Vehicle battery thermal management system and thermal management method based on FPC

Abstract

The invention relates to the technical field of battery thermal management, in particular to an FPC-based vehicle battery thermal management system and a thermal management method.The system comprises a battery cell, an FPC, a temperature control device and a protection device, a current collector is provided with a temperature measurement area and a heat conduction layer, and the heat conduction layer collects heat to the temperature measurement area; the FPC circuit board is provided with a sensor array and an AI chip. The protection device is provided with a neutralizer and an exhaust mechanism. According to the invention, the heat of the current collector is collected in the temperature measurement area through the heat conduction layer, the sensor array collects the data of the temperature measurement area, and the AI chip predicts the working temperature of the battery cell according to the temperature, current, voltage and SOC time sequence data of the battery cell and controls the temperature control device to accurately regulate and control the working temperature of the battery cell, so that the battery cell works at a proper temperature; during thermal runaway, the neutralizer of the protective device can neutralize harmful substances generated during thermal runaway of the battery cell to delay temperature rise of the battery cell, and the exhaust mechanism exhausts gas, so that the performance, the service life and the safety of the battery are effectively guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of battery thermal management, and particularly to a vehicle battery thermal management system and a thermal management method based on FPC. Background Art

[0002] In the field of vehicle batteries, battery thermal management directly affects their performance, lifespan, and safety. Traditional vehicle battery thermal management systems have obvious shortcomings.

[0003] In terms of temperature monitoring, traditional systems mostly rely on simple temperature sensors for local temperature measurement, unable to comprehensively and accurately grasp the temperature changes of the battery cells, and even less able to predict future temperature trends. This means that under complex working conditions, the thermal management system cannot respond to temperature anomalies in advance and can only adjust after problems occur, making it difficult to effectively guarantee the battery performance and service life.

[0004] In terms of heat conduction and temperature regulation, the heat conduction path of traditional systems is unreasonable, with heat dispersion, making it difficult to quickly concentrate and process heat and regulate temperature. The thermal management efficiency is low, and the battery temperature cannot be timely controlled within an appropriate range, affecting the battery stability and safety.

[0005] In terms of thermal runaway safety protection, traditional systems lack effective countermeasures. When the battery undergoes thermal runaway, harmful substances decomposed from the electrolyte spread, and the internal pressure surges suddenly, extremely likely to trigger serious accidents such as explosion and fire, posing a huge threat to personnel and vehicles. Therefore, it is extremely urgent to develop a vehicle battery thermal management system with accurate monitoring and prediction, efficient thermal management, and perfect thermal runaway protection. Summary of the Invention

[0006] The purpose of the present invention is to provide a vehicle battery thermal management system and a thermal management method based on FPC in view of the deficiencies of the prior art. The heat of the current collector is collected in the temperature measurement area through the heat conduction layer, the sensor array collects data in the temperature measurement area, the AI chip predicts the working temperature of the battery cell based on the data and controls the temperature control device to accurately regulate the working temperature of the battery cell, so that the battery cell works at an appropriate temperature; when thermal runaway occurs, the neutralizer of the protection device can neutralize the harmful substances generated during the thermal runaway of the battery cell, delay the temperature rise of the battery cell, and the exhaust mechanism discharges gas, effectively guaranteeing the battery performance, lifespan, and safety.

[0007] To achieve the above purpose, a vehicle battery thermal management system based on FPC of the present invention includes battery cells, the battery cells are provided with current collectors and outer casings, the current collectors are arranged inside the outer casings, and further includes an FPC circuit board, a temperature control device, and a protection device. The FPC circuit board is electrically connected to the battery cells, the temperature control device, and the protection device; A temperature measurement area is arranged on the upper part of the current collector, and a heat conduction layer is arranged on the periphery of the current collector. The heat conduction layer collects the heat of the current collector to the temperature measurement area; The FPC circuit board is provided with a sensor array and an AI chip. The sensor array is used to collect the temperature data of the temperature measurement area in real time. The AI chip is used to run the LSTM model, and according to the temperature, current, voltage and SOC time series data of the battery cell, output the predicted temperature field of the battery cell in the next 5 minutes and generate a control instruction to control the temperature control device. The temperature control device is connected to the heat conduction layer and is used to respond to the control instruction to adjust the temperature of the current collector through the heat conduction layer. The protection device is provided with a neutralizer and an exhaust mechanism. When the thermal runaway of the battery cell reaches a preset temperature, the neutralizer neutralizes the harmful substances generated by the decomposition of the electrolyte, delaying the temperature rise of the battery cell. The exhaust mechanism is used to exhaust the gas generated during the neutralization process.

[0008] Preferably, the heat conduction layer is further provided with a heat conduction belt connecting the upper and lower sides of the current collector.

[0009] Preferably, the sensor array includes a thin film thermocouple and a pressure sensor, and both the pressure sensor and the thin film thermocouple are arranged in the temperature measurement area.

