Method for manufacturing dry electrode film, dry electrode film, and dry electrode comprising same

Abstract

The present disclosure includes a method for manufacturing a dry electrode film, a dry electrode film, and a dry electrode including the same. The method for manufacturing a dry electrode film includes preparing a dry mixture by dry mixing an active material, a conductive material, and a binder, manufacturing a mixture mass by kneading the dry mixture, obtaining an electrode powder by pulverizing the mixture mass, manufacturing a sample using the electrode powder through a mold, testing a yield strength of the sample, and drying the sample to obtain the dry electrode film. And manufacturing a sheet-type dry electrode film having a given thickness by rolling the electrode powder when the test result of the yield strength satisfies a predetermined criterion.

Description

Technical Field

[0001] Embodiments of this disclosure relate to methods for manufacturing dry electrode films, dry electrode films, and dry electrodes including dry electrode films. Background Technology

[0002] Unlike primary batteries, which are not designed for (re)charging, secondary (or rechargeable) batteries are typically designed to discharge and recharge. Low-capacity secondary batteries are typically used in portable small electronic devices, such as smartphones, feature phones, laptops, digital cameras, and camcorders, while high-capacity secondary batteries are widely used as power sources to drive motors in hybrid and electric vehicles and for storing electricity (e.g., residential and / or utility-scale power storage). A secondary battery typically includes an electrode assembly containing positive and negative electrodes, a housing that houses the electrode assembly, and electrode terminals connected to the electrode assembly.

[0003] Dry electrodes may include an electrode substrate, an active material, a binder, and a conductive material. Film-type dry electrode films can be formed by pressurizing the active material, binder, and conductive material. Dry electrodes can be manufactured by bonding the electrode substrate and the dry electrode film through a lamination process. The mechanical stability of the dry electrode film can be an advantageous factor, and therefore various efforts can be made to predict its mechanical properties in advance.

[0004] The information disclosed in this Background section is intended to enhance the understanding of the background of this disclosure, and therefore may contain information that does not constitute related (or prior art). Summary of the Invention

[0005] This disclosure addresses at least the aforementioned technical problems, and the exemplary embodiments of this disclosure include a method for manufacturing a dry electrode film, a dry electrode film, and a dry electrode comprising therethe.

[0006] These and other aspects and features of this disclosure are described in, or become apparent from, the following description of exemplary embodiments of this disclosure.

[0007] To achieve this objective, according to an example embodiment of this disclosure, a method for manufacturing a dry electrode film includes: preparing a dry mixture by dry mixing an active material, a conductive material, and a binder; manufacturing a lump of the mixture by kneading the dry mixture; obtaining electrode powder by crushing the lump of the mixture; manufacturing a sample using the electrode powder through a mold; testing the yield strength of the sample; and, when the test result of the yield strength meets a predetermined or desired (required) standard, manufacturing a sheet-type dry electrode film with a given thickness by calendering the electrode powder.

[0008] According to an example embodiment, manufacturing a sample using electrode powder via a mold may include: filling the mold with electrode powder; and pressurizing the electrode powder filled in the mold.

[0009] According to an example embodiment, filling the mold with electrode powder may include filling the mold with electrode powder such that the weight of the electrode powder filled in the mold is in the range of about 1 g to about 5 g.

[0010] According to an example embodiment, pressurizing electrode powder filled in a mold may include: pressurizing the electrode powder using a pressurizing member at a pressure in the range of about 10 MPa to about 100 MPa.

[0011] According to an example implementation, testing the yield strength of a specimen may include: applying pressure to the specimen using a clamp until it is broken; measuring the load applied to the specimen at the moment it is broken; and calculating the yield strength of the specimen based on the measured load.

[0012] According to an example implementation, calculating the yield strength of a specimen may include: calculating the yield strength of the specimen based on Equation 1 below.

[0013] Equation 1:

[0014] .

[0015] According to an example implementation, testing the yield strength of the specimen may further include: after calculating the yield strength of the specimen, if the yield strength calculated by Equation 1 is less than a given value, crushing the electrode powder.

[0016] According to the example implementation, the given value can be approximately 2.3 MPa.

[0017] According to an example implementation, testing the yield strength of the specimen may further include: measuring the internal friction angle of the electrode powder after calculating the yield strength of the specimen; and using the internal friction angle to calculate the tensile strength of the specimen.

[0018] According to an example implementation, measuring the internal friction angle of electrode powder may include: measuring the internal friction angle of electrode powder using a powder flowability evaluation method.

[0019] According to an example implementation, calculating the tensile strength of a specimen may include calculating the tensile strength of the specimen based on Equation 2 below.

[0020] Equation 2:

[0021] .

[0022] According to the example implementation, calculating the tensile strength of the specimen may further include: after calculating the tensile strength of the specimen, if the tensile strength calculated by Equation 2 is less than a given value, crushing the electrode powder.

[0023] According to the example implementation, the given value may be equal to approximately 0.5 MPa.

[0024] According to an example embodiment of this disclosure, a dry electrode film includes electrode powder comprising an active material, a conductive material, and a binder, wherein the electrode powder has a sheet shape manufactured by calendering and having a given thickness, and in the sheet shape state, the yield strength of the electrode powder is in the range of about 2.3 MPa or greater.

[0025] According to an example embodiment, the internal friction angle of the electrode powder can be in the range of about 30° to about 50°.

[0026] According to the example implementation, the tensile strength of the dry electrode membrane can be in the range of about 0.5 MPa or greater.

[0027] According to the example implementation, the porosity of the dry electrode membrane can be in the range of about 50% to about 70%.

[0028] According to an example embodiment, the active material may include at least one of lithium nickel cobalt aluminum oxide (NCA), lithium iron phosphate (LFP), and graphite.

[0029] According to an example embodiment, the adhesive may include at least one of polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), and polyacrylonitrile (PAN).

[0030] According to an exemplary embodiment of this disclosure, a dry electrode includes a substrate and a dry electrode film on at least one surface of the substrate. The dry electrode film includes electrode powder comprising an active material, a conductive material, and a binder, and the electrode powder has a sheet shape manufactured by calendering and having a given thickness. In the sheet shape state, the yield strength of the electrode powder is in the range of about 2.3 MPa or greater.

[0031] According to some exemplary embodiments of this disclosure, a method for manufacturing a dry electrode film with improved mechanical properties, a dry electrode film, and a dry electrode including the same may be disclosed.

