Electrode composite film, manufacturing method thereof, and dry electrode and lithium secondary battery comprising same

Abstract

The present invention relates to a composite film comprising: an electrode active material including an active material core and a carbon coating layer disposed on the surface of the core; and a fiberized binder, wherein the conductive path connectivity index (CPCI) defined by factors such as the cohesion of the binder, the volume cumulative average particle diameter D50 of the electrode active material, and the thickness of the carbon coating layer in the electrode active material is 0.09-0.45. The dry electrode has excellent resistance characteristics due to excellent conductive path connectivity, even when not including a conductive material. By including the dry electrode, it is possible to provide a lithium secondary battery having excellent output and excellent energy density on the basis of excellent resistance characteristics.

Description

Electrode composite film, method for producing same, dry electrode and lithium secondary battery comprising same The present invention relates to an electrode composite film, a method for producing the same, a dry electrode comprising the same, and a lithium secondary battery. Secondary batteries are used in small products such as digital cameras, P-DVDs, MP3Ps, mobile phones, PDAs, portable game devices, power tools, and e-bikes, as well as 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 as backup power storage devices. Typically, secondary batteries are manufactured by applying electrode active material slurry to a positive electrode collector and a negative electrode collector to form an electrode active material layer, then drying and rolling the electrodes to manufacture the positive and negative electrodes, and laminating them on both sides of a separator to form an electrode assembly of a predetermined shape, then housing the electrode assembly in a battery case, injecting electrolyte, and sealing the 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, during the drying process, the inside and outside of the electrode active material slurry are not uniformly dried, so there is a concern that the quality of the electrode may deteriorate due to the powder floating phenomenon caused by the difference in the solvent evaporation rate, that is, the powder in the area that dries first rises and forms a gap with the area that dries relatively later. To solve the above problem, drying devices capable of controlling the evaporation rate of the solvent so that the inside and outside of the electrode active material slurry can be uniformly dried are being considered, but these 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 included in the conventional electrode active material slurry is N-methyl-2-pyrrolidone (NMP), which has a high boiling point, so it requires high heat energy and a very long drying process to dry, which is very disadvantageous for mass production. In addition, N-methyl-2-pyrrolidone (NMP) is a toxic substance and is harmful to living organisms, so it is not environmentally friendly. Accordingly, research on dry electrodes that manufacture electrodes without using a solvent has been actively conducted recently. The dry electrode is generally manufactured by laminating a free-standing type electrode composite film manufactured in the form of a sheet, which includes an electrode active material, a binder, a conductive material, etc., onto a current collector. The electrode composite film includes a process of first mixing an electrode active material, a carbon material as a conductive material, and a fiberized 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 manufacturing dry electrodes, since materials are mixed without a solvent or dispersant, a method for dispersing each material so that it is homogeneously distributed is a key technology. Recently, linear conductive materials such as CNTs, which have been widely used in wet electrodes and can reduce the content of conductive materials, have the problem of being difficult to disperse in the dry process, making it difficult to achieve an increase in the loading of active materials by reducing the content of conductive materials. Accordingly, dry electrodes require a relatively large amount of conductive material compared to wet electrodes, and development of materials or processes capable of reducing this amount is necessary. One object of the present invention is to solve the above problems, and to provide an electrode composite film in which a conductive path can be smoothly formed even in a situation where a conductive material is insufficient, and in which the amount of conductive material input can be reduced, thereby increasing the amount of active material loaded. In addition, an object of the present invention is to solve the above problems and to provide a lithium secondary battery in which resistance characteristics and life characteristics are improved and capacity characteristics can be expected to be improved by applying the electrode composite film. [1] An electrode composite film is provided, which includes an electrode active material and a fiberized binder, wherein the electrode active material includes an active material core and a carbon coating layer disposed on a surface of the core, and has a CPCI (Conductive Path Connectivity Index) of 0.09 to 0.45 defined by the following equation 1. [Formula 1] CPCI = A B x R x (T C / D AM ) In the above equation 1, A B is the cohesion of the binder in the electrode composite film, and D AM The volume cumulative average particle diameter D of the silver electrode active material 50 (㎛), and T C is the thickness (㎛) of the carbon coating layer of the electrode active material, and R is [(W AM / W B )x(1+2W C )] is calculated, where W B is the weight percentage (wt%) of the binder relative to the total weight of the electrode composite film, and W AM is the weight percentage (wt%) of the electrode active material relative to the total weight of the electrode composite film, and W C is a unitless number of the weight percentage (wt%) of the conductive material with respect to the total weight of the electrode composite film. [2] In the above [1], the cohesion (A) of the binder B) is a step of obtaining a target image having a resolution of 1280 x 960 or higher by BSE (Back Scattered Electron) measurement using a field emission scanning electron microscope (FESEM) for a cross-section of the composite film formed by the ion milling method; a step of adjusting a set contrast value for the target image, and adjusting the set contrast value of each of an active material region and a binder region to a maximum and a minimum, thereby distinguishing active material pixels and binder pixels belonging to each region; and a step of forming a binder region in which a plurality of binder pixels are adjacently formed, with an area of ​​3 ㎛ for the binder pixels. 2 It may be derived by a method including the steps of calculating the number of cohesive binder pixels in an ideal cohesive binder region and calculating the total number of binder pixels in the entire binder region, thereby calculating the cohesion of the binder, which is defined by the following equation 2. [Formula 2] A B = (Number of Cohesive Binder Pixels) / (Number of Total Binder Pixels) [3] In the above [1] and / or [2], the electrode active material has a volume cumulative average particle diameter D 50 This may be between 0.1 ㎛ and 5.0 ㎛. [4] In one or more of the above [1] to [3], the electrode active material has a volume cumulative average particle diameter D 50 (D AM ) may be a ratio of the average thickness (TC) of the carbon coating layer to 0.0002 to 0.1. [5] In one or more of the above [1] to [4], the cohesion (A) of the binder B ) can be between 0.3 and 0.9. [6] In any one or more of the above [1] to [5], R in the above formula 1 may be 16 to 70. [7] In any one or more of the above [1] to [6], the active material core may include at least one selected from the group consisting of lithium-manganese oxide, lithium-nickel oxide, lithium-nickel-manganese oxide, lithium-nickel-cobalt oxide, lithium-manganese-cobalt oxide, lithium-nickel-manganese-cobalt oxide, lithium-nickel-cobalt-transition metal (M) oxide, and lithium metal phosphate compound. [8] In any one or more of the above [1] to [7], the active material core may include a lithium metal phosphate compound represented by the following chemical formula 1. [Chemical Formula 1] Li 1+a Fe 1-x M x PO 4 In the chemical formula 1 above, M is at least one selected from Mn, Co, Ni, Al, Mg, and Ti, and -0.5≤a≤0.5, 0≤x<1. [9] In any one or more of the above [1] to [8], the fiberized binder may include polytetrafluoroethylene (PTFE).

[0010] In any one or more of the above [1] to [9], the electrode composite film may contain 92 to 99.5 parts by weight of an electrode active material and 0.5 to 8 parts by weight of a fiberized binder, and may not contain a conductive material.

[0011] In any one or more of the above [1] to

[0010] , the electrode composite film may have a porosity of 29 volume% or less.

[0012] In any one or more of the above [1] to

[0011] , the electrode active material may have a powder resistance of 1 Ωcm to 100 Ωcm.

[0013] A method for producing the above-described electrode composite film is provided, comprising: a step (S1) of forming a composite mixture by mixing an electrode active material and a fiberizable binder; a step (S2) of kneading the composite mixture while applying a shear force to form a mixed aggregate; a step (S3) of pulverizing the mixed aggregate to produce a mixed powder; and a step (S4) of sheeting the mixed powder to produce a composite film.

[0014] In the above

[0013] , the S1 step may be performed at a mixing speed of 3,000 rpm to 20,000 rpm for 0.5 to 60 minutes.

[0015] In the above

[0013] and / or

[0014] , the S2 step may be performed at a mixing speed of 10 rpm to 100 rpm for 3 to 60 minutes.

[0016] In any one or more of the above

[0013] to

[0015] , the S3 step may be performed in a grinding device at a speed of 1,000 rpm to 15,000 rpm for 5 seconds to 30 minutes.

[0017] A dry electrode is provided, comprising: a current collector; and the above-described electrode composite film disposed on the current collector.

[0018] In the above

[0017] , the electrode may be an anode.

[0019] A lithium secondary battery is provided, which includes a plurality of electrodes, at least one of which includes the electrode composite film described above.

