A visualized coating release film porosity test method and system

Abstract

The application discloses a kind of visual coating release film porosity test method and system, it is related to porosity test technical field.The method includes the following steps: flat plate is horizontally placed on rotating platform, circular contour line is drawn on flat plate, coating release film is placed on flat plate, and coating release film is located in circular contour line;Indicator is configured, and in the process of flat plate rotation, indicator is added dropwise on coating release film according to set rate, until indicator reaches circular contour line, wherein, the color of indicator reaching circular contour line is detected in real time using visual detection network, to determine the dropwise adding stop time of indicator;The porosity of coating release film is calculated according to the consumption mass of indicator.The application realizes visual porosity test experiment by the method of indicator dropwise adding, and the result point is accurately identified by combining computer vision technology, to prevent larger random error.

Description

Technical Field

[0001] This invention relates to the field of porosity testing technology, and in particular to a visual method and system for testing the porosity of coated isolation membranes. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] The main components of a lithium-ion battery include positive and negative electrode materials, electrolyte, separator, and battery casing. The separator is a crucial element of a lithium battery, positioned between the positive and negative electrodes. Its primary function is to isolate the electrodes to prevent short circuits, while simultaneously ensuring that lithium ions can pass through the microporous channels during charging and discharging to guarantee normal battery operation. Its performance directly affects the battery's capacity, rate capability, lifespan, and safety. To ensure the separator's structural integrity and functionality, and considering the needs of further lithium battery production and manufacturing, lithium battery separators must possess characteristics such as electronic insulation, chemical stability, thermal stability, and appropriate porosity.

[0004] Porosity affects not only the permeability of the separator and the electrolyte capacity, but also its ion permeability, thus influencing the battery's internal resistance and power density. Higher porosity provides more ion transport channels, reducing internal resistance and improving charge / discharge efficiency. Excessive porosity may lead to over-absorption of the electrolyte, increasing the risk of battery swelling, while insufficient porosity may hinder ion transport, affecting battery performance. Therefore, the porosity of the separator needs to be controlled within a certain range to ensure battery safety and performance.

[0005] For porosity testing of separator base membranes, the industry typically uses the gravimetric method. Porosity is calculated based on the density of the membrane material and the apparent density of the membrane. This involves cutting a certain area of ​​the membrane, measuring its thickness, obtaining its volume, weighing it, and then calculating its density. This method requires knowledge of the density of the membrane raw materials, making it suitable for separator base membranes. However, the density of coated separator membranes is difficult to measure, limiting the effectiveness of this method for porosity testing. Currently, for porosity testing of coated separator membranes, there are mercury intrusion porosimetry and liquid immersion methods. Mercury is toxic, making mercury intrusion porosimetry costly and environmentally unfriendly. Liquid immersion methods suffer from significant random errors, primarily due to inconsistent interpretation of result points. To reduce costs, some studies use water as a medium, combined with a lithium battery separator membrane porosity analyzer for auxiliary testing. However, water has limitations in its wetting ability; without external pressure, water cannot completely penetrate the pores of the separator membrane, requiring instrumental assistance and thus limiting application conditions. Furthermore, the existing porosity testing process is not visible, making direct testing impossible.

[0006] In summary, how to efficiently and accurately visualize and test the porosity of coated isolation membranes has become a technical problem that urgently needs to be solved by existing technologies. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide a visual method and system for testing the porosity of coated isolation membranes. By setting contour boundary lines and adding indicators, a visual porosity testing experiment can be achieved. Furthermore, computer vision technology is used to accurately identify the result points, preventing large random errors.

[0008] To achieve the above objectives, the present invention is implemented through the following technical solution: The first aspect of this invention provides a method for visually testing the porosity of a coated isolation membrane, comprising the following steps: Place the flat plate horizontally on the rotating platform. A circular outline is drawn on the flat plate. Place the coating release film on the flat plate, with the coating release film inside the circular outline. The indicator is prepared and added drop by drop onto the coated isolation film at a set rate during the rotation of the plate until the indicator reaches the circular outline. The color of the indicator at the circular outline is detected in real time using a visual inspection network to determine the indicator addition stop time. The porosity of the coating isolation membrane is calculated based on the mass of indicator consumed.