[0010] Preferably, the temperature control device includes a micro liquid cooling channel and a thermoelectric cooler. The micro liquid cooling channel is thermally coupled with one side of the thermoelectric cooler through boron nitride-filled silica gel. The other side of the thermoelectric cooler is thermally coupled with the heat conduction layer through boron nitride-filled silica gel.

[0011] Preferably, the protection device is provided with neutralization chambers at the four corners inside the housing. A heat conduction frame is arranged inside the neutralization chambers, and the neutralizer is fixed to the heat conduction frame. The neutralizer is a hollow mesoporous silica sphere nano-reactor, and a neutralization powder is encapsulated inside the hollow mesoporous silica sphere nano-reactor. The neutralization powder neutralizes the harmful substances generated by the decomposition of the electrolyte when the battery cell undergoes thermal runaway, delaying the temperature rise of the battery cell. The exhaust mechanism includes an exhaust cavity arranged at the top of the neutralization chamber. The exhaust cavity is provided with a one-way exhaust valve communicating with the outside, and the gas generated during the neutralization process is exhausted through the one-way exhaust valve to relieve the internal pressure of the battery cell.

[0012] Preferably, a sealing film for sealing the neutralization chamber is arranged on the side of the neutralization chamber facing the battery cell, and the dissolution temperature of the sealing film is the same as the preset temperature.

[0013] Preferably, the battery cell is further provided with a heat conduction module, and the heat conduction module is connected between the current collector and the sealing film. A low melting point alloy layer is arranged between the neutralizer and the heat conduction frame, and the triggering temperature of the low melting point alloy layer is set to be ±5°C of the preset temperature of the thermal runaway of the battery cell.

[0014] Preferably, the heat-conducting module comprises a heat-conducting sheet and a heat-conducting bridge disposed in the housing, and the heat of the current collector is conducted to the sealing film and the low-melting-point alloy layer via the heat-conducting sheet and the heat-conducting bridge.

[0015] On the other hand, a thermal management method is also provided, including the above-mentioned vehicle battery thermal management system, and the specific steps are: S1, the sensor array collects the temperature of the battery cell in real time to form temperature data; S2, AI chip predicts the temperature field in the next 5 minutes based on the temperature, current, voltage and SOC time series data of the battery cell through the LSTM model, and generates optimization instructions for the temperature control device; S3, the temperature control device responds to the instruction and adjusts the temperature of the current collector; S4: When it is detected that the battery cell temperature reaches the preset temperature, it is judged as thermal runaway, triggering the exhaust mechanism to release pressure in a directional manner, and simultaneously activating the neutralizer to neutralize the harmful substances produced by the decomposition of the electrolyte.

[0016] Beneficial effects of the present invention: The battery cell generates heat when it is working, and the heat-conducting layer collects the heat generated by the current collector to the upper temperature measurement area. The sensor array on the FPC circuit board collects temperature data of the temperature measurement area in real time. The AI ​​chip runs the LSTM model to predict the temperature field in the next 5 minutes and generate control instructions based on the temperature, current, voltage and SOC timing data. The temperature control device responds to the instruction and heats or cools the current collector through the heat-conducting layer to ensure that the battery cell is at an appropriate temperature. When the thermal runaway temperature of the battery cell rises to the preset value, the protective device is activated. The neutralizer reacts with harmful substances decomposed by the electrolyte, absorbs heat, and delays temperature rise. The exhaust mechanism discharges the gas generated by neutralization to prevent excessive internal pressure from causing safety accidents. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the front cross-sectional structure of the present invention.

[0018] Figure 2 It is a schematic diagram of the lateral partial explosion structure of the present invention.

[0019] Figure 3 It is a schematic diagram of the partial structure of the present invention in a front cross-sectional view.

[0020] Reference numerals include: 1. Battery cell; 11. Current collector; 12. Outer shell; 13. Temperature measurement area; 14. Heat conduction layer; 141. Heat conduction belt; 142. Temperature conduction connector; 143. Temperature conduction sheet; 15. Sealing cover; 16. Temperature conduction component; 161. Insertion connection sheet; 162. Temperature conduction groove; 17. Separation film; 18. Heat conduction module; 181. Heat conduction sheet; 182. Heat conduction bridge; 2. FPC circuit board; 21. Sensor array; 211. Thin film thermocouple; 212. Pressure sensor; 22. AI chip; 3. Temperature control device; 31. Micro liquid cooling channel; 32. Thermoelectric cooler; 4. Protection device; 41. Neutralizer; 42. Exhaust mechanism; 421. Exhaust cavity; 422. One-way exhaust valve; 423. Breathable liquid isolation film; 43. Neutralization chamber; 431. Sealing film; 44. Heat conduction frame. Detailed implementation mode

[0021] The present invention will be described in detail below with reference to the accompanying drawings.

