A method and device for judging the wettability of lithium-ion battery pole piece

Abstract

The invention discloses a method and device for judging the wettability of a lithium-ion battery pole piece, comprising the following steps: weighing a battery pole piece to be tested and spreading it on a filter component; vertically distributing a spray component, a filter component and a base component; during testing, controlling the spray component to spray an electrolyte, and the electrolyte sprays out from the spray component and then sprays onto the pole piece on the filter component, and finally reaches the base component; weighing the tested battery pole piece again; weighing the spray liquid on the base component after the test, and judging the change in weight for multiple times to determine the infiltration speed of the electrolyte; the filter plate of the invention can realize the testing of the electrolyte infiltration speed of the pole piece at different positions, and by comparing the weight of the pole piece after and before infiltration, and the weight of the base component before and after infiltration, after multiple tests, the pole piece wettability is judged by comparing the weight change, thereby achieving qualitative analysis and judgment, and further improving the accuracy of the pole piece wettability.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium batteries, and in particular to a method and a device for judging the wettability of a lithium-ion battery pole piece. Background Art

[0002] Currently, lithium-ion batteries are increasingly used in the automotive and energy storage fields. According to relevant surveys, by 2024, more than 50% of consumers will consider buying electric vehicles, but electric vehicles still face many market challenges. Price acceptance, range anxiety, charging time and difficulty, among which the requirement for range is one of the important challenges for the full popularization of electric vehicles.

[0003] To achieve increased mileage, the energy density of the battery cell needs to be increased within the limited space of the vehicle body to achieve the goal of increased mileage. For single cells, the energy density is mainly improved from the aspects of material system and battery cell design. As the performance of the material system gradually improves, its performance is getting closer and closer to the theoretical limit. Therefore, it is necessary to strengthen the optimization of battery cell design. Improving energy density by reducing weight is an easy-to-implement measure, among which the design of thick electrodes is one of the key means. Increasing the surface density of the positive and negative electrodes, thereby reducing the number of folds or layers of the electrode sheets, can achieve the purpose of reducing the amount of copper and aluminum foil. Because the density of copper and aluminum metals is relatively high, reducing the amount has a significant benefit in reducing the weight of the battery cell. However, after adopting the thick electrode design, the battery cell process and performance will be affected. It is necessary to develop a matching conductive agent or adhesive to build a suitable conductive network to ensure that the resistivity of the electrode sheet does not increase and the peel strength of the electrode sheet does not decrease; at the same time, it is necessary to ensure that the core or stacked core is fully infiltrated to ensure the normal performance, and reliable judgment of wettability is particularly important.

[0004] How to judge the wettability of the electrode? The traditional method is to determine it by contact angle or wetting area; the existing patent document with application number CN202011635678.9 discloses a method for evaluating the wettability and wetting time of the electrolyte on the electrode, which is to test it by contact angle. The patent discloses "using a syringe to drip the electrolyte on the surface of the electrode on the sample table, and photographing the electrolyte dripping process, and capturing the image when the electrolyte completely contacts the electrode but has not begun to spread, thereby obtaining the contact angle at that moment". This test method requires timely shooting at the moment of dripping, which has high requirements on the operator's operating skills. At the same time, the fluctuations of the test environment (such as surrounding wind, temperature and humidity, etc.) and the solvent used will affect the accuracy of the contact angle test value, thereby affecting the judgment of the wettability of the electrode.

[0005] The wetting area method generally uses titration of a certain amount of liquid to compare the area of ​​liquid diffusion within a specified time. Although this method is simple and easy to operate, the diffusion area of ​​the liquid is not a regular shape, and its qualitative analysis is easily affected by the subjective factors of the staff. It cannot accurately calculate the precise value of the diffusion area, thus affecting the accurate judgment of the wettability. Summary of the invention

[0006] The problem to be solved by the present invention is: how to solve the problem that the wettability test value of the battery electrode is inaccurate during the wettability test of the battery electrode, thereby affecting the wettability judgment of the electrode.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A method for determining the wettability of a lithium-ion battery electrode comprises the following steps:

[0009] S1, first weigh the battery electrode to be tested and set the weight of the battery electrode to M1, and then spread it on the filter component;

[0010] S2, setting the spray component, the filter component and the bottom support component to be vertically distributed from top to bottom, and then entering the pre-test state;

[0011] S3, start the test, first control the spray component to spray the electrolyte, the electrolyte is sprayed from the spray component and then sprayed onto the battery electrode on the filter component, and finally reaches the bottom support component until the spraying is completed;

[0012] S4, weigh the tested battery electrode again, and set the weight to M2, and set ΔM=M2-M1;

[0013] S5, weighing the spray liquid on the bottom bracket component after the test, and setting the weight F;

[0014] S6. Determine the infiltration speed of the electrolyte by judging the changes in F and ΔM.

[0015] The present invention judges the wettability of the battery electrode electrolyte by comparing the weight M1 before the electrode wetting test and the weight M2 after the electrode wetting test to obtain the difference ΔM between the two; at the same time, the spray liquid collected on the bottom support component is weighed, the weight is F, and the change of F can provide further auxiliary judgment for the wettability of the electrolyte. In this way, the qualitative analysis of the electrolyte can be achieved, and the comparison of double data can improve the accurate judgment of the electrode wettability; at the same time, the present invention is not affected by the use of solvents, the test environment (such as surrounding wind, temperature and humidity, etc.) and the operating method of the operator, and the operation is simple and the design is reasonable.

[0016] As a further solution of the present invention: in step S2, the upper and lower positions of the spray component, the filter component and the bottom support component are adjusted using a cylinder; the filter component includes filter element 1 and filter element 2, and filter element 1 and filter element 2 are distributed up and down, and both filter element 1 and filter element 2 are used to place battery electrodes.

[0017] As a further solution of the present invention: in step S3, after the spraying is stopped, the bottom support plate 1 and the bottom support plate 2 are driven by a cylinder to move, and the two are placed under the filter element 1 and the filter element 2 respectively.

[0018] As a further solution of the present invention: after step S5 is completed, the value of ΔM is recorded, and steps S3, S4 and S5 are re-executed to obtain the weight ΔM′ of the electrode sheet after two infiltrations, and the weight ΔM" of the electrode sheet after three infiltrations is obtained by analogy;

[0019] By comparing the changes among ΔM, ΔM′ and ΔM", if the values ​​gradually increase, it is judged that the wettability of the battery electrode is better, otherwise the wettability is worse.

[0020] As a further solution of the present invention: after step S5 is completed, the value of F is recorded, and steps S3, S4 and S5 are re-executed to obtain the weight F' of the spray liquid on the support plate component after two infiltrations, and the weight F" of the spray liquid on the support plate component after three infiltrations is obtained by analogy;

[0021] By comparing the changes among F, F′ and F", if the value gradually increases, it is judged that the wettability of the battery electrode is worse, otherwise it is judged that the wettability is better.

[0022] As a further solution of the present invention: in the three electrode sheet immersion processes, the time of each immersion is 5 minutes to 10 minutes.

[0023] The present invention also provides a device for judging the wettability of a lithium-ion battery pole piece, and the device executes the above-mentioned method for judging the wettability of a lithium-ion battery pole piece.

[0024] A device for judging the wettability of a lithium-ion battery pole piece comprises a cylinder, and a spray component, a filter component and a bottom support component arranged in sequence from top to bottom, wherein a battery pole piece is placed on the filter component;

[0025] The cylinder drives the spray component, the filter component and the bottom support component to be vertically distributed in the up and down directions through the cylinder rotating shaft.

[0026] As a further solution of the present invention: it also includes a bottom support plate 1 and a bottom support plate 2, and the bottom support plate 1 and the bottom support plate 2 are connected to the cylinder shaft of the cylinder;

[0027] The filter component includes a filter element 1 and a filter element 2 which are vertically distributed up and down. The filter element 1 and the filter element 2 are both used to place battery pole pieces. The filter element 1 and the filter element 2 are both provided with filter element baffles on both sides.

[0028] The cylinder can drive the bottom support plate 1 and the bottom support plate 2 to move to the bottom of the filter element 1 and the filter element 2 respectively through the cylinder rotating shaft.

