State of health assessment system and method based on battery micro heat production and computer equipment

Abstract

The invention relates to a battery micro heat production-based health state evaluation system and method and computer equipment. Comprising a high vacuum subsystem used for providing a high vacuum environment; the charging and discharging subsystem is used for controlling the charging and discharging state of the to-be-tested battery according to a preset charging and discharging condition; the compensation subsystem is located in the high-vacuum environment and used for receiving heat of the battery to be tested; the temperature measurement subsystem is used for detecting the real-time temperature of the compensation subsystem when the to-be-measured battery is in the charging and discharging state; the data processing subsystem is used for outputting corresponding compensation current according to the real-time temperature and the reference temperature; the compensation subsystem is also used for keeping the temperature of the compensation subsystem stable at the reference temperature according to the heat conducted by the to-be-measured battery and the compensation current when the to-be-measured battery is in the charging and discharging state; the data processing subsystem is also used for determining the health state of the to-be-tested battery according to the compensation current of the to-be-tested battery in different charging and discharging states. The system can accurately evaluate the health state of the battery.

Description

Technical Field

[0001] The present application relates to the technical field of battery testing, and particularly to a health state assessment system, method, and computer device based on battery micro heat generation. Background Art

[0002] In recent years, with the rapid development of electric vehicles and consumer electronics products, the demand for lithium-ion batteries has increased sharply. However, the heat generation analysis and heat management during the charging and discharging process of the battery are crucial for the evaluation of the battery's life and health state.

[0003] However, in related technologies, the accuracy of the heat generation analysis during the charging and discharging process of the battery is relatively low, resulting in inaccurate evaluation of the battery's health state. Summary of the Invention

[0004] Based on this, in order to solve the above technical problems, it is necessary to provide a health state assessment system, method, and computer device based on battery micro heat generation that can accurately evaluate the health state of the battery.

[0005] In a first aspect, the present application provides a health state assessment system based on battery micro heat generation, the system comprising:

[0006] A high-vacuum subsystem for providing a high-vacuum environment and accommodating the battery under test;

[0007] A charge and discharge subsystem connected to the battery under test for controlling the charge and discharge state of the battery under test according to preset charge and discharge conditions;

[0008] A compensation subsystem in contact with the battery under test and located in the high-vacuum environment for receiving the heat of the battery under test;

[0009] A temperature measurement subsystem connected to the compensation subsystem for detecting the real-time temperature of the compensation subsystem when the battery under test is in a charge and discharge state;

[0010] A data processing subsystem connected to the compensation subsystem for outputting a corresponding compensation current according to the real-time temperature and a reference temperature;

[0011] The compensation subsystem is further configured to maintain the temperature of the compensation subsystem stable at the reference temperature according to the heat conducted by the battery under test and the compensation current when the battery under test is in a charge and discharge state;

[0012] The data processing subsystem is further configured to determine the health state of the battery under test according to the compensation current when the battery under test is in different charge and discharge states.

[0013] In one embodiment, the compensation subsystem includes: a heat conduction structure, a stage, and a temperature control circuit;

[0014] The heat conduction structure wraps the battery under test and is located on the stage, and conducts the heat generated by the battery under test to the stage; the temperature control circuit is located inside the stage and maintains the temperature of the stage stable at the reference temperature according to the compensation current.

[0015] In one embodiment, the temperature measurement subsystem includes: at least one thermocouple, connected to the compensation subsystem, for detecting the real-time temperature of the compensation subsystem when the battery under test is in a charge / discharge state.

[0016] In a second aspect, a method for evaluating the health state based on the micro heat generation of a battery is applied to the health state evaluation system based on the micro heat generation of a battery described in any of the above embodiments. The method includes:

[0017] Providing a high-vacuum environment; wherein, the battery under test and the compensation subsystem are located in the high-vacuum environment;

[0018] Controlling the charge / discharge state of the battery under test according to preset charge / discharge conditions;

[0019] Detecting the real-time temperature of the compensation subsystem when the battery under test is in a charge / discharge state;

[0020] Outputting a corresponding compensation current to the compensation subsystem according to the real-time temperature and the reference temperature;

[0021] Determining the health state of the battery under test according to the compensation current when the battery under test is in different charge / discharge states.

[0022] In one embodiment, the determining the health state of the battery under test according to the compensation current when the battery under test is in different charge / discharge states includes:

[0023] Determining the heat generation amount of the battery under test in different charge / discharge states according to the compensation current when the battery under test is in different charge / discharge states;

[0024] Determining the health state of the battery under test according to the heat generation amount of the battery under test in different charge / discharge states and the preset reference heat generation amount of the battery under test in different charge / discharge states.

[0025] In one embodiment, the charge / discharge conditions include charge / discharge voltage, multiple charge / discharge rates, and test times corresponding to each charge / discharge rate;

[0026] The controlling the charge / discharge state of the battery under test according to preset charge / discharge conditions includes:

[0027] Control the battery under test to charge and discharge at the charge-discharge voltage and each of the charge-discharge rates respectively until the charge-discharge time of the battery under test reaches the corresponding test time;

[0028] Repeat the step of controlling the battery under test to charge and discharge at the charge-discharge voltage and each of the charge-discharge rates respectively until the charge-discharge time of the battery under test reaches the corresponding test time until the number of test times of the battery under test in each of the charge-discharge states reaches a preset number.

[0029] In one embodiment, the determining the heat generation amount of the battery under test in different charge-discharge states according to the compensation current of the battery under test in different charge-discharge states includes:

[0030] Determine a plurality of candidate heat generation amounts of the battery under test in different charge-discharge states according to the compensation current of the battery under test in different charge-discharge states, wherein the number of candidate heat generation amounts of the battery under test in a charge-discharge state is the same as the number of test times of the battery under test in the corresponding charge-discharge state;

[0031] Determine at least one target heat generation amount of the battery under test in different charge-discharge states from each of the candidate heat generation amounts of the battery under test in different charge-discharge states, wherein the heat generation volatility of the target heat generation amount is less than or equal to a preset volatility threshold;

[0032] Determine the heat generation amount of the battery under test in different charge-discharge states according to the average value of each target heat generation amount of the battery under test in different charge-discharge states.

