Dry electrode, manufacturing method therefor, and lithium secondary battery comprising same

Abstract

The present invention relates to a dry electrode comprising: a current collector; and an electrode mixture film which is disposed on the current collector and comprises an electrode active material and a fiberizable binder, wherein the modulus of the current collector is 13 GPa to 30 GPa.

Description

Dry electrode, method for manufacturing same, and lithium secondary battery including same Cross-citation with related applications This application claims the benefit of priority from Korean Patent Application No. 10-2023-0147269, dated October 30, 2023, the entire contents of which are incorporated herein by reference. Technology field The present invention relates to a dry electrode, a method for manufacturing the same, and a lithium secondary battery including the same. Secondary batteries are used not only in small products such as digital cameras, P-DVDs, MP3 players, mobile phones, PDAs, portable game devices, power tools, and e-bikes, but also in large products requiring high output such as electric vehicles and hybrid vehicles, as well as in power storage devices that store surplus generated power or renewable energy and power storage devices for backup purposes. Typically, secondary batteries are manufactured by applying electrode active material slurry to a positive electrode current collector and a negative electrode current collector to form an electrode active material layer, then manufacturing a positive electrode and a negative electrode through a drying and rolling process, and then laminating these on both sides of a separator to form an electrode assembly of a predetermined shape, and then housing the electrode assembly in a battery case, injecting electrolyte, and sealing the electrode assembly. Meanwhile, during the drying process of the electrode active material slurry, the solvent contained in the slurry may evaporate, causing defects such as pinholes or cracks in the electrode active material layer formed on the current collector. In addition, since the inside and outside of the electrode active material slurry are not uniformly dried during the drying process, there is a concern that the powder floating phenomenon due to the difference in solvent evaporation rate may occur, i.e., the powder in the area that dries first may rise and form a gap with the area that dries relatively later, which may deteriorate the electrode quality. To solve the above problem, a drying device capable of controlling the evaporation rate of the solvent so that the inside and outside of the electrode active material slurry can be dried evenly is being considered, but such drying devices are very expensive and require considerable cost and time to operate, which is disadvantageous in terms of manufacturing process. On the other hand, the solvent typically used in electrode active material slurries is N-methyl-2-pyrrolidone (NMP). Its high boiling point necessitates high heat energy and a very long drying process for drying, making it highly unsuitable for mass production. Furthermore, NMP is toxic and harmful to living organisms, making it unfriendly to the environment. Accordingly, there has been a recent trend of active research on dry electrodes that manufacture electrodes without using solvents. The dry electrodes are generally manufactured by laminating a free-standing electrode composite film, which is manufactured in the form of a sheet and includes an electrode active material, a binder, etc., onto a current collector. This electrode composite film includes a process of first mixing an electrode active material and a fiberizable binder together using a blender, etc., and then fiberizing the binder by applying a shear force through a process such as jet milling or kneading, and then calendering the obtained mixture into a film form to manufacture a free-standing film. Meanwhile, in the conventional dry electrode manufacturing process, electrode powder is fed between two or more calendar rolls having different rotation ratios to form an electrode composite film, and then the electrode is manufactured by laminating it to a current collector coated with a conductive adhesive layer (primer). However, in the case of a cell manufactured using an electrode including an adhesive layer, there is a problem that a loss of capacity occurs in proportion to the mass and volume of the adhesive layer of each electrode, and in the case of not including an adhesive layer, there is a problem that peeling occurs between the current collector and the electrode composite film, resulting in a deterioration in battery characteristics. Therefore, there is a need for the development of a dry electrode that does not include an adhesive layer to increase capacity density and does not cause delamination between the current collector and the electrode composite film. The object of the present invention is to solve the above-mentioned problems, and to provide a dry electrode having a high capacity density and improved adhesive strength between a current collector and an electrode composite film so that peeling between the current collector and the electrode composite film does not occur, a method for manufacturing the same, and a lithium secondary battery including the same. [1] The present invention provides a dry electrode comprising: a current collector; an electrode composite film comprising an electrode active material and a fiberizable binder disposed on the current collector; and a modulus of the current collector of 13 GPa to 30 GPa. [2] In the present invention, in the above [1], the iron (Fe) content of the current collector may be 0.75 wt% or less based on the total weight of the current collector. [3] In the present invention, in the above [1] or [2], the modulus of the entire collector may be 14.4 GPa to 24.6 GPa. [4] In at least one of the above [1] to [3], the adhesive force between the current collector and the electrode composite film may be 37 gf / 20 mm to 200 gf / 20 mm. [5] In at least one of the above [1] to [4], the tensile strength of the entire body may be 50 MPa to 250 MPa. [6] The present invention is characterized in that in at least one of the above [1] to [5], the interface resistance between the current collector and the electrode composite film is 0.0100Ωcm. 2 0.9900Ωcm 2 It could be. [7] In at least one of the above [1] to [6], the electrode active material may include a phosphorus oxide represented by the following chemical formula 1. [Chemical Formula 1] Li 1+x [Fe 1-a-b Mn a M 1 b ]PO4 In the above chemical formula 1, M 1 It contains one or more elements selected from the group consisting of Al, Mg, Ni, Co, Ti, Ga, Cu, V, Mo, Nb, W, Zr, Ce, In, Zn and Y, and -0.5≤x≤0.5, 0≤a≤0.8, 0≤b≤0.1. [8] The present invention relates to at least one of the above [1] to [7], wherein the average particle diameter (D) of the electrode active material 50 ) can be 0.1㎛ to 10㎛. [9] In at least one of the above [1] to [8], the fiberizable binder may include polytetrafluoroethylene (PTFE).

[0010] The present invention provides a method for manufacturing a dry electrode, comprising the steps of: (S1) preparing an electrode composite film and a current collector including an electrode active material and a fiberizable binder; (S2) heat-treating the current collector to manufacture a current collector having a modulus of 13 GPa to 30 GPa; and (S3) positioning the electrode composite film on at least one surface of the current collector and laminating it.

[0011] In the present invention, in the above

[0010] , the heat treatment can be performed at a temperature of 240°C to 320°C.

[0012] In the present invention, in the above

[0010] or

[0011] , the heat treatment can be performed at a temperature of 280°C to 300°C.

[0013] In at least one of the above

[0010] to

[0012] , the heat treatment can be performed for 1.5 hours to 12 hours.

[0014] In at least one of the above

[0010] to

[0013] , the heat treatment can be performed for 3.0 hours to 8.0 hours.

