Electrode arrangement, cylindrical battery and battery pack and vehicle with the same

Abstract

An electrode assembly in which a first electrode, a second electrode, and a separator disposed therebetween are wound around a winding axis to define a core and an outer periphery, wherein each of the first electrode and the second electrode has an uncoated portion not coated with an active material layer at a long side end and a coated portion coated with an active material layer in a region other than the uncoated portion, wherein the first electrode has an insulating layer configured to cover a boundary of the uncoated portion and the coated portion along a winding direction; wherein the uncoated portion of the first electrode has a plurality of segments separated from each other by a plurality of cutting lines repeatedly formed along the winding direction, wherein a gap is provided between the plurality of cutting lines and the active material layer, wherein the plurality of segments are bent along a radial direction of the electrode assembly and overlap each other into multiple layers along a winding axis direction to form a bent surface at one end in the winding axis direction of the electrode assembly, and wherein, when a line parallel to the winding direction and passing through the lowermost end of the plurality of cutting lines is defined as a reference line, and when a minimum segment among the segments constituting the curved surface is a segment having the smallest height, a separation distance between an end of the separator and the reference line is 30% or less of the height of the minimum segment.

Description

TECHNICAL FIELDThe present disclosure relates to an electrode assembly, a cylindrical battery, and a battery pack, and a vehicle including the cylindrical battery. Moreover, the present disclosure relates to an electrode for an electrochemical device having improved electrochemical properties and an electrode assembly including the electrode.The present application claims priority to Korean Patent Application No. 10-2021-0142192 filed in the Republic of Korea on Oct. 22, 2021, the disclosures of which are incorporated herein by reference.Prior ArtSecondary batteries that are easily applicable to various product groups and have electrical characteristics such as high energy density are universally applied not only to portable devices but also to electric vehicles (EVs) or hybrid electric vehicles (HEVs) driven by an electric drive source. Hereinafter, a secondary battery refers to a battery that enables repeated charging and discharging.These batteries are attracting attention as a new energy source to improve environmental friendliness and energy efficiency because they have the primary advantage that they can dramatically reduce the use of fossil fuels as well as the secondary advantage that no byproducts are generated by the use of energy.Batteries that are widely used in the prior art at present include lithium ion batteries, lithium polymer batteries, nickel cadmium batteries, nickel hydrogen batteries, nickel zinc batteries, and the like, and a secondary battery unit has an operating voltage of about 2.5 V to 4.5 V. When a higher output voltage is required, a battery pack in which a plurality of batteries are connected in series may be provided. In addition, a plurality of batteries may be connected in parallel to form a battery pack according to the charge / discharge capacity required for the battery pack. Accordingly, the number of batteries included in the battery pack and the form of electrical connection may be set differently according to the required output voltage and / or charge / discharge capacity.As one kind of battery unit, cylindrical, rectangular and pouch-shaped batteries are known. In the case of a cylindrical battery, a separator serving as an insulator is disposed between a positive electrode and a negative electrode, and they are wound to form a wound roll (jellyroll) electrode assembly that is inserted into a battery case to form a battery. In addition, a strip-shaped electrode tab may be connected to an uncoated portion of both the positive electrode and the negative electrode, and the electrode tab electrically connects the electrode assembly and an electrode terminal exposed to the outside. For example, the positive electrode terminal is a cover plate of a shutter body that closes the opening of the battery case, and the negative electrode terminal is the battery case. However, the current is concentrated in the strip-shaped electrode tab coupled to the positive electrode uncoated portion and / or the negative electrode uncoated portion of a conventional cylindrical battery having such a structure, so that the current collection efficiency is not good due to a large resistance and a large heat generation.For small cylindrical batteries with a form factor of 1865, or 2170, resistance and heat are not a great problem. However, if the form factor is increased to use the cylindrical battery in an electric vehicle, the cylindrical battery may ignite when much heat is generated around the electrode tab during the rapid charging process.To solve this problem, a cylindrical battery (so-called tabless (tabless) cylindrical battery) is provided in which the positive electrode uncoated portion and the negative electrode uncoated portion are configured to be positioned at the top and bottom of the wound roll type (jellyroll type) electrode assembly, respectively, and the current collecting plate is welded to the uncoated portion to improve the current collecting efficiency.FIGS. 1 to 3 are drawings showing a process for manufacturing a tabless cylindrical battery. FIG. 1 shows the structure of an electrode, FIG. 2 shows a process for winding the electrode, and FIG. 3 shows a process for welding a current collecting plate to a bent surface of an uncoated portion.Referring to FIGS. 1 to 3, a positive electrode P and a negative electrode N have a structure in which a sheet-shaped current collector F is coated with an active material layer M, and have an uncoated portion U on a long side along the winding direction X.An electrode assembly A is manufactured by stacking the positive electrode P and the negative electrode N together with two sheets of separators S in an order as shown in FIG. 2, and then winding them in a direction X. At this time, the uncoated portions of the positive electrode P and the negative electrode N are arranged in opposite directions.After the winding process, the uncoated portion PU of the positive electrode P and the uncoated portion NU of the negative electrode N are bent toward the core. Thereafter, current collecting plates 30, 31 are welded and coupled to the uncoated portions PU, NU, respectively.An electrode tab is not separately coupled to the positive electrode uncoated portion PU and the negative electrode uncoated portion NU, the current collecting plates 30, 31 are connected to external electrode terminals, and a current path is formed with a large cross-sectional area along the winding axis direction of the electrode assembly A (see arrow), which has an advantage of lowering the resistance of the battery. This is because the resistance is inversely proportional to the cross-sectional area of the path through which the current flows.In the tabless cylindrical battery, in order to improve the welding properties of the uncoated portions PU and NU and the current collecting plates 30 and 31, it is necessary to bend the uncoated portions PU and NU as flat as possible by applying a strong pressure to the welding points of the uncoated portions PU and NU.However, when the welding points of the uncoated portions PU and NU are bent, the shapes of the uncoated portions PU and NU may be irregularly distorted and deformed. In this case, the deformed portion may contact an electrode having opposite polarity, thus causing an internal short circuit or fine cracks in the uncoated portions PU and NU. In addition, when the uncoated portion 32 adjacent to the core of the electrode assembly A is bent, all or a significant portion of the cavity 33 is blocked in the core of the electrode assembly A. In this case, a problem occurs in the electrolyte injection process. That is, the cavity 33 in the core of the electrode assembly A is used as a passage through which electrolyte is introduced. However, if the corresponding passage is blocked, it is difficult to introduce the electrolyte. In addition, while an electrolyte injector is being inserted into the cavity 33, interference with the uncoated portion 32 may occur near the core and cause the uncoated portion 32 to crack.In addition, the bent portions of the uncoated portions PU and NU to which the current collecting plates 30 and 31 are welded must be overlapped in multiple layers, and there should be no empty space (gap). In this way, sufficient welding strength can be obtained, and even when the latest technology such as laser welding is used, the problem that a laser enters the electrode assembly A and melts the separator or the active material can be prevented.In the conventional tabless cylindrical battery, the positive electrode uncoated portion PU is formed as a whole on the electrode assembly A. Therefore, when the bead portion is formed by pressing the outer periphery of the upper surface of the battery case inward, the upper edge portion 34 of the electrode assembly A is pressed by the battery case. Such a pressure may cause partial deformation of the electrode assembly A, and thereby an internal short circuit may occur when the separator S is ruptured. If a short circuit occurs within the battery, the battery may heat up or explode.Here, the separator S may be a single-side coated separator in which an inorganic coating layer is formed only on one side of the porous polymer substrate to improve the heat shrinkage properties of the substrate. Since one side of the separator S is a porous substrate and the other side is an inorganic coating layer, the electrolyte impregnation properties are asymmetric. Due to the asymmetry of the electrolyte impregnation properties, when the electrode assembly is impregnated with the electrolyte, the pressure / vacuum conditions must be increased, resulting in a cost increase. Moreover, when an appropriate impregnation process is not applied, there also occurs a problem of deterioration of battery performance.The conventional separator S has a limit of heat resistance because the fabric is exposed on one side. Particularly at a high temperature of 130° C. or above, the shrinkage of the separator is large. Therefore, when a thermal shock of 130° C. or above occurs inside the battery, the separator contracts, resulting in electrode short-circuiting, and thereby the internal temperature of the battery rapidly rises, which may result in a misfire.The upper and lower surfaces of the electrode assembly A are closed due to the bending of the uncoated portions PU and NU. The curved surface of the uncoated portions PU and NU interferes with the flow of the electrolyte, increasing the impregnation time and deteriorating the impregnation uniformity of the electrolyte. When impregnation uniformity deteriorates, an unstable solid electrolyte interface (SEI) layer is formed, which increases the resistance distribution of batteries manufactured in the same production line.In the process of winding the electrode assembly A, the positive electrode and / or the negative electrode may move in the winding axis direction due to meanders. When the electrode moves in the winding axis direction, the end of the positive electrode and / or the negative electrode may be disposed near the end of the separator. In particular, when the positive electrode and / or the negative electrode protrude further outward than the end of the separator, a short circuit may occur inside the battery due to the electrical contact between the positive electrode and the negative electrode. Since an internal short circuit of the battery causes an explosion accident, it is necessary to design an insulation structure to prevent electrical contact between the positive electrode and the negative electrode.Meanwhile, along with recent development of electric vehicle technology, there is an increasing demand for large-diameter cylindrical batteries. Small cylindrical batteries with a form factor of 1865 or 2170 have a small capacity, so that heat generated by internal resistance does not have a significant effect on battery performance. However, when the design specifications of a conventional small cylindrical battery are applied as applied to a large cylindrical battery, a serious problem may arise in the safety of the battery.As the size of the battery increases, the amount of heat generated by the battery also increases. An increase in heat generation increases the possibility of battery ignition. In order to prevent ignition of the battery, the surface area of the battery, which is a passage for dissipating heat, needs to increase according to the increase in the volume of the battery. However, the increase in the area of the battery surface does not coincide with the increase in the volume. Therefore, the heat dissipation efficiency decreases as the size of the battery increases, which increases the risk of explosion and decreases the battery power. For this reason, there is a need in the art to develop a cylindrical battery with high safety while having a large volume to implement a high capacity.On the other hand, by applying a conventional positive electrode active material containing secondary particles, particle breakage may occur during electrode manufacture, and the amount of gas generated due to an internal crack during charging and discharging may increase, which may cause problems with battery stability.In order to solve this problem, a positive electrode active material has been developed in the form of a single particle or pseudo-single particle having a relatively large primary particle size. However, when the positive electrode active material is applied in the form of a single particle or pseudo-single particle to a high load electrode and then rolling is performed, there is a problem that the electrode is broken in a state in which the electrode porosity is not reached to a target level, and there is a problem that the resistance properties and the charge / discharge efficiency of the lithium secondary battery are not good.DisclosureTechnical TaskThe present disclosure is designed to solve the problems of the related art, and therefore, the present disclosure is directed to providing an electrode assembly having a structure capable of effectively preventing an internal short circuit caused by meandering electrodes when the electrode assembly is manufactured.The present disclosure is also directed to providing an electrode assembly having an uncoated portion to which a segment structure is applied to relieve stress applied to the uncoated portion when the uncoated portion exposed at both ends of the electrode assembly is bent.The present disclosure is also directed to providing an electrode assembly in which an electrolyte injection passage is not blocked even when the uncoated portion is bent.The present disclosure is also directed to providing an electrode assembly having improved electrolyte impregnation properties by optimizing the position of the separator around the segment structure of the uncoated portion.The present disclosure is also directed to providing an electrode assembly having a structure capable of preventing contact between the upper edge of the electrode assembly and the inner surface of the battery case when the upper surface of the battery case is crimped.The present disclosure is also directed to providing an electrode assembly with improved energy density and reduced resistance.The present disclosure is also directed to providing a cylindrical battery having the electrode assembly with an improved structure, a battery pack having the cylindrical battery, and a vehicle having the battery pack.The present disclosure is also directed to providing an electrode and an electrode assembly including the same, which can implement excellent thermal stability and can have high electric conductivity and high rolling properties by applying a single particle or pseudo-single particle as a positive electrode active material.The present disclosure is also directed to providing an electrode assembly having improved energy density by including a silicon-based negative electrode active material in the negative electrode.The present disclosure is also directed to providing an electrode assembly in which the area of the positive electrode active material portion is increased without providing for lithium deposition.The present disclosure is also directed to providing a cylindrical battery that can have excellent thermal stability even when the volume of the battery increases due to an increase in shape factor.However, the technical object to be achieved by the present disclosure is not limited to the above, and other objects not mentioned herein will be clearly understood by those skilled in the art from the following disclosure.Technical SolutionIn an aspect of the present disclosure, there is provided an electrode assembly in which a first electrode, a second electrode, and a separator interposed therebetween are wound around a winding axis to define a core and an outer periphery, each of the first electrode and the second electrode having an uncoated portion not coated with an active material layer at a long side end; and a coated portion coated with an active material layer in a region other than the uncoated portion, the first electrode having an insulation layer configured to cover a boundary of the uncoated portion and the coated portion along a winding direction; wherein the uncoated portion of the first electrode includes a plurality of segments separated from each other by cut lines repeatedly formed along the winding direction, at least a part of the plurality of segments is bent along a radial direction of the electrode assembly to form a bent surface at an end in a winding axis direction of the electrode assembly, and when a line passing through a point corresponding to the smallest height in the area of the uncoated portion of the first electrode parallel to the winding direction is a reference line and a segment having the smallest height among the segments forming the bent surface is a minimum segment, a separation distance between an end in the winding axis direction of the separator and the reference line is 30% or less of the height of the minimum segment.The position of the reference line may correspond to a lower position of the cut line.The separation distance between an end in the winding axis direction of the separator and the reference line may be 1.5 mm or less.The insulation layer may be provided on both surfaces of the first electrode, and an end in the winding axis direction of the insulation layer may be disposed at the same height as an end in the winding axis direction of the separator or on an outer side.An end in the winding axis direction of the second electrode facing the insulation layer with the separator interposed therebetween cannot project outward more than an end in the winding axis direction of the separator.The electrode assembly may include a first sliding portion in which the thickness of the active material layer is reduced in a boundary region between the coated portion and the uncoated portion of the first electrode, and a second sliding portion in which the thickness of the active material layer is contained in a boundary region between the coated portion and the uncoated portion of the second electrode. The first sliding portion and the second sliding portion may be disposed in opposite directions with respect to the winding axis direction.The coated portion of the first electrode may include a charge reduction portion in which a charge amount of the active material is reduced, and the position of the charge reduction portion may correspond to the position of the second sliding portion.The insulation layer may cover at least a part of the first sliding portion.The insulation layer formed on one side of both sides of the uncoated portion of the first electrode facing the core may extend to the end in the winding axis direction of the uncoated portion of the first electrode.The insulation layer formed on a side of both sides of the uncoated portion of the first electrode opposite to a side facing the core may extend to a bending point of the uncoated portion of the first electrode.The length in the winding axis direction of the coated portion of the first electrode may be shorter than the length in the winding axis direction of the coated portion of the second electrode, and one end and the other end in the winding axis direction of the coated portion of the second electrode may be disposed more outward than one end and the other end in the winding axis direction of the coated portion of the first electrode.At least one of the height in the winding axis direction and the width in the winding direction of the plurality of segments may increase stepwise from the core toward the outer periphery individually or in groups.The plurality of segments may form a plurality of segment groups from the core to the outer periphery, and the segments belonging to a same segment group may be identical in at least one of the width in the winding direction, the height in the winding axis direction, and the separation distance in the winding direction.The segments belonging to a same segment group may gradually increase from the core to the outer periphery with respect to at least one of the width in the winding direction, the height in the winding axis direction, and the separation distance in the winding direction.The plurality of segments may be bent in the radial direction and overlap each other into a plurality of layers along the winding axis direction.The uncoated portion of the first electrode may include a core-side uncoated portion adjacent to the core of the electrode assembly, an outer circumferential-side uncoated portion adjacent to the outer circumference of the electrode assembly, and an intermediate uncoated portion disposed between the core-side uncoated portion and the outer circumferential-side uncoated portion, wherein the core-side uncoated portion and / or the outer circumferential-side uncoated portion may have a comparatively lower height in the winding axis direction than the intermediate uncoated portion, and a radial length of the core-side uncoated portion may be equal to or greater than a bending length of an innermost segment of the intermediate uncoated portion.A gap may be provided between an underside of the intersection line of the segments and the active material layer.The active material layer of the first electrode may include a positive electrode active material having a single particle, a pseudo-single particle, or a combination thereof.Dmin, which is a minimum particle size in a cumulative volume distribution of the positive electrode active material, may be 1.0 μm or more.In the cumulative volume distribution of the positive electrode active material, D50, which is a particle size when a cumulative volume amount is 50%, may be 5.0 μm or less.Dmax, which is a maximum particle size in the cumulative volume distribution of the positive electrode active material, may be 12 μm to 17 μm.The positive electrode active material may have a monomodal particle size distribution showing a single peak in a graph of the cumulative volume particle size distribution, and the particle size distribution (PSD) represented by the following formula is 3 or less:The single particle, the pseudo single particle, or the combination thereof may be contained in an amount of 95% by weight to 100% by weight based on the total weight of the positive electrode active material contained in the active material layer of the first electrode.The positive electrode active material may include a lithium nickel-based oxide containing 80 mol % or more of Ni based on the total molar number of a transition metal.The active material layer of the first electrode may have a porosity of 15% to 23%.The active material layer of the first electrode may contain flake graphite in a weight ratio of 0.05 wt % to 5 wt %.The active material layer of the first electrode may further include carbon nanotubes.The second electrode active material layer may include a silicon-based negative electrode active material and a carbon-based negative electrode active material.The silicon-based negative electrode active material and the carbon-based negative electrode active material may be contained in the second electrode active material layer in a weight ratio of 1:99 to 20:80.In another aspect of the present disclosure, there is also provided a cylindrical battery including: an electrode assembly including at least one of the above features; a battery case configured to accommodate the electrode assembly through an opening formed on one side and electrically connected to the uncoated portion of the second electrode; a terminal electrically connected to the uncoated portion of the first electrode and at least partially exposed to the outside; and a shutter body configured to cover the opening of the battery case.In another aspect of the present disclosure, there is also provided a battery pack including a plurality of cylindrical batteries, and a vehicle including the battery pack.Advantageous EffectsAccording to an aspect of the present disclosure, by preventing electrical contact between the positive electrode and the negative electrode of the electrode assembly, it is possible to effectively prevent short-circuit inside the cylindrical battery.According to another aspect of the present disclosure, the internal resistance of the battery can be reduced and the energy density can be increased by using the uncoated portions themselves protruding from the upper and lower portions of the electrode assembly as electrode tabs.According to still another aspect of the present disclosure, by improving the structure of the uncoated portion of the electrode assembly to prevent interference between the electrode assembly and the inner periphery of the battery case in the process of forming a bead portion of the battery case, it is possible to prevent an internal short circuit from occurring in the cylindrical battery due to partial deformation of the electrode assembly.According to still another aspect of the present disclosure, by improving the structure of the uncoated portion of the electrode assembly, it is possible to prevent the uncoated portion from being torn when the uncoated portion is bent, and it is possible to improve the welding strength by sufficiently increasing the number of overlapping layers of the uncoated portion.According to still another aspect of the present disclosure, by improving the structure of the uncoated portion adjacent to the core of the electrode assembly, it is possible to prevent the cavity in the core of the electrode assembly from being blocked when the uncoated portion is bent, thereby enabling the electrolyte injection process and the process of welding the battery case and the current collecting plate to be easily performed.According to still another aspect of the present disclosure, electrolyte impregnability may be improved by applying a segment structure to the uncoated portion of the electrode assembly and adjusting the position of the separator based on the cut groove of the segment.According to still another aspect of the present disclosure, it is possible to provide a cylindrical battery having a structure having low internal resistance, internal short-circuit prevention, and improved welding strength between the current collecting plate and the uncoated portion, and a battery pack and a vehicle including the same.According to still another aspect of the present disclosure, since the positive electrode includes positive electrode active material powder with Dmin of 1.0 μm or more, the thermal safety of the battery can be further improved. According to the study of the inventors of the present disclosure, even when a single particle and / or pseudo-single particle is applied as the positive electrode active material, the effect of suppressing particle breakage and improving thermal safety after rolling is different depending on the particle size of the positive electrode active material powder. In particular, when particles having a particle diameter of less than 1.0 μm are contained in the positive electrode active material powder, the line pressure during the rolling process increases, resulting in increased particle breakage and decreased thermal stability, so that it is impossible to sufficiently secure the thermal stability when applying a large-diameter cylindrical battery. Therefore, in the present disclosure, the effect of improving thermal safety can be maximized by using a positive electrode active material powder having a minimum particle size (Dmin) controlled to 1.0 μm or more.According to still another aspect of the present disclosure, it is possible to implement excellent capacity characteristics and performance characteristics because the positive electrode contains a positive electrode active material powder whose D50, Dmax, and particle size distribution (PSD) are suitably adjusted to minimize the increase in resistance due to the single particle application.According to still another aspect of the present disclosure, the conductivity of the electrode can be improved by including a single-particle-based positive electrode active material coated with a conductive coating layer or by including novel CNT as the conductive material.According to still another aspect of the present disclosure, since the positive electrode active material layer contains flake graphite, when the positive electrode active material layer is rolled, the flake graphite provides a sliding effect for the positive electrode active material, so that the rolling properties of the electrode can be improved and the electrode porosity can be lowered to the target level. Accordingly, stability, initial resistance characteristics, and charging / discharging efficiency of the cylindrical battery are improved.According to still another aspect of the present disclosure, a higher energy density can be implemented by incorporating a silicon-based negative electrode active material having a large capacity into the negative electrode.According to still another aspect of the present disclosure, since a charge reduction portion having a small charge amount of the positive electrode active material is incorporated into the positive electrode, the area of the positive electrode active material portion can be increased without causing lithium deposition.According to still another aspect of the present disclosure, as compared with a conventional battery having a strip-shaped electrode tab, internal heat generation of the battery can be effectively reduced, so that thermal safety of the battery can be improved.Moreover, the present disclosure may have various other effects described in each embodiment, or effects that can be easily derived by those skilled in the art will not be described.DESCRIPTION OF THE DRAWINGSThe accompanying drawings illustrate a preferred embodiment of the present disclosure and together with the above disclosure serve to provide further understanding of the technical features of the present disclosure, and thus the present disclosure is not construed as being limited to the drawings. FIG. 1 is a plan view showing a structure of an electrode used for manufacturing a conventional tabless cylindrical battery. FIG. 2 is a drawing showing a process for winding an electrode of the conventional tabless cylindrical battery. FIG. 3 illustrates a process for welding a current collector plate to a bent surface of an uncoated portion in the conventional tabless cylindrical battery. FIG. 4 is a perspective view showing the appearance of a cylindrical battery according to an embodiment of the present disclosure. FIG. 5 is a longitudinal sectional view showing the cylindrical battery of FIG. 4. FIG. 6 is a drawing showing the structure of an electrode assembly included in the cylindrical battery of FIG. 4. FIG. 7 is a drawing showing a part of a longitudinal sectional view of the electrode assembly of FIG. 6. FIG. 8 is a perspective view showing the appearance of an electrode assembly according to another embodiment of the present disclosure. FIG. 9 is a drawing showing a part of the longitudinal sectional view of the electrode assembly of FIG. 8. FIGS. 10 aand 10 bare drawings showing modified examples of the electrode assembly of FIG. 9. FIG. 11 is a drawing showing the structure of a conventional electrode assembly (comparative example). FIG. 12 is a graph showing power distribution in a plurality of short-circuit cases in the battery. FIG. 13 ais a schematic view showing a battery pack including the cylindrical battery according to an embodiment of the present disclosure. FIG. 13 bis a schematic view showing a vehicle including the battery pack of FIG. 13 a. FIG. 14 is a plan view showing the structure of an electrode according to the first embodiment of the present disclosure. FIG. 15 is a plan view showing the structure of an electrode according to the second embodiment of the present disclosure. FIG. 16 is a plan view showing the structure of an electrode according to the third embodiment of the present disclosure. FIG. 17 ais a plan view showing the structure of an electrode according to the fourth embodiment of the present disclosure. FIG. 17 bis a drawing showing an example of the positional relationship between the reference line and the end of the separator based on the electrode according to the fourth embodiment of the present disclosure. FIG. 17 cis a drawing showing another example of the positional relationship between the reference line and the end of the separator based on the electrode according to the fourth embodiment of the present disclosure. FIG. 18 is a drawing showing definitions of width, height, and separation distance of a segment included in the electrode according to the fourth embodiment of the present disclosure. FIG. 19 ais a plan view showing the structure of an electrode according to the fifth embodiment of the present disclosure. FIG. 19 bis a drawing showing an example of the positional relationship between the reference line and the end of the separator based on the electrode according to the fifth embodiment of the present disclosure. FIG. 19 cis a drawing showing another example of the positional relationship between the reference line and the end of the separator based on the electrode according to the fifth embodiment of the present disclosure. FIG. 20 is a drawing showing definitions of width, height, and separation distance of a segment included in the electrode according to the fifth embodiment of the present disclosure. FIG. 21 is a cross-sectional view showing a jelly roll type electrode assembly in which the electrode of the first embodiment is applied to a first electrode (positive electrode) and a second electrode (negative electrode) along the Y-axis direction (winding axis direction). FIG. 22 is a cross-sectional view showing a jelly roll type electrode assembly in which the electrode of the second embodiment is applied to the first electrode (positive electrode) and the second electrode (negative electrode) along the Y-axis direction (winding axis direction). FIG. 23 is a cross-sectional view showing a jelly roll type electrode assembly in which any one of the electrodes of the third to fifth embodiments (modifications thereof) is applied to the first electrode (positive electrode) and the second electrode (negative electrode) along the Y-axis direction (winding axis direction). FIG. 24 is a cross-sectional view showing an electrode assembly according to still another embodiment of the present disclosure along the Y-axis direction (winding axis direction). FIG. 25 is a cross-sectional view showing an electrode assembly according to still another embodiment of the present disclosure along the Y axis direction (winding axis direction). FIG. 26 is a cross-sectional view showing an electrode assembly according to still another embodiment of the present disclosure along the Y-axis direction (winding axis direction). FIG. 27 is a cross-sectional view showing a cylindrical battery according to an embodiment of the present disclosure along the Y-axis direction. FIG. 28 is a cross-sectional view showing a cylindrical battery according to another embodiment of the present disclosure along the Y-axis direction. FIG. 29 is a cross-sectional view showing a cylindrical battery according to still another embodiment of the present disclosure along the Y-axis