[0033] In one embodiment, the determining a plurality of candidate heat generation amounts of the battery under test in different charge-discharge states according to the compensation current of the battery under test in different charge-discharge states includes:

[0034] Determine the cooling capacity of the compensation subsystem when the battery under test is in different charge-discharge states according to the compensation current of the battery under test in different charge-discharge states, a preset reference temperature, a preset Seebeck coefficient, and the internal resistance of the preset compensation subsystem;

[0035] Determine the candidate heat generation amount of the battery under test in different charge-discharge states according to the cooling capacity of the compensation subsystem when the battery under test is in different charge-discharge states.

[0036] In one embodiment, the determining the health state of the battery under test according to the heat generation amount of the battery under test in different charge-discharge states and the preset reference heat generation amount of the battery under test in different charge-discharge states includes:

[0037] Draw a reference heat generation curve based on the reference heat generation of the battery under test in different charge and discharge states;

[0038] Draw a test heat generation curve of the battery under test based on the heat generation of the battery under test in different charge and discharge states;

[0039] Calculate the reference heat generation area and the test heat generation area respectively according to the reference heat generation curve and the test heat generation curve of the battery under test;

[0040] Determine the health state of the battery under test according to the reference heat generation area and the test heat generation area.

[0041] In a third aspect, the present application provides a computer device, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, the steps of the method described in any one of the above embodiments are implemented.

[0042] The above-mentioned health state evaluation system, method and computer device based on battery micro heat generation include a high-vacuum subsystem, a charge and discharge subsystem, a compensation subsystem, a temperature measurement subsystem and a data processing subsystem. Among them, the high-vacuum subsystem is used to provide a high-vacuum environment and to accommodate the battery under test and the compensation subsystem to isolate the interference of external heat on the battery under test and the compensation subsystem. The temperature measurement subsystem is used to detect the real-time temperature of the compensation subsystem when the battery under test is in a charge and discharge state. The data processing subsystem is used to output a corresponding compensation current to the compensation subsystem according to the real-time temperature and the reference temperature, so that the compensation subsystem can be stabilized at the reference temperature according to the heat conducted by the battery under test and the compensation current when the battery under test is in a charge and discharge state. Furthermore, the data processing subsystem can determine the health state of the battery under test according to the compensation current when the battery under test is in different charge and discharge states. First, the present application provides a high-vacuum environment through the high-vacuum subsystem, which can ensure the thermal stability during the measurement process and reduce external interference; second, the present application indirectly calculates the heat generation of the battery under test through the compensation current that maintains the compensation subsystem at the reference temperature, which can avoid the calculation difficulty caused by the inestimable specific heat capacity of the battery. At the same time, since the specific heat capacity of the battery does not need to be used to calculate the heat generation of the battery, the calculation accuracy can also be improved; third, the present application comprehensively obtains the heat generation data of the battery under test in different charge and discharge states. In summary, the battery health state evaluation system of the present application can accurately evaluate the battery health state. Description of the Drawings

[0043] To more clearly illustrate the technical solutions in the embodiments of the present application or in the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0044] Figure 1 It is a schematic structural diagram of a health state evaluation system based on battery micro-heat generation in an embodiment;

[0045] Figure 2 It is a schematic structural diagram of a health state evaluation system based on battery micro-heat generation in another embodiment;

[0046] Figure 3 It is a schematic flowchart of a health state evaluation method based on battery micro-heat generation in an embodiment;

[0047] Figure 4 It is a schematic flowchart of step S305 in an embodiment;

[0048] Figure 5 It is a schematic flowchart of step S302 in an embodiment;

[0049] Figure 6 It is a schematic flowchart of step S401 in an embodiment;

[0050] Figure 7 It is a schematic flowchart of step S601 in an embodiment;

[0051] Figure 8 It is a schematic flowchart of step S402 in an embodiment;

[0052] Figure 9 It is a heat generation curve diagram of a first battery under test, a second battery under test, and a healthy battery in an embodiment. Detailed implementation manners

[0053] To facilitate the understanding of the present application, the following will describe the present application more comprehensively with reference to the relevant drawings. Embodiments of the present application are shown in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0054] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present application belongs. The terms used in the description of the present application herein are only for the purpose of describing specific embodiments and are not intended to limit the present application.

[0055] It will be understood that the terms "first", "second", etc. used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element.

[0056] Spatial relationship terms such as "under", "below", "beneath", "underneath", "above", "over", etc. may be used herein to describe the relationship of one element or feature shown in the figures to other elements or features. It should be understood that, in addition to the orientation shown in the figures, spatial relationship terms also include different orientations of the device in use and operation. For example, if the device in the figures is flipped, an element or feature described as "under" or "beneath" or "underneath" another element will be oriented "over" the other element or feature. Thus, the exemplary terms "under" and "beneath" can include both an upper and a lower orientation. In addition, the device may also have other orientations (such as, rotated 90 degrees or other orientations), and the spatial descriptors used herein are to be interpreted accordingly.

[0057] It should be noted that when an element is considered to be "connected" to another element, it may be directly connected to the other element or connected to the other element through an intervening element. In addition, in the following embodiments, "connection", if there is a transfer of electrical signals or data between the connected objects, should be understood as "electrical connection", "communication connection", etc.

[0058] As used herein, the singular forms "a", "an" and "the" may also include the plural forms unless the context clearly dictates otherwise. It should also be understood that the terms "comprises / comprising" or "has / including" etc. specify the presence of the stated features, integers, steps, operations, components, parts or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the related listed items.

