A non-position limited cycling fixture for battery testing

Abstract

This utility model provides a non-limiting cyclic fixture for battery testing, belonging to the field of new energy batteries. The fixture includes a battery under test, an upper pressure plate, a lower pressure plate, a slide rod, a spring, and a pressure sensor. The battery under test is clamped between the upper and lower pressure plates. The pressure sensor is located on the side of the upper pressure plate away from the battery under test. A mounting hole is provided on the lower pressure plate. One end of the slide rod is fixedly connected to the upper pressure plate, and the other end passes through the mounting hole. The lower pressure plate is slidably mounted on the slide rod. The spring is sleeved on the slide rod and located on the side of the lower pressure plate away from the battery under test. Using the non-limiting cyclic fixture for battery testing provided by this utility model can solve the problem of low accuracy in test results in the prior art.

Description

Technical Field

[0001] This utility model relates to the field of new energy batteries, and in particular to an unrestricted cyclic clamp for battery testing. Background Technology

[0002] With the widespread application of lithium-ion batteries in electric vehicles, portable electronic devices, and energy storage systems, their cycle performance and safety performance are receiving increasing attention. During the charge-discharge cycle of a lithium-ion battery, the battery expands, which increases internal stress and consequently affects cycle life and safety performance. To study and control the expansion phenomenon during cycling, it is usually necessary to set up a battery cycle test fixture to clamp the battery.

[0003] In existing technologies, batteries are typically clamped between two fixing plates, with a pressure sensor positioned on the other side of the fixing plates to measure the expansion force of the battery pack. However, during battery charging and discharging, as the battery expands, the pressure applied to the battery by the clamp increases significantly, sometimes even doubling. This drastic pressure change can cause excessive stress on the battery, potentially damaging its internal structure, thus accelerating capacity decay and shortening cycle life. Furthermore, existing clamps often lack effective pressure regulation mechanisms, failing to maintain constant pressure during battery expansion, resulting in inaccurate expansion force measurements.

[0004] Existing cycle clamps typically use fixed plates to hold the battery pack, which accelerates battery capacity decay, shortens battery cycle life, and makes it difficult to apply constant pressure to the battery, resulting in low accuracy of test results. Utility Model Content

[0005] This utility model provides a non-limiting cyclic fixture for battery testing, which can solve the problem of low accuracy of test results in the prior art. The technical solution is as follows:

[0006] A non-limiting cyclic fixture for battery testing includes: a battery under test, an upper pressure plate, a lower pressure plate, a slide bar, a spring, and a pressure sensor.

[0007] The battery under test is clamped and disposed between the upper pressure plate and the lower pressure plate. The pressure sensor is disposed on the side of the upper pressure plate away from the battery under test. The lower pressure plate has a mounting hole. One end of the slide rod is fixedly connected to the upper pressure plate, and the other end passes through the mounting hole. The lower pressure plate is slidably disposed on the slide rod. The spring is sleeved on the slide rod and disposed on the side of the lower pressure plate away from the battery under test.

[0008] Optionally, an end cap is provided on the other end of the slide rod, and the spring is disposed between the lower pressure plate and the end cap. Multiple end caps are provided, and the multiple end caps have different heights.

[0009] Optionally, an end cap is provided on the other end of the slide rod, the spring is disposed between the lower pressure plate and the end cap, the slide rod is provided with external threads, the end cap is provided with internal threads, and the end cap and the slide rod are threadedly connected.

[0010] Optionally, a plurality of mounting holes are provided, the number of sliding rods matches the number of mounting holes, and the plurality of mounting holes are arranged in a rectangular array on the lower pressure plate.

[0011] Optionally, a fixing plate is provided on the side of the pressure sensor away from the upper pressure plate, and the pressure sensor is clamped and fixed between the fixing plate and the upper pressure plate.

[0012] Optionally, a support column is provided between the fixed plate and the upper pressure plate, and the height of the support column is the same as the height of the pressure sensor.

[0013] Optionally, the system further includes a signal conditioning circuit and a data acquisition system, wherein the pressure sensor is signal-connected to the signal conditioning circuit and the signal conditioning circuit is signal-connected to the data acquisition system.

[0014] Optionally, the spring is a rectangular cross-section compression spring.

