Membrane clamping device for testing puncture strength of lithium battery diaphragm and equipment thereof

Abstract

The utility model provides a diaphragm clamping device and equipment for testing the puncture strength of a diaphragm of a lithium battery, and the diaphragm clamping device comprises a lower clamping plate, an upper clamping plate and a lower clamping plate, the gasket is arranged in the groove; the upper clamping plate is opposite to the lower clamping plate and is arranged on one side close to the groove, and a through hole is formed in the center of the upper clamping plate and corresponds to the groove; the air cylinder is arranged on the side, opposite to the groove, of the lower clamping plate. The friction between the diaphragm and the supporting plate is reduced, so that the pressure stress is reduced, and the diaphragm is not easy to damage; the to-be-detected diaphragm can be quickly and flatly positioned through the inclination angle of the supporting plate; through the gasket, the upper plate and the lower plate are better in coincidence and higher in leakproofness when being pressed, so that the influence of gaps on the test is reduced, and the stress surface of the diaphragm is uniform and data is stable when the puncture needle is punctured; by reducing replacement of parts, generation of foreign matter such as scrap iron and powder is reduced, and the mechanical service life is longer; by means of the technology, testing errors are reduced, the maintenance frequency of the clamp is reduced, and manpower waste is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium batteries, in particular to a film clamping device and equipment thereof for testing the puncture strength of lithium battery diaphragms. Background Art

[0002] The structure of lithium batteries mainly includes four major materials: positive electrode materials, negative electrode materials, electrolytes and diaphragms. The diaphragm is one of the most important components of lithium batteries and is a key inner component. The performance of the diaphragm determines the interface structure and internal resistance of the battery, and directly affects the battery's capacity, cycle and safety performance. The diaphragm cost once accounted for one-third of the cost of lithium batteries. Diaphragms with excellent performance play a vital role in improving the overall performance of batteries. The main function of the diaphragm is to separate the positive and negative electrodes of the battery, allowing ions to pass through and electrons to be isolated to prevent the positive and negative electrodes from contacting and short-circuiting. The diaphragm material is non-conductive, and its physical and chemical properties have a great influence on the performance of the battery. The diaphragm is mainly divided into two types according to the process: wet method and dry method. Different types of batteries use different diaphragms. Since the main chemical reaction with the diaphragm in the lithium battery is the electrolyte, and the electrolyte is an organic solvent liquid, a diaphragm material resistant to organic solvents is required. Therefore, a high-strength diaphragm-type polyolefin porous membrane is generally used to ensure the normal operation of the positive and negative electrodes of the battery.

[0003] The key properties of the diaphragm are puncture strength, air permeability, porosity, tensile strength and shrinkage. Among them, puncture strength is particularly important. Insufficient puncture strength can easily cause foreign matter or electrode burrs to puncture the diaphragm and cause a short circuit in the battery. Currently, most tests on diaphragm puncture strength use manual pressing methods such as bolts to tighten the diaphragm by controlling the pressure plate. However, the rotating parts of the bottom clamp usually cause the support parts to wear due to frequent friction. Foreign matter such as iron filings and powder will be generated in the process, causing damage to the diaphragm and ultimately affecting the test results.

[0004] Even with the current pneumatic pressing method for membrane clamping, there are still certain defects in the flatness and tightness of the diaphragm pressing. Often, the test data of different parts vary greatly due to inadequate pressing or insufficient flatness, and abnormalities are more likely to occur during use.

[0005] The frequent replacement of important parts also has a certain impact on process stability. In addition to increasing test errors and failing to ensure data consistency, it also increases labor and testing costs. Utility Model Content

[0006] The purpose of the utility model is to reduce test errors, reduce the number of fixture maintenance times and save manpower waste. Specifically, one purpose of the utility model is to reduce the friction between the diaphragm and the support plate to reduce the compressive stress so that the diaphragm is not easily damaged; another purpose of the utility model is to quickly and smoothly complete the positioning of the diaphragm to be tested through the inclination angle of the support plate; the gasket is used to make the upper and lower plates fit better and more airtight when pressed together, so as to reduce the influence of the gap on the test and ensure that the force surface of the diaphragm is uniform and the data is stable when the puncture needle penetrates; another purpose of the utility model is to reduce the replacement of parts and reduce the generation of foreign matter such as iron filings and powder, so as to extend the life of the machine.

