Electrode quality evaluation method and electrode manufacturing method

Abstract

The present invention relates to a method for evaluating the quality of an electrode, the method including the steps of: preparing a plurality of electrodes each including a current collector and an active material layer formed on the current collector, and not undergoing a rolling process; measuring the color coordinate value of the active material layer of each of the plurality of electrodes using an optical system to calculate an average value; and determining the electrode as non-defective if the difference between the color coordinate value measured from each electrode and the average value is equal to or less than a predetermined value, and determining the electrode as defective if the difference exceeds the predetermined value. The present invention also relates to a method for manufacturing an electrode, including the steps of applying a slurry containing an active material, a conductive material, and a binder onto a current collector, followed by drying to form an active material layer, thereby manufacturing a plurality of electrodes that have not undergone a rolling process; evaluating the quality of the electrodes using the above-mentioned method; and rolling the electrodes that have been determined to be non-defective.

Description

[Technical field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2020-0044900 filed on April 13, 2020, and Korean Patent Application No. 10-2020-0119926 filed on September 17, 2020, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a method for evaluating the quality of an electrode and a method for producing an electrode including a step of evaluating the quality of the electrode in a corresponding manner. [Background technology]

[0003] Although electrodes manufactured under the same recipe and process conditions should theoretically have the same physical properties, there may be differences in physical properties between manufacturing units during actual electrode production. Therefore, even if electrodes are manufactured under the same conditions, defective electrodes may exist, and defective electrodes must be screened out through electrode quality inspection.

[0004] Commonly known quality inspection items for electrodes include adhesive strength, thickness, loading amount, etc. Among the quality inspection items for electrodes, adhesive strength is a very important quality inspection item as it is used to remove electrodes that have detached during the electrode assembly process or electrodes that have peeled off during the activation process.

[0005] However, in order to check the adhesive strength of the electrode, a rolling process must be performed, and there is a problem in that the quality of the electrode cannot be evaluated in real time. Therefore, there is a need to develop a method for evaluating the quality of electrodes by evaluating their physical properties before the rolling process and for sorting out defective electrodes. Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention is intended to solve the above problems, and provides a method for evaluating the quality of electrodes, which can easily and quickly remove defective electrodes from among electrodes by simply measuring the color coordinate values ​​of the electrodes before the rolling process. [Means for solving the problem]

[0007] According to one embodiment, the present invention provides a method for evaluating the quality of an electrode, the method including the steps of: preparing a plurality of electrodes, each of which includes a current collector and an active material layer formed on the current collector and has not been subjected to a rolling process; measuring color coordinate values ​​of the active material layer of each of the plurality of electrodes using an optical system to calculate an average value; and determining that the electrode is a good product if the difference between the color coordinate values ​​measured from each electrode and the average value is equal to or less than a predetermined value, and determining that the electrode is defective if the difference exceeds the predetermined value.

[0008] In addition, according to another embodiment, the present invention provides a method for manufacturing an electrode, the method including the steps of: applying a slurry containing an active material, a conductive material, and a binder onto a current collector, and then drying the slurry to form an active material layer, thereby manufacturing a plurality of electrodes that have not undergone a rolling process; evaluating the quality of the electrodes by the above-mentioned method; and rolling the electrodes that have been determined to be non-defective. Effect of the Invention

[0009] The electrode quality evaluation method according to the present invention can easily and quickly remove defective electrodes from among electrodes by measuring the color coordinate value of the electrodes before the rolling process. That is, defective electrodes can be selected without going through the rolling process, and thus the defective rate of finished electrodes that have gone through the rolling process can be significantly reduced. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The terms and words used in this specification and the claims should not be interpreted in a limited manner to their ordinary or dictionary meanings, but should be interpreted in a manner that is consistent with the technical idea of ​​the present invention, based on the principle that the inventors can appropriately define the concepts of terms in order to best describe their invention.

[0011] It should be understood that, as used herein, terms such as "comprises," "comprising," or "having" are intended to specify the presence of embodied features, numbers, steps, components, or combinations thereof, but do not preclude the presence or additional possibility of one or more other features, numbers, steps, components, or combinations thereof.

[0012] The present invention will now be described in more detail. <Electrode quality evaluation method> The electrode quality evaluation method according to the present invention is characterized by comprising the steps of: preparing a plurality of electrodes each including a current collector and an active material layer formed on the current collector and not undergoing a rolling process; measuring the color coordinate value of the active material layer of each of the plurality of electrodes using an optical system and calculating an average value; and judging the electrode as a good product if the difference between the color coordinate value measured from each electrode and the average value is equal to or less than a predetermined value, and judging the electrode as a defective product if the difference exceeds the predetermined value.

