Electrode current collector testing equipment, electrode manufacturing equipment, and electrode manufacturing methods.

Abstract

The electrode current collector testing apparatus according to the invention comprises a data acquisition unit, which is located on the electrode current collector between several transport rollers for transporting or stopping the electrode current collector in the longitudinal direction, and is constructed to perform XRD analysis on the electrode current collector in the static state to collect data on the maximum width of the maximum half of the plane (hkl), and a selector constructed to select the electrode current collector with a potential density difference (α) of 0.20 or less as determined by Equation 1 below using the above data. [Equation 1] In Equation 1 above, A(hkl) is the maximum width of the maximum half of the plane (hkl) of the reference electrode current collector, where A(111)=0.089, A(200)=0.102, A(220)=0.113, and A(311)=0.138, and B(hkl) is the maximum width of the maximum half of the plane (hkl) of the electrode current collector to be tested.

Description

Inspection device for electrode current collector, electrode manufacturing device and electrode manufacturing method This application claims the benefit of priority from Korean Patent Application No. 10-2023-0133820, filed October 6, 2023, the entire contents of which are incorporated herein by reference. The present invention relates to an inspection device for an electrode current collector, an electrode manufacturing device, and an electrode manufacturing method. With the technological development and increasing demand for electric vehicles and energy storage systems (ESS), the demand for batteries as an energy source is rapidly increasing. Consequently, research is being conducted to develop batteries that can meet diverse needs. In particular, active research is being conducted on lithium secondary batteries, which possess high energy density and excellent lifespan and cycling characteristics as power sources for these devices. In general, lithium secondary batteries are classified into can-type batteries in which the electrode assembly is housed in a cylindrical or square metal can, and pouch-type batteries in which the electrode assembly is housed in a pouch-type case made of aluminum laminate sheet, depending on the material of the battery case. The electrode assembly is a power generation device that can be charged and discharged, consisting of a positive electrode, a negative electrode, and a separator structure interposed between the positive and negative electrodes. Here, the positive electrode may have a structure in which a positive electrode current collector and a positive electrode active material layer are sequentially laminated, and the negative electrode may have a structure in which a negative electrode current collector and a negative electrode active material layer are sequentially laminated. The positive electrode current collector may generally be made of aluminum foil, and the negative electrode current collector may generally be made of copper foil. Conventionally, the mechanical properties of electrode current collectors, such as strength and elongation, are evaluated through destructive tests such as tensile testing. Therefore, electrode current collectors that have undergone tensile testing are unusable. Furthermore, destructive testing methods for evaluating mechanical properties can result in deviations in results depending on sampling conditions and the tester's skill level, making it difficult to accurately determine the mechanical properties of electrode current collectors. Consequently, there is a pressing need for technologies that can accurately assess the mechanical properties of electrode current collectors through non-destructive testing. The present invention is intended to solve the above problems, and provides an electrode current collector inspection device, an electrode manufacturing device, and an electrode manufacturing method that can increase the accuracy of evaluating mechanical properties such as strength and elongation of an electrode current collector through non-destructive testing. [1] The present invention provides an inspection device for an electrode current collector, comprising: a data collection unit that collects data on the half-width of the (hkl) plane by performing XRD analysis on a stationary electrode current collector on an electrode current collector between a plurality of conveying rollers that convey or stop the electrode current collector in the longitudinal direction; and a selection unit that selects an electrode current collector having a potential density difference (α) of 0.20 or less, defined by Equation 1 below, using the data. [Formula 1] In the above equation 1, A(hkl) is the half width of the (hkl) plane of the reference electrode collector, A(111)=0.089, A(200)=0.102, A(220)=0.113 and A(311)=0.138, B(hkl) is the half-width of the (hkl) surface of the electrode collector to be inspected. [2] The present invention provides an inspection device for an electrode current collector, wherein, in the above [1], the selection unit selects an electrode current collector having a potential density difference (α) of 0.18 or less. [3] The present invention provides an inspection device for an electrode current collector, wherein in at least one of the above [1] and [2], the electrode current collector includes a plurality of coated regions each coated with an electrode slurry composition, and a non-coated region between the plurality of coated regions, and the data collection unit collects half-width data of the (hkl) plane by performing XRD analysis on the non-coated region. [4] The present invention is characterized in that in any one or more of the above [1] to [3], the ultimate tensile strength (UTS) of the electrode current collector selected in the selection section is 20.0 kfg / mm. 2 An inspection device for an electrode current collector is provided. [5] The present invention provides an inspection device for an electrode current collector, wherein, in any one or more of the above [1] to [4], the elongation (EL) of the electrode current collector selected in the selection unit is 1.5% or more. [6] The present invention provides an inspection device for an electrode current collector, wherein the crystal grain size of the electrode current collector selected in the selection unit is 0.70 ㎛ or less in any one or more of the above [1] to [5]. [7] The present invention provides an inspection device for an electrode current collector, wherein in any one or more of the above [1] to [6], the electrode current collector is a positive electrode current collector. [8] The present invention provides an electrode manufacturing device comprising: a roller-shaped unwinding unit in which an electrode current collector is wound in one direction; a conveying unit that continuously conveys the electrode current collector; a coating unit that applies and dries an electrode active material layer on at least one surface of the electrode current collector; and an inspection unit that includes the inspection device of claim 1; in any one or more of the above [1] to [7]. [9] The present invention provides an electrode manufacturing device, wherein, in any one or more of the above [1] to [8], an electrode current collector heat-treated in the coating section is selected through the inspection section.

