Battery pole piece porosity testing device

Abstract

The utility model provides a battery pole piece porosity testing device, which belongs to the technical field of batteries, and comprises a testing box, a gas detection assembly and a pressure detection piece, a closed cavity for placing a piece to be tested is arranged in the testing box, a vacuum extraction opening and a gas inlet are arranged on the closed cavity, the vacuum extraction opening is suitable for being connected with a vacuumizing piece, and the gas inlet is suitable for being connected with the vacuumizing piece. The air inlet is suitable for being connected with an air source through an air pipe; the gas detection assembly is arranged on the gas pipe and is suitable for controlling the on-off of gas and detecting the flow of the gas filled into the closed cavity; and the pressure detection piece is arranged in the closed cavity. Through the arrangement of the gas detection assembly and the pressure detection piece, different gas flow values charged under the conditions that a to-be-tested piece is not placed, the to-be-tested piece is placed and the same pressure value is reached in the closed cavity can be obtained, the porosity is calculated, the testing device obtains the size of the porosity by comparing the volumes of the introduced gas, and the testing device is simple in structure, easy to operate and high in practicability. Safety and reliability.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and in particular to a battery pole piece porosity testing device. Background Art

[0002] In the production and manufacturing process of batteries, the electrode process is an indispensable process. The main material of the battery is granular. After the granular main material is mixed with a conductive agent, a binder, and a solvent to form a slurry, it is coated on the current collector and then dried. After drying, it is rolled to form a electrode. The accumulation of particles on the electrode after drying and rolling directly determines the subsequent battery performance, that is, the porosity of the electrode is crucial to the battery performance.

[0003] Currently, the commonly used method for determining porosity is the mercury injection method, which uses a mercury injection instrument for measurement. The equipment cost is high, and the metallic mercury used in the measurement process is highly toxic and volatile, which poses a safety problem. Utility Model Content

[0004] Therefore, the technical problem to be solved by the utility model is to overcome the defects of the prior art that the equipment is high in cost and there are safety issues when measuring by mercury intrusion, thereby providing a battery pole piece porosity testing device.

[0005] In order to solve the above technical problems, the utility model provides a battery electrode porosity testing device, comprising:

[0006] The test box has a sealed cavity for placing the test piece inside, and the sealed cavity is provided with a vacuum suction port and an air inlet, the vacuum suction port is suitable for connecting with the vacuum pump, and the air inlet is suitable for connecting with the air source through the air pipe;

[0007] A gas detection component, arranged on the gas pipe, suitable for controlling the on-off of the gas and detecting the flow of the gas filled into the closed cavity;

[0008] The pressure detection component is arranged in the sealed cavity and is suitable for detecting the air pressure in the sealed cavity.

[0009] Optionally, the test box comprises:

[0010] A first box body having a first cavity with an opening at one end;

[0011] The second box body has a second cavity with one end opened, and the open ends of the first cavity and the second cavity are butted together to form the closed cavity.

[0012] Optionally, it also includes:

[0013] An adjusting component, whose adjusting end is connected to the first box body and / or the second box body, is suitable for driving the first box body and the second box body to move closer to each other or away from each other.

[0014] Optionally, the first box body and the second box body are butted against each other to clamp the foil material of the test piece.

[0015] Optionally, a sealing member is provided between the first box and the piece to be tested, and between the second box and the piece to be tested.

[0016] Optionally, the first cavity and the second cavity are both provided with the pressure detection component, the vacuum suction port, the air inlet and an air pipe connected to the air inlet, and the air pipe is both provided with the gas detection component.

[0017] Optionally, the first cavity and the second cavity have the same volume.

[0018] Optionally, the cross-sectional size of the foil is larger than the cross-sectional sizes of the first cavity and the second cavity;

[0019] The cross-sectional size of the active material layer of the test piece is smaller than the cross-sectional sizes of the first cavity and the second cavity.

[0020] Optionally, the gas detection component includes a gas on-off valve and a flow detection component arranged on the gas on-off valve.

[0021] Optionally, it also includes:

[0022] The controller is electrically connected to the gas detection component and the pressure detection component. The controller controls the gas detection component to switch the gas in the air pipe and obtain the gas flow rate filled into the closed cavity according to the air pressure signal of the pressure detection component.

[0023] The technical solution of the utility model has the following advantages:

[0024] The utility model provides a battery pole piece porosity testing device, comprising a testing box, a gas detection assembly and a pressure detection piece. The testing box has a closed cavity for placing a test piece inside, and a vacuum suction port and an air inlet are provided on the closed cavity. The vacuum suction port is suitable for being connected to the vacuum suction piece, and the air inlet is suitable for being connected to an air source through an air pipe. The gas detection assembly is arranged on the air pipe, and is suitable for controlling the on and off of the gas and detecting the gas flow rate filled into the closed cavity. The pressure detection piece is arranged in the closed cavity, and is suitable for detecting the air pressure in the closed cavity.