[0015] The present invention provides a lithium secondary battery comprising at least one dry electrode among the above [1] to [9]. The dry electrode according to the present invention is characterized by improving the adhesion between the current collector and the electrode composite film by attaching an electrode composite film onto a current collector that has been heat-treated under specific conditions to make it soft. Accordingly, while achieving excellent capacity density, it is possible to achieve excellent interfacial resistance characteristics without delamination between the current collector and the electrode composite film. The drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the contents of the invention described above, serve to further enhance the understanding of the technical spirit of the present invention. Therefore, the present invention is not limited to the matters described in these drawings. Meanwhile, the shape, size, scale, or ratio of elements in the drawings included in this specification may be exaggerated to emphasize a clearer explanation. Figure 1 illustrates an example of a stress-strain curve of a collector for obtaining modulus. Hereinafter, the present invention will be described more preferably. 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 meanings and concepts that conform to the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the term to explain his or her own invention in the best possible manner. In this specification, the term "composite composition" means a mixture comprising an electrode active material and a fiberizable binder, which is physically mixed to form a uniform dispersion phase, and may be a powder mixture as a product of the mixing process (mixing process) according to this specification, and may be substantially solvent-free. Here, substantially solvent-free means that no solvent is added or only a very small amount of solvent is added during mixing of the composite composition. In this specification, the “mixed aggregate” is a product of the kneading process (kneading process) according to this specification in which the above composite composition is subjected to a shear force, the binder is fiberized, and the powder mixture is combined or linked to each other to convert into a paste-like aggregate, and may be a product of the kneading process according to this specification with a solid content of 100%. In this specification, “electrode powder” may mean a powder-type electrode material that is a material in which the above mixed aggregate is pulverized to form smaller particles and is in a powder form, and includes an electrode active material, a binder, and optionally a conductive material. In this specification, the "electrode composite film" may refer to a free-standing type single sheet manufactured using an "electrode composite" containing an electrode active material and a binder without the use of a solvent, or an electrode composite layer laminated on a current collector. The term "free-standing" in this specification means that it can maintain its own shape without relying on other members and can be moved or handled on its own. The electrode composite film may be formed by compressing the electrode powder as described below. For example, the electrode powder may have a layered structure formed by being accumulated by compression. In this specification, the term "powder-sheeting film" refers to a film formed from the time the electrode powder is first passed through a rolling roll in a roll-to-roll process to the time before passing through the last rolling roll in the process, and may be a self-supporting sheet, but may have relatively weak self-supporting force. Here, the "powder-sheeting" refers to the process in which the electrode powder is formed into a self-supporting sheet by a rolling roll in the roll-to-roll process, and the "sheeting" refers to a process performed in the process in which the powder-sheeting film is manufactured into an electrode composite film, and may refer to a process in which the powder-sheeting film is rolled. In this specification, the MD direction (Machine Direction) means the longitudinal direction of the target object (current collector or electrode composite film), i.e., the direction in which the target object (current collector or electrode composite film) runs during production, and the TD direction (Transverse Direction) means the width direction of the target object (current collector or electrode composite film), i.e., the direction perpendicular to the MD direction. In the present invention, the average particle diameter (D 50 ) means the particle size corresponding to 50% of the volume accumulation in the particle size distribution curve. The above D 50 For example, it can be measured using the laser diffraction method. The laser diffraction method can generally measure particle diameters from the submicron range to several mm, and can obtain results with high reproducibility and high resolution. In the present invention, the specific surface area is measured by the BET (Brunauer-Emmett-Teller) method, and can be calculated from the nitrogen gas adsorption amount at liquid nitrogen temperature (77 K) using BELSORP-mino II of BEL Japan. The inventors of the present invention have conducted continuous research on a dry electrode that has excellent interfacial resistance characteristics and does not cause delamination between the current collector and the electrode composite film while realizing an excellent capacity density of the battery, and as a result, they have found that when the modulus of the current collector is controlled within a certain range, the current collector can have high strength and ductility without breaking during the roll-to-roll process, and the adhesive strength and interfacial resistance characteristics between the current collector and the electrode composite film can be improved, thereby completing the present invention. dry electrode Hereinafter, a dry electrode according to the present invention will be described. A dry electrode according to the present invention comprises: a current collector; an electrode composite film comprising an electrode active material and a fiberizable binder disposed on the current collector; and a modulus of the current collector is 13 GPa to 30 GPa. The modulus of the above-mentioned collector refers to the slope (stress / strain) in the elastic section of the stress-strain curve of the collector. Since the methods for measuring the modulus are known to experts in the art, a detailed description thereof will be omitted, and the equipment used to measure the modulus may be, for example, a universal testing machine. More preferably, the modulus can be measured by calculating the slope when the strain is 0.2% in the graph appearing in the stress-strain curve. For example, as shown in the figure in Fig. 1, the modulus value can be obtained by measuring the slope value (differential value) when the strain is 0.2%. According to one embodiment of the present invention, the modulus of the current collector is 13 GPa to 30 GPa. Preferably, it may be 13.5 GPa or more, 14.0 GPa or more, or 14.4 GPa or more, and may be 30 GPa or less, 28 GPa or less, 26 GPa or less, 25.5 GPa or less, 25.0 GPa or less, or 24.6 GPa or less, and more preferably, it may be 14.4 GPa to 24.6 GPa. When the modulus of the current collector exceeds 30 GPa, the electrode composite film and the current collector must be laminated under strong pressure to prevent delamination. This reduces the electrode's porosity, reducing its flexibility and making it susceptible to breakage, thus compromising processability and high-rate charge / discharge performance. Furthermore, the strong pressure can damage the active material, causing excessive side reactions with the electrolyte, thereby reducing the battery's lifespan. If the modulus of the current collector is less than 13 GPa, the possibility of damage to the current collector increases during the process of rolling the electrode to improve the energy density of the battery, and the problem of the current collector being easily deformed or broken due to the tension applied to the current collector during the roll-to-roll manufacturing process occurs. Therefore, when the above range is satisfied, the current collector can be processed into a dry electrode with high strength and strong adhesive strength, so that the adhesive strength between the current collector and the electrode composite film can be excellent even without an adhesive layer or conductive primer layer, and accordingly, the energy density of the cell can be improved, and a significant increase in energy density can be expected in the module or pack unit. In addition, damage to the active