Electrode, lithium secondary battery, and method for manufacturing electrode

Abstract

The present invention relates to an electrode comprising an electrode current collector and an electrode active material layer positioned on the electrode current collector, wherein the electrode active material layer includes an electrode active material, a single-walled carbon nanotube structure, a first dispersant comprising a hydrogenated nitrile-based copolymer, and a second dispersant comprising a fluorine-based polymer, the average diameter of the single-walled carbon nanotube structure is 60-300 nm, and the interfacial resistance between the electrode active material layer and the electrode current collector, which is measured by multi-probe resistance (MP resistance) measurement method, is 0.43 Ω·cm2 or less.

Description

Electrode, lithium secondary battery and method for manufacturing electrode Cross-citation with related applications This application claims the benefit of priority to Korean Patent Application No. 10-2023-0159800, filed on November 17, 2023, the entire contents of which are incorporated herein by reference. Technical field The present invention relates to an electrode, a lithium secondary battery, and a method for manufacturing the electrode, and more specifically, to an electrode having excellent cell resistance characteristics and life characteristics, a lithium secondary battery, and a method for manufacturing the same. As the demand for and technological development of mobile devices increases, the demand for secondary batteries as an energy source is rapidly increasing. Among these secondary batteries, lithium secondary batteries with high energy density and voltage, long cycle life, and high self-discharge rate have been commercialized and are widely used. In addition, research is actively being conducted on methods for manufacturing electrodes with high energy density per unit volume by improving electrode density as electrodes for such high-capacity lithium secondary batteries. In general, high-density electrodes are formed by molding electrode active material particles having a size of several μm to several tens μm using a high-pressure press. However, during the molding process, the particles may be deformed and the space between the particles may be reduced, so that the electrolyte permeability is likely to deteriorate. In order to solve the above problems, a conductive material having excellent electrical conductivity and strength is used during the manufacture of the electrode. The conductive material is positioned between the electrode active materials, and even when going through a molding process, it maintains micropores between the active material particles, allowing the electrolyte to easily penetrate, and has excellent electrical conductivity, thereby reducing the resistance within the electrode. Among such conductive materials, the use of carbon nanotubes, which are fibrous carbon-based conductive materials that can further reduce the electrode resistance by forming an electrically conductive path within the electrode, is increasing. Carbon nanotubes, a type of fine carbon fiber, are tubular carbon fibers with a diameter of less than 1㎛. Due to their unique structure, they are expected to be applied and commercialized in various fields due to their high conductivity, tensile strength, and heat resistance. However, carbon nanotubes have the problem of low dispersibility and agglomeration due to the strong van der Waals attraction between them due to their high specific surface area. At this time, if the carbon nanotubes present in the electrode of a lithium secondary battery are not evenly distributed, a path through which current can flow is not formed locally within the electrode, which may lead to problems such as increased resistance within the battery or occurrence of a current concentration phenomenon, which may actually deteriorate the performance and safety of the battery. Therefore, there is a need for the development of an electrode that can realize high energy density using carbon nanotubes as a conductive material, while solving the problems of increased internal battery resistance and decreased battery performance due to the use of carbon nanotubes. The present invention is intended to solve the above problems, and to provide an electrode including a single-walled carbon nanotube structure having excellent output characteristics and lifespan characteristics while implementing high energy density and improving initial battery resistance characteristics, a lithium secondary battery, and a method for manufacturing the electrode. [1] The present invention comprises an electrode current collector and an electrode active material layer positioned on the electrode current collector, wherein the electrode active material layer comprises an electrode active material, a single-walled carbon nanotube structure, a first dispersant including a hydrogenated nitrile-based copolymer, and a second dispersant including a fluorine-based polymer, wherein the average diameter of the single-walled carbon nanotube structure is 60 nm to 300 nm, and the interfacial resistance of the electrode active material layer and the electrode current collector measured by a multi-probe resistance (MP resistance) measurement method is 0.43Ω cm. 2 Below, the electrode is provided. [2] The present invention provides an electrode in which the weight average molecular weight of the hydrogenated nitrile copolymer in the above [1] is 5,000 g / mol to 200,000 g / mol. [3] The present invention provides an electrode, wherein, in the above [1] or [2], the hydrogenated nitrile-based copolymer is a hydrogenated nitrile-based butadiene rubber. [4] The present invention provides an electrode, wherein in at least one of the above [1] to [3], the fluorine-based polymer is at least one selected from the group consisting of polyvinylidene fluoride (PVDF), and polyvinylidene fluoride-co-hexafluoropropylene (PVdF-HFP) copolymers. [5] The present invention provides an electrode, wherein in at least one of the above [1] to [4], the second dispersant contains a carboxylic acid, and the carboxylic acid is contained in an amount of 0.1 to 2.0 parts by weight based on 100 parts by weight of the second dispersant. [6] The present invention provides an electrode, wherein the weight average molecular weight of the second dispersant is 600,000 g / mol to 1,500,000 g / mol in at least one of the above [1] to [5]. [7] The present invention provides an electrode, wherein, in at least one of the above [1] to [6], the single-walled carbon nanotube structure is included in an amount of 0.001 wt% to 0.1 wt% based on the total weight of the electrode active material layer. [8] The present invention provides an electrode, wherein, in at least one of the above [1] to [7], the first dispersant is contained in an amount of 0.0001 wt% to 0.05 wt% based on the total weight of the electrode active material layer. [9] The present invention provides an electrode, wherein, in at least one of the above [1] to [8], the second dispersant is contained in an amount of 0.001 wt% to 0.25 wt% based on the total weight of the electrode active material layer.

[0010] The present invention provides a lithium secondary battery comprising a positive electrode; a negative electrode; an electrolyte and a separator, wherein at least one of the positive electrode and the negative electrode is an electrode according to any one of [1] to [9].

[0011] The present invention provides a method for manufacturing an electrode, comprising: a step (S1) of manufacturing a conductive dispersion comprising bundled single-walled carbon nanotubes, a first dispersant, a second dispersant, and a dispersion medium; and a step (S2) of applying an electrode slurry comprising the conductive dispersion and an electrode active material onto a current collector to manufacture an electrode comprising an electrode active material layer; wherein the first dispersant comprises a hydrogenated nitrile-based copolymer, the second dispersant comprises a fluorinated polymer, and the electrode active material layer comprises a single-walled carbon nanotube structure, the first dispersant, the second dispersant, and the electrode active material, wherein the single-walled carbon nanotube structure has an average diameter of 60 nm to 300 nm.

[0012] The present invention provides a method for manufacturing an electrode, wherein, in the above

[0011] , the step S1 comprises a step (S1-1) of manufacturing a first dispersion liquid containing a bundle-shaped single-walled carbon nanotube, a first dispersant, and a dispersion medium; and a step (S1-2) of manufacturing a conductive dispersion liquid by mixing a second dispersant into the first dispersion liquid.

[0013] The present invention provides a method for manufacturing an electrode, wherein, in the above

[0011] , the step S1 comprises: a step (S1-1) of manufacturing a first dispersion comprising a bundle-shaped single-walled carbon nanotube, a first dispersant, and a dispersion medium; a step (S1-2) of manufacturing a conductive dispersion by mixing a second dispersant with the first dispersion; and a step (S1-3) of passing the conductive dispersion through a high pressure homogenizer.

[0014] The present invention provides a method for manufacturing an electrode, wherein, in the above

[0012] or

[0013] , the first dispersion and the conductive dispersion are manufactured by mixing using an inline mixer.

[0015] The present invention provides a method for manufacturing an electrode, wherein in at least one of the above

[0012] to

[0014] , the step S1-1 includes a step of stirring the first dispersion at 500 rpm to 3,000 rpm for 15 to 60 minutes.

[0016] The present invention provides a method for manufacturing an electrode, wherein in at least one of the above

[0012] to

[0015] , the step S1-2 includes a step of stirring the conductive dispersion at 500 rpm to 3,000 rpm for 15 to 60 minutes.

[0017] The present invention provides a method for manufacturing an electrode, wherein in at least one of the above

