WO2020199416A1 - 动力电池热失控安全性的定量评价方法及系统 - Google Patents

动力电池热失控安全性的定量评价方法及系统 Download PDF

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WO2020199416A1
WO2020199416A1 PCT/CN2019/095775 CN2019095775W WO2020199416A1 WO 2020199416 A1 WO2020199416 A1 WO 2020199416A1 CN 2019095775 W CN2019095775 W CN 2019095775W WO 2020199416 A1 WO2020199416 A1 WO 2020199416A1
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thermal runaway
battery
battery cell
safety
tested
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PCT/CN2019/095775
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English (en)
French (fr)
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王昱
冯旭宁
任东生
卢兰光
欧阳明高
何向明
王莉
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清华大学
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
    • G01R31/367—Software therefor, e.g. for battery testing using modelling or look-up tables

Definitions

  • This application relates to the field of battery technology, and in particular to a quantitative evaluation method and system for the safety of power battery thermal runaway.
  • Electric vehicles are the main body of new energy vehicles, and power batteries are the core energy source of electric vehicles.
  • the driving range of an electric vehicle depends on the specific energy of the power battery and the number of batteries in the electric vehicle. Due to the space and cost constraints of electric vehicles, increasing the specific energy of power batteries has become the key to increasing the range of electric vehicles.
  • a power battery with a higher specific energy under the same volume stores more energy, and may release more energy when the heat is out of control, bringing more serious safety hazards. Therefore, it is necessary to fully evaluate and consider the thermal runaway safety of the power battery of the designed system in the power battery design process.
  • a quantitative evaluation method for the safety of power battery thermal runaway including:
  • S400 Quantitatively evaluate the thermal runaway safety of the battery cell to be tested according to the characteristic value.
  • the adiabatic runaway test is performed in a calorimeter capable of providing an adiabatic environment, and before the adiabatic runaway test is performed, it is ensured that the calorimeter has completed calibration and calibration.
  • the battery under test is charged or discharged, so that the battery under test is adjusted to a specified charge. Electric state.
  • the S400 quantitatively evaluating the safety of the thermal runaway of the battery cell to be tested according to the characteristic value, includes:
  • the first reference value, the second reference value and the third reference value corresponding to the standard battery are provided, wherein the temperature at which the standard battery starts to generate heat is the first reference temperature and the large-scale heat release inside the standard battery starts The temperature at time is the second reference temperature, and the highest temperature of the standard battery during the thermal runaway process is the third reference temperature;
  • the first temperature, the second temperature, and the maximum temperature of the battery cell to be tested are respectively compared with the first reference temperature, the second reference temperature, and the first reference temperature of the standard battery. Three reference temperatures for comparison;
  • the safety of thermal runaway of the battery cell to be tested is lower than the safety of thermal runaway of the standard battery
  • the thermal runaway safety of the battery cell to be tested is lower than the thermal runaway safety of the standard battery
  • the safety of the thermal runaway of the battery cell to be tested is higher than that of the standard battery.
  • the S400 quantitatively evaluates the thermal runaway safety of the battery under test according to the characteristic value, and further includes evaluating the battery under test by one or more of the following steps The level of safety of the thermal runaway of the monomer:
  • the absolute value of the difference between the third reference temperature and the maximum temperature is used to quantitatively evaluate the safety of the thermal runaway of the battery cell to be tested.
  • the S400 quantitatively evaluates the safety of the thermal runaway of the battery cell to be tested according to the characteristic value, which previously further includes:
  • the characteristic value includes: the maximum temperature rise rate during the thermal runaway process of the power battery to be tested; the reference value of the maximum temperature rise rate during the thermal runaway process of the standard battery;
  • the S400 quantitatively evaluating the safety of the thermal runaway of the battery cell to be tested according to the characteristic value, includes:
  • the thermal runaway safety of the battery under test is higher than that of the standard battery.
  • the step S400 of quantitatively evaluating the safety of the thermal runaway of the battery cell to be tested according to the characteristic value further includes:
  • the absolute value of the difference between the maximum temperature rise rate and the reference value minus the maximum temperature rise rate is used to quantitatively evaluate the safety of the thermal runaway of the battery cell to be tested.
  • the S400 quantitatively evaluates the safety of the thermal runaway of the battery cell to be tested according to the characteristic value, which previously further includes:
  • the time from the start of self-generation of the battery cell under test to the start of the thermal runaway of the battery cell under test is recorded as the first time period;
  • the time from the start of the thermal runaway of the battery under test to the time the battery under test reaches the highest temperature of the thermal runaway process is recorded as the second time period;
  • the characteristic value includes: the first time period and the second time period of the battery cell to be tested; the first time period reference value and the second time period reference during the thermal runaway process of the standard battery value;
  • the S400 quantitatively evaluating the safety of the thermal runaway of the battery cell to be tested according to the characteristic value, includes:
  • the thermal runaway safety of the battery under test is higher than the thermal runaway safety of the standard battery
  • the thermal runaway safety of the battery under test is higher than the thermal runaway safety of the standard battery.
  • the S400 quantitatively evaluates the thermal runaway safety of the battery under test according to the characteristic value, and further includes evaluating the battery under test by one or more of the following steps The level of safety of the thermal runaway of the monomer:
  • the absolute value of the difference of the length of the second time period minus the length of the reference value of the second time period is used to quantitatively evaluate the safety of the thermal runaway of the battery cell to be tested.
  • the step of performing an adiabatic runaway test on the battery cell to be tested includes:
  • one or more temperature detection devices are respectively provided on the outer surface and inside of the battery cell to be tested, and a voltage collecting device is connected to the tabs of the battery cell to be tested;
  • S40 Perform an adiabatic thermal runaway test on the battery cell to be tested, and record the battery cell voltage during the thermal runaway process and the battery cell temperature during the thermal runaway process.
  • the battery cell to be tested includes any one of a soft pack battery, a square battery or a cylindrical battery.
  • the voltage test frequency and temperature test frequency are the same, and the voltage test frequency and temperature test frequency are greater than or equal to 1 Hz.
  • one or more temperature detection devices are respectively provided on the outer surface and inside of the battery cell to be tested, and the step of connecting a voltage collecting device at the tabs of the battery cell to be tested includes:
  • S301 Partially disassemble the battery cell to be tested in a dry room or a glove box to facilitate the arrangement of a temperature detection device;
  • S302. Provide a protective layer to protect the temperature detection device, and arrange the protected temperature detection device inside the battery to be tested, and arrange one or more protections inside the battery to be tested The temperature detection device;
  • S303 Perform a secondary sealing arrangement on the battery under test, and set one or more sets of voltage acquisition devices at the tabs of the battery under test after sealing.
  • a power battery safety evaluation system includes:
  • Thermal insulation device used to provide thermal insulation conditions for the battery cell to be tested
  • One or more sets of voltage acquisition devices are arranged at the tabs of the housing of the battery cell to be tested, and are used to test the voltage of the battery cell to be tested;
  • One or more temperature detection devices arranged on the inner or outer surface of the battery cell to be tested, for testing the temperature of the battery cell to be tested;
  • the control device is electrically connected to the plurality of voltage acquisition devices and the plurality of temperature detection devices, respectively, and is used for generating an adiabatic thermal runaway test curve according to the temperature and voltage of the battery cell to be tested, and for evaluating the The thermal runaway safety of the battery cell to be tested is described.
  • a computer device includes a memory and a processor, the memory stores a computer program, and when the processor executes the computer program, the steps or steps of the method for quantitative evaluation of the safety of the thermal runaway of the power battery described in any one of the above are realized.
  • the computer equipment is used to perform the functions of the control device described above.
  • the application relates to a quantitative evaluation method and system for the safety of thermal runaway of power batteries.
  • the evaluation method of the present application includes providing a battery cell to be tested, and performing an adiabatic runaway test on the battery cell to be tested.
  • the adiabatic runaway test the temperature and voltage of the battery cell to be tested are monitored in real time to generate a thermal runaway test curve.
  • the characteristic value of the battery cell to be tested is obtained.
  • the characteristic value includes: the first temperature when the battery cell under test itself starts to generate heat, the second temperature when the large-scale heat release inside the battery cell under test starts, and the battery cell under test The maximum temperature during thermal runaway.
  • the thermal runaway safety of the battery cell to be tested is quantitatively evaluated according to the characteristic value.
  • one or more sets of characteristic values can be used to evaluate their thermal runaway characteristics.
  • the characteristic values obtained by the unified test method are used to describe battery safety, and the safety of newly developed batteries can also be conveniently compared and evaluated horizontally with historical battery safety data.
  • the characteristic values involved in this application are directly related to the internal process of the thermal runaway of the single battery, which can point out a clear direction for the improvement of the thermal safety of the battery.
  • FIG. 1 is a schematic flowchart of a method for quantitatively evaluating the safety of thermal runaway of a power battery provided in an embodiment of the application;
  • FIG. 2 is a schematic flowchart of a method for quantitatively evaluating the safety of power battery thermal runaway provided in an embodiment of the application;
  • FIG. 3 is a schematic diagram of the steps of the adiabatic runaway test provided in an embodiment of the application
  • FIG. 4 is a schematic diagram of the steps of the adiabatic runaway test provided in an embodiment of the application.
  • FIG. 5 is a flowchart of steps for setting a temperature detection device and a voltage acquisition device for the battery cell to be tested provided in an embodiment of the application;
  • Fig. 6 is a schematic diagram of a power battery safety evaluation system provided in an embodiment of the application.
  • an embodiment of the present application provides a quantitative evaluation method for the safety of thermal runaway of a power battery.
  • the quantitative evaluation method for the safety of thermal runaway of the power battery is a quantitative evaluation method for the safety of thermal runaway of the power battery.
  • S100 Provide a battery cell to be tested, and perform an adiabatic runaway test on the battery cell to be tested.
  • the battery cell to be tested may be any one of a soft pack battery, a square battery or a cylindrical battery.