material due to strong pressure can be prevented, so that the lifespan of the battery can be improved. The modulus of the above current collector is maintained at a high strength to withstand the pressure applied by rolling during electrode manufacturing and the tension applied during the roll-to-roll process, while the current collector is appropriately softened to improve the adhesion between the current collector and the electrode composite film. In the past, the goal was to manufacture ultra-high-strength current collectors by considering only the fracture of the current collector. However, when the modulus is increased to manufacture ultra-high-strength current collectors, the surface does not soften, so the adhesive strength between the current collector and the electrode composite film decreases rapidly, making lamination between the current collector and the electrode composite film impossible. In other words, the problem of not being able to manufacture the dry electrode itself may occur. Therefore, conventionally, an adhesive layer or a conductive primer layer was formed between the current collector and the electrode composite film so that lamination between the current collector and the electrode composite film could be properly performed as described above. However, when the adhesive layer or the conductive primer layer is formed, the dry electrode thickness increases, which reduces the energy density of the battery, and a large amount of binder included in the adhesive layer or the conductive primer layer may be wet and swollen by the electrolyte, which may disconnect the conductive network and increase the resistance of the battery. In addition, a large amount of binder may be oxidized or degraded at high potentials, which may increase the resistance of the battery, and there may be a problem that additional processes and costs are required to form the adhesive layer or the conductive primer layer. However, in the present invention, a current collector satisfying specific conditions is heat-treated at an appropriate temperature and time, thereby appropriately softening the current collector surface. Accordingly, the current collector surface is softened, allowing the electrode active materials contained within the electrode composite film to strongly support and bond with the current collector surface, thereby achieving excellent adhesion between the current collector and the electrode composite film even without an adhesive layer or conductive primer layer. According to one embodiment of the present invention, the iron (Fe) content of the current collector may be 0.75 wt% or less based on the total weight of the current collector. Preferably, it may be 0.70 wt% or less, 0.65 wt% or less, 0.60 wt% or less, 0.55 wt% or less, 0.50 wt% or less, 0.45 wt% or less, 0.40 wt% or less, 0.35 wt% or less, 0.30 wt% or less, 0.25 wt% or less, 0.20 wt% or less, 0.15 wt% or less, or 0.10 wt% or less, and may be 0.01 wt% or more, and preferably 0.01 wt% to 0.10 wt%. If the iron (Fe) content of the current collector is excessive, it may not be easy to achieve adhesion between the current collector and the electrode composite film within the aforementioned modulus range, and a problem may arise in which the interfacial resistance rapidly increases due to a delamination phenomenon between the current collector and the electrode composite film. Therefore, if the above range is satisfied, the current collector can have excellent ductility and strength to prevent fracture, while also achieving excellent adhesiveness, energy density, and interfacial resistance characteristics. According to one embodiment of the present invention, the adhesive strength between the current collector and the electrode composite film may be 37 gf / 20 mm to 200 gf / 20 mm, preferably 38 gf / 20 mm to 80 gf / 20 mm, and more preferably 40 gf / 20 mm to 45 gf / 20 mm. When the above range is satisfied, peeling between the current collector and the electrode composite film does not occur, so that the electrochemical characteristics of the battery can be improved, and a dry electrode can be manufactured without an adhesive layer, so that the energy density and processability of the cell can be excellent. According to one embodiment of the present invention, the tensile strength of the current collector may be 50 MPa to 250 MPa, preferably 50 MPa or more, 60 MPa or more, 70 MPa or more, 80 MPa or more, 85 MPa or more, or 90 MPa or more, and may be 250 MPa or less, 225 MPa or less, 200 MPa or less, 175 MPa or less, 150 MPa or less, 125 MPa or less, 120 MPa or less, 115 MPa or less, 110 MPa or less, or 105 MPa or less. More preferably, it may be 90 MPa to 105 MPa. When the above range is satisfied, the current collector may not be broken during rolling for manufacturing a dry electrode, and even when the process speed is increased to increase production volume, the current collector can sufficiently withstand tension, thereby preventing the current collector from breaking. In addition, it may be suitable for mass production because it has a tensile strength that is not excessively high, and the process difficulty is not high, so the processability may be excellent. According to one embodiment of the present invention, the elongation at break of the entire collector may be 1.5% to 10%, preferably 2% to 7%, and more preferably 3% to 5%. When the above range is satisfied, the processability may be improved due to the appropriate ductility. There are no special restrictions on the method for measuring the above tensile strength and elongation at break, but for example, they can be measured using the ASTM D638 method using UTM equipment from ZwickRoell. According to one embodiment of the present invention, the interfacial resistance between the current collector and the electrode composite film is 0.0100Ωcm. 2 0.9900Ωcm 2 It can be, preferably 0.1000Ωcm 2 0.8000Ωcm 2 It can be, and more preferably 0.3000Ωcm 2 0.7500Ωcm 2If the above range is satisfied, the resistance characteristics and output characteristics of the battery can be improved, and the rapid charging performance and life characteristics can be improved. Meanwhile, there may be various factors affecting the adhesion and interface resistance between the current collector and the electrode composite film, such as the current collector heat treatment temperature, but other examples may include the composition of the electrode active material or the average particle size of the electrode active material. There is no special limitation on the above electrode active material as long as it is a commonly used electrode active material. For example, the above electrode active material may be a positive electrode active material or a negative electrode active material. The above-mentioned positive electrode active material is a compound capable of reversible intercalation and deintercalation of lithium, and may preferably include a lithium metal oxide containing lithium and one or more metals such as cobalt, manganese, nickel or aluminum. More preferably, the lithium metal oxide is a lithium-manganese oxide (e.g., LiMnO2, LiMn2O4, etc.), a lithium-cobalt oxide (e.g., LiCoO2, etc.), a lithium-nickel oxide (e.g., LiNiO2, etc.), a lithium-nickel-manganese oxide (e.g., LiNi 1-Y Mn Y O2 (here, 0 <Y<1), LiMn 2-Z Ni Z O4 (where 0<Z<2), etc.), lithium-nickel-cobalt oxides (e.g., LiNi 1-Y1 Co Y1 O2 (here, 0 <Y1<1) 등), 리튬-망간-코발트계 산화물(예를 들면, LiCo 1-Y2 Mn Y2 O2 (here, 0 <Y2<1), LiMn 2-Z1 Co Z1 O4 (wherein, 0<Z1<2) etc.), lithium-nickel-manganese-cobalt oxides (e.g., Li(Ni p Co q Mn r)O2(wherein, 0<p<1, 0<q<1, 0<r<1, p+q+r=1) or Li(Ni p1 Co q1 Mn r1 )O4 (wherein, 0<p1<2, 0<q1<2, 0<r1<2, p1+q1+r1=2) etc.), or lithium-nickel-cobalt-transition metal (M) oxide (e.g., Li(Ni p2 Co q2 Mn r2 M s2 )O2 (wherein, M is selected from the group consisting of Al, Fe, V, Cr, Ti, Ta, Mg and Mo, and p2, q2, r2 and s2 are atomic fractions of independent elements, respectively, 0<p2<1, 0<q2<1, 0<r2<1, 0<s2<1, p2+q2+r2+s2=1), etc.), lithium iron phosphate (e.g., Li 1+a Fe 1-x M x (PO 4-b )X b (Here, M is at least one selected from Al, Mg, and Ti, X is at least one selected from F, S, and N, -0.5≤a≤0.5, 0≤x≤0.5, 0≤b≤0.1), and any one or two or more compounds thereof may be included. Among these, the lithium metal oxides are LiCoO2, LiMnO2, LiNiO2, lithium nickel manganese cobalt oxide (e.g., Li(Ni)) in that they can improve the capacity characteristics and stability of the battery. 