[0020] An electric device including the aforementioned lithium secondary battery is provided. An electrode composite film according to one embodiment of the present invention has excellent connectivity of a conductive path by controlling the conductivity of the electrode active material itself and the degree of contact between the active materials and the distribution of the binder even in a situation where the conductive material is insufficient, and does not depend on the conductive material for formation of the conductive path, thereby solving problems caused by uneven distribution of the conductive material and increasing the loading amount of the active material. Furthermore, the electrode composite film according to one embodiment of the present invention can implement an electrode with excellent performance that is less affected by a conductive agent, while omitting a process for dispersing a conductive agent during the manufacturing process, and thus can greatly contribute to improving unit price competitiveness through reduction in cost and process cost. In addition, a lithium secondary battery according to another embodiment of the present invention can improve the resistance characteristics and life characteristics of the battery by solving the problem caused by the uneven distribution of the conductive material by including the electrode composite film, and can expect improvement in the capacity characteristics and energy density due to the increase in the loading amount of the electrode active material. 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 that conform to 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. In this specification, "Volume cumulative average particle diameter D 50 "In the particle size distribution curve, it means the particle size corresponding to 50% of the volume accumulation amount. The above D 50For 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 this specification, the "average particle diameter" means an arithmetic average value calculated by measuring the particle diameters of at least 30 particles observed in a scanning electron microscope image when observed at a field of view of 5,000 times to 20,000 times using a scanning electron microscope. In this case, the particle diameter means the longest axis diameter of the particle. The "volume cumulative average particle diameter D 50 " and "average particle size" have different measurement methods, but their values ​​can be derived similarly, and the volume-accumulated average particle size D50 measured in a powder state can have a similar value within an error range to the average particle size observed in a scanning electron microscope image of an electrode after the powder is manufactured into an electrode. In this specification, the "mixture" means a mixture including an electrode active material and a binder (optionally, also including a conductive material), which is physically mixed to form a uniform dispersion phase, and may be a powder mixture as a product of a mixing process (mixing process) according to this specification, and may be one in which substantially no solvent is involved. Here, substantially no solvent is involved means that no solvent is added or only a very small amount of solvent is added when mixing the mixture. In this specification, the “mixed aggregate” refers to a product of the kneading process (kneading process) according to this specification that is converted into an aggregate in a dough state by the binder being fiberized as the composite mixture is subjected to a shear force and the powder mixture is combined or linked to each other, and may be a solids content of 100%. In this specification, “electrode powder” may mean a material in a powder state in which the mixed aggregate is pulverized to make the particle size smaller. In this specification, the "electrode composite film" may mean a film manufactured in the form of a free-standing single sheet using the electrode powder without the intervention of a solvent. The term "free-standing" in this specification means that it can maintain a single form without relying on other members and can be moved or handled by itself. The electrode composite film may be formed by compressing electrode composite powder as described below. For example, it may have a shape in which the composite powder is accumulated by compressing to form a layered structure. In this specification, the “average thickness of the carbon coating layer” may mean an average value of values ​​derived after measuring the thickness of the carbon coating layer at 100 or more points on the surface of the active material using a transmission electron microscope (TEM). In this case, when selecting 100 or more points, they may be selected at an appropriate interval so as to cover the entire particle. In this specification, the “degree of cohesion of the binder” is a measure that can evaluate the degree to which the binder is dispersed and cohesive within the electrode composite film, and the degree of cohesion of the binder can be measured by the following method. 1) (Preparation of target image) The electrode composite film is cut by the ion milling method to prepare a cross-section sample, and a target image with a resolution of 1280 x 960 or higher is obtained by measuring BSE (Back Scattered Electron) with respect to the cross-section using a field emission scanning electron microscope (FESEM, Hitachi, Su8020, etc. can be used). 2) (Adjusting the setting contrast level) Using a commercial image processing program (e.g., Mountains), adjust the setting contrast level of the target image, adjusting the active material area to the highest contrast level and the binder area to the lowest contrast level, thereby distinguishing each pixel in the image into a binder pixel and an active material pixel. 3) (Calculation of the ratio of the cohesive area) For the above binder pixels, a binder area formed by a plurality of binder pixels being adjacent to each other, with an area of ​​3 ㎛ 2 The number of cohesive binder pixels in the ideal cohesive binder region is calculated, and the total number of binder pixels in the entire binder region is calculated, and the cohesion of the binder (A) is calculated by the following equation 2. B ) can be derived. [Formula 2] A B = (Number of Cohesive Binder Pixels) / (Number of Total Binder Pixels) *63 In the present specification, the “three-dimensional fiber network structure” may mean a structure that can be formed by fiberization of a binder during the process of sheet-forming an electrode composite film from a composite composition including an electrode active material and a binder. Specifically, the three-dimensional fiber network structure may mean various structures in which fine fibers formed by fiberization of a binder form a skeleton, thereby functioning as a support that enables the electrode composite film to be a self-supporting film. At this time, the electrode active material and, optionally, a conductive material may be accommodated in the pores formed in the three-dimensional fiber network structure. In this specification, the “conductive material” may mean a conductive material existing in addition to an electrode active material including an active material core and a carbon coating layer disposed on the core. That is, the “conductive material” herein may be present in an electrode composite film separately from the electrode active material. In this specification, each of the electrode composite film, the method for producing the same, the dry electrode, and the lithium secondary battery including the same includes at least one of the technical features and / or technical configurations described below, and these technical features and / or technical configurations can be combined in various ways. Electrode composite film An electrode composite film according to the present invention comprises an electrode active material and a fiberized binder, wherein the electrode active material comprises an active material core and a carbon coating layer disposed on the surface of the core, and is characterized in that a CPCI (Conductive Path Connectivity Index) defined by the following Equation 1 is 0.09 to 0.45. [Formula 1] CPCI = A B x R x (T C / D AM ) In the above equation 1, A B is the cohesion of the binder in the electrode composite film, and D AM The volume cumulative average particle diameter D of the silver electrode active material 50 (㎛), and T C is the thickness (㎛) of the carbon coating layer of the electrode active material, and R is [(W AM / W B )x(1+2W C )] is calculated, where W B is the weight percentage (wt%) of the binder relative to the total weight of the electrode composite film, and W AM is the weight percentage (wt%) of the electrode active material relative to the total weight of the electrode composite film, and W C is a unitless number of the weight percentage (wt%) of the conductive material with respect to the total weight of the electrode composite film. In general, since dry electrodes are manufactured without using a solvent, unlike wet electrodes, uniformly dispersing electrode materials is an important and difficult process, which greatly affects electrode performance. In addition, in order to increase the loading amount of electrode active material, the input amount must be reduced, and in order to prevent performance degradation, a high-performance conductive material must be used. However, high-performance conductive materials, such as carbon nanotubes, have the problem of poor dispersibility. In other words, in the manufacture of dry electrodes, there are two problems: difficulty in dispersion due to not using a solvent and difficulty in dispersion due to using a material with poor dispersibility. However, in the present invention, in order to eliminate the difficulty of dispersion due to the characteristics of the conductive material as described above, instead of using the conductive material or using the conductive material in a minimum amount, an electrode composite film is proposed that can improve the resistance characteristics of the battery by increasing the loading amount while also having excellent connectivity of the conductive path by using an active material having low powder resistance, particularly an active material including a carbon coating layer. CPCI (Conductive Path Connectivity Index) According to one embodiment of the present invention, the electrode composite film is characterized in that the CPCI defined by the following Equation 1 is 0.09 to 0.45. [Formula 1] CPCI = A B x R x (T C / D AM ) In the above equation 1, A B is the cohesion of the binder in the electrode composite film, and D AM The volume cumulative average particle diameter D of the silver electrode active material 50 (㎛), and T C is the thickness (㎛) of the carbon coating layer of the electrode active material, and R is [(W AM / W B )x(1+2W C )] is calculated, where WB is the weight percentage (wt%) of the binder relative to the total weight of the electrode composite film, and W AM is the weight percentage (wt%) of the electrode active material relative to the total weight of the electrode composite film, and W C is a unitless number of the weight percentage (wt%) of the conductive material with respect to the total weight of the electrode composite film. The above CPCI can be an indicator for determining how well a conductive path capable of increasing electron mobility and ion mobility is formed within an electrode composite film, and by manufacturing an electrode composite film that satisfies the above range, the resistance characteristics of a battery can be improved even if a very small amount of conductive material is included or even if no conductive material is included. The above CPCI is the content ratio of electrode active material and binder (R) and the volume cumulative average particle diameter of electrode active material (D AM ) for the average thickness of the carbon coating layer (T C ) ratio, and the cohesion of the binder (A B ) is defined as the product of The degree of cohesion of the binder can be used to determine the proportion of the binder that is cohesive in a fiberized state within the