[0059] As described in the background art, in recent years, with the rapid development of electric vehicles and consumer electronics, the demand for lithium-ion batteries has increased sharply. However, the heat generation analysis and heat management during the charging and discharging process of the battery are crucial for the battery life and safety reliability. Currently, the commonly used method for measuring the heat generation of the battery is to calculate the heat generation converted from the temperature rise of the battery by attaching thermocouples to the battery surface after monitoring the battery temperature rise. However, this method has the following three disadvantages. First, due to the presence of air, the heat generated inside the battery will diffuse into the air, resulting in inaccurate temperature measurement. Second, there is a certain delay in the heat conduction from the inside of the battery to the outside after heat generation, and the heat will diffuse from all sides of the battery, resulting in inaccurate temperature measurement. Third, using thermocouples to measure is insensitive to the micro heat generated by the battery, and there will be a large error in the process of converting heat generation and heat dissipation. Therefore, this measurement method in the prior art has a relatively high complexity and limited measurement accuracy, and cannot accurately evaluate the health status of the battery.

[0060] For the above reasons, in an exemplary embodiment, please refer to Figure 1 , this application provides a health status evaluation system based on battery micro heat generation, which includes a high-vacuum subsystem 11, a charge and discharge subsystem 12, a compensation subsystem 13, a temperature measurement subsystem 14, and a data processing subsystem 15.

[0061] Among them, the high-vacuum subsystem 11 is used to provide a high-vacuum environment and to accommodate the battery under test 20 and the compensation subsystem 13. The charge and discharge subsystem 12 is connected to the battery under test 20 and is used to control the charge and discharge state of the battery under test 20 according to preset charge and discharge conditions. The compensation subsystem 13 is in contact with the battery under test 20 and is located in the high-vacuum environment and is used to receive the heat of the battery under test 20. The temperature measurement subsystem 14 is connected to the compensation subsystem 13 and is used to detect the real-time temperature of the compensation subsystem 13 when the battery under test 20 is in the charge and discharge state. The data processing subsystem 15, which is connected to the compensation subsystem 13, is used to output a corresponding compensation current according to the real-time temperature and the reference temperature. The compensation subsystem 13 is also used to keep the temperature of the compensation subsystem 13 stable at the reference temperature according to the heat conducted by the battery under test 20 and the compensation current when the battery under test 20 is in the charge and discharge state; the data processing subsystem 15 is also used to determine the health status of the battery under test 20 according to the compensation current when the battery under test 20 is in different charge and discharge states.

[0062] In this embodiment, when detecting the health state of the battery under test, first connect the battery under test 20 to the charge and discharge electronic system 12, connect the compensation subsystem 13 to the temperature measurement subsystem 14, and connect the data processing subsystem 15 to the compensation subsystem 13 and the temperature measurement subsystem 14 respectively. Then, place the battery under test 20 and the compensation subsystem 13 together in the high vacuum subsystem 11. The battery under test 20 contacts the compensation subsystem 13, and control the high vacuum subsystem 11 to provide a high vacuum environment for testing for the battery under test 20 and the compensation subsystem 13 to isolate the interference of external heat on the battery under test 20 and the compensation subsystem 13. At the same time, control the charge and discharge electronic system 12 to control the charge and discharge state of the battery under test 20 according to the preset charge and discharge conditions, control the temperature measurement subsystem 14 to detect the real-time temperature of the compensation subsystem 13 when the battery under test 20 is in the charge and discharge state. The temperature measurement subsystem 14 can send the detected real-time temperature of the compensation subsystem 13 to the data processing subsystem 15, and the data processing subsystem 15 can deliver a compensation current to the compensation subsystem 13 according to the real-time temperature of the compensation subsystem 13 and the reference temperature of the compensation subsystem 13 to control the temperature of the compensation subsystem 13 to be stable at the reference temperature. Wherein, the reference temperature of the compensation subsystem 13 refers to the temperature of the compensation subsystem 13 in the high vacuum environment when the battery under test 20 does not conduct heat to the compensation subsystem 13.

[0063] In a high vacuum environment. When the battery under test 20 is in the charge and discharge state, the heat generated by the battery under test 20 will be conducted to the compensation subsystem 13, and the compensation subsystem 13 maintains a constant temperature under the action of the compensation current, that is, the heat generated by the battery under test 20 is offset by the cooling capacity generated by the compensation subsystem 13 under the action of the compensation current. Therefore, in this application, the heat generation of the battery under test 20 can be accurately determined by calculating the cooling capacity of the compensation subsystem 13, and then the health state of the battery under test 20 can be accurately evaluated according to the accurate heat generation of the battery under test 20.

[0064] The above-mentioned health state evaluation system based on battery micro heat generation includes a high-vacuum subsystem 11, a charge-discharge subsystem 12, a compensation subsystem 13, a temperature measurement subsystem 14, and a data processing subsystem 15. Among them, the high-vacuum subsystem 11 is used to provide a high-vacuum environment and to accommodate the battery under test 20 and the compensation subsystem 13 to isolate the interference of external heat on the battery under test 20 and the compensation subsystem 13. The temperature measurement subsystem 14 is used to detect the real-time temperature of the compensation subsystem 13 when the battery under test 20 is in the charge-discharge state. The data processing subsystem 15 is used to output a corresponding compensation current to the compensation subsystem 13 according to the real-time temperature and the reference temperature, so that the compensation subsystem 13 can be stabilized at the reference temperature according to the heat conducted by the battery under test 20 and the compensation current when the battery under test 20 is in the charge-discharge state. Furthermore, the data processing subsystem 15 can determine the health state of the battery under test 20 according to the compensation current when the battery under test 20 is in different charge-discharge states. First, the present application provides a high-vacuum environment through the high-vacuum subsystem 11, which can ensure the thermal stability during the measurement process and reduce external interference. Second, the present application indirectly calculates the heat generation of the battery under test 20 by maintaining the compensation current of the compensation subsystem 13 at the reference temperature, which can reduce the calculation difficulty of the heat index due to the inestimable specific heat capacity of the battery. At the same time, since it is not necessary to use the specific heat capacity of the battery to calculate the heat generation of the battery, the calculation accuracy can be improved. Third, the present application comprehensively obtains the battery heat generation data when the battery under test 20 is in different charge-discharge states. In summary, the battery health state evaluation system of the present application can accurately evaluate the battery health state.

