Method and system for analyzing electrode surfaces

Abstract

The present invention relates to an electrode surface analysis method and an electrode surface analysis system, and more specifically, to an electrode surface analysis method and an electrode surface analysis system that use a hyperspectral CCD to precisely analyze foreign matter remaining on the electrode surface during the electrode manufacturing process, thereby improving process efficiency and product reliability.

Description

[Technical Field]

[0001] Mutual citation with related applications This application claims priority under Korean Patent Application No. 10-2024-0069391 dated 28 May 2024, and all content disclosed in the documents of the said Korean Patent Application is incorporated herein as part of this specification.

[0002] This invention relates to an electrode surface analysis method and an electrode surface analysis system for analyzing electrode surfaces during the manufacturing process of secondary batteries, and for precisely analyzing foreign matter on the electrode surface. [Background technology]

[0003] With increasing technological development and demand for mobile devices, the demand for rechargeable batteries as an energy source is surging, and consequently, a lot of research is being conducted on rechargeable batteries that can meet diverse requirements.

[0004] Such secondary batteries are manufactured in a form in which the electrode assembly is built into the battery case together with the electrolyte. The electrode assembly is classified into stack type, folding type, stack-folding type, etc., depending on the manufacturing method. In the case of stack type or stack-folding type electrode assemblies, the unit assembly has a structure in which the positive electrode and negative electrode are sequentially stacked with a separating membrane in between. In order to make such an electrode assembly, it is necessary to first manufacture the positive electrode and negative electrode, which have electrode tabs formed on them.

[0005] The electrode manufacturing process for secondary batteries includes (1) a mixing process, (2) a coating process, (3) a rolling process, and (4) a slitting and notching process, and these processes are carried out in-line.

[0006] The mixing step described above (1) is a step in which a slurry is manufactured for forming the active material layer of the electrode. The slurry can be manufactured by weighing and mixing various raw materials necessary for forming the active material layer, including the electrode active material, binder, and conductive material.

[0007] Furthermore, the coating step (2) is a step of thinly coating the slurry onto the current collector and drying it to form an electrode active material layer. The structure including the current collector and the electrode active material layer formed on the current collector is called an electrode sheet.

[0008] Furthermore, the rolling process described in (3) above is a process of passing the electrode sheet between two rolls to stretch it to a uniform length. The rolling process is also called the roll press process.

[0009] Furthermore, the (4) slitting and notching process is a process of cutting the electrode sheet to match the size of the battery. The slitting process can cut the battery sheet in the longitudinal direction according to the battery design standard. The notching process is a process of forming V grooves and electrode tabs after the slitting process. In this notching process, the electrode sheet is generally positioned on a die, and a part of the electrode sheet can be punched out using a press, or the electrode tabs can be formed by etching. On the other hand, in a small pouch line, there may be an etching process between the rolling process and the slitting process.

[0010] However, there is a possibility that foreign matter generated during such etching processes may remain on the electrode surface, leading to a decrease in electrode quality. If the type and amount of foreign matter remaining on the electrode surface could be identified, the etching process could be designed and implemented to minimize the generation of this foreign matter. Here, "foreign matter" refers to residues such as binders contained in the active material layer of the electrode.

[0011] Generally, the presence or absence of remaining foreign matter is confirmed using a vision camera provided in an inline device for an inline process for electrode manufacturing. However, the vision camera has a large set field of view (FOV) and can only confirm the presence or absence of remaining foreign matter, and it is difficult to specifically confirm the type and residual amount of the remaining foreign matter. The electrode etching process is performed in an inline process, and due to the limitations of the inline device, a vision camera must be installed. There were technical limitations in installing a camera that could analyze foreign matter more precisely in addition to the vision camera.

[0012] Therefore, after the electrode etching process, there is a need for technological development of an analysis method for the electrode surface that can confirm the type and amount of foreign matter remaining on the electrode surface.

