Electrode assembly, battery and battery pack and vehicle including the same

Abstract

An electrode assembly, a battery, a battery pack, and a vehicle incorporating them are described. In the electrode assembly, an uncoated portion of an electrode includes a segment fragment section divided into several segment fragments, and this segment fragment section includes several groups of segment fragments separated by intergroup steps along the winding direction. A final portion of the electrode assembly includes several segment fragment alignment units.In the winding turns corresponding to the segment fragment alignment units, the intergroup steps of the segment fragment groups arranged in the same winding turn are practically equal, and the steps between the segment fragment groups are larger in the winding turns of the regions near the outer circumferential surface than in the winding turns of the regions near the core.

Description

Electrode assembly, battery and battery pack and vehicle including the same Technical field This disclosure relates to an electrode assembly, a battery and a battery pack and a vehicle including the same. This application claims priority for Korean patent applications No. 10-2021-0160469, 10-2021-0160474 and 10-2021-0160823 filed on November 19, 2021 in the Republic of Korea and Korean patent application No. 10-2022-0076274 filed on June 22, 2022 in the Republic of Korea. Background of the technique Secondary batteries (hereinafter referred to as batteries in this document) that are easily applicable to various product groups and have electrical characteristics such as high energy density are universally applicable not only to portable devices, but also to electric vehicles (EVs) or hybrid electric vehicles (HEVs) powered by an electric drive source. These batteries are attracting attention as a new energy source to improve environmental responsibility and energy efficiency because they have the primary advantage of being able to drastically reduce the use of fossil fuels, as well as the secondary advantage of not generating byproducts from energy use. Batteries currently widely used in technology include lithium-ion batteries, lithium-polymer batteries, nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, and similar types. A single battery unit has an operating voltage of approximately 2.5 V to 4.5 V. Therefore, when a higher output voltage is required, a battery pack can be configured by connecting multiple batteries in series. Alternatively, multiple batteries can be connected in parallel to form a battery pack according to the required charge / discharge capacity. Consequently, the number of batteries in the battery pack and their electrical connection configuration can be determined in various ways depending on the required output voltage and / or charge / discharge capacity. On the other hand, as a type of unit battery, cylindrical, rectangular, and pouch batteries are known. In the case of a cylindrical battery, a separator that serves as an insulator is placed between a positive and a negative electrode, and these are rolled together to form a jelly-roll electrode assembly, which is inserted into a battery housing to form a battery. Additionally, a strip-shaped electrode tab can be connected to an uncoated portion of each of the positive and negative electrodes, and the electrode tab electrically connects the electrode assembly to an externally exposed electrode terminal. For reference, the positive electrode terminal is a cap plate of a sealing body that seals the opening of the battery housing, and the negative electrode terminal is the battery housing itself.However, according to the conventional cylindrical battery that has this type of structure, because the current is concentrated in the strip-shaped electrode tab attached to the uncoated portion of the positive electrode and / or the uncoated portion of the negative electrode, the current capture efficiency is not good due to high resistance and high heat generation. For small cylindrical batteries with a form factor of 1865 or 2170, resistance and heat are not a significant problem. However, when the form factor is increased to apply the cylindrical battery to an electric vehicle, the battery can overheat and generate a lot of heat around the electrode flange during the fast-charging process. To solve this problem, a cylindrical battery (so-called a tabless cylindrical battery) is provided in which the uncoated portion of the positive electrode and the uncoated portion of the negative electrode are designed to be placed on the top and bottom of the gypsy-arm type electrode assembly, respectively, and the current-collecting plate is welded to the uncoated portion to improve current-harvesting efficiency. Figures 1 to 3 are diagrams showing a process for manufacturing a flangeless cylindrical battery. Figure 1 shows the structure of an electrode, Figure 2 shows a process for rolling the electrode, and Figure 3 shows a process for welding a current collector plate to a flex surface region of an uncoated portion. Referring to Figures 1 to 3, a positive electrode 10 and a negative electrode 11 have a structure in which a current-collecting sheet 20 is coated with an active material 21, and include an uncoated portion 22 on a long side along the winding direction X. The long side means a relatively long side in a direction parallel to the X-axis direction. An electrode assembly A is manufactured by sequentially stacking the positive electrode 10 and the negative electrode 11 together with two spacer sheets 12 as shown in Figure 2 and then rolling them up in an X direction. At this point, the uncoated portions of the positive electrode 10 and the negative electrode 11 are arranged in opposite directions. After the winding process, the uncoated portion 10a of the positive electrode 10 and the uncoated portion 11a of the negative electrode 11 are bent towards the core. Following this, the current collector plates 30 and 31 are welded and coupled to the uncoated portions 10a and 11a, respectively. An electrode tab is not separately attached to the uncoated portion of the positive electrode 10a and the uncoated portion of the negative electrode 11a. The current-collecting plates 30, 31 are connected to external electrode terminals, and a current path with a large cross-sectional area is formed along the winding axis direction of the electrode assembly A (see arrow), which has the advantage of lowering the battery resistance. This is because resistance is inversely proportional to the cross-sectional area of ​​the path through which the current flows. In the cylindrical battery without flanges, to improve the welding characteristics between the uncoated portions 10a, 11a and the current collector plates 30, 31, strong pressure should be applied to the welding regions of the uncoated portions 10a, 11a to bend the uncoated portions 10a, 11a to make them as flat as possible. When weld regions of the uncoated portions 10a and 11a are bent, the shapes of these portions can become distorted and irregularly deformed. In this case, the deformed portion may come into contact with an electrode of opposite polarity, causing an internal short circuit or hairline cracks in the uncoated portions 10a and 11a. Furthermore, when the electrode assembly is manufactured in a state where the uncoated portions 10a, 11a are bent, the efficiency of the electrolyte injection process following the insertion of the electrode assembly into the battery housing is reduced. Because there are insufficient gaps in the bending surface region of the uncoated portions 10a, 11a, which cover the entire upper and lower surfaces of electrode assembly A, it takes a long time for the electrolyte to penetrate the interior space of the electrode assembly, and the uniformity of electrolyte impregnation in the radial direction of electrode assembly A deteriorates. Therefore, it is necessary to improve the structure of the uncoated portions 10a, 11a, which can improve (the speed and uniformity of) the electrolyte impregnation while improving the flexural quality of the uncoated portions 10a, 11a. Patent applications EP 3902046 A1 and WO 2021 / 020119 A1 disclose electrode assemblies in accordance with the state of the art. Divulgation Technical problem The present disclosure is designed to address problems in the related art and, therefore, the present disclosure is directed to provide an electrode assembly having an uncoated portion structure that is improved to relieve stress applied to uncoated portions when the exposed uncoated portions at both ends of an electrode assembly are bent. This disclosure is also directed to providing an electrode assembly that can improve (the speed and uniformity of) electrolyte impregnation by applying a plurality of segments to the uncoated portion of the electrode, arranging the plurality of segments in a predetermined direction when the electrode is wound, and exposing the end of the active material layer formed on the electrode in a region where the segments are not arranged. This disclosure is also directed to providing an electrode assembly in which the electrolyte injection passage is not blocked even when the uncoated portion is bent. This disclosure is also directed to providing a set of electrodes with improved weld region properties by applying a segmented structure to the uncoated portion of the electrode and sufficiently increasing the number of segment stacks in the area used as the target weld zone. This disclosure also aims to provide an electrode assembly with improved energy density and reduced resistance by applying a structure in which a current-collecting plate is welded to the flex surface region formed by bending the segments. This disclosure also aims to provide a battery including a terminal and a current collector plate with an improved design such that electrical wiring can be performed on the upper portion. This disclosure also aims to provide a battery including an electrode assembly having an improved structure, a battery pack including the battery, and a vehicle including the battery pack. The technical issues to be addressed by this disclosure are not limited to the above, and other issues not mentioned herein will be clearly understood by experts in the field from the following disclosure. Technical solution In the present invention, an electrode assembly is provided in which a first electrode, a second electrode, and a separator interposed between them are wound around a winding axis to define a core and an outer circumference. The first electrode includes a first portion of active material coated with a layer of active material along a winding direction and a first uncoated portion not coated with a layer of active material and protruding outside the separator. The first uncoated portion includes a region divided into a plurality of independently bendable segments by a plurality of shear grooves provided along the winding direction. The segment region includes a plurality of segment groups divided by a group separation step along the winding direction, and one end of the electrode assembly may include a plurality of segment alignments in which the plurality of segment groups are aligned to overlap along a radial direction. The overlapping of the plurality of segments included in the segment alignment in the radial direction means that, when a predetermined straight line is drawn through the segment alignment from the center of the core, all segments intersect the corresponding straight line. The segments included in each segment alignment bend along the radial direction to form a flexural surface region. In winding turns corresponding to the plurality of segment alignments, the separation steps of groups of segments arranged in the same winding turn are substantially identical, and the separation step of the groups of segments is greater in a winding turn of a region adjacent to the outer circumference than in a winding turn of a region adjacent to the core. Each alignment of segments includes a radial region in which the group separation step increases in a stepped or gradual manner from the coiling turn of the region adjacent to the core to the