Device for testing wettability of pole piece

Abstract

The utility model belongs to the field of battery testing, and particularly relates to a pole piece wettability testing device which comprises a measuring container used for containing electrolyte and comprising an upper cover. The pole piece moving device is used for moving the pole piece up and down; the mass meter is used for measuring the mass of the pole piece moving device and the pole piece before and after being infiltrated with the electrolyte; the pole piece surface floating liquid removing device is used for removing floating liquid on the surface of the infiltrated pole piece; when the pole piece wettability testing device works, the pole piece moving device is arranged in the measuring container, and the pole piece moving device penetrates through the upper cover to be connected with the mass meter; and the pole piece surface floating liquid removing device is fixed in the measuring container. By adopting the technical scheme provided by the utility model, the liquid absorption amount, the infiltration rate and the time required for completely infiltrating the pole piece can be qualitatively and quantitatively measured, the infiltration effect of the pole piece can be intuitively evaluated, and a reference basis is provided for battery cell liquid injection.

Description

Technical Field

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

[0002] As the electrode thickness increases, the impact of electrolyte infiltration on battery performance is crucial. How to accurately know the electrolyte infiltration situation has an important impact on the development of thick electrodes.

[0003] When the electrolyte infiltration effect is not good, the ion transmission path becomes longer, which hinders the shuttling of lithium ions between the positive and negative electrodes. The electrodes that are not in contact with the electrolyte cannot participate in the electrochemical reaction of the battery. At the same time, the battery interface resistance increases, affecting the rate performance, discharge capacity and service life of the lithium battery.

[0004] At present, there are three conventional methods for evaluating the wetting effect of the electrode:

[0005] The first method is to test the contact angle of the electrolyte on the electrode, and use the contact angle to evaluate the wetting effect of the electrolyte. However, the electrode absorbs the electrolyte quickly, the test is difficult, and the saturated adsorption amount and adsorption rate of the electrolyte cannot be evaluated. It is also greatly affected by the surface state of the electrode, and the result has poor reliability.

[0006] The second method is to measure the climbing height of the electrode when it is immersed in the electrolyte, and measure the climbing height of the electrolyte. This method can only qualitatively judge the liquid absorption effect of the joint, and cannot quantitatively calculate the amount of liquid absorbed by the electrode.

[0007] The third method is the electrode immersion weighing method, which calculates the electrode weight by weighing the electrode weight at different time periods. Although this method is simple to operate, the floating liquid and environment on the electrode surface will affect the accuracy of the test results. Utility Model Content

[0008] The utility model aims to overcome the defects in the prior art and provide a pole piece wettability testing device.

[0009] In order to achieve the above-mentioned purpose, the utility model adopts the following technical solutions:

[0010] A device for testing the wettability of a pole piece, comprising:

[0011] A measuring container, used for containing electrolyte, including an upper cover;

[0012] A pole piece moving device, used to move the pole piece up and down;

[0013] The mass meter is used to measure the mass of the electrode moving device and the electrode before and after being soaked in electrolyte;

[0014] A floating liquid removal device on the electrode surface, used to remove the floating liquid on the electrode surface after infiltration;

[0015] When the electrode wettability testing device is working, the electrode moving device is placed in the measuring container, and the electrode moving device passes through the upper cover and is connected to the mass meter; the electrode surface floating liquid removing device is fixed in the measuring container.

[0016] Furthermore, the electrode wettability testing device also includes a constant temperature water bath, and the measuring container is placed in the constant temperature water bath.

[0017] Furthermore, the measuring container comprises a measuring container body and an upper cover; the measuring container body is threadedly connected to the upper cover.

[0018] Furthermore, the pole piece moving device comprises a first connecting rod, an elastic member and a second connecting rod which are connected in sequence, and the pole piece moving device is connected to the mass meter through the first connecting rod;

[0019] The pole piece moving device also includes a power piece, which passes through the wall of the measuring container and is connected to the pole piece, so as to realize the up and down movement of the pole piece.