Prior Art Documents

Patent Documents

[0013]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0014] As a result of conducting research in various aspects to solve the above problems, the inventors of the present invention confirmed that in addition to a vision camera, which is an inline device provided in an inline process for manufacturing electrodes, by introducing a hyperspectral CCD (Charge Coupled Device) as an offline device, the electrode surface can be analyzed more precisely.

[0015] Therefore, an object of the present invention is to provide an analysis method for an electrode surface using a hyperspectral CCD.

[0016] Another object of the present invention is to provide an analysis system for an electrode surface using a hyperspectral CCD. [Means for solving the problem]

[0017] To achieve the above objective, the present invention provides an electrode surface analysis method using a hyperspectral CCD (Charge Coupled Device), (a) A step of taking an image of the electrode surface with a hyperspectral CCD and obtaining the spectrum of the electrode surface; (b) A step of visualizing the electrode surface using the spectrum of the electrode surface; and (c) a step of quantifying the visualized electrode surface; Using the following formula 1, the discrimination index (T) is obtained from the spectrum of the electrode surface obtained in step (a) above. A / B ) is calculated, and the discrimination index (T A / B The present invention provides an electrode surface analysis method that involves dividing the electrode surface based on the brightness intensity of the electrode surface corresponding to ), and then visualizing and quantifying the divided individual regions to analyze the electrode surface.

[0018] [Formula 1] T A / B =(μ A -μ B ) / (σ A -σ B )

[0019] In the above formula 1, A and B are any different substances present on the electrode surface. T A / B This is the discrimination index between A and B, μ is the average of multiple intensities of brightness corresponding to multiple wavelengths in the electrode surface spectrum. σ is the deviation of multiple luminances corresponding to the aforementioned multiple wavelengths.

[0020] In one embodiment of the present invention, a method for analyzing the surface of an electrode is provided, wherein A and B are different materials selected from the group consisting of a current collector, an electrode active material layer, and foreign matter.

[0021] In one embodiment of the present invention, the individual regions include the surface region of the current collector, the surface region of the electrode active material layer, and the foreign matter region, and a method for analyzing the electrode surface is provided.

[0022] In one embodiment of the present invention, the method for analyzing an electrode surface is provided, in step (b), in which different colors that are visually distinguishable are matched to the individual regions that were divided in step (a), and the individual regions are materialized and visualized with the matched colors.

[0023] In one embodiment of the present invention, the method for analyzing an electrode surface is provided, in step (c), which quantifies the electrode surface by calculating the proportion of pixels in each individual region included in the electrode surface, based on the total number of pixels of the electrode surface visualized in step (b).

[0024] In one embodiment of the present invention, the hyperspectral CCD provides a method for analyzing the electrode surface, which precisely inspects for foreign matter in any specific region contained within the electrode surface.

[0025] In one embodiment of the present invention, a method for analyzing the surface of an electrode is provided, wherein the field of view (FOV) of the specific region includes an area with a width of 0.1 mm to 5 mm and a height of 0.1 mm to 5 mm.

[0026] In one embodiment of the present invention, the electrode is an electrode after an electrode etching process in which an electrode tab is formed during the electrode manufacturing process, and a method for analyzing the surface of an electrode is provided.

[0027] The present invention also includes a hyperspectral CCD unit that uses a hyperspectral CCD to image the electrode surface and obtain the spectrum of the electrode surface; A visualization unit that visualizes the electrode surface using the spectrum of the electrode surface; and An electrode surface analysis system comprising a quantification unit for quantifying the visualized electrode surface; Using the following formula (1), a discrimination index (T A / B ) is calculated from the spectrum of the electrode surface obtained by the hyperspectral CCD unit, and after classifying the electrode surface based on the brightness (intensity of brightness) of the electrode surface corresponding to the discrimination index (T A / B ), the individual regions thus classified are visualized and quantified to analyze the electrode surface, thereby providing an electrode surface analysis system.