  • the battery cells that can be detected in this embodiment may also be battery cells of other forms, which are not limited here.
  • the adiabatic runaway test can be performed in a large calorimeter that can provide an adiabatic environment. Before performing the adiabatic runaway test, it is necessary to ensure that the calorimeter has completed calibration and calibration to avoid danger during the test. In addition, before the adiabatic thermal runaway test is performed, the battery under test needs to be adjusted to a specified state of charge through a charging and discharging device according to test requirements.
  • a temperature detection device and a voltage acquisition device can be provided to monitor the temperature and voltage of the battery cell to be tested in the thermal runaway process in real time.
  • the adiabatic thermal runaway test curve is generated, as shown in FIG. 5.
  • the abscissa in the left picture of Figure 5 is time
  • the coordinate time range is the test time range, that is, the time from when the data acquisition device starts recording data to when the battery temperature returns to below 100°C.
  • the abscissa in the right panel of Figure 5 is the temperature change rate.
  • the characteristic value includes: the first temperature when the battery cell to be tested begins to generate heat, the second temperature when the large-scale heat release inside the battery cell to be tested starts, and the battery cell to be tested The maximum temperature of the body during thermal runaway.
  • the characteristic value includes the first temperature, the second temperature, and the maximum temperature.
  • the evaluation method may also include other characteristic values to quantitatively evaluate the safety of thermal runaway of the battery cell to be tested.
  • S400 Quantitatively evaluate the thermal runaway safety of the battery cell to be tested according to the characteristic value.
  • the thermal runaway safety evaluation of the battery cell to be tested can be compared with the size of the characteristic value.
  • the larger the characteristic value the higher the thermal runaway safety of the battery cell to be tested. Or the smaller the characteristic value, the lower the safety of thermal runaway of the battery cell to be tested.
  • a reference battery and a reference characteristic value can also be set, and the relationship between the characteristic value and the reference characteristic value can be compared to determine the battery cell under test The safety of thermal runaway.
  • the selection of the reference battery can be adjusted based on experience or the needs of the actual application environment.
  • the evaluation method of the present application includes providing a battery cell to be tested, and performing an adiabatic runaway test on the battery cell to be tested.
  • the adiabatic runaway test the temperature and voltage of the battery cell to be tested are monitored in real time to generate a thermal runaway test curve. From the adiabatic runaway test curve, the characteristic value of the battery cell to be tested is obtained.
  • the characteristic value includes: the first temperature when the battery cell under test itself starts to generate heat, the second temperature when the large-scale heat release inside the battery cell under test starts, and the battery cell under test The maximum temperature during thermal runaway.
  • the thermal runaway safety of the battery cell to be tested is quantitatively evaluated according to the characteristic value.
  • the quantitative evaluation index ie, the characteristic value of the battery to be tested mentioned in this application
  • the quantitative evaluation index is directly related to the internal process of the thermal runaway of the single battery, which can point out a clear direction for the improvement of the battery's thermal safety.
  • the S400 quantitatively evaluates the safety of the thermal runaway of the battery cell to be tested according to the characteristic value, including:
  • S401 Provide a first reference value, a second reference value, and a third reference value corresponding to a standard battery, where the temperature at which the standard battery starts to generate heat is the first reference temperature and the large-scale internal discharge of the standard battery.
  • the temperature at the beginning of the heating is the second reference temperature, and the highest temperature of the standard battery during the thermal runaway process is the third reference temperature.
  • a standard battery is set, and the standard battery can be a battery with a known material system and design parameters that has test data for adiabatic thermal runaway characteristics.
  • the reference characteristic values are the first reference temperature, the second reference temperature, and the third reference temperature during the thermal runaway of the battery.
  • the first temperature represents the temperature when the battery cell starts to generate heat.
  • the higher the first temperature the less likely it is for the battery to reach the first temperature under abuse conditions.
  • the safety of battery cell thermal runaway is higher.
  • the lower the first temperature the worse the safety of battery cell thermal runaway.
  • the second temperature represents the temperature at the beginning of large-scale heat generation inside the battery cell.
  • the higher the second temperature the less likely it is for the battery to reach the second temperature under abuse conditions.
  • the safety of battery cell thermal runaway is higher.
  • the lower the second temperature the worse the safety of battery cell thermal runaway.
  • the third reference temperature is the highest temperature of the battery cell during the thermal runaway process.
  • the higher the maximum temperature the more violent the reaction when the battery is thermally out of control. Therefore, the higher the maximum temperature, the worse the safety of battery cell thermal runaway. On the contrary, the lower the maximum temperature, the higher the safety of battery cell thermal runaway.
  • the evaluation method of the thermal runaway safety of the battery cell to be tested is quantitatively given by the size of the characteristic value. According to the first temperature, the second temperature and the maximum temperature, the evaluation result of the safety of the thermal runaway of the power battery is more clear and objective.
  • the S400 quantitatively evaluates the thermal runaway safety of the battery cell under test based on the characteristic value, and previously further includes: generating the battery under test according to the adiabatic thermal runaway test curve The temperature-temperature change rate curve of the monomer. The maximum temperature rise rate of the battery cell to be tested is obtained from the temperature-temperature change rate change curve.
  • the characteristic value includes: the maximum temperature rise rate during the thermal runaway process of the power battery to be tested.
  • the S400 quantitatively evaluating the safety of the thermal runaway of the battery cell to be tested according to the characteristic value, includes:
  • the maximum temperature rise rate is less than the reference value of the maximum temperature rise rate, and the thermal runaway safety of the battery to be tested is higher than the thermal runaway safety of the standard battery.
  • the maximum temperature rise rate is provided as another characteristic value.
  • the thermal runaway safety of the battery cell is evaluated by the maximum temperature rise rate. The lower the maximum temperature rise rate of the battery cell during the thermal runaway process, the higher the safety of the battery cell.
  • the S400 quantitatively evaluates the safety of the thermal runaway of the battery cell to be tested according to the characteristic value, which previously further includes:
  • the time from the start of self-generation of the battery cell under test to the start of the thermal runaway of the battery cell under test is recorded as the first time period.
  • the time from the start of the thermal runaway of the battery cell under test to the time when the battery cell under test reaches the highest temperature of the thermal runaway process is recorded as the second time period.
  • the characteristic value includes: the first time period and the second time period of the battery cell to be tested.
  • the first time period reference value and the second time period reference value during the thermal runaway process of the standard battery.
  • the S400 quantitatively evaluating the safety of the thermal runaway of the battery cell to be tested according to the characteristic value, includes:
  • the first time period is greater than the first time period reference value, and the thermal runaway safety of the battery to be tested is higher than the thermal runaway safety of the standard battery.
  • the second time period is greater than the second time period reference value, and the thermal runaway safety of the battery under test is higher than the thermal runaway safety of the standard battery.
  • the first time period and the second time period are provided as the other two types of characteristic values.
  • the safety of thermal runaway of the battery cell is evaluated through the first time period and the second time period. During the thermal runaway process of the battery cell, the longer the first time period and the second time period are, the less likely the battery cell is to cause thermal runaway, or the easier it is to prevent thermal runaway before the thermal runaway occurs. The higher the safety is out of control.
  • the first temperature, the second temperature, and the maximum temperature respectively represent the temperature at which the battery cell under test starts to generate heat, the temperature at which the battery cell under test starts to run out of control, The highest temperature of the battery cell to be tested during the thermal runaway process.
  • the maximum temperature rise rate represents the maximum temperature rise rate of the battery cell under test when thermal runaway occurs severely.
  • the first time period represents the time from the start of self-generation of the battery cell under test to the start of the thermal runaway of the battery cell under test.
  • the second time period represents the time from when the battery cell under test starts to generate heat to the battery cell under test reaching the highest temperature of the thermal runaway process.
  • the above six characteristic values are taken as examples to comprehensively analyze the safety of the thermal runaway of the battery cell to be tested. Since the battery cell built-in sensor (which can be a thermocouple) is closest to the true temperature of the battery material in the thermal runaway process, the battery built-in sensor is used to measure the characteristic value of the temperature data (the first temperature T1, the second temperature) The temperature T2, the maximum temperature T3, the maximum temperature rise rate dT/dt, the first time period t1 and the second time period t2) are used as indicators for quantitative evaluation of battery thermal safety, which are relatively reasonable and accurate of.
  • the battery cell built-in sensor which can be a thermocouple
  • the S400 quantitatively evaluates the thermal runaway safety of the battery cell to be tested according to the characteristic value, and further includes, through the following steps One or more of evaluating the safety of the thermal runaway of the battery cell to be tested:
  • the absolute value of the difference of the length of the second time period minus the length of the reference value of the second time period is used to quantitatively evaluate the safety of the thermal runaway of the battery cell to be tested.
  • the thermal runaway safety of the battery cell to be tested is quantitatively evaluated by using six characteristic values. For example, referring to other battery evaluation methods, it can be concluded that the battery to be tested is safer than another battery (or the reference battery), but it is impossible to know in which aspects the thermal runaway characteristics perform better, and it is impossible to Know how much better a certain performance of the thermal runaway characteristic is. In this embodiment, it can be specifically learned that, from the perspective of self-generated heat temperature, the battery under test has an increase of 20°C compared to another battery (or a reference battery).
  • the quantitative evaluation method provided can also provide guidance for improving battery safety. For example, by knowing the self-generated heat temperature difference of the battery under test through the method of this application, it is possible to focus on increasing the self-generated heat temperature of the battery under test.
  • Specific methods for increasing the self-heating temperature of the battery to be tested may include finding new materials to replace, using some coating methods or adjusting electrolyte, but it is not limited to the above adjustment methods.
  • T1 is the first temperature, that is, the temperature at which the battery cell to be tested starts to generate heat as detected by the calorimeter, that is, the self-generated heat temperature of the battery cell to be tested.