direction. FIG. 30 is a cross-sectional view showing a cylindrical battery according to still another embodiment of the present disclosure along the Y-axis direction. FIG. 31 is a cross-sectional view showing a cylindrical battery according to still another embodiment of the present disclosure along the Y-axis direction. FIG. 32 is a cross-sectional view showing a cylindrical battery according to still another embodiment of the present disclosure along the Y-axis direction. FIG. 33 is a cross-sectional view showing a cylindrical battery according to still another embodiment of the present disclosure along the Y-axis direction. FIG. 34 is a cross-sectional view showing a cylindrical battery according to still another embodiment of the present disclosure along the Y-axis direction. FIG. 35 is a cross-sectional view showing a cylindrical battery according to still another embodiment of the present disclosure along the Y-axis direction. FIG. 36 is an SEM photograph showing a novel CNT according to an embodiment of the present disclosure. FIG. 37 is a photograph of a scanning electron microscope (SEM) showing a carbon nanotube (existing CNT) commonly used in the related art. Fig. 38 is a table showing the comparison of physical properties of the existing CNT and the new CNT. FIGS. 39 to 42 are graphs showing sheet resistance and high temperature lifetime characteristics for each conductive material ratio when single-particle-based active material particles are applied as the positive electrode active material. FIG. 43 is a table comparatively showing the solid content and the viscosity of the positive electrode slurry and the resistance values of the MP coating layer and the MP interfacial layer when carbon nanotubes (new CNTs) having a BET specific surface area of 300 m2 / g to 500 m2 / g are applied and when carbon nanotubes (existing CNTs) having a BET of 200 m2 / g or more and less than 300 m2 / g are applied. FIG. 44 ais an SEM image showing a positive electrode active material used in Example 2-1 of the present disclosure. FIG. 44 bis an SEM image showing a positive electrode active material used in Example 2-2 of the present disclosure. FIG. 44 cis an SEM image showing a positive electrode active material used in Comparative Example 2-2 of the present disclosure. FIG. 45 ais a graph showing a hot box test result of a 4680 cell manufactured by Example 1 of the present disclosure. FIG. 45 bis a graph showing a hot box test result of a 4680 cell manufactured by Comparative Example 1. FIG. 45 cis a graph showing hot box test results of Sample 1 of Example 2-1 of the present disclosure and a 4680 cell manufactured by Comparative Example 2-1. FIG. 45 dis a graph showing hot box test results of samples 2 and 3 of Example 2-1 of the present disclosure, samples 1 and 2 of Example 2-2, and a 4680 cell manufactured by Comparative Example 2-2. FIG. 46 ais a cross-sectional SEM image of the positive electrode prepared in Example 2-1 of the present disclosure. FIG. 46 bis a cross-sectional SEM image of the positive electrode prepared in Comparative Example 2-1. FIG. 47 ais a graph showing the results of measuring resistance characteristics according to SOC during charging of a coin half cell including a positive electrode according to Example 3-3 of the present disclosure, Comparative Example 3-1, and Comparative Example 3-2 to 4.2 V. FIG. 47 bis a graph showing the measurement result of capacity retention and resistance increase (DCIR increase) obtained by a charge / discharge cycle experiment for a 4680 cell according to Example 3-1 and Example 3-3 of the present disclosure and Comparative Example 3-1. FIG. 48 is a drawing showing an electrode assembly according to an embodiment of the present disclosure. Fig. 49 is a cross-sectional view taken along the line A-A' in Fig. 34. FIGS. 50 and 51 are drawings illustrating a process for manufacturing a negative electrode according to an embodiment of the present disclosure. FIG. 52 is a perspective view illustrating a negative electrode according to an embodiment of the present disclosure. FIGS. 53 and 54 are drawings illustrating a process for manufacturing a positive electrode according to an embodiment of the present disclosure. FIG. 55 is a perspective view illustrating a positive electrode according to an embodiment of the present disclosure. FIG. 56 is a drawing showing an electrode assembly according to a comparative example. Fig. 57 is a cross-sectional view taken along the line B-B' in Fig. 56. FIG. 58 is a drawing showing a process for manufacturing a negative electrode according to a comparative example. FIG. 59 is a drawing showing a process for manufacturing a positive electrode according to a comparative example. FIG. 60 is a graph showing the change in energy density depending on the content of a silicon-based negative electrode active material and the presence or absence of doping of the silicon-based negative electrode active material in a battery using a mixture of a silicon-based negative electrode active material and a carbon-based negative electrode active material as the negative electrode active material.BEST EMBODIMENTHereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Before description, it is understood that the terms used in the specification and the appended claims should not be construed as being limited to general and dictionary-like meanings, but should be construed based on the meanings and concepts corresponding to technical aspects of the present disclosure on the principle that the inventor is allowed to define terms as appropriate for best explanation. Therefore, the description provided herein is only a preferred example for purposes of illustration only and is not intended to limit the scope of the disclosure, so that it should be understood that other equivalents and modifications could be made thereto without departing from the scope of the disclosure.Moreover, in order to facilitate understanding of the present disclosure, the accompanying drawings are not drawn to scale, but the dimensions of some components may be exaggerated. In addition, the same reference numerals may be assigned to the same components in different embodiments.Since the size and thickness of each component shown in the drawings are arbitrarily illustrated for convenience of description, the present disclosure is not necessarily limited to the drawings. In the drawings, the thickness is shown enlarged to clearly express the various layers and regions. Moreover, in the drawings, for convenience of explanation, the thicknesses of some layers and regions are exaggerated.Moreover, when a part such as a layer, a film, a region, a plate, etc. is described as being "over" or "on" another part, this includes not only the case where it is "directly on" another part but also the case where still another part exists therebetween. Conversely, when a part is described as being "directly on" another part, this means that no other part is present therebetween. Moreover, "above" or "on" a reference part means to be disposed above or below the reference part, and does not mean to be disposed "above" or "on" in a direction opposite to gravity.Moreover, throughout the specification, when a certain part is described as "including" a certain component, it means that it may further include other components without excluding other components unless otherwise stated.Moreover, when referred to as "in a planar shape" throughout the specification, this means when the target part is viewed from above, and when referred to as "in a cross-sectional shape", this means when the target part is vertically cut and viewed from the side.Referring to FIGS. 4 to 6, a cylindrical battery 1 according to an embodiment of the present disclosure includes an electrode assembly A, BH, a shutter body 40, and a terminal 50.The cylindrical battery 1 may further include a first current collector plate 36 and / or an insulator 37 and / or an insulating gasket 35 and / or a second current collector plate 38 and / or a gasket 39 in addition to the above-described components.Referring to FIGS. 4 to 6, the electrode assembly A includes a first electrode 11 having a first polarity, a second electrode 12 having a second polarity, a separator 13 disposed between the first electrode 11 and the second electrode 12, and an insulating layer 14 for covering at least a part of the first electrode 11.The first electrode 11 is a positive electrode or a negative electrode, and the second electrode 12 corresponds to an electrode having a polarity opposite to that of the first electrode 11. The first electrode 11 and the second electrode 12 may have a sheet shape. The electrode assembly A may have a jelly-roll shape, for example. That is, the electrode assembly A may be manufactured by winding a stack formed by sequentially stacking the first electrode 11, the separator 13, the second electrode 12, and the separator 13 at least once with respect to the winding center C. In this case, an additional separator 13 may be provided on the outer periphery of the electrode assembly A to insulate the electrode assembly from the battery case BH. The separator 13 may include a porous substrate and a heat-resistant coating layer formed on at least one surface of the substrate. The heat-resistant coating layer may comprise inorganic particles and / or heat-resistant polymer particles and a binder.The first electrode 11 and the second electrode 12 may have uncoated portions 11 a, 12 ain which no active material layer is coated at long side ends. The first electrode 11 and the second electrode 12 may have coated portions 11 b, 12 bin which an active material layer is coated in regions other than the uncoated portions 11 a, 12 a.Specifically, the first electrode 11 includes a first electrode current collector and a first electrode active material coated on one surface or both surfaces of the first electrode current collector. A region where the first electrode active material is coated on the first electrode current collector is referred to as a first coated portion 11 bprovided in the first electrode 11. A first uncoated portion 11 athat is not coated with the first electrode active material may be present at one end in the width direction (direction parallel to the Z axis) of the first electrode current collector. At least a part of the first uncoated portion 11 ais itself used as an electrode tab. The first uncoated portion 11 aprovided in the first electrode 11 is located in the upper portion in the height direction (direction parallel to the Z axis) of the electrode assembly A accommodated in the battery case BH.The second electrode 12 includes a second electrode current collector and a second electrode active material coated on one surface or both surfaces of the second electrode current collector. A region where the second electrode active material is coated on the second electrode current collector is referred to as a second coated portion 12 bprovided in the second electrode 12. A second uncoated portion 12 a, which is not coated with the second electrode active material, may be present at the other end in the width direction (direction parallel to the Z axis) of the second electrode current collector. At least a part of the second uncoated portion 12 ais itself used as an electrode tab. The second uncoated portion 12 aprovided in the second electrode 12 is located in the lower portion in the height direction (direction parallel to the Z axis) of the electrode assembly A accommodated in the battery case BH.The first uncoated portion 11 aprovided in the first electrode 11 and the second uncoated portion 12 aprovided in the second electrode 12 may protrude in opposite directions. For example, referring to FIGS. 6 and 7, the first uncoated portion 11 aprovided in the first electrode 11 may protrude upward in the height direction (direction parallel to the Z axis) of the electrode assembly A, and the second uncoated portion 12 aprovided in the second electrode 12 may protrude downward in the height direction (direction parallel to the Z axis) of the electrode assembly A. Accordingly, the first uncoated portion 11 aprovided in the first electrode and the second uncoated portion 12 aprovided in the second electrode may be in the form of extending and protruding in opposite directions to each other along the width direction of the electrode assembly A, that is, the height direction (direction parallel to the Z axis) of the cylindrical battery 1.Meanwhile, the first and second coated portions 11 b, 12 bmay include a sliding portion in which the active material layer has a reduced thickness as compared to the central region of the first and second coated portions 11 b, 12 b. For example, referring to FIG. 7, each of the first electrode 11 and the second electrode 12 may have a sliding portion, which is a region where the thickness of the active material layer is reduced, at one end or the other end.The slip phenomenon means a phenomenon in which an electrode active material in the boundary region coated with the slurry is less coated as compared with a region other than the boundary region coated with the slurry due to the spread of the slurry containing the electrode active material, so that the slurry of the coated boundary region has an approximately inclined shape. Here, when the electrode as a whole is dried, the slurry volume decreases as the solvent contained in the slurry evaporates, so that the sliding phenomenon can be further enhanced in the vicinity of the boundary between the region where the electrode active material is coated and the region where the electrode active material is not coated.The sliding portion may be formed in a boundary region of the first coated portion 11 band the first uncoated portion 11 aand a boundary region of the second coated portion 12 band the second uncoated portion 12 a. For example, the sliding portion may be provided at one end of the first electrode 11 and at the other end of the second electrode 12, respectively. That is, the sliding portion of the first coated portion 11 bprovided in the first electrode 11 and the sliding portion of the second coated portion 12 bprovided in the second electrode 12 may be provided in opposite directions. For example, referring to FIG. 7, the sliding portion of the first electrode 11 may be formed in the upper portion in the winding axis direction (direction parallel to the Z axis), and the sliding portion of the second electrode 12 may be formed in the lower portion in the winding axis direction (direction parallel to the Z axis), which is a direction opposite to the above.The length in the winding axis direction (direction parallel to the Z axis) of the first coated portion 11 bprovided in the first electrode 11 may be shorter than the length in the winding axis direction (direction parallel to the Z axis) of the second coated portion 12 bprovided in the second electrode 12. In addition, the first coated portion 11 bprovided in the first electrode 11 may be disposed more inward in the winding axis direction (direction parallel to the Z axis) than the second coated portion 12 bprovided in the second electrode 12. For example, referring to FIG. 7, the length in the winding axis direction (direction parallel to the Z axis) of the second coated portion 12 bprovided on the second electrode 12 may be larger than the length in the winding axis direction (direction parallel to the Z axis) of the first coated portion 11 bprovided in the first electrode 11. Further, referring to FIG. 7, the length in the winding axis direction (direction parallel to the Z axis) of the first coated portion 11 bprovided in the first electrode 11 may be made shorter than the length in the winding axis direction (direction parallel to the Z axis) of a region of the second coated portion 12 bprovided in the second electrode 12 except for the sliding portion. This structure is intended to prevent the NP ratio of the positive / negative electrode from being reduced to less than 100% and thus lithium metal from being deposited.Meanwhile, the first and second coated portions 11 b, 12 bmay not protrude further than the separator 13 in the winding axis direction (direction parallel to the Z axis). That is, when the first and second coated portions 11 b, 12 bprotrude more than the separator 13 in the winding axis direction (direction parallel to the Z axis), the possibility of contact between the first electrode 11 and the second electrode 12 may increase. If this is the case, an internal short circuit may occur in the contact area, which increases the risk of ignition. Therefore, it is important that the first and second coated portions 11 b, 12 bprotrude not more than the separator 13 in the winding axis direction (direction parallel to the Z axis). That is, the first and second coated portions 11 b, 12 bare preferably disposed more inside than the separator 13.In order to minimize the possibility of contact between the first electrode 11 and the second electrode 12, the first electrode 11 of the present disclosure may include at least one insulation layer 14 for simultaneously covering at least a part of the first uncoated portion 11 aand at least a part of the first coated portion 11 b. Electrical contact between the first electrode 11 and the second electrode 12 can be effectively prevented by the insulation layer 14. In particular, electrical contact between the first uncoated portion 11 aprovided in the first electrode 11 and the second coated portion 12 bprovided in the second electrode 12 can be effectively prevented.The insulating layer 14 may be provided on at least one surface of the first electrode 11. For example, the insulation layer 14 may be provided on both surfaces of the first electrode 11. In FIG. 7, the separator 13 is disposed on both the left side and the right side of the first electrode 11, and another second electrode 12 is disposed on the left side of the separator 13 disposed on the left side. Therefore, in order to prevent electrical contact with the second electrodes 12 disposed on the left and right sides, it is preferable that the insulation layer 14 be provided on both surfaces of the first electrode 11.The insulating layer 14 may be provided in the entire region that may face the second coated portion 12 bprovided in the second electrode 12 among the regions of the first electrode 11. For example, an end in the winding axis direction (direction parallel to the Z axis) of the insulating layer 14 may be disposed at the same height as an end in the winding axis direction (direction parallel to the Z axis) of the separator 13 or outside an end. Specifically, with reference to FIG. 7, as an example, an end in the winding axis direction (direction parallel to the Z axis) of the insulating layer 14 may be disposed at the same height as an end in the winding axis direction of the separator 13. Since the separator 13 protrudes in the winding axis direction (direction parallel to the Z axis) between the first electrode 11 and the second electrode 12, electrical contact between the first electrode 11 and the second electrode 12 can be prevented to some extent. However, since a movement such as meandering of the first electrode 11 or the second electrode 12 may occur inside the cylindrical battery 1, the possibility that the second electrode 12 is disposed near the end of the separator 13 cannot be eliminated. Therefore, when the second electrode 12 is disposed even at the end of the separator 13 due to movement such as meander, or when the second electrode 12 protrudes further outward than the end of the separator 13, electrical contact between the first electrode 11 and the second electrode 12 cannot be avoided. Alternatively, if the separator 13 is damaged for some reason, electrical contact between the first electrode 11 and the second electrode 12 cannot be avoided. Therefore, even if this case occurs, in order to prevent electrical contact between the first electrode 11 and the second electrode 12, the insulation layer 14 provided on the first electrode 11 preferably extends to at least the same height as an end of the separator 13 or to the outside of an end.However, when the insulating layer 14 covers the entire first uncoated portion 11 aprovided in the first electrode 11, since the first electrode 11 cannot function as an electrode, the insulating layer 14 should cover only a part of the first uncoated portion 11 aprovided in the first electrode 11. That is, the first uncoated portion 11 amay have a shape that protrudes further outward than the insulation layer 14.The insulating layer 14 may be an insulating coating layer or an insulating tape provided on the boundary region of the first uncoated portion 11 aand the first coated portion 11 b. However, the shape of the insulating layer 14 is not limited thereto, and any shape may be used in the present disclosure as long as the insulating layer 14 can be attached to the first electrode 11 while securing the insulation performance. Meanwhile, the insulation layer 14 may include, for example, an oil-based SBR binder and alumina to secure insulation performance.The insulation layer 14 may simultaneously cover at least a part of the first uncoated portion 11 aand at least a part of the first coated portion 11 b. For example, the insulation layer 14 may be provided on a boundary region of the first coated portion 11 band the first uncoated portion 11 a. For example, the insulation layer 14 may cover at least a part of the sliding portion.For example, the insulation layer 14 may extend to a point of about 0.3 mm to 5 mm from the boundary point between the first uncoated portion 11 aand the first coated portion 11 bin the entire area of the first uncoated portion 11 aprovided in the first electrode 11. More preferably, the insulation layer 14 may extend to a point of about 1.5 mm to 3 mm from the boundary point between the first uncoated portion 11 aand the first coated portion 11 bin the entire area of the first uncoated portion 11 aprovided in the first electrode 11.When there is no insulation layer 14, since there is a possibility that an internal short circuit occurs due to the contact between the first electrode 11 and the second electrode 12, the insulation layer 14 is preferably extended to a position where no electrical contact occurs between the first electrode 11 and the second electrode 12.Meanwhile, the insulation layer 14 may extend to a point of about 0.1 mm to 3 mm from the boundary point between the first uncoated portion 11 aand the first coated portion 11 bin the entire area of the first coated portion 11 bprovided in the first electrode 11. More preferably, the insulation layer 14 may extend to a point of about 0.2 mm to 0.5 mm from the boundary point between the first uncoated portion 11 aand the first coated portion 11 bin the entire area of the first coated portion 11 bprovided in the first electrode 11.When the insulating layer 14 covers a part of the first coated portion 11 bprovided in the first electrode 11, a battery capacity loss occurs, and thus there is a need to minimize the length of the insulating layer 14 covering the coated portion. However, since the first coated portion 11 bprovided in the first electrode 11 has a possibility of contacting the second electrode 12, in order to prevent this problem, the insulation layer 14 needs to cover at least a part of the first coated portion 11 bprovided in the first electrode 11.Referring to FIG. 7, the separator 13 may have a shape that protrudes further outward than the other end of the first electrode 11 and one end of the second electrode 12. one end means an upper end in the winding axis direction (direction parallel to the Z axis) in the drawing, and the other end means a lower end in the winding axis direction (direction parallel to the Z axis) in the drawing. Accordingly, the separator 13 may have a shape that protrudes further outward than the lower end of the first electrode 11 and protrudes further outward than the upper end of the second electrode 12. That is, the upper end of the first electrode 11, that is, the first uncoated portion 11 aitself functions as an electrode tab of the first electrode 11. Similarly, the separator 13 does not protrude beyond the lower end of the second electrode 12. That is, the lower end of the second electrode 12, that is, the second uncoated portion 12 aitself functions as an electrode tab of the second electrode 12.An end of the second electrode 12 facing the insulation layer 14 with the separator 13 interposed therebetween may have a shape that does not protrude outward more than an end of the separator 13. For example, referring to FIG. 7, the insulating layer 14 is provided at an end of the first electrode 11, and an end of the second electrode 12 facing the insulating layer 14 is disposed toward the inside of the separator 13. Therefore, even when an end of the first electrode 11 protrudes to the outside of the separator 13, since an end of the second electrode 12 is disposed inside the separator 13, the possibility of contact between the first electrode 11 and the second electrode 12 is significantly reduced.Referring to FIGS. 4 and 6, the battery case BH is a substantially cylindrical container having an open portion formed at a lower end thereof, and is made of, for example, a conductive material such as metal. The material of the battery case BH may be, for example, aluminum or steel. The lower portion of the battery case BH provided with an open portion is referred to as an open end. The side surface (outer periphery) and the upper surface of the battery case BH may be integrally formed. The upper surface (parallel to the X-Y plane) of the battery case BH has a substantially flat shape. The upper surface located on the opposite side of the open end is referred to as a closed end. The battery case BH accommodates the electrode assembly A through the open portion formed on a lower side, and also accommodates an electrolyte together.The battery case BH is electrically connected to the electrode assembly A. The battery case BH may be electrically connected to one of the first electrode 11 and the second electrode 12. For example, the battery case may be electrically connected to the second electrode 12 of the electrode assembly A. In this case, the battery case BH may have the same polarity as the second electrode 12.Referring to FIG. 5, the battery case BH may include a bead portion 23 and a crimp portion 24 formed at a lower end thereof. The bead portion 23 is located in the lower portion of the electrode assembly A. The bead portion 23 is formed by press-fitting the periphery of the outer periphery of the battery case BH. The bead portion 23 prevents the electrode assembly A, which may have a size approximately equal to the width of the battery case BH, from escaping through the open portion formed at the lower end of the battery case BH, and functions as a support on which the shutter body 40 is seated.The crimping portion 24 is formed below the bead portion 23. The crimping portion 24 has an elongated and bent shape to surround the outer periphery of the shutter body 40 disposed below the bead portion 23 and a part of the lower surface of the shutter body 40.However, the present disclosure does not exclude the case where the battery case BH does not include the bead portion 23 and / or the crimp portion 24. That is, in the present disclosure, when the battery case BH does not include the bead portion 23 and / or the crimp portion 24, the electrode assembly A may be fixed and / or the battery case BH may be sealed by additionally applying a component that may function as a stopper for the electrode assembly A, for example. In addition, when the cylindrical battery 1 of the present disclosure includes the shutter body 40, the electrode assembly A may be fixed and / or the battery case BH may be sealed by additionally applying a structure on which the shutter body 40 may be seated and / or by welding the battery case BH and the shutter body 40 to each other, for example. That is, the shutter body may close the open end of the battery case.Referring to FIG. 5, the closure body 40 may be made of, for example, a metal material to secure rigidity. The shutter body 40 may cover the open end formed at the lower end of the battery case BH. That is, the shutter body 40 forms the lower surface of the cylindrical battery 1. in the cylindrical battery 1 of the present disclosure, the shutter body 40 does not have polarity even when made of a metal material having conductivity. Having no polarity may mean that the closure body 40 is electrically insulated from the battery case BH and the terminal 50. Accordingly, the shutter body 40 cannot function as the positive electrode terminal E 1 or the negative electrode terminal E. Accordingly, the shutter body 40 may not be electrically connected to the electrode assembly A and the battery case BH, and the material may not necessarily be a conductive metal.When the battery case BH of the present disclosure includes the bead portion 23, the shutter body 40 may be seated on the bead portion 23 formed in the battery case BH. When the battery case BH of the present disclosure includes the crimping portion 24, the shutter body 40 may be additionally fixed by the crimping portion 24. A gasket 39 may be disposed between the shutter body 40 and the crimping portion 24 of the battery case BH to ensure airtightness of the battery case BH. Meanwhile, as described above, the battery case BH of the present disclosure may not include the bead portion 23 and / or the crimp portion 24, and in this case, the gasket 39 may be disposed between a fixing structure provided at the open portion of the battery case BH and the shutter body 40 to ensure airtightness of the battery case BH.Referring to FIGS. 4 and 5, the terminal 50 may be electrically connected to another one of the first electrode 11 and the second electrode 12. That is, the terminal 50 may have a polarity opposite to that of the battery case BH. For example, the terminal 50 may be electrically connected to the first electrode 11 of the electrode assembly A. In addition, the surface of the terminal 50 may be exposed to the outside.The terminal 50 is made of a conductive metal material. For example, the terminal 50 may pass through approximately the center of the closed end formed on the upper surface of the battery case BH. A part of the terminal 50 may be exposed to the upper part of the battery case BH, and the remaining part may be located inside the battery case BH. The terminal 50 may be fixed to the inner surface of the closed end of the battery case BH by riveting, for example. The terminal 50 may pass through the insulator 37 and be coupled to the first current collecting plate 36 or the uncoated portion 11 aprovided in the first electrode 11. In this case, the terminal 50 may have a first polarity. Accordingly, the terminal 50 can function as a first electrode terminal E 1 in the cylindrical battery 1 of the present disclosure. When the terminal 50 has the first polarity as above, the terminal 50 is electrically insulated from the battery case BH having the second polarity. Electrical insulation between the terminal 50 and the battery case BH can be realized in various ways. For example, the electrical insulation can be realized by disposing an insulation packing 35 to be explained later between the terminal 50 and the battery case BH. Alternatively, the insulation may be realized by forming an insulating coating layer on a part of the terminal 50. Alternatively, a method of fixedly structurally fixing the terminal 50 may be employed so that contact between the terminal 50 and the battery case BH is impossible. Alternatively, a plurality of methods among the above-described methods may be applied together.Referring to FIG. 5, the first current collecting plate 36 may be coupled to an upper portion of the electrode assembly A. For example, the first current collecting plate 36 may be coupled to the first uncoated portion 11 aprovided in the first electrode 11 at the upper portion of the electrode assembly A. The first current collector plate 36 may be made of a conductive metal material. Although not shown in the drawing, the first current collecting plate 36 may include a plurality of irregularities radially formed on its lower surface. When the irregularities are formed, the irregularities can be press-fitted into the first uncoated portion 11 aprovided in the first electrode 11 by pressing the first current collecting plate 36.A cylindrical battery 1 according to another embodiment of the present disclosure may not include the first current collecting plate 36. In this case, the first uncoated portion 11 aprovided in the first electrode 11 may be directly electrically connected to the terminal 50.Referring to FIG. 5, the first current collecting plate 36 may be coupled to an end of the first uncoated portion 11 aprovided in the first electrode 11. The first uncoated portion 11 aprovided in the first electrode 11 and the first current collecting plate 36 may be coupled by laser welding, for example. The laser welding may be performed by partially melting the base material of the first current collecting plate 36, or may be performed in a state where a solder for welding is disposed between the first current collecting plate 36 and the first uncoated portion 11 a. In this case, the solder preferably has a lower melting point as compared with the first current collector plate 36 and the first uncoated portion 11 a. Meanwhile, in addition to laser welding, resistance welding, ultrasonic welding, or the like may be used, but the welding method is not limited thereto.Referring to FIG. 8, the first current collecting plate 36 may be coupled to a bent surface formed by bending an end of the first uncoated portion 11 aprovided in the first electrode 11 in a direction parallel to the first current collecting plate 36. A bending direction of the first uncoated portion 11 amay be, for example, a direction toward the winding center C of the electrode assembly A. When the first uncoated portion 11 ahas a curved shape as above, the space occupied by the first uncoated portion 11 acan be reduced, resulting in an improvement in energy density. In addition, due to an increase in the coupling area between the first uncoated portion 11 aand the first current collecting plate 36, the coupling strength can be improved and the resistance can be reduced.Referring to FIG. 5, the insulator 37 may be provided between the top surface of the electrode assembly A and the inner surface of the battery case BH or between the first current collecting plate 36 coupled to the upper portion of the electrode assembly A and the inner surface of the battery case BH. The insulator 37 prevents contact between the first uncoated portion 11 aprovided in the first electrode 11 and the battery case BH and / or contact between the first current collecting plate 36 and the battery case BH. That is, the insulator 37 is accommodated inside the battery case BH and is configured to block electrical connection between the first uncoated portion 11 aprovided in the first electrode 11 and the battery case BH. Accordingly, the insulator 37 may be made of a material having an insulating performance. For example, the insulator 37 may include a polymer material.Referring to FIGS. 4 and 5, the insulation packing 35 is disposed between the battery case BH and the terminal 50 to prevent contact between the battery case BH and the terminal 50 having opposite polarities. That is, the insulating gasket 35 blocks electrical connection between the battery case BH and the terminal 50. as a result, the upper surface of the battery case BH having a substantially flat shape can function as a second electrode terminal E 2 of the cylindrical battery 1.Referring to FIG. 5, the second current collecting plate 38 may be coupled to the lower portion of the electrode assembly A. The second current collector plate 38 may be made of a conductive metal material. The second current collector plate 38 may be connected to the second uncoated portion 12 aprovided in the second electrode 12. In addition, the second current collector plate 38 may be electrically connected to the battery case BH. As shown in FIG. 5, the second current collecting plate 38 may be disposed and fixed between the inner surface of the battery case BH and the gasket 39. Alternatively, the second current collecting plate 38 may be welded to the inner wall of the battery case BH.Although not shown in the drawings, the second current collecting plate 38 may include a plurality of irregularities radially formed on a surface thereof. When the irregularities are formed, the second current collecting plate 38 may be pressed so that the irregularities are press-fitted into the second uncoated portion 12 aprovided in the second electrode 12.Referring to