Composite cooling battery box based on tab heat dissipation and battery module

Abstract

The application relates to a composite cooling battery box based on pole ear heat dissipation and a battery module, and relates to the technical field of battery heat dissipation plates. The application solves the problems that the heat management technology in the prior art is not obvious in pertinence at the battery pole ear and the cooling plate in the prior art has high requirements for cooling liquid. The composite cooling battery box based on pole ear heat dissipation and the battery module comprise a battery box shell, a battery module, a PCM heat conduction plate, a liquid cooling system and a control system, the control system is a BMS system, the battery box shell is internally provided with an inner cavity one, an inner cavity two and an inner cavity three, the battery module, the PCM heat conduction plate and the liquid cooling plate are arranged in the inner cavity one, a fan is arranged on the outer shell of the inner cavity one, the liquid cooling system is arranged in the inner cavity two and is used in cooperation with a heat exchanger, and the BMS system is arranged in the inner cavity three. The liquid cooling plate with the reinforcing rib structure which is tightly attached to the surface where the battery module pole ear is located is also suitable for the technical field of battery preheating in the northeast cold region.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of battery heat dissipation plates. BACKGROUND

[0002] A patent with the name of a lithium battery heat dissipation plate with uniform heat dissipation is disclosed in the existing Chinese patent database, the patent document number is CN207587929 U, and the announcement date is 2018.07.06, the device comprises: a first cooling plate, a second cooling plate, a heat conduction plate and a liquid inlet block, the liquid inlet block is connected with one end of the first cooling plate and the second cooling plate respectively, the first cooling plate and the second cooling plate are connected and arranged together through the heat conduction plate; the first cooling plate and the second cooling plate are both connected with the liquid inlet block, the liquid inlet block comprises a single hole end and a multi-hole end; the first cooling plate is connected with the heat conduction plate through a turbulent cylinder, a plurality of vertical plates are installed at the end of the heat conduction plate opposite to the liquid inlet block, and the connection mode of the heat conduction plate and the second cooling plate is the same as that of the heat conduction plate and the first cooling plate.

[0003] The deficiency is that the highest temperature of the battery is often near the tab and not on other surfaces, and through the battery box heat dissipation technology proposed, the existing heat management technology is not obvious in the tab, and the liquid cooling plate is set in the tab, which may contact the positive and negative tabs, causing the battery pack to short circuit and causing thermal runaway accident. In the battery heat dissipation, the cooling liquid has high requirements, such as insulation, thermal conductivity and so on. There are only a few such cooling liquids on the market and the price is relatively high, and there are defects such as poor temperature control effect, slow thermal response speed, low efficiency and reliability of the heat dissipation system, especially in the high-rate charging working condition, due to the defects of slow thermal response speed and low heat dissipation efficiency, the protection effect of the heat dissipation plate on the battery is very ideal, which ultimately makes the battery charge in high temperature, resulting in shortening of battery life and reduction of cruising range.

[0004] In the prior art, since the lithium battery is applied in the cold regions such as northeast China and other high-cold regions, it is easy to cause low temperature and cannot start normally in these high-cold regions. SUMMARY

[0005] The application solves the problem of high requirements of direct cooling on cooling liquid and high price of existing cooling liquid, and also solves the problem that the lithium battery is applied in high-cold regions and is easy to cause low temperature and cannot start normally.

[0006] The heat dissipation plate in the prior art only takes away the heat of the battery through the cooling liquid, has poor temperature control effect, slow thermal response speed, low efficiency and reliability of the heat dissipation system, and especially in the working condition of high-rate charging, the protection effect of the heat dissipation plate on the battery is very poor, finally the battery is charged in a high temperature condition, which causes the problem of shortening the service life of the battery.

[0007] To achieve the above object, the application adopts the following technical solutions:

[0008] The composite cooling battery box based on the tab heat dissipation comprises a battery box shell, a liquid cooling plate and at least one PCM heat conduction plate, an inner cavity one is arranged in the battery box shell and is used for placing a battery pack, the at least one PCM heat conduction plate is located inside the inner cavity one and is used for isolating battery cells in the battery pack and closely contacting adjacent battery cells to realize heat conduction, at least one liquid flow channel is arranged inside each PCM heat conduction plate and is used for filling phase change material into the PCM heat conduction plate, the liquid cooling plate is located at the top of the battery box and is adjacent to the tab of the battery pack, at least one liquid flow channel is arranged inside the liquid cooling plate, and a liquid inlet and a liquid outlet are further included.

