CN222965272U - A test fixture and battery cell testing system - Google Patents

Abstract

The application provides a test fixture and a battery cell test system, and relates to the technical field of battery tests. The test fixture comprises a frame, an elastic piece, a movable component, a pressure sensor and a distance measuring piece. According to the application, the top plate is fixedly connected with the guide rod, the position of the top plate in the length direction of the guide rod is adjustable, the first movable plate is movably sleeved on the guide rod and can move along the length direction of the guide rod under the action of external force driving, a cell to be tested is placed between the top plate and the first movable plate, the distance measuring piece is used for acquiring the position of the first movable plate on the guide rod or the moving distance along the guide rod in the test process, and the pressure sensor is used for acquiring the extrusion force of the first movable plate in the length direction of the guide rod in the test process, so that the expansion deformation and the expansion force of the cell in the charge-discharge process can be accurately measured.

Description

Test fixture and electric core test system

Technical Field

The application relates to the technical field of battery testing, in particular to a testing clamp and a battery cell testing system.

Background

At present, new energy automobiles are raised worldwide, and lithium ion power batteries with high specific energy, high power and long service life are widely applied to the fields of electric automobiles, large energy storage and the like. The battery cell belongs to a core component of the lithium ion power battery, and the development of the battery cell technology is also gradually changed, so that the development of the battery cell is in progress. For example, unlike conventional artificial graphite-based negative lithium ion cells, lithium metal negative cells have a greater energy density, but their expansion behavior during charge and discharge is also significantly different from that of conventional graphite-based negative lithium cells, particularly with the expansion and contraction during charge and discharge, resulting in higher and reversible volume changes.

Therefore, in the development process of the battery system, the battery cells need to be subjected to a cyclic test to explore the cyclic performance and the expansion behavior of the battery cells, and test data are provided for the design of the battery module.

Disclosure of utility model

The application provides a test fixture and a battery cell test system, wherein the test fixture can accurately measure expansion deformation and expansion force of a battery cell during charge and discharge.

In one aspect, the application provides a test fixture for testing the expansion deformation and expansion force of a battery cell, wherein the test fixture comprises a frame, an elastic piece, a movable assembly, a pressure sensor and a distance measuring piece;

The frame comprises a bottom plate, a top plate and a plurality of guide rods which are arranged in parallel, wherein the top plate and the bottom plate are respectively fixedly connected with each guide rod and are oppositely arranged along the length direction of the guide rods;

the movable assembly comprises a first movable plate, a first connecting rod, a second connecting rod, a first connecting rod and a second connecting rod, wherein the first movable plate is positioned between the bottom plate and the top plate, and is movably sleeved on the guide rod and can move along the length direction of the guide rod under the driving action of external force;

The elastic piece is arranged on one side of the first movable plate, which faces the bottom plate, and two ends of the elastic piece are respectively abutted against the first movable plate and the bottom plate;

The distance measuring piece is used for acquiring the position of the first movable plate on the guide rod or the moving distance along the guide rod in the test process;

the pressure sensor is used for acquiring the extrusion force of the first movable plate in the length direction of the guide rod in the testing process.

In one possible implementation manner of the application, a groove is formed in one surface of the bottom plate, facing the top plate, the groove is used for installing the pressure sensor, and one end, facing away from the first movable plate, of the elastic piece is abutted with the bottom plate through the pressure sensor.

In one possible implementation of the application, the first movable plate is a rigid plate, and/or

The thickness of the first movable plate is 0.2mm to 0.5mm.

In one possible implementation of the present application, the material for preparing the first movable plate is a metal, or an alloy, or a fiber composite material.

In one possible implementation manner of the application, the movable assembly further comprises a second movable plate, the second movable plate is arranged between the elastic piece and the pressure sensor, the second movable plate is movably sleeved on the guide rod and can move along the length direction of the guide rod under the driving action of external force, and two sides of the second movable plate are respectively abutted against the elastic piece and the pressure sensor.

In one possible implementation of the application, the second movable plate is a rigid plate, and/or

The thickness of the second movable plate is 0.2mm to 0.5mm, and/or

The material for preparing the second movable plate is metal, or alloy, or fiber composite material.

In one possible implementation of the application, the elastic member comprises a number of springs.

In one possible implementation manner of the present application, the test fixture further includes a locking member, the locking member is connected to the guide rod, the top plate is sleeved on the guide rod and can move along the guide rod, and the locking member is used for fixing the top plate on the guide rod.

