Method and device for testing cell stack

Abstract

The invention provides a method and a device for testing a cell stack, wherein the device comprises a pressure sensor, a lower bearing plate, a pressing plate and two side plates, and the lower bearing plate, the pressing plate and the two side plates form a cell stack accommodating cavity; the two sides of the pressing plate are fixedly connected with the two side plates respectively. And the pressure sensor is arranged on one side, far away from the battery cell stack accommodating cavity, of the lower bearing plate. The battery cell stack testing device has the advantages that the lower bearing plate, the pressing plate and the two side plates form the battery containing cavity, the battery cell stack is placed in the battery cell stack containing cavity, corresponding data are measured through the displacement sensor or the pressure sensor, the detection range of the battery cell stack testing device can be greatly widened, and the detection efficiency of the battery cell stack testing device can be greatly improved.

Description

Technical Field

[0001] The present invention relates to the field of new energy, and in particular to a method and device for testing a battery cell stack. Background Art

[0002] With the development of the new energy industry, more and more batteries are being used in the field of electric vehicles and energy storage. As the power source of new energy vehicles, lithium-ion batteries will increase the internal expansion pressure of the battery pack and produce expansion deformation along the thickness direction under the coupling effect of changes in stress such as lithium insertion and extraction, thermal expansion and lithium precipitation during the charging and discharging process, which will affect the electrical performance of the lithium-ion battery and shorten its service life. Foam is placed at intervals of a certain number of lithium-ion batteries in the battery pack. The foam absorbs the internal expansion pressure of the lithium-ion battery pack and the expansion deformation along the thickness direction, which can improve the electrical performance of the lithium-ion battery and extend its service life. In order to determine the parameters of the foam and the position of the interval placement, it is necessary to test the expansion pressure of the lithium-ion battery and the expansion deformation produced along the thickness direction.

[0003] The existing expansion deformation test requires a long test cycle and high test cost, and the test results will also affect the progress of the project. Summary of the invention

[0004] The main purpose of the present invention is to provide a method and device for testing a battery cell stack, aiming to solve the problem that the existing expansion deformation test requires a long test cycle.

[0005] The present invention provides a testing device for a battery stack, comprising: a pressure sensor, a lower pressure plate, a pressure plate and two side plates, wherein the lower pressure plate, the pressure plate and the two side plates constitute a battery stack accommodating chamber; two sides of the pressure plate are respectively fixedly connected to the two side plates; the lower pressure plate is slidably connected to the two side plates, and is used to limit the size of the battery stack accommodating chamber;

[0006] The pressure sensor is arranged on a side of the lower pressure bearing plate away from the battery cell stack accommodating cavity.

[0007] Furthermore, the side plate is a liquid cooling plate.

[0008] Furthermore, it also includes a base, which is arranged on a side of the pressure sensor away from the lower pressure plate.

[0009] Furthermore, the base includes a base bottom plate and two base side plates, the two base side plates are detachably connected to the base bottom plate, and the pressure sensor is arranged on the base bottom plate.

[0010] Furthermore, the two base side panels are contact-connected with the two side panels in a one-to-one correspondence.

[0011] Furthermore, the base side panels are also provided with handles.

[0012] Furthermore, it also includes a positive and negative side plate mounting bracket, a positive side plate and a negative side plate, the positive and negative side plate mounting bracket is fixed on the lower pressure plate, and the positive side plate and the negative side plate are fixed on the positive and negative side plate mounting bracket.

[0013] Furthermore, it also includes at least one displacement sensor, and the at least one displacement sensor is suspended above the pressure plate.

[0014] Furthermore, it also includes a displacement sensor fixing bracket and two side frames, the two side frames are respectively attached to and fixedly connected to the two side plates, and the upper ends of the side frames have protruding portions extending out of the side plates, the two ends of the displacement sensor fixing bracket are respectively fixedly connected to the protruding portions of the two side frames, and the at least one displacement sensor is fixedly mounted on the displacement sensor fixing bracket and suspended above the pressure plate.

[0015] The present invention also provides a testing device for a battery stack, comprising: a displacement sensor, a lower pressure plate, a pressure plate and two side plates, wherein the lower pressure plate, the pressure plate and the two side plates constitute a battery stack accommodating chamber; two sides of the pressure plate are respectively fixedly connected to the two side plates;

[0016] The displacement sensor is arranged on a side of the pressing plate away from the cell stack accommodating cavity and is suspended above the pressing plate.