[0009] Furthermore, the indicator is methyl red alcohol indicator, which is prepared by weighing 0.1g-0.15g of methyl red, dissolving it in an alcohol solution and diluting it to 100ml to obtain methyl red alcohol indicator.

[0010] Furthermore, the coating release film is cut into a circle with a diameter of 10cm-15cm.

[0011] Furthermore, the coating isolation film overlaps with the center of the circular outline, and the diameter of the circular outline is 1 cm larger than that of the circular outline.

[0012] Furthermore, the rotational speed of the rotating platform is 100 rpm / min-200 rpm / min.

[0013] Furthermore, the indicator drop rate is 10-15 drops per minute.

[0014] Furthermore, the experiment was conducted inside a drying chamber.

[0015] Furthermore, the specific steps for using a visual inspection network to detect the color of the indicator at the circular outline in real time are as follows: Acquire RGB and spectral image sequences of the plate during the dropping process; Preprocessing of RGB and spectral image sequences; A visual detection network is used to perform color recognition and detection at circular contour lines in RGB and spectral image sequences.

[0016] Furthermore, the specific steps for color recognition and detection at circular contour lines in RGB and spectral image sequences using a visual detection network are as follows: A multimodal fusion module is used to fuse RGB images and spectral image sequences to obtain fused features; The fused features are encoded, and the channel attention module and spatial attention module are used to extract features from the fused features in turn to obtain a feature map; The feature map is decoded and classified to obtain the color recognition detection results.

[0017] A second aspect of the present invention provides a testing system for the visualization method for testing the porosity of a coating isolation membrane as described in the first aspect, comprising: Flat plate, used to support the coating release film; A rotating platform includes a base and a platform. The base supports the platform, and a flat plate is placed on the platform, allowing for adjustment of the rotation rate.

[0018] The above one or more technical solutions have the following beneficial effects: This invention discloses a visualized method and system for testing the porosity of coated isolation membranes, overcoming the shortcomings of existing technologies and achieving efficient, accurate, and visualized testing of the porosity of coated isolation membranes. The use of a rotating platform effectively disperses the methyl red indicator uniformly on the isolation membrane, preventing liquid accumulation, and reduces experimental time, thus improving efficiency. The methyl red alcohol indicator uses a very small amount of methyl red dissolved in a n-butanol solution, which does not affect the wetting properties of n-butanol and serves as a visualized experimental endpoint to determine whether the experiment is complete. The entire experiment is conducted in a drying chamber, which greatly slows down the evaporation rate of n-butanol, further ensuring the accuracy of the test results. The visual detection network can accurately detect the color of the indicator at the circular outline in real time, accurately determine the stopping time of the droplet addition, and thus accurately calculate the porosity of the coated isolation membrane, avoiding errors caused by human judgment or insufficient instrument assistance in traditional methods, and greatly improving the accuracy of the test results. This invention provides a simple and visual method for testing the porosity of coated separators. The method is easy to operate and produces accurate test results. It is of great significance for the quality control and performance optimization of coated separators in the lithium battery manufacturing process and has broad application prospects.

[0019] Existing porosity testing processes are not visible, making it impossible to intuitively observe the test results. This invention, however, establishes a circular outline on a flat plate, places the coated isolation membrane within it, and adds an indicator drop onto a rotating platform, making the entire testing process clearly visible. Operators can directly observe the diffusion of the indicator on the coated isolation membrane and the moment it reaches the outline, facilitating timely detection and adjustment of anomalies. This enhances the controllability of the testing process and provides a more intuitive basis for subsequent experimental analysis and research.

[0020] This invention adds an indicator dropwise at a set rate during the plate rotation process. Both the rotational speed of the platform and the indicator drop acceleration rate can be precisely controlled according to actual needs, allowing the indicator to diffuse evenly and rapidly to all parts of the coated separator, significantly shortening the testing time. Simultaneously, the real-time monitoring function of the visual inspection network reduces human intervention and waiting time, further improving testing efficiency and enabling rapid and accurate porosity testing results, meeting the demand for rapid porosity detection of coated separators in lithium battery manufacturing processes.

