Battery diaphragm air permeability tester

Abstract

The invention relates to the technical field of air permeability testers, in particular to a battery diaphragm air permeability tester which comprises a placement platform and a plurality of test units, and the placement platform is used for bearing a plurality of test samples; each test unit comprises a lower cavity, a lifting seat, a sealing assembly and a self-adaptive flattening assembly. According to the air permeability tester for the battery diaphragm, the flatness of a test sample is automatically and adaptively adjusted in the process that the self-adaptive flattening assembly moves downwards in the upper cavity and is in press fit with the lower cavity, and the sealing performance in the test process is fully improved in combination with three-stage sealing of the sealing assembly; meanwhile, the test sample is effectively prevented from wrinkling to reduce the sealing performance of the test, the accuracy of the test result is fully improved, the whole test process is convenient and rapid, the integration degree of the whole structure is high, the test sample only needs to cover the upper opening end of the lower cavity before the test and is taken down after the test, and the test efficiency is improved. And complicated loading and disassembling steps are not needed.

Description

Technical Field

[0001] The present invention relates to the technical field of air permeability testers, and specifically to a battery separator air permeability tester. Background Art

[0002] As one of the key components of lithium-ion batteries, the core function of the battery separator is to achieve the conduction and isolation of ions inside the battery through its microporous structure, while ensuring the safety and stability of the battery. The air permeability of the separator directly determines the charge and discharge efficiency, cycle life and thermal stability of the battery. Therefore, the air permeability test is an important link in evaluating the quality of the separator. At present, in the industry, the air permeability is mainly quantified by measuring the rate or time of gas passing through the separator under a certain pressure difference. However, during the test, it is easy to reduce the sealing performance of the test process due to the wrinkling of the separator, thereby reducing the accuracy of the test results. The existing solutions to this problem are as follows: 1. Most traditional air permeability test instruments adopt a single-sample test mode. During the test, the separator sample is manually fixed in the test chamber and its flatness is manually adjusted to avoid the problem of poor sealing caused by wrinkling. However, manual operation is not only inefficient, but also difficult to ensure the consistency of samples in batch tests, and is prone to introducing human errors, affecting the repeatability and reliability of test results.

[0003] 2. Some improved test devices attempt to introduce a multi-sample test mode and a mechanical auxiliary unfolding structure. For example, the Chinese invention patent with the publication number CN118777170B discloses a battery separator air permeability tester, which unfolds the separator through the cooperation of a counterweight and a clamping assembly, and can effectively avoid the generation of wrinkles to a certain extent. However, in specific operations, the top of the separator needs to be fixed in the clamping member, the bottom is connected to the counterweight, and the separator is stretched by the action of gravity to achieve flatness. This solution has significant defects: First, the test process is cumbersome and requires steps to complete the upper-end fixation, lower-end counterweight connection and tension adjustment of the separator; Second, the gravity loading method of the counterweight is difficult to achieve rapid clamping and release in batch tests, which overall restricts the improvement of test efficiency.

[0004] In summary, there are still obvious deficiencies in the operation convenience and test efficiency of the battery separator air permeability test equipment in the prior art. There is an urgent need for a solution with high operation efficiency, high test result accuracy, and stable repeatability and reliability in batch tests. Summary of the Invention

[0005] To solve the above technical problems, the present invention provides a battery separator air permeability tester, comprising: a placement platform and a plurality of test units, the placement platform being used for carrying a plurality of test samples; each test unit includes: a lower cavity, a lifting seat, a sealing assembly and an adaptive flattening assembly, the lower cavity being fixedly arranged on the placement platform, and the test sample covering the upper opening end of the lower cavity; the bottom of the lifting seat is provided with an upper cavity corresponding to the lower cavity, and the downward movement of the lifting seat drives the upper cavity to press-fit with the lower cavity, so that the test sample is directly sealed and clamped between the upper cavity and the lower cavity; the sealing assembly is arranged at the bottom of the upper cavity and includes a first sealing ring, a second sealing ring and a third sealing ring which are coaxially arranged in sequence from inside to outside; in the initial state, the bottom surface of the second sealing ring is lower than those of the first sealing ring and the third sealing ring, and the three are in wedge-shaped fit; the adaptive flattening assembly is used for adaptively adjusting the flatness of the test sample during the pressing process of the upper cavity and the lower cavity.

