Battery module detection device

Abstract

The utility model belongs to the technical field of battery modules, and particularly relates to a battery module detection device. Comprising an object placing table configured to place a to-be-tested battery module, at least one elastic air bag configured to be used for replacing a part of battery cells in a module shell, and a pressure measuring unit configured to replace other parts of battery cells in the module shell so as to obtain expansion pressure borne by the battery cells at the replacement position, the testing assembly is installed on the object placing table, the testing assembly is configured to measure the deformation quantity of at least one end plate of the module shell in real time, the elastic air bag can expand to preset pressure and extrude towards the periphery so as to simulate thermal runaway gas expansion of the part of battery cells, and the pressure measuring unit measures the internal expansion pressure of the module shell. Different preset gas expansion pressures are applied to the interior of the battery cell by using the elastic air bag, the deformation quantity of the end plate of the module shell is measured through the test assembly, the ultimate bearing capacity of the module for resisting the gas pressure is obtained, and the structural reliability of the module shell when the battery is in thermal runaway is evaluated.

Description

Technical Field

[0001] The utility model belongs to the technical field of battery modules, and particularly relates to a battery module detection device. Background Art

[0002] With the rapid development of new energy vehicles and energy storage products, whether it is power batteries or energy storage batteries, lithium-ion batteries are widely used. Although people have higher and higher requirements for battery performance, battery safety is still an inescapable topic in the industry; and during the process of ensuring battery safety, the problem of battery thermal runaway has always attracted people's attention.

[0003] Thermal runaway refers to a chain reaction phenomenon triggered by various incentives. Thermal runaway is a cyclic process of positive energy feedback. The increasing temperature causes the system to heat up, and after the system heats up, the temperature further increases, which in turn makes the system hotter. Eventually, the large amount of heat and harmful gases emitted during battery thermal runaway cause the battery to catch fire and explode.

[0004] When a lithium-ion battery system undergoes thermal runaway, due to the violent occurrence of side reactions, a large amount of gas will accumulate inside the battery cell. Before the battery cell relieves pressure, the gas pressure is all loaded on the module end plate. Therefore, higher requirements are imposed on the reliability of the battery module; it is necessary to ensure that the ultimate bearing capacity of the module to resist gas pressure is higher than the pressure relief pressure of the battery cell, so as to ensure that the structure will not break and fail before the battery cell relieves pressure. For this reason, a battery module detection device is proposed. By simulating the battery thermal runaway working condition and testing the battery module, the maximum gas expansion pressure that the battery module can withstand during the thermal runaway of the battery cell is obtained, and the structural reliability of the battery module is evaluated. Summary of the Utility Model

[0005] The purpose of the utility model is to provide a battery module detection device, aiming to simulate the battery thermal runaway working condition and test the battery module, and evaluate the structural reliability of the module housing during the thermal runaway of the battery cell.

[0006] The utility model is realized as follows. The battery module detection device, wherein the battery module to be tested includes a module housing and multiple groups of battery cells arranged inside the module housing. The detection device includes:

[0007] A placement table configured to place the battery module to be tested;

[0008] An elastic airbag configured to be at least one and used to replace some of the battery cells inside the module housing. The elastic airbag can expand to a preset pressure and squeeze towards the surroundings to simulate the thermal runaway gas expansion of this part of the battery cells;

[0009] A pressure measurement unit configured to replace other parts of the battery cells inside the module housing to obtain the expansion pressure received by the battery cells at the replacement position;

[0010] The test component is installed on the placement table and is configured to measure in real time the deformation of at least one end plate of the module housing.

[0011] Preferably, the elastic airbag includes: an airbag body, an air inlet pipeline and an air outlet pipeline respectively communicating with the airbag body and used for connecting with an external air pressure control system, and a pressure relief valve arranged on the airbag body and configured to have an opening pressure equal to the air release pressure of the battery cell.

[0012] Preferably, two elastic airbags are configured, and are respectively arranged between the outermost battery cells of the module housing and the inner wall of the housing end plate located outside the outermost battery cells along the arrangement direction of the battery cells.

[0013] Preferably, the test component includes:

[0014] A guiding unit installed on the placement table;

[0015] A moving frame body, which is movably installed on the guiding unit and is at least one; it is configured to be movable along the guiding unit to the side of the module housing to be tested and then fixed to the guiding unit;

[0016] A testing unit installed on the moving frame body, which is configured to abut against the outer wall of the module housing through the moving frame body to measure in real time the deformation of the end plate of the module housing.