In one possible implementation of the application, the distance measuring element is a scale or a displacement sensor.

The second aspect of the application provides a battery cell testing system, which comprises a battery cell and the testing fixture.

The beneficial effects are that:

According to the application, the top plate is fixedly connected with the guide rod, the position of the top plate in the length direction of the guide rod is adjustable, the first movable plate is movably sleeved on the guide rod and can move along the length direction of the guide rod under the action of external force driving, a cell to be tested is placed between the top plate and the first movable plate, the distance measuring piece is used for acquiring the position of the first movable plate on the guide rod or the moving distance along the guide rod in the test process, and the pressure sensor is used for acquiring the extrusion force of the first movable plate in the length direction of the guide rod in the test process, so that the expansion deformation and the expansion force of the cell in the charge-discharge process can be accurately measured.

In addition, compared with some test fixtures which apply a certain pretightening force and directly clamp the surface of the battery cell, the test fixture can prevent the battery cell to be tested between the top plate and the first movable plate from being pretightened by the top plate or the first movable plate before testing by adjusting the position of the top plate in the length direction of the guide rod, thereby being beneficial to further improving the test accuracy.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings that are needed in the description of the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present utility model, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Reference numerals:

100. Test fixture 10, frame 11, bottom plate 12, top plate 13, guide rod 20, elastic member 30, movable assembly 31, first movable plate 32, second movable plate 40, pressure sensor 50, distance measuring member 60 and locking member.

FIG. 1 is a schematic view of a first embodiment of a test fixture according to an embodiment of the present application;

FIG. 2 is a schematic diagram of a second embodiment of a test fixture provided in an embodiment of the present application;

FIG. 3 is a schematic view of an assembly of one embodiment of a top plate, guide bar and retaining member provided in an embodiment of the present application;

fig. 4 is an assembly schematic diagram of an embodiment of the first movable plate, the guide bar, and the distance measuring member provided in the embodiment of the present application.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to fall within the scope of the utility model.

In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate orientations or positional relationships based on the drawings are merely for convenience in describing the present utility model and simplifying the description, and do not indicate or imply that the apparatus or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more of the described features. In the description of the present utility model, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In the present utility model, the term "exemplary" is used to mean "serving as an example, instance, or illustration. Any embodiment described as "exemplary" in this disclosure is not necessarily to be construed as preferred or advantageous over other embodiments. The following description is presented to enable any person skilled in the art to make and use the utility model. In the following description, details are set forth for purposes of explanation. It will be apparent to one of ordinary skill in the art that the present utility model may be practiced without these specific details. In other instances, well-known structures and processes have not been described in detail so as not to obscure the description of the utility model with unnecessary detail. Thus, the present utility model is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.

At present, new energy automobiles are raised worldwide, and lithium ion power batteries with high specific energy, high power and long service life are widely applied to the fields of electric automobiles, large energy storage and the like. The battery cell belongs to a core component of the lithium ion power battery, and the development of the battery cell technology is also gradually changed, so that the development of the battery cell is in progress. For example, unlike conventional artificial graphite-based negative lithium ion cells, lithium metal negative cells have a greater energy density, but their expansion behavior during charge and discharge is also significantly different from that of conventional graphite-based negative lithium cells, particularly with the expansion and contraction during charge and discharge, resulting in higher and reversible volume changes. Therefore, in the development process of the battery system, the battery cells need to be subjected to a cyclic test to explore the cyclic performance and the expansion behavior of the battery cells, and test data are provided for the design of the battery module. In view of this, it is necessary to develop a test fixture capable of more accurately measuring the expansion deformation and expansion force of the battery cells during charge and discharge.

The application provides a novel test fixture, which simulates the real expansion condition of a battery cell through an elastic piece, a movable assembly and a pressure sensor, enables the battery cell to expand freely through a top plate, a spring and the movable assembly, avoids deformation caused by the fact that the battery cell is extruded by a housing by pretightening force before testing, limits expansion, and interferes the inside of the battery cell, so that the test accuracy is improved, and the expansion and service life prediction accuracy of the battery cell is further improved. For ease of understanding, the test fixture of the present application is further described below in connection with specific embodiments.

