A honeycomb battery module thermal management system integrating thermoelectric devices and PCMs

Abstract

A kind of honeycomb type battery module thermal management system integrated thermoelectric device and PCM, the system shell, hexagonal honeycomb battery heat conduction frame is installed in shell interior, battery heat conduction frame center is equipped with pipe hole, liquid cooling pipe passes through pipe hole, liquid cooling pipe is connected with heat exchanger to carry out heat exchange.The outer wall surface of battery heat conduction frame is all closely attached with thermoelectric device, the hot end of thermoelectric device is closely attached with liquid cooling plate, and liquid cooling plate is connected with heat exchanger to carry out heat exchange.Battery heat conduction frame is distributed with multiple grooves at equal intervals, respectively for installing battery, PCM6, fin, groove is filled with PCM, fin is closely attached on battery, and PCM6 is wrapped around battery and fin.The application carries out the thermal management of battery by the active refrigeration / heat function of thermoelectric device and the temperature invariable characteristics of phase change material PCM when phase change, so that battery is maintained in specified operating temperature range;It improves the temperature distribution uniformity of battery unit, prevents battery thermal runaway, improves battery life and stability in different working conditions.

Description

Technical Field

[0001] This invention relates to the field of thermal management of energy storage batteries, and more specifically to a thermal management system for a cellular battery module that integrates thermoelectric devices and PCM. Background Technology

[0002] Lithium-ion batteries are considered the primary choice for power battery systems due to their high energy density, high voltage, low self-discharge rate, long cycle life, and specific energy. Typically, the optimal operating temperature range for lithium-ion batteries is 20°C to 40°C, with a temperature uniformity of 5°C. However, due to the lack of effective heat dissipation methods, lithium-ion batteries struggle to dissipate heat during periods of sustained temperature increases and heat accumulation, which in turn exacerbates electrochemical reactions. Therefore, thermal runaway (TR), especially under harsh conditions, can lead to flame, fire, and explosion accidents. The chance of TR occurring during stress and abusive battery operation is higher, such as under conditions of high discharge rates, high ambient temperatures (>40°C), overcharging and discharging, and mechanical impact. Therefore, developing an efficient, scientific, and appropriate battery thermal management system (BTMS) is crucial for improving battery life and stability under different operating conditions. Specifically, it must meet the following functions: (1) accurately monitor and measure the battery operating temperature in real time; (2) efficiently dissipate heat from the battery pack at high temperatures and rapidly heat the battery pack at low temperatures; (3) continuously maintain the battery within the specified operating temperature range; and (4) improve the uniformity of temperature distribution within the battery cells. Summary of the Invention

[0003] This invention provides a thermal management system for a cellular battery module that integrates thermoelectric devices and PCM. By utilizing the active cooling / heating function of the thermoelectric devices and the temperature-constant characteristics of the phase change material PCM during phase change, the system manages the battery's thermal performance, maintaining it within a specified operating temperature range. Furthermore, it improves the uniformity of temperature distribution within the battery cells, prevents thermal runaway, and enhances battery life and stability under different operating conditions.

[0004] The technical solution adopted in this invention is as follows:

[0005] A thermal management system for a cellular battery module integrating thermoelectric devices and PCM, the system comprising:

[0006] The outer shell has a hexagonal honeycomb battery heat-conducting frame installed inside. The battery heat-conducting frame has a through hole in the center. The liquid cooling pipe passes through the through hole and is installed with the battery heat-conducting frame. The liquid cooling pipe is connected to a heat exchanger for heat exchange.

[0007] The outer wall of the battery thermal conductive frame is tightly attached to thermoelectric devices. The hot end of the thermoelectric devices is tightly attached to a liquid cooling plate, which is connected to a heat exchanger for heat exchange.

[0008] The battery thermally conductive frame has multiple grooves evenly distributed around the through-hole. This invention has 11 grooves, which are used to install the battery, PCM6, and fins respectively. The grooves are filled with PCM, and the fins are tightly attached to the battery. The fins are added to improve the thermal conductivity of PCM6 and reduce the heat storage and release time. PCM6 wraps around the battery and fins, which can fully absorb the heat emitted by various parts of the battery and reduce the temperature difference of the battery.

