Battery thermal management system and method

Abstract

A battery thermal management system and method. The battery thermal management system comprises: a top-bottom liquid cooling plate for exchanging heat with a battery, a first liquid cooling device for performing liquid cooling on the battery in a non-overcharge state, and a second liquid cooling device for performing liquid cooling on the battery in an overcharge state, wherein one end of the first liquid cooling device and one end of the second liquid cooling device are communicated with a first flow channel opening of a liquid cooling flow channel, and the other end of the first liquid cooling device and the other end of the second liquid cooling device are communicated with a second flow channel opening of the liquid cooling flow channel.

Description

Battery thermal management system and method

[0001] This application claims priority to Chinese Patent Application No. 202422408561.7 and 202411388918.8, filed on September 30, 2024, with the Chinese Patent Office, the contents of which are incorporated herein by reference in their entirety. TECHNICAL FIELD

[0002] The present application relates to the technical field of batteries, in particular to a battery thermal management system and method. BACKGROUND

[0003] Battery thermal management system (BTMS) is a crucial component in new energy vehicles. Its main function is to form a closed-loop regulation system through heat-conducting media, control units, and temperature control equipment, so that the power battery works within the appropriate temperature range to maintain its optimal use state. The temperature of the battery has a significant impact on its performance, lifespan, and safety. SUMMARY

[0004] However, during the thermal management of the battery by the battery thermal management system, the battery has a temperature that is too high and a temperature difference that is too large, resulting in poor safety and low reliability of the battery system.

[0005] The present application provides a battery thermal management system and method, which can avoid excessive temperature and excessive temperature difference during battery charging, ensure that the battery temperature during the overcharging process is within a safe range, and improve the reliability of the battery.

[0006] In a first aspect, the present application provides a battery thermal management system, comprising:

[0007] A top-bottom liquid cooling plate is provided with a liquid cooling flow channel, which includes a first flow channel opening and a second flow channel opening. The top-bottom liquid cooling plate exchanges heat with the battery pack.

[0008] A first liquid cooling device is connected to the first flow channel opening at one end and to the second flow channel opening at the other end.

[0009] A second liquid cooling device is connected to the first flow channel opening at one end and to the second flow channel opening at the other end.

[0010] The first liquid cooling device is configured to at least liquid cool the battery pack in a non-overcharging state, and the second liquid cooling device is configured to at least liquid cool the battery pack in an overcharging state.

[0011] In a second aspect, the application provides a battery thermal management method applied to a battery thermal management system, the battery thermal management system comprising a top-bottom liquid cooling plate, a first liquid cooling device and a second liquid cooling device, the first liquid cooling device; the method comprising:

[0012] obtaining a current working state of the battery pack;

[0013] if the working state is a charging state, determining whether the battery pack is in an overcharging state;

[0014] if the battery pack is in a non-overcharging state, using the first liquid cooling device to control heat exchange between the top-bottom liquid cooling plate and the battery pack to perform liquid cooling on the battery pack;

[0015] if the battery pack is in an overcharging state, using the second liquid cooling device to control heat exchange between the top-bottom liquid cooling plate and the battery pack to perform liquid cooling on the battery pack. Advantages

[0016] The battery thermal management system provided by the application comprises a top-bottom liquid cooling plate, a first liquid cooling device and a second liquid cooling device, the top-bottom liquid cooling plate is provided with a liquid cooling flow channel, the liquid cooling flow channel comprises a first flow channel opening and a second flow channel opening, the top-bottom liquid cooling plate exchanges heat with the battery pack, one end of the first liquid cooling device is communicated with the first flow channel opening, the other end of the first liquid cooling device is communicated with the second flow channel opening, one end of the second liquid cooling device is communicated with the first flow channel opening, the other end of the second liquid cooling device is communicated with the second flow channel opening, the first liquid cooling device is configured to perform liquid cooling on at least the battery in a non-overcharging state, and the second liquid cooling device is configured to perform liquid cooling on at least the battery pack in an overcharging state, so that the temperature of the battery pack during charging can be prevented from being too high and the temperature difference can be prevented from being too large, the temperature of the battery pack during overcharging can be ensured to be within a safe range, and the reliability of the battery is improved.

[0017] The battery thermal management method provided by the application comprises the following steps: after obtaining a current working state of the battery pack, if the working state is a charging state, determining whether the battery pack is in an overcharging state; if the battery pack is in a non-overcharging state, using the first liquid cooling device to control heat exchange between the top-bottom liquid cooling plate and the battery pack to perform liquid cooling on the battery pack; and if the battery pack is in an overcharging state, using the second liquid cooling device to control heat exchange between the top-bottom liquid cooling plate and the battery pack to perform liquid cooling on the battery pack, so that the temperature of the battery during charging can be prevented from being too high and the temperature difference can be prevented from being too large, the temperature of the battery during overcharging can be ensured to be within a safe range, and the reliability of the battery is improved. BRIEF DESCRIPTION OF DRAWINGS

[0018] FIG. 1 is a schematic block diagram of the battery thermal management system provided by the application;

[0019] FIG. 2 is a flowchart of the battery thermal management method provided by the application.

[0020] Reference signs:

[0021] 100, battery pack; 200, top-bottom liquid cooling plate; 201, first liquid cooling plate; 202, second liquid cooling plate; 300, first liquid cooling device; 400, second liquid cooling device; 500, liquid cooling socket; 600, liquid pouring pot; T1, first three-way valve; T2, second three-way valve; T3, third three-way valve; T4, fourth three-way valve; T5, first three-way joint; T6, second three-way joint. Embodiments of the application

[0022] In related technologies, in order to shorten the charging time of an electric vehicle, a battery is usually equipped with a fast charging mode and an ultra-fast charging mode (super-fast charging mode). Among them, when the battery is in the fast charging mode, a vehicle-mounted air conditioning system can be added to the thermal management system to assist in cooling the battery; when the battery is in the ultra-fast charging mode, it requires a lower water inlet temperature of the liquid cooling plate where the battery is located, and a larger flow rate is required.

[0023] However, after adding the vehicle-mounted air conditioning system to the thermal management system to assist in cooling the battery, the water inlet temperature of the liquid cooling plate cannot be reduced to the preset temperature, and the flow rate cannot meet the requirements, thereby causing the battery thermal management system to be unable to effectively reduce the temperature of the battery when the battery is in the ultra-fast charging mode, resulting in a large temperature difference of the battery, thereby affecting the service life of the battery.