electrode composite film. In other words, the degree of cohesion of the binder can be used to determine how much contact area can be secured between electrode active materials when the binder is fiberized to form a three-dimensional fiber network structure within the electrode composite film. However, in cases where the binder is excessively coagulated, the diversity of conductive paths may have a more significant effect than securing the contact area between the active material and the trace conductive material or the active materials accommodated in the pores within the matrix, and there is a problem that it may be difficult to form a complex conductive path due to excessive coagulation of the binder. Furthermore, since the mechanical properties of the electrode composite film are poor, there is a concern that this may lead to problems ranging from deterioration of appearance characteristics to deterioration of durability, and therefore, it may be necessary to control this to an appropriate level. The average particle size of the electrode active material is related to the spacing between pores in the matrix of the fiberized binder in the electrode composite film. As the particle size becomes smaller, the area of ​​contact between the electrode active material particles or between the electrode active material and a small amount of conductive particles may become larger. In other words, since the electrode active material includes a carbon coating layer, this may mean that more conductive paths may be formed through such contact. In order to form an electrode composite film, which is a free-standing film, from the electrode powder, it is necessary to increase the amount of binder input as the average particle size of the electrode active material decreases. In dry electrodes, the binder is a key component that forms the support structure of the film. If the content increases within a certain range, the durability or the fairness of the sheet forming process can be improved. However, this means that an increase in the binder content not only decreases the loading of the active material, but also decreases the contact area between the electrode active materials and increases the resistance. Intuitively, since the binder is a resistor, it has the potential to cause problems in conductivity. Therefore, it may be necessary to limit the increase in the binder content. Therefore, it is difficult to say that applying an active material with a small particle size is the only way to improve performance. The degree of cohesion of the binder can be intuitively interpreted as meaning that the distribution of the binder is uneven, but conversely, if there is an area where the binder is cohesive, it can mean that there is also an area where the active material, or the active material and the conductive material are cohesive. Accordingly, the higher the degree of cohesion of the binder, the more the contact area between the electrode-active material increases to form a conductive path, and the smaller the particle size of the electrode-active material, the more the contact between the active materials can be improved within the three-dimensional fiber network structure of the binder. This can be interpreted as meaning that even if the active materials are accommodated in the internal pores and there is no area where the binder is uniformly distributed and cohesive, if the contact between them is not smooth, the formation of a conductive path is not sufficient, and it can mean that the contact between the active material, or the active material and the conductive material can be indirectly identified through the degree of cohesion of the binder. However, the degree of cohesion of the binder can vary depending on the amount of binder input, and the smaller the particle size of the electrode active material, the more the binder content should be increased, but this increase in the binder can increase the resistance independently of the degree of cohesion. In addition, the carbon coating layer is essential, but it can affect the mobility of lithium ions depending on its thickness. Therefore, by identifying the factors that affect securing a conductive path in an electrode composite film where the conductive material is insufficient, CPCI is defined from these factors. According to one embodiment of the present invention, the CPCI of the electrode composite film is 0.09 to 0.45. When the CPCI is less than 0.09, it may mean that the fiberization of the binder is excessively advanced, resulting in a low cohesion value of the binder, which may manifest as poor mechanical properties. In addition, it means that although the electrode active material is evenly distributed, there are many parts that are not in contact with each other, so that many parts in which the conductive path is disconnected may occur, and when the conductive material is included in a small amount or not included at all, there is a problem that the electrode resistance is too high, and thus the performance of the battery may become very poor. The above CPCI may mean that a conductive path is formed better the larger the value, but unlike this theoretical expectation, if it exceeds 0.45, the cohesion of the binder may be excessively high, which may cause a problem of reduced conductivity due to the failure to form a complex conductive path, and the durability may be poor due to problems such as low mechanical properties of the electrode composite film or appearance characteristics, such as stripes or cracks on the surface. In addition, the thickness of the carbon coating layer is thick compared to the average particle size of the electrode active material, which may cause poor lithium ion mobility, relatively low capacity, and short battery life. In other words, although a conductive path may be formed better the larger the CPCI value, this technical meaning may be satisfied when the CPCI is 0.45 or less, and if it exceeds 0.45, various problems as mentioned above may occur, and therefore it may be necessary to adjust the value. When the above CPCI satisfies the range of 0.09 to 0.45, even if only a small amount of the conductive agent is included or not included, the relationship between the distribution of the binder, the average particle size of the electrode active material, and the thickness of the carbon coating layer has a synergistic effect, so that the resistance characteristics of the battery can be improved. The resistance measured in the electrode state may be lower when the conductive material is included, but the resistance value measured while operating the battery may be more advantageous, because the resistance of the electrode evaluates only the electron mobility, whereas the resistance of the battery can reflect not only the electron mobility but also the ion mobility. Accordingly, preferably, the CPCI may be 0.10 or more, 0.11 or more, 0.12 or more, 0.13 or more, 0.15 or more, 0.17 or more, or 0.18 or more, and further may be 0.43 or less, 0.40 or less, 0.38 or less, 0.36 or less, 0.35 or less, or 0.33 or less. In other words, since the mobility of lithium ions is affected by various factors, such as the path through which lithium ions escape from inside the active material and the path through which lithium ions escape from the surface of the active material to the outermost surface of the electrode composite film, the resistance characteristics of the battery are not improved simply by securing an electron movement path through a conductive material. Therefore, it is possible to provide an electrode composite film capable of improving resistance characteristics without including a conductive material, as in the present invention. According to one embodiment of the present invention, the average particle diameter (D) of the electrode active material 50 ) may be 0.1 ㎛ to 5.0 ㎛, specifically 0.5 ㎛ to 4.0 ㎛, and more specifically 0.7 ㎛ to 3.5 ㎛. If the average particle size of the electrode active material is excessively large, there may be a problem that the capacity characteristics of the battery are deteriorated, and the high-rate charge / discharge characteristics are deteriorated due to high internal resistance and a decrease in ion movement speed, and there may be a problem that physical contact between the active materials within the fiberized binder matrix becomes impossible and a conductive path is not formed. In addition, if the average particle size of the electrode active material is excessively small, there may be a problem that the mechanical strength such as the tensile strength and elongation at break of the electrode composite film is deteriorated when manufacturing an electrode composite film including the same in the future. Therefore, the average particle diameter (D) of the electrode active material 50 ) satisfies the above range, the particle size of the obtained composite 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, it is easy to form a film, and mechanical properties such as tensile strength and elongation at break can be improved. In addition, according to one embodiment of the present invention, the carbon coating layer of the electrode active material may have an average thickness of 1 nm to 30 nm. Preferably, it may be 2 nm or more, or 3 nm or more, and 25 nm or less, 20 nm or less, 15 nm or less, or 10 nm or less. When the thickness of the carbon coating layer satisfies the above range, it may contribute to satisfying the CPCI value, thereby improving the conductive path connectivity without losing capacity. Here, the average thickness may mean a value obtained by measuring the thickness of the carbon coating layer at 100 points or more on the surface of the electrode active material particle using a transmission electron microscope, and averaging the measured values. Furthermore, according to one embodiment, the ratio of the average thickness (㎛) of the carbon coating layer to the volume cumulative average particle diameter (㎛) of the electrode active material may be 0.0002 to 0.1, and preferably, the ratio may be 0.0004 or more, 0.0006 or more, or 0.0008 or more, and further may be 0.08 or less, 0.06 or less, 0.05 or less, 0.03 or less, or 0.01 or less. It may be necessary to manufacture or select the electrode active material so as to satisfy the above ratio. Prior to satisfying the ranges of the above-described volume cumulative average particle diameter and the average thickness of the carbon coating layer, respectively, it is necessary to understand the ratio of the thickness occupied by the carbon coating layer in the entire electrode active material, which may play a major role in affecting the CPCI, and thus may contribute to improving battery performance. According to one embodiment of the present invention, the cohesion of the binder among the factors defining the CPCI may be 0.3 to 0.9, preferably 0.35 or more, 0.40 or more, or 0.50 or more, and further 0.88 or less, 0.87 or less, 0.85 or less, 0.83 or less, or 0.80 or less. The cohesion of the binder may be determined as the binder is fiberized during a process of manufacturing an electrode composite film, for example, a process of mixing an electrode active material and a binder, applying a shear force through kneading, and finally forming an electrode powder into a sheet through roll rolling, and thus the cohesion of the binder can be achieved by appropriately controlling the mixing conditions, kneading conditions, and sheet forming conditions. When the degree of cohesion of the binder is within the above range, it may mean that the degree of fiberization of the binder is appropriate for forming the electrode composite film, and it may mean that the spacing of the fiberized binder matrix is ​​appropriately configured to enable physical contact between the conductively coated electrode active materials. The cohesion of the above binder can be measured by the following method. 1) (Preparation of target image) The electrode composite film is cut by the ion milling method to prepare a cross-section sample, and a target image with a resolution of 1280 x 960 or higher is obtained by measuring BSE (Back Scattered Electron) with respect to the cross-section using a field emission scanning electron microscope (FESEM, Hitachi, Su8020, etc. can be used). 