[0009] Multiple thermoelectric devices are evenly distributed on the outer walls of the battery's thermally conductive frame. These thermoelectric devices prevent the PCM6 from becoming saturated with heat while simultaneously heating the battery. The number of thermoelectric devices on each outer wall is A, where 1 ≤ A ≤ 16. These A thermoelectric devices are connected in series, with their positive and negative terminals connected to the positive and negative terminals of an external power source, respectively. Furthermore, the current direction of each thermoelectric device can be switched.

[0010] The thermoelectric device includes a horizontally placed upper ceramic plate and a lower ceramic plate, and X copper electrodes closely attached between the two. 2X thermoelectric semiconductors are placed between the copper electrodes. The 2X thermoelectric semiconductors include X P-type semiconductors and X N-type semiconductors, which are connected in series to form X pairs of thermoelectric arms in a PNP manner.

[0011] The outer shell is a hexagonal recessed container with a mounting hole in the center for the passage of a liquid cooling pipe; the liquid cooling pipe is a circular pipe that is closely attached to the through hole of the battery heat-conducting frame, and the liquid cooling pipe is filled with heat exchange liquid.

[0012] The outer casing 1 has a first hole at its left end, which corresponds to the inlet of the liquid cooling pipe 4. The heat exchange liquid is introduced through the inlet of the liquid cooling pipe. The outer casing 1 has a second hole at its right end, which corresponds to the outlet of the liquid cooling pipe. The heat exchange liquid flows out through the outlet of the liquid cooling pipe. The liquid cooling pipe is connected to the pump and the heat exchanger for heat exchange.

[0013] The bottom surface of the liquid cooling plate is equal to the area of ​​the ceramic plate of the thermoelectric device. The liquid cooling plate is in close contact with the ceramic plate of the thermoelectric device to improve the heat exchange efficiency of the thermoelectric device during cooling.

[0014] The liquid cooling plate includes an end cap, a plate body, and liquid cooling pipe channels; wherein the liquid cooling pipe channels are arranged in a bent and folded manner inside the plate body, closely attached to the bottom surface of the plate body; heat exchange liquid inlet and outlet are opened at both ends of the liquid cooling pipe channels;

[0015] The liquid cooling plate has a liquid inlet on the lower right, through which heat exchange liquid is introduced via liquid cooling pipe channels, and a liquid outlet on the upper left, through which heat exchange liquid flows out. The liquid cooling plate is connected to the pump and heat exchanger for heat exchange.

[0016] The battery → PCM → battery thermal conductive frame → liquid cooling pipe inside the outer casing form a thermal conductive path.

[0017] Battery → PCM → Battery thermal conductive frame → Thermoelectric device → Liquid cooling plate form a thermal conductive path;

[0018] The external pump draws and circulates the liquid heat exchange liquid from the liquid pipes and liquid cooling plates through the heat exchanger to form a liquid heat exchange path.

[0019] The battery is equipped with a temperature sensor to measure the battery temperature; the PCM is equipped with a liquid sensor to measure the liquid volume of the PCM; both the temperature sensor and the liquid sensor are connected to the controller; the controller is connected to the power supply, the pump, and the thermoelectric device respectively.

[0020] Depending on the battery temperature and the degree of phase transition in the PCM, corresponding control strategies are adopted:

[0021] 1) When the battery temperature T≥T target During normal charging and discharging, the battery temperature rises. At this time, the PCM that wraps the battery exchanges heat with the battery and absorbs the heat emitted by the battery, thus reducing the battery temperature. The fins installed on the battery and wrapped by the PCM improve the thermal conductivity of the PCM, so that the battery heat can be quickly absorbed by the PCM and thus reduce the battery temperature.

[0022] 2) When the PCM liquid volume fraction is between 80% and 90%, the controller controls the power supply to provide a positive current to the thermoelectric device. The temperature of the upper ceramic plate of the thermoelectric device decreases, becoming the cooling end, while the temperature of the lower ceramic plate of the thermoelectric device increases, becoming the heat dissipation end. The heat conduction through the battery thermal conductive frame prevents the PCM from becoming saturated with stored heat, keeping the PCM in a phase change process. The temperature of the PCM itself remains almost constant before the phase change is complete, forming a wide temperature plateau, which makes the temperature distribution of the enclosed battery uniform. At the same time, the controller controls the power supply to provide current to the pump, and the heat generated by the heat dissipation end of the thermoelectric device and the latent heat absorbed by the PCM can be carried away and discharged through the circulation of the heat-conducting liquid in the thermal conductive path.

