Device and method for measuring heat generation of lithium ion battery thermal runaway based on mass change

Abstract

This invention belongs to the field of lithium-ion battery thermal safety testing technology, and relates to a device and method for measuring the heat generation of lithium-ion battery thermal runaway based on mass change. Addressing the technical problems of existing battery thermal runaway heat generation measurement methods, such as complex heat dissipation paths, insufficient consideration of battery mass changes during measurement, and interference from ejection impacts, leading to poor measurement accuracy, this application provides a lithium-ion battery thermal runaway heat generation measurement device, comprising: an electronic balance; a support component for placing the battery cell under test, the support component being disposed on the electronic balance and placing the battery cell under test in a horizontal position; an insulation covering component covering the outside of the battery cell under test, the insulation covering component having a pre-drilled hole corresponding to the safety valve position of the battery cell under test; a thermal runaway triggering component; a temperature acquisition component; and a limiting component; wherein, the ejection direction of the safety valve of the battery cell under test is not parallel to the weighing sensitive direction of the electronic balance, to reduce the influence of ejection impacts on the symmetry.

Description

Technical Field

[0001] This invention belongs to the field of lithium-ion battery thermal safety testing technology, specifically relating to a device and method for measuring the heat generation of lithium-ion battery thermal runaway based on mass change. Background Technology

[0002] Lithium-ion batteries, due to their high energy density, long cycle life, and good environmental adaptability, have been widely used in electric vehicles, energy storage systems, and portable electronic devices. As battery energy density continues to increase, their safety has become a growing concern. Specifically, batteries may experience thermal runaway under abuse conditions (such as overcharging, short circuits, nail penetration, or external heating), leading to violent heat release, jetting, or even fire and explosion. Therefore, accurately obtaining the total heat generated during the thermal runaway process of lithium-ion batteries is crucial for assessing battery safety, optimizing battery structure design, and establishing thermal runaway simulation models.

[0003] In existing technologies, research on battery thermal behavior mainly relies on the following types of methods: One type of testing method is based on differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), or accelerated adiabatic calorimetry (ARC). These methods can reflect the exothermic characteristics of battery materials or the battery as a whole to a certain extent, but they have problems such as high equipment cost, long test cycle, and limited sample size. Moreover, it is difficult to completely capture all the exothermic behavior during battery thermal runaway during the test, especially for large-capacity power batteries, and the test results often deviate from the actual operating conditions.

[0004] Another approach involves measuring changes in battery surface temperature and combining this with thermal models or simulations to estimate the heat generation of the battery. For example, by recording the temperature change curve during battery heating and obtaining the heat dissipation coefficient and internal temperature distribution through simulation fitting, the heat generation during thermal runaway can be estimated. However, this type of method relies on model assumptions and parameter fitting, and the calculation results are greatly affected by the accuracy of the model, making it difficult to directly reflect the actual heat release.

[0005] In addition, some technical solutions improve the thermal insulation of the test by setting up thermal insulation structures or heat-insulating cavities to reduce heat exchange between the battery and the external environment. However, in practical applications, the battery will be accompanied by the ejection of a large amount of high-temperature gas during thermal runaway. This ejection process will not only take away some heat, but also have an impact on the measurement system, resulting in measurement errors. Existing technologies usually fail to consider the following factors at the same time: (1) there is obvious uneven temperature spatial distribution during battery thermal runaway; (2) the heat taken away by the gas generated during battery ejection; (3) the impact of ejection impact on the stability of the measurement device (such as the weighing system); (4) the problem of multi-path heat loss between the battery and the environment.

[0006] In particular, in scenarios where energy calculations are based on mass changes, the impact force generated by the thermal runaway of the battery can cause instantaneous disturbances to the measurement device, thus affecting the accuracy of mass measurement and consequently the reliability of the heat calculation results. Currently, there is a lack of a measurement scheme that can suppress heat loss while reducing the impact of the eruption impact on the measurement, and comprehensively consider the heat from both the battery cell itself and the erupted gases.