[0025] Through the setting of the gas detection component and the pressure detection component, different gas flow values ​​filled in the closed cavity at the same pressure value can be obtained in two cases where the test piece is not placed and the test piece is placed, that is, different filled volumes are obtained. The theoretical volume of the space without the test piece is the actual volume filled when the test piece is placed. The difference between the two volumes is the true volume of the test piece. The porosity of the test piece is calculated by: porosity = 1-(theoretical volume of the space-actual volume filled) / (volume of the test piece). The test device obtains the true volume of the test piece by comparing the volume of the gas introduced. It has a simple structure, simple operation, and is safe and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 A schematic diagram of the structure of a test piece provided in an embodiment of the utility model;

[0028] Figure 2 It is a structural schematic diagram of an implementation manner of a battery pole piece porosity testing device provided in an embodiment of the utility model without placing a test piece;

[0029] Figure 3 for Figure 2 A schematic diagram of the structure of the test device in which the test piece is placed;

[0030] Figure 4 for Figure 3 Side view of the support column in the figure.

[0031] Description of reference numerals:

[0032] 1. Test box; 2. Part to be tested; 3. Vacuum exhaust port; 4. Air inlet; 5. Air pipe; 6. Air source; 7. Gas detection component; 8. Pressure detection component; 9. First box; 10. First cavity; 11. Second box; 12. Second cavity; 13. Adjustment component; 14. Foil; 15. Active material layer; 16. Sliding groove; 17. Support column; 18. Connecting rod. DETAILED DESCRIPTION

[0033] The technical solution of the utility model will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0034] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are 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 therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0035] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0037] The battery pole piece porosity testing device provided in this embodiment is used to test the porosity of the pole piece.

[0038] like Figure 2 and Figure 3 As shown, a specific implementation of the battery electrode porosity testing device provided in this embodiment includes a test box 1, a gas detection component 7 and a pressure detection component 8. The test box 1 has a closed cavity inside for placing the test piece 2, and the closed cavity is provided with a vacuum suction port 3 and an air inlet 4. The vacuum suction port 3 is suitable for connecting to the vacuum pump, and the air inlet 4 is suitable for connecting to the gas source 6 through the air pipe 5; the gas detection component 7 is arranged on the air pipe 5, suitable for controlling the on and off of the gas and detecting the gas flow filled in the closed cavity; the pressure detection component 8 is arranged in the closed cavity, suitable for detecting the air pressure in the closed cavity.

[0039] Through the arrangement of the gas detection component 7 and the pressure detection component 8, different gas flow values ​​filled in the closed cavity at the same pressure value can be obtained in the two cases of not placing the test piece 2 and placing the test piece 2, that is, different filled volumes can be obtained. The theoretical volume of the space when the test piece 2 is not placed, and the actual filled volume when the test piece 2 is placed. The difference between the two volumes is the true volume of the test piece. The porosity of the test piece 2 is calculated by: porosity = 1-(theoretical volume of the space-actual filled volume) / (volume of the test piece). The test device obtains the true volume of the test piece 2 by comparing the volume of the gas introduced, and has a simple structure, simple operation, safety and reliability.

[0040] Before the test, the inside of the closed cavity is evacuated through the vacuum exhaust port 3 to prevent the remaining gas from affecting the test accuracy.

[0041] Specifically, the battery electrode includes an active material layer 15 and a foil 14. The porosity of the electrode is the porosity of the active material layer 15 on the electrode. It is assumed that there is no void in the foil 14. In this embodiment, the test piece 2 is the electrode. During the test, the electrode can be directly placed in a closed cavity, or only the active material layer on the electrode can be removed and placed in a closed cavity. When the electrode is placed in a closed cavity, pay attention to removing the volume of the foil when calculating.

[0042] Specifically, the pressure detection component 8 is a pressure sensor, and the vacuum pumping component is a vacuum pump. There is no limitation on the specific types of the pressure detection component 8 and the vacuum pumping component; there is no limitation on the specific position of the gas detection component 7 on the trachea 5, and it can be close to the gas source or close to the air inlet 4. If it is set at the air inlet 4, the volume filled is the volume entering the closed cavity. If it is set at other places, the volume detected is the sum of the volume entering the closed cavity and the volume of the gas in the trachea 5 between the gas detection component 7 and the air inlet 4. When calculating, it can be converted into the gas volume in the closed cavity only, or the gas volume in the trachea 5 between the gas detection component 7 and the air inlet 4 can be regarded as part of the closed cavity volume.

[0043] Specifically, the object to be tested 2 is generally round or square, which is convenient for volume calculation.

[0044] Specifically, a pump body may be provided on the gas source 6 or the gas pipe 5 to facilitate the filling of gas.