[0028] [Formula 1] T A / B =(μ A -μ B ) / (σ A -σ B )

[0029] In the above formula (1), A and B are any different substances present on the electrode surface, T A / B is the discrimination index between A and B, μ is the average of the brightness (intensity of brightness) corresponding to a plurality of wavelengths in the electrode surface spectrum, σ is the deviation of the brightness corresponding to the plurality of wavelengths.

Advantages of the Invention

[0030] According to the present invention, during the process of manufacturing the electrode of a secondary battery, it is possible to more precisely analyze the types and amounts of foreign substances present on the electrode surface after the etching process for forming the electrode tab, improving the efficiency of the process and the reliability of the manufactured electrode product. Further, by utilizing the advantage of being able to precisely analyze foreign substances, it is also possible to inspect the performance of the apparatus used in the etching process, for example, the etching laser.

Brief Description of the Drawings

[0031] ​​​​​This is a schematic diagram illustrating the process of obtaining a discrimination index from electrode surface spectra obtained from a hyperspectral CCD using Equation 1. [Figure 1c] This is a schematic diagram illustrating the process of obtaining a discrimination index from electrode surface spectra obtained from a hyperspectral CCD using Equation 1. [Figure 2] This figure shows the correlation between wavelength and brightness intensity obtained from images captured with a hyperspectral CCD. [Figure 3] This figure shows individual spectra of the current collector surface, electrode active material layer surface, and foreign matter contained within the negative electrode surface, captured by a hyperspectral CCD. [Modes for carrying out the invention]

[0032] The present invention will be described in more detail below to aid in understanding it.

[0033] The terms and words used herein and in the claims are not to be interpreted in a manner limited to their ordinary or dictionary meanings, but rather in a manner consistent with the technical idea of ​​the present invention, based on the principle that inventors may appropriately define the concepts of terms in order to best describe their invention.

[0034] As used herein, the term "electrode surface analysis" means sensing or measuring the materials forming the electrode surface and deriving their types and quantities. In this specification, the electrode subject to electrode surface analysis may be an electrode after the etching process during the electrode manufacturing process. The etching process refers to the process of etching and removing the electrode active material layer in an electrode in which a current collector and electrode active material layer have been formed during the electrode manufacturing process, in order to form an electrode tab. Therefore, after the etching process, the electrode surface may contain the surface of the current collector, the surface of the electrode active material layer, and foreign matter. The foreign matter may be binder that was contained in the electrode active material layer. In short, the electrode surface analysis is for analyzing the types and quantities of foreign matter contained in the electrode surface. Note that the electrode active material layer is formed by coating it on the current collector, and is therefore also called the electrode coating layer.

[0035] Methods for analyzing electrode surfaces The present invention relates to a method for analyzing electrode surfaces.

[0036] The electrode surface analysis method according to the present invention is an electrode surface analysis method that analyzes the electrode surface using a hyperspectral CCD (Charge Coupled Device), (a) A step of taking an image of the electrode surface with a hyperspectral CCD and obtaining the spectrum of the electrode surface; (b) A step of visualizing the electrode surface using the spectrum of the electrode surface; and (c) a step of quantifying the visualized electrode surface; Using the following formula 1, the discrimination index (T) is obtained from the spectrum of the electrode surface obtained in step (a) above. A / B ) is calculated, and the discrimination index (T A / B The present invention provides an electrode surface analysis method that involves dividing the electrode surface based on the brightness intensity of the electrode surface corresponding to ), and then visualizing and quantifying the divided individual regions to analyze the electrode surface.

[0037] [Formula 1] T A / B =(μ A-μ B ) / (σ A -σ B )

[0038] In the above formula 1, A and B are any different substances present on the electrode surface. T A / B This is the discrimination index between A and B, μ is the average of multiple intensities of brightness corresponding to multiple wavelengths in the electrode surface spectrum. σ is the deviation of multiple luminances corresponding to the aforementioned multiple wavelengths.

