A structure to improve the conductivity of lithium-ion battery separator samples in SEM

Abstract

The utility model discloses a structure for improving the conductivity of lithium-ion battery diaphragm samples in SEM, and relates to the technical field of coal impurity removal, including a sample table, a bottom conductive glue is pasted on the table top of the sample table, a diaphragm is pasted on the upper end face of the bottom conductive glue, an upper conductive glue is pasted on the upper end face of the diaphragm and close to the side edge of the diaphragm, and one end of the upper conductive glue is pasted on the upper end face of the sample table, and the sample table is placed on the operating table of an ion sputtering instrument, and the ion sputtering instrument is placed on the table top of a laboratory table. The utility model pastes the diaphragm on the table top of the sample table through the bottom conductive glue, and the method is simple and easy to operate, shortens the pre-processing time of the diaphragm sample ion sputtering instrument, does not damage the structure and surface morphology of the diaphragm sample, increases the conductive path between the diaphragm and the sample table, reduces the "charging effect" phenomenon produced by poorly conductive samples such as lithium-ion battery diaphragms, and improves the quality of the SEM images of the diaphragm samples.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium ion battery experimental testing, in particular to a structure for improving the conductivity of a lithium ion battery diaphragm sample in a SEM. Background Art

[0002] The diaphragm is located between the positive and negative electrodes in lithium-ion batteries. It is a thin film with a microporous structure. It has two main functions: on the one hand, it separates the positive and negative electrodes of the battery to prevent the two parts from directly contacting each other and forming a short circuit, which can cause danger; on the other hand, it provides a channel for the transmission of lithium ions between the positive and negative electrodes. Therefore, as an important component of lithium-ion batteries, the performance of the diaphragm directly affects the capacity, internal resistance, cycle performance and safety performance of lithium-ion batteries.

[0003] In order to observe the various parameters of the diaphragm sample more intuitively, we will choose a scanning electron microscope (SEM) to observe the microscopic morphology of the diaphragm. When the scanning electron microscope is working, the high-speed electron flow generated by the electron gun bombards the surface of the sample, and the atoms on the surface of the sample interact with each other, causing the electrons outside the nucleus to ionize and form secondary electrons. If the sample has good conductivity, the charge can be quickly derived and present electrical neutrality; if the sample has poor conductivity, local charging will occur due to charge accumulation, that is, the charging effect. The diaphragm is not conductive, and the incident electron beam will cause negative charges to accumulate on the surface of the diaphragm. This layer of negative charge will affect the incident electron beam and the excited signal, causing image distortion, local overbrightness, etc. The charging effect on the sample surface will also change or even destroy the details of the sample, thereby affecting the results and conclusions of electron microscopy observations.

[0004] The generation of charge has a great influence on the observation of scanning electron microscope, so normal scanning electron microscope observation can only be carried out by eliminating or reducing the charging effect. The most commonly used method to reduce the charging effect is to change the conductive properties of the sample surface by sputtering a gold film, a platinum film or a carbon film on the surface of a non-conductor sample, so that the accumulated charge can flow out through the sample stage. However, the difficulty of this method lies in controlling the thickness of the sputtered conductive film. If the thickness is too thin, the charge cannot be effectively extracted; if the thickness is too thick, the original morphology of the sample surface will be covered. If the diaphragm sample is sputtered and vacuumed for a long time, the base film of the diaphragm will break, causing certain damage to the sample. Utility Model Content

[0005] The utility model aims to provide a structure for improving the conductivity of lithium ion battery separator samples in SEM, so as to solve the above-mentioned multiple defects caused by the prior art.

[0006] A structure for improving the conductivity of a lithium-ion battery diaphragm sample in a SEM comprises a sample stage, a bottom conductive adhesive is pasted on the surface of the sample stage, a diaphragm is pasted on the upper end surface of the bottom conductive adhesive, an upper conductive adhesive is pasted on the upper end surface of the diaphragm and close to the side edge of the diaphragm, and one end of the upper conductive adhesive is pasted on the upper end surface of the sample stage, the sample stage is placed on an operating table of an ion sputtering instrument, and the ion sputtering instrument is placed on the table of a laboratory table.