[0017] The present invention also provides a method for testing a battery cell stack, which is implemented by the above-mentioned battery cell stack testing device, comprising:

[0018] Placing a battery cell stack in the battery cell stack accommodating cavity;

[0019] Connecting the battery cell stack to an external charging and discharging device for multiple cycles of charging and discharging;

[0020] Measuring displacement data and / or pressure data by means of a displacement sensor and / or a pressure sensor;

[0021] The parameters of the foam required for the battery cell stack are set according to the measured displacement data and / or pressure data.

[0022] The beneficial effects of the present invention are as follows: a battery accommodating chamber is formed by a lower pressure plate, a pressure plate and two side plates, and a battery cell stack is placed in the battery cell stack accommodating chamber. Corresponding data is measured by a displacement sensor or a pressure sensor, which can greatly improve the detection range and detection efficiency of a test device for the battery cell stack. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of a testing device for a battery cell stack according to an embodiment of the present invention;

[0024] Figure 2 This is a structural exploded diagram of a testing device for a battery stack according to an embodiment of the present invention;

[0025] Figure 3 is a cross-sectional view of a testing device for a battery cell stack according to an embodiment of the present invention;

[0026] Figure 4 is a front view of a side frame according to an embodiment of the present invention;

[0027] Figure 5 This is a relationship diagram of the number of battery cell cycles-battery cell expansion force-battery cell capacity according to an embodiment of the present invention;

[0028] Figure 6 The present invention is a graph showing the relationship between the number of battery cell cycles, the displacement of a pressure plate, and the battery cell capacity according to an embodiment of the present invention.

[0029] Figure 1-4 Middle: 10, bottom plate of base; 20, side plate of base; 30, lower pressure plate; 40, side plate; 41, water outlet of liquid cooling pipe; 42, water inlet of liquid cooling pipe; 50, pressure sensor; 60, mounting bracket of positive and negative side plates; 61, negative side plate; 62, positive side plate; 70, pressure plate; 80, battery cell stack; 90, side frame; 100, fixing bracket of displacement sensor; 110, displacement sensor; 120, handle; 130, fixing bracket; 200, accommodating chamber of battery cell stack; 901, mounting hole of fixing bracket of displacement sensor; 902, fixing hole of side plate; 903, fixing hole of side frame.

[0030] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly. The connection can be a direct connection or an indirect connection.

[0033] The term "and / or" in this article is only a description of the association relationship of associated objects, indicating that there may be three relationships. For example, A and B can represent three situations: A exists alone, A and B exist at the same time, and B exists alone.

[0034] In addition, in the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0035] Reference Figure 1-3 The present invention proposes a testing device for a battery cell stack 80, comprising: a pressure sensor 50, a lower pressure plate 30, a pressure plate 70 and two side plates 40, wherein the lower pressure plate 30, the pressure plate 70 and the two side plates 40 constitute a battery cell stack accommodating chamber 200; the two sides of the pressure plate 70 are respectively fixedly connected to the two side plates 40; the lower pressure plate 30 is slidably connected to the two side plates 40 to limit the size of the battery cell stack accommodating chamber 200; the pressure sensor 50 is arranged on a side of the lower pressure plate 30 away from the battery cell stack accommodating chamber 200.

[0036] In this embodiment, a cell stack accommodating chamber 200 is formed by a pressure sensor 50, a lower pressure plate 30, a pressure plate 70 and two side plates 40, and a cell stack 80 is placed in the cell stack accommodating chamber 200. Since the lower pressure plate 30 is not fixedly connected to the side plates 40, the size of the cell stack accommodating chamber 200 can be adjusted by adjusting the position of the lower pressure plate 30 to accommodate cell stacks 80 of different thicknesses. After the cell stack 80 is installed, under the gravity of the cell stack 80, the cell stack 80 is in contact and connected with the lower pressure plate 30, and at the same time, the cell stack 80 is in contact and connected with the pressure plate 70. During the installation process, the height of the lower pressure plate 30 is raised, so that the cell stack 80 can be in contact and connected with the pressure plate to provide a pre-tightening force to clamp the cell stack 80. The two side plates 40 are preferably arranged close to the cell stack 80. During the installation process, since the pressure sensor 50 at the bottom needs to contact the lower pressure plate 30, the height of the lower pressure plate 30 can be raised by setting the height of the pressure sensor 50. When the battery cell stack 80 performs multiple cycles of discharge, while the pressure plate 70 and the lower pressure plate 30 provide corresponding pre-tightening force, the battery cell stack 80 will expand. Therefore, the battery cell stack 80 will provide pressure to the lower pressure plate 30, so that the pressure sensor 50 set at the bottom of the lower pressure plate 30 will measure the change in pressure, that is, the added pressure. That is, when multiple cycles of discharge are not performed, the pressure sensor 50 measures the pressure of the lower pressure plate 30, the pressure plate 70, and the battery cell stack 80. The measured value after multiple cycles of discharge also includes the pressure caused by the expansion of the battery cell stack 80, that is, the pressure change of the battery cell stack 80 during the multiple cycles of charge and discharge is measured. Therefore, the change in pressure can be measured by the pressure sensor 50. There is no need to set up different detection devices for different battery cell stacks 80. The battery cell stack 80 only needs to be placed in the battery cell stack accommodating cavity 200, which greatly improves the detection range and detection efficiency of the test device of the battery cell stack 80. The battery cell stack 80 is a stack in which multiple battery cells are stacked and connected in series one by one, and can be discharged independently.