[0039] A and B each comprise different materials selected from the group consisting of a current collector, an electrode active material layer, and foreign matter. More specifically, A and B each comprise the surface of the current collector, the surface of the electrode active material, and foreign matter such as a binder.

[0040] In the present invention, in step (a), the electrode surface can be imaged using a hyperspectral CCD to obtain the spectrum of the electrode surface.

[0041] A hyperspectral CCD is a type of camera capable of measuring hyperspectral images (HSI). While RGB images have three channels, HSIs typically measure a wide range of wavelengths, often exceeding 200 bands. Because of this, HSIs can detect complex features not visible in RGB images. While RGB images only possess spatial features, HSIs possess both spectral and spatial features, resulting in superior classification capabilities. Consequently, HSIs can finely classify similar colors and have broad applications in diverse fields, including remote sensing.

[0042] In one embodiment of the present invention, the hyperspectral CCD can be applied to the analysis of the electrode surface to perform a more precise analysis of the electrode surface.

[0043] The hyperspectral CCD includes (i) an optical unit that scans and measures the object to be measured, (ii) a spectroscopic unit that spectrally analyzes the light captured by the optical unit, and (iii) a detection unit that converts the spectrally analyzed light into a spectrum.

[0044] The optical part (i) above includes an optical lens. The optical lens can be used to scan and measure the electrode surface to be measured. Light is captured from the electrode surface through the optical lens. The wavelength of the captured light changes depending on the properties of the electrode surface, the presence, type and amount of foreign matter.

[0045] Furthermore, the (ii) spectroscopic section includes a dispersion element that spectrally separates light.

[0046] Furthermore, the detection unit (iii) is also called the sensor unit and can convert the spectrally separated light into a spectrum.

[0047] In one embodiment of the present invention, the hyperspectral CCD can precisely inspect or measure any specific region contained within the electrode surface.

[0048] The field of view (FOV) of the aforementioned specific region allows for inspection or measurement of a narrow area including a horizontal range of 0.1 mm to 5 mm and a vertical range of 0.1 mm to 5 mm.

[0049] Existing vision cameras have a field of view (FOV) that is limited to a wide area of ​​400mm horizontally and 400mm vertically, resulting in poor accuracy. Thus, existing vision cameras have a large FOV, making it difficult to precisely analyze the type and amount of foreign matter remaining on the electrode surface, as they can only detect the presence or absence of such material.

[0050] In the embodiment of formula 1, the surface spectrum may be an integrated spectrum obtained by superimposing individual spectra.

[0051] When the operator arbitrarily selects discrimination criteria in the aforementioned integrated spectrum, there was a problem of reduced accuracy. However, by using Equation 1 to calculate the discrimination index and setting it as the discrimination criterion, it becomes possible to analyze the quantity and / or type of any substance contained in the electrode surface by more precisely classifying, visualizing, and quantifying these substances.

[0052] Furthermore, Equation 1 can be interpreted as indicating a higher discrimination index when the difference in intensity of brightness (gap) between any given substances is large and the deviation is small.

[0053] Figures 1a to 1c are schematic diagrams illustrating the process of obtaining a discrimination index from electrode surface spectra obtained from a hyperspectral CCD using Equation 1.

[0054] Figure 1a shows a graph for calculating the mean (μ, Avg.) and deviation (σ, sigma) of an electrode surface spectrum obtained from a hyperspectral CCD, using multiple intensities corresponding to multiple wavelengths for any material. The arbitrary material can be a current collector (foil), foreign matter (binder), or electrode active material (coating). The mean and deviation are calculated using multiple intensities corresponding to multiple wavelengths. Substituting the mean and deviation obtained using the multiple intensities into Equation 1, the discrimination index (T) is calculated. A / B ) can be calculated.

[0055] For example, as shown in Figure 1a, the wavelength was divided into regions A, B, C, and D. After selecting multiple specific wavelengths within each region, the average (Avg.) and deviation (σ) of the luminances were calculated using the multiple luminances corresponding to the selected wavelengths. These were then applied to Equation 1 to obtain the discrimination index.

