Test fixture and battery cell test system

Abstract

The utility model provides a test fixture and a battery cell test system, and relates to the technical field of battery test. The test fixture comprises a frame, an elastic piece, a movable assembly, a pressure sensor and a distance measuring piece. A top plate is fixedly connected with a guide rod, the position of the top plate in the length direction of the guide rod is adjustable, and a first movable plate movably sleeves the guide rod and can move in the length direction of the guide rod under the driving action of external force; a to-be-tested battery cell is placed between the top plate and the first movable plate, and the distance measuring piece is used for obtaining the position of the first movable plate on the guide rod or the moving distance of the first movable plate along the guide rod in the testing process. The pressure sensor is used for obtaining the extrusion force borne by the first movable plate in the length direction of the guide rod in the testing process, and therefore the expansion deformation and the expansion force of the battery cell in the charging and discharging period can be accurately measured.

Description

Technical Field

[0001] The present application relates to the technical field of battery testing, and particularly relates to a test fixture and a battery cell testing system. Background Art

[0002] Currently, new energy vehicles are emerging worldwide. Lithium-ion power batteries with high specific energy, high power, and long life are widely used in fields such as electric vehicles and large energy storage. The battery cell is the core component of the lithium-ion power battery, and the development of battery cell technology is also advancing rapidly and is in the ascendant. For example, different from traditional artificial graphite-based anode lithium-ion battery cells, lithium metal anode battery cells have a larger energy density, but their expansion performance during charge and discharge is also quite different from that of traditional graphite-based anode lithium-ion battery cells. Specifically, it is manifested that with the expansion and contraction during the charge and discharge process, it brings a relatively high and reversible volume change.

[0003] Therefore, during the development of the battery system, it is necessary to conduct cycle tests on the battery cells to explore the cycle performance and expansion behavior of the battery cells and provide test data for the design of the battery module. Utility Model Content

[0004] The present application provides a test fixture and a battery cell testing system. The test fixture can accurately measure the expansion deformation and expansion force of the battery cell during charge and discharge.

[0005] On the one hand, the present application provides a test fixture for testing the expansion deformation amount and expansion force of a battery cell. The test fixture includes a frame, an elastic member, a movable assembly, a pressure sensor, and a distance measuring member;

[0006] The frame includes a bottom plate, a top plate, and a plurality of parallel guide rods. The top plate and the bottom plate are respectively fixedly connected to each guide rod and are oppositely arranged along the length direction of the guide rod; the position of the top plate in the length direction of the guide rod is adjustable;

[0007] The movable assembly includes a first movable plate located between the bottom plate and the top plate. 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 an external driving force; the battery cell to be tested is placed between the top plate and the first movable plate;

[0008] The elastic member is arranged on the side of the first movable plate facing the bottom plate, and its two ends are respectively abutted against the first movable plate and the bottom plate;

[0009] The distance measuring member is used to obtain the position of the first movable plate on the guide rod or the moving distance along the guide rod during the test;

[0010] The pressure sensor is used to obtain the squeezing force exerted on the first movable plate in the length direction of the guide rod during the test.

[0011] In a possible implementation of the present application, a groove is provided on a side of the bottom plate facing the top plate, the groove is used to install the pressure sensor, and an end of the elastic member facing away from the first movable plate abuts against the bottom plate through the pressure sensor.

[0012] In a possible implementation of the present application, the first movable plate is a rigid plate; and / or

[0013] The thickness of the first movable plate is 0.2 mm to 0.5 mm.

[0014] In a possible implementation of the present application, the material used to make the first movable plate is metal, alloy, or fiber composite material.

[0015] In a possible implementation of the present application, the movable component also includes a second movable plate, which is arranged between the elastic member and the pressure sensor, and the second movable plate can be movably mounted on the guide rod, and can move along the length direction of the guide rod under the action of external force; the two sides of the second movable plate are respectively abutted against the elastic member and the pressure sensor.

[0016] In a possible implementation of the present application, the second movable plate is a rigid plate; and / or

[0017] The thickness of the second movable plate is 0.2 mm to 0.5 mm; and / or

[0018] The material for making the second movable plate is metal, alloy, or fiber composite material.

[0019] In a possible implementation of the present application, the elastic member includes a plurality of springs.