[0012] to

[0016] , the step S1-3 includes a step of applying a pressure of 100 bar to 2,500 bar to the conductive dispersion liquid and introducing the conductive dispersion liquid into the inlet of a high-pressure homogenizer and passing it through a microchannel. An electrode according to the present invention comprises a single-walled carbon nanotube structure, a first dispersant including a hydrogenated nitrile-based copolymer, and a second dispersant including a fluorinated polymer, wherein the average diameter of the single-walled carbon nanotube structure satisfies a specific range, and at the same time, an interfacial resistance between an electrode active material layer and an electrode current collector satisfies a specific range. According to the present invention, when the average diameter of the single-walled carbon nanotube structure satisfies a specific range and the interfacial resistance between the electrode active material layer and the electrode current collector satisfies a specific range, high energy density can be realized while improving the dispersibility of the single-walled carbon nanotube and uniformly forming a conductive path within the electrode active material layer as a whole. Accordingly, the initial resistance characteristics of the battery can be improved, and thus the output characteristics and life characteristics of the battery can be enhanced. Hereinafter, the present invention will be described in more detail. The terms or words used in this specification and claims should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted as having meanings and concepts consistent with the technical idea of ​​the present invention, based on the principle that the inventor can appropriately define the concept of the term in order to explain his or her own invention in the best manner. The terminology used in this specification is for the purpose of describing exemplary embodiments only and is not intended to limit the invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this specification, it should be understood that the terms “include,” “comprising,” or “having” are intended to specify the presence of a feature, number, step, component, or combination thereof, but do not preclude the possibility of the presence or addition of one or more other features, numbers, steps, components, or combinations thereof. In the present invention, unless otherwise stated, the term 'bundle type single-walled carbon nanotube' refers to a single-walled carbon nanotube having a secondary shape in the form of a bundle in which a plurality of carbon nanotube units are arranged in a parallel manner with their longitudinal axes substantially in the same orientation, and in the present invention, refers to a single-walled carbon nanotube that has not undergone a dispersion process of a conductive agent. In general, the bundled single-walled carbon nanotube refers to a large aggregate having a diameter in the micron unit that has not undergone a dispersion process and does not have flexibility, and for example, it can refer to a single-walled carbon nanotube in the form of an aggregate bundle in which the average diameter of the aggregate is 1 ㎛ or more. In the present invention, the 'single-walled carbon nanotube structure' refers to a structure formed by combining a plurality of single-walled carbon nanotube units with each other, and means a structure in which the bundled carbon nanotubes are obtained through a dispersion process. More specifically, in the carbon nanotube structure, the single-walled carbon nanotube units are arranged in a parallel manner with their longitudinal axes substantially in the same orientation (the long axes of the units are combined in parallel to each other to form a flexible cylindrical structure), and accordingly, the carbon nanotube structure can be in the form of a rope or bundle having a diameter in the nanometer range. In the present invention, the 'single-walled carbon nanotube unit' means a single-walled carbon nanotube strand constituting the bundle-type single-walled carbon nanotube or single-walled carbon nanotube structure. In the present invention, the “average diameter of the single-walled carbon nanotube structure” can be measured from an image of an electrode including a carbon nanotube structure observed through a scanning electron microscope (SEM). Specifically, the average diameter of the single-walled carbon nanotube structure can be measured as an arithmetic mean value of the top 100 single-walled carbon nanotube structures and the bottom 100 single-walled carbon nanotube structures in order of increasing diameter by observing the electrode including the carbon nanotube structure through a scanning electron microscope. In the present invention, "D n " means the particle size at the point where the volume accumulation amount is n% in the volume accumulation particle size distribution of the target powder. That is, D 10 The particle diameter at the point where the volume accumulation is 10%, D 50 D is the particle diameter at the point where the volume accumulation is 50%. 90 D means the particle size at the point where the volume accumulation is 90%. n can be measured using a laser diffraction method. For example, the target powder (i.e., positive active material powder or porous carbon powder) is dispersed in a dispersion medium, introduced into a commercially available laser diffraction particle size measuring device (e.g., Microtrac MT 3000), and ultrasonic waves of about 28 kHz are irradiated at an output of 60 W, and then a volume cumulative particle size distribution graph is obtained, and then the particle size at the corresponding volume cumulative amount is measured using the volume cumulative particle size distribution graph. In the present invention, the “interfacial resistance of the electrode active material layer and the electrode collector measured by the Multi-Probe resistance (MP resistance) measuring method” may be measured using a Multi-Probe resistance measuring device (Manufacturer: Hioki, Product name: RM2510). Specifically, the “interfacial resistance of the electrode active material layer and the electrode collector measured by the Multi-Probe resistance (MP resistance) measuring method” may be obtained as an average value of the interfacial resistances of the electrode active material layer and the electrode collector obtained by evenly distributing several to several tens of voltage and current probes on the surface of the electrode active material layer, flowing a constant current on the surface of the electrode active material layer, and measuring the potential distribution generated on the surface. The electrode, lithium secondary battery and method for manufacturing the electrode according to the present invention include at least one of the following disclosed configurations, and may include any combination between technically possible configurations among the following configurations. Hereinafter, the present invention will be described in more detail. electrode According to one embodiment, an electrode according to the present invention includes an electrode current collector and an electrode active material layer positioned on the electrode current collector, wherein the electrode active material layer includes an electrode active material, a single-walled carbon nanotube structure, a first dispersant including a hydrogenated nitrile-based copolymer, and a second dispersant including a fluorinated polymer, wherein an average diameter of the single-walled carbon nanotube structure is 60 nm to 300 nm, and an interfacial resistance of the electrode active material layer and the electrode current collector measured by a multi-probe resistance (MP resistance) measurement method is 0.43 Ωcm or less. Recently, lithium secondary batteries have been attracting attention as batteries for electric vehicles, etc., and the energy density, output characteristics, and life characteristics of lithium secondary batteries are considered important performance characteristics. Among these, attempts are being made to increase the content of electrode active materials in the electrode active material layer in order to improve energy density. However, in order to increase the content of electrode active materials, the content of conductive material or binder must be reduced. Accordingly, there has been an attempt to apply single-walled carbon nanotubes as a conductive material with high electrical conductivity even at a low content. However, single-walled carbon nanotubes have a high surface area, so they easily aggregate with each other, preventing the formation of even conductive paths within the electrode, which in turn worsens the resistance characteristics of the battery, and thus reduces the output characteristics and lifespan characteristics of the battery. Therefore, the inventors of the present invention have conducted repeated studies to develop an electrode that does not cause a problem of deterioration in the resistance characteristics of a battery even when single-walled carbon nanotubes are applied, and as a result, an electrode active material layer includes a single-walled carbon nanotube structure, a first dispersant including a hydrogenated nitrile-based copolymer, and a second dispersant including a fluorinated polymer, and the average diameter of the single-walled carbon nanotube structure is 60 to 300 nm, and the interfacial resistance of the electrode active material layer and the electrode current collector measured by a multi-probe resistance measurement method is 0.43 Ω cm. 2 The present invention was completed by finding that when the electrode described below is applied to a battery, high energy density is achieved while improving the resistance characteristics of the entire battery, resulting in excellent output characteristics and excellent life characteristics. Specifically, when the electrode active material layer includes a first dispersant including a hydrogenated nitrile-based copolymer and a second dispersant including a fluorinated polymer together with a single-walled carbon nanotube structure, aggregation between single-walled carbon nanotubes can be suppressed, and the single-walled carbon nanotubes can be evenly dispersed in the electrode active material layer, so that a conductive path within the electrode can be formed evenly throughout. According to the inventors, even if the average diameter of the single-walled carbon nanotube structure satisfies 60 to 300 nm, the interfacial resistance of the electrode active material layer and the electrode current collector measured by the Multi-Probe resistance measurement method is 0.43 Ω cm. 2 If it exceeds , the single-walled carbon nanotube structures do not aggregate with each other, but the conductive network within the electrode is not uniformly formed throughout, so that the current may be concentrated in a specific area of ​​the interface between the current collector and the electrode active material layer, and thus the resistance characteristics of the battery cannot be sufficiently improved. Alternatively, if the interfacial resistance of the electrode active material layer and the electrode current collector measured by the Multi-Probe resistance measurement method is 0.43 Ω cm 2 Even if the average diameter of the single-walled carbon nanotube structure is less than 60 nm, the single-walled carbon nanotubes may not be sufficiently connected to each other, which may cause the electron movement path to be broken within the electrode active material layer and may cause them to aggregate with each other, thereby restricting the electron flow. In addition, if the average diameter of the single-walled carbon nanotube structure exceeds 300 nm, the flexibility may be reduced, making it difficult to distribute uniformly between the electrode active material particles, and may restrict the electron movement path. As a result, the resistance characteristics of the battery cannot be sufficiently improved. Hereinafter, each component of the present invention will be described in detail. The electrode includes an electrode current collector and an electrode active material layer positioned on the electrode current collector. Specifically, the electrode may include an electrode current collector; and an electrode active material layer positioned on one or both surfaces of the current collector. The above electrode current collector is not particularly limited as long as it has high conductivity without causing chemical changes in the battery. Specifically, the electrode current collector may include at least one selected from the group consisting of copper, stainless steel, aluminum, nickel, titanium, calcined carbon, and an aluminum-cadmium alloy, and specifically may include aluminum. The above electrode current collector may typically have a thickness of 3 to 500 μm. The electrode current collector may also form fine unevenness on the surface to strengthen the bonding strength of the electrode active material. For example, the electrode current collector may be used in various forms such as a film, a sheet, a foil, a net, a porous body, a foam, a non-woven fabric, etc. The electrode active material layer includes an electrode active material; a single-walled carbon nanotube structure; a first dispersant including a hydrogenated nitrile-based copolymer; and a second dispersant including a fluorinated polymer. The above electrode active material may be a positive electrode active material or negative electrode active material generally used in the relevant technical field, and its type is not particularly limited. For example, as a cathode active material, a lithium-transition metal composite oxide containing lithium and at least one transition metal composed of nickel, cobalt, manganese, and aluminum, which is a compound capable of reversible intercalation and deintercalation of lithium, can be used. More specifically, the lithium transition metal composite oxide is a lithium-manganese oxide (e.g., LiMnO 2 , LiMn 2 O 4 etc.), lithium-cobalt oxides (e.g., LiCoO 2 etc.), lithium-nickel oxides (e.g., LiNiO 2 etc.), lithium-nickel-manganese oxides (e.g., LiNi 1-Y Mn Y O 2 (Here, 0 <Y<1), LiMn 2-zNi z O 4 (wherein, 0<Z<2) etc.), lithium-nickel-cobalt oxides (e.g., LiNi 1-Y1 Co Y1 O 2 (Here, 0 <Y1<1) 등), 리튬-망간-코발트계 산화물(예를 들면, LiCo 1-Y2 Mn Y2 O 2 (Here, 0 <Y2<1), LiMn 2-z1 Co z1 O 4 (wherein, 0<Z1<2) etc.), lithium-nickel-manganese-cobalt oxides (e.g., Li(Ni p Co q Mn r1 )O 2 (Here, 0<p<1, 0<q<1, 0<r1<1, p+q+r1=1) or Li(Ni p1 Co q1 Mn r2 )O 4 (wherein, 0<p1<2, 0<q1<2, 0<r2<2, p1+q1+r2=2) etc.), or lithium-nickel-cobalt-transition metal(M) oxide (e.g., Li(Ni p2 Co q2 Mn r3 M S2 )O 2 (wherein, M is selected from the group consisting of Al, Fe, V, Cr, Ti, Ta, Mg and Mo, and p2, q2, r3 and s2 are atomic fractions of independent elements, 0<p2<1, 0<q2<1, 0<r3<1, 0<s2<1, p2+q2+r3+s2=1), etc.), and one or more compounds among these may be included. Among these, the lithium transition metal composite oxide is LiCoO in that it can increase the capacity characteristics and stability of the battery. 