[0007] Therefore, there is an urgent need to provide a simple, low-cost, and highly accurate device and method for measuring the thermal runaway heat generation of lithium-ion batteries, so as to improve the accuracy and reliability of the thermal runaway heat generation measurement results. Summary of the Invention

[0008] 1. The technical problem the invention aims to solve. To address the common technical problems in existing methods for measuring the heat generation during thermal runaway of lithium-ion batteries, such as complex heat dissipation paths, insufficient consideration of battery mass changes during measurement, and interference from ejection impacts on the measurement results, leading to poor accuracy, this application provides a device for measuring the heat generation during thermal runaway of lithium-ion batteries.

[0009] Furthermore, this application also provides a method for measuring the heat generated by thermal runaway in lithium-ion batteries.

[0010] 2. Technical Solution Based on the objectives of this invention, a first aspect of this invention provides a lithium-ion battery thermal runaway heat generation measurement device, comprising: Electronic balance; A support assembly for placing the battery cell under test is provided on the electronic balance, and the battery cell under test is placed in a horizontal position. A thermal insulation covering assembly is provided to cover the outside of the battery cell under test. The thermal insulation covering assembly has a reserved hole at the position corresponding to the safety valve of the battery cell under test. Thermal runaway triggering component; Temperature acquisition component; Limiting components; The safety valve ejection direction of the battery cell under test is not parallel to the weighing sensitive direction of the electronic balance, so as to reduce the impact of the ejection impact on the symmetry.

[0011] Preferably, the thermal insulation covering assembly includes a thermal insulation shell and a thermal insulation cover, which together form a covering structure that matches the shape of the battery cell; temperature sensors are provided at the center of mass of the battery cell and on the surface of the battery cell to obtain temperature changes inside and on the surface of the battery cell.

[0012] According to any embodiment of the first aspect of the present invention, in a lithium-ion battery thermal runaway heat generation measuring device, the safety valve ejection direction is perpendicular to the electronic balance weighing direction.

[0013] By aligning the ejection direction of the safety valve with the weighing direction of the electronic balance, the impact force generated by the ejection can be further prevented from being transmitted along the weighing direction, thereby further improving weighing stability and reducing measurement errors.

[0014] Preferably, the horizontal position is such that the large surface of the battery cell is placed parallel to the weighing surface of the electronic balance, which is different from the vertical placement of the battery cell, and the emission direction is deviated from the weighing direction.

[0015] According to any embodiment of the first aspect of the present invention, a lithium-ion battery thermal runaway heat generation measuring device includes a weighing pan as the bearing component and a blocking structure as the limiting component for limiting cell displacement.

[0016] By setting up a weighing pan and a blocking structure to support and limit the battery cell, the displacement of the battery cell caused by the eruption during thermal runaway can be suppressed, the stability of the battery cell during the weighing process can be improved, and the accuracy of the mass change data can be guaranteed.

[0017] Preferably, the weighing pan is a metal plate structure with openings for fixing the battery cells; the blocking structure is located at the edge of the weighing pan to resist the impact of the ejection.

[0018] According to any embodiment of the first aspect of the present invention, in a lithium-ion battery thermal runaway heat generation measurement device, the thermal insulation covering assembly covers the remaining outer surface of the cell under test except for the reserved hole.

[0019] By covering the rest of the cell's outer surface with the insulation coating except for the pre-drilled holes, heat loss to the outside during thermal runaway can be minimized, improving the insulation performance of the measurement system and thus enhancing the accuracy of heat generation calculation.

[0020] Preferably, the size of the reserved hole matches the opening of the cell safety valve to ensure smooth ejection and reduce additional heat loss.

[0021] According to any embodiment of the first aspect of the present invention, the thermal runaway heat generation measurement device for lithium-ion batteries, wherein the thermal insulation coating component is composed of one or more of ceramic fiber cotton, aerogel or nano-insulating materials.

[0022] By using one or more of ceramic fiber cotton, aerogel, or nano-insulation materials to form an insulation covering component, the insulation performance can be effectively improved, heat conduction and convection heat loss can be reduced, thereby improving the accuracy of measurement results.

[0023] Preferably, the insulation material is an insulation material with an air pore structure to further reduce heat conduction efficiency.