  • T1 reflects the temperature at which the original interface of the battery cell under test begins to lose thermal stability.
  • the calorimeter enters adiabatic working mode.
  • T2 is the second temperature, that is, T2 is the battery temperature when the temperature rise rate of the battery cell under test reaches a certain characteristic temperature rise rate.
  • the temperature rise rate is one order of magnitude higher than the previous moment, that is, the temperature at which the battery cell under test begins to run out of control.
  • T3 is the maximum temperature, and T3 is the maximum temperature of the battery cell under test during the entire thermal runaway process.
  • the time from the battery cell self-generation to the battery cell thermal runaway is recorded as t1.
  • the time from the thermal runaway of the battery cell to the maximum temperature of the thermal runaway process is recorded as t2.
  • the evaluation method of battery cell thermal runaway can refer to the following:
  • the T1 value is the quantitative evaluation index of the battery's self-generated heat safety.
  • the T2 value is a quantitative evaluation index for the safety of battery thermal runaway.
  • the T3 value is the quantitative evaluation index for the hazard of battery thermal runaway.
  • the dT/dt value is the quantitative evaluation index of the hazard of battery thermal runaway.
  • t2 is the longer it takes for the battery cell to reach the maximum temperature of thermal runaway after thermal runaway, the slower the heat release rate of the battery after thermal runaway, and the better the safety of the battery cell.
  • the value of t1 and t2 is the quantitative evaluation index of the heat accumulation of the battery thermal runaway and the heat release rate after the battery thermal runaway.
  • the above quantitative evaluation index is the characteristic value of the battery to be tested mentioned in this application.
  • a battery cell built-in sensor such as a thermocouple
  • the thermal safety of different battery cells is evaluated according to the characteristic value.
  • adiabatic thermal runaway test was performed on a certain type of battery cell in four different systems.
  • the results of the adiabatic runaway test are shown in Table 1.
  • the negative electrodes of the four battery systems are all graphite, and the positive electrodes are different types of active materials.
  • Table 1 Characteristic values of thermal runaway of battery cells in different systems
  • the first temperature T1 starting temperature of self-heating: Cell1>Cell2>Cell3 ⁇ Cell4. That is, in terms of self-generated heat temperature, Cell 1 is safer than Cell 2, and Cell 2 is better than Cell 3 and Cell 4. Furthermore, if the thermal runaway of the battery is evaluated and self-generated heat (using Cell 1 as the reference battery), the thermal stability of Cell 2 is 42.1°C lower than that of the reference battery, and the thermal stability of Cell 3 is 73.3°C lower than that of the reference battery. 4 Compared with the reference battery, the thermal stability has a 71.6°C drop.
  • the second temperature T2 (thermal runaway start temperature): Cell 3>Cell 1>Cell 4>Cell 2. That is, from the point of view of the trigger temperature of thermal runaway, the safety of thermal runaway: Cell 3>Cell 1>Cell 4>Cell 2. Furthermore, if the difficulty of triggering the battery thermal runaway is evaluated (using Cell 1 as the reference battery), the thermal stability of Cell 2 is 47.1°C lower than that of the reference battery, and the thermal stability of Cell 3 is 32.7°C higher than that of the reference battery. , Cell 4 has a 24.3°C drop in thermal stability compared to the reference battery.
  • the maximum temperature T3 (maximum temperature of thermal runaway): Cell 4>Cell 3>Cell 2>Cell 1. That is, from the point of view of the total exotherm of the reaction, that is, the hazard of thermal runaway, the safety of thermal runaway: Cell 4 ⁇ Cell 3 ⁇ Cell 2 ⁇ Cell 1. Furthermore, if the hazard of the battery after thermal runaway is evaluated (using Cell 1 as the reference battery), the thermal stability of Cell 2 is 280.1°C lower than the reference battery, and the thermal stability of Cell 3 is 473°C lower than the reference battery. Cell 4 has a 530.3°C drop in thermal stability compared to the reference battery.
  • the maximum temperature rise rate dT/dt Cell 2>Cell 4>Cell 3>Cell 1. That is, from the perspective of the total heat release of the reaction, that is, the hazard of thermal runaway, the safety of thermal runaway: Cell 2 ⁇ Cell 4 ⁇ Cell 3 ⁇ Cell 1. Furthermore, if the hazard of the battery after thermal runaway is quantitatively evaluated (using Cell 1 as the reference battery), the maximum temperature rise rate of Cell 2 and Cell 3 is about 1000 times higher than that of the reference battery. Cell 4 is compared to the reference battery. The maximum temperature rise rate of thermal runaway is increased by about 10,000 times.
  • the first time period t1 (the time from self-heating of the battery to the triggering of thermal runaway): Cell 1>Cell 3>Cell 4 ⁇ Cell 2. That is, from the perspective of heat accumulation speed, the safety of thermal runaway: Cell 1>Cell 3>Cell 4 ⁇ Cell 2. Furthermore, if the development speed of battery thermal runaway is quantitatively evaluated (using Cell 1 as the reference battery), Cell 3 is 0.9 hours ahead of the reference battery thermal runaway, and Cell 4 and Cell2 are about 1.9 hours ahead of the reference thermal runaway.
  • the second time period t2 (the time from when the battery thermal runaway is triggered to the highest temperature of the battery thermal runaway): Cell 1>Cell 3>Cell 2>Cell 4. That is, from the perspective of heat release speed after thermal runaway, thermal runaway safety: Cell 1>Cell 3>Cell 2>Cell 4. Furthermore, if the battery thermal runaway energy release rate is quantitatively evaluated (using Cell 1 as the reference battery), the energy release rate of Cell 3 is 15 seconds faster than that of the reference battery during thermal runaway, and Cell 2 is compared to the energy of the reference battery during thermal runaway. The release speed is 20 seconds faster, and the energy release speed of Cell 4 is 28 seconds faster than the reference battery during thermal runaway.
  • Sanyuan 111 and Sanyuan 532 materials can be coated with negative electrodes or electrolyte additives Methods such as increasing the decomposition temperature of SEI to increase T1 and improve safety; ternary 532 and lithium cobalt oxide materials can further increase T2 by using a separator with higher thermal stability, increasing internal short circuit or positive and negative electrode contact temperature. Improve the safety of thermal runaway of the whole battery.
  • T3 is usually directly related to the specific energy of the battery, and it is difficult to improve it through material modification. You can consider strengthening the heat dissipation link in the practical application of ternary material batteries.
  • the quantitative evaluation method of the thermal runaway safety of the power battery proposed in this application is explained in detail through a specific embodiment above.
  • the evaluation method is based on the repeatable adiabatic thermal runaway test of the power battery cell, combined with the thermal runaway mechanism of the power battery cell, and selects characteristic values during the thermal runaway process to evaluate the thermal runaway safety of the power battery cell.
  • the characteristic value includes the first temperature, the second temperature, the maximum temperature, the maximum temperature rise rate, the first time period, and the second time period.
  • the characteristic value can be quantitatively determined by means of experimental testing.
  • the safety evaluation of the thermal runaway of the power battery cell is realized by comparing the quantitatively determined characteristic value.
  • the step of performing an adiabatic runaway test on the battery cell to be tested includes:
  • S10 Select a battery cell to be tested from the first type of battery cell.
  • one or more temperature detection devices are respectively provided on the outer surface and inside of the battery cell to be tested, and a voltage collecting device is connected to the tabs of the battery cell to be tested.
  • S40 Perform an adiabatic thermal runaway test on the battery cell to be tested, and record the battery cell voltage during the thermal runaway process and the battery cell temperature during the thermal runaway process.
  • the voltage test frequency and the temperature test frequency are the same, and the voltage test frequency and the temperature test frequency are greater than or equal to 1 Hz.
  • the frequency of data collection should be greater than 1 Hz (that is, data is collected at least once per second).
  • the voltage and temperature measurement frequency must be consistent to ensure that the characteristic value can be accurately obtained.
  • a plurality of temperature detection devices are respectively provided on the outer surface and inside of the battery cell to be tested, and a voltage is connected to the tabs of the battery cell to be tested
  • the steps of the collection device include:
  • the temperature detection device may be a thermocouple.
  • the partial disassembly of the battery cell to be tested can be understood as: when the battery cell to be tested is a soft pack battery, a small opening can be made on the aluminum plastic film outside of the soft pack battery (the size of the small opening is large enough to connect the thermocouple Just plug it in), then plug the thermocouple in from a small opening, and then perform the corresponding fixing operation to complete the layout of the temperature detection device.
  • the partial disassembly of the battery unit to be tested can also be understood as: when the battery unit to be tested is a square-shell battery, saw along the top cover of the battery and insert the thermocouple into it.
  • the fixing operation (such as sealing with glue) to complete the layout of the temperature detection device.
  • a protective layer is provided, and the protective layer may use a diaphragm or other materials to protect the temperature detection device.
  • the protected temperature detection device is arranged inside the battery to be tested (for example, it can be between the positive electrode and the separator, or between the negative electrode and the separator).
  • One or more protected temperature detection devices may be arranged inside the battery to be tested.
  • S303 Perform a secondary sealing arrangement on the battery under test, and set one or more sets of voltage acquisition devices at the tabs of the battery under test after sealing.
  • the temperature detection device is arranged inside the battery cell (the temperature detection device may be (temperature sensor).
  • the temperature detection device may be (temperature sensor).
  • the temperature sensor is arranged inside the disassembled battery cell, and the battery cell is sealed twice.
  • multiple temperatures can be arranged at different positions inside the battery cell and on different positions on the battery cell surface as required Sensors.
  • Multiple temperature sensors are provided to accurately obtain the temperature values of the battery cells at different positions during the thermal runaway process.
  • multiple sets of voltage sensors can be used for measurement to prevent the battery cells from being thermally runaway. Data is missing or unstable due to the sensor falling off.
  • a safety evaluation system 100 for thermal runaway of a power battery includes: a thermal insulation device 10, a plurality of voltage acquisition devices 20, a plurality of temperature detection devices 30, and a control device 40.