2 , LiMnO 2 , LiNiO 2 , lithium nickel-manganese-cobalt oxide (e.g., Li(Ni 0.6 Mn 0.2Co 0.2 )O 2 , Li(Ni 0.5 Mn 0.3 Co 0.2 )O 2 , Li(Ni 0.7 Mn 0.15 Co 0.15 )O 2 or Li(Ni 0.8 Mn 0.1 Co 0.1 )O 2 etc.), or lithium nickel cobalt aluminum oxide (e.g., Li(Ni 0.8 Co 0.15 Al 0.05 )O 2 etc.), and considering the remarkable improvement effect according to the control of the type and content ratio of the constituent elements forming the lithium transition metal composite oxide, the lithium transition metal composite oxide may be Li(Ni 0.6 Mn 0.2 Co 0.2 )O 2 , Li(Ni 0.5 Mn 0.3 Co 0.2 )O 2 , Li(Ni 0.7 Mn 0.15 Co 0.15 )O 2 or Li(Ni 0.8 Mn 0.1 Co 0.1 )O 2 and a mixture of any one or two or more of these may be used. Preferably, a lithium-nickel-manganese-cobalt-based oxide may be used as the positive electrode active material, and most preferably, a lithium-nickel-manganese-cobalt-based oxide represented by the following chemical formula 1 may be used. [Chemical Formula 1] Li 1+a (Ni x3 Co y3 Mn z3 M w3 )O 2 In the chemical formula 1 above, M is at least one doping element selected from W, Cu, Fe, V, Cr, Ti, Zr, Zn, Al, In, Ta, Y, La, Sr, Ga, Sc, Gd, Sm, Ca, Ce, Nb, Mg, B and Mo, and 1+a, x3, y3, z3 and w3 are atomic fractions of independent elements, respectively, and 0≤a≤0.2, 0.80≤x3<1, 0 <y3≤0.2, 0<z3≤0.2, 0≤w3≤0.1, x3+y3+z3+w3 =1이다. Meanwhile, as negative active materials, compounds capable of reversible intercalation and deintercalation of lithium are possible, and specific examples thereof include carbonaceous materials such as artificial graphite, natural graphite, graphitized carbon fiber, and amorphous carbon; metallic compounds capable of alloying with lithium, such as Si, Al, Sn, Pb, Zn, Bi, In, Mg, Ga, Cd, Si alloy, Sn alloy, or Al alloy; SiO β (0 < β < 2), SnO 2, a metal oxide capable of doping and dedoping lithium, such as vanadium oxide, lithium vanadium oxide; or a composite including the above-mentioned metallic compound and a carbonaceous material, such as a Si-C composite or a Sn-C composite, and any one or a mixture of two or more of these may be used. In addition, a metallic lithium thin film may be used as the negative electrode active material. In addition, both low-crystalline carbon and high-crystalline carbon may be used as the carbon material. Representative examples of low-crystallization carbon include soft carbon and hard carbon, and representative examples of high-crystallization carbon include amorphous, plate-like, flaky, spherical or fibrous natural or artificial graphite, Kish graphite, pyrolytic carbon, mesophase pitch-based carbon fiber, mesophase pitch microbeads, mesophase pitches, and high-temperature calcined carbon such as petroleum or coal tar pitch derived cokes. The electrode active material may be included in an amount of 80 wt% to 99 wt%, preferably 92 wt% to 99 wt%, and more preferably 94 wt% to 99 wt%, based on the total weight of the electrode active material layer. When the content of the electrode active material satisfies the above range, excellent energy density, electrode adhesion, and electrical conductivity can be realized. The above single-walled carbon nanotube structure can act as a conductive material that provides electrical conductivity by forming an electrically conductive path within an electrode active material layer. Carbon nanotubes are graphite sheets that have a cylindrical shape with a nano-sized diameter and an sp2 bonding structure, and exhibit the properties of a conductor or a semiconductor depending on the angle and structure at which the graphite sheets are rolled. Carbon nanotubes can be classified into single-walled carbon nanotubes (SWCNTs), double-walled carbon nanotubes (DWCNTs), and multi-walled carbon nanotubes (MWCNTs) depending on the number of bonds forming the wall. In the past, multi-walled carbon nanotubes (MWCNTs) with a large number of bonds forming the wall were used, but in this case, there was a problem that their conductivity decreased as the cycle progressed, and the length of the carbon nanotubes was relatively short, which was disadvantageous in securing conductivity between active materials. In addition, conventional electrodes including carbon nanotubes are generally manufactured by dispersing bundle type or entangled type carbon nanotubes (single-walled carbon nanotube units or multi-walled carbon nanotube units attached or entangled to each other) in a dispersion medium to manufacture a conductive dispersion, and then using the conductive dispersion. At this time, the carbon nanotubes are completely dispersed in the conventional conductive dispersion, and the conductive dispersion exists as a single-stranded carbon nanotube unit. In the conventional conductive dispersion, the carbon nanotube units are easily cut due to an excessive dispersion process, so that the carbon nanotube units have a shorter length than the initial length. In addition, the carbon nanotube units can be easily cut during the rolling process of the electrode. Additionally, there is a problem that the carbon nanotube units are cut due to a change in the volume of the electrode active material when the battery is operated. Accordingly, the conductivity of the electrode is reduced, and there is a problem that the input characteristics, output characteristics, and life characteristics of the battery are reduced. Moreover, in the case of multi-walled carbon nanotube units, the structural defects are high due to the mechanism of node growth (nodes exist due to defects occurring during the growth process, not in a smooth linear manner). Therefore, the multi-walled carbon nanotube units are more easily cut during the dispersion process, and the multi-walled carbon nanotube units cut short by π-π stacking by carbon of the units are easily aggregated with each other. Accordingly, it is difficult to be more uniformly dispersed and exist in the electrode slurry. Accordingly, in the case of the carbon nanotube structure included in the electrode of the present invention, since a plurality of single-walled carbon nanotube units are relatively long and maintain high crystallinity compared to multi-walled carbon nanotubes and are joined in a parallel manner, the length can be smoothly maintained without being cut even when the battery is operated, thereby maintaining the conductivity of the electrode. In addition, due to the high conductivity of the single-walled carbon nanotube units having high crystallinity, the conductivity of the electrode can be increased, so that the input characteristics, output characteristics, and life characteristics of the battery can be significantly improved. In addition, since the carbon nanotube structures within the electrode can be connected to each other to have a network structure, excessive volume change of the electrode active material can be suppressed while securing a strong conductive path, and desorption of the electrode active material can be suppressed, so that the electrode adhesion can be significantly improved. Specifically, the average diameter of the single-walled carbon nanotube structure is characterized by being 60 nm to 300 nm, preferably 100 nm to 200 nm, and more preferably 130 nm to 170 nm. The average diameter of the above single-walled carbon nanotube structure may vary depending on the dispersant used and the dispersion method applied, and depending on the average diameter, whether the conductive network connection path is densely formed when included in an electrode and how well the conductive network formed in this way is maintained can be determined. Specifically, when the average diameter is less than 60 nm, the diameter and length of the single-walled carbon nanotube structure are insufficient, so that it may be difficult to form a conductive network by connecting the single-walled carbon nanotube structures within the electrode, and the maintenance performance of the conductive network may also be poor. Accordingly, the electrical conductivity within the electrode may be reduced, which may cause a problem in that the cycle characteristics of the battery may be reduced. In addition, when the average diameter of the single-walled carbon nanotube structure is greater than 300 nm, the degree of securing the conductive network obtained relative to the amount introduced into the electrode may be minimal due to the aggregation of the single-walled carbon nanotube structure, and the flexibility of the single-walled carbon nanotube structure may be insufficient, so that the electrical network within the electrode may not be uniformly secured. Accordingly, the resistance within the electrode may not be improved, the electrical conductivity may be reduced, and problems may occur in the performance and stability of the battery. Therefore, when the average diameter of the single-walled carbon nanotube structure satisfies the range of 60 nm to 300 nm, the single-walled carbon nanotube structure has an appropriate size so that it can be uniformly distributed within the electrode, and a sufficient structure length can be secured so that a conductive path within the electrode can be efficiently formed, and the cell resistance can be effectively improved and the electrical conductivity can be sufficiently secured. Accordingly, even if the single-walled carbon nanotube structure is included in a small amount in the electrode, the electrical conductivity is excellent, so that the energy density of the electrode can be improved, so that the capacity characteristics can be improved, and the current concentration phenomenon can be improved so that the stability of the battery can be improved. The single-walled carbon nanotube structure may be included in an amount of 0.001 wt% to 0.1 wt% based on the total weight of the electrode active material layer. Specifically, the single-walled carbon nanotube structure may be included in an amount of 0.001 wt% or more, 0.003 wt% or more, 0.005 wt% or more, 0.008 wt% or more, 0.01 wt% or more, and 0.1 wt% or less, 0.08 wt% or less, 0.06 wt% or less, 0.04 wt% or less, 0.02 wt% or less, 0.015 wt% or less, or 0.012 wt% or less based on the total weight of the electrode active material layer. For example, the single-walled carbon nanotube structure may be included at 0.001 wt% to 0.1 wt%, preferably 0.003 wt% to 0.06 wt%, more preferably 0.005 wt% to 0.03 wt%, and even more preferably 0.007 wt% to 0.015 wt%. When the above range is satisfied, the viscosity of the conductive dispersion and the electrode slurry can be prevented from becoming excessively high during the electrode manufacturing process, and the single-walled carbon nanotube structure is appropriately dispersed within the electrode active material layer, thereby securing sufficient conductivity and improving the battery energy density. The above first dispersant comprises a hydrogenated nitrile copolymer. The above hydrogenated nitrile copolymer plays a role in enabling the bundle-type single-walled carbon nanotubes to be evenly dispersed as a single-walled carbon nanotube structure without agglomerating into bundle lumps in the conductive dispersion during the dispersion process. Specifically, the bundle-type single-walled carbon nanotubes have a problem in that they cannot be dispersed in the solvent but rather agglomerate due to their poor affinity with organic solvents. Accordingly, the present invention includes a hydrogenated nitrile copolymer having a high affinity for the bundle-type single-walled carbon nanotubes in an electrode active material layer, thereby enhancing the wetting of the bundle-type single-walled carbon nanotubes with respect to the solvent during the dispersion process, and thus the bundle-type single-walled carbon nanotubes can be smoothly dispersed into a single-walled carbon nanotube structure having an average diameter according to the present invention. The above hydrogenated nitrile-based copolymer may include a copolymer including an α,β-unsaturated nitrile-derived structural unit and a hydrogenated conjugated diene-derived structural unit, or may include a copolymer including an α,β-unsaturated nitrile-derived structural unit, a conjugated diene-derived structural unit, and a hydrogenated conjugated diene-derived structural unit. Specifically, the hydrogenated nitrile-based copolymer may be a hydrogenated nitrile-based copolymer in which all of the conjugated diene-derived structural units are hydrogenated and no conjugated diene-derived structural units are included, or alternatively, may be a partially hydrogenated nitrile-based copolymer in which a part of the conjugated diene-derived structural units are hydrogenated and the hydrogenated conjugated diene-derived structural units are included together with the conjugated diene-derived structural units. The above hydrogenated nitrile-based copolymer may be a hydrogenated nitrile-based butadiene rubber (HNBR), specifically a hydrogenated acrylonitrile-butadiene rubber, more specifically a partially hydrogenated acrylonitrile-butadiene rubber. The above method for hydrogenating the conjugated diene can be performed through a hydrogenation reaction known in the art, for example, a catalytic hydrogenation reaction using a catalyst system such as Rh, Ru, Pd, or Ir, and the hydrogenation rate can be controlled by controlling the amount of the catalyst, the