[0007] Preferably, a transparent glass cover is installed on the operating table of the ion sputtering instrument, a sputtering handle is installed on the upper end of the transparent glass cover, and a gas exhaust port connected to the operating table is provided at the rear end of the ion sputtering instrument.

[0008] Preferably, a mechanical pump is placed on the table top of the experimental table and located on one side of the ion sputtering instrument, and the mechanical pump is provided with an air inlet and an air outlet.

[0009] Preferably, an operation panel is provided at the front end of the ion sputtering instrument.

[0010] Preferably, the air inlet and the air outlet are connected via a bellows.

[0011] The advantages of the utility model are:

[0012] 1. The utility model adheres the diaphragm to the table of the sample table through the bottom conductive glue. The method is simple and easy to operate, which can shorten the pre-treatment time of the ion sputtering instrument of the diaphragm sample and will not damage the structure and surface morphology of the diaphragm sample;

[0013] 2. The utility model increases the conductive path between the diaphragm and the sample stage through the bottom conductive glue and the upper conductive glue, reduces the "charging effect" phenomenon caused by samples with poor conductivity such as lithium-ion battery diaphragms, and thus improves the quality of the SEM images of the diaphragm samples. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The utility model is a schematic structural diagram of the assembly of the ion sputtering apparatus and the mechanical pump.

[0015] Figure 2 It is a schematic diagram of the structure inside the transparent glass cover of the utility model.

[0016] Figure 3 The utility model is a schematic diagram of the structure of the operating table, sample table and diaphragm assembly.

[0017] Figure 4 The utility model is a schematic diagram of the structure of the bottom conductive adhesive, the diaphragm, the upper conductive adhesive and the operating table.

[0018] Figure 5In order to explore the optimal current and sputtering time of the diaphragm in the ion sputtering instrument, pictures were taken of the sample base film breakage and the phenomenon of no charge.

[0019] Figure 6 In order to explore the optimal current and sputtering time of the diaphragm in the ion sputtering instrument, pictures were taken during the process of sample base film without breakage and with obvious charging phenomenon.

[0020] Figure 7 This is a picture taken by scanning electron microscope of Example 1.

[0021] Figure 8 This is a picture taken by scanning electron microscope for comparative example 1

[0022] Fig. 9 This is a picture taken by scanning electron microscope of Example 2.

[0023] Fig.10 This is a picture taken by scanning electron microscope for comparative example 2

[0024] Among them: 1-sample table; 2-bottom conductive glue; 3-diaphragm; 4-upper conductive glue; 5-ion sputtering instrument; 6-operating table; 7-laboratory table; 8-transparent glass cover; 9-sputtering handle; 10-exhaust port; 11-mechanical pump; 12-air inlet; 13-air outlet. DETAILED DESCRIPTION

[0025] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below in conjunction with specific implementation methods.

[0026] like Figures 1 to 10 As shown, a structure for improving the conductivity of lithium-ion battery diaphragm samples in SEM includes a sample stage 1, a bottom conductive glue 2 is pasted on the surface of the sample stage 1, a diaphragm 3 is pasted on the upper end surface of the bottom conductive glue 2, an upper conductive glue 4 is pasted on the upper end surface of the diaphragm 3 and close to the side edge of the diaphragm 3, and one end of the upper conductive glue 4 is pasted on the upper end surface of the sample stage 1, and the sample stage 1 is placed on the operating table 6 of the ion sputtering instrument 5, and the ion sputtering instrument 5 is placed on the surface of the experimental table 7. The ion sputtering instrument 5 is connected to the power supply line of the laboratory through a power cord, and the mechanical pump 11 is connected to the power supply port of the ion sputtering instrument 5 through a power cord.