[0020] In a possible implementation of the present application, the test fixture also includes a locking piece, which 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 piece is used to fix the top plate on the guide rod.

[0021] In a possible implementation of the present application, the distance measuring component is a scale or a displacement sensor.

[0022] A second aspect of the present application provides a battery cell testing system, which includes a battery cell and the test fixture.

[0023] Beneficial effects:

[0024] In this application, the top plate is fixedly connected to the guiding rod, and the position of the top plate in the length direction of the guiding rod is adjustable. The first movable plate is movably sleeved on the guiding rod and can move along the length direction of the guiding rod under the action of an external driving force. A to-be-tested battery cell is placed between the top plate and the first movable plate. The distance measuring member is used to obtain the position of the first movable plate on the guiding rod or the moving distance along the guiding rod during the test, and the pressure sensor is used to obtain the extrusion force received by the first movable plate in the length direction of the guiding rod during the test, so that the expansion deformation and expansion force of the battery cell during charge and discharge can be measured more accurately.

[0025] In addition, compared with some test jigs that directly clamp the surface of the battery cell with a certain pre-tightening force, before the test, the test jig in this application can adjust the position of the top plate in the length direction of the guiding rod, so that the to-be-tested battery cell located between the top plate and the first movable plate can avoid being subjected to the pre-tightening force applied by the top plate or the first movable plate before the test, which is beneficial to further improving the test accuracy. Description of the Drawings

[0026] In order to more clearly illustrate the technical solutions in the embodiments of this application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0027] Reference Numerals in the Drawings:

[0028] 100, test jig; 10, frame; 11, bottom plate; 12, top plate; 13, guiding rod; 20, elastic member; 30, movable assembly; 31, first movable plate; 32, second movable plate; 40, pressure sensor; 50, distance measuring member; 60, locking member.

[0029] Figure 1 is a schematic structural diagram of the first embodiment of the test jig provided by the embodiment of this application;

[0030] Figure 2 is a schematic structural diagram of the second embodiment of the test jig provided by the embodiment of this application;

[0031] Figure 3 is an assembly schematic diagram of an embodiment of the top plate, guiding rod and locking member provided by the embodiment of this application;

[0032] Figure 4 is an assembly schematic diagram of an embodiment of the first movable plate, guiding rod and distance measuring member provided by the embodiment of this application. Detailed Description of the Embodiments

[0033] Next, in combination with the accompanying drawings in the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts belong to the protection scope of the present invention.

[0034] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation to the present invention.

[0035] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood 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 the described features. In the description of the present invention, "a plurality" means two or more, unless otherwise specifically defined.

[0036] In this application, the word "exemplary" is used to mean "serving as an example, illustration, or description". Any embodiment described as "exemplary" in this application is not necessarily to be construed as more preferred or more advantageous than other embodiments. In order for any person skilled in the art to implement and use the present invention, the following description is given. In the following description, details are set forth for the purpose of explanation. It should be understood that those of ordinary skill in the art can recognize that the present invention can be implemented without the use of these specific details. In other instances, well-known structures and processes are not elaborated in detail to avoid unnecessary details from obscuring the description of the present invention. Therefore, the present invention 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 in this application.

[0037] At present, new energy vehicles are emerging worldwide. Lithium-ion power batteries with high specific energy, high power, and long life are widely used in electric vehicles, large energy storage, and other fields. The battery cell is the core component of the lithium-ion power battery, and the development of battery cell technology is also changing with each passing day and is in the ascendant. For example, different from traditional artificial graphite-based negative electrode lithium-ion battery cells, lithium metal negative electrode battery cells have a larger energy density, but their expansion performance during charging and discharging is also quite different from that of traditional graphite-based negative electrode lithium-ion battery cells. Specifically, it is manifested in the expansion and contraction during the charging and discharging process, bringing a relatively high and reversible volume change. Therefore, during the development of the battery system, it is necessary to conduct cyclic tests on the battery cells to explore the cyclic performance and expansion behavior of the battery cells and provide test data for the design of the battery module. In view of this, it is necessary to develop a test fixture that can accurately measure the expansion deformation and expansion force of the battery cell during charging and discharging.