2) (Adjusting the setting contrast level) Using a commercial image processing program (e.g., Mountains), adjust the setting contrast level of the target image, adjusting the active material area to the highest contrast level and the binder area to the lowest contrast level, thereby distinguishing each pixel in the image into a binder pixel and an active material pixel. 3) (Calculation of the ratio of the cohesive area) For the above binder pixels, a binder area formed by a plurality of binder pixels being adjacent to each other, with an area of ​​3 ㎛ 2 The number of cohesive binder pixels in the ideal cohesive binder region is calculated, and the total number of binder pixels in the entire binder region is calculated, and the cohesion of the binder (A) is calculated by the following equation 2. B ) can be derived. [Formula 2] A B = (Number of Cohesive Binder Pixels) / (Number of Total Binder Pixels) As described above, the degree of cohesion of the binder can be calculated through a series of processes including preparing a target image, adjusting the contrast level through an image program in the prepared image, and calculating the ratio of the cohesive area. At this time, the standard for determining the cohesive area when calculating the ratio of the cohesive area is 3 ㎛. 2 It could be more than 3 ㎛ 2If a smaller area is included in the cohesion area, the influence of the contact with the active material may not be accurately reflected, so it may be desirable to set the standard as above. In addition, if the fiberization progresses normally and the sheet is formed normally, there will not be an excessively large cohesion area, but if the width of the cohesion area, that is, the length of the longest width within the area, exceeds 10 ㎛, this can be judged to be a manufacturing defect of the electrode. According to one embodiment of the present invention, the ratio of the contents of the electrode active material and the fiberized binder included as factors in the CPCI may be considered. For example, the content of the electrode active material and the content of the binder may be reflected as R in the CPCI, and specifically, R may be defined as the ratio of the weight percentage (wt%) of the electrode active material to the weight percentage (wt%) of the binder with respect to the total weight of the electrode composite film. The above R can be, for example, 16 to 70, 17 to 66, or as another example, 19 or more, 21 or more, or 24 or more, and also 60 or less, 50 or less, or 47 or less. When R satisfies the above range, it is possible to maximize the loading amount to improve the energy density, while also contributing to satisfying the CPCI by maximizing the cohesion of the binder and the contact area between the active material and the complex diversification of the conductive path. The above R is [(W AM / W B )x(1+2W C )] can be calculated. In general, although the conductive material can greatly contribute to the formation of a conductive path, it reflects the fact that it is not well dispersed, which may mean that the value of CPCI may change depending on the amount of conductive material input compared to the influence of the content of the electrode active material or binder. For example, although a conductive agent can function as an auxiliary agent that can improve resistance by contributing to the movement of charges, if it is not evenly distributed throughout while filling the pores within the electrode, it can become a factor that inhibits the mobility of lithium ions, and thus, if the amount generally input is applied, it may not contribute to improving the overall resistance characteristics. Meanwhile, according to one embodiment of the present invention, the electrode active material may be included in an amount of 90 to 99.5 parts by weight based on 100 parts by weight of the total weight of the electrode composite film, and preferably 91 parts by weight or more, 92 parts by weight or more, 93 parts by weight or more, 94 parts by weight or more, or 95 parts by weight or more, and further 99 parts by weight or less, 98.5 parts by weight or less, 98 parts by weight or less, or 97.5 parts by weight or less. When included in the above range, it may be preferable in terms of both the aspect of increasing the capacity and energy density of the electrode and the aspect of optimizing the functions of the conductive material and the binder, which are auxiliary materials, and this may be a value directly reflected as a weight percentage in the R. The above binder may be included in an amount of 0.5 parts by weight to 10.0 parts by weight based on 100 parts by weight of the total weight of the electrode composite film, and preferably, may be included in an amount of 1.0 parts by weight or more, 1.3 parts by weight or more, 1.5 parts by weight or more, 1.7 parts by weight or more, or 2.0 parts by weight or more, and may also be included in an amount of 9.0 parts by weight or less, 8.0 parts by weight or less, 7.0 parts by weight or less, 6.5 parts by weight or less, 6.0 parts by weight or less, 5.5 parts by weight or less, or 5.0 parts by weight or less. In the case of a fiberized binder, if it is included in the above range, there may not occur a problem of acting as resistance or a problem with the degree of fiberization for manufacturing in the form of a self-supporting sheet, and this may be a value directly reflected in the R as a weight percentage. According to one embodiment of the present invention, the electrode composite film is characterized in that it contains a trace amount of a conductive agent, or does not contain one, and specifically, the conductive agent may be contained in an amount of 0.8 part by weight or less, 0.7 part by weight or less, 0.5 part by weight or less, 0.3 part by weight or less, 0.1 part by weight or less, 0.05 part by weight or less, or 0.01 part by weight or less, based on 100 parts by weight of the total weight of the electrode composite film, and most preferably, the conductive agent may not be contained. Even if the conductive agent is contained in an amount of 1 / 10 or even 1 / 100 of the amount generally contained, or is not contained, when the relationship between the degree of cohesion of the binder and the thickness and average particle diameter of the carbon coating layer of the electrode active material and the appropriate values ​​thereof are controlled as described above, an electrode composite film having excellent connectivity of conductive paths can be implemented, and ultimately, the resistance characteristics of the battery can be improved, and the capacity can also be increased according to an increase in the loading amount. Electrode active material According to one embodiment of the present invention, there is no particular limitation on the electrode active material as long as it is a commonly used electrode active material. For example, the electrode active material may be a positive electrode active material or a negative electrode active material, and is characterized by including a carbon coating layer on the surface of the active material core. According to one embodiment of the present invention, the electrode composite film includes an electrode active material including a carbon coating layer and a fiberized binder. The above positive electrode active material may include a lithium transition metal compound containing at least one selected from the group consisting of nickel (Ni), cobalt (Co), manganese (Mn), and iron (Fe), which is a compound capable of reversible intercalation and deintercalation of lithium. Specifically, it may include a lithium metal oxide containing lithium and one or more metals such as cobalt, manganese, nickel or aluminum. More specifically, the lithium metal oxide is a lithium-manganese oxide (e.g., LiMnO2 , 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-Z Ni 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 r )O 2 (Here, 0<p<1, 0<q<1, 0<r<1, p+q+r=1) or Li(Ni p1 Co q1 Mn r1 )O 4 (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 )O 2(Here, 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, such that 0<p2<1, 0<q2<1, 0<r2<1, 0<s2<1, p2+q2+r2+s2=1), etc.), and one or more compounds of these may be included. Among these, the lithium metal oxide is LiCoO in that it can improve the capacity characteristics and stability of the battery. 2 , LiMnO 2 , LiNiO 2 , lithium nickel manganese cobalt oxide (e.g. Li(Ni 1 / 3 Mn 1 / 3 Co 1 / 3 )O 2 , 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 and Li(Ni 0.8 Mn 0.1 Co 0.1 )O 2 etc.), lithium nickel cobalt aluminum oxide (e.g., Li(Ni 0.8 Co 0.15 Al 0.05 )O 2 etc.), or lithium nickel manganese cobalt aluminum oxide (e.g. Li(Ni 0.86 Co 0.05 Mn 0.07 Al 0.02 )O 2 ), lithium iron phosphate (e.g. LiFePO 4 ) may be used, and any one of these or a mixture of two or more of these may be used. In addition, the positive electrode active material may include a lithium metal phosphate compound containing iron, and specifically may be lithium iron phosphate, and may be represented by, for example, the following chemical formula 1. [Chemical Formula 1] Li 1+a Fe 1-x M x PO 4 In the chemical formula 1 above, M is at least one selected from Mn, Co, Ni, Al, Mg, and Ti, and -0.5≤a≤0.5, 0≤x<1. When the above-mentioned positive electrode active material is a lithium metal phosphate-based compound, particularly when it is lithium iron phosphate, the positive electrode active material has a disadvantage in that its safety is guaranteed but its capacity is relatively small compared to lithium nickel-based oxide. However, according to one embodiment of the present invention, since a dry electrode capable of high loading can be implemented, it is possible to apply lithium iron phosphate with improved safety and improved capacity, and to implement a lithium secondary battery with excellent unit price competitiveness. 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 metalloid material; and a transition metal oxide. As the above carbon-based material, any carbon-based negative electrode active material generally used in lithium ion secondary batteries may be used without particular limitation, and representative examples thereof include crystalline carbon, amorphous carbon, or a combination of these. Examples of the crystalline carbon include graphite such as amorphous, plate-shaped, flake-shaped, spherical, or fibrous natural graphite or artificial graphite, and examples of the amorphous carbon include soft carbon (low-temperature calcined carbon) or hard carbon, mesophase pitch carbide, calcined coke, and the like. 