[0024] Therefore, the present application provides a battery thermal management method and system, which can avoid high temperature and large temperature difference during battery charging, can ensure that the battery temperature during the ultra-fast charging process is within a safe range, and improves the reliability of the battery.

[0025] Please refer to FIG. 1, which is a schematic block diagram of the battery thermal management system provided by the present application. As shown in FIG. 1, the present application provides a battery thermal management system, which comprises:

[0026] The top-bottom liquid cooling plate 200 is provided with a liquid cooling flow channel, the liquid cooling flow channel comprises a first flow channel port and a second flow channel port, and the top-bottom liquid cooling plate 200 exchanges heat with the battery pack 100;

[0027] The first liquid cooling device 300 is connected to the first flow channel port at one end, and connected to the second flow channel port at the other end;

[0028] The second liquid cooling device 400 is connected to the first flow channel port at one end, and connected to the second flow channel port at the other end;

[0029] The first liquid cooling device 300 is configured to at least liquid cool the battery pack 100 in a non-super charging state, and the second liquid cooling device 400 is configured to at least liquid cool the battery pack 100 in a super charging state.

[0030] In the embodiment, the first liquid cooling device 300 can be a liquid cooling device at the vehicle end, that is, the first liquid cooling device 300 can be a liquid cooling device on an electric vehicle; and the second liquid cooling device 400 can be a liquid cooling device at the non-vehicle end, that is, the second liquid cooling device 400 can be a liquid cooling device arranged at a charging station.

[0031] Therefore, the liquid cooling power of the first liquid cooling device 300 is much smaller than that of the second liquid cooling device 400, and the second liquid cooling device 400 can rapidly reduce the temperature of the battery pack 100, so as to ensure that the temperature of the battery pack 100 in the super charging process is within a safe range, thereby improving the reliability of the battery pack 100.

[0032] Meanwhile, the first liquid cooling device 300 can be provided with a water pump, a heat exchange device and a heater. Similarly, the second liquid cooling device 400 can also be provided with the first liquid cooling device 300, but the liquid cooling power of the second liquid cooling device 400 needs to be much greater than that of the first liquid cooling device 300.

[0033] Specifically, the battery pack 100 mentioned in the present application can be understood as a battery pack 100, and the battery pack 100 is liquid cooled in a top and bottom liquid cooling manner. The top and bottom liquid cooling technology realizes efficient temperature control by installing liquid cooling plates on the top and bottom of the battery pack 100, and using forced convection of the cooling liquid in the channel to take away heat.

[0034] In the first liquid cooling device 300, the temperature at the liquid inlet of the top and bottom liquid cooling plate 200 can be 15℃ under normal circumstances, and the liquid cooling flow rate can be 10L / min; in the second liquid cooling device 400, the temperature at the liquid inlet of the top and bottom liquid cooling plate 200 can be 10℃ under normal circumstances, and the liquid cooling flow rate can be 20L / min.

[0035] It should be noted that the reason why the second liquid cooling device 400 is added to the thermal management system is that after the battery pack 100 is liquid cooled in the top and bottom liquid cooling manner, the battery pack 100 is configured with a super charging mode (4C high-rate charging mode), but it is found that the top and bottom liquid cooling manner cannot control the temperature and temperature difference of the battery pack 100 within a safe range, so the vehicle-mounted air conditioning system is added to assist in cooling the battery pack 100.

[0036] However, the addition of the vehicle-mounted air conditioning system to assist in cooling the battery pack 100 still cannot control the temperature and temperature difference of the battery pack 100 within a safe range, so the second liquid cooling device 400 is added to the thermal management system, and the second liquid cooling device 400 is configured to at least liquid cool the battery pack 100 in the supercharging state.

[0037] In addition, the non-supercharging state mentioned in the present application can be that the battery pack 100 is in a fast charging state, or the battery pack 100 is in a normal charging state, or the battery pack 100 is in a discharging state (for example, the vehicle in which the battery pack 100 is located is in a driving state).

[0038] The battery thermal management system provided by the present application comprises a top-bottom liquid cooling plate 200, a first liquid cooling device 300 and a second liquid cooling device 400. The top-bottom liquid cooling plate 200 is provided with a liquid cooling flow channel, and the liquid cooling flow channel comprises a first flow channel opening and a second flow channel opening. The top-bottom liquid cooling plate 200 exchanges heat with the battery pack 100. One end of the first liquid cooling device 300 communicates with the first flow channel opening, and the other end of the first liquid cooling device 300 communicates with the second flow channel opening. One end of the second liquid cooling device 400 communicates with the first flow channel opening, and the other end of the second liquid cooling device 400 communicates with the second flow channel opening. The first liquid cooling device 300 is configured to at least liquid cool the battery pack 100 in a non-supercharging state, and the second liquid cooling device 400 is configured to at least liquid cool the battery pack 100 in a supercharging state. This can avoid excessive temperature and excessive temperature difference of the battery pack 100 during charging, and can ensure that the temperature of the battery pack 100 during supercharging is within a safe range, thereby improving the reliability of the battery pack 100.

[0039] In some embodiments, as shown in FIG. 1, the battery thermal management system further comprises a first three-way valve T1 and a second three-way valve T2. The first end 1 of the first three-way valve T1 communicates with the first flow channel opening, the second end 2 of the first three-way valve T1 communicates with one end of the first liquid cooling device 300, and the third end 3 of the first three-way valve T1 communicates with one end of the second liquid cooling device 400. The first end 1 of the second three-way valve T2 communicates with the other end of the first liquid cooling device 300, the second end 2 of the second three-way valve T2 communicates with the second flow channel opening, and the third end 3 of the second three-way valve T2 communicates with the other end of the second liquid cooling device 400.

[0040] In the present embodiment, the first three-way valve T1 and the second three-way valve T2 can isolate the first liquid cooling device 300 and the second liquid cooling device 400 in waterway, so that the first liquid cooling device 300 can independently liquid cool the battery pack 100 when the battery pack 100 is in a non-supercharging state, and the second liquid cooling device 400 can independently liquid cool the battery pack 100 when the battery pack 100 is in a supercharging state.