[0065] In an exemplary embodiment, please refer to Figure 2 , the compensation subsystem 13 includes: a heat conduction structure 131, a carrier stage 132, and a temperature control circuit 133. The heat conduction structure 131 wraps the battery under test 20 and is located on the carrier stage 132, and conducts the heat generated by the battery under test 20 to the carrier stage 132; the temperature control circuit 133 is located inside the carrier stage 132 and keeps the temperature of the carrier stage 132 stable at the reference temperature according to the compensation current.

[0066] The temperature measurement subsystem 14 includes at least one thermocouple. The thermocouple is connected to the compensation subsystem 13 and is used to detect the real-time temperature of the compensation subsystem 13 when the battery under test 20 is in the charge-discharge state. Exemplarily, the temperature measurement subsystem 14 includes at least one T-type thermocouple, and the error rate of the T-type thermocouple is ±0.001°C.

[0067] The high-vacuum subsystem 11 may include a vacuum chamber and a vacuum pump connected to each other.

[0068] In one example, the heat conduction structure 131 can be a high heat conduction copper heat sink. When testing the battery under test, the entire battery under test 20 can be tightly wrapped with the high heat conduction copper heat sink first, and the thermocouple can be attached to the stage 132. Then, the battery under test 20 wrapped by the high heat conduction copper heat sink can be placed on the stage 132, and the battery under test 20 wrapped by the high heat conduction copper heat sink and the stage 132 can be placed in the vacuum chamber. After that, the vacuum pump is started to evacuate the air, and the vacuum degree can be lower than 10 - ³ Pa. After that, the power supply and discharge electronic system 12 can be used to apply power to the battery under test 20, control the battery under test 20 to be in the charge and discharge state, and test the health state of the battery under test 20.

[0069] In an exemplary embodiment, please refer to Figure 3 , the present application further provides a method for evaluating the health state based on the micro heat generation of the battery, which is applied to the system for evaluating the health state based on the micro heat generation of the battery in any of the above embodiments. The method includes steps S301 to S305.

[0070] S301: Provide a high vacuum environment; wherein, the battery under test and the compensation subsystem are located in the high vacuum environment.

[0071] During the test, first, the entire battery under test 20 is tightly wrapped with the heat conduction structure 131, and the thermocouple is attached to the stage 132. Then, the battery under test 20 wrapped by the heat conduction structure 131 is placed on the stage 132, and the stage 132 and the battery under test 20 wrapped by the heat conduction structure 131 are placed in the vacuum chamber. After that, the vacuum pump is started to evacuate the air, so that the vacuum degree in the vacuum chamber is lower than 10 - ³ Pa and maintained.

[0072] S302: Control the charge and discharge state of the battery under test according to the preset charge and discharge conditions.

[0073] In this embodiment, the preset charge and discharge conditions may include the charge and discharge voltage, charge and discharge rate, and test time of the battery under test 20. In one example, the charge and discharge voltage of the battery under test 20 may be within the range of (1.0~1.2)*Vmin~(0.8~1.0)*Vmax, where Vmin is the rated minimum voltage of the battery under test 20 and Vmax is the rated maximum voltage of the battery under test 20. The charge and discharge rate of the battery under test 20 may be 0.5C, 1C, 2C, 3C, 5C, where 1C means that the battery under test 20 is fully discharged or charged within one hour, 0.5C means that the battery under test 20 is fully discharged or charged within two hours, and 2C means that the battery under test 20 is fully discharged or charged within half an hour. The test time is the time of three working cycles of the battery under test 20. Specifically, one charge and one discharge of the battery under test 20 is one working cycle. Among them, the charge and discharge rate is the ratio of the charge and discharge current to the rated capacity of the battery under test 20. According to the charge and discharge rate and the rated capacity of the battery under test 20, the magnitude of the charge and discharge current of the battery under test 20 at each charge and discharge rate can be calculated. By controlling the charge and discharge of the battery under test 20 at different charge and discharge rates, the battery under test 20 can be controlled to be in different working states.

[0074] S303: Detect the real-time temperature of the compensation subsystem when the battery under test is in the charge and discharge state.

[0075] When the battery under test 20 is in the charge and discharge state, the battery under test 20 will generate heat. The heat generated by the battery under test 20 will be conducted to the stage 132 through the heat conduction structure 131, causing a temperature change of the stage 132. Therefore, the real-time temperature of the compensation subsystem 13 when the battery under test 20 is in the charge and discharge state can be detected by the temperature measurement subsystem 14.

[0076] S304: Output a corresponding compensation current to the compensation subsystem according to the real-time temperature and the reference temperature.

[0077] In application, the temperature measurement subsystem 14 will also send the detected real-time temperature of the stage 132 to the data processing subsystem 15 in real time. Furthermore, the data processing subsystem 15 can output a corresponding compensation current to the temperature control circuit 133 inside the stage 132 according to the real-time temperature of the stage 132 and the reference temperature, so that the temperature control circuit 133 cools down and the temperature of the stage 132 is restored to the reference temperature.

[0078] S305: Determine the health state of the battery under test according to the compensation current when the battery under test is in different charge and discharge states.

[0079] It can be understood that the data processing subsystem 15 can deduce the refrigeration power of the temperature control circuit 133 based on the compensation current output to the temperature control circuit 133, and further deduce the refrigeration capacity of the temperature control circuit 133. Since the battery under test 20 wrapped by the stage 132 and the heat-conducting structure 131 is in a high-vacuum environment and there is no interference from external heat, when the temperature of the stage 132 is stable at the reference temperature, the refrigeration capacity of the temperature control circuit 133 is the heat generation amount of the battery under test 20. According to the heat generation amounts of the battery under test 20 in different charge and discharge states, it can be determined whether the heat generation of the battery under test 20 is normal in each charge and discharge state, and further determine the health state of the battery under test 20.

[0080] In an exemplary embodiment, please refer to Figure 4 , step S305, determining the health state of the battery under test according to the compensation current when the battery under test is in different charge and discharge states, including step S401 and step S402.

[0081] S401: Determine the heat generation amounts of the battery under test in different charge and discharge states according to the compensation current when the battery under test is in different charge and discharge states.

[0082] Specifically, the refrigeration power of the temperature control circuit 133, that is, the real-time heat generation power of the battery under test 20, can be calculated according to the compensation current output by the data processing subsystem 15 to the temperature control circuit 133 when the battery under test 20 is in different charge and discharge states, and then the heat generation amount of the battery under test 20 can be obtained.

