Lithium metal battery pack health monitoring system and method of thin film sensor

Abstract

The invention relates to the technical field of lithium metal battery health monitoring, and particularly discloses a lithium metal battery pack health monitoring system and method based on thin film sensors, the system comprises a plurality of thin film sensors distributed among lithium metal battery pack cells, and each thin film sensor comprises a temperature measuring unit, a pressure measuring unit, a flexible circuit board and silica gel foam; the adapter plate is electrically connected with the plurality of thin film sensors; the signal acquisition unit is electrically connected with the adapter plate and comprises a constant current source circuit, a signal conditioning circuit, a filter circuit and an analog-to-digital conversion circuit; the input end of the data transmission unit is electrically connected with the output of the analog-to-digital conversion circuit; the input end of the digital signal processor is electrically connected with the output end of the data transmission unit; and the input end of the battery management unit is electrically connected with the output end of the digital signal processor. The mechanical information and the temperature information between the battery monomers can be monitored at the same time, the battery management can evaluate the health state of the battery more comprehensively based on the information, and the abnormal problem can be warned in advance.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium metal battery health monitoring, and in particular to a lithium metal battery pack health monitoring system and method using a thin film sensor. Background Art

[0002] With the rapid development of new energy technologies, the demand for high-performance and high-safety energy storage systems is growing. Lithium metal batteries have attracted widespread attention due to their high energy density, but in practical applications, the safety and stability of lithium metal batteries still face challenges. Among them, problems such as diaphragm damage, abnormal growth of negative electrode lithium dendrites, and abnormal accumulation of "dead lithium" are important factors leading to battery failure and even safety accidents.

[0003] Existing battery management systems mainly rely on monitoring parameters such as voltage, current and temperature to evaluate the health status of the battery, but these methods are incomplete and "hysteresis" in evaluating the health status of the battery. They can often only be detected through voltage, current and temperature characterization after the battery has internal short circuits, broken tabs and other problems. In addition, traditional temperature sensors are difficult to arrange directly between single cells, resulting in low accuracy of temperature feedback values ​​and inability to accurately characterize the temperature distribution on the surface of the single cell. This makes it impossible for the battery management system to detect problems such as local overheating in a timely manner, thereby affecting the overall performance and safety of the battery. Lithium metal single cells have more obvious expansion characteristics than batteries of other systems, which means that changes in the mechanical state between battery cells have a more significant impact on battery health. Therefore, monitoring of mechanical properties becomes particularly important in evaluating the health status of lithium metal batteries, and the existing health monitoring system lacks effective monitoring in this regard.

[0004] Based on this technical background, the present invention studies a lithium metal battery pack health monitoring system and method using a thin film sensor. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a lithium metal battery pack health monitoring system and method using a thin film sensor. The system places multiple thin film sensors between lithium metal battery cells, and can simultaneously monitor the mechanical information and temperature information between the battery cells. Based on this information, battery management can more comprehensively evaluate the health status of the battery, and can provide early warning of potential problems such as abnormal growth of negative electrode lithium dendrites, abnormal accumulation of "dead lithium", and local temperature abnormalities. This solves the problem that traditional lithium metal battery health monitoring systems cannot accurately monitor the surface temperature of battery cells and lack mechanical property monitoring.

[0006] In order to achieve the above object, the first aspect of the present invention provides a lithium metal battery pack health monitoring system of a thin film sensor, comprising:

[0007] A plurality of thin film sensors are distributed between the battery cells of the lithium metal battery pack and are used to collect temperature information and pressure information of the battery cells. Each thin film sensor includes a temperature measuring unit, a pressure measuring unit, a flexible circuit board and silicone foam.

[0008] An adapter board, electrically connected to the plurality of thin film sensors, for transferring signals;

[0009] A signal acquisition unit, electrically connected to the adapter board, comprising a constant current source circuit, a signal conditioning circuit, a filter circuit and an analog-to-digital conversion circuit;

[0010] A data transmission unit, the input end of which is electrically connected to the output of the analog-to-digital conversion circuit;

[0011] a digital signal processor, an input end of which is electrically connected to an output end of the data transmission unit;

[0012] The battery management unit has an input end electrically connected to the output end of the digital signal processor, and is used to monitor the temperature and pressure information of the battery cell, evaluate the battery health status, and realize the battery protection function.

[0013] A second aspect of the present invention provides a lithium metal battery pack health monitoring method using a thin film sensor, comprising:

[0014] According to the needs of health monitoring of lithium metal battery packs, multiple thin film sensors are distributed between battery cells in the lithium metal battery pack;

[0015] Connecting the plurality of thin film sensors using an adapter plate;

[0016] Using the multiple thin film sensors to collect temperature and pressure information between battery cells;

[0017] Connecting the adapter board to a signal acquisition unit;

[0018] Providing current excitation to the plurality of thin film sensors through the signal acquisition unit, and converting the temperature and pressure information into digital signals containing temperature and pressure data;

[0019] Transmitting the digital signal to a digital signal processor via a data transmission unit;

[0020] Processing the temperature and pressure data by the digital signal processor, and transmitting the processed temperature and pressure data to the battery management unit in a suitable format and rate;

[0021] The battery management unit monitors the temperature and pressure information of the battery cells, evaluates the battery health status, and implements the battery protection function.