[0022] As Figures 1 to 3 shown, a vehicle - used battery thermal management system based on FPC of the present invention includes a battery cell 1. The battery cell 1 is provided with a current collector 11 and an outer shell 12, and the current collector 11 is arranged inside the outer shell 12. It also includes an FPC circuit board 2, a temperature control device 3, and a protection device 4. The FPC circuit board 2 is electrically connected to the battery cell 1, the temperature control device 3, and the protection device 4 respectively.

[0023] A temperature measurement area 13 is arranged on the upper part of the current collector 11, and a heat conduction layer 14 is arranged on the periphery of the current collector 11. The heat conduction layer 14 collects the heat of the current collector 11 to the temperature measurement area 13; The FPC circuit board 2 is provided with a sensor array 21 and an AI chip 22. The sensor array 21 is used to collect the temperature data of the temperature measurement area 13 in real time; The AI chip 22 is used to run the LSTM model, and according to the temperature, current, voltage, and SOC time - series data of the battery cell 1, output the predicted temperature field of the battery cell 1 in the next 5 minutes and generate a control instruction to control the temperature control device 3; The temperature control device 3 is connected to the heat conduction layer 14 and is used to respond to the control instruction to adjust the temperature of the current collector 11 through the heat conduction layer 14; The protection device 4 is provided with a neutralizer 41 and an exhaust mechanism 42. When the battery cell 1 reaches a preset temperature in thermal runaway, the neutralizer 41 neutralizes the harmful substances generated by the decomposition of the electrolyte, delaying the temperature rise of the battery cell 1, and the exhaust mechanism 42 is used to exhaust the gas generated during the neutralization process.

[0024] Specifically, a temperature measurement area 13 is provided on the upper part of the current collector 11, and the sensor array 21 collects data from the temperature measurement area 13 in real time. The AI ​​chip runs the LSTM model, outputs the temperature field prediction of the battery cell 1 in the next 5 minutes and generates control instructions based on the temperature, current, voltage and SOC timing data. It can accurately predict temperature changes in advance, provide a forward-looking basis for temperature regulation, and effectively ensure battery performance and service life. Among them, the AI ​​chip can be NXP S32G274A, NVIDIA JetsonXavier NX or Horizon Journey 5 and other chips.

[0025] A heat-conducting layer 14 is provided around the edges of the current collector 11 to collect heat to the temperature measuring area 13. The temperature control device 3 is connected to the heat-conducting layer 14, and responds to control instructions to adjust the temperature of the current collector 11 through the heat-conducting layer 14. The heat is quickly collected and processed centrally, and the temperature of the current collector 11 is adjusted in time, thereby improving the thermal management efficiency of the battery cell 1 and ensuring that the battery cell 1 works at an appropriate temperature.

[0026] On the other hand, the effective protection of the edge burrs of the current collector 11 by the thermal conductive layer 14 greatly reduces the risk of puncture of the diaphragm, fundamentally reducing the probability of internal short circuit of the battery, thereby effectively avoiding thermal runaway, fire, explosion and other safety accidents caused by short circuit, providing reliable safety protection for vehicles and personnel, and meeting the strict safety requirements of automotive batteries.

[0027] The protection device 4 is provided with a neutralizer 41 and an exhaust mechanism 42. When the thermal runaway reaches a preset temperature, the neutralizer 41 neutralizes the electrolyte to decompose harmful substances and delay the temperature rise, and the exhaust mechanism 42 discharges the neutralized gas. The harm of harmful substances is reduced, the temperature rise is delayed to gain emergency time, and the gas is discharged to prevent excessive pressure, thereby improving the safety of the battery system.

[0028] When working, the battery cell 1 generates heat, and the heat-conducting layer 14 collects the heat generated by the current collector 11 to the upper temperature measurement area 13. The sensor array 21 on the FPC circuit board collects the temperature data of the temperature measurement area 13 in real time. The AI ​​chip runs the LSTM model to predict the temperature field in the next 5 minutes and generate control instructions based on the temperature, current, voltage and SOC timing data. The temperature control device 3 responds to the instruction and heats up or cools the current collector 11 through the heat-conducting layer 14 to ensure that the battery cell 1 is at a suitable temperature. When the thermal runaway temperature of the battery cell 1 rises to the preset value, the protection device 4 is activated. The neutralizer 41 reacts with the harmful substances decomposed by the electrolyte, absorbs heat, and delays the temperature rise. The exhaust mechanism 42 discharges the gas generated by neutralization to prevent excessive internal pressure from causing safety accidents.

[0029] like Figure 1 As shown, the heat-conducting layer 14 of this embodiment is further provided with a heat-conducting belt 141 connecting the upper side and the lower side of the current collector 11 .

[0030] Specifically, the material of the heat-conducting layer 14 is an epoxy resin heat-conducting adhesive containing alumina filler, a boron nitride-filled polyimide heat-conducting film, a silicone rubber heat-conducting gasket containing graphite filler, or a graphene / epoxy resin composite heat-conducting material with surface insulation treatment.