[0024] According to any embodiment of the first aspect of the present invention, a lithium-ion battery thermal runaway heat generation measurement device is provided, wherein the thermal runaway triggering component includes a heating element disposed inside or outside the cell under test.

[0025] By incorporating a heating element inside the battery cell to trigger thermal runaway, the heat source can be located within the cell, facilitating a thermal runaway process that develops from the inside out. This improves the realism of the test conditions and the reliability of the measurement results. Alternatively, the heating element can be positioned on the outside of the battery cell under test to trigger thermal runaway from the outside.

[0026] Preferably, the heating element is positioned at the center of mass of the battery cell core to trigger thermal runaway from the central region of the battery cell.

[0027] Preferably, the heating element has a size of 15 mm × 15 mm to 60 mm × 60 mm and a power of 150 W to 700 W.

[0028] According to any embodiment of the first aspect of the present invention, a lithium-ion battery thermal runaway heat generation measurement device includes a temperature acquisition component comprising a temperature sensor for measuring the cell temperature and / or the temperature of the ejected gas.

[0029] By setting up temperature sensors to measure the cell temperature and / or the temperature of the ejected gas, information on temperature changes during thermal runaway can be obtained, providing basic data support for subsequent heat generation calculations.

[0030] Preferably, the temperature sensor is disposed on the surface of the battery cell and at the center of mass of the battery cell cassette to obtain spatial distribution information of the battery cell temperature.

[0031] Based on the objectives of this invention, a second aspect of this invention provides a method for measuring the heat generated during thermal runaway of a lithium-ion battery, comprising: Place the battery cell under test inside the heat insulation covering assembly and ensure that the safety valve corresponds to the reserved hole; The battery cell to be tested is placed horizontally on the electronic balance, and the direction of the safety valve of the battery cell is not parallel to the weighing direction of the electronic balance. This triggers thermal runaway in the battery cell under test. Record the changes in cell mass and temperature during thermal runaway; The total heat generated by thermal runaway is calculated based on the mass and temperature changes.

[0032] Preferably, the internal temperature and surface temperature of the battery cell are acquired simultaneously during the recording process to calculate the average temperature of the battery cell.

[0033] According to any embodiment of the second aspect of the present invention, the method for measuring the heat generated by thermal runaway of a lithium-ion battery includes the heat generated by the cell body and the heat generated by the ejected gas.

[0034] By dividing the total heat generated by thermal runaway into the heat of the battery cell itself and the heat of the ejected gas, the heat storage inside the battery cell and the energy release during the ejection process can be considered simultaneously, thereby improving the completeness and accuracy of the heat generation calculation.

[0035] Preferably, the mass of the ejected gas can be determined based on the mass change of the battery cell during thermal runaway and in combination with the composition of the ejected material.

[0036] According to any embodiment of the second aspect of the present invention, the heat generated by thermal runaway of a lithium-ion battery is determined based on the mass of the ejected gas, the specific heat capacity of the gas, and the temperature rise of the gas.

[0037] Preferably, the mass of the ejected gas is the mass of the gaseous portion of the ejected material during thermal runaway, which can be determined based on the change in cell mass and the composition of the ejected material; the mass of the ejected gas does not necessarily have to be equal to the total mass difference of the cell before and after thermal runaway.

[0038] According to any embodiment of the second aspect of the present invention, the heat generated by thermal runaway of a lithium-ion battery is determined based on the cell mass, average temperature rise, and specific heat capacity.

[0039] By calculating the heat of the battery cell itself based on cell mass, average temperature rise, and specific heat capacity, the energy change corresponding to the overall temperature rise of the battery cell can be reflected, thus providing a basis for calculating the total heat generation.

[0040] Preferably, the average temperature rise is calculated based on the internal temperature and surface temperature of the battery cell.

[0041] According to any embodiment of the second aspect of the present invention, the method for measuring the heat generation of thermal runaway in a lithium-ion battery releases the ejected material through the reserved hole and utilizes a transverse arrangement to reduce the impact of the ejection impact on the measurement results.