[0041] Specifically, when the battery pack 100 is in a non-supercharging state, the first end 1 and the third end 3 of the first three-way valve T1 are communicated, the first end 1 and the second end 2 of the first three-way valve T1 are not communicated, the first end 1 and the second end 2 of the second three-way valve T2 are communicated, and the second end 2 and the third end 3 of the second three-way valve T2 are not communicated, so that the first liquid cooling device 300 can be used to independently liquid cool the battery pack 100; when the battery pack 100 is in a supercharging state, the first end 1 and the third end 3 of the first three-way valve T1 are not communicated, the first end 1 and the second end 2 of the first three-way valve T1 are communicated, the first end 1 and the second end 2 of the second three-way valve T2 are not communicated, and the second end 2 and the third end 3 of the second three-way valve T2 are communicated, so that the first liquid cooling device 300 can be used to independently liquid cool the battery pack 100. The first three-way valve T1 and the second three-way valve T2 can be controlled by the battery pack 100 management system of the battery pack 100.

[0042] In some embodiments, as shown in FIG. 1, the battery thermal management system further comprises a liquid cooling socket 500; wherein the first end of the liquid cooling socket 500 is communicated with the third end 3 of the first three-way valve T1, the second end of the liquid cooling socket 500 is communicated with the third end 3 of the second three-way valve T2, the third end of the liquid cooling socket 500 is communicated with one end of the second liquid cooling device 400, and the fourth end of the liquid cooling socket 500 is communicated with the other end of the second liquid cooling device 400; the first end and the third end of the liquid cooling socket 500 are communicated, and the second end and the fourth end of the liquid cooling socket 500 are communicated.

[0043] In this embodiment, the liquid cooling socket 500 can be installed in the automobile body. When the battery pack 100 needs to be supercharged, the second liquid cooling device 400 can be communicated through the liquid cooling socket 500, so that the second liquid cooling device 400 can liquid cool the battery pack 100 in the supercharging state, thereby ensuring that the temperature and temperature difference of the battery pack 100 in the supercharging state are within a safe range.

[0044] The liquid cooling socket 500 is a charging socket that uses liquid cooling technology and is configured in the charging system of an electric vehicle. The liquid cooling socket 500 reduces the temperature during charging through cooling liquid, thereby improving charging efficiency and safety. The advantage of the liquid cooling socket 500 is that it can effectively reduce the temperature during charging, thereby reducing the demand for cable cross-sectional area, reducing the weight of the plug and cable, and improving operational convenience.

[0045] In addition, the liquid cooling socket 500 can also help the charging pile to stably reach a higher charging power. For example, in high-power charging, the liquid cooling socket 500 can make the charging power stably reach 500 kW, and even reach 700 kW for a short time.

[0046] In some embodiments, as shown in FIG. 1, the top-bottom liquid cooling plate 200 includes a first liquid cooling plate 201 and a second liquid cooling plate 202, and the liquid cooling flow channel includes a first liquid cooling flow channel and a second liquid cooling flow channel; wherein the first liquid cooling flow channel is arranged in the first liquid cooling plate 201, and the second liquid cooling flow channel is arranged in the second liquid cooling plate 202; one end of the first liquid cooling flow channel and one end of the second liquid cooling flow channel are connected to the first flow channel port by a first three-way joint T5, and the other end of the first liquid cooling flow channel and the other end of the second liquid cooling flow channel are connected to the second flow channel port by a second three-way joint T6.

[0047] In this embodiment, the first liquid cooling plate 201 and the second liquid cooling plate 202 can be respectively located on the corresponding two sides of the battery pack 100. Specifically, the first liquid cooling plate 201 can be arranged at the top of the battery pack 100, and the second liquid cooling plate 202 can be arranged at the bottom of the battery pack 100, so as to realize the liquid cooling of the battery pack 100 in a top-bottom liquid cooling mode.

[0048] At the same time, in order to ensure that the battery pack 100 can realize top-bottom liquid cooling, one end of the first liquid cooling flow channel and one end of the second liquid cooling flow channel are connected to the first flow channel port by a first three-way joint T5, and the other end of the first liquid cooling flow channel and the other end of the second liquid cooling flow channel are connected to the second flow channel port by a second three-way joint T6.

[0049] Specifically, the first end 1 of the first three-way joint T5 is connected to one end of the first liquid cooling flow channel, the second end 2 of the first three-way joint T5 is connected to one end of the second liquid cooling flow channel, and the third end 3 of the first three-way joint T5 is connected to the first flow channel port; the first end 1 of the second three-way joint T6 is connected to the other end of the first liquid cooling flow channel, the second end 2 of the second three-way joint T6 is connected to the other end of the second liquid cooling flow channel, and the third end 3 of the second three-way joint T6 is connected to the second flow channel port.

[0050] In some embodiments, the liquid cooling flow rate of the first liquid cooling flow channel is less than the liquid cooling flow rate of the second liquid cooling flow channel.

[0051] In this embodiment, the first liquid cooling plate 201 is arranged at the top of the battery pack 100, and the second liquid cooling plate 202 is arranged at the bottom of the battery pack 100, which can make the battery pack 100 achieve better liquid cooling effect, but this mode can cause the cooling effect of the top of the battery pack 100 to be better, and the cooling effect of the bottom of the battery pack 100 to be poor, thereby causing a large temperature difference between the top and the bottom.

[0052] For example, if the first liquid cooling plate 201 is a stamping liquid cooling plate and the second liquid cooling plate 202 is an extrusion liquid cooling plate, and the liquid cooling effect of the stamping liquid cooling plate is better than that of the extrusion liquid cooling plate, which will cause the cooling effect of the top of the battery pack 100 to be better, and the cooling effect of the bottom of the battery pack 100 to be poor, thereby causing a large temperature difference between the top and the bottom.

[0053] To this end, the first liquid cooling flow channel needs to be set to have a smaller liquid cooling flow rate than the second liquid cooling flow channel. Specifically, the liquid cooling flow rate ratio between the first liquid cooling flow channel and the second liquid cooling flow channel can be 3:7.

[0054] In some embodiments, in the process of realizing that the liquid cooling flow rate of the first liquid cooling flow channel is smaller than that of the second liquid cooling flow channel, the inner diameter of the first end 1 of the first tee joint T5 can be set to be smaller than that of the second end 2 of the first tee joint T5, and the inner diameter of the first end 1 of the second tee joint T6 can be set to be smaller than that of the second end 2 of the second tee joint T6.

[0055] It should be noted that setting the liquid cooling flow rate of the first liquid cooling flow channel to be smaller than that of the second liquid cooling flow channel can be selected according to actual application, and the present application does not make specific limitation.

[0056] For example, the first tee joint T5 and the second tee joint T6 can be replaced by a tee valve to realize.

[0057] In some embodiments, the first liquid cooling plate 201 comprises a punched liquid cooling plate, and the second liquid cooling plate 202 comprises an extruded liquid cooling plate.