[0031] Burrs on the edge of the current collector 11 are likely to pierce the separator, and heat is likely to accumulate at the edge of the current collector 11. The heat-conducting layer 14 effectively reduces the temperature of the current collector 11, reduces the risk of damage to the separator caused by heat accumulation, reduces the probability of internal short circuit of the battery, and improves the safety and service life of the battery.

[0032] Heat-conducting strips 141 are provided on the upper and lower sides of the current collector 11. Utilizing the high heat conductivity of the heat-conducting strips 141, an additional conduction path for heat is provided. According to the principle that heat can diffuse more rapidly in a medium with good heat conduction, heat can be more evenly distributed and conducted. Further optimizing the heat distribution inside the battery, avoiding local overheating, improving the performance stability of the battery, and ensuring the normal operation of the battery under various working conditions.

[0033] As Figure 2 shown, the sensor array 21 of this embodiment includes thin-film thermocouples 211 and pressure sensors 212, and both the pressure sensors 212 and the thin-film thermocouples 211 are arranged in the temperature measurement area 13.

[0034] Specifically, the thin-film thermocouple 211 is based on the thermoelectric effect. When there is a temperature gradient in a closed loop composed of two different metal materials, a thermoelectric potential will be generated in the loop, and the temperature value can be determined by measuring the magnitude of the thermoelectric potential. Setting it in the temperature measurement area 13 can directly contact this area to sense temperature changes. It can accurately measure the temperature of the temperature measurement area 13, obtain accurate temperature data, help detect temperature anomalies in a timely manner, provide a reliable basis for battery thermal management, and ensure the battery operates within an appropriate temperature range.

[0035] The pressure sensor 212 utilizes principles such as the piezoelectric effect and the strain effect. When subjected to pressure, its internal physical properties change and a measurable electrical signal is generated. The magnitude of the pressure can be calculated by detecting this electrical signal. Being arranged in the temperature measurement area 13 can sense the pressure changes in this area. It can real-time monitor the pressure condition of the temperature measurement area 13, and send a signal in a timely manner when the pressure shows abnormal fluctuations, which can assist in judging whether there are problems such as structural damage and abnormal gas accumulation in the battery, early warning of potential safety risks, and enhancing the safety of battery use.

[0036] Combining the temperature measurement function of the thin-film thermocouple 211 and the pressure measurement function of the pressure sensor 212, two key parameters of temperature and pressure are simultaneously obtained in the same temperature measurement area 13. By utilizing the correlation and mutual influence between different physical quantities, the state of the temperature measurement area 13 can be more comprehensively reflected. It realizes multi-dimensional and comprehensive monitoring of the temperature measurement area 13, improves the accuracy and reliability of battery state judgment, can more timely and comprehensively detect potential problems of the battery, optimizes the battery's thermal management and safety guarantee measures, and extends the battery's service life.

[0037] In actual use, the sensor array 21 also includes a current sensor and a voltage sensor. The current sensor is, for example, a Hall current sensor. The measurement hole of the Hall current sensor passes through the wire of the circuit where the battery cell 1 is located to ensure accurate measurement of the current passing through the battery cell 1. The voltage sensor is, for example, a voltage divider resistor type voltage sensor. The measurement end of the voltage sensor is connected to the positive and negative electrodes of the battery cell 1 to ensure that the actual voltage across the battery cell 1 is measured. Multiple parameters of current, voltage, and temperature are integrated for SOC estimation. It facilitates the AI chip 22 to run the LSTM model and output the predicted temperature field of the battery cell 1 in the next 5 minutes according to the temperature, current, voltage, and SOC time series data.

[0038] As Figure 2 shown, the temperature control device 3 of this embodiment includes a micro liquid cooling channel 31 and a thermoelectric cooler 32. One side of the micro liquid cooling channel 31 is thermally coupled to the thermoelectric cooler 32 through boron nitride-filled silica gel; the other side of the thermoelectric cooler 32 is thermally coupled to the heat conduction layer 14 through boron nitride-filled silica gel.

[0039] It realizes that both the micro liquid cooling channel 31 and the heat conduction layer 14 are connected to the thermoelectric cooler 32 in a thermally coupled manner, improving the heat transfer efficiency. The cold or heat generated by the thermoelectric cooler 32 is transferred to the micro liquid cooling channel 31 more quickly, accelerating the response speed of the temperature control device 3, enabling the temperature of the battery cell 1 to reach the set value faster, and improving the accuracy and timeliness of temperature control.

[0040] Specifically, when the thermoelectric cooler 32 cools and reduces the temperature of the heat conduction layer 14, the micro liquid cooling channel 31 continuously absorbs the heat of the thermoelectric cooler 32 through coolant circulation (such as ethylene glycol aqueous solution) to make the thermoelectric cooler 32 work stably. When the thermoelectric cooler 32 heats and heats the heat conduction layer 14, the micro liquid cooling channel 31 reduces or stops the coolant circulation speed.

[0041] The thermoelectric cooler 32 is based on the Peltier effect and realizes refrigeration or heating by switching the direction of the current.

