A battery cell thermal runaway test device

Abstract

A battery cell thermal runaway test device includes a test seal, an isolator, a test assembly, and an adjustment assembly. The isolator is disposed in the inner cavity of the test seal and divides the inner cavity of the test seal into a test space and an adjustment space that are sealed to each other. The test space is used to place batteries for thermal runaway testing. The test assembly is disposed on the test seal and is used to perform battery cell thermal runaway testing. The adjustment assembly is disposed in the adjustment space and is used to drive the isolator to move in the inner cavity of the test seal to change the volume of the test space. When performing a battery cell thermal runaway test, the volume of the test space is first controlled by controlling the movement of the isolator through the adjustment assembly, thereby setting the volume of the test space of different sizes according to different models of batteries. After that, the test battery is placed in the test space and the battery cell thermal runaway test is performed through the test assembly.

Description

Technical Field

[0001] The present application relates to the technical field of thermal runaway testing, and in particular to a battery cell thermal runaway testing device. Background Art

[0002] In order to adapt to market demand, the types of lithium-ion battery cells are constantly increasing, and the cell capacity has increased from a few ampere-hours to hundreds of ampere-hours or even thousands of ampere-hours. As a result, the safety risk of the battery cells increases. When the battery is in thermal runaway, a large amount of gas will be generated, and a large amount of gas can easily cause the battery pack to swell or even cause the battery pack to explode. Therefore, in the battery pack production process, it is particularly important to evaluate the safety performance of lithium-ion batteries.

[0003] When conducting thermal runaway tests on batteries, the safety of batteries of different types and capacities is evaluated. The batteries are subjected to thermal abuse, electrical abuse, mechanical abuse, etc. to cause the batteries to fail and cause thermal runaway. The safety performance of the battery is estimated by recording and evaluating various characterization data of battery failure. At present, there are two ways to test thermal runaway of battery packs. One way is to use a simple simulation device to test the thermal runaway of the battery pack. Although this method is low in cost, it cannot truly reflect the thermal runaway state of the battery pack, resulting in poor overall test results. The other way is to use the battery pack for thermal runaway testing. This method can truly reflect the thermal runaway state of the battery pack. Commonly used equipment includes ARC. However, the test space of the tank is limited, and it is difficult to evaluate the safety performance of large-capacity batteries such as 150Ah. Researchers usually test the thermal runaway of batteries in sealed tanks to study the temperature, voltage, gas production and gas composition after the thermal runaway of the batteries to further study the safety performance of the batteries.

[0004] Therefore, when using ARC equipment to conduct thermal runaway experiments, the volume of the test tank is certain. A small-capacity test tank is difficult to accommodate the size of a large-capacity battery cell, and a large-capacity test tank is difficult to ensure the accuracy of the small-capacity battery cell test, and they are not compatible. Utility Model Content

[0005] The present application provides a battery cell thermal runaway test device that can be compatible with testing small-capacity and large-capacity batteries.

[0006] According to one aspect of the present application, an embodiment provides a battery cell thermal runaway test device, comprising:

[0007] A test seal, wherein an isolator is disposed in the inner cavity of the test seal, and the isolator is used to separate the inner cavity of the test seal into a test space and an adjustment space that are sealed from each other, the test space is used to place a battery for testing, and a test assembly is disposed on the test seal, and the test assembly is used to perform a thermal runaway test on a battery cell; and

[0008] An adjusting component is arranged in the adjusting space and is used to drive the isolating component to move in the inner cavity of the test sealing component to change the volume of the test space.

[0009] In another embodiment, the test seal includes a sealed tank body, a top cover and a locking piece. The sealed tank body is configured as a vertical structure with an opening on the top. The top cover is used to close the top opening of the sealed tank body. The locking piece is used to connect the top cover and the sealed tank body to ensure the sealing of the inner cavity of the test seal.