[0023] 3) When the volume fraction of PCM liquid is above 90%, the controller controls the power supply to supply a large current to the pump, so that it works in heat dissipation mode. By dissipating heat into the environment through heat exchange, the power of the pump is increased, and the heat transfer liquid is driven to circulate in the liquid-cooled heat exchange path at a greater flow rate, thereby improving heat dissipation efficiency.

[0024] 4) When the battery temperature is T≤T targetDuring this process, the controller controls the power supply to provide a reverse current to the thermoelectric device. The upper ceramic plate of the thermoelectric device heats up, becoming the heating end, while the lower ceramic plate heats down, becoming the heat-absorbing end. The PCM is heated via heat conduction through the battery's thermally conductive frame. Heating stops once the PCM has completely undergone a phase change. When the PCM cools, the stored heat dissipates into the environment within a certain temperature range, undergoing a reverse phase change from liquid to solid. At this point, the dissipated heat is absorbed by the battery, and the battery temperature rises to T. target above.

[0025] This invention discloses a thermal management system for a honeycomb battery module integrating thermoelectric devices and PCM, with the following technical advantages:

[0026] 1) This invention relates to a battery module thermal management system. Based on thermoelectric devices combined with a PCM (Polymer Heat Dissipation Module) for integrated heat dissipation and preheating, and utilizing the characteristic that the PCM does not cause a temperature rise or fall when only absorbing or releasing latent heat, the system maintains the battery within a specified operating temperature range and improves the uniformity of temperature distribution within the battery cells, preventing thermal runaway. Pre-set instructions in the controller make the battery's heat pipes more flexible and controllable, solving the problems of excessively high battery temperatures in high-temperature environments, large temperature differences between different parts of the battery, and the inability to heat the battery rapidly in low-temperature environments. Maintaining the battery temperature within a suitable operating environment plays a crucial role in improving battery life and stability under different operating conditions.

[0027] 2) The battery module thermal management system of the present invention is capable of independently heating and dissipating heat from thermoelectric devices. However, when the hot end temperature of the thermoelectric device is too high, it will affect the cooling effect of the thermoelectric device. Therefore, the hot end of the thermoelectric device is closely attached to the liquid cooling plate, and the problem of slow heat dissipation of the hot end of the thermoelectric device is solved by liquid cooling heat exchange, thereby enhancing the cooling effect of the thermoelectric device.

[0028] 3) The battery module thermal management system of this invention features thermoelectric devices tightly attached to the outer walls of the battery's thermally conductive frame, with a liquid-cooling pipe running through the center to prevent PCM heat storage saturation. This allows for rapid battery heat dissipation, significantly improving battery life and safety. Based on the thermoelectric effect, this battery thermal management system offers advantages such as fast thermal response, scalable size, vibration-free operation, high reliability, high temperature control accuracy, and noiselessness. Furthermore, the compact internal arrangement of the battery thermal management module maximizes space utilization, resulting in a smaller size, increased energy density, and a neat external layout for easy arrangement. Attached Figure Description

[0029] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0030] Figure 1 This is a schematic diagram of the main structure of the battery module thermal management system of the present invention.

[0031] Figure 2This is a three-dimensional structural diagram of the battery module thermal management system of the present invention.

[0032] Figure 3 A schematic diagram showing the direction of DC current flow during cooling and preheating of semiconductor thermoelectric devices.

[0033] Figure 4 This is a diagram of the liquid cooling plate assembly of the thermal management system of the present invention.

[0034] Figure 5 This is a schematic diagram of the fins of the present invention being tightly attached to the battery.

[0035] Figure 6 This is a flowchart illustrating the different operating modes of the controller of the present invention. Detailed Implementation

[0036] like Figures 1-5 As shown, a thermal management system for a honeycomb battery module integrating thermoelectric devices and PCM is disclosed. The system includes: a housing 1, a hexagonal honeycomb battery thermally conductive frame 8 installed inside the housing 1, a through hole in the center of the battery thermally conductive frame 8, a liquid cooling pipe 4 passing through the through hole and installed with the battery thermally conductive frame 8, and the liquid cooling pipe 4 being connected to a heat exchanger 10 for heat exchange.