[0058] Specifically, the liquid cooling plate usually configured by the battery pack 100 adopts a punched liquid cooling plate. Since the top and bottom liquid cooling method is adopted in the present application, the bottom of the battery pack 100 cannot be stressed, so the liquid cooling plate at the bottom of the battery pack 100 needs to be configured as an extruded liquid cooling plate.

[0059] The punched liquid cooling plate is a kind of liquid cooling plate manufactured by punching process, which is usually configured to manufacture cooling plates with simple shapes. Among them, the punched liquid cooling plate has the advantages of arbitrary design of flow channel, large contact area, good heat exchange effect, high production efficiency, good pressure resistance and strength, etc. At the same time, in the manufacturing process, the punched liquid cooling plate needs to be degreased to remove surface dirt and impurities, so as to ensure that the punched liquid cooling plate can play the best performance in the use process.

[0060] The extruded liquid cooling plate is a product combining extrusion technology and liquid cooling technology, which is configured for occasions that need efficient heat dissipation and heat preservation. The extruded liquid cooling plate can combine the heat preservation performance of the extruded plate with the heat dissipation performance of the liquid cooling plate, and be configured in application scenarios that need to have efficient heat dissipation and heat preservation at the same time.

[0061] In some embodiments, the battery thermal management system further comprises an exhaust assembly; one end of the exhaust assembly is respectively communicated with the first flow channel port and one end of the first liquid cooling device 300, and the other end of the exhaust assembly is communicated with the outside.

[0062] Specifically, the application can further be provided with an exhaust assembly at the first flow passage opening, so as to facilitate the exhaust of air in the pipeline, thereby improving the liquid cooling effect of the top and bottom liquid cooling.

[0063] Since the liquid cooling power of the second liquid cooling device 400 is much greater than that of the first liquid cooling device 300, the exhaust assembly can be arranged in the vehicle and used in cooperation with the first liquid cooling device 300, thereby improving the liquid cooling effect of the first liquid cooling device 300.

[0064] In some embodiments, as shown in FIG. 1, the exhaust assembly includes an exhaust pipe and a third three-way valve T3; wherein the first end 1 of the third three-way valve T3 is connected to the first flow passage opening, the second end 2 of the third three-way valve T3 is connected to one end of the first liquid cooling device 300, the third end 3 of the third three-way valve T3 is connected to one end of the exhaust pipe, and the other end of the exhaust pipe is connected to the outside.

[0065] In this embodiment, by arranging the third three-way valve T3 at the first flow passage opening and one end of the first liquid cooling device 300, the first end 1 and the third end 3 of the third three-way valve T3 are connected when the pipeline needs to be exhausted, and the first end 1 and the second end 2 of the third three-way valve T3 are connected and the first end 1 and the third end 3 of the third three-way valve T3 are not connected when the pipeline does not need to be exhausted.

[0066] In some embodiments, as shown in FIG. 1, the exhaust assembly further includes a liquid injection pot 600 and a fourth three-way valve T4; wherein the liquid injection pot 600 is connected to the first end 1 of the fourth three-way valve T4, the second end 2 of the fourth three-way valve T4 is connected to the second end 2 of the third three-way valve T3, the third end 3 of the fourth three-way valve T4 is connected to one end of the first liquid cooling device 300, and the other end of the exhaust pipe is connected to the outside through the liquid injection pot 600.

[0067] Specifically, the application can further be provided with a fourth three-way valve T4 between the third three-way valve T3 and the first liquid cooling device 300, and a liquid injection pot 600 between the third three-way valve T3 and the fourth three-way valve T4, which can not only avoid the reduction of cooling liquid during the exhaust process of the pipeline, but also facilitate the liquid supplement of the pipeline.

[0068] In this embodiment, the first end 1 and the third end 3 of the third three-way valve T3 are connected when the pipeline needs to be exhausted. When the first liquid cooling device 300 is used to liquid cool the battery pack 100 and the pipeline needs to be exhausted, the first end 1 and the third end 3 of the third three-way valve T3 are connected, and the first end 1 and the second end 2 of the fourth three-way valve T4 are connected. The first end 1 and the second end 2 of the third three-way valve T3 can be connected or not connected; the second end 2 of the fourth three-way valve T4 can be connected or not connected.

[0069] It should be noted that the third three-way valve T3 and the fourth three-way valve T4 can also be provided as a three-way joint, which can also achieve the purpose of the first liquid cooling device 300 liquid cooling the battery pack 100 and exhausting the pipeline.

[0070] In addition, when the pipeline needs to be exhausted, the first end 1 and the third end 3 of the third three-way pipe can be communicated.

[0071] In some embodiments, referring to FIG. 2, FIG. 2 is a flowchart of a battery thermal management method provided by the present application. The battery thermal management method can be executed by a battery management system.

[0072] As shown in FIG. 2, the method comprises steps S110-S140.

[0073] S110, obtaining the current working state of the battery pack 100.

[0074] Specifically, the current working state of the battery pack 100 can be obtained by the battery management system of the battery pack 100, which can be identified and judged by collecting the charge and discharge of the battery pack 100, and then the current working state of the battery pack 100 can be obtained. The working state of the battery pack 100 includes the charging state and the discharging state.

[0075] In some embodiments, after step S110, the method further comprises the steps of: if the working state is the discharging state, determining whether the vehicle in which the battery pack 100 is located is in the driving state; if the vehicle is in the driving state, using the first liquid cooling device 300 to control the heat exchange of the top and bottom liquid cooling plates 200 and the battery pack 100 to liquid cool the battery pack 100.

[0076] In this embodiment, the working state of the battery pack 100 also includes the discharging state. Since the battery pack 100 generates heat when discharging, the temperature of the battery pack 100 will rise.

[0077] Therefore, when the current working state of the battery pack 100 is obtained and it is determined that the working state is the discharging state, the thermal management system needs to be started to manage the battery pack 100, so as to ensure that the temperature of the battery pack 100 is within a safe range during discharging.

[0078] At the same time, the battery pack 100 mentioned in the present application is installed in the vehicle. After it is determined that the battery pack 100 is in the discharging state, it is also necessary to determine whether the vehicle in which the battery pack 100 is located is in the driving state. If the vehicle is in the driving state, the flow rate and temperature of the liquid inlet of the top and bottom liquid cooling plates 200 can be controlled at this time to ensure that the temperature and temperature difference of the battery pack 100 are within a safe range.