[0010] In another embodiment, an elastic sealing member is provided between the top of the sealed tank body and the top cover, and the elastic sealing member is kept in a compressed state by the locking member.

[0011] In another embodiment, a embedding groove is provided on the top of the sealed tank body or / and the side of the top cover close to each other, and the embedding groove is used to place the elastic sealing member.

[0012] In another embodiment, the top cover is hinged to the sealed tank body.

[0013] In another embodiment, there are at least two groups of locking members distributed along the circumference of the sealed tank body, including a telescopic portion and a locking portion, the locking portion is fixed on the top cover, the telescopic portion includes a connecting end connected to the sealed tank body, a locking end locked in the locking portion, and a telescopic section connecting the connecting end and the locking end, the telescopic section is used to adjust the distance between the connecting end and the locking end.

[0014] In another embodiment, the telescopic section is configured as a thread group structure.

[0015] In another embodiment, a sliding seal is provided between the isolation member and the inner cavity of the test seal, the isolation member can be raised and lowered and moved on the test seal through the adjustment assembly, and the sliding seal is used to ensure the sealing between the isolation member and the inner cavity of the test seal.

[0016] In another embodiment, the test assembly includes a heating module, a temperature collection module, an air pressure collection module and a pressure relief component. The heating module is used to heat the battery cell, and the temperature collection module is used to collect temperature data of the battery cell and the gas inside the test space in real time; the air pressure collection module can record the air pressure data in real time; the pressure relief component is arranged on the top cover to discharge the gas out of the sealed tank.

[0017] In another embodiment, a plurality of test interfaces and gas interfaces are provided on the top cover, wherein the test interface is used to introduce a test line into the inner cavity of the sealed tank body, and the test line is used for the test assembly to perform cell testing; and the gas interface is used to evacuate the test space and introduce inert gas.

[0018] According to the battery cell thermal runaway test device of the above embodiment, a test seal and an isolating member movably arranged in the inner cavity of the test seal are adopted, and the inner cavity of the test seal is separated into a test space and an adjustment space that are sealed to each other by the isolating member. The movement of the isolating member is controlled by an adjustment component arranged in the adjustment space, thereby controlling the volume of the test space, so that the volume of the thermal runaway test seal can be adjusted, so that the volume of the test space of different sizes can be set according to different types of batteries, and it can be compatible with testing small-capacity and large-capacity batteries, thereby improving the accuracy of testing the total amount of gas and the proportion of gas production components after large-capacity thermal runaway of small-capacity batteries, and reducing the cost of making sealed test tanks of different specifications according to battery cell models. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the overall structure of a battery cell thermal runaway test device in an embodiment;

[0020] Figure 2 This is a schematic diagram of the structure of the inner cavity of a sealed tank in one embodiment;

[0021] Figure 3 The figure is a schematic diagram of the structure of the connection between the sealed tank body and the top cover in one embodiment.

[0022] Figure numerals: 1. test seal; 11. sealed tank body; 111. test space; 112. adjustment space; 12. top cover; 13. locking piece; 131. threaded column; 132. chuck; 133. positioning block; 134. positioning notch; 14. elastic seal; 15. embedding groove; 2. isolation piece; 3. adjustment assembly; 4. test assembly. DETAILED DESCRIPTION

[0023] The present application is further described in detail below by specific embodiments in conjunction with the accompanying drawings. Wherein similar elements in different embodiments adopt associated similar element numbers. In the following embodiments, many detailed descriptions are intended to enable the present application to be better understood. However, those skilled in the art can easily recognize that some of the features can be omitted in different situations, or can be replaced by other elements, materials, and methods. In some cases, some operations related to the present application are not shown or described in the specification, in order to avoid the core part of the present application being overwhelmed by too much description, and for those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations based on the description in the specification and the general technical knowledge in the art.