coiling turn of the region adjacent to the outer circumference. The bending surface region partially covers one end of the electrode array. This region may be roughly geometric in shape, and the width in the winding direction of groups of segments located within the geometric figure may increase gradually or in a stepped fashion along the radial direction of the electrode array. The geometric figure can be fan-shaped. Alternatively, the geometric figure can have a rectangular or trapezoidal shape. Between adjacent flex surface regions in a circumferential direction, an electrolyte impregnation portion may be provided, wherein one end of the first active material portion is recessed into the electrode assembly more than one end of the separator and is exposed between the winding turns of the separator. The plurality of segment alignments can extend radially based on the center of the core. The electrolyte impregnation portion may be provided in a plural number, and the plurality of electrolyte impregnation portions may extend radially from the center of the core. The plurality of segment alignments can be spread in a cross shape (+), a radial shape (X), or a linear shape based on the center of the core, when viewed in the direction of the winding axis of the electrode assembly. When a line connecting the core center and a geometric center of a figure approximately corresponding to the bending surface region is defined as an angle measurement line, the angles between angle measurement lines of adjacent bending surface regions in a circumferential direction can be substantially identical. When a line connecting the core center and a geometric center of a figure approximately corresponding to the bending surface region is defined as an angle measurement line, an angle between angle measurement lines of adjacent bending surface regions in a circumferential direction can be 30° ± 10°, 40° ± 10°, 45° ± 10°, 60° ± 10°, 72° ± 10°, 90° ± 10°, 120° ± 10° or 180° ± 10°. When a line connecting the core center and a geometric center of a figure approximately corresponding to the bending surface region is defined as an angle measurement line, the angle between angle measurement lines of adjacent bending surface regions in a circumferential direction can be 90° ± 10°, and the group separation pitch between groups of segments arranged on the same winding turn can be set within the range of 8 mm to 50 mm.In the present case, the group separation step can increase in a stepwise or gradual manner as the number of winding turns increases. When a line connecting the core center and a geometric center of a figure approximately corresponding to the bending surface region is defined as an angle measurement line, the angle between angle measurement lines of adjacent bending surface regions in a circumferential direction can be 180° ± 10°, and the group spacing between groups of segments arranged on the same winding turn can be set within the range of 30 mm to 90 mm. In this case, the group spacing can be increased in a stepwise or gradual manner as the number of winding turns increases. Each of the segments can have the shape of a geometric figure in which one or more straight lines, one or more curved lines, or combinations thereof are connected. Each segment may be wider at its lower portion than at its upper portion. Each segment may have a tapered shape in which the width decreases gradually or continuously from a folded lower portion to an upper portion. The segment alignment may include a height-variable region in which the segment heights increase in steps from an initial height (h1) to an N-th height (hN-1, N is a natural number from 3 or greater) from the core of the electrode array toward the outer circumference, and a height-uniform region in which the segment heights remain uniform as an N-th height (hN, greater than hN-1). When an initial radius of a winding turn containing a segment with height hk (k is a natural number from 1 to N) is rk and the core radius is rc, the segment height hk can satisfy the following formula: Based on a cross-section along the winding axis direction, sequentially along the radial direction, the segment alignment may include a segment skip region that has no segments, a height-variable region where the segment heights vary, and a height-uniform region where the segment heights are uniform, and the plurality of segments may be arranged in the height-variable region and the height-uniform region. When the number of segments intersecting an imaginary line parallel to the winding axis direction at an arbitrary radius location of the bending surface region based on the core center of the electrode array is defined as a stacking number of the segments at the corresponding radius location, the bending surface region may include a uniform stacking number region where the stacking number of the segments is uniform from the core to the outer circumference and a decreasing stacking number region where the stacking number of the segments decreases towards the outer circumference, the decreasing stacking number region being located on an outer side of the uniform stacking number region. In the uniform stacking number region, the stacking number of the segments can be from 10 to 35. The first electrode can be a positive electrode, and a stacking thickness of the segments in the uniform stacking number region can be in the range of 100 µm to 875 µm. The first electrode can be a negative electrode, and the stacking thickness of the segments in the uniform region in stacking number can be in the range of 50 µm to 700 µm. The second electrode may include a second active material portion coated with a layer of active material and a second uncoated portion not coated with a layer of active material along the winding direction; the second uncoated portion may include a segment region divided into a plurality of independently bendable segments by a plurality of shear slots provided along the winding direction; the segment region of the second uncoated portion may include a plurality of segment groups divided by a group separation step along the winding direction; the other end of the electrode assembly may include a plurality of segment alignments in which the plurality of segment groups of the second uncoated portion are aligned along the radial direction.The segments included in each alignment of segments of the second uncoated portion can be bent along the radial direction to form a flexural surface region, and in winding turns corresponding to the plurality of alignments of segments of the second uncoated portion, the separation steps of groups of segments arranged in the same winding turn can be substantially identical, and the separation step of the groups of segments can be greater in the winding turn of the region adjacent to the outer circumference than in the winding turn of the region adjacent to the core. A plurality of segment alignments included at one end of the electrode assembly and a plurality of segment alignments included at the other end of the electrode assembly can be arranged to be symmetrical with respect to a plane to each other. The total number of winding turns of the electrode assembly can be from 20 to 55, and the electrode assembly can have a diameter of 35 mm to 50 mm. In another aspect of this disclosure, a battery is also provided, comprising an electrode assembly having one or more of the above-described features. The battery may also comprise a battery housing configured to house the electrode assembly and electrically connected to one of the first and second electrodes to have a first polarity; a sealing body configured to seal an open end of the battery housing; and a terminal having an outside surface and electrically connected to the other of the first and second electrodes to have a second polarity. The battery may further comprise a flange portion formed by press-fitting an outer circumference of the open end of the battery housing into the interior of the battery housing; a current-collecting plate electrically coupled to the flex surface region; and an insulator configured to cover the current-collecting plate and having a flange interposed and fixed between an inner circumference of the flange portion and the current-collecting plate. In the battery, a cavity may be provided in the core of the electrode assembly, and the cavity may not be blocked by the flex surface region and may be open to the outside. The sealing body may include a cap plate configured to seal the open end of the battery housing, and a gasket configured to surround an edge of the cap plate and crimped into the top end of the battery housing, and the terminal that has the second polarity may be the cap plate. The battery according to this disclosure may further include a current collector plate electrically connected to an uncoated portion of a second electrode having the first polarity and having an edge at least partially attached to a side wall of the battery housing. In this case, the sealing body may include a cap plate without any polarity, and a gasket configured to surround the edge of the cap plate and crimped into the upper end of the battery housing, and the battery housing may include a rivet terminal installed to be insulated in a drilled hole formed in the center of a sealing surface thereof and electrically connected to the first electrode to have the second polarity. In another aspect of this disclosure, a battery pack comprising a plurality of batteries having at least one of the above characteristics is also provided. In another aspect of this disclosure, a vehicle comprising the battery package is also provided. Advantageous effects According to one aspect of this disclosure, the internal resistance of the battery can be reduced and the energy density can be increased by using the uncoated portion that protrudes from the upper and lower portions of the electrode assembly as an electrode tab. According to another aspect of this disclosure, tearing of the uncoated portion when the uncoated portion is bent can be prevented by improving the structure of the uncoated portion of the electrode assembly, and the welding strength of the current collector plate can be improved by sufficiently increasing the number of overlapping layers of the uncoated portion. According to another aspect of the present disclosure, it is possible to improve (the speed and uniformity of) electrolyte impregnation by applying a plurality of segments to the uncoated portion of the electrode, arranging the plurality of segments in a predetermined direction when the electrode is wound, and exposing the end of the active material layer formed on the electrode between the winding turn of the separator in a region where the segments are not arranged. According to another aspect of this disclosure, by sufficiently increasing the number of stacked segments in the area used as the target welding zone, it is possible to improve the physical properties of the area where the current collector plate is welded. According to another aspect of this disclosure, an electrode assembly having improved energy density and reduced resistance can be provided by applying a structure in which a current-collecting plate is welded to the flex surface region formed by bending the segments. According to another aspect of this disclosure, a cylindrical battery may be provided which has an improved design such that electrical wiring can be carried out on the upper portion thereof. According to another aspect of this disclosure, by improving the structure of the uncoated portion adjacent to the core of the electrode assembly, the cavity in the core of the electrode assembly is prevented from being blocked when the uncoated portion is bent, so that the electrolyte injection process and the process for welding the battery housing (or rivet terminal) and the current collector plate can be easily performed. According to another aspect of this disclosure, it is possible to provide a cylindrical battery having a structure in which the internal resistance is low, an internal short circuit is avoided, and the solder resistance between the current collector plate and the uncoated portion is improved, and a