[0009] Further, the box further comprises an inner cavity two and a liquid control unit, the liquid control unit is arranged inside the inner cavity two, and the liquid control unit is used for controlling the flow rate of the liquid in the heat transfer liquid loop.

[0010] Further, the liquid loop further comprises a liquid cooling plate, a pump, a regulating valve and a heat exchanger, the liquid cooling plate, the pump, the regulating valve and the heat exchanger are connected in series, and the heat exchanger is a finned radiator.

[0011] Further, the box further comprises an inner cavity three, and the inner cavity three is used for accommodating a BMS system; the BMS system is used for controlling the working mode of the battery pack.

[0012] Further, at least one reinforcing rib is arranged on both sides of the liquid cooling plate, and the at least one reinforcing rib is used for fixed connection with the battery box.

[0013] Further, the flow channel inside the liquid cooling plate adopts a straight flow channel.

[0014] Further, the PCM heat conduction plate adopts a U-shaped plate, and the U-shaped opening of the U-shaped plate is used for embedding a battery cell and closely contacting the embedded battery cell.

[0015] Further, the PCM heat conduction plate further comprises a filling port, and the filling port is arranged on the side wall of the bottom surface of the PCM heat conduction plate.

[0016] Further, the battery box further comprises a fan arranged on the shell of the inner cavity I for cooling the battery box.

[0017] The battery box further comprises a fan arranged on the shell of the inner cavity I for cooling the battery box.

[0018] When the surface temperature of the battery module is monitored to be below 40 DEG C, passive heat dissipation is performed by the phase change material in the PCM heat conduction plate.

[0019] When the surface temperature of the battery module is monitored to be 40 DEG C to 45 DEG C, the heat dissipation mode of the battery box is phase change material heat dissipation and air cooling.

[0020] When the surface temperature of the battery module is monitored to be above 45 DEG C, the heat dissipation mode of the battery box is phase change material heat dissipation, air cooling and liquid cooling.

[0021] When the surface temperature of the battery module is monitored to be below 10 DEG C, a preheating mode is started, the liquid cooling plate is filled with high-temperature fluid, the battery surface is heated, and the heat management mode of the battery box is liquid cooling plate heating.

[0022] Compared with the prior art, the present application has the advantages that: the present application solves the problem that direct cooling requires high-quality cooling liquid in the prior art, such as insulation, thermal conductivity and the like, there are only a few kinds of such cooling liquid on the market and the cooling liquid is expensive, the temperature control effect is poor, the thermal response speed is slow, the efficiency of the heat dissipation system is low, and the reliability is low, especially in the high-rate charging working condition, the protection effect of the heat dissipation plate on the battery is very poor, and finally the battery is charged at high temperature, which shortens the service life of the battery and reduces the cruising range.

[0023] Since the liquid cooling plate is arranged to realize indirect cooling and indirect preheating and other heat management of the lithium battery, the cooling liquid does not need to directly contact the battery pack, and therefore the requirement for the working fluid is very low, and the working fluid can be any heat-conducting fluid, such as water and liquid metal.

[0024] The present application adopts the liquid cooling plate with a reinforcing rib structure which is tightly attached to the surface where the battery module tab is located, and the flow channel in the liquid flow plate can be a straight flow channel, but is not limited to a straight flow channel, the battery is heat-exchanged by the liquid cooling plate, and the cooling liquid is not limited, and any cooling liquid in the prior art can be applied to the present application.

[0025] When the energy density of the battery is improved, the heat emitted at the tab is quickly taken away by the cold fluid in the liquid cooling plate, the maximum temperature of the battery module is reduced, the temperature consistency of the battery is improved, and the service life of the battery is prolonged.

[0026] The battery box can control the battery module to perform different heat dissipation modes under low, medium and high rate charging and discharging working conditions respectively, so that the energy saving effect can be realized on the basis of meeting the heat dissipation power.

[0027] In the present application, we use insulating thermal pads when arranging the liquid cooling plate. The liquid cooling plate is arranged at the tab, which may contact the positive and negative tabs, causing the battery pack to short circuit and resulting in a thermal runaway accident. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 A two-dimensional structural schematic diagram of a battery box combined with a PCM heat-conducting plate according to the present application.

[0029] Figure 2 A three-dimensional structural schematic diagram of a battery module according to the present application.

[0030] Figure 3 Structural schematic diagrams of three PCM heat-conducting plates according to the present application.

[0031] Figure 4 A structural schematic diagram of a liquid cooling plate with reinforcing ribs according to the present application.