[0056] Figure 1b is a graph showing the discrimination index by wavelength. The discrimination index (T) is calculated using multiple luminances corresponding to the multiple wavelengths. A / B This is a graph showing the relationship between the two factors.

[0057] Figure 1c shows the discrimination index (T) between any given substance in the selected wavelength range. A / B This graph shows that the value of ) was selected as the final discrimination criterion. The front and back surfaces of the current collector (foil) can be distinguished and displayed as shiny (glossy) and matte (non-glossy), respectively. Therefore, Binder_shiny, Coating_shiny, and Foil_shiny refer to foreign matter (Binder) and electrode active material (Coating) based on the front surface of the current collector (foil).

[0058] In one embodiment of the present invention, the electrode surface can be divided into individual regions based on the discrimination index. For example, the individual regions divided on the electrode surface may include the surface region of the current collector, the surface region of the electrode active material layer, and the foreign matter region.

[0059] In the present invention, in step (b), the electrode surface can be visualized by utilizing the spectrum of the electrode surface.

[0060] In the stage described in (a) above, different colors that visually distinguish the individual regions can be matched. In this case, the matching colors are not fixed to any particular color, but are not particularly limited as long as these individual regions are visually distinguishable by different colors.

[0061] Here, "visualization" means representing individual regions of the electrode surface, each matched with a different color, with the matched color. The visualization can be represented by a visualization software program, and is not particularly limited as long as the software program is driven by logic that can represent each individual region of the electrode surface, separated by a discrimination criterion, with the matched color.

[0062] In the present invention, in step (c), the visualized electrode surface can be quantified.

[0063] Specifically, the electrode surface can be quantified by calculating the proportion of pixels in each individual region based on the total number of pixels on the visualized electrode surface. In particular, the proportion of pixels contained in the individual region corresponding to the divided foreign matter can be calculated to obtain the amount of each foreign matter remaining on the electrode surface.

[0064] The quantification is performed by a quantification software program, and is not particularly limited as long as the software program is driven by logic that calculates the proportion of pixels corresponding to each component based on the total number of pixels on the electrode surface.

[0065] Electrode surface analysis system The present invention also relates to an analysis system for electrode surfaces.

[0066] The electrode surface analysis system according to the present invention includes: a hyperspectral CCD unit for capturing images of the electrode surface; a visualization unit for visualizing the electrode surface using the spectrum of the electrode surface captured by the hyperspectral CCD; and a quantification unit for quantifying the visualized electrode surface. Using the following formula 1, the discrimination index (T) is obtained from the spectrum of the electrode surface obtained in the hyperspectral CCD section. A / B ) is calculated, and the discrimination index (T A / B After dividing the electrode surface based on the brightness intensity of the electrode surface corresponding to the specified region, the electrode surface is analyzed by visualizing and quantifying the divided individual regions.

[0067] [Formula 1] T A / B =(μ A -μ B ) / (σ A -σ B )

[0068] In the above formula 1, A and B are any different substances present on the electrode surface. T A / B This is the discrimination index between A and B, μ is the average of multiple luminances (intensity of brightness) corresponding to multiple wavelengths in the electrode surface spectrum. σ is the deviation of multiple luminances corresponding to the aforementioned multiple wavelengths.

[0069] The hyperspectral CCD section may include a hyperspectral CCD.

[0070] Furthermore, the visualization unit may include a visualization software program, and is not particularly limited as long as it is a software program driven by logic that represents the regions of each component separated on the electrode surface by discrimination criteria with matched colors.

[0071] Furthermore, the quantification unit may include a quantification software program, and is not particularly limited as long as it is a software program driven by logic that calculates the proportion of pixels corresponding to each component based on the total number of pixels on the electrode surface.