[0017] Preferably, the guiding unit includes:

[0018] At least one first guide rail, which is fixedly installed on the placement table and extends along a first direction;

[0019] At least one second guide rail, which is slidably connected to the at least one first guide rail and extends along a second direction, and the first direction and the second direction are perpendicular;

[0020] The moving frame body is slidably connected to the at least one second guide rail; fixation can be achieved between the first guide rail and the second guide rail, and between the moving frame body and the second guide rail through locking members.

[0021] Preferably, two first guide rails are arranged in parallel along the second direction, two second guide rails are arranged in parallel along the first direction, the two ends of the second guide rail are respectively slidably connected to the two first guide rails, the moving frame body is slidably connected to the second guide rail and is arranged in one-to-one correspondence with it, and the two moving frame bodies are configured to be distributed on both sides of the module housing to be tested.

[0022] Preferably, the testing unit includes: at least one displacement sensor arranged on the side of the moving frame body close to the module housing to be tested and used for abutting against the outer wall of the end plate of the module housing to be tested.

[0023] Preferably, the displacement sensor is configured as an LVDT sensor and multiple LVDT sensors are provided. The multiple LVDT sensors are distributed in a rectangular shape on one side of the moving frame close to the housing of the module to be measured.

[0024] Preferably, a first plate body and a second plate body are arranged in parallel along a first direction on the moving frame. The first plate body is configured to be attached to the outer wall of the end plate of the module housing; through holes corresponding to the displacement sensors one by one are formed through the first plate body; the testing unit further includes:

[0025] Mounting sleeves, fixedly installed on the second plate body and provided corresponding to the displacement sensors one by one, and configured to allow the ends of the displacement sensors to be inserted;

[0026] Elastic members, installed inside the mounting sleeves and configured to abut against the ends of the displacement sensors;

[0027] One end of the displacement sensor for contacting the outer wall of the module housing passes through the through hole, and the other end is inserted into the mounting sleeve and abuts against the elastic member.

[0028] Preferably, the pressure measuring unit includes:

[0029] Two attaching plates, arranged in parallel, and configured to be respectively attached to other battery cells on both sides of the position where the battery cell is to be replaced;

[0030] Connectors, connected to the opposite sides of the two attaching plates, and configured to be at least three;

[0031] A pressure sensor, installed between the two attaching plates, and configured to measure the pressure exerted on the battery cell at the replacement position.

[0032] Preferably, the connectors are configured as telescopic guide rails and are correspondingly distributed at the four corners of the attaching plates, and the pressure sensor is located at the middle position between the two attaching plates.

[0033] Preferably, the attaching plate includes a hard plastic plate and an alloy steel plate spliced by hard rubber. The two ends of the connector are respectively connected to the alloy steel plates of the two attaching plates, and the hard plastic plate is configured to contact other battery cells beside the position where the battery cell is to be replaced.

[0034] Compared with the prior art, the beneficial effects of the present utility model are as follows: First, place the battery cell module to be tested on the placement table, take out some battery cells inside the module casing, and place the elastic airbag at the position of these battery cells; then take out other battery cells and replace them with the pressure measurement unit; the elastic airbag can simulate the gas expansion during thermal runaway of some battery cells at the replacement position, so as to apply expansion pressure to other battery cells or the inner wall of the module casing. The expansion pressure loaded on the end plate of the module casing can impact the end plate of the module casing and cause its deformation; measure the expansion pressure inside the module casing through the pressure measurement unit, so that different preset gas expansion pressures can be applied to the inside of the module casing by the elastic airbag, and the deformation amount of the end plate of the module casing can be measured by the test assembly installed on the placement table, thereby obtaining the ultimate bearing capacity of the module to resist gas pressure, and further evaluating the structural reliability of the module casing during battery thermal runaway. Description of the Drawings

[0035] Figure 1 Stereoscopic structure diagram of the battery module detection device provided by the present utility model;

[0036] Figure 2 Stereoscopic structure diagram when the elastic airbag and the pressure measurement unit of the battery module detection device provided by the present utility model are installed in the module casing;

[0037] Figure 3 Stereoscopic structure diagram of the elastic airbag of the battery module detection device provided by the present utility model;