Referring to fig. 1 to 4, an embodiment of the present application provides a test fixture 100 for testing the expansion deformation and expansion force of a cell. Illustratively, the cell may be a lithium metal negative electrode cell, with the cell having a generally square configuration. Of course, the test fixture 100 of the present application may be used in other situations where the inflation process is required to be tested, and is not limited thereto.

In an embodiment of the present application, the test fixture 100 includes a frame 10, an elastic member 20, a movable assembly 30, a pressure sensor 40, and a distance measuring member 50. Wherein the frame 10 is used to provide support and provide installation space. The movable assembly 30 and the elastic assembly are used for supporting the battery cell to be tested and moving under the extrusion action of the battery cell when the battery cell expands. The pressure sensor 40 is used for acquiring a pressure value generated in the cell expansion process, and the distance measuring piece 50 is used for acquiring a deformation amount generated in the cell expansion process.

In the embodiment of the application, the frame 10 comprises a bottom plate 11, a top plate 12 and a plurality of parallel directional rods 13, wherein the top plate 12 and the bottom plate 11 are respectively fixedly connected with each of the directional rods 13 and are oppositely arranged along the length direction of the directional rods 13, and the position of the top plate 12 in the length direction of the directional rods 13 can be adjusted.

Specifically, the bottom plate 11 and the top plate 12 are substantially square and are disposed substantially in parallel, and the orthographic projections of the bottom plate 11 and the top plate 12 substantially coincide. The frame 10 includes four guide bars 13, each guide bar 13 extending in a vertical direction, that is, a length direction of the guide bar 13 is a vertical direction. Four guide bars 13 are provided corresponding to the four corners of the bottom plate 11 and the top plate 12, respectively, and each guide bar 13 is provided substantially perpendicular to the bottom plate 11 and the top plate 12, respectively.

Specifically, the bottom plate 11 is disposed near the bottom end of the guide bar 13 and is fixedly connected to the guide bar 13. For example, the base plate 11 is screwed with the guide bar 13 by welding.

Specifically, the top plate 12 is disposed at an end of the guide bar 13 facing away from the bottom end. The top plate 12 is provided with mounting holes at positions corresponding to the guide rods 13, the mounting holes are used for being matched with the guide rods 13, the top plate 12 is sleeved on the guide rods 13 through the mounting holes, and the top plate 12 can move up and down along the length direction of the guide rods 13 so as to change the position of the top plate 12 in the length direction of the guide rods 13. After the top plate 12 is adjusted to the proper position, the top plate 12 is fixed on the guide rod 13, so that the top plate 12 is prevented from moving in the testing process.

Illustratively, the top plate 12 has a thickness of 1mm to 2mm.

Further, the test fixture 100 further includes a locking member 60, the locking member 60 is connected to the guide rod 13, and the locking member 60 is used for fixing the top plate 12 on the guide rod 13. Illustratively, the locking member 60 may be a threaded fastener, with external threads on the guide bar 13 correspondingly, which cooperate with the external threads on the guide bar 13 to secure the top plate 12 to the guide bar 13. Of course, in other embodiments of the present application, a plurality of positioning holes may be provided on the guide rod 13, and accordingly, the locking member 60 may be a positioning pin, through which the top plate 12 is fixed to the guide rod 13.

In the embodiment of the present application, the movable assembly 30 includes a first movable plate 31 located between the bottom plate 11 and the top plate 12, where the first movable plate 31 is movably sleeved on the guide rod 13, and can move along the length direction of the guide rod 13 under the driving action of an external force. And a battery core to be tested is placed between the top plate 12 and the first movable plate 31.

Specifically, the first movable plate 31 is slidably connected to the guide rod 13. It should be noted that the specific manner in which the first movable plate 31 is slidably connected to the guide rod 13 is not a major improvement of the present application, and is not limited herein.

Specifically, the first movable plate 31 and the top plate 12 are rigid plates. In this way, deformation of the top plate 12 during the testing process can be avoided, which is beneficial to improving the testing accuracy. The rigid plate has high strength and is not easy to deform. Illustratively, the material from which the first movable plate 31 and the top plate 12 are made is a metal, or an alloy, or a fiber composite. In addition, in order to further improve the test accuracy, the thickness of the first movable plate 31 needs to be thin, for example, the thickness of the first movable plate 31 is 0.2mm to 0.5mm.