1 / 3 Mn 1 / 3 Co 1 / 3 )O2, Li(Ni 0.6 Mn 0.2 Co 0.2 )O2, Li(Ni) 0.5 Mn 0.3 Co 0.2 )O2, Li(Ni 0.7 Mn 0.15 Co 0.15 )O2 and Li(Ni 0.8 Mn 0.1 Co0.1 )O2, etc.), lithium nickel cobalt aluminum oxide (e.g., Li(Ni 0.8 Co 0.15 Al 0.05 )O2, etc.), or lithium nickel cobalt manganese aluminum oxide (e.g. Li(Ni 0.86 Co 0.05 Mn 0.07 Al 0.02 )O2), lithium iron phosphate (e.g., LiFePO4), etc., and any one of these or a mixture of two or more thereof may be used. The above negative active material may include at least one selected from the group consisting of lithium metal, a carbon material capable of reversibly intercalating / deintercalating lithium ions, a metal or an alloy of these metals and lithium, a metal composite oxide, a material capable of doping and dedoping lithium, and a transition metal oxide. As the carbon material capable of reversibly intercalating / deintercalating the lithium ions, any carbon-based negative electrode active material commonly used in lithium-ion secondary batteries can be used without particular limitation, and representative examples thereof include crystalline carbon, amorphous carbon, or a combination thereof. Examples of the crystalline carbon include graphite such as natural graphite or artificial graphite in an amorphous, plate-like, flake-like, spherical, or fibrous form, and examples of the amorphous carbon include soft carbon (low-temperature calcined carbon) or hard carbon, mesophase pitch carbide, calcined coke, etc. As the above metal or an alloy of these metals with lithium, a metal selected from the group consisting of Cu, Ni, Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, Ra, Ge, Al and Sn or an alloy of these metals with lithium may be used. The above metal composite oxides include PbO, PbO2, Pb2O3, Pb3O4, Sb2O3, Sb2O4, Sb2O5, GeO, GeO2, Bi2O3, Bi2O4, Bi2O5, Li x Fe2O3(0≤x≤1), Li x WO2(0≤x≤1) and Sn x Me 1-x Me' y O z (Me: Mn, Fe, Pb, Ge; Me': Al, B, P, Si, elements of group 1, 2, and 3 of the periodic table, halogens; 0 <x≤1; 1≤y≤3; 1≤z≤8) 로 이루어진 군에서 선택되는 것이 사용될 수 있다. Materials capable of doping and dedoping the above lithium include Si, SiO x (0 <x≤2), Si-Y 합금(상기 Y는 알칼리 금속, 알칼리 토금속, 13족 원소, 14족 원소, 전이금속, 희토류 원소 및 이들의 조합으로 이루어진 군에서 선택되는 원소이며, Si은 아님), Sn, SnO2, Sn-Y(상기 Y는 알칼리 금속, 알칼리 토금속, 13족 원소, 14족 원소, 전이금속, 희토류 원소 및 이들의 조합으로 이루어진 군에서 선택되는 원소이며, Sn은 아님) 등을 들 수 있고, 또한 이들 중 적어도 하나와 SiO2를 혼합하여 사용할 수도 있다. 상기 원소 Y로는 Mg, Ca, Sr, Ba, Ra, Sc, Y, Ti, Zr, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg, Tc, Re, Bh, Fe, Pb, Ru, Os, Hs, Rh, Ir, Pd, Pt, Cu, Ag, Au, Zn, Cd, B, Al, Ga, Sn, In, Ge, P, As, Sb, Bi, S, Se, Te, Po 및 이들의 조합으로 이루어진 군에서 선택될 수 있다. Examples of the above transition metal oxides include lithium-containing titanium composite oxide (LTO), vanadium oxide, and lithium vanadium oxide. Preferably, the electrode active material may include a phosphorus oxide represented by the following chemical formula 1. [Chemical Formula 1] Li 1+x [Fe 1-a-b Mn a M 1 b ]PO4 In the above chemical formula 1, M 1 It contains one or more elements selected from the group consisting of Al, Mg, Ni, Co, Ti, Ga, Cu, V, Mo, Nb, W, Zr, Ce, In, Zn and Y, and -0.5≤x≤0.5, 0≤a≤0.8, 0≤b≤0.1. When the above conditions are satisfied, it may be desirable in terms of being able to implement excellent economic efficiency and stability. More preferably, the electrode active material may include a phosphorus oxide represented by the following chemical formula 1-1. [Chemical Formula 1-1] LiFePO4 When the above conditions are satisfied, the adhesive strength between the current collector and the electrode composite film according to the present invention is excellent, so that the peeling phenomenon between the current collector and the electrode composite film can be prevented. More preferably, the lithium iron phosphate used as the electrode active material typically has an average particle diameter (D 50 ) is small, when laminating a current collector that has not been heat-treated with an electrode composite film containing lithium iron phosphate, adhesion may not be easily performed, which may cause a problem in that a dry electrode cannot be manufactured. Therefore, a current collector having a softly processed surface through heat treatment can exhibit excellent adhesion with an electrode composite film containing lithium iron phosphate without an additional adhesive layer or conductive primer layer, thereby preventing a peeling phenomenon between the current collector and the electrode composite film. The average particle diameter (D) of the above electrode active material 50) may be 0.1㎛ to 10㎛, preferably 0.5㎛ to 8.0㎛, and more preferably 1㎛ to 5㎛. If the average particle diameter of the electrode active material is excessively large, a problem of deterioration in the capacity characteristics of the battery may occur, and a problem of deterioration in the high-rate charge / discharge characteristics may occur due to high internal resistance and a decrease in the ion movement speed. In addition, if the average particle diameter of the electrode active material is excessively small, a problem of deterioration in the mechanical strength, such as the tensile strength and elongation at break, of the electrode composite film including the same may occur in the future when manufacturing the electrode composite film. Therefore, the average particle diameter (D) of the electrode active material 50 ) satisfies the above range, the particle size of the obtained electrode powder can be uniform, and the specific surface area of ​​the electrode active material particles can be appropriate, so that the capacity characteristics, electrical conductivity, and high-rate charge / discharge characteristics of the battery can be improved. In addition, when manufacturing an electrode composite film, film formation is easy, and mechanical properties such as tensile strength and elongation at break can be improved. According to one embodiment of the present invention, a coating layer formed on the electrode active material and including carbon (C) may be further included. When the above conditions are satisfied, ionic conductivity and electronic conductivity can be improved. According to one embodiment of the present invention, the electrode composite film may further include a conductive agent. The conductive agent is a component for further improving the conductivity of the electrode active material. The conductive agent is not particularly limited as long as it has conductivity without causing a chemical change in the battery. For example, carbon powder such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, or thermal black; graphite powder such as natural graphite, artificial graphite, or graphite with a highly developed crystal structure; conductive fibers such as carbon fibers or metal fibers; fluorinated carbon powder; conductive powder such as aluminum powder or nickel powder; conductive whiskers such as zinc oxide or potassium titanate; conductive metal oxides such as titanium oxide; and conductive materials such as polyphenylene derivatives may be used. Specifically, the conductive agent may include at least one selected from the group consisting of activated carbon, graphite, carbon black, and carbon nanotubes (CNTs) for uniform mixing of the conductive agent and improvement of conductivity. The above-mentioned fiberizable binder is not specific as long as it is fibrillizable, and the fibrillation refers to a process of dividing a polymer into small pieces. For example, it can be performed using a mechanical shear force, etc., and the surface of the fibrillated polymer fiber is loosened to generate a large number of fine fibers (fibrils). The fiberizable binder may preferably include at least one selected from the group consisting of polytetrafluoroethylene (PTFE) and polyolefin, more preferably polytetrafluoroethylene (PTFE), and even more preferably polytetrafluoroethylene (PTFE). Preferably, the polytetrafluoroethylene (PTFE) may be included in an amount of 60 wt% or more based on the total binder weight. At this time, the binder may additionally include at least one of PEO (polyethylene oxide), PVdF (polyvinylidene fluoride), PVdF-HFP (polyvinylidene fluoride-cohexafluoropropylene), and a polyolefin-based binder. According to one embodiment of the present invention, when the electrode composite film further includes a conductive material, the weight ratio of the electrode active material, the conductive material, and the fiberizable binder may be 80 to 98 wt% : 0.5 to 10 wt% : 0.5 to 10 wt%, and preferably 85 to 98 wt% : 0.5 to 5 wt% : 0.5 to 10 wt%. When the above range is satisfied, the content of the binder may be appropriately included, so that sufficient fiberization can be achieved and the particles can be aggregated to form an electrode powder, and the particles can be aggregated to form an electrode composite film, and the physical properties of the electrode composite film can be improved. When the above dry electrode is a positive electrode, the current collector may be any conductive material that does not cause chemical