[0027] In this embodiment, a transparent glass cover 8 is installed on the operating table 6 of the ion sputtering instrument 5, a sputtering handle 9 is installed on the upper end of the transparent glass cover 8, and a suction port 10 connected to the operating table 6 is provided at the rear end of the ion sputtering instrument 5. A suction inlet is provided at the center of the operating table 6, and the mechanical pump 11 removes the air in the transparent glass cover 8 through the suction inlet, the suction port 10 and the air inlet 12, and makes the inside of the transparent glass cover 8 a vacuum state, and an air port for controlling air intake is provided on the sputtering handle 9.

[0028] In this embodiment, a mechanical pump 11 is placed on the surface of the experimental table 7 and located on one side of the ion sputtering device 5 , and an air inlet 12 and an air outlet 13 are provided on the mechanical pump 11 .

[0029] In this embodiment, an operation panel is provided at the front end of the ion sputtering instrument 5. The operation panel controls the start and stop of the ion sputtering instrument 5 and the mechanical pump 11, and the control panel can adjust the time length and intensity of the ion sputtering instrument 5 sputtering ions.

[0030] In this embodiment, the air inlet 12 is connected to the air outlet 10 via a bellows.

[0031] The specific steps are:

[0032] 1. Stick a layer of bottom conductive glue 2 on the sample stage 1;

[0033] 2. Use scissors to cut a small piece of diaphragm 3 with a size of 1mm*1mm-3mm*3mm, and stick the diaphragm 3 on the bottom conductive glue 2;

[0034] 3. Place in ion sputtering apparatus 5, current is 1.0-3mA, sputtering time is 70-90s;

[0035] 4. Stick an upper layer of conductive glue 4 around the diaphragm 3 , and the upper layer of conductive glue 4 should be stuck to the sample stage 1 .

[0036] Embodiment 1 (patented method):

[0037] 1. Explore the optimal current and sputtering time of the diaphragm in the ion sputtering instrument (model JYSC-100);

[0038] 2. Under the optimal conditions, adhere the upper conductive adhesive 4 around the membrane sample as described in the technical solution;

[0039] 3. Place the membrane sample 1 in a scanning electron microscope (model: Zeiss EVO10) and photograph it. See the attached pictures. Figure 7 .

[0040] Embodiment 2 (patented method):

[0041] 1. The membrane sample 2 is sputtered in an ion sputtering apparatus at an optimal current and time, and the membrane sample is pasted with an upper layer of conductive adhesive 4 around the membrane sample as described in the technical solution;

[0042] 2. Place the diaphragm sample 2 in a scanning electron microscope and photograph it. See the attached pictures. Fig. 9 ;

[0043] Comparative Example 1 (common method):

[0044] 1. The optimal current and time for sputtering of the membrane sample 1 in the ion sputtering instrument;

[0045] 2. Place the membrane sample 1 in a scanning electron microscope and photograph it. See the attached pictures. Figure 8 .

[0046] Comparative Example 2 (common method):

[0047] 1. The optimal current and time for sputtering of membrane sample 2 in the ion sputtering instrument;

[0048] 2. Place the diaphragm sample 2 in a scanning electron microscope and photograph it. See the attached pictures. Fig.10 .

[0049] Explore the optimal current and sputtering time of the diaphragm 3 in the ion sputtering apparatus 5 (as shown in the following table):

[0050]

[0051]

[0052] According to the data in the table, the optimal current is 2mA and the time is 80s.

[0053] Basement membrane rupture, no charge phenomenon: as attached Figure 5 shown.

[0054] The basement membrane has no cracks and has obvious charging phenomenon: Figure 6 shown.

[0055] Comparison of Example 1 and Comparative Example 1: Figure 7 and attached Figure 8 Comparing the two pictures, it can be clearly seen that the diaphragm picture taken using the method of this patent has uniform color and is not affected by the charging effect.