[0029] As a further solution of the present invention: a base component lining paper is provided on the top of the base component, and a base component liquid-absorbing material is placed above the base component lining paper.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] Firstly, the present invention arranges a spray component, a filter component and a bottom support component, and places the electrode on the filter component. The filter component includes at least two groups of filter plates, so that the electrode can be tested for electrolyte infiltration speed at different positions. By comparing the weight of the electrode before and after infiltration, and the weight of the bottom support component before and after infiltration, after multiple tests, the change of weight is compared, so as to judge the wettability of the electrode, thereby achieving qualitative analysis and judgment, and further improving the accuracy of the wettability of the electrode. At the same time, the present invention is not affected by the use of solvents, the test environment and the operating techniques of the operator, and is simple to operate and reasonably designed.

[0032] Secondly, the present invention can be adjusted accordingly according to the characteristics of the electrode, and the spray component can control the flow rate, and adjust the flow rate according to the requirements of the electrode characteristics; the filter component is segmented, and the filter holes on the filter components of different segments are different in size, and the number of filter components can also be changed, so that multiple groups of electrode pieces can be tested at the same time, and the comparison parameters are increased, so that the test accuracy can be further improved;

[0033] Finally, since the electrolyte sprayed by the spray component is generally a corrosive chemical reagent, this application chooses to use a cylinder through a cylinder shaft to replace manual labor to prevent the reagent from causing harm to the workers; by setting up bottom support plate one and bottom support plate two, when the infiltration is completed, the bottom support plate is placed under the two filters, which can support the filter elements and the electrodes thereon, avoiding dripping of electrolyte during weighing and causing inaccurate weight. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a schematic diagram of the structure of a device for judging the wettability of a lithium-ion battery electrode according to an embodiment of the present invention;

[0035] Figure 2 This is a schematic structural diagram of a filter element 2 according to an embodiment of the present invention;

[0036] Figure 3 This is a schematic structural diagram of a bottom support component according to an embodiment of the present invention;

[0037] Figure 4 A graph showing the weight change of the pole piece after infiltration and the electrolyte increment of the motor pole piece according to an embodiment of the present invention;

[0038] Figure 5 A curve diagram showing the weight change of the bottom support component after infiltration and the electrolyte increment of the bottom support component according to an embodiment of the present invention;

[0039] Explanation of the reference numerals: 1. spray component; 2. filter element 1; 3. filter element 2; 4-1. bottom support component; 4-2. bottom support plate 1; 4-3. bottom support plate 2; 5. electrolyte; 6. battery electrode; 7. cylinder; 8. cylinder shaft; 9. filter element baffle; 10. bottom support component lining paper; 11. bottom support component liquid absorbing material. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] Reference Figure 1 A device for judging the wettability of a lithium-ion battery electrode comprises a cylinder 7, and a spray component 1, a filter component, a bottom support component 4-1, a bottom support plate 1 4-2 and a bottom support plate 2 4-3 arranged in sequence from top to bottom, a battery electrode 6 is placed on the filter component; the spray component 1 sprays electrolyte, it should be noted that the electrolyte here is a chemical reagent with certain corrosiveness, so the present application adopts the cylinder 7 to drive to avoid harm to workers.

[0042] Reference Figure 1 The cylinder 7 is connected to the filter component through the cylinder shaft 8, and the cylinder 7 is also connected to the base component 4-1 through the cylinder shaft 8. The cylinder 7 can drive the filter component and the base component 4-1 to adjust their positions, and then adjust the filter component and the base component 4-1 to be directly below the spray component 1, and make the spray component 1, the filter component and the base component 4-1 equidistantly distributed in the vertical direction.

[0043] Reference Figure 1 The filter component includes a filter element 2 and a filter element 3 which are vertically distributed up and down. The filter element 2 and the filter element 3 are used to place the battery electrode 6. The filter element 2 and the filter element 3 are provided with a filter element baffle 9 on both sides (such as Figure 2 As shown), two groups of battery pole pieces 6 can be subjected to immersion testing at the same time;

[0044] In one embodiment, the other parts are the same as above, except that: the filter component includes three groups of filters vertically distributed up and down, and the three groups of filters are used to place battery pole pieces 6, so that the three groups of battery pole pieces 6 can be subjected to infiltration testing at the same time.