[0010] The present invention provides an electrode manufacturing device, wherein in any one or more of the above [1] to [9], the electrode current collector is a positive electrode current collector.

[0011] The present invention provides a method for manufacturing an electrode, comprising: (S1) a step of unwinding a current collector from a roller-shaped unwinding portion in which an electrode current collector is wound in one direction and continuously supplying and conveying the current collector; (S2) a step of applying and drying an electrode active material layer on at least one surface of the electrode current collector; and (S3) a step of inspecting the electrode current collector, wherein the step of inspecting the electrode current collector comprises: (a) a step of stopping the electrode current collector during transportation and performing XRD analysis on the electrode current collector to collect data on the half width at half maximum of the (hkl) plane; (b) a step of selecting an electrode current collector having a potential density difference (α) defined by the following Equation 1 of 0.20 or less using the data; and (c) a step of resuming transportation of the electrode current collector.

[0012] The present invention provides a method for manufacturing an electrode, wherein the electrode manufacturing method further comprises (S4) a step of rolling an electrode current collector on which the electrode active material layer is applied and dried; and (S5) a winding step of winding the rolled electrode current collector into a roll shape. The inspection device for an electrode current collector according to the present invention selects an electrode current collector having a potential density difference (α) of 0.20 or less, as defined by Equation 1 below, from the half-width data of the (hkl) planes of a reference electrode current collector and an electrode current collector to be inspected by XRD analysis, thereby evaluating the mechanical properties of the electrode current collector by utilizing XRD, which is a non-destructive inspection, unlike a destructive inspection in which deviations in results occur depending on the sampling state or the skill of the inspector. Therefore, the present invention enables monitoring or screening of the mechanical properties of an electrode current collector with high accuracy. [Formula 1] In the above equation 1, A(hkl) is the half width of the (hkl) plane of the reference electrode collector, A(111)=0.089, A(200)=0.102, A(220)=0.113 and A(311)=0.138, B(hkl) is the half-width of the (hkl) surface of the electrode collector to be inspected. In addition, if a technology for accurately evaluating the mechanical properties of the electrode current collector is introduced as an in-line process, it is possible to predict and prevent in advance the deterioration of the strength of the electrode current collector heat-treated during the process, thereby improving defects such as rolling breakage, tab breakage, and tab folding that may occur during electrode production. FIG. 1 is a schematic diagram illustrating an electrode manufacturing device according to one embodiment of the present invention. Figure 2 is an XRD graph for a reference positive electrode collector in an experimental example. Figure 3 is an XRD graph of sample 4 in the experimental example. Figure 4 is a graph showing the relationship between the difference in potential density (α) compared to normal and the failure rate. The advantages and features of the present invention, and the methods for achieving them, will become clearer with reference to the embodiments described in detail below together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments are provided only to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims. Like reference numerals designate like elements throughout the specification. Unless otherwise defined, all terms (including technical and scientific terms) used herein may be used in their common sense to those of ordinary skill in the art to which the present invention pertains. Furthermore, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively unless explicitly and specifically defined otherwise. The terminology used herein is for the purpose of describing embodiments and is not intended to limit the present invention. In this specification, singular forms also include plural forms, unless specifically stated otherwise. As used herein, the terms "comprises" and / or "comprising" do not exclude the presence or addition of one or more other components in addition to the components mentioned. In this specification, when it is said that a part includes a certain component, this does not mean that other components are excluded, but rather that other components may be included, unless specifically stated otherwise. In this specification, the description of “A and / or B” means A, or B, or A and B. In this specification, “%” means weight percent unless explicitly indicated otherwise. In this specification, “crystal grain” means a single crystal particle unit having a regular atomic arrangement, which can be confirmed through EBSD (Electron Backscatter Diffraction) analysis. Inspection device for electrode collector The inspection device of an electrode current collector according to the present invention comprises: a data collection unit that collects data on the half width of the (hkl) plane by performing XRD analysis on a stationary electrode current collector on top of the electrode current collector between a plurality of conveying rollers that convey or stop the electrode current collector in the longitudinal direction; and a selection unit that selects an electrode current collector having a potential density difference (α) defined by Equation 1 below of 0.20 or less using the data. [Formula 1] In the above equation 1, A(hkl) is