Specifically, the first movable plate 31 is generally square, and a surface of the first movable plate 31 facing the battery cell is adapted to a surface of the battery cell facing the first movable plate 31. The surface of the first movable plate 31 facing the battery cell is a horizontal surface, and correspondingly, the surface of the first movable plate 31 facing the battery cell is also a horizontal surface, so that a larger contact area between the battery and the first movable plate 31 in the testing process can be ensured, and the testing precision is improved.

In the embodiment of the present application, the distance measuring member 50 is used to obtain the position of the first movable plate 31 on the guide bar 13 or the distance along the guide bar 13 during the test. It will be appreciated that during testing, since the top plate 12 is fixed to the guide bar 13, there is no relative movement between the top plate 12 and the guide bar 13. The first movable plate 31 is pressed during the expansion of the battery cell, so that the first movable plate 31 moves downward along the guide rod 13. When the cell expansion reaches the maximum and starts to shrink, the first movable plate 31 moves upward along the guide rod 13 under the elastic action of the elastic member 20. In this way, the distance measuring member 50 obtains the position of the first movable plate 31 on the guide rod 13 or the distance along the guide rod 13 during the test, so as to obtain the expansion deformation of the battery cell. Illustratively, the distance measuring member 50 may be a scale or a displacement sensor. Taking the distance measuring piece 50 as a scale, the position of the first movable plate 31 in the idle state may be a position with the scale of zero on the distance measuring piece 50.

In the embodiment of the present application, the pressure sensor 40 is configured to obtain the pressing force applied to the first movable plate 31 in the length direction of the guide rod 13 during the testing process. Similarly, the first movable plate 31 is pressed during the expansion process of the battery cell, and the pressing force of the first movable plate 31 on the guide rod 13 is obtained during the test process by the pressure sensor 40, so that the expansion force of the battery cell can be obtained.

In summary, the top plate 12 is fixedly connected with the guide rod 13, the position of the top plate 12 in the length direction of the guide rod 13 is adjustable, the first movable plate 31 is movably sleeved on the guide rod 13 and can move along the length direction of the guide rod 13 under the action of external force driving, a battery cell to be tested is placed between the top plate 12 and the first movable plate 31, the distance measuring piece 50 is used for acquiring the position of the first movable plate 31 on the guide rod 13 or the moving distance along the guide rod 13 in the test process, and the pressure sensor 40 is used for acquiring the extrusion force of the first movable plate 31 in the length direction of the guide rod 13 in the test process, so that the expansion deformation and the expansion force of the battery cell in the charge-discharge process can be accurately measured.

In addition, compared with some test fixtures which apply a certain pretightening force to directly clamp the surface of the battery cell, the test fixture 100 in the application can prevent the battery cell to be tested between the top plate 12 and the first movable plate 31 from being pretightened by the top plate 12 or the first movable plate 31 before testing by adjusting the position of the top plate 12 in the length direction of the guide rod 13, thereby being beneficial to further improving the test accuracy.

In some embodiments of the present application, a groove is formed on a surface of the bottom plate 11 facing the top plate 12, the groove is used for installing the pressure sensor 40, and an end of the elastic member 20 facing away from the first movable plate 31 abuts against the bottom plate 11 through the pressure sensor 40. This embodiment is advantageous in that the stability of the pressure sensor 40 is improved by providing a recess in the side of the bottom plate 11 facing the top plate 12 for mounting the pressure sensor 40.

In some embodiments of the present application, the movable assembly 30 further includes a second movable plate 32, the second movable plate 32 is disposed between the elastic member 20 and the pressure sensor 40, the second movable plate 32 is movably sleeved on the guide rod 13 and can move along the length direction of the guide rod 13 under the driving action of an external force, and two sides of the second movable plate 32 respectively abut against the elastic member 20 and the pressure sensor 40. In this embodiment, the second movable plate 32 is movably sleeved on the guide rod 13, so that the pressure sensors 40 with different sizes can be installed between the second movable plate 32 and the bottom plate 11, which is beneficial to improving the application scenario of the test fixture 100 in the present application.

Illustratively, the second movable plate 32 is a rigid plate. The material of which the second movable plate 32 is made is a metal, or an alloy, or a fiber composite material. In addition, in order to further improve the test accuracy, the thickness of the first movable plate 31 needs to be thin, for example, the thickness of the second movable plate 32 is 0.2mm to 0.5mm.