[0007] To achieve the above-mentioned purpose, the utility model provides a membrane clamping device for lithium battery diaphragm puncture strength testing, which includes: a lower clamping plate having a groove in the center; a gasket arranged in the groove; an upper clamping plate opposite to the lower clamping plate and arranged on one side close to the groove, and a through hole is opened in the center thereof and arranged corresponding to the groove; and a cylinder is arranged on one side of the lower clamping plate opposite to the groove.

[0008] Preferably, a diaphragm support plate is further provided between the lower clamping plate and the cylinder.

[0009] Preferably, the device further comprises a mounting plate, the cylinder is fixed on the mounting plate, and the mounting plate is located on a side of the cylinder opposite to the lower clamping plate.

[0010] Preferably, U-shaped grooves are respectively provided on both sides of the mounting plate.

[0011] Preferably, the device is further provided with a hand pressure valve, which is vertically mounted on the mounting plate and connected to the cylinder via an air pressure regulating valve.

[0012] Preferably, the air pressure regulating valve is L-type, C-type, U-type, V-type, M-type, N-type, W-type, Z-type or S-type.

[0013] Preferably, the upper clamping plate is spaced a distance from the lower clamping plate.

[0014] The utility model provides another clamping device for lithium battery diaphragm puncture strength testing, which includes: a lower clamping plate, having a groove in the center; a gasket, arranged in the groove; an upper clamping plate, opposite to the lower clamping plate and arranged on one side close to the groove, and a through hole is opened in the center and arranged corresponding to the groove; a cylinder, arranged on one side of the lower clamping plate opposite to the groove; a diaphragm support plate, arranged between the lower clamping plate and the cylinder; a mounting plate, the cylinder is fixed on the mounting plate, and the mounting plate is located on one side of the cylinder opposite to the lower clamping plate; and a hand pressure valve, vertically mounted on the mounting plate and connected to the cylinder with an air pressure regulating valve.

[0015] The utility model provides another clamping device for lithium battery diaphragm puncture strength testing, which includes: a lower clamping plate, having a groove in the center; a gasket, arranged in the groove; an upper clamping plate, opposite to the lower clamping plate and arranged on one side close to the groove, and a through hole is opened in the center and arranged corresponding to the groove; a cylinder, arranged on one side of the lower clamping plate opposite to the groove; a diaphragm support plate, arranged between the lower clamping plate and the cylinder; a mounting plate, the cylinder is fixed on the mounting plate, the mounting plate is located on one side of the cylinder opposite to the lower clamping plate, and U-shaped grooves are respectively arranged on both sides of the mounting plate; and a hand pressure valve, which is vertically mounted on the mounting plate and connected to the cylinder with an air pressure regulating valve.

[0016] The utility model provides a film clamping device for testing the puncture strength of lithium battery diaphragms.

[0017] It is characterized in that the device further includes a base; a column vertically installed on the base; and a top seat arranged parallel to the base, wherein the film clamping device as mentioned above is arranged between the base and the top seat, and the column and the hand pressure valve are located on the same side or opposite sides of the film clamping device.

[0018] The beneficial effects of the utility model are that the diaphragm to be tested can be positioned quickly and smoothly by the tilt angle of the support plate; the upper and lower plates can be pressed together with better fit and stronger airtightness by the gasket, so as to reduce the influence of the gap on the test and ensure that the force surface of the diaphragm is uniform and the data is stable when the puncture needle penetrates; by reducing the replacement of parts and reducing the generation of foreign matter such as iron filings and powder, the life of the machine is extended; the above technology can reduce test errors, reduce the number of fixture maintenance times and save manpower waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the utility model.

[0020] Figure 2 It is a left view of the utility model.

[0021] Figure 3 It is a top view of the utility model.

[0022] Figure 4 It is a structural schematic diagram of the utility model.

[0023] Figure 5 It is a front view of the utility model. DETAILED DESCRIPTION

[0024] In order to make the above and / or other purposes, effects, and features of the present invention more obvious and easy to understand, the following is a detailed description of the preferred implementation modes:

[0025] See also Figure 1 and Figure 2 The utility model provides a clamping device 100 for lithium battery diaphragm puncture strength test, which includes: a lower clamping plate 6, the center of which has a groove; a gasket 8, which is arranged in the groove; an upper clamping plate 2, which is opposite to the lower clamping plate 6 and is arranged near one side of the groove, see Figure 3 , a through hole 21 is provided at the center thereof and is arranged corresponding to the groove; and a cylinder 5 is arranged on one side of the lower clamping plate 6 opposite to the groove.