FIG. 5, the second current collecting plate 38 is coupled to an end of the second uncoated portion 12 aprovided in the second electrode 12. The coupling between the second uncoated portion 12 aof the second electrode 12 and the second current collecting plate 38 may be performed by laser welding, for example. The laser welding may be performed by partially melting the base material of the second current collecting plate 38 or by disposing a solder for welding between the second current collecting plate 38 and the second uncoated portion 12 a. In this case, the solder preferably has a lower melting point as compared with the second current collecting plate 38 and the second uncoated portion 12 a. Meanwhile, in addition to laser welding, resistance welding, ultrasonic welding, or the like may be used, but the welding method is not limited thereto.Similarly to FIG. 8, the second current collecting plate 38 may be coupled to a coupling surface formed by bending an end of the second uncoated portion 12 aprovided in the second electrode 12 in a direction parallel to the second current collecting plate 38. The bending direction of the second uncoated portion 12 aprovided in the second electrode 12 may be, for example, a direction toward the winding center C of the electrode assembly A. When the second uncoated portion 12 aprovided in the second electrode 12 has such a curved shape, the space occupied by the second uncoated portion 12 acan be reduced, resulting in an improvement in energy density. In addition, due to the increase in the coupling area between the second uncoated portion 12 aand the second current collecting plate 38, the coupling strength can be improved and the resistance can be reduced.Referring to FIG. 5, the seal 39 may have a substantially annular shape surrounding the closure body 40. The gasket 39 may simultaneously cover the bottom surface, the top surface, and the side surface of the closure body 40. A radial length of a portion of the seal 39 covering the upper surface of the closure body 40 may be less than or equal to a radial length of a portion of the seal 39 covering the lower surface of the closure body 40. In the vertical compression sizing process of the battery case BH, if the radial length of the portion of the packing 39 covering the upper surface of the shutter body 40 is too long, the packing 39 may press the second current collecting plate 38 to damage the second current collecting plate 38 or damage the battery case BH. Accordingly, it is necessary to keep the radial length of the portion of the packing 39 covering the upper surface of the closure body 40 small at a certain level.The electrode assembly A according to the embodiment of FIG. 8 is similar to the electrode assembly A of the embodiment of FIG. 7, so features substantially identical or similar to those of the previous embodiment will not be described in detail, and features different from those of the previous embodiment will be described in detail below.Referring to FIG. 8, the electrode assembly A according to another embodiment of the present disclosure may have a structure in which at least a part of the first and second uncoated portions 11 a, 12 ais bent toward the core. For example, referring to FIG. 8, at least a part of the first and second uncoated portions 11 a, 12 amay be divided into a plurality of segments. Here, the plurality of segments may have a multilayer overlapping structure while being bent toward the core. For example, a plurality of segments may be formed by laser notching. The segment may be formed by a known metal foil cutting process such as ultrasonic cutting or stamping.In order to prevent damage to the active material layer and / or the insulating layer 14 when the first and second uncoated portions 11 a, 12 aare bent, it is preferable to leave a predetermined gap between the lower end of the cut line between the segments and the active material layer. This is because stress is concentrated near the lower end of the cut line when the first and second uncoated portions 11 a, 12 aare bent. The gap is preferably 0.2 mm to 4 mm. When the gap is set to the corresponding numerical range, it is possible to prevent damage to the active material layer and / or the insulation layer 14 near the lower end of the cut line due to stress generated when the first and second uncoated portions 11 a, 12 aare bent. In addition, the gap may prevent damage to the active material layer and / or the insulation layer 14 due to tolerances in notching or cutting the segments.The bending direction of the first and second uncoated portions 11 a, 12 amay be toward the winding center C of the electrode assembly A, for example. When the first and second uncoated portions 11 a, 12 ahave such a curved shape, the space occupied by the uncoated portions 11 a, 12 ais reduced, resulting in an improvement in energy density. In addition, due to the increase in the coupling area between the first and second uncoated portions 11 a, 12 aand the first and second current collecting plates 36, 38, the coupling strength can be improved and the resistance can be reduced.Referring to FIGS. 8 and 9, the first uncoated portion 11 aprovided in the first electrode 11 may be bent in one direction. For example, the +X direction in FIG. 9 may be a direction toward the core. When the first uncoated portion 11 ais bent toward the core as above, the first uncoated portion 11 aof the first electrode 11 may pass through the separator 13 and approach the second electrode 12. Therefore, the insulation layer 14 may extend to the end of the first uncoated portion 11 aor a location near the end on the surface facing the core among both surfaces of the first uncoated portion 11 aprovided in the first electrode 11. According to this structure, even when the first uncoated portion 11 ais bent toward the core and approaches the second electrode 12 beyond the separator 13, electrical contact between the first electrode 11 and the second electrode 12 can be prevented. Therefore, internal short-circuit of the cylindrical battery 1 can be effectively prevented.Referring to FIG. 9, the insulation layer 14 may be provided only in a partial region on one surface of the two surfaces of the first uncoated portion 11 afacing the core. That is, the first uncoated portion 11 amay be exposed to the outside in a remaining portion of the surface of the two surfaces of the first uncoated portion 11 afacing the core. Therefore, it is possible to electrically contact the first uncoated portion 11 aprovided in the adjacent first electrode 11 or the first current collecting plate 36 through the exposed uncoated portion 11 aon the opposite surface of the surface facing the core. That is, the first uncoated portion 11 amay be electrically coupled to the first current collecting plate 36 in an area not covered by the insulating layer 14 among the entire area of the first uncoated portion 11 a. Further, the first uncoated portion 11 amay be coupled to the first current collecting plate 36 by welding in an area not covered by the insulating layer 14 under the entire area of the first uncoated portion 11 a. The welding may be, for example, laser welding. The laser welding may be performed by partially melting the base material of the first current collecting plate 36, or may be performed in a state where a solder for welding is disposed between the first current collecting plate 36 and the first uncoated portion 11 a. In this case, the solder preferably has a lower melting point as compared with the first current collector plate 36 and the first uncoated portion 11 a. Meanwhile, in addition to laser welding, resistance welding, ultrasonic welding, or the like is available, but the welding method is not limited thereto.Referring to FIG. 10 a, the insulation layer 14 may have a shape surrounding an end of the first uncoated portion 11 a. Specifically, the insulation layer 14 may have a structure surrounding an end surface of the first uncoated portion 11 a. For example, when the length of the bent uncoated portion 11 ais long, the possibility of contact with the second electrode 12 increases. Further, there is a possibility that the bent uncoated portion 11 ais further bent by movement or external pressure. At this time, the possibility that the end surface of the first uncoated portion 11 acontacts the second electrode 12 increases. However, according to the above structure of the present disclosure, even when the first uncoated portion 11 ais further bent or deformed, since the insulating layer 14 even covers the end surface of the first uncoated portion 11 a, electrical contact between the first electrode 11 and the second electrode 12 can be prevented.Referring to FIG. 10 b, the insulation layer 14 may extend to a bending point of the first uncoated portion 11 aon a surface of both surfaces of the first uncoated portion 11 afacing the core. Another separator 13 and another second electrode 12 are arranged to the left of the first electrode 11. That is, the first electrode 11 has the possibility of electrically contacting the second electrode 12 located to the left of the first electrode 11 and the second electrode 12 located to the right of the first electrode 11. However, according to the above structure of the present disclosure, it is possible to securely prevent the first electrode 11 from electrically contacting the second electrodes 12 located on both sides.FIG. 11 is a drawing showing a cross section of an electrode assembly A without an insulating layer 14 as a comparative example of the present disclosure. Referring to FIG. 11, no separate insulating layer 14 is provided in the boundary region of the first uncoated portion 11 aand the first coated portion 11 bof the first electrode 11. According to this structure, when movement occurs due to meandering of the first electrode 11 or the second electrode 12, the second electrode 12 may be disposed even at the end of the separator 13, or the second electrode 12 may protrude further outward than the end of the separator 13, which may cause electrical contact between the first electrode 11 and the second electrode 12. Alternatively, if the separator 13 is damaged for some reason, electrical contact may occur between the first electrode 11 and the second electrode 12. In this case, in the electrode assembly A having the structure shown in FIG. 11, occurrence of an internal short circuit due to electrical contact between the first electrode 11 and the second electrode 12 cannot be avoided. Therefore, the risk of ignition increases.FIG. 12 is a graph showing power distribution in a plurality of short-circuit cases inside the cylindrical battery 1. Referring to FIG. 12, four short-circuit cases that may occur inside the cylindrical battery 1 may be assumed as follows.FIG. 13 is a graph showing the following structure: (i) the case where the coated portion provided in the positive electrode and the coated portion provided in the negative electrode are in electrical contact, (ii) the case where the coated portion provided in the positive electrode and the uncoated portion provided in the negative electrode are in electrical contact, (iii) the case where the coated portion provided in the negative electrode and the uncoated portion provided in the positive electrode are in electrical contact with each other, and (iv) the case where the uncoated portion provided in the positive electrode and the uncoated portion provided in the negative electrode are in electrical contact.Referring to FIG. 12, it can be determined that the performance is highest in the case (iii) where the coated portion provided in the negative electrode and the uncoated portion provided in the positive electrode are in electrical contact. That is, in the case (iii) where the coated portion provided in the negative electrode and the uncoated portion provided in the positive electrode are in electrical contact, the possibility of occurrence of ignition was very high. This is because the resistance is very low and the short-circuit current is large, resulting in a rapid rise in temperature.Therefore, in consideration of the structure of the electrode assembly A of the present disclosure, it is requested to search for a structure capable of preventing electrical contact between the coated portion provided in the negative electrode and the uncoated portion provided in the positive electrode.As a result of examining this object, the inventors have completed the present disclosure after deriving the fact that, when the insulating layer 14 is provided on at least a portion of the uncoated portion provided in the positive electrode, electrical contact with the coated portion provided in the negative electrode can be effectively prevented. That is, the first electrode 11 may be a positive electrode. However, the first electrode 11 is not necessarily limited to a positive electrode, and may be a negative electrode. Moreover, in the present disclosure, it is not excluded that the second electrode 12 is provided with an insulating layer 14. That is, the insulation layer 14 may be provided for both the positive electrode and the negative electrode. In this case, all possible short-circuit cases can be prevented.Preferably, the cylindrical battery may be, for example, a battery whose aspect ratio (defined as a value obtained by dividing the diameter of the battery by height, namely, a ratio of height (H) to diameter (Φ)) is greater than about 0.4.Here, the shape factor means a value indicating the diameter and height of a cylindrical battery. The shape factor of the cylindrical battery according to an embodiment of the present disclosure may be, for example, a 46110 battery, 4875 battery, 48110 battery, 4880 battery, or 4680 battery. In the numerical value representing the form factor, the first two numbers indicate the diameter of the battery, and the remaining numbers indicate the height of the battery.A battery according to an embodiment of the present disclosure may be a battery having an approximately cylindrical shape whose diameter is approximately 46 mm, whose height is approximately 110 mm, and whose shape factor ratio is 0.418.A battery according to another embodiment may be a battery having a substantially cylindrical shape whose diameter is about 48 mm, whose height is about 75 mm, and whose shape factor ratio is 0.640.A battery according to still another embodiment may be a battery having an approximately cylindrical shape whose diameter is approximately 48 mm, whose height is approximately 110 mm, and whose shape factor ratio is 0.436.A battery according to still another embodiment may be a battery having an approximately cylindrical shape whose diameter is approximately 48 mm, whose height is approximately 80 mm, and whose shape factor ratio is 0.600.A battery according to still another embodiment may be a battery having an approximately cylindrical shape whose diameter is approximately 46 mm, whose height is approximately 80 mm, and whose shape factor ratio is 0.575.Conventionally, batteries having a form factor ratio of about 0.4 or less have been used. That is, conventionally, for example, a 1865 battery, a 2170 battery, etc. have been used. The 1865 battery has a diameter of about 18 mm, a height of about 65 mm, and a form factor ratio of 0.277. The 2170 battery has a diameter of about 21 mm, a height of about 70 mm, and a form factor ratio of 0.300.The cylindrical battery according to the above embodiment can be used to manufacture a battery pack.FIG. 13 ais a schematic view showing the configuration of a battery pack according to an embodiment of the present disclosure.Referring to FIG. 13 a, the battery pack 3 according to an embodiment of the present disclosure includes an assembly to which the cylindrical batteries 1 are electrically connected, and a pack case 2 for accommodating the assembly. The cylindrical battery 1 may be a battery according to the above embodiment. In the drawing, for convenience of illustration, components such as a bus bar for electrically connecting the cylindrical batteries 1, a cooling unit, and an external terminal are omitted.The battery pack 3 may be mounted in a vehicle. The vehicle may be, for example, an electric vehicle, a hybrid electric vehicle, or a plug-in hybrid vehicle. The vehicle includes a 4-wheel vehicle or a 2-wheel vehicle.FIG. 13 bis a diagram schematically showing a vehicle including the battery pack 3 of FIG. 13 a.Referring to FIG. 13 b, the vehicle 5 according to an embodiment of the present disclosure includes the battery pack 3 according to an embodiment of the present disclosure. The vehicle 5 operates by receiving power from the battery pack 3 according to an embodiment of the present disclosure.In the present disclosure, the uncoated portion of the electrode may have various structures. In addition, when the uncoated portion is divided into a plurality of segments along the winding direction, the position of an end of the separator in the winding axis direction may be adjusted in association with the structure of the segments in consideration of the impregnability of the electrolyte. Hereinafter, various structures of the electrode and embodiments related to the positioning of the separator will be described in detail.FIG. 14 is a plan view showing the structure of an electrode 60 aaccording to the first embodiment of the present disclosure.Referring to FIG. 14, the electrode 60 aof the first embodiment includes a current collector 61 made of a metal foil and an active material layer 62. The metal foil may be aluminum or copper, and is appropriately selected according to the polarity of the electrode 60 a. The active material layer 62 is formed on at least one surface of the current collector 61 and has an uncoated portion 63 at the long side end in the winding direction X. The uncoated portion 63 is a region not coated with an active material. An insulating coating layer 64 may be formed at a boundary between the active material layer 62 and the uncoated portion 63. At least a part of the insulating coating layer 64 is formed to overlap the boundary between the active material layer 62 and the uncoated portion 63. The insulating coating layer 64 may include a polymer resin and may include an inorganic filler such as Al2O3.The uncoated portion 63 includes a core-side uncoated portion B 1 adjacent to the core of the electrode assembly, an outer peripheral-side uncoated portion B 3 adjacent to the outer periphery of the electrode assembly, and an intermediate uncoated portion B 2 disposed between the core-side uncoated portion B 1 and the outer peripheral-side uncoated portion B 3.The core-side uncoated portion B 1, the outer peripheral-side uncoated portion B 3, and the intermediate uncoated portion B 3 may be defined as an uncoated portion of a region adjacent to the core, an uncoated portion of a region adjacent to the outer periphery, and an uncoated portion of the other region excluding them, respectively, when the electrode 60 ais wound into a jelly roll electrode assembly. The boundary of B 1 / B 2 may be appropriately defined as a point at which the height (or the change pattern) of the uncoated portion substantially changes as it goes from the core of the electrode assembly to the outer periphery, or as a point of a predetermined % based on the radius of the electrode assembly (e.g., 5%, 10%, or 15% point of the radius). The boundary of B 2 / B 3 may be appropriately defined as a point at which the height (or the change pattern) of the uncoated portion substantially changes as it goes from the outer periphery of the electrode assembly to the core, or as a point of a predetermined % based on the radius of the electrode assembly (e.g., 85%, 90%, or 95% point of the radius). When the boundary of B 1 / B 2 and the boundary of B 2 / B 3 are specified, the intermediate uncoated portion B 2 can be automatically specified. When only the boundary of B 1 / B 2 is specified, the boundary of B 2 / B 3 at a point near the outer periphery of the electrode assembly may be appropriately selected. Conversely, when only the boundary of B 2 / B 3 is specified, the boundary of B 1 / B 2 at a point near the core of the electrode assembly may be appropriately selected. In the first embodiment, the height of the uncoated portion 63 is not constant and has a relative difference in the winding direction X. That is, the height (length in the Y-axis direction) of the outer peripheral side uncoated portion B 3 is relatively less than the height of the core side uncoated portion B 1 and the intermediate uncoated portion B 2.FIG. 15 is a plan view showing the structure of an electrode 60 baccording to the second embodiment of the present disclosure.Referring to FIG. 15, the electrode 60 bof the second embodiment is substantially identical to the first embodiment except that the height of the outer peripheral side uncoated portion B 3 gradually decreases toward the outer periphery.In a modification, the outer peripheral-side uncoated portion B 3 may be modified into a step shape (see a broken line) in which the height decreases stepwise.FIG. 16 is a plan view showing the structure of an electrode 60 caccording to the third embodiment of the present disclosure.Referring to FIG. 16, in the electrode 60 cof the third embodiment, the heights of the core-side uncoated portion B 1 and the outer peripheral-side uncoated portion B 3 are relatively lower than the height of the intermediate uncoated portion B 2. In addition, the heights of the core-side uncoated portion B 1 and the outer peripheral-side uncoated portion B 3 may be the same or different.Preferably, the height of the intermediate uncoated portion B 2 may have a step shape that gradually increases from the core toward the outer periphery.The samples 1 to 7 classify the intermediate uncoated portion B 2 based on the position where the height of the uncoated portion 63 changes. Preferably, the number of the patterns, and the height (length in the Y-axis direction) and width (length in the X-axis direction) of each pattern may be adjusted to distribute the stress to the maximum during bending of the uncoated portion 63. The stress distribution serves to prevent cracking of the uncoated portion 63.The width (dB 1) of the core-side uncoated portion B 1 is designed under the condition that the cavity of the core of the electrode assembly is not covered when the patterns of the intermediate uncoated portion B 2 are bent toward the core.In an example, the width (dB 1) of the core-side uncoated portion B 1 may increase in proportion to the bending length of the sample 1. The bending length corresponds to the height of the pattern based on the bending point of the pattern.In a specific example, when the electrode 60 cis used to manufacture an electrode assembly of a cylindrical battery having a shape factor of 4680, the width (dB 1) of the core-side uncoated portion B 1 may be set to 180 mm to 350 mm depending on the diameter of the core of the electrode assembly.In one embodiment, the width of each pattern may be designed to configure the same winding turn of the electrode assembly.In a modification, the height of the intermediate uncoated portion B 2 may have a step shape in which the height increases and then decreases as it goes from the core to the outer periphery.In another modification, the outer peripheral-side uncoated portion B 3 may be modified to have the same structure as the second embodiment.In still another modification, the pattern structure applied to the intermediate uncoated portion B 2 may be expanded to the outer peripheral side uncoated portion B 3 (see a broken line).FIG. 17 ais a plan view showing the structure of an electrode 60 daccording to the fourth embodiment of the present disclosure.Referring to FIG. 17 a, in the electrode 60 dof the fourth embodiment, the heights of the core-side uncoated portion B 1 and the outer peripheral-side uncoated portion B 3 are relatively lower than the height of the intermediate uncoated portion B 2. In addition, the heights of the core-side uncoated portion B 1 and the outer peripheral-side uncoated portion B 3 may be the same or different.Preferably, at least a portion of the intermediate uncoated portion B 2 may include a plurality of segments 66. The heights of the plurality of segments 66 may gradually increase from the core toward the outer periphery.Segment 66 may be laser scored. The segment 66 may be formed by a known metal foil cutting process such as ultrasonic cutting or stamping.In the fourth embodiment, it is preferable to leave a predetermined gap between the lower side of the intersection line between the segments 66 and the active material layer 62, in order to prevent damage to the active material layer 62 and / or the insulating coating layer 64 during bending of the uncoated portion 63. This is because stress is concentrated near the lower side of the cut line when the uncoated portion 63 is bent. The gap is preferably 0.2 mm to 4 mm. When the gap is set to the corresponding numerical range, it is possible to prevent the active material layer 62 and / or the insulating coating layer 64 from being damaged near the lower side of the cut line by a stress generated during bending of the uncoated portion 63. In addition, the gap may prevent damage to the active material layer 62 and / or the insulating coating layer 64 due to tolerances in notching or cutting the segment 66. When the electrode 60 dis wound into an electrode assembly, preferably, at least a part of the insulating coating layer 64 may be exposed to the outside of the separator. In this case, when the segment 66 is bent, the insulating coating layer 64 may support the bending point.The plurality of segments 66 may form a plurality of segment groups as they go from the core to the outer periphery. The width, height, and separation distance of segments belonging to a same segment group may be substantially the same.When the electrode 60 dof the fourth embodiment is included as a positive electrode or a negative electrode of the jelly roll type electrode assembly, the separator SP may face the active material layer 62 and / or the insulating coating layer 64.In order to improve the impregnability of the electrolyte in the process of impregnating the electrode assembly with the electrolyte, the position of the end of the separator SP in the winding axis direction may be adjusted as follows.In an example, a reference line DL is a line passing through a point having the smallest height among the core-side uncoated portion, the outer circumferential-side uncoated portion, and the intermediate uncoated portion of the electrode 60 dparallel to the winding direction X, and a minimum segment among the segments 66 forming the curved surface is a segment having the smallest height (Ha), and the end (SL) in the width direction of the separator SP in an outer direction of the electrode assembly may be disposed within 30% of the height (Ha) of the minimum segment with respect to the reference line DL. Here, the outer direction of the electrode assembly refers to a direction from the active material layer 62 of the electrode 60 dto the uncoated portion 63. in the drawing, the symbol Hb represents a distance between the end of the separator SP in the width direction and the reference line DL.If some of the segments included in the uncoated portion 63 do not form a curved surface, the corresponding segment(s) may be excluded from the minimum segment selection target. When the height of the uncoated portion corresponding to the bottom of the cut line between the segments 66 is the lowest, the reference line DL may pass through the bottom of the cut line. The bottom of the empty space corresponding to the cut line may be referred to as a kerf valley.In another example, the end (SL) of the separator SP in the width direction in an inner direction of the electrode assembly may be disposed within 30% of the height (Ha) of the minimum segment with respect to the reference line DL. Here, the inner direction of the electrode assembly refers to a direction from the uncoated portion 63 of the electrode 60 dto the active material layer 62.According to an embodiment of the present disclosure, the widthwise end of the separator SP is set to be near the reference line DL. As a result, the electrolyte flows into the electrode assembly along the dent valley, thereby improving the electrolyte impregnationability. Specifically, when the electrolyte is introduced into the electrode assembly, the electrolyte moves to the dent between the segments 66. Thereafter, the electrolyte is impregnated again to the end of the separator SP located near the dent (or the reference line DL), and finally impregnated into the active material layer of the electrode. As a result, the uniformity of electrolyte impregnation within the electrode assembly is increased.Since the end of the separator SP in the width direction deviates in the outer direction of the electrode assembly, the welding properties may be adversely affected. Conversely, when the end of the separator SP in the width direction enters the inner direction of the electrode assembly, the risk of a short circuit between the positive electrode and the negative electrode may increase.Therefore, in the present disclosure, the end of the separator SP in the width direction is controlled to be disposed in the outer direction of the electrode assembly within 30% of the height (Ha) of the minimum segment with respect to the reference line DL, or the end of the separator SP in the width direction is controlled to be disposed in the inner direction of the electrode assembly within 30% of the height (Ha) of the minimum segment with respect to the reference line DL.According to an embodiment of the present disclosure, the end of the separator SP in the width direction in the outer direction of the electrode assembly may be disposed within 1.5 mm with respect to the reference line DL, or the end of the separator SP in the width direction may be disposed within 1.5 mm with respect to the reference line DL in the inner direction of the electrode assembly.FIG. 18 is a drawing showing definitions of width, height, and separation distance of a segment 66 according to an embodiment of the present disclosure.Referring to FIG. 18, the width C 1, the height C 2, and the separation distance C 3 of the segment 66 are configured to prevent abnormal deformation of the uncoated portion 63 while sufficiently increasing the number of overlapping layers of the uncoated portion 63 to prevent cracking of the uncoated portion 63 during bending and improve weld strength. The abnormal deformation means that the uncoated portion below the bending point C 4 does not maintain a straight state and is irregularly deformed while collapsing.Preferably, the width C 1 of the segment 66 may be set in the range of 1 mm to 6 mm. When C1 is less than 1 mm, a non-overlapping area or void (gap) occurs to thereby not ensure sufficient welding strength when the segments 66 are bent toward the core. On the other hand, when C 1 exceeds 6 mm, there is a possibility that the uncoated portion 63 near the bending point C 4 is torn by stress when the segments 66 are bent. In addition, the height of the segment may be set in the range of 2 mm to 10 mm. When C2 is less than 2 mm, a non-overlapping area or void (gap) occurs to thereby not ensure sufficient welding strength when the segments 66 are bent toward the core. On the other hand, when C2 exceeds 10 mm, it is difficult to manufacture an electrode while maintaining uniform flatness of the uncoated portion in the winding direction X. That is, the height of the uncoated portion 63 increases, resulting in swelling. In addition, the separation distance C 3 of the segments 66 may be set in the range of 0.05 mm to 1 mm. When C 3 is less than 0.05 mm, the uncoated portion 63 near the bending point C 4 may be torn due to stress when the segments 66 are bent. On the other hand, if C3 exceeds 1 mm, a non-overlapping area or empty space (gap) may occur in which the segments 66 do not overlap each other, thereby not ensuring sufficient welding strength when the segments 66 are bent.Referring back to FIG. 17 a, the width (dB 1) of the core-side uncoated portion B 1 is designed under the condition that the cavity of the electrode array core is not covered when the segment 66 of the intermediate uncoated portion B 2 is bent toward the core.In one example, the width (dB 1) of the core-side uncoated portion B 1 may increase in proportion to the bending length of the segment 66 of the group 1. The bending length corresponds to the height of the segment 66 based on the bending point (C 4 in FIG. 18 ).In a specific example, when the electrode 60 dis used to manufacture an electrode assembly of a cylindrical battery having a shape factor of 4680, the width (dB 1) of the core-side uncoated portion B 1 may be set to 180 mm to 350 mm depending on the diameter of the core of the electrode assembly.In one embodiment, the width of each segment group may be designed to configure the same winding turn of the electrode assembly.In a modification, the width and / or height and / or separation distance of segments 66 belonging to a same segment group may gradually and / or stepwise and / or irregularly increase or decrease within the group.Groups 1 to 7 are only examples of the segment groups. The number of groups and the number of segments 66 included in each group may be set so that the segments 66 are overlapped in multiple layers to maximize stress distribution during the bending process of the uncoated portion 63 and ensure sufficient welding strength.In another modification, the height of the outer peripheral side uncoated portion B 3 may gradually or stepwise decrease as in the first and second embodiments. In addition, the segment structure of the intermediate uncoated portion B 2 may be expanded to the outer peripheral side uncoated portion B 3 (see a broken line). In this case, the outer peripheral-side uncoated portion B 3 may also include a plurality of segments, such as the intermediate uncoated portion B 2. In this case, the segments of the outer peripheral-side uncoated portion B 3 may have a larger width and / or height and / or a larger separation distance than that of the intermediate uncoated portion B 2.In a specific example, when the electrode 60 dis used to fabricate an electrode assembly of a cylindrical battery having a form factor of 4680, segments may be formed into eight groups. Here, the segments of the groups 1 to 7 may be formed on the intermediate uncoated portion B 2, and the segments of the group 8 may be formed on the outer circumferential side uncoated portion B 3, as in the modification described above.In a specific example, the width (dB 1) of the core-side uncoated portion B 1 may be 180 mm to 350 mm. The width of the group 1 may be 35% to 40% of the width of the core-side uncoated portion B 1. The width of the group 2 may be 130% to 150% of the width of the group 1. The width of the group 3 may be 120% to 135% of the width of the group 2. The width of the group 4 may be 85% to 90% of the width of the group 3. The width of the group 5 may be 120% to 130% of the width of the group 4. The width of the group 6 may be 100% to 120% of the width of the group 5. The width of the group 7 may be 90% to 120% of the width of the group 6. The width of the group 8 may be 115% to 130% of the width of the group 7.The widths of the groups 1 to 8 do not show a constant increasing or decreasing pattern because the widths of the segments gradually increase from the group 1 to the group 8, but the number of segments included in the group is limited to an integer. Therefore, the number of segments in a specific segment group can be reduced. Therefore, the width of the group can show an irregular pattern of change as shown in the above example while going from the core to the outer periphery.That is, when the widths in the winding direction of three segment groups that are consecutively adjacent in the radial direction of the electrode assembly are W 1, W 2, and W 3, respectively, a combination of segment groups in which W 3 / W 2 is less than W 2 / W 1 may be included.In the specific example, groups 4 to 6 correspond to this. The Group 5 to Group 4 width ratio is 120% to 130%, and the Group 6 to Group 5 width ratio is 100% to 120%, which is less than 120% to 130%.FIG. 19 ais a plan view showing the structure of an electrode 60 eaccording to the fifth embodiment of the present disclosure. FIGS. 19 band 19 care drawings showing an embodiment of adjusting the position of the end of the separator SP in the width direction based on the reference line DL.Referring to FIGS. 19a to 19c, the electrode 60e of the fifth embodiment is substantially identical to the fourth embodiment (or the modifications) except that the shape of the segment 66' is changed from a quadrangular shape