[0032] In the present application, 1 is a battery box shell, 2 is a battery module, 3 is a PCM heat-conducting plate, 4 is a liquid cooling plate, 5 is a pump, 6 is a regulating valve, 7 is a heat exchanger, 8 is a fan, 9 is a BMS system, 101 is an inner cavity one, 102 is an inner cavity two, 103 is an inner cavity three, 301 is a filling port, 401 is a cold fluid inlet, and 402 is a cold fluid outlet. DETAILED DESCRIPTION

[0033] To make the purposes, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described below in connection with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application.

[0034] Embodiment one, see Figure 1 In the present embodiment, the composite cooling battery box based on tab heat dissipation includes a battery box shell 1, the battery box further includes a liquid cooling plate 4 and at least one PCM heat-conducting plate 3, an inner cavity one 101 is arranged in the battery box shell 1, the inner cavity one 101 is used to place a battery pack, the at least one PCM heat-conducting plate 3 is located inside the inner cavity one 101 and is used to isolate battery cells in the battery pack and tightly contact adjacent battery cells to achieve heat conduction; at least one liquid flow channel is arranged inside each PCM heat-conducting plate 3 and is used to fill phase change material into the PCM heat-conducting plate 3, the liquid cooling plate 4 is located at the top of the battery box and is adjacent to the tab of the battery pack, at least one liquid flow channel is arranged inside the liquid cooling plate 4, and the liquid cooling plate 4 further includes a liquid inlet and a liquid outlet.

[0035] The composite cooling battery box based on the tab heat dissipation in the embodiment, in actual application, the battery pack is embedded in the inner cavity 101, the PCM heat conduction plate 3 is arranged between the adjacent battery units to realize the timely heat dissipation of the heat generated by the battery units, or the function of heating the adjacent battery units through the PCM heat conduction plate 3. The liquid cooling plate 4 is fixed at the tab position on the top of the battery pack, which is used to realize the timely heat dissipation of the heat generated by the tab part to avoid heat concentration. The inner part of the liquid cooling plate 4 is provided with a flow channel, and the inner part of the PCM heat conduction plate 3 is provided with a liquid flow channel, all the flow channels are connected to form a heat transfer liquid loop to realize the effective heat transfer, and the flow rate of the liquid can adjust the heat transfer efficiency, which can be flexibly controlled according to the actual situation.

[0036] The size of the liquid cooling plate 4 covers the tab part of the battery pack, and it is not too large, and the heat transfer efficiency is higher under the premise of limited area.

[0037] Embodiment two, the embodiment is a further limitation of the composite cooling battery box based on the tab heat dissipation in the embodiment one, the box further includes an inner cavity 102 and a liquid control unit, the liquid control unit is arranged in the inner cavity 102, and the liquid control unit is used to control the flow rate of the liquid in the heat transfer liquid loop.

[0038] The embodiment separately sets up an inner cavity 102 in the tab heat dissipation composite cooling battery box, which is used to accommodate the liquid control unit, the liquid control unit is used to control the flow rate of the liquid in the heat transfer liquid loop, and the heat transfer efficiency is realized. For example, the liquid control unit can adopt a pump 5. An adjusting valve 6 can also be added to realize the control of the heat transfer liquid loop. A heat exchanger 7 can also be added to realize the heat exchange between the heat transfer liquid loop and the heat exchanger 7, and the efficiency of cooling or heating is further improved. The heat exchanger 7 can adopt the PCM heat conduction plate 3.

[0039] Embodiment three, see Figure 1 The embodiment is a further limitation of the composite cooling battery box based on the tab heat dissipation in the embodiment one, the liquid loop further includes a pump 5, an adjusting valve 6 and a heat exchanger 7, the liquid cooling plate 4, the pump 5, the adjusting valve 6 and the heat exchanger 7 are connected in series, and the heat exchanger 7 is a fin type radiator.

[0040] Embodiment four, the embodiment is a further limitation of the composite cooling battery box based on the tab heat dissipation in the embodiment one, the box further includes an inner cavity 103, the inner cavity 103 is used to accommodate a BMS system 9; the BMS system 9 is used to control the working mode of the battery pack.

[0041] The increased inner cavity 103 of the present embodiment is used to accommodate the BMS system 9, i.e., the control part in the battery module is arranged separately from the battery pack, thereby improving the safety of the battery module and reducing the influence of the battery pack on the control circuit due to heat generation, thereby improving the working stability of the battery module.