[0015] The beneficial effects of the technical solution provided by this utility model embodiment include at least the following:

[0016] This utility model provides a non-limiting cyclic clamp for battery testing. An upper and lower pressure plate are used to clamp and fix the battery under test. During the test, the expansion force of the battery under test is transmitted to a pressure sensor through the upper pressure plate and recorded. Regarding the expansion force of the lower pressure plate, a spring and a sliding rod are provided. The expansion force of the battery under test pushes the lower pressure plate to slide on the sliding rod, thereby compressing the spring. Due to the effect of the spring, the pressure of the upper and lower pressure plates on the battery under test is significantly reduced when the battery expands, avoiding excessive stress that could damage the battery and extending its lifespan. This results in measured data that more closely reflects the true state of the battery under test, effectively solving the problem of low accuracy in existing test results. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall structure provided in an embodiment of the present utility model;

[0019] Figure 2 This is a schematic diagram of the lower pressure plate structure provided in an embodiment of the present utility model;

[0020] Figure 3 This is a schematic diagram of the spring cross-section structure provided in an embodiment of the present invention;

[0021] Figure 4 This is a schematic diagram of signal transmission provided in an embodiment of the present invention.

[0022] In the diagram: 1-Battery under test; 2-Upper pressure plate; 3-Lower pressure plate; 31-Mounting hole; 4-Slide rod; 5-Spring; 6-Pressure sensor; 61-Signal conditioning circuit; 62-Data acquisition system; 7-End cap; 8-Fixing plate; 9-Support column. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this utility model clearer, the embodiments of this utility model will be described in further detail below with reference to the accompanying drawings.

[0024] Figure 1 This is a schematic diagram of the overall structure provided in an embodiment of the present utility model; Figure 2 This is a schematic diagram of the lower pressure plate structure provided in an embodiment of the present utility model; Figure 3 This is a schematic diagram of the spring cross-section structure provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of signal transmission provided by an embodiment of this utility model. (See diagram below.) Figures 1 to 4 The diagram shows a non-limiting cyclic fixture for battery testing, comprising: a battery under test 1, an upper pressure plate 2, a lower pressure plate 3, a slide rod 4, a spring 5, and a pressure sensor 6. The battery under test 1 is clamped and disposed between the upper pressure plate 2 and the lower pressure plate 3. The pressure sensor 6 is disposed on the side of the upper pressure plate 2 away from the battery under test 1. The lower pressure plate 3 has a mounting hole 31. One end of the slide rod 4 is fixedly connected to the upper pressure plate 2, and the other end passes through the mounting hole 31. The lower pressure plate 3 is slidably disposed on the slide rod 4. The spring 5 is sleeved on the slide rod 4 and is disposed on the side of the lower pressure plate 3 away from the battery under test 1.

[0025] Exemplarily, in this embodiment of the invention, both the upper pressure plate 2 and the lower pressure plate 3 are made of high-strength alloy steel with anti-corrosion treatment, exhibiting good durability and stability. The dimensions of the upper pressure plate 2 and the lower pressure plate 3 are designed according to the size of the battery 1 under test. Typically, the area of ​​the upper pressure plate 2 and the lower pressure plate 3 is slightly larger than the area of ​​the upper and lower surfaces of the battery 1 under test to ensure uniform pressure distribution. The spring 5 is made of high-quality spring steel and has undergone surface treatment, exhibiting good elasticity and fatigue resistance. The spring 5 has a diameter of 25mm and a height of 30mm, with each spring having a load-bearing capacity of 60-70kg and a compression ratio of 40%. The spring diameter is 25mm, and the height of 30mm was chosen considering the expansion of the lithium-ion battery during cycling, ensuring sufficient compression space for the spring when the battery expands. The load-bearing capacity of the spring is 60-70kg, a range determined based on the expansion pressure characteristics of common lithium-ion batteries, effectively coping with pressure changes generated during battery cycling. A 40% compression ratio means that the spring can be compressed to 60% of its original height, that is, from 30mm to 18mm, providing enough flexibility to accommodate changes in battery expansion.

[0026] The device is placed on a workbench, and the battery under test 1 is placed on the lower pressure plate 3. Then, the upper pressure plate 2 is placed on the battery under test 1, and the slide rod 4 is installed through the mounting hole 31. At this time, the spring 5 is in direct contact with the workbench. When the battery under test 1 is installed between the upper pressure plate 2 and the lower pressure plate 3, the spring 5 is not in its shortest state and can still continue to be compressed. The end of the slide rod 4 is also located inside the spring 5 and does not contact the workbench, so that the battery under test 1 will not be interfered with by its own components when it expands. When cyclic testing is performed, the battery under test 1 expands. Since the lower pressure plate 3 has a spring 5 at the bottom, the battery under test 1 compresses the spring 5 after it expands. Due to the characteristics of the spring 5, the pushing force from the bottom on the battery under test remains unchanged. Therefore, the expansion force of the battery under test 1 on the upper pressure plate 2 can still be accurately measured by the pressure sensor 6. Through experimental comparison, it was found that the pressure changes particularly large during the charging and discharging process of the battery using a traditional fixture. When the battery discharges to the cutoff voltage, the pressure reaches the lowest value; when the battery charges to the cutoff voltage, the pressure reaches the maximum value, and the pressure increases by 40%. Such large pressure changes can damage the internal structure of the battery and shorten its cycle life. However, the non-limiting cycle clamp in this embodiment, due to the addition of spring 5, exhibits minimal pressure change during the charging and discharging of the battery under test 1, with a change of less than 10%. This is because when the battery under test 1 expands, spring 5 compresses, absorbing some of the expansion force and maintaining a relatively constant pressure on the battery. This design avoids excessive stress damaging the battery and effectively extends its cycle life.