to a trapezoidal shape.Figure 20 shows the definition of width, height and separation distance of a trapezoidal segment 66'.Referring to FIG. 20, the width D1, the height D2, and the separation distance D3 of the segment 66' are configured to prevent the uncoated portion 63 near the bending point D4 from being torn during the bending of the uncoated portion 63 and to prevent abnormal deformation of the uncoated portion 63 while sufficiently increasing the number of overlaps of the uncoated portion 63 to ensure sufficient welding strength.Preferably, the width D1 of the segment 66' can be set in the range of 1 mm to 6 mm. If D1 is less than 1 mm, when the segments 66' are bent toward the core, there may occur an area or empty space (gap) in which the segments 66' do not overlap each other, thereby failing to ensure sufficient welding strength. On the other hand, when D1 exceeds 6 mm, there is a possibility that the uncoated portion 63 near the bending point D4 is torn by stress when the segments 66' are bent. In addition, the height of the segment 66' may be set in the range of 2 mm to 10 mm. If D2 is less than 2 mm, when the segments 66' are bent toward the core, there may occur an area or empty space (gap) in which the segments 66' do not overlap each other, thereby failing to ensure sufficient welding strength. On the other hand, when D 2 exceeds 10 mm, it is difficult to manufacture an electrode while uniformly maintaining the flatness of the uncoated portion 63 in the winding direction. In addition, the separation distance D3 of the segment 66' may be set in the range of 0.05 mm to 1 mm. If D3 is less than 0.05 mm, the uncoated portion 63 near the bending point D4 may be torn due to stress when the segments 66' are bent. Whereas, if D3 exceeds 1 mm, there may occur an area or empty space (gap) in which the segments 66' do not overlap each other, thereby not ensuring sufficient welding strength when the segments 66' are bent.In the fifth embodiment, the lower internal angle ( 0) of a trapezoidal shape may increase from the core to the outer periphery of the plurality of segments 66'. As the radius of the electrode array increases, the curvature decreases. As the lower internal angle (θ) of the segment 66' increases as the radius of the electrode assembly increases, the stress generated in the radial direction and the circumferential direction when the segments 66' are bent can be relieved. In addition, as the lower inner angle (0) increases, the area overlapping with a segment 66' on an inner side and the number of the overlapping layers increase as the segments 66' are bent, so that it is possible to ensure uniform welding strength in the radial direction and the circumferential direction and form a flat bent surface.In one example, when the electrode 60 eis used to fabricate an electrode array of a cylindrical battery having a form factor of 4680, as the radius of the electrode array increases from 4 mm to 22 mm, the internal angle of the segment 66' may be increased stepwise in the range of 60 degrees to 85 degrees.In a modification, the height of the outer peripheral side uncoated portion B 3 may gradually or stepwise decrease as in the first and second embodiments. In addition, the segment structure of the intermediate uncoated portion B 2 may extend to the outer peripheral side uncoated portion B 3 (see a broken line). In this case, the outer peripheral-side uncoated portion B 3 may also include a plurality of segments, such as the intermediate uncoated portion B 2. In this case, the segments of the outer peripheral-side uncoated portion B 3 may have a larger width and / or height and / or a larger separation distance than the intermediate uncoated portion B 2.Like the fourth and fifth embodiments, when the intermediate uncoated portion B2 has a plurality of segments 66, 66', the shape of each segment 66, 66' may be modified into a triangle, a semicircle, a half ellipse, or a parallelogram.In addition, it is possible to change the shape of the segment 66, 66' differently depending on the area of the intermediate uncoated portion B2. In an example, the region where the stress is concentrated may have a round shape (e.g., a semicircular shape, a semi-elliptical shape, etc.) advantageous for stress distribution, and the region where the stress is relatively low may have a polygonal shape (e.g., a rectangular shape, a trapezoidal shape, a parallelogram shape, etc.) with the largest possible area.In the fourth and fifth embodiments, the segment structure of the intermediate uncoated portion B 2 is also applicable to the core-side uncoated portion B 1. However, when the segment structure is applied to the core-side uncoated portion B1, a reverse forming may occur in which the end of the core-side uncoated portion B1 is bent toward the outer periphery when the segments 66, 66' of the intermediate uncoated portion B2 are bent depending on the radius of curvature of the core. Therefore, there is no segment structure in the core-side uncoated portion B1, or even if the segment structure is applied, the width and / or the height and / or the separation distance of the segments 66, 66' are preferably set to a level at which reverse shaping does not occur in consideration of the radius of curvature of the core.The electrode structure of the above-described embodiments (modifications) may be applied to the first electrode and / or the second electrode having different polarities included in the jelly roll type electrode assembly. In addition, when the electrode structure of the embodiments (modifications) is applied to the first electrode and / or the second electrode, a conventional electrode structure may be applied to the other. In addition, the electrode structures applied to the first electrode and the second electrode may not be the same and may be different.For example, when the first electrode and the second electrode are a positive electrode and a negative electrode, respectively, one of the embodiments (modifications) may be applied to the first electrode, and a conventional electrode structure (see FIG. 1 ) may be applied to the second electrode.As another example, when the first electrode and the second electrode are a positive electrode and a negative electrode, respectively, one of the embodiments (modifications) may be selectively applied to the first electrode, and one of the embodiments (modifications) may be selectively applied to the second electrode.Hereinafter, the structure of an electrode assembly according to an embodiment of the present disclosure will be described in detail.FIG. 21 is a cross-sectional view showing a jelly roll type electrode assembly A 1 in which the electrode 60 aof the first embodiment is applied to a first electrode (positive electrode) and a second electrode (negative electrode) along the Y-axis direction (winding axis direction).The electrode assembly A 1 can be manufactured by the winding method described in FIG. 2. For convenience of description, the protruding structures of the uncoated portions 43 a, 43 bextending to the outside of the separator are shown in detail, and the winding structure of the first electrode, the second electrode, and the separator is omitted. The uncoated portion 43 aprotruding upward extends from the first electrode, and the uncoated portion 43 bprotruding downward extends from the second electrode.The pattern in which the heights of the uncoated portions 43 a, 43 bchange is schematically shown. That is, the heights of the uncoated portions 43 a, 43 bmay vary irregularly according to the position at which the portion is cut. For example, when a side portion of the trapezoidal segment 66, 66' is cut, the height of the uncoated portion in the cross section becomes lower than that of the segment 66, 66'. Accordingly, it is understood that the heights of the uncoated portions 43 a, 43 bshown in the cross-sectional views of the electrode assembly correspond to the average of the height (C 2 in FIG. 18, D 2 in FIG. 20 ) of the uncoated portion included in each winding turn.Referring to FIG. 21, the first electrode uncoated portion 43 aincludes a core-side uncoated portion B 1 adjacent to the core of the electrode assembly A 1, an outer peripheral-side uncoated portion B 3 adjacent to the outer periphery of the electrode assembly A 1, and an intermediate uncoated portion B 2 disposed between the core-side uncoated portion B 1 and the outer peripheral-side uncoated portion B 3.The height (length in the Y-axis direction) of the outer peripheral side uncoated portion B 3 is comparatively less than the height of the intermediate uncoated portion B 2. Therefore, it is possible to prevent an internal short circuit from occurring while the outer peripheral-side uncoated portion B 3 is pressed against the bead portion of the battery case.The lower uncoated portion 43 bhas the same structure as the upper uncoated portion 43 a. In a modification, the lower uncoated portion 43 bmay have a conventional electrode structure or an electrode structure of other embodiments (modifications).The ends 81 of the upper uncoated portion 43 aand the lower uncoated portion 43 bmay be bent toward the core from the outer periphery of the electrode assembly A 1. In this case, the outer peripheral-side uncoated portion B 3 cannot be substantially bent.FIG. 22 is a cross-sectional view showing a jelly roll type electrode assembly A 2 in which the electrode 60 bof the second embodiment is applied to the first electrode (positive electrode) and the second electrode (negative electrode) along the Y-axis direction (winding axis direction).Referring to FIG. 22, the first electrode uncoated portion 43 aincludes a core-side uncoated portion B 1 adjacent to the core of the electrode assembly A 2, an outer peripheral-side uncoated portion B 3 adjacent to the outer periphery of the electrode assembly A 2, and an intermediate uncoated portion B 2 disposed between the core-side uncoated portion B 1 and the outer peripheral-side uncoated portion B 3.The height of the outer peripheral side uncoated portion B 3 is comparatively lower than the height of the intermediate uncoated portion B 2, and gradually or stepwise decreases from the core toward the outer periphery. Therefore, it is possible to prevent an internal short circuit from occurring while the outer peripheral-side uncoated portion B 3 is pressed against the bead portion of the battery case.The lower uncoated portion 43 bhas the same structure as the upper uncoated portion 43 a. In a modification, the lower uncoated portion 43 bmay have a conventional electrode structure or an electrode structure of other embodiments (modifications).The ends 91 of the upper uncoated portion 43 aand the lower uncoated portion 43 bmay be bent toward the core from the outer periphery of the electrode assembly A 2. In this case, the outermost side 92 of the outer peripheral side uncoated portion B 3 cannot be substantially bent.FIG. 23 is a cross-sectional view showing a jelly roll type electrode assembly A 3 in which one of the electrodes 60 c, 60 d, 60 eof the third to fifth embodiments (modifications thereof) is applied to the first electrode (positive electrode) and the second electrode (negative electrode) along the Y-axis direction (winding axis direction).Referring to FIG. 23, the first electrode uncoated portion 43 aincludes a core-side uncoated portion B 1 adjacent to the core of the electrode assembly A 3, an outer peripheral-side uncoated portion B 3 adjacent to the outer periphery of the electrode assembly A 3, and an intermediate uncoated portion B 2 disposed between the core-side uncoated portion B 1 and the outer peripheral-side uncoated portion B 3.The height of the core-side uncoated portion B 1 is comparatively lower than the height of the intermediate uncoated portion B 2. In addition, in the intermediate uncoated portion B 2, the bending length of the innermost uncoated portion 43 ais equal to or less than the radial length R of the core-side uncoated portion B 1. The bending length H corresponds to a height of the uncoated portion 43 abased on a point at which the uncoated portion 43 ais bent (C 4 in FIG. 18 and D 4 in FIG. 20 ).Therefore, even when the intermediate uncoated portion B 2 is bent, the bent portion does not block the cavity 102 of the core of the electrode assembly A 3. When the cavity 102 is not blocked, there is no difficulty in the electrolyte injection process, and the electrolyte injection efficiency is improved. In addition, by inserting a welding device through the cavity 102, a welding process between the negative electrode current collecting plate and the battery case can be easily performed.The height of the outer peripheral-side uncoated portion B 3 is comparatively lower than the height of the intermediate uncoated portion B 2. Therefore, it is possible to prevent an internal short circuit from occurring while the outer peripheral-side uncoated portion B 3 is pressed against the bead portion of the battery case.In a modification, the height of the outer peripheral side uncoated portion B 3 may decrease gradually or stepwise, unlike shown in FIG. 23. Also, in FIG. 23, the height of the intermediate uncoated portion B 2 is the same in a partial outer periphery, but the height of the intermediate uncoated portion B 2 may gradually or stepwise increase from the boundary between the core-side uncoated portion B 1 and the intermediate uncoated portion B 2 to the boundary between the intermediate uncoated portion B 2 and the outer peripheral-side uncoated portion B 3.The lower uncoated portion 43 bhas the same structure as the upper uncoated portion 43 a. In a modification, the lower uncoated portion 43 bmay have a conventional electrode structure or an electrode structure of other embodiments (modifications).The ends 101 of the upper uncoated portion 43 aand the lower uncoated portion 43 bmay be bent toward the core from the outer periphery of the electrode assembly A 3. Here, the core-side uncoated portion B 1 and the outer peripheral-side uncoated portion B 3 are substantially not bent.When the intermediate uncoated portion B 2 has a plurality of segments, bending stress is reduced, so that it is possible to prevent cracking or abnormal deformation of the uncoated portion 43 atoward the bending point. In addition, when the width and / or height and / or separation distance of the segments is adjusted according to the numerical range of the above embodiment, the segments do not form an empty hole (gap) in the bent surface (surface as viewed in the Y axis) while being bent toward the core and overlapping in multiple layers enough to ensure sufficient welding strength.FIG. 24 is a cross-sectional view showing an electrode assembly A 4 along the Y-axis direction (winding axis direction) according to still another embodiment of the present disclosure.Referring to FIG. 24, the electrode assembly A 4 has substantially the same configuration as the electrode assembly A 3 of FIG. 23, except that the height of the outer peripheral side uncoated portion B 3 is substantially equal to the height of the outermost side of the intermediate uncoated portion B 2.The outer peripheral uncoated portion B 3 may include a plurality of segments. The fourth and fifth embodiments (modifications) can be applied substantially identically to the configuration of the plurality of segments.In the electrode assembly A 4, the height of the core-side uncoated portion B 1 is comparatively lower than the height of the intermediate uncoated portion B 2. In addition, in the intermediate uncoated portion B 2, the bending length H of the innermost uncoated portion is equal to or less than the radial length R of the core-side uncoated portion B 1.Therefore, even when the intermediate uncoated portion B 2 is bent, the bent portion does not block the cavity 112 of the core of the electrode assembly A 4. When the cavity 112 is not blocked, there is no difficulty in the electrolyte injection process, and the electrolyte injection efficiency is improved. In addition, by inserting a welding device through the cavity 112, a welding process between the negative electrode current collecting plate and the battery case can be easily performed.In a modification, a structure in which the height of the intermediate uncoated portion B 2 gradually or stepwise increases from the core toward the outer periphery may extend toward the outer periphery-side uncoated portion B 3. In this case, the height of the uncoated portion 43 amay gradually or stepwise increase from the boundary between the core-side uncoated portion B 1 and the intermediate uncoated portion B 2 to the outermost side surface of the electrode assembly A 4.The lower uncoated portion 43 bhas the same structure as the upper uncoated portion 43 a. In a modification, the lower uncoated portion 43 bmay have a conventional electrode structure or an electrode structure of other embodiments (modifications).The ends 111 of the upper uncoated portion 43 aand the lower uncoated portion 43 bmay be bent toward the core from the outer periphery of the electrode assembly A 4. At this time, the core-side uncoated portion B 1 is substantially not bent.When the intermediate uncoated portion B 2 and the outer peripheral uncoated portion B 3 have a plurality of segments, the bending stress is relaxed, so that it is possible to prevent cracking or abnormal deformation of the uncoated portion 43 a, 43 btoward the bending point. In addition, when the width and / or height and / or separation distance of the segments is adjusted according to the numerical range of the above embodiment, the segments do not form an empty hole (gap) in the bent surface (surface as viewed in the Y axis) while being bent toward the core and overlapping in multiple layers enough to ensure sufficient welding strength.FIG. 25 is a cross-sectional view showing an electrode assembly A 5 along the Y-axis direction (winding axis direction) according to still another embodiment of the present disclosure.Referring to FIG. 25, the electrode assembly A 5 has substantially the same configuration as the electrode assembly A 3 of FIG. 23 except that it has a pattern in which the height of the intermediate uncoated portion B 2 gradually or stepwise increases and then decreases.Such a change in height of the intermediate uncoated portion B 2 can be implemented by adjusting the height of a step pattern (see FIG. 16 ) or a height of the segment (see FIG. 17 aor 19 b) included in the intermediate uncoated portion B 2.In the electrode assembly A 5, the height of the core-side uncoated portion B 1 is comparatively lower than the height of the intermediate uncoated portion B 2. In addition, in the intermediate uncoated portion B 2, the bending length H of the innermost uncoated portion is equal to or less than the radial length R of the core-side uncoated portion B 1.Therefore, even when the intermediate uncoated portion B 2 is bent toward the core, the bent portion does not block the cavity 122 of the core of the electrode assembly A 5. When the cavity 122 is not blocked, there is no difficulty in the electrolyte injection process, and the electrolyte injection efficiency is improved. In addition, by inserting a welding device through the cavity 122, a welding process between the negative electrode current collecting plate and the battery case can be easily performed.In addition, the height of the outer peripheral-side uncoated portion B 3 is comparatively lower than the height of the intermediate uncoated portion B 2. Therefore, it is possible to prevent an internal short circuit from occurring while the outer peripheral-side uncoated portion B 3 is pressed against the bead portion of the battery case. In a modification, the height of the outer peripheral side uncoated portion B 3 may gradually or stepwise decrease toward the outer periphery.The lower uncoated portion 43 bhas the same structure as the upper uncoated portion 43 a. In a modification, the lower uncoated portion 43 bmay have a conventional electrode structure or an electrode structure of other embodiments (modifications).The ends 121 of the upper uncoated portion 43 aand the lower uncoated portion 43 bmay be bent toward the core from the outer periphery of the electrode assembly A 5. Here, the core-side uncoated portion B 1 and the outer peripheral-side uncoated portion B 3 are substantially not bent.When the intermediate uncoated portion B 2 has a plurality of segments, bending stress is reduced, so that it is possible to prevent cracking or abnormal deformation of the uncoated portion 43 a, 43 b. In addition, when the width and / or height and / or separation distance of the segments is adjusted according to the numerical range of the above embodiment, the segments do not form an empty hole (gap) in the bent surface (surface as viewed in the Y axis) while being bent toward the core and overlapping in multiple layers enough to ensure sufficient welding strength.FIG. 26 is a cross-sectional view showing an electrode assembly A 6 along the Y-axis direction (winding axis direction) according to still another embodiment of the present disclosure.Referring to FIG. 26, the electrode assembly A 6 is substantially identical to the electrode assembly A 5 of FIG. 25 except that the height of the outer peripheral side uncoated portion B 3 has a pattern that gradually or stepwise decreases from the boundary point between the outer peripheral side uncoated portion B 3 and the intermediate uncoated portion B 2 to the outermost side surface of the electrode assembly A 6.The change in height of the outer peripheral side uncoated portion B 3 can be implemented by expanding the step pattern (see FIG. 16 ) included in the intermediate uncoated portion B 2 to the outer peripheral side uncoated portion B 3 and simultaneously gradually or stepwise decreasing the height of the pattern toward the outer periphery. In addition, in another modification, the change in height of the outer peripheral side uncoated portion B 3 may be implemented by expanding the segment structure of the intermediate uncoated portion B 2 to the outer peripheral side uncoated portion B 3 and simultaneously gradually or stepwise decreasing the height of the segment toward the outer periphery.In the electrode assembly A 6, the height of the core-side uncoated portion B 1 is comparatively lower than the height of the intermediate uncoated portion B 2. In addition, in the intermediate uncoated portion B 2, the bending length H of the innermost uncoated portion is equal to or less than the radial length R of the core-side uncoated portion B 1.Therefore, even when the intermediate uncoated portion B 2 is bent toward the core, the bent portion does not block the cavity 132 of the core of the electrode assembly A 5. When the cavity 132 is not blocked, there is no difficulty in the electrolyte injection process, and the electrolyte injection efficiency is improved. In addition, by inserting a welding device through the cavity 132, a welding process between the negative electrode current collecting plate and the battery case can be easily performed.The lower uncoated portion 43 bhas the same structure as the upper uncoated portion 43 a. In a modification, the lower uncoated portion 43 bmay have a conventional electrode structure or an electrode structure of other embodiments (modifications).The ends 131 of the upper uncoated portion 43 aand the lower uncoated portion 43 bmay be bent toward the core from the outer periphery of the electrode assembly A 6. At this time, the core-side uncoated portion B 1 is substantially not bent.When the intermediate uncoated portion B 2 and the outer peripheral uncoated portion B 3 have a plurality of segments, the bending stress is relaxed, so that it is possible to prevent cracking or abnormal deformation of the uncoated portion 43 a, 43 btoward the bending point. In addition, when the width and / or height and / or separation distance of the segments is adjusted according to the numerical range of the above embodiment, the segments do not form an empty hole (gap) in the bent surface (surface as viewed in the Y axis) while being bent toward the core and overlapping in multiple layers enough to ensure sufficient welding strength.Various electrode arrangement structures according to embodiments of the present disclosure may be applied to a cylindrical jelly roll type battery.Preferably, the cylindrical battery may be, for example, a cylindrical battery having a shape factor ratio (defined as a value obtained by dividing the diameter of the cylindrical battery by the height, namely, the ratio of the diameter (Φ) to the height (H)) greater than about 0.4.The cylindrical battery according to an embodiment of the present disclosure may be, for example, a 46110 battery, 4875 battery, 48110 battery, 4880 battery, or 4680 battery.When an electrode assembly having a tabless structure is applied to a cylindrical battery whose aspect ratio exceeds 0.4, the stress applied in the radial direction is large when the uncoated portion is bent, so that the uncoated portion is easily torn. In addition, when welding the current collector plate to the curved surface of the uncoated portion, the number of overlapping layers of the uncoated portion needs to be sufficiently increased to ensure sufficient welding strength and lower resistance. These requirements can be achieved by the electrodes and the electrode assemblies according to the embodiments (modifications) of the present disclosure.Hereinafter, a cylindrical battery according to an embodiment of the present disclosure will be described in detail.FIG. 27 is a cross-sectional view showing a cylindrical battery 140 along the Y-axis direction according to an embodiment of the present disclosure.Referring to FIG. 27, the cylindrical battery 140 according to an embodiment of the present disclosure includes an electrode assembly 141 including a first electrode, a separator, and a second electrode, a battery case 142 for accommodating the electrode assembly 141, and a shutter body 143 for closing the opening of the battery case 142.The battery case 142 is a cylindrical container having an opening formed on an upper surface. The battery case 142 is made of a metal material having conductivity, such as aluminum or steel. The battery case 142 accommodates the electrode assembly 141 in the internal space through the upper opening and also accommodates the electrolyte.The electrode assembly 141 may have a jelly-roll shape. As shown in FIG. 2, the electrode assembly 141 may be manufactured by winding a stack formed by sequentially stacking a lower separator, a first electrode, an upper separator, and a second electrode at least eleven times with respect to the winding center C.The first and second electrodes have different polarities. That is, when one has a positive polarity, the other has a negative polarity. At least one of the first electrode and the second electrode may have an electrode structure according to the above embodiments (modifications). In addition, the other of the first electrode and the second electrode may have a conventional electrode structure or an electrode structure according to embodiments (modifications).The uncoated first electrode portion 146 aand the uncoated second electrode portion 146 bprotrude from the upper and lower portions of the electrode assembly 141, respectively. The first electrode has the electrode structure of the first embodiment (modification). Therefore, in the first electrode uncoated portion 146 a, the height of the outer peripheral side uncoated portion B 3 is lower than the height of the uncoated portion of the other region. The outer peripheral side uncoated portion B 3 is spaced apart from the inner periphery of the battery case 142, specifically, the bead portion 147, by a predetermined distance. Therefore, the outer peripheral side first electrode uncoated portion B 3 does not contact the battery case 142 electrically connected to the second electrode, thereby preventing internal short-circuiting of the battery 140.The uncoated portion 146 bof the second electrode has the same height. In a modification, the uncoated second electrode portion 146 bmay have the same structure as the uncoated first electrode portion 146 a. In another modification, the uncoated second electrode portion 146 bmay selectively have an uncoated portion structure of the electrodes according to the embodiments (modifications).The closure body 143 may include a cover plate 143 a, a first gasket 143 bfor providing airtightness between the cover plate 143 aand the battery case 142 and having insulation property, and a connection plate 143 celectrically and mechanically coupled to the cover plate 143 a.The cover plate 143 ais a component made of a conductive metal material and covers the upper opening of the battery case 142. The cover plate 143 ais electrically connected to the first electrode uncoated portion 146 aand is electrically insulated from the battery case 142 by the first gasket 143 b. Accordingly, the cover plate 143 acan function as a first electrode terminal of the cylindrical battery 140.The cover plate 143 ais seated on the bead portion 147 formed on the battery case 142, and is fixed by the crimping portion 148. A first packing 143 bmay be disposed between the cover plate 143 aand the crimping portion 148 to ensure airtightness of the battery case 142 and electrically insulate the battery case 142 and the cover plate 143 a. The cover plate 143 amay include a protrusion 143 dprotruding upward from the center thereof.The battery case 142 is electrically connected to the second electrode uncoated portion 146 b. Therefore, the battery case 142 has the same polarity as the second electrode. When the second electrode has a negative polarity, the battery case 142 also has a negative polarity.The battery case 142 has a bead portion 147 and a crimp portion 148 at the upper side. The bead portion 147 is formed by press-fitting the periphery of the outer periphery of the battery case 142. The bead portion 147 prevents the electrode assembly 141 accommodated in the battery case 142 from escaping through the upper opening of the battery case 142, and can function as a support portion on which the shutter body 143 sits.The inner periphery of the bead portion 147 is spaced apart from the outer peripheral side first electrode uncoated portion B 3 by a predetermined distance. Specifically, the bottom of the inner periphery of the bead portion 147 is spaced apart from the outer peripheral side first electrode uncoated portion B 3 by a predetermined distance. In addition, since the outer peripheral side uncoated portion B 3 has a small height, the outer peripheral side uncoated portion B 3 is not significantly affected even when the battery case 142 is press-fitted from the outside to form the bead portion 147. Therefore, the outer peripheral side uncoated portion B 3 is not pressed by other components such as the bead portion 147, and thus partial shape deformation of the electrode assembly 141 is prevented, thereby preventing a short circuit in the cylindrical battery 140.When the press-fit depth of the bead portion 147 is defined as D 1 and the radial length from the inner periphery of the battery case 142 to the boundary point between the outer peripheral side uncoated portion B 3 and the intermediate uncoated portion B 2 is defined as D 2, the relationship D 1≤D 2 may preferably be satisfied. In this case, when the battery case 142 is press-fitted to form the bead portion 147, damage to the outer peripheral side uncoated portion B 3 is substantially prevented.The crimping portion 148 is formed at the upper portion of the bead portion 147. The crimping portion 148 has an elongated and bent shape to surround the outer periphery of the cover plate 143 adisposed on the bead portion 147 and a part of the upper surface of the cover plate 143 a.The cylindrical battery 140 may further include a first current collector plate 144 and / or a second current collector plate 145 and / or an insulator 146.The first current collector plate 144 is coupled to the upper portion of the electrode assembly 141. The first current collector plate 144 is made of a conductive metal material such as aluminum, copper, or nickel, and is electrically connected to the first electrode uncoated portion 146 a. A lead 149 may be connected to the first current collector plate 144. The lead 149 may extend upward from the electrode assembly 141 and be coupled to the connection plate 143 cor be directly coupled to the lower surface of the cover plate 143 a. The conduit 149 may be coupled to other components by welding.Preferably, the first current collector plate 144 may be integrally formed with the lead 149. In this case, the lead 149 may have a long plate shape extending outward from the center of the first current collecting plate 144.The first current collector plate 144 may have a plurality of irregularities (not shown) formed radially on the lower surface thereof. When the radial irregularities are provided, the irregularities can be press-fitted into the uncoated portion 146 aof the first electrode by pressing the first current collecting plate 144.The first current collector plate 144 is coupled to the end of the uncoated portion 146 aof the first electrode. The coupling between the uncoated portion 146 aand the first current collector plate 144 may be performed by laser welding, for example. The laser welding may be performed by partially melting the base material of the current collecting plate. In a modification, the welding may be performed between the first current collecting plate 144 and the uncoated portion 146 awith a solder interposed therebetween. In this case, the solder may have a lower melting point as compared to the first current collector plate 144 and the uncoated portion 146 a. The laser welding may be replaced by resistance welding or ultrasonic welding.The second current collector plate 145 may be coupled to the lower surface of the electrode assembly 141. One surface of the second current collecting plate 145 may be coupled to the second electrode uncoated portion 146 bby welding, and the opposite surface may be coupled to the inner bottom surface of the battery case 142 by welding. The coupling structure between the second current collector plate 145 and the second electrode uncoated portion 146 bmay be substantially the same as the coupling structure between the first current collector plate 144 and the first electrode uncoated portion 146 a.The uncoated portions 146 a, 146 bare not limited to the illustrated structure. Accordingly, the uncoated portions 146 a, 146 bmay selectively have an uncoated portion structure of an electrode according to embodiments (modifications) as well as a conventional uncoated portion structure.The insulator 146 may cover the first current collector plate 144. The insulator 146 can prevent direct contact between the first current collecting plate 144 and the inner periphery of the battery case 142 by covering the first current collecting plate 144 on the upper surface of the first current collecting plate 144.The insulator 146 has a lead hole 151 so that the lead 149 extending upward from the first current collecting plate 144 can be pulled out. The lead 149 is pulled up through the lead hole 151 and coupled to the lower surface of the connection plate 143 cor the lower surface of the cover plate 143 a.A peripheral portion of the edge of the insulator 146 may be disposed between the first current collecting plate 144 and the bead portion 147 to fix the combination of the electrode assembly 141 and the first current collecting plate 144. Accordingly, in the combination of the electrode assembly 141 and the first current collecting plate 144, the movement of the battery 140 in the height direction is restricted, so that the assembly stability of the battery 140 can be improved.The insulator 146 may be made of an insulating polymer resin. In one example, the insulator 146 may be made of polyethylene, polypropylene, polyimide, or polybutylene terephthalate.The battery case 142 may further include a vent portion 152 formed on the lower surface thereof. The vent portion 152 corresponds to a region having a smaller thickness as compared with the surrounding region in the lower surface of the battery case 142. The vent portion 152 is structurally weak compared to the surrounding area. Therefore, when abnormality occurs in the cylindrical battery 140 and the internal pressure increases to a predetermined level or more, the vent portion 152 may be broken, so that the gas generated inside the battery case 142 may be discharged to the outside.The vent portion 152 may be formed continuously or discontinuously while a circle is drawn on the lower surface of the battery case 142. In a modification, the vent portion 152 may be formed in a straight line pattern or other patterns.FIG. 28 