[0006] The adaptive flattening assembly includes: a plurality of elastic hinge members evenly distributed circumferentially on the upper cavity; a flattening head which is in an arc-shaped column structure and is hinged to the lower end of the elastic hinge member; during the downward movement of the upper cavity, the flattening head automatically contacts the test sample and unfolds outward; a synchronization assembly for adaptively controlling the synchronous outward unfolding of all the flattening heads; and an elastic stabilizing member connected between the elastic hinge member and the flattening head.

[0007] In a possible implementation manner, the lifting seat includes a lifting cylinder and a solenoid valve, and the solenoid valve controls the lifting stroke of the upper cavity by adjusting the air intake of the lifting cylinder.

[0008] In a possible implementation manner, the test unit further includes: a pressure application cylinder for applying air pressure to the upper cavity; a reference positioning module for setting an initial reference height; before each test, the pressure application cylinder rises to the initial reference height.

[0009] In a possible implementation manner, an assembly seat is detachably installed on the upper cavity, and the adaptive flattening assembly is first installed on the assembly seat and then installed on the upper cavity through the assembly seat.

[0010] In a possible implementation manner, the synchronization assembly includes a synchronization ring and a plurality of hinge rods, the synchronization ring is slidably arranged along the axial direction of the upper cavity, and the hinge rods are hinged between the respective elastic hinge members and the synchronization ring.

[0011] In a possible implementation manner, the elastic hinge member includes a connecting rod and an elastic member, the connecting rod is hinged to the upper cavity in a manner that the lower end inclines outward, and the elastic member is used for controlling the reset of the connecting rod.

[0012] In a possible implementation manner, the wedge-shaped surfaces of the first sealing ring and the third sealing ring are respectively inclined towards the second sealing ring, forming a double-sided extrusion sealing structure.

[0013] One or more of the above technical solutions in the embodiments of the present invention have at least one of the following technical effects: A battery separator air permeability tester provided by the present invention automatically and adaptively adjusts the flatness of a test sample during the process of the upper cavity moving downward and pressing against the lower cavity. Combined with the three-stage sealing of the sealing component, the sealing performance of the test process is fully improved. At the same time, it effectively avoids the test sample from wrinkling and reducing the test sealing performance, and avoids leakage. The accuracy of the test results is fully improved. The entire test process is convenient and fast, the integration degree of the overall structure is high, which is convenient for efficient and stable batch testing. And the entire test process only requires covering the test sample at the upper opening end of the lower cavity before the test and removing it after the test, without complex loading and disassembly steps, which is convenient for quickly completing the loading and unloading work and is beneficial to improving the batch testing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 FIG. is a schematic diagram of the overall structure of a battery separator air permeability tester provided by an embodiment of the present invention.

[0015] Figure 2 FIG. is a schematic diagram of a partial structure of a battery separator air permeability tester provided by an embodiment of the present invention.

[0016] Figure 3 FIG. is a schematic diagram of the structure of a pressure application cylinder, a battery valve and a reference positioning module of a battery separator air permeability tester provided by an embodiment of the present invention.

[0017] Figure 4 FIG. is a schematic diagram of the state when the upper cavity and the lower cavity of a battery separator air permeability tester provided by an embodiment of the present invention do not press the test sample.

[0018] Figure 5 is Figure 4 an enlarged view of part A in

[0019] Figure 6 FIG. is a top view structural diagram of a connecting rod and a flattening head of a battery separator air permeability tester provided by an embodiment of the present invention.

[0020] In the figure: 1. Placement platform; 2. Test sample; 3. Lower cavity; 4. Lifting seat; 41. Lifting cylinder; 42. Battery valve; 5. Upper cavity; 6. Sealing component; 61. First sealing ring; 62. Second sealing ring; 63. Third sealing ring; 7. Adaptive flattening component; 71. Elastic hinge; 711. Connecting rod; 712. Elastic member; 72. Flattening head; 73. Synchronization component; 731. Synchronization ring; 732. Hinge rod; 74. Elastic stabilizing member; 8. Pressure application cylinder; 9. Reference positioning module; 10. Assembly seat; 11. Bottom plate; 12. Outer shell; 13. Installation groove; 14. Pressure sensor. Detailed Embodiments