[0042] In actual use, the outer shell 12 is provided with a sealing cover 15. The sealing cover 15 is provided with a heat conducting member 16. The heat conducting member 16 is provided with a plurality of connected insertion connecting pieces 161 on the inner side facing the outer shell 12. There are heat conducting grooves 162 between the insertion connecting pieces 161. The other side of the heat conducting member 16 is thermally coupled to the thermoelectric cooler 32.

[0043] One end of the heat conducting layer 14 is provided with a heat conducting connector 142. The heat conducting connector 142 includes at least two connected heat conducting pieces 143. The heat conducting pieces 143 are arranged in the heat conducting grooves 162, so that the heat conducting layer 14 is thermally coupled and connected to the thermoelectric cooler 32.

[0044] Both the heat conducting member 16 and the heat conducting connector 142 are made of metal materials, graphite materials, ceramic matrix composite materials, boron nitride materials or polymer matrix thermally conductive insulating materials, so that the heat conducting member 16 and the heat conducting connector 142 have good thermal conductivity.

[0045] The sealing cover 15 is also provided with an isolation film 17. The isolation film 17 covers the connection between the temperature connection head and the insertion connecting piece 161 and the connection between the temperature measurement area 13 and the heat conductor. The connection between the temperature connection head and the insertion connecting piece 161 and the temperature measurement area 13 are separated from the inside of the battery cell 1. The isolation film 17 can be a polypropylene film, a polyimide film and a polytetrafluoroethylene film.

[0046] As Figure 3 shown, the protection device 4 of this embodiment is provided with neutralization chambers 43 at the four corners inside the outer shell 12, making reasonable use of the internal space of the outer shell 12. A heat conducting frame 44 is arranged inside the neutralization chamber 43. The neutralizer 41 is fixed to the heat conducting frame 44, so that the neutralizer 41 is fixed in the neutralization chamber 43. And the heat conducting frame 44 can conduct the heat inside the neutralizer 41 and the battery cell to the neutralizer 41, melting the protective layer on the surface of the neutralizer 41 and quickly activating the neutralizer 41 to carry out a neutralization reaction.

[0047] The neutralizer 41 is a hollow mesoporous silica sphere nano reactor. The hollow mesoporous silica sphere nano reactor is internally encapsulated with a neutralization powder. The neutralization powder neutralizes the harmful substances generated by the decomposition of the electrolyte during the thermal runaway of the battery cell 1, delaying the temperature rise of the battery cell 1. The hollow mesoporous silica sphere nano reactor has a unique mesoporous structure. This structure has a large specific surface area, enabling the internally encapsulated neutralization powder to fully contact and react with the harmful substances, thus achieving neutralization. The neutralizer 41 can be prepared by a chemical synthesis method of the sol-gel method. The internally encapsulated neutralization powder can be selected according to the types of harmful substances. For example, for hydrogen fluoride acidic harmful substances, a basic neutralization powder of magnesium hydroxide can be selected.

[0048] The exhaust mechanism 42 includes an exhaust cavity 421 provided at the top of the neutralization chamber 43. A one-way exhaust valve 422 communicating with the outside is provided in the exhaust cavity 421. The gas generated during the neutralization process is discharged through the one-way exhaust valve 422 to relieve the internal pressure of the battery cell 1. Specifically, gas is generated during the neutralization process, causing the internal pressure of the battery cell 1 to increase. When the internal pressure of the battery cell 1 reaches the opening pressure of the one-way exhaust valve 422, the one-way exhaust valve 422 opens, and the gas is discharged to the outside through the one-way exhaust valve 422. Discharging the gas generated by neutralization in a timely manner relieves the internal pressure of the battery cell 1, prevents dangers such as explosion caused by excessive pressure, and ensures the safety of the battery cell 1.

[0049] Wherein, a breathable liquid separation membrane 423 is provided in the exhaust cavity 421. A tear line is provided at the connection between the breathable liquid separation membrane 423 and the inner wall of the exhaust cavity 421. The liquid inside the exhaust cavity 421 is filtered through the breathable liquid separation membrane 423, and the gas is allowed to be discharged from the exhaust cavity 421 through the one-way exhaust valve 422. When the internal pressure of the exhaust cavity 421 is too high, the breathable liquid separation membrane 423 tears along the tear line to reduce the internal pressure of the exhaust cavity 421. The breathable liquid separation membrane 423 can be an expanded polytetrafluoroethylene membrane, a polyurethane breathable membrane or a polyvinylidene fluoride membrane.

[0050] In actual use, the neutralization chamber 43 can be made of a plastic material, such as polycarbonate (PC), which has good insulation and certain mechanical strength, can effectively protect the internal neutralizer 41 and heat conduction frame 44, and does not affect the normal operation of the battery cell 1 at the same time.

[0051] The heat conduction frame 44 can use an aluminum alloy material, and the aluminum alloy has a high heat conduction coefficient and can conduct heat quickly.