[0038] This application provides a new test fixture, which simulates the true expansion situation of the battery cell through an elastic member, a movable component, and a pressure sensor. The battery cell can expand freely through the top plate, the spring, and the movable component, avoiding the deformation of the battery cell caused by the pre-tightening force squeezing the housing before the test, restricting the expansion, and causing interference to the inside of the battery cell, thereby improving the accuracy of the test and further improving the accuracy of predicting the expansion and life of the battery cell. For the convenience of understanding, the test fixture in this application will be further described below with reference to specific embodiments.

[0039] Please refer to Figures 1 to 4 , an embodiment of this application provides a test fixture 100 for testing the expansion deformation amount and expansion force of a battery cell. Exemplarily, the battery cell can be a lithium metal negative electrode battery cell, and the battery is generally square in structure. Of course, the test fixture 100 in this application can also be used in other scenarios that require testing the expansion process, which is not limited here.

[0040] In the embodiment of this application, the test fixture 100 includes a frame 10, an elastic member 20, a movable component 30, a pressure sensor 40, and a ranging member 50. Among them, the frame 10 is used to provide support and an installation space. The movable component 30 and the elastic component are used to support the battery cell to be tested and move under the extrusion of the battery cell when the battery cell expands. The pressure sensor 40 is used to obtain the pressure value generated during the expansion of the battery cell, and the ranging member 50 is used to obtain the deformation amount generated during the expansion of the battery cell.

[0041] In the embodiment of this application, the frame 10 includes a bottom plate 11, a top plate 12, and a plurality of parallel guide rods 13. The top plate 12 and the bottom plate 11 are respectively fixedly connected to each of the guide rods 13 and are arranged opposite to each other along the length direction of the guide rods 13; the position of the top plate 12 in the length direction of the guide rods 13 is adjustable.

[0042] Specifically, the bottom plate 11 and the top plate 12 are generally square and are generally arranged in parallel, and the orthographic projections of the bottom plate 11 and the top plate 12 largely coincide. The frame 10 includes four guide rods 13, each guide rod 13 extending in the vertical direction, that is, the length direction of the guide rod 13 is the vertical direction. The four guide rods 13 are respectively arranged corresponding to the four corners of the bottom plate 11 and the top plate 12, and each guide rod 13 is generally perpendicular to the bottom plate 11 and the top plate 12.

[0043] Specifically, the bottom plate 11 is arranged near the bottom end of the guide rod 13 and is fixedly connected to the guide rod 13. For example, the bottom plate 11 is threadedly connected or welded to the guide rod 13.

[0044] Specifically, the top plate 12 is arranged at one end of the guide rod 13 away from the bottom end. Mounting holes are provided at positions on the top plate 12 corresponding to the guide rods 13. The mounting holes are used to fit with the guide rods 13. The top plate 12 is sleeved on the plurality of guide rods 13 through the mounting holes and can move up and down along the length direction of the guide rods 13 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 a suitable position, the top plate 12 is fixed on the guide rod 13 to prevent the top plate 12 from moving during the test.

[0045] Exemplarily, the thickness of the top plate 12 is 1 mm to 2 mm.

[0046] 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 to fix the top plate 12 on the guide rod 13. Exemplarily, the locking member 60 can be a threaded fastener. Correspondingly, external threads are provided on the guide rod 13, and the threaded fastener cooperates with the external threads on the guide rod 13 to fix the top plate 12 on the guide rod 13. Of course, in some other embodiments of the present application, a plurality of positioning holes can also be provided on the guide rod 13. Correspondingly, the locking member 60 can be a positioning pin, and the top plate 12 is fixed on the guide rod 13 by inserting the positioning pin into the corresponding positioning hole.

[0047] 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. 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 an external driving force. A to-be-tested battery cell is placed between the top plate 12 and the first movable plate 31.

[0048] Specifically, the first movable plate 31 is slidably connected to the guide rod 13. It should be noted that the specific manner of the slidable connection between the first movable plate 31 and the guide rod 13 does not belong to the main improvement point of the present application and is not limited herein.

[0049] 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 test can be avoided, which is beneficial to improving the test accuracy. It should be noted that a rigid plate refers to a plate with high strength and is not easily deformed. Exemplarily, the materials for preparing the first movable plate 31 and the top plate 12 are metal, or alloy, or fiber composite material. In addition, to further improve the test accuracy, the thickness of the first movable plate 31 needs to be relatively thin. For example, the thickness of the first movable plate 31 is 0.2 mm to 0.5 mm.