[0072] In a preferred embodiment of the present invention, a correlation between wavelength and intensity of brightness is obtained from an image captured by a hyperspectral CCD (Figure 2). This correlation was used to obtain the spectrum of the negative electrode surface and analyze the negative electrode surface as follows. In this case, the correlation between wavelength and intensity is also called the spectrum of the pixel.

[0073] (1) Spectrum acquisition for the negative electrode surface A hyperspectral CCD (Mitutoyo Corporation) was used to photograph the electrode surface after the etching process for forming electrode tabs during the electrode manufacturing process. The electrode, as the negative electrode, includes a Cu current collector and a negative electrode active material layer formed on one surface of the Cu current collector. The surface of the negative electrode includes the surface of the Cu current collector (bare foil), a binder (binder resin) separated from the negative electrode active material layer, and the negative electrode active material layer (coating).

[0074] Individual spectra were obtained for the bare foil, binder resin, and coating from images of the negative electrode surface captured by the hyperspectral CCD (Figure 3). These individual spectra were realized as boxplot spectra by securing raw data extracted from the hyperspectral CCD images. The microscope images were taken with an optical microscope, and the single-wavelength images were taken with a single-wavelength spectrophotometer.

[0075] (2) Establishment of classification criteria for foreign matter on the negative electrode surface After obtaining an integrated spectrum by combining the individual spectra of Bare foil, Binder Residue, and Coating, the discrimination index was calculated using Equation 1.

[0076] First, the mean (μ) and deviation (σ) of the luminance were calculated using multiple luminances corresponding to multiple wavelengths in the individual spectra included in the integrated spectrum of the electrode surface. After obtaining the mean (μ) and deviation (σ) of the luminance using the luminances corresponding to multiple wavelengths, these were applied to Equation 1 to obtain multiple discrimination indices (T A / B ) was calculated.

[0077] The aforementioned multiple discrimination indices (T A / BThe wavelength range corresponding to the largest value among the given values ​​was selected, and the average luminance value or intermediate luminance value of the luminance range corresponding to the given wavelength range was used as the discrimination threshold.

[0078] For example, the final selection criteria were foil > 1.2, 1.2 > binder > 0.8, 0.9 > coating.

[0079] The negative electrode surface was classified using the aforementioned discrimination criteria.

[0080] Table 1 below is a classification table of negative electrode surfaces as determined by the aforementioned discrimination criteria.

[0081] [Table 1]

[0082] As shown in Table 1 above, the negative electrode surface and the color to which it is matched can be defined based on the discrimination criteria. The color is not particularly limited as long as it is a color that can visually distinguish the negative electrode surfaces classified by the discrimination criteria.

[0083] (3) Visualization of the negative electrode surface The negative electrode surface was visualized using the individual regions separated by the aforementioned discrimination criteria and the corresponding colors. This visualization was performed using a software program driven by a logic that could represent the object of visualization, i.e., the individual regions, with specific colors.

[0084] (4) Quantification of the negative electrode surface The quantification method involved measuring the number of pixels corresponding to Bare foil, Binder Residue, and Coating on the visualized negative electrode surface, and then calculating the proportion of each corresponding pixel within the total number of pixels on the negative electrode surface. This quantification was performed using a software program driven by logic capable of calculating the proportion of pixels in a specific region (i.e., an individual region) relative to the total number of pixels on the negative electrode surface.

[0085] Table 2 below quantifies the negative electrode surface, including the individual regions of Bare foil, Binder, and Coating. Noise is an indistinguishable substance, and the discrimination ability decreased because the attempt was made to distinguish substances in a wavelength band where the brightness difference between substances was not large.

[0086] [Table 2]

[0087] This is a comparative embodiment of the present invention, in which the electrode surface was analyzed in the same manner as in the above embodiment, except that instead of the discrimination index calculated by Equation 1 above, the measurer arbitrarily used the region with a large difference in brightness between foil, binder, and coating from the integrated spectrum of the electrode surface as the discrimination criterion.

[0088] [Table 3]

[0089] Referring to Tables 2 and 3 above, it can be seen that the noise generation rate in Example 1, in which the electrode surface was analyzed using the discrimination index calculated from Equation 1, decreased.