[0079] S120, if the working state is the charging state, determine whether the battery pack 100 is in the overcharging state.

[0080] In the embodiment, when the battery pack 100 is in the charging state, it can be in the ordinary charging state, or in the fast charging state, or in the overcharging state. When the battery pack 100 is in the fast charging state, the heat generated by the battery pack 100 is higher than that in the ordinary charging state, and the first liquid cooling device 300 can be used to control the heat exchange between the top and bottom liquid cooling plates 200 and the battery pack 100 to liquid cool the battery pack 100; when the battery pack 100 is in the overcharging state, the heat generated by the battery pack 100 is higher than that in the fast charging state, and if the first liquid cooling device 300 is used to control the heat exchange between the top and bottom liquid cooling plates 200 and the battery pack 100, it cannot guarantee that the temperature and temperature difference of the battery pack 100 are within the safe range.

[0081] Therefore, when it is determined that the battery pack 100 is in the charging state, it is also necessary to determine whether the battery pack 100 is in the overcharging state to ensure that the temperature and temperature difference of the battery pack 100 during the charging process are within the safe range.

[0082] S130, if the battery pack 100 is in the non-overcharging state, the first liquid cooling device 300 is used to control the heat exchange between the top and bottom liquid cooling plates 200 and the battery pack 100 to liquid cool the battery pack 100.

[0083] In the embodiment, the non-overcharging state includes the fast charging state and the ordinary charging state. When the battery pack 100 is in the non-overcharging state, the first liquid cooling device 300 can be used to control the flow rate and temperature of the liquid inlet of the top and bottom liquid cooling plates 200, so that the liquid in the top and bottom liquid cooling plates 200 can fully liquid cool the battery pack 100, thereby ensuring that the temperature and temperature difference of the battery pack 100 are within the safe range.

[0084] In some embodiments, before the first liquid cooling device 300 is used to control the heat exchange between the top and bottom liquid cooling plates 200 and the battery pack 100, it further includes: obtaining the first liquid cooling temperature at the liquid inlet of the liquid cooling flow channel of the top and bottom liquid cooling plates 200; if the first liquid cooling temperature is greater than or equal to the preset first temperature, determining whether the first liquid cooling flow rate at the liquid inlet reaches the preset first flow rate; if the first liquid cooling flow rate reaches the first flow rate, controlling the first end and the third end of the first three-way valve T1 to be communicated, and the second end and the third end of the second three-way valve T2 to be communicated; using the second liquid cooling device 400 to adjust the first liquid cooling flow rate at the liquid inlet to the preset second flow rate; wherein the second flow rate is greater than the first flow rate.

[0085] In the embodiment, when the first liquid cooling device 300 is used to control the heat exchange between the top and bottom liquid cooling plate 200 and the battery pack 100, the temperature of the liquid at the liquid inlet of the top and bottom liquid cooling plate 200, i.e. the first liquid cooling temperature, can be too high due to the external environment, and can be higher than the first temperature, which can be 15°C. At this time, the flow rate at the liquid inlet, i.e. the first liquid cooling flow rate, can be the maximum flow rate that the first liquid cooling device 300 can increase, i.e. the first flow rate. At this time, if the first liquid cooling device 300 is continued to be used to control the heat exchange between the top and bottom liquid cooling plate 200 and the battery pack 100, it cannot be guaranteed that the temperature and temperature difference of the battery pack 100 are within the safe range. The liquid cooling power of the second liquid cooling device 400 is much larger than that of the first liquid cooling device 300 in the present application. Therefore, when it is determined that the first liquid cooling flow rate reaches the first flow rate, the first end and the third end of the first three-way valve T1 are connected, and the second end and the third end of the second three-way valve T2 are connected, and the first liquid cooling flow rate at the liquid inlet is adjusted to the preset second flow rate by using the second liquid cooling device 400, so that the temperature and temperature difference of the battery pack 100 are within the safe range.

[0086] In some embodiments, after the first liquid cooling flow rate at the liquid inlet is adjusted to the preset second flow rate by using the second liquid cooling device 400, the second liquid cooling temperature at the liquid inlet is obtained after a preset first time. If the second liquid cooling temperature is less than or equal to the preset second temperature, the first end and the second end of the first three-way valve T1 are connected, and the second end and the second end of the second three-way valve T2 are connected. The second temperature is less than the first temperature. The first liquid cooling device 300 is used to adjust the liquid cooling flow rate at the liquid inlet to the preset third flow rate. The third flow rate is less than or equal to the first flow rate.

[0087] In the embodiment, the second temperature can be the first temperature. Since the battery pack 100 is in a non-fast charging state, if the second liquid cooling device 400 is continuously used to control the heat exchange between the top and bottom liquid cooling plate 200 and the battery pack 100, it will cause waste of resources. Therefore, during the process of adjusting the first liquid cooling flow rate at the liquid inlet to the preset second flow rate by using the second liquid cooling device 400, the second liquid cooling temperature at the liquid inlet is obtained after a preset first time.

[0088] If the second liquid cooling temperature is less than or equal to the preset second temperature, the first end and the second end of the first three-way valve T1 are connected, and the second end and the second end of the second three-way valve T2 are connected. The third flow rate can be less than or equal to the first flow rate.

[0089] In some embodiments, the first liquid cooling device 300 is used to control the heat exchange between the top and bottom liquid cooling plate 200 and the battery pack 100 to liquid cool the battery pack 100, including: if the first liquid cooling flow does not reach the first flow, controlling the communication between the first end and the second end of the first three-way valve T1 and the communication between the first end and the second end of the second three-way valve T2; using the first liquid cooling device 300 to increase the first liquid cooling flow at the liquid inlet to the first flow to liquid cool the battery pack 100.

[0090] Specifically, the flow at the liquid inlet of the top and bottom liquid cooling plate 200 can be controlled by the first liquid cooling device 300. When the flow at the liquid inlet is controlled by the first liquid cooling device 300, the maximum flow that can be reached at the liquid inlet can be the first flow.

[0091] When the first liquid cooling flow does not reach the first flow, the communication between the first end and the second end of the first three-way valve T1 and the communication between the first end and the second end of the second three-way valve T2 can be controlled; using the first liquid cooling device 300 to increase the first liquid cooling flow at the liquid inlet to the first flow to liquid cool the battery pack 100.