[0020] Furthermore, the elastic member is two springs, which are respectively connected to the head and tail ends of the first connecting rod and the second connecting rod.

[0021] Furthermore, a screw is provided on the first connecting rod; a thread groove matching the screw is provided on the base of the mass meter; the screw is connected to the thread groove to realize the connection between the mass meter and the pole piece moving device.

[0022] Furthermore, a fixing clamp for clamping the pole piece is arranged on the second connecting rod; preferably, there are two fixing clamps, which are respectively arranged at the head and tail ends of the second connecting rod.

[0023] Furthermore, the power member includes a rigid column and a moving part connected to the rigid column;

[0024] The rigid column passes through the measuring container, and a sealing plug is provided at the contact point between the rigid column and the measuring container.

[0025] Furthermore, the pole piece surface floating liquid removal device comprises a fixing part and a double roller structure connected to the fixing part;

[0026] The fixing piece is used to fix the double roller structure in the measuring container;

[0027] The double-roller structure comprises a support and two roller shafts arranged on the support, and a gap is provided between the two roller shafts for the pole piece to pass through.

[0028] Furthermore, the double-roller structure is fixed to the upper cover via a fixing member.

[0029] Compared with the prior art, the beneficial effects of the utility model are:

[0030] The utility model is provided with a floating liquid removal device on the surface of the pole piece, which can remove the residual liquid on the surface of the pole piece after being infiltrated, thereby avoiding affecting the accuracy of the test result;

[0031] The technical solution of the utility model can be used to qualitatively and quantitatively measure the liquid absorption amount of the electrode, the wetting rate and the time required for the electrode to be completely wetted, intuitively evaluate the wetting effect of the electrode, and provide a reference basis for the liquid injection of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the overall structure of the electrode wettability testing device of the utility model;

[0033] Figure 2 It is a schematic diagram of the double-roller structure of the electrode wettability testing device of the utility model;

[0034] Figure 3 It is a schematic diagram of the connection between the mass meter and the pole piece moving device of the pole piece wettability testing device of the utility model;

[0035] In the figure, there are measuring container 1, upper cover 2, mass meter 3, power part 4, rigid column 41, moving part 42, double roller structure 5, bracket 51, fixing part 52, roller shaft 53, pole piece moving device 6, first connecting rod 61, elastic part 62, second connecting rod 63, and fixing clamp 7. DETAILED DESCRIPTION

[0036] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and the best embodiment.

[0037] Figure 1-Figure 3 A device for testing the wettability of a pole piece is shown, comprising:

[0038] A measuring container 1, used for containing electrolyte, comprising an upper cover 2;

[0039] A pole piece moving device 6, used to move the pole piece up and down;

[0040] A mass meter 3, used to measure the mass of the electrode moving device and the electrode before and after being soaked in electrolyte;

[0041] A floating liquid removal device on the electrode surface, used to remove the floating liquid on the electrode surface after infiltration;

[0042] When the electrode wettability testing device is working, the electrode moving device is placed in the measuring container, and the electrode moving device passes through the upper cover 2 and is connected to the mass meter 3; the electrode surface floating liquid removing device is fixed in the measuring container.

[0043] The electrode wettability testing device further comprises a constant temperature water bath (not shown), and the measuring container is placed in the constant temperature water bath.

[0044] The measuring container 1 comprises a measuring container body and an upper cover 2 ; the measuring container body is threadedly connected to the upper cover 2 , and the thread design facilitates the installation and disassembly of the upper cover 2 .

[0045] The pole piece moving device 6 includes a first connecting rod 61, an elastic member 62 and a second connecting rod 63 connected in sequence, and the pole piece moving device 6 is connected to the mass meter 3 through the first connecting rod 61; a screw is provided on the first connecting rod 61, and a thread groove (not shown) matching the screw is provided on the base of the mass meter, and the screw is connected to the thread groove to realize the connection between the mass meter and the pole piece moving device (the screw on the first connecting rod passes through the upper cover 2 and is connected to the mass meter), or, the thread groove is provided on the first connecting rod 61, and the screw is provided on the base of the mass meter, which can also realize the connection between the mass meter and the pole piece moving device.