battery pack and vehicle including the cylindrical battery. In particular, this disclosure may provide a cylindrical battery having a diameter-to-height ratio of 0.4 or more and a resistance of 4 milliohms or less, and a battery pack and vehicle including the cylindrical battery. Furthermore, this disclosure may have several other effects, and such effects will be described in each instance, or any description that can be readily inferred by a person skilled in the art for an effect will be omitted. Description of the drawings The accompanying drawings illustrate a preferred embodiment of the present disclosure and, together with the foregoing disclosure, serve to provide further understanding of the technical features of the present disclosure and, therefore, the present disclosure is not to be construed as being limited to the drawing. Figure 1 is a plan view showing a structure of an electrode used to manufacture a conventional flangeless cylindrical battery. Figure 2 is a diagram showing a conventional flangeless cylindrical battery electrode winding process. Figure 3 is a diagram showing a process for welding a current collector plate to a flex surface region of an uncoated portion of the conventional flangeless cylindrical battery. Figure 4a is a plan view showing an electrode structure according to an embodiment of the present disclosure. Figure 4b is a diagram showing definitions of a width in the winding direction, a height in the winding axis direction, and a pitch in the winding direction of segments and a group separation pitch between groups of segments according to an embodiment of this disclosure. Figure 4c is a diagram showing an arc (A1A2) formed by a lower segment end, where e defines the width D of the segment, with respect to the center O of the electrode assembly core, when the electrode is wound according to an embodiment of this disclosure. Figure 4d is a partially cross-sectional view showing the electrode assembly, taken along a winding axis to pass through the segment alignment according to an embodiment of the present disclosure, and schematically shows the relationship between segment heights h1, h2, h3, h4, core radius rc, and winding turn radii r1, r2, r3, r4 where segments begin to appear. Figure 4e is a conceptual diagram for determining a maximum value (hmax) for the height (H) of the segment in a height-variable region of the segment according to an embodiment of the present disclosure. Figure 4f is a schematic diagram to explain the formula that determines a lower interior angle () of the segment according to an embodiment of the present disclosure. Figure 4g is a plan view showing an electrode structure according to another embodiment of the present disclosure. Figure 4h is a plan view showing an electrode structure according to yet another embodiment of the present disclosure. Figure 5 is a partial perspective view showing a structure in which a flex surface region formed by flex segments covers the entire end portion of the electrode assembly according to an embodiment of the present disclosure. Figures 6a and 6b are top plan views showing respectively a plurality of regions in which an alignment of segments is formed at one end of the electrode assembly and a flex surface region formed by bending the segments included in the alignment of segments according to an embodiment of the present disclosure. Figures 7a and 7b are top plan views showing respectively a plurality of regions in which an alignment of segments is formed at one end of the electrode assembly and a flex surface region formed by bending the segments included in the alignment of segments according to another embodiment of the present disclosure. Figure 8 is a top plan view showing the flexural surface region formed at one end of the electrode assembly according to yet another embodiment of the present disclosure. Figure 9 is a diagram showing a segment structure according to various modifications of this disclosure. Figure 10 is a schematic diagram showing a cross-section of a bending surface region formed by bending the segment toward the core of the electrode assembly according to an embodiment of the present disclosure. Figure 11a shows graphs of the results of counting the number of stacked segments along a radial direction in the flexural surface region of a positive electrode formed on the upper portion of the electrode assemblies according to embodiments 1-1 to 1-7 and the comparative example. Figure 11b shows graphs of the results of counting the number of stacked segments along the radial direction in the flexural surface region of the positive electrode formed on the upper portion of the electrode assemblies according to embodiments 2-1 to 2-5, embodiments 3-1 to 3-4, embodiments 4-1 to 4-3, and embodiments 5-1 to 5-2. Figure 11c shows graphs that display the results of counting the number of stacked segments measured along the radial direction in the flexural surface region of the positive electrode formed in the upper portion of the electrode assembly according to embodiments 6-1 to 6-6 and embodiments 7-1 to 7-6. Figure 12 is a top plan view of the electrode assembly showing a uniform stacking number b1 region and a decreasing stacking number b2 region in the bending surface region of the segment according to an embodiment of the present disclosure. Figure 13 is a cross-sectional view of a gypsy arm-type electrode assembly in which the electrode is applied according to an embodiment of the present disclosure to a first electrode (positive electrode) and a second electrode (negative electrode), taken along the Y-axis direction (the winding axis direction) to pass through the segment alignment. Figure 14 is a cross-sectional view of a gypsy arm-type electrode assembly in which an electrode is applied according to another embodiment of the present disclosure to the first electrode (positive electrode) and to the second electrode (negative electrode), taken along the Y-axis direction (the winding axis direction) to pass through the segment alignment. Figure 15 is a cross-sectional view of a gypsy arm-type electrode assembly in which an electrode is applied according to another embodiment of the present disclosure to the first electrode (positive electrode) and to the second electrode (negative electrode), taken along the Y-axis direction (the winding axis direction) to pass through the segment alignment. Figure 16 is a cross-sectional view of a gypsy arm-type electrode assembly in which an electrode is applied according to another embodiment of the present disclosure to the first electrode (positive electrode) and to the second electrode (negative electrode), taken along the Y-axis direction (the winding axis direction) to pass through the segment alignment. Figure 17 is a cross-sectional view showing a cylindrical battery according to an embodiment of the present disclosure, taken along the Y-axis direction to pass through the bending surface region of the segments included in the segment alignment. Figure 18 is a cross-sectional view showing a cylindrical battery according to another embodiment of the present disclosure, taken along the Y-axis direction to pass through the bending surface region of the segments included in the alignment step of segments through the bending surface region. Figure 19 is a cross-sectional view showing a cylindrical battery according to yet another embodiment of the present disclosure, taken along the Y-axis direction to pass through the bending surface region of the segments included in the segment alignment. Figure 20 is a cross-sectional view showing a cylindrical battery according to yet another embodiment of the present disclosure, taken along the Y-axis direction to pass through the bending surface region of the segments included in the segment alignment. Figure 21 is a top plan view showing a structure of a first current collector plate according to an embodiment of the present disclosure. Figure 22 is a perspective view showing a structure of a second current collector plate according to an embodiment of the present disclosure. Figure 23 is a top plan view showing a state in which a plurality of cylindrical batteries are electrically connected. Figure 24 is a partially enlarged view of Figure 23. Figure 25 is a diagram schematically showing a battery pack according to an embodiment of the present disclosure. Figure 26 is a diagram schematically showing a vehicle including the battery pack according to an embodiment of the present disclosure. Best way Hereafter in this document, preferred embodiments of this disclosure will be described in detail with reference to the accompanying drawings. Prior to the description, it should be understood that the terms used in the specification and the accompanying claims should not be interpreted as limited to general, dictionary meanings, but should be interpreted based on the meanings and concepts corresponding to technical aspects of this disclosure, in accordance with the principle that the inventor is permitted to define terms as appropriate for the sake of clarity. Therefore, the description proposed in this document is only a preferred example for illustrative purposes only, without intending to limit the scope of the invention. Furthermore, to aid in understanding this disclosure, the accompanying drawings are not drawn to scale, and the dimensions of some components may be exaggerated. Additionally, the same part numbers may be assigned to the same items in different embodiments. When two objects are described as "identical," this means that they are "substantially identical." Consequently, substantially identical objects may include deviations that are considered low in the art, for example, deviations within 5%. Similarly, when certain parameters are described as uniform in a region, this may mean that the parameters are uniform in terms of an average over the relevant region. In addition, terms or expressions such as "approximately" or "around" refer to cases where there is a deviation of approximately 1%, 2%, 3%, ..., 20% based on the number for which the corresponding term is used. Although the terms first, second, or similar terms are used to describe different elements, these elements are not limited by the terms. These terms are used to distinguish one element from another, and unless otherwise stated, a first element can be a second element. Throughout the entire descriptive report, unless otherwise stated, each element may be singular or plural. When an element is "above (or below)" or "on (or under)" another element, the element may be on a higher surface (or a lower surface) of the other element, and there may be intermediate elements present between the element and the other element above (or below) the element. Additionally, when an element is referred to as "connected", "coupled" or "linked" to another element, the element may be directly connected or coupled to the other element, but it should be understood that there may be intermediate elements present between each element, or each element may be "connected", "coupled" or "linked" to one another through another element. Throughout the descriptive report, "A and / or B" refers to A or B or both A and B unless expressly stated otherwise, and "C to D" refers to C or higher and D or lower unless expressly stated otherwise. A direction along the longitudinal axis of the winding of a coiled electrode array is referred to herein as the Y-axis direction. A direction around the winding axis is referred to herein as the circumferential or peripheral X-direction. A direction toward or away from the winding axis is referred to herein as the radial direction. Specifically, the direction toward the winding axis is referred to as the centripetal direction, and the direction away from the winding axis is referred to as the centrifugal direction. First, an electrode assembly according to one embodiment of the present disclosure will be described. The electrode assembly is a gypsy-arm type electrode assembly in which a first electrode and a second electrode, both having a sheet shape and a separator interposed between them, are wound in one direction. At least one of the first and second electrodes includes an