[0026] In some embodiments, the groove is a circular groove or a polygonal groove; the gasket 8 is a circular gasket or a polygonal gasket provided corresponding to the groove.

[0027] In some preferred embodiments, the groove is O-shaped, the gasket 8 is an O-ring, and its outer diameter is 15-21 mm, and the wire diameter is 1.1-1.7 mm; in some preferred embodiments, the outer diameter of the gasket 8 is 17-19 mm, and the wire diameter is 1.3-1.5 mm; in some more preferred embodiments, the outer diameter of the gasket 8 is 18 mm, and the wire diameter is 1.4 mm.

[0028] In some embodiments, the diameter of the through hole 21 is smaller than the diameter of the groove.

[0029] In some embodiments, the material of the gasket 8 may be fluororubber, silicone rubber, hydrogenated nitrile butadiene rubber, fluorinated silicon, Teflon, epichlorohydrin, perfluororubber, chlorinated polyethylene, chlorosulfonated polyethylene, chloroether rubber, nitrile butadiene rubber, ethylene propylene rubber, chloroprene rubber, perfluoroether rubber, polyurethane rubber, acrylic rubber, or polysulfide rubber, but is not limited thereto.

[0030] In some embodiments, the diameter of the through hole is Φ8mm, Φ10mm, Φ12mm, or Φ14mm, but is not limited thereto. In some preferred embodiments, the diameter of the through hole is Φ10mm.

[0031] In some embodiments, the cylinder is a cylinder with a guide rod, and the guide rod can ensure that there is no deviation when rising or falling.

[0032] See also Figure 1 A diaphragm support plate 1 is further provided between the lower clamping plate 6 and the cylinder 5 .

[0033] See also Figure 1 The device further includes a mounting plate 4 , the cylinder 5 is fixed to the mounting plate 4 , and the mounting plate 4 is located on a side of the cylinder 5 opposite to the lower clamping plate 6 .

[0034] In some embodiments, the mounting plate 4 may be, but is not limited to, nickel-plated or chrome-plated to prevent rust.

[0035] See also Figure 1The mounting plate 4 is further provided with U-shaped grooves 9 on both sides thereof.

[0036] See also Figure 1 The device is further provided with a hand pressure valve 7, which is vertically mounted on the mounting plate 4 and connected to the cylinder 5 via an air pressure regulating valve 3, wherein the air pressure regulating valve 3 is connected to the hand pressure valve 7 via a first connecting member 31 and a second connecting member 32.

[0037] In some embodiments, the air pressure regulating valve 3 is L-type, C-type, U-type, V-type, M-type, N-type, W-type, Z-type or S-type.

[0038] In some embodiments, the upper clamping plate 2 and the lower clamping plate 6 are separated by a distance, wherein the distance is 3 to 7 mm. In some preferred embodiments, the distance is 5 mm.

[0039] The utility model provides another clamping device for lithium battery diaphragm puncture strength testing, which includes: a lower clamping plate 6, having a groove in the center; a gasket 8, arranged in the groove; an upper clamping plate 2, opposite to the lower clamping plate 6 and arranged on one side close to the groove, and a through hole is opened in the center and arranged corresponding to the groove; a cylinder 5, arranged on the lower clamping plate 6, and the mounting plate 4 is located on the side of the cylinder 5 opposite to the groove; a diaphragm support plate 1, arranged between the lower clamping plate 6 and the cylinder 5; a mounting plate 4, and the cylinder 5 is fixed on the mounting plate 4 on one side opposite to the lower clamping plate 6; and a hand pressure valve 7, vertically mounted on the mounting plate 4, and connected to the cylinder 5 by an air pressure regulating valve 3.