[0021] To make the above objects, features, and advantages of the present invention more apparent and understandable, the following detailed description of the specific embodiments of the present invention will be provided in conjunction with the accompanying drawings. Many specific details are set forth in the following description to facilitate a thorough understanding of the present invention. However, the present invention can be implemented in many other ways different from those described below, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0022] Please refer to Figure 1 、 Figure 2 and Figure 4 For a battery separator air permeability tester, it includes a bottom plate 11, a housing 12, a placement platform 1, and multiple test units. The test units and the placement platform 1 are both installed on the bottom plate 11. The placement platform 1 is used to carry multiple test samples 2. Each test unit includes a lower chamber 3, a lifting seat 4 with an upper chamber 5 provided at the bottom, a sealing component 6, and an adaptive flattening component 7. The lower chamber 3 is fixedly arranged on the placement platform 1, and the upper opening end of the lower chamber 3 is exposed outside the housing 12. The test sample 2 covers the upper opening end of the lower chamber 3. The upper chamber 5 is located directly above the lower chamber 3. The sealing component 6 and the adaptive flattening component 7 are both arranged on the lower end surface of the upper chamber 5. When the lifting seat 4 moves downward, it drives the upper chamber 5 to press against the lower chamber 3, so that the test sample 2 is directly sealed and clamped between the upper chamber 5 and the lower chamber 3, and the test area of the test sample 2 is defined. During the pressing process, the adaptive flattening component 7 first automatically flattens the test sample 2, and then the sealing component 6 presses and seals the test sample 2 in the flattened state. During the entire test process, only manual or mechanical means are needed to cover the test sample 2 on the upper opening end of the lower chamber 3, and then the lifting seat 4 moves downward to drive the upper chamber 5 to press against the lower chamber 3. This not only has high convenience but also can effectively avoid the reduction of test sealing performance and the accuracy of the actual test area of the test sample 2 due to the existence of wrinkles, effectively improving the accuracy of the test results and facilitating efficient, convenient, and stable batch testing.

[0023] Refer to Figure 2 、 Figure 4 and Figure 5 The sealing component 6 includes a first sealing ring 61, a second sealing ring 62, and a third sealing ring 63 which are coaxially arranged in sequence from the inside out. In the initial state, the bottom surface of the second sealing ring 62 is lower than those of the first sealing ring 61 and the third sealing ring 63, and the three are wedge-fitted; as Figure 5As shown, the wedge surfaces of the first sealing ring 61 and the third sealing ring 63 are respectively inclined towards the second sealing ring 62, forming a double-direction extrusion sealing structure. During the process of the upper cavity 5 moving downward and pressing against the lower cavity 3, after the test sample 2 is leveled, the bottom surface of the second sealing ring 62 first contacts the test sample 2 and abuts against the placement platform 1. Then, as the upper cavity 5 continues to move downward, the bottom surfaces of the first sealing ring 61 and the third sealing ring 63 contact the test sample 2. During this process, the second sealing ring 62 is in wedge-shaped cooperation with the first sealing ring 61 and the third sealing ring 63, and radially extrudes the second sealing ring 62 and the third sealing ring 63. Overall, a three-stage sealing is formed from the inside out. Combining with the adjustment of the flatness of the test sample 2 by the adaptive flattening assembly 7, the sealing performance during the test is fully improved, the sealing strength is ensured, the occurrence of air leakage is avoided, and the stability of the test results is improved.

[0024] Refer to Figure 4 and Figure 5 , an assembly seat 10 is arranged between the adaptive flattening assembly 7 and the upper cavity 5. An annular installation groove 13 is opened on the bottom surface of the upper cavity 5. The adaptive flattening assembly 7 is installed on the installation groove 13 through the assembly seat 10, which is convenient for the assembly and maintenance of the instrument.