[0042] By setting up pre-drilled holes to release the ejected material, and combining this with a transverse arrangement to deviate the ejection direction from the weighing direction, interference from the ejection symmetry can be reduced, while ensuring a smooth ejection process, thereby improving measurement stability and accuracy.

[0043] Preferably, the reserved hole is only set at the position corresponding to the safety valve, and the remaining area is completely covered by heat insulation material.

[0044] Based on the above method, this invention further calculates the total heat generated by thermal runaway of lithium-ion batteries. The total heat generated includes the heat generated by the battery cell itself and the heat carried by the ejected gas. The calculation method is as follows: Q = Q cell + Q gas Wherein, the heat Q of the battery cell body cellThe heat of the ejected gas, Q, is determined based on cell mass and temperature changes. gas Determined based on changes in gas mass and gas temperature.

[0045] Furthermore, the heat generated by the battery cell body and the heat generated by the ejected gas are calculated as follows: Q cell = c × m2 × T avg - c × m1 × T1 - q × t Q gas = c gas × m gas ×ΔT gas in, Q represents the total heat generated during battery thermal runaway; Q cell The heat generated by the battery cell itself; Q gas The heat carried by the ejected gases; c represents the specific heat capacity of the battery cell; m1 is the mass of the cell before the experiment; m2 is the mass of the battery cell when it reaches its peak temperature; T1 is the temperature of the battery cell before the experiment; T avg This represents the overall average temperature at the peak of thermal runaway in the battery cell. q represents the power of the heating element; t is the thermal runaway trigger time; c gas The specific heat capacity of the ejected gas; m gas Mass of the ejected gas; ΔT gas This represents the temperature change of the ejected gas.

[0046] Any embodiment of any aspect of the present invention can be combined with other embodiments without contradiction. Furthermore, in any embodiment of any aspect of the present invention, any technical feature can be applied to the same technical feature in other embodiments without contradiction.

[0047] Without causing contradictions, any technical feature of any aspect or embodiment of the present invention is equally applicable to any other embodiment or embodiment of any other aspect. Of course, when applicable to each other, appropriate modifications may be made to the corresponding features as necessary. The various aspects and features of the present invention are further described below.

[0048] 3. Beneficial effects Compared with existing known technologies, the technical solution provided by this invention has the following beneficial effects: (1) The lithium-ion battery thermal runaway heat generation measurement device of this application, by insulating the battery cell and setting a reserved hole at the safety valve position, effectively suppresses heat loss to the environment while ensuring normal pressure relief during battery thermal runaway, thereby improving the heat retention capacity of the measurement system. At the same time, by placing the battery cell horizontally on the electronic balance and fixing the battery cell with a limiting structure, the impact force generated by the battery during thermal runaway does not act on the weighing direction of the electronic balance, thereby reducing the interference of the impact on the weighing results and improving the stability and accuracy of mass measurement. Therefore, this device can simultaneously achieve heat loss suppression and weighing stability control during thermal runaway testing, providing a reliable experimental basis for subsequent heat generation measurement.

[0049] (2) The lithium-ion battery thermal runaway heat generation measurement method of this application acquires battery mass change and temperature change data simultaneously during thermal runaway, and calculates the total heat generation of battery thermal runaway based on the coupling relationship between mass and temperature. Compared with methods that rely solely on temperature measurement or simulation calculation, this method can more realistically reflect the actual heat release of the battery during thermal runaway. Furthermore, by considering the heat carried by the gas generated during thermal runaway in the heat generation calculation, it effectively compensates for the calculation deviation caused by ignoring the heat of the gas in the prior art, thereby improving the accuracy and reliability of thermal runaway heat generation assessment.

[0050] Therefore, the method of the present invention can achieve direct measurement and accurate evaluation of the heat generated by battery thermal runaway without the need for complex simulation models. Attached Figure Description

[0051] Figure 1 This is a schematic diagram of the overall structure of the lithium-ion battery thermal runaway heat generation measurement device in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the thermal insulation coating component and the battery cell under test in an embodiment of the present invention; Figure 3 This is a schematic diagram of the electronic balance and fixture structure in an embodiment of the present invention; Figure 4 This is a schematic diagram of the temperature distribution of the battery cell in the large-area direction in an embodiment of the present invention.