  • the thermal insulation device 10 is used to provide thermal insulation conditions for the battery cell to be tested.
  • the thermal insulation device 10 may include an adiabatic acceleration calorimeter.
  • the multiple voltage collecting devices 20 are arranged at the tabs of the battery cell to be tested.
  • the multiple voltage collecting devices 20 may be voltmeters for testing the voltage of the battery cell to be tested.
  • a plurality of voltage collecting devices 20 may be provided at the tabs of the battery cell to be tested.
  • the multiple temperature detection devices 30 are arranged inside the battery cell to be tested.
  • the plurality of temperature detection devices 30 may be temperature sensors. Such as thermocouple or thermal resistance.
  • the multiple temperature detection devices 30 are used to test the temperature of the battery cell to be tested.
  • the control device 40 is electrically connected to the plurality of voltage acquisition devices and the plurality of temperature detection devices, respectively.
  • the control device 40 is used for generating an adiabatic thermal runaway test curve according to the temperature and voltage of the battery cell to be tested.
  • the control device is also used to evaluate the safety of thermal runaway of the battery cell to be tested.
  • the control device may be a computer or a control device based on calculation and sum.
  • the power battery safety evaluation system 100 provided in this embodiment includes the thermal insulation device 10, the multiple voltage acquisition devices 20, the multiple temperature detection devices 30, and the control device 40.
  • the power battery safety evaluation system 100 can obtain the voltage and temperature of the battery cell to be tested according to the multiple voltage acquisition devices 20 and the multiple temperature detection devices 30.
  • the adiabatic heat runaway test curve is generated by the control device 40.
  • the control device 40 obtains the characteristic value of the battery cell to be tested from the adiabatic thermal runaway test curve.
  • the power battery safety evaluation system 100 can obtain characteristic values of different types of battery materials, and quantitatively evaluate the thermal runaway safety of the battery cell to be tested based on the characteristic values.
  • a unified one or more sets of quantitative indicators can be used to evaluate their thermal runaway characteristics.
  • the quantitative evaluation index is directly related to the internal process of the thermal runaway of the single battery, which can point out a clear direction for the improvement of the thermal safety of the battery.
  • a computer device includes a memory and a processor, the memory stores a computer program, and the processor implements the steps of any one of the above methods when the computer program is executed. Or the computer equipment is used to execute the function of the control device 40.
  • Non-volatile memory may include read only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory.
  • Volatile memory may include random access memory (RAM) or external cache memory.
  • RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous chain Channel (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

Abstract

一种动力电池热失控安全性的定量评价方法及系统，所述评价方法包括对待测电池单体实施绝热热失控测试。在所述绝热热失控测试中实时监测所述待测电池单体的温度和电压，生成绝热热失控测试曲线（S200）。从所述绝热热失控测试曲线中，获取第一温度、第二温度和热失控过程中的最高温度作为特征值。对于不同类型或者不同材料体系的待测电池单体，可以用统一的一组或多组特征值来评价其热失控特性。使用统一测试方法得到的特征值来描述电池安全性，也可以将新开发电池的安全性方便地与历史电池安全性数据进行横向对比和评价。且所述的特征值与单体电池热失控内部过程直接相关，可以给电池热安全性的改进指出明确的方向。

Description

动力电池热失控安全性的定量评价方法及系统
相关申请
本申请要求2019年04月02日申请的，申请号为201910259977.8，名称为“动力电池热失控安全性的定量评价方法及系统”的中国专利申请的优先权，在此将其全文引入作为参考。
技术领域
本申请涉及电池技术领域，特别是涉及一种动力电池热失控安全性的定量评价方法及系统。
背景技术
电动汽车是新能源汽车的主体，动力电池是电动汽车的核心能量源。电动汽车的续驶里程取决于动力电池的比能量和电动汽车搭载的电池数量。由于电动汽车的空间和成本的限制，提高动力电池的比能量成为增加电动汽车续驶里程的关键。一般地，相同体积下更高比能量的动力电池存储的能量更多，在热失控时可能释放出更多的能量，带来更加严重的安全隐患。因此，需要在动力电池设计过程中就对所设计体系的动力电池的热失控安全性进行充分评价和考量。
传统的技术方案在进行动力电池单体安全性评价时，主要针对电池单体在机、电、热滥用条件下的热失控特性进行测试，包括针刺、过充、加热测试等。然而，传统的安全性评价的测试主要涉及对电池材料及电池单体在受热条件下的外部表现进行测试。传统的评价电池单体安全性的指标多为对电池单体热失控现象的定性比较，且与电池单体热失控时内部变化机理无关。仅仅对电池单体热失控安全性给出定性的评价不足以指导电池单体设计方案的改进，也不足以实现对电池单体热失控的积极防控。
发明内容
基于此，有必要针对传统的电池单体热失控安全性评价仅仅通过定性的方法进行，这种定性评价方法与电池单体热失控时的内部变化机理无关，不足以指导电池单体设计方案的改进，也不足以实现对电池单体热失控的积极防控的问题，因此提供一种动力电池热失控安全性的定量评价方法及系统。
一种动力电池热失控安全性的定量评价方法，包括：
S100，提供待测电池单体，并对所述待测电池单体实施绝热热失控测试；
S200，在所述绝热热失控测试中实时监测所述待测电池单体的温度和电压，生成绝热 热失控测试曲线；