[0083] S402: Determine the health state of the battery under test according to the heat generation amounts of the battery under test in different charge and discharge states and the preset reference heat generation amounts of the battery under test in different charge and discharge states.

[0084] In this embodiment, the reference heat generation amount of the battery under test 20 can be obtained by testing an unused battery or a healthy battery produced in the same batch as the battery under test 20 through the battery health state evaluation method of the present application. By comparing the heat generation amounts of the battery under test 20 in different charge and discharge states with the preset reference heat generation amounts of the battery under test in different charge and discharge states, the health state of the battery under test can be determined.

[0085] In an exemplary embodiment, please refer to Figure 5 , step S302, controlling the charge and discharge state of the battery under test according to the preset charge and discharge conditions, including step S501 and step S502.

[0086] S501: Control the battery under test to charge and discharge at the charge and discharge voltage and each charge and discharge rate respectively until the charge and discharge time of the battery under test reaches the corresponding test time.

[0087] The charge and discharge conditions include the charge and discharge voltage, multiple charge and discharge rates, and the test time corresponding to each charge and discharge rate.

[0088] In one example, the charge and discharge voltage of the battery 20 to be tested can be within the range of (1.0~1.2)*Vmin~(0.8~1.0)*Vmax, where Vmin is the rated minimum voltage of the battery 20 to be tested, and Vmax is the rated maximum voltage of the battery 20 to be tested. The charge and discharge rates of the battery 20 to be tested can be 0.5C, 1C, 2C, 3C. Here, 1C means that the battery 20 to be tested is fully discharged or charged within one hour, 0.5C means that the battery 20 to be tested is fully discharged or charged within two hours, 2C means that the battery 20 to be tested is fully discharged or charged within half an hour, and 3C means that the battery 20 to be tested is fully discharged or charged within twenty minutes. The test time can be the time of three working cycles of the battery 20 to be tested. One working cycle of the battery 20 to be tested is completed when it undergoes one charge and one discharge. The test time corresponding to the charge and discharge rate of 0.5C for the battery 20 to be tested is 12 hours, the test time corresponding to the charge and discharge rate of 1C for the battery 20 to be tested is 6 hours, the test time corresponding to the charge and discharge rate of 2C for the battery 20 to be tested is 3 hours, and the test time corresponding to the charge and discharge rate of 3C for the battery 20 to be tested is 2 hours.

[0089] Since the charge and discharge rate is the ratio of the charge and discharge current to the rated capacity of the battery 20 to be tested, the magnitude of the charge and discharge current of the battery 20 to be tested at each charge and discharge rate can be calculated based on the charge and discharge rate and the rated capacity of the battery 20 to be tested. By controlling the battery 20 to be tested to charge and discharge at different charge and discharge rates, the battery 20 to be tested can be controlled to be in different working states.

[0090] S502: Repeat the step of separately controlling the battery to be tested to charge and discharge at the charge and discharge voltage and each charge and discharge rate until the charge and discharge time of the battery to be tested reaches the corresponding test time, until the number of test times of the battery to be tested in each charge and discharge state reaches the preset number of times.

[0091] In the application, in order to reduce the test error, the battery 20 to be tested can be controlled to be tested multiple times in each charge and discharge state. For example, the battery 20 to be tested can be controlled to be tested multiple times in each charge and discharge state, and the heat generation value of the battery 20 to be tested in each test round with a heat generation volatility less than the preset threshold is used as the heat generation value of the battery 20 to be tested.

[0092] In an exemplary embodiment, please refer to Figure 6 , step S401, determining the heat generation amount of the battery to be tested in different charge and discharge states according to the compensation current of the battery to be tested in different charge and discharge states, including step S601 and step S603.

[0093] S601: Determine multiple candidate heat generations of the battery under test in different charge and discharge states according to the compensation current of the battery under test in different charge and discharge states, where the number of candidate heat generations of the battery under test in a charge and discharge state is the same as the number of test times of the battery under test in the corresponding charge and discharge state.

[0094] In one example, when testing the battery under test 20, four charge and discharge conditions are set, corresponding to four charge and discharge states of the battery under test 20. The four charge and discharge conditions are respectively (U, 0.5C, 12h), (U, 1C, 6h), (U, 2C, 3h), and (U, 3C, 2h), where U is the charge and discharge voltage of the battery under test 20, nC is the charge and discharge rate of the battery under test 20, n = 0.5, 1, 2, 3, and h is hour. The battery under test 20 is tested multiple times according to each charge and discharge condition. Then, for each charge and discharge condition, multiple heat generation values of the battery under test 20 can be obtained respectively.

[0095] S602: Determine at least one target heat generation of the battery under test in different charge and discharge states from the candidate heat generations of the battery under test in different charge and discharge states, where the heat generation volatility of the target heat generation is less than or equal to a preset volatility threshold.

[0096] After that, calculate the heat generation volatility of the battery under test 20 in each test round according to the multiple heat generation values of the battery under test 20 in the charge and discharge state, where the heat generation volatility R H = (Hx - H nC ) / H nC , Hx is the heat generation of the battery under test 20 in a single test, that is, the candidate heat generation, and H nC is the average value of the heat generations of the battery under test in each test round in the same test state of the battery under test 20. In one example, for the charge and discharge condition (U, 0.5C, 12h), the battery under test 20 is controlled to be tested 5 times respectively, and 5 candidate heat generations H 0.5C1 , H 0.5C2 , H 0.5C3 , H 0.5C4 , H 0.5C5 are obtained. H 0.5C1 is the candidate heat generation of the first test round of the battery under test 20 in this charge and discharge state, H 0.5C2 is the candidate heat generation of the second test round of the battery under test 20 in this charge and discharge state, H 0.5C3 is the candidate heat generation of the third test round of the battery under test 20 in this charge and discharge state, H 0.5C4 is the candidate heat generation of the fourth test round of the battery under test 20 in this charge and discharge state, H 0.5C5 is the candidate heat generation of the fifth test round of the battery under test 20 in this charge and discharge state. H nC = (H0.5C1 +H 0.5C2 +H 0.5C3 +H 0.5C4 +H 0.5C5 (+H) / 5. Thus, the heat generation volatility R of each test round of the battery 20 to be measured under this charge and discharge state can be calculated. H . Then, the heat generation volatility R H less than or equal to the preset volatility threshold can be selected, and the corresponding candidate heat generation amount of the test round is used as the target heat generation amount of the battery 20 to be measured under this charge and discharge state.