[0052] in: 1. Insulation material; 2. Balance; 2-1. Weighing pan; 2-2. Balance body; 3. Clamp; 4. Insulation shell; 5. Insulation cover; 6. Hole; 7. Battery cell to be tested; 8. Block. Detailed Implementation

[0053] The present invention will be further described below with reference to specific embodiments.

[0054] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0055] like Figures 1 to 3 As shown, the present invention provides a lithium-ion battery thermal runaway heat generation measurement device, including an electronic balance 2, a load-bearing component, an insulation coating component, a thermal runaway triggering component, a temperature acquisition component, and a limiting component.

[0056] To facilitate understanding of the technical solution of the present invention, the functional components are described as follows in this embodiment: In this embodiment, the bearing component is specifically a weighing pan 2-1 set on the electronic balance 2, which is used to bear the battery cell 7 to be tested. In this embodiment, the limiting component is specifically a blocking block 8 disposed on the weighing pan 2-1, which is used to limit the displacement of the battery cell during thermal runaway. In this embodiment, the heat insulation covering assembly specifically includes a heat insulation shell 4 and a heat insulation cover 5, which work together to cover the battery cell. In this embodiment, the thermal runaway triggering component is specifically a heating element (not shown in the accompanying drawings) disposed inside the battery cell. In this embodiment, the temperature acquisition component is specifically a temperature sensor (not shown in the accompanying drawings) arranged on the surface and / or inside the battery cell.

[0057] It should be noted that the heating element and temperature sensor not shown in the accompanying drawings can be implemented using conventional structures in the art, and their specific installation methods do not constitute a limitation of the present invention.

[0058] Example 1 In this embodiment, the battery cell 7 to be tested is placed on the weighing pan 2-1 and fixed by the clamp 3 to keep the battery cell stable during the test.

[0059] The battery cell 7 is arranged horizontally, meaning its large surface is substantially parallel to the bearing surface of the weighing pan 2-1. This arrangement ensures that the ejection direction of the battery cell safety valve is not parallel to the weighing-sensitive direction of the electronic balance 2, thereby preventing the impact force generated during thermal runaway from being transmitted along the weighing direction and reducing interference with the weighing results. In this embodiment, the ejection direction of the safety valve is preferably perpendicular to the weighing direction of the electronic balance.

[0060] like Figure 2As shown, the thermal insulation covering assembly includes an thermal insulation shell 4 and an thermal insulation cover 5, which together form a closed space adapted to the shape of the battery cell for covering the battery cell. The thermal insulation covering assembly covers the rest of the outer surface of the battery cell except for the position corresponding to the safety valve. A hole 6 is provided at the position corresponding to the safety valve to ensure that the ejected gas can be released smoothly during thermal runaway.

[0061] The insulation material 1 can be one or more of ceramic fiber cotton, aerogel, or nano-insulation materials to reduce heat loss to the outside.

[0062] The thermal runaway triggering component employs a heating element disposed inside the battery cell to trigger thermal runaway. Preferably, the heating element is positioned at the center of mass of the battery cell casing, so that thermal runaway occurs from the central region inside the battery cell. The size and power of the heating element can be selected according to the battery cell specifications, for example: The heating element measures 35 mm × 35 mm. The heating power is 200 W.

[0063] The temperature acquisition component includes multiple temperature sensors, which are respectively arranged on the surface and inside the battery cell to record the temperature changes of the battery cell in real time during the thermal runaway process.

[0064] A blocking block 8 is installed on the weighing pan 2-1 to limit the battery cell when thermal runaway occurs, thereby preventing significant displacement of the battery cell and ensuring the stability of the mass measurement.

[0065] Example 2 Based on Example 1, the insulation material 1 adopts a composite structure of aerogel and ceramic fiber cotton to further improve the insulation performance.

[0066] The heat insulation shell 4 and the heat insulation cover 5 are connected by bolts to improve sealing and reduce heat leakage.

[0067] The size of the hole 6 is matched with the opening size of the battery cell safety valve, which is 20 mm × 30 mm, in order to reduce additional heat loss while ensuring smooth gas release.