S300，从所述绝热热失控测试曲线中，获取所述待测电池单体的特征值，其中，所述特征值包括：所述待测电池单体自身开始产热时的第一温度、所述待测电池单体内部大规模放热开始时的第二温度和所述待测电池单体在热失控过程中的最高温度；
S400，根据所述特征值定量的评价所述待测电池单体的热失控安全性。
在一个实施例中，所述绝热热失控测试在能够提供绝热环境的量热仪中进行，在进行所述绝热热失控测试之前确保所述量热仪已经完成校准和标定工作。
在一个实施例中，在对所述待测电池单体实施绝热热失控测试之前，对所述待测电池单体进行充电或放电操作，以使得所述待测电池单体调整至指定的荷电状态。
在一个实施例中，所述S400，根据所述特征值定量的评价所述待测电池单体的热失控安全性，包括：
提供标准电池对应的第一参考值、第二参考值和第三参考值，其中，所述标准电池开始产热时的温度为所述第一参考温度、所述标准电池内部大规模放热开始时的温度为所述第二参考温度、所述标准电池在热失控过程中的最高温度为所述第三参考温度；
将所述待测电池单体的所述第一温度、所述第二温度和所述最高温度，分别与所述标准电池的所述第一参考温度、所述第二参考温度和所述第三参考温度进行对比；
若所述第一温度小于所述第一参考温度，则所述待测电池单体的热失控安全性低于所述标准电池的热失控安全性；
若所述第二温度小于所述第二参考温度，则所述待测电池单体的热失控安全性低于所述标准电池的热失控安全性；
若所述最高温度小于所述第三参考温度，则所述待测电池单体的热失控安全性高于所述标准电池的热失控安全性。
在一个实施例中，所述S400，根据所述特征值定量的评价所述待测电池单体的热失控安全性，还包括，通过以下步骤中的一种或多种评价所述待测电池单体的热失控安全性的高低：
通过所述第一温度减去所述第一参考温度的差值的绝对值的大小来定量评价所述待测电池单体的热失控安全性的高低；或者
通过所述第二温度减去所述第二参考温度的差值的绝对值的大小来定量评价所述待测电池单体的热失控安全性的高低；或者
通过所述第三参考温度减去所述最高温度的差值的绝对值的大小来定量评价所述待测电池单体的热失控安全性的高低。
在一个实施例中，所述S400，根据所述特征值定量的评价所述待测电池单体的热失控安全性，之前还包括：
根据所述绝热热失控测试曲线，生成所述待测电池单体的温度-温度变化率的变化曲线；
从所述温度-温度变化率的变化曲线中获取所述待测电池单体的所述最大温升速率；
所述特征值包括：所述待测试动力电池发生热失控过程中的最大温升速率；所述标准 电池发生热失控过程中的最大温升速率参考值；
所述S400，根据所述特征值定量的评价所述待测电池单体的热失控安全性，包括：
所述最大温升速率小于所述最大温升速率的参考值，则所述待测电池热失控安全性高于所述标准电池的热失控安全性。
在一个实施例中，所述S400，根据所述特征值定量的评价所述待测电池单体的热失控安全性，还包括：
通过所述最大温升速率的参考值减去所述最大温升速率的差值的绝对值的大小用于来定量评价所述待测电池单体的热失控安全性的高低。
在一个实施例中，所述S400，根据所述特征值定量的评价所述待测电池单体的热失控安全性，之前还包括：
从所述绝热热失控测试曲线中获取，从所述待测电池单体自产热开始到所述待测电池单体热失控开始的时间记为所述第一时间段；以及
从所述绝热热失控测试曲线中获取，从所述待测电池单体热失控开始到所述待测电池单体达到热失控过程最高温度的时间记为所述第二时间段；
所述特征值包括：所述待测试电池单体的所述第一时间段和所述第二时间段；所述标准电池发生热失控过程中的第一时间段参考值和第二时间段参考值；
所述S400，根据所述特征值定量的评价所述待测电池单体的热失控安全性，包括：
所述第一时间段大于所述第一时间段参考值，则所述待测电池热失控安全性高于所述标准电池的热失控安全性；
所述第二时间段大于所述第二时间段参考值，则所述待测电池热失控安全性高于所述标准电池的热失控安全性。
在一个实施例中，所述S400，根据所述特征值定量的评价所述待测电池单体的热失控安全性，还包括，通过以下步骤中的一种或多种评价所述待测电池单体的热失控安全性的高低：
通过所述第一时间段的长度减去所述第一时间段参考值的长度的差值的绝对值的大小来定量评价所述待测电池单体的热失控安全性的高低；或者
通过所述第二时间段的长度减去所述第二时间段参考值的长度的差值的绝对值的大小来定量评价所述待测电池单体的热失控安全性的高低。
在一个实施例中，所述对所述待测电池单体实施绝热热失控测试的步骤包括：
S10，提供待测电池单体；
S20，确认温度条件和电压条件，确认环境条件可满足绝热状态；
S30，在所述待测电池单体的外表面和内部分别设置一个或多个温度检测装置，在所述待测电池单体的极耳处连接电压采集装置；
S40，对所述待测电池单体实施绝热热失控测试，并记录热失控过程中的电池单体电压和热失控过程中的电池单体温度。
在一个实施例中，所述待测电池单体包括软包电池、方形电池或者圆柱形电池中的任意一种。
在一个实施例中，在对所述待测电池单体实施绝热热失控测试过程中：
电压测试频率和温度测试频率相同，且电压测试频率和温度测试频率大于等于1Hz。
在一个实施例中，在所述待测电池单体的外表面和内部分别设置一个或多个温度检测装置，在所述待测电池单体的极耳处连接电压采集装置的步骤包括：
S301，在干房或者手套箱中对所述待测电池单体部分拆解，以便于布置温度检测装置；
S302，提供保护层，对所述温度检测装置进行保护，并将保护后的所述温度检测装置布置在所述待测电池的内部，在所述待测电池的内部布置一个或多个保护后的所述温度检测装置；
S303，对所述待测电池进行二次密封设置，并在密封后的所述待测电池的极耳处设置一组或多组电压采集装置。
一种动力电池安全性评价系统，所述系统包括：
绝热装置，用于为待测电池单体提供绝热条件；
一组或多组电压采集装置，设置于所述待测电池单体壳体的极耳处，用于测试所述待测电池单体的电压；
一个或多个温度检测装置，设置于所述待测电池单体的内部或外表面，用于测试所述待测电池单体的温度；
控制装置，与所述多个电压采集装置和所述多个温度检测装置分别电连接，用于根据所述待测电池单体的温度和电压，生成绝热热失控测试曲线，以及用于评价所述待测电池单体的热失控安全性。
一种计算机设备，包括存储器和处理器，所述存储器存储有计算机程序，所述处理器执行所述计算机程序时实现上述任一项所述动力电池热失控安全性的定量评价方法的步骤或者所述计算机设备用于执行上述所述控制装置的功能。
本申请涉及一种动力电池热失控安全性的定量评价方法及系统。本申请的评价方法包括提供待测电池单体，并对所述待测电池单体实施绝热热失控测试。在所述绝热热失控测试中实时监测所述待测电池单体的温度和电压，生成绝热热失控测试曲线。从所述绝热热失控测试曲线中，获取所述待测电池单体的特征值。所述特征值包括：所述待测电池单体自身开始产热时的第一温度、所述待测电池单体内部大规模放热开始时的第二温度和所述待测电池单体在热失控过程中的最高温度。根据所述特征值定量的评价所述待测电池单体的热失控安全性。因此，对于不同类型或者不同材料体系的待测电池单体，可以用统一的一组或多组特征值来评价其热失控特性。使用统一测试方法得到的特征值来描述电池安全性，也可以将新开发电池的安全性方便地与历史电池安全性数据进行横向对比和评价。且本申请涉及的特征值与单体电池热失控内部过程直接相关，可以给电池热安全性的改进指出明确的方向。
附图说明
为了更清楚地说明本申请实施例或现有技术中的技术方案，下面将对实施例或现有技 术描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本申请的实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据公开的附图获得其他的附图。
图1为本申请一个实施例中提供的一种动力电池热失控安全性的定量评价方法的流程示意图；
图2为本申请一个实施例中提供的一种动力电池热失控安全性的定量评价方法的流程示意图；
图3为本申请一个实施例中提供的绝热热失控测试的步骤流程示意图；
图4为本申请一个实施例中提供的绝热热失控测试的步骤流程示意图；
图5为本申请实施例中提供的对所述待测电池单体设置温度检测装置及电压采集装置的步骤流程图；
图6为本申请实施例中提供的动力电池安全性评价系统示意图。
附图标记说明
动力电池安全性评价系统100
绝热装置10
电压采集装置20
温度检测装置30
控制装置40
具体实施方式
下面将结合本申请实施例中的附图，对本申请实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅仅是本申请一部分实施例，而不是全部的实施例。基于本申请中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本申请保护的范围。
目前，在进行动力电池单体安全性评价时，主要针对电池单体在机、电、热滥用条件下的热失控特性进行测试，包括针刺、过充、加热测试等。然而，目前的安全性测试主要涉及电池单体在受热条件下的外部表现，评价指标多为对热失控现象的定性比较，且与电池热失控时内部变化机理无关，不同电池单体间的测试数据可比较的指标很少。
基于上述分析，需要提供一种对于不同类型与材料体系的电池，可以用统一的一组或多组定量指标来评价其热失控特性的方法。且评价指标与单体电池热失控内部过程直接相关，可以给电池热安全性的改进指出明确的方向。对于电动车用动力电池的安全设计与热失控防控具有重要的实用价值和指导意义。
请参阅图1，本申请实施例提供一种动力电池热失控安全性的定量评价方法。所述动力电池热失控安全性的定量评价方法。
S100，提供待测电池单体，并对所述待测电池单体实施绝热热失控测试。
本步骤中，所述待测电池单体可以为软包电池、方形电池或者圆柱形电池中的任意一 种。本实施例中所能够检测的电池单体还可以是其他形态的电池单体，在此不作限定。在对所述待测电池单体实施绝热热失控测试之前需要确认绝热热失控的实验条件与测试环境是否满足热失控的安全测试要求。所述绝热热失控测试可以在能够提供绝热环境的大型量热仪中进行，在进行绝热热失控测试之前需确保量热仪已经完成校准和标定工作，避免测试过程中发生危险。另外，在所述绝热热失控测试进行前，需要通过充、放电设备按测试需求将所述待测电池单体调整至指定的荷电状态。
S200，在所述绝热热失控测试中实时监测所述待测电池单体的温度和电压，生成绝热热失控测试曲线。
本步骤中，可以设置温度检测装置和电压采集装置实时监测所述待测电池单体在热失控过程中的温度和电压。根据测试数据生成所述绝热热失控测试曲线，可以参阅图5所示。图5左图中的横坐标为时间，坐标时间范围即测试时间范围，即从数据采集装置开始记录数据到电池温度恢复至100℃以下的时间。图5右图中的横坐标为温度变化率。