uncoated portion with an active material at one long end in the winding direction. At least part of the uncoated portion is used as an electrode tab. That is, a strip-shaped tab is not separately attached to the uncoated portion, and a portion of the uncoated portion is used as the tab. Figure 4a is a plan view showing the structure of an electrode 60 according to an embodiment of the present disclosure, and Figure 4b is a diagram showing segment parameter definitions 61 and a separation step between segment groups 61g. Referring to Figures 4a and 4b, the electrode 60, according to one embodiment, includes a sheet-shaped current collector 41 and an active material layer 42. The current collector 41 can be made of a metal sheet. The metal sheet can be a conductive metal such as aluminum or copper. The current collector 41 can be appropriately selected according to the polarity of the electrode 60. The metal sheet can be replaced with a metal mesh or similar material. The metal sheet can have a structure in which thin metal films are coated onto both surfaces of a substrate made of an insulating film. The active material layer 42 is formed on at least one surface of the current collector 41. The active material layer 42 is formed along the winding direction X. The electrode 60 includes an uncoated portion 43 at the long end in the winding direction X.The uncoated portion 43 is a partial area of ​​the current collector 41 not coated with the active material. At electrode 60, the area of ​​the current collector 41 where the active material layer 42 forms can be called the active material portion. The width of electrode 60 along the short side of current collector 41 can be from 60 mm to 70 mm, and the length of electrode 60 along the long side of current collector 41 can be from 3 m to 5 m. Therefore, the ratio of the short side to the long side of electrode 60 can be from 1.2% to 2.3%. This ratio is significantly lower than the 6% to 11% ratio of the short side to the long side of an electrode used in a cylindrical battery with a form factor of 1865 or 2170. Preferably, an insulating coating layer 44 may be formed at a boundary between the active material layer 42 and the uncoated portion 43. The insulating coating layer 44 is formed such that at least a portion of it overlaps with the boundary between the active material layer 42 and the uncoated portion 43. The insulating coating layer 44 prevents a short circuit between two electrodes of opposite polarity oriented towards each other with a separator interposed between them. The insulating coating layer 44 may cover a boundary between the active material layer 42 and the uncoated portion 43 with a width of 0.3 mm to 5 mm. The insulating coating layer 44 may include a polymeric resin and an inorganic filler such as Al₂O₃ or SiO₂.Because the portion of the current collector 41 covered by the insulating coating layer 44 is not an area coated with a layer of active material, it can be considered an uncoated portion. The uncoated portion 43 includes a first portion B1 adjacent to the core, a second portion B3 adjacent to the outer circumference, and a third portion B2 interposed between the first portion B1 and the second portion B3. The core and the outer circumference refer to a central region and an outer circumferential region of the electrode assembly when the electrode 60 is wound onto an electrode assembly. Of the first portion B1, the second portion B3, and the third portion B2, the third portion B2 is the longest and occupies most of the length of electrode 60. The first portion B1 can form a plurality of winding turns adjacent to the core of the electrode assembly. The second portion B3 can form one or more winding turns adjacent to the outer circumference of the electrode assembly. The third portion B2 corresponds to a segmented region. The segmented region has a structure in which the uncoated portion 43 is divided into a plurality of segments 61. The segments 61 can be folded independently. In one respect, each of the segments 61 may have a greater width in a lower portion rather than in an upper portion. In another respect, each of the segments 61 may have a tapered shape in which the width decreases gradually or continuously from the lower portion to the upper portion. Preferably, segment 61 can be trapezoidal. Alternatively, segment 61 can be rectangular, parallelogram-shaped, semicircular, or semi-elliptical. As will be described later, the geometric shape of segment 61 can be modified in various ways. Segment 61 can be formed by laser notching. Alternatively, segment 61 can be formed by a known sheet metal cutting process, such as ultrasonic cutting or punching. The third portion B2 includes a plurality of 61g segment groups arranged along the coiling direction X. Each 61g segment group contains one or more 61 segments. Adjacent 61g segment groups in the coiling direction X are separated by a PG group separation step. When electrode 60 is wound as a positive or negative electrode of the electrode assembly, the groups of segments 61g align along a radial direction at one end of the electrode assembly to form a plurality of segment alignment 50 as shown in Figure 6a. Segment alignment 50 refers to an assembly of groups of segments 61g arranged to overlap along the radial direction of the JR electrode assembly. The overlapping of the plurality of segments included in the segment alignment 50 in the radial direction means that, when a predetermined straight line is drawn through the segment alignment 50 from the center of the core, all segments 61 intersect the corresponding straight line. The segments 61 included in each alignment of segments 50 bend towards the core C to form a flexural surface region F, as shown in Figure 6b. When the segments 61 are bent, the flexural surface region F corresponds to an upper region of the alignment of segments 50. To bend the segments 61 included in the alignment of segments 50, a bending force can be applied to the segments 61 using a template or similar device. The bending force is preferably applied in multiple directions as indicated by the arrows in Figure 6a. The alignment of segments 50, or the flexural surface region F, has the shape of an approximate geometric figure when viewed in the direction of the winding axis of the electrode assembly. The width in the winding direction of the groups of segments 61g located within the geometric figure may increase in a stepped or gradual manner along the radial direction of the electrode assembly. The alignment of segment 50 or the flex surface region F may have an approximate fan shape when viewed in the direction of the winding axis of the electrode assembly. Alternatively, the alignment of segment 50 or the flex surface region F may have a rectangular or trapezoidal shape when viewed in the direction of the winding axis of the electrode assembly. When the segment alignment 50 or bending surface region F has a rectangular shape, the segment alignment 50 or bending surface region F can be arranged so that the line connecting the centers of opposite short sides follows the radial direction of the electrode assembly. When the segment alignment 50 or the bending surface region F has a trapezoidal shape, the segment alignment 50 or the bending surface region F can be arranged such that the line connecting the centers of the opposite short and long sides follows the radial direction of the electrode assembly and the short side is oriented towards the core of the electrode assembly. In winding turns corresponding to the plurality of segment alignments 50, the PG group separation steps of the segment groups 61g arranged in the same winding turn are substantially identical to each other. In the present case, it should be understood that the fact that the PG group separation step is substantially identical includes not only the case where the deviation of the PG group separation steps is 0%, but also the case where the deviation of the PG group separation steps is 10% or less or 5% or less. The separation step of the PG group of the 61g segment group can be greater in the winding turn adjacent to the outer circumference than in the winding turn adjacent to the core C. Preferably, the PG group separation pitch of the 61g segment group included in the n+1st winding turn may be greater than the PG group separation pitch of the 61g segment group included in the nth winding turn. In the present case, the winding turns may be counted as they increase by 1 each time the electrode is wound one turn, using the position of the first 61 segment closest to the first B1 portion as a reference point. In one embodiment, when the group separation step of the 61g segment group included in the k-th winding turn is called PGk, PGk can increase proportionally as the k-index of the winding turn increases. In another embodiment, when the group separation step of the 61g segment group included in the k-th winding turn is PGk, PGk can be increased proportionally as long as the k-index of the winding turn increases by a predetermined interval. Consequently, each alignment of segments 50 may include a radial region in which the PG group separation step increases in a stepped or gradual manner from the winding turn in a region adjacent to the core to the winding turn in a region adjacent to the outer circumference. The number of segment alignments 50 corresponds to the number of segment groups 61g included in each winding turn. In one example, as shown in Figures 4a, 6a, and 6b, if the number of groups of segments 61g arranged in the winding turn is 4, the number of alignments of segments 50 and bending surface regions F is also 4, respectively. In another example, if the number of segment groups 61 g included in the coil turn of the electrode 60 shown in Figure 4a is reduced to two, as shown in Figures 7a and 7b, the number of segment alignments 50 and bending surface regions F is also reduced to two, respectively. On the other hand, in Figures 6a and 7a, the 61g segment groups are shown regularly aligned along the radial direction. However, it is obvious to those skilled in the art that the alignment position of the 61g segment group can be rotated a predetermined angle clockwise or counterclockwise from the design position due to the thickness deviation of the electrode that constitutes each winding turn or imperfections in the winding process. Referring to Figures 6b and 7b, the flex surface region F partially covers the surface of one end of the electrode assembly. Therefore, between adjacent flex surface regions F in the circumferential direction, an electrolyte impregnation portion 55 is provided where the end of the active material layer is recessed further into the electrode assembly than the end of the spacer and is exposed between the winding turns of the spacer. The electrolyte impregnation portion 55 corresponds to a portion of the winding turns formed by winding a region of the uncoated portion 43 where the second cutting groove 63' is formed. The electrolyte impregnation portion 55 is a region where the electrolyte EL can be primarily impregnated, and it has a lower height than the flex surface region F in the winding axis direction Y. In the electrolyte impregnation portion 55, there is no segment 61 that protrudes outside the spacer Se. Furthermore, in the electrolyte impregnation portion 55, the ends of the active material layer a1 of the positive electrode E1 and the active material layer a2 of the negative electrode E2 are tapered downwards to separate from the end of the spacer Se by a predetermined separation distance between adjacent spacers Se in the radial direction of the electrode assembly JR.Therefore, isolation can be maintained between the positive electrode E1 and the negative electrode E2. In one embodiment, the separation distance can be between 0.6 mm and 1 mm. An insulating coating layer 44 can be formed on at least one end of the positive electrode E1 and the negative electrode E2. The end of the positive electrode E1 can include a sliding portion in which the thickness of the active material layer a1 gradually decreases. The electrode and separator arrangement shown in Figures 6b and 7b can also be applied to the