[0097] S603: Determine the heat generation amount of the battery to be measured under different charge and discharge states according to the average value of the target heat generation amounts of the battery to be measured under different charge and discharge states.

[0098] After that, the average value of the target heat generation amount of the battery 20 to be measured under this charge and discharge state can be calculated as the heat generation amount of the battery 20 to be measured under this charge and discharge state.

[0099] In another example, the target heat generation amount of the battery 20 to be measured may not be determined according to the heat generation volatility. For example, the battery 20 to be measured can be tested multiple times according to each charge and discharge condition. For each charge and discharge condition, multiple candidate heat generation values of the battery 20 to be measured can be obtained. Then, for the candidate heat generation amounts of each charge and discharge condition, one highest value and one lowest value are discarded, and the remaining candidate heat generation amounts are used as the target heat generation amounts. Then, the average value of the target heat generation amount of the battery 20 to be measured under this charge and discharge state is calculated as the heat generation amount of the battery 20 to be measured under this charge and discharge state.

[0100] In an exemplary embodiment, please refer to Figure 7 , step S601, determining multiple candidate heat generation amounts of the battery to be measured under different charge and discharge states according to the compensation current of the battery to be measured under different charge and discharge states, including step S701 and step S702.

[0101] S701: Determine the cooling capacity of the compensation subsystem when the battery to be measured is in different charge and discharge states according to the compensation current of the battery to be measured in different charge and discharge states, the preset reference temperature, the preset Seebeck coefficient, and the internal resistance of the preset compensation subsystem.

[0102] In this embodiment, the cooling power of the compensation subsystem when the battery to be measured is in different charge and discharge states can be determined according to the compensation current of the battery to be measured in different charge and discharge states, the preset reference temperature, the preset Seebeck coefficient, and the internal resistance of the temperature control circuit 133 in the compensation subsystem, and then the cooling capacity of the compensation subsystem when the battery to be measured is in different charge and discharge states can be determined according to the cooling power. Among them, Qc = STI - RI 2, Qc is the refrigeration power, S is the preset Seebeck coefficient, T is the reference temperature, I is the compensation current, and R is the sum of the internal resistances of the temperature control circuit 133.

[0103] S702: Determine the candidate heat generation amounts of the battery under test in different charge and discharge states according to the refrigeration amounts of the compensation subsystem when the battery under test is in different charge and discharge states.

[0104] Since the stage 132 and the battery under test 20 wrapped by the heat conduction structure 131 are in a high-vacuum environment and there is no interference from external heat, when the temperature of the stage 132 is stable at the reference temperature, the refrigeration amount of the temperature control circuit 133 is the heat generation amount of the battery under test 20. Furthermore, the candidate heat generation amounts of the battery under test in different charge and discharge states can be determined according to the refrigeration amounts of the temperature control circuit 133 when the battery under test is in different charge and discharge states.

[0105] In an exemplary embodiment, please refer to Figure 8 , step S402, determine the health state of the battery under test according to the heat generation amounts of the battery under test in different charge and discharge states and the preset reference heat generation amounts of the battery under test in different charge and discharge states, including steps S801 to S804.

[0106] S801: Draw a reference heat generation curve according to the reference heat generation amounts of the battery under test in different charge and discharge states.

[0107] The abscissa of the reference heat generation curve is the charge and discharge rate, and the ordinate is the heat generation amount. According to the preset reference heat generation amounts of the battery under test in different charge and discharge states, a relationship curve representing the charge and discharge rate corresponding to each charge and discharge state and the reference heat generation amount corresponding to each charge and discharge state can be drawn, that is, the reference heat generation curve.

[0108] S802: Draw a test heat generation curve of the battery under test according to the heat generation amounts of the battery under test in different charge and discharge states.

[0109] Similarly, the abscissa of the test heat generation curve is the charge and discharge rate, and the ordinate is the heat generation amount. According to the measured heat generation amounts of the battery under test in different charge and discharge states, a relationship curve representing the charge and discharge rate corresponding to each charge and discharge state and the heat generation amount corresponding to each charge and discharge state can be drawn, that is, the test heat generation curve.

[0110] S803: Calculate the reference heat generation area and the test heat generation area according to the reference heat generation curve and the test heat generation curve of the battery under test respectively.

[0111] After that, the reference heat generation area can be calculated according to the reference heat generation curve of the battery under test, and the test heat generation area can be calculated according to the test heat generation curve of the battery under test.

[0112] S804: Determine the health status of the battery under test based on the reference heat generation area and the measured heat generation area.

[0113] Further, the reference heat generation area and the measured heat generation area can be compared, and the health status of the battery 20 under test can be determined according to the ratio of the reference heat generation area to the measured heat generation area. For example, if the reference heat generation area is S0 and the measured heat generation area is Sn, when Sn ≤ 2S0, it can be determined that the health status of the battery 20 under test is high; when 2S0 < Sn < 5S0, it can be determined that the health status of the battery 20 under test is medium; when Sn ≥ 5S0, it can be determined that the health status of the battery 20 under test is low.

[0114] In a detailed embodiment, if it is necessary to evaluate the health status of two batteries under test (the first battery under test and the second battery under test), the first battery under test, the second battery under test, a healthy battery, and the battery health status evaluation system of the present application can be prepared in advance.