In some embodiments of the application, the elastic member 20 comprises a plurality of springs. It should be noted that the number of springs and the spring rate of each spring may be set as required. The spring rate of a spring directly affects the stiffness and elastic deformability of the spring. The larger the spring rate, the larger the spring rate and the smaller the deformation. Under the same stress condition, the spring with a large elastic coefficient is more difficult to deform than the spring with a small elastic coefficient, and has higher rigidity and higher elastic capability. Therefore, in practical applications, it is necessary to select an appropriate spring type and spring rate according to specific needs. For example, for square aluminum cells where deformation is more pronounced and the deformation locations are concentrated on a large central plane, springs with larger outer diameters and elastic coefficients of 8000N/M to 120000N/M may be used. For another example, for a large energy storage cell, the cell is larger in size, heavy in weight and insignificant in deformation, and a spring with a higher spring coefficient is required to be selected at this time, which is about 20000N/M. For another example, for a soft-package cell with smaller deformation in the thickness direction, lower bearable stress and a deformation position of the whole large surface, a plurality of root springs can be used, each spring has an outer diameter of 1 cm, and five springs are taken as an example and are respectively arranged at four corner points and the central large surface of the cell, and the elastic modulus of the springs is 100GPa to 140GPa.

The test procedure is described below in connection with the specific construction of the test fixture.

Before testing, the mass M of the battery cell to be tested is weighed and recorded, and the thickness H of the battery cell is measured. According to the mass of the battery cell to be measured and the spring constant (or the elastic piece 20) of the spring, the initial compression deformation X of the battery cell when the battery cell is loaded on the spring is calculated by a formula of KX=Mg, wherein g is a gravity constant.

Then, the spring is compressed to make its deformation amount X, at this time, the cell to be tested is placed on the first movable plate 31.

After the to-be-measured cell on the first movable plate 31 is basically stable, the top plate 12 is adjusted to move towards the first movable plate 31, so that the distance between the top plate 12 and the first movable plate 31 is H, one surface of the top plate 12 facing the first movable plate 31 is just contacted with one surface of the to-be-measured cell facing the top plate 12, at this time, the top plate 12 does not have extrusion force along the length direction of the guide rod 13, interference is not caused to the to-be-measured cell, and then the top plate 12 is fixed on the guide rod 13.

And performing performance test on the battery cell to be tested. The performance test includes, but is not limited to, a cycle test, a storage test, a lithium precipitation test, etc., and the battery cells undergo volume expansion during the performance test, and the expanded battery cells press the first movable plate 31 and press the spring, the second movable plate 32, and the pressure sensor 40 through the first movable plate 31. The pressure sensor 40 acquires the extrusion force of the first movable plate 31 in the length direction of the guide rod 13 in real time, and the distance measuring piece 50 acquires the position of the first movable plate 31 on the guide rod 13 in real time, so that the expansion deformation and the expansion force of the battery cell in the performance test process of the battery cell to be tested can be obtained.

For example, the test fixture 100 provided by the embodiment of the present application may obtain the position of the first movable plate 31 of the battery cell in the 0SOC state at different test stages, so as to obtain the time point and the deformation amount of the irreversible expansion in the whole test process. The full test process may be to continuously cycle the cell from a start state to an end of life, i.e., a BOL state to an EOL state. The different test phases refer to the change of a certain time point in the whole test process, such as the 50 th circle of the battery cell cycle, corresponding to the change at the 0SOC time.

Also, for example, the test fixture 100 provided by the embodiment of the present application can test the initial position of the first movable plate 31 in the state of BOL 0SOC and the position of the first movable plate 31 in the state of EOL 0SOC, so as to obtain the accurate irreversible deformation amount of the battery cell.

In the foregoing embodiments, the descriptions of the embodiments are focused on, and the portions of one embodiment that are not described in detail in the foregoing embodiments may be referred to in the foregoing detailed description of other embodiments, which are not described herein again.

While the basic concepts have been described above, it will be apparent to those skilled in the art that the foregoing detailed disclosure is by way of example only and is not intended to be limiting. Although not explicitly described herein, various modifications, improvements and adaptations of the application may occur to one skilled in the art. Such modifications, improvements, and modifications are intended to be suggested within the present disclosure, and therefore, such modifications, improvements, and adaptations are intended to be within the spirit and scope of the exemplary embodiments of the present disclosure.

Meanwhile, the present application uses specific words to describe embodiments of the present application. Reference to "one embodiment," "an embodiment," and/or "some embodiments" means that a particular feature, structure, or characteristic is associated with at least one embodiment of the application. Thus, it should be emphasized and should be appreciated that two or more references to "an embodiment" or "one embodiment" or "an alternative embodiment" in various positions in this specification are not necessarily referring to the same embodiment. Furthermore, certain features, structures, or characteristics of one or more embodiments of the application may be combined as suitable.