lower portion of the JR electrode assembly. Preferably, the insulating coating layer 44 and the sliding portion can be formed on one end of the negative electrode E2 in the lower portion of the JR electrode assembly. The electrolyte EL can impregnate the electrode assembly JR while coming into direct contact with the positive electrode E1 and the negative electrode E2 through the gap provided between the ends of the spacers Se. Specifically, the electrolyte EL falling to the top of the electrode assembly JR rapidly penetrates the assembly while simultaneously contacting the ends of the positive electrode E1 and the negative electrode E2, as well as the end of the spacer Se. As a result, the rate and uniformity of electrolyte impregnation can be significantly improved. Figure 5 is a partial perspective view showing the top surface of a JR electrode assembly wound using an electrode 60' in which the uncoated portion 43 lacks the spaced structure of the segment groups 61g, and the segments 61 are arranged continuously along a winding direction. Referring to Figure 5, when viewed along the winding axis, in the bending surface region F, there is substantially no gap through which an electrolyte can directly penetrate the JR electrode assembly. Therefore, the electrolyte impregnability (both in speed and uniformity) is poor compared to the implementation described herein. Referring again to Figure 4a, in each group of segments 61g, a first cutting groove 63 is interposed between adjacent segments 61 in the winding direction X. In addition, a second cutting groove 63' is interposed between groups of adjacent segments 61g in the winding direction X. In the winding direction X, the width of the second cutting groove 63' is greater than the width of the first cutting groove 63. The first cutting groove 63 and the second cutting groove 63' can be formed together in the notching process. As shown in Figure 4b, the first cutting slot 63 includes a flat bottom portion 63a, a rounded portion 63b adjacent to it, and a side portion 63c of segment 61. Similarly, the second cutting slot 63' also includes a flat bottom portion 63'a, a rounded portion 63'b adjacent to it, and a side portion 63'c of segment 61. The level of the bottom portion 63a of the first cutting slot 63 and the level of the bottom portion 63'a of the second cutting slot 63' can be substantially the same. The rounded portion 63c, 63'c can prevent cracking from occurring at the lower end of segment 61 by relieving stress when segment 61 is bent. To prevent damage to the active material layer 42 and / or the insulating coating layer 44 during bending of segment 61, a predetermined gap is preferably provided between the bottom portion 63a, 63'a of the first and second cutting grooves 63, 63' and the active material layer 42. This is because, when segment 61 is bent, the stress is concentrated near the bottom portion 63a, 63'a. The gap is from 0.2 mm to 4 mm, preferably from 1.5 mm to 2.5 mm. When the gap is adjusted to the corresponding numerical interval, the active material layer 42 and / or the insulating coating layer 44 near the lower end (bottom portion 63a, 63'a of the first and second cutting grooves 63, 63'). In addition, the gap can prevent damage to the active material layer 42 and / or the insulating coating layer 44 due to tolerances during notching or cutting of segment 61.The bottom portion 63a, 63'a of the first and second cutting grooves 63, 63' can be separated from the insulating coating layer 44 by 0.5 mm to 1.0 mm. When the electrode 60 is wound, the end of the insulating coating layer 44 in the winding axis direction Y can be located in the range of -2 mm to 2 mm along the winding axis direction, based on the end of the separator. The insulating coating layer 44 can prevent a short circuit between two electrodes with opposite polarities oriented towards each other with a separator interposed between them, and can withstand a bending point when segment 61 is bent. To improve the short-circuit prevention effect between the two electrodes, the insulating coating layer 44 can be exposed to the outside of the separator.Furthermore, to further maximize the effect of preventing a short circuit between the two electrodes, the width of the insulating coating layer 44 can be increased such that the end of the insulating coating layer 44 in the direction of the winding axis Y is located above the bottom portion 63a, 63'a of the first and second cutting grooves 63, 63'. In one embodiment, the end of the insulating coating layer 44 in the direction of the winding axis Y can be located within a range of -1 mm to +1 mm based on the bottom portion 63a, 63'a of the first and second cutting grooves 63, 63'. Referring to figure 4b, the width (D), height (H), and separation pitch (P) of segment 61 are designed to prevent the uncoated portion 43 near the bending point from tearing during bending of the uncoated portion 43 and to prevent abnormal deformation of the uncoated portion 43 while sufficiently increasing the number of overlapping layers of the uncoated portion 43 to ensure sufficient weld strength. Segment 61 is bent along line G, which passes through either the underside or the top of the first cutting groove 63. The first cutting groove 63 allows for smooth and easy bending of segment 61 in the radial direction of the electrode assembly. The width (D) of segment 61 is defined as the length between two points where two straight lines extending from both side portions 63c of segment 61 intersect a straight line extending from the bottom portion 63a of the first cutting slot 63. The height (H) of segment 61 is defined as the shortest distance between the top edge of segment 61 and a straight line extending from the bottom portion 63a of the first cutting slot 63. The separation pitch (P) of segment 61 is defined as the length between two points where a straight line extending from the bottom portion 63a of the first cutting slot 63 meets straight lines extending from both side portions 63c connected to the bottom portion 63a.When the side portion 63c and / or the bottom portion 63a are curved, the straight line may be replaced by a tangent extending from the side portion 63c and / or the bottom portion 63a at a point of intersection where the side portion 63c and the bottom portion 63a meet. The group separation pitch PG between the segment groups 61g is defined substantially the same as the separation pitch (P) between the segments 61. That is, the group separation pitch PG corresponds to the length between two points where a straight line extending from the bottom portion 63'a of the second cutting groove 63' and the side portion 63'c of the segment 61 adjacent to both ends of the bottom portion 63'a meet. Preferably, the width (D) of segment 61 is 1 mm or more. If D is less than 1 mm, when segment 61 is bent towards the core, an area or gap (void) may occur where the segments 61 do not overlap sufficiently to ensure adequate weld strength. Preferably, the width (D) of the 61 segments can be adaptively adjusted depending on the radius of the winding turn where the 61 segments are located, such that the 61 segments overlap well in the radial direction when the 61 segments are bent towards the core of the electrode assembly. Figure 4c is a diagram showing an arc (A1A2) formed by a lower end (line Dab in Figure 4b) of segment 61, where the width D of segment 61 is defined, with respect to the center O of the electrode assembly core, when electrode 60 is wound according to an embodiment of this disclosure. Referring to Figure 4c, the arc (A1A2) has a length corresponding to the width (D) of segment 61 and has a circumferential angle (θ) with respect to the center O of the electrode assembly core. The circumferential angle (θ) can be defined as the angle between two line segments connecting both ends of the arc (A1A2) and the center O of the core in a plane perpendicular to the winding axis passing through the arc (A1A2). When the arc length (A1A2) of segment 61 is the same, the circumferential angle () decreases as the radius (r) of the winding turn where segment 61 is located increases. Conversely, when the circumferential angle () of segment 61 is the same, the arc length (A1A2) increases proportionally as the radius (r) of the winding turn where segment 61 is located increases. The circumferential angle (θ) affects the bending quality of segment 61. In the drawing, a solid arrow indicates the direction of applied force bending segment 61, and a dotted arrow indicates the direction in which segment 61 bends. The bending direction is toward the center O of the core. According to experiments, when the circumferential angle (θ) of segment 61 exceeds 30 degrees, the bending pattern of segment 61 is not uniform. The difference between the force applied to the middle of segment 61 and the force applied to the side increases, resulting in non-uniform compression of segment 61 in the circumferential direction. Furthermore, if the compressive force is increased to achieve uniform bending, cracks may occur in the uncoated portion 43 near the first shear groove 63. Therefore, the circumferential angle () of segment 61 is preferably 30° or less regardless of the radius (r) of the winding turn where segment 61 is located to improve bending uniformity and avoid cracking. In one embodiment, the circumferential angles () of the segments 61 included in the electrode 60 are substantially the same, and the widths of the segments 61 can increase proportionally as the radius (r) of the winding turn in which the segment 61 is located increases. The term "substantially the same" means completely identical or with a variance of less than 5%. For example, when the radius of the electrode assembly is 22 mm and the core radius is 4 mm, and the segments 61 are arranged starting from the winding turn located at the point where the radius is 7 mm, if the circumferential angles (θ) of the segments 61 are uniform, such as 28.6 degrees, the widths (D) of the segments 61 can increase proportionally according to the radius (r) of the winding turn where the segments 61 are located, as shown in Table 1 below. That is, the widths of the segments 61 can increase at the same rate of 0.5 mm whenever the radius (r) of the winding turn increases by 1 mm. Preferably, the width D(r) of segment 61 located on a winding turn having a radius of r based on the center O of the electrode assembly core can be determined within a range that satisfies Formula 1 below. Referring to Figure 4b again, the height (H) of segment 61 can be 2 mm or more. If the height (H) is less than 2 mm, when segment 61 is bent towards the core, an area or gap (void) may occur where the segments 61 do not overlap sufficiently to ensure adequate weld strength. The height (H) of segment 61 can be determined by applying the condition that segment 61 does not block the core when bent toward it. Preferably, the height (H) of segment 61 can be adjusted so that 90% or more of the core diameter can be exposed to the outside. Preferably, the heights (H) of the segments 61 can increase from the core towards the outer circumference depending on the radius of the winding turn and the radius of the core where the segments 61 are located. In one embodiment, when the heights (H) of the segments 61 increase stepwise in N steps from h1 to hN as the radius of the winding turn increases, assuming that the k-th height of segment 61 (k being a natural number from 1 to N) is hk, the starting radius of the winding turn that includes the segment 61 having height hk is rk and the core radius is rc, the heights h1 to hN of the segments 61 can be determined to satisfy Formula 2 below. If the heights (hk) of segments 61 comply with Formula 2, even if segments 61 are bent towards the core, 90% or more of the core diameter can be opened to the outside. In one example, the radius of all the winding turns of electrode 60 is 22 mm, the heights of segments 61 start at 3 mm and increase sequentially to 3 mm, 4 mm, 5 mm, and 6 mm each time the radius of the winding turn including segment 61 increases by 1 mm, and the heights can remain substantially identical at 6 mm in the remaining winding turns. That is, among