[0115] First, tightly wrap the entire healthy battery with the heat conduction structure 131, attach the thermocouple to the stage 132, then place the healthy battery wrapped by the heat conduction structure 131 on the stage 132, and place the stage 132 and the healthy battery wrapped by the heat conduction structure 131 in the vacuum chamber. After that, start the vacuum pump to evacuate, so that the vacuum degree in the vacuum chamber is lower than 10 - ³ Pa and maintain it. Then, use the charge and discharge electronic system to power on the healthy battery, set the charge and discharge voltage of the healthy battery to V, and set the charge and discharge rates to 0.5C, 1C, 2C, and 3C respectively. Cycle 3 weeks at each charge and discharge rate, and record the stable heat generation values Hx at different charge and discharge rates in real time. It is required that the heat generation volatility R H ≤ 15%. Finally, the average value of the stable heat generation in 3 weeks of the healthy battery at each current density is taken as the reference heat generation amount.

[0116] First, tightly wrap the entire healthy battery with the heat conduction structure 131, attach the thermocouple to the stage 132, then place the healthy battery wrapped by the heat conduction structure 131 on the stage 132, and place the stage 132 and the healthy battery wrapped by the heat conduction structure 131 in the vacuum chamber. After that, start the vacuum pump to evacuate, so that the vacuum degree in the vacuum chamber is lower than 10 - ³ Pa and maintain it. Then, use the charge and discharge electronic system to power on the healthy battery, set the charge and discharge voltage of the healthy battery to U, and set the charge and discharge rates to 0.5C, 1C, 2C, and 3C respectively. Cycle 3 weeks at each charge and discharge rate, and record the stable heat generation values Hx at different charge and discharge rates in real time. It is required that the heat generation volatility R H≤15%, and finally, the heat generation of the healthy battery at each current density is averaged over 3 weeks of stable heat generation as the reference heat generation, and the reference heat generations H of the healthy battery at each charge-discharge rate are recorded respectively. 0.5C 、H 1C 、H 2C 、H 3C Among them, the data acquisition frequency is 2 points per second, and the heat generation resolution is ≥10 - ³ J.

[0117] After obtaining the reference heat generations of the healthy battery at each charge-discharge rate, the first battery under test can be tested. Similarly, the entire first battery under test is tightly wrapped with the heat conduction structure 131, and the thermocouple is attached to the stage 132. Then, the first battery under test wrapped by the heat conduction structure 131 is placed on the stage 132, and the stage 132 and the first battery under test wrapped by the heat conduction structure 131 are placed in the vacuum chamber. After that, the vacuum pump is started to evacuate, so that the vacuum degree in the vacuum chamber is lower than 10 - ³ Pa and maintained. Then, the charge-discharge electronic system is used to power on the first battery under test. The charge-discharge voltage of the first battery under test is set to U, and the charge-discharge rates are set to 0.5C, 1C, 2C, and 3C respectively. It is cycled for 3 weeks at each charge-discharge rate, and the stable heat generation values Hx at different charge-discharge rates are recorded in real time. The heat generation volatility R is required to be H ≤15%. Finally, the target heat generation of the first battery under test at each current density is averaged over 3 weeks of stable heat generation as the heat generation of the first battery under test, and the heat generations H of the first battery under test at each charge-discharge rate are recorded respectively. 0.5C 、H 1C 、H 2C 、H 3C Among them, the data acquisition frequency is 2 points per second, and the heat generation resolution is ≥10 - ³ J.

[0118] After obtaining the heat generations of the first battery under test at each charge-discharge rate, the second battery under test can be tested. Similarly, the entire second battery under test is tightly wrapped with the heat conduction structure 131, and the thermocouple is attached to the stage 132. Then, the second battery under test wrapped by the heat conduction structure 131 is placed on the stage 132, and the stage 132 and the second battery under test wrapped by the heat conduction structure 131 are placed in the vacuum chamber. After that, the vacuum pump is started to evacuate, so that the vacuum degree in the vacuum chamber is lower than 10 - ³ Pa and maintained. Then, the charge-discharge electronic system is used to power on the second battery under test. The charge-discharge voltage of the second battery under test is set to U, and the charge-discharge rates are set to 0.5C, 1C, 2C, and 3C respectively. It is cycled for 3 weeks at each charge-discharge rate, and the stable heat generation values Hx at different charge-discharge rates are recorded in real time. The heat generation volatility R is required to beH ≤ 15%, and finally, the target heat generation of the second battery under test at each current density is taken as the average value of the stable heat generation in 3 weeks as the heat generation of the second battery under test, and the heat generations H 0.5C 、H 1C 、H 2C 、H 3C of the second battery under test at each charge-discharge rate are respectively recorded. Among them, the data acquisition frequency is 2 points per second, and the heat generation resolution ≥ 10 -3 J.

[0119] Finally, according to the heat generations of the first battery under test at each charge-discharge rate, the heat generations of the second battery under test at each charge-discharge rate, and the reference heat generations of the healthy battery at each charge-discharge rate, a heat generation curve can be plotted. In one example, the heat generation curve can be as shown in Figure 9 . The thermal area Sn of the battery under test is respectively compared with S0. If Sn ≤ 2S0, the health status of the battery under test 20 can be determined to be high; if 2S0 < Sn < 5S0, the health status of the battery under test 20 can be determined to be medium; if Sn ≥ 5S0, the health status of the battery under test 20 can be determined to be low.

[0120] As shown in Figure 9 , the measured thermal area S1 of the first battery under test = 50.94; the measured thermal area S2 of the second battery under test 2 = 14.32; the reference thermal area S0 of the healthy battery = 7.18; among them, S1 / S0 = 7.09. Therefore, the health status of the S1 battery can be determined to be low; S2 / S0 = 1.99. Therefore, the health status of the S2 battery can be determined to be high.

[0121] It should be understood that although the steps in the flowchart of Figures 3 - 8 are shown in sequence according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless there is a clear indication in this article, the execution of these steps has no strict order limit, and these steps can be executed in other orders. Moreover, Figures 3 - 8 at least a part of the steps in

[0122] In one embodiment, a computer device is provided, including a memory and a processor. A computer program is stored in the memory, and when the processor executes the computer program, the steps of the method in any one of the above embodiments are implemented.

[0123] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method in any of the above embodiments are implemented.