[0032] According to some exemplary embodiments of this disclosure, a method for manufacturing a dry electrode film with improved mechanical properties, a dry electrode film, and a dry electrode comprising the present invention may be disclosed by testing the mechanical properties of the electrode powder before the electrode powder is calendered and then manufactured into a dry electrode film.

[0033] According to some exemplary embodiments of this disclosure, a sample can be prepared with a small amount of electrode powder before the electrode powder is calendered and then manufactured into a dry electrode film, and thus the mechanical properties can be easily measured.

[0034] However, the aspects and features of this disclosure are not limited to those described above, and those skilled in the art will clearly understand from the specific embodiments described below that other aspects and features not mentioned are also present. Attached Figure Description

[0035] The following accompanying drawings illustrate exemplary embodiments of the present disclosure and further describe aspects and features of the present disclosure together with specific embodiments thereof. Therefore, the present disclosure should not be construed as limited to the drawings:

[0036] Figure 1 This is a flowchart illustrating an example of a method for manufacturing a dry electrode film according to some exemplary embodiments of the present disclosure.

[0037] Figure 2 This is a diagram illustrating a method for manufacturing a dry electrode film according to some exemplary embodiments of the present disclosure.

[0038] Figure 3 This is a diagram illustrating examples of molds and pressure components according to some exemplary embodiments of the present disclosure.

[0039] Figure 4 This is a diagram illustrating an example of filling electrode powder into a mold according to some exemplary embodiments of the present disclosure.

[0040] Figure 5 This is a diagram illustrating examples of electrode powder and pressure components filled in a mold according to some exemplary embodiments of the present disclosure.

[0041] Figure 6 This is a diagram illustrating an example of pressurizing electrode powder filled in a mold according to some exemplary embodiments of the present disclosure.

[0042] Figure 7 This is a diagram illustrating an example of a sample manufactured using electrode powder according to some exemplary embodiments of the present disclosure.

[0043] Figure 8 This is a diagram illustrating an example of a specimen pressurized by a clamp and a measuring device for measuring load, according to some exemplary embodiments of this disclosure.

[0044] Figure 9 This is a diagram illustrating Equation 1 for calculating the yield strength of a specimen based on a measured load, according to some example embodiments of this disclosure.

[0045] Figure 10 This is a graph illustrating Equation 2 for calculating the tensile strength of a specimen based on the calculated yield strength and the measured angle of internal friction (AIF) of the specimen, according to some example embodiments of this disclosure.

[0046] Figure 11 A cross-sectional view of an example of a dry electrode according to some exemplary embodiments of the present disclosure is shown. Detailed Implementation

[0047] In the following description, embodiments of the present disclosure are described in detail with reference to the accompanying drawings. The terms or words used in this specification and claims should not be construed as limited to their ordinary or dictionary meanings, but should be interpreted as meanings and concepts consistent with the technical spirit of the present disclosure based on the principle that the inventors may, for their own lexicographers, appropriately define the concepts of the terms to best interpret the present disclosure.

[0048] The exemplary embodiments described in this specification and the configurations shown in the accompanying drawings are merely some of the exemplary embodiments of this disclosure and do not represent all the technical spirit, aspects, and features of this disclosure. Therefore, it should be understood that various equivalents and modifications may exist to replace or modify the exemplary embodiments described herein at the time of filing this application.

[0049] Understand that when a component or layer is referred to as being "on," "connected to," or "coupled to" another component or layer, it may be directly on, directly connected to, or directly coupled to said other component or layer, or one or more intermediate components or layers may be present. When a component or layer is referred to as being "directly on," "directly connected to," or "directly coupled to" another component or layer, no intermediate components or layers are present. For example, when a first component is described as being "coupled" or "connected" to a second component, the first component may be directly coupled to or connected to the second component, or the first component may be indirectly coupled to or connected to the second component via one or more intermediate components.

[0050] In the accompanying drawings, the dimensions of various elements, layers, etc., may be enlarged for clarity. The same reference numerals designate the same elements. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. Furthermore, the use of "may" when describing exemplary embodiments of this disclosure refers to "one or more embodiments of this disclosure." Expressions such as "at least one of..." and "any one of..." modify the entire list of elements, not individual elements, when preceding or following it. When phrases such as "at least one of A, B, and C," "at least one of A, B, or C," "at least one selected from A, B, and C," or "at least one selected from A, B, and C" are used to specify a list of elements A, B, and C, the phrase may refer to any and all suitable combinations or subsets of A, B, and C, such as A, B, C, A and B, A and C, B and C, or A and B and C. As used herein, the term "use" may be considered synonymous with the term "utilize." As used herein, the terms “substantially,” “about,” and similar terms are used as approximate terms rather than terms of degree and are intended to explain the inherent biases in the measured or calculated values ​​that will be recognized by one of ordinary skill in the art.

[0051] It is understood that although the terms first, second, third, etc., may be used herein to describe various elements, components (components), regions, layers, and / or segments, these elements, components (components), regions, layers, and / or segments should not be limited by these terms. These terms are used to distinguish one element, component (component), region, layer, or segment from another element, component (component), region, layer, or segment. Therefore, without departing from the teachings of the exemplary embodiments, the first element, component (component), region, layer, or segment discussed below may be referred to as the second element, component (component), region, layer, or segment.

[0052] For ease of description, spatial relative terms such as “below,” “under,” “lower,” “above,” and “upper” are used herein to describe the relationship between one element or feature as shown in the figures and another element or feature. It will be understood that, in addition to the orientations shown in the figures, spatial relative terms are intended to cover different orientations of the device in use or operation. For example, if the device in the figures is flipped, an element described as “below” or “under” other elements or features will be oriented “above” or “upper” other elements or features. Therefore, the term “below” can cover both orientations above and below. The device may be oriented in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptors used herein should be interpreted accordingly.

[0053] The terminology used herein is for the purpose of describing exemplary embodiments of the present disclosure and is not intended to limit the scope of the disclosure. As used herein, the singular form “a (indefinite article, a, an)” is also intended to include the plural form unless the context clearly indicates otherwise. It will be further understood that, when used in this specification, the terms “comprising” and / or “including” specify the presence of the stated features, integrals, steps, operations, elements, and / or components (components), but do not preclude the presence or addition of one or more other features, integrals, steps, operations, elements, components (components), and / or collections thereof.