[0037] In one embodiment, the side plate 40 is a liquid cooling plate.

[0038] In the present embodiment, since the battery cell stack 80 generates heat during multiple cycles of charge and discharge, the generated heat will gradually accumulate, and will cause harm to the battery cell stack 80 when reaching a certain level. At the same time, the generated heat will also affect the discharge of the battery cell stack 80. On the other hand, in the application scenario of the battery cell stack 80, a liquid cooling device will also be arranged around the battery cell stack 80 for cooling. Therefore, setting the side panel 40 as a liquid cooling plate can simulate the charge and discharge scenario of the battery cell stack 80 to a certain extent, so that the detection result is more accurate. Therefore, the side panel 40 can be set as a liquid cooling plate, and a liquid cooling pipe water outlet 41 and a liquid cooling pipe water inlet 42 are provided on the liquid cooling plate to facilitate timely cooling and reduce damage to the battery cell stack 80 during the charge and discharge process.

[0039] In one embodiment, a base is further included, and the base is arranged on a side of the pressure sensor 50 away from the lower pressure plate 30 .

[0040] In this embodiment, in order to enable the pressure sensor 50 to accurately measure the pressure of the lower pressure plate 30, the pressure plate 70, and the battery cell stack 80, and improve the detection accuracy of the pressure sensor 50, a base can be set at the bottom to make the entire device in a flat state to avoid errors caused by uneven force on the pressure sensor 50. The base can be used to receive the pressure sensor 50, and the base can also protect the pressure sensor 50. It should be noted that the battery cell stack 80 can be brought into contact with the pressure plate 70 in the battery accommodating cavity by adjusting the size of the pressure sensor 50 or setting a pad under the pressure sensor 50. In a specific embodiment, the pressure sensor 50 can also be fixedly connected to the base to ensure the stability of the pressure sensor 50.

[0041] In a specific embodiment, two displacement sensors 110 are provided, respectively located at the two ends of the lower pressure plate 30. The two displacement sensors 110 can keep the lower pressure plate 30 horizontal, so that the displacement sensors 110 can accurately measure the change in pressure.

[0042] In one embodiment, an insulating film is also attached to the side of the pressure sensor 50 close to the battery receiving cavity, so that the pressure sensor 50 is insulated from the battery stack 80 to ensure the safety of the test. Since the battery stack 80 may have leakage during the discharge process, an insulating film can be attached to the side of the pressure sensor 50 close to the battery receiving cavity in advance during the installation of the pressure sensor 50. Since the pressure sensor 50 measures the change in pressure, the provision of the insulating film will not cause measurement errors.

[0043] In some embodiments, the base includes a base bottom plate 10 and two base side plates 20 , the two base side plates 20 are detachably connected to the base bottom plate 10 , and the pressure sensor 50 is disposed on the base bottom plate 10 .