[0045] like Figure 2 and Figure 3As shown, the battery electrode porosity test device provided in this embodiment, the test box 1 includes a first box body 9 and a second box body 11, the first box body 9 has a first cavity 10 with an opening at one end; the second box body 11 has a second cavity 12 with an opening at one end, and the opening ends of the first cavity 10 and the second cavity 12 are connected to form the closed cavity. The split setting of the test box 1 facilitates the placement of the test piece 2.

[0046] Specifically, the cross-sectional sizes of the first box body 9 and the second box body 11 are the same, which facilitates the setting of a sealed environment.

[0047] like Figure 3 and Figure 4 As shown, the battery electrode porosity testing device provided in this embodiment also includes an adjusting component 13, and the adjusting end of the adjusting component 13 is connected to the first box body 9 and / or the second box body 11, and is suitable for driving the first box body 9 and the second box body 11 to move closer to or away from each other.

[0048] A specific implementation of the adjustment component 13 is as follows Figures 2 to 4 As shown, the adjustment component 13 includes a support column 17 and two connecting rods 18. The support column 17 is provided with a vertical sliding groove 16. One end of the two connecting rods 18 is fixed in the sliding groove 16 by a nut, and the other end is respectively connected to the first box body 9 and the second box body 11. By loosening the nut, the height of the connecting rod 18 is manually adjusted, and then the distance between the first box body 9 and the second box body 11 is adjusted. The test piece 2 is placed in the closed cavity, and then the first box body 9 and the second box body 11 are docked and pressed to fix the nut.

[0049] In addition, as an alternative embodiment, the adjustment component 13 can also be electrically driven. For example, the adjustment component 13 is a vertically arranged linear module, and the linear module has two sliding seats. The two sliding seats are respectively connected to the first box body 9 and the second box body 11. By driving the sliding seats to move, the distance between the first box body 9 and the second box body 11 can be adjusted.

[0050] like Figure 3 As shown, in the battery electrode porosity testing device provided in this embodiment, the first box body 9 and the second box body 11 are connected to each other and are suitable for clamping the foil 14 of the test piece 2. The clamping fixing method improves the stability of the test piece 2 in the cavity, and avoids the free movement of the test piece 2 to the air port during air extraction or air supply, which affects the testing process.

[0051] A specific implementation of the test piece 2 is as follows: Figure 1As shown, the edge of the test piece 2 is scrubbed or cleaned to expose the foil 14 at the edge, and the first box 9 and the second box 11 clamp the foil 14 at the edge in a full circle, and the active material layer 15 on the test piece 2 is placed in the first cavity 10 and the second cavity 12.

[0052] It should be noted that, the theoretical volume of the space is calculated by taking the case where the first cavity 10 and the second cavity 12 are equal in size. Since the first cavity 10 and the second cavity 12 are in a connected state when the test piece 2 is not placed, there are two ways to calculate the spatial volume of the first cavity 10 and the second cavity 12 when the gas is introduced: the first is that since the two gas detection components 7 detect the gas at the same time, when the internal air pressure reaches the set pressure, the flow rate detected by the two gas detection components 7 is the flow rate passing through their respective closed cavities; the second is to first add the detection values ​​of the two gas detection components 7, and then divide them into two as the volumes in their respective closed cavities. If the two closed cavities are of different sizes, the corresponding values ​​are converted according to the volume ratio.

[0053] In other embodiments, the first box body 9 and the second box body 11 are directly connected and sealed, and the entirety of the test piece 2 (the foil 14 and the active material layer 15 ) is placed in the sealed cavity.

[0054] In the battery electrode porosity testing device provided in this embodiment, sealing members are provided between the first box 9 and the test piece 2, and between the second box 11 and the test piece 2, to achieve sealing in the first cavity 10 and the second cavity 12. Specifically, the sealing member is a sealing ring, a sealing gasket, etc.

[0055] like Figure 3 As shown, the battery electrode porosity testing device provided in this embodiment, the first cavity 10 and the second cavity 12 are both provided with the pressure detection component 8, the vacuum exhaust port 3, the air inlet 4 and the air pipe 5 connected to the air inlet 4, and the air pipe 5 is provided with the gas detection component 7. This implementation method is to test the test piece 2 of the first method.

[0056] In the battery electrode porosity testing device provided in this embodiment, the volumes of the first cavity and the second cavity are the same, which facilitates the calculation of the theoretical volume in each cavity.

[0057] like Figure 3 As shown, in the battery electrode porosity testing device provided in this embodiment, the cross-sectional size of the foil 14 is larger than the cross-sectional size of the first cavity 10 and the second cavity 12; the cross-sectional size of the active material layer 15 of the test piece 2 is smaller than the cross-sectional size of the first cavity 10 and the second cavity 12, so as to achieve clamping of the foil 14 and testing of the active material layer 15.