[0054] Furthermore, any numerical ranges disclosed and / or enumerated herein are intended to include all subranges with the same numerical precision contained within the enumerated ranges. For example, the range “1.0 to 10.0” is intended to include all subranges between the minimum value of 1.0 and the maximum value of 10.0 (and including the endpoints) (i.e., a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0), such as 2.4 to 7.6. Any maximum numerical limit stated herein is intended to include all lower numerical limits contained therein, and any minimum numerical limit stated in this specification is intended to include all higher numerical limits contained therein. Therefore, the applicant reserves the right to amend this specification (including the claims) to expressly state any subranges contained within the ranges expressly stated herein.

[0055] Referring to two compared elements, characteristics, etc., as “identical” can mean that they are “substantially identical.” Therefore, the phrase “substantially identical” can include cases with what is considered a low deviation in the field (e.g., 5% or less). Furthermore, when a given parameter is said to be uniform in a given region, this can mean that it is uniform on average.

[0056] Throughout this specification, unless otherwise stated, each element may be singular or plural.

[0057] Arranging any element "above (or below)" or "on (below)" another element may indicate that any element may be configured to contact the upper (or lower) surface of the element, and other elements may be inserted between the element and any element disposed on (or below) the element.

[0058] Furthermore, it will be understood that when a component is referred to as “linked,” “coupled,” or “connected” to another component, the components may be directly “coupled,” “linked,” or “connected” to each other, or other components may be “inserted” between the components.

[0059] Throughout this specification, when “A and / or B” is stated, it means A, B, or A and B, unless otherwise specified. That is, “and / or” includes any or all of the listed items. When “C to D” is stated, it means C or more and D or fewer, unless otherwise specified.

[0060] As stated above, when the terms “about” or “substantially” are used in conjunction with numerical values ​​in this specification, they mean that the relevant numerical value includes a tolerance of ±10% around the stated value. When a range is specified, the range includes all values ​​within that range, such as increments of 0.1%.

[0061] In this disclosure, for clarity, the scales and relative scales of layers and regions shown in the accompanying drawings may be enlarged. That is, the scales shown in the drawings are for ease of understanding only and are not limiting. Furthermore, the same reference numerals designate the same elements throughout the specification.

[0062] Figure 1 This is a flowchart illustrating an example of a method for manufacturing a dry electrode film according to some exemplary embodiments of the present disclosure, and Figure 2 This is a diagram illustrating a method for manufacturing a dry electrode film according to some exemplary embodiments of the present disclosure. Figure 2 The method shown for manufacturing a dry electrode film may include a mixing process 410, a kneading process 420, a pulverizing process 430, a sample manufacturing process 440, a process 450 for testing the yield strength of the sample, and a calendering process 460 including passing the material through one or more rollers.

[0063] refer to Figure 1 The method S300 for manufacturing a dry electrode film may include preparing a dry mixture S310 by dry mixing an active material, a conductive material, and a binder. For example, the dry mixture may be prepared by... Figure 2 The mixing process 410 shown is used to dry mix the active material, conductive material and binder to manufacture the product.

[0064] refer to Figure 1 Mixture clumps S320 can be produced by kneading dry mixtures. For example, dry mixtures can be produced by kneading dry mixtures. Figure 2 The kneading process 420 shown forms a mixture agglomerate. In this example, the binder included in the dry mixture can be subjected to shear forces during the kneading process 420 to be fibrillated. The fibrillated binder allows the active and conductive materials included in the dry mixture to combine or couple together. For example, the mixture agglomerate can be formed using a kneader.

[0065] refer to Figure 1Powder for electrodes (hereinafter referred to as powder) can be obtained by crushing the mixture clumps. Figure 2 The electrode powder shown is 520, S330. For example, the mixture clumps can be... Figure 2 The pulverization process 430 shown forms electrode powder 520. In this example, the pulverization process 430 can be performed using a pulverizer. Pulverized electrode powder 520 can be formed, and therefore the formation of a film from the electrode powder 520 can be facilitated.

[0066] refer to Figure 1 Sample S340 can be manufactured using electrode powder 520 through a mold.

[0067] In some example implementations, it is used for passing through a mold (see Figure 3 510) The sample was prepared using electrode powder 520 (see 510). Figure 7 The process S340 (of 800) may include a process for filling electrode powder 520 into mold 510 and a process for pressurizing the electrode powder 520 filled into mold 510. In some example embodiments, the process of filling electrode powder 520 into mold 510 may include a process of filling electrode powder 520 into mold 510 such that the weight of electrode powder 520 filled into mold 510 is in the range of about 1 g to about 5 g. In some example embodiments, the process of pressurizing electrode powder 520 filled into mold 510 may include using a pressurizing member (see Figure 3 and Figure 5 The process of pressurizing electrode powder 520 under a pressure ranging from about 10 MPa to about 100 MPa (530).

[0068] Return to reference Figure 1 It can test the yield strength S350 of the specimen.

[0069] In some example implementations, the process S350 of testing the yield strength of specimen 800 may include using a fixture (see...). Figure 8 The process of applying pressure to the specimen 800 until it is destroyed, measuring the load applied to the specimen 800 at the moment of destruction, and calculating the yield strength of the specimen 800 based on the measured load.

[0070] In some example implementations, the process of calculating the yield strength of specimen 800 may include a process of calculating the yield strength of the specimen based on Equation 1 below.

[0071] Equation 1:

[0072] .

[0073] In some example embodiments, after calculating the yield strength of the sample, the method S300 for manufacturing the dry electrode membrane may further include: pulverizing the electrode powder 520 when the yield strength calculated by Equation 1 is less than a given value. In some example embodiments, the given value may be equal to about 2.3 MPa. Through the pulverization process, the binder can be pulverized in the form of fine fibers, and thus the surface area of ​​the binder can be increased, the particles can be finer, and the porosity can be increased. Therefore, the mechanical properties of the dry electrode membrane can be improved.

[0074] In some example embodiments, after calculating the yield strength of the sample 800, the method S300 for manufacturing a dry electrode film may further include measuring the angle of internal friction (AIF) of the electrode powder 520 and calculating the tensile strength of the sample 800 using the angle of internal friction. In some example embodiments, the process of measuring the angle of internal friction (AIF) of the electrode powder may include measuring the angle of internal friction (AIF) of the electrode powder 520 using a powder flowability evaluation method.

[0075] In some example implementations, the process of calculating the tensile strength of a specimen may include a process of calculating the tensile strength of the specimen based on Equation 2 below.

[0076] Equation 2:

[0077] .