[0022] The beneficial effects of the present invention include:

[0023] (1) The thin-film sensor lithium metal battery pack health monitoring system proposed in the present invention places multiple thin-film sensors between lithium metal battery cells, which can simultaneously monitor the mechanical information and temperature information between the battery cells. Based on this information, the battery management can more comprehensively evaluate the health status of the battery, and can provide early warning of potential problems such as abnormal growth of negative electrode lithium dendrites, abnormal accumulation of "dead lithium", and local temperature abnormalities. This solves the problem that traditional lithium metal battery health monitoring systems cannot accurately monitor the surface temperature of battery cells and lack mechanical property monitoring.

[0024] (2) The thin-film sensor lithium metal battery pack health monitoring system proposed in the present invention can simultaneously obtain mechanical and temperature information between battery cells. Compared with the traditional monitoring method that only relies on voltage, current and temperature, it adds the monitoring of the mechanical state and temperature distribution between the single cells in the battery pack, thereby improving the comprehensiveness and accuracy of the battery health status assessment. By accurately measuring the temperature distribution and mechanical changes between the single cells, the actual working state inside the battery pack can be fed back in real time, and potential problems can be discovered in time.

[0025] (3) The thin-film sensor lithium metal battery pack health monitoring system proposed in the present invention directly arranges temperature measuring points whose number and position distribution can be arbitrarily adjusted between lithium metal battery cells, effectively overcoming the shortcomings of conventional temperature sensors in the application of lithium metal battery packs. On the basis of the existing technology, it supplements the temperature distribution on the surface of the single cell in the battery pack and can more accurately characterize the temperature of the single cell, so as to more accurately judge the battery health status and the temperature difference of the battery cells in the battery pack.

[0026] (4) The thin-film sensor lithium metal battery pack health monitoring system proposed in the present invention, based on the existing technology, supplements the pressure information between battery cells in the lithium metal battery pack, solves the "lag" problem of existing monitoring parameters, and can timely predict diaphragm damage, abnormal growth of negative electrode lithium dendrites, abnormal accumulation of "dead lithium", abnormal increase in expansion force and other problems before serious battery failure occurs by real-time monitoring of abnormal changes in mechanics and pressure distribution between battery cells. This provides sufficient time for taking preventive measures, greatly improves the safety and reliability of energy storage battery packs, and reduces safety risks and economic losses caused by battery failure.

[0027] (5) The thin film sensor lithium metal battery pack health monitoring system proposed in the present invention has a buffer foam structure formed by combining the sensor and the silicone foam. On the one hand, it prevents the battery cells from being damaged due to expansion and mutual squeezing, and ensures that no local stress will be generated when the battery cells contact the temperature and pressure sensors to cause safety problems. On the other hand, it protects the sensor from mechanical damage and ensures that the sensor works safely and reliably in a complex mechanical environment. In addition, it can ensure good contact between the sensor and the battery cells and improve measurement accuracy.

[0028] (6) The thin-film sensor lithium metal battery pack health monitoring system proposed in the present invention has the function of interconnecting the sensor with the battery management unit, so that the data collected and processed by the sensor can be directly used by the battery management unit. At the same time, the battery management unit can directly adjust the working state of the battery according to the temperature and pressure information transmitted by the sensor, thereby realizing refined management of the battery and improving the safety and reliability of the lithium metal battery during use.

[0029] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings.

[0031] Figure 1 This is a structural schematic diagram of a temperature and pressure integrated thin film sensor applied to a lithium metal battery pack in a specific embodiment of the lithium metal battery pack health monitoring system of the thin film sensor proposed in the present invention (the temperature and pressure integrated thin film sensor is placed between battery cells).

[0032] Figure 2 A schematic structural diagram of another perspective of a lithium metal battery pack in which a temperature and pressure integrated thin film sensor is applied to the lithium metal battery pack in a specific embodiment of the lithium metal battery pack health monitoring system of the thin film sensor proposed in the present invention (the temperature and pressure integrated thin film sensor is placed between battery cells).

[0033] Figure 3 This is a schematic structural diagram of a temperature and pressure integrated thin film sensor in a specific embodiment of the lithium metal battery pack health monitoring system of the thin film sensor proposed in the present invention.

[0034] Figure 4 This is a schematic diagram of the pressure and temperature signal sampling, processing and transmission structure in a specific implementation of the lithium metal battery pack health monitoring system of the thin film sensor proposed in the present invention.

[0035] Figure 5A schematic diagram of the health monitoring and control process according to the pressure data between battery cells in a specific embodiment of the lithium metal battery pack health monitoring system of the thin film sensor proposed by the present invention.

[0036] Figure 6 A schematic diagram of the health monitoring and control process according to the temperature data between battery cells in a specific embodiment of the lithium metal battery pack health monitoring system of the thin film sensor proposed by the present invention.