[0050] Specifically, the first movable plate 31 is generally square, and the surface of the first movable plate 31 facing the battery cell is adapted to the surface of the battery cell facing the first movable plate 31. Exemplarily, the surface of the first movable plate 31 facing the battery cell is a horizontal plane. Correspondingly, the surface of the battery cell facing the first movable plate 31 is also a horizontal plane. In this way, it can be ensured that the battery has a large contact area with the first movable plate 31 during the test, which is beneficial to improving the test accuracy.

[0051] 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 rod 13 or the moving distance along the guide rod 13 during the test. It can be understood that during the test, since the top plate 12 is fixed on the guide rod 13, at this time, there is no relative movement between the top plate 12 and the guide rod 13. During the expansion of the battery cell, the first movable plate 31 will be squeezed, so that the first movable plate 31 moves downward along the guide rod 13. When the expansion of the battery cell reaches the maximum and begins to contract, the first movable plate 31 moves upward along the guide rod 13 under the elastic action of the elastic member 20. In this way, by obtaining the position of the first movable plate 31 on the guide rod 13 or the moving distance along the guide rod 13 through the distance measuring member 50 during the test, the magnitude of the expansion deformation of the battery cell can be obtained. Exemplarily, the distance measuring member 50 can be a scale or a displacement sensor. Taking the distance measuring member 50 as a scale as an example, the position where the first movable plate 31 is located in the no-load state can be the position with a scale of zero on the distance measuring member 50.

[0052] In the embodiment of the present application, the pressure sensor 40 is used to obtain the extrusion force received by the first movable plate 31 in the length direction of the guide rod 13 during the test. Similarly, during the expansion of the battery cell, the first movable plate 31 will be squeezed. By obtaining the extrusion force received by the first movable plate 31 on the guide rod 13 through the pressure sensor 40 during the test, the magnitude of the expansion force of the battery cell can be obtained.

[0053] In summary, in the present application, the top plate 12 is fixedly connected to 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 an external driving force; a to-be-tested battery cell is placed between the top plate 12 and the first movable plate 31, the distance measuring member 50 is used to obtain the position of the first movable plate 31 on the guide rod 13 or the moving distance along the guide rod 13 during the test, and the pressure sensor 40 is used to obtain the extrusion force received by the first movable plate 31 in the length direction of the guide rod 13 during the test, so that the expansion deformation and expansion force of the battery cell during charge and discharge can be measured more accurately.

[0054] In addition, compared with some test jigs that directly clamp the battery cell surface with a certain pre-tightening force, before the test, the test jig 100 in the present application can adjust the position of the top plate 12 in the length direction of the guide rod 13, so that the to-be-tested battery cell located between the top plate 12 and the first movable plate 31 can avoid the pre-tightening force applied by the top plate 12 or the first movable plate 31 before the test, which is beneficial to further improving the test accuracy.

[0055] In some embodiments of the present application, a groove is provided on the surface of the bottom plate 11 facing the top plate 12, and the groove is used to install the pressure sensor 40. One 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. In this embodiment, by providing a groove on the surface of the bottom plate 11 facing the top plate 12, and the groove is used to install the pressure sensor 40, it is beneficial to improve the stability of the pressure sensor 40.

[0056] 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 action of an external driving force; both sides of the second movable plate 32 abut against the elastic member 20 and the pressure sensor 40 respectively. In this embodiment, by providing the second movable plate 32, and the second movable plate 32 is movably sleeved on the guide rod 13, different sizes of pressure sensors 40 can be installed between the second movable plate 32 and the bottom plate 11, which is beneficial to improving the applicable scenarios of the test jig 100 in the present application.

[0057] Exemplarily, the second movable plate 32 is a rigid plate. The material for preparing the second movable plate 32 is metal, or alloy, or fiber composite material. In addition, to further improve the test accuracy, the thickness of the first movable plate 31 needs to be relatively thin. For example, the thickness of the second movable plate 32 is 0.2 mm to 0.5 mm.