the half width of the (hkl) plane of the reference electrode collector, A(111)=0.089, A(200)=0.102, A(220)=0.113 and A(311)=0.138, B(hkl) is the half-width of the (hkl) surface of the electrode collector to be inspected. Conventionally, the mechanical properties of electrode current collectors, such as strength and elongation, are evaluated through destructive tests such as tensile testing. Therefore, electrode current collectors that have undergone tensile testing are unusable. Furthermore, destructive testing methods for evaluating mechanical properties can result in deviations in results depending on sampling conditions and the tester's skill level, making it difficult to accurately determine the mechanical properties of electrode current collectors. Consequently, there is a pressing need for technologies that can accurately assess the mechanical properties of electrode current collectors through non-destructive testing. Accordingly, the inventors of the present invention selected an electrode collector having a potential density difference (α) of 0.20 or less, defined by Equation 1 below, from the half-width data of the (hkl) planes of a reference electrode collector and an electrode collector to be tested by XRD analysis, thereby confirming that, unlike a destructive test in which a deviation in the result value occurs depending on the sampling state or the skill of the tester, the mechanical properties of the electrode collector can be evaluated with high accuracy using XRD, which is a non-destructive test. Hereinafter, the inspection device for the electrode current collector according to the present invention will be described in more detail. (1) Data collection department The above data collection unit performs the function of collecting half-width data of the (hkl) plane by performing XRD analysis on the stationary electrode collector on the electrode collector between a plurality of transport rollers that transport or stop the electrode collector in the longitudinal direction. Specifically, the electrode current collector includes a plurality of coated regions, each coated with an electrode slurry composition, and a non-coated region between the plurality of coated regions, and the data collection unit can collect half-width data of the (hkl) plane by performing XRD analysis on the non-coated region. Since the electrode production process involves various heat treatment steps, the electrode current collector's strength gradually decreases with each process. In this case, there is a risk of the electrode current collector breaking due to tension during the roll-to-roll process. In particular, if the strength of the electrode current collector's uncoated region is reduced, there is a problem that defects such as rolling breakage, tab breakage, and tab folding increase during electrode production. Accordingly, if a technology for accurately evaluating the mechanical properties of the electrode current collector is introduced as an in-line process, it is possible to predict and prevent strength degradation in the non-conductive portion of the electrode current collector in advance, thereby improving defects that may occur during electrode production. (2) Selection Department The above selection unit performs the function of selecting an electrode current collector using the half-width data of the (hkl) plane collected by XRD analysis in the above data collection unit. Specifically, the selection unit can select an electrode current collector having a potential density difference (α) defined by Equation 1 below of 0.20 or less, preferably 0.18 or less, and more preferably 0.01 to 0.18. An electrode current collector having a potential density difference (α) exceeding 0.20 has a problem in that mechanical properties such as ultimate tensile strength (UTS) and elongation (EL) are greatly reduced, and thus the probability of fracture during a roll-to-roll process increases. [Formula 1] In the above equation 1, A(hkl) is the half width of the (hkl) plane of the reference electrode collector, A(111)=0.089, A(200)=0.102, A(220)=0.113 and A(311)=0.138, B(hkl) is the half-width of the (hkl) surface of the electrode collector to be inspected. That is, the inspection device for an electrode current collector according to the present invention evaluates the mechanical properties of an electrode current collector by utilizing XRD, a non-destructive inspection, unlike a destructive inspection in which a deviation in the result value occurs depending on the sampling state or the skill of the tester, by selecting an electrode current collector having a potential density difference (α) of 0.20 or less. For example, in the case of an electrode current collector having a potential density difference (α) exceeding 0.20, it is not selected in the above selection section, and if the mechanical properties such as tensile strength (UTS) and elongation (EL) are deteriorated, there is a high possibility of breakage during the production process or defects such as wrinkles and sagging, and it is impossible to improve this, so it is desirable to remove it. Therefore, the present invention enables monitoring or screening of the mechanical properties of an electrode current collector with high accuracy. The ultimate tensile strength (UTS) of the electrode current collector selected from the above selection section is 20.0 kfg / mm 2 Ideally, 20.0kfg / mm 2 35.0kfg / mm 2 , more preferably 25.0kfg / mm 2 30.0kfg / mm 2 It could be. The elongation (EL) of the electrode current collector selected in the above selection section may be 1.5% or more, preferably 1.5% to 5.0%, and more preferably 1.6% to 3.0%. The crystal grain size of the electrode current collector selected in the above selection unit may be 0.70 ㎛ or less, preferably 0.01 ㎛ to 0.70 ㎛, and more preferably 0.10 ㎛ to 0.60 ㎛. If the electrode