[0037] Description of reference numerals:

[0038] 1-lithium metal battery pack, 2-thin film sensor, 3-buffer foam, 4-battery cell, 5-battery cell ear, 6-adapter board, 7-pressure measuring unit, 8-temperature measuring unit, 9-wire, 10-flexible circuit board, 11-silicone foam, 12-thin film sensor interface, 13-constant current source circuit, 14-signal conditioning circuit, 15-filtering circuit, 16-analog-to-digital conversion circuit, 17-signal acquisition unit, 18-data transmission unit, 19-digital signal processor, 20-battery management unit. DETAILED DESCRIPTION

[0039] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0040] The present invention provides a lithium metal battery pack health monitoring system using a thin film sensor, such as Figure 1 As shown, including:

[0041] A plurality of thin film sensors 2 are distributed between the battery cells 4 of the lithium metal battery pack 1 and are used to collect temperature information and pressure information of the battery cells 4. Each thin film sensor 2 includes a temperature measuring unit 8, a pressure measuring unit 7, a flexible circuit board 10 and a silicone foam 11;

[0042] An adapter board 6, electrically connected to the plurality of thin film sensors 2, for transferring signals;

[0043] The signal acquisition unit 17 is electrically connected to the adapter board 6 and includes a constant current source circuit 13, a signal conditioning circuit 14, a filter circuit 15 and an analog-to-digital conversion circuit 16;

[0044] The data transmission unit 18, the input end of which is electrically connected to the output of the analog-to-digital conversion circuit 16;

[0045] A digital signal processor 19, an input end of which is electrically connected to an output end of the data transmission unit 18;

[0046] The battery management unit 20 has an input end electrically connected to an output end of the digital signal processor 19 and is used to monitor the temperature and pressure information of the battery cell 4, evaluate the battery health status, and implement the battery protection function.

[0047] In the present invention, multiple thin-film sensors are placed between lithium metal battery cells, which can simultaneously monitor the mechanical information and temperature information between the battery cells. Based on this information, battery management can more comprehensively evaluate the health status of the battery, and can provide early warning of potential problems such as abnormal growth of negative electrode lithium dendrites, abnormal accumulation of "dead lithium", and local temperature abnormalities. This solves the problem that traditional lithium metal battery health monitoring systems cannot accurately monitor the surface temperature of battery cells and lack mechanical property monitoring.

[0048] In the present invention, the mechanical and temperature information between battery cells can be obtained simultaneously. Compared with the traditional monitoring method that only relies on voltage, current and temperature, the monitoring of the mechanical state and temperature distribution between the single cells in the battery pack is added, and the comprehensiveness and accuracy of the battery health status assessment are improved; by accurately measuring the temperature distribution and mechanical changes between the single cells, the actual working state inside the battery pack can be fed back in real time, and potential problems can be discovered in time.

[0049] According to the present invention, each thin film sensor 2 is a temperature and pressure integrated thin film sensor having a buffer foam 3 structure formed by using a silicone foam 11;

[0050] The temperature measuring unit 8 is a thermal resistance temperature sensor, which is used to collect the surface temperature information of the battery cell 4;

[0051] The pressure measuring unit 7 is a piezoresistive pressure sensor, which is used to collect the surface pressure information of the battery cell 4;

[0052] The flexible circuit board 10 is used as a carrier of the temperature and pressure test unit, and is used to connect the temperature measuring unit 8 and the pressure measuring unit 7, and provide necessary mechanical support for the temperature and pressure measuring units 7;

[0053] The data transmission unit 18 is used to transmit the temperature and pressure data processed by the signal acquisition unit 17 to the digital signal processor 19;

[0054] The digital signal processor 19 is used to process the temperature and pressure data transmitted by the data transmission unit 18, and transmit the processed temperature and pressure data to the battery management unit 20 in a suitable format and rate.

[0055] In the present invention, the temperature measuring points whose number and position distribution can be arbitrarily adjusted are directly arranged between lithium metal battery cells, which effectively overcomes the shortcomings of conventional temperature sensors in the application of lithium metal battery packs. On the basis of the existing technology, the temperature distribution on the surface of the single cell in the battery pack is supplemented, and the temperature of the single cell can be more accurately characterized, so as to more accurately judge the battery health status and the temperature difference of the battery cells in the battery pack.

[0056] In the present invention, on the basis of the existing technology, the pressure information between battery cells in the lithium metal battery pack is supplemented, and the "lag" problem of the existing monitoring parameters is solved. By real-time monitoring of the abnormal changes in the mechanics and pressure distribution between the single cells, it is possible to timely predict the problems such as diaphragm damage, abnormal growth of negative electrode lithium dendrites, abnormal accumulation of "dead lithium", and abnormal increase in expansion force before serious battery failure occurs. This provides sufficient time for taking preventive measures, greatly improves the safety and reliability of the energy storage battery pack, and reduces the safety risks and economic losses caused by battery failure.