reaction hydrogen pressure, the reaction time, etc. The above hydrogenated nitrile copolymer can be produced by copolymerizing an α,β-unsaturated nitrile monomer and a conjugated diene monomer, and then hydrogenating the C=C double bond in the copolymer. The polymerization reaction and hydrogenation process of the above monomers can be performed according to a conventional method. As the above α, β-unsaturated nitrile monomer, for example, acrylonitrile or methacrylonitrile may be used, and one kind alone or a mixture of two or more kinds thereof may be used. As the above conjugated diene monomer, for example, conjugated diene monomers having 4 to 6 carbon atoms, such as 1,3-butadiene, isoprene or 2,3-methyl butadiene may be used, and one kind alone or a mixture of two or more kinds thereof may be used. The above α, β-unsaturated nitrile-derived structural unit may be included in the hydrogenated nitrile-based copolymer at 20 wt% to 50 wt%, and specifically, may be included at 30 wt% to 40 wt%. When the above range is satisfied, the affinity between the hydrogenated nitrile-based copolymer and the dispersion medium is at an appropriate level, so it is effective in producing a conductive dispersion liquid during the electrode manufacturing process. The weight average molecular weight of the above-mentioned hydrogenated nitrile-based copolymer may be 5,000 g / mol to 200,000 g / mol, preferably 15,000 g / mol to 100,000 g / mol, more preferably 20,000 g / mol to 70,000 g / mol, and even more preferably 25,000 g / mol to 45,000 g / mol. When the above-mentioned weight average molecular weight range is satisfied, the hydrogenated nitrile-based copolymer can easily penetrate between the single-walled carbon nanotube units in the bundle-type single-walled carbon nanotubes, so that the bundle-type single-walled carbon nanotubes can be appropriately dispersed as a single-walled carbon nanotube structure, and the phase stability of the conductive dispersion can be improved during the electrode manufacturing process. The first dispersant may be included in an amount of 0.0001 wt% to 0.05 wt% based on the total weight of the electrode active material layer. For example, the first dispersant may be included in an amount of 0.0001 wt% or more, 0.0002 wt% or more, 0.0003 wt% or more, 0.0004 wt% or more, 0.0005 wt% or more, 0.0006 wt% or more, 0.0007 wt% or more, 0.0008 wt% or more, 0.0009 wt% or more, 0.001 wt% or more, and 0.05 wt% or less, 0.04 wt% or less, 0.03 wt% or less, 0.02 wt% or less, 0.01 wt% or less, 0.009 wt% or less, 0.008 wt% or less, 0.007 wt% or less, 0.006 wt% or less, 0.005 wt% or less, 0.004 wt% or less, 0.003 wt% or less, based on the total weight of the electrode active material layer. Hereinafter, it may be included up to 0.002 wt%. For example, the first dispersant may be included in an amount of 0.0001 wt% to 0.05 wt%, preferably 0.0003 wt% to 0.02 wt%, 0.0005 wt% to 0.01 wt%, and more preferably 0.0007 wt% to 0.002 wt%, based on the total weight of the electrode active material layer. When the first dispersant is included in an amount exceeding 0.05 wt% based on the total weight of the electrode active material layer, the viscosity of the conductive material dispersion excessively increases in the dispersion process, and when it is included in an amount less than 0.0001 wt%, the bundled carbon nanotubes are not effectively dispersed in the conductive material dispersion, which may cause agglomeration of the conductive material. Therefore, when the first dispersion is included in the above range, bundled carbon nanotubes can be effectively dispersed in the dispersion process, so that the average diameter of the single-walled carbon nanotube structure obtained in the dispersion process can be appropriately controlled, and shear force can be effectively transmitted in the dispersion process. In addition, gelation due to compatibility between the binder and the hydrogenated nitrile-based butadiene copolymer can be prevented, so that the output and life characteristics of the battery can be improved. The above second dispersant contains a fluorinated polymer. When a hydrogenated nitrile copolymer is used alone as a conductive dispersant in the electrode active material layer, the viscosity of the conductive dispersion may change significantly over time during the dispersion process, which may cause a problem of quality deterioration during distribution. Accordingly, the present invention includes a second dispersant containing a fluorinated polymer in the electrode active material layer together with the first dispersant, thereby preventing aggregation of bundled single-walled carbon nanotubes and single-walled carbon nanotube structures during the dispersion process and electrode manufacturing process due to the nonpolar nature of the fluorine element contained in the fluorinated polymer and the repulsive effect of the unshared electron pair. The above fluorinated polymer may be at least one selected from the group consisting of polyvinylidene fluoride (PVDF), and polyvinylidene fluoride-co-hexafluoropropylene (PVdF-HFP) copolymers, and preferably polyvinylidene fluoride. In this case, there is an advantage in that it has excellent affinity for a solvent compared to other fluorinated polymers, and thus can be added to a conductive material dispersion as a solution in a process. The second dispersant may contain carboxylic acid. The carboxylic acid may be contained in an amount of 0.1 to 2.0 parts by weight, preferably 0.5 to 1.8 parts by weight, and more preferably 0.7 to 1.4 parts by weight, based on 100 parts by weight of the second dispersant. When the carboxylic acid is contained within the above range, the affinity between the second dispersant and the solvent may be further increased due to the polar functional group contained in the carboxylic acid. The weight average molecular weight of the second dispersant may be 600,000 g / mol to 1,500,000 g / mol, preferably 700,000 g / mol to 1,300,000 g / mol, and more preferably 850,000 g / mol to 1,150,000 g / mol. When the weight average molecular weight is less than 600,000 g / mol, the steric resistance effect of the second dispersant is greatly reduced, and when it is greater than 1,500,000 g / mol, the solvent affinity of the second dispersant is reduced, which has a disadvantage in that it is difficult to process in a solution phase in a dispersion process. Therefore, when the above range is satisfied, the aggregation between conductive materials can be suppressed due to the steric resistance, while the solvent affinity of the second dispersant is excellent, making it easy to handle in the process. The second dispersant may be included in an amount of 0.001 wt% to 0.25 wt% based on the total weight of the electrode active material layer. Specifically, the second dispersant may be included in an amount of 0.001 wt% or more, 0.003 wt% or more, 0.005 wt% or more, 0.007 wt% or more, 0.009 wt% or more, 0.01 wt% or more, 0.012 wt% or more, 0.014 wt% or more, 0.016 wt% or more, 0.018 wt% or more, and 0.25 wt% or less, 0.23 wt% or less, 0.21 wt% or less, 0.2 wt% or less, 0.19 wt% or less, 0.17 wt% or less, 0.15 wt% or less, 0.13 wt% or less, 0.11 wt% or less, 0.1 wt% or less, 0.08 wt% or less, 0.06 wt% or less, 0.04 wt% or less, 0.02 wt% or less, based on the total weight of the electrode active material layer. It may be included at 0.019 wt% or less. For example, the second dispersant may be included at 0.001 wt% to 0.25 wt%, preferably 0.01 wt% to 0.15 wt%, more preferably 0.012 wt% to 0.05 wt%, and even more preferably 0.016 wt% to 0.02 wt%, based on the total weight of the electrode active material layer. When the above range is satisfied, the single-walled carbon nanotube structure, which is a conductive material, can be sufficiently dispersed in the conductive material dispersion and the electrode active material layer, while preventing the viscosity of the conductive material dispersion and electrode slurry from excessively increasing during the electrode manufacturing process. The above electrode active material layer may optionally further include a binder. The above binder is intended to secure adhesion between electrode active materials or between the electrode active materials and the electrode current collector, and general binders used in the relevant technical field can be used, and the type thereof is not particularly limited. Examples of the binder include polyvinylidene fluoride (PVDF), vinylidene fluoride-hexafluoropropylene copolymer (PVDFco-HFP), polyvinyl alcohol, polyacrylonitrile, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinyl pyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene polymer (EPDM), sulfonated-EPDM, styrene-butadiene rubber (SBR), fluororubber, or various copolymers thereof, and one type alone or a mixture of two or more types thereof may be used. The above binder may be included in an amount of 5 wt% or less based on the total weight of the electrode active material layer, preferably 0.5 wt% to 3 wt%, more preferably 1 wt% to 2 wt%. When the content of the binder satisfies the above range, excellent electrode adhesion can be implemented while minimizing an increase in electrode resistance. The interfacial resistance between the electrode active material layer and the electrode current collector measured by the Multi-Probe resistance (MP resistance) measurement method was 0.43Ω cm. 2Below. The interfacial resistance of the electrode active material layer and the electrode current collector measured by the above Multi-Probe resistance (MP resistance) measuring method can be controlled by the type and content of the first dispersant and the second dispersant, the content and average diameter of the single-walled carbon nanotubes, etc. The inventors of the present invention have found that even if a single-walled carbon nanotube structure having an average diameter of a specific range is included in the electrode, the dispersibility of the conductive material is improved, but when the interfacial resistance of the electrode active material layer and the electrode current collector does not satisfy the above range, the conductive path within the electrode is not formed evenly overall, so that the resistance of the battery is not sufficiently improved. Specifically, the interfacial resistance between the electrode active material layer and the electrode current collector measured by the Multi-Probe resistance (MP resistance) measurement method was 0.43Ω·cm. 2 Below, 0.4 Ω cm 2 Below, 0.38Ω·cm 2 Below, 0.35Ω cm 2 Below, 0.33Ω·cm 2 Below, 0.32Ω·cm 2 Below, 0.3Ω·cm 2 Below, 0.28Ω·cm 2 Below, 0.27Ω·cm 2 Below, 0.25Ω·cm 2 Below, 0.24Ω·cm 2 Below, 0.23Ω·cm 2 Below, 0.2Ω·cm 2 Below, 0.18Ω·cm 2 Below, 0.15Ω·cm 2 Below, 0.13Ω·cm 2 Below, 0.1Ω·cm 2 Below, 0.09Ω cm 2 Below, 0.08Ω·cm 2 Below, 0.01Ω·cm 2 Above, 0.05Ω cm 2 Above, 0.07Ω cm 2 Above, 0.1Ω·cm 2 Above, 0.13Ω cm 2 Above, 0.15Ω cm 2Above, 0.17Ω cm 2 Above, 0.2Ωcm 2 Above, 0.23Ω cm 2 Above, 0.25Ω cm 2 Above, 0.27Ω cm 2 Above, 0.3Ω·cm 2 Above, 0.32Ω cm 2 It may be abnormal. For example, the interfacial resistance of the electrode active material layer and the electrode current collector measured by the Multi-Probe resistance (MP resistance) measurement method is 0.43Ω·cm. 2 Below, preferably 0.01Ω·cm 2 Within 0.43Ω cm 2 , more preferably 0.07Ω·cm 2 Within 0.4Ω cm 2 , more preferably 0.1Ω·cm 2 Within 0.38Ω cm 2 , more preferably 0.2Ω·cm 2 Within 0.38Ω cm 2 , more preferably 0.3Ω·cm 2 Within 0.38Ω cm 2 If the above range is satisfied, the initial resistance characteristics of the battery can be improved, so that the life characteristics and output characteristics of the battery can be excellent. Method for manufacturing electrodes According to another embodiment of the present invention, a method for manufacturing an electrode comprises the steps of: (S1) manufacturing a conductive dispersion comprising bundled single-walled carbon nanotubes, a first dispersant, a second dispersant, and a dispersion medium; and (S2) applying an electrode slurry comprising the conductive dispersion and an electrode active material onto a current collector to manufacture an electrode comprising an electrode active material layer, wherein the first dispersant comprises a hydrogenated nitrile-based copolymer, the second dispersant comprises a fluorinated polymer, and the electrode active material layer comprises a single-walled carbon nanotube structure, the first dispersant, the second dispersant, and the electrode active material, wherein the single-walled carbon nanotube structure has an average diameter of 60 nm to 300 nm. (1) S1 step: Preparation of challenge dispersion solution A conductive dispersion solution containing bundled single-walled carbon nanotubes, a first dispersant, a second dispersant, and a dispersion medium is prepared. In the step S1, the bundled single-walled carbon nanotubes can be dispersed into single-walled carbon nanotube structures having an appropriate average diameter, and the single-walled carbon nanotube structures can be uniformly distributed in the conductive dispersion solution. The step S1 may include a step (S1-1) of preparing a first dispersion comprising bundle-shaped single-walled carbon nanotubes, a first dispersant, and a dispersion medium; and a step (S1-2) of preparing a conductive dispersion by mixing a second dispersant with the first dispersion; and the step S1 may include a step (S1-1) of preparing a first dispersion comprising bundle-shaped single-walled carbon nanotubes, a first dispersant, and a dispersion medium; a step (S1-2) of preparing a conductive dispersion by mixing a second dispersant with the first dispersion; and a step (S1-3) of passing the conductive dispersion through a high pressure homogenizer. When the above step S1 is performed by subdividing into the steps S1-1, S1-2, and / or S1-3, it is very easy to obtain a single-walled carbon nanotube structure having an appropriate average diameter, and the single-walled carbon nanotube structure can be more uniformly distributed within the conductive dispersion, so that the initial resistance characteristics, output characteristics, and life characteristics of an electrode and battery using