[0045] In another embodiment, the other parts are the same as above, except that: the filter component includes four groups of filter elements distributed vertically up and down, and the four groups of filter elements are used to place the battery pole pieces 6, so that four groups of battery pole pieces 6 can be simultaneously tested for wetting. The specific number of groups of filter elements is selected according to the needs of the user, and this application does not limit it here, and only provides three reference solutions.

[0046] Reference Figure 1 The bottom support plate 1 4-2 and the bottom support plate 2 4-3 are connected to the cylinder shaft 8 of the cylinder 7. The bottom support plate 1 4-2 and the bottom support plate 2 4-3 can be driven by the cylinder shaft 8 to move their positions, and then the bottom support plate 1 4-2 and the bottom support plate 2 4-3 can be moved to the bottom of the filter element 1 2 and the filter element 2 3, that is, the bottom support plate 1 4-2 moves to the bottom of the filter element 1 2, and the bottom support plate 2 4-3 moves to the bottom of the filter element 2 3; when the test is completed, the bottom support plate is moved to the bottom of the corresponding filter element in time to prevent the electrolyte from flowing out again.

[0047] Reference Figure 3 The tops of the bottom support component 4-1, the bottom support plate 1 4-2 and the bottom support plate 2 4-3 are all covered with a bottom support component lining paper 10, and a bottom support component absorbent material 11 is placed above the bottom support component lining paper 10. In the infiltration test, the electrolyte will drip onto the bottom support component 4-1, and then soak into the bottom support component absorbent material 11, and be absorbed by the bottom support component absorbent material 11. Finally, the bottom support component absorbent material 11 can be weighed as a whole; the operator of the bottom support component absorbent material 11 can choose to use EPE, which is made of high-foam polyethylene products and has the advantages of waterproofing, moisture-proofing, shockproofing, sound insulation, heat preservation, environmental protection, etc., and also has good corrosion resistance and chemical resistance.

[0048] The present invention also provides a method for determining the wettability of a lithium-ion battery electrode, comprising the following steps:

[0049] S1, first weigh the battery electrode to be tested and set the weight of the battery electrode to M1, and then spread it on the filter component;

[0050] S2, using a driving mechanism to place the spray component, the filter component and the bottom support component in a vertical distribution state from top to bottom, and then enter a pre-test state;

[0051] S3, start the test, first control the spray component to spray the electrolyte, the electrolyte is sprayed from the spray component and then sprayed onto the battery electrode on the filter component, and finally reaches the bottom support component until the spraying is completed;

[0052] S4, weigh the tested battery electrode again, and set the weight to M2, and set ΔM=M2-M1;

[0053] S5, weighing the spray liquid on the bottom bracket component after the test, and setting the weight F;

[0054] S6. Determine the infiltration speed of the electrolyte by judging the changes in F and ΔM.

[0055] After step S5 is finished, after recording the value of ΔM, steps S3, S4 and S5 are re-executed to obtain the weight ΔM′ of the electrode after two infiltrations, and the weight ΔM" of the electrode after three infiltrations is obtained by analogy; in this process, the three infiltrations are all the same time, and the infiltration is stopped after 5 minutes; by comparing the changes among ΔM, ΔM′ and ΔM", if the value gradually increases, it is determined that the wettability of the battery electrode is better, otherwise the wettability is worse (such as Figure 4 As shown in the figure, when the values ​​of ΔM, ΔM′ and ΔM" gradually increase, it also means that the battery electrode 6 carries more and more electrolyte, and the electrolyte penetrates into the battery electrode 6 and is not easy to fall off, which means that the battery electrode 6 has good wettability. When the maximum weight that the battery electrode 6 can carry is reached, the increase of electrolyte in the battery electrode no longer changes regardless of whether it is wetted again (as shown in the figure). Figure 4 On the contrary, when the electrolyte infiltrating the battery pole piece 6 is getting less and less, it means that the electrolyte falls from the battery pole piece 6 and cannot stay on the pole piece, which means that the wettability of the battery pole piece 6 is getting worse. Through the qualitative analysis of the weight ΔM of the pole piece after infiltration, the staff recorded and summarized it and drew a Figure 4 The curve graph shown can ensure the accuracy of the wettability of the battery electrode.