[0042] Embodiment five, the present embodiment is a further limitation of the composite cooling battery box based on the tab heat dissipation of the first embodiment, and the liquid cooling plate 4 has at least one reinforcing rib on both sides, and the at least one reinforcing rib is used for fixed connection with the battery box.

[0043] The reinforcing rib has excellent heat conduction performance. By arranging the reinforcing rib on the liquid cooling plate at the tab, the heat on the surface where the battery tab is located can be conducted to the liquid cooling plate, and then taken away by the cooling liquid, thereby realizing the temperature uniformity effect of the battery surface.

[0044] In the fifth embodiment, the surface where the tab is located is tightly attached to the liquid cooling plate 4 with a reinforcing rib structure. Since the PCM heat conduction plate is used at the tab and the liquid cooling plate 4 with a reinforcing rib structure is arranged at the surface where the tab is located, the poor temperature control effect, low heat dissipation system efficiency and low reliability mentioned in the background art are solved, thereby achieving better heat dissipation effect.

[0045] Embodiment six, the present embodiment is a further limitation of the composite cooling battery box based on the tab heat dissipation of the first embodiment, and the flow channel inside the liquid cooling plate 4 adopts a straight flow channel.

[0046] In the sixth embodiment, the liquid flow channel is at least one, and the arrangement can be one or more circles.

[0047] Since the liquid cooling plate is arranged to realize the indirect cooling and indirect preheating of the lithium battery and the like heat management, the cooling liquid does not need to directly contact the battery pack, and therefore the requirement for the cooling liquid is extremely low, and the cooling liquid does not need to have the performance of insulation, non-toxicity and the like. The cooling liquid can be any heat-conducting fluid, such as water, liquid metal and the like.

[0048] In the present embodiment, the form of the flow channel can be described in various ways. Referring to Figure 4 The liquid inlet 401 and the liquid outlet 402 can be arranged at both ends or the same end.

[0049] Embodiment seven, the present embodiment is a further limitation of the composite cooling battery box based on the tab heat dissipation of the first embodiment, and the PCM heat conduction plate 3 adopts a U-shaped plate, and the U-shaped opening of the U-shaped plate is used to embed the battery unit and is in close contact with the embedded battery unit.

[0050] The U-shaped opening structure in the embodiment enables the battery cells to be embedded in the 3, and the three surfaces of the battery cells are in close contact with the 3 to achieve heat transfer, thereby increasing the area of heat transfer and improving the transfer efficiency.

[0051] Embodiment eight, the embodiment is a further limitation of the composite cooling battery box based on the tab heat dissipation of the first embodiment, the PCM heat conduction plate 3 further comprises a filling port 301, and the filling port 301 is arranged on the side wall of the bottom surface of the PCM heat conduction plate (3).

[0052] Embodiment nine, the embodiment is a further limitation of the composite cooling battery box based on the tab heat dissipation of the eighth embodiment, and the battery box further comprises: a fan 8 arranged on the shell of the inner cavity one 101 for cooling the battery box.

[0053] In the embodiment, the fan 8 on the shell of the inner cavity one 101 is used for the air cooling mode of the battery box, and when the battery module 2 needs air cooling heat dissipation, the fan 8 on the shell of the inner cavity one 101 is started; the fan 8 on the shell of the inner cavity one 101 is not only two, and the fan 8 on the shell of the inner cavity two 102 is not only one.

[0054] In actual application, the number and type of the fan 8 are set according to the size of the battery pack.

[0055] Embodiment ten, the heat dissipation control method of the battery box, the control method is:

[0056] When the battery box operates in a low-rate charging and discharging condition, that is, when the surface temperature of the battery module is monitored to be not more than 40℃, passive heat dissipation of the phase change material in the PCM heat conduction plate 3 can be used, and the air cooling mode and the liquid cooling mode do not need to be started, and at this time, the heat dissipation mode of the battery box is only the phase change material heat dissipation;

[0057] When the battery box is in a medium-rate charging and discharging condition, that is, when the surface temperature of the battery module is monitored to be 40℃-45℃, the air cooling mode is started, and at this time, the heat dissipation mode of the battery box is the phase change material heat dissipation and the air cooling;

[0058] When the battery box is in a high-rate charging and discharging condition, that is, when the surface temperature of the battery module is monitored to be more than 45℃, the air cooling and liquid cooling modes are started at the same time, and at this time, the heat dissipation mode of the battery box is the phase change material heat dissipation, air cooling and liquid cooling.