[0025] Refer to Figure 2 , Figure 4 , Figure 5 and Figure 6 , the adaptive flattening assembly 7 includes a plurality of elastic hinge members 71 evenly distributed circumferentially. The lower end of the elastic hinge member 71 is provided with a flattening head 72; as Figure 5As shown, the elastic hinge 71 includes a connecting rod 711 and an elastic member 712. The upper end of the connecting rod 711 is hinged on the assembly seat 10, and the lower end is fixedly connected to the flattening head 72. In the initial state, the lower end of the connecting rod 711 is inclined outward, one end of the elastic member 712 is connected to the non-end position of the connecting rod 711, and the other end is connected to the assembly seat 10; during the downward movement of the upper chamber 5, the flattening head 72 contacts the test sample 2 before the second sealing ring 62, and then as the upper chamber 5 continues to move downward, under the limit of the placement platform 1, the flattening head 72 automatically expands outward to adjust the flatness of the test sample 2 in a smoothing manner, so that the test sample 2 is in a flat state before contacting the second sealing ring 62, avoiding wrinkles in the test sample 2 and reducing the sealing of the detection process and the accuracy of the actual test area, and no additional drive is required. The entire flatness adjustment and sealing process are automatically completed during the pressing process of the upper chamber 5 and the lower chamber 3. After the test is completed, the upper cavity 5 moves upward, and the connecting rod 711 is reset under the action of the elastic member 712 and before the flattening head 72 completely leaves the limiting state of the placement platform 1, the flattening head 72 is retracted and moved inward along the placement platform 1. On the one hand, it can prevent the test sample 2 from being adsorbed on the upper cavity 5, affecting the convenience and efficiency of batch testing. On the other hand, during the process of the flattening head 72 retracting inward along the placement platform 1, a certain force can be generated on the test sample 2, which can effectively prevent the test sample 2 from being tightly adsorbed on the lower cavity 3 and difficult to remove quickly, affecting the efficiency and convenience of batch testing.

[0026] See also Figure 4 and Figure 5 The adaptive flattening assembly 7 further includes a synchronization assembly 73, which includes a synchronization ring 731 and a plurality of hinged rods 732. The synchronization ring 731 is vertically slidably connected to the assembly seat 10, and the hinged rods 732 are hinged between each connecting rod 711 and the synchronization ring 731; Figure 5 As shown, when the connecting rod 711 rotates, the synchronous ring 731 is pushed to slide by the hinge rod 732, and the synchronous ring 731 is used to restrain the multiple connecting rods 711, so that all the connecting rods 711 are synchronously expanded outward or contracted inward, and the flattening head 72 applies force evenly accordingly, avoiding the test sample 2 from shifting due to uneven force, resulting in the test sample 2 not completely covering the upper opening end of the lower cavity 3, ensuring the stability and reliability of the test process and the stability of the flatness adjustment process, and further improving the stability of the test process and the reliability of the batch test process.

[0027] See also Figure 5 and Figure 6, the spreading flat head 72 is an arc-shaped columnar structure, and the spreading flat head 72 is hinged to the connecting rod 711, and an elastic stabilizing member 74 is connected between the two; the spreading flat head 72 contacts the test sample 2 as the upper cavity 5 moves downward, and then continues to move downward with the upper cavity 5, and automatically unfolds outward to adjust the flatness of the test sample 2 in a smoothing manner. During the process of adjusting the flatness of the test sample 2 by the arc-shaped spreading flat head 72, multi-directional folds can be smoothed, fully improving the flatness of the test sample 2. Among them, the elastic stabilizing member 74 continuously applies pressure on the spreading flat head 72 as the connecting rod 711 rotates, so that the spreading flat head 72 stably fits the test sample 2 and unfolds outward, further improving the stability of the flatness adjustment process.

[0028] Refer to Figure 2 and Figure 3 , the test unit further includes a pressure application cylinder 8, a reference positioning module 9 and a pressure sensor 14. The pressure sensor 14 and the pressure application cylinder 8 are both connected to the upper cavity 5. The pressure sensor 14 is used to detect the pressure in the upper cavity 5, and the pressure application cylinder 8 is used to apply air pressure into the upper cavity 5. The reference positioning module 9 is a groove-shaped switch and is fixedly installed on the bottom plate 11 and is used to set the initial reference; as Figure 3 shown, the pressure application cylinder 8 needs to rise to the position of the reference positioning module 9 before the test to uniformly define the reference for each test of the pressure application cylinder 8, which is beneficial to improving the accuracy and consistency of the test data, and further beneficial to improving the reliability of batch testing. For example, in the process of measuring air permeability by the Gurley method, it is necessary to measure the quantitative gas volume (usually the standard is 100CC) under a fixed pressure difference (usually the standard is 1.22 kPa), and the time (t) through the test sample 2. According to the formula Gurley value = t / A, the air permeability of the test sample 2 is calculated, where: A is the test area (cm²), and the standard value is 6.45 cm². The setting of the reference positioning module 9 is beneficial to improving the accuracy of the quantitative gas volume input, and further beneficial to improving the accuracy of the test result.