[0058] In some embodiments of the present application, the elastic member 20 includes a plurality of springs. It should be noted that the number of springs and the magnitude of the elastic coefficient of each spring can be set according to needs. The elastic coefficient of the spring directly affects the stiffness and elastic deformation ability of the spring. The larger the elastic coefficient, the greater the stiffness of the spring and the smaller the deformation amount. Under the same force condition, a spring with a larger elastic coefficient is more difficult to deform than a spring with a smaller elastic coefficient, has a higher stiffness, and stronger elastic ability. Therefore, in practical applications, it is necessary to select the appropriate spring type and elastic coefficient according to specific requirements. Exemplarily, for a square aluminum battery cell with obvious deformation and the deformation position concentrated on the central large surface, a spring with a larger outer diameter and an elastic coefficient of 8000 N / M to 120000 N / M can be used. Another example is that for a large energy storage battery cell, the battery cell has a larger size, heavier weight, and less obvious deformation amount. At this time, a spring with a higher spring coefficient, about 20000 N / M, needs to be selected. Another example is that for a soft-pack battery cell with a smaller deformation amount in the thickness direction, a lower stress tolerance, and the deformation position being the entire large surface, multiple springs can be used. Taking five springs as an example, each spring has an outer diameter of 1 cm and is respectively placed at the four corner points and the central large surface of the battery cell. The elastic modulus of the spring is 100 GPa to 140 GPa.

[0059] The following describes the test process in combination with the specific structure of the detection fixture.

[0060] Before the test, first weigh and record the mass M of the battery cell to be tested, and measure the thickness H of the battery cell. According to the mass of the battery cell to be tested and the spring constant of the spring (or the elastic member 20), the initial compression deformation amount X of the battery cell when it is carried on the spring is calculated by the formula: KX = Mg, where g is the gravitational constant.

[0061] Then, compress the spring to make its deformation amount X. At this time, place the battery cell to be tested on the first movable plate 31.

[0062] After the battery cell to be tested on the first movable plate 31 is basically stable, adjust the top plate 12 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, and the surface of the top plate 12 facing the first movable plate 31 just contacts the surface of the battery cell to be tested facing the top plate 12. At this time, the top plate 12 does not exert a squeezing force on the battery cell to be tested along the length direction of the guide rod 13 and does not interfere with the battery cell to be tested. Then fix the top plate 12 on the guide rod 13.

[0063] Perform performance tests on the battery cell to be tested. The performance tests include, but are not limited to, cycle tests, storage tests, lithium plating tests, etc. During the performance tests, the battery cell will experience volume expansion. The expanded and deformed battery cell will squeeze the first movable plate 31, and through the first movable plate 31, squeeze the spring, the second movable plate 32, and the pressure sensor 40. The pressure sensor 40 obtains in real time the extrusion force received by the first movable plate 31 in the length direction of the guide rod 13, and the distance measuring member 50 obtains in real time the position of the first movable plate 31 on the guide rod 13, so that the expansion deformation amount and expansion force of the battery cell to be tested during the performance test can be obtained.

[0064] Exemplarily, the test fixture 100 provided in the embodiment of the present application can obtain the position of the first movable plate 31 in the 0SOC state of the battery cell at different test stages, and the time point and deformation amount at which irreversible expansion occurs during the entire test process can be obtained. Among them, the entire test process can be to continuously cycle test the battery cell from the starting state to the end of its life, that is, from the BOL state to the EOL state. Different test stages refer to the changes at a certain time point during the entire test process. For example, when the battery cell cycles the 50th time, the corresponding changes at 0SOC.

[0065] Also exemplarily, the test fixture 100 provided in the embodiment of the present application can test the initial position of the first movable plate 31 of the battery cell in the BOL 0SOC state and the position of the first movable plate 31 in the EOL 0SOC state, so that the accurate irreversible deformation amount of the battery cell can be obtained.

[0066] In the above embodiments, the descriptions of each embodiment have their own focuses. For the parts not detailed in a certain embodiment, reference can be made to the detailed descriptions of other embodiments above, and they will not be repeated here.

[0067] The basic concepts have been described above. Obviously, for those skilled in the art, the above detailed disclosure is only an example and does not constitute a limitation to the present application. Although not explicitly stated here, those skilled in the art may make various modifications, improvements, and corrections to the present application. Such modifications, improvements, and corrections are proposed in the present application, so such modifications, improvements, and corrections still fall within the spirit and scope of the exemplary embodiments of the present application.