[0059] When the battery box is in a low-temperature cold start condition, that is, when the surface temperature of the battery module is monitored to be less than 10℃, the preheating mode is started, the liquid cooling plate is filled with high-temperature fluid, and the surface of the battery is heated, and at this time, the heat management mode of the battery box is the liquid cooling plate heating.

[0060] The above merely describes the preferred embodiments of the present application and is not intended to limit the present application. The innovation of the present application is that the liquid cooling plate 4 with a reinforcing rib structure is tightly arranged at the surface where the battery module 2 pole lug is located; the flow channel of the liquid cooling plate 4 adopts a straight channel form, the cooling fluid enters from the cold fluid inlet 401 and flows out from the cold fluid outlet 402; the battery is heat-exchanged by the liquid cooling plate 4, and the cooling liquid realizes the heat dissipation function of the battery, and the cooling liquid can be any one in the prior art to realize the heat dissipation effect of the present application.

[0061] Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can modify the technical solutions recorded in the foregoing embodiments or make equivalent replacements to some of the technical features, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A heat dissipation control method for a composite cooling battery case based on tab heat dissipation, the battery case comprising a battery case housing (1), characterized in that, The battery box further comprises a liquid cooling plate (4) and at least one PCM heat conduction plate (3), an inner cavity one (101) is arranged in the battery box shell (1), the inner cavity one (101) is used for placing the battery pack, the at least one PCM heat conduction plate (3) is located inside the inner cavity one (101), and is used for isolating the battery cells in the battery pack, and is in close contact with adjacent battery cells to realize heat conduction; at least one liquid flow channel is arranged in each PCM heat conduction plate (3), and is used for filling the phase change material into the PCM heat conduction plate (3); the liquid cooling plate (4) is located at the top of the battery box and is adjacent to the tab of the battery pack, at least one liquid flow channel is arranged in the liquid cooling plate (4), and the liquid cooling plate (4) further comprises a liquid inlet and a liquid outlet; The battery box shell (1) further comprises an inner cavity two (102) and a liquid control unit, the liquid control unit is arranged in the inner cavity two (102), and the liquid control unit is used for controlling the flow rate of the liquid in the heat transfer liquid loop; The battery box shell (1) further comprises an inner cavity three (103), and the inner cavity three (103) is used for accommodating a BMS system (9); the BMS system (9) is used for controlling the working mode of the battery pack; The battery box further comprises a fan (8), the fan is arranged on the shell of the inner cavity one (101) and is used for cooling the battery box; The control method is: When the surface temperature of the battery module is monitored to be below 40 DEG C, the phase change material in the PCM heat conduction plate (3) is used for passive heat dissipation; When the surface temperature of the battery module is monitored to be 40 DEG C-45 DEG C, the heat dissipation mode of the battery box is phase change material heat dissipation and air cooling; When the surface temperature of the battery module is monitored to be above 45 DEG C, the heat dissipation mode of the battery box is phase change material heat dissipation, air cooling and liquid cooling; When the surface temperature of the battery module is monitored to be below 10 DEG C, a preheating mode is started, the liquid cooling plate (4) is filled with high-temperature fluid, the battery surface is heated, and the heat management mode of the battery box is liquid cooling plate heating.

2. The heat dissipation control method of the tab-ear-based heat dissipation composite cooling battery box according to claim 1, characterized in that, The liquid control unit comprises a pump (5), an adjusting valve (6) and a heat exchanger (7), the pump (5), the adjusting valve (6) and the heat exchanger (7) are connected in series with the liquid loop, and the heat exchanger (7) is a finned radiator.

3. The heat dissipation control method of the tab-based heat dissipation composite cooling battery box according to claim 1, characterized in that, At least one reinforcing rib is arranged on the two sides of the liquid cooling plate (4), and the at least one reinforcing rib is used for fixed connection with the battery box.

4. The heat dissipation control method of the tab-ear-based heat dissipation composite cooling battery box according to claim 1, characterized in that, The flow channel in the liquid cooling plate (4) adopts a straight flow channel.

5. The heat dissipation control method of the tab-based heat dissipation composite cooling battery box according to claim 1, wherein, The PCM heat conduction plate (3) adopts a U-shaped plate, and the U-shaped opening of the U-shaped plate is used for embedding the battery cell and is in close contact with the embedded battery cell.

6. The heat dissipation control method of the tab-based heat dissipation composite cooling battery box according to claim 1, wherein, The PCM heat conduction plate (3) further comprises a filling port (301), and the filling port (301) is arranged on the side wall of the bottom surface of the PCM heat conduction plate (3).

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