changes in the battery, and is not particularly limited. For example, the current collector may be stainless steel, aluminum, nickel, titanium, calcined carbon, or aluminum or stainless steel surface-treated with carbon, nickel, titanium, silver, etc. When the above dry electrode is a negative electrode, the current collector is not particularly limited as long as it has high conductivity without causing changes in the battery, and for example, copper, stainless steel, aluminum, nickel, titanium, calcined carbon, copper or stainless steel surface-treated with carbon, nickel, titanium, silver, etc., aluminum-cadmium alloy, etc. can be used. For example, it may be an aluminum alloy thin film that satisfies the aforementioned iron (Fe) content. If the above conditions are satisfied, it is easy to implement the modulus of the current collector while also having high strength. The thickness of the above-mentioned collector may be 3 μm to 50 μm, but is not limited thereto. In addition, fine irregularities may be formed on the surface of the collector to increase the adhesive strength of the composite film. According to one embodiment of the present invention, a conductive primer layer may not be included between the current collector and the electrode composite film. For example, the surface of the current collector may not have a conductive primer layer formed thereon, and preferably, the surface of the current collector may not have an adhesive layer or a conductive primer layer formed thereon, and more preferably, the surface of the current collector may not have an adhesive layer or a conductive primer layer formed thereon for lowering resistance and improving adhesion. Here, the adhesive layer or the conductive primer layer may include a conductive material and a binder, and the conductive material is not limited as long as it is a conductive material, but may be, for example, a carbon-based material. The binder may include a fluorine-based (including PVDF and PVDF copolymer), an acrylic-based binder, and an aqueous binder that can be dissolved in a solvent. If the adhesive layer or conductive primer layer is not included, the dry electrode can be manufactured with a thin thickness, thereby increasing the energy density of the battery. In addition, the problem of a large amount of binder included in the adhesive layer or conductive primer layer being wet and swollen by the electrolyte and disconnecting the conductive network, thereby increasing the resistance of the battery, can be prevented. In addition, the problem of an increase in the resistance of the battery can be prevented because a large amount of binder is prevented from being oxidized or degraded at high potential. In addition, the processability can be excellent because no additional process or cost is required to form the adhesive layer or conductive primer layer. Dry electrode manufacturing method Hereinafter, a method for manufacturing a dry electrode according to the present invention will be described. A method for manufacturing a dry electrode according to the present invention comprises the steps of: (S1) preparing an electrode composite film and a current collector including an electrode active material and a fiberizable binder; (S2) heat-treating the current collector to manufacture a current collector having a modulus of 13 GPa to 30 GPa; and (S3) positioning the electrode composite film on at least one surface of the current collector and laminating it. Hereinafter, the dry electrode manufacturing method according to the present invention will be preferably described step by step. ((S1) step) (S1) A step of preparing an electrode composite film and a current collector including an electrode active material and a fiberizable binder. First, an electrode composite film including an electrode active material and a fiberizable binder is described. As the above electrode active material and fiberizable binder have been described above, a detailed description thereof will be omitted, and the electrode composite film can be manufactured as follows. First, the above-described electrode active material, fiberizable binder, and / or conductive agent are mixed to obtain a composite composition. At this time, the mixing is performed so that the electrode active material, fiberizable binder, and / or conductive agent can be uniformly distributed. Since the mixture is in powder form, any method that allows simple mixing thereof is not limited and can be mixed by various methods. However, since the present invention is manufactured as a dry electrode that does not use a solvent, the mixing can be performed by dry mixing, and the materials can be mixed by putting them into a device such as a mixer or blender. At this time, the mixing can be performed in a mixer at 100 rpm to 50,000 rpm for 1 to 60 minutes, and preferably at 500 rpm to 20,000 rpm for 2 to 30 minutes. When performed within the above range, the materials can be uniformly mixed, thereby improving battery performance. Next, a fiberization process can be performed on the composite composition obtained from the above mixture to fiberize the fiberizable binder. The above fiberization process is not particularly limited as long as it is a generally performed mixing process, but preferably, it can be performed by high-temperature, low-shear kneading (kneading), and can be performed using a kneader, for example. By such kneading, the fiberizable binder is fiberized, thereby combining or linking the electrode active material and / or conductive material powders, thereby forming a mixed aggregate having a solid content of 100%. The above mixing can be performed at a speed of 10 rpm to 100 rpm, preferably 20 rpm to 70 rpm. In addition, the mixing can be performed for 1 minute to 120 minutes, preferably 2 minutes to 60 minutes. When the above range is satisfied, appropriate fiberization can occur, thereby improving the characteristics of the battery. In addition, the mixing can be performed under conditions of high temperature and pressure higher than atmospheric pressure, and preferably under conditions of pressure higher than atmospheric pressure. More preferably, the mixing can be performed at a temperature of 50°C to 230°C, preferably 90°C to 200°C. When mixing is performed at a high temperature such as the above range, the fiberization and lump formation of the binder through mixing can be well achieved, and the problem of breakage of the fiberized binder can be appropriately prevented. In addition, it can be performed at a pressure higher than atmospheric pressure, preferably 1 to 3 atm, more preferably 1.1 to 3 atm. When performed within the above range, the problem of breakage of the binder undergoing fiberization can be appropriately prevented, and the problem of the density of the mixed aggregate becoming too high can be prevented. That is, according to the present invention, when a high-temperature-low-shear mixing process is performed under high-temperature and higher-than-normal pressure conditions instead of high-shear mixing, the intended effect of the present invention can be achieved. Next, a step of pulverizing the mixed aggregate manufactured through the above mixing step to obtain powder for electrodes can be performed. The mixed aggregates produced through the above mixing process can be directly calendered. However, in this case, the mixed aggregates must be pressed under high pressure and high temperature to form a thin film. This may result in problems such as the film density becoming too high or the inability to obtain a uniform film. Therefore, the mixed aggregates produced as described above are pulverized to produce powder for electrodes. The device used for the above crushing is not particularly limited, but it can preferably be performed by a device such as a blender or grinder. The above grinding can be performed at a speed of 1000 rpm to 20,000 rpm for 5 seconds to 10 minutes, preferably at a speed of 2000 rpm to 18,000 rpm for 10 seconds to 5 minutes. When performed within the above range, sufficient grinding can be achieved to produce powder of a size suitable for filming, and a large amount of fine powder can be prevented from being generated in the mixed aggregate. The average particle size of the above electrode powder may be 10 µm to 3000 µm, preferably 50 µm to 1500 µm, and more preferably 100 µm to 700 µm. When the above range is satisfied, an electrode composite film having a uniform thickness and density can be formed, and excellent electrode composite film properties can be secured. Meanwhile, the electrode powder according to the present invention may additionally include fillers, although not essential, to suppress electrode expansion. The fillers are not particularly limited as long as they are