the radii of all the winding turns, the width of the height-variable region of segment 61 is 3 mm, and the remaining radial region corresponds to the height-uniform region. In this case, when it is 1 and the equal sign condition is applied in the right inequality, the initial radius r1, r2, r3, r4 of the winding turns that include the segments 61 having heights of 3 mm, 4 mm, 5 mm and 6 mm depending on the radius (rc) of the core of the electrode assembly can be as shown in Table 2 below. T l 2 When segments 61 are positioned at the radius locations shown in Table 2, the core is not blocked even if segments 61 are bent toward the core. On the other hand, r1, r2, r3, and r4 shown in Table 1 can be offset toward the core according to the value of . For example, when is 0, 90, r1, r2, r3, and r4 can be offset toward the core by 10% of the core radius. In this case, when segment 61 is bent toward the core, segment 61 blocks 10% of the core radius. r1, r2, r3, and r4 shown in Table 1 are boundary values ​​for the location where segment 61 begins. Therefore, the location of segment 61 can be offset toward the outer circumference by a predetermined distance instead of the radius shown in Table 2. Figure 4d is a partially cross-sectional view showing the electrode assembly, taken along a winding axis to pass through the alignment of segments 50, and schematically shows the relationship between segment heights h1, h2, h3, h4, core radius (rc), and winding turn radii r1, r2, r3, r4 where segments begin to appear. Referring to Table 2 and Figure 4d together, for example, when the radius (rc) of core C is 3 mm, the initial radii r1, r2, r3, and r4 of the winding turns that include segments 61 with heights of 3 mm (h1), 4 mm (h2), 5 mm (h3), and 6 mm (h4) can be 6 mm, 7 mm, 8 mm, and 9 mm, respectively, and the heights of segments 61 can be maintained at 6 mm from the 9 mm radius to the last winding turn. Furthermore, segment 61 can be excluded from the winding turn with a radius less than 6 mm (r1). In this example, because segment 61, which has a height of 3 mm (h1), is located closest to core C from the winding turn, which has a radius of 6 mm, even if segments 61 are bent towards core C, segments 61 cover only the radial region from 3 mm to 6 mm and substantially do not block core C.According to the value in Formula 2, the location of segment 61 can be shifted towards core C within 10% of the core radius (rc). Preferably, the height (H) of segment 61 satisfies Formula 2 and, at the same time, the maximum height can be limited. Figure 4e is a conceptual diagram for determining a maximum value (hmax) for the height (H) of segment 61 in a height-variable region of segment 61. Referring to Figure 4e, in the coiled structure of the electrode assembly, electrode E1, which includes segment 61, is oriented towards the oppositely polarized electrode E2, with the spacer S interposed between them in the radial direction. Both surfaces of electrode E1 are coated with a layer of active material (E1, active), and both surfaces of electrode E2 are also coated with a layer of active material (E2, active). For electrical insulation, the end (Sextreme) of the spacer S may extend further outwards from the end (E2, end) of electrode E2 to a length corresponding to the insulation gap (Wgap). Similarly, the end of electrode E1 does not extend further outwards beyond the end of electrode E2 for electrical insulation. Therefore, a region corresponding to the insulation gap (Wgap) should be fixed to the lower end of the uncoated portion 43.Furthermore, when the electrodes (E1, E2) and the separator S are wound together, the end (Sextremo) of the separator S causes snaking. Therefore, for segment 61 to be exposed to the outside of the separator S, the region (Wmargen, min) corresponding to a minimum snaking margin of the separator S must be allocated to the uncoated portion 43. Additionally, to cut segment 61, a minimum cutting allowance (Wrecorte, min) should be allocated to the end of the current collector film. Therefore, the maximum height (hmax) of segment 61 in the height-variable region of segment 61 can be determined using Formula 3 below. In Formula 3, Wfilm corresponds to the width of the current collector before the current collector is cut. In one example, the minimum cut-off margin (Wcut, min) may be 1.5 mm, and the minimum serpentine margin (Wmargin, min) of the separator S may be 0.5 mm. Under these conditions, when the width (Wfilm) of the current collector sheet before forming segment 61 is 8 mm to 12 mm and the insulation gap (Wgap) is 0.6 mm, 0.8 mm, and 1.0 mm, the maximum height (hmax) of segment 61 can be calculated using Formula 3 as in Table 3 below. T l Considering Table 3, the maximum height (hmax) of segment 61 in the height-variable region of segment 61 can be set at 10 mm. Therefore, in the height-variable region of segment 61, the height of segment 61 satisfies Formula 2 and can increase in a stepwise or gradual manner along the radial direction of the electrode array in the range of 2 mm to 10 mm. Referring again to Figure 4b, the gap pitch (P) of segment 61 can be adjusted within the range of 0.05 mm to 1 mm. If the gap pitch (P) is less than 0.05 mm, cracks may occur in the uncoated portion 43 near the lower end of the first cutting groove 63 due to stress when the electrode 60 moves during the winding process or similar operation. On the other hand, if the gap pitch (P) exceeds 1 mm, a gap or void may occur where the segments 61 do not overlap sufficiently to ensure adequate weld strength when segment 61 is bent. On the other hand, when the current collector 41 of the electrode 60 is made of aluminum, it is preferable to set the gap pitch (P) to 0.5 mm or more. When the gap pitch (P) is 0.5 mm or more, even if the electrode 60 is moved at a speed of 100 mm / s or more under a voltage of 300 gf or more in the winding process or similar, cracks can be avoided in the area below the first cutting groove 63. According to the experimental results, when the current collector 41 of the electrode 60 is an aluminum film with a thickness of 15 µm and the separation step (P) is 0.5 mm or more, no cracks are generated in the lower part of the first cutting groove 63 when the electrode 60 is displaced under the above displacement conditions. As shown in Figure 4b, the first cutting groove 63 corresponds to a space created by removing the uncoated portion 43. Preferably, one edge of the bottom portion of the first cutting groove 63 has a rounded shape. That is, the first cutting groove 63 includes a substantially flat bottom portion 63a and a rounded portion 63b. The rounded portion 63b connects the bottom portion 63a and the side portion 63c of segment 61. In a modified example, the bottom portion 63a of the first cutting groove 63 can be replaced with an arc shape. In this case, the side portions 63c of segments 61 can be smoothly connected by the arc shape of the bottom portion 63a. Preferably, the radius of curvature of the rounded portion 63b may be greater than 0 and less than or equal to 0.1 mm. More preferably, the rounded portion 63b may have a radius of curvature from 0.01 mm to 0.05 mm. When the radius of curvature of the rounded portion 63b falls within the above numerical range, cracking in the lower portion of the first cutting groove 63 can be prevented while the electrode 60 is being moved during the winding process or similar. It is obvious to experts in the field that the structural features of the first cutting groove 63 described above can be applied substantially identically to the second cutting groove 63' formed between the segment groups 61g. The lower internal angles () of the plurality of segments 61 included in the alignment of segments 50 can increase from the core toward the outer circumference. The lower internal angle () is an angle between a straight line extending from the bottom portion 63a of the first cutting groove 63 and a straight line extending from the side portion 63c of segment 61. When segment 61 is symmetric in the left and right directions, the lower internal angles () of the left and right sides are substantially the same. Increasing the radius of the JR electrode assembly increases the curvature. If the lower internal angle () of segment 61 increases as the radius of the electrode assembly increases, the stress generated in the radial and circumferential directions when segment 61 is bent can be relieved. Furthermore, if the lower internal angle () increases, when segment 61 is bent, the area overlapping with segment 61 on the inner side and the number of overlapping layers also increase, so that the weld strength can be ensured uniformly in the radial and circumferential directions, and the bending surface region can be formed flat. Preferably, the lower internal angle () can be determined by the radius of the winding turn where segment 61 is located in the alignment of segments 50 and the width (D) of segment 61. Figure 4f is a schematic diagram to explain the formula that determines a lower interior angle () of segment 61. Referring to figure 4f, the sides of segment 61 ideally coincide with line segment AE and line segment DE connecting center E of the core center to both endpoints A and D of line segment AD corresponding to the width (D) of segment 61. When the side of segment 61 is extended in the most ideal direction, assuming that line segment EF is approximately equal to line segment AE and line segment DE, the lower internal angle (refer) of segment 61 can be approximately determined from the width (D) of segment 61 and the radius (r) of the winding turn where segment 61 is located using Formula 4 below. The angle in Formula 4 is an ideal criterion angle for the lower internal angle (refer) of segment 61. Furthermore, there is a separation pitch (P) between adjacent segments 61 located on the same winding turn. The length of the separation pitch (P) is expressed as p. Because the separation pitch (P) exists between adjacent segments 61, a tolerance of 50% of the separation pitch (p) can be provided for the lower internal angle (). That is, the width of the upper side BC of segment 61 can be increased by a maximum of p / 2 to the upper side B'C'. The lower internal angle (') with the reflected tolerance can be expressed as in Formula 5 below. The lower internal angle (refer) is the ideal criterion angle BAG, and the lower internal angle (') is the angle B'AG' that reflects the tolerance according to the separation pitch (p). In Formula 5, H is the height of segment 61, and p corresponds to the separation pitch. Preferably, the lower internal angle () of segment 61 included in the alignment of segments 50 and located at each winding turn can satisfy Formula 6 below. Then, when segments 61 are bent toward the center of the electrode assembly core, adjacent segments 61 in the circumferential direction do not interfere with each other and can be bent smoothly. In one example, when electrode 60 forms a coil structure with a diameter of 22 mm and a core radius of 4 mm, the lower internal angle of segment 61 can increase in a stepwise fashion in the range of 60 degrees to 85 degrees in the height-variable region. Referring again to Figure 4a, the width (dB1) of the first portion B1 is designed such that the core of the electrode assembly opens outward by 90% or more based on the diameter when segment 61 of the third portion B2, included in the alignment of segments 50, is bent toward the core. The width (dB1) of the first portion B1 may be increased in proportion to the bending length of segment 61 closest to the first portion B1. The bending length corresponds to the length from the bending point to the upper end side of segment 61. Preferably, when electrode 60 is used to manufacture an electrode assembly for a cylindrical battery having a form factor of 4680, the width (dB1) of the first portion B1 may be set from 180 mm to 350 mm depending on the diameter of the core of the electrode assembly and the height of segment 61 closest to the first portion B1. The bending point of segment 61 can be set on a line passing through the lower end of the first cutting groove 63 or at a point a predetermined distance above this line. When