[0092] In some embodiments, after obtaining the first liquid cooling temperature at the liquid inlet of the liquid cooling flow channel of the top and bottom liquid cooling plate 200, if the first liquid cooling temperature is less than or equal to a preset third temperature, the communication between the first end and the second end of the first three-way valve T1 and the communication between the first end and the second end of the second three-way valve T2 are controlled; wherein the third temperature is less than the first temperature; using the heater in the first liquid cooling device 300 to increase the liquid cooling temperature at the liquid inlet to a preset fourth temperature to heat the battery pack 100.

[0093] Specifically, during the charging process of the battery pack 100, the liquid in the pipeline can cause the temperature at the liquid inlet of the top and bottom liquid cooling plate 200 to be too low due to the excessively low external temperature, and the battery pack 100 needs to be heated to normally charge. However, the battery pack 100 provided by the present application does not use a heating film or the like to heat, but the first liquid cooling device 300 is provided with a heater, and when the first liquid cooling temperature is less than or equal to a preset third temperature, the communication between the first end and the second end of the first three-way valve T1 and the communication between the first end and the second end of the second three-way valve T2 are controlled, and the heater in the first liquid cooling device 300 is used to increase the liquid cooling temperature at the liquid inlet to a preset fourth temperature to heat the battery pack 100, thereby ensuring that the battery pack 100 normally charges.

[0094] The heating and cooling of the battery pack 100 mentioned in the present application can be controlled by the top and bottom liquid cooling plate 200 to control the temperature and temperature difference, which can reduce the production cost of the battery pack 100 while improving the safety and reliability of the battery pack 100.

[0095] S140, if the battery pack 100 is in the overcharge state, the second liquid cooling device 400 is used to control the heat exchange of the top and bottom liquid cooling plates 200 and the battery pack 100, so as to liquid cool the battery pack 100.

[0096] In the embodiment, the liquid cooling power of the second liquid cooling device 400 is much greater than that of the first liquid cooling device 300, which can increase the temperature and flow rate at the liquid inlet of the top and bottom liquid cooling plates 200, and further ensure that the temperature and temperature difference of the battery pack 100 in the overcharge process are within a safe and controllable range, thereby improving the safety and reliability of the battery pack 100.

[0097] In some embodiments, step S140 includes the steps of: if the battery pack 100 is in the overcharge state, obtaining a third liquid cooling temperature at the liquid inlet of the liquid cooling flow channel of the top and bottom liquid cooling plates 200; if the third liquid cooling temperature is greater than or equal to a preset fifth temperature, controlling the communication between the first end and the third end of the first three-way valve T1 and the communication between the first end and the third end of the second three-way valve T2; and adjusting the liquid cooling flow rate at the liquid inlet to a preset fourth flow rate by using the second liquid cooling device 400 to liquid cool the battery pack 100.

[0098] Specifically, when the battery pack 100 in the overcharge state uses the second liquid cooling device 400 to achieve thermal management, the temperature at the liquid inlet of the top and bottom liquid cooling plates 200 of the battery pack 100 is usually within a preset temperature range, which can be represented by a fifth temperature and a sixth temperature, the fifth temperature being greater than the sixth temperature, and the average value between the fifth temperature and the sixth temperature being 10℃. When the temperature at the liquid inlet of the liquid cooling flow channel of the top and bottom liquid cooling plates 200, i.e., the third liquid cooling temperature, is higher than the fifth temperature, it cannot be guaranteed that the temperature and temperature difference of the battery pack 100 in the overcharge state are within a safe range. At this time, the first end and the third end of the first three-way valve T1 are controlled to be in communication, and the first end and the third end of the second three-way valve T2 are controlled to be in communication, and the liquid cooling flow rate at the liquid inlet is adjusted to a preset fourth flow rate by using the second liquid cooling device 400, so as to ensure that the temperature at the liquid inlet is within a preset temperature range, and further ensure that the temperature and temperature difference of the battery pack 100 in the overcharge state are within a safe range.

[0099] In some embodiments, after adjusting the liquid cooling flow rate at the liquid inlet to a preset fourth flow rate by using the second liquid cooling device 400 to liquid cool the battery pack 100, it further includes: after a preset second time, obtaining a fourth liquid cooling temperature at the liquid inlet; if the fourth liquid cooling temperature is less than or equal to a preset sixth temperature, adjusting the liquid cooling flow rate at the liquid inlet to a preset fifth flow rate; wherein the fifth flow rate is less than or equal to the fourth flow rate.

[0100] In the embodiment, the liquid cooling flow rate at the liquid inlet is increased to the fourth flow rate, and the fourth flow rate is large, which can quickly reduce the temperature at the liquid inlet to the sixth temperature. If the fourth flow rate is continuously used, the temperature at the liquid inlet can be too low. Therefore, after the preset second time, the fourth liquid cooling temperature at the liquid inlet is obtained. If the fourth liquid cooling temperature is less than or equal to the preset sixth temperature, the liquid cooling flow rate at the liquid inlet is adjusted to the preset fifth flow rate. The fifth flow rate can be 20 L / min.

[0101] In some embodiments, before the first liquid cooling device 300 is used to control the heat exchange between the top and bottom liquid cooling plate 200 and the battery pack 100 to liquid cool the battery pack 100, the method further includes: if an exhaust instruction of the battery thermal management system is received, controlling the first end and the third end of the third three-way valve T3 to communicate, so as to exhaust the gas in the battery thermal management system through the exhaust pipe; and if the exhaust instruction is not received, controlling the first end and the second end of the third three-way valve T3 to communicate.

[0102] Specifically, the application can also be provided with an exhaust assembly at the first flow channel opening, so as to exhaust the air in the pipeline, thereby improving the liquid cooling effect of the top and bottom liquid cooling.

[0103] Since the liquid cooling power of the second liquid cooling device 400 is much greater than that of the first liquid cooling device 300, the exhaust assembly can be arranged in the vehicle and used in cooperation with the first liquid cooling device 300, thereby improving the liquid cooling effect of the first liquid cooling device 300.

[0104] In some embodiments, controlling the first end and the third end of the third three-way valve T3 to communicate to exhaust the gas in the battery thermal management system through the exhaust pipe includes: controlling the first end and the third end of the third three-way valve T3 to communicate, and the first end and the third end of the fourth three-way valve T4 to communicate, so as to exhaust the gas in the battery thermal management system through the exhaust pipe and the liquid filling kettle 600 in sequence.

[0105] In the embodiment, the third three-way valve T3 is arranged at one end of the first liquid cooling device 300 and the first flow channel opening, so that when it is necessary to exhaust the pipeline, the first end and the third end of the third three-way valve T3 are communicated, and when it is not necessary to exhaust the pipeline, the first end and the second end of the third three-way valve T3 are communicated and the first end and the third end of the third three-way valve T3 are not communicated.