[0078] In some example embodiments, after the process of calculating the tensile strength of the sample 800, the method S300 for manufacturing the dry electrode film may further include: pulverizing the electrode powder 520 when the tensile strength calculated by Equation 2 is less than a given value. In some example embodiments, the given value may be equal to about 0.5 MPa.

[0079] Return to reference Figure 1 When the yield strength test results meet the predetermined or desired criteria, a sheet-type dry electrode film S360 with a given thickness can be manufactured by calendering electrode powder. For example, pulverized electrode powder 520 can be formed into a dry electrode film through a calendering process 460. In this example, the calendering process allows fibrillated binders to combine or couple the active and conductive materials and support or maintain the film shape, enabling the formation of a dry electrode film. In this example, the dry electrode film can be formed without a separate solvent.

[0080] Dry electrode films can be formed in the form of self-supporting films (self-standing films). For example, a self-supporting film can be described as a film that can be formed independently without being laminated to a substrate. In this example, after the dry electrode film is formed in the form of a self-supporting film, the dry electrode film can be laminated to the substrate.

[0081] Dry electrode films may include active materials, conductive materials, and binders. For example, the active material may be or include positive electrode active materials or negative electrode active materials.

[0082] The positive electrode active material may include compounds capable of intercalating and deintercalating lithium (lithiation intercalation compounds). For example, it may include at least one composite oxide of lithium and a metal (such as or including at least one of cobalt, manganese, nickel and combinations thereof).

[0083] The composite oxide may be or include lithium transition metal composite oxides. Specific examples of composite oxides may include at least one of the following: lithium nickel-based oxides, lithium cobalt-based oxides, lithium manganese-based oxides, lithium iron phosphate (LiFePO4)-based compounds, cobalt-free lithium nickel manganese-based oxides, or combinations thereof.

[0084] As an example, it may include the following compounds represented by any of the following chemical formulas. Li a A 1-b X b O 2-c D c (0.90≤a≤1.8, 0≤b≤0.5, and 0≤c≤0.05); Li a Mn 2-b X b O 4-c D c (0.90≤a≤1.8, 0≤b≤0.5, and 0≤c≤0.05); Li a Ni 1-b-c Co b X c O 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, and 0<α<2); Li a Ni 1-b- c Mn b X c O 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, and 0<α<2); Li a Ni b Co c L 1 d G e O2 (0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, and 0≤e≤0.1); Li a NiGb O2(0.90≤a≤1.8, and 0.001≤b≤0.1); Li a CoG b O2(0.90≤a≤1.8, and 0.001≤b≤0.1); Li a Mn 1-b G b O2(0.90≤a≤1.8, and 0.001≤b≤0.1); Li a Mn2G b O4 (0.90≤a≤1.8, and 0.001≤b≤0.1); Li a Mn 1-g G g PO4 (0.90≤a≤1.8, and 0≤g≤0.5); Li (3-f) Fe2(PO4)3 (0≤f≤2); or Li a FePO4 (0.90≤a≤1.8).

[0085] In the above chemical formula, A is or includes at least one of Ni, Co, Mn, or a combination thereof; X is or includes at least one of Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, rare earth elements, or a combination thereof; D is or includes at least one of O, F, S, P, or a combination thereof; G is or includes at least one of Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; and L 1 It is or includes at least one of Mn, Al, or combinations thereof.

[0086] The positive electrode active material may be, for example, a high-nickel-based positive electrode active material having a nickel content of greater than or equal to about 80 mol%, greater than or equal to about 85 mol%, greater than or equal to about 90 mol%, greater than or equal to about 91 mol%, or greater than or equal to about 94 mol% and less than or equal to about 99 mol%, based on 100 mol% of metals other than lithium in the lithium transition metal complex oxide. The high-nickel-based positive electrode active material can be configured to achieve high capacity and can be used in high-capacity, high-density rechargeable lithium batteries.

[0087] The negative electrode active material may include at least one of the following: a material that can reversibly insert / deintercalate lithium ions, lithium metal, lithium metal alloy, a material capable of doping / dedoping lithium, or a transition metal oxide.

[0088] Materials capable of reversibly inserting / extracting lithium ions may include at least one carbon-based negative electrode active material, such as, for example, at least one of crystalline carbon, amorphous carbon, or a combination thereof. The crystalline carbon may be or include graphite, such as natural graphite or artificial graphite in non-shaped, flaky, scaly, spherical, or fibrous form. The amorphous carbon may be or include at least one of soft carbon, hard carbon, mesophase pitch carbonized product, calcined coke, etc.

[0089] Lithium metal alloys include alloys of lithium and metals (such as or including at least one of Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, Ra, Ge, Al, and Sn).

[0090] Materials capable of doping / undoping lithium may be or include Si-based negative electrode active materials or Sn-based negative electrode active materials. The Si-based negative electrode active materials may include silicon, silicon-carbon composites, SiO x (0 < x < 2), and at least one of Si-Q alloys (where Q is or includes at least one of alkali metals, alkaline earth metals, group 13 elements, group 14 elements (excluding Si), group 15 elements, group 16 elements, transition metals, rare earth elements, and combinations thereof). The Sn-based negative electrode active materials may include at least one of Sn, SnO2, Sn-based alloys, or combinations thereof.

[0091] The silicon-carbon composites may be or include composites of silicon and amorphous carbon. According to an exemplary embodiment, the silicon-carbon composites may be in the form of silicon particles and amorphous carbon coated on the surface of the silicon particles. For example, the silicon-carbon composites may include secondary particles (cores) in which primary silicon particles are aggregated and an amorphous carbon coating layer (shells) on the surface of the secondary particles. The amorphous carbon may also be between the primary silicon particles, and for example, the primary silicon particles may be coated with amorphous carbon. The secondary particles may be dispersed in an amorphous carbon matrix.

[0092] The silicon-carbon composites may further include crystalline carbon. For example, the silicon-carbon composites may include: a core including crystalline carbon and silicon particles, and an amorphous carbon coating layer on the surface of the core.

[0093] Si-based negative electrode active materials or Sn-based negative electrode active materials may be included in combination with the carbon-based negative electrode active materials.

[0094] Conductive materials may be included to impart conductivity (e.g., electrical conductivity) to the electrodes. Any material that does not cause chemical changes (e.g., does not cause undesirable chemical changes in a rechargeable lithium battery) and conducts electrons may be included in the battery. Examples of conductive materials may include: at least one of carbon-based materials such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fibers, carbon nanofibers, and carbon nanotubes; metal-based materials comprising at least one of copper, nickel, aluminum, silver, etc., in the form of metal powder or metal fibers; conductive polymers such as polyphenylene derivatives; or mixtures thereof.