[0037] The outer wall of the battery thermally conductive frame 8 is tightly attached to thermoelectric devices 2. The hot end of the thermoelectric device 2 is tightly attached to a liquid cooling plate 3. The liquid cooling plate 3 is connected to the heat exchanger 10 for heat exchange.

[0038] The battery thermally conductive frame 8 has multiple grooves evenly distributed around the through-hole. In this invention, there are 11 grooves, which are used to install the battery 5, PCM6, and fins 7, respectively. The grooves are filled with PCM6, and the fins 7 are tightly attached to the battery 5. The fins 7 are added to improve the thermal conductivity of PCM6 and reduce the heat storage and release time. PCM6 wraps around the battery 5 and the fins 7, which can fully absorb the heat emitted by various parts of the battery 5 and reduce the temperature difference of the battery 5.

[0039] Multiple thermoelectric devices 2 are evenly distributed on the outer walls of the battery thermally conductive frame 8. The thermoelectric devices 2 are used to prevent the PCM6 from becoming saturated with heat and to heat the battery 5. The number of thermoelectric devices 2 placed on each outer wall of the battery thermally conductive frame 8 is A, satisfying 1 ≤ A ≤ 16. The A thermoelectric devices 2 are connected in series, with their positive and negative terminals connected to the positive and negative terminals of the power supply 12 outside the casing 1, respectively; and the current direction of the thermoelectric devices 2 can be switched.

[0040] The thermoelectric device 2 includes a horizontally placed upper ceramic plate 13 and a lower ceramic plate 14, and X copper electrodes 18 closely attached between the two. 2X thermoelectric semiconductors are placed between the copper electrodes 18. The 2X thermoelectric semiconductors include X P-type semiconductors and X N-type semiconductors, which are connected in series with each other in a PNP manner to form X pairs of thermoelectric arms.

[0041] The outer shell 1 is a hexagonal recessed container with a mounting hole in the center for the passage of liquid cooling pipe 4; the liquid cooling pipe 4 is a circular pipe that is closely attached to the through hole of the battery heat conduction frame 8, and the liquid cooling pipe 4 is filled with heat exchange liquid.

[0042] The outer casing 1 has a first hole at the left end, which corresponds to the liquid inlet 19 of the liquid cooling pipe 4, through which heat exchange liquid is introduced.

[0043] A second hole is opened at the right end of the outer casing 1, corresponding to the outlet 20 of the liquid cooling pipe 4. The heat exchange liquid flows out through the outlet 20 of the liquid cooling pipe 4. The liquid cooling pipe 4 is connected to the pump 9 and the heat exchanger 10 for heat exchange.

[0044] The bottom surface of the liquid cooling plate 3 is equal to the area of ​​the ceramic plate of the thermoelectric device 2. The liquid cooling plate 3 is in close contact with the ceramic plate of the thermoelectric device 2 to improve the heat exchange efficiency of the thermoelectric device 2 during cooling.

[0045] The liquid-cooled plate 3 includes an end cap 15, a plate body 16, and liquid-cooled pipe channels 17. The liquid-cooled pipe channels 17 are arranged in a bent and folded configuration inside the plate body 16, closely adhering to the inner bottom surface of the plate body 16. The inlet and outlet of the liquid-cooled pipe channels 17 are respectively connected to heat exchange liquid inlets and outlets provided by the liquid-cooled plate 3. Specifically, the liquid-cooled plate 3 has a liquid inlet 21 at the lower right, through which heat exchange liquid is introduced via the liquid-cooled pipe channels 17, and a liquid outlet 22 at the upper left, through which heat exchange liquid flows out. The liquid-cooled plate 3 is connected to the pump 9 and the heat exchanger 10 for heat exchange.

[0046] The battery 5, PCM6, battery heat-conducting frame 8, and liquid cooling pipe 4 inside the outer casing 1 form a heat conduction path.