is a cross-sectional view showing a cylindrical battery 150 according to another embodiment of the present disclosure along the Y-axis direction.Referring to FIG. 28, the cylindrical battery 150 is substantially identical to the cylindrical battery 140 of FIG. 27 except that the electrode structure of the second embodiment (modification) is used in the first electrode uncoated portion 146 a.Referring to FIG. 28, the first electrode uncoated portion 146 amay have a shape in which the height of the outer peripheral side uncoated portion B 3 gradually or stepwise decreases toward the inner periphery of the battery case 142. Preferably, an imaginary line connecting the top of the outer circumferential side uncoated portion B 3 may have a shape identical or similar to the inner circumference of the bead portion 147.The outer peripheral-side uncoated portion B 3 forms an inclined surface. Therefore, when the battery case 142 is press-fitted to form the bead portion 147, it is possible to prevent the outer peripheral-side uncoated portion B 3 from being compressed and damaged by the bead portion 147. In addition, a phenomenon in which the outer peripheral-side uncoated portion B 3 contacts the battery case 142 having a different polarity and causes an internal short circuit can be suppressed.The other configuration of the cylindrical battery 150 is substantially the same as the above-described embodiment (modification).The uncoated portions 146 a, 146 bare not limited to the illustrated structure. Accordingly, the uncoated portions 146 a, 146 bmay selectively have an uncoated portion structure of the electrodes according to embodiments (modifications) as well as a conventional uncoated portion structure.FIG. 29 is a cross-sectional view showing a cylindrical battery 160 along the Y-axis direction according to still another embodiment of the present disclosure.Referring to FIG. 29, the cylindrical battery 160 is substantially identical to the above-described cylindrical batteries 140, 150 except that the lead 149 connected to the first current collecting plate 144 is directly connected to the cover plate 143 aof the shutter body 143 through the lead hole 151 of the insulator 146, and the insulator 146 and the first current collecting plate 144 have a structure closely adhered to the lower surface of the cover plate 143 a.In the cylindrical battery 160, the diameter of the first current collecting plate 144 and the diameter of the outermost side of the intermediate uncoated portion B 2 are smaller than the minimum inner diameter of the battery case 142. In addition, the diameter of the first current collecting plate 144 may be equal to or larger than the diameter of the outermost side of the intermediate uncoated portion B 2.Specifically, the minimum inner diameter of the battery case 142 may correspond to the inner diameter of the battery case 142 at a position where the bead portion 147 is formed. Here, the diameters of the first current collecting plate 144 and the outermost side of the intermediate uncoated portion B 2 are smaller than the inner diameter of the battery case 142 at the position where the bead portion 147 is formed. In addition, the diameter of the first current collecting plate 144 may be equal to or larger than the diameter of the outermost side of the intermediate uncoated portion B 2. The peripheral portion of the edge of the insulator 146 may be disposed between the uncoated outer peripheral portion B 3 and the bead portion 147 in a bent-down state to fix the combination of the electrode assembly 141 and the first current collecting plate 144.Preferably, the insulator 146 includes a part covering the uncoated outer peripheral portion B 3 and a part covering the first current collecting plate 144, and a part connecting the two parts may have a bent shape corresponding to the curved shape of the bead portion 147. The insulator 146 may insulate the uncoated outer circumferential portion B 3 and the inner circumference of the bead portion 147 and simultaneously insulate the first current collecting plate 144 and the inner circumference of the bead portion 147.The first current collector plate 144 may be positioned higher than the bottom of the bead portion 147 and may be coupled to the core-side uncoated portion B 1 and the intermediate uncoated portion B 2. Here, the press-fit depth D 1 of the bead portion 147 is equal to or less than the distance D 2 from the inner periphery of the battery case 142 to the boundary between the outer peripheral side uncoated portion B 3 and the intermediate uncoated portion B 2. Accordingly, the core-side uncoated portion B 1, the intermediate uncoated portion B 2, and the first current collecting plate 144 coupled thereto may be positioned higher than the bottom of the bead portion 147. The bottom of the bead portion 147 means a bending point B between the portion of the battery case 142 where the electrode assembly 141 is accommodated and the bead portion 147.Since the core-side uncoated portion B 1 and the intermediate uncoated portion B 2 occupy the inner space in the radial direction of the bead portion 147, an empty space between the electrode assembly 141 and the cover plate 143 acan be minimized. In addition, the connection plate 143 clocated in the empty space between the electrode assembly 141 and the cover plate 143 ais omitted. Accordingly, the lead 149 of the first current collecting plate 144 may be directly coupled to the lower surface of the cover plate 143 a. According to the above structure, the empty space in the battery is reduced, and the energy density can be maximized up to the reduced empty space.In the cylindrical battery 160, the first current collecting plate 144 and the second current collecting plate 145 can be welded to the ends of the uncoated portions 146 a, 146 bin the same manner as in the above embodiment, respectively.The uncoated portions 146 a, 146 bare not limited to the illustrated structure. Accordingly, the uncoated portions 146 a, 146 bmay selectively have an uncoated portion structure of an electrode according to embodiments (modifications) as well as a conventional uncoated portion structure.FIG. 30 is a cross-sectional view showing a cylindrical battery 170 along the Y-axis direction according to still another embodiment of the present disclosure.Referring to FIG. 30, the structure of the electrode assembly of the cylindrical battery 170 is substantially identical to that of the cylindrical battery 140 shown in FIG. 27, but the structure except for the electrode assembly is changed.Specifically, the cylindrical battery 170 includes a battery case 171 through which an external terminal 172 is installed. The external terminal 172 is installed on the closed surface (upper surface in the drawing) of the battery case 171.The external terminal 172 is riveted to the perforated hole of the battery case 171 with the insulating second packing 173 interposed therebetween. The external terminal 172 is exposed outward in a direction opposite to the gravity direction.The external terminal 172 includes a terminal exposing portion 172 aand a terminal inserting portion 172 b. The terminal exposing portion 172a is exposed outwardly from the closed surface of the battery case 171. The terminal exposing portion 172 amay be positioned approximately at the center of the closed surface of the battery case 171. The maximum diameter of the terminal exposing portion 172a may be larger than the maximum diameter of the perforated hole formed in the battery case 171. The terminal insert portion 172 bmay be electrically connected to the first electrode uncoated portion 146 athrough a substantially central portion of the closed surface of the battery case 171. The terminal insertion portion 172 bmay be riveted to the inner surface of the battery case 171. That is, the lower edge of the terminal insertion portion 172 bmay have a curved shape toward the inner surface of the battery case 171. The maximum diameter of the lower part of the terminal insertion portion 172 bmay be larger than the maximum diameter of the perforated hole of the battery case 171.The bottom surface of the terminal insert portion 172 bmay be welded to the first current collector plate 144 connected to the first electrode uncoated portion 146 a. An insulator 174 made of an insulating material may be disposed between the first current collector plate 144 and the inner surface of the battery case 171. The insulator 174 covers the upper portion of the first current collecting plate 144 and the upper edge of the electrode assembly 141. Thereby, the outer peripheral-side uncoated portion B 3 of the electrode assembly 141 can be prevented from contacting the inner surface of the battery case 171 having a different polarity to cause a short circuit. The terminal insertion portion 172 bof the external terminal 172 may be welded to the first current collector plate 144 through the insulator 174.The second packing 173 is disposed between the battery case 171 and the external terminal 172 to prevent electrical contact between the battery case 171 and the external terminal 172 having opposite polarities. As a result, the upper surface of the battery case 171 having a substantially flat shape can function as a second electrode terminal of the cylindrical battery 170.The second seal 173 includes a seal exposing portion 173 aand a seal insert portion 173 b. The seal exposing portion 173 ais disposed between the terminal exposing portion 172 aof the external terminal 172 and the battery case 171. The seal insert portion 173 bis disposed between the terminal insert portion 172 bof the external terminal 172 and the battery case 171. The seal insert portion 173 bmay be deformed together during riveting of the terminal insert portion 172 bto come into close contact with the inner surface of the battery case 171. The second gasket 173 may be made of, for example, a polymer resin having insulating properties. The seal exposing portion 173 aof the second seal 173 may have an expanded shape to cover the outer periphery of the terminal exposing portion 172 aof the external terminal 172. When the second packing 173 covers the outer periphery of the external terminal 172, a short circuit can be prevented from occurring during a process of coupling an electrical connection component such as a bus bar to the upper surface of the battery case 171 and / or the external terminal 172. Although not shown in the drawing, the seal exposing portion 173 amay have an expanded shape to cover not only the outer periphery of the terminal exposing portion 172 abut also a part of the upper surface.When the second gasket 173 is made of a polymer resin, the second gasket 173 may be coupled to the battery case 171 and the external terminal 172 by thermal fusion. In this case, airtightness at the coupling interface between the second packing 173 and the external terminal 172 and at the coupling interface between the second packing 173 and the battery case 171 can be improved. On the other hand, when the seal exposing portion 173 aof the second seal 173 is formed to extend to the upper surface of the terminal exposing portion 172 a, the external terminal 172 may be integrally coupled to the second seal 173 by insert injection.In the upper surface of the battery case 171, a region 175 other than a region occupied by the external terminal 172 and the second packing 173 corresponds to a second electrode terminal having a polarity opposite to that of the external terminal 172.The second current collector plate 176 is coupled to the lower portion of the electrode assembly 141. The second current collector plate 176 is made of a conductive metal material such as aluminum, steel, copper, or nickel, and is electrically connected to the second electrode uncoated portion 146 b.Preferably, the second current collector plate 176 is electrically connected to the battery case 171. To this end, at least a part of the edge of the second current collecting plate 176 may be disposed and fixed between the inner surface of the battery case 171 and the first packing 178 b. In an example, at least a part of the edge of the second current collecting plate 176 may be fixed to the bead portion 180 by welding while being supported on the bottom surface of the bead portion 180 formed on the lower surface of the battery case 171. In a modification, at least a part of the edge of the second current collecting plate 176 may be directly welded to the inner wall surface of the battery case 171.The second current collector plate 176 may include a plurality of irregularities (not shown) radially formed on a surface facing the uncoated portion 146 b. When the irregularities are formed, the irregularities can be press-fitted into the uncoated portion 146 bby pressing the second current collecting plate 176.Preferably, the second current collector plate 176 and the end of the uncoated portion 146 bmay be coupled by welding, for example, laser welding.The shutter body 178 that closes the lower opening of the battery case 171 includes a cover plate 178 aand a first packing 178 b. The first seal 178 belectrically disconnects the cover plate 178 aand the battery case 171. The crimping portion 181 fixes the edge of the cover plate 178 aand the first packing 178 bto each other. A vent portion 179 is provided on the cover plate 178 a. The configuration of the vent portion 179 is substantially the same as the above-described embodiment (modification).Preferably, the cover plate 178 ais made of a conductive metal material. However, since the first packing 178 bis disposed between the cover plate 178 aand the battery case 171, the cover plate 178 ahas no electrical polarity. The shutter body 178 closes the opening of the lower portion of the battery case 171 and functions to discharge gas when the internal pressure of the battery 170 increases to a critical value or more.Preferably, an external terminal 172 electrically connected to the first electrode uncoated portion 146 ais used as the first electrode terminal. In addition, in the upper surface of the battery case 171 electrically connected to the second electrode uncoated portion 146 bthrough the second current collecting plate 176, a portion 175 excluding the external terminal 172 is used as the second electrode terminal having a different polarity from the first electrode terminal. When two electrode terminals are located at the upper portion of the cylindrical battery 170 as above, it is possible to arrange electrical connection components such as bus bars on only one side of the cylindrical battery 170. This may result in simplification of the battery pack structure and improvement of the energy density. In addition, since the portion 175 used as the second electrode terminal has a substantially flat shape, a sufficient connection area for coupling electrical connection components such as bus bars can be ensured. Accordingly, the cylindrical battery 170 can reduce the resistance at the connection portion of the electrical connection components to a desirable level.The structure of the electrode assembly 141 and the structure of the uncoated portion are not limited to those shown, and may be replaced with structures of the above embodiments (modifications).FIG. 31 is a cross-sectional view showing a cylindrical battery 180 along the Y-axis direction according to still another embodiment of the present disclosure.Referring to FIG. 31, the electrode assembly 141 of the cylindrical battery 180 has substantially the same structure as that of the cylindrical battery 150 shown in FIG. 28, and the configuration other than the electrode assembly 141 is substantially the same as the cylindrical battery 170 shown in FIG. 30.Accordingly, the configuration of the embodiments (modification) of the cylindrical batteries 150, 170 can be similarly applied to the cylindrical battery 180.In addition, the structure of the electrode assembly 141 and the structure of the uncoated portion are not limited to those shown, and may be replaced with structures of the above embodiments (modifications).FIG. 32 is a cross-sectional view showing a cylindrical battery 190 along the Y-axis direction according to still another embodiment of the present disclosure.Referring to FIG. 32, the cylindrical battery 190 includes the electrode assembly A 4 shown in FIG. 24, and other configurations except for the electrode assembly A 4 are substantially the same as those of the cylindrical battery 140 shown in FIG. 27.Referring to FIG. 32, the uncoated portions 146 a, 146 bof the electrode assembly A 4 are bent from the outer periphery toward the core. Since the core-side uncoated portion B 1 has a lower height than other portions, it is substantially not bent at this time. The first current collector plate 144 may be welded to the curved surface of the uncoated portion 146 aand the second current collector plate 145 may be welded to the curved surface of the uncoated portion 146 b. When the uncoated portions 146 a, 146 bare bent, the bent surfaces may be formed at the upper and lower portions of the electrode assembly A 4 while overlapping into multiple layers along the Y-axis direction.In the electrode assembly A 4, the core-side uncoated portion B 1 has a comparatively lower height than the other portions. In addition, as shown in FIG. 24, the bending length H of the innermost uncoated portion in the intermediate uncoated portion B 2 is equal to or less than the radial length R of the core-side uncoated portion B 1.Therefore, even when the uncoated portion 146 ais bent toward the core, the cavity 112 of the core of the electrode assembly A 4 can be opened upward without being blocked (see the dotted circle).When the cavity 112 is not blocked, there is no difficulty in the electrolyte injection process, and the electrolyte injection efficiency is improved. In addition, a welding process between the second current collecting plate 145 and the battery case 142 can be performed simply by inserting a welding device through the cavity 112.When the uncoated portions 146 a, 146 bhave a segment structure, when the width and / or height and / or the separation distance of the segments is adjusted to satisfy the numerical range of the above embodiment, when the segments are bent, the segments are overlapped in multiple layers to sufficiently ensure the welding strength, and no empty space (gap) is formed on the bent surface.The structures of the uncoated portions 146 a, 146 bmay be changed as desired to structures according to the above embodiments (modifications) different from those shown in the drawings. In addition, a conventional uncoated portion structure may be applied to any of the uncoated portions 146 a, 146 bwithout limitation.FIG. 33 is a cross-sectional view showing a cylindrical battery 200 according to still another embodiment of the present disclosure along the Y-axis direction.Referring to FIG. 33, the cylindrical battery 200 includes the electrode assembly A 4 shown in FIG. 24, and other configurations except for the electrode assembly A 4 are substantially the same as those of the cylindrical battery 180 shown in FIG. 31.Referring to FIG. 33, the uncoated portions 146 a, 146 bof the electrode assembly A 4 are bent from the outer periphery toward the core. Since the core-side uncoated portion B 1 has a lower height than other portions, it is substantially not bent at this time. The first current collector plate 144 may be welded to the curved surface of the uncoated portion 146 aand the second current collector plate 176 may be welded to the curved surface of the uncoated portion 146 b.In the electrode assembly A 4, the core-side uncoated portion B 1 has a comparatively lower height than the other portions. In addition, as shown in FIG. 24, the bending length H of the innermost uncoated portion in the intermediate uncoated portion B 2 is equal to or less than the radial length R of the core-side uncoated portion B 1.Therefore, even if the uncoated portions 146 a, 146 bare bent toward the core, the cavity 112 of the core of the electrode assembly A 4 can be opened upward without being blocked (see the dotted circle).When the cavity 112 is not blocked, there is no difficulty in the electrolyte injection process, and the electrolyte injection efficiency is improved. In addition, a welding process between the second current collecting plate 176 and the battery case 171 can be performed simply by inserting a welding device through the cavity 112.When the uncoated portions 146 a, 146 bhave a segment structure, when the width and / or height and / or the separation distance of the segments is adjusted to satisfy the numerical range of the above embodiment, when the segments are bent, the segments are overlapped in multiple layers to sufficiently ensure the welding strength, and no empty space (gap) is formed on the bent surface.The structures of the uncoated portions 146 a, 146 bmay be changed as desired to structures according to the above embodiments (modifications) different from those shown in the drawings. In addition, a conventional uncoated portion structure may be applied to any of the uncoated portions 146 a, 146 bwithout limitation.FIG. 34 is a cross-sectional view showing a cylindrical battery 210 along the Y-axis direction according to still another embodiment of the present disclosure.Referring to FIG. 34, the cylindrical battery 210 includes the electrode assembly A 3 shown in FIG. 23, and other configurations except the electrode assembly A 3 are substantially the same as those of the cylindrical battery 140 shown in FIG. 27.Preferably, the uncoated portions 146 a, 146 bof the electrode assembly A 3 are bent from the outer periphery toward the core. At this time, since the core-side uncoated portion B 1 and the outer peripheral-side uncoated portion B 3 of the uncoated portion 146 aare lower in height than other portions, they are not substantially bent. This is the same for the uncoated portion 146 b. The first current collector plate 144 may be welded to the curved surface of the uncoated portion 146 aand the second current collector plate 145 may be welded to the curved surface of the uncoated portion 146 b.The height of the core-side uncoated portion B 1 is comparatively lower than that of the intermediate uncoated portion B 2. In addition, as shown in FIG. 23, the bending length H of the innermost uncoated portion in the intermediate uncoated portion B 2 is equal to or less than the radial length R of the core-side uncoated portion B 1.Therefore, even if the uncoated portions 146 a, 146 bare bent toward the core, the cavity 102 of the core of the electrode assembly A 3 can be opened upward without being blocked (see the dotted circle).When the cavity 112 is not blocked, there is no difficulty in the electrolyte injection process, and the electrolyte injection efficiency is improved. In addition, a welding process between the second current collecting plate 145 and the battery case 142 can be performed simply by inserting a welding device through the cavity.In addition, the height of the outer peripheral-side uncoated portion B 3 is comparatively lower than that of the intermediate uncoated portion B 2. Therefore, when the uncoated portion 146 ais bent, the outer peripheral-side uncoated portion B 3 is substantially not bent. Moreover, since the outer peripheral side uncoated portion B 3 is sufficiently spaced apart from the bead portion 147, it is possible to solve the problem that the outer peripheral side uncoated portion B 3 is damaged during the press-fitting of the bead portion 147.When the uncoated portions 146 a, 146 bhave a segment structure, when the width and / or height and / or the separation distance of the segments is adjusted to satisfy the numerical range of the above embodiment, when the segments are bent, the segments are overlapped in multiple layers to sufficiently ensure the welding strength, and no empty space (gap) is formed on the bent surface.The structures of the uncoated portions 146 a, 146 bmay be changed as desired to structures according to the above embodiments (modifications) different from those shown in the drawings. In addition, a conventional uncoated portion structure may be applied to any of the uncoated portions 146 a, 146 bwithout limitation.FIG. 35 is a cross-sectional view showing a cylindrical battery 220 along the Y-axis direction according to still another embodiment of the present disclosure.Referring to FIG. 35, the cylindrical battery 220 includes the electrode assembly A 3 shown in FIG. 23, and other configurations except the electrode assembly A 3 are substantially the same as those of the cylindrical battery 180 shown in FIG. 31.Preferably, the uncoated portions 146 a, 146 bof the electrode assembly A 3 are bent from the outer periphery toward the core. At this time, since the core-side uncoated portion B 1 of the uncoated portion 146 ahas a height lower than other portions, it is not substantially bent. This is the same for the uncoated portion 146 b. The first current collector plate 144 may be welded to the curved surface of the uncoated portion 146 aand the second current collector plate 176 may be welded to the curved surface of the uncoated portion 146 b.In the electrode assembly A 3, the height of the core-side uncoated portion B 1 is comparatively lower than that of the intermediate uncoated portion B 2. In addition, as shown in FIG. 23, the bending length H of the innermost uncoated portion in the intermediate uncoated portion B 2 is equal to or less than the radial length R of the core-side uncoated portion B 1.Therefore, even if the uncoated portions 146 a, 146 bare bent toward the core, the cavity 102 of the core of the electrode assembly A 3 can be opened upward without being blocked (see the dotted circle).When the cavity 112 is not blocked, there is no difficulty in the electrolyte injection process, and the electrolyte injection efficiency is improved. In addition, a welding process between the second current collecting plate 176 and the battery case 171 can be performed simply by inserting a welding device through the cavity 102.In addition, the height of the outer peripheral side uncoated portion B 3 of the uncoated portion 146 ais comparatively lower than that of the intermediate uncoated portion B 2. Therefore, when the uncoated portion 146 ais bent, the outer peripheral-side uncoated portion B 3 is substantially not bent. These features may also be applied to the uncoated portion 146 b.When the uncoated portions 146 a, 146 bhave a segment structure, when the width and / or height and / or the separation distance of the segments is adjusted to satisfy the numerical range of the above embodiment, when the segments are bent, the segments are overlapped in multiple layers to sufficiently ensure the welding strength, and no empty space (gap) is formed on the bent surface.The structures of the uncoated portions 146 a, 146 bmay be changed as desired to structures according to the above embodiments (modifications) different from those shown in the drawings. In addition, a conventional uncoated portion structure may be applied to any of the uncoated portions 146 a, 146 bwithout limitation.The cylindrical battery according to the above embodiments (modifications) may be used to manufacture a battery pack (see FIG. 13 a ), and the battery pack may be mounted on a vehicle (see FIG. 13 b ).According to the present invention, it is possible to effectively prevent an internal short circuit from being caused by meandering of the electrodes during the manufacture of the electrode assembly.According to another present disclosure, the internal resistance of a cylindrical battery can be reduced and the energy density can be increased by using the uncoated portion itself protruding from the upper and lower portions of the electrode assembly as an electrode tab.According to another aspect of the present disclosure, by improving the structure of the uncoated portion of the electrode assembly to prevent interference between the electrode assembly and the inner periphery of the battery case in the process of forming the bead portion of the battery case, it is possible to prevent a short circuit from occurring in the cylindrical battery due to partial deformation of the electrode assembly.According to still another aspect of the present disclosure, by improving the structure of the uncoated portion of the electrode assembly, it is possible to prevent the uncoated portion from being torn in the vicinity of the bending point when the uncoated portion is bent, and it is possible to improve the welding strength by sufficiently increasing the number of overlapping layers of the uncoated portion.According to still another aspect of the present disclosure, by improving the structure of the uncoated portion adjacent to the core of the electrode assembly, it is possible to prevent the cavity in the core of the electrode assembly from being blocked when the uncoated portion is bent, so that the electrolyte injection process and the process of welding the battery case and the current collector plate can be easily performed.According to still another aspect of the present invention, it is possible to provide an electrode assembly having improved electrolyte impregnation properties by optimizing the position of the separator around the segment structure of the uncoated region.According to still another aspect of the present disclosure, it is possible to provide a cylindrical battery having a structure having low internal resistance, internal short-circuit prevention, and improved welding strength between the current collecting plate and the uncoated portion, and a battery pack and a vehicle including the cylindrical battery.Hereinafter, an embodiment of a positive electrode active material used in the cylindrical battery according to the present disclosure will be described.In an embodiment, the "primary particle" is a particle in which no grain boundary occurs when viewed in a field of view with a magnification of 5000 to 20000 using a scanning electron microscope (SEM) or electron back scattering diffraction (EBSD). "Average particle diameter of primary particles" means an arithmetic mean value calculated after measuring particle diameters of primary particles viewed in an SEM or EBSD image."Secondary particle" is a particle formed by aggregating a plurality of primary particles. In the present disclosure, a secondary particle in which 10 or less primary particles are aggregated is referred to as pseudo-single particles to distinguish it from a conventional secondary particle formed by aggregating ten to one hundred primary particles.In the present disclosure, "specific surface area" is measured by the BET method, and in particular, can be calculated from the nitrogen gas adsorption amount under liquid nitrogen temperature (77K) using BELSORP mini II of BEL Japan.In the present disclosure, "Dmin", "D50", and "Dmax" are particle size values of the cumulative volume distribution of the positive electrode active material measured using a laser diffraction method. Specifically, Dmin is a minimum particle size occurring in the cumulative volume distribution, D 50 is a particle size when the cumulative volume amount is 50%, and Dmax is a maximum particle size occurring in the cumulative volume distribution. When the positive electrode active material is a single particle, D50 means an average particle diameter of the primary particles. In addition, when the positive electrode active material is a pseudo single particle, D50 means an average particle diameter of particles formed by aggregating primary particles.The particle size value of the cumulative volume distribution can be measured, for example, by dispersing the positive electrode active material in a dispersion medium, then placing it in a commercially available laser diffraction particle size measurement device (e.g., Microtrac MT 3000), irradiating ultrasonic waves of about 28 kHz with a power of 60 W thereto, and obtaining a graph of the cumulative volume particle size distribution.In the present disclosure, "consisting essentially of A" means that the A component and all non-mentioned components that do not substantially affect the basic and novel characteristics of the present disclosure are included. The basic and novel characteristics of the present disclosure include at least one of minimizing particle breakage during battery manufacture, minimizing gas generated by such particle breakage, and minimizing the occurrence of internal cracks. A person skilled in the art can recognize the material influence of these properties.As a result of the repeated research for developing a positive electrode for an electrochemical device with high safety while realizing a high capacity and an electrochemical device including the same, the present inventors have confirmed that safety of a large cylindrical battery can be dramatically improved when the positive electrode active material in the form of a single particle consisting of a primary particle or a pseudo-single particle which is an aggregate of 10 or less primary particles is used alone as the positive electrode active material.In one aspect, the positive electrode includes a positive electrode current collector and a positive electrode active material layer formed on at least one side surface of the positive electrode current collector, wherein the positive electrode active material layer may include a positive electrode active material and optionally a conductive material and / or a binder.The positive electrode may have a structure in which a positive electrode active material layer is formed on at least one surface or both surfaces of a long sheet-shaped positive electrode current collector, and the positive electrode active material layer may include a positive electrode active material and a binder.Specifically, the positive electrode can be produced by applying a positive electrode slurry prepared by dispersing a positive electrode active material, a conductive material, and a binder in a solvent such as dimethyl sulfoxide (DMSO), isopropyl alcohol, N-methylpyrrolidone (NMP), acetone, water, or the like to one surface or both surfaces of a long sheet-shaped positive electrode current collector, removing the solvent of the positive electrode slurry by a drying process, and then roll-pressing it. Meanwhile, when the positive electrode slurry is applied, a positive electrode having an uncoated portion (uncoated portion) can be manufactured by not applying the positive electrode slurry to a partial region of the positive electrode current collector, for example, an end of the positive electrode current collector.In another aspect, the positive electrode active material contains single-particle-based active material particles. In one embodiment, the single-particle-based active material particles may be 90% by weight or more, 95% by weight or more, 98% by weight or more, or 99% by weight or more, based on 100% by weight of the positive electrode active material. In a specific embodiment, the positive electrode active material may be composed of only the single-particle-based active material particles.In this specification, the single-particle-based active material particle refers to a single particle, a pseudo-single particle, or both. The single particle is a particle consisting of a primary particle, and the pseudo single particle is an aggregate of 10 or less primary particles.Conventionally, it has been common to use a spherical secondary particle in which ten to hundred primary particles are aggregated as a positive electrode active material of a lithium battery. However, in the case of a positive electrode active material in the form of secondary particles in which many primary particles are aggregated, it is easy to cause particle breakage in which primary particles fall off to occur in the rolling process in the production of a positive electrode, and cracks occur within the particles during the charging and discharging process. When particles of the positive electrode active material are broken or cracks occur within the particles, the contact area with the electrolyte increases, so that there is a problem that gas generation increases due to a side reaction with the electrolyte. As gas generation within the cylindrical battery increases, the pressure within the battery increases and there is a risk of battery explosion. In particular, as the volume of the cylindrical battery is increased, the amount of active material inside the battery increases as the volume increases, and as a result, the amount of gas generated significantly increases, so that the risk of ignition and / or explosion of the battery further increases.In contrast, the single-particle-based active material particles in the form of a single particle composed of a primary particle or a pseudo-single particle in which 10 or less primary particles