[0095] like Figure 2 As shown, dry electrode films can be manufactured using a dry process. In this specification, a dry process or dry electrode can refer to a process or electrode that does not contain or substantially does not contain solvents, or in which solvents are not intentionally included in the electrode manufacturing process. Solvents may include process solvents, process solvent residues, process solvent impurities, etc. Dry electrode films may include dry (dry) active materials and dry (dry) binders, and may be formed in sheet form. Dry binders may be or include binders that are not impregnated with solvents. Dry binders may be or include: binders that do not contain solvents.

[0096] Dry binders may include fibrillated binders. Fibrous binders can be configured as a matrix to support and bind dry active materials and / or other components included in the dry electrode membrane. Fibrous binders can be identified in fibrous form in scanning electron microscopy images of the dry electrode membrane. Fibrous binders may have an aspect ratio (length-to-width ratio) in the range of about 10 or greater, 20 or greater, 50 or greater, or 100 or greater.

[0097] In some example embodiments, the dry binder may include at least one of polytetrafluoroethylene (PTFE), polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) copolymer, polyvinylidene fluoride (PVDF), polyvinyl alcohol, polyacrylonitrile (PAN), carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, cellulose, polyvinylpyrrolidone, polyethylene, polypropylene, ethylene propylene diene monomer (EPDM), sulfonated EPDM, styrene-butadiene rubber (SBR), fluorinated elastomers, or copolymers thereof. However, the dry binder is not limited to these and may include any binder used in the manufacture of the dry electrode membrane. For example, the dry binder may include a fluorinated binder. A fluorinated binder may include at least one of polytetrafluoroethylene (PTFE), polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) copolymer, or polyvinylidene fluoride (PVDF). The content of the dry binder may range from about 0.5% by weight to about 10% by weight, or from 1% by weight to 5% by weight, of the total weight of the dry electrode membrane. The dry electrode film may include a dry binder within the above-mentioned range, and thus may improve the cohesion between the dry electrode film and the substrate, and the dry electrode including the dry electrode film may maintain a high energy density.

[0098] According to some example embodiments, the dry electrode film may include electrode powder comprising an active material, a conductive material, and a binder. The dry electrode film may have a sheet shape manufactured by calendering the electrode powder and having a given thickness, and in its sheet shape state has a yield strength of about 2.3 MPa or greater. The porosity of the dry electrode film may be in the range of about 50% to about 70%. The angle of internal friction (AIF) of the electrode powder may be in the range of about 30° to about 50°. For example, the tensile strength of the dry electrode film may be in the range of about 0.5 MPa or greater.

[0099] According to some example embodiments, the electrode active material may include at least one of lithium nickel cobalt aluminum oxide (NCA), lithium iron phosphate (LFP), and graphite. However, this disclosure is not limited thereto.

[0100] A dry electrode may include a dry electrode film and a substrate. The dry electrode film may be disposed on at least one surface of the substrate.

[0101] The substrate may include materials that do not cause chemical changes and have high electrical conductivity. For example, the substrate may include at least one of copper, aluminum, stainless steel (SUS), nickel, polymers coated with conductive materials, titanium, sintered carbon, or combinations thereof.

[0102] In some example embodiments, the substrate may be formed in the form of a metal foil or a thin metal sheet (such as at least one of copper, copper alloy, nickel, or nickel alloy). In other example embodiments, the substrate may be formed in the form of a metal foil or a thin metal sheet (such as aluminum or aluminum alloy).

[0103] Figure 1 and Figure 2 The flowcharts and their detailed descriptions are merely examples of this disclosure, and the scope of this disclosure is not limited to... Figure 1 and Figure 2 The flowchart and its detailed description. For example, one or more processes can be added / changed / deleted from the flowchart and its detailed description, the order of one or more processes can be changed, and one or more processes can be performed simultaneously.

[0104] Figure 3 This is a diagram illustrating examples of molds and pressure components according to some exemplary embodiments of the present disclosure. Figure 4 This is a diagram illustrating an example of filling electrode powder into a mold according to some exemplary embodiments of the present disclosure. Figure 5 This is a diagram illustrating examples of electrode powder and pressure components filled in a mold according to some exemplary embodiments of the present disclosure. Figure 6 This is a diagram illustrating an example of pressurizing electrode powder filled in a mold according to some exemplary embodiments of the present disclosure. Figure 7 This is a diagram illustrating an example of a sample manufactured using electrode powder according to some exemplary embodiments of the present disclosure.

[0105] refer to Figures 3 to 7 The sample 800 can be manufactured using electrode powder 520 through a mold 510. The mold 510 may include a cylindrical cavity formed therein. The pressure member 530 may include a protrusion to be inserted into the cavity of the mold 510. However, the shapes of the mold 510 and the pressure member 530 are not limited thereto, and they may have various shapes (different shapes).

[0106] The material used for mold 510 can be determined based on machinability, process conditions, etc. For example, the material used for mold 510 may include at least one of steel, aluminum (Al), copper alloy, ceramic, carbon fiber, etc.

[0107] The electrode powder 520 may include an active material, a conductive material, and a binder. The active material may include a positive electrode active material and a negative electrode active material. The positive electrode active material may include at least one of lithium nickel cobalt aluminum oxide (NCA), lithium iron phosphate (LFP), etc., and the negative electrode active material may include graphite. However, this disclosure is not limited thereto.

[0108] According to some exemplary embodiments, electrode powder 520 may be filled into the cavity of mold 510. For example, electrode powder 520 may be filled into mold 510 such that the weight of electrode powder 520 filled into mold 510 is in the range of about 1 g to about 5 g. Therefore, specimen 800 can be easily prepared with a small amount of electrode powder 520, and the yield strength of specimen 800 can be measured. However, the weight of the filled electrode powder 520 is not limited to this.

[0109] According to some exemplary embodiments, electrode powder 520 can be pressurized by a pressurizing member 530 at a pressure ranging from about 10 MPa to about 100 MPa. Therefore, sample 800 can be manufactured by pressurizing electrode powder 520 at various pressures, and thus sample 800 corresponding to dry electrode films to be manufactured under various pressure conditions can be manufactured. For example, when the dry electrode film has various densities depending on various process conditions, electrode powder 520 can be pressurized at various pressures, and thus sample 800 corresponding to the density of the dry electrode film can be manufactured. Therefore, the mechanical properties of sample 800 can be measured before manufacturing the dry electrode film, and the mechanical properties of the dry electrode film can be measured (measured) in advance. However, the pressure applied to electrode powder 520 is not limited to this, and a wide range of pressures can be applied to electrode powder 520.