[0047] Battery 5 → PCM6 → Battery thermal conductive frame 8 → Thermoelectric device 2 → Liquid cooling plate 3 form a thermal conductive path.

[0048] The pump 9 outside the outer casing 1 draws and circulates the heat exchange liquid in the liquid pipe 4 and the liquid cooling plate 3 through the heat exchanger 10 to form a liquid heat exchange passage.

[0049] The battery 5 is equipped with a temperature sensor to measure the temperature of the battery 5; the PCM6 is equipped with a liquid sensor to measure the liquid volume of the PCM6; both the temperature sensor and the liquid sensor are connected to the controller 11; the controller 11 is connected to the power supply 12, the pump 10, and the thermoelectric device 2 respectively.

[0050] This invention mainly utilizes the characteristics of thermoelectric device 2 based on thermoelectric effect, which can actively cool / heat, and PCM6, which only absorbs (or releases) latent heat without causing a temperature increase (or decrease), to perform thermal management on battery 5 during operation.

[0051] Temperature sensors are installed inside battery 5 to monitor its internal temperature. In high-temperature environments, PCM6 undergoes a phase change and stores the heat generated during battery discharge as latent heat. The cooling effect of thermoelectric device 2 and liquid cooling prevent PCM6 from becoming saturated with heat. In low-temperature environments, the heating effect of thermoelectric device 2 preheats battery 5. PCM6 controls the temperature rise during battery discharge and provides insulation after discharge. A liquid cooling plate 3 is placed at the heating end of thermoelectric device 2 to rapidly cool the heating end, improving the cooling effect. Fins 7 are added to PCM6 to improve thermal conductivity and reduce heat storage and release time.

[0052] Thermoelectric devices 2 are placed on the outer walls of the battery thermally conductive frame 8, forming a heat conduction path with the battery 5, PCM6, liquid cooling plate 3, and liquid cooling pipe 4. A temperature sensor inside the battery 5 transmits a temperature signal to the controller 11. A liquid sensor inside the PCM6 measures the volume fraction of the PCM6 liquid and transmits the signal to the controller 11. The controller 11 is connected to the power supply 12, pump 10, and thermoelectric devices 2, and adopts corresponding control strategies based on the temperature of the battery 5 and the phase change degree of the PCM6.

[0053] (1): When the temperature of battery 5 is T≥0℃, the PCM6 that wraps battery 5 absorbs the heat emitted by battery 5 and reduces the temperature of battery 5; the fins 7 that are installed on battery 5 and wrapped by PCM6 can improve the thermal conductivity of PCM6 and enhance the cooling effect of PCM6 on battery 5.

[0054] (2): When the volume fraction of PCM liquid is between 80% and 90%, the power supply 12 supplies positive current to the thermoelectric device 2, the temperature of the ceramic plate 13 at the upper end of the thermoelectric device 2 drops, and it becomes a cooling end. It absorbs the heat of PCM6 through the battery heat conduction frame 8 to prevent heat storage saturation. Therefore, PCM6 is in the phase change process. The temperature of PCM6 itself remains almost constant before the phase change is completed, forming a wide temperature plateau. This makes the temperature distribution of the enclosed battery 5 uniform. At the same time, the controller 11 controls the power supply 12 to supply current to the pump 9. The heat generated by the heat dissipation end of the thermoelectric device 2 and the latent heat absorbed by PCM6 can be carried away and discharged through the circulation of the heat conduction liquid in the heat conduction path.

[0055] (3): When the volume fraction of PCM liquid is above 90%, the power supply 12 supplies a large current to the pump 9, so that it works in the heat dissipation mode. By dissipating heat in the environment, the power of the pump 9 is increased, and the heat transfer liquid is driven to circulate in the liquid-cooled heat exchange path at a greater flow rate, thereby improving the heat dissipation efficiency.

[0056] (4): When the battery temperature is T≤0℃, the power supply 12 supplies reverse current to the thermoelectric device 2, the temperature of the ceramic plate 13 at the upper end of the thermoelectric device 2 rises, and it becomes the heating end. The PCM6 is heated by heat conduction through the battery heat conduction frame 8. When the PCM6 has completely undergone the phase change process, the heating stops. When the PCM6 cools down, the stored heat will be dissipated into the environment within a certain temperature range, and the reverse phase change from liquid to solid will be carried out. At this time, the dissipated heat is absorbed by the battery 5, and the battery temperature rises to above 0℃.