[0106] In some embodiments, after controlling the first end and the second end of the third three-way valve T3 to communicate, the method further includes: controlling the second end and the third end of the fourth three-way valve T4 to communicate.

[0107] Specifically, the application can further arrange a fourth three-way valve T4 between the third three-way valve T3 and the first liquid cooling device 300, and arrange a liquid injection jug 600 between the third three-way valve T3 and the fourth three-way valve T4, which can avoid the reduction of the cooling liquid in the pipeline during the exhaust process, so as to supplement the liquid in the pipeline.

[0108] In the embodiment, when the pipeline needs to be exhausted, the first end and the third end of the third three-way pipe can be communicated. When the first liquid cooling device 300 needs to be used to liquid cool the battery and the pipeline needs to be exhausted, the first end and the third end of the third three-way pipe and the first end and the second end of the fourth three-way pipe can be communicated.

[0109] The first end and the second end of the third three-way pipe can be communicated or not communicated, and the second end of the fourth communication pipe can be communicated or not communicated.

[0110] The battery thermal management method provided by the application can obtain the current working state of the battery pack 100, determine whether the battery pack 100 is in an overcharging state if the working state is a charging state, use the first liquid cooling device 300 to control the heat exchange between the top and bottom liquid cooling plates 200 and the battery pack 100 if the battery pack 100 is not in the overcharging state, so as to liquid cool the battery pack 100, and use the second liquid cooling device 400 to control the heat exchange between the top and bottom liquid cooling plates 200 and the battery pack 100 if the battery pack 100 is in the overcharging state, so as to liquid cool the battery pack 100, which can avoid the excessively high temperature and excessively large temperature difference during the battery charging process, ensure that the temperature of the battery during the overcharging process is within a safe range, and ensure the reliability of the battery.

Claims

1. A battery thermal management system, comprising: a top-bottom liquid cooling plate (200) provided with a liquid cooling flow channel, the liquid cooling flow channel comprising a first flow channel port and a second flow channel port, the top-bottom liquid cooling plate (200) being in heat exchange with a battery pack (100); a first liquid cooling device (300), one end of the first liquid cooling device (300) being in communication with the first flow channel port, the other end of the first liquid cooling device (300) being in communication with the second flow channel port; a second liquid cooling device (400), one end of the second liquid cooling device (400) being in communication with the first flow channel port, the other end of the second liquid cooling device (400) being in communication with the second flow channel port; wherein the first liquid cooling device (300) is configured to at least liquid cool the battery (100) in a non-overcharge state, and the second liquid cooling device (400) is configured to at least liquid cool the battery pack (100) in an overcharge state.

2. The battery thermal management system according to claim 1, further comprising a first three-way valve (T1) and a second three-way valve (T2); wherein a first end of the first three-way valve (T1) being in communication with the first flow channel port, a second end of the first three-way valve (T1) being in communication with one end of the first liquid cooling device (300), a third end of the first three-way valve (T1) being in communication with one end of the second liquid cooling device (400); a first end of the second three-way valve (T2) being in communication with the other end of the first liquid cooling device (300), a second end of the second three-way valve (T2) being in communication with the second flow channel port, a third end of the second three-way valve (T2) being in communication with the other end of the second liquid cooling device (400).

3. The battery thermal management system according to claim 2, further comprising a liquid cooling socket (500); wherein a first end of the liquid cooling socket (500) being in communication with the third end of the first three-way valve (T1), a second end of the liquid cooling socket (500) being in communication with the third end of the second three-way valve (T2), a third end of the liquid cooling socket (500) being in communication with one end of the second liquid cooling device (400), a fourth end of the liquid cooling socket (500) being in communication with the other end of the second liquid cooling device (400); the first end and the third end of the liquid cooling socket (500) being in communication, and the second end and the fourth end of the liquid cooling socket (500) being in communication.

4. The battery thermal management system of claim 1, wherein, the top-bottom liquid cooling plate (200) comprising a first liquid cooling plate (201) and a second liquid cooling plate (202), the liquid cooling flow channel comprising a first liquid cooling flow channel and a second liquid cooling flow channel; wherein the first liquid cooling flow channel is arranged in the first liquid cooling plate (201), and the second liquid cooling flow channel is arranged in the second liquid cooling plate (202); one end of the first liquid cooling flow channel and one end of the second liquid cooling flow channel are in communication with the first flow channel port by a first three-way joint (T5), and the other end of the first liquid cooling flow channel and the other end of the second liquid cooling flow channel are in communication with the second flow channel port by a second three-way joint (T6).

5. The battery thermal management system of claim 4, wherein, the first liquid cooling plate (201) and the second liquid cooling plate (202) are respectively located on the corresponding two sides of the battery pack (100).

6. The battery thermal management system of claim 4, wherein, The liquid cooling flow of the first liquid cooling channel is less than the liquid cooling flow of the second liquid cooling channel; or / and, The first liquid cooling plate (201) comprises a stamped liquid cooling plate, and the second liquid cooling plate (202) comprises an extruded liquid cooling plate.

7. The battery thermal management system of any one of claims 1-6, wherein, The first liquid cooling device (300) is arranged at a whole vehicle end, the second liquid cooling device (400) is arranged at a non-whole vehicle end, and the liquid cooling power of the first liquid cooling device (300) is less than the liquid cooling power of the second liquid cooling device (400).

8. The battery thermal management system according to any one of claims 1-6, further comprising an exhaust assembly; wherein One end of the exhaust assembly is respectively communicated with the first flow channel port and one end of the first liquid cooling device (300), and the other end of the exhaust assembly is communicated with the outside.

9. The battery thermal management system of claim 8, wherein, The exhaust assembly comprises an exhaust pipe and a third three-way valve (T3); The first end of the third three-way valve (T3) is communicated with the first flow channel port, the second end of the third three-way valve (T3) is communicated with one end of the first liquid cooling device (300), the third end of the third three-way valve (T3) is communicated with one end of the exhaust pipe, and the other end of the exhaust pipe is communicated with the outside.

10. The battery thermal management system of claim 9, wherein, The exhaust assembly comprises a liquid injection pot (600) and a fourth three-way valve (T4); The liquid injection pot (600) is communicated with the first end of the fourth three-way valve (T4), the second end of the fourth three-way valve (T4) is communicated with the second end of the third three-way valve (T3), the third end of the fourth three-way valve (T4) is communicated with one end of the first liquid cooling device (300), and the other end of the exhaust pipe is communicated with the outside through the liquid injection pot (600).