[0110] Figure 8 This is a diagram illustrating examples of specimens pressurized by clamps and a measuring device for measuring load, according to some exemplary embodiments of this disclosure. Figure 9 This is a diagram illustrating Equation 1, discussed below, for calculating the yield strength of a specimen based on a measured load, according to some example embodiments of this disclosure.

[0111] refer to Figure 8 The specimen 800 can be pressurized to the point of failure using a clamp 900. The clamp 900 can have various shapes and sizes (different shapes and sizes) for applying pressure to the specimen 800. The clamp 900 can be coupled to a measuring device 910 that can measure the load applied at a specific moment.

[0112] The specimen 800 can be compressed to the point of failure using the clamp 900. For example, the specimen 800 can be compressed using the clamp 900 in an unconstrained (unconfined) state. The load applied to the specimen 800 at the moment of failure can then be measured. Figure 9 As shown, the load applied to specimen 800 at the moment of failure can be the load corresponding to the maximum value in the figure.

[0113] The yield strength of specimen 800 can be calculated based on the measured load. For example, the yield strength of specimen 800 can be the yield strength of specimen 800 calculated based on Equation 1 discussed below, such as the unconstrained yield strength (unconfined yield strength, UYS). Unconstrained yield strength (UYS) can refer to the maximum compressive strength of electrode powder 520 when specimen 800 is simply compressed without lateral restraint, with the sides of specimen 800 unconstrained.

[0114] Equation 1:

[0115] .

[0116] exist Figure 9 In the equations shown, "c" can correspond to the value of 0.001 as a unit conversion constant, "m" can correspond to the measured load (kg), and "g" can correspond to the gravitational acceleration (m / s²). 2 ), and "A" can correspond to the cross-sectional area of ​​the sample (m²). 2 ).therefore, Figure 9 The equation shown corresponds to Equation 1 above.

[0117] After calculating the yield strength of specimen 800, Figure 1 The method S300 for manufacturing a dry electrode film shown may further include a process of pulverizing the electrode powder when the yield strength calculated by Equation 1 is less than a given value. Through the pulverization process, the binder can be pulverized in the form of fine fibers, and thus the surface area of ​​the binder can be increased, the particles can be finer, and the porosity can be increased. Therefore, the mechanical properties of the dry electrode film can be improved.

[0118] When using dry electrode films to manufacture dry electrodes, the following is desirable: the tensile strength of the dry electrode film is in the range of about 0.5 MPa or greater to facilitate manufacturing and handling. According to Equation 2 below, when the yield strength of the dry electrode film is in the range of about 2.3 MPa or greater, at about 40°, the electrode powder (see...) Figure 4 At an internal friction angle (AIF) of 520°, the tensile strength of the dry electrode film can be in the range of about 0.5 MPa or greater. Therefore, the yield strength of sample 800 is expected to be in the range of about 2.3 MPa or greater.

[0119] Dry electrode films can be manufactured when the yield strength test results meet the predetermined or expected criteria. Therefore, when the yield strength of sample 800 is in the range of about 2.3 MPa or greater, sheet-type dry electrode films with a given thickness can be manufactured by a calendering process.

[0120] After calculating the yield strength of sample 800, if the yield strength calculated by Equation 1 is less than about 2.3 MPa, the electrode powder 520 can be additionally pulverized. When the additionally pulverized electrode powder 520 meets the above-mentioned yield strength test results, a dry electrode film can be manufactured.

[0121] Figure 10 This is a graph illustrating Equation 2, discussed below, for calculating the tensile strength of a specimen based on the calculated yield strength and measured internal friction angle (AIF) of the specimen, according to some example embodiments of this disclosure.

[0122] In calculating the sample (see Figure 7 After the process of determining the yield strength of the electrode powder (800), the electrode powder (see [reference]) can be measured. Figure 2 The internal friction angle (AIF) of 520° can be used to calculate the tensile strength of specimen 800. Tensile strength refers to the maximum stress that specimen 800 can tolerate when subjected to a tensile load.

[0123] The internal friction angle (AIF) of electrode powder 520 indicates the resistance generated when particles in electrode powder 520 slide against each other. The internal friction angle (AIF) of electrode powder 520 can be measured using powder flowability evaluation methods. These methods can be used to calculate the internal friction angle (AIF) by measuring the resistance that occurs when the electrode powder is subjected to shear force.

[0124] The tensile strength of specimen 800 can be calculated based on the calculated unconstrained yield strength (UYS) of specimen 800 and the measured internal friction angle (AIF) of electrode powder 520. For example, the tensile strength of specimen 800 can be calculated based on Equation 2 below.

[0125] Equation 2:

[0126] .

[0127] exist Figure 10 In the equation shown, " "It can be the tensile strength (kPa)," "Can be the internal friction angle (°), and " "It can be the yield strength (kPa). Therefore, Figure 10 The equation shown corresponds to Equation 2 above.

[0128] When using a dry electrode membrane to manufacture a dry electrode, the following is desirable: the tensile strength of the dry electrode membrane is in the range of about 0.5 MPa or greater to facilitate manufacturing and handling. Therefore, the tensile strength of sample 800 is desirable to be in the range of about 0.5 MPa or greater.

[0129] Dry electrode films can be manufactured when the tensile strength test results meet the predetermined or expected standards. Therefore, when the tensile strength of sample 800 is in the range of about 0.5 MPa or greater, sheet-type dry electrode films with a given thickness can be manufactured by a calendering process.

[0130] After calculating the tensile strength of sample 800, if the tensile strength calculated by Equation 2 is less than about 0.5 MPa, the electrode powder 520 can be additionally pulverized. When the additionally pulverized electrode powder 520 meets the above-mentioned tensile strength test results, a dry electrode film can be manufactured.

[0131] Figure 11 A cross-sectional view of an example of a dry electrode according to some exemplary embodiments of the present disclosure is shown.

[0132] refer to Figure 11 The dry electrode may include a dry electrode film 110 and a substrate 120. The dry electrode film 110 may be disposed on at least one surface of the substrate 120.