[0021] Mercury intrusion porosimetry (MIP) is costly and environmentally polluting due to the use of mercury. This invention utilizes methyl red alcohol as an indicator, which is inexpensive, and the entire testing system eliminates the need for toxic or harmful substances like mercury, reducing testing costs and meeting environmental requirements. Furthermore, the testing method of this invention is simple to operate, requiring no complex instruments or cumbersome procedures, thus reducing labor and equipment costs and demonstrating high economic efficiency and practicality.

[0022] The testing process of this invention is carried out in a drying chamber, which effectively avoids the influence of external environmental factors such as humidity on the test results and ensures the stability of the test. At the same time, this invention optimizes the cutting shape and size of the coated separator, making it easier to operate and control, and has good adaptability to coated separators of different specifications. It can be widely used in the porosity testing of various types of lithium battery coated separators, exhibiting strong versatility and flexibility.

[0023] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1This is a schematic diagram of a flat plate with a coated isolation film placed on it, as described in this invention. Detailed Implementation

[0026] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0027] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof. The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0028] This invention provides a visual method for testing the porosity of coated isolation membranes, comprising the following steps: Step 1: Place the flat plate horizontally on the rotating platform. A circular outline is drawn on the flat plate. Place the coating release film on the flat plate, with the coating release film inside the circular outline.

[0029] The flat plate of this invention can be a glass plate or other transparent material. For example... Figure 1 As shown, the coated release film is placed on a flat plate. The coated release film is cut into a circle with a diameter of 10cm-15cm. The center of the coated release film overlaps with the center of the circular outline, and the diameter of the circular outline is 1cm larger than the circular outline. Since it cannot be guaranteed that all pores are uniformly soaked in the indicator solution when the indicator diffuses to the boundary of the release film, a tolerance range needs to be set. Through experiments, this invention has determined that a tolerance range of 1cm is most suitable.

[0030] Step 2: Prepare the indicator. While the plate is rotating, add the indicator drop by drop onto the coating release film at a set rate until the indicator reaches the circular outline.

[0031] Step 2.1: Prepare the indicator.

[0032] In this invention, the indicator is methyl red alcohol indicator. The preparation method is to weigh 0.1g-0.15g of methyl red, dissolve it in an alcohol solution and dilute it to 100ml to obtain methyl red alcohol indicator.

[0033] It should be noted that the methyl red alcohol indicator diffuses evenly on the coated isolation film and has a color indication function. Other indicators with indication function and uniform diffusion can also be used for the experiment.

[0034] Step 2.2: Add the indicator drop by drop onto the coating release film at the set rate until the indicator reaches the circular outline.

[0035] In this invention, the rotational speed of the rotating platform is set to 100 rpm / min-200 rpm / min. The indicator drop rate is 10-15 drops per minute. The entire experimental process is carried out in a drying chamber, and the isolation membrane needs to be a smooth, wrinkle-free coated isolation membrane fixed on a flat plate.

[0036] Step 2.3: Use a visual inspection network to detect the color of the indicator at the circular outline in real time to determine the indicator addition stop time.

[0037] Step 2.3.1: Obtain the RGB image and spectral image sequence of the plate during the dropping process.

[0038] Color variations can be identified not only through RGB images but also through enhanced spectral information. Multispectral cameras can capture RGB images, while high-definition cameras can capture spectral images; these cameras capture richer spectral information, helping to distinguish subtle color changes. This invention acquires image sequences at a high frequency (e.g., 10 frames per second).

[0039] Step 2.3.2: Preprocess the RGB image and spectral image sequences.

[0040] This invention performs cleaning and normalization processing on RGB images and spectral image sequences.

[0041] Step 2.3.3: Use a visual detection network to perform color recognition and detection at the circular contour lines of the RGB image and spectral image sequences.

[0042] First, a visual detection network is constructed. The visual detection network includes a multimodal fusion module, a channel attention module, a spatial attention module, and a color recognition module.