[0038] Figure 4 Stereoscopic structure diagram of the pressure measurement unit of the battery module detection device provided by the present utility model;

[0039] Figure 5 Side structure diagram of the battery module detection device provided by the present utility model;

[0040] Figure 6 Structural schematic diagram of the test assembly of the battery module detection device provided by the present utility model;

[0041] Figure 7 For Figure 1 Partial enlarged view at A in

[0042] In the drawings: 1 placement table, 2 elastic airbag, 21 airbag body, 22 inlet pipeline, 23 outlet pipeline, 24 pressure relief valve, 3 pressure measurement unit, 31 fitting plate, 311 hard plastic plate, 312 alloy steel plate, 32 connecting piece, 33 pressure sensor, 4 test assembly, 41 guiding unit, 411 first guide rail, 412 second guide rail, 413 locking piece, 42 moving frame body, 421 first plate body, 422 second plate body, 423 through hole, 43 test unit, 431 displacement sensor, 432 mounting sleeve, 5 module casing, 6 battery cell. Detailed implementation manners

[0043] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the following will further describe the specific technical solutions of the present application in detail with reference to the accompanying drawings in the embodiments of the present application. The following embodiments are used to illustrate the present application, but are not used to limit the scope of the present application.

[0044] In the embodiments of the present application, the terms "first" and "second" are only used for descriptive purposes, and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the embodiments of the present application, unless otherwise stated, the meaning of "a plurality" is two or more.

[0045] In addition, in the embodiments of the present application, orientation terms such as "upper", "lower", "left" and "right" are defined with respect to the orientation of the components shown in the accompanying drawings. It should be understood that these directional terms are relative concepts, and they are used for relative description and clarification, and they may change accordingly with the change of the orientation of the components placed in the accompanying drawings.

[0046] In the embodiments of the present application, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense. For example, "connection" may be a fixed connection, a detachable connection, or integrated; it may be directly connected, or indirectly connected through an intermediate medium.

[0047] In the embodiments of the present application, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, such that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, the element defined by the phrase "including one..." does not exclude the existence of additional identical elements in the process, method, article or device including such element.

[0048] In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design solution described as "exemplary" or "for example" in the embodiments of the present application should not be construed as being more preferred or more advantageous than other embodiments or design solutions. Rather, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific manner.

[0049] Combined with the prior art, thermal runaway refers to a phenomenon in which the battery current and internal temperature rise occur in a cumulative and mutually reinforcing manner, resulting in battery damage. The main factors causing thermal runaway of power lithium-ion batteries include external short circuit, external high temperature, and internal short circuit, etc.

[0050] In most cases of battery thermal runaway causing fires in recent years, it is mostly triggered by internal short circuit first. The heat and temperature create an external high-temperature environment for adjacent batteries, triggering thermal runaway of adjacent batteries, and then leading to a chain reaction of the entire PACK.

[0051] In a short period of time during the thermal runaway of the battery cell, a large amount of gas is generated during the intense reaction, and at the same time a large amount of heat is generated. The heat heats the gas, so that the battery cells that originally had a spacing are now close to each other. The expanding gas generated by the battery cells causes a large impact on the module housing, and then causes the deformation of the module housing. Therefore, at the beginning of design and production processing, it is necessary to conduct a strength test on the battery cell module housing to ensure that the ultimate bearing capacity of the module to resist gas pressure is higher than the pressure relief pressure of the battery cell, so as to ensure that the module structure will not break and fail before the battery cell relieves pressure.

[0052] Reference Figure 1 , is a perspective view of the battery module detection device provided by the present utility model. The battery module to be tested includes a module housing 5 and multiple groups of battery cells 6 arranged inside the module housing 5. The detection device includes: a placement table 1 configured to place the battery module to be tested, an elastic airbag 2 configured to be at least one and used to replace some of the battery cells 6 inside the module housing 5, a pressure measurement unit 3 configured to replace other parts of the battery cells 6 inside the module housing 5 to obtain the expansion pressure received by the battery cells 6 at the replacement position, and a test component 4 installed on the placement table 1. The test component 4 is configured to measure the deformation amount of at least one end plate of the module housing 5 in real time. The elastic airbag 2 can expand to a preset pressure and squeeze towards the surroundings to simulate the expansion of the thermal runaway gas of this part of the battery cells 6.