[0029] Refer to Figure 2 and Figure 3 , the lifting seat 4 includes a lifting cylinder 41 and a plate-type solenoid valve 42. The upper cavity 5 is connected to the lower end of the lifting cylinder 41. The lifting cylinder 41 is installed on the bottom plate 11 through a mounting bracket. The plate-type solenoid valve 42 is connected to the lifting cylinder 41 and controls the intake air volume of the lifting cylinder 41 to control the lifting stroke of the upper cavity 5, so as to accurately control the lifting of the upper cavity 5, and then stably and reliably perform batch testing.

[0030] In the embodiments of the present invention, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature may mean that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "below" and "beneath" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the horizontal height of the first feature is lower than that of the second feature.

[0031] In the description of the present invention, it should also be noted that, unless otherwise clearly defined and limited, the terms "arranged", "connected", "installed" and "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, an integral connection or a sliding connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] The embodiments of the specific implementation manners are all preferred embodiments of the present invention, and do not limit the protection scope of the present invention accordingly. Therefore, all equivalent changes made according to the structure, shape and principle of the present invention shall be covered within the protection scope of the present invention.

Claims

1. A battery separator air permeability tester, characterized in that: Comprising: A placement platform for carrying a plurality of test samples; A plurality of test units, each test unit comprising: A lower cavity fixedly provided on the placement platform, and the test sample covers the upper opening end of the lower cavity; A lifting seat having an upper cavity corresponding to the lower cavity at its bottom, and the lifting seat moves downward to drive the upper cavity to press-fit with the lower cavity, so that the test sample is directly sealed and clamped between the upper cavity and the lower cavity; A sealing assembly provided at the bottom of the upper cavity, including a first sealing ring, a second sealing ring, and a third sealing ring coaxially arranged from inside to outside in sequence; in the initial state, the bottom surface of the second sealing ring is lower than the first sealing ring and the third sealing ring, and the three are in wedge-shaped fit; An adaptive flattening assembly for adaptively adjusting the flatness of the test sample during the press-fitting process of the upper cavity and the lower cavity; The adaptive flattening assembly includes: A plurality of elastic hinge members circumferentially and uniformly distributed on the upper cavity; A flattening head having an arc-shaped columnar structure and hinged to the lower end of the elastic hinge member; during the downward movement of the upper cavity, the flattening head automatically contacts the test sample and unfolds outward; A synchronization assembly for adaptively controlling the synchronous outward unfolding of all the flattening heads; An elastic stabilizing member connected between the elastic hinge member and the flattening head.

2. The air permeability tester for battery separator according to claim 1, characterized in that: The lifting seat includes a lifting cylinder and a battery valve, and the battery valve controls the lifting stroke of the upper cavity by adjusting the air intake of the lifting cylinder.

3. The air permeability tester for battery separator according to claim 1, wherein: The test unit further includes: A pressing cylinder for applying air pressure to the upper cavity; A reference positioning module for setting an initial reference height; before each test, the pressing cylinder rises to the initial reference height.

4. The air permeability tester for battery separator according to claim 1, wherein: An assembly seat is detachably installed on the upper cavity, and the adaptive flattening assembly is first installed on the assembly seat and then installed on the upper cavity through the assembly seat.

5. The air permeability tester for battery separator according to claim 1 or 4, characterized in that: The synchronization assembly includes a synchronization ring and a plurality of hinge rods, the synchronization ring is slidably arranged along the axial direction of the upper cavity, and the hinge rods are hinged between the elastic hinge members and the synchronization ring.

6. The air permeability tester for battery separator according to claim 1 or 4, characterized in that: The elastic hinge member includes a connecting rod and an elastic member, the connecting rod is hinged to the upper cavity in a manner that the lower end inclines outward, and the elastic member is used to control the reset of the connecting rod.

7. The air permeability tester for battery separator according to claim 1, characterized in that: The wedge-shaped surfaces of the first sealing ring and the third sealing ring are respectively inclined towards the second sealing ring to form a double-sided extrusion sealing structure.

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