[0056] In another embodiment, the other aspects are the same as above, except that: the three infiltration times are the same, and the infiltration is stopped after 8 minutes, and then the changes among ΔM, ΔM′ and ΔM" are compared.

[0057] In another embodiment, the other aspects are the same as above, except that: the three infiltration times are the same, and the infiltration is stopped after 10 minutes, and then the changes among ΔM, ΔM′ and ΔM" are compared.

[0058] After step S5 is finished, the value of F is recorded, and steps S3, S4 and S5 are re-executed to obtain the weight F' of the spray liquid on the support plate component after two infiltrations, and the weight F" of the spray liquid on the support plate component after three infiltrations is obtained by analogy; in this process, the time of the three infiltrations is the same, and the infiltration is stopped after 5 minutes; by comparing the changes among F, F' and F", if the value gradually increases, it is determined that the wettability of the battery electrode is worse, otherwise the wettability is better (such as Figure 5 As shown in the figure, when the values ​​of F, F′ and F" gradually increase, the amount of electrolyte carried on the bottom bracket component 4-1 is increasing, indicating that the electrolyte has penetrated from the upper electrode sheet to the lower part, which indicates that the wettability of the battery electrode sheet is worse; on the contrary, when the amount of electrolyte carried on the bottom bracket component 4-1 is decreasing, indicating that the electrolyte has fallen on the upper electrode sheet and cannot penetrate from the electrode sheet, which indicates that the wettability of the battery electrode sheet is better; through qualitative analysis of the spray liquid weight F, the staff recorded and summarized it, and drew a Figure 5 The curve graph shown can further ensure the accuracy of the wettability of the battery electrode.

[0059] In another embodiment, the other aspects are the same as above, except that: the three infiltration times are the same, and the infiltration is stopped after 8 minutes, and then the changes among F, F′ and F″ are compared.

[0060] In another embodiment, the other aspects are the same as above, except that: the three infiltration times are the same, and the infiltration is stopped after 10 minutes, and then the changes among F, F′ and F″ are compared.

[0061] The filter component includes a filter element 1 2 and a filter element 2 3, and the filter element 1 2 and the filter element 2 3 are both in a vertical position distributed up and down, and the filter element 1 2 and the filter element 2 3 are used to place the battery electrode 6. In step S3, after the spraying is stopped, the driving mechanism, i.e., the cylinder 7, is used to drive the bottom support plate 1 4-2 and the bottom support plate 2 4-3 to move, and the two are placed under the filter element 1 2 and the filter element 2 3 respectively.

[0062] The present application solves the problem of inaccurate values ​​of battery electrode wettability test in the wettability test of battery electrode, which in turn affects the electrode wettability judgment. In the present embodiment, the number of spraying times of the working state can be repeated; the filter elements in the filter component are not limited to the two groups given in the attached drawings, and the number of bottom trays is not limited to two groups. The number of bottom trays and filter elements is the same. After the infiltration is completed, the bottom tray needs to be moved to the bottom of the filter element to prevent the electrolyte from continuing to fall; similarly, the corresponding weight judgment is not limited to two groups, that is, if there are as many groups of electrode tests, then the weight judgment of as many groups of electrode tests will be continued, and finally one by one can be judged. The weight of the electrolyte carried by the battery electrode 6 at the top should be the largest, and the weight of the electrolyte carried by the battery electrode 6 at the bottom gradually decreases; at the same time, as the number of tests of the same battery electrode 6 increases, the increment of the electrolyte carried by the battery electrode 6 also decreases accordingly, and a gentle state is gradually formed (such as Figure 4 Similarly, as the number of tests increases, the weight of the electrolyte carried by the bottom support component decreases, gradually forming a flat state (as shown in Figure 5 shown).