[0053] In actual operation of this embodiment, first place the battery cell 6 module to be tested on the placement table 1, take out some of the battery cells 6 inside the module housing 5, and place the elastic airbag 2 at the position of this part of the battery cells 6; then take out other parts of the battery cells 6 and replace them with the pressure measurement unit 3; use the elastic airbag 2 to simulate the expansion of the thermal runaway gas of this part of the battery cells 6 at the replacement position, so as to apply an expansion pressure to other battery cells 6 or the inner wall of the module housing 5. The expansion pressure loaded on the end plate of the module housing 5 can impact the end plate of the module housing 5 and cause its deformation; measure the internal expansion pressure of the module housing 5 through the pressure measurement unit 3, so that different preset gas expansion pressures can be applied to the module housing 5 by using the elastic airbag 2, and the deformation amount of the end plate of the module housing 5 can be measured by the test component 4 installed on the placement table 1, thereby obtaining the ultimate bearing capacity of the module to resist gas pressure, and then evaluating the structural reliability of the module housing 5 during battery thermal runaway.

[0054] It should be noted that with reference to Figure 2 , the battery module to be tested in this embodiment includes a module housing 5 and multiple groups of battery cells 6 arranged inside the module housing 5. Generally, the battery cells 6 are arranged at equal intervals inside the housing, and the battery cells 6 at both ends are in contact with the inner wall of the housing. Of course, the battery module to be tested may also have different arrangements according to the actual product. In this embodiment, the structure and specific form of the battery module are not restrictively described.

[0055] In actual operation of this embodiment, preferably, the replaced battery cells 6 for placing the elastic airbag 2 and for placing the pressure measuring unit 3 are not continuous, so as to ensure that the elastic airbag 2 can fully contact the battery cell 6 or the inner wall of the module housing 5, and the pressure measuring unit 3 can contact other battery cells 6, so that the measured internal gas expansion pressure is more in line with the internal gas pressure of the battery cell 6 under the actual battery thermal runaway condition.

[0056] In one case of this embodiment, when some of the battery cells 6 at both ends are taken out to place the elastic airbag 2, and some other battery cells 6 at the middle position are taken out to place the pressure measuring unit 3, after the elastic airbag 2 is inflated, it can press the battery cell 6 at the middle position onto the pressure measuring unit 3. At the same time, the elastic airbag 2 squeezes the inner wall of the module housing 5 to simulate the gas expansion during battery thermal runaway. The pressure of the elastic airbag 2 is adjusted according to the internal gas pressure measured by the pressure measuring unit 3, and combined with the deformation amount of the end plate of the module housing 5 measured by the test component 4, the maximum gas expansion pressure that the module housing 5 can withstand is obtained, and then the strength of the structure of the module housing 5 is evaluated.

[0057] In actual operation of this embodiment, with reference to Figure 3 , the elastic airbag 2 includes: an airbag body 21, an inlet pipeline 22 and an outlet pipeline 23 that are respectively connected to the airbag body 21 and used to connect to an external air pressure control system, and a pressure relief valve disposed on the airbag body 21 and configured to have an opening pressure equal to the air leakage pressure of the battery cell 6.

[0058] It can be known that by using the airbag body 21 and through the inlet pipeline 22 and the outlet pipeline 23, it can be connected to an external air pressure control system, so as to inflate or deflate the airbag body 21. By using the pressure relief valve 24 disposed on the airbag body 21, its opening pressure is equal to the air leakage pressure of the battery cell 6, so that the airbag body 21 can be inflated to the air leakage pressure of the battery cell 6 and then relieved of pressure, so as to more truly simulate the actual gas expansion and pressure relief conditions during the thermal runaway of the battery cell 6.

[0059] It should be noted that the above external air pressure control system can be equipped with a peristaltic pump. The peristaltic pump can be used for precise control such as constant flow and constant pressure. The external air pressure control system can be signal-connected to the pressure measurement unit 3, and the internal gas expansion pressure of the module housing 5 can be fed back through the pressure measurement unit 3, so as to control the internal pressure of the module housing 5 in real time. By regulating different gas expansion conditions and combining the test of the end plate deformation of the module housing 5 by the test component 4, the evaluation result of the structural reliability of the module mechanism can be comprehensively obtained.