[0052] As Figure 3 shown, a sealing film 431 for sealing the neutralization chamber 43 is provided on one side of the neutralization chamber 43 facing the battery cell 1, and the dissolution temperature of the sealing film 431 is the same as the preset temperature. Among them, the sealing film 431 can be a polyvinyl alcohol (PVA) film or a polyethylene oxide (PEO) film.

[0053] Specifically, the sealing film 431 is provided on one side of the neutralization chamber 43 facing the battery cell 1, and its dissolution temperature is the same as the preset temperature. When the battery cell 1 is operating normally, the temperature is lower than the preset temperature, and the sealing film 431 remains intact to seal the neutralization chamber 43, preventing the neutralization powder in the neutralizer 41 from contacting the outside environment in advance and avoiding unnecessary reactions or powder leakage. When the battery cell 1 undergoes thermal runaway and the temperature reaches the preset temperature, the sealing film 431 dissolves, enabling the neutralization chamber 43 to communicate with the inside of the battery cell 1, and the neutralization powder can contact and react with the harmful substances generated by the decomposition of the electrolyte.

[0054] Effectively control the starting timing of the neutralization reaction to ensure that it takes effect in a timely manner when the battery cell 1 undergoes thermal runaway, while avoiding interference with the performance of the battery cell 1 during its normal operation, thereby improving the reliability and stability of the protection device 4.

[0055] As Figure 3 shown, the battery cell 1 of this embodiment is further provided with a heat conduction module 18, and the heat conduction module 18 is connected between the current collector 11 and the sealing film 431, as well as between the current collector 11 and the heat conduction frame 44; There is a low-melting-point alloy layer between the neutralizer 41 and the heat conduction frame 44, and the trigger temperature of the low-melting-point alloy layer is set to be ±5 °C of the preset temperature of the thermal runaway of the battery cell 1.

[0056] Specifically, the heat conduction module 18 is connected between the current collector 11 and the sealing film 431. When the battery cell 1 is working, the generated heat will be conducted to the current collector 11. The heat conduction module 18 utilizes its good heat conduction performance to quickly transfer the heat on the current collector 11 to the sealing film 431 and the heat conduction frame 44. When the battery cell 1 undergoes thermal runaway, the heat conduction module 18 can assist in heat transfer, creating conditions for the subsequent dissolution of the sealing film 431 and the start of the neutralization reaction. The heat conduction module 18 can be a graphite sheet and / or a copper foil, which plays a role in efficiently conducting heat.

[0057] The low-melting-point alloy layer can be a bismuth-based alloy (bismuth, tin, lead alloy, with a melting point range between 70 °C and 200 °C) or an indium-based alloy (indium, tin alloy, with a melting point range between 118 °C and 232 °C). The low-melting-point alloy layer is arranged between the neutralizer 41 and the heat conduction frame 44, and the trigger temperature is set to be ±5 °C of the preset temperature of the thermal runaway of the battery cell 1. When the temperature of the battery cell 1 reaches the preset temperature, the low-melting-point alloy layer will melt, causing the connection state between the neutralizer 41 and the heat conduction frame 44 to change. The neutralizer 41 originally fixed to the heat conduction frame 44 will be separated from the heat conduction frame 44 due to the melting of the alloy, enabling the neutralizer 41 to be in close contact with the harmful substances inside the battery cell 1. On the other hand, it also makes way for other neutralizers 41 densely arranged on the heat conduction frame 44, allowing the neutralizers 41 on the heat conduction frame 44 to all carry out neutralization reactions with the harmful substances. Precise control of the contact timing between the neutralizer 41 and the harmful substances can timely start the neutralization reaction when the thermal runaway of the battery cell 1 reaches a certain temperature, effectively delaying the temperature rise of the battery cell 1 and reducing the harm caused by thermal runaway.

[0058] As Figure 3 shown, the heat conduction module 18 of this embodiment includes a heat conduction sheet 181 and a heat conduction bridge 182 arranged inside the housing 12. Both the current collector 11 and the heat conduction bridge 182 are connected to the heat conduction sheet 181, and the heat conduction bridge 182 is connected to the heat conduction frame 44; The heat of the current collector 11 is conducted to the sealing film 431 through the heat conduction sheet 181, and is conducted to the low-melting-point alloy layer through the heat conduction sheet 181, the heat conduction bridge 182 and the heat conduction frame 44.

[0059] Specifically, the heat of the current collector 11 is conducted to the sealing film 431 through the heat conducting sheet 181, so that when the battery cell 1 undergoes thermal runaway, the sealing film 431 can be triggered to dissolve in time, facilitating the harmful substances generated by the thermal runaway to smoothly enter the neutralization chamber 43 and react with the neutralizer 41. The heat of the current collector 11 is conducted to the low melting point alloy layer through the heat conducting sheet 181, the heat conducting bridge 182 and the heat conducting frame 44, melting the low melting point alloy layer, separating the neutralizer 41 from the heat conducting frame 44, and precisely controlling the contact timing between the neutralizer 41 and the harmful substances.