[0057] According to the present invention, the number of pressure measuring units 7 and temperature measuring units 8 are changed according to the size of the battery cells 4 and the health monitoring requirements of the lithium metal battery pack 1;

[0058] The size of the flexible circuit board 10 is determined according to the number and distribution of the pressure measuring units 7 and the temperature measuring units 8;

[0059] The distribution of the pressure measuring unit 7 and the temperature measuring unit 8 on the flexible circuit board 10 is changed according to the battery pack health monitoring requirements.

[0060] According to the present invention, the signal conditioning circuit 14, the filtering circuit 15 and the analog-to-digital conversion circuit 16 are electrically connected in sequence;

[0061] The constant current source circuit 13 is electrically connected to the pressure measuring unit 7 and the temperature measuring unit 8, and is used to provide current excitation for the pressure measuring unit 7 and the temperature measuring unit 8;

[0062] The signal conditioning circuit 14 is used to amplify and linearize the signals output by the pressure measuring unit 7 and the temperature measuring unit 8;

[0063] The filter circuit 15 is used to remove high-frequency noise and other interference components in the output signal of the signal conditioning circuit 14 to improve the signal quality;

[0064] The analog-to-digital conversion circuit 16 is used to convert the analog signal filtered by the filtering circuit 15 into a digital signal.

[0065] In the present invention, the buffer foam structure formed by combining the sensor and the silicone foam can, on the one hand, prevent the battery cell from being damaged due to expansion and mutual squeezing, and can also ensure that no local stress will be generated when the battery cell contacts the temperature and pressure sensor to cause safety problems. On the other hand, it protects the sensor from mechanical damage and ensures that the sensor works safely and reliably in a complex mechanical environment. In addition, it can also ensure good contact between the sensor and the battery cell and improve measurement accuracy.

[0066] According to the present invention, during the pressure data monitoring process of the battery management unit 20,

[0067] If the pressure between the battery cells 4 is monitored to be abnormally increased, it is judged that the battery cell 4 has abnormal growth of lithium dendrites and abnormal accumulation of dead lithium according to the distribution position of the abnormal pressure increase and the pressure size at the corresponding position, and a first-level pressure warning is issued, and the abnormal pressure increase is improved by adjusting the charging and discharging strategy;

[0068] If the abnormal pressure increase worsens further, it is judged that the pressure between the 4 battery cells exceeds the limit, and there is a diaphragm damage, a short circuit in the battery cell 4, or a broken tab, and a secondary pressure warning is issued, the charge / discharge circuit is disconnected, the faulty battery pack is isolated, and the pressure changes between the 4 battery cells are continuously monitored;

[0069] The battery management unit 20 analyzes the pressure data between the battery cells 4 and predicts the life of the lithium metal battery pack 1 according to the pressure change.

[0070] Preferably, during the temperature data monitoring process of the battery management unit 20,

[0071] If the temperature between the battery cells 4 is monitored to be abnormally increased, it is judged that the battery cells 4 have uneven electrode reaction and uneven lithium deposition according to the distribution position of the abnormal temperature increase and the temperature size of the corresponding position, and a first-level temperature warning is issued, and the abnormal temperature increase is improved by adjusting the charging and discharging strategy;

[0072] If the abnormal temperature increase worsens further, it is judged that the temperature between the 4 battery cells exceeds the limit, and there is a short circuit in the battery cell 4 and the electrolyte decomposition, and a secondary temperature warning is issued, the charge / discharge circuit is disconnected, the faulty battery pack is isolated, and the temperature changes between the 4 lithium metal battery cells are continuously monitored;

[0073] The battery management unit 20 compares the historical temperature data between the battery cells 4 and assists in determining the health status of the lithium metal battery pack 1 according to the temperature change trend.

[0074] In the present invention, the sensor has the function of interconnecting with the battery management unit, so that the data collected and processed by the sensor can be directly used by the battery management unit. At the same time, the battery management unit can directly adjust the working state of the battery according to the temperature and pressure information transmitted by the sensor, thereby realizing refined management of the battery and improving the safety and reliability of the lithium metal battery during use.

[0075] The present invention also provides a lithium metal battery pack health monitoring method with a thin film sensor, comprising:

[0076] According to the needs of health monitoring of the lithium metal battery pack 1, a plurality of thin film sensors 2 are distributed between the battery cells 4 in the lithium metal battery pack 1;

[0077] Connecting multiple thin film sensors 2 using an adapter plate 6;

[0078] Using multiple thin film sensors 2 to collect temperature and pressure information between battery cells 4;

[0079] Connect the adapter board 6 to the signal acquisition unit 17;

[0080] Provide current excitation to multiple thin film sensors 2 through the signal acquisition unit 17, and convert the temperature and pressure information into digital signals containing temperature and pressure data;

[0081] The digital signal is transmitted to the digital signal processor 19 via the data transmission unit 18;

[0082] Processing the temperature and pressure data by the digital signal processor 19 and transmitting the processed temperature and pressure data to the battery management unit 20 in a suitable format and rate;

[0083] The battery management unit 20 monitors the temperature and pressure information of the battery cell 4, evaluates the battery health status, and implements the battery protection function.