current collector selected from the above selection section satisfies the above ultimate tensile strength (UTS), elongation (EL) and grain size, the risk of short circuit due to tensile and compressive forces during the roll-to-roll process of the electrode can be significantly reduced. If the thickness of the electrode is increased or the thickness of the current collector is reduced to achieve high energy density, the risk of short circuit becomes even greater, and the above conditions need to be met. The above electrode current collector may be a positive electrode current collector. The positive electrode current collector increases its strength through work hardening through cold rolling, and has a very dense microstructure and high dislocation density. However, since the electrode production process includes various heat treatment processes, the positive electrode current collector is characterized by a gradual decrease in strength and hardness when absorbing heat energy, an increase in the size of crystal grains, and a decrease in dislocation density. Therefore, a positive electrode current collector with reduced strength after the heat treatment process can be a direct cause of defects such as rolling breakage, tab breakage, and tab folding during electrode manufacturing. Therefore, when the inspection device for the electrode current collector according to the present invention is introduced into an in-line process, it is possible to predict and prevent a decrease in strength in the uncoated portion of the electrode current collector in advance, thereby improving the above defects. Electrode manufacturing device FIG. 1 is a schematic diagram illustrating an electrode manufacturing device according to one embodiment of the present invention. An electrode manufacturing device (100) according to the present invention includes a roller-shaped unwinding unit (110) in which an electrode current collector is wound in one direction; a conveying unit (120) that continuously conveys the electrode current collector; a coating unit (130) that applies and dries an electrode active material layer on at least one surface of the electrode current collector conveyed from the unwinding unit (110); and an inspection unit (140) that includes the inspection device for the electrode current collector described above. The above-mentioned winding unit (110) is configured to wind an electrode current collector wound in a roll shape. Specifically, the winding unit (110) may have a roller shape, and the electrode current collector may be wound or unwound depending on the direction of rotation. The winding unit (110) can continuously supply the electrode current collector by unwinding the electrode current collector wound in a roll shape. The electrode current collector is not particularly limited as long as it has high conductivity without causing chemical changes in the battery, and may include, for example, at least one selected from the group consisting of copper, stainless steel, aluminum, nickel, titanium, heat-treated carbon, and aluminum-cadmium alloy. The above electrode current collector may form fine irregularities on the surface to strengthen the bonding strength of the active material. For example, it may be used in various forms such as a film, sheet, foil, net, porous body, foam, non-woven fabric, etc. Specifically, the electrode current collector may be a negative electrode current collector or a positive electrode current collector. When the electrode current collector is a negative electrode current collector, the negative electrode current collector may generally include a copper material. In addition, when the electrode current collector is a positive electrode current collector, the positive electrode current collector may generally include an aluminum material. More specifically, the electrode current collector may be a positive electrode current collector. In addition, the electrode current collector may typically have a thickness of 3 μm to 500 μm, and may have fine irregularities formed on the surface of the current collector to enhance the adhesive strength of the positive electrode active material. For example, it may be used in various forms such as a film, sheet, foil, net, porous body, foam, or non-woven fabric. The above-mentioned transfer unit (120) receives the electrode current collector unwound from the unwinding unit (110) and transfers the electrode current collector to the coating unit (130) and the inspection unit (140). Here, the transfer unit may be a roll. Next, the electrode current collector unwound from the unwinding unit (110) and transferred by the transfer unit (120) is transferred to the coating unit (130). The above coating portion (130) is configured such that an active material slurry is applied and dried on the surface of the electrode current collector to form an active material layer. The active material slurry may include an active material and a solvent. The surface of the electrode current collector may include a plurality of coated regions each coated with the active material slurry, and a non-coated region between the plurality of coated regions where the electrode current collector is exposed to the outside. The above-mentioned active material layer can be applied using any slurry application method known in the art without limitation. Specifically, a slit-die method, a gravure method, a doctor blade method, a silk screen method, an offset method, a spray method, a dip method, etc. can be used. The drying of the above active material layer can be performed by any drying method known in the art without limitation, as long as it can form an active material layer by evaporating a solvent from the active material slurry and does not cause a chemical change in the active material slurry. For example, the drying can be performed by