[0060] The loss function of the LSTM model in this embodiment is: ;

[0061] Among them, is the mean squared error term, Specifically, , which is used to measure the predicted temperature field and the true temperature field point-by-point difference. MSE measures the average of the squared errors between the predicted value and the true value , paying attention to the prediction accuracy of the overall value to ensure the absolute accuracy of the overall temperature prediction.

[0062] is the gradient penalty term, Specifically, , the gradient penalty term is used to measure the spatial gradient difference between the predicted temperature field and the true temperature field, that is, the severity of the temperature change. It plays a role in forcing the model to learn a reasonable temperature distribution law, such as avoiding local mutations and conforming to the characteristics of thermodynamic conduction. By combining the mean squared error term and the gradient penalty term, the model is more in line with the real situation in both the overall value and spatial characteristics, improving the model's fitting ability and generalization ability for complex data.

[0063] The weight coefficient α is used to control the weight of the absolute temperature accuracy; the weight coefficient β controls the weight of the temperature gradient consistency. In the specific usage process, α = 0.7 and β = 0.3 can be set, which means paying more attention to the overall temperature error while taking into account the gradient smoothness. For different battery types, such as ternary lithium and lithium iron phosphate, different weight distributions may be required. For high-energy density batteries (such as solid-state batteries) that are sensitive to gradients, the value of the weight coefficient β needs to be increased. For scenarios with high real-time requirements, such as fast charging scenarios, the value of the weight coefficient α needs to be increased to ensure the absolute temperature accuracy first. Setting a reasonable weight range enables the model to balance numerical prediction and feature capture during the training process. It can avoid the model over-focusing on one aspect due to the excessive weight of a certain error term, thereby improving the comprehensive performance of the model and achieving good prediction results in different data distributions and task scenarios.

[0064] On the other hand, a thermal management method is also provided, including the above-mentioned vehicle battery thermal management system. The specific steps are as follows: S1. The sensor array 21 collects the temperature of the battery cell 1 in real time to form temperature data. S2. The AI chip 22 predicts the temperature field in the next 5 minutes through the LSTM model based on the temperature, current, voltage, and SOC time series data of the battery cell 1, and generates an optimization instruction for the temperature control device 3. S3. The temperature control device 3 responds to the instruction and adjusts the temperature of the current collector 11. S4. When it is detected that the temperature of the battery cell 1 reaches the preset temperature, it is determined that thermal runaway occurs, triggering the exhaust mechanism 42 to release pressure in a targeted manner, and simultaneously activating the neutralizer 41 to neutralize the harmful substances generated by the decomposition of the electrolyte.

[0065] Specifically, the temperature data of the battery cell 1 is obtained in real time through the sensor array 21, providing a solid foundation for subsequent accurate temperature prediction and formulating thermal management strategies, and being able to detect the abnormal state of the battery cell 1 in a timely manner.

[0066] The LSTM model is good at processing time series data. The AI chip 22 inputs the collected temperature data into the model. The model learns the correlation patterns of temperature with time and parameters such as current, voltage, and SOC in the historical data, predicts the temperature field distribution in the next 5 minutes, and generates an optimization instruction for the temperature control device 3 accordingly. Predicting the temperature change in advance to achieve active thermal management, and the accurate instruction can effectively guide the operation of the temperature control device 3, ensuring that the battery operates at an appropriate temperature and improving the battery performance and safety.

[0067] The temperature control device 3 includes heating, cooling elements and a control circuit. After receiving the instruction, the control circuit adjusts the working states of the heating and cooling elements according to the instruction. If cooling is required, the power of the cooling element is increased; if heating is required, the power of the heating element is increased. It responds quickly to the instruction and accurately adjusts the temperature of the battery cell 1 to ensure that the battery is in the best working temperature range, improving the battery charge and discharge efficiency and service life.

[0068] The preset temperature is used as the thermal runaway determination threshold. When the temperature of the battery cell 1 reaches this threshold, it is determined that thermal runaway has occurred, triggering the pressure relief of the exhaust mechanism 42. At the same time, the neutralizer 41 is activated, and the substances in the neutralizer 41 chemically react with the harmful substances generated by the decomposition of the electrolyte. When thermal runaway occurs, rapid pressure relief is carried out to prevent the battery from exploding, neutralize harmful substances, reduce environmental pollution, and significantly improve the safety and reliability of the system.

[0069] The above content is only a preferred embodiment of the present invention. For those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. The content of this specification should not be construed as a limitation of the present invention.