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 can be used. The above metal composite oxides include PbO, PbO 2 , Pb 2 O 3 , Pb 3 O 4 , Sb 2 O 3 , Sb 2 O 4 , Sb 2 O 5 , GeO, GeO 2 , Bi 2 O 3 , Bi 2 O 4 , Bi 2 O 5 , Li x Fe 2 O 3 (0≤x≤1), Li x WO 2 (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. The above metalloid substances 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, SnO 2, Sn-Y (wherein Y is an element selected from the group consisting of alkali metals, alkaline earth metals, group 13 elements, group 14 elements, transition metals, rare earth elements and combinations thereof, but not Sn), and also at least one of these and SiO 2 can also be used in combination. The element Y may be selected from the group consisting of Mg, Ca, Sr, Ba, Ra, Sc, Y, Ti, Zr, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg, Tc, Re, Bh, Fe, Pb, Ru, Os, Hs, Rh, Ir, Pd, Pt, Cu, Ag, Au, Zn, Cd, B, Al, Ga, Sn, In, Ge, P, As, Sb, Bi, S, Se, Te, Po, and combinations thereof. Examples of the above transition metal oxides include lithium-containing titanium composite oxide (LTO), vanadium oxide, and lithium vanadium oxide. According to one embodiment of the present invention, the electrode active material including the carbon coating layer may preferably be a cathode active material, and the cathode active material may include a lithium phosphate-based material. The lithium phosphate-based material has a relatively small volume cumulative average particle diameter compared to other cathode active materials, and can easily reduce powder resistance by using a carbon coating, so it may be optimized for satisfying the CPCI value. In addition, the electrode active material may have a powder resistance of 1 Ωcm to 100 Ωcm, preferably 2 Ωcm or more, or 3 Ωcm or more, and 90 Ωcm or less, 80 Ωcm or less, or 70 Ωcm or less. The powder resistance may mean that the active material is highly conductive, and it is preferable that the electrode active material included in the electrode composite film of the present invention, which is characterized by not including a conductive material, has a powder resistance in the aforementioned range. Here, the powder resistance is measured by putting 2 g of active material powder into a ceramic container having a diameter of 22 mm and having a 4-point probe built into the bottom, pressing it with a force of 2000 kgf, that is, a pressure of approximately 50 MPa, using a commercial powder resistance meter (for example, HPRM-AM2-L of Hantech), and calculating the resistance by multiplying the resistance by the thickness of the pressurized active material powder. Fiberized binder In one aspect, the binder has a function of forming a three-dimensional fiber network structure so that the electrode composite film can be self-supporting. The binder is not specifically specified as being fiberizable, that is, as long as it can form a three-dimensional fiber network structure in the electrode composite film through fiberization and provide pores capable of accommodating an electrode active material and optionally a conductive material. The fiberization of the above binder means a treatment to finely divide the high molecular polymer applied as the binder, and can be performed, for example, by applying a mechanical shear force, etc., and as a result, the surface is released and fiberized, thereby forming a plurality of fine fibers, and through this, a three-dimensional fiber network structure can be included. Such a fiberized 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). Specifically, 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 further include at least one of polyethylene oxide (PEO), polyvinylidene fluoride (PVdF), polyvinylidene fluoride-cohexafluoropropylene (PVdF-HFP), and a polyolefin-based binder. Challenge According to one embodiment of the present invention, the conductive material is not particularly limited as long as it has conductivity without causing a chemical change in the battery, and for example, carbon black such as acetylene black, Ketjen black, channel black, furnace black, lamp black, or thermal black; fluorinated carbon powder; graphite materials such as natural graphite or artificial graphite with a highly developed crystal structure; fibrous carbon materials such as carbon fibers, carbon nanotubes, and carbon nanofibers; metal fibers; metal powders such as aluminum powder and nickel powder; conductive whiskers such as zinc oxide or potassium titanate; conductive metal oxides such as titanium oxide; conductive polymers such as polyphenylene derivatives, and the like can be used. Preferably, graphite materials, carbon black, and carbon nanotubes (CNTs) can be applied for uniform mixing of the conductive material and improvement of conductivity. According to one embodiment of the present invention, the electrode composite film may have a porosity of 17 vol% to 30 vol%, preferably 19 vol% or more, or 20 vol% or more, and may also be 29 vol% or less, 28 vol% or less, 27 vol% or less, or 26 vol% or less. When the above range is satisfied, the electrolyte impregnation may be excellent, so that the life characteristics and output characteristics may be improved, and the energy density may be excellent. The porosity can be calculated using the following mathematical formula A. [Mathematical Formula A] Porosity (vol%) = {1-(electrode density / true density)} × 100 In the above mathematical expression A, the true density is the density of the electrode composite film measured when the electrode composite film is cut into a certain size and pressed with a press device until the thickness of the film does not change, and the electrode density is the density of the electrode composite film measured when the film is cut into a certain size. Method for manufacturing electrode composite film The method for manufacturing an electrode composite film according to the present invention comprises the steps of: (S1) forming a composite mixture by mixing an electrode active material and a fiberizable binder; (S2) kneading the composite mixture while applying a shear force to form a mixed aggregate; (S3) pulverizing the mixed aggregate to produce a mixed powder; and (S4) sheeting the mixed powder to produce a composite film. Since the description of the above electrode active material and the fiberizable binder (same as the fiberized binder) is the same as that described above, a detailed description is omitted, and the manufacturing process for each step is described below. S1 stage According to one embodiment of the present invention, in the method for manufacturing the electrode composite film, the step S1 is a step of obtaining a composite mixture by mixing an electrode active material and a fiberizable binder. At this time, the mixing is performed so that the electrode active material and the fiberizable binder can be uniformly distributed, and optionally, a conductive material may be further included and mixed, and since it is mixed in a powder form, if it enables simple mixing thereof, it 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. The above mixing can be performed at 3,000 rpm to 20,000 rpm in a mixer, and preferably at 5,000 rpm to 15,000 rpm. When performed in the above range, the materials can be uniformly mixed, thereby improving battery performance. For example, the mixing speed can be 5,500 rpm or more, 6,000 rpm or more, or 6,500 rpm or more, and further 14,000 rpm or less, 13,000 rpm or less, or 12,000 rpm or less can be applied. The mixing can be performed at the same mixing speed as described above in the mixer, and can be mixed for 0.5 minutes to 60 minutes, and preferably 1 minute to 30 minutes, 1 minute to 20 minutes, or 1 minute to 10 minutes. When the mixing process is controlled to satisfy the above-mentioned range, an appropriate level of cohesion can be provided because it affects the binder cohesion, and the problem of increased resistance caused by hindering contact between electrode active materials due to too low a cohesion, or the durability problem caused by low mechanical strength of the composite film due to too high a cohesion, can be prevented in advance. Therefore, it is preferable to control the mixing process within the above-mentioned range, and through this, an electrode composite film satisfying CPCI can be implemented. S2 stage According to one embodiment of the present invention, in the method for manufacturing the electrode composite film, the step S2 includes applying a shear force to the composite mixture obtained in the mixing of the step S1 to form a mixed aggregate. That is, the step S2 may be a fiberization process for fiberizing a fiberizable binder. The above fiberization process can be performed, for example, through mechanical milling or kneading, and there is no particular limitation if it is generally performed, but preferably, it can be performed by high temperature, low shear kneading, and can be performed through a kneader such as a twin-screw extruder. By this kneading, the fiberizable binder is fiberized, thereby combining or linking the electrode active material and conductive powders, so that a mixed aggregate having a solid content of 100% can be formed. The above mixing can be performed at a speed of 10 rpm to 100 rpm, preferably 20 rpm or more, 30 rpm or more, 40 rpm or more, or 45 rpm or more, and can be performed at a speed of 80 rpm or less, 70 rpm or less, or 60 rpm or less. In addition, the mixing can be performed for 3 minutes to 60 minutes, preferably 4 minutes or more, or 5 minutes or more, and further, can be performed for 40 minutes or less, 30 minutes or less, 25 minutes or less, or 20 minutes or less. When the above range is satisfied, appropriate fiberization can proceed to improve the characteristics of the battery. The content of the composite mixture introduced during the above mixing can also be controlled. For example, the composite mixture discharged from the above mixing process can be introduced in an amount of 50 to 150 parts by volume relative to the internal volume of a mixing device such as a kneader, preferably 60 to 140 parts by volume, 70 to 130 parts by volume, or 80 to 120 parts by volume. By controlling the amount of the composite mixture introduced during mixing in this way, the fiberization of the binder can be controlled, and by controlling this simultaneously with the conditions of the mixing process, the extent to which the binder network structure formed according to the degree of fiberization of the binder affects the contact area between active materials can be controlled, and the degree of cohesion of the binder can be controlled. In addition, the above mixing can be performed under conditions of high temperature and pressure higher than atmospheric pressure, and more specifically, can be performed under conditions of pressure higher than atmospheric pressure. Preferably, the mixing can be performed at a temperature of 50°C to 230°C, preferably 90°C to 200°C, more preferably 100°C or higher, 110°C or higher, or 120°C or higher, and furthermore, 180°C or lower, 170°C or lower, or 160°C or lower. When the mixing is performed at a high temperature such as the above range, the fiberization and lumping of the binder due to the mixing can be well performed, and the problem of breakage of the fiberized binder can be appropriately prevented. It can be performed at a pressure higher than atmospheric pressure, specifically at a pressure of 1 atm to 3 atm, more specifically at 1.1 atm to 3 atm. When performed within the above range, the problem of breakage of the binder in which fiberization has progressed can be appropriately prevented, and the problem of the density of the aggregate becoming too high can be prevented. In the mixing process of the above step S2, when a high-temperature-low-shear mixing process is performed under conditions of high temperature and pressure higher than normal pressure instead of high-shear mixing, the effect intended by the present invention can be achieved. By controlling the conditions of the mixing process of the S2 stage, a three-dimensional fiber network structure can be formed within the mixed aggregate through the shear force applied to the binder, and the degree of formation of this structure can affect the degree of cohesion of the binder, so the conditions can be controlled as described above. S3 stage According to one embodiment of the present invention, in the method for manufacturing the electrode composite film, the step S3 includes pulverizing a mixed aggregate manufactured through a mixing step to obtain a powder for electrodes. The mixed aggregates manufactured through the above mixing can be directly pressurized and formed into sheets (sheeting, for example, in a calendaring process), but in this case, the aggregates must be pressed at high pressure and high temperature to be manufactured into a thin film, and thus, problems may arise in that the density of the film becomes too high or a uniform film cannot be obtained. Therefore, the mixed aggregates manufactured as described above are pulverized to manufacture a powder-like electrode powder. The device used for the above grinding 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 1,000 rpm to 15,000 rpm for 5 seconds to 30 minutes, preferably at a speed of 3,000 rpm to 8,000 rpm for 30 seconds to 15 minutes. When performed within the above range, sufficient grinding can be achieved so that powder having a size appropriate for film formation can be manufactured, and a large amount of fine powder may not be generated in the agglomerates. In the case of the above-mentioned crushing process, it serves the function of helping to properly form a free-standing film in the subsequent sheet forming process, and at the same time, all factors affecting CPCI may be affected depending on the degree thereof. Therefore, it may be desirable to control the process so as to satisfy the conditions as described above. The average particle size of the above electrode powder may be 10 ㎛ to 3,000 ㎛, specifically 50 ㎛ to 1,500 ㎛, and more specifically 100 ㎛ to 700 ㎛. 