[0043] Secondly, the visual detection network is trained. This invention uses existing labeled data to construct the dataset, focusing on annotating images where the indicator reaches the contour line and the optimal dispensing time is reached. Data augmentation preprocessing is performed on the dataset to improve the model's robustness to color changes. In the data preprocessing stage, in addition to conventional operations such as rotation, flipping, and cropping, color jittering is added, i.e., randomly adjusting brightness, contrast, and saturation to enhance the model's adaptability to color changes. The dataset is divided into training and testing sets, and the visual detection network is trained. Dice Loss or cross-entropy loss is used for boundary detection, and binary cross-entropy loss is used for boundary color recognition. The Adam optimizer is used with a learning rate set to 0.001.

[0044] The training process includes: Initialize the visual detection network parameters.

[0045] The output results of boundary detection and boundary color recognition are calculated through forward propagation.

[0046] Calculate the loss function and update the parameters through backpropagation.

[0047] Evaluate model performance on the test set and save the best model.

[0048] Then, a trained visual detection network was used to perform color recognition and detection at the circular contour lines of the real-time acquired RGB images and spectral image sequences.

[0049] The specific data processing steps are as follows: Step 2.3.3.1: Use the multimodal fusion module to fuse the RGB image and the spectral image sequence to obtain the fused features.

[0050] Using RGB and spectral images as input, a Convolutional Long Short-Term Memory (ConvLSTM) network is used to process the time-series information in the images, enhancing the ability to perceive color changes. Then, the RGB and spectral images are concatenated to form a 5-channel input image, and the output is the fused feature.

[0051] Step 2.3.3.2: Encode the fused features, and use the channel attention module and spatial attention module to extract features from the fused features in sequence to obtain the feature map.

[0052] In one specific implementation, the encoder section includes three convolutional layers and two max-pooling layers. The fused features pass through convolutional layers, max-pooling layers, convolutional layers, max-pooling layers, and another convolutional layer. The three convolutional layers are used sequentially to extract low-level features, further features, and high-level features. The pooling layers are used to reduce spatial resolution and computational cost. After passing through the encoder section, the features are further extracted and input into the channel attention module and the spatial attention module. The channel attention module enhances the network's focus on important channels, thereby improving sensitivity to color gradations. Specifically, a Squeeze-and-Excitation (SE) module is added after the last convolutional layer in the encoder section to weight the channels. These modules dynamically adjust the channel weights by learning the dependencies between channels, enhancing focus on important channels. The spatial attention mechanism enhances the network's focus on important regions, thereby improving the local perception of color changes. Specifically, a Convolutional Block Attention (CBAM) module is added after the channel attention module to weight spatial locations. These modules learn spatial location dependencies and dynamically adjust the weights of spatial locations, thereby enhancing the focus on important areas.

[0053] Step 2.3.3.3: Decode and classify the feature map to obtain the color recognition detection results.

[0054] In one specific implementation, the decoder section includes two upsampling layers, two convolutional layers, and an output layer. The upsampling layers are used to progressively recover the spatial resolution of the feature map through transposed convolutional layers. The upsampling layers are followed by convolutional layers for further feature processing, refining the feature map. Finally, the output layer generates the final boundary detection map, using a 1x1 convolutional kernel to map the feature map to a single-channel boundary map, and normalizing the pixel values ​​to the [0, 1] range using a sigmoid activation function. The color recognition module is used for feature map classification and recognition, determining whether the optimal drop-off end time has been reached. It includes fully connected layers and an output layer, with the output layer finally outputting the final binary classification result, indicating whether the optimal drop-off end time has been reached.

[0055] The aforementioned visual detection network can effectively fuse multimodal information, enhance attention to important features using an attention mechanism, and partially restore image resolution through a decoder, ultimately achieving accurate recognition of color depth variations.

[0056] Stop adding the indicator when the indicator has reached the circular outline and the optimal color has been detected, and record the mass of the methyl red alcohol solution used.

[0057] Step 3: Calculate the porosity of the coating membrane based on the mass of indicator consumed.

[0058] The calculation formula is: .

[0059] Where P is the porosity, W is the mass of the methyl red alcohol solution, V is the apparent volume of the membrane, and d is the density of the alcohol.

[0060] .

[0061] Where r is the radius of the separator and h is the thickness of the separator.