[0044] By setting the base to be a base bottom plate 10 and two base side plates 20, the installation of the battery stack 80 can be facilitated, that is, during the installation process, the base side plates 20 are disassembled, and then the battery stack 80 is placed in the battery cell accommodating cavity, and the pressure sensor 50 is placed under the lower pressure plate 30, and then placed on the base bottom plate 10, and then the base side plates 20 are fixedly connected to the base bottom plate, so that the battery stack 80 can be limited to prevent it from moving. In a specific embodiment, the base bottom plate 10 and the two base sides are connected by hinges, and the hinges are opened before the battery stack 80 is installed. After the installation is completed, the hinges are closed and fixed by fixing bolts. The fixing bolts can be fixed base bottom plate 10 and base side plates 20, or fixed base side plates 20 and side plates 40, and this application does not limit this. In a specific embodiment, during the installation process, the battery stack 80 is first placed on the lower pressure plate 30, the pressure sensor 50 is set under the lower pressure plate 30 and placed together on the base bottom plate 10, and then the pressure plate 70 and the two side plates 40 are placed. Finally, the base side plate 20 is connected to the side plate 40 by closing the hinge, the side plate 40 is limited, and finally the base side plate 20 and the side plate 40 are fixed by bolts. In order to ensure the reliability of the connection, multiple bolt holes can be set for connection, such as Figure 2 In the present invention, 8 bolt holes are arranged, which are respectively located on both sides of the base side plate 20.

[0045] In one embodiment, the two base side panels 20 are contact-connected with the two side panels 40 in a one-to-one correspondence.

[0046] In this embodiment, the two base side panels 20 are in contact and connection with the two side panels 40 in a one-to-one manner, so that the base side panels 20 can protect the two side panels 40 laterally, and the side panels 40 can also be limited by the base side panels 20, so as to better achieve the horizontal limitation of the battery cell stack 80.

[0047] In one embodiment, the base side panel 20 is further provided with a handle 120 .

[0048] In this embodiment, the handle 120 can facilitate the disassembly of the base side panel 20. If the base side panel 20 is not connected to the base bottom plate 10 by a hinge, the handle 120 can be used to manually limit the position and then fixed by bolts. That is, the handle 120 plays a role in manually limiting the base side panel 20. If the base side panel 20 is connected to the base bottom plate 10 by a hinge, it is also necessary to manually grasp the handle to provide a pressure on the base side panel 20 so that the base side panel 20 can be set close to the side panel 40 to provide a certain pre-tightening force to the side panel 40, thereby realizing the horizontal pre-tightening force on the battery cell stack 80. In addition, each base side panel 20 can be provided with two handles 120, and the two handles 120 are respectively located at both ends of the base side panel 20, so as to apply a uniform pre-tightening force to the base side panel 20.

[0049] In one embodiment, it also includes a positive and negative side plate mounting bracket 60, a positive side plate 62 and a negative side plate 61, wherein the positive and negative side plate mounting bracket 60 is fixed on the lower pressure plate 30, and the positive side plate 62 and the negative side plate 61 are fixed on the positive and negative side plate mounting bracket 60.

[0050] In this embodiment, since the battery cell stack 80 needs to perform multiple cycles of charge and discharge operations, a positive and negative electrode side plate mounting bracket 60 can be set on the lower pressure plate 30, and the positive and negative electrode side plate mounting bracket 60 is provided with a positive electrode side plate 62 and a negative electrode side plate 61. The pole ears on the battery cell stack 80 are connected to the positive electrode side plate 62 and the negative electrode side plate 61, so as to facilitate multiple cycles of charge and discharge operations of the battery cell stack 80.

[0051] In one embodiment, at least one displacement sensor 110 is further included. The at least one displacement sensor 110 is suspended above the pressure plate 70 .

[0052] In this embodiment, at least one displacement sensor 110 is suspended above the pressure plate 70, so that the displacement of the pressure plate 70 can be detected. It should be noted that the fixing method of the displacement sensor 110 is not limited. It can be fixed above the pressure plate 70 by other devices, or a fixing device can be set on the side plate 40 to fix the displacement sensor 110. The displacement sensor 110 can include a mechanical displacement sensor 110 and an infrared displacement sensor 110. If it is a mechanical displacement sensor 110, the bottom of the mechanical displacement sensor 110 needs to be in contact with the pressure plate 70. If it is an infrared displacement sensor 110, there is no need to make the bottom of the infrared displacement sensor 110 contact with the pressure plate 70.

[0053] In one embodiment, it also includes a displacement sensor fixing bracket 100 and two side frames 90, the two side frames 90 are respectively attached to and fixedly connected to the two side panels 40, and the upper ends of the side frames 90 have extensions extending from the side panels 40, and the two ends of the displacement sensor fixing bracket 100 are respectively fixedly connected to the extensions of the two side frames 90, and the at least one displacement sensor 110 is fixedly mounted on the displacement sensor fixing bracket 100 and suspended above the pressure plate 70.