[0133] The dry electrode film 110 may include an active material, a conductive material, and a binder. For example, the active material may be a positive electrode active material or a negative electrode active material.

[0134] The positive electrode active material may include compounds capable of intercalating and deintercalating lithium (lithiation intercalation compounds). For example, it may include at least one composite oxide of lithium and a metal (such as or including at least one of cobalt, manganese, nickel and combinations thereof).

[0135] The composite oxide may be or include lithium transition metal composite oxides. Specific examples of composite oxides may include at least one of lithium nickel-based oxides, lithium cobalt-based oxides, lithium manganese-based oxides, lithium iron phosphate compounds, cobalt-free nickel manganese-based oxides, or combinations thereof.

[0136] As an example, it may include the following compounds represented by any of the following chemical formulas. Li a A 1-b X b O 2-c D c (0.90≤a≤1.8, 0≤b≤0.5, and 0≤c≤0.05); Li a Mn 2-b X b O 4-c D c (0.90≤a≤1.8, 0≤b≤0.5, and 0≤c≤0.05); Li a Ni 1-b-c Co b X c O 2-α D α(0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, and 0<α<2); Li a Ni 1-b-c Mn b X c O 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, and 0<α<2); Li a Ni b Co c L 1 d G e O2 (0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, and 0≤e≤0.1); Li a NiG b O2 (0.90≤a≤1.8 and 0.001≤b≤0.1); Li a CoG b O2 (0.90≤a≤1.8 and 0.001≤b≤0.1); Li a Mn 1-b G b O2 (0.90≤a≤1.8 and 0.001≤b≤0.1); Li a Mn2G b O4 (0.90≤a≤1.8 and 0.001≤b≤0.1); Li a Mn 1- g G g PO4 (0.90≤a≤1.8 and 0≤g≤0.5); Li (3-f) Fe2(PO4)3 (0≤f≤2); or Li a FePO4 (0.90≤a≤1.8).

[0137] In the above chemical formula, A is or includes at least one of Ni, Co, Mn, or a combination thereof; X is or includes at least one of Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, rare earth elements, or a combination thereof; D is or includes at least one of O, F, S, P, or a combination thereof; G is or includes at least one of Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; and L 1 It is or includes at least one of Mn, Al, or combinations thereof.

[0138] The positive electrode active material may be or include, for example, a high-nickel-based positive electrode active material having a nickel content of greater than or equal to about 80 mol%, greater than or equal to about 85 mol%, greater than or equal to about 90 mol%, greater than or equal to about 91 mol%, or greater than or equal to about 94 mol% and less than or equal to about 99 mol%, based on 100 mol% of the metals other than lithium in the lithium transition metal composite oxide. The high-nickel-based positive electrode active material can be configured to achieve a high capacity and can be applied to high-capacity, high-density rechargeable lithium batteries.

[0139] The negative electrode active material may include at least one of a material that reversibly intercalates / deintercalates lithium ions, lithium metal, a lithium metal alloy, a material capable of doping / de-doping lithium, or a transition metal oxide.

[0140] The material that reversibly intercalates / deintercalates lithium ions may include a carbon-based negative electrode active material, such as at least one of crystalline carbon, amorphous carbon, or a combination thereof. The crystalline carbon may be or include graphite, such as natural graphite or artificial graphite in non-shaped, sheet-shaped, flake-shaped, spherical, or fibrous form. The amorphous carbon may be or include at least one of soft carbon, hard carbon, mesophase pitch carbonized product, calcined coke, etc.

[0141] The lithium metal alloy includes an alloy of lithium and a metal (such as or including at least one of Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, Ra, Ge, Al, and Sn).

[0142] The material capable of doping / de-doping lithium may be or include a Si-based negative electrode active material or a Sn-based negative electrode active material. The Si-based negative electrode active material may include silicon, a silicon-carbon composite, SiO x (0 < x < 2), and at least one of a Si-Q alloy (where Q is or includes at least one of an alkali metal, an alkaline earth metal, a Group 13 element, a Group 14 element (excluding Si), a Group 15 element, a Group 16 element, a transition metal, a rare earth element, and a combination thereof). The Sn-based negative electrode active material may include at least one of Sn, SnO2, a Sn-based alloy, or a combination thereof.

[0143] The silicon-carbon composite may be or include a composite of silicon and amorphous carbon. According to an exemplary embodiment, the silicon-carbon composite may be in the form of silicon particles and amorphous carbon coated on the surface of the silicon particles. For example, the silicon-carbon composite may include secondary particles (cores) in which primary silicon particles are aggregated and an amorphous carbon coating layer (shell) on the surface of the secondary particles. The amorphous carbon may also be between the primary silicon particles, and for example, the primary silicon particles may be coated with amorphous carbon. The secondary particles may be dispersed in an amorphous carbon matrix.

[0144] The silicon-carbon composite may further include crystalline carbon. For example, the silicon-carbon composite may include a core comprising crystalline carbon and silicon particles, and an amorphous carbon coating layer on the surface of the core.

[0145] It can be combined with carbon-based negative electrode active materials, including Si-based negative electrode active materials or Sn-based negative electrode active materials.

[0146] Conductive materials may be included to impart conductivity to the electrodes. Any material that does not cause a chemical change and conducts electrons may be included in the battery. Examples of conductive materials may include: at least one of carbon-based materials such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fibers, carbon nanofibers, and carbon nanotubes; metal-based materials comprising at least one of copper, nickel, aluminum, silver, etc., in the form of metal powder or metal fibers; conductive polymers such as polyphenylene derivatives; or mixtures thereof.

[0147] The dry electrode film 110 can be produced by a dry process (e.g., as referenced above). Figures 1 to 10 The dry electrode is manufactured using a dry process (explained in this specification). In this specification, a dry process or dry electrode may refer to a process or electrode that does not include solvents, or in which solvents are not intentionally included in the electrode manufacturing process. Solvents may include process solvents, process solvent residues, process solvent impurities, etc. The dry electrode film 110 may include a dry active material and a dry binder, and may be formed in sheet form. The dry binder may be or include a binder that is not impregnated with solvent. The dry binder may be or include: a binder that does not include solvents.

[0148] Dry binders may include fibrillated binders. The fibrillated binders may be configured as a matrix supporting and binding the dry active material and / or other components included in the dry electrode membrane 110. The fibrillated binders can be identified in fibrous form in scanning electron microscopy images of the dry electrode membrane 110. The fibrillated binders may have an aspect ratio in the range of about 10 or greater, 20 or greater, 50 or greater, or 100 or greater.