[0027] This utility model provides a non-limiting cyclic fixture for battery testing. An upper pressure plate 2 and a lower pressure plate 3 are provided to clamp and fix the battery 1 under test. During the testing process, the expansion force of the battery 1 under test is transmitted to a pressure sensor 6 through the upper pressure plate 2 and recorded. Regarding the expansion force of the lower pressure plate 3, due to the presence of a spring 5 and a sliding rod 4, the expansion force of the battery 1 under test pushes the lower pressure plate 3 to slide on the sliding rod 4, thereby compressing the spring 5. Due to the action of the spring 5, when the battery 1 under test expands, the pressure of the upper pressure plate 2 and the lower pressure plate 3 on the battery under test is significantly reduced, avoiding excessive stress that could damage the battery and extending its lifespan. This results in measured data that more closely reflects the true state of the battery under test, effectively solving the problem of low accuracy in existing test results.

[0028] Optionally, an end cap 7 is provided on the other end of the slide bar 4, and a spring 5 is provided between the lower pressure plate 3 and the end cap 7. Multiple end caps 7 are provided, and the heights of the multiple end caps 7 are different.

[0029] Exemplarily, in this embodiment of the present invention, this arrangement allows the end cap 7 to directly contact the worktable, increasing the contact area between the device and the worktable and improving the stability of the fixture. By using multiple end caps 7 of different heights, the degree of compression of the spring 5 in the initial state can be adjusted. End caps 7 of different heights can also be selected to adapt to batteries 1 of different thicknesses, thereby preventing motion interference caused by mismatched end caps 7. This structure improves the applicability of the fixture.

[0030] Optionally, an end cap 7 is provided on the other end of the slide rod 1, the spring 5 is provided between the lower pressure plate 3 and the end cap 7, the slide rod 4 is provided with external threads, the end cap 7 is provided with internal threads, and the end cap 7 and the slide rod 4 are threadedly connected.

[0031] For example, in this embodiment of the present invention, this arrangement allows the bottom of the slide bar 4 to directly contact the worktable, and the end cap 7 is set in the form of a nut to cooperate with the thread on the slide bar 4, so that the end cap 7 can slide on the slide bar 4, thereby adjusting the compression degree of the spring 5 in the initial state. By setting the end cap 7 in this structure, it is not necessary to set multiple end caps 7 of different heights. The purpose of adjusting the initial compression degree of the spring 5 can be achieved simply by rotating the end cap 7, thereby improving the ease of operation of this fixture.

[0032] Optionally, multiple mounting holes 31 are provided, and the number of slide rods 4 matches the number of mounting holes 31. The multiple mounting holes 31 are arranged in a rectangular array on the lower pressure plate 3.

[0033] For example, in this embodiment of the present invention, the lower pressure plate 3 is a rectangular structure with four mounting holes 31 located at the four corners of the lower pressure plate 3. By providing multiple mounting holes 31 and multiple sliding rods 4, the force exerted on the lower pressure plate when the battery under test 1 expands is more stable, thereby making the data measured by the pressure sensor 6 more accurate, thus improving the accuracy of the test results of this fixture.

[0034] Optionally, a fixing plate 8 is provided on the side of the pressure sensor 6 away from the upper pressure plate 2, and the pressure sensor 6 is clamped and fixed between the fixing plate 8 and the upper pressure plate 2.

[0035] For example, in this embodiment of the present invention, the pressure sensor 6 can be fixed by setting the fixing plate 8 to prevent external forces from affecting the pressure sensor 6 during the test. On the other hand, the fixing plate 8 can also provide physical protection for the pressure sensor, thereby extending the service life of the fixture.

[0036] Optionally, a support column 9 is provided between the fixed plate 8 and the upper pressure plate 2, and the height of the support column 9 is the same as the height of the pressure sensor 6.

[0037] For example, in this embodiment of the present invention, by setting a support column 9, a supporting force can be provided for the fixing plate 8, preventing the fixing plate 8 from directly pressing on the pressure sensor 6 and interfering with the test value of the pressure sensor 6. By setting a support column 9 at the same height as the pressure sensor 6, the accuracy of the test results of this fixture can be further improved.