S300，从所述绝热热失控测试曲线中，获取所述待测电池单体的特征值。其中，所述特征值包括：所述待测电池单体自身开始产热时的第一温度、所述待测电池单体内部大规模放热开始时的第二温度和所述待测电池单体在热失控过程中的最高温度。
本步骤中，所述特征值包括所述第一温度、所述第二温度和所述最高温度。当然所述评价方法中还可以包括其他的特征值，来定量评价待测试电池单体的热失控安全性。
S400，根据所述特征值定量的评价所述待测电池单体的热失控安全性。
本步骤中，对于所述待测电池单体的热失控安全性的评价可以比较所述特征值的大小，所述特征值越大，所述待测电池单体的热失控安全性越高，或者所述特征值越小，所述待测电池单体的热失控安全性越低。对于所述待测电池单体的热失控安全性的评价，也可以设定参考电池以及参考特征值，比较所述特征值与所述参考特征值的关系，来判定所述待测电池单体的热失控安全性。本步骤中，所述参考电池的选取可以根据经验也可以根据实际应用环境的需要进行调整。
本申请的评价方法包括提供待测电池单体，并对所述待测电池单体实施绝热热失控测试。在所述绝热热失控测试中实时监测所述待测电池单体的温度和电压，生成绝热热失控测试曲线。从所述绝热热失控测试曲线中，获取所述待测电池单体的特征值。所述特征值包括：所述待测电池单体自身开始产热时的第一温度、所述待测电池单体内部大规模放热开始时的第二温度和所述待测电池单体在热失控过程中的最高温度。根据所述特征值定量的评价所述待测电池单体的热失控安全性。对于不同类型与材料体系的电池，可以用统一的一组或多组定量指标来评价其热失控特性。且定量评价指标(即本申请中提到的所述待测试电池的特征值)与单体电池热失控内部过程直接相关，可以给电池热安全性的改进指出明确的方向。
请参阅图2，在一个实施例中，所述S400，根据所述特征值定量的评价所述待测电池单体的热失控安全性，包括：
S401，提供标准电池对应的第一参考值、第二参考值和第三参考值，其中，所述标准电池开始产热时的温度为所述第一参考温度、所述标准电池内部大规模放热开始时的温度 为所述第二参考温度、所述标准电池在热失控过程中的最高温度为所述第三参考温度。
本步骤中，设置一项标准电池，所述标准电池可以为已有绝热热失控特性测试数据的某已知材料体系和设计参数的电池。参考特征值即为该电池热失控过程中的第一参考温度、第二参考温度和第三参考温度。
S402，将所述待测电池单体的所述第一温度、所述第二温度和所述最高温度，分别与所述标准电池的所述第一参考温度、所述第二参考温度和所述第三参考温度进行对比。本步骤中，对两种温度值实施对比的动作可以采用控制器或者计算机来实现。
S403，若所述第一温度小于所述第一参考温度，则所述待测电池单体的热失控安全性低于所述标准电池的热失控安全性。
本步骤中，由于所述第一温度表示电池单体开始产热时的温度。所述第一温度越高，则电池在滥用条件下越不容易达到所述第一温度。不容易达到所述第一温度时，电池单体热失控安全性越高。相反，所述第一温度越低，电池单体热失控安全性越差。
S404，若所述第二温度小于所述第二参考温度，则所述待测电池单体的热失控安全性低于所述标准电池的热失控安全性。
本步骤中，由于所述第二温度表示电池单体内部大规模放热开始时的温度。所述第二温度越高，则电池在滥用条件下越不容易达到所述第二温度。不容易达到所述第二温度时，电池单体热失控安全性越高。相反，所述第二温度越低，电池单体热失控安全性越差。
S405，若所述最高温度小于所述第三参考温度，则所述待测电池单体的热失控安全性高于所述标准电池的热失控安全性。
本步骤中，所述第三参考温度为电池单体在热失控过程中的最高温度。所述最高温度越高，则电池发生热失控时，反应越剧烈。因此所述最高温度越高，电池单体热失控安全性越差。相反，所述最高温度越低，电池单体热失控安全性越高。
本实施例中，通过所述特征值的大小，定量地给出了所述待测电池单体的热失控安全性的评价方法。根据所述第一温度、所述第二温度和所述最高温度评价所述动力电池热失控安全性的评价结果更加明确、更加客观。
在一个实施例中，所述S400，根据所述特征值定量的评价所述待测电池单体的热失控安全性，之前还包括：根据所述绝热热失控测试曲线，生成所述待测电池单体的温度-温度变化率的变化曲线。从所述温度-温度变化率的变化曲线中获取所述待测电池单体的所述最大温升速率。
所述特征值包括：所述待测试动力电池发生热失控过程中的最大温升速率。所述标准电池发生热失控过程中的最大温升速率参考值。
所述S400，根据所述特征值定量的评价所述待测电池单体的热失控安全性，包括：
S411，所述最大温升速率小于所述最大温升速率的参考值，则所述待测电池热失控安全性高于所述标准电池的热失控安全性。
本实施例中，提供所述最大温升速率作为另外一种所述特征值。通过所述最大温升速率来评价电池单体的热失控安全性的。电池单体在热失控过程中所述最大温升速率越小，电池单体的安全性越高。
在一个实施例中，所述S400，根据所述特征值定量的评价所述待测电池单体的热失控安全性，之前还包括：
从所述绝热热失控测试曲线中获取，从所述待测电池单体自产热开始到所述待测电池单体热失控开始的时间记为所述第一时间段。以及
从所述绝热热失控测试曲线中获取，从所述待测电池单体热失控开始到所述待测电池单体达到热失控过程最高温度的时间记为所述第二时间段。
所述特征值包括：所述待测试电池单体的所述第一时间段和所述第二时间段。所述标准电池发生热失控过程中的第一时间段参考值和第二时间段参考值。
所述S400，根据所述特征值定量的评价所述待测电池单体的热失控安全性，包括：
S421，所述第一时间段大于所述第一时间段参考值，则所述待测电池热失控安全性高于所述标准电池的热失控安全性。
S422，所述第二时间段大于所述第二时间段参考值，则所述待测电池热失控安全性高于所述标准电池的热失控安全性。
本实施例中，提供所述第一时间段和所述第二时间段作为另外两种所述特征值。通过所述第一时间段和所述第二时间段来评价电池单体的热失控安全性的。电池单体在热失控过程中所述第一时间段和所述第二时间段越长，电池单体越不容易发生热失控，或者说在发生热失控之前越容易预防，电池单体的热失控安全性越高。
以上实施例中，所述第一温度、所述第二温度和所述最高温度分别代表所述待测电池单体自身开始产热的温度、所述待测电池单体热失控开始的温度、所述待测电池单体在热失控过程中的最高温度。
以上实施例中，所述最大温升速率代表所述待测电池单体热失控剧烈发生时的最大温升速率。
以上实施例中，所述第一时间段代表从所述待测电池单体自产热开始到所述待测电池单体热失控开始的时间。所述第二时间段代表从所述待测电池单体自产热开始到所述待测电池单体达到热失控过程最高温度的时间。
在一个具体的实施例中以上述六种特征值为例，综合分析所述待测电池单体的热失控安全性。由于电池单体内置传感器(可以是热电偶)最接近电池材料在热失控过程中的真实温度，因此使用电池内置传感器测量温度数据的所述特征值(所述第一温度T1、所述第二温度T2、所述最高温度T3、所述最大温升速率dT/dt、所述第一时间段t1和所述第二时间段t2)作为电池热安全性定量评价的指标，是较为合理并且准确的。
具体的综合上述六种特征值对电池热安全性定量评价的过程中，所述S400，根据所述特征值定量的评价所述待测电池单体的热失控安全性，还包括，通过以下步骤中的一种或多种评价所述待测电池单体的热失控安全性的高低：
通过所述第一温度减去所述第一参考温度的差值的绝对值的大小来定量评价所述待测电池单体的热失控安全性的高低；或者
通过所述第二温度减去所述第二参考温度的差值的绝对值的大小来定量评价所述待测电池单体的热失控安全性的高低；或者
通过所述第三参考温度减去所述最高温度的差值的绝对值的大小来定量评价所述待测电池单体的热失控安全性的高低；或者
通过所述最大温升速率的参考值减去所述最大温升速率的差值的绝对值的大小来定量评价所述待测电池单体的热失控安全性的高低；或者
通过所述第一时间段的长度减去所述第一时间段参考值的长度的差值的绝对值的大小来定量评价所述待测电池单体的热失控安全性的高低；或者
通过所述第二时间段的长度减去所述第二时间段参考值的长度的差值的绝对值的大小来定量评价所述待测电池单体的热失控安全性的高低。本实施例中，通过将六种特征值进行定量的评价所述待测电池单体的热失控安全性的高低。比如，参照其他的电池评价方法可能够得出所述待测试电池会比另外一块电池(或者是参考电池)的安全性好，但无法得知热失控特性在哪些方面表现的更好，也无法知道热失控特性的某一个性能具体好了多少。本实施例中，可以具体得知，如：从自生热温度的角度，所述待测电池相比于另外一块电池(或者是参考电池)有20℃的提升。本实施例中，提供的定量评价方法，还可以给电池的安全性改进提供指导方向。比如通过本申请的方法得知，所述待测电池的自生热温度差，就可以专注于提高所述待测试电池的自生热温度。具体提高所述待测试电池的自生热温度的方法可以包括找新材料替代、通过一些包覆方法或者调整电解液的方法来实现，但也并不仅仅限于以上的调节方法。
请参阅图5为电池绝热热失控的温度、温升速率曲线及三个特征温度点、最大温升速率、特征时间示意。图5中T1为所述第一温度，即量热仪探测到所述待测电池单体开始产热的温度，即所述待测电池单体的自产热温度。T1反映了所述待测电池单体原始界面开始失去热稳定性时的温度。对于目前广泛使用的液态有机电解质体系，即为负极固体电解质膜开始分解的温度。在T1之后量热仪进入绝热工作模式。
图5中T2为所述第二温度，即T2为所述待测电池单体温升速率达到某一特征温升速率时的电池温度。一般地，该温升速率比上一时刻高一个数量级，即所述待测电池单体热失控开始的温度。图5中T3为所述最高温度，T3为所述待测电池单体在整个热失控过程中的最高温度。
请参考图5右侧为所述待测电池单体温度-温升速率的变化曲线。图5中所述待测电池单体在热失控过程中，温升速率的最大值记为dT/dt。
所述第一时间段，从电池单体自产热开始，到电池单体热失控开始的时间记为t1。所述第二时间段，从电池单体热失控开始，到电池单体达到热失控过程最高温度的时间记为t2。
具体的，电池单体热失控的评价方法可以参照以下：
T1越低，电池单体越容易发生自生热，电池单体安全性越差。T1数值即为电池自生热安全性的定量评价指标。
T2越低，电池单体在自生热后越容易引发热失控，电池单体安全性越差。T2数值即为电池热失控安全性的定量评价指标。
T3越低，电池单体在热失控后造成的危害越小，热量越不容易传递给周边的其它电池 单体或可燃物，电池单体的安全性越好。T3数值即为电池热失控危害性的定量评价指标。