the conductive dispersion manufactured through the above process can be improved. First, a step (S1-1) of preparing a first dispersion liquid including bundle-shaped single-walled carbon nanotubes, a first dispersant, and a dispersion medium can be performed. According to the above step S1-1, by first preparing a first dispersion solution containing only a first dispersant, bundle-shaped single-walled carbon nanotubes, and a dispersion medium before adding a second dispersant to the conductive dispersion solution, the wetting properties of the bundle-shaped single-walled carbon nanotubes with respect to the dispersion medium can be improved by the first dispersant, and thus the bundle-shaped single-walled carbon nanotubes can have a high affinity for the dispersion medium, thereby enabling the bundle-shaped single-walled carbon nanotubes to be dispersed more smoothly in step S1-2 described below. The step (S1-1) of preparing the first dispersion can be performed as a wetting process that evenly mixes each component. The step (S1-1) of preparing the first dispersion may include a step of stirring at 500 rpm to 3,000 rpm, preferably 1,200 rpm to 2,800 rpm, and more preferably 2,000 rpm to 2,600 rpm. In addition, the step (S1-1) of preparing the first dispersion may include a step of stirring for 15 minutes to 60 minutes, preferably 20 minutes to 50 minutes, and more preferably 20 minutes to 40 minutes. When the above range is satisfied, the bundle-shaped single-walled carbon nanotubes and the first dispersant are sufficiently mixed, thereby improving the wetting properties for the dispersion medium. Specifically, the step (S1-1) of preparing the first dispersion liquid can be performed using a conventional mixing method, for example, a mixing device such as an inline mixer, a homogenizer, a bead mill, a ball mill, a basket mill, an attrition mill, a universal stirrer, a clear mixer, a spike mill, or a TK mixer, and preferably, the first dispersion liquid can be prepared by mixing using an inline mixer. At this time, the mixing order of each component is not particularly limited. That is, the first dispersion may be formed by adding bundle-type single-walled carbon nanotubes to a dispersion medium and then adding a first dispersant and mixing, or may be formed by first adding the first dispersant to the dispersion medium and then mixing the bundle-type single-walled carbon nanotube structure, or may be formed by adding the first dispersant and bundle-type single-walled carbon nanotubes together to the dispersion medium and then mixing. The above first dispersant comprises a hydrogenated nitrile copolymer. Since the content of the above first dispersant is the same as described above, a detailed description is omitted. The above dispersion medium can serve as a medium for dispersing bundle-shaped single-walled carbon nanotubes into a single-walled carbon nanotube structure. The above dispersion medium can be an organic solvent, and for example, an amide organic solvent such as dimethylformamide (DMF), diethyl formamide, dimethyl acetamide (DMAc), N-methyl pyrrolidone (NMP); alcohols such as methanol, ethanol, 1-propanol, 2-propanol (isopropyl alcohol), 1-butanol (n-butanol), 2-methyl-1-propanol (isobutanol), 2-butanol (sec-butanol), 1-methyl-2-propanol (tert-butanol), pentanol, hexanol, heptanol, or octanol; glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,5-pentanediol, or hexylene glycol; Examples thereof include polyhydric alcohols such as glycerin, trimethylolpropane, pentaerythritol, or sorbitol; glycol ethers such as ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, tetraethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, triethylene glycol monoethyl ether, tetraethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, or tetraethylene glycol monobutyl ether; ketones such as acetone, methyl ethyl ketone, methyl propyl ketone, or cyclopentanone; and esters such as ethyl acetate, γ-butyl lactone, and ε-propiolactone, and the like may be any one of these or a mixture of two or more thereof. Preferably, the solvent may be an amide-based organic solvent such as dimethylformamide (DMF), diethyl formamide, dimethyl acetamide (DMAc), N-methyl pyrrolidone (NMP), and more preferably, the dispersion medium may be N-methyl pyrrolidone. When the first dispersion is prepared through the above step S1-1, a step (step S1-2) of preparing a conductive dispersion by mixing a second dispersant into the first dispersion can be performed. The method for manufacturing an electrode according to the present invention further comprises mixing a second dispersant containing a fluorinated polymer into the first dispersion prepared through step S1-1, thereby enabling the distance between single-walled carbon nanotube units within bundled single-walled carbon nanotubes, whose wetting characteristics and affinity for a dispersion medium are improved by the first dispersant, to be widened more smoothly by using the second dispersant. The step of mixing the second dispersant into the first dispersion can be performed as a wetting process to evenly mix each component. The step of mixing a second dispersant into the first dispersion may include a step of stirring at 500 rpm to 3,000 rpm, preferably 1,200 rpm to 2,800 rpm, and more preferably 2,000 rpm to 2,600 rpm. In addition, the step of mixing a second dispersant into the first dispersion may include a step of stirring for 15 minutes to 60 minutes, preferably 20 minutes to 50 minutes, and more preferably 20 minutes to 40 minutes. When the above range is satisfied, the distance between single-walled carbon nanotube units in the bundled single-walled carbon nanotubes can be widened more smoothly by the second dispersant, the viscosity of the conductive dispersion may not be excessively high, and when the S1-3 step is performed, the particle size of the conductive dispersion may be smaller than the diameter of the microchannel of the high-pressure homogenizer, so that the conductive dispersion can smoothly pass through the microchannel. Specifically, the step of mixing the second dispersant into the first dispersion can be performed using a conventional mixing method, for example, a mixing device such as an inline mixer, a homogenizer, a bead mill, a ball mill, a basket mill, an attrition mill, a universal stirrer, a clear mixer, a spike mill, or a TK mixer, and preferably, the mixing can be performed using an inline mixer. The second dispersant may include a fluorinated polymer. Since the second dispersant is the same as described above, a detailed description is omitted. Next, when the conductive dispersion is manufactured through the above step S1-2, a step (step S1-3) of passing the conductive dispersion through a high pressure homogenizer can be performed. The conductive dispersion of the above step S2 can be the conductive dispersion that has performed the above step S1-3. As the above-described conductive dispersion is passed through a high-pressure homogenizer, the conductive dispersion is subjected to a shear force so that the bundles of the bundle-shaped single-walled carbon nanotube structures are further pulverized, and a conductive dispersion including single-walled carbon nanotube structures having a smaller average diameter can be obtained. At this time, the high pressure homogenizer may include an inlet, an outlet, and a microchannel connecting the inlet and the outlet. Specifically, the step of passing the conductive dispersion through a high-pressure homogenizer may include the step of introducing the conductive dispersion into an inlet of the high-pressure homogenizer and passing it through a microchannel. Accordingly, as the conductive dispersion passes through the microchannel, it receives a shear force so that bundles of bundle-shaped single-walled carbon nanotube structures are pulverized, and the conductive dispersion may include single-walled carbon nanotube structures having a smaller average diameter. The above microchannel may have a diameter of 50 ㎛ to 800 ㎛, preferably 100 ㎛ to 700 ㎛, more preferably 200 ㎛ to 600 ㎛. In addition, the conductive dispersion may be introduced into the inlet of a high-pressure homogenizer by applying a pressure of 100 bar to 2,500 bar, preferably 500 bar to 2,000 bar, more preferably 1,000 bar to 1,700 bar, and may pass through the microchannel. The conductive dispersion that has passed through the high-pressure homogenizer in the above step S1-3 may include a single-walled carbon nanotube structure, a first dispersant, and a second dispersant. (2) S2 step: Electrode manufacturing step A step (step S2) of manufacturing an electrode including an electrode active material layer by applying an electrode slurry including a conductive dispersion and an electrode active material manufactured through the above step S1 onto a current collector is performed. Specifically, the electrode can be manufactured by applying the electrode slurry containing the conductive dispersion and the electrode active material onto a current collector, drying it, and then rolling it to form an electrode active material layer. Alternatively, the electrode slurry can be applied onto a separate support, and then the film obtained by peeling it off from the support is laminated onto a current collector. The above application can be performed continuously or discontinuously using various application methods well known in the art, such as slot die coating, slide coating, curtain coating, etc. The drying serves to dry the solvent included in the applied electrode slurry, leaving only the solid content in the slurry. The drying can be performed at 40°C to 180°C, preferably 50°C to 140°C, more preferably 60°C to 120°C, and even more preferably 70°C to 110°C. The above rolling serves to compress the electrode to a desired thickness in order to increase the energy density of the electrode and to increase the adhesion between the current collector and the electrode active material. The above rolling can be performed by a roll press method in which the thickness of the anode is adjusted by adjusting the upper / lower gap of the rolls, but is not limited thereto. The above electrode slurry includes a conductive dispersion and an electrode active material. Specifically, the electrode slurry may include a conductive dispersion, an electrode active material, a binder, and a solvent. Since the above-mentioned conductive dispersion, electrode active material, and binder are the same as those described above, a detailed description is omitted. The above solvent may be included in the electrode slurry for viscosity control, etc. At this time, the solvent may be water, an organic solvent, or a mixture thereof. Examples of the organic solvent include amide-based polar organic solvents such as dimethylformamide (DMF), diethyl formamide, dimethyl acetamide (DMAc), N-methyl pyrrolidone (NMP); alcohols such as methanol, ethanol, 1-propanol, 2-propanol (isopropyl alcohol), 1-butanol (n-butanol), 2-methyl-1-propanol (isobutanol), 2-butanol (sec-butanol), 1-methyl-2-propanol (tert-butanol), pentanol, hexanol, heptanol, or octanol; glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,5-pentanediol, or hexylene glycol; Examples thereof include polyhydric alcohols such as glycerin, trimethylolpropane, pentaerythritol, or sorbitol; glycol ethers such as ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, tetraethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, triethylene glycol monoethyl ether, tetraethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, or tetraethylene glycol monobutyl ether; ketones such as acetone, methyl ethyl ketone, methyl propyl ketone, or cyclopentanone; and esters such as ethyl acetate, γ-butyl lactone, and ε-propiolactone, and the like can be used as one or a mixture of two or more thereof, but are not limited thereto. The solvent may be included in an amount such that the solid content in the electrode slurry is 60 to 85 wt%, preferably 65 to 80 wt%. When the above range is satisfied, binder migration can be suppressed, thereby improving electrode adhesion, the drying temperature can be lowered, thereby improving coatability, and the coating speed can be increased, thereby improving productivity. Since the above-mentioned entire body is the same as described above, a detailed description is omitted. The electrode manufactured as described above includes an electrode active material layer, and specifically includes a current collector and an electrode active material layer positioned on one or both surfaces of the current collector. The above electrode active material layer may include a single-walled carbon nanotube structure, a first dispersant, a second dispersant, and an electrode active material, and may additionally include a binder. The average bundle diameter of the single-walled carbon nanotube structure included in the electrode active material layer manufactured as described above is 60 nm to 300 nm, preferably 100 nm to 200 nm, more preferably 130 nm to 170 nm. The method for manufacturing an electrode according to the present invention comprises a series of processes in which a first dispersion is first mixed to improve the wetting properties of bundle-type single-walled carbon nanotubes for a dispersion medium by a hydrogenated nitrile-based copolymer, and then a second dispersant including a fluorinated polymer is used to increase the distance between single-walled carbon nanotube units in the bundle-type single-walled carbon nanotubes, and then the second dispersion is passed through a high-pressure homogenizer to manufacture a conductive dispersion, thereby evenly dispersing bundle-type single-walled carbon nanotubes into a single-walled carbon nanotube structure more effectively. That is, the method for manufacturing an electrode according to the present invention appropriately controls conditions such as the combination and physical properties of the bundle-type single-walled carbon nanotubes, the first dispersant, and the second dispersant, and the mixing order of the dispersants, so that the obtained single-walled carbon nanotube structure satisfies an appropriate average diameter range, so that the single-walled carbon nanotube structure