[0013] When the color coordinate values ​​of the active material layer of each of a plurality of electrodes that have not been rolled, measured using the optical system, are compared with the average value, if the difference between the color coordinate values ​​of each electrode measured and the average value is within a predetermined range, the electrode undergoes a rolling process, and the adhesive strength between the current collector and the active material layer is excellent and no adhesive strength defects occur. For example, if an electrode classified as a good product according to the present invention undergoes a rolling process, the adhesive strength between the current collector and the active material layer of the electrode can be ensured to be 20 gf / 20 mm or more.

[0014] According to the present invention, by simply measuring the color coordinates of the electrodes before rolling, it is possible to easily and quickly remove defective electrodes from among the electrodes. That is, it is possible to select defective electrodes without going through a rolling process, and the defective rate of the finished electrodes that have gone through the rolling process can be significantly reduced.

[0015] Each step of the electrode quality evaluation method according to the present invention will now be described in more detail. Providing a plurality of electrodes that have not been subjected to a rolling process The present invention includes the step of preparing a plurality of electrodes that include a current collector and an active material layer formed on the current collector, the electrodes not having been subjected to a rolling process.

[0016] According to the present invention, the plurality of electrodes may be manufactured under the same recipe and process conditions. Electrodes manufactured under the same recipe and process conditions should theoretically have the same physical properties, but there may be differences in physical properties between manufacturing units during actual electrode production. Therefore, even if electrodes are manufactured under the same recipe and process conditions, defective electrodes may exist among them, and the inventors of the present invention have embodied the present invention in order to easily and quickly select defective electrodes.

[0017] The present invention does not evaluate electrodes that have been through a rolling process as in the conventional quality evaluation of battery electrodes, but evaluates the quality of electrodes that have not been through a rolling process, and removes defective electrodes before the rolling process, thereby significantly reducing the defect rate after the rolling process.

[0018] A step of measuring the color coordinate value of the active material layer of each of the plurality of electrodes and calculating the average value. The present invention includes a step of measuring the color coordinate values ​​of the active material layer of each of the electrodes using an optical system and calculating an average value.

[0019] The optical system is a device including a light source and an image sensor, and when the active material layer of each of the electrodes is photographed using the optical system, color information of the surface of the active material layer of each of the electrodes is converted into color coordinate values ​​and detected. The image sensor is a device that converts incoming light into an electrical signal, and may be, for example, a CCD (Charge Coupled Device) sensor or a CMOS (Complementary Metal Oxide Semiconductor) sensor.

[0020] According to the present invention, the optical system may be a spectrophotometer or a colorimeter. The color coordinate values ​​refer to numerical values ​​represented by coordinates in a three-dimensional color space. For example, the color coordinate values ​​are * , a * , b * , whiteness, or yellowness values.

[0021] According to the present invention, the color coordinate value of the active material layer may be measured by a contact or non-contact colorimeter. That is, the colorimeter may be a contact or non-contact colorimeter. When a non-contact colorimeter is used, the measurement can be performed without directly contacting the sample, which is advantageous in that the measurement is simple and can be performed during a continuous production process.

[0022] The color coordinate value of the active material layer may be measured, for example, using a color difference meter CM2600d manufactured by Konica Minolta, Inc. Specifically, using a Konica Minolta CM2600d as the color difference meter, the measurement mode may be set to SCI (Specular Component Included) or SCE (Specular Component Excluded), standard light source D65 (color temperature: 6500K), CIE 1976 10° standard observer, and the color difference meter may be brought into contact with the position to be measured after white correction.

[0023] A step of comparing the color coordinate values ​​measured from each electrode with the average value and judging the product as good or bad. The present invention includes a step of determining that the electrode is good if the difference between the color coordinate value measured from each electrode and the average value is equal to or less than a preset value, and determining that the electrode is bad if the difference exceeds the preset value. For example, when the preset value is 1, the electrode is determined to be good if the difference between the color coordinate value measured from each electrode and the average value is 0.5, and is determined to be bad if the difference between the color coordinate value measured from each electrode and the average value is 1.5.

[0024] When the difference between the measured color coordinate value of each electrode and the average value is within a predetermined range, excellent adhesion between the current collector and the active material layer after rolling can be ensured, thereby significantly reducing the defective rate of the finished electrode product after the rolling process.