[0068] Example 3 Based on Example 1, the temperature sensor further includes: A surface temperature sensor is located in the center area of ​​the battery cell surface, and an internal temperature sensor is located at the center of mass of the battery cell cascade.

[0069] By using the above arrangement, the spatial distribution of cell temperature can be obtained, which can then be used to calculate the overall average temperature of the cell.

[0070] Example 4 The method for measuring the heat generation during thermal runaway of a lithium-ion battery using the above-mentioned device includes the following steps: First, place the battery cell 7 to be tested inside the heat insulation shell 4, and align the battery cell safety valve with the corresponding hole 6; then install the heat insulation cover 5 to form a heat insulation wrapped state for the battery cell. Then, the battery cell is placed horizontally on the weighing pan 2-1 of the electronic balance 2 and fixed by the clamp 3, while the blocking block 8 is used to limit the movement of the battery cell. The temperature acquisition component is activated to record the cell temperature in real time. Thermal runaway in the battery cell is triggered by a heating element located inside the cell. During thermal runaway, the cell's mass and temperature changes are recorded in real time. Finally, the total heat generated by thermal runaway of the battery cell is calculated based on the recorded mass and temperature change data.

[0071] Heat generation calculation method: Due to the arrangement characteristics of the current collector inside the battery cell, the heat conduction of the battery cell is faster and the temperature difference is smaller in the non-large surface direction. Therefore, it can be approximated that the temperature distribution of the battery cell is mainly along the large surface direction. By integrating the temperature distribution, the overall average temperature of the battery cell can be obtained.

[0072] Based on the above measurement data, the total heat generated by battery thermal runaway can be expressed as the sum of the heat generated by the cell itself and the heat generated by the ejected gases, that is: Q = Q cell + Q gas Wherein, the heat Q of the battery cell body cell The heat of the ejected gas, Q, is determined based on cell mass and temperature changes. gas Determined based on changes in gas mass and gas temperature.

[0073] Furthermore, the heat generated by the battery cell body and the heat generated by the ejected gas are calculated as follows: Q cell = c × m2 × T avg - c × m1× T1- q × t=1.1 × 1.2 × 350 - 1.1 ×1.5 × 25 - 0.2 × 50=410.75 kJ Q gas = c gas × m gas ×ΔT gas =4 × 0.03 × 250 = 30 kJ Q = Q cell + Q gas = 410.75 kJ + 30 kJ = 440.75 kJ in, Q represents the total heat generated during battery thermal runaway; Q cell The heat generated by the battery cell itself; Q gas The heat carried by the ejected gases; c represents the specific heat capacity of the battery cell; m1 is the mass of the cell before the experiment; m2 is the mass of the battery cell when it reaches its peak temperature; T1 is the temperature of the battery cell before the experiment; T avg This represents the overall average temperature at the peak of thermal runaway in the battery cell. q represents the power of the heating element; t is the thermal runaway trigger time; c gas The specific heat capacity of the ejected gas; m gas Mass of the ejected gas; ΔT gas This represents the temperature change of the ejected gas.

[0074] The above calculation results are used to characterize the total heat released during battery thermal runaway, and can be used in scenarios such as battery thermal diffusion analysis, selection of thermal insulation materials, and parameter input for thermal safety simulation models.

[0075] Comparative Example 1 The battery cell was placed vertically on the electronic balance, and the other conditions were the same as in Example 1.

[0076] Experimental results show that during thermal runaway eruption, the mass measurement fluctuates significantly due to the impact force of the eruption acting along the weighing direction, with a measurement error of 18%.

[0077] Comparative Example 2 The test was conducted without the thermal insulation covering component, and all other conditions were the same as in Example 1.

[0078] Experimental results show that due to the large amount of heat loss to the environment, the calculated heat production is significantly lower, with a deviation of 21%.

[0079] Comparative Example 3 The heat generation is calculated based solely on the temperature rise of the battery cell, without considering the heat carried by the ejected gas.

[0080] Experimental results show that the total heat production obtained by this method is lower than the actual value, with an error of 5.6%.