changing a hot air method, a direct heating method, an induction heating method, etc., and specifically, the drying temperature can be 30°C to 250°C, specifically 40°C to 200°C, and more specifically 50°C to 170°C. In addition, the drying time can be 10 seconds to 300 seconds, specifically 20 seconds to 240 seconds, and more specifically 30 seconds to 180 seconds. The above active material may be an active material generally used in the relevant technical field, and specifically may be a negative electrode active material or a positive electrode active material. The negative electrode active material may include at least one selected from the group consisting of lithium metal, a carbon material capable of reversibly intercalating / deintercalating lithium ions, a metal or an alloy of these metals with lithium, a metal composite oxide, a material capable of doping and dedoping lithium, and a transition metal oxide. The positive electrode active material may be a compound capable of reversibly intercalating and deintercalating lithium, and specifically may include a lithium metal oxide containing one or more metals such as cobalt, manganese, nickel, or aluminum and lithium. More specifically, the lithium metal oxide may include a lithium-manganese oxide, a lithium-cobalt oxide, a lithium-nickel oxide, a lithium-nickel-manganese oxide, a lithium-nickel-cobalt oxide, a lithium-manganese-cobalt oxide, a lithium-nickel-manganese-cobalt oxide, a lithium-nickel-manganese-cobalt oxide, or a lithium-nickel-cobalt-transition metal (M) oxide, and one or two or more compounds thereof may be included. The solvent may be a solvent generally used in the art, and specifically, may be an organic solvent or an aqueous solvent. The organic solvent may include at least one selected from the group consisting of dimethyl sulfoxide (DMSO), isopropyl alcohol, N-methylpyrrolidone (NMP), dimethyl formamide (DMF), and acetone. The aqueous solvent may be water (H2O). The amount of the solvent used is sufficient to dissolve or disperse the active material, binder, and conductive material in consideration of the coating thickness and manufacturing yield of the slurry, and to have a viscosity that can exhibit excellent thickness uniformity during subsequent coating for electrode manufacturing. The above active material slurry may further include at least one of a conductive material and a binder, together with the active material and the solvent. The conductive material is used to provide conductivity to the electrode, and in the battery to be formed, as long as it does not cause a chemical change and has electronic conductivity, it can be used without any particular limitation. Specific examples include graphite such as natural graphite or 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 powders or metal fibers such as copper, nickel, aluminum, and silver; conductive tubes such as carbon nanotubes; conductive whiskers such as zinc oxide or potassium titanate; conductive metal oxides such as titanium oxide; or conductive polymers such as polyphenylene derivatives, and the like. One of these may be used alone or a mixture of two or more may be used. The conductive material may be included in an amount of 0.01 wt% to 10 wt%, preferably 0.1 wt% to 9 wt%, and more preferably 0.1 wt% to 5 wt%, based on the total weight of the positive electrode active material layer. The above binder serves to improve the adhesion between positive electrode active material particles and the adhesion between the positive electrode active material and the current collector. Specific examples include polyvinylidene fluoride (PVDF), polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-co-HFP), polyvinylalcohol, polyacrylonitrile, polymethyl methacrylate, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, polytetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene polymer (EPDM), sulfonated-EPDM, styrene butadiene rubber (SBR), fluoroelastomer, polyacrylic acid, and polymers in which hydrogens of these are substituted with Li, Na, or Ca, or various copolymers thereof, and one of these may be used alone or a mixture of two or more thereof. The above binder may be included in an amount of 1 wt% to 30 wt%, preferably 1 wt% to 20 wt%, and more preferably 1 wt% to 10 wt%, based on the total weight of the positive electrode active material layer. The above inspection unit (140) includes the inspection device for the electrode current collector described above. Specifically, the inspection unit (140) can receive the heat-treated electrode current collector from the coating unit (130) and perform the function of selecting the electrode current collector. The electrode manufacturing device (100) according to the present invention introduces the inspection unit for accurately evaluating the mechanical properties of the electrode current collector as an in-line process, thereby being able to predict and prevent a decrease in the strength of the electrode current collector in advance, thereby improving defects that may occur during electrode production. The electrode manufacturing device (100) according to the present invention may further include a rolling unit (150) for rolling the electrode current collector on which the electrode active material layer is applied and dried, and a winding unit (160) for winding the rolled electrode current collector into a roll shape. The rolling unit (150) is configured to pressurize the electrode current collector coated with an active material layer between a pair of rolling rolls to increase the density of the coating. The winding unit (160) is configured to wind the electrode current collector coated with the active material layer into a roll shape. After the electrode current collector is wound into a roll shape in the winding unit (170), the rolled electrode current collector can be stored or transported for subsequent processes for manufacturing electrodes or batteries (e.g., rolling of the active material layer, manufacturing of the electrode assembly, activation, etc.). Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement them. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein. Electrode manufacturing method The present invention provides a method for manufacturing an electrode, including a process for inspecting an electrode current collector. The electrode manufacturing method of the present invention comprises: (S1) a step of continuously supplying and conveying an electrode collector by unwinding the electrode collector from a roller-shaped unwinding portion in which the electrode collector is wound in one direction; (S2) a step of applying and drying an electrode active material layer on at least one surface of the electrode collector; and (S3) a step of inspecting the electrode collector, wherein the step of inspecting the electrode collector comprises: (a) a step of stopping the electrode collector during transportation and performing XRD analysis on the electrode collector to collect data on the half width at half maximum of the (hkl) plane; (b) a step of selecting an electrode collector having a potential density difference (α) defined by Equation 1 below of 0.20 or less using the data; and (c) a step of resuming transportation of the electrode collector. [Formula 1] In the above equation 1, A(hkl) is the half width of the (hkl) plane of the reference electrode collector, A(111)=0.089, A(200)=0.102, A(220)=0.113 and A(311)=0.138, B(hkl) is the half-width of the (hkl) surface of the electrode collector to be inspected. The electrode manufacturing method of the present invention temporarily stops the transfer of the electrode current collector during the roll-to-roll process for electrode manufacturing, collects data on the half-width of the (hkl) plane by analyzing the electrode current collector by XRD, and then selects the electrode current collector having a potential density difference (α) of 0.20 or less defined by Equation 1, thereby enabling high-precision monitoring or screening of the mechanical properties of the electrode current collector as an in-line process during electrode manufacturing. In addition, by introducing a technology for accurately evaluating the mechanical properties of the electrode current collector as an in-line process, it is possible to predict and prevent in advance the deterioration of the strength of the electrode current collector heat-treated during the process, thereby improving defects such as rolling breakage, tab breakage, and tab folding that may occur during electrode production. The electrode manufacturing method according to one embodiment of the present invention may further include (S4) a process of rolling an electrode current collector on which the electrode active material layer is applied and dried; and (S5) a winding process of winding the rolled electrode current collector into a roll shape. The above rolling process is a process of increasing the density of the electrode active material layer by pressing the electrode current collector on which the electrode active material layer has been applied and dried, and can be performed, for example, by pressing the electrode current collector on which the electrode active material layer has been formed while passing it between a pair of rolling rolls. The above-mentioned winding process is a process of obtaining the electrode current collector in a roll shape by winding the electrode active material layer formed through application, drying, and rolling of the electrode active material layer, and the electrode current collector wound in a roll shape can be stored or transported for subsequent processes for manufacturing electrodes or batteries (e.g., rolling of the active material layer, manufacturing of an electrode assembly, activation, etc.). Experimental Example 1: XRD Analysis of the Positive Current Collector and Calculation of the Potential Density Difference (1) XRD analysis of the positive electrode collector A commercially available 15 μm thick aluminum foil was prepared as a reference positive electrode current collector, and four types of 15 μm thick aluminum foil (samples 1 to 4) were prepared as test target positive electrode current collectors. X-ray diffraction analysis (XRD) was performed on each aluminum foil sample. At this time, the X-ray diffraction analysis was measured using an X-ray diffraction analyzer (Bruker AXS D4 Endeavor) at 25°C under the following conditions. - Source: Cu Target (λ=1.5418Å) - 2θ: 20°~ 120° - Step size: 0.02° / s - Total scan time: 150 min - Voltage: 40 kV - Current: 40 mA (2) Calculation of the full width at half maximum (FWHM) and potential density difference (α) of the positive electrode collector For each aluminum foil of the reference positive current collector and the test target positive current collector, Samples 1 to 4, according to Experimental Example 1, the full width at half maximum (FWHM) of each peak was measured from the XRD graph obtained by X-ray diffraction analysis, and then the difference in potential density (α) defined by Equation 1 below was calculated. The results are shown in [Table 1] below, and the XRD graphs of the reference positive current collector and Sample 4 are shown in Figs. 2 and 3, respectively. [Formula 1] In the above equation 1, A(hkl) is the half-width of the (hkl) surface of the reference electrode collector, A(111)=0.089, A(200)=0.102, A(220)=0.113, and A(311)=0.138, and B(hkl) is the half-width of the (hkl) surface of the electrode collector to be inspected. Specifically, Samples 1 to 4 are heat-treated samples of the reference positive electrode collector under different conditions. Sample 1 is heat-treated sample of the reference positive electrode collector