[0025] According to the present invention, the color coordinate value is L * If a value, the default value may be 1, preferably 0.5. According to the present invention, the color coordinate value is a * If a value, the default value may be 0.02, preferably 0.01.

[0026] According to the present invention, the color coordinate value is b * If it is a value, the default value may be 0.06, preferably 0.03. According to the present invention, when the color coordinate value is a whiteness value, the default value may be 0.7, preferably 0.3. According to the present invention, when the color coordinate value is a yellowness value, the default value may be 0.2.

[0027] As a result of the comparison, the color coordinate values ​​of each electrode measured, i.e., L * , a * , b * An electrode classified as a good product because the differences between the average values ​​of the whiteness, whiteness, and yellowness values ​​and the respective color coordinates fall within the above-mentioned predetermined value ranges can have excellent electrode quality when subjected to a rolling process. Specifically, an electrode classified as a good product by the electrode quality evaluation method according to the present invention can have excellent adhesive strength between the current collector and the active material layer when subjected to a rolling process. For example, the adhesive strength between the current collector and the active material layer can be ensured to be 20 gf / 20 mm or more.

[0028] <Electrode manufacturing method> The method for manufacturing an electrode according to the present invention is characterized by comprising the steps of applying a slurry containing an active material, a conductive material, and a binder onto a current collector, followed by drying to form an active material layer, thereby manufacturing a plurality of electrodes that have not undergone a rolling process, evaluating the quality of the electrodes by the above-described method, and rolling the electrodes that have been determined to be non-defective.

[0029] Each step of the method for producing an electrode according to the present invention will now be described in more detail. Producing a plurality of electrodes that have not been subjected to a rolling process. The present invention includes a step of manufacturing a plurality of electrodes that are not subjected to a rolling process by coating a current collector with a slurry containing an active material, a conductive material, and a binder, and then drying the coating to form an active material layer. The active material layer may be formed on one or both sides of the current collector.

[0030] The current collector is not particularly limited as long as it does not induce a chemical change in the battery and has conductivity. In the case of a positive electrode current collector, for example, stainless steel, aluminum, nickel, titanium, calcined carbon, or aluminum or stainless steel whose surface is surface-treated with carbon, nickel, titanium, silver, or the like may be used. In the case of a negative electrode current collector, for example, copper, stainless steel, aluminum, nickel, titanium, calcined carbon, copper or stainless steel whose surface is surface-treated with carbon, nickel, titanium, silver, or the like, aluminum-cadmium alloy, or the like may be used.

[0031] The current collector may have a thickness of typically 3 μm to 500 μm, and may have fine irregularities formed on the surface of the current collector to enhance adhesion of the positive or negative electrode material, and may be used in various forms, such as a film, sheet, foil, net, porous body, foam, nonwoven fabric, etc.

[0032] The slurry may be prepared by dissolving or dispersing the active material, the conductive material, and the binder in a solvent. When the active material is a positive electrode active material, the positive electrode active material may be a compound capable of reversibly inserting and extracting lithium, specifically a lithium composite metal oxide containing one or more transition metals such as cobalt, manganese, nickel, or aluminum, and lithium. More specifically, the lithium composite metal oxide may be a lithium-manganese oxide (e.g., LiMnO2, LiMn2O4, etc.), a lithium-cobalt oxide (e.g., LiCoO2, etc.), a lithium-nickel oxide (e.g., LiNiO2, etc.), a lithium-nickel-manganese oxide (e.g., LiNi 1-Y Mn Y O2(0 <Y<1)、LiMn 2-zNi z O4 (0 < Z < 2), lithium-nickel-cobalt-based oxide (e.g., LiNi 1-Y1 Co Y1 O2 (0 < Y1 < 1), lithium-manganese-cobalt-based oxide (e.g., LiCo 1-Y2 Mn Y2 O2 (0 < Y2 < 1), LiMn 2-z1 Co z1 O4 (0 < Z1 < 2), lithium-nickel-manganese-cobalt-based oxide (e.g., Li(Ni p Co q Mn r1 )O2 (0 < p < 1, 0 < q < 1, 0 < r1 < 1, p + q + r1 = 1), or Li(Ni p1 Co q1 Mn r2 )O4 (0 < p1 < 2, 0 < q1 < 2, 0 < r2 < 2, p1 + q1 + r2 = 2), or lithium-nickel-cobalt-transition metal (M) oxide (e.g., Li(Ni p2 Co q2 Mn r3 M S2 )O2 (M is selected from the group consisting of Al, Fe, V, Cr, Ti, Ta, Mg, and Mo, and p2, q2, r3, and s2 are atomic fractions of independent elements, 0 < p2 < 1, 0 < q2 < 1, 0 < r3 < 1, 0 < s2 < 1, p2 + q2 + r3 + s2 = 1), etc. may be mentioned, and any one or two or more of these compounds may be included.