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. The electrode powder according to one embodiment of the present invention may additionally include fillers, although not essential, to suppress expansion of the electrode. The filler is not particularly limited as long as it is a fibrous material that does not cause a chemical change 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. S4 stage According to one embodiment of the present invention, in the method for manufacturing the electrode composite film, the step S4 includes thermally compressing the electrode powder. The above step S4 may be a process of manufacturing an electrode composite film in the form of a self-supporting sheet by heating and compressing the electrode powder obtained as described above using a rolling roll in a roll-to-roll process (calendering process, sheeting process) including two or more pairs of rolling rolls. The above roll-to-roll process (calendaring process) may include a roll press section, and the roll press section may have rolling rolls arranged in pairs facing each other, and a plurality of such rolling roll pairs may be arranged continuously in the roll press section. When the rolling rolls are arranged in a plurality of consecutive rows, the roll temperature and main speed ratio (rotation speed ratio of one pair of rolls) of each may be the same or different. In addition, the temperature of the rolling roll may be 60°C to 120°C, preferably 70°C to 100°C, and the rotation speed ratio of the rolling roll may be appropriately controlled within 1:1 to 1:10 independently. In addition, the manufactured electrode composite film may be put into the roll press section again and subjected to heating and pressing 1 to 10 times in order to be controlled to an appropriate thickness. In this S4 step sheet forming process, the electrode powder is formed into a film by applying heat and pressure to the rolling roll in the roll-to-roll process, and during this process, the binder is additionally subjected to shear force, so that further fiberization can occur, and the three-dimensional fiber network structure within each powder of the powder can be assembled with each other. Since the formation and assembly process of this structure can affect the cohesion of the binder, the conditions can be controlled as described above. Dry electrode A dry electrode according to the present invention comprises an electrode composite film according to one embodiment of the present invention described above. Preferably, the dry electrode may comprise a current collector; and an electrode composite film of the present invention formed on the current collector. The above dry electrode can be manufactured by laminating the electrode composite film on one side or both sides of a current collector and laminating the resultant product. The above lamination may be a step of rolling and attaching the electrode composite film onto a current collector. The above lamination may be performed by a roll press method using a lamination roller, and at this time, the lamination roller may be maintained at a temperature of 20°C to 200°C. When the above dry electrode is a positive electrode, the current collector may be any conductive material that does not cause a chemical change 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 cathode, 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., an aluminum-cadmium alloy, etc. can be used. The thickness of the above-mentioned collector may be 3 ㎛ to 100 ㎛, preferably 8 ㎛ to 80 ㎛, but is not limited thereto. In addition, fine unevenness may be formed on the surface of the collector to increase the adhesive strength of the composite film. The above-mentioned collector may be used wholly or partially coated with a conductive primer to lower the resistance on the surface and improve the adhesion. Here, the conductive primer may include a conductive material and a binder, and the conductive material is not limited to 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. Lithium secondary battery The lithium secondary battery according to the present invention comprises a dry electrode as described above, and the dry electrode comprises an electrode composite film as described above on a current collector. For example, the lithium secondary battery may include a secondary battery including a liquid electrolyte and an all-solid-state battery including a solid electrolyte. In the case where the lithium secondary battery according to one embodiment of the present invention is a secondary battery including a liquid electrolyte, a separator may be included between the plurality of electrodes. The 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 may be used without particular limitation, and in particular, one having low resistance to ion movement of the electrolyte and excellent electrolyte moisture retention capacity is preferable. 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 may 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. may also be used. Additionally, a coated separator containing ceramic components or polymer materials may be used to secure heat resistance or mechanical strength, and may optionally be used in a single-layer or multi-layer structure. In addition, when the lithium secondary battery is an all-solid-state battery, the solid electrolyte membrane can be manufactured so as to perform the function of the separator. In addition, the electrolyte may be selected from organic liquid electrolytes, inorganic liquid electrolytes, solid polymer electrolytes, gel-type polymer electrolytes, solid inorganic electrolytes, and molten inorganic electrolytes that can be used in the manufacture of lithium secondary batteries, but is not limited thereto. Specifically, the electrolyte may include an organic solvent and a lithium salt. The organic solvent may be used without particular limitation as long as it can act as a medium through which ions involved in the electrochemical reaction of the battery can move. Specifically, the organic solvent may include 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; Examples of solvents that can be used include carbonate solvents such as dimethylcarbonate (DMC), diethylcarbonate (DEC), ethylmethylcarbonate (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 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; and sulfolanes. 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 low-viscosity linear carbonate compound (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 capable of providing lithium ions used in lithium secondary batteries. Specifically, the anion of the above lithium salt is F - , Cl - , Br - , I - , NO 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 , LiAl0 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 concentration of the lithium salt is preferably used within the range of 0.1 M to 4.0 M, preferably 0.5 M to 3.0 M, and more preferably 1.0 M to 2.0 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, 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-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 10.0 wt% with respect to 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, including power tools; electric vehicles including electric vehicles (EVs), hybrid electric vehicles, and plug-in hybrid electric vehicles (PHEVs); or power storage systems. Example Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein. Example 1 97 g of lithium iron phosphate (LFP-S20, Sangjoo Liwon Co., Ltd.) having a volume cumulative average particle size of 1.09 ㎛ and a carbon coating layer thickness of 0.01 ㎛ as a cathode active material and 3 g of polytetrafluoroethylene (PTFE) as a fiberizable binder were placed into a blender and mixed at 10,000 rpm for 1 minute to prepare a composite mixture, then the composite mixture was placed into a kneader and kneaded at 1.1 atm, 150°C, and a rotation speed of 50 rpm for 5 minutes to prepare a mixed aggregate, then the mixed aggregate was placed into a blender, pulverized at 10,000 rpm for 40 seconds, and classified through a sieve having pores of 1 mm to prepare an electrode powder. Thereafter, the electrode powder was sheeted onto a calendaring roll (roll diameter: 88 mm, roll speed: 20 rpm, roll temperature: 100°C) in a roll-to-roll process to manufacture an electrode composite film. A dry electrode is manufactured by laminating two sheets of the above electrode composite film on both sides of an aluminum foil (thickness 15 ㎛) equipped with a conductive primer layer through a roll press maintained at 150°C, and the loading amount is 3.5 mAh / cm. 2 , the porosity was set to 26.0 volume%. At this time, the cohesion of the binder measured by the method described below was 0.8. Example 2 A dry electrode was manufactured in the same manner as in Example 1, except that the process was controlled so that the cohesion of the binder became 0.6 by setting the blender operation time in the mixing process to 3 minutes and the kneader operation time in the kneading process to 10 minutes. Example 3 A dry electrode was manufactured in the same manner as in Example 1, except that the process was controlled so that the cohesion of the binder became 0.4 by setting the blender operation time in the mixing process to 5 minutes and the kneader operation time in the kneading process to 10 minutes. Example 4 A dry electrode was manufactured in the same manner as in Example 2, except that 98 g of lithium iron phosphate having a volumetric cumulative average particle size of 1.09 ㎛ and a carbon coating layer thickness of 0.01 ㎛ and 2 g of polytetrafluoroethylene were added. Example 5 A dry electrode was manufactured in the same manner as in Example 2, except that 96 g of lithium iron phosphate having a volumetric cumulative average particle size of 1.09 ㎛ and a carbon coating layer thickness of 0.01 ㎛ and 4 g of polytetrafluoroethylene were added. Example 6 A dry electrode was manufactured in the same manner as in Example 2, except that 95 g of lithium iron phosphate having a volumetric cumulative average particle size of 1.09 ㎛ and a carbon coating layer thickness of 0.01 ㎛ and 5 g of polytetrafluoroethylene were added. Example 7 A dry electrode was manufactured in the same manner as in Example 2, except that lithium iron phosphate (Hwayu Corporation, SF17) having a volumetric cumulative average particle size of 0.9 ㎛ and a carbon coating layer thickness of 0.01 ㎛ was used as the positive electrode active material. Example 8 A dry electrode was manufactured in the same manner as in Example 7, except that 98 g of lithium iron phosphate and 2 g of polytetrafluoroethylene were added. Comparative Example 1 A dry electrode was manufactured in the same manner as in Example 4, except that the process was controlled so that the cohesion of the binder became 0.9 by setting the blender operation time in the mixing process to 1 minute and the kneader operation time in the kneading process to 3 minutes. Comparative Example 2 A dry electrode was manufactured in the same manner as in Example 1, except that the process was controlled so that the cohesion of the binder became 0.2 by setting the blender operation time in the mixing process to 5 minutes and the kneader operation time in the kneading process to 20 minutes. Comparative Example 3 A dry electrode was manufactured in the same manner as in Example 1, except that the process was controlled so that the cohesion of the binder became 0.1 by setting the blender operation time in the mixing process to 5 minutes and the kneader operation time in the kneading process to 30 minutes. Comparative Example 4 A dry electrode was manufactured in the same manner as in Example 2, except that 93 g of lithium iron phosphate having a volumetric cumulative average particle size of 1.09 ㎛ and a carbon coating layer thickness of 0.01 ㎛ and 7 g of