Claims

1. A thermal management system for a honeycomb battery module integrating thermoelectric devices and PCM, characterized in that... The system includes: a shell (1), a hexagonal honeycomb battery heat-conducting frame (8) installed inside the shell (1), the battery heat-conducting frame (8) has a through hole in the center, a liquid cooling pipe (4) passes through the through hole and is installed with the battery heat-conducting frame (8), and the liquid cooling pipe (4) is connected to a heat exchanger (10) for heat exchange; The outer wall of the battery heat-conducting frame (8) is tightly attached to thermoelectric devices (2), and the hot end of the thermoelectric device (2) is tightly attached to a liquid cooling plate (3). The liquid cooling plate (3) is connected to a heat exchanger (10) for heat exchange. The battery heat-conducting frame (8) has multiple grooves evenly distributed around the through hole, which are used to install the battery (5), PCM (6) and fins (7), respectively. The grooves are filled with PCM (6), the fins (7) are tightly attached to the battery (5), and the PCM (6) wraps around the battery (5) and the fins (7).

2. The thermal management system for a honeycomb battery module integrating thermoelectric devices and PCM according to claim 1, characterized in that: The battery thermally conductive frame (8) has multiple thermoelectric devices (2) evenly distributed on its outer wall. The thermoelectric devices (2) are used to prevent the PCM (6) from becoming saturated with heat and to heat the battery (5) at the same time.

3. The thermal management system for a honeycomb battery module integrating thermoelectric devices and PCM according to claim 2, characterized in that: The number of thermoelectric devices (2) placed on each outer wall of the battery heat-conducting frame (8) is A, and satisfies 1≤A≤16. The A thermoelectric devices (2) are connected in series, and their positive and negative terminals are connected to the positive and negative terminals of the power supply (12) outside the shell (1), respectively. Furthermore, the current direction of the thermoelectric devices (2) can be switched.

4. A thermal management system for a cellular battery module integrating thermoelectric devices and PCM according to claim 2 or 3, characterized in that: The thermoelectric device (2) includes a horizontally placed upper ceramic plate (13) and a lower ceramic plate (14), and X copper electrodes (18) closely attached between the two. 2X thermoelectric semiconductors are placed between the copper electrodes (18). The 2X thermoelectric semiconductors include X P-type semiconductors and N-type semiconductors, which are connected in series with each other in a PNP manner to form X pairs of thermoelectric arms.

5. The thermal management system for a honeycomb battery module integrating thermoelectric devices and PCM according to claim 1, characterized in that: The outer shell (1) is a hexagonal groove container with a mounting hole in the center for passing through the liquid cooling pipe (4); the liquid cooling pipe (4) is a circular pipe that is close to the through hole of the battery heat conduction frame (8), and the liquid cooling pipe (4) is filled with heat exchange liquid. The first hole is opened at the left end of the outer shell (1), corresponding to the liquid inlet (19) of the liquid cooling pipe (4), and the heat exchange liquid is introduced through the liquid inlet (19) of the liquid cooling pipe (4); A second hole is opened at the right end of the outer shell (1), corresponding to the liquid outlet (20) of the liquid cooling pipe (4), through which the heat exchange liquid flows out; The liquid cooling pipe (4) is connected to the pump (9) and the heat exchanger (10) for heat exchange.

6. The thermal management system for a cellular battery module integrating thermoelectric devices and PCM according to claim 1, characterized in that: The bottom surface of the liquid cooling plate (3) is equal to the area of ​​the ceramic plate of the thermoelectric device (2). The liquid cooling plate (3) is in close contact with the ceramic plate of the thermoelectric device (2) to improve the heat exchange efficiency of the thermoelectric device (2) during cooling.