dT/dt越小，电池单体在热失控后造成的危害越小，热量越不容易传递给周边的其它电池单体或可燃物，电池单体的安全性越好。dT/dt数值即为电池热失控危害性的定量评价指标。
t1越长，电池单体在自生热后发展成热失控所需的时间越长，热量累积速度慢，电池单体的安全性越好。
t2越长，电池单体在热失控后达到热失控最高温度所需的时间越长，电池热失控后热量释放速度慢，电池单体的安全性越好。t1、t2数值即为电池热失控热量积累以及电池热失控后热量释放速度的定量评价指标。
本实施例中，上述定量评价指标即本申请中提到的所述待测试电池的特征值。本实施例中，使用电池单体内置传感器(比如热电偶)测量所述特征值，根据所述特征值实现对不同电池单体的热安全性的评价。
按照上述的方法，对四种不同体系某型号电池单体实施绝热热失控测试。实施绝热热失控测试的结果如表1所示。四种电池体系的负极均为石墨，正极为不同种类的活性材料。
表1：不同体系电池单体热失控特征值
Figure PCTCN2019095775-appb-000001
从表1中对比可以看出，所述第一温度T1(自生热起始温度)：Cell 1>Cell 2>Cell 3≈Cell 4。即从自产热温度讲，Cell 1的安全性好于Cell 2，Cell 2好于Cell 3和Cell 4。进一步讲，若评价电池热失控自产热(以Cell 1作为参考电池)，则Cell 2相比参考电池热稳定性有42.1℃的下降，Cell 3相比参考电池热稳定性降低73.3℃，Cell 4相比参考电池热稳定性有71.6℃的下降。
所述第二温度T2(热失控起始温度)：Cell 3＞Cell 1＞Cell 4＞Cell 2。即从热失控触发温度讲，热失控安全性：Cell 3＞Cell 1＞Cell 4＞Cell 2。进一步讲，若评价电池热失控触发的难易程度(以Cell 1作为参考电池)，则Cell 2相比参考电池热稳定性有47.1℃的下降，Cell 3相比参考电池热稳定性提高32.7℃，Cell 4相比参考电池热稳定性有24.3℃的下降。
所述最高温度T3(热失控最高温度)：Cell 4＞Cell 3＞Cell 2＞Cell 1。即从反应总放热即热失控危害性来看，热失控安全性：Cell 4＜Cell 3＜Cell 2＜Cell 1。进一步讲，若评价电池热失控后的危害性(以Cell 1作为参考电池)，则Cell 2相比参考电池热稳定性有280.1℃的下降，Cell 3相比参考电池热稳定性降低473℃，Cell 4相比参考电池热稳定性有 530.3℃的下降。
所述最大温升速率dT/dt：Cell 2＞Cell 4＞Cell 3＞Cell 1。即从反应总放热即热失控危害性来看，热失控安全性：Cell 2＜Cell 4＜Cell 3＜Cell 1。进一步讲，若定量评价电池热失控后的危害性(以Cell 1作为参考电池)，则Cell 2和Cell 3相比参考电池热失控最大温升速率提高了约1000倍，Cell 4相比参考电池热失控最大温升速率提高了约10000倍。
所述第一时间段t1(电池自产热到热失控触发的时间)：Cell 1＞Cell 3＞Cell 4≈Cell 2。即从热量积累速度来看，热失控安全性：Cell 1＞Cell 3＞Cell 4≈Cell 2。进一步讲，若定量评价电池热失控发展速度(以Cell 1作为参考电池)，则Cell 3相比参考电池热失控提前了0.9小时，Cell 4和Cell2相比参考热失控提前了约1.9小时。
所述第二时间段t2(电池热失控触发到电池热失控最高温度的时间)：Cell 1＞Cell 3＞Cell 2＞Cell 4。即从热失控后热量释放速度来看，热失控安全性：Cell 1＞Cell 3＞Cell 2＞Cell 4。进一步讲，若定量评价电池热失控能量释放速度(以Cell 1作为参考电池)，则Cell 3相比参考电池热失控过程中能量释放速度快15秒，Cell 2相比参考电池热失控过程中能量释放速度快20秒，Cell 4相比参考电池热失控过程中能量释放速度快28秒。
综上，几款电池的综合安全性为：Cell 1(磷酸铁锂/石墨)>Cell 2(钴酸锂/石墨)>Cell 3(三元111/石墨)≈Cell 4(三元532/石墨)。另外由于电池的三个定量评价指标(所述特征值)与热失控过程直接相关，还可以给出不同款电池的改进方向：三元111和三元532材料可以通过负极包覆或电解液添加剂等方法，提高SEI的分解温度以提高T1，改善安全性；三元532和钴酸锂材料可以通过使用热稳定性更高的隔膜、提高内短路或正负极接触温度，以进一步提高T2来提高全电池的热失控安全性。T3通常与电池的比能量直接相关，较难通过材料改性来改进，可以考虑在三元材料电池的实际应用中加强散热环节。
以上通过一具体实施例详细的解释了本申请提出的动力电池热失控安全性的定量评价方法。所述评价方法以动力电池单体可重复的绝热热失控试验为基础，结合动力电池单体的热失控机理，选取热失控过程中的特征值来评价动力电池单体的热失控安全性。所述特征值包括所述第一温度、所述第二温度、所述最高温度、所述最大温升速率、所述第一时间段和所述第二时间段。所述特征值可以通过实验测试的手段定量确定。通过对比定量确定的所述特征值实现对动力电池单体的热失控安全性评价。
请参阅图3，在一个实施例中，所述对所述待测电池单体实施绝热热失控测试的步骤包括：
S10，从第一类电池单体中选取一个待测电池单体。
S20，确认温度条件和电压条件，确认环境条件处于绝热状态。
S30，在所述待测电池单体的外表面和内部分别设置一个或多个温度检测装置，在所述待测电池单体的极耳处连接电压采集装置。
S40，对所述待测电池单体实施绝热热失控测试，并记录热失控过程中的电池单体电压和热失控过程中的电池单体温度。
本实施例中，给出了对一种类型的所述待测电池单体实施绝热热失控测试的具体步骤。可以理解所述具体步骤并不限定，还可以通过其他的方式来实现。
在一个实施例中，在对所述待测电池单体实施绝热热失控测试过程中：电压测试频率和温度测试频率相同，且电压测试频率和温度测试频率大于等于1Hz。
本实施例中，在进行电池单体的绝热热失控测试时，需要实时记录热失控过程中电池单体的电压、电池单体的温度。在对电池单体电压和电池单体温度进行测量时，采集数据的频率应大于1Hz(即每秒最少采集一次数据)。并且电压和温度测量频率需保持一致，以保证能够准确的获取所述特征值。
请参阅图4，在一个实施例中，所述S30，在所述待测电池单体的外表面和内部分别设置多个温度检测装置，在所述待测电池单体的极耳处连接电压采集装置的步骤包括：
S301，在干房或者手套箱中对所述待测电池单体部分拆解，以便于布置温度检测装置。本步骤中，所述温度检测装置可以是热电偶。对所述待测电池单体部分拆解可以理解为，当所述待测电池单体是软包电池，可以在软包电池外包的铝塑膜上开一个小口(小口的大小足够将热电偶塞进去即可)，然后从小口把热电偶塞进去，之后进行相应的固定操作，以完成所述温度检测装置的布设。对所述待测电池单体部分拆解还可以理解为，当所述待测电池单体是方壳电池，沿所述方可电池的顶盖锯开，把热电偶塞进去之后进行相应的固定操作(比如用胶封上)，以完成所述温度检测装置的布设。
S302，提供保护层，所述保护层可以用隔膜或其他材料对所述温度检测装置进行保护。并将保护后的所述温度检测装置布置在所述待测电池的内部(比如可以是正极与隔膜间，或负极与隔膜间)。可以在所述待测电池的内部布置一个或多个保护后的所述温度检测装置。
S303，对所述待测电池进行二次密封设置，并在密封后的所述待测电池的极耳处设置一组或多组电压采集装置。
本实施例中，至少在电池单体的内部布置一个温度检测装置(所述温度检测装置可以是(温度传感器)。在设置所述温度传感器时需要在干房或手套箱中将电池部分拆解。将温度传感器布置在拆解后的电池单体的内部，并对电池单体进行二次密封。具体的可以根据需要在电池单体内部的不同位置及电池单体表面不同位置布置多个温度传感器。设置多个温度传感器是为了能够准确的获取所述电池单体在热失控过程中的不同位置的温度值。另外，可以使用多组电压传感器进行测量，以防止电池单体在热失控过程中由于传感器脱落造成的数据缺失或不稳定。
请参阅图6，在一个实施例中提供一种动力电池热失控安全性评价系统100。所述系统包括：绝热装置10、多个电压采集装置20、多个温度检测装置30和控制装置40。
所述绝热装置10用于为待测电池单体提供绝热条件。所述绝热装置10可以包括绝热加速量热仪。
所述多个电压采集装置20设置于所述待测电池单体的极耳处。所述多个电压采集装置20可以为电压表，用于测试所述待测电池单体的电压。为了防止所述电压采集装置20在测试过程中的脱落可以在所述待测电池单体的极耳处设置多个电压采集装置20。
所述多个温度检测装置30设置于所述待测电池单体的内部。所述多个温度检测装置30可以是温度传感器。比如热电偶或者热电阻。所述多个温度检测装置30用于测试所述 待测电池单体的温度。
所述控制装置40与所述多个电压采集装置和所述多个温度检测装置分别电连接。所述控制装置40用于根据所述待测电池单体的温度和电压，生成绝热热失控测试曲线。所述控制装置还用于评价所述待测电池单体的热失控安全性。所述控制装置可以是计算机或者基于计算及的控制设备。
本实施例中提供的所述动力电池安全性评价系统100包括所述绝热装置10、所述多个电压采集装置20、所述多个温度检测装置30和所述控制装置40。所述动力电池安全性评价系统100可以根据所述多个电压采集装置20和所述多个温度检测装置30获取待测电池单体的电压和温度。通过所述控制装置40生成所述绝热热失控测试曲线。通过所述控制装置40从所述绝热热失控测试曲线中，获取所述待测电池单体的特征值。所述动力电池安全性评价系统100可以获取不同类型电池材料的特征值，根据所述特征值定量的评价所述待测电池单体的热失控安全性。根据本申请，对于不同类型与材料体系的电池，可以用统一的一组或多组定量指标来评价其热失控特性。且定量评价指标与单体电池热失控内部过程直接相关，可以给电池热安全性的改进指出明确的方向。
另外结合本申请的技术方案，在电池设计阶段，根据不同种类材料电池测试的特征值，指出电池安全性改进的方向，指导材料组合制成安全性较高的动力电池。基于动力电池绝热热失控测试曲线和特征值来指导电动车用动力电池的设计，可以进一步提高动力电池安全性设计的效率、节约电池研发成本，对于电动车用动力电池的安全设计与防控具有重要的实用价值和指导意义。
一种计算机设备，包括存储器和处理器，所述存储器存储有计算机程序，所述处理器执行所述计算机程序时实现上述任一项所述方法的步骤。或者所述计算机设备用于执行所述控制装置40的功能。