[0081] In summary, this invention effectively reduces the impact of impact forces on the scalar measurement results during thermal runaway by arranging the battery cell under thermal insulation and ensuring that the direction of its safety valve ejection is not parallel to the weighing sensitivity direction of the electronic balance. Simultaneously, the thermal insulation structure reduces heat loss to the environment. Based on this, and by simultaneously measuring changes in cell mass and temperature, and further considering the heat carried by the ejected gases, a relatively accurate measurement of the total heat generated during thermal runaway of lithium-ion batteries is achieved. This device has a simple structure, is easy to implement, and provides reliable measurement results, offering effective data support for battery safety assessment, thermal management design, and the determination of relevant simulation model parameters.

[0082] It should be noted that the above embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Those skilled in the art can make various modifications or equivalent substitutions to the present invention without departing from the technical concept of the present invention, and all such modifications or substitutions should fall within the scope of protection of the present invention.

Claims

1. A device for measuring the heat generated during thermal runaway of a lithium-ion battery, characterized in that, include: Electronic balance; A support assembly for placing the battery cell under test is provided on the electronic balance, and the battery cell under test is placed in a horizontal position. A thermal insulation covering assembly is provided to cover the outside of the battery cell under test. The thermal insulation covering assembly has a reserved hole at the position corresponding to the safety valve of the battery cell under test. Thermal runaway triggering component; Temperature acquisition component; Limiting components; The safety valve ejection direction of the battery cell under test is not parallel to the weighing sensitive direction of the electronic balance, so as to reduce the impact of the ejection impact on the symmetry.

2. The lithium-ion battery thermal runaway heat generation measuring device according to claim 1, characterized in that, The direction of the safety valve's ejection is perpendicular to the weighing direction of the electronic balance.

3. The lithium-ion battery thermal runaway heat generation measuring device according to claim 1, characterized in that, The bearing component includes a weighing pan, and the limiting component includes a blocking structure for limiting the displacement of the battery cell.

4. The lithium-ion battery thermal runaway heat generation measuring device according to claim 1, characterized in that, The thermal insulation covering component covers the remaining outer surface of the battery cell under test, except for the reserved hole.

5. The lithium-ion battery thermal runaway heat generation measuring device according to claim 1, characterized in that, The thermal insulation covering component is composed of one or more of ceramic fiber cotton, aerogel, or nano-insulation materials.

6. The lithium-ion battery thermal runaway heat generation measuring device according to claim 1, characterized in that, The thermal runaway triggering component includes a heating element disposed inside or outside the battery cell under test.

7. The lithium-ion battery thermal runaway heat generation measuring device according to claim 1, characterized in that, The temperature acquisition component includes a temperature sensor for measuring the cell temperature and / or the temperature of the ejected gas.

8. A method for measuring the heat generated during thermal runaway of a lithium-ion battery, characterized in that, include: Place the battery cell under test inside the heat insulation covering assembly and ensure that the safety valve corresponds to the reserved hole; The battery cell to be tested is placed horizontally on the electronic balance, and the direction of the safety valve of the battery cell is not parallel to the weighing direction of the electronic balance. This triggers thermal runaway in the battery cell under test. Record the changes in cell mass and temperature during thermal runaway; The total heat generated by thermal runaway is calculated based on the mass and temperature changes.

9. The method for measuring the heat generated by thermal runaway of a lithium-ion battery according to claim 8, characterized in that, The total heat generated by thermal runaway includes the heat from the battery cell itself and the heat from the ejected gas.

10. The method for measuring the heat generated by thermal runaway of a lithium-ion battery according to claim 9, characterized in that, The heat generated by the ejected gas is determined based on the mass of the ejected gas, the specific heat capacity of the gas, and the temperature rise of the gas.

11. The method for measuring the heat generated by thermal runaway of a lithium-ion battery according to claim 8, characterized in that, The heat capacity of the battery cell is determined based on the cell mass, average temperature rise, and specific heat capacity.

12. The method for measuring the heat generated by thermal runaway of a lithium-ion battery according to claim 8, characterized in that, The ejecta is released through the pre-reserved holes, and the horizontal arrangement reduces the impact of the ejection impact on the symmetry results.

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