[0040] The utility model provides another clamping device for lithium battery diaphragm puncture strength testing, which includes: a lower clamping plate 6, having a groove in the center; a gasket 8, arranged in the groove; an upper clamping plate 2, opposite to the lower clamping plate 6 and arranged on one side close to the groove, and a through hole is opened in the center and arranged corresponding to the groove; a cylinder 5, arranged on the lower clamping plate 6, and the mounting plate 4 is located on the side of the cylinder 5 opposite to the groove; a diaphragm support plate 1, arranged between the lower clamping plate 6 and the cylinder 5; a mounting plate 4, the cylinder 5 is fixed on the mounting plate 4 on one side opposite to the lower clamping plate 6, and U-shaped grooves 9 are respectively arranged on both sides of the mounting plate 4; and a hand pressure valve 7, vertically mounted on the mounting plate 4, and connected to the cylinder 5 by an air pressure regulating valve 3.

[0041] The utility model provides a film clamping device for lithium battery diaphragm puncture strength test, characterized in that in addition to the film clamping device 100 as described above, Figure 4, further includes a base 11; a column 12, vertically installed on the base 11; and a top seat 10, which is arranged parallel to the base 11, wherein the aforementioned film clamping device 100 is arranged between the base 11 and the top seat 10, and the column 12 and the hand pressure valve 7 are located on the same side or opposite side of the film clamping device.

[0042] The specific working principle is that by pressing the hand pressure valve 7, the cylinder 5 pushes the lower clamping plate 6 up and closes with the upper clamping plate 2. In addition, please refer to Figure 5 The two ends of the diaphragm support plate 1 are inclined at 15 degrees to facilitate the placement of the diaphragm; in addition, the air pressure regulating valve 3 can adjust the air pressure, and the gasket 8 is used to provide a buffer when the upper and lower clamps are pressed together, so that the diaphragm can be pressed tightly, and the puncture needle can pierce the diaphragm from top to bottom at a speed set by the program, and the force data is fed back to the terminal device through the sensor, and the terminal device calculates the puncture strength value through software.

[0043] Example:

[0044] (1) Prepare the sample: Cut a 70mm*1040mm diaphragm;

[0045] (2) Turn on the main power, start the computer, and set the test program according to the standard;

[0046] (3) The diaphragm passes through the diaphragm support plate 1 and the upper clamping plate 2, and is laid flat on the diaphragm support plate 1, with both ends at an angle of 15 degrees, keeping it horizontal and flat.

[0047] (4) The air inlet of the ultra-thin guide rod type cylinder 5 is connected to the hand pressure valve 7 by two L-shaped air pressure regulating valves 3. The manual valve pressure is adjusted to 0.1-0.3 MPa. By pressing the hand pressure valve 7, the ultra-thin guide rod type cylinder 5 is controlled to rise and clamp the sample;

[0048] (5) Run the test machine, and the puncture needle passes through the ￠18*1.4mm O-shaped groove in the center of the lower clamping plate 6 to puncture the diaphragm;

[0049] (6) Read test data.

[0050] (7) The data of diaphragm puncture strength are obtained from 10 points on the same straight line. The maximum and minimum values ​​are eliminated, and the arithmetic mean of the remaining 8 values ​​is taken as the final diaphragm puncture strength data.

[0051] Example Testing

[0052] Three-layer co-extruded PP separators of 20μm, 18μm and 16μm were taken to test the puncture strength values / gf at 10 points on the same straight line, and the maximum and minimum values ​​were eliminated to calculate the arithmetic mean of the remaining 8 values.

[0053] Table 1

[0054] Point 1 Point 2 Point 3 Point 4 Point 5 Point 6 Point 7 Point 8 Point 9 Point 10 average value 20umPP 432.1 436.9 441.2 442.6 435.6 430.6 456.3 449.2 436.2 448.8 440.3 18umPP 389.2 390.5 391.4 387.6 392.3 394.4 389.9 398.3 387.7 394.3 391.2 16umPP 356.2 360.4 361.2 358.2 365.4 357.9 364.2 361.5 364.2 364.1 361.5

[0055] Comparative example: No gasket, diaphragm support plate and cylinder added

[0056] (1) Prepare the sample: Cut a 70mm*1040mm diaphragm;

[0057] (2) Turn on the main power, start the computer, and set the test program according to the standard;

[0058] (3) Place the membrane to be tested face up and flatly between the needle of the puncture strength tester and the test table, keeping it level.

[0059] (4) Pull down the right clamp handle to the first position, and the clamp will fall down to fix the sample to be tested;

[0060] (5) Run the test machine and let the puncture needle penetrate directly into the septum;

[0061] (6) Read test data.