[0084] According to the present invention, each thin film sensor 2 is formed into a temperature and pressure integrated thin film sensor having a buffer foam 3 structure through a special process;

[0085] Utilize the temperature measuring unit 8 of each thin film sensor 2 to collect the surface temperature information of the battery cell 4;

[0086] Using the pressure measuring unit 7 of each thin film sensor 2 to collect the surface pressure information of the battery cell 4;

[0087] The flexible circuit board 10 of each thin film sensor 2 is used as a carrier of the temperature and pressure test unit, connecting the temperature measuring unit 8 and the pressure measuring unit 7 , and providing necessary mechanical support for the temperature and pressure measuring units 7 .

[0088] According to the present invention, during the pressure data monitoring process of the battery management unit 20,

[0089] If the pressure between the battery cells 4 is monitored to be abnormally increased, it is judged that the battery cell 4 has abnormal growth of lithium dendrites and abnormal accumulation of dead lithium according to the distribution position of the abnormal pressure increase and the pressure size at the corresponding position, and a first-level pressure warning is issued, and the abnormal pressure increase is improved by adjusting the charging and discharging strategy;

[0090] If the abnormal pressure increase worsens further, it is judged that the pressure between the 4 battery cells exceeds the limit, and there is a diaphragm damage, a short circuit in the battery cell 4, or a broken tab, and a secondary pressure warning is issued, the charge / discharge circuit is disconnected, the faulty battery pack is isolated, and the pressure changes between the 4 battery cells are continuously monitored;

[0091] The battery management unit 20 analyzes the pressure data between the battery cells 4 and predicts the life of the lithium metal battery pack 1 according to the pressure change.

[0092] According to the present invention, during the temperature data monitoring process of the battery management unit 20,

[0093] If the temperature between the battery cells 4 is monitored to be abnormally increased, it is judged that the battery cells 4 have uneven electrode reaction and uneven lithium deposition according to the distribution position of the abnormal temperature increase and the temperature size of the corresponding position, and a first-level temperature warning is issued, and the abnormal temperature increase is improved by adjusting the charging and discharging strategy;

[0094] If the abnormal temperature increase worsens further, it is judged that the temperature between the 4 battery cells exceeds the limit, and there is a short circuit in the battery cell 4 and the electrolyte decomposition, and a secondary temperature warning is issued, the charge / discharge circuit is disconnected, the faulty battery pack is isolated, and the temperature changes between the 4 lithium metal battery cells are continuously monitored;

[0095] The battery management unit 20 compares the historical temperature data between the battery cells 4 and assists in determining the health status of the lithium metal battery pack 1 according to the temperature change trend.

[0096] The present invention will be described in more detail below by way of examples.

[0097] Embodiment 1:

[0098] like Figure 1-4 As shown, this embodiment provides a lithium metal battery pack health monitoring system using a thin film sensor, comprising:

[0099] The temperature and pressure integrated thin film sensor 2 is placed between the battery cells 4 of the lithium metal battery pack 1 and is used to collect temperature information on the surface of the battery cells and pressure information between the battery cells.

[0100] The temperature and pressure integrated thin film sensor 2 comprises a pressure measuring unit 7, a temperature measuring unit 8, a wire 9, a flexible circuit board 10, a silicone foam 11, and a thin film sensor interface 12.

[0101] The pressure measuring unit 7 adopts a piezoresistive pressure sensor, and the number of the pressure measuring units 7 can be arbitrarily changed according to the size of the lithium metal battery cell 4 and the battery pack health monitoring requirements;

[0102] The temperature measuring unit 8 uses a thermal resistance temperature sensor, and the number of the temperature measuring units 8 can be arbitrarily changed according to the size of the lithium metal battery cell 4 and the battery pack health monitoring requirements;

[0103] The flexible circuit board 10, as a carrier of the pressure test unit 7 and the temperature test unit 8, uses the wire 9 to electrically connect the pressure test unit 7 and the temperature test unit 8, and provides necessary mechanical support for the pressure test unit 7 and the temperature test unit 8. The size of the flexible circuit board 10 is determined according to the number and distribution of the pressure test unit 7 and the temperature test unit 8;

[0104] The distribution of the pressure measuring unit 7 and the temperature measuring unit 8 on the flexible circuit board 10 can be arbitrarily changed according to the battery pack health monitoring requirements;

[0105] The flexible circuit board 10 and the silicone foam 11 are combined by a special process to form a temperature-pressure integrated thin film sensor 2 with a buffer foam structure, and the temperature-pressure integrated thin film sensor 2 with a buffer foam structure is arranged between the lithium metal battery cells 4;

[0106] The adapter board 6 is used to connect multiple integrated temperature and pressure thin film sensors 2 and is connected to the temperature and pressure signal acquisition circuit 17;

[0107] The signal acquisition unit 17 includes a constant current source circuit 13, a signal conditioning circuit 14, a filter circuit 15, and an analog-to-digital conversion circuit (ADC) 16;

[0108] The constant current source circuit 13 is connected to the pressure measuring unit 7 and the temperature measuring unit 8 to provide current excitation for the pressure measuring unit 7 and the temperature measuring unit 8;

[0109] The signal conditioning circuit 14 is used to amplify and linearize the signals output by the pressure measuring unit 7 and the temperature measuring unit 8;