[0056] Comparison of Example 2 and Comparative Example 2: In order to make our data more convincing, we selected another diaphragm 3 to compare the method of this patent with the common method. Fig. 9 and attached Fig.10 It can be explained that the patented method can reduce the "charging effect" phenomenon caused by the non-conductive nature of the diaphragm sample.

[0057] The working principle of the utility model is as follows: the air inlet 12 of the mechanical pump 11 is connected to the air exhaust port 10 through a bellows, and then the diaphragm 3 is pasted on the table top of the sample stage 1 through the bottom conductive glue 2, and the sample stage 1 is placed on the operating table 6, and then the transparent glass cover 8 is installed on the operating table 6, and the sample stage 1 is covered inside the transparent glass cover 8, and the sputtering head 9 is buckled on the upper end of the transparent glass cover 8, and the mechanical pump 11 is started to evacuate the inside of the transparent glass cover 8, and the ion sputtering instrument 5 is started to sputter ions to the diaphragm 3, and then the upper conductive glue 4 is pasted around the diaphragm 3, and one end of the upper conductive glue 4 is pasted on the table top of the sample stage 1, and then the diaphragm 3 and the sample stage 1 are placed in a scanning electron microscope to photograph them.

[0058] The utility model adheres the diaphragm 3 to the table surface of the sample table 1 through the bottom conductive glue 2. The method is simple and easy to operate, and can shorten the pre-treatment time of the diaphragm sample ion sputtering instrument 5 without damaging the structure and surface morphology of the diaphragm 3 sample.

[0059] The utility model increases the conductive path between the diaphragm 3 and the sample stage 1 through the bottom conductive glue 2 and the upper conductive glue 4, reduces the "charging effect" phenomenon produced by samples with poor conductivity such as the lithium ion battery diaphragm 3, and thus improves the quality of the SEM image of the diaphragm 3 sample.

[0060] It is known from common technical knowledge that the present invention can be implemented by other embodiments that do not deviate from its spirit or essential features. Therefore, the embodiments disclosed above are only illustrative in all respects and are not exclusive. All changes within the scope of the present invention or within the scope equivalent to the present invention are included in the present invention.

Claims

1. A structure for improving the conductivity of a lithium-ion battery separator sample in SEM, characterized in that: The invention comprises a sample stage (1), wherein a bottom conductive adhesive (2) is pasted on the surface of the sample stage (1), a diaphragm (3) is pasted on the upper end surface of the bottom conductive adhesive (2), an upper conductive adhesive (4) is pasted on the upper end surface of the diaphragm (3) and close to the side edge of the diaphragm (3), and one end of the upper conductive adhesive (4) is pasted on the upper end surface of the sample stage (1), the sample stage (1) is placed on an operating table (6) of an ion sputtering instrument (5), and the ion sputtering instrument (5) is placed on the surface of an experimental table (7).

2. A structure for improving the conductivity of a lithium-ion battery separator sample in SEM according to claim 1, characterized in that: A transparent glass cover (8) is installed on the operating table (6) of the ion sputtering instrument (5), a sputtering handle (9) is installed on the upper end of the transparent glass cover (8), and a gas extraction port (10) connected to the operating table (6) is provided at the rear end of the ion sputtering instrument (5).

3. A structure for improving the conductivity of a lithium-ion battery separator sample in SEM according to claim 2, characterized in that: A mechanical pump (11) is placed on the surface of the experimental table (7) and located on one side of the ion sputtering device (5), and the mechanical pump (11) is provided with an air inlet (12) and an air outlet (13).

4. The structure for improving the conductivity of a lithium-ion battery separator sample in SEM according to claim 1, characterized in that: An operation panel is provided at the front end of the ion sputtering instrument (5).

5. The structure for improving the conductivity of a lithium-ion battery separator sample in SEM according to claim 3, characterized in that: The air inlet (12) and the air extraction port (10) are connected via a bellows.

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