fibrous materials that do not cause chemical changes in the battery, and examples thereof include at least one selected from olefin polymers such as polyethylene and polypropylene; and fibrous materials such as glass fiber and carbon fiber. Next, an electrode composite film can be manufactured by a calendering method in which the electrode powder according to the present invention is supplied to a calendering device and the supplied material is thermally compressed using calendering roll(s) included in the calendering device. Preferably, the electrode powder according to the present invention is supplied to a calendering roll and thermally compressed to manufacture a sheet-shaped electrode composite film. The above calendar device may include a roll press section in which two of the above calendaring rolls are arranged facing each other, and a plurality of the above roll press sections may be arranged continuously. At this time, each roll press section can independently adjust the rotation speed ratio of the two calendaring rolls appropriately within 1:1 to 1:10. In addition, the electrode composite film manufactured above can be put into a roll press section again and subjected to heat pressing 1 to 10 times to adjust it to an appropriate thickness. As the above-mentioned entire house has been described above, it is omitted. ((S2) step) Next, (S2) a step of heat-treating the above-mentioned collector to manufacture a collector having a modulus of 13 GPa to 30 GPa is described. According to one embodiment of the present invention, the current collector is controlled to have a modulus of 13 GPa to 30 GPa through heat treatment, thereby preventing breakage and damage to the current collector while realizing excellent adhesion and interfacial resistance between the current collector and the electrode composite film. In addition, the current collector has the characteristic of realizing excellent adhesion and interfacial resistance regardless of the presence or absence of a conductive primer layer between the current collector and the electrode composite film, thereby realizing excellent energy density. According to one embodiment of the present invention, the heat treatment can be performed at a temperature condition of 240°C to 320°C, preferably 240°C or higher, 245°C or higher, 250°C or higher, 255°C or higher, 260°C or higher, 265°C or higher, 270°C or higher, 275°C or higher, or 280°C or higher, and 320°C or lower, 315°C or lower, 310°C or lower, 305°C or lower, or 300°C or lower, and more preferably 280°C to 300°C. When the temperature is excessively low, the current collector cannot be properly ductile processed, making it difficult to easily achieve the above-mentioned modulus, which causes a problem of reduced adhesive strength between the current collector and the electrode composite film. In addition, if the temperature is excessively high, the tensile strength of the current collector may be excessively reduced, which may cause the current collector to be easily deformed or broken during the rolling process, and it may be difficult to easily achieve the above-mentioned modulus, which may result in reduced adhesive strength and lower interfacial resistance. Therefore, if the temperature is satisfied, the above-mentioned modulus can be achieved, so that the adhesive strength and interfacial resistance characteristics between the current collector and the electrode composite film can be improved, and the problem of the current collector being broken can be prevented. In addition, since the adhesive strength is sufficient, an adhesive layer may not be included in the dry electrode, which may increase the capacity density within the battery. According to one embodiment of the present invention, the heat treatment may be performed for 1.5 hours to 12 hours, preferably 1.5 hours or more, 2.0 hours or more, 2.5 hours or more, or 3.0 hours or more, and may be 12 hours or less, 11.5 hours or less, 11 hours or less, 10.5 hours or less, 10 hours or less, 9.5 hours or less, 9.0 hours or less, 8.5 hours or less, or 8.0 hours or less, and more preferably 3.0 hours to 8.0 hours. When the above range is satisfied, the current collector can be appropriately ductile processed, so that the adhesion between the current collector and the electrode composite film can be improved, and the resistance characteristics and life characteristics of the battery can be improved. In addition, sufficient tensile strength can be secured, so that breakage of the current collector can be prevented. ((S3) step) Next, (S3) a step of positioning and laminating the electrode composite film on at least one surface of the current collector is described. The above lamination is a step of positioning the electrode composite film on at least one surface of the current collector and rolling it to attach it, thereby manufacturing a dry electrode according to the present invention. According to one embodiment of the present invention, the lamination can be performed using a lamination unit including two lamination rolls, and the rotational speed ratio of the lamination rolls can be 1:1.000 to 1:1.100. When the above range is satisfied, the electrode composite film and the current collector can be appropriately rolled, so that excellent adhesive strength can be realized between the electrode composite film and the current collector. The above lamination can be performed by a roll press method using a lamination roller, and at this time, the lamination roller can be maintained at a temperature of 20°C to 200°C. lithium secondary battery Hereinafter, a lithium secondary battery according to the present invention will be described. A lithium secondary battery according to the present invention comprises a dry electrode according to the present invention. Preferably, the battery comprises a positive electrode, a negative electrode, a separator, and an electrolyte, wherein the positive electrode and / or the negative electrode may be dry electrodes, and preferably, the battery may be a lithium secondary battery comprising a dry electrode, a negative electrode, a separator, and an electrolyte according to the present invention. When only one of the positive electrode or the negative electrode is a dry electrode according to the present invention, the other electrode may be an electrode manufactured through a conventional wet manufacturing method. The above separator separates the negative electrode and the positive electrode and provides a passage for lithium ions to move. Any separator commonly used in lithium secondary batteries can be used without any particular restrictions, and in particular, one having low resistance to ion movement of the electrolyte and excellent electrolyte moisture retention capacity is preferable. Preferably, 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 fiber, polyethylene terephthalate fiber, etc. may be used. In addition, a coated separator containing a ceramic component or a polymer material to secure heat resistance or mechanical strength may be used, and may optionally be used in a single-layer or multi-layer structure. In addition, 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 lithium secondary battery. Preferably, the electrolyte may include an organic solvent and a lithium salt. As the organic solvent, any solvent that can serve as a medium through which ions involved in the electrochemical reaction of the battery can move may be used without particular limitation. Preferably, the organic solvent includes ester solvents such as methyl acetate, ethyl acetate, γ-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 dimethylcarbonate (DMC), diethylcarbonate (DEC), methylethylcarbonate (MEC), ethylmethylcarbonate (EMC), ethylene carbonate (EC), and propylene carbonate (PC); alcohol solvents such as ethyl alcohol and isopropyl alcohol; nitriles such as R-CN (where R represents a linear, branched, or cyclic hydrocarbon group having 2 to 20 carbon atoms and 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, etc.) having high ionic conductivity and high dielectric constant that can improve the charge / discharge performance of the battery and a linear carbonate compound having low viscosity (e.g., ethyl methyl carbonate, dimethyl carbonate, or diethyl carbonate, etc.) is more preferable. The above lithium salt can be used without any special limitation as long as it is a compound that can provide lithium ions used in a lithium secondary battery. Preferably, the anion of the lithium salt is F - , Cl - , Br - , I - , NO3 - , N(CN)2 - , BF4 - , CF3CF2SO3 - , (CF3SO2)2N - , (FSO2)2N - , CF3CF2(CF3)2CO - , (CF3SO2)2CH - , (SF5)3C - , (CF3SO2)3C - , CF3(CF2)7SO3 - , CF3CO2 - , CH3CO2 - , SCN - and (CF3CF2SO2)2N - The lithium salt may be at least one selected