[0110] The filter circuit 15 is used to remove high-frequency noise and other interference components in the output signal of the signal conditioning circuit 14 to improve the signal quality;

[0111] The analog-to-digital conversion circuit 16 converts the analog signal conditioned by the signal conditioning circuit 14 and filtered by the filtering circuit 15 into a digital signal;

[0112] The data transmission unit 18 is responsible for transmitting the processed temperature and pressure data to the digital signal processor 19;

[0113] The digital signal processor 19 is responsible for processing the temperature and pressure data and transmitting the processed temperature and pressure data to the battery management unit 20 in a suitable format and rate;

[0114] The battery management unit 20 evaluates the battery health status and implements the battery protection function by receiving the temperature and pressure information between the lithium metal battery cells;

[0115] Pressure data monitoring 21, if it is detected that the pressure between the battery cells 4 increases abnormally 20, according to the distribution position of the abnormal pressure increase and the pressure size at the corresponding position, if it is determined that the lithium metal battery cell 4 has abnormal growth of lithium dendrites, abnormal accumulation of "dead lithium", etc., the battery management unit 20 performs a first-level pressure warning 23, and improves the abnormal pressure increase by adjusting the charge and discharge strategy 24; if the abnormal pressure increase improves, the pressure data monitoring 21 is continued; if the abnormal pressure increase between the battery cells 4 further deteriorates, according to the distribution position of the abnormal pressure increase and the pressure size at the corresponding position, if it is determined that the pressure between the lithium metal battery cells 4 exceeds the limit, and there is a diaphragm damage, a short circuit in the battery cell, a tab breakage, etc., the battery management unit 20 performs a second-level pressure warning 25, disconnects the charge / discharge circuit, isolates the faulty battery pack, and continuously monitors the pressure changes between the lithium metal battery cells 4 26;

[0116] The battery management unit 20 analyzes 27 the pressure data between lithium metal battery cells and predicts the life of the lithium metal battery pack 1 according to the pressure change 28;

[0117] Temperature data monitoring 29, if it is detected that the temperature between the battery cells 4 is abnormally increased 30, according to the distribution position of the abnormal temperature increase and the temperature size of the corresponding position, if it is determined that the lithium metal battery cell 4 has uneven electrode reaction, uneven lithium deposition, etc., the battery management unit 20 will issue a first-level temperature warning 31, and improve the abnormal temperature increase by adjusting the charge and discharge strategy 32; if the abnormal temperature increase is improved, the pressure data monitoring 29 will continue; if the abnormal temperature increase between the battery cells 4 further deteriorates, according to the distribution position of the abnormal temperature increase and the temperature size of the corresponding position, if it is determined that the temperature between the lithium metal battery cells 4 exceeds the limit, and there is a short circuit in the battery cell, electrolyte decomposition, etc., the battery management unit 20 will issue a second-level temperature warning 33, disconnect the charge / discharge circuit, isolate the faulty battery pack, and continue to monitor the temperature changes between the lithium metal battery cells 4 34;

[0118] The battery management unit 20 compares 35 the historical temperature data between lithium metal battery cells and assists in determining the health status 36 of the lithium metal battery pack 1 according to the temperature change trend;

[0119] The use method and operation steps of the lithium metal battery pack health monitoring system based on the temperature and pressure integrated thin film sensor are as follows:

[0120] According to the needs of health monitoring of the lithium metal battery pack 1, a plurality of integrated temperature and pressure thin film sensors 2 are placed between the 4 battery cells in the lithium metal battery pack 1 at a certain interval, and a plurality of integrated temperature and pressure thin film sensors 2 are connected by an adapter plate 6, and a silicone foam 11 is placed between the remaining 4 battery cells;

[0121] The temperature and pressure integrated thin film sensor 2 is used to collect temperature and pressure information between battery cells 4;

[0122] The adapter board 6 is connected to the signal acquisition unit 17 to provide current excitation for the temperature and pressure integrated thin film sensor 2 and convert the temperature and pressure information into digital signals;

[0123] The temperature and pressure data are transmitted to the digital signal processor 19 via the data transmission unit 18;

[0124] The digital signal processor 19 is responsible for processing the temperature and pressure data and transmitting the processed temperature and pressure data to the battery management unit 20 in a suitable format and rate;

[0125] The battery management unit 20 evaluates the battery health status and implements the battery protection function by receiving the temperature and pressure information between the lithium metal battery cells;

[0126] like Figure 5 As shown, pressure data monitoring 21, such as monitoring that the pressure between the battery cells 4 increases abnormally 20, according to the distribution position of the abnormal pressure increase and the pressure size at the corresponding position, if it is judged that the lithium metal battery cell 4 has abnormal growth of lithium dendrites, abnormal accumulation of "dead lithium", etc., the battery management unit 20 performs a first-level pressure warning 23, and improves the abnormal pressure increase by adjusting the charge and discharge strategy 24; if the abnormal pressure increase improves, the pressure data monitoring 21 is continued; if the abnormal pressure increase between the battery cells 4 further deteriorates, according to the distribution position of the abnormal pressure increase and the pressure size at the corresponding position, if it is judged that the pressure between the lithium metal battery cells 4 exceeds the limit, and there is a diaphragm damage, a short circuit in the battery cell, a tab breakage, etc., the battery management unit 20 performs a second-level pressure warning 25, disconnects the charge / discharge circuit, isolates the faulty battery pack, and continuously monitors the pressure change between the lithium metal battery cells 4 26;