[0024] In addition, the features, operations or characteristics described in the specification can be combined in any appropriate manner to form various implementations, and the operation steps involved in each embodiment can also be replaced or adjusted in a sequence in a manner that is obvious to those skilled in the art. Therefore, the specification and drawings are only for the purpose of clearly describing a certain embodiment and do not mean that the composition and / or sequence are necessary.

[0025] The serial numbers of the components in this document, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in this application, unless otherwise specified, include direct and indirect connections (couplings).

[0026] At present, there are two ways to test the thermal runaway of battery packs. One way is to use a simple simulation device to test the thermal runaway of the battery pack. Although this method is low-cost, it cannot truly reflect the thermal runaway state of the battery pack, resulting in poor overall test results. The other way is to use the battery pack for thermal runaway testing. This method can truly reflect the thermal runaway state of the battery pack. Commonly used equipment includes ARC, etc. However, the ARC tank test space is limited, and it is difficult to evaluate the safety performance of large-capacity batteries. Researchers usually test the thermal runaway of batteries in sealed tanks to study the temperature, voltage, gas production and gas production composition after the thermal runaway of the batteries to further study the safety performance of the batteries. Therefore, when conducting thermal runaway experiments, the volume of the test tank is fixed. The small-capacity test tank is difficult to accommodate the size of the large-capacity battery, and the large-capacity test tank is difficult to ensure the accuracy of the small-capacity battery test, and they are not compatible.

[0027] The present application provides a battery cell thermal runaway testing device, which has an adjustable test space 111 and sets the volume of the test space 111 of different sizes according to different types of batteries, and can be compatible with testing small-capacity and large-capacity batteries. It is used to test the air pressure value and gas composition analysis of thermal runaway of battery cells of different types, and can ensure that small-capacity test batteries also have a certain measurement accuracy in the test tank.

[0028] Please refer to Figure 1 and Figure 2 In one embodiment, a battery cell thermal runaway test device is provided, including a test seal 1, an isolator 2, a test assembly 4 and an adjustment assembly 3. The isolator 2 is arranged in the inner cavity of the test seal 1, and divides the inner cavity of the test seal 1 into a test space 111 and an adjustment space 112 which are sealed with each other. The test space 111 is used to place the battery for thermal runaway test; the test assembly 4 is arranged on the test seal 1, and is used to perform a battery cell thermal runaway test; the adjustment assembly 3 is arranged in the adjustment space 112, and is used to drive the isolator 2 to move in the inner cavity of the test seal 1 to change the volume of the test space 111. When performing a battery cell thermal runaway test, the isolator 2 is first controlled to move and control the volume of the test space 111 through the adjustment assembly 3, so that the volume of the test space 111 of different sizes is set according to different models of batteries, and then the test battery is placed in the test space 111 and the battery cell thermal runaway test is performed through the test assembly 4.

[0029] In the embodiment of the present application, due to the use of a test seal 1 and an isolating member 2 movably arranged in the inner cavity of the test seal 1, the inner cavity of the test seal 1 is separated into a test space 111 and an adjustment space 112 that are sealed to each other by the isolating member 2, and the movement of the isolating member 2 is controlled by an adjustment component 3 arranged in the adjustment space 112, thereby controlling the volume of the test space 111, so that the volume of the thermal runaway test seal is adjustable, so that the volume of the test space 111 of different sizes can be set according to different models of batteries, and it is compatible with testing small-capacity and large-capacity batteries, thereby improving the accuracy of testing the total amount of gas and the proportion of gas production components after large-capacity thermal runaway of small-capacity batteries; and reducing the cost of producing sealed test tanks of different specifications according to battery models.

[0030] Please refer to Figure 1 and Figure 2 The test seal 1 includes a sealed tank body 11, a top cover 12 and a locking member 13. The sealed tank body 11 is a vertical structure with an opening at the top. The sealed tank body 11 is a cylindrical tank body. The top cover 12 is used to close the top opening of the sealed tank body 11. The locking member 13 is used to connect the top cover 12 and the sealed tank body 11 to ensure the sealing of the inner cavity of the test seal 1. Please refer to Figure 3An elastic seal 14 is provided between the top of the sealed tank body 11 and the top cover 12 , and the elastic seal 14 is kept in a compressed state by a locking member 13 ; in the embodiment of the present application, the elastic seal 14 is an O-ring.