from the group consisting of LiPF6, LiClO4, LiAsF6, LiBF4, LiSbF6, LiAl04, LiAlCl4, LiCF3SO3, LiC4F9SO3, LiN(C2F5SO3)2, LiN(C2F5SO2)2, LiN(CF3SO2)2, LiCl, LiI, or LiB(C2O4)2. The concentration of the lithium salt is preferably used within the range of 0.1M to 4.0M, preferably 0.5M to 3.0M, and more preferably 1.0M to 2.0M. When the concentration of the lithium salt is within the above range, the electrolyte can exhibit excellent electrolyte performance because it has appropriate conductivity and viscosity, and lithium ions can move effectively. In addition to the electrolyte components, the electrolyte may further include one or more additives, such as haloalkylene carbonate compounds such as difluoroethylene carbonate, pyridine, triethylphosphite, triethanolamine, cyclic ethers, ethylene diamine, n-glyme, hexaphosphoric acid triamide, nitrobenzene derivatives, sulfur, quinone imine dyes, N-substituted oxazolidinones, N,N-substituted imidazolidines, ethylene glycol dialkyl ethers, ammonium salts, pyrrole, 2-methoxyethanol, 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. At this time, the additives may be included in an amount of 0.1 to 10.0 wt% based on the total weight of the electrolyte. In addition, since the lithium secondary battery according to the present invention stably exhibits excellent discharge capacity, output characteristics, and capacity retention rate, it is useful in portable devices such as mobile phones, laptop computers, and digital cameras, and 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, such as power tools; electric vehicles including electric vehicles (EVs), hybrid electric vehicles, and plug-in hybrid electric vehicles (PHEVs); or power storage systems. Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement them. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein. Hereinafter, the present invention will be more preferably described through specific examples. Example 1: Preparation of dry electrodes Lithium iron phosphate (LFePO4, Aleees Co., M121, D) as an electrode active material 50 2.2㎛) 94g, 1.5g of carbon black as a conductive agent, and 4.5g of polytetrafluoroethylene (PTFE) as a binder were added and mixed at a rotation speed of 10,000 rpm for 1 minute to prepare a composite composition. After the above composite composition was put into a kneader, it was kneaded at a rotation speed of 50 rpm at a temperature of 150°C and 1.1 atm for 5 minutes to produce a mixed aggregate. The above mixed aggregates were placed in a blender and ground at a rotation speed of 10,000 rpm for 40 seconds to produce powder for electrodes. The above electrode powder was calendered to manufacture an electrode composite film (roll diameter: 88 mm, temperature: 100°C, roll speed ratio: 20 / 24 rpm). After that, an aluminum alloy thin film having a thickness of 15 ㎛ and an iron (Fe) content of 0.1 wt% or less was heat-treated in a kiln maintained at 280°C for 8 hours to obtain a ductile processing treatment, and then the composite film was positioned on both sides of the ductile processing-treated current collector, and laminated using a roll press maintained at 150°C to manufacture a dry electrode. Examples 2 to 5 and Comparative Examples 1 to 8: Preparation of dry electrodes A dry electrode was manufactured in the same manner as in Example 1, except that the heat treatment temperature and time were controlled as described in Table 1. Heat treatment temperature (℃) Time (h) Example 1 2808 Example 2 28012 Example 3 3003 Example 4 3006 Example 5 3008 Comparative Example 1 -- Comparative Example 2 2306 Comparative Example 3 2801 Comparative Example 4 3001 Comparative Example 5 3300.5 Comparative Example 6 3306 Comparative Example 7 33012 Comparative Example 8 3706 Experimental Example 1: Measurement of modulus, tensile strength, and elongation at break of the entire collector. The collectors manufactured in Examples 1 to 5 and Comparative Examples 1 to 8 were cut into 100 mm x 20 mm pieces, and then the modulus, tensile strength, and elongation at break were measured using a UTM device from ZwickRoell according to the ASTM D638 method. At this time, the pre-load was 0.01 kg / cm, and the speed was 1 mm / min. Here, the modulus is the elastic coefficient, and is the slope of the elastic section (stress / strain) that appears in the stress-strain curve, preferably the value measured as the slope when the strain on the graph is 0.2%, the tensile strength is obtained as the maximum value (MPa) of the force applied until the sample does not break, and the elongation at break is obtained by multiplying (length at the point of sample breakage - initial sample length) / initial sample length by 100. The measurement results are shown in [Table 2] below. Collector Modulus (GPa) Tensile Strength (MPa) Elongation at Break (%) Example 124.6 104.96 3.54 Example 218.9 103.56 3.58 Example 318.49 9.92 3.54 Example 417.19 6.56 3.14 Example 514.49 1.58 3.48 Comparative Example 135.42 81.00 3.00 Comparative Example 238.7 16 1.20 2.00 Comparative Example 333.7 14 1.40 2.16 Comparative Example 430.7 12 5.60 2.90 Comparative Example 532.6 12 1.40 3.02 Comparative Example 612.98 6.20 3.48 Comparative Example 711.887.423.76Comparison example 810.381.123.58 Experimental Example 2: Adhesion Measurement The adhesive strength between the electrode composite film and the current collector was measured in each dry electrode manufactured according to Examples 1 to 5 and Comparative Examples 1 to 8. Preferably, each of the dry electrodes manufactured according to Examples 1 to 5 and Comparative Examples 1 to 8 was cut to 100 mm x 20 mm, and the surface of the electrode composite film inside the dry electrode was attached to a slide glass measuring 75 mm x 25 mm using double-sided tape. That is, the slide glass was attached to an area corresponding to half of the length of the electrode. Then, a roller was rubbed 10 times to ensure that the double-sided tape was evenly attached, thereby manufacturing an evaluation sample. Next, the slide glass portion of the evaluation sample was fixed to the sample stage of a universal testing machine (UTM), and the electrode half without the slide glass was connected to the load cell of the UTM equipment. The load cell was moved up to 80 mm at a speed of 100 mm / min, and the load applied to the load cell was measured. At this time, the minimum value of the load measured in the 20 mm to 40 mm section of the moving section was measured as the adhesive strength (gf / 20 mm) of each sample. A total of 5 measurements were performed for each electrode, and the average value is shown in [Table 3] below. At this time, the current collector and electrode composite film were laminated through a roll press, but in cases where adhesion between the current collector and the electrode composite film was impossible and immediate peeling occurred, the adhesive strength could not be measured and was marked as “-“. Experimental Example 3: Interfacial Resistance Measurement For the dry electrodes manufactured in Examples 1 to 5 and Comparative Examples 1 to 8, they were cut into 50 mm x 50 mm, and then a current of 100 uA was applied to the electrode using the MP resistance measurement method, and the resistance value between the electrode composite film and the current collector layer was measured by the potential difference measured between 46 probes. The measurement results are shown in [Table 3] below. At this time, the current collector and electrode composite film were laminated through a roll press, but in cases where adhesion between the current collector and the electrode composite film was impossible and immediate peeling occurred, the interfacial resistance could not be measured and was indicated as “-“. Adhesion (gf / 20mm)Interfacial resistance (Ωcm) 2 ) Example 142.260.4724 Example 243.560.7366 Example 340.410.4697 Example 442.410.5798 Example 541.960.5394 Comparative Example 1--Comparative Example 2--Comparative Example 336.400.6951 Comparative Example 432.710.5669 Comparative Example 5--Comparative Example 647.171.0019 Comparative Example 748.920.9981 Comparative Example 843.361.0923 Referring to the above [Table 3], it can be confirmed that in the case of Examples 1 to 5, the adhesion between the current collector and the electrode composite film is excellent compared to the comparative examples, and the interfacial resistance is also low. In particular, in the case of Comparative Examples 1 to 5 where the modulus is excessively high, it can be seen that the bonding of the current collector and the electrode composite film is impossible or the adhesive strength is low, and in the case of Comparative Examples 6 to 8 where the modulus is excessively small, it can be seen that the interfacial resistance is excessively high.