Similarly, it should be noted that in order to simplify the description of the present disclosure and thereby aid in understanding one or more inventive embodiments, various features are sometimes grouped together in a single embodiment, figure, or description thereof. This method of disclosure does not imply that the subject utility model requires more features than are set forth in the claims. Indeed, less than all of the features of a single embodiment disclosed above.

In some embodiments, numbers describing the components, number of attributes are used, it being understood that such numbers being used in the description of embodiments are modified in some examples by the modifier "about," approximately, "or" substantially. Unless otherwise indicated, "about," "approximately," or "substantially" indicate that the number allows for a 20% variation. Accordingly, in some embodiments, numerical parameters set forth in the specification and claims are approximations that may vary depending upon the desired properties sought to be obtained by the individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and employ a method for preserving the general number of digits. Although the numerical ranges and parameters set forth herein are approximations in some embodiments for use in determining the breadth of the range, in particular embodiments, the numerical values set forth herein are as precisely as possible.

While the foregoing describes in detail a test fixture and a system for testing a battery cell according to embodiments of the present utility model, specific examples are used herein to illustrate the principles and embodiments of the present utility model, the foregoing examples are provided for aiding in understanding of the method and core concept of the present utility model, and meanwhile, the present disclosure should not be construed as limiting the utility model to any extent possible, as long as the person skilled in the art can make any changes in the specific embodiments and application scope according to the inventive concept.

Claims (10)

1. The test fixture is characterized by being used for testing the expansion deformation and expansion force of the battery cell, and comprises a frame, an elastic piece, a movable component, a pressure sensor and a distance measuring piece;

The frame comprises a bottom plate, a top plate and a plurality of guide rods which are arranged in parallel, wherein the top plate and the bottom plate are respectively fixedly connected with each guide rod and are oppositely arranged along the length direction of the guide rods;

the movable assembly comprises a first movable plate, a first connecting rod, a second connecting rod, a first connecting rod and a second connecting rod, wherein the first movable plate is positioned between the bottom plate and the top plate, and is movably sleeved on the guide rod and can move along the length direction of the guide rod under the driving action of external force;

The elastic piece is arranged on one side of the first movable plate, which faces the bottom plate, and two ends of the elastic piece are respectively abutted against the first movable plate and the bottom plate;

The distance measuring piece is used for acquiring the position of the first movable plate on the guide rod or the moving distance along the guide rod in the test process;

the pressure sensor is used for acquiring the extrusion force of the first movable plate in the length direction of the guide rod in the testing process.

2. The test fixture of claim 1, wherein a recess is provided in a side of the bottom plate facing the top plate, the recess being configured to mount the pressure sensor, and an end of the elastic member facing away from the first movable plate is abutted to the bottom plate by the pressure sensor.

3. The test fixture of claim 1, wherein the first movable plate is a rigid plate, and/or

The thickness of the first movable plate is 0.2mm to 0.5mm.

4. A test fixture as claimed in claim 3, wherein the material from which the first movable plate is made is a metal, or an alloy, or a fibre composite.

5. The test fixture of any one of claims 1-4, wherein the movable assembly further comprises a second movable plate, the second movable plate is arranged between the elastic piece and the pressure sensor, the second movable plate is movably sleeved on the guide rod and can move along the length direction of the guide rod under the driving action of an external force, and two sides of the second movable plate are respectively abutted against the elastic piece and the pressure sensor.

6. The test fixture of claim 5, wherein the second movable plate is a rigid plate, and/or

The thickness of the second movable plate is 0.2mm to 0.5mm, and/or

The material for preparing the second movable plate is metal, or alloy, or fiber composite material.

7. The test fixture of any one of claims 1-4, wherein the resilient member comprises a plurality of springs.

8. The test fixture of any one of claims 1 to 4, further comprising a locking member coupled to the guide bar, the top plate being positioned over and movable along the guide bar, the locking member being configured to secure the top plate to the guide bar.

9. A test fixture as claimed in any one of claims 1 to 4, wherein the distance measuring member is a scale or a displacement sensor.

10. A cell testing system, characterized in that it comprises a cell and a test fixture according to any of claims 1 to 9.