are aggregated have a higher particle strength than the positive electrode active material in the present secondary particle form in which ten to one hundred primary particles are aggregated, so that particle breakage rarely occurs during the rolling process. In addition, since the number of primary particles constituting the single-particle-based active material particle is small, the volume expansion and contraction of the primary particles during charging and discharging is small, and thus the occurrence of cracks inside the particle is significantly reduced.Therefore, when using the single-particle-based active material particles as in the present disclosure, the amount of gas generated due to particle breakage and internal cracks can be significantly reduced. Accordingly, when the single-particle-based active material particles are applied to a large cylindrical battery, excellent safety can be realized.Meanwhile, the single particle and / or pseudo-single particle is contained in an amount of 95% by weight to 100% by weight, preferably 98% by weight to 100% by weight, more preferably 99% by weight to 100% by weight, further preferably 100% by weight, based on the total weight of the positive electrode active material contained in the positive electrode.When the content of single particle and / or pseudo single particle satisfies the above range, sufficient safety can be achieved when applied to a large-diameter battery. When the positive electrode active material in the form of a secondary particle is contained in the entire positive electrode active material in an amount of more than 5 wt %, the side reaction with the electrolyte increases due to fine powder generated from the secondary particle during electrode manufacture and charging / discharging, which may deteriorate the suppression of gas generation and reduce the stability improvement effect when applied to a large-diameter battery.Meanwhile, positive electrode active materials containing single particles and / or pseudo-single particles according to the present disclosure may have Dminof 1.0 μm or more, 1.1 μm or more, 1.15 μm or more, 1.2 μm or more, or 1.25 μm or more, 1.3 μm or more, or 1.5 μm or more. When the Dmin of the positive electrode active material is less than 1.0 μm, the line pressure during the positive electrode rolling process increases, which may easily result in particle breakage and deteriorate the thermal stability, making it impossible to ensure sufficient thermal stability when applied to a large-diameter cylindrical battery.Meanwhile, considering resistance and power characteristics Dmin of the positive electrode active material, 3 μm or less, 2.5 μm or less, or 2 μm or less may be used. If Dmin is too large, the lithium ion diffusion distance within the particles may increase, and thus the resistance and performance characteristics may deteriorate.For example, Dmin of the positive electrode active material may be 1.0 μm to 3 μm, 1.0 μm to 2.5 μm, or 1.3 μm to 2.0 μm.Meanwhile, the positive electrode active material may have a D50 of 5 μm or less, 4 μm or less, or 3 μm or less, and may be, for example, 0.5 μm to 5 μm, preferably 1 μm to 5 μm, more preferably 2 μm to 5 μm.The positive electrode active material in the form of individual particles and / or pseudo single particles has a lower lithium mobility than the positive electrode active material in the form of secondary particles because there are fewer interfaces between primary particles serving as a diffusion path for lithium ions within the particles, and accordingly, there is a problem that the resistance increases. The increase in resistance increases as the size of the particles increases, and as the resistance increases, capacitance and performance characteristics are adversely affected. Therefore, by setting D50 of the positive electrode active material to 5 μm or less, it is possible to suppress an increase in resistance by minimizing the lithium ion diffusion distance within the positive electrode active material particle.In addition, the positive electrode active material may have a Dmax of 12 μm to 17 μm, preferably 12 μm to 16 μm, and more preferably 12 μm to 15 μm. When Dmax of the positive electrode active material satisfies the above range, the resistance properties and capacitance properties are more excellent. When Dmax of the positive electrode active material is too large, aggregation between individual particles has occurred, and the lithium movement path within the agglomerated particles is elongated, resulting in poor lithium mobility, which may increase resistance. On the other hand, if Dmax of the positive electrode active material is too small by an excessive squeezing process, Dmin may decrease to less than 1 μm, resulting in particle breakage during rolling and degrading thermal stability.Meanwhile, the positive electrode active material may have a particle size distribution (PSD) represented by the following Formula 1 of 3 or less, preferably 2 to 3, more preferably 2.3 to 3.When the positive electrode active material has the above particle size distribution, the electrode density of the positive electrode can be properly maintained, and particle breakage and an increase in resistance can be effectively suppressed.Meanwhile, the positive electrode active material may have an average particle diameter of the primary particles of 5 μm or less, 4 μm or less, 3 μm or less, or 2 μm or less, and may be, for example, 0.5 μm to 5 μm, preferably 1 μm to 5 μm, more preferably 2 μm to 5 μm. When the average particle diameter of the primary particles satisfies the above range, the positive electrode active material may be formed in the form of a single particle and / or pseudo-single particle having excellent electrochemical properties. When the average particle diameter of the primary particles is too small, the number of aggregations of the primary particles constituting the positive electrode active material increases, which reduces the effect of suppressing particle breakage during rolling. If the average particle diameter of the primary particles is too large, the lithium diffusion path may be elongated, which increases the resistance and deteriorates the performance.In the present disclosure, the positive electrode active material preferably has a monomodal particle size distribution. Conventionally, for improving the electrode density of the positive electrode active material layer, bimodal positive electrode active materials in which a large-particle-diameter positive electrode active material having a large average particle diameter and a small-particle-diameter positive electrode active material having a small average particle diameter are mixed have been widely used. However, in the positive electrode active material in the form of single particles or pseudo-single particles, the lithium movement path increases as the particle size increases, and the resistance remarkably increases. Thus, when large-diameter particles are mixed and used, a problem of deterioration in capacity and performance characteristics may occur. Therefore, in the present disclosure, the increase in resistance can be minimized by using a positive electrode active material having a monomodal distribution.Meanwhile, the positive electrode active material may include a lithium nickel-based oxide, and more specifically, may include a lithium nickel-based oxide containing 80 mol % or more of Ni based on the total molar number of a transition metal. Preferably, the lithium nickel-based oxide may contain 80 mol % or more and less than 100 mol % of Ni, 82 mol % or more and less than 100 mol % of Ni, or 83 mol % or more and less than 100 mol % of Ni. When the lithium nickel-based oxide having a high Ni content is used as above, a high capacity can be realized.Specifically, the positive electrode active material may include a lithium nickel-based oxide represented by the following [Chemical Formula 1]. Li a Ni b Co c M 1 aM 2e O 2[ Chemical Formula 1]In Chemical Formula 1, M1may be Mn, Al, or a combination thereof, and may preferably be Mn or Mn and Al.M2is at least one selected from the group consisting of Zr, W, Y, Ba, Ca, Ti, Mg, Ta and Nb, preferably at least one selected from the group consisting of Zr, Y, Mg and Ti, more preferably Zr, Y or a combination thereof. The M2element is not necessarily contained, but when contained in an appropriate amount, it may play a role in promoting grain growth or improving crystal structure stability during sintering.The a represents the molar ratio of lithium in the lithium nickel-based oxide, and may be 0.8≤a≤1.2, 0.85≤a≤1.15, or 0.9≤a≤1.2. When the molar ratio of lithium satisfies the above range, a crystal structure of the lithium nickel-based oxide can be stably formed.The b represents the molar ratio of nickel among all metals other than lithium in the lithium nickel-based oxide, and may be 0.8≤b<1, 0.82≤b<1, 0.83≤b<1, 0.85≤b<1, 0.88≤b<1, or 0.90≤b<1. When the molar ratio of nickel satisfies the above range, it is possible to realize high capacity by having high energy density.The c represents the molar ratio of cobalt among all metals other than lithium in the lithium nickel-based oxide, and may be 0<c<0.2, 0<c<0.18, 0.01≤c≤0.17, 0.01≤c≤0.15, 0.01≤c≤0.12, or 0.01≤c≤0.10. When the molar ratio of cobalt satisfies the above range, good resistance characteristics and performance characteristics can be implemented.The d represents the molar ratio of M1 element among all metals other than lithium in the lithium nickel-based oxide, and may be 0<d<0.2, 0<d<0.18, 0.01≤d≤0.17, 0.01≤d≤0.15, 0.01≤d≤0.12, or 0.01≤d≤0.10. When the molar ratio of M1element satisfies the above range, the structural stability of the positive electrode active material is excellent.The e represents the molar ratio of M2element among all metals other than lithium in the lithium nickel-based oxide, and may be 0≤e≤0.1 or 0≤e≤0.05.Meanwhile, the positive electrode active material according to the present disclosure may further include, if necessary, a coating layer including at least one coating element selected from the group consisting of Al, Ti, W, B, F, P, Mg, Ni, Co, Fe, Cr, V, Cu, Ca, Zn, Zr, Nb. On the surface of the lithium nickel-based oxide particle, the positive electrode active material may include at least one coating element selected from the group consisting of Al, Ti, W, B, F, P, Mg, Ni, Co, Fe. Preferably, the coating element may be Al, B, Co, or a combination thereof.When the coating layer is present on the surface of the lithium nickel-based oxide particles, contact between the electrolyte and the lithium nickel-based oxide is suppressed by the coating layer, thereby reducing elution of the transition metal or gas generation due to side reactions with the electrolyte.The positive electrode active material may be contained in an amount of 80 wt % to 99 wt %, preferably 85 wt % to 99 wt %, more preferably 90 wt % to 99 wt %, based on the total weight of the positive electrode active material layer.Meanwhile, as the positive electrode current collectors, various positive electrode current collectors used in the related art may be used. For example, stainless steel, aluminum, nickel, titanium, calcined carbon, or aluminum or stainless steel surface-treated with carbon, nickel, titanium, silver, or the like can be used as the positive electrode current collector. The positive electrode current collector may typically have a thickness of 3 μm to 500 μm, and fine irregularities may be formed on the surface of the positive electrode current collector to increase the adhesion of the positive electrode active material. The positive electrode current collector can be used in various forms of, for example, foil, sheet, foil, mesh, porous material, foam or nonwoven fabric.Meanwhile, in an embodiment of the present disclosure, all or some of the single-particle-based active material particles may have a core-shell structure in which the particle surface is coated with a conductive coating layer. The conductive coating layer may cover at least some or all of the particles. The conductive coating layer includes conductive nanomaterials.The single-particle-based active material particle has a problem in that the electric conductivity is lowered because the resistance is higher than that of the conventional secondary-particle positive electrode active material and the contact area with the conductive material is small. When an excessive amount of conductive material is added to improve the electric conductivity, aggregation occurs in the positive electrode slurry, resulting in increased viscosity, resulting in poor coating properties. Therefore, in order to implement smooth coating properties, the viscosity of the positive electrode slurry must be lowered by lowering the solid content. However, when the solid content in the positive electrode slurry decreases, the active material content decreases, which may deteriorate the capacity properties. In the present disclosure, in order to solve this problem, the surface of the single-particle-based active material is coated with a conductive nanomaterial, so that excellent electrical conductivity can be realized without adding a separate conductive material to the positive electrode slurry.In an embodiment of the present disclosure, when the single-particle-based active material coated with a conductive nanomaterial is applied as the positive electrode active material, the positive electrode active material layer may not contain a conductive material on a portion other than the conductive coating layer. Since there is no need to additionally use a conductive material that causes aggregation of the positive electrode slurry as described above, the viscosity of the positive electrode slurry can be reduced, the solid content can be reduced, and the efficiency of the electrode coating process and the electrode adhesion can be improved.In the present disclosure, the conductive nanomaterial may be a conductive material having a nano-size to be uniformly coated on particles, and the type is not particularly limited. For example, the conductive nanomaterial may be a carbon nanotube, a carbon nanoparticle, or the like.The conductive nanomaterial may have various shapes and may be, for example, spherical, flake, or fibrous.Meanwhile, the conductive coating layer may be formed by mixing single-particle-based active material particles, which are a core part, and a conductive nanomaterial, and then thermally treating the mixture. The mixing can be carried out as solid mixing or liquid mixing.In an embodiment of the present disclosure, the positive electrode active material layer contains flake graphite. When the single-particle-based active material is used as the positive electrode active material, when the positive electrode active material layer contains flake graphite, in the case of rolling the positive electrode active material layer, the sliding effect of the flake graphite on the positive electrode active material is provided to improve the rolling properties of the electrode, and the porosity of the electrode can be lowered to a desired level. Accordingly, stability, initial resistance characteristics, and charging / discharging efficiency of a battery to which the positive electrode according to the present disclosure is applied can be improved.In an embodiment of the present disclosure, the flake graphite may be contained in an amount of 0.1 wt % to 5 wt %, preferably 0.1 wt % to 3 wt %, based on 100 wt % of the positive electrode active material layer.When the content of flake graphite satisfies the above range, the rolling properties of the positive electrode are improved, and an excellent electrode density can be realized. If the content of flake graphite is too small, the effect of improving the rolling properties is insignificant, and if it is too large, it may cause an increase in slurry viscosity and a decrease in phase stability, and the resistance may increase due to a decrease in electrode uniformity by coupling with a conductive material.Meanwhile, the flake graphite used in the present disclosure may have an average particle diameter of 1 μm to 20 μm, preferably 2 μm to 10 μm, more preferably 3 μm to 5 μm, but is not limited thereto. If the size of the flake graphite is too small, it is difficult to realize the desired porosity and the current density can be lowered, resulting in a lower capacity. At this time, the average particle diameter of the flake graphite can be measured using a laser diffraction method (ISO 13320).In addition, the flake graphite may have an aspect ratio of 0.1 to 500, preferably 1 to 100, more preferably 1 to 30. When the aspect ratio of flake graphite satisfies the above range, the effect of lowering the electrode resistance by improving the conductivity occurs.In addition, the flake graphite may have a density of 2.0 g / cm3to 2.5 g / cm3, preferably 2.1 g / cm3to 2.4 g / cm3, more preferably 2.2 g / cm3to 2.3 g / cm3.Meanwhile, in the present disclosure, the porosity of the positive electrode active material layer may be 15% to 23%, preferably 17% to 23%, more preferably 18% to 23%. When the porosity of the positive electrode active material layer satisfies the above range, the electrode density increases to realize excellent capacitance, and the resistance decreases. If the porosity is too low, the electrolyte impregnation ability is low, and lithium deposition may occur due to non-impregnation of the electrolyte. If the porosity is too high, the contact between the electrodes is not good, increasing the resistance and decreasing the energy density, so that the effect of the capacitance improvement is insignificant.The porosity value of the positive electrode active material layer can be obtained by i) the positive electrode active material containing single-particle-based active material particles and ii) adding flake graphite to the positive electrode active material.In implementing a high charge electrode having a relatively high charge amount of the positive electrode active material, when a positive electrode active material in the form of a single particle or pseudo-single particle is used as in the present disclosure, particle breakage of the active material during rolling is significantly reduced as compared with the conventional positive electrode active material in the form of a secondary particle, and damage to the positive electrode current collector (Al foil) is reduced, so that rolling with a relatively high line pressure is possible. Therefore, the porosity of the positive electrode active material layer can be reduced to the numerical range as described above, so that the energy density can be increased.In addition, when the positive electrode active material layer contains flake graphite as in the present disclosure, the flake graphite can provide a sliding effect during rolling and fill the pores of the positive electrode active material layer, so that the porosity of the positive electrode active material layer can be reduced to the above numerical range.In addition, the positive electrode may have a charge amount of 570 mg / 25 cm2or more, preferably 600 mg / 25 cm2to 800 mg / 25 cm2, more preferably 600 mg / 25 cm2to 750 mg / 25 cm2. In particular, in the lithium secondary battery according to the present disclosure, since the rolling properties of the electrode are improved by applying a single particulate and / or pseudo-single particulate positive electrode active material and flake graphite, the charge amount of the positive electrode can be secured at a relatively high level, and thereby high capacity properties can be implemented.In an embodiment of the present disclosure, the positive electrode active material layer may further include a conductive material. The conductive material is used to impart conductivity to the electrode, and any material that does not cause chemical change within the battery and has electronic conductivity may be used without particular limitations. Specific examples may include graphite such as natural graphite or artificial graphite; carbon-based materials such as carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, thermal black, carbon fiber or carbon nanotubes; metal powder or metal fiber such as copper, nickel, aluminum or silver; conductive whiskers such as zinc oxide or potassium titanate; conductive metal oxides such as titanium oxide; and conductive polymers of polyphenylene derivatives and the like, which may be used alone or as a mixture. The conductive material may be contained typically in an amount of 1 wt % to 30 wt %, preferably 1 wt % to 20 wt %, more preferably 1 wt % to 10 wt %, based on the total weight of the positive electrode active material layer.In a specific embodiment of the present disclosure, the conductive material may include carbon nanotubes.In an embodiment of the present disclosure, the positive electrode active material may include a multi-wall carbon nanotube having a large specific surface area and a small number of walls as a conductive material. The multi-wall carbon nanotube may be contained in an amount of 50% by weight or more, 70% by weight or more, 90% by weight or more, or 99% by weight or more, based on 100% by weight of the conductive material. In a specific embodiment of the present disclosure, the conductive material may include only the multi-wall carbon nanotube.In the present disclosure, the multi-wall carbon nanotube has a BET specific surface area of 300 m2 / g to 500 m2 / g. The multi-wall carbon nanotube is referred to as "new CNT" to be distinguished from the conventional one.The carbon nanotube (conventional CNT) commonly used in the art had a BET specific surface area of less than 300 m2 / g. The SEM images and physical properties (FIG. 38 ) of the new CNT (FIG. 36 ) used in the present disclosure and the existing CNT (FIG. 37 ) may be compared as follows.As can be seen from the SEM images, the new CNT applied to the present disclosure is a bundled type and has a multi-wall structure, but has a higher BET and a smaller wall number and a smaller diameter than the conventional CNT.In the case of using the positive electrode active material in the form of a secondary particle, sufficient electric conductivity could be obtained even if the existing CNT was used at a level of 0.4 wt % to 0.6 wt %. However, the single-particle or pseudo single-particle positive electrode active material has a higher resistance compared to the conventional secondary-particle positive electrode active material, and the contact area with the conductive material is small, so that the electric conductivity is low. Therefore, in order to realize sufficient electric conductivity using the existing CNT having a BET specific surface area of less than 300 m2 / g, the content of the conductive material needs to be 0.9 wt % or more.FIGS. 39 to 42 are graphs showing sheet resistance and high temperature lifetime characteristics for each conductive material ratio when single particles or pseudo single particles are applied as the positive electrode active material.It is understood from the graphs that when a single particle or pseudo-single particle is applied as the positive electrode active material, the use amount of conductive material should increase compared to the case of applying an existing positive electrode active material in the form of a secondary particle.However, when the content of carbon nanotubes is increased to 0.9% by weight or more, aggregation occurs in the positive electrode slurry, leading to an increase in viscosity, and hence the coating properties deteriorate. Therefore, in order to implement smooth coating properties, the viscosity of the positive electrode slurry must be lowered by lowering the solid content in the positive electrode slurry. However, when the solid content in the positive electrode slurry decreases, the content of active material decreases, and the capacity characteristics deteriorate.As a result of repeated investigation to solve this problem, the present inventors have found that when a carbon nanotube having a BET specific surface area of 300 m2 / g to 500 m2 / g is applied together with a positive electrode active material, which is a single-particle-based active material particle, as a conductive material, sufficient electrical conductivity can be secured with only a relatively small amount of carbon nanotubes, and accordingly, the slurry viscosity can be kept low even when the solid content of the positive electrode slurry is formed to be as high as 70% by weight to 80% by weight.In particular, the carbon nanotube used in the present disclosure may be a multi-wall carbon nanotube having a BET specific surface area of 300 m2 / g to 500 m2 / g, preferably 300 m2 / g to 450 m2 / g. When the BET specific surface area satisfies the above range, sufficient electrical conductivity can be secured even with a small amount of carbon nanotubes.In addition, the carbon nanotube may be a multi-wall carbon nanotube having a wall number of 2 to 8, preferably 2 to 6, more preferably 3 to 6.In addition, the carbon nanotube may have a diameter of 1 nm to 8 nm, preferably 3 nm to 8 nm, more preferably 3 nm to 6 nm.The carbon nanotube may be contained in an amount of 0.7% by weight or less, preferably 0.3% by weight to 0.7% by weight, more preferably 0.4% by weight to 0.6% by weight, based on the total weight of the positive electrode active material layer. When the content of the carbon nanotube satisfies the above range, sufficient electric conductivity can be achieved, and the solid content in the positive electrode slurry can be kept high, so that the content of the positive electrode active material in the positive electrode active material layer can be high, and as a result, excellent capacity characteristics can be implemented.The table shown in FIG. 43 comparatively shows the solid content and the viscosity of the positive electrode slurry and the resistance values at the MP coating layer and the MP interfacial layer in the case where a carbon nanotube (new CNT) having a BET specific surface area of 300 m2 / g to 500 m2 / g is applied and in the case where a carbon nanotube (existing CNT) having a BET of 200 m2 / g or more and less than 300 m2 / g is applied. From the table, it can be found that when the novel CNT is applied, the positive electrode slurry has a lower viscosity and an excellent electric conductivity even if the solid content of the positive electrode slurry is higher than that of the conventional CNT.The binder serves to improve the adhesion between the particles of the positive electrode active material and the adhesion between the positive electrode active material and the positive electrode current collector. Specific examples of the binder include polyvinylidene fluoride (PVDF), vinylidene fluoride-hexafluoropropylene copolymer (PVDF-co-HFP), polyvinyl alcohol, polyacrylonitrile, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, polytetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene monomer rubber (EPDM rubber), sulfonated EPDM, styrene-butadiene rubber (SBR), fluororubber, or various copolymers thereof, which may be used alone or as a mixture. The binder may be contained in an amount of 1 wt % to 30 wt %, preferably 1 wt % to 20 wt %, more preferably 1 wt % to 10 wt %, based on the total weight of the positive electrode active material layer.Another aspect of the present disclosure relates to an electrode assembly including the positive electrode and a battery including the electrode assembly. The electrode assembly includes a negative electrode and a positive electrode, and the positive electrode has the characteristics described above.In the electrode assembly, for example, a separator may be stacked to be disposed between the negative electrode and the positive electrode to form a stacked or stacked / folded structure, or may be wound to form a jelly roll structure. In addition, when the jelly roll structure is formed, a separator may be additionally placed on the outside to prevent the negative electrode and the positive electrode from contacting each other.The negative electrode includes a negative electrode current collector and a negative electrode active material layer formed on at least one side surface of the negative electrode current collector. The negative electrode may have a structure in which a negative electrode active material layer is formed on one surface or both surfaces of a long sheet-shaped negative electrode current collector, and the negative electrode active material layer may include a negative electrode active material, a conductive material, and a binder.Specifically, the negative electrode can be produced by applying a negative electrode slurry prepared by dispersing a negative electrode active material, a conductive material, and a binder in a solvent such as dimethyl sulfoxide (DMSO), isopropyl alcohol, N-methylpyrrolidone (NMP), acetone, or water to one surface or both surfaces of a long sheet-shaped negative electrode current collector, removing the solvent of the negative electrode slurry by a drying process, and then roll-pressing. When the negative electrode slurry is coated, a negative electrode having an uncoated portion can be produced by not applying the negative electrode slurry to a partial region of the negative electrode current collector, for example, an end of the negative electrode current collector.As the negative electrode active material, a compound capable of reversibly intercalation and deintercalation of lithium may be used. Specific examples of the negative electrode active material include carbonaceous materials such as artificial graphite, natural graphite, graphitized carbon fiber, or amorphous carbon; silicon-based materials such as Si, Si-Me alloy (wherein Me is at least one selected from the group consisting of Al, Sn, Mg, Cu, Fe, Pb, Zn, Mn, Cr, Ti, and Ni), SiOy (wherein 0<y<2), or Si-C composites; lithium metal thin film; metal materials that can be alloyed with lithium such as Sn or Al; and the like, which can be used alone or as a mixture.In the present disclosure, the negative electrode may contain a silicon-based negative electrode active material. The silicon-based negative electrode active material may be a Si, Si-Me alloy (where Me is one selected from the group consisting of Al, Sn, Mg, Cu, Fe, Pb, Zn, Mn, Cr, Ti, and Ni), SiOy (here 0<y<2), Si-C composites, or a combination thereof, and may preferably be SiOy (here 0<y<2). Since the silicon-based negative electrode active material has a high theoretical capacity, capacity characteristics can be improved when the silicon-based negative electrode active material is contained.The silicon-based negative electrode active material may be doped with Mb metal, and in this case, the Mb metal may be a group 1 metal element or a group 2 metal element, and may be, in particular, Li, Mg, or the like. Specifically, the silicon-based negative electrode active material may be Si, SiOy(here, 0<y<2), Si-C composites, or the like doped with Mb metal. In the case of the metal-doped negative electrode active material based on silicon, the capacity of the active material due to the dopant element is somewhat lowered, but a high energy density can be realized due to its high efficiency.FIG. 60 is a graph showing the change in energy density depending on the content of a silicon-based negative electrode active material and the presence or absence of doping of the silicon-based negative electrode active material in a battery using a mixture of a silicon-based negative electrode active material and a carbon-based negative electrode active material as the negative electrode active material.In FIG. 60, SiO with low efficiency refers to undoped SiO, and SiO with ultra-high efficiency refers to Mg / Li-doped SiO. From FIG. 60, it can be found that the energy density improves as the content of the silicon-based negative electrode active material among the entire negative electrode active materials increases. In addition, it can be found that as the ratio of the doped silicon-based negative electrode active material among the silicon-based negative electrode active materials increases, the effect of improving the energy density becomes better.The silicon-based negative electrode active material may further include a carbon coating layer on the particle surface. At this time, the carbon coating amount may be 20 wt % or less, preferably 1 wt % to 20 wt %, based on the total weight of the silicon-based negative electrode active material. The carbon coating layer may be formed by a method such as dry coating, wet coating, chemical vapor deposition (CVD), physical vapor deposition (PVD), or atomic layer deposition (ALD).In an embodiment of the present disclosure, the silicon-based negative electrode active material may have a capacity of 1000 mAh / g to 4000 mAh / g and an initial efficiency of about 60% to 95%.In another embodiment of the present disclosure, D50 of the silicon-based negative electrode active material may be 3 μm to 8 μm, and Dmin to Dmax may be included in the range of 0.5 μm to 30 μm.The negative electrode may further contain a carbon-based negative electrode active material as the negative electrode active material, if necessary. The carbon-based negative electrode active material may be, for example, artificial graphite, natural graphite, graphitized carbon fiber, amorphous carbon, soft carbon, hard carbon, or the like, but is not limited thereto.When a mixture of the silicon-based negative electrode active material and the carbon-based negative electrode active material is used as the negative electrode active material, the mixing ratio of the silicon-based negative electrode active material and the carbon-based negative electrode active material may be 1:99 to 20:80, preferably 1:99 to 15:85, more preferably 1:99 to 10:90, in a weight ratio.The negative electrode active material may be contained in an amount of 80 wt % to 99 wt %, preferably 85 wt % to 99 wt %, more preferably 90 wt % to 99 wt %, based on the total weight of the negative electrode active material layer.If necessary, the negative electrode active material may further include at least one selected from lithium metal and metal materials capable of alloying with lithium, such as Sn or Al.As the negative electrode current collector, negative electrode current collectors generally used in the related art may be used, and for example, copper, stainless steel, aluminum, nickel, titanium, calcined carbon; copper or stainless steel surface-treated with carbon, nickel, titanium, silver, etc.; aluminum-cadmium alloy; and the like may be used. The negative electrode current collector may typically have a thickness of 3 μm to 500 μm, and like the positive electrode current collector, fine irregularities may be formed on the surface of the current collector to improve the joining force of the negative electrode active material. For example, the negative electrode current collector can be used in various forms such as films, sheets, films, nets, porous materials, foams, or nonwoven fabrics.The conductive material is used to impart conductivity to the negative electrode, and any material having electronic conductivity without causing chemical change inside the battery may be used without particular limitations. Specific examples of the conductive material include graphite such as natural graphite or artificial graphite; carbon-based materials such as carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, thermal black, carbon fiber or carbon nanotubes; metal powder or metal fibers such as copper, nickel, aluminum or silver; conductive whiskers such as zinc oxide or potassium titanate; conductive metal oxides such as titanium oxide; and conductive polymers such as polyphenylene derivatives, which may be used alone or as a mixture. The conductive material may be contained typically in an amount of 1 wt % to 30 wt %, preferably 1 wt % to 20 wt %, more preferably 1 wt % to 10 wt %, based on the total weight of the negative electrode active material layer.The binder serves to improve the adhesion between the particles of the negative electrode active material and the adhesion between the negative electrode active material and the negative electrode current collector. Specific examples of the binder include polyvinylidene fluoride (PVDF), vinylidene fluoride-hexafluoropropylene copolymer (PVDF-co-HFP), polyvinyl alcohol, polyacrylonitrile and carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, polytetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene monomer rubber (EPDM rubber), sulfonated EPDM, styrene-butadiene rubber (SBR), fluororubber or various copolymers thereof, and the like, which may be used alone or as a mixture. The binder may be contained in an amount of 1 wt % to 30 wt %, preferably 1 wt % to 20 wt %, more preferably 1 wt % to 10 wt %, based on the total weight of the