[0127] The battery management unit 20 analyzes 27 the pressure data between lithium metal battery cells and predicts the life of the lithium metal battery pack 1 according to the pressure change 28;

[0128] like Figure 6 As shown, temperature data monitoring 29, such as monitoring that the temperature between the battery cells 4 increases abnormally 30, according to the distribution position of the abnormal temperature increase and the temperature size of the corresponding position, if it is judged that the lithium metal battery cell 4 has uneven electrode reaction, uneven lithium deposition, etc., the battery management unit 20 performs a first-level temperature warning 31, and improves the abnormal temperature increase by adjusting the charge and discharge strategy 32; if the abnormal temperature increase improves, the pressure data monitoring 29 is continued; if the abnormal temperature increase between the battery cells 4 further deteriorates, according to the distribution position of the abnormal temperature increase and the temperature size of the corresponding position, if it is judged that the temperature between the lithium metal battery cells 4 exceeds the limit, and there is a short circuit in the battery cell, electrolyte decomposition, etc., the battery management unit 20 performs a second-level temperature warning 33, disconnects the charge / discharge circuit, isolates the faulty battery pack, and continuously monitors the temperature changes between the lithium metal battery cells 4 34;

[0129] The battery management unit 20 compares 35 the historical temperature data between lithium metal battery cells and assists in determining the health status 36 of the lithium metal battery pack 1 according to the temperature change trend.

[0130] The lithium metal battery pack health monitoring system of the thin film sensor proposed in the embodiment of the present invention places multiple thin film sensors between lithium metal battery cells, which can simultaneously monitor the mechanical information and temperature information between the battery cells. Based on this information, the battery management can more comprehensively evaluate the health status of the battery, and can provide early warning of potential problems such as abnormal growth of negative electrode lithium dendrites, abnormal accumulation of "dead lithium", and local temperature abnormalities, thereby solving the problem that traditional lithium metal battery health monitoring systems cannot accurately monitor the surface temperature of battery cells and lack mechanical property monitoring.

[0131] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A lithium metal battery health monitoring system with a thin film sensor, characterized in that: include: A plurality of thin film sensors are distributed between the battery cells of the lithium metal battery pack and are used to collect temperature information and pressure information of the battery cells. Each thin film sensor includes a temperature measuring unit, a pressure measuring unit, a flexible circuit board and silicone foam. An adapter board, electrically connected to the plurality of thin film sensors, for transferring signals; A signal acquisition unit, electrically connected to the adapter board, comprising a constant current source circuit, a signal conditioning circuit, a filter circuit and an analog-to-digital conversion circuit; A data transmission unit, the input end of which is electrically connected to the output of the analog-to-digital conversion circuit; a digital signal processor, an input end of which is electrically connected to an output end of the data transmission unit; The battery management unit has an input end electrically connected to the output end of the digital signal processor, and is used to monitor the temperature and pressure information of the battery cell, evaluate the battery health status, and realize the battery protection function.

2. The system according to claim 1, characterized in that Each thin film sensor is a temperature and pressure integrated thin film sensor with a buffer foam structure formed by the silicone foam; The temperature measuring unit is a thermal resistance temperature sensor, which is used to collect the surface temperature information of the battery cell; The pressure measuring unit is a piezoresistive pressure sensor, which is used to collect the surface pressure information of the battery cell; The flexible circuit board is used as a carrier of the temperature and pressure test unit to connect the temperature measuring unit and the pressure measuring unit and provide necessary mechanical support for the temperature and pressure measuring units; The data transmission unit is used to transmit the temperature and pressure data processed by the signal acquisition unit to the digital signal processor; The digital signal processor is used to process the temperature and pressure data transmitted by the data transmission unit, and transmit the processed temperature and pressure data to the battery management unit in a suitable format and rate.

3. The system according to claim 1, characterized in that The number of the pressure measuring units and the temperature measuring units are changed according to the size of the battery cells and the health monitoring requirements of the lithium metal battery pack; The size of the flexible circuit board is determined according to the number and distribution of the pressure measuring units and the temperature measuring units; The distribution of the pressure measuring unit and the temperature measuring unit on the flexible circuit board is changed according to the battery pack health monitoring requirements.

4. The system according to claim 1, characterized in that The signal conditioning circuit, the filtering circuit and the analog-to-digital conversion circuit are electrically connected in sequence; The constant current source circuit is electrically connected to the pressure measuring unit and the temperature measuring unit, and is used to provide current excitation for the pressure measuring unit and the temperature measuring unit; The signal conditioning circuit is used to amplify and linearize the signals output by the pressure measuring unit and the temperature measuring unit; The filtering circuit is used to remove high-frequency noise and other interference components in the output signal of the signal conditioning circuit to improve the signal quality; The analog-to-digital conversion circuit is used to convert the analog signal filtered by the filtering circuit into a digital signal.