can be uniformly dispersed in the conductive dispersion, and in an electrode manufactured using the conductive dispersion, the single-walled carbon nanotube structure can be uniformly dispersed to sufficiently secure an electrically conductive path. Specifically, when the average diameter of the single-walled carbon nanotube structure is smaller than 60 nm, the diameter and length of the single-walled carbon nanotube structure are insufficient to secure a sufficient electrical conductive path within the electrode, which may cause a problem of reduced electrical conductivity. When the average diameter of the single-walled carbon nanotube structure is larger than 300 nm, the single-walled carbon nanotube structures may excessively aggregate with each other, thereby reducing dispersibility, and as a result, the resistance within the electrode may not be improved, the electrical conductivity may be reduced, and problems may occur with the performance and stability of the battery. Therefore, when the average diameter of the single-walled carbon nanotube structure satisfies the range of 60 nm to 300 nm, the single-walled carbon nanotube structure has an appropriate size so as to sufficiently form an electrically conductive path inside the electrode, and the single-walled carbon nanotube structure can be evenly dispersed inside the electrode without agglomeration, so that the improvement of battery resistance is effective and electrical conductivity can be sufficiently secured. Accordingly, even if the single-walled carbon nanotube structure is included in a relatively small content in the electrode, the electrical conductivity is excellent, so that the energy density of the electrode can be improved, so that the capacity characteristics can be improved, and the current concentration phenomenon can be improved, so that the stability of the battery can be improved. In addition, the interfacial resistance of the electrode active material layer and the electrode current collector measured by the Multi-Probe resistance (MP resistance) measurement method in the electrode manufactured as described above was 0.43Ω·cm. 2 Below. The interfacial resistance of the electrode active material layer and the electrode current collector measured by the above Multi-Probe resistance (MP resistance) measuring method can be controlled by the type and content of the first dispersant and the second dispersant, the content and average diameter of the single-walled carbon nanotubes, etc. The inventors of the present invention have found that even if a single-walled carbon nanotube structure having an average diameter of a specific range is included in the electrode, the dispersibility of the conductive material is improved, but when the interfacial resistance of the electrode active material layer and the electrode current collector does not satisfy the above range, the conductive path within the electrode is not formed evenly overall, so that the resistance of the battery is not sufficiently improved. Specifically, the interfacial resistance between the electrode active material layer and the electrode current collector measured by the Multi-Probe resistance (MP resistance) measurement method was 0.43Ω·cm. 2 Below, 0.4 Ω cm 2 Below, 0.38Ω·cm 2 Below, 0.35Ω cm 2 Below, 0.33Ω·cm 2 Below, 0.32Ω·cm 2Below, 0.3Ω·cm 2 Below, 0.28Ω·cm 2 Below, 0.27Ω·cm 2 Below, 0.25Ω·cm 2 Below, 0.24Ω·cm 2 Below, 0.23Ω·cm 2 Below, 0.2Ω·cm 2 Below, 0.18Ω·cm 2 Below, 0.15Ω·cm 2 Below, 0.13Ω·cm 2 Below, 0.1Ω·cm 2 Below, 0.09Ω cm 2 Below, 0.08Ω·cm 2 Below, 0.01Ω·cm 2 Above, 0.05Ω cm 2 Above, 0.07Ω cm 2 Above, 0.1Ω·cm 2 Above, 0.13Ω cm 2 Above, 0.15Ω cm 2 Above, 0.17Ω cm 2 Above, 0.2Ωcm 2 Above, 0.23Ω cm 2 Above, 0.25Ω cm 2 Above, 0.27Ω cm 2 Above, 0.3Ω·cm 2 Above, 0.32Ω cm 2 It may be abnormal. For example, the interfacial resistance of the electrode active material layer and the electrode current collector measured by the Multi-Probe resistance (MP resistance) measurement method is 0.43Ω·cm. 2 Below, preferably 0.01Ω·cm 2 Within 0.43Ω cm 2 , more preferably 0.07Ω·cm 2 Within 0.4Ω cm 2 , more preferably 0.1Ω·cm 2 Within 0.38Ω cm 2 , more preferably 0.2Ω·cm 2 Within 0.38Ω cm 2 , more preferably 0.3Ω·cm 2Within 0.38Ω cm 2 If the above range is satisfied, the initial resistance characteristics of the battery can be improved, so that the life characteristics and output characteristics of the battery can be excellent. In addition, since the single-walled carbon nanotube structure is the same as described above for the electrode, a detailed description is omitted. Since the above first dispersant, second dispersant and electrode active material are the same as those described above for the electrode, a detailed description is omitted. Lithium secondary battery According to another embodiment of the present invention, a lithium secondary battery comprises a positive electrode; a negative electrode; an electrolyte; and a separator, wherein at least one of the positive electrode and the negative electrode is an electrode according to the above-described embodiment. Preferably, the positive electrode may be an electrode according to the above-described embodiment. Since the electrode according to the present invention has been described above, a detailed description is omitted. The above separator is interposed between the positive and negative electrodes, separates the negative and positive electrodes, and provides a passage for lithium ions to move. If it is a separator commonly used in lithium secondary batteries, it can be used without special restrictions, and in particular, it is preferable that it has low resistance to ion movement of the electrolyte and excellent electrolyte moisture retention capacity. Specifically, a porous polymer film, for example, a porous polymer film made of a polyolefin polymer such as an ethylene homopolymer, a propylene homopolymer, an ethylene / butene copolymer, an ethylene / hexene copolymer, and an ethylene / methacrylate copolymer, or a laminated structure of two or more layers thereof, can be used. In addition, a conventional porous nonwoven fabric, for example, a nonwoven fabric made of high-melting-point glass fibers, polyethylene terephthalate fibers, etc. can be used. In addition, a coated separator containing a ceramic component or a polymer material can be used to secure heat resistance or mechanical strength, and can be selectively used in a single-layer or multi-layer structure. The electrolyte used in the present invention may include, but is not limited to, an organic liquid electrolyte, an inorganic liquid electrolyte, a solid polymer electrolyte, a gel-type polymer electrolyte, a solid inorganic electrolyte, a molten inorganic electrolyte, etc. that can be used in the manufacture of a secondary battery. Specifically, the electrolyte may include an organic solvent and a lithium salt. As the organic solvent, any solvent that can act as a medium through which ions involved in the electrochemical reaction of the battery can move may be used without particular limitation. Specifically, the organic solvent may include: ester solvents such as methyl acetate, ethyl acetate, gamma-butyrolactone, and ε-caprolactone; ether solvents such as dibutyl ether or tetrahydrofuran; ketone solvents such as cyclohexanone; aromatic hydrocarbon solvents such as benzene and fluorobenzene; carbonate solvents such as dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), ethylene carbonate (EC), and propylene carbonate (PC); alcohol solvents such as ethyl alcohol and isopropyl alcohol; nitriles such as R-CN (R is a C2 to C20 linear, branched, or cyclic hydrocarbon group, which may include a double-bonded aromatic ring or an ether bond); Amides such as dimethylformamide; dioxolanes such as 1,3-dioxolane; or sulfolanes can be used. Among these, a carbonate solvent is preferable, and a mixture of a cyclic carbonate (e.g., ethylene carbonate or propylene carbonate) having high ionic conductivity and high dielectric constant, which can improve the charge / discharge performance of the battery, and a low-viscosity linear carbonate compound (e.g., ethyl methyl carbonate, dimethyl carbonate, or diethyl carbonate) is more preferable. In this case, when the cyclic carbonate and the chain carbonate are mixed and used in a volume ratio of about 1:1 to about 1:9, the performance of the electrolyte can be excellent. The above lithium salt can be used without any special limitation as long as it is a compound capable of providing lithium ions used in a lithium secondary battery. Specifically, the anion of the above lithium salt is F - , Cl - , Br - , I - ,O 3 - , N(CN) 2 - , BF 4 - , CF 3 CF 2 SO 3 - , (CF 3 SO 2 ) 2 N - , (FSO 2 ) 2 N - , CF 3 CF 2 (CF 3 ) 2 CO - , (CF 3 SO 2 ) 2 CH - , (SF 5 ) 3 C - , (CF 3 SO 2 ) 3 C - , CF 3 (CF 2 ) 7 SO 3 - , CF 3 CO 2 - , CH 3 CO 2 - , SCN - And (CF 3 CF 2 SO 2 ) 2 N - At least one selected from the group consisting of, and the lithium salt is LiPF 6 , LiClO 4, LiAsF 6 , LiBF 4 , LiSbF 6 , LiAlO 4 , LiAlCl 4 , LiCF 3 SO 3 , LiC 4 F 9 SO 3 , LiN(C 2 F 5 SO 3 ) 2 , LiN(C 2 F 5 SO 2 ) 2 , LiN(CF 3 SO 2 ) 2 , LiCl, LiI, or LiB(C 2 O 4 ) 2 The above lithium salt concentration is preferably used within the range of 0.1 to 4.0 M. When the concentration of the lithium salt is within the above range, the electrolyte has appropriate conductivity and viscosity, so that it can exhibit excellent electrolyte performance, and lithium ions can move effectively. In addition to the electrolyte components, the electrolyte may further contain one or more additives, such as, for example, haloalkylene carbonate compounds such as difluoroethylene carbonate, pyridine, triethyl phosphite, triethanolamine, cyclic ethers, ethylene diamine, n-glyme, hexaphosphate triamide, nitrobenzene derivatives, sulfur, quinone imine dyes, N-substituted oxazolidinones, N,N-substituted imidazolidines, ethylene glycol dialkyl ethers, ammonium salts, pyrrole, 2-methoxy ethanol, or aluminum trichloride, for the purpose of improving the life characteristics of the battery, suppressing battery capacity decrease, and improving the discharge capacity of the battery. In this case, the additives may be contained in an amount of 0.1 to 5 wt% with respect to the total weight of the electrolyte. The lithium secondary battery according to the present invention is useful in portable devices such as mobile phones, laptop computers, and digital cameras, and in electric vehicles such as hybrid electric vehicles (HEVs). Accordingly, according to another embodiment of the present invention, a battery module including the lithium secondary battery as a unit cell and a battery pack including the same are provided. The above battery module or battery pack can be used as a power source for one or more medium- to large-sized devices, including power tools; electric vehicles including electric vehicles (EVs), hybrid electric vehicles, and plug-in hybrid electric vehicles (PHEVs); or power storage systems. There is no particular limitation on the external shape of the lithium secondary battery of the present invention, but it may be in the shape of a cylinder, a square, a pouch, or a coin using a can. The lithium secondary battery according to the present invention can be used not only as a battery cell used as a power source for a small device, but can also be preferably used as a unit battery in a medium- to large-sized battery module including a plurality of battery cells. Examples of the above medium and large-sized devices include, but are not limited to, electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, and power storage systems. Hereinafter, the present invention will be described in more detail through specific examples. Example 1 <Challenge Dispersion Solution Preparation> Using bundle-shaped single-walled carbon nanotubes with an average diameter of 1 ㎛ as a raw material, hydrogenated nitrile-based butadiene rubber (first dispersant) with a weight average molecular weight of about 40,000 g / mol was added to an N-methyl pyrrolidone dispersion medium at a weight ratio of 1.2:0.6, and stirred at 2,400 rpm for 30 minutes using an inline mixer (IM002, KNS Corporation) to prepare a first dispersion. (Solid content: 1.8%) To the first dispersion, polyvinylidene fluoride (PVDF) (second dispersant) having a weight average molecular weight of about 1,000,000 g / mol and N-methyl pyrrolidone were further added, and stirred at 2,400 rpm for 30 minutes using an inline mixer (IM002, KNS Corporation) to prepare a conductive dispersion. At this time, the weight ratio of bundle-shaped single-walled carbon nanotubes, hydrogenated nitrile-based butadiene rubber, and polyvinylidene fluoride in the conductive dispersion was 1.2:0.6:1.8. (Solid content: 3.6%) The above-mentioned dispersion of the challenge agent was introduced into the inlet of a high-pressure homogenizer (PICOMAX) at a pressure of 1500 bar, and the second dispersion was passed and circulated through the microchannel 30 times. Based on the total weight of the above-mentioned conductive dispersion that passed through the high-pressure homogenizer, the single-walled carbon nanotube structure was contained at 1.2 wt%, the hydrogenated nitrile-based butadiene rubber was contained at 0.6 wt%, and the polyvinylidene fluoride (PVDF) was contained at 1.8 wt%. <Polar manufacturing> Li(Ni) in the conductive dispersion prepared above 0.8 Mn 0.1 Co 0.1 )O 2 , polyvinylidene fluoride (PVDF) was additionally added as a binder and mixed to prepare a cathode slurry. Li(Ni) as a cathode active material 0.8 Mn 0.1 Co 0.1 )O 2, a conductive dispersion prepared above and a binder, polyvinylidene fluoride (PVDF), were mixed in a weight ratio of 97.5:0.7:1.8 to prepare a cathode slurry. The slurry was applied to a 15 μm thick aluminum (Al) thin film current collector, dried, and rolled to prepare a cathode including a 70 μm thick cathode active material layer. Example 2 A positive electrode was manufactured in the same manner as in Example 1, except that a hydrogenated nitrile-based butadiene rubber (first dispersant) having a weight average molecular weight of about 10,000 g / mol was used in the manufacture of the first dispersion. Example 3 A positive electrode