[0031] Further, please refer to 3, the elastic seal 14 can be adhered and fixed on the top cover 12, and a embedding groove 15 is provided on the top of the sealed tank body 11. The embedding groove 15 is used to embed the elastic seal 14 to prevent the top cover 12 from being offset, which is convenient for the top cover 12 to be sealed, and the depth of the embedding groove 15 is less than the height of the elastic seal 14, which is convenient for the top cover 12 to press the elastic seal 14 to achieve sealing. In other embodiments, the embedding groove 15 is provided on the top cover 12, and the elastic seal 14 is adhered and fixed on the top of the sealed tank body 11. The embedding groove 15 can also be provided on the top of the top cover 12 and the top of the sealed tank body 11 to increase the assembly accuracy of the top cover 12 and the sealed tank body 11.

[0032] In the embodiment of the present application, the inner wall of the sealed tank body 11 is set to be a material that is resistant to high temperature and high pressure and is not easily corroded by the electrolyte, such as stainless steel and nickel-plated, and the test tank body thickness is ≥5mm, the tank body diameter is 50mm-300mm, and the tank body height is 200-1000mm. The use of a large-sized sealed tank body 11 can not only meet the requirements of high-capacity battery cell testing, but also can adjust the volume of the test space 111 in the sealed tank body 11 by adjusting the component 3, and can also ensure more accurate test data when testing the thermal runaway test pressure and gas composition analysis of small-capacity battery cells.

[0033] For further information, please refer to Figure 1 The top cover 12 is hingedly arranged with the sealed tank body 11, so that the two can be flipped and connected by a hinge. At the same time, the top cover 12 does not need to be stored in the top cover 12, so that the top cover 12 can close the opening of the sealed tank body 11 at any time. There are at least two groups of locking members 13 distributed along the circumference of the sealed tank body 11, including a telescopic part and a locking part. In the embodiment of the present application, seven groups of locking members 13 are arranged. Except for the hinged position of the top cover 12, multiple locking members 13 are evenly distributed along the circumference. The locking part is fixed on the top cover 12, and the telescopic part includes a connecting end connected to the sealed tank body 11, a locking end locked in the locking part, and a telescopic section connecting the locking end and the connecting end, and the telescopic section is used to adjust the distance between the connecting end and the locking end.

[0034] Specifically, in the embodiment of the present application, the telescopic section is configured as a threaded group structure, namely, a threaded column 131 and a chuck 132 that are threadedly connected to each other, the end of the threaded column 131 away from the chuck 132 is a connecting end, and the connecting end is provided with a hinge seat fixed to the outside of the sealed tank body 11, the connecting end is hinged to the sealed tank body 11 through the hinge seat, and the hinge axis of the connecting end is horizontally arranged; the chuck 132 is configured as a clamping end of the telescopic part, the chuck 132 is coaxially threadedly connected to the threaded column 131, the clamping part adopts a clamping block 133 provided with a clamping notch 134, the clamping notch 134 is used to clamp the threaded column 131 between the connecting end and the clamping end, the chuck 132 is tightly against the upper end surface of the clamping part, and the top cover 12 is pressed and fixed on the sealed tank body 11 by the rotation of the chuck 132, so as to realize the sealing between the sealed tank body 11 and the top cover 12.