Claims

1. A vehicle battery thermal management system based on FPC, comprising a battery cell (1), the battery cell (1) being provided with a current collector (11) and a housing (12), the current collector (11) being disposed within the housing (12), characterized in that, It also includes an FPC circuit board (2), a temperature control device (3), and a protection device (4). The FPC circuit board (2) is electrically connected to the battery cell (1), the temperature control device (3), and the protection device (4). A temperature measurement area (13) is provided on the upper part of the current collector (11), and a heat conduction layer (14) is provided on the periphery of the current collector (11). The heat conduction layer (14) collects the heat of the current collector (11) to the temperature measurement area (13). The FPC circuit board (2) is provided with a sensor array (21) and an AI chip (22). The sensor array (21) is used to collect the temperature data of the temperature measurement area (13) in real time. The AI chip (22) is used to run the LSTM model, and according to the temperature, current, voltage, and SOC time series data of the battery cell (1), output the temperature field prediction of the battery cell (1) in the next 5 minutes and generate a control instruction to control the temperature control device (3). The temperature control device (3) is connected to the heat conduction layer (14) and is used to respond to the control instruction to adjust the temperature of the current collector (11) through the heat conduction layer (14). The protection device (4) is provided with a neutralizer (41) and an exhaust mechanism (42). When the thermal runaway of the battery cell (1) reaches a preset temperature, the neutralizer (41) neutralizes the harmful substances generated by the decomposition of the electrolyte, delaying the temperature rise of the battery cell (1). The exhaust mechanism (42) is used to exhaust the gas generated during the neutralization process.

2. The vehicle battery thermal management system based on FPC according to claim 1, wherein The heat conduction layer (14) is also provided with a heat conduction belt (141) connecting the upper and lower sides of the current collector (11).

3. A vehicle battery thermal management system based on FPC according to claim 1, characterized in that, The sensor array (21) includes a thin film thermocouple (211) and a pressure sensor (212). The pressure sensor (212) and the thin film thermocouple (211) are both arranged in the temperature measurement area (13).

4. A vehicle battery thermal management system based on FPC according to claim 1, characterized in that, The temperature control device (3) includes a micro liquid cooling channel (31) and a thermoelectric cooler (32). One side of the micro liquid cooling channel (31) is thermally coupled to the thermoelectric cooler (32) through boron nitride-filled silica gel. The other side of the thermoelectric cooler (32) is thermally coupled to the heat conduction layer (14) through boron nitride-filled silica gel.

5. The vehicle battery thermal management system based on FPC according to claim 1, characterized in that, The protection device (4) is provided with neutralization chambers (43) at the four corners inside the housing (12). A heat conduction frame (44) is arranged inside the neutralization chambers (43), and the neutralizer (41) is fixed to the heat conduction frame (44). The neutralizer (41) is a hollow mesoporous silica sphere nano-reactor. A neutralization powder is encapsulated inside the hollow mesoporous silica sphere nano-reactor. The neutralization powder neutralizes the harmful substances generated by the decomposition of the electrolyte when the battery cell (1) undergoes thermal runaway, delaying the temperature rise of the battery cell (1). The exhaust mechanism (42) includes an exhaust cavity (421) arranged at the top of the neutralization chamber (43). The exhaust cavity (421) is provided with a one-way exhaust valve (422) connected to the outside. The gas generated during the neutralization process is exhausted through the one-way exhaust valve (422) to relieve the internal pressure of the battery cell (1).

6. The vehicle battery thermal management system based on FPC according to claim 5, wherein, A sealing film (431) for sealing the neutralization chamber (43) is provided on one side of the neutralization chamber (43) facing the battery cell (1), and the dissolution temperature of the sealing film (431) is the same as the preset temperature.

7. The vehicle battery thermal management system based on FPC according to claim 6, characterized in that, The battery cell (1) is further provided with a heat conduction module (18), and the heat conduction module (18) is connected between the current collector (11) and the sealing film (431); A low melting point alloy layer is provided between the neutralizer (41) and the heat conduction frame (44), and the triggering temperature of the low melting point alloy layer is set to be ±5 °C of the preset thermal runaway temperature of the battery cell (1).

8. The vehicle battery thermal management system based on FPC according to claim 7, wherein The heat conduction module (18) includes a heat conduction sheet (181) and a heat conduction bridge (182) disposed in the outer shell (12). Both the current collector (11) and the heat conduction bridge (182) are connected to the heat conduction sheet (181), and the heat conduction bridge (182) is connected to the heat conduction frame (44); The heat of the current collector (11) is conducted to the sealing film (431) through the heat conduction sheet (181), and is conducted to the low melting point alloy layer through the heat conduction sheet (181), the heat conduction bridge (182) and the heat conduction frame (44).

9. A thermal management method, characterized in that, Including the vehicle battery thermal management system according to any one of claims 1-8, the specific steps are as follows: S1. The sensor array (21) collects the temperature of the battery cell (1) in real time to form temperature data; S2. The AI chip (22) predicts the future 5-minute temperature field through the LSTM model according to the temperature, current, voltage and SOC time series data of the battery cell (1), and generates an optimization instruction for the temperature control device (3); S3. The temperature control device (3) responds to the instruction and adjusts the temperature of the current collector (11); S4. When it is detected that the temperature of the battery cell (1) reaches the preset temperature, it is determined that thermal runaway occurs, the exhaust mechanism (42) is triggered to release pressure in a specific direction, and at the same time, the neutralizer (41) is activated to neutralize the harmful substances generated by the decomposition of the electrolyte.

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