[0038] Optionally, it also includes a signal conditioning circuit 61 and a data acquisition system 62, with the pressure sensor 6 connected to the signal conditioning circuit 61 and the signal conditioning circuit 61 connected to the data acquisition system 62.

[0039] Exemplary, in embodiments of this utility model, such as Figure 4 As shown, pressure sensor 6 is connected to signal conditioning circuit 61 via a dedicated wire. The standard signal output from signal conditioning circuit 61 is connected to data acquisition system 62 via a data cable. Data acquisition system 62 can be a standalone data logger or a data acquisition card connected to a computer. The system sampling frequency is adjustable, typically set to 1Hz, meaning it acquires pressure data once per second, ensuring that pressure changes during the cycle of the battery under test 1 can be captured. This configuration ensures accurate reception of test results and accurate analysis of the data.

[0040] Optionally, spring 5 is a rectangular cross-section compression spring.

[0041] Exemplary, in embodiments of this utility model, such as Figure 3As shown, rectangular cross-section compression springs have high stiffness. Under the same spatial conditions, the stiffness of a rectangular cross-section cylindrical helical compression spring is greater than that of a circular cross-section spring. It can absorb more energy or generate a larger spring force, making it suitable for applications with large forces. Furthermore, the characteristic curve of a rectangular cross-section compression spring is closer to a straight line, which means that its stiffness is closer to a constant. This makes it suitable for force measuring devices that require stable spring stiffness. The rectangular cross-section design increases the force-bearing area of ​​spring 5, resulting in a more uniform load distribution, thereby improving the load-bearing capacity and stability of spring 5. This design also helps to improve the fatigue resistance and durability of spring 5.

[0042] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains. The terms “first,” “second,” and similar terms used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an” or “a” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “comprising” or “including” and similar terms mean that the elements or objects preceding “comprising” or “including” encompass the elements or objects listed following “comprising” or “including” and their equivalents, and do not exclude other elements or objects. The terms “connected” or “linked” and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms “upper,” “lower,” “left,” and “right” are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0043] The above description is only an optional embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A non-limiting cyclic fixture for battery testing, characterized in that, include: The components include the battery under test (1), the upper pressure plate (2), the lower pressure plate (3), the slide bar (4), the spring (5), and the pressure sensor (6). The battery under test (1) is clamped between the upper pressure plate (2) and the lower pressure plate (3). The pressure sensor (6) is located on the side of the upper pressure plate (2) away from the battery under test (1). The lower pressure plate (3) has a mounting hole (31). One end of the slide rod (4) is fixedly connected to the upper pressure plate (2), and the other end passes through the mounting hole (31). The lower pressure plate (3) is slidably mounted on the slide rod (4). The spring (5) is sleeved on the slide rod (4) and located on the side of the lower pressure plate (3) away from the battery under test (1).

2. The non-limiting cyclic fixture for battery testing according to claim 1, characterized in that, An end cap (7) is provided on the other end of the slide bar (4). The spring (5) is provided between the lower pressure plate (3) and the end cap (7). There are multiple end caps (7), and the heights of the multiple end caps (7) are different.

3. The non-limiting cyclic fixture for battery testing according to claim 1, characterized in that, An end cap (7) is provided on the other end of the slide rod (1), the spring (5) is provided between the lower pressure plate (3) and the end cap (7), the slide rod (4) is provided with an external thread, the end cap (7) is provided with an internal thread, and the end cap (7) and the slide rod (4) are threaded together.

4. The non-limiting cyclic fixture for battery testing according to claim 1, characterized in that, The mounting holes (31) are provided in multiple ways, and the number of slide rods (4) matches the number of mounting holes (31). The multiple mounting holes (31) are arranged in a rectangular array on the lower pressure plate (3).

5. A non-limiting cyclic fixture for battery testing according to claim 1, characterized in that, A fixing plate (8) is provided on the side of the pressure sensor (6) away from the upper pressure plate (2), and the pressure sensor (6) is clamped and fixed between the fixing plate (8) and the upper pressure plate (2).

6. A non-limiting cyclic fixture for battery testing according to claim 5, characterized in that, A support column (9) is provided between the fixed plate (8) and the upper pressure plate (2), and the height of the support column (9) is the same as the height of the pressure sensor (6).

7. A non-limiting cyclic fixture for battery testing according to claim 1, characterized in that, It also includes a signal conditioning circuit (61) and a data acquisition system (62), wherein the pressure sensor (6) is connected to the signal conditioning circuit (61) and the signal conditioning circuit (61) is connected to the data acquisition system (62).

8. A non-limiting cyclic fixture for battery testing according to claim 1, characterized in that, The spring (5) is a rectangular cross-section compression spring.

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