Claims

1. A current collector; an electrode composite film including an electrode active material and a fiberizable binder disposed on the current collector; A dry electrode having a modulus of the entire body of 13 GPa to 30 GPa.

2. In claim 1, A dry electrode having an iron (Fe) content of 0.75 wt% or less based on the total weight of the current collector.

3. In claim 1, A dry electrode having a modulus of 14.4 GPa to 24.6 GPa.

4. In claim 1, A dry electrode having an adhesive strength between the above-mentioned collector and the electrode composite film of 37 gf / 20 mm to 200 gf / 20 mm.

5. In claim 1, A dry electrode having a tensile strength of 50 MPa to 250 MPa.

6. In claim 1, The interfacial resistance between the above-mentioned collector and the above-mentioned electrode composite film is 0.0100Ωcm. 2 0.9900Ωcm 2 Dry electrode.

7. In claim 1, The above electrode active material is a dry electrode including a phosphorus oxide represented by the following chemical formula 1: [Chemical Formula 1] Li 1+x [Fe 1-a-b Mn a M 1 b ]PO4 In the above chemical formula 1, M 1 It contains one or more elements selected from the group consisting of Al, Mg, Ni, Co, Ti, Ga, Cu, V, Mo, Nb, W, Zr, Ce, In, Zn and Y, and -0.5≤x≤0.5, 0≤a≤0.8, 0≤b≤0.

1.

8. In claim 1, The average particle diameter (D) of the above electrode active material 50 ) is a dry electrode of 0.1㎛ to 10㎛.

9. In claim 1, The above fiberizable binder is a dry electrode comprising polytetrafluoroethylene (PTFE). 10.(S1) A step of preparing an electrode composite film and a current collector including an electrode active material and a fiberizable binder; (S2) a step of heat-treating the above-mentioned collector to manufacture a collector having a modulus of 13 GPa to 30 GPa; and (S3) A method for manufacturing a dry electrode, comprising the step of positioning and laminating the electrode composite film on at least one surface of the current collector.

11. In claim 10, A method for manufacturing a dry electrode, wherein the above heat treatment is performed at a temperature of 240°C to 320°C.

12. In claim 10, A method for manufacturing a dry electrode, wherein the above heat treatment is performed at a temperature of 280°C to 300°C.

13. In claim 10, A method for manufacturing a dry electrode, wherein the above heat treatment is performed for 1.5 to 12 hours.

14. In claim 10, A method for manufacturing a dry electrode, wherein the above heat treatment is performed for 3.0 to 8.0 hours.

15. A lithium secondary battery comprising the dry electrode of claim 1.

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