[0054] In this embodiment, the displacement sensor 110 can be limited by providing a displacement sensor fixing bracket 100 and two side frames 90. In some specific embodiments, a plurality of side frames 90 can be provided in pairs to achieve installation of a plurality of displacement sensors 110 at different positions. A fixing bracket 130 can also be provided between the displacement sensor fixing brackets 100 to achieve installation of the displacement sensors 110 at different positions, such as Figure 1-2 As described above, in this embodiment, 7 displacement sensors 110 are installed, and the side frame 90 can be fixedly connected to the base side plate 20 by bolts. The side frame 90 needs to exceed the height of the pressure plate 70 to prevent the displacement sensor 110 from being unable to be installed above the pressure plate 70. Of course, if the displacement sensor 110 is a physical displacement sensor, it is necessary to ensure that the displacement sensor 110 is in contact with the pressure plate 70. If the displacement sensor 110 is an infrared displacement sensor, it is only necessary to ensure that the displacement sensor 110 is above the pressure plate 70, and a certain distance needs to be maintained to avoid contact with the displacement sensor 110 during the deformation of the pressure plate 70. Sensor 110, two displacement sensor fixing brackets 100 are provided, and a fixing bracket 130 is also provided. A displacement sensor 110 is provided at the middle position of the fixing bracket 130, and three displacement sensors 110 are provided at equal distances on the displacement sensor fixing bracket 100. The displacement changes at different positions of the pressure plate 70 can be detected by the seven displacement sensors 110, and the pressure plate 70 is uniformly used, which can further improve the accuracy of the detection. In the subsequent calculation process, the calculations can be performed separately, or the average value, median value, etc. can be taken for calculation. It should be noted that the pressure plate and the liquid cooling plate are fixedly connected, and the displacement sensor here measures the deformation of the pressure plate.

[0055] The present invention also provides a testing device for a battery cell stack 80, comprising: a displacement sensor 110, a lower pressure plate 30, a pressure plate 70 and two side plates 40, wherein the lower pressure plate 30, the pressure plate 70 and the two side plates 40 constitute a battery cell stack accommodating chamber 200; the two sides of the pressure plate 70 are respectively fixedly connected to the two side plates 40; the displacement sensor 110 is arranged on a side of the pressure plate 70 away from the battery cell stack accommodating chamber 200, and is suspended above the pressure plate 70.

[0056] In this embodiment, the fixing method of the displacement sensor 110 is not limited. It can be fixed on the top of the pressure plate 70 by other devices, or a fixing device can be set on the side plate 40 to fix the displacement sensor 110. The displacement sensor 110 can include a mechanical displacement sensor 110 and an infrared displacement sensor 110. If it is a mechanical displacement sensor 110, it is necessary to make the bottom of the mechanical displacement sensor 110 contact with the pressure plate 70. If it is an infrared displacement sensor 110, it is not necessary to make the bottom of the infrared displacement sensor 110 contact with the pressure plate 70. The displacement sensor 110 can be limited by setting a displacement sensor fixing bracket 100 and two side frames 90. In some specific embodiments, multiple side frames 90 that appear in pairs can also be set to install multiple displacement sensors 110 at different positions. Fixed brackets 130 can also be set between the displacement sensor fixing brackets 100 to install displacement sensors 110 at different positions. As shown in the figure, 7 displacement sensors 110 are installed in this embodiment. In the subsequent calculation process, they can be calculated separately, or the average value, median value, etc. can be taken for calculation. Specifically, refer to Figure 4 The side frame 90 is also provided with a displacement sensor fixing bracket mounting hole 901, a side plate fixing hole position 902 and a side frame fixing hole position 903. The displacement sensor fixing bracket mounting hole 901 is used to realize the fixed connection between the side frame 90 and the displacement sensor fixing bracket 100, the side plate fixing hole position 902 is used to realize the fixed connection between the side plate 40 and the side frame 90, and the side frame fixing hole position 903 is used to realize the fixed connection between the side frame 90 and the base side plate 20, and the fixed connection method is bolt connection.

[0057] The present invention further provides a method for testing a battery cell stack 80, which is implemented by the above-mentioned testing device for the battery cell stack 80, comprising:

[0058] S1: placing the battery cell stack 80 in the battery cell stack accommodating chamber 200;

[0059] S2: connecting the battery cell stack 80 to an external charging and discharging device for multiple cycles of charging and discharging;

[0060] S3: measuring displacement data and / or pressure data by the displacement sensor 110 and / or the pressure sensor 50;

[0061] S4: Setting the parameters of the foam required for the battery cell stack 80 according to the measured displacement data and / or pressure data.