[0060] In actual operation of this embodiment, the airbag body 21 is configured as a fabric airbag, and its initial length and width are both greater than the length and width of the battery cell 6. The size of the airbag being larger than that of the battery cell 6 can ensure its full contact with the adjacent battery cells 6, and smoothly transfer the gas expansion pressure to other battery cells 6 and the inner wall of the module housing 5.

[0061] Exemplarily, the airbag filaments of the above fabric airbag can be selected as high-strength nylon 66 multifilament. Utilizing its characteristics such as low initial modulus, appropriate elongation at break, good elasticity, wear resistance, and high heat enthalpy, the airbag body 21 made of fabric is more suitable for pressure testing. Utilizing its excellent heat resistance and folding performance, it is convenient to simulate the gas expansion of the battery cell 6. Of course, the airbag fabric can also be selected as nylon 46 and nylon 6. Regarding the specific material of the airbag body 21, this embodiment does not make specific limitations here.

[0062] In actual operation of this embodiment, two elastic airbags 2 are configured, and they are respectively arranged between the battery cells 6 at the two ends of the module housing 5 and the inner wall of the housing end plate outside the battery cells 6 at the two ends along the arrangement direction of the battery cells 6.

[0063] Specifically, setting the elastic airbag 2 at the positions of the battery cells 6 at the two ends of the module housing 5 can simulate the gas expansion condition when the battery cell 6 at the end position undergoes thermal runaway. This situation is more in line with the most frequently occurring gas expansion scenario of the battery cell 6 in actual use.

[0064] It should be noted that in this embodiment, regarding the elastic airbag 2, it can be set to one, or two or more. It can replace some of the battery cells 6 at the end position of the module housing 5, or replace some of the battery cells 6 at the middle position. The installation position, actual quantity, and pressure relief pressure of the elastic airbag 2 can all be adjusted according to the test needs. This embodiment does not make specific limitations here.

[0065] In this embodiment, referring to Figure 1 、 Figures 5 to 7, the test component 4 includes: a guiding unit 41 installed on the placement table 1, at least one movable frame 42 movably installed on the guiding unit 41, and a testing unit 43 installed on the movable frame 42. The movable frame 42 is configured to move along the guiding unit 41 to the side of the module casing 5 to be tested and then be fixed to the guiding unit 41; the testing unit 43 is configured to abut against the outer wall of the module casing 5 through the movable frame 42 to measure the deformation of the end plate of the module casing 5 in real time.

[0066] It is not difficult to see that the guiding unit 41 can be used to move the movable frame 42 to a preset position, so that the testing unit 43 installed thereon abuts against the outer wall of the module casing 5, and the deformation of the end plate of the module casing 5 can be detected in real time, and the structural strength of the module casing 5 during thermal runaway can be evaluated.

[0067] Furthermore, the guiding unit 41 includes: a first guide rail 411 fixedly installed on the placement table 1 and extending along a first direction, and a second guide rail 412 slidably connected to at least one first guide rail 411 and extending along a second direction. Both the first guide rail 411 and the second guide rail 412 are configured to be at least one, and the first direction and the second direction are perpendicular; the movable frame 42 is slidably connected to at least one second guide rail 412; both between the first guide rail 411 and the second guide rail 412 and between the movable frame 42 and the second guide rail 412 can be fixed by a locking member 413.

[0068] It can be known that the first guide rail 411 can be used for the second guide rail 412 to move along it, and the second guide rail 412 can be used for the movable frame 42 to move along it. When the second guide rail 412 reaches the preset position and the movable frame 42 reaches the preset position, both can be fixed to each other by the locking member 413, so as to ensure the stable installation of the test component 4 relative to the module casing 5.

[0069] Even further, two first guide rails 411 are arranged in parallel along the second direction, and two second guide rails 412 are arranged in parallel along the first direction. Both ends of the second guide rail 412 are slidably connected to the two first guide rails 411, and the movable frame 42 is slidably connected to the second guide rail 412 and is arranged corresponding to it one by one. The two movable frames 42 are configured to be distributed on both sides of the module casing 5 to be tested.

[0070] It is not difficult to see that by setting the first guide rail 411 to two and arranging the second guide rail 412 to slide vertically along the first guide rail 411, the movable frame 42 can be driven to move along the first direction and the second direction respectively, and the testing unit 43 can be moved to the preset position.