polytetrafluoroethylene were added. Comparative Example 5 A dry electrode was manufactured in the same manner as in Example 2, except that lithium iron phosphate (ALEEES, M121) having a volumetric cumulative average particle size of 2.0 ㎛ and a carbon coating layer thickness of 0.008 ㎛ was used as the positive electrode active material. Comparative Example 6 A dry electrode was manufactured in the same manner as in Example 2, except that lithium iron phosphate having a volumetric cumulative average particle size of 4.0 ㎛ and a carbon coating layer thickness of 0.015 ㎛ was used as the positive electrode active material. Comparative Example 7 A dry electrode was manufactured in the same manner as in Example 2, except that 96 g of lithium iron phosphate having a volumetric cumulative average particle size of 1.09 ㎛ and a carbon coating layer thickness of 0.01 ㎛ was added as the positive electrode active material, 3 g of polytetrafluoroethylene, and additionally 1 g of carbon black (Denka, Li-400) was added. Comparative Example 8 A dry electrode was manufactured in the same manner as in Example 2, except that 95 g of lithium iron phosphate having a volumetric cumulative average particle size of 1.09 ㎛ and a carbon coating layer thickness of 0.01 ㎛ was added as the positive electrode active material, 3 g of polytetrafluoroethylene, and additionally 2 g of carbon black (Denka, Li-400) was added. [Measuring the cohesion of the binder] In the above examples and comparative examples, the cohesion of the binder was derived as follows. For the cross-section of the electrode composite film, a target image with a resolution of 1280 x 960 was obtained by BSE (Back Scattered Electron) measurement using a field emission scanning electron microscope (FESEM, Hitachi, Su8020). After that, a commercial image processing program Mountains was used to adjust the set contrast level in the target image, and the active material region was adjusted to the highest contrast level, and the binder region was adjusted to the lowest contrast level, so that each pixel in the image was distinguished into a binder pixel and an active material pixel. For the binder pixels, a binder region formed by a plurality of binder pixels being adjacent to each other and having an area of ​​3 ㎛ was 2 The number of cohesive binder pixels in the ideal area is calculated, and the total number of binder pixels in the entire binder area is calculated, and the cohesion of the binder (A) is calculated by the following equation 2. B ) was derived. [Formula 2] A B = (Number of Cohesive Binder Pixels) / (Number of Total Binder Pixels) [Porosity] The porosity was calculated using the following mathematical formula A. [Mathematical Formula A] Porosity (vol%) = {1-(electrode density / true density)} × 100 In the above mathematical expression A, the true density is the density of the electrode composite film measured when the electrode composite film is cut into a certain size and pressed with a press device until the thickness of the film does not change, and the electrode density is the density of the electrode composite film measured when the film is cut into a certain size. A B RT C / D AM CPCI Example 10.832.30.00920.24 Example 20.632.30.00920.18 Example 30.432.30.00920.12 Example 40.649.00.00920.27 Example 50.624.00.00920.13 Example 60.619.00.00920.10 Example 70.632.30.01110.22 Example 80.649.00.01110.33 Comparative Example 10.949.00.01110.49 Comparative Example 20.232.30.00920.06 Comparative Example 30.132.30.00920.03Comparative Example 40.613.30.00920.07Comparative Example 50.632.30.00400.08Comparative Example 60.632.30.00380.07Comparative Example 70.696.00.00920.53Comparative Example 80.6158.30.00920.87 Experimental Example 1: Evaluation of Dry Electrodes For the dry electrodes manufactured in the above examples and comparative examples, the physical properties were evaluated by the following method and are shown in Table 2 below. 1) Tensile strength (MPa): In the above examples and comparative examples, the film before lamination with the collector was sampled as 50 mm (MD) x 10 mm (TD), and the sample was measured using UTM equipment (ZwickRoell) in accordance with ASTM 638 under the conditions of a pre-load of 0.01 kgf / cm and a speed of 50 mm / min. The maximum value of the force applied until the sample did not break was obtained. 2) Powder resistance (Ωcm): After injecting 2.0 g of the electrode powder obtained during the dry electrode manufacturing of the above examples and comparative examples into a cylindrical geometry, the surface resistance was measured using a powder resistance meter (HPRM-AM2-L of Hantech Co., Ltd.) while increasing the pressure in a pressure-measuring press, and the volume decreased as the pressure increased was also measured to measure the powder resistance when the packing density became 2.3 g / cc. 3) Interface resistance (Ωcm) 2 ): For the dry electrodes manufactured in the examples and comparative examples, they were cut to 100 mm x 100 mm, and 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. Powder resistance (Ωcm) Tensile strength (MPa) Interfacial resistance (Ωcm) 2 ) Example 115.00.440.0956 Example 215.80.360.1050 Example 316.80.300.0911 Example 411.90.290.0825 Example 513.10.660.1586 Example 614.20.710.2114 Example 716.20.480.1102 Example 813.20.280.0899 Comparative Example 111.50.120.0768 Comparative Example 220.10.210.1255 Comparative Example 322.50.180.1421 Comparative Example 430.50.840.2944 Comparative Example 5178.80.581.0070Comparative Example 630.10.780.2852Comparative Example 78.10.370.0842Comparative Example 86.70.380.0410 Referring to Table 2 above, in the case of Examples 1 to 8 where the degree of cohesion of the binder was well controlled according to the binder content, film forming was possible without a significant decrease in the tensile strength of the film, and it can be confirmed that the interface resistance of the electrode could also achieve a satisfactory level despite not including a conductive material. However, in the case of Comparative Example 1 where the binder content was low but the degree of cohesion of the binder was greatly increased where the CPCI value was not controlled, for example, the resistance improvement was not great compared to the Examples, but the tensile strength of the film was too low, resulting in process defects and appearance defects during sheet forming. In addition, in the case of Comparative Example 2 where the degree of cohesion of the binder was too low, the mechanical properties were poor, and it can be confirmed that the same problem may occur. Looking at the remaining Comparative Examples, it can be seen that in order to satisfy both the mechanical properties and the resistance characteristics, it is not simply a matter of individually controlling the binder content or the degree of cohesion of the binder, but rather factors related to the CPCI must be controlled in a complex manner. Experimental Example 2: Battery Performance Evaluation 1) Manufacturing of lithium secondary battery: Artificial graphite was used as the negative active material. An anode including a negative active material layer containing the negative active material, CMC and SBR as negative binders, and carbon black as negative conductive material in a weight ratio of 96.7:2.8:0.5 was prepared. The weight loading of the negative active material layer was 277 mg / 25 cm 2 , the thickness was 67 ㎛, and a copper foil with a thickness of 10 ㎛ was used as the negative electrode collector. The dry positive electrode, the negative electrode, and the porous polyethylene separator of the examples and comparative examples were assembled using the winding method, and an electrolyte (ethylene carbonate (EC) / ethyl methyl carbonate (EMC) = 3 / 7 (volume ratio), lithium hexafluorophosphate (LiPF6 1 mol)) was injected into the assembled battery to manufacture a lithium secondary battery. The above lithium secondary battery was charged to 3.6 V at a C-rate of 0.1 C and then discharged to 2.5 V to perform an activation process. 2) Cell resistance (mΩ): After charging and discharging the lithium secondary battery, and then fully charging and discharging it again, a 2.5C pulse current was applied for a specific period of time according to the change in SOC, and the pulse resistance (0.1 second resistance) was measured. 3) Discharge capacity (mAh): For the lithium secondary battery, the capacity measured while charging to 3.6 V at 0.2 C in CCCV mode (end current 1 / 20 C), then discharging to 2.5 V at 0.2 C constant current was used as the low-rate discharge capacity, and the capacity measured while discharging to 2.5 V at 2.0 C constant current was used as the high-rate discharge capacity. Each value was obtained, and the ratio of the high-rate discharge capacity to the low-rate discharge capacity was obtained. 0.1 sec cell resistance (mohm) low rate discharge capacity (mAh) high rate discharge capacity (mAh) high rate / low rate (%) embodiment 1377.5107.182.176.66 embodiment 2377.9107.282.076.49 embodiment 3375.5107.382.376.70 embodiment 4376.2108.082.876.67 embodiment 5384.9106.281.276.46 embodiment 6390.6104.679.776.20 embodiment 7379.2107.582.576.74 embodiment 8373.3108.383.176.73 comparative example 1370.5108.182.776.50Comparative Example 2385.4107.282.276.68Comparative Example 3392.1107.182.076.56Comparative Example 4415.2102.577.976.00Comparative Example 5450.7106.381.076.20Comparative Example 6406.8108.982.675.85Comparative Example 7359.8105.979.575.07Comparative Example 8327.0104.879.675.95 Referring to Table 3 above, in the case of Examples 1 to 8, since the conductive material was not included, the dispersion process was eliminated, and the processability was dramatically improved, and in addition, it can be confirmed that the cell resistance and discharge capacity were all at satisfactory levels compared to the comparative examples. In addition, even though the conductive material was not included, the ratio of the high-rate discharge capacity to the low-rate discharge capacity was not low, and it can be confirmed that the output also showed satisfactory performance. In this regard, in the case of Comparative Examples 7 and 8, although the conductive material was included, the discharge capacity ratio was lower than that of the examples, and although the cell resistance characteristic itself was excellent, it can be confirmed that the output aspect, which reflects the overall resistance characteristic of the battery, showed inferior performance. In particular, when looking at Examples 1 to 3 and 7, which had the same amount of active material (97 parts by weight), and Comparative Examples 3, 5, and 6, the capacity characteristic and output were at similar levels, but the cell resistance was inferior, showing poor mobility of lithium ions, and it can be expected that this will ultimately lead to a difference in rapid charging performance. In addition, when looking at Example 5 and Comparative Example 7, which have the same active material amount of 96 parts by weight, it can be seen that although there is a difference in cell resistance, it shows superior performance in capacity characteristics, and as a performance at the electrode end, the tensile strength of the film is about half as poor, which may cause problems in the fairness of sheet forming, and it can be confirmed that it is a composition with a significantly high defect rate. When comparing Example 6, which has the same active material amount of 95 parts by weight, with Comparative Example 8, it can be seen that the same trend is shown. That is, when the CPCI according to one embodiment of the present invention is not satisfied, it can be confirmed that the tensile strength of the film is poor so that sheet forming cannot be performed normally, or even if normal electrode production is possible, the cell resistance is high or at least one of the capacity characteristics or output characteristics is poor. It was confirmed that when the CPCI value is satisfied, it is possible to secure the capacity and output characteristics without lowering the cell resistance and without using a conductive material, as well as the fairness of the manufacturing process.