at 160°C for 3 minutes, Sample 2 is heat-treated sample of the reference positive electrode collector at 170°C for 3 minutes, Sample 3 is heat-treated sample of the reference positive electrode collector at 200°C for 3 minutes, and Sample 4 is heat-treated sample of the reference positive electrode collector at 230°C for 3 minutes. Even if the same current collector is used and produced under the same conditions, a situation may occur in which the actual current collector is heat-treated at a higher temperature than the reference due to process errors and production variables, and thus, assuming such a case, samples heat-treated at various temperatures were set as experimental conditions. XRD Full width at half maximum (FWHM) Dislocation density difference (α) (111) (200) (220) (311) Standard 0.089 0.102 0.113 0.138 - Sample 10.07 10.065 0.086 0.098 0.12 Sample 20.061 0.065 0.071 0.087 0.18 Sample 30.054 0.059 0.065 0.069 0.22 Sample 40.045 0.057 0.062 0.065 0.24 Experimental Example 2: Measurement of mechanical properties and average grain size of a cathode current collector. (1) Mechanical properties of the positive electrode collector The mechanical properties, namely ultimate tensile strength (UTS) and elongation (EL), of the aluminum foils of each of the above-mentioned reference positive electrode collector and the test target positive electrode collector, Samples 1 to 4, were measured. Specifically, the positive electrode current collector was punched to 150 mm X 12.7 mm. At this time, the punching direction was parallel to the electrode running direction (MD direction). The specimen was fastened to the upper / lower jigs of a Universal Testing Machine (UTM), with a gauge distance of 50 mm, and the measurement speed set to 20 mm / min, and the specimen was pulled in the up-and-down direction until it broke, to measure the ultimate tensile strength (UTS). Specifically, the aluminum foil of each of the reference positive electrode collector and the test positive electrode collectors, Samples 1 to 4, was cut to a width of 12.7 mm. The two ends of the cut samples were respectively fastened to the upper and lower jigs of a measuring device (UTM, Zwick) and then pulled in the vertical direction to measure the elongation (unit: %) of the positive electrode collector. The measurement results are shown in [Table 2] below. (2) Average grain size of the positive electrode collector The average grain size was measured for each aluminum foil of the reference positive electrode collector and the test positive electrode collectors, Samples 1 to 4. Specifically, the average grain size in the copper foil was measured using EBSD (Electron Backscatter Diffraction) analysis. The measurement results are shown in [Table 2] below. Ultimate tensile strength [UTS, kfg / mm 2 ]Elongation [EL, %]Average grain size [㎛]Standard 27.62.80.1Less sample 124.52.10.43Sample 221.21.90.52Sample 318.31.40.73Sample 417.31.30.75 Referring to the above [Table 1] and [Table 2], for samples 1 and 2 in which the potential density difference (α) of the produced positive electrode collector is 0.20 or less, the ultimate tensile strength of the positive electrode collector is 20 kfg / mm. 2It can be confirmed that the elongation is 2.0% or more. In addition, it can be confirmed that the mechanical properties such as ultimate tensile strength and elongation are greatly reduced as the potential density difference (α) of the produced positive electrode current collector increases beyond 0.20. The ultimate tensile strength is 20 kfg / mm. 2 In the case of a cathode current collector having an elongation of less than 2.0% or an elongation of less than 2.0%, the possibility of aluminum foil breakage during the roll-to-roll process of the electrode increases significantly, and the defect rate tends to increase rapidly. (c) Relationship between the difference in potential density (α) compared to normal and the failure rate 50 sets of 10 pieces each of 9 aluminum foils (sample A) having a thickness of 15 ㎛, 9 aluminum foils (sample B) having a thickness of 15 ㎛, and 10 aluminum foils (sample C) having a thickness of 15 ㎛ were prepared and heat-treated as shown in Table 3 below. As described above, X-ray diffraction analysis (XRD) was performed for each, and the difference in dislocation density (α) compared to the normal was calculated, and the average value was obtained. Sample No. (5 sets each) Heat treatment conditions Sample A Sample B Sample C Temperature (℃ Time (min) Average α value Average α value Average α value 1100 30.01 0.05 0.01 2120 30.03 0.07 0.03 3140 30.05 0.09 0.07 4160 30.07 0.110 09 5170 30.09 0.13 0.116 180 30.110 190 157 190 30.19 0.23 0.218 200 30.27 0.31 0.27 9230 30.31 -- In addition, the ultimate tensile strength and elongation were measured for the above samples, and the ultimate tensile strength was 20 kfg / mm. 2 The proportion of positive electrode current collectors with an elongation of less than 2.0% or less was obtained. Sample number (5 sets each) Sample A Sample B Sample C Average α value Defect rate (%) Average α value Defect rate (%) Average α value Defect rate (%) 10.0110.0120.01220.0310.0330.03130.0530.0530.05240.0750.0750.07550.0960.0940.09460.1160.1160.11870.19210.1390.151980.27520.19260.213490.3187--0.2754 As can be seen from Table 4 and Figure 4 above, it can be seen that as the difference in potential density compared to normal (α) increases, the defect rate shows an increasing trend, and it can be seen that as the difference in potential density compared to normal (α) has a higher value, the defect rate increases even more. [Explanation of symbols] 100: Electrode manufacturing device 110: The book of volumes 120: Transport section 130: Coating section 131: Active material application part 132: Drying section 140: Inspection Department 150: Rolling section 160: Winding part