11. A battery thermal management method applied to a battery thermal management system, the battery thermal management system comprising a top-bottom liquid cooling plate (200), a first liquid cooling device (300) and a second liquid cooling device (400), and the battery thermal management system being configured to perform thermal management on a battery pack (100); the battery thermal management method comprising: obtaining a current working state of the battery pack (100); if the working state is a charging state, determining whether the battery pack (100) is in an overcharging state; if the battery pack (100) is in a non-overcharging state, using the first liquid cooling device (300) to perform heat exchange control on the top-bottom liquid cooling plate (200) and the battery pack (100) to perform liquid cooling on the battery pack (100); if the battery pack (100) is in an overcharging state, using the second liquid cooling device (400) to perform heat exchange control on the top-bottom liquid cooling plate (200) and the battery pack (100) to perform liquid cooling on the battery pack (100).

12. The battery thermal management method of claim 11, wherein, After the step of obtaining the current working state of the battery pack (100), the method further comprises: if the working state is a discharging state, determining whether a vehicle in which the battery pack (100) is located is in a driving state; if the vehicle is in a driving state, using the first liquid cooling device (300) to perform heat exchange control on the top-bottom liquid cooling plate (200) and the battery pack (100) to perform liquid cooling on the battery pack (100).

13. The battery thermal management method of claim 11, wherein, The battery thermal management system further comprises a first three-way valve (T1) and a second three-way valve (T2); Before the heat exchange control of the top and bottom liquid cooling plate (200) and the battery pack (100) by the first liquid cooling device (300), the method further comprises: obtaining a first liquid cooling temperature at an inlet of a liquid cooling flow channel of the top and bottom liquid cooling plate (200); if the first liquid cooling temperature is greater than or equal to a preset first temperature, determining whether a first liquid cooling flow rate at the inlet reaches a preset first flow rate; if the first liquid cooling flow rate reaches the first flow rate, controlling the first end and the third end of the first three-way valve (T1) to be communicated, and the second end and the third end of the second three-way valve (T2) to be communicated; adjusting the first liquid cooling flow rate at the inlet to a preset second flow rate by the second liquid cooling device (400); wherein the second flow rate is greater than the first flow rate.

14. The battery thermal management method of claim 13, wherein, After the first liquid cooling flow rate at the inlet is adjusted to the preset second flow rate by the second liquid cooling device (400), the method further comprises: after a preset first time, obtaining a second liquid cooling temperature at the inlet; if the second liquid cooling temperature is less than or equal to a preset second temperature, controlling the first end and the second end of the first three-way valve (T1) to be communicated, and the second end and the second end of the second three-way valve (T2) to be communicated; wherein the second temperature is less than the first temperature; adjusting the liquid cooling flow rate at the inlet to a preset third flow rate by the first liquid cooling device (300); wherein the third flow rate is less than or equal to the first flow rate.

15. The battery thermal management method of claim 13, wherein, The heat exchange control of the top and bottom liquid cooling plate (200) and the battery pack (100) by the first liquid cooling device (300) to liquid cool the battery pack (100) comprises: if the first liquid cooling flow rate does not reach the first flow rate, controlling the first end and the second end of the first three-way valve (T1) to be communicated, and the first end and the second end of the second three-way valve (T2) to be communicated; adjusting the first liquid cooling flow rate at the inlet to the first flow rate by the first liquid cooling device (300) to liquid cool the battery pack (100).

16. The battery thermal management method of claim 13, wherein, After the first liquid cooling temperature at the inlet of the liquid cooling flow channel of the top and bottom liquid cooling plate (200) is obtained, the method further comprises: if the first liquid cooling temperature is less than or equal to a preset third temperature, controlling the first end and the second end of the first three-way valve (T1) to be communicated, and the first end and the second end of the second three-way valve (T2) to be communicated; wherein the third temperature is less than the first temperature; adjusting the liquid cooling temperature at the inlet to a preset fourth temperature by a heater in the first liquid cooling device (300) to heat the battery pack (100).

17. The battery thermal management method of claim 11, wherein, The battery thermal management system further comprises a first three-way valve (T1) and a second three-way valve (T2); If the battery pack (100) is in an overcharge state, the second liquid cooling device (400) is used to control heat exchange between the top and bottom liquid cooling plates (200) and the battery pack (100) to liquid cool the battery pack (100), comprising: If the battery pack (100) is in an overcharge state, a third liquid cooling temperature at an inlet of a liquid cooling flow channel of the top and bottom liquid cooling plates (200) is obtained; If the third liquid cooling temperature is greater than or equal to a preset fifth temperature, the first end and the third end of the first three-way valve (T1) are controlled to be communicated, and the first end and the third end of the second three-way valve (T2) are controlled to be communicated; The liquid cooling flow at the inlet is adjusted to a preset fourth flow by the second liquid cooling device (400) to liquid cool the battery pack (100).

18. The battery thermal management method of claim 17, wherein, After the liquid cooling flow at the inlet is adjusted to the preset fourth flow by the second liquid cooling device (400) to liquid cool the battery pack (100), further comprising: After a preset second time, a fourth liquid cooling temperature at the inlet is obtained; If the fourth liquid cooling temperature is less than or equal to a preset sixth temperature, the liquid cooling flow at the inlet is adjusted to a preset fifth flow; wherein the fifth flow is less than or equal to the fourth flow.

19. The battery thermal management method of any one of claims 11-18, wherein, The battery thermal management system further comprises a third three-way valve (T3) and an exhaust pipe; Before the battery thermal management system further comprises: If the battery thermal management system receives an exhaust instruction, the first end and the third end of the third three-way valve (T3) are controlled to be communicated to exhaust the gas in the battery thermal management system through the exhaust pipe; If the exhaust instruction is not received, the first end and the second end of the third three-way valve (T3) are controlled to be communicated.

20. The battery thermal management method of claim 19, wherein, The battery thermal management system further comprises a fourth three-way valve (T4) and a liquid injection pot (600); The battery thermal management system further comprises a fourth three-way valve (T4) and a liquid injection pot (600); The battery thermal management system further comprises a fourth three-way valve (T4) and a liquid injection pot (600); After the first end and the second end of the third three-way valve (T3) are controlled to be communicated, further comprising: The second end and the third end of the fourth three-way valve (T4) are controlled to be communicated.

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