intermediate positioning groove (311) being provided on the side of the positioning plate (3) facing the negative electrode of the battery cell (1) along the direction of the liquid cooling gap, one end of two adjacent intermediate positioning grooves (311) being connected to each other by bypassing an arc groove (321) of the battery cell (1), one intermediate positioning groove (311) and two connected arc grooves (321) forming an S groove, and the intermediate liquid cooling tube (4) being arranged along the continuous S groove and extending into the liquid cooling gap; The intermediate liquid cooling tube (4) is divided into a long tube (41) matching the intermediate positioning groove (311) and an end tube (42) matching the arc groove (321), and the adjacent long tube (41) and end tube (42) are detachably connected; the positioning plate (3) comprises a main plate (31) provided with the intermediate positioning groove (311) and a block plate (32) provided with the arc groove (321), and the main plate (31) and the block plate (32) are detachably connected; A heat-conducting silicone gasket is provided between the intermediate liquid cooling tube (4) and the battery core (1), and the heat-conducting silicone gasket is divided into a plurality of sub-units along the interface between the long tube (41) and the end tube (42).

2. The lithium battery pack structure with high efficiency heat dissipation according to claim 1, characterized in that: The main board (31) is of a hollow structure and is provided with at least two liquid inlet ports and at least two liquid outlet ports, one of the liquid inlet ports being used to connect to a long tube (41) located at an initial section of the intermediate liquid cooling tube (4), and one of the liquid outlet ports being used to connect to a long tube (41) located at an end section of the intermediate liquid cooling tube (4); the main board (31) is also provided with at least one air inlet port and one air outlet port.

3. The lithium battery pack structure with high efficiency heat dissipation according to claim 2, characterized in that: A notch is formed on one side of the end of the long tube (41) facing the positioning plate (3), and a lap portion extends outwardly from the inner edge of the port of the end tube (42), the lap portion being inserted into the end of the long tube (41) through the notch.

4. The lithium battery pack structure with high efficiency heat dissipation according to claim 3, characterized in that: It also includes a temperature sensor (51), an air pump (6) and a controller (7); a detection end of the temperature sensor (51) is built into or contacts the intermediate liquid cooling tube (4); an air outlet port of the air pump (6) is connected to an air inlet port on the main board (31); a liquid inlet port, a liquid outlet port, an air inlet port and an air outlet port on the main board (31) for connecting to the long tube (41) are respectively provided with electromagnetic valves (52); the controller (7) is electrically connected to the temperature sensor (51), the air pump (6) and the electromagnetic valve (52); and the controller (7) is configured as follows: Obtaining a temperature detection value output by a temperature sensor (51); It is determined whether the temperature detection value meets the liquid inlet condition. If so, the liquid outlet port of the main board (31), the electromagnetic valve (52) of the air inlet port and the air pump (6) are opened.

5. The lithium battery pack structure with high efficiency heat dissipation according to claim 4, characterized in that: The controller (7) is electrically connected to a hydraulic sensor (53), a detection end of the hydraulic sensor (53) extends into the intermediate liquid cooling pipe (4), and the controller (7) is configured as follows: Obtaining a pressure detection value of a hydraulic pressure sensor (53); Determine whether the pressure detection value meets the stop condition of the air pump (6), and if so, close the solenoid valve (52) of the air inlet port of the air pump (6) and the main board (31); If the current vehicle behavior data meets the preset self-checking conditions, the change parameter of the pressure detection value is monitored after the air pump (6) stops working, and when the change parameter exceeds the threshold value, a liquid cooling abnormality prompt message is output.

6. The lithium battery pack structure with high efficiency heat dissipation according to claim 1, characterized in that: A pressure relief valve (54) communicating with the inner cavity is mounted on the main board (31).

7. The lithium battery pack structure with high efficiency heat dissipation according to claim 6, characterized in that: The positioning plate (3) is a heat-insulating structure at least in the portion not contacted by the intermediate liquid cooling tube (4).

8. The lithium battery pack structure with high efficiency heat dissipation according to claim 6, characterized in that: A filling body formed of thermally conductive silica gel is filled between the thermally conductive silica gel gasket, the battery core (1) and the intermediate liquid cooling tube (4), and a baffle surrounding the intermediate liquid cooling tube (4) is provided on the positioning plate (3).

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