[0058] In the battery electrode porosity testing device provided in this embodiment, the gas detection assembly 7 includes a gas on-off valve and a flow detection component arranged on the gas on-off valve. Specifically, the flow detection component is a flow meter.

[0059] The battery electrode porosity testing device provided in this embodiment also includes a controller, which is electrically connected to the gas detection component 7 and the pressure detection component 8. The controller controls the gas detection component 7 to realize the on-off of the gas in the gas pipe 5 and obtain the gas flow filled in the closed cavity according to the air pressure signal of the pressure detection component 8. The setting of the controller improves the automation of the device, further improves the test efficiency and can more accurately grasp the set pressure and flow detection.

[0060] The test steps of the battery electrode porosity test device provided in this embodiment are as follows:

[0061] The electrode piece is cut to obtain the test piece 2. Specifically, the electrode piece is first cut into a circular structure, and the front and back surfaces of the electrode piece are laser cleaned to clean the large circle particles, and the test piece 2 is obtained after cleaning;

[0062] The test piece 2 is placed in the sealed cavity, and the first box 9 and the second box 11 clamp the foil 14 to perform a sealing test. If there is no problem with the sealing test, continue with the subsequent operations;

[0063] Take out the test piece 2, evacuate the sealed cavity, and then introduce gas into the sealed cavity through the gas source. Detect the amount of gas introduced under the set pressure to obtain the theoretical volume of the space.

[0064] Then, the test piece 2 is placed in the sealed cavity, and the sealed cavity is first vacuumed, and then gas is introduced into the sealed cavity through the gas source, and the amount of gas introduced under the set pressure is detected to obtain the actual volume filled;

[0065] The porosity of the test piece 2 is calculated by: porosity = 1 - (theoretical space volume - actual filled volume) / (volume of the test piece).

[0066] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the scope of protection of the present utility model.

Claims

1. A battery pole piece porosity testing device, characterized in that: include: A test box (1) has a sealed cavity inside which a test piece (2) is placed, and the sealed cavity is provided with a vacuum suction port (3) and an air inlet (4), wherein the vacuum suction port (3) is suitable for being connected to a vacuum pump, and the air inlet (4) is suitable for being connected to an air source (6) via an air pipe (5); A gas detection component (7), arranged on the gas pipe (5), suitable for controlling the on-off of the gas and detecting the flow rate of the gas filled into the closed cavity; The pressure detection element (8) is arranged in the sealed cavity and is suitable for detecting the air pressure in the sealed cavity.

2. The battery pole piece porosity testing device according to claim 1, characterized in that: The test box (1) comprises: A first box (9) having a first cavity (10) with an opening at one end; The second box (11) has a second cavity (12) with one end open, and the open ends of the first cavity (10) and the second cavity (12) are butted together to form the closed cavity.

3. The battery pole piece porosity testing device according to claim 2, characterized in that: Also includes: An adjusting component (13), whose adjusting end is connected to the first box (9) and / or the second box (11), is suitable for driving the first box (9) and the second box (11) to move closer to each other or farther away from each other.

4. The battery pole piece porosity testing device according to claim 2, characterized in that: The first box body (9) and the second box body (11) are butted against each other and are suitable for clamping the foil material (14) of the test piece (2).

5. The battery pole piece porosity testing device according to claim 4, characterized in that: Sealing members are provided between the first box body (9) and the object to be tested (2), and between the second box body (11) and the object to be tested (2).

6. The battery pole piece porosity testing device according to claim 4, characterized in that: The first cavity (10) and the second cavity (12) are both provided with the pressure detection component (8), the vacuum suction port (3), the air inlet (4) and an air pipe (5) connected to the air inlet (4), and the air pipe (5) is both provided with the gas detection component (7).

7. The battery pole piece porosity testing device according to claim 4, characterized in that: The volumes of the first cavity (10) and the second cavity (12) are the same.

8. The battery pole piece porosity testing device according to claim 4, characterized in that: The cross-sectional size of the foil (14) is larger than the cross-sectional sizes of the first cavity (10) and the second cavity (12); The cross-sectional size of the active material layer (15) of the test object (2) is smaller than the cross-sectional sizes of the first cavity (10) and the second cavity (12).

9. The battery pole piece porosity testing device according to claim 1, characterized in that: The gas detection component (7) comprises a gas on-off valve and a flow detection component arranged on the gas on-off valve.

10. The battery pole piece porosity testing device according to any one of claims 1 to 9, characterized in that: Also includes: A controller is electrically connected to the gas detection component (7) and the pressure detection component (8), and the controller controls the gas detection component (7) to realize the on-off of the gas in the air pipe (5) and obtain the gas flow rate filled into the closed cavity according to the air pressure signal of the pressure detection component (8).

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