[0068] At the same time, the present application uses specific terms to describe the embodiments of the present application. Such as "one embodiment", "an embodiment", and / or "some embodiments" mean a certain feature, structure, or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that the "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more at different positions in this specification is not necessarily the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of the present application can be appropriately combined.

[0069] Similarly, it should be noted that, in order to simplify the description disclosed in this application and thus help the understanding of one or more utility model embodiments, in the foregoing description of the embodiments of this application, sometimes multiple features are incorporated into one embodiment, drawing or description thereof. However, this disclosure method does not mean that the features required by the object of this application are more than those mentioned in the claims. In fact, the features of the embodiments are less than all the features of the single embodiments disclosed above.

[0070] In some embodiments, numbers describing components and attribute quantities are used. It should be understood that such numbers used for the description of embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise specified, "about", "approximately" or "substantially" indicate that the numbers allow a variation of ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, and such approximate values may change according to the characteristics required by individual embodiments. In some embodiments, the numerical parameters should consider the specified significant digits and adopt the method of retaining the general number of digits. Although the numerical ranges and parameters used to confirm the breadth of the scope in some embodiments of this application are approximate values, in specific embodiments, the setting of such numerical values is as precise as possible within the feasible range.

[0071] The above has introduced in detail a test fixture and a battery cell test system provided by the embodiments of this application. Specific examples are used herein to elaborate on the principle and implementation manner of this utility model. The description of the above embodiments is only used to help understand the method and its core idea of this utility model; at the same time, for those skilled in the art, based on the idea of this utility model, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to this utility model.

Claims

1. A test fixture, characterized in that: Used for testing the expansion deformation and expansion force of the battery cell, the test fixture includes a frame, an elastic member, a movable component, a pressure sensor and a distance measuring member; The frame comprises a bottom plate, a top plate and a plurality of parallel guide rods, wherein the top plate and the bottom plate are respectively fixedly connected to each guide rod and are arranged opposite to each other along the length direction of the guide rod; the position of the top plate in the length direction of the guide rod is adjustable; The movable assembly includes a first movable plate located between the bottom plate and the top plate, the first movable plate can be movably mounted on the guide rod, and can move along the length direction of the guide rod under the driving action of an external force; the battery cell to be tested is placed between the top plate and the first movable plate; The elastic member is arranged on a side of the first movable plate facing the bottom plate, and two ends thereof are respectively in contact with the first movable plate and the bottom plate; The distance measuring member is used to obtain the position of the first movable plate on the guide rod or the distance moved along the guide rod during the test; The pressure sensor is used to obtain the squeezing force exerted on the first movable plate in the length direction of the guide rod during the test.

2. The test fixture according to claim 1, characterized in that: A groove is provided on a side of the bottom plate facing the top plate, and the groove is used to install the pressure sensor. An end of the elastic member facing away from the first movable plate abuts against the bottom plate through the pressure sensor.

3. The test fixture according to claim 1, characterized in that: The first movable plate is a rigid plate; and / or The thickness of the first movable plate is 0.2 mm to 0.5 mm.

4. The test fixture as claimed in claim 3, characterized in that: The material for making the first movable plate is metal, alloy, or fiber composite material.

5. The test fixture according to any one of claims 1 to 4, characterized in that: The movable component also includes a second movable plate, which is arranged between the elastic member and the pressure sensor. The second movable plate can be movably mounted on the guide rod and can move along the length direction of the guide rod under the action of external force; the two sides of the second movable plate are respectively abutted against the elastic member and the pressure sensor.

6. The test fixture as claimed in claim 5, characterized in that: The second movable plate is a rigid plate; and / or The thickness of the second movable plate is 0.2 mm to 0.5 mm; and / or The material for making the second movable plate is metal, alloy, or fiber composite material.

7. The test fixture according to any one of claims 1 to 4, characterized in that: The elastic member includes a plurality of springs.

8. The test fixture according to any one of claims 1 to 4, characterized in that: The test fixture further comprises a locking member, which is connected to the guide rod. The top plate is sleeved on the guide rod and can move along the guide rod. The locking member is used to fix the top plate on the guide rod.

9. The test fixture according to any one of claims 1 to 4, characterized in that: The distance measuring component is a scale or a displacement sensor.

10. A battery cell testing system, characterized in that: The battery cell testing system comprises a battery cell and the test fixture according to any one of claims 1 to 9.

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