was manufactured in the same manner as in Example 1, except that the first dispersion was manufactured by adding bundled single-walled carbon nanotubes and hydrogenated nitrile-based butadiene rubber (first dispersant) in a weight ratio of 1.2:0.12. Comparative Example 1 <Challenge Dispersion Solution Preparation> A conductive dispersion was prepared by adding bundle-shaped single-walled carbon nanotubes with an average diameter of 1 ㎛ as a raw material to an N-methyl pyrrolidone dispersion medium with polyvinylidene fluoride (second dispersant) at a weight ratio of 1.2:2.4 and stirring the mixture at 2,400 rpm for 30 minutes using an inline mixer (IM002, KNS Corporation). (Solid content: 3.6%) At this time, the weight average molecular weight of the polyvinylidene fluoride was about 1,000,000 g / mol. The above-mentioned conductive dispersion was introduced into the inlet of a high-pressure homogenizer (PICOMAX) at a pressure of 1,500 bar, and the dispersion was passed and circulated through the microchannel 30 times. Based on the total weight of the conductive dispersion that passed through the high-pressure homogenizer, the single-walled carbon nanotube structure was contained at 1.2 wt% and polyvinylidene fluoride (PVDF) was contained at 2.4 wt%. <Polar manufacturing> A positive electrode was manufactured using the same method as in Example 1, except that the conductive dispersion manufactured above was used. Comparative Example 2 <Challenge Dispersion Solution Preparation> A conductive dispersion was prepared by adding bundle-shaped single-walled carbon nanotubes with an average diameter of 1 ㎛ as a raw material to an N-methyl pyrrolidone dispersion medium with polyvinylidene fluoride (second dispersant) at a weight ratio of 1.2:2.4 and stirring the mixture at 2,400 rpm for 30 minutes using an inline mixer (IM002, KNS Corporation). (Solid content: 3.6%) At this time, the weight average molecular weight of the polyvinylidene fluoride was about 1,000,000 g / mol. The above-mentioned conductive dispersion was introduced into the inlet of a high-pressure homogenizer (PICOMAX) at a pressure of 2,000 bar, and the dispersion was passed and circulated through the microchannel 50 times. Based on the total weight of the conductive dispersion that passed through the high-pressure homogenizer, single-walled carbon nanotubes were contained at 1.2 wt% and polyvinylidene fluoride (PVDF) was contained at 2.4 wt%. <Polar manufacturing> A positive electrode was manufactured using the same method as in Example 1, except that the conductive dispersion manufactured above was used. Comparative Example 3 <Challenge Dispersion Solution Preparation> Using bundle-shaped single-walled carbon nanotubes with an average diameter of 1 ㎛ as a raw material, hydrogenated nitrile-based butadiene rubber (first dispersant) with a weight average molecular weight of about 40,000 g / mol was added to an N-methyl pyrrolidone dispersion medium at a weight ratio of 1.2:2.4, and stirred at 1,500 rpm for 30 minutes using an inline mixer (IM002, KNS Corporation) to prepare a conductive dispersion. (Solid content: 3.6%) <Polar manufacturing> A positive electrode was manufactured using the same method as in Example 1, except that the conductive dispersion manufactured above was used. Comparative Example 4 <Challenge Dispersion Solution Preparation> Using bundle-shaped single-walled carbon nanotubes with an average diameter of 1 ㎛ as a raw material, hydrogenated nitrile-based butadiene rubber (first dispersant) with a weight average molecular weight of about 40,000 g / mol was added to an N-methyl pyrrolidone dispersion medium at a weight ratio of 1:1, and stirred at 2,400 rpm for 30 minutes using an inline mixer (IM002, KNS Corporation) to prepare a first dispersion. (Solid content: 1.8%) To the above first dispersion, polyvinylidene fluoride (PVDF) (second dispersant) having a weight average molecular weight of about 1,000,000 g / mol and N-methyl pyrrolidone were further added, and stirred at 2,400 rpm for 30 minutes using an inline mixer (IM002, KNS Corporation) to prepare a conductive dispersion. At this time, the weight ratio of single-walled carbon nanotubes, hydrogenated nitrile-based butadiene rubber, and polyvinylidene fluoride in the conductive dispersion was 1.2:0.6:1.8. (Solid content: 3.6%) The above-mentioned conductive dispersion was introduced into the inlet of a high-pressure homogenizer (PICOMAX) at a pressure of 2,000 bar, and the conductive dispersion was passed and circulated through the microchannel 50 times. Based on the total weight of the above-mentioned conductive dispersion that passed through the high-pressure homogenizer, the single-walled carbon nanotube structure was contained at 1.2 wt%, the hydrogenated nitrile-based butadiene rubber was contained at 1.2 wt%, and the polyvinylidene fluoride (PVDF) was contained at 1.8 wt%. <Polar manufacturing> A positive electrode was manufactured using the same method as in Example 1, except that the conductive dispersion manufactured above was used. Comparative Example 5 <Challenge Dispersion Solution Preparation> A conductive dispersion was prepared using a commercially available single-walled carbon nanotube pre-dispersion (PD0521, OCSiAl). Based on the total weight of the conductive dispersion, the single-walled carbon nanotube structure was contained in an amount of 1.0 wt%, and polyvinylidene fluoride (PVDF) (second dispersant) was contained in an amount of 2.0 wt%. <Polar manufacturing> A positive electrode was manufactured using the same method as in Example 1, except that the conductive dispersion manufactured above was used. The contents of the components constituting the positive electrodes manufactured in the above Examples 1 to 3 and Comparative Examples 1 to 5 are shown in Table 1 below based on the total weight of the positive electrode active material layer. Cathode active material Binder Single-walled carbon nanotube structure System 1 Dispersant 2 Dispersant Example 197.5 wt% 1.8 wt% 0.01 wt% 0.005 wt% 0.015 wt% Example 297.5 wt% 1.8 wt% 0.01 wt% 0.005 wt% 0.015 wt% Example 397.5 wt% 1.8 wt% 0.01 wt% 0.001 wt% 0.019 wt% Comparative Example 197.5 wt% 1.8 wt% 0.01 wt% -0.02 wt% Comparative Example 297.5 wt% 1.8 wt% 0.01 wt% -0.02 wt% Comparative Example 3 Sample formation is not possible because a high-pressure homogenizer cannot be used due to an increase in viscosity Comparative Example 497.5 wt% 1.8 wt% 0.01 wt% 0.01 wt% 0.01 wt% Comparative Example 597.5 wt% 1.8 wt% 0.01 wt% - 0.01 wt% Experimental Example 1: Measurement of the average diameter of single-walled carbon nanotubes and the interfacial resistance between the electrode active material layer and the electrode current collector (1) Measurement of the average diameter of single-walled carbon nanotubes The average diameter of the single-walled carbon nanotube structures included in the electrodes manufactured in Examples 1 to 3 and Comparative Examples 1 to 5 was measured from images observed with a scanning electron microscope (SEM, Hitachi, Ltd.), respectively. Specifically, the electrodes manufactured in Examples 1 to 3 and Comparative Examples 1 to 5 were observed through a scanning electron microscope, and the average diameter of the single-walled carbon nanotube structures was measured as the arithmetic mean value of the diameters of the top 100 single-walled carbon nanotube structures with large diameters and the bottom 100 single-walled carbon nanotube structures. The measurement results are shown in Table 2 below. (2) Measurement of the interface resistance between the electrode active material layer and the electrode current collector The interfacial resistance of the electrode active material layer and the electrode current collector in the electrodes manufactured in the above Examples 1 to 3 and Comparative Examples 1 to 5 was measured using a Multi-Probe resistance measuring device (Manufacturer: Hioki, Product Name: RM2510). Specifically, for each electrode, 20 voltage and current probes were evenly distributed on the surface of the electrode active material layer, a constant current of 1 mA was applied to the surface of the electrode active material layer, and the potential distribution generated on the surface was measured to measure the interfacial resistance between the electrode active material layer and the electrode current collector, and the average value thereof was calculated, thereby measuring the interfacial resistance between the electrode active material layer and the electrode current collector in the electrodes manufactured in Examples 1 to 3 and Comparative Examples 1 to 5. The measurement results are shown in Table 2 below. Average diameter of single-walled carbon nanotube structures [nm] Interfacial resistance of electrode active material layer-electrode current collector [Ω cm 2 ]Example 160nm0.0706Ω·cm 2 Example 270 nm 0.2316 Ω cm 2 Example 3150 nm 0.327 Ω cm 2 Comparative example 1350 nm 0.4331 Ω cm 2 Comparative example 2280nm0.4511Ω·cm 2Comparative Example 3 Sample formation is not possible due to the use of a high-pressure homogenizer due to an increase in viscosity Comparative Example 440 nm 0.2749 Ω cm 2 Comparative example 5400 nm 0.094 Ω cm 2 Referring to Table 2 above, the electrodes manufactured in Examples 1 to 3 have an average diameter of the single-walled carbon nanotube structure of 60 nm to 300 nm, and an interfacial resistance between the electrode active material layer and the electrode current collector of 0.43 Ω cm. 2 Below. On the other hand, the electrodes manufactured in Comparative Examples 1 to 2 and 4 to 5 have an average diameter of the single-walled carbon nanotube structure of 60 nm to 300 nm and an interfacial resistance of the electrode active material layer and the electrode current collector of 0.43Ω cm. 2 It can be verified that at least one of the following is not satisfied. Experimental Example 2: Evaluation of electrode initial discharge resistance and measurement of R value Graphite as an anode active material, carbon black as a conductive material, and styrene-butadiene rubber (SBR) / carboxymethyl cellulose (CMC) as a binder were mixed in a weight ratio of 95.5:1.05:3.4 to prepare an anode slurry. The slurry was applied to a 15 μm thick copper (Cu) thin film current collector, dried, and rolled to prepare an anode including a 70 μm thick anode active material layer. An electrode assembly was manufactured by interposing a separator between the positive electrode manufactured in Examples 1 to 3 and Comparative Examples 1 to 5 and the negative electrode manufactured above, and the electrode assembly was placed inside a case for a secondary battery, and an electrolyte was injected into the case to manufacture a lithium secondary battery, respectively. At this time, the electrolyte was a mixture of ethylene carbonate (EC) and ethyl methyl carbonate (EMC) in a volume ratio of 3:7 and LiPF at 0.7 M. 6 It was manufactured by adding . The lithium secondary batteries manufactured above were each charged to 50% SOC at 25°C and then discharged at 3C for 10 seconds. The initial resistance was calculated through the voltage drop that occurred at that time, and for comparison, it was expressed by indexing based on Comparative Example 1. The results are shown in Table 3 below. Initial Discharge Resistance [Ω] Initial Discharge Resistance Index Example 11.3796.48 Example 21.3695.78 Example 31.3494.37 Comparative Example 11.42100.0 Comparative Example 21.4199.30 Comparative Example 3 Not Measurable - Comparative Example 41.4098.59 Comparative Example 51.43100.7 Referring to Table 3 above, it can be confirmed that the lithium secondary batteries including the positive electrodes manufactured in Examples 1 to 3 have superior initial resistance characteristics than the lithium secondary batteries including the positive electrodes manufactured in Comparative Examples 1 to 5. Specifically, it can be confirmed that the initial discharge resistance in the Examples and Comparative Examples is lower by about 5% on average. Experimental Example 3: Capacity Retention Rate Evaluation The lithium secondary batteries manufactured in the above Experimental Example 2 were charged to 4.2 V at 0.33 C at 25°C, and then discharged to 2.3 V at 0.33 C for 200 cycles, which constituted one cycle. Then, the capacity retention rate at 100 and 200 cycles was measured. The measurement results are shown in Table 4 below. Capacity Retention [%] (@100cycle, 25℃)Capacity Retention [%] (@200cycle, 25℃)Example 190.488.9Example 290.288.5Example 392.091.0Comparative Example 188.087.5Comparative Example 288.985.2Comparative Example 3Not Measurable-Comparative Example 483.571.0Comparative Example 588.584.1 Referring to Table 4 above, it can be seen that the lithium secondary battery including the positive electrodes manufactured in Examples 1 to 3 has a better capacity retention rate than the lithium secondary battery including the positive electrodes manufactured in Comparative Examples 1 to 5. In particular, the lithium secondary battery including the positive electrode manufactured in Comparative Example 2 has a single-wall carbon nanotube structure having an average diameter of 60 nm to 300 nm; and an interfacial resistance of the electrode active material layer and the electrode current collector of 0.43 Ω cm. 2 Comparative Examples 2, 4, and 5, which do not satisfy at least one of the following; It can be confirmed that the capacity retention rate is inferior to that of the lithium secondary battery including the positive electrode manufactured in Examples 1 to 3. That is, even if the average diameter of the single-walled carbon nanotube structure is 60 nm to 300 nm, if the interfacial resistance between the electrode active material layer and the electrode current collector does not satisfy the range according to the present invention, sufficient life characteristics cannot be obtained, and no matter how low the interfacial resistance between the electrode active material layer and the electrode current collector is, if the average diameter of the single-walled carbon nanotube structure does not satisfy 60 nm to 300 nm, it can be confirmed that sufficient life characteristics cannot be obtained.