[0071] Exemplarily, sliders slidably connected to the two first guide rails 411 are respectively fixed at both ends of the bottom of the two second guide rails 412. Sliders slidably connected to the second guide rails 412 are fixed at both ends of the bottom of the moving frame body 42, and through threaded holes are provided on each slider. The locking member 413 can be set as a bolt or a locking knob threadedly connected inside the threaded hole.

[0072] Specifically, when the second guide rail 412 or the moving frame body 42 reaches the preset position, the bolt is rotated and abutted against the side surface of the first guide rail 411 or the second guide rail 412, so as to fix the second guide rail 412 relative to the first guide rail 411, or the moving frame body 42 relative to the second guide rail 412. Of course, the above locking structure can also be adjusted to the form of a plug hole and a plug-in member according to needs, and no specific limitation is made in this embodiment.

[0073] In one case of this embodiment, the moving frame body 42 can be slidably connected to the two second guide rails 412 at the same time, and the moving frame body 42 is set to be a telescopic structure. The testing unit 43 is installed on the moving frame body 42 and distributed on both sides of the module housing 5 to be tested. By moving the two second guide rails 412 on the first guide rail 411, the testing units 43 on both sides are driven to approach the module housing 5 at the same time and abut against the outer walls on both sides thereof, so as to measure the deformation amounts of the end plates at both ends of the module housing 5 simultaneously.

[0074] In another case of this embodiment, the moving frame body 42 can be slidably connected to the two second guide rails 412 in one-to-one correspondence. With the two second guide rails 412 distributed in parallel, the movement of the moving frame body 42 is more stable. Therefore, the specific connection structure between the moving frame body 42 and the second guide rails 412 is not a restrictive regulation of this embodiment.

[0075] In this embodiment, the first direction and the second direction can be respectively parallel to the length direction and the width direction of the module housing 5. At this time, the first direction is the same as the arrangement direction of the battery cells 6, and the second direction is perpendicular to the arrangement direction of the battery cells 6; or the first direction and the second direction can be respectively parallel to the width direction and the length direction of the module housing 5. At this time, the first direction is perpendicular to the arrangement direction of the battery cells 6, and the second direction is the same as the arrangement direction of the battery cells 6; the angle between the first guide rail 411 and the second guide rail 412 can also be adjusted according to the specific structure of the module housing 5 to facilitate the testing unit 43 on the moving frame body 42 to fit on its outer wall; therefore, the arrangement directions of the first direction and the second direction and the angle between the two are not restrictive regulations of this embodiment.

[0076] In this embodiment, the second guide rails 412 distributed on both sides of the module housing 5 and the moving frame body 42 correspondingly arranged on the second guide rails 412 mainly function to fit the testing unit 43 on the outer wall of the corresponding side end plate, so as to measure its deformation amount in real time.

[0077] In actual operation of this embodiment, with reference to Figure 6 , the test unit 43 includes: at least one displacement sensor 431 disposed on the side of the moving frame 42 close to the housing 5 of the module to be tested and configured to abut against the outer wall of the end plate of the housing 5 of the module to be tested.

[0078] It can be known that the displacement sensor 431 facilitates the fitting of the moving frame 42 to the outer side wall of the module housing 5; so as to measure the deformation amount of its end plate when the gas expands during thermal runaway.

[0079] Furthermore, the displacement sensor 431 is configured as an LVDT sensor and there are multiple of them. The multiple LVDT sensors are arranged in a rectangular distribution on the side of the moving frame 42 close to the housing 5 of the module to be tested.

[0080] It should be noted that multiple sensors can correspondingly measure the deformation amounts of different regions of the end plate of the module housing 5, so as to more intuitively detect the expansion degrees of different positions of the housing end plate when the battery cell 6 undergoes thermal runaway. In addition to the rectangular arrangement, it can also be adjusted to other ways according to needs to adapt to the end plates of module housings 5 with different shapes.

[0081] Exemplarily, the above-mentioned LVDT sensor can convert the deformation movement of the housing end plate mechanically coupled to it into a corresponding electrical signal, so as to obtain the deformation amount of the housing end plate at that place. In addition to using the LVDT sensor for the displacement sensor 431, it can also be replaced with other sensors according to needs, such as a laser displacement sensor 431 or a linear displacement sensor 431, etc. Therefore, the specific type of the above-mentioned displacement sensor 431 is not a restrictive regulation of this embodiment.