[0033] When the active material is a negative electrode active material, as the negative electrode active material, various negative electrode active materials used in the art, for example, carbon-based negative electrode active materials, silicon-based negative electrode active materials, metal alloys, etc. may be used.

[0034] As the carbon-based negative electrode active material, various carbon-based negative electrode active materials used in the art may be used, for example, graphite-based materials such as natural graphite, artificial graphite, and Kish graphite; pyrolytic carbon, mesophase pitch-based carbon fiber, meso-carbon microbeads, mesophase pitches, and high-temperature calcined carbon such as petroleum or coal tar pitch-derived cokes, soft carbon, hard carbon, etc. The shape of the carbon-based negative electrode active material is not particularly limited, and substances with various shapes such as amorphous, plate-like, scaly, spherical, or fibrous may be used.

[0035] The silicon-based negative electrode active material is metallic silicon (Si), silicon oxide (SiO x , where 0 < x < 2), silicon carbide (SiC), and Si-Y alloy (where Y is an element selected from the group consisting of alkali metals, alkaline earth metals, Group 13 elements, Group 14 elements, transition metals, rare earth elements, and combinations thereof, and is not Si), and may contain one or more selected from the group consisting of. As the element Y, it may be selected from the group consisting of Mg, Ca, Sr, Ba, Ra, Sc, Y, Ti, Zr, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg, Tc, Re, Bh, Fe, Pb, Ru, Os, Hs, Rh, Ir, Pd, Pt, Cu, Ag, Au, Zn, Cd, B, Al, Ga, Sn, In, Ti, Ge, P, As, Sb, Bi, S, Se, Te, Po, and combinations thereof.

[0036] The active material may be contained in a content of 80% to 99% by weight, more specifically 85% to 98% by weight, based on the total weight of the active material layer. When the content of the active material is within the above range, excellent capacity characteristics and electrochemical characteristics can be obtained.

[0037] The conductive material is used to give the electrode conductivity, and can be used without any particular limitation as long as it does not cause chemical changes in the battery that is constructed and has electronic conductivity.Specific examples include graphite such as natural graphite and artificial graphite; carbon-based materials such as carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, thermal black, and carbon fiber; metal powder or metal fiber such as copper, nickel, aluminum, and silver; conductive whiskers such as zinc oxide and potassium titanate; conductive metal oxides such as titanium oxide; or conductive polymers such as polyphenylene derivatives, and the like, and one of these may be used alone or a mixture of two or more of them may be used. The conductive material may be contained in an amount of 1% by weight to 30% by weight based on the total weight of the active material layer.

[0038] The binder serves to improve adhesion between active material particles and between the active material and the current collector. Specific examples of the binder include polyvinylidene fluoride (PVDF), vinylidene fluoride-hexafluoropropylene copolymer (PVDF-co-HFP), polyvinyl alcohol, polyacrylonitrile, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene polymer (EPDM), sulfonated EPDM, styrene-butadiene rubber (SBR), fluororubber, and various copolymers thereof, and one or more of these may be used alone or in combination. The binder may be contained in an amount of 1 wt % to 30 wt % based on the total weight of the positive electrode active material layer.

[0039] The solvent may be a solvent commonly used in the art, such as dimethyl sulfoxide (DMSO), isopropyl alcohol, N-methylpyrrolidone (NMP), acetone, water, etc., and one or more of these may be used alone or in combination. The amount of the solvent used is not particularly limited as long as it can be adjusted to give the slurry an appropriate viscosity, taking into consideration the coating thickness of the slurry, production yield, workability, etc.

[0040] According to the present invention, a slurry containing an active material, a conductive material, and a binder is applied to a current collector at a density of 0.005 g / cm. 2 ~0.050g / cm 2 The loading amount of the slurry is preferably 0.005 g / cm and then dried to form an active material layer. 2 ~0.030g / cm 2 and more preferably 0.005 g / cm 2 ~0.025g / cm 2 When the loading amount of the slurry is within the above range, an active material layer having an appropriate thickness may be formed on the current collector.