Claims

1. A data collection unit that collects data on the half-width of the (hkl) plane by performing XRD analysis on the stationary electrode collector on the electrode collector between a plurality of transfer rollers that transfer or stop the electrode collector in the longitudinal direction; and A selection unit for selecting an electrode current collector having a potential density difference (α) of 0.20 or less, defined by Equation 1 below, using the above data; An inspection device for an electrode current collector, comprising: [Formula 1] In the above equation 1, A(hkl) is the half width of the (hkl) plane of the reference electrode collector, A(111)=0.089, A(200)=0.102, A(220)=0.113 and A(311)=0.138, B(hkl) is the half-width of the (hkl) surface of the electrode collector to be inspected.

2. In claim 1, An inspection device for an electrode current collector, wherein the above selection unit selects an electrode current collector having a potential density difference (α) of 0.18 or less.

3. In claim 1, The electrode current collector includes a plurality of coating regions each coated with an electrode slurry composition, and a non-coated region between the plurality of coating regions, An inspection device for an electrode current collector, wherein the above data collection unit collects half-width data of the (hkl) plane by analyzing the above-mentioned portion by XRD.

4. In claim 1, The ultimate tensile strength (UTS) of the electrode current collector selected from the above selection section is 20.0 kfg / mm 2 An inspection device for an electrode current collector.

5. In claim 1, An inspection device for an electrode current collector, wherein the elongation (EL) of the electrode current collector selected from the above selection section is 1.5% or more.

6. In claim 1, An inspection device for an electrode current collector, wherein the crystal grain size of the electrode current collector selected in the above selection section is 0.70㎛ or less.

7. In claim 1, An inspection device for an electrode current collector, wherein the above electrode current collector is a positive electrode current collector.

8. A roller-shaped winding portion in which the electrode collector is wound in one direction; A transport unit that continuously transports the above electrode collector; A coating section for applying and drying an electrode active material layer on at least one surface of the electrode current collector; and An electrode manufacturing device comprising an inspection unit including the inspection device of claim 1.

9. In claim 8, An electrode manufacturing device that selects an electrode current collector heat-treated in the above coating section through the above inspection section.

10. In claim 8, An electrode manufacturing device, wherein the above electrode current collector is a positive electrode current collector. 11.(S1) A process of continuously supplying and transporting a current collector by unwinding it from a roller-shaped unwinding part in which the electrode current collector is wound in one direction; (S2) A process of applying and drying an electrode active material layer on at least one surface of the electrode current collector; and (S3) A method for manufacturing an electrode, including a process for inspecting the electrode collector, The process for inspecting the above electrode collector comprises the steps of (a) stopping the electrode collector during transport and performing XRD analysis on the electrode collector to collect half-width data of the (hkl) plane; (b) a step of selecting an electrode current collector having a potential density difference (α) of 0.20 or less defined by Equation 1 below using the above data; and (c) a method for manufacturing an electrode, comprising the step of resuming the transfer of the electrode current collector: [Formula 1] In the above equation 1, A(hkl) is the half width of the (hkl) plane of the reference electrode collector, A(111)=0.089, A(200)=0.102, A(220)=0.113 and A(311)=0.138, B(hkl) is the half-width of the (hkl) surface of the electrode collector to be inspected.

12. In claim 11, The above electrode manufacturing method further comprises (S4) a process of rolling an electrode current collector on which the electrode active material layer is applied and dried; and (S5) a winding process of winding the rolled electrode current collector into a roll shape.

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