[0082] Even further, with reference to Figure 7 , the moving frame 42 is sequentially and parallelly provided with a first plate body 421 and a second plate body 422 along a first direction. The first plate body 421 is configured to fit against the outer wall of the end plate of the module housing 5: The test unit 43 further includes: a mounting sleeve 432 fixedly installed on the moving frame 42 and provided corresponding to the displacement sensor 431 one by one, an elastic member (not shown in the figure) installed inside the mounting sleeve 432, and a through hole 423 opened on the side of the moving frame 42 close to the housing 5 of the module to be tested and corresponding to the displacement sensor 431 one by one; the mounting sleeve 432 is configured to allow the end of the displacement sensor 431 to be inserted; the elastic member is configured to abut against the end of the displacement sensor 431; one end of the displacement sensor 431 for contacting the outer wall of the module housing 5 passes through the through hole 423, and the other end is inserted into the mounting sleeve 432 and abuts against the elastic member.

[0083] It can be known that the displacement sensor 431 is installed by using the first plate body 421 and the second plate body 422 distributed in parallel. The displacement sensor 431 is movably inserted into the through hole 423 and the inner part of the mounting sleeve 432. Thus, by the elastic action of the elastic member, when the moving frame body 42 approaches the module housing 5, the displacement sensor 431 is driven to abut against the outer wall of the module housing 5, and the elastic member gives a certain displacement space to the displacement sensor 431, so as to ensure that it always fits against the outer wall of the module housing 5.

[0084] Exemplarily, the installation structure of the above displacement sensor 431 can ensure its fit against the outer wall of the module housing 5. The elastic member can be set as a spring or a compression spring, and the two ends are respectively fixed to the displacement sensor 431 and the inner wall of the mounting sleeve 432. The displacement sensor 431 can be installed perpendicular to the first plate body 421 and the second plate body 422, or can be placed obliquely relative to the two. Therefore, the specific installation method of the displacement sensor 431 is not a restrictive regulation of this embodiment.

[0085] It should be noted that this application aims to simulate the working condition when the internal battery cells 6 expand due to thermal runaway of the battery cells 6. By using the pressure measuring unit 3 and the test component 4, the deformation amount of the module housing end plate and the internal pressure of the battery cells 6 are measured, and then the structural reliability of the module housing is evaluated. In addition to the above method, the test unit 43 for measuring the deformation amount of the module housing end plate can also adopt a method such as laser measurement. Therefore, the specific form of the test component 4 is not a restrictive regulation of this embodiment.

[0086] In the actual operation of this embodiment, refer to Figure 2 and Figure 4 The pressure measuring unit 3 includes: two fitting plates 31 arranged in parallel and configured to respectively fit against the other battery cells 6 on both sides of the position where the battery cell 6 is replaced, connecting members 32 connected to the opposite sides of the two fitting plates 31 and configured to be at least three; and a pressure sensor 33 installed between the two fitting plates 31 and configured to measure the pressure received by the battery cell 6 at the replacement position.

[0087] Specifically, the fitting plates 31 are used to fit against the other battery cells 6 on both sides of the replacement position, and at the same time, the gas expansion pressure received inside is transmitted to the pressure sensor 33, so as to realize the measurement of the internal pressure of the battery cell 6.

[0088] In one case of this embodiment, the number of the connecting members 32 is four, and they are configured as telescopic guide rails and are respectively distributed at the four corners of the fitting plates 31, and the pressure sensor 33 is located at the middle position between the two fitting plates 31.

[0089] In another case of this embodiment, the fitting plate 31 includes a hard plastic plate 311 and an alloy steel plate 312 spliced by hard rubber. The two ends of the connecting member 32 are respectively connected to the alloy steel plates 312 of the two fitting plates 31, and the hard plastic plate 311 is configured to contact other battery cells 6 beside the replaced position.

[0090] It can be known that the pressure sensor 33 can be signal-connected to an external controller or an air pump, so as to obtain the gas expansion pressure at the replaced position in real time, and adjust the charging and discharging amount of the elastic airbag 2 according to the internal pressure of the battery cell 6 to meet different test requirements.