negative electrode active material layer.The electrode assembly further includes a separator, and the separator is disposed in the electrode assembly in a manner interposed between the negative electrode and the positive electrode. The separator separates the negative electrode from the positive electrode and provides a pathway for lithium ion movement. Any material used as a separator in a lithium battery may be used without particular limitations.The separator may use a porous polymer film, for example, a porous polymer film made of polyolefin-based polymers such as ethylene homopolymer, propylene homopolymer, ethylene / butene copolymer, ethylene / hexene copolymer, and ethylene / methacrylate copolymer, or a laminated structure of two or more layers thereof. In addition, conventional porous nonwoven fabrics, for example, nonwoven fabrics made of high melting point glass fibers, polyethylene terephthalate fibers or the like can be used. In addition, a coated separator containing a ceramic component or a polymer material may be used to ensure heat resistance or mechanical strength.Another aspect of the present disclosure relates to a battery including the electrode assembly. The battery includes a battery case in which the electrode assembly and an electrolyte are accommodated together. As for the battery case, any compartment commonly used in the art, such as a pouch type or a metal can type, can be selected without particular limitation.As the electrolyte used in the present disclosure, various electrolytes that can be used in lithium batteries, such as organic liquid electrolyte, inorganic liquid electrolyte, solid polymer electrolyte, gel polymer electrolyte, inorganic solid electrolyte, or molten inorganic electrolyte, may be used, and the type is not particularly limited.In particular, the electrolyte may contain an organic solvent and a lithium salt.The organic solvent may use any material that can serve as a medium through which ions involved in the electrochemical reaction of the battery can move without particular limitation. More specifically, as the organic solvent, ester-based solvents such as methyl acetate, ethyl acetate, γ-butyrolactone or ε-caprolactone; ether-based solvents such as dibutyl ether or tetrahydrofuran; ketone-based solvents such as cyclohexanone; aromatic hydrocarbon-based solvents such as benzene or fluorobenzene; carbonate-based solvents such as dimethyl carbonate (DMC), diethyl carbonate (DEC), methylethyl carbonate (MEC), ethylmethyl carbonate (EMC), ethylene carbonate (EC) or propylene carbonate (PC); alcohol-based solvents such as ethyl alcohol or isopropyl alcohol; may be used; Nitriles such as R-CN (R is a C2 to C20 straight chain, branched or cyclic hydrocarbon group and may contain a double-bonded aromatic ring or an ether bond); amides such as dimethylformamide; dioxolanes such as 1,3-dioxolane; or sulfolanes may be used. Among these, carbonate-based solvents are preferable, and a mixture of cyclic carbonates (e.g., ethylene carbonate or propylene carbonate) having high ionic conductivity and high permittivity capable of increasing the charging and discharging performance of the battery and a linear low viscosity carbonate compound (e.g., ethylmethyl carbonate, dimethyl carbonate, or diethyl carbonate) is more preferable.As the lithium salt, any compound capable of providing lithium ions used in a lithium battery can be used without particular limitation. Specifically, LiPF6, LiClO4, LiAsF6, LiB4, LiMnF6, LiAlO4, LiAlCl4, LiCF3SO3, LiC4F9SO3, LiN(C2F5SO3)2, LiN(C2F5SO2)2, LiN(CF3SO2)2, LiCl, LiI, LiB(C2O4)2, or the like may be used as the lithium salt. The concentration of the lithium salt is preferably in the range of 0.1 M to 5.0 M, preferably 0.1 M to 3.0 M. When the concentration of the lithium salt is within the above range, the electrolyte has appropriate conductivity and viscosity, so that it can have excellent electrolyte performance and lithium ions can effectively move.In addition to the components of the electrolyte, the electrolyte may further include additives for the purpose of improving the life characteristics of the battery, suppressing the decrease in battery capacity, and improving the discharge capacity of the battery. For example, haloalkylene carbonate-based compounds such as difluoroethylene carbonate, pyridine, triethyl phosphite, triethanolamine, cyclic ether, ethylenediamine, n-glyme, hexamethylphosphate triamide, nitrobenzene derivatives, sulfur, quinoneimine dyes, N-substituted oxazolidinones, N,N-substituted imidazolidines, ethylene glycol dialkyl ethers, ammonium salts, pyrroles, 2-methoxyethanol, aluminum trichloride, or the like may be used alone or as a mixture as the additives, without being limited thereto. The additive may be contained in an amount of 0.1 wt % to 10 wt %, preferably 0.1 wt % to 5 wt %, based on the total weight of the electrolyte.In another embodiment of the present disclosure, the positive electrode may include a charge reduction portion having a smaller charge amount of the positive electrode active material as compared to an adjacent region. When the positive electrode has such a structure, the area of the positive electrode active material portion can be increased without causing deposition of lithium. Accordingly, the energy density of the electrode assembly can be improved.Recently, development is going to be advanced toward enlargement of the battery to realize high energy density and reduce cost. Depending on the size of the battery, the resistance of the battery should decrease as the energy increases. In order to reduce the resistance, a method of using the current collector of the electrode as an electrode tab may be used instead of a method of attaching an electrode tab to the electrode. At this time, due to the type of the electrode manufacturing process for applying the electrode slurry to the electrode current collector, a portion in which the charge amount is reduced occurs at the boundary between the negative electrode active material portion coated with the negative electrode slurry and the negative electrode current collector. In consideration of the N / P ratio, there is a possibility that metallic lithium is deposited on the positive electrode active material portion facing the portion where the charge amount is reduced. Here, the N / P ratio is a value obtained by dividing the negative electrode capacitance calculated in consideration of the area and capacitance per mass of the negative electrode by the positive electrode capacitance obtained in consideration of the area and capacitance per mass of the positive electrode, and generally has a value of 1 or more. That is, the capacity of the negative electrode is set large. For example, when the N / P ratio is less than 1, metallic lithium is likely to be deposited during charging and discharging, causing rapid deterioration of the safety of the battery during high-speed charging and discharging. In other words, the N / P ratio significantly affects the safety and capacity of the battery. Due to the risk of metal lithium deposition as described above, the positive electrode active material portion may not be on the positive electrode portion facing the portion where the negative electrode charge amount is reduced. This causes the energy density of the battery not to increase. Accordingly, in the present disclosure, the energy density is improved by increasing the area of the positive electrode active material portion.FIG. 48 is a drawing showing an electrode assembly according to an embodiment of the present disclosure, and FIG. 49 is a cross-sectional view taken along the line of intersection A-A' in FIG. 48.Referring to FIGS. 48 and 49, an electrode assembly 300 according to an embodiment of the present disclosure includes a negative electrode 400, a positive electrode 500, and a separator 600. The separator 600 is disposed between the negative electrode 400 and the positive electrode 500. The negative electrode 400, the positive electrode 500, and the separator 600 are wound together to form a jelly roll structure 300S. Here, the jelly roll structure 300S refers to a structure formed by winding the negative electrode 400, the positive electrode 500, and the separator 600. In addition, when the jelly roll structure 300S is formed, it is preferable that a separator 600 is additionally disposed on the outside to prevent the negative electrode 400 and the positive electrode 500 from contacting each other.The negative electrode 400 includes a negative electrode current collector 410 and a negative electrode active material portion 420 formed by coating the negative electrode current collector 410 with a negative electrode active material. Specifically, as shown in the drawings, the negative electrode active material may be coated on both surfaces of the negative electrode current collector 410 to form the negative electrode active material portion 420. In addition, in the negative electrode current collector 410, a negative electrode uncoated portion 430 to which the negative electrode active material is not applied extends in the first direction d 1. The negative electrode uncoated portion 430 extends along one end of the wound negative electrode 400. In addition, the negative electrode uncoated portion 430 extends beyond the separator 600 in the first direction d 1. Accordingly, the negative electrode uncoated portion 430 may be exposed at an end in the first direction of the jelly roll structure 300S.The positive electrode 500 includes a positive electrode current collector 510 and a positive electrode active material portion 520 formed by coating the positive electrode current collector 510 with a positive electrode active material. Specifically, as shown in the drawings, the positive electrode active material may be coated on both surfaces of the positive electrode current collector 510 to form the positive electrode active material portion 520. Also, in the positive electrode current collector 510, a positive electrode uncoated portion 530 to which the positive electrode active material is not applied extends in the second direction d 2. The positive electrode uncoated portion 530 extends along one end of the wound positive electrode 500. In addition, the positive electrode uncoated portion 530 extends beyond the separator 600 in the second direction d 2. Accordingly, the positive electrode uncoated portion 530 may be exposed at an end in the second direction of the jelly roll structure 300S.Here, the first direction d 1 and the second direction d 2 are opposite directions to each other. Also, the first direction d 1 and the second direction d 2 may be directions parallel to the height direction of the jelly roll structure 300S.The electrode assembly 300 according to this embodiment has a structure in which no separate electrode tab is attached, but the negative electrode uncoated portion 430 of the negative electrode current collector 410 and the positive electrode uncoated portion 530 of the positive electrode current collector 510 itself are used as electrode tabs to reduce the resistance.Although not shown in the drawings, the negative electrode uncoated portion 430 and / or the positive electrode uncoated portion 530 may have substantially the same structure as the uncoated portion of the electrode described above.In an embodiment, the positive electrode active material portion 520 includes a charge reduction portion 500D having a smaller charge amount of the positive electrode active material than an adjacent region, and the charge reduction portion 500D is located at one end in the first direction d 1 of the positive electrode 500. Specifically, in the charge reduction portion 500D, the charge amount of the positive electrode active material may gradually decrease in the first direction d 1.Here, the charge amount means the amount of active material applied per unit area. In a portion having a large charge amount, a lot of negative electrode active material or positive electrode active material is applied to the unit area, so that the negative electrode active material portion or the positive electrode active material portion can have a relatively larger thickness. In a portion having a small charge amount, a small amount of negative electrode active material or positive electrode active material is applied to the unit area, so that the negative electrode active material portion or the positive electrode active material portion may have a relatively smaller thickness.The active material portion may be formed by applying a slurry containing an active material. In this process, a boundary portion having a gradually decreasing charge amount may be formed between the uncoated portion and the active material portion.Specifically, the negative electrode active material portion 420 may include a negative electrode boundary portion 420B that forms a boundary between the negative electrode active material portion 420 and the uncoated negative electrode portion 430. The charge amount of the negative electrode boundary portion 420B may decrease in a direction toward the uncoated negative electrode portion 430.Similarly, the positive electrode active material portion 520 may include a positive electrode boundary portion 520B that forms a boundary between the positive electrode active material portion 520 and the uncoated positive electrode portion 530. The charge amount of the positive electrode boundary portion 520B may decrease in a direction toward the uncoated positive electrode portion 530.The negative electrode boundary portion 420B or the positive electrode boundary portion 520B in which the charge amount gradually decreases as above is naturally generated in the process of applying the slurry containing the active material to the negative electrode current collector 410 or the positive electrode current collector 510.In this case, in a region corresponding to the positive electrode boundary portion 520B based on a direction perpendicular to the second direction d 2, the amount of the positive electrode active material may be less than the amount of the negative electrode active material. Since the N / P ratio has a value larger than 1, the problem of depositing metallic lithium does not occur.However, there is a problem in a region corresponding to the negative electrode boundary portion 420B. In the region corresponding to the negative electrode boundary portion 420B based on a direction perpendicular to the first direction d 1, the amount of the negative electrode active material may be less than the amount of the positive electrode active material. This may cause a problem of depositing metallic lithium because the N / P ratio has a value less than 1.Accordingly, in this embodiment, the charge reduction portion 500D is provided on the positive electrode 500, and the negative electrode active material portion 420 may be disposed in a portion corresponding to the charge reduction portion 500D based on a direction perpendicular to the first direction d 1. Specifically, the negative electrode boundary portion 420B may be disposed at a portion corresponding to the charge reduction portion 500D based on a direction perpendicular to the first direction d 1.The charge reducing portion 500D having a smaller charge amount of positive electrode active material than adjacent regions is provided at a position corresponding to the negative electrode boundary portion 420B having a gradually decreasing charge amount, so that the region in which the positive electrode active material is applied can be increased without causing deposition of lithium. Specifically, the charge amount of the positive electrode active material in the charge reducing portion 500D may gradually decrease along the first direction d 1, corresponding to the shape of the negative electrode boundary portion 420B in which the charge amount gradually decreases in a direction toward the uncoated negative electrode portion 430. Therefore, it is possible to maintain a high N / P ratio of the negative electrode 400 and the positive electrode 500 in the region where the negative electrode boundary portion 420B is formed, thereby preventing deposition of lithium.Hereinafter, a method of manufacturing an electrode assembly according to an embodiment of the present disclosure will be described in detail with reference to FIGS. 50 to 55.FIGS. 50 and 51 are drawings illustrating a process for manufacturing a negative electrode according to an embodiment of the present disclosure. Specifically, FIG. 50 is a plan view showing the negative electrode sheet from above, and FIG. 51 is a front view showing the negative electrode sheet of FIG. 50 from front.Referring to FIGS. 50 and 51, the method for manufacturing an electrode assembly according to an embodiment of the present disclosure includes a step of manufacturing a negative electrode sheet 400S such that a negative electrode active material portion 420 coated with a negative electrode active material and a negative electrode non-coating portion 430 not coated with a negative electrode active material are alternately disposed on a negative electrode current collector 410.Specifically, the negative electrode active material portion 420 may be formed by applying the negative electrode active material to extend along the third direction d 3. In addition, a plurality of negative electrode active material portions 420 may be arranged to be spaced apart along the fourth direction d 4 by the coated portions being spaced apart along the fourth direction d 4 perpendicular to the third direction d 3. That is, the coating process may be performed such that the negative electrode uncoated portion 430 is positioned between the plurality of negative electrode active material portions 420.Here, the third direction d 3 and the fourth direction d 4 are directions for explanation based on the negative electrode sheet 400S, and are directions unrelated to the first direction d 1 and the second direction d 2 in the above-described jelly roll structure 300S.Thereafter, a step of manufacturing a negative electrode 400 may be followed by slitting the negative electrode uncoated portion 430 and the negative electrode active material portion 420. FIG. 52 is a perspective view illustrating a negative electrode according to an embodiment of the present disclosure.Referring to FIGS. 50 to 52, slitting in a direction parallel to the third direction d 3 may be performed for the negative electrode plating portion 430 and the negative electrode active material portion 420, respectively, as indicated by broken lines in FIGS. 50 and 51. Accordingly, as shown in FIG. 52, a plurality of negative electrodes 400 may be made of the negative electrode sheet 400S. That is, the negative electrode 400 of FIG. 52 corresponds to one of a plurality of negative electrodes manufactured by slitting the negative electrode sheet 400S of FIGS. 50 and 51. By slitting the negative electrode non-coating portion 430 and the negative electrode active material portion 420 of the negative electrode sheet 400S, respectively, the negative electrode 400 in which the negative electrode non-coating portion 430 extends on one side can be manufactured.When the negative electrode active material portion 420 is formed, a slurry containing the negative electrode active material may be applied to the negative electrode current collector 410. In the process for applying the slurry, a negative electrode boundary portion 420B having a charge amount decreasing in a direction toward the uncoated negative electrode portion 430 may be formed at the boundary between the negative electrode active material portion 420 and the uncoated negative electrode portion 430.FIGS. 53 and 54 are drawings illustrating a process for manufacturing a positive electrode according to an embodiment of the present disclosure. Specifically, FIG. 53 is a plan view showing the positive electrode sheet from above, and FIG. 54 is a front view showing the positive electrode sheet of FIG. 53 from front.Referring to FIGS. 53 and 54, the method for manufacturing an electrode assembly according to an embodiment of the present disclosure includes a step of manufacturing a positive electrode sheet 500S such that a positive electrode active material portion 520 coated with a positive electrode active material and a positive electrode non-coating portion 530 not coated with a positive electrode active material are alternately disposed on the positive electrode current collector 510.Specifically, the positive electrode active material portion 520 may be formed by applying the positive electrode active material to extend along the third direction d 3. In addition, a plurality of positive electrode active material portions 520 may be arranged to be spaced apart along the fourth direction d 4 perpendicular to the third direction d 3 by adjusting the coating interval. That is, the coating process may be performed such that the positive electrode uncoated portion 530 is disposed between the plurality of positive electrode active material portions 520.Here, the third direction d 3 and the fourth direction d 4 are directions for description based on the positive electrode sheet 500S, and are directions unrelated to the first direction d 1 and the second direction d 2 in the above-described jelly roll structure 300S.Thereafter, a step of manufacturing a positive electrode 500 may be followed by slitting the positive electrode uncoated portion 530 and the positive electrode active material portion 520. FIG. 55 is a perspective view showing a positive electrode 500 according to an embodiment of the present disclosure.Referring to FIGS. 53 to 55, slitting in a direction parallel to the third direction d 3 may be performed for the positive electrode plating portion 530 and the positive electrode active material portion 520, respectively, as indicated by broken lines in FIGS. 53 and 54. Accordingly, as shown in FIG. 55, a plurality of positive electrodes 500 can be made of the positive electrode sheet 500S. That is, the positive electrode 500 of FIG. 55 corresponds to one of a plurality of positive electrodes manufactured by slitting the positive electrode sheet 500S of FIGS. 53 and 54. By slitting the positive electrode plating portion 530 and the positive electrode active material portion 520 of the positive electrode sheet 500S, respectively, the positive electrode 500 in which the positive electrode plating portion 530 extends on one side can be manufactured.When the positive electrode active material portion 520 is formed, a slurry containing the positive electrode active material may be applied to the positive electrode current collector 510. In the process for applying the slurry, a positive electrode boundary portion 520B having a charge amount decreasing in a direction toward the positive electrode uncoated portion 530 may be formed at the boundary between the positive electrode active material portion 520 and the positive electrode uncoated portion 530.Referring to FIGS. 48, 52, and 55 together, a step of forming a jelly roll structure 300S may be followed by winding the negative electrode 400 and the positive electrode 500 together with the separator 600. Here, in the jelly roll structure 300S, the negative electrode uncoated portion 430 may extend beyond the separator 600 in a first direction d 1, and the positive electrode uncoated portion 530 may extend beyond the separator 600 in a second direction d 2 opposite to the first direction d 1.Referring back to FIGS. 53 to 55, in the method for manufacturing an electrode assembly according to an embodiment of the present disclosure, the positive electrode sheet 500S includes a charge reduction region 500DA in which the charge amount of the positive electrode active material is smaller than that of the adjacent region. There is no particular limitation in the method of forming the charge reduction region 500DA, and it can be formed by adjusting the coating degree of the slurry, for example.In the step of manufacturing the positive electrode 500, the charge reduction region 500DA of the positive electrode active material portion 520 is slit. The slotted charge reduction region 500DA forms a charge reduction portion 500D having a smaller charge amount of the positive electrode active material than the adjacent region in the jelly roll structure 300S shown in FIGS. 48 and 49.Specifically, a charge reduction region 500DA having a smaller charge amount of the positive electrode active material than the adjacent region is formed in the positive electrode active material portion 520 formed on the positive electrode sheet 500S. As shown in FIG. 54, the charge reduction region 500DA may be formed in the center of the positive electrode active material portion 520. Meanwhile, the charge reduction region 500DA may be configured such that the charge amount of the positive electrode active material gradually decreases toward the center portion 500C of the charge reduction region 500DA, and in the step of manufacturing the positive electrode 500, the charge reduction portion 500D according to this embodiment may be provided by slitting the center portion 500C of the charge reduction region 500DA.That is, when applying the slurry containing a positive electrode active material, by forming the charge reduction portion 500DA and slitting the central portion 500C of the charge reduction portion 500DA, a plurality of positive electrodes 500 having the charge reduction portion 500D can be produced.Referring to FIG. 55, the charge reduction portion 500D may be provided at one end of the manufactured positive electrode 500, and the uncoated positive electrode portion 530 may be provided at the other end of the positive electrode 500 opposite to the one end.Referring to FIGS. 48 and 49, when the positive electrode 500 is wound to form a jelly roll structure 300S, the charge reducing portion 500D may be disposed at one end in the first direction d 1 of the positive electrode 500, and the positive electrode uncoated portion 530 may be disposed at one end in the second direction d 2 of the positive electrode 500.In addition, when the central portion 500C of the charge reduction region 500DA is slit, the charge amount of the positive electrode active material in the charge reduction portion 500D may gradually decrease along the first direction d 1.In addition, in the jelly roll structure 300S, the negative electrode active material portion 420 may be disposed at a portion corresponding to the charge reducing portion 500D based on a direction perpendicular to the first direction d 1. Specifically, in the jelly roll structure 300S, the negative electrode boundary portion 420B may be disposed at a portion corresponding to the charge reduction portion 500D based on a direction perpendicular to the first direction d 1.The corresponding positional relationship between the charge reduction portion 500D and the negative electrode boundary portion 420B has already been described above and therefore will not be described again.Hereinafter, with reference to FIGS. 56 to 59, an electrode assembly according to a comparative example will be described, and advantages of the electrode assembly according to this embodiment will be described compared to the electrode assembly according to the comparative example.FIG. 56 is a drawing showing an electrode assembly according to a comparative example. Fig. 57 is a cross-sectional view taken along the line B-B' in Fig. 56.Referring to FIGS. 56 and 57, the electrode assembly 600 according to the comparative example includes a negative electrode 700, a positive electrode 800, and a separator 900, and the negative electrode 700, the positive electrode 800, and the separator 900 are wound to form a jelly roll structure 600S.The negative electrode 700 may include a negative electrode current collector 710, a negative electrode active material portion 720, and a negative electrode uncoated portion 730. In addition, the negative electrode uncoated portion 730 may extend in the first direction d 1, and the negative electrode active material portion 720 may include a negative electrode boundary portion 720B that forms a boundary between the negative electrode active material portion 720 and the negative electrode uncoated portion 730 and has a gradually decreasing charge amount.FIG. 58 is a drawing showing a process for manufacturing a negative electrode 700 according to a comparative example.Referring to FIG. 58, after the negative electrode sheet 700S is manufactured such that the negative electrode active material portion 720 and the negative electrode non-coating portion 730 are alternately positioned along the fourth direction d 4, a plurality of negative electrodes 700 may be manufactured by slitting the negative electrode non-coating portion 730 and the negative electrode active material portion 720.Referring again to FIGS. 56 and 57, the positive electrode 800 may include a positive electrode current collector 810, a positive electrode active material portion 820, and a positive electrode uncoated portion 880. In addition, the positive electrode uncoated portion 830 may extend in the second direction d 2 opposite to the first direction d 1, and the positive electrode active material portion 820 may include a positive electrode boundary portion 820B that forms a boundary between the positive electrode active material portion 820 and the positive electrode uncoated portion 830 and has a gradually decreasing charge amount.FIG. 59 is a drawing showing a process for manufacturing a positive electrode 800 according to a comparative example.Referring to FIG. 59, after the positive electrode sheet 800S is manufactured such that the positive electrode active material portion 820 and the positive electrode non-coating portion 830 are alternately positioned along the fourth direction d 4, a plurality of positive electrodes 800 may be manufactured by slitting the positive electrode non-coating portion 830 and the positive electrode active material portion 820.Thereafter, the negative electrode 700 and the positive electrode 800 manufactured as above may be wound together with the separator 900 to manufacture an electrode assembly 600 according to the comparative example.That is, the electrode assembly 600 according to the comparative example may have a structure similar to that of the electrode assembly 300 according to this embodiment except for the charge reducing portion 500D (see FIG. 49 ).Referring to FIGS. 56 and 57, in the case of the electrode assembly 600 according to the comparative example, the positive electrode active material portion 820 may not be disposed in a portion corresponding to the negative electrode boundary portion 720B based on a direction perpendicular to the first direction d 1. When the positive electrode active material portion 820 extends to a portion corresponding to the negative electrode boundary portion 720B, the corresponding portion has a low N / P ratio value and metallic lithium is highly likely to be deposited. Therefore, in order to prevent deposition of lithium, the length of the positive electrode active material portion 820 needs to be limited. That is, the positive electrode active material portion 820 may be formed only in the region B 1 shown in the drawing, and the positive electrode active material portion 820 may not be formed in the region B 2. This results in a reduction in the length of the positive electrode active material portion 820 due to the negative electrode boundary portion 720B.Referring to FIGS. 48 and 49, in the case of the electrode assembly 300 according to this embodiment, based on the direction perpendicular to the first direction d 1, the positive electrode active material portion 520, specifically, the charge reducing portion 500D may be disposed in a portion corresponding to the negative electrode boundary portion 420B. Since the charge reduction portion 500D having a smaller charge amount of the positive electrode active material than the adjacent region is provided at a position corresponding to the negative electrode boundary portion 420B, the N / P ratio in the corresponding portion can be kept high and deposition of lithium can be prevented. Accordingly, the positive electrode active material portion 520 can be formed as much as the region A 1, and the region A 2 in which the positive electrode active material portion 520 cannot be formed can be reduced. For example, the width of the positive electrode 500 in the height direction may be increased to 98% or more compared to the width of the negative electrode 400 in the height direction.In the electrode assembly 300 according to this embodiment, when the region A 1 of FIGS. 48 and 49 is compared with the region B 1 of FIGS. 56 and 57, the length of the positive electrode active material portion up to the charge reduction portion 500D can be increased, and thus a higher energy density can be provided in a limited space as compared with the electrode assembly 600 according to the comparative example.Another aspect of the present disclosure relates to a cylindrical battery including a jelly roll type electrode assembly having a structure in which a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode are wound in one direction; a cylindrical battery case in which the electrode assembly is accommodated; and a battery cover serving as a closing body disposed at the upper portion of the battery case to close the battery case. Here, the positive electrode according to the present disclosure is manufactured and contains single-particle-based active material particles having an average particle diameter D 50 of 5 μm or less as the positive electrode active material. The cylindrical battery may further include an electrolyte, and the above description may be referred to for the electrolyte.The electrode assembly may have a stack type, stack / fold type or jelly roll type structure as described above. In a specific embodiment of the present disclosure, the positive electrode in the electrode assembly may include a charge reduction portion as described above.In the case of a conventional cylindrical battery, current is concentrated on a strip-shaped electrode tab, resulting in a large resistance, a high heat generation, and a poor current collection efficiency.As the demand for high capacity batteries increases with recent development of electric vehicle technology, development of bulky large-diameter cylindrical batteries is required. In the case of a conventional small cylindrical battery generally used in the prior art, i.e., a cylindrical battery having a form factor of 1865 or 2170, resistance or heat generation does not seriously affect the battery performance because the capacity is small. However, when the specifications of the conventional small cylindrical battery are applied as applied to a large cylindrical battery, a serious problem in battery safety may occur.As the size of the battery increases, the amount of heat and gas generated inside the battery also increases, and the temperature and pressure inside the battery increase due to such heat and gas, which may cause the battery to ignite or explode. To prevent this, heat and gas inside the battery must be properly discharged to the outside, and therefore, the cross-sectional area of the battery serving as a passage for discharging heat to the outside of the battery must increase to coincide with the increase in volume. However, since the increase in the cross-sectional area does not achieve the increase in the volume, the amount of heat generated inside the battery increases as the size of the battery increases, leading to problems such as an increased risk of explosion and a decreased power. In addition, when rapid charging is performed at a high voltage, a large amount of heat is generated around the electrode tab for a short period of time, and the battery may ignite. Accordingly, the present disclosure proposes a cylindrical battery having high safety while having a large volume to implement a high capacity.In addition, since a high charge electrode to which the positive electrode active material is applied in the form of a single particle or a pseudo-single particle can be applied to the cylindrical battery, the initial resistance characteristics and the charging / discharging efficiency of the cylindrical battery can be improved.The cylindrical battery according to the present disclosure significantly reduces gas generation compared to the related art by applying a positive electrode active material in the form of a single particle or a pseudo-single particle. Accordingly, even a large cylindrical battery having a shape factor ratio of 0.4 or more can have excellent safety.The cylindrical battery according to the present disclosure may preferably be a battery having a tabless structure that does not have an electrode tab, but is not limited thereto.In