7. The thermal management system for a honeycomb battery module integrating thermoelectric devices and PCM according to claim 1, characterized in that: The liquid cooling plate (3) includes an end cap (15), a plate body (16), and a liquid cooling pipe guide (17); wherein the liquid cooling pipe guide (17) is bent and folded inside the plate body (16) and closely attached to the inner bottom surface of the plate body (16); heat exchange liquid inlet and outlet are opened at both ends of the liquid cooling pipe guide (17); The liquid cooling plate (3) has a liquid inlet (21) on the lower right, through which heat exchange liquid is introduced via the liquid cooling pipe guide (17), and a liquid outlet (22) on the upper left, through which heat exchange liquid flows out. The liquid cooling plate (3) is connected to the pump (9) and the heat exchanger (10) for heat exchange.

8. The thermal management system for a cellular battery module integrating thermoelectric devices and PCM according to claim 1, characterized in that: The battery (5) → PCM (6) → battery heat-conducting frame (8) → liquid cooling pipe (4) inside the outer shell (1) form a heat conduction path; Battery (5) → PCM (6) → Battery thermally conductive frame (8) → Thermoelectric device (2) → Liquid cooling plate (3) form a thermally conductive path; the pump (9) outside the outer shell (1) draws and circulates the heat exchange liquid in the liquid cooling pipe (4) and liquid cooling plate (3) through the heat exchanger (10) to form a liquid heat exchange path.

9. The thermal management system for a cellular battery module integrating thermoelectric devices and PCM according to claim 1, characterized in that: The battery (5) is equipped with a temperature sensor to measure the temperature of the battery (5); the PCM (6) is equipped with a liquid sensor to measure the liquid volume of the PCM (6); the temperature sensor and the liquid sensor are both connected to the controller (11); the controller (11) is connected to the power supply (12), the pump (9), and the thermoelectric device (2) respectively.

10. The battery thermal management method of the battery module thermal management system according to claim 4, characterized in that: Based on the temperature of the battery (5) and the degree of phase transition of the PCM (6), corresponding control strategies are adopted: 1) When the battery (5) temperature T≥T target When the battery (5) is charging and discharging normally, the temperature rises. At this time, the PCM (6) that wraps the battery (5) exchanges heat with the battery (5) and absorbs the heat emitted by the battery (5), thus reducing the temperature of the battery (5). The fins (7) that are installed on the battery (5) and wrapped by the PCM (6) improve the thermal conductivity of the PCM (6), so that the heat of the battery (5) can be quickly absorbed by the PCM (6) and thus reduce the temperature of the battery (5). 2) When the volume fraction of PCM liquid is between 80% and 90%, the controller (11) controls the power supply (12) to supply positive current to the thermoelectric device (2), the temperature of the upper ceramic plate (13) of the thermoelectric device (2) drops, becoming the cooling end, while the temperature of the lower ceramic plate (14) of the thermoelectric device rises, becoming the heat dissipation end; and through the heat conduction of the battery heat conduction frame (8), the heat storage saturation of PCM (6) is prevented, so that PCM (6) is always in the phase change process; the temperature of PCM (6) itself remains unchanged before the phase change is completed, so that the temperature distribution of the enclosed battery (5) is uniform; at the same time, the controller (11) controls the power supply (12) to supply current to the pump (9), and the heat generated by the heat dissipation end of the thermoelectric device (2) and the latent heat absorbed by PCM (6) can be carried out through the circulation of the heat conduction liquid in the heat conduction path; 3) When the volume fraction of PCM6 liquid is above 90%, the controller (11) controls the power supply (12) to supply a large current to the pump (9) so that it works in the heat dissipation mode. By dissipating heat in the environment, the power of the pump (9) is increased, and the heat transfer liquid is driven to circulate in the liquid-cooled heat exchange path at a greater flow rate, thereby improving the heat dissipation efficiency. 4) When the battery temperature is T≤T target At this time, the controller (11) controls the power supply (12) to supply a reverse current to the thermoelectric device (2), wherein the temperature of the upper ceramic plate (13) of the thermoelectric device (2) rises and becomes the heating end, while the temperature of the lower ceramic plate (14) of the thermoelectric device (2) drops and becomes the heat absorption end; the PCM (6) is heated by heat conduction through the battery heat conduction frame (8), and the heating stops when the PCM (6) has completely undergone the phase change process; when the PCM (6) cools down, the stored heat will be dissipated into the environment within a certain temperature range, and the reverse phase change from liquid to solid will be carried out. At this time, the dissipated heat is absorbed by the battery (5), and the battery temperature rises to T. target above.

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