Claims

1. It comprises an electrode current collector and an electrode active material layer positioned on the electrode current collector, The electrode active material layer comprises an electrode active material, a single-walled carbon nanotube structure, a first dispersant comprising a hydrogenated nitrile-based copolymer, and a second dispersant comprising a fluorinated polymer. The average diameter of the single-walled carbon nanotube structure is 60 nm to 300 nm, The interfacial resistance between the electrode active material layer and the electrode current collector measured by the Multi-Probe resistance (MP resistance) measurement method was 0.43Ω cm. 2 Below, electrode.

2. In paragraph 1, An electrode wherein the weight average molecular weight of the hydrogenated nitrile copolymer is 5,000 g / mol to 200,000 g / mol.

3. In paragraph 1, The above hydrogenated nitrile copolymer is a hydrogenated nitrile butadiene rubber, an electrode.

4. In paragraph 1, An electrode, wherein the fluorine-based polymer is at least one selected from the group consisting of polyvinylidene fluoride (PVDF), and polyvinylidene fluoride-co-hexafluoropropylene (PVdF-HFP) copolymers.

5. In paragraph 1, The second dispersant comprises a carboxylic acid, An electrode wherein the carboxylic acid is contained in an amount of 0.1 to 2.0 parts by weight based on 100 parts by weight of the second dispersant.

6. In paragraph 1, An electrode wherein the weight average molecular weight of the second dispersant is 600,000 g / mol to 1,500,000 g / mol.

7. In paragraph 1, An electrode, wherein the single-walled carbon nanotube structure is included in an amount of 0.001 wt% to 0.1 wt% based on the total weight of the electrode active material layer.

8. In paragraph 1, An electrode, wherein the first dispersant is included in an amount of 0.0001 wt% to 0.05 wt% based on the total weight of the electrode active material layer.

9. In paragraph 1, An electrode, wherein the second dispersant is included in an amount of 0.001 wt% to 0.25 wt% based on the total weight of the electrode active material layer.

10. Containing an anode; a cathode; an electrolyte; and a separator; A lithium secondary battery, wherein at least one of the positive and negative electrodes is an electrode according to any one of claims 1 to 9.

11. Step (S1) of preparing a conductive dispersion solution including bundle-type single-walled carbon nanotubes, a first dispersant, a second dispersant, and a dispersion medium; and A step (S2) of manufacturing an electrode including an electrode active material layer by applying an electrode slurry including the conductive dispersion and the electrode active material onto a current collector; The above first dispersant comprises a hydrogenated nitrile copolymer, The second dispersant comprises a fluorinated polymer, The above electrode active material layer comprises a single-walled carbon nanotube structure, a first dispersant, a second dispersant and an electrode active material. A method for manufacturing an electrode, wherein the average diameter of the single-walled carbon nanotube structure is 60 nm to 300 nm.

12. In paragraph 11, The above step S1 is a step (S1-1) of preparing a first dispersion liquid including a bundle-shaped single-walled carbon nanotube, a first dispersant, and a dispersion medium; and A method for manufacturing an electrode, comprising: a step (S1-2) of manufacturing a conductive dispersion by mixing a second dispersant into the first dispersion.

13. In paragraph 11, A method for manufacturing an electrode, wherein the step S1 comprises the steps of (S1-1) preparing a first dispersion comprising a bundle-shaped single-walled carbon nanotube, a first dispersant, and a dispersion medium; (S1-2) preparing a conductive dispersion by mixing a second dispersant with the first dispersion; and (S1-3) passing the conductive dispersion through a high pressure homogenizer.

14. In paragraph 12, A method for manufacturing an electrode, wherein the first dispersion and the conductive dispersion are manufactured by mixing using an inline mixer.

15. In paragraph 12, The above step S1-1 is a method for manufacturing an electrode, comprising a step of stirring the first dispersion at 500 rpm to 3,000 rpm for 15 to 60 minutes.

16. In paragraph 12, A method for manufacturing an electrode, wherein the step S1-2 includes a step of stirring the conductive dispersion at 500 rpm to 3,000 rpm for 15 to 60 minutes.

17. In paragraph 13, The above step S1-3 is a method for manufacturing an electrode, which includes a step of applying a pressure of 100 bar to 2,500 bar to the conductive dispersion liquid and introducing it into the inlet of a high-pressure homogenizer and passing it through a microchannel.