本领域普通技术人员可以理解实现上述实施例方法中的全部或部分流程，是可以通过计算机程序来指令相关的硬件来完成，所述的计算机程序可存储于一非易失性计算机可读取存储介质中，该计算机程序在执行时，可包括如上述各方法的实施例的流程。其中，本申请所提供的各实施例中所使用的对存储器、存储、数据库或其它介质的任何引用，均可包括非易失性和/或易失性存储器。非易失性存储器可包括只读存储器(ROM)、可编程ROM(PROM)、电可编程ROM(EPROM)、电可擦除可编程ROM(EEPROM)或闪存。易失性存储器可包括随机存取存储器(RAM)或者外部高速缓冲存储器。作为说明而非局限，RAM以多种形式可得，诸如静态RAM(SRAM)、动态RAM(DRAM)、同步DRAM(SDRAM)、双数据率SDRAM(DDRSDRAM)、增强型SDRAM(ESDRAM)、同步链路(Synchlink)DRAM(SLDRAM)、存储器总线(Rambus)直接RAM(RDRAM)、直接存储器总线动态RAM(DRDRAM)、以及存储器总线动态RAM(RDRAM)等。
最后，还需要说明的是，在本文中，诸如第一和第二等之类的关系术语仅仅用来将一个实体或者操作与另一个实体或操作区分开来，而不一定要求或者暗示这些实体或操作之间存在任何这种实际的关系或者顺序。而且，术语“包括”、“包含”或者其任何其他变体意在涵盖非排他性的包含，从而使得包括一系列要素的过程、方法、物品或者设备不仅包 括那些要素，而且还包括没有明确列出的其他要素，或者是还包括为这种过程、方法、物品或者设备所固有的要素。在没有更多限制的情况下，由语句“包括一个……”限定的要素，并不排除在包括所述要素的过程、方法、物品或者设备中还存在另外的相同要素。
本说明书中各个实施例采用递进的方式描述，每个实施例重点说明的都是与其他实施例的不同之处，各个实施例之间相同相似部分互相参见即可。
对所公开的实施例的上述说明，使本领域专业技术人员能够实现或使用本申请。对这些实施例的多种修改对本领域的专业技术人员来说将是显而易见的，本文中所定义的一般原理可以在不脱离本申请的精神或范围的情况下，在其它实施例中实现。因此，本申请将不会被限制于本文所示的这些实施例，而是要符合与本文所公开的原理和新颖特点相一致的最宽的范围。

Claims (15)

  1. 一种动力电池热失控安全性的定量评价方法，其特征在于，包括：
    S100，提供待测电池单体，并对所述待测电池单体实施绝热热失控测试；
    S200，在所述绝热热失控测试中实时监测所述待测电池单体的温度和电压，生成绝热热失控测试曲线；
    S300，从所述绝热热失控测试曲线中，获取所述待测电池单体的特征值，其中，所述特征值包括：所述待测电池单体自身开始产热时的第一温度、所述待测电池单体内部大规模放热开始时的第二温度和所述待测电池单体在热失控过程中的最高温度；
    S400，根据所述特征值定量地评价所述待测电池单体的热失控安全性。
  2. 如权利要求1所述的动力电池热失控安全性的定量评价方法，其特征在于，所述绝热热失控测试在能够提供绝热环境的量热仪中进行，在进行所述绝热热失控测试之前确保所述量热仪已经完成校准和标定工作。
  3. 如权利要求1所述的动力电池热失控安全性的定量评价方法，其特征在于，在对所述待测电池单体实施绝热热失控测试之前，对所述待测电池单体进行充电或放电操作，以使得所述待测电池单体调整至指定的荷电状态。
  4. 如权利要求1所述的动力电池热失控安全性的定量评价方法，其特征在于，
    所述S400，根据所述特征值定量地评价所述待测电池单体的热失控安全性，包括：
    提供标准电池对应的第一参考值、第二参考值和第三参考值，其中，所述标准电池开始产热时的温度为所述第一参考温度、所述标准电池内部大规模放热开始时的温度为所述第二参考温度、所述标准电池在热失控过程中的最高温度为所述第三参考温度；
    将所述待测电池单体的所述第一温度、所述第二温度和所述最高温度，分别与所述标准电池的所述第一参考温度、所述第二参考温度和所述第三参考温度进行对比；
    若所述第一温度小于所述第一参考温度，则所述待测电池单体的热失控安全性低于所述标准电池的热失控安全性；
    若所述第二温度小于所述第二参考温度，则所述待测电池单体的热失控安全性低于所述标准电池的热失控安全性；
    若所述最高温度小于所述第三参考温度，则所述待测电池单体的热失控安全性高于所述标准电池的热失控安全性。
  5. 如权利要求4所述的动力电池热失控安全性的定量评价方法，其特征在于，所述S400，根据所述特征值定量的评价所述待测电池单体的热失控安全性，还包括，通过以下步骤中的一种或多种评价所述待测电池单体的热失控安全性的高低：
    通过所述第一温度减去所述第一参考温度的差值的绝对值的大小来定量评价所述待测电池单体的热失控安全性的高低；或者
    通过所述第二温度减去所述第二参考温度的差值的绝对值的大小来定量评价所述待测电池单体的热失控安全性的高低；或者
    通过所述第三参考温度减去所述最高温度的差值的绝对值的大小来定量评价所述待 测电池单体的热失控安全性的高低。
  6. 如权利要求4所述的动力电池热失控安全性的定量评价方法，其特征在于，
    所述S400，根据所述特征值定量地评价所述待测电池单体的热失控安全性，之前还包括：
    根据所述绝热热失控测试曲线，生成所述待测电池单体的温度-温度变化率曲线；
    从所述温度-温度变化率曲线中获取所述待测电池单体的所述最大温升速率；
    所述特征值包括：所述待测试动力电池发生热失控过程中的最大温升速率；所述标准电池发生热失控过程中的最大温升速率参考值；
    所述S400，根据所述特征值定量地评价所述待测电池单体的热失控安全性，包括：
    所述最大温升速率小于所述最大温升速率的参考值，则所述待测电池热失控安全性高于所述标准电池的热失控安全性。
  7. 如权利要求6所述的动力电池热失控安全性的定量评价方法，其特征在于，
    所述S400，根据所述特征值定量的评价所述待测电池单体的热失控安全性，还包括：
    通过所述最大温升速率的参考值减去所述最大温升速率的差值的绝对值的大小用于来定量评价所述待测电池单体的热失控安全性的高低。
  8. 如权利要求6所述的动力电池热失控安全性的定量评价方法，其特征在于，
    所述S400，根据所述特征值定量地评价所述待测电池单体的热失控安全性，之前还包括：
    从所述绝热热失控测试曲线中获取，从所述待测电池单体自产热开始到所述待测电池单体热失控开始的时间记为所述第一时间段；以及
    从所述绝热热失控测试曲线中获取，从所述待测电池单体热失控开始到所述待测电池单体达到热失控过程最高温度的时间记为所述第二时间段；
    所述特征值包括：所述待测试电池单体的所述第一时间段和所述第二时间段；所述标准电池发生热失控过程中的第一时间段参考值和第二时间段参考值；
    所述S400，根据所述特征值定量地评价所述待测电池单体的热失控安全性，包括：
    所述第一时间段大于所述第一时间段参考值，则所述待测电池热失控安全性高于所述标准电池的热失控安全性；
    所述第二时间段大于所述第二时间段参考值，则所述待测电池热失控安全性高于所述标准电池的热失控安全性。
  9. 如权利要求8所述的动力电池热失控安全性的定量评价方法，其特征在于，所述S400，根据所述特征值定量的评价所述待测电池单体的热失控安全性，还包括，通过以下步骤中的一种或多种评价所述待测电池单体的热失控安全性的高低：
    通过所述第一时间段的长度减去所述第一时间段参考值的长度的差值的绝对值的大小来定量评价所述待测电池单体的热失控安全性的高低；或者
    通过所述第二时间段的长度减去所述第二时间段参考值的长度的差值的绝对值的大小来定量评价所述待测电池单体的热失控安全性的高低。
  10. 如权利要求9所述的动力电池热失控安全性的定量评价方法，其特征在于，所述 对所述待测电池单体实施绝热热失控测试的步骤包括：
    S10，提供待测电池单体；
    S20，确认温度条件和电压条件，确认环境条件可满足绝热状态；
    S30，在所述待测电池单体的外表面和内部分别设置一个或多个温度检测装置，在所述待测电池单体的极耳处连接电压采集装置；
    S40，对所述待测电池单体实施绝热热失控测试，并记录热失控过程中的电池单体电压和热失控过程中的电池单体温度。
  11. 如权利要求10所述的动力电池热失控安全性的定量评价方法，其特征在于，所述待测电池单体包括软包电池、方形电池或者圆柱形电池中的任意一种。
  12. 如权利要求10所述的动力电池热失控安全性的定量评价方法，其特征在于，在对所述待测电池单体实施绝热热失控测试过程中：
    电压测试频率和温度测试频率相同，且电压测试频率和温度测试频率大于等于1Hz。
  13. 如权利要求10所述的动力电池热失控安全性的定量评价方法，其特征在于，所述S30，在所述待测电池单体的外表面和内部分别设置多个温度检测装置，在所述待测电池单体的极耳处连接电压采集装置的步骤包括：
    S301，在干房或者手套箱中对所述待测电池单体部分拆解，以便于布置温度检测装置；
    S302，提供保护层，对所述温度检测装置进行保护，并将保护后的所述温度检测装置布置在所述待测电池的内部，在所述待测电池的内部布置一个或多个保护后的所述温度检测装置；
    S303，对所述待测电池进行二次密封设置，并在密封后的所述待测电池的极耳处设置一组或多组电压采集装置。
  14. 一种动力电池安全性评价系统，其特征在于，所述系统包括：
    绝热装置，用于为待测电池单体提供绝热条件；
    一组或多组电压采集装置，设置于所述待测电池极耳处，用于测试所述待测电池单体的电压；
    一个或多个温度检测装置，设置于所述待测电池单体的内部或外表面，用于测试所述待测电池单体的温度；
    控制装置，与所述多个电压采集装置和所述多个温度检测装置分别电连接，用于根据所述待测电池单体的温度和电压，生成绝热热失控测试曲线，以及用于评价所述待测电池单体的热失控安全性。
  15. 一种计算机设备，包括存储器和处理器，所述存储器存储有计算机程序，所述处理器执行所述计算机程序时实现权利要求1-13中任一项所述动力电池热失控安全性的定量评价方法的步骤或者所述计算机设备用于执行权利要求15中所述控制装置的功能。
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