[0062] As described in the above steps S1-S4, the displacement data and / or pressure data are acquired. Figure 5 As shown in the figure, according to the pressure sensor 50 in this example, a relationship diagram between the number of battery cell cycles, the battery cell expansion force and the battery cell capacity can be measured; Figure 6As shown, according to the displacement sensor 110 in this example, a relationship diagram of the number of cycles of the battery cell-the displacement of the pressure plate 70-the battery cell capacity can be measured; combined with Figure 5 and Figure 6 It can be seen that the expansion force of the battery cell and the deformation of the pressure plate 70 will increase with the increase of the number of battery cell cycles. Therefore, if the expansion force of the battery cell and the deformation of the pressure plate 70 exceed the preset values, it can be determined that the design of the pressure plate 70 may not meet the requirements.

[0063] Beneficial effects of the present invention: a battery accommodating cavity is formed by a lower pressure plate 30, a pressure plate 70 and two side plates 40, and a battery cell stack 80 is placed in the battery cell stack accommodating cavity 200. The corresponding data is measured by a displacement sensor 110 or a pressure sensor 50, which can greatly improve the detection range and detection efficiency of the test device for the battery cell stack 80.

[0064] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, device, article or method including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, device, article or method. In the absence of further restrictions, an element defined by the sentence "includes a ..." does not exclude the existence of other identical elements in the process, device, article or method including the element.

[0065] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of the claims of the present invention.

Claims

1. A testing device for a battery cell stack, characterized in that: include: A pressure sensor, a lower pressure plate, a pressure plate and two side plates, wherein the lower pressure plate, the pressure plate and the two side plates constitute a cell stack accommodating chamber; the two sides of the pressure plate are fixedly connected to the two side plates respectively; the lower pressure plate is slidably connected to the two side plates to limit the size of the cell stack accommodating chamber; The pressure sensor is arranged on a side of the lower pressure bearing plate away from the battery cell stack accommodating cavity.

2. The testing device for a battery cell stack according to claim 1, characterized in that: The side plate is a liquid cooling plate.

3. The testing device for a battery cell stack according to claim 1, characterized in that: It also includes a base, which is arranged on a side of the pressure sensor away from the lower pressure plate.

4. The testing device for a battery cell stack as claimed in claim 3, characterized in that: The base comprises a base bottom plate and two base side plates, the two base side plates are detachably connected to the base bottom plate, and the pressure sensor is arranged on the base bottom plate.

5. The testing device for a battery cell stack as claimed in claim 4, characterized in that: The two base side plates are contact-connected with the two side plates in a one-to-one correspondence.

6. The testing device for a battery cell stack according to claim 4, characterized in that: The base side panels are also provided with handles.

7. The testing device for a battery cell stack according to claim 1, characterized in that: It also includes positive and negative side plate mounting brackets, a positive side plate and a negative side plate. The positive and negative side plate mounting brackets are fixed on the lower pressure plate, and the positive side plate and the negative side plate are fixed on the positive and negative side plate mounting brackets.

8. The testing device for a battery cell stack according to claim 1, characterized in that: Also included is at least one displacement sensor suspended above the pressure plate.

9. The testing device for a battery cell stack as claimed in claim 8, characterized in that: It also includes a displacement sensor fixing bracket and two side frames, the two side frames are respectively attached to and fixedly connected to the two side plates, and the upper ends of the side frames have protruding parts extending out of the side plates, the two ends of the displacement sensor fixing bracket are respectively fixedly connected to the protruding parts of the two side frames, and the at least one displacement sensor is fixedly mounted on the displacement sensor fixing bracket and suspended above the pressure plate.

10. A testing device for a battery cell stack, characterized in that: include: A displacement sensor, a lower pressure plate, a pressure plate and two side plates, wherein the lower pressure plate, the pressure plate and the two side plates constitute a cell stacking chamber; two sides of the pressure plate are fixedly connected to the two side plates respectively; The displacement sensor is arranged on a side of the pressing plate away from the cell stack accommodating cavity and is suspended above the pressing plate.

11. A method for testing a battery cell stack, characterized in that: The method is implemented by the battery cell stack testing device according to any one of claims 1 to 10, comprising: Placing a battery cell stack in the battery cell stack accommodating cavity; Connecting the battery cell stack to an external charging and discharging device for multiple cycles of charging and discharging; Measuring displacement data and / or pressure data by means of a displacement sensor and / or a pressure sensor; The parameters of the foam required for the battery cell stack are set according to the measured displacement data and / or pressure data.

Images