[0124] Those of ordinary skill in the art can understand that all or part of the processes of implementing the methods in the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, storage, database, or other medium used in the various embodiments provided in the present application can include at least one of non-volatile and volatile memories. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, or optical memory, etc. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0125] In the description of this specification, the description referring to terms such as "some embodiments", "other embodiments", "ideal embodiments", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic description of the above terms does not necessarily refer to the same embodiment or example.

[0126] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0127] The above-described embodiments only represent several implementation manners of the present application. Their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A health status assessment system based on battery micro heat generation, characterized in that, The system includes: A high-vacuum subsystem for providing a high-vacuum environment and for accommodating the battery under test; A charge-discharge subsystem connected to the battery under test for controlling the charge-discharge state of the battery under test according to preset charge-discharge conditions; A compensation subsystem in contact with the battery under test and located within the high-vacuum environment for receiving the heat of the battery under test; A temperature measurement subsystem connected to the compensation subsystem for detecting the real-time temperature of the compensation subsystem when the battery under test is in a charge-discharge state; A data processing subsystem connected to the compensation subsystem for outputting a corresponding compensation current according to the real-time temperature and a reference temperature; The compensation subsystem is further configured to maintain the temperature of the compensation subsystem stable at the reference temperature according to the heat conducted by the battery under test and the compensation current when the battery under test is in a charge-discharge state; The data processing subsystem is further configured to determine the health state of the battery under test according to the compensation current when the battery under test is in different charge-discharge states.

2. The health status evaluation system based on battery micro heat generation according to claim 1, characterized in that, The compensation subsystem includes: a heat-conducting structure, a stage, and a temperature control circuit; The heat-conducting structure wraps the battery under test and is located on the stage for conducting the heat generated by the battery under test to the stage; the temperature control circuit is located inside the stage for maintaining the temperature of the stage stable at the reference temperature according to the compensation current.

3. The health status evaluation system based on battery micro heat generation according to claim 1, wherein The temperature measurement subsystem includes: at least one thermocouple connected to the compensation subsystem for detecting the real-time temperature of the compensation subsystem when the battery under test is in a charge-discharge state.

4. A health status assessment method based on battery micro heat generation, characterized in that, Applied to the health state evaluation system based on battery micro-heat generation according to any one of claims 1-3, the method includes: Providing a high-vacuum environment; wherein, the battery under test and the compensation subsystem are located in the high-vacuum environment; Controlling the charge-discharge state of the battery under test according to preset charge-discharge conditions; Detecting the real-time temperature of the compensation subsystem when the battery under test is in a charge-discharge state; Outputting a corresponding compensation current to the compensation subsystem according to the real-time temperature and the reference temperature; Determining the health state of the battery under test according to the compensation current when the battery under test is in different charge-discharge states.

5. The health state evaluation method based on battery micro heat generation according to claim 4, characterized in that The determining the health state of the battery under test according to the compensation current when the battery under test is in different charge-discharge states includes: Determining the heat generation amount of the battery under test in different charge-discharge states according to the compensation current when the battery under test is in different charge-discharge states; Determining the health state of the battery under test according to the heat generation amount of the battery under test in different charge-discharge states and the preset reference heat generation amount of the battery under test in different charge-discharge states.

6. The method for evaluating the health state based on battery micro heat generation according to claim 5, characterized in that, The charge-discharge conditions include charge-discharge voltage, multiple charge-discharge rates, and test times corresponding to each of the charge-discharge rates; The controlling the charge-discharge state of the battery under test according to preset charge-discharge conditions includes: Controlling the battery under test to be charged and discharged respectively at the charge-discharge voltage and each of the charge-discharge rates until the charge-discharge time of the battery under test reaches the corresponding test time; Repeat the step of separately controlling the battery under test to charge and discharge at the charge-discharge voltage and each of the charge-discharge rates until the charge-discharge time of the battery under test reaches the corresponding test time, until the number of tests of the battery under test in each of the charge-discharge states reaches a preset number of times.

7. The method for evaluating the health state based on battery micro heat generation according to claim 6, wherein, The determining the heat generation amount of the battery under test in different charge-discharge states according to the compensation current of the battery under test in different charge-discharge states includes: Determining a plurality of candidate heat generation amounts of the battery under test in different charge-discharge states according to the compensation current of the battery under test in different charge-discharge states, wherein the number of candidate heat generation amounts of the battery under test in a charge-discharge state is the same as the number of tests of the battery under test in the corresponding charge-discharge state; Determining at least one target heat generation amount of the battery under test in different charge-discharge states from each of the candidate heat generation amounts of the battery under test in different charge-discharge states, wherein the heat generation volatility of the target heat generation amount is less than or equal to a preset volatility threshold; Determining the heat generation amount of the battery under test in different charge-discharge states according to the average value of each target heat generation amount of the battery under test in different charge-discharge states.

8. The method for evaluating the health state based on battery micro heat generation according to claim 7, wherein The determining a plurality of candidate heat generation amounts of the battery under test in different charge-discharge states according to the compensation current of the battery under test in different charge-discharge states includes: Determining the cooling capacity of the compensation subsystem when the battery under test is in different charge-discharge states according to the compensation current of the battery under test in different charge-discharge states, a preset reference temperature, a preset Seebeck coefficient, and the internal resistance of the preset compensation subsystem; Determining the candidate heat generation amounts of the battery under test in different charge-discharge states according to the cooling capacity of the compensation subsystem when the battery under test is in different charge-discharge states.

9. The method for evaluating the health status based on battery micro heat generation according to claim 5, wherein The determining the health state of the battery under test according to the heat generation amount of the battery under test in different charge-discharge states and the reference heat generation amount of the battery under test in different charge-discharge states preset includes: Drawing a reference heat generation curve according to the reference heat generation amount of the battery under test in different charge-discharge states; Drawing a test heat generation curve of the battery under test according to the heat generation amount of the battery under test in different charge-discharge states; Calculating a reference heat generation area and a test heat generation area according to the reference heat generation curve and the test heat generation curve of the battery under test respectively; Determining the health state of the battery under test according to the reference heat generation area and the test heat generation area.

10. A computer device, comprising a memory and a processor, the memory storing a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 4 to 9.

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