[0062] This invention also provides a testing system for a visual method of testing the porosity of coated isolation membranes, comprising: Flat plate, used to support the coating release film; A rotating platform includes a base and a platform. The base supports the platform, and a flat plate is placed on the platform, allowing for adjustment of the rotation rate.

[0063] It also includes a motor, which drives the rotating platform to rotate.

[0064] The present invention also discloses the following embodiments and comparative examples for determining optimal test parameters: Example 1 Preparation of methyl red alcohol indicator: Weigh 0.1g of methyl red, dissolve and dilute with n-butanol solution to 100ml to obtain the methyl red alcohol indicator. Select a flat, wrinkle-free separating membrane and cut it into a circle with a diameter of 15cm. Place the coated separating membrane on a glass plate, and draw a circular outline with a diameter of 16cm on the glass plate. Place the bottom of the glass plate on a rotating platform and rotate it at a speed of 150rpm / min. Add the methyl red alcohol indicator dropwise to the coated separating membrane using a dropper, 10 drops per minute, until the red solution overflows to the boundary of the circular outline. The entire experiment was conducted in a drying room.

[0065] Example 2 Preparation of methyl red alcohol indicator: Weigh 0.1g of methyl red, dissolve and dilute with n-butanol solution to 100ml to obtain the methyl red alcohol indicator. Select a flat, wrinkle-free separating membrane and cut it into a circle with a diameter of 15cm. Place the coated separating membrane on a glass plate, and draw a circular outline with a diameter of 11cm on the glass plate. Place the bottom of the glass plate on a rotating platform and rotate it at a speed of 200rpm / min. Add the methyl red alcohol indicator dropwise to the coated separating membrane using a dropper, adding 10 drops per minute, until the red solution overflows to the boundary of the circular outline. The entire experiment was conducted in a drying room.

[0066] Example 3 Preparation of methyl red alcohol indicator: Weigh 0.1g of methyl red, dissolve and dilute with n-butanol solution to 100ml to obtain the methyl red alcohol indicator. Select a flat, wrinkle-free separating membrane and cut it into a circle with a diameter of 15cm. Place the coated separating membrane on a glass plate, and draw a circular outline with a diameter of 11cm on the glass plate. Place the bottom of the glass plate on a rotating platform and rotate it at 100rpm / min. Add the methyl red alcohol indicator dropwise to the coated separating membrane using a dropper, 10 drops per minute, until the red solution overflows to the boundary of the circular outline. The entire experiment was conducted in a drying room.

[0067] Example 4 Preparation of methyl red alcohol indicator: Weigh 0.1g of methyl red, dissolve and dilute with n-butanol solution to 100ml to obtain the methyl red alcohol indicator. Select a flat, wrinkle-free separating membrane and cut it into a circle with a diameter of 10cm. Place the coated separating membrane on a glass plate, and draw a circular outline with a diameter of 11cm on the glass plate. Place the bottom of the glass plate on a rotating platform and rotate it at a speed of 200rpm / min. Add the methyl red alcohol indicator dropwise to the coated separating membrane using a dropper, adding 15 drops per minute, until the red solution overflows to the boundary of the circular outline. The entire experiment was conducted in a drying room.

[0068] Comparative Example 1 Select a flat, wrinkle-free release liner and cut it into a circle with a diameter of 15 cm. Place the coated release liner on a glass plate, and draw a circular outline with a diameter of 16 cm on the glass plate. Place the bottom of the glass plate on a rotating platform and rotate it at a speed of 150 rpm / min. Add n-butanol dropwise to the coated release liner using a dropper, 10 drops per minute, until the n-butanol solution overflows to the boundary of the circular outline. The entire experiment was conducted in a drying room.

[0069] Comparative Example 2 Preparation of methyl red alcohol indicator: Weigh 0.1g of methyl red, dissolve and dilute with n-butanol solution to 100ml to obtain the methyl red alcohol indicator. Select a flat, wrinkle-free separating membrane and cut it into a circle with a diameter of 15cm. Place the coated separating membrane on a glass plate and draw a circular outline with a diameter of 16cm on the glass plate. Add the methyl red alcohol indicator dropwise to the coated separating membrane using a dropper, 10 drops per minute, until the red solution overflows to the boundary of the circular outline. The entire experiment was conducted in a drying room.