[0149] In some example embodiments, the dry binder may include at least one of polytetrafluoroethylene (PTFE), polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) copolymer, polyvinylidene fluoride (PVDF), polyvinyl alcohol, polyacrylonitrile (PAN), carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, cellulose, polyvinylpyrrolidone, polyethylene, polypropylene, ethylene propylene diene monomer (EPDM), sulfonated EPDM, styrene-butadiene rubber (SBR), fluorinated elastomers, or copolymers thereof. However, the dry binder is not limited to these and may include any binder used in the manufacture of the dry electrode membrane. The dry binder may include a fluorinated binder. A fluorinated binder may include at least one of polytetrafluoroethylene (PTFE), polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) copolymer, or polyvinylidene fluoride (PVDF). The content of the dry binder may range from about 0.5% by weight to about 10% by weight, or from 1% by weight to 5% by weight, of the total weight of the dry electrode membrane 110. The dry electrode film 110 may include a dry adhesive within the above-described range, and thus may improve the cohesion between the dry electrode film 110 and the substrate 120, and the dry electrode 100 including the dry electrode film 110 may maintain a high energy density.

[0150] According to some example embodiments, the dry electrode film 110 may include electrode powder comprising an active material, a conductive material, and a binder. The dry electrode film 110 may have a sheet shape manufactured by calendering the electrode powder and having a given thickness, and in its sheet shape state has a yield strength of about 2.3 MPa or greater. The porosity of the dry electrode film 110 may be in the range of about 50% to about 70%. The internal friction angle of the electrode powder may be in the range of about 30° to about 50°. For example, the tensile strength of the dry electrode film may be in the range of about 0.5 MPa or greater.

[0151] According to some example embodiments, the electrode active material may include at least one of lithium nickel cobalt aluminum oxide (NCA), lithium iron phosphate (LFP), and graphite. However, this disclosure is not limited thereto.

[0152] The substrate 120 may include a material that does not cause chemical changes and has high electrical conductivity. For example, the substrate 120 may include at least one of copper, aluminum, stainless steel, nickel, polymer coated with a conductive material, titanium, sintered carbon, or combinations thereof.

[0153] In some example embodiments, the substrate 120 may be formed in the form of a metal foil or a thin metal sheet (such as at least one of copper, copper alloy, nickel, or nickel alloy). In other example embodiments, the substrate 120 may be formed in the form of a metal foil or a thin metal sheet (such as aluminum or aluminum alloy).

[0154] Although the present disclosure has been described above with reference to exemplary embodiments thereof, the present disclosure is not limited thereto. Various modifications and variations may be made by those skilled in the art within the spirit of the present disclosure and the equivalents of the appended claims.

[0155] Description of some figure references:

[0156] 510: Mold

[0157] 520: Electrode powder

[0158] 530: Pressure-applying component

[0159] 800: Sample

[0160] 900: Fixture

[0161] 910: Measuring equipment

Claims

1. A method for manufacturing a dry electrode film, the method comprising: Dry mixtures are prepared by dry mixing of active materials, conductive materials and binders; The mixture is formed into clumps by kneading the dry mixture; Electrode powder is obtained by crushing the mixture clumps; The electrode powder is used to manufacture a sample using a mold; Test the yield strength of the specimen; and When the test results of the yield strength meet the predetermined standard, a sheet-type dry electrode film with a given thickness is manufactured by calendering the electrode powder.

2. The method of claim 1, wherein manufacturing the sample using the electrode powder through the mold comprises: The electrode powder is filled into the mold; and The electrode powder filled in the mold is pressurized.

3. The method according to claim 2, wherein filling the mold with the electrode powder comprises: The electrode powder is filled into the mold such that the weight of the electrode powder filled into the mold is in the range of about 1 g to about 5 g.

4. The method of claim 2, wherein pressurizing the electrode powder filled in the mold comprises: The electrode powder is pressurized using a pressurizing component at a pressure ranging from about 10 MPa to about 100 MPa.

5. The method according to claim 1, wherein testing the yield strength of the specimen comprises: The sample was pressurized using a clamp until it was destroyed; Measure the load applied to the specimen when the specimen is damaged; and The yield strength of the specimen is calculated based on the measured load.

6. The method of claim 5, wherein calculating the yield strength of the specimen comprises: The yield strength of the specimen is calculated based on Equation 1; Equation 1: 。 7. The method of claim 6, further comprising, after calculating the yield strength of the specimen: When the yield strength calculated by Equation 1 is less than a given value, the electrode powder is crushed.

8. The method of claim 7, wherein the given value is equal to about 2.3 MPa.

9. The method of claim 6, further comprising, after calculating the yield strength of the specimen: Measure the internal friction angle of the electrode powder; and The tensile strength of the specimen was calculated using the internal friction angle.

10. The method of claim 9, wherein measuring the internal friction angle of the electrode powder comprises: The internal friction angle of the electrode powder was measured using a powder flowability evaluation method.

11. The method of claim 9, wherein calculating the tensile strength of the specimen comprises: The tensile strength of the specimen is calculated based on Equation 2; Equation 2: 。 12. The method of claim 11, further comprising: After calculating the tensile strength of the sample, if the tensile strength calculated by Equation 2 is less than a given value, the electrode powder is crushed.

13. The method of claim 12, wherein the given value is equal to about 0.5 MPa.

14. Dry electrode membrane, comprising: Electrode powder, comprising active material, conductive material, and binder, The electrode powder has a sheet shape manufactured by calendering and having a given thickness, and in the sheet shape state, the yield strength of the electrode powder is in the range of about 2.3 MPa or greater.

15. The dry electrode film according to claim 14, wherein the internal friction angle of the electrode powder is in the range of about 30° to about 50°.

16. The dry electrode membrane according to claim 14, wherein the tensile strength of the dry electrode membrane is in the range of about 0.5 MPa or greater.

17. The dry electrode membrane according to claim 14, wherein the porosity of the dry electrode membrane is in the range of about 50% to about 70%.

18. The dry electrode membrane according to claim 14, wherein the active material comprises at least one of lithium nickel cobalt aluminum oxide (NCA), lithium iron phosphate (LFP), and graphite.

19. The dry electrode membrane according to claim 14, wherein the binder comprises at least one of polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), and polyacrylonitrile (PAN).

20. Dry electrodes, including: substrate; and A dry electrode film according to any one of claims 14 to 19 on at least one surface of the substrate.

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