[0091] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. Battery module detection device, wherein the battery module to be tested includes a module housing and multiple groups of battery cells arranged inside the module housing, and is characterized in that, The detection device includes: A placement table configured to place the battery module to be tested; An elastic airbag configured to be at least one and used to replace some of the battery cells in the module casing. The elastic airbag can expand to a preset pressure and squeeze the surrounding to simulate the gas expansion during thermal runaway of this part of the battery cells; A pressure measurement unit configured to replace other parts of the battery cells in the module casing to obtain the expansion pressure received by the battery cells at the replacement position; A test component installed on the placement table and configured to measure the deformation amount of at least one end plate of the module casing in real time.

2. The battery module detection device according to claim 1, wherein The elastic airbag includes: an airbag body, an air inlet pipeline and an air outlet pipeline respectively connected to the airbag body and used to connect to an external air pressure control system, and a pressure relief valve arranged on the airbag body and configured to have an opening pressure equal to the air release pressure of the battery cells.

3. The battery module detection device according to claim 1, wherein The elastic airbag is configured to be two, and is respectively arranged between the battery cells at the two outermost ends of the module casing and the inner wall of the casing end plate outside the battery cells at the two outermost ends along the arrangement direction of the battery cells.

4. The battery module detection device according to claim 1, characterized in that The test component includes: A guiding unit installed on the placement table; A moving frame body movably installed on the guiding unit and at least one; configured to be movable along the guiding unit to the side of the module casing to be tested and then fixed to the guiding unit; A test unit installed on the moving frame body and configured to abut against the outer wall of the module casing through the moving frame body to measure the deformation amount of the module casing end plate in real time.

5. The battery module detection device according to claim 4, wherein, The guiding unit includes: At least one first guide rail fixedly installed on the placement table and extending along a first direction; At least one second guide rail slidably connected to the at least one first guide rail and extending along a second direction, the first direction and the second direction being perpendicular; The moving frame body is slidably connected to the at least one second guide rail; fixation can be achieved between the first guide rail and the second guide rail, and between the moving frame body and the second guide rail through locking members.

6. The battery module detection device according to claim 5, wherein, Two first guide rails are arranged in parallel along the second direction, two second guide rails are arranged in parallel along the first direction, both ends of the second guide rail are slidably connected to the two first guide rails respectively, the moving frame body is slidably connected to the second guide rail and is arranged corresponding to it one by one, and the two moving frame bodies are configured to be distributed on both sides of the module casing to be tested.

7. The battery module detection device according to any one of claims 4-6, characterized in that The test unit includes: at least one displacement sensor arranged on the side of the moving frame body close to the module casing to be tested and used to abut against the outer wall of the end plate of the module casing to be tested.

8. The battery module detection device according to claim 7, wherein The displacement sensor is configured to be an LVDT sensor and there are multiple of them. The multiple LVDT sensors are distributed in a rectangular shape on the side of the moving frame body close to the module casing to be tested.

9. The battery module detection device according to claim 7, characterized in that The moving frame body is sequentially provided with a first plate body and a second plate body in parallel along the first direction. The first plate body is configured to fit against the outer wall of the end plate of the module casing; through holes corresponding to the displacement sensors one by one are formed through the first plate body; the test unit further includes: A mounting sleeve fixedly installed on the second plate body and arranged corresponding to the displacement sensors one by one, configured to allow the end of the displacement sensor to be inserted. The elastic member is installed inside the installation sleeve and is configured to abut against the end of the displacement sensor. One end of the displacement sensor for contacting the outer wall of the module housing passes through the through hole, and the other end is inserted into the installation sleeve and abuts against the elastic member.

10. The battery module detection device according to claim 1, characterized in that, The pressure measuring unit includes: Two fitting plates are arranged in parallel and are configured to respectively fit against other battery cells on both sides of the position where the battery cell is to be replaced. The connecting members are connected to the opposite sides of the two fitting plates and are configured to be at least three. The pressure sensor is installed between the two fitting plates and is configured to measure the pressure exerted on the battery cell at the replacement position.

11. The battery module detection device according to claim 10, wherein The connecting members are configured as telescopic guide rails and are sequentially distributed at the four corners of the fitting plates, and the pressure sensor is located at the middle position between the two fitting plates.

12. The battery module detection device according to claim 10 or 11, characterized in that, The fitting plate includes a hard plastic plate and an alloy steel plate spliced by hard rubber. The two ends of the connecting member are respectively connected to the alloy steel plates of the two fitting plates, and the hard plastic plate is configured to contact other battery cells beside the position where the battery cell is to be replaced.

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