[0070] Comparative Example 3 Preparation of methyl red alcohol indicator: Weigh 0.1g of methyl red, dissolve and dilute with n-butanol solution to 100ml to obtain the methyl red alcohol indicator. Select a flat, wrinkle-free separating membrane and cut it into a circle with a diameter of 15cm. Place the coated separating membrane on a glass plate, and draw a circular outline with a diameter of 16cm on the glass plate. Place the bottom of the glass plate on a rotating platform and rotate it at a speed of 150rpm / min. Add the methyl red alcohol indicator dropwise to the coated separating membrane using a dropper, adding 10 drops per minute, until the red solution overflows to the boundary of the circular outline.

[0071] Table 1 Comparison of results from the examples and comparative examples (the density of n-butanol used in the calculation is 0.8 g / ml)

[0072] As shown in Table 1, the porosity value measured in Example 1 is closest to the theoretical value, and the relative deviation remains within 5% (relative deviation = (calculated porosity - theoretical porosity) / theoretical porosity). (100%). In Example 2, the porosity value deviated more from the theoretical value than in Example 1. This was because the rotational speed of the rotary table was too high, causing the separator membrane to not be fully soaked, while the methyl red alcohol indicator reached the boundary of the circular outline under the high-speed centrifugal force of the rotary table. In Example 3, the porosity value deviated more from the theoretical value than in Example 1, possibly because the slower rotational speed resulted in a slower liquid wetting rate. In Example 4, the calculated value was lower, possibly because the separator membrane area was too small. At the platform's rotational speed, the liquid wetting was extremely rapid, easily causing liquid overflow and resulting in a larger random error.

[0073] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A visual method for testing the porosity of a coated isolation membrane, characterized in that, Includes the following steps: Place the flat plate horizontally on the rotating platform. A circular outline is drawn on the flat plate. Place the coating release film on the flat plate, with the coating release film inside the circular outline. A methyl red alcohol solution is prepared and, while the plate is rotating, the methyl red alcohol solution is added dropwise to the coated isolation film at a set rate until the methyl red alcohol solution reaches the circular outline. A visual detection network is used to detect the color of the methyl red alcohol solution at the circular outline in real time to determine the stopping time of the methyl red alcohol solution dropwise. Specifically: The process involves acquiring RGB and spectral image sequences of the plate during the dropping process; preprocessing the RGB and spectral image sequences; fusing the RGB and spectral image sequences using a multimodal fusion module to obtain fused features; encoding the fused features and extracting features sequentially using a channel attention module and a spatial attention module to obtain feature maps; and decoding and classifying the feature maps to obtain color recognition and detection results. The porosity of the coating membrane is calculated based on the mass of the methyl red alcohol solution consumed, using the following formula: Where P is the porosity, W is the total mass of methyl red alcohol solution consumed when dropped to the circular outline, V is the apparent volume of the coating membrane, and d is the density of the alcohol. Where r is the radius of the coating and h is the thickness of the coating; The methyl red alcohol solution is prepared by weighing 0.1g~0.15g of methyl red, dissolving it in an alcohol solution and diluting it to 100ml to obtain the methyl red alcohol solution.

2. The method for visualizing the porosity of a coated isolation membrane as described in claim 1, characterized in that, The coating release film is cut into a circle with a diameter of 10cm to 15cm.

3. The method for visualizing the porosity of a coated isolation membrane as described in claim 2, characterized in that, The center of the coating release film overlaps with the center of the circular outline, and the diameter of the circular outline is 1 cm larger than the diameter of the coating release film.

4. The method for visualizing the porosity of a coated isolation membrane as described in claim 1, characterized in that, The rotating platform rotates at a speed of 100 rpm to 200 rpm.

5. The method for visualizing the porosity of a coated isolation membrane as described in claim 1, characterized in that, The methyl red alcohol solution is added at a rate of 10 to 15 drops per minute.

6. The method for visualizing the porosity of a coated isolation membrane as described in claim 1, characterized in that, The experiment was conducted in a drying room.

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