[0041] According to the present invention, the drying may be performed with a total heat amount of 1000 kW to 1500 kW. The drying may be performed with a total heat amount of preferably 1100 kW to 1400 kW, more preferably 1200 kW to 1400 kW. When the total heat amount during drying is within the above range, the electrodes are dried so as not to cause defects, and the quality of the electrodes can be excellent.

[0042] According to the present invention, the active material layer may have a thickness of 100 μm to 500 μm. The active material layer may have a thickness of preferably 200 μm to 500 μm, more preferably 250 μm to 450 μm. When the thickness of the active material layer is within the above range, the defect rate of the electrode can be significantly reduced while maximizing the performance of the active material layer.

[0043] Steps for assessing the quality of the electrodes The method of manufacturing an electrode according to the present invention includes a step of evaluating the quality of the electrode by the method described above.

[0044] That is, the method includes a step of measuring the color coordinate value of the active material layer of each of the electrodes (electrodes that have not been subjected to a rolling process) by an optical system, calculating an average value, and judging the electrode as a non-defective product if the difference between the color coordinate value measured from each electrode and the average value is equal to or less than a predetermined value, and judging the electrode as a defective product if the difference exceeds the predetermined value. The specific content is as described above.

[0045] A step of rolling the electrodes that are judged to be non-defective. The present invention includes a step of rolling the electrode determined to be a non-defective product to manufacture an electrode.

[0046] As described above, the electrode determined to be a non-defective product by the electrode quality evaluation method according to the present invention may be used to manufacture a lithium secondary battery after being rolled, and in this case, the lithium secondary battery has a significantly low defect rate. The lithium secondary battery can be usefully used in portable devices such as mobile phones, notebook computers, and digital cameras, and in electric vehicles such as hybrid electric vehicles (HEVs). EXAMPLES

[0047] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the accompanying drawings, in which: FIG. 1 is a schematic diagram of a semiconductor device according to an embodiment of the present invention;

[0048] Manufacturing Example A slurry was prepared by mixing 10 parts by weight of natural graphite, 35 parts by weight of artificial graphite, 0.5 parts by weight of conductive material, 3.5 parts by weight of SBR, and 1 part by weight of CMC into 50 parts by weight of water.

[0049] The slurry was applied to one surface of a copper current collector having a thickness of 8 μm at a rate of 0.015 g / cm. 2 After coating with a loading amount of 1,300 kW, it was dried with a total heat amount of 1,300 kW to form an active material layer with a thickness of 340 μm, and an active material layer was formed on the other side of the current collector with the same prescription and under the same process conditions to manufacture an electrode. Seven electrodes (electrodes A to G) manufactured by the above method were prepared.

[0050] Example: Electrode quality evaluation A Konica Minolta CM2600d was used as a color difference meter, and the measurement mode was set to SCI, standard light source D65 (color temperature: 6500K) and CIE 1976 10° standard observer. After white correction, the color difference meter was brought into contact with the position to be measured, and the color coordinate L of the active material layer on both sides (one side, the other side) of each of electrodes A to G was measured. * Value, color coordinate a * value, color coordinate b * The value, whiteness and yellowness were measured and the results are shown in Table 1 below.

[0051] [Table 1]

[0052] [Table 2]

[0053] Referring to Table 2, the difference between the color coordinate value of the active material layer on both sides of each of the electrodes A to F and the average value is * If the color coordinate is a * If the color coordinate is b, the color is within 0.02. * When the color coordinate was whiteness, the difference was within 0.06, when the color coordinate was yellowness, the difference was within 0.7, and when the color coordinate was yellowness, the difference was within 0.2. Therefore, electrodes A to F were determined to be non-defective. On the other hand, electrode G was determined to be defective because the difference between the color coordinate value of the active material layer on the other surface and the average value was both outside the range of the predetermined values.

[0054] Experimental example: Evaluation of adhesive strength After each of electrodes A to G was roll pressed, the rolled electrodes were attached to a slide glass using double-sided tape. Then, using a UTM device (Lloyed), the electrodes were pulled at an angle of 90° at a speed of 100 mm / min, and the force at which they were peeled off from the slide glass was measured. The results are shown in Table 3 below.