[0046] The elastic member 62 is two springs, which are respectively connected to the first connecting rod 61 and the second connecting rod 63 at both ends. The second connecting rod 63 is provided with a fixing clip 7 for clamping the pole piece. There are two fixing clips 7, which are respectively provided at the first and last ends of the second connecting rod 63.

[0047] The pole piece moving device further comprises a power piece 4, which passes through the wall of the measuring container and is connected to the pole piece, so as to realize the up and down movement of the pole piece.

[0048] The power member 4 includes a rigid column 41 and a moving part 42 connected to the rigid column; the rigid column 41 passes through the measuring container, and a sealing plug is provided at the contact point between the rigid column 41 and the measuring container.

[0049] When in use, by moving the moving part 42 placed outside the measuring container, the rigid column 41 connected thereto can be driven to move, and the rigid column 41 can be placed on the surface of the electrode, and the movement of the rigid column 41 can drive the electrode to move up and down. The sealing plug (not shown in the figure) can ensure the sealing of the measuring container during the movement, and does not affect the measurement result of the mass meter 3.

[0050] The pole piece surface floating liquid removal device comprises a fixing member 52 and a double roller structure 5 connected to the fixing member 52;

[0051] The fixing member 52 is used to fix the double roller structure in the measuring container 1;

[0052] The double-roller structure 5 comprises a support 51 and two roller shafts 53 arranged on the support, and there is a gap between the two roller shafts for the pole piece to pass through.

[0053] By driving the pole piece 8 through the gap between the two rollers 53 through the power member 4, the residual liquid on the surface of the pole piece after being wetted can be removed, thereby avoiding affecting the accuracy of the test result.

[0054] The double-roller structure 5 is fixed to the upper cover via a fixing member 52 .

[0055] The screw on the connecting rod 61 passes through the upper cover 2 and is anchored into the threaded groove on the base of the mass meter 3 to realize the connection between the mass meter 3 and the electrode moving device 6. The power member 4 drives the electrode to move under the action of the elastic member 62, so that the electrode moves up and down on the electrolyte surface to realize the process of electrode absorbing liquid, and the change of the reading of the mass meter 3 is used to record;

[0056] At the same time, due to the existence of the double-roller structure 5, the pole piece can be moved by the power piece 4 so that the pole piece passes through the gap between the two roller shafts 53 of the double-roller structure 5 to remove the foam, thereby making the result more accurate. Since the mass of the components connected to the mass meter 3 does not change except the pole piece, the mass display will not be affected.

[0057] The assembly steps and testing principle of the test device of the utility model are as follows:

[0058] The power member 4 passes through the wall of the measuring container and is installed on the measuring container;

[0059] The double roller structure 5 is fixed on the upper cover 2 via the fixing member 52;

[0060] Fix the pole piece with a fixing clip 7 connected to the elastic member;

[0061] The pole piece moving device 6 passes through the upper cover 2 and is connected to the mass meter 3;

[0062] The upper cover 2 is screwed onto the test container body, and the sum of the weights of the pole piece and the pole piece moving device M1 is recorded. At this time, the pole piece is not immersed in the electrolyte;

[0063] The moving part 42 of the moving power member 4 is moved to make the rigid column 41 on the upper part of the second connecting rod 63, and the moving part 42 is pushed, so that the rigid column 41 presses down the second connecting rod 63, and then controls the pole piece to move downward, and the pole piece passes through the gap between the two roller shafts 53 of the double roller structure 5 and is immersed in the electrolyte; after a fixed time interval, the pressing down of the pole piece is stopped, the rigid column 41 is separated from the second connecting rod 63, and the pole piece slowly rises under the action of the elastic member 62, and passes through the gap between the two roller shafts 53 of the double roller structure 5 during the rising process, thereby removing the residual liquid on the surface of the test sample;

[0064] When the mass change of the sample to be tested does not exceed 1%, the sum of the masses of the electrode and the electrode moving device after immersion is recorded by the mass meter 3. The difference between the sum of the masses of the electrode and the electrode moving device after immersion and M1 is the mass of the electrode immersed in the electrolyte.