[0090] Although the present invention has been described above with reference to limited embodiments and drawings, it goes without saying that the present invention is not limited thereto, and that a wide range of modifications and variations are possible within the same scope as the technical concept of the present invention and the claims described below by a person with ordinary skill in the art to which the present invention pertains.

Claims

1. A method for analyzing electrode surfaces using a hyperspectral CCD (charge-coupled device), (a) A step of taking an image of the electrode surface with a hyperspectral CCD and obtaining the spectrum of the electrode surface, (b) A step of visualizing the electrode surface using the spectrum of the electrode surface, and (c) The step of quantifying the visualized electrode surface, Using the following formula 1, the discrimination index (T) is obtained from the electrode surface spectrum obtained in step (a). Ａ／Ｂ ) is calculated, and the discrimination index (T Ａ／Ｂ Based on the brightness of the electrode surface corresponding to the specified region, the electrode surface is divided, and the divided individual regions are visualized and quantified to analyze the electrode surface. [Formula 1] T Ａ／Ｂ =(μ Ａ -m Ｂ ) / (s Ａ -s Ｂ ) In the above formula 1, A and B are any different substances present on the electrode surface. T Ａ／Ｂ This is the discrimination index between A and B, μ is the average of multiple brightness levels corresponding to multiple wavelengths in the electrode surface spectrum. A method for analyzing the electrode surface, wherein σ is the deviation of multiple brightness levels corresponding to the multiple wavelengths.

2. The method for analyzing the electrode surface according to claim 1, wherein A and B are different substances selected from the group consisting of a current collector, an electrode active material layer, and foreign matter.

3. The method for analyzing the electrode surface according to claim 1, wherein the individual regions include the surface region of the current collector, the surface region of the electrode active material layer, and the foreign matter region.

4. The method for analyzing an electrode surface according to claim 1, wherein in step (b), different colors that are visually distinguishable are matched to the individual regions that were divided in step (a), and the individual regions are materialized and visualized with the matched colors.

5. The method for analyzing an electrode surface according to claim 1, wherein in step (c), the electrode surface is quantified by calculating the proportion of pixels in each individual region included in the electrode surface based on the total number of pixels of the electrode surface visualized in step (b).

6. The method for analyzing an electrode surface according to claim 1, wherein the hyperspectral CCD precisely inspects for foreign matter in any specific region contained within the electrode surface.

7. The method for analyzing the electrode surface according to claim 6, wherein the field of view (FOV) of the specified region is a region including a width of 0.1 mm to 5 mm and a height of 0.1 mm to 5 mm.

8. The method for analyzing the surface of an electrode according to claim 1, wherein the electrode is an electrode after an electrode etching process in which an electrode tab is formed during the electrode manufacturing process.

9. A hyperspectral CCD (charge-coupled device) is used to image the electrode surface and obtain the spectrum of the electrode surface. A visualization unit that visualizes the electrode surface using the spectrum of the electrode surface, and An electrode surface analysis system including a quantification unit for quantifying the visualized electrode surface, Using the following formula (1), a discrimination index (T Ａ／Ｂ ) is calculated from the spectrum of the electrode surface obtained by the hyperspectral CCD unit, and the electrode surface is classified based on the luminance of the electrode surface corresponding to the discrimination index (T Ａ／Ｂ ). The classified individual regions are visualized and quantified to analyze the electrode surface. [Formula 1] T Ａ／Ｂ =(μ Ａ -m Ｂ ) / (s Ａ -s Ｂ ) In the above formula 1, A and B are any different substances present on the electrode surface. T Ａ／Ｂ This is the discrimination index between A and B, μ is the average of multiple brightness levels corresponding to multiple wavelengths in the electrode surface spectrum. An electrode surface analysis system in which σ is the deviation of multiple brightness levels corresponding to the aforementioned multiple wavelengths.

Images