[0062] (7) The data of diaphragm puncture strength are obtained from 10 points on the same straight line. The maximum and minimum values ​​are eliminated, and the arithmetic mean of the remaining 8 values ​​is taken as the final diaphragm puncture strength data.

[0063] Comparative test

[0064] Three-layer co-extruded PP separators of 20μm, 18μm and 16μm were taken to test the puncture strength values / gf at 10 points on the same straight line, and the maximum and minimum values ​​were eliminated to calculate the arithmetic mean of the remaining 8 values.

[0065] Table 2

[0066]

[0067]

[0068] The control group is affected by compressive stress or uneven force surface caused by loose pressing, which makes the data obviously unstable. In addition, in terms of puncture strength, referring to the average values ​​of Table 1 and Table 2, it can be seen that the embodiment is better than the control group. It can be seen that adding gaskets, diaphragm support plates and cylinders helps to improve the fit when the upper and lower plates are pressed together and ensure that the force surface of the diaphragm is uniform and the data is stable when the puncture needle pierces.

[0069] However, what is described above is only a preferred embodiment of the present utility model, but it cannot be used to limit the patent protection scope of the present utility model; therefore, any simple equivalent changes and modifications made according to the patent protection scope of the present utility model and the contents of the specification still fall within the patent protection scope of the present utility model.

Claims

1. A film clamping device for lithium battery diaphragm puncture strength test, comprising: a lower splint having a groove in the center thereof; a gasket, disposed in the groove; An upper clamping plate, opposite to the lower clamping plate and disposed on one side close to the groove, with a through hole formed in the center thereof corresponding to the groove; and The cylinder is arranged on a side of the lower clamping plate opposite to the groove.

2. The film clamping device according to claim 1, characterized in that: A diaphragm support plate is further arranged between the lower clamping plate and the cylinder.

3. The film clamping device according to claim 1, characterized in that: The device further comprises a mounting plate, the cylinder is fixed on the mounting plate, and the mounting plate is located on a side of the cylinder opposite to the lower clamping plate.

4. The film clamping device according to claim 3, characterized in that: U-shaped grooves are respectively arranged on both sides of the mounting plate.

5. The film clamping device according to claim 3, characterized in that: The device is further provided with a hand pressure valve, which is vertically mounted on the mounting plate and connected to the cylinder via an air pressure regulating valve.

6. The film clamping device according to claim 5, characterized in that: The air pressure regulating valve is of L-type, C-type, U-type, V-type, M-type, N-type, W-type, Z-type or S-type.

7. The film clamping device according to claim 1, characterized in that: The upper clamping plate is spaced a distance from the lower clamping plate.

8. A film clamping device for lithium battery diaphragm puncture strength test, comprising: a lower splint having a groove in the center thereof; a gasket, disposed in the groove; An upper clamping plate, opposite to the lower clamping plate and disposed near one side of the groove, with a through hole formed in the center thereof corresponding to the groove; A cylinder is disposed on a side of the lower clamping plate opposite to the groove; A diaphragm support plate is disposed between the lower clamping plate and the cylinder; A mounting plate, the cylinder is fixed to the mounting plate, the mounting plate is located on a side of the cylinder opposite to the lower clamping plate; and The hand pressure valve is vertically mounted on the mounting plate and connected to the cylinder via a gas pressure regulating valve.

9. A film clamping device for lithium battery diaphragm puncture strength test, comprising: a lower splint having a groove in the center thereof; a gasket, disposed in the groove; An upper clamping plate, opposite to the lower clamping plate and disposed near one side of the groove, with a through hole formed in the center thereof corresponding to the groove; A cylinder is disposed on a side of the lower clamping plate opposite to the groove; A diaphragm support plate is disposed between the lower clamping plate and the cylinder; A mounting plate, the cylinder is fixed on the mounting plate, the mounting plate is located on a side of the cylinder opposite to the lower clamping plate, and U-shaped grooves are respectively provided on both sides of the mounting plate; and The hand pressure valve is vertically mounted on the mounting plate and connected to the cylinder via a gas pressure regulating valve.

10. A film clamping device for lithium battery diaphragm puncture strength test, characterized in that: The device further includes a base; a column vertically mounted on the base; and a top seat arranged parallel to the base, wherein the film clamping device described in any one of claims 5, 8, and 9 is arranged between the base and the top seat, and the column and the hand pressure valve are located on the same side or opposite sides of the film clamping device.

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