the battery of the tabless structure, for example, each of the positive electrode and the negative electrode has an uncoated portion on which no active material layer is formed, and may have a structure in which the uncoated portion of the positive electrode and the uncoated portion of the negative electrode are respectively located at the upper and lower ends of the electrode assembly, a collector plate is coupled to the uncoated portion of the positive electrode and the uncoated portion of the negative electrode, and the collector plate is connected to an electrode terminal.When the cylindrical battery is formed in a tabless structure as described above, since the concentration of the current is lower than that of the conventional battery equipped with an electrode tab, heat generation inside the battery can be effectively reduced, thereby improving the thermal safety of the battery.Hereinafter, the present disclosure will be described in more detail by specific examples.Example 1A single-particle positive electrode active material Li[Ni0,9Co0,06Mn0,03Al0,01]O2 having a monomodal particle size distribution with an average particle diameter D50 of 3 μm: carbon nanotube: PVDF binder was mixed in N-methylpyrrolidone in a weight ratio of 97.8:0.6:1.6 to prepare a positive electrode slurry. The positive electrode slurry was applied to a surface of an aluminum current collector sheet, dried at 120° C., and then rolled to produce a positive electrode.A negative electrode active material (graphite:SiO=95:5 mixture by weight): conductive material (Super C): styrene-butadiene rubber (SBR): carboxymethyl cellulose (CMC) were mixed in water in a weight ratio of 96:2:1.5:0.5 to prepare a negative electrode slurry. The negative electrode slurry was applied to a surface of a copper current collector sheet, dried at 150° C., and then rolled to produce a negative electrode.A separator was disposed between the positive electrode and the negative electrode as prepared above, stacked in the separator / positive electrode / separator / negative electrode order, and then wound to produce a jelly roll type electrode assembly. The electrode assembly prepared as described above was inserted into a cylindrical battery can, and an electrolyte was placed thereon to produce a 4680 cell.Comparative Example 1A 4680 cell was prepared in the same manner as in Example 1, except that Sekundärpartikel-Li[Ni0,9Co0,05Mn0,04Al0,01]O2 having a bimodal particle size distribution with a large average particle diameter D50of 9 μm and a small average particle diameter D50of 4 μm was used as the positive electrode active material.Experimental Example 1A hot box test was performed on the 4680 cells prepared by Example 1 and Comparative Example 1.Specifically, each of the 4680 cells produced by Example 1 and Comparative Example 1 was placed in a hot box chamber at room temperature, heated to 130° C. at a heating rate of 5° C. / min, and held for 30 minutes to perform hot box evaluation, and the temperature change of the battery with time was measured. For accurate evaluation, hot box evaluation was performed twice on the cell of Example 1. The measurement results are shown in Figs. 45a and 45b.FIG. 45 ais a graph showing a hot box test result of the 4680 cell manufactured by Example 1 of the present disclosure, and FIG. 45 bis a graph showing a hot box test result of the 4680 cell manufactured by Comparative Example 1.It can be determined by FIGS. 45 aand 45 b that in the case of the lithium secondary battery of Example 1 using the single-particle positive electrode active material, the voltage and temperature of the battery were stably maintained up to 65 minutes, whereas in the lithium secondary battery of Comparative Example 1, the temperature of the battery rapidly increased after 35 minutes.Example 2-1A positive electrode active material (composition: Li[Ni0,9Co0,06Mn0,03Al0,01]O 2) having a monomodal particle size distribution, in which Dmin=1.78 μm, D50=4.23 μm and Dmax=13.1 μm and in which individual particles and pseudo-individual particles were mixed, was prepared. FIG. 44 ashows an SEM image of the positive electrode active material used in Example 2-1.The positive electrode active material: carbon nanotube: PVDF binder was mixed in N-methylpyrrolidone in a weight ratio of 97.8:0.6:1.6 to prepare a positive electrode slurry. The positive electrode slurry was applied to a surface of an aluminum current collector sheet, dried at 120° C., and then rolled to produce a positive electrode.A negative electrode active material (graphite:SiO=95:5 mixture by weight): conductive material (Super C): styrene-butadiene rubber (SBR): carboxymethyl cellulose (CMC) were mixed in water in a weight ratio of 96:2:1.5:0.5 to prepare a negative electrode slurry. The negative electrode slurry was applied to a surface of a copper current collector sheet, dried at 150° C., and then rolled to produce a negative electrode.A separator was disposed between the positive electrode and the negative electrode as prepared above, stacked in the separator / positive electrode / separator / negative electrode order, and then wound to produce a jelly roll type electrode assembly. The electrode assembly prepared as described above was inserted into a battery can, and an electrolyte was placed thereon to prepare a 4680 cell.Example 2-2A 4680 cell was prepared in the same manner as in Example 2-1, except that a positive electrode active material (composition: Li[Ni0,9Co0,06Mn0,03Al0,01]O 2) having a monomodal particle size distribution in which Dmin=1.38 μm, D50=4.69 μm, and Dmax=118.5 μm and in which single particles and pseudo-single particles were mixed was used as the positive electrode active material. FIG. 44 bshows an SEM image of the positive electrode active material used in Example 2-2.Comparative Example 2-1A 4680 cell was produced in the same manner as in Example 2-1, except that a secondary particle positive electrode active material (composition: Li[Ni0,9Co0,05Mn0,04Al0,01]O 2) having a bimodal particle size distribution with a large average particle diameter D 50 of 9 μm and a small average particle diameter D 50 of 4 μm was used as the positive electrode active material.Comparative Example 2-2A 4680 cell was prepared in the same manner as in Example 2-1, except that a positive electrode active material (composition: Li[Ni0,9Co0,06Mn0,03Al0,01]O 2) having a monomodal particle size distribution in which Dmin=0.892 μm, D50=3.02 μm, and Dmax=11 μm and in which single particles and pseudo-single particles were mixed was used as the positive electrode active material.FIG. 44 cshows an SEM image of the positive electrode active material used in Comparative Example 2-2.Experimental Example 2-1A hot box test was performed on the 4680 cells prepared by Examples 2-1 and 2-2 and Comparative Examples 2-1 and 2-2.Specifically, each of the 4680 cells produced by Example 2-1 and Comparative Example 2-1 was placed in a hot box chamber at room temperature, heated to 130° C. at a heating rate of 5° C. / min, and held for 30 minutes, and then the temperature change of the cell was measured. A case where no heat runaway and no ignition occurred during the test was marked as pass, and a case where heat runaway and / or ignition occurred was marked as fail. In addition, the test for the accuracy of the test was performed more than twice for the cells of Examples 2-1 and 2-2.The measurement results are shown in Table 1 below and FIGS. 45 cand 45 d. FIG. 45 cis a graph showing hot box test results of Sample 1 of Example 2-1 and the 4680 cell manufactured by Comparative Example 2-1, and FIG. 45 dis a graph showing hot box test results of Samples 2 and 3 of Example 2-1, Samples 1 and 2 of Example 2-2, and the 4680 cell manufactured by Comparative Example 2-2. Table 1 Table 1Example 2-1116139Runaway occurs220,9141Runaway occurs323,7137Runaway occursExample 2-2116,0148Runaway occurs215,8147Runaway occursComparative Example 2-1117The non-measurable non-measurable is not measurableFailComparative Example 2-2116,2The non-measurable non-measurable is not measurableFailReferring to Table 1 and FIGS. 45 cand 45 d, it can be found that in the case of the 4680 cell of Example 2-1 to which the positive electrode active material was applied in the form of a single particle / pseudo single particle having Dmin of 1.0 μm or more, the voltage and temperature of the battery were stably maintained for up to 65 minutes, whereas in the case of the 4680 cells of Comparative Example 2-1 to which a secondary particle was applied as the positive electrode active material and Comparative Example 2-2 to which a positive electrode active material was applied in the form of a single particle / pseudo single particle having Dmin of less than 1.0 μm, the battery temperature of the 4680 cell rapidly increased.Experimental Example 2-2After rolling the positive electrodes prepared in Example 2-1 and Comparative Example 2-1 to check the degree of fracture of the positive electrode active material particles, the positive electrode was cut with an ion milling device and the cross section was photographed with an SEM. FIG. 46 ashows a cross-sectional SEM image of the positive electrode prepared in Example 2-1, and FIG. 46 bshows a cross-sectional SEM image of the positive electrode prepared in Comparative Example 2-1.By FIGS. 46 aand 46 b, the positive electrode of Example 2-1 has almost no particle breakage of the positive electrode active material even after rolling, whereas in the positive electrode of Comparative Example 2-2 using secondary particles, a number of cracks were observed in the particles of the positive electrode active material after rolling.Example 3-1A positive electrode active material powder (composition: Li[Ni0,9Co0,06Mn0,03Al0,01]O 2) having a monomodal particle size distribution, wherein Dmin=1.78 μm, D50=4.23 μm, Dmax=13.1 μm, and in which single particles and pseudo-single particles were mixed, flake graphite (SFG6L), conductive material (multi-wall carbon nanotube), and PVDF binder were mixed in N-methylpyrrolidone in a weight ratio of 96.3:1.5:0.4:1.8 to prepare a positive electrode slurry. The positive electrode slurry was applied to a surface of an aluminum current collector sheet, dried and rolled at a line pressure of 3.0 tons / cm to produce a positive electrode. The porosity of the positive electrode active material layer of the positive electrode prepared as described above was measured, and the porosity was measured to be 17.5%.Example 3-2A positive electrode was prepared in the same manner as in Example 3-1 except that the positive electrode active material, flake graphite, conductive material and binder were mixed in a weight ratio of 97.2:0.6:0.4:1.8, and the porosity of the positive electrode active material layer was measured. The porosity of the positive electrode active material layer was measured to be 19%.Example 3-3A positive electrode was prepared in the same manner as in Example 3-1 except that the positive electrode active material, flake graphite, conductive material and binder were mixed in a weight ratio of 97.4:0.4:0.4:1.8, and the porosity of the positive electrode active material layer was measured. The porosity of the positive electrode active material layer was measured to be 20%.Example 3-4A positive electrode was prepared in the same manner as in Example 3-1 except that the positive electrode active material, flake graphite, conductive material and binder were mixed in a weight ratio of 97.6:0.2:0.4:1.8, and the porosity of the positive electrode active material layer was measured. The porosity of the positive electrode active material layer was measured to be 21%.Comparative Example 3-1A positive electrode was prepared in the same manner as in Example 3-1 except that the positive electrode slurry was prepared by mixing the positive electrode active material, conductive material and binder in N-methylpyrrolidone in a weight ratio of 97.8:0.4:1.8 without adding flake graphite, and the porosity of the positive electrode active material layer was measured. The porosity of the positive electrode active material layer was measured to be 24%.Comparative Example 3-2A positive electrode was prepared in the same manner as in Example 3-1, except that the positive electrode active material, conductive material and binder were mixed in N-methylpyrrolidone in a weight ratio of 97.8:0.4:1.8 to prepare a positive electrode slurry, and rolled at a line pressure of 2.0 tons / cm without adding flake graphite, and the porosity of the positive electrode active material layer was measured. The porosity of the positive electrode active material layer was measured to be 30%.Experimental Example 3-1 - Measurement of Charging / Discharging Capacity and Charging / Discharging EfficiencyCoin half cells including the positive electrodes according to Examples 3-1 to 3-4 and Comparative Examples 3-1 and 3-2 were prepared, charged up to 4.25 V under a 0.2C current condition and then discharged to 2.5 V under a 0.2C current condition, and the charging capacity (mAh / g) and discharging capacity (mAh / g) of each coin half cell were measured. The measurement results are shown in Table 2 below. Table 2 Table 2Example 3-11,517,5230,3209,390,9Example 3-20,619229,4206,990,2Example 3-30,420230,4207,390,0Example 3-40,221229,1205,589,7Comparative Example 3-1024229,1204,289,1Comparative Example 3-2030225,4199,788,6From Table 2, it can be found that Examples 3-1 to 3-4 using a positive electrode to which flake graphite is added show lower porosity and excellent capacity characteristics compared to Comparative Examples 3-1 to 3-2.Experimental Example 3-2 - Evaluation of Resistance PropertiesDuring charging of coin half cells including the positive electrodes according to Example 3-3, Comparative Example 3-1, and Comparative Example 3-2 to 4.2 V, resistance characteristics were measured according to SOC. The test results are shown in Fig. 47a.Referring to FIG. 47 a, it can be determined that the resistance value of Example 3-3 in which flake graphite is added to the positive electrode active material layer is lower than those of Comparative Example 3-1 and Comparative Example 3-2 that do not include flake graphite, based on SOC 10%. This shows that when flake graphite is added to the positive electrode active material layer, the low SOC resistance properties are improved.Experimental Example 3-3 - Measurement of High Temperature Life Characteristics and Resistance Increase RateA separator was disposed between the positive electrode and the negative electrode according to Example 3-1, Example 3-3, and Comparative Example 3-1, and was stacked in the separator / positive electrode / separator / negative electrode order, and then wound to produce a jelly roll type electrode assembly. The electrode assembly prepared as described above was inserted into a cylindrical battery can, and then an electrolyte was introduced thereon to produce a 4680 cell.At this time, a negative electrode active material (graphite:SiO=95:5 mixture by weight): conductive material (Super C): styrene-butadiene rubber (SBR): carboxymethyl cellulose (CMC) was mixed in water in a weight ratio of 96:2:1.5:0.5 to prepare a negative electrode slurry, and then the negative electrode slurry was applied to a surface of a copper current collector sheet, dried at 150° C., and then rolled to prepare a negative electrode.Based on a cycle in which the 4680 cell prepared as described above was charged to 4.2 V at 40° C. at 0.5 C. and then discharged to 2.5 V at 0.5 C., 50 cycles of charging and discharging were performed, and then capacity retention and resistance increase rate (DCIR increase) were measured. The measurement results are shown in FIG. 47 b.Referring to FIG. 47 b, in the case of the secondary batteries of Examples 3-1 and 3-3, it is shown that the change in capacity retention according to the number of cycles is smaller than that of the secondary battery of Comparative Example 3-1, and the change in resistance increase rate according to the number of cycles is also small.Finally, the effect of the separation distance of the end in the width direction of the separator and the reference line on the impregnability of the electrolyte was evaluated.< Conditions of Electrode>A positive electrode and a negative electrode were prepared to have the electrode structure shown in FIG. 17a. An aluminum thin film having a thickness of 15 μm was used as the positive electrode current collector, and a copper thin film having a thickness of 10 μm was used as the negative electrode current collector.The positive electrode current collector has a length of 4000 mm along the winding direction and a width of 75 mm along the winding axis direction. The negative electrode current collector has a length of 4000 mm along the winding direction and a width of 80 mm along the winding axis direction.In the positive electrode and the negative electrode, the length of the core-side uncoated portion B 1 is 350 mm, the length of the intermediate uncoated portion B 2 is 3500 mm, and the length of the outer peripheral-side uncoated portion B 3 is 150 mm.In the positive electrode and the negative electrode, the length along the winding direction of each group is 500 mm, the height of the segment included in the group 1 is 5 mm, and the height of the segments included in the groups 2 to 7 is 6 mm.In the intermediate uncoated portion B 2, the widths of the segments along the winding direction are 5 mm and the separation distance of the segments is 0.5 mm.< Of Negative Electrode>Natural peanut graphite having an average particle diameter (D50) of 11 μm, carbon black, carboxymethylcellulose (CMC), and styrene-butadiene rubber (SBR) were mixed with water in a weight ratio of 94:1.5:2:2.5 to prepare a slurry for a negative electrode active material layer having a concentration of 50% by weight of the remaining components except water. The prepared slurry was coated on a portion of the copper film corresponding to the coated portion using a slot die at a running speed of 40 m / min. The width in the winding axis direction of the coated portion was 70 mm and the width in the winding axis direction of the uncoated portion was 10 mm. The charge amount of the negative electrode active material was 16 mg / cm2with respect to the electrode area. The copper thin film coated with the slurry for a negative electrode active material layer was dried by passing it through a hot air oven having a length of 60 m. The temperature of the furnace was controlled to maintain 130°C. The dried electrode was roll-pressed to obtain a negative electrode coated with a negative electrode active material layer. Finally, the uncoated portion of the negative electrode was laser-grained to form segments having the above conditions, and the notch depth was adjusted so that the bottom of the notch valley substantially corresponds to the reference line DL (FIG. 17 b ).<Production of Positive Electrode>Li(Ni0,6Mn0,2Co0,2)O2 (NCM-622) as a positive electrode active material, carbon black as a conductive material, and polyvinylidene fluoride (PVdF) as a binder were added to water serving as a dispersion medium in a weight ratio of 96:2:2 to prepare a slurry for a positive electrode active material. The prepared slurry was coated on an aluminum thin film and then dried and rolled under the same conditions as the negative electrode to prepare a positive electrode. The width in the winding axis direction of the coated portion was 65 mm and the width in the winding axis direction of the uncoated portion was 10 mm. The positive electrode active material layer was formed such that the NP ratio of the battery was 1.18 (118%, about 27.7 cm2) in consideration of the theoretical discharge capacity of the NMC 622. The uncoated portion of the positive electrode was laser-grained to form segments having the above conditions, and the notch depth was adjusted so that the bottom of the notch valley substantially corresponds to the reference line DL (FIG. 17 b ).< Of Separator>After adding about 5 wt % polyvinylidene fluoride-hexafluoropropylene copolymer (PVdF-HFP) to tetrahydrofuran (THF), it was dissolved at a temperature of 50° C. for about 12 hours or more to prepare a polymer solution. BaTiO3powder having a particle diameter of about 400 nm was added to this polymer solution at a total solid content of 20% by weight and dispersed to prepare a mixed solution (BaTiO3 / PVdF-HFP=80:20 (weight ratio)). The prepared mixed solution was coated on both surfaces of a porous polypropylene substrate using the doctor blade method. After coating, the THF was dried to obtain a final porous organic / inorganic composite separator. The final separator had a thickness of about 30 μm. As a result of measurement with a porosimeter, the pore size and porosity of the final porous organic / inorganic composite film were 0.4 μm and 60%, respectively.< Of Electrode Assembly>The separator, the negative electrode, the separator, and the positive electrode were laminated and wound in order to produce a jelly roll type electrode assembly.In Example 4-1, the winding condition was set such that the end of the separator in the width direction was located at 30% (1.5 mm) of the height of the minimum bending segment (group 1) with respect to the reference line in the outer direction of the electrode assembly.In Example 4-2, the winding condition was set such that the end of the separator in the width direction was located at 10% (0.5 mm) of the height of the minimum bending segment (group 1) with respect to the reference line in the outer direction of the electrode assembly.In Comparative Example 4-1, the winding condition was set such that the end of the separator in the width direction was located at 50% of the height of the minimum bending segment (group 1) with respect to the reference line in the outer direction of the electrode assembly.< Of 4680 Cell>The segments of the groups 1 to 7 exposed at the upper and lower portions of the electrode assembly of Example 4-1 were bent toward the core, and then the positive and negative current collectors were welded to the upper and lower curved surfaces, respectively. Then, a cylindrical battery shown in Fig. 35 was produced. That is, the electrode assembly to which the positive electrode current collector and the negative electrode current collector were welded was inserted into a battery case having external terminals previously installed, the positive electrode current collector and the external terminal were welded, and the edge of the negative electrode current collector was welded to the bead portion. Then, the battery case was placed in the chamber of the electrolyte injector, and the battery case was erected so that the opening of the battery case faces in a direction opposite to the gravity. Next, LiPF6was dissolved to a concentration of 1.0 M in an organic solvent in which ethylene carbonate (EC), dimethyl carbonate (DMC), and diethyl carbonate (DEC) were mixed in a composition of 1:2:1 (volume ratio) to prepare a nonaqueous electrolyte. Then, after the electrolyte was introduced through the opening of the battery case, the pressure of the chamber was increased to 800 kPa for 20 seconds, maintained for 150 seconds, and decreased again to -90 kPa for 20 seconds, and then the essential vacuum condition was maintained for 20 seconds. After the electrolyte impregnation process was completed, the opening of the battery case was sealed with the sealing body of a gasket to complete the production of the cylindrical cell.The 4680 cells of Example 4-2 and Comparative Example 4-1 were also prepared using substantially the same manufacturing process as above.Next, the 4680 cells of Examples 4-1, 4-2 and Comparative Example 4-1 were decomposed to obtain a positive electrode and a negative electrode, respectively. Thereafter, samples having a size of 10 cm2were obtained by cutting out the negative electrode and the positive electrode at a total of 9 points. When the electrodes were spread out, among nine samples, three samples were taken in the area adjacent to the core of the electrode assembly, three samples in the area adjacent to the outer periphery of the electrode assembly, and three samples were taken in the central area of the electrode with respect to the winding direction. When taking three samples from each sampling region, one sample was taken from the lower end, the center, and the upper end of the active material layer along the winding axis direction, respectively.The electrolyte impregnation amount was determined from the difference between the weight of the control sample and the weight of the collected sample. The control samples were prepared in the same manner as the electrodes used in Examples 4-1 and 4-2 and Comparative Example 4-1, and were obtained from the positive electrodes and the negative electrodes at the same sampling areas.The electrolyte impregnation amount of the electrode assembly was determined as the sum mean value (A+B) calculated by adding the mean value (A) of the electrolyte impregnation amounts for the nine samples obtained from the positive electrode and the mean value of the electrolyte impregnation amounts for the nine samples obtained from the negative electrode (B).The electrolyte impregnation amount of the electrode assembly of Example 4-1 was 60.3 mg, the electrolyte impregnation amount of the electrode assembly of Example 4-2 was 59.6 mg, and the electrolyte impregnation amount of the electrode assembly of Comparative Example 4-1 was 56.3 mg. It was found that the electrolyte impregnation amounts in Examples 4-1 and 4-2 were higher than those of Comparative Example 4-1.In addition, the sum of the electrolyte impregnation amount of the positive electrode sample and the negative electrode sample collected at the center of the active material layer with respect to the winding axis direction under the sample collecting region adjacent to the core of the electrode assembly was 55.1 mg for the electrode assembly of Example 4-1, 59 mg for the electrode assembly of Example 4-2, and 47.7 mg for the electrode assembly of Comparative Example 4-1. From this, it can be found that the electrolyte impregnation amounts of Examples 4-1 and 4-2 are higher than those of Comparative Example 4-1, even in the vicinity of the core of the electrode assembly having a relatively low electrolyte impregnation amount.The present disclosure has been described in detail. It is to be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the disclosure, are given by way of illustration only, since various changes and modifications within the scope of the disclosure will become apparent to those skilled in the art from this detailed description.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedKR 10-2021-0142192

[0002]

Claims

An electrode assembly in which a first electrode, a second electrode, and a separator interposed therebetween are wound around a winding axis to define a core and an outer periphery, each of the first electrode and the second electrode having an uncoated portion not coated with an active material layer at a long side end and a coated portion coated with an active material layer in a region other than the uncoated portion, the first electrode having an insulation layer configured to cover a boundary of the uncoated portion and the coated portion along a winding direction; wherein the uncoated portion of the first electrode includes a plurality of segments separated from each other by a plurality of cut lines repeatedly formed along the winding direction, a gap is provided between the plurality of cut lines and the active material layer, the plurality of segments are bent along a radial direction of the electrode assembly and overlap each other into a plurality of layers along a winding axis direction to form a bent surface at an end in the winding axis direction of the electrode assembly, and wherein when a line parallel to the winding direction and passing through the lowermost end of the plurality of cut lines is defined as a reference line, and when a minimum segment among the segments forming the bent surface is a segment having the smallest height, a separation distance between an end of the separator and the reference line is 30% or less of the height of the minimum segment.The electrode assembly according to claim 1, wherein the separation distance between an end of the separator and the reference line is 1.5 mm or less.The electrode assembly according to claim 1, wherein the insulation layer is provided on both surfaces of the first electrode, and wherein an end of the insulation layer along the winding direction is disposed at a same height as an end of the separator along the winding direction or is disposed beyond the one end of the separator, and wherein an end of the second electrode along the winding axis facing the insulation layer with the separator interposed therebetween does not protrude beyond an end of the separator along the winding axis.The electrode assembly according to claim 1, wherein a first sliding portion in which the thickness of the active material layer is reduced is included in a boundary region between the coated portion and the uncoated portion of the first electrode, a second sliding portion in which the thickness of the active material layer is reduced is included in a boundary region between the coated portion and the uncoated portion of the second electrode, the first sliding portion and the second sliding portion are arranged in opposite directions with respect to the winding axis, the coated portion of the first electrode includes a load reducing portion in which a load amount of the active material is reduced, and the position of the load reducing portion corresponds to the position of the second sliding portion.The electrode assembly according to claim 1, wherein the insulation layer formed on one side of both sides of the uncoated portion of the first electrode facing the core extends to the end of the uncoated portion of the first electrode along the winding axis.The electrode assembly according to claim 1, wherein the insulation layer formed on a side of both sides of the uncoated portion of the first electrode opposite to a side facing the core extends to a bending point of the uncoated portion of the first electrode.The electrode assembly of claim 1, wherein the length of the coated portion of the first electrode along the winding axis is shorter than the length of the coated portion of the second electrode along the winding axis, and wherein one end and the other end of the coated portion of the second electrode are disposed further outward along the winding axis than one end and the other end of the coated portion of the first electrode along the winding axis.The electrode assembly according to claim 1, wherein at least one of the height in the winding axis direction and the width in the winding direction of the plurality of segments increases stepwise from the core toward the outer periphery individually or in groups.The electrode assembly according to claim 1, wherein the plurality of segments form a plurality of segment groups from the core to the outer periphery, and the segments belonging to a same segment group are identical in at least one of the width in the winding direction, the height in the winding axis direction, and the separation distance in the winding direction.The electrode assembly according to claim 9, wherein the segments belonging to a same segment group gradually increase from the core to the outer periphery with respect to at least one of the width in the winding direction, the height in the winding axis direction, and the separation distance in the winding direction.The electrode assembly of claim 1, wherein the uncoated portion of the first electrode comprises a core-side uncoated portion adjacent to the core of the electrode assembly, an outer circumferential-side uncoated portion adjacent to the outer circumference of the electrode assembly, and an intermediate uncoated portion disposed between the core-side uncoated portion and the outer circumferential-side uncoated portion, wherein the core-side uncoated portion and / or the outer circumferential-side uncoated portion has a comparatively lower height along the winding axis than the intermediate uncoated portion, or a radial length of the core-side uncoated portion is equal to or greater than a bending length of an innermost segment of the intermediate uncoated portion.An electrode assembly in which a first electrode, a second electrode, and a separator interposed therebetween are wound around a winding axis, thereby defining a core and an outer periphery, each of the first electrode and the second electrode having an uncoated portion not coated with an active material layer at a respective long side end and a coated portion coated with an active material layer in a region other than the uncoated portion, the first electrode having an insulation layer configured to cover a boundary between the uncoated portion and the coated portion along a winding direction; wherein the uncoated portion of the first electrode includes a plurality of segments separated from each other by a plurality of cut lines repeatedly formed along the winding direction, a gap is provided between the cut lines and the active material layer, the plurality of segments are bent along a radial direction of the electrode assembly and overlap each other into a plurality of layers along the winding axis, thereby forming a bent surface at an end in a winding axis direction of the electrode assembly, and wherein when a line parallel to the winding direction passing through the lowermost end of the plurality of cut lines is defined as a reference line, and when a minimum segment is a segment having the smallest height among the segments forming the bent surface, a separation distance between an end of the separator and the reference line along the winding axis is 1.5 mm or less.The electrode assembly according to any one of claims 1 to 12, wherein the active material layer of the first electrode contains a positive electrode active material having a single particle, a pseudo-single particle, or a combination thereof, Dmin which is a minimum particle size in a cumulative volume distribution of the positive electrode active material is 1.0 μm or more; in the cumulative volume distribution of the positive electrode active material, D50 which is a particle size when a cumulative volume amount is 50%, is 5.0 μm or less, and Dmax which is a maximum particle size in the cumulative volume distribution of the positive electrode active material is 12 μm to 17 μm.The electrode assembly according to claim 13, wherein the positive electrode active material has a monomodal particle size distribution showing a single peak in a graph of the cumulative volume particle size distribution, and the particle size distribution (PSD) represented by the following formula is 3 or less: PSD = ( D max - D min ) / D 50. The electrode assembly according to claim 13, wherein the single particle, the pseudo-single particle, or the combination thereof is contained in an amount of 95% by weight to 100% by weight based on the total weight of the positive electrode active material contained in the active material layer of the first electrode.The electrode assembly according to claim 13, wherein the positive electrode active material contains a lithium nickel-based oxide containing 80 mol% or more of Ni based on the total molar number of a transition metal.The electrode assembly according to claim 13, wherein the first electrode active material layer has a porosity of 15% to 23%, and the first electrode active material layer contains flake graphite in a weight ratio of 0.05% to 5% by weight.The electrode assembly of claim 13, wherein the active material layer of the first electrode further includes carbon nanotubes.The electrode assembly according to claim 13, wherein the second electrode active material layer contains a silicon-based negative electrode active material and a carbon-based negative electrode active material, and the silicon-based negative electrode active material and the carbon-based negative electrode active material are contained in a weight ratio of 1:99 to 20:80.A cylindrical battery comprising: an electrode assembly according to any one of claims 1 to 19; a battery case configured to accommodate the electrode assembly through an opening formed on one side and electrically connected to the uncoated portion of the second electrode; a terminal electrically connected to the uncoated portion of the first electrode and at least partially exposed to the outside; and a shutter body configured to cover the opening of the battery case.A battery pack comprising a plurality of cylindrical batteries according to claim 20.A vehicle comprising the battery pack according to claim 21.

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