Claims

1. Containing an electrode active material and a fiberized binder, The above electrode active material comprises an active material core and a carbon coating layer disposed on the surface of the core, An electrode composite film having a CPCI (Conductive Path Connectivity Index) of 0.09 to 0.45, as defined by the following equation 1: [Formula 1] CPCI = A B x R x (T C / D AM ) In the above equation 1, A B is the cohesion of the binder in the electrode composite film, and D AM The volume cumulative average particle diameter D of the silver electrode active material 50 (㎛), and T C is the thickness (㎛) of the carbon coating layer of the electrode active material, and R is [(W AM / W B )x(1+2W C )] is calculated, where W B is the weight percentage (wt%) of the binder relative to the total weight of the electrode composite film, and W AM is the weight percentage (wt%) of the electrode active material relative to the total weight of the electrode composite film, and W C is a unitless number of the weight percentage (wt%) of the conductive material with respect to the total weight of the electrode composite film.

2. In paragraph 1, Cohesion of the above binder (A B ) is an electrode composite film defined by the following equation 2: [Formula 2] A B = (Number of Cohesive Binder Pixels) / (Number of Total Binder Pixels) In the above equation 2, the number of cohesive binder pixels and the total number of binder pixels are derived as follows: 1) A step of obtaining a target image having a resolution of 1280 x 960 or higher by measuring back scattered electrons (BSE) using a field emission scanning electron microscope (FESEM) on a cross-section of the composite film formed by the ion milling method; 2) For the above target image, the step of adjusting the set contrast level of the active material area to the highest contrast level and the set contrast level of the binder area to the lowest contrast level to distinguish between active material pixels and binder pixels belonging to each area; and 3) For the above binder pixels, a binder region formed by a plurality of binder pixels being adjacent to each other, having an area of ​​3 ㎛ 2 A step of calculating the number of cohesive binder pixels in an ideal cohesive binder region and calculating the total number of binder pixels in the entire binder region.

3. In paragraph 1, The above electrode active material has a volume cumulative average particle diameter D 50 An electrode composite film having a thickness of 0.1 ㎛ to 5.0 ㎛.

4. In paragraph 1, The above electrode active material has a volume cumulative average particle diameter D 50 (D AM ) for the average thickness of the carbon coating layer (T C ) is 0.0002 to 0.1, an electrode composite film.

5. In paragraph 1, Cohesion of the above binder (A B ) is 0.3 to 0.9, electrode composite film.

6. In paragraph 1, An electrode composite film, wherein R in the above formula 1 is 16 to 70.

7. In paragraph 1, An electrode composite film, wherein the active material core comprises at least one selected from the group consisting of lithium-manganese oxide, lithium-nickel oxide, lithium-nickel-manganese oxide, lithium-nickel-cobalt oxide, lithium-manganese-cobalt oxide, lithium-nickel-manganese-cobalt oxide, lithium-nickel-cobalt-transition metal (M) oxide, and lithium metal phosphate compound.

8. In paragraph 1, The above active material core is an electrode composite film including a lithium metal phosphate compound represented by the following chemical formula 1: [Chemical Formula 1] Li 1+a Fe 1-x M x P.O. 4 In the chemical formula 1 above, M is at least one selected from Mn, Co, Ni, Al, Mg, and Ti, and -0.5≤a≤0.5, 0≤x<1.

9. In paragraph 1, An electrode composite film, wherein the fiberized binder comprises polytetrafluoroethylene (PTFE).

10. In paragraph 1, The above electrode composite film contains 92 to 99.5 parts by weight of an electrode active material and 0.5 to 8 parts by weight of a fiberized binder. An electrode composite film that does not contain a conductive material.

11. In paragraph 1, The above electrode composite film is an electrode composite film having a porosity of 29 volume% or less.

12. In paragraph 1, The electrode active material is an electrode composite film having a powder resistance of 1 Ωcm to 100 Ωcm.

13. A dry electrode comprising a current collector; and an electrode composite film of claim 1 disposed on the current collector.

14. In paragraph 13, The above electrode is a positive electrode, a dry electrode.

15. Containing multiple electrodes, A lithium secondary battery, wherein at least one of the above electrodes comprises a dry electrode according to claim 13.

16. An electrical device including a lithium secondary battery of Article 15.