[0065] By recording the change in the sum of the mass of the test electrode and the electrode moving device at different time intervals, the saturated infiltration volume M2 of the test sample can be obtained. According to the change in the infiltration mass of the test sample, the liquid absorption time required for the saturation of the test sample and the infiltration rate at different stages can be obtained respectively.

[0066] From the above, it can be seen that the utility model provides a floating liquid removal device on the surface of the pole piece under the pole piece, which can specifically be a double-roller structure, so as to remove the residual liquid on the surface of the pole piece after being wetted, thereby avoiding affecting the accuracy of the test results.

[0067] The technical solution of the utility model can be used to qualitatively and quantitatively measure the liquid absorption amount of the electrode, the wetting rate and the time required for the electrode to be completely wetted, intuitively evaluate the wetting effect of the electrode, and provide a reference basis for the liquid injection of the battery cell.

[0068] The above contents are only preferred embodiments of the present invention. For ordinary technicians in this field, according to the concept of the present invention, there will be changes in the specific implementation methods and application scopes. The contents of this specification should not be understood as limiting the present invention.

Claims

1. A device for testing the wettability of a pole piece, characterized in that: include: A measuring container, used for containing electrolyte, including an upper cover; A pole piece moving device, used to move the pole piece up and down; The mass meter is used to measure the mass of the electrode moving device and the electrode before and after being soaked in electrolyte; A floating liquid removal device on the electrode surface, used to remove the floating liquid on the electrode surface after infiltration; When the electrode wettability testing device is working, the electrode moving device is placed in the measuring container, and the electrode moving device passes through the upper cover and is connected to the mass meter; the electrode surface floating liquid removing device is fixed in the measuring container.

2. The electrode wettability testing device according to claim 1, characterized in that: The electrode wettability testing device further comprises a constant temperature water bath, and the measuring container is placed in the constant temperature water bath.

3. The electrode wettability testing device according to claim 1, characterized in that: The measuring container comprises a measuring container body and an upper cover; the measuring container body is threadedly connected to the upper cover.

4. The electrode wettability testing device according to claim 1, characterized in that: The pole piece moving device comprises a first connecting rod, an elastic member and a second connecting rod which are connected in sequence; the pole piece moving device is connected to the mass meter via the first connecting rod; The pole piece moving device also includes a power piece, which passes through the wall of the measuring container and is connected to the pole piece, so as to realize the up and down movement of the pole piece.

5. The electrode wettability testing device according to claim 4, characterized in that: The elastic member is two springs, which are respectively connected to the first connecting rod and the second connecting rod at both ends.

6. The electrode wettability testing device according to claim 5, characterized in that: The first connecting rod is provided with a screw; the base of the mass meter is provided with a thread groove matching the screw, and the screw is connected with the thread groove to realize the connection between the mass meter and the pole piece moving device.

7. The electrode wettability testing device according to claim 4, characterized in that: The second connecting rod is provided with a fixing clamp for clamping the pole piece.

8. The electrode wettability testing device according to claim 4, characterized in that: The power member includes a rigid column and a moving part connected to the rigid column; The rigid column passes through the measuring container, and a sealing plug is provided at the contact point between the rigid column and the measuring container.

9. The electrode wettability testing device according to claim 1, characterized in that: The pole piece surface floating liquid removal device comprises a fixing part and a double roller structure connected to the fixing part; The fixing piece is used to fix the double roller structure in the measuring container; The double-roller structure comprises a support and two roller shafts arranged on the support, and a gap is provided between the two roller shafts for the pole piece to pass through.

10. The electrode wettability testing device according to claim 9, characterized in that: The double-roller structure is fixed to the upper cover via a fixing piece.

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