5. The system according to claim 2, characterized in that During the pressure data monitoring process of the battery management unit, If the pressure between battery cells is monitored to be abnormally increased, the distribution position of the abnormal pressure increase and the pressure size at the corresponding position will be used to determine that the battery cells have abnormal growth of lithium dendrites and abnormal accumulation of dead lithium, and a first-level pressure warning will be issued. The abnormal pressure increase will be improved by adjusting the charging and discharging strategy; If the abnormal pressure increase worsens further, it is judged that the pressure between battery cells exceeds the limit, and there is a diaphragm damage, a short circuit in the battery cell, or a broken tab. A secondary pressure warning is issued, the charge / discharge circuit is disconnected, the faulty battery pack is isolated, and the pressure changes between battery cells are continuously monitored; The battery management unit predicts the life of the lithium metal battery pack according to the pressure change by analyzing the pressure data between battery cells.

6. The system according to claim 2, characterized in that During the temperature data monitoring process of the battery management unit, If the temperature between battery cells is abnormally increased, the distribution of the abnormal temperature increase and the temperature at the corresponding position will determine that the battery cells have uneven electrode reaction and uneven lithium deposition, and a first-level temperature warning will be issued. The abnormal temperature increase will be improved by adjusting the charging and discharging strategy; If the abnormal temperature increase worsens further, it is judged that the temperature between battery cells exceeds the limit, and there is a short circuit in the battery cell or electrolyte decomposition. A secondary temperature warning is issued, the charge / discharge circuit is disconnected, the faulty battery pack is isolated, and the temperature changes between lithium metal battery cells are continuously monitored; The battery management unit compares the historical temperature data between battery cells and assists in judging the health status of the lithium metal battery pack according to the temperature change trend.

7. A method for monitoring the health of a lithium metal battery pack with a thin film sensor, characterized in that: include: According to the needs of health monitoring of lithium metal battery packs, multiple thin film sensors are distributed between battery cells in the lithium metal battery pack; Connecting the plurality of thin film sensors using an adapter plate; Using the multiple thin film sensors to collect temperature and pressure information between battery cells; Connecting the adapter board to a signal acquisition unit; Providing current excitation to the plurality of thin film sensors through the signal acquisition unit, and converting the temperature and pressure information into digital signals containing temperature and pressure data; Transmitting the digital signal to a digital signal processor via a data transmission unit; Processing the temperature and pressure data by the digital signal processor, and transmitting the processed temperature and pressure data to the battery management unit in a suitable format and rate; The battery management unit monitors the temperature and pressure information of the battery cells, evaluates the battery health status, and implements the battery protection function.

8. The method according to claim 7, characterized in that Each thin film sensor is formed into a temperature and pressure integrated thin film sensor with a buffer foam structure through a special process; Using the temperature measuring unit of each thin film sensor to collect the surface temperature information of the battery cell; Using the pressure measuring unit of each thin film sensor to collect the surface pressure information of the battery cell; The flexible circuit board of each thin film sensor is used as a carrier of the temperature and pressure test unit, connecting the temperature measuring unit and the pressure measuring unit, and providing necessary mechanical support for the temperature and pressure measuring units.

9. The method according to claim 7, characterized in that: During the pressure data monitoring process of the battery management unit, If the pressure between battery cells is monitored to be abnormally increased, the distribution position of the abnormal pressure increase and the pressure size at the corresponding position will be used to determine that the battery cells have abnormal growth of lithium dendrites and abnormal accumulation of dead lithium, and a first-level pressure warning will be issued. The abnormal pressure increase will be improved by adjusting the charging and discharging strategy; If the abnormal pressure increase worsens further, it is judged that the pressure between battery cells exceeds the limit, and there is a diaphragm damage, a short circuit in the battery cell, or a broken tab. A secondary pressure warning is issued, the charge / discharge circuit is disconnected, the faulty battery pack is isolated, and the pressure changes between battery cells are continuously monitored; The battery management unit predicts the life of the lithium metal battery pack according to the pressure change by analyzing the pressure data between battery cells.

10. The method according to claim 7, characterized in that During the temperature data monitoring process of the battery management unit, If the temperature between battery cells is abnormally increased, the distribution of the abnormal temperature increase and the temperature at the corresponding position will determine that the battery cells have uneven electrode reaction and uneven lithium deposition, and a first-level temperature warning will be issued. The abnormal temperature increase will be improved by adjusting the charging and discharging strategy; If the abnormal temperature increase worsens further, it is judged that the temperature between battery cells exceeds the limit, and there is a short circuit in the battery cell or electrolyte decomposition. A secondary temperature warning is issued, the charge / discharge circuit is disconnected, the faulty battery pack is isolated, and the temperature changes between lithium metal battery cells are continuously monitored; The battery management unit compares the historical temperature data between battery cells and assists in judging the health status of the lithium metal battery pack according to the temperature change trend.

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