[0035] Please refer to Figure 2 , a sliding seal is provided between the isolator 2 and the inner cavity of the test seal 1, and the isolator 2 can be lifted and moved in the test seal 1 through the adjustment component 3, and the sliding seal is used to ensure the seal between the isolator 2 and the inner cavity of the test seal 1. In the embodiment of the present application, the isolator 2 adopts a partition of the same material as the sealed tank body 11, which is equivalent to the bottom plate of the test space 111, and the sliding seal can adopt a sliding sealing ring to maintain the airtightness between the two spaces when the partition is lifted and lowered along the inner cavity of the sealed tank body 11. The adjustment component 3 in the embodiment of the present application can adopt hydraulic equipment. In other embodiments, a cylinder, a motor screw combination, and other structures that can drive the partition to lift can also be adopted. Through a liftable hydraulic device, it is used to push the partition to change the height of the partition in the sealed tank body 11, thereby changing the volume of the test space 111.

[0036] Thermal runaway testing of lithium-ion batteries usually requires collecting the temperature and voltage of the battery cells, heating or charging the battery, etc. Further analysis requires vacuuming, passing inert gas, air pressure data collection, gas composition analysis, etc. The test tank needs to be able to simultaneously connect to multiple test equipment such as temperature, voltage, and heating sources. The use of this technology can not only reduce the cost of preparing multiple sealed tanks of different models, but also reduce the test time wasted due to the need to reconnect multiple test lines and acquisition lines due to the replacement of the test tank body.

[0037] In the embodiment of the present application, the test component 4 includes a heating module, a temperature collection module, an air pressure collection module and a pressure relief component. The heating module is arranged in the test space 111 and is used to heat the battery cell. The temperature collection module adopts a thermocouple or a temperature sensor to collect the temperature data of the battery cell and the gas inside the test space 111 in real time; the air pressure collection module adopts an air pressure sensor, and the air pressure sensor is installed on the top cover 12 to record the air pressure data in real time; the pressure relief component is arranged on the top cover 12, and the pressure relief component includes a pressure relief valve and a safety valve for gas discharge and safety settings.

[0038] Specifically, the top cover 12 is provided with a plurality of test interfaces and gas interfaces. The test interface is used to introduce the test line into the inner cavity of the sealed tank body 11. The test line is connected to the thermocouple, voltage test line, heating line, charge and discharge line, etc. for battery cell testing. To ensure the sealing of the test device, an aviation plug or other interface can be used for connection. The gas interface is used to evacuate the test space 111 and introduce inert gas. The gas interface is provided with an airflow regulating valve for controlling the airflow, and all gas interfaces are provided with a filter for dust filtering.

[0039] In other embodiments, the specific configuration of the test component 4 may be assembled according to specific circumstances, and testing may also be performed in the test seal 1 through other test components 4 .

[0040] When conducting a thermal runaway test of a battery cell, a sealed tank 11 with a volume of 30L was used to test a 100Ah lithium iron phosphate battery thermal runaway test. The barometer range accuracy of the sealed tank 11 was 0.001Mpa. The test first evacuated the inside of the tank, then introduced inert gas, started the heating module for testing, and recorded the battery cell temperature, ambient temperature, voltage, air pressure and other data during the test. The peak air pressure of the test was 0.328MPa, and the air pressure value after the gas was cooled was 0.189MPa. The gas composition was tested using GCMS, in which the proportion of inert gas was 66.18%, and the proportion of gas production was 33.82%. The sealed tank 11 was used to test a 5Ah 21700 ternary battery cell, in which the peak air pressure was 0.679MPa, and the stable value of the air pressure after cooling was 0.021MPa, in which the proportion of inert gas was 88.46%, and the proportion of gas production was 11.54%. The gas-producing component C was not detected 3 H 6 and C 5 H 12 The thermal runaway of 100Ah battery cells cannot be tested using the 3.5L sealed tank 11. The thermal runaway of 5Ah ternary battery cells of the same batch of 21700 batteries can be tested using this device. The inert gas ratio is 26.16% and the gas production ratio is 73.84%. The C 5 H 12 , and 0.01% C 3 H 6 Therefore, the test accuracy of this type of battery in a small-capacity sealed tank 11 is higher, and gas components with extremely low contents can be measured. Therefore, by using the battery cell thermal runaway test device of the present application and adjusting the small-volume test space 111 according to the small-capacity battery cell, a higher-precision test result can be obtained.