[0055] [Table 3]

[0056] As shown in Table 3, in the case of Electrodes A to F which are classified as non-defective by the electrode quality evaluation method according to the present invention, it can be confirmed that the adhesive strength of the electrodes after the rolling process is excellent, being 20 gf / 20 mm or more.

[0057] In contrast, in the case of electrode G, in which the difference between the color coordinate value and the average value of the active material layer on the other side was both outside the range of the predetermined values, the adhesive strength of the other side of the electrode after the rolling process was 15 gf / 20 mm, which was confirmed to be unsuitable for use as an electrode, i.e., the adhesive strength was poor.

[0058] Therefore, according to the present invention, it is possible to easily and quickly remove defective electrodes from among electrodes by simply measuring the color coordinate values ​​of the electrodes before rolling. In other words, it is possible to select defective electrodes without going through a rolling process, and it is possible to significantly reduce the defective rate of finished electrodes.

Claims

1. A method for producing a plurality of electrodes that are not subjected to a rolling process, comprising the steps of: applying a slurry containing an active material, a conductive material, and a binder onto a current collector, and then drying the slurry to form an active material layer; assessing the quality of the electrodes; rolling the electrodes that are determined to be non-defective; Including, The step of evaluating the quality of the electrode comprises: preparing a plurality of electrodes including a current collector and an active material layer formed on the current collector, the electrodes not having been subjected to a rolling process; measuring color coordinate values ​​of the active material layers of the respective electrodes using an optical system and calculating an average value; determining the product as good if the difference between the color coordinate values ​​measured from the respective electrodes and the average value is equal to or smaller than a predetermined value, and determining the product as bad if the difference exceeds the predetermined value; The method for manufacturing an electrode includes evaluating the quality of the electrode by a method comprising the steps of:

2. The color coordinate value is L ＊ The method of claim 1 , wherein the predetermined value is 1.

3. The color coordinate value is a ＊ The method of claim 1 , wherein the predetermined value is 0.

02.

4. The color coordinate value is b ＊ The method of claim 1 , wherein the predetermined value is 0.

06.

5. the color coordinate value is a whiteness value, and the default value is 0.7; The method for manufacturing an electrode according to claim 1 , wherein the whiteness value is in accordance with the ASTM E313 standard.

6. the color coordinate value is a yellowness value, and the default value is 0.2; The method for manufacturing an electrode according to claim 1 , wherein the yellowness value is in accordance with ASTM E313 / ASTM D1925 standards.

7. The method for manufacturing an electrode according to claim 1 , wherein the plurality of electrodes are produced with the same formulation and under the same process conditions.

8. The method for manufacturing an electrode according to claim 1 , wherein the optical system is a spectrophotometer or a color difference meter.

9. The method for manufacturing an electrode according to claim 8 , wherein the color difference meter is a contact or non-contact color difference meter.

10. The slurry was adjusted to a density of 0.005 g / cm ２ ~0.050g / cm ２ The method for producing an electrode according to claim 1 , wherein the coating is carried out at a loading amount of

11. The method for producing an electrode according to any one of claims 1 to 10, wherein the drying is performed with a total heat amount of 1000 kW to 1500 kW.

12. The method for producing an electrode according to any one of claims 1 to 11, wherein the active material layer has a thickness of 100 µm to 500 µm.

13. A method of manufacturing a semiconductor device comprising the steps of: preparing a plurality of electrodes including a current collector and an active material layer formed on the current collector, the electrodes not having been subjected to a rolling process; measuring color coordinate values ​​of the active material layers of the respective electrodes using an optical system and calculating an average value; determining the product as good if the difference between the color coordinate values ​​measured from the respective electrodes and the average value is equal to or smaller than a predetermined value, and determining the product as bad if the difference exceeds the predetermined value; Including, the color coordinate value is a whiteness value, and the default value is 0.7; The whiteness value is in accordance with the ASTM E313 standard.

14. A method of manufacturing a semiconductor device comprising the steps of: preparing a plurality of electrodes including a current collector and an active material layer formed on the current collector, the electrodes not having been subjected to a rolling process; measuring color coordinate values ​​of the active material layers of the respective electrodes using an optical system and calculating an average value; determining the product as good if the difference between the color coordinate values ​​measured from the respective electrodes and the average value is equal to or smaller than a predetermined value, and determining the product as bad if the difference exceeds the predetermined value; Including, the color coordinate value is a yellowness value, and the default value is 0.2; The yellowness value is in accordance with the ASTM E313 / ASTM D1925 standard, a method for evaluating the quality of an electrode.

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