[0063] The test time of each test in the present application is not limited to 5 minutes, 8 minutes and 10 minutes; the number of battery electrodes is not limited to two, and the number of battery electrodes on a filter element is not limited to one; the above mentioned will be adjusted accordingly according to the characteristics of different electrodes.

[0064] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for determining the wettability of a lithium-ion battery electrode, characterized in that: The steps include: S1, first weigh the battery electrode to be tested and set the weight of the battery electrode to M1, and then spread it on the filter component; S2, setting the spray component, the filter component and the bottom support component to be vertically distributed from top to bottom, and then entering the pre-test state; The spray parts, filter parts and bottom support parts are adjusted up and down by using cylinders; The filter component includes a filter element 1 and a filter element 2, the filter element 1 and the filter element 2 are arranged up and down, and the filter element 1 and the filter element 2 are both used to place battery pole pieces; S3, start the test, first control the spray component to spray the electrolyte, the electrolyte is sprayed from the spray component and then sprayed onto the battery electrode on the filter component, and finally reaches the bottom support component until the spraying is completed; When the spraying stops, the cylinder is used to drive the bottom support plate 1 and the bottom support plate 2 to move, and the two are placed under the filter element 1 and the filter element 2 respectively; S4, weigh the tested battery electrode again, set the weight to M2, and set ∆M=M2-M1; S5, weighing the spray liquid on the bottom bracket component after the test, and setting the weight F; S6. Determine the electrolyte infiltration rate by judging the changes in F and ∆M.

2. A method for determining the wettability of a lithium-ion battery electrode according to claim 1, characterized in that: After step S5 is completed, the value of ∆M is recorded, and steps S3, S4 and S5 are re-executed to obtain the weight ∆M′ of the electrode sheet after two infiltrations, and the weight ∆M" of the electrode sheet after three infiltrations is obtained by analogy; By comparing the changes among ∆M, ∆M′ and ∆M", if the values ​​gradually increase, it means that the wettability of the battery electrode is better, otherwise it means that the wettability is worse.

3. A method for determining wettability of a lithium-ion battery electrode according to claim 1, characterized in that: After step S5 is completed, the value of F is recorded, and steps S3, S4 and S5 are re-executed to obtain the weight F' of the spray liquid on the support plate component after two infiltrations, and the weight F" of the spray liquid on the support plate component after three infiltrations is obtained by analogy; By comparing the changes among F, F′ and F ", if the value gradually increases, it means that the wettability of the battery electrode is worse, otherwise it means that the wettability is better.

4. A method for determining wettability of a lithium-ion battery electrode according to claim 2 or 3, characterized in that: During the three electrode immersion processes, the time for each immersion is 5 minutes to 10 minutes.

5. A device for determining the wettability of a lithium-ion battery electrode, characterized in that: The device executes a method for determining wettability of a lithium-ion battery electrode as described in any one of claims 1 to 4.

6. The device for judging wettability of a lithium-ion battery electrode according to claim 5, characterized in that: It includes a cylinder, and a spray component, a filter component and a bottom support component which are arranged in sequence from top to bottom, and a battery pole piece is placed on the filter component; The cylinder drives the spray component, the filter component and the bottom support component to be vertically distributed in the up and down directions through the cylinder rotating shaft.

7. The device for determining wettability of a lithium-ion battery electrode according to claim 6, characterized in that: It also includes a bottom support plate 1 and a bottom support plate 2, wherein the bottom support plate 1 and the bottom support plate 2 are connected to the cylinder rotating shaft of the cylinder; The filter component includes a filter element 1 and a filter element 2 which are vertically distributed up and down. The filter element 1 and the filter element 2 are both used to place battery pole pieces. The filter element 1 and the filter element 2 are both provided with filter element baffles on both sides. The cylinder can drive the bottom support plate 1 and the bottom support plate 2 to move to the bottom of the filter element 1 and the filter element 2 respectively through the cylinder rotating shaft.

8. The device for judging wettability of a lithium-ion battery electrode according to claim 7, characterized in that: The tops of the bottom support component, the bottom support plate 1 and the bottom support plate 2 are all provided with bottom support component lining paper, and the bottom support component liquid-absorbing material is placed above the bottom support component lining paper.

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