[0041] The above specific examples are used to illustrate the present invention, which are only used to help understand the present invention and are not intended to limit the present invention. For those skilled in the art of the present invention, some simple deductions, deformations or substitutions can be made based on the idea of ​​the present invention.

Claims

1. A battery cell thermal runaway test device, characterized in that: include: A test seal (1), wherein an isolating member (2) is disposed in an inner cavity of the test seal (1), and the isolating member (2) is used to separate the inner cavity of the test seal (1) into a test space (111) and an adjustment space (112) that are sealed from each other, the test space (111) being used to place a battery for testing, and a test assembly (4) is disposed on the test seal (1), and the test assembly (4) is used to perform a thermal runaway test on a battery cell; as well as An adjustment component (3), the adjustment component (3) is arranged in the adjustment space (112) and is used to drive the isolation component (2) to move in the inner cavity of the test seal (1) to change the volume of the test space (111).

2. The battery cell thermal runaway test device according to claim 1, characterized in that: The test seal (1) comprises a sealed tank body (11), a top cover (12) and a locking piece (13); the sealed tank body (11) is configured as a vertical structure with an opening at the top; the top cover (12) is used to close the top opening of the sealed tank body (11); and the locking piece (13) is used to connect the top cover (12) and the sealed tank body (11) to ensure the sealing of the inner cavity of the test seal (1).

3. The battery cell thermal runaway test device according to claim 2, characterized in that: An elastic sealing member (14) is provided between the top of the sealed tank body (11) and the top cover (12), and the elastic sealing member (14) is kept in a compressed state by the locking member (13).

4. The battery cell thermal runaway test device according to claim 3, characterized in that: A embedding groove (15) is provided on the top of the sealed tank body (11) or / and the side where the top cover (12) is close to each other, and the embedding groove (15) is used to place the elastic sealing member (14).

5. The battery cell thermal runaway test device according to any one of claims 2 to 4, characterized in that: The top cover (12) is hingedly connected to the sealed tank body (11).

6. The battery cell thermal runaway test device according to any one of claims 2 to 4, characterized in that: The locking member (13) has at least two groups distributed along the circumference of the sealed tank body (11), including a telescopic portion and a locking portion, wherein the locking portion is fixed to the top cover (12), and the telescopic portion includes a connecting end connected to the sealed tank body (11), a locking end locked in the locking portion, and a telescopic section connecting the connecting end and the locking end, wherein the telescopic section is used to adjust the distance between the connecting end and the locking end.

7. The battery cell thermal runaway test device according to claim 6, characterized in that: The telescopic section is arranged as a thread group structure.

8. The battery cell thermal runaway test device according to claim 1, characterized in that: A sliding seal is provided between the isolation member (2) and the inner cavity of the test seal (1); the isolation member (2) can be raised and lowered and moved on the test seal (1) through the adjustment assembly (3); and the sliding seal is used to ensure the sealing between the isolation member (2) and the inner cavity of the test seal (1).

9. The battery cell thermal runaway test device according to claim 2, characterized in that: The test assembly (4) comprises a heating module, a temperature collection module, an air pressure collection module and a pressure relief component. The heating module is used to heat the battery cell. The temperature collection module is used to collect temperature data of the battery cell and the gas inside the test space (111) in real time. The air pressure collection module can record air pressure data in real time. The pressure relief component is arranged on the top cover (12) and is used to discharge gas from the sealed tank body (11).

10. The battery cell thermal runaway test device according to claim 9, characterized in that: The top cover (12) is provided with a plurality of test interfaces and gas interfaces. The test interfaces are used to introduce test lines into the inner cavity of the sealed tank body (11), and the test lines are used for the test assembly (4) to perform cell testing. The gas interfaces are used to evacuate the test space (111) and introduce inert gas.

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