segment 61 is bent toward the core at a point a certain distance from the lower end of the first cutting groove 63, the segments overlap better in the radial direction. When segments 61 are bent, one segment on an outer side presses against a segment on an inner side, based on the center of the core. At this point, if the bending point is a predetermined distance from the lower end of the first cutting groove 63, the segment on the inner side is pressed in the direction of the winding axis by the segment on the outer side, and the segments overlap better. The separation distance of the bending points can be 3 mm or less, preferably 2 mm or less. In the present disclosure, the number of groups of segments 61g included in each winding turn, the number of groups of segments 61 included in each group of segments 61g, and the width of each group of segments 61g may be desirablely adjusted to disperse the stress to the maximum during the bending process of the uncoated portion 43, overlap the segments 61 in several layers to ensure sufficient welding strength of the current collector plate in the bending surface region F, and sufficiently improve (the speed and uniformity of) the electrolyte impregnation by providing a plurality of electrolyte impregnation portions 55 in the circumferential direction. The segment structure of the third portion B2 can be extended to the second portion B3. In this case, the coil formed by the second portion B3 can also include a plurality of segment groups 61g, just like the third portion B2. In this case, the features applied to the segment structure of the third portion B2 can also be applied to the segment structure of the second portion B3 without limitation. The number of segments 61, the width of segments 61, the height of segments 61 and / or the separation pitch of segments 61 that constitute groups of segments 61g included in different winding turns may be different. That is, as shown in Figure 4g, the number of segments in the group of segments 61g included in a winding turn located near the outer circumference can be greater than the number of segments in the group of segments 61g included in a winding turn located closer to the core. In another aspect, the segment height of the 61g segment group included in the winding turn located closest to the outer circumference may be greater than the segment height of the 61g segment group included in the winding turn located closest to the core. In another aspect, the segment width of the 61g segment group included in the winding turn located near the outer circumference may be greater than the segment width of the 61g segment group included in the winding turn located closer to the core. In another aspect, the segment separation pitch of the 61g segment group included in the winding turn located closest to the outer circumference may be greater than the segment separation pitch of the 61g segment group included in the winding turn located closest to the core. In this disclosure, the third portion B2 of electrode 60 can be divided into two subregions. That is, as shown in Figure 4h, the third portion B2 can be divided into a first region B2a in which the segments 61 are arranged continuously without a separate arrangement structure from the segment groups 61g, and a second region B2b in which there is a separate arrangement structure from the segment groups 61g. The first region B2a can be adjacent to the first portion B1, and the second region B2b can be adjacent to the second portion B3. When the electrode assembly is wound using the electrode 60 which includes the first region B2a and the second region B2b, as shown in Figure 8, an annular bending surface region F is additionally formed near the core C of the electrode assembly JR in addition to the radial bending surface region F formed by the segments 61 included in the alignment of segments 50. This structure has the effect of increasing the welding strength of the current collector plate without substantially affecting the electrolyte impregnability by further increasing the area of ​​the bending surface region F. In the present disclosure, the plurality of segment alignments 50 (or bending surface regions F) may be arranged symmetrically in a cross shape (+), a radial shape (X), or a linear shape based on the core center when viewed in the direction of the JR electrode assembly winding axis. For reference, Figures 6a and 6b show an example in which a plurality of alignments of 50 segments (F bending surface regions) are arranged in a cross shape (+) based on the core center when viewed in the direction of the JR electrode assembly winding axis. Figures 7a and 7b show an example in which a plurality of alignments of segments 50 (flexing surface regions F) are arranged in a linear form based on the core center when viewed in the winding axis direction of the JR electrode assembly. In one respect, the line connecting the core center of the JR electrode array and a geometric center of the figure approximating the bending surface region F can be defined as an angle measurement line L, and the angle between the angle measurement lines L of adjacent bending surface regions F in the circumferential direction can be substantially equal. The geometric center of the figure can be, for example, the center of gravity of the figure. When determining the geometric center, it is assumed that all regions contained within the figure have the same mass. Specifically, when the angle measurement line L is defined as the line connecting the core center of the JR electrode assembly and the geometric center of the figure approximating the bending surface region F, the angle between the angle measurement lines L of adjacent bending surface regions F in the circumferential direction can be 30° ± 10°, 40° ± 10°, 45° ± 10°, 60° ± 10°, 72° ± 10°, 90° ± 10°, 120° ± 10° or 180° ± 10°. In one aspect, among various arrangements of the bending surface region F, when the angle between the angle measurement lines L of adjacent bending surface regions F in the circumferential direction is 90° ± 10° (see Figure 6b), the PG group separation step of the 61g segment groups forming the 50 segment alignment can be set to increase gradually or in stages within a range of 8 mm to 50 mm, preferably 10 mm to 45 mm, as the winding turn increases.In another respect, among various arrangements of the bending surface region F, when the angle between the angle measurement lines L of adjacent bending surface regions F in the circumferential direction is 180° ± 10° (see Figure 7b), the PG group separation step of the 61g segment groups forming the 50 segment alignment can be set to increase gradually or in stages within a range of 30 mm to 90 mm, preferably 35 mm to 70 mm, as the winding turn increases.On the other hand, when the figure that approximately corresponds to the bending surface region F is symmetrical in line when viewed in the direction of the winding axis of the electrode assembly, the angle measurement line L can be replaced by a line connecting the center of the core of the electrode assembly JR and the center of the winding turn region located on the outermost side of the bending surface region F. For example, when the figure is fan-shaped, a line connecting the center of the fan arc and the center of the core can be defined as the angle measurement line L. When the separation pitch of the PG groups of segments 61g is set to increase according to the number of winding turns within the specified range, the segment groups 61g are arranged radially and regularly along the radial direction of the electrode assembly. As a result, the electrolyte impregnation portions 55 are also formed radially, thus significantly improving electrolyte impregnation. Furthermore, because the segments 61 are arranged in a localized area along the radial direction of the electrode assembly, the stress generated during bending of segment 61 is dispersed, allowing segment 61 to bend easily. Therefore, the stacking number of segments 61 is sufficiently increased along the winding axis to improve the welding strength with the current collector plate.The improved welding resistance reduces the resistance of the electrode assembly or the cylindrical battery manufactured using it. In this disclosure, segment 61 can be deformed in various ways while at least one of the following conditions is satisfied. Condition 1: The width of the lower portion is greater than the width of the upper portion Condition 2: The width of the lower portion is the same as the width of the upper portion Condition 3: The width remains uniform from the top portion to the bottom portion. Condition 4: The width decreases from the lower portion to the upper portion Condition 5: The width decreases and then increases from the bottom to the top. Condition 6: The width increases and then decreases from the bottom to the top. Condition 7: The width increases from the bottom to the top and then remains constant. Condition 8: The width decreases from the bottom to the top and then remains constant. Condition 9: The interior angle of one side and the interior angle of the other side of the lower portion are equal. In this case, the interior angle can be defined as the angle formed by the lateral portion of the segment based on the width direction of the lower portion of the segment. If the lateral portion is a curve, the interior angle is defined as the angle between the tangent drawn at the lowest point of the curve and the width direction of the lower portion of the segment. Condition 10: The interior angle of one side of the lower portion and the interior angle of the other side are different. Condition 11: The interior angle of one side of the lower portion and the interior angle of the other side of the lower portion have an acute angle, a right angle, or an obtuse angle, respectively. Condition 12: Symmetrical in the left and right directions based on the winding axis direction. Condition 13: Asymmetrical in the left and right directions based on the winding axis direction. Condition 14: The side portion is straight. Condition 15: the lateral portion is curved Condition 16: the lateral portion is convex outwards Condition 17: the lateral portion is convex inwards Condition 18: The corner of the upper portion and / or the lower portion has a structure where straight lines are found Condition 19: The corner of the upper portion and / or the lower portion has a structure where a straight line and a curve meet. Condition 20: The corner of the upper portion and / or the lower portion has a structure where curves are found Condition 21: The corner of the upper portion and / or the lower portion has a rounded structure Figure 9 is a diagram showing, as an example, the shapes of segments 61 according to various modifications of this disclosure. As shown in the drawing, segment 61 can have various geometric shapes, with a dotted line connecting the lower portions 63a of the first cutting grooves 63 on both sides as a basis. The geometric shape has a structure in which at least one straight line, at least one curved line, or a combination of both are connected. In one example, segment 61 can have a polygonal shape, a round shape, or various combinations thereof. Specifically, segment 61 can have a left-right symmetric trapezoidal shape () ; a left-right asymmetric trapezoidal shape () ; a parallelogram shape (©) ; a triangular shape () ; a pentagonal shape () ; an arc shape () ; or an elliptical shape () . Because the shape of segment 61 is not limited to those shown in Figure 9, it can be transformed into other polygonal shapes, other round shapes, or combinations thereof to satisfy at least one of the conditions 1 to 21 described above. In the polygonal shapes , , , and of segment 61, the corners of the upper portion and / or the lower portion can have a shape where straight lines meet or a round shape (see the enlarged view of the corners of the upper portion and / or the lower portion of the shape ). In the polygonal shapes of segment 61 and the curved shapes of segment 61, the interior angle (1) on one side and the interior angle (2) on the other side of the lower portion can be equal or different, and the interior angle (1) on one side and the interior angle (2) on the other side of the lower portion can be an acute angle, a right angle, or an obtuse angle, respectively. An interior angle is an angle formed by the base and a side of a geometric figure. When the side is curved, the straight line can be replaced by a tangent line extending from the point where the base meets the side. The shape of the lateral portion of segment 61, which has a polygonal shape, can be modified in various ways. In one example, the lateral portion of the segment shape can be transformed into an outwardly convex curve, such as the shape , or it can be transformed into an inwardly curved segment, such as the shape or . In another example, the lateral portion of the segment shape can be transformed into a curved, indented straight line, such as the shape shown. Although not shown, the lateral portion of the segment shape can be transformed into a straight line that is convex outwards. In segment forms, , , and in which the lateral portion is modified in various ways, the interior angle (1) on one side and the interior angle (2) on the other side of the lower portion can be equal or different, and the interior angle (1) on one side and the interior angle (2) on the other side of the lower portion can be any one of an acute angle, a right angle, and an obtuse angle, respectively. The width (length in the winding direction) of segment 61 may have various patterns of change from the bottom to the top. In one example, the width of segment 61 can remain uniform from bottom to top (shape ). In another example, the width of segment 61 can gradually decrease from bottom to top (shapes , , , , and ). In yet another example, the width of segment 61 can gradually decrease and then increase from bottom to top (shapes and ). In yet another example, the width of segment 61 can gradually increase and then decrease from bottom to top (shape ). In yet another example, the width of segment 61 can gradually decrease from bottom to top and then remain uniform (shape ). Although not shown, the width of segment 61 can gradually increase from bottom to top and then remain uniform. On the other hand, among the shapes of segment 61 illustrated in Figure 9, the polygonal shape with a flat top can be rotated 180 degrees. In one example, when the segment shape is rotated 180 degrees, the width of segment 61 can gradually increase from the bottom to the top. In another example, when the segment shape is rotated 180 degrees, the width of segment 61 can remain uniform from the bottom to the top and then gradually increase. In the embodiments (modifications) described above, in accordance with another aspect of this disclosure, it is possible to change the shape of segment 61 in different ways according to the area of ​​the third portion B2. For example, for a region where stress is concentrated, a round shape (e.g., semicircle, ellipse, etc.) can be applied, which is advantageous for stress distribution, and for a region where stress is relatively low, a polygonal shape (e.g., square, trapezoid, parallelogram, etc.) with as large an area as possible can be applied. In the embodiments (modifications), the segment structure of the third portion B2 can also be applied to the first portion B1. However, when the segment structure is applied to the first portion B1, a reverse forming phenomenon can occur in which the end of the first portion B1 curves towards the outer circumference when segment 61 of the third portion B2 is bent according to the radius of curvature of the core. Therefore, even if there is no segment structure in the first portion B1, or even if the segment structure is applied, it is desirable to adjust the width and / or height and / or separation pitch of segment 61 to be as small as possible to a level where reverse forming does not occur, taking into account the radius of curvature of the core. According to another aspect of the present disclosure, after the electrode 60 is wound onto the JR electrode assembly, the segments that constitute the exposed segment alignment 50 over the upper and lower portions of the JR electrode assembly can overlap in several layers along the radial direction of the JR electrode assembly to form the bending surface regions F. Figure 10 is a schematic diagram showing a cross-section of the bending surface region F formed by bending segments 61 toward the core C of the JR electrode assembly. The cross-sectional structure of the bending surface region F is shown when the alignment of segments 50 is cut in the radial direction. The bending surface region F is formed by bending segments 61 whose heights change in a stepped fashion from the core toward the outer circumference of the JR electrode assembly. In Figure 10, the cross-section of the bending surface region F is shown only on the left side, relative to the winding axis of the JR electrode assembly. The bending surface region F can be formed on either the upper or lower portion of the JR electrode assembly. Referring to Figure 10, the bending surface region F has a structure in which the segments 61 overlap in a plurality of layers in the winding axis direction. The overlap direction is the winding axis Y direction. The region is a segment-skipping region (first portion) without any segments, and the regions and are regions where the winding turns containing the groups of segments 61g arranged in the winding direction with a gap between them are located. The region is a height-variable region in which the heights of the segments 61 vary, and the region is a height-uniform region in which the segment heights are maintained uniformly up to the outer circumference of the electrode assembly. As will be described later, the lengths of the region and the region in the radial direction can be variable.On the other hand, the uncoated portion (second portion) included in at least one winding turn, including the outermost winding turn, may not include a segmented structure. In this case, the second portion may be excluded from the region. In the region, the heights of segments 61 can be changed in steps from the minimum height h1 (= hmin) to the maximum height hN (= hmax) in the region of radius r1 to rN of the JR electrode array. The height-varying regions where the heights of segments 61 vary are from r1 to rN. From radius rN to radius R of the JR electrode array, the heights of segments 61 are maintained uniformly at hN. Uniform heights means that the height deviation is within 5%. At any radius location in the region and the region, the stacking number of segments 61 varies depending on the radius location. Furthermore, the stacking number of segments 61 can vary depending on the width of the region, the minimum height (h1) and maximum height (hN-1) of the segments in the height-varying region of segments 61, and the height-change width (h) of segments 61. The stacking number of segments 61 is the number of segments that intersect an imaginary line when the imaginary line is drawn in the winding axis direction from an arbitrary radius location of the JR electrode array. Preferably, the stacking number of segments 61 at each location of the bending surface region F can be optimized according to the required weld strength of the current collector plate by adjusting the height, width (length in the winding direction) and separation pitch of the segments 61 according to the radius of the winding turn containing the segment 61. First, in the height-variable region () of the segments 61, when the minimum height (h1) of the segments is the same, it will be described through specific realizations how the stacking number of the segments 61 varies along the radial direction of the bending surface region F according to the change in the maximum height (hN-1) of the segments 61. The electrode assemblies of embodiments 1-1 to 1-7 are prepared. The electrode assemblies in these embodiments have a radius of 22 mm and a core diameter of 4 mm. The positive and negative electrodes included in the electrode assembly have the electrode structure shown in Figure 4a. The second portion B3 of the positive and negative electrodes does not contain a segment. The length of the second portion B3 is 2% to 4% of the total electrode length. The positive electrode, negative electrode, and spacer are wound using the method described in Figure 2. The number of winding turns is between 48 and 56, but the number of winding turns in these embodiments is 51. The thicknesses of the positive electrode, negative electrode, and spacer are 149 µm, 193 µm, and 13 µm, respectively.The thickness of the positive and negative electrodes includes the thickness of the active material layer. The thicknesses of the positive and negative electrode current collectors are 15 µm and 10 µm, respectively. The lengths of the positive and negative electrodes in the winding direction are 3948 mm and 4045 mm, respectively. In each embodiment, the minimum height of the segments 61 is set to 3 mm such that the height-variable region () of the segments 61 starts with a radius of 5 mm. Furthermore, in each embodiment, the heights of the segments 61 are increased by 1 mm for each 1 mm increase in the radius, and the maximum height of the segments 61 is varied from 4 mm to 10 mm. Specifically, in embodiment 1-1, the height-variable region () of segments 61 is from 5 mm to 6 mm, and the heights of segments 61 are variable from a radius of 3 mm to 4 mm. In embodiment 1-2, the height-variable region () of segments 61 is from 5 mm to 7 mm, and the heights of segments 61 are variable from 3 mm to 5 mm. In embodiment 1-3, the height-variable region () of segments 61 is from 5 mm to 8 mm, and the heights of segments 61 are variable from 3 mm to 6 mm. In embodiment 1-4, the height-variable region () of segments 61 is from 5 mm to 9 mm, and the heights of segments 61 are variable from 3 mm to 7 mm. In embodiment 1-5, the height-variable region () of segments 61 is from 5 mm to 10 mm, and the heights of segments 61 are variable from 3 mm to 8 mm. In embodiment 1-6, the height-variable region () of segments 61 is from 5 mm to 11 mm, and the heights of segments 61 are variable from 3 mm to 9 mm.In embodiment 1-7, the height-variable region () of the segments 61 ranges from 5 mm to 12 mm, and the heights of the segments 61 vary from 3 mm to 10 mm. In embodiments 1-1 to 1-7, the heights of the segments 61 are uniform from the radius corresponding to the upper limit of the height-variable region () to the outer circumference. For example, in embodiment 1-7, the heights of the segments 61 are uniform at 10 mm from a radius of 12 mm to 22 mm. On the other hand, in the electrode assembly of the comparative example, the heights of the segments 61 are maintained at a single height of 3 mm from a radius of 5 mm to a radius of 22 mm. Figure 11a shows graphs of the results of counting the number of segment stacks along the radial direction in the bending surface region F of the positive electrode formed in the upper portion of the electrode assemblies according to embodiments 1-1 to 1-7 and the comparative example. The bending surface region F is formed by bending the segments 61 included in the alignment of segments 50 toward the core of the electrode assembly JR. The bending surface region of the negative electrode also shows substantially the same results. The horizontal axis of the graph is the radius based on the center of the core, and the vertical axis of the graph is the number of segment stacks counted at each radius point, which also applies in the same way to Figures 11b and 11c, explained later. Referring to Figure 11a, the uniform stacking number region b1 of the segments is commonly shown in embodiments 1-1 to 1-7 and Comparative Example 1. The uniform stacking number region b1 is a radial region with a flattened area in each graph. The length of the uniform stacking number region b1 increases as the maximum height of the segments decreases, and the uniform stacking number region b1' in the Comparative Example is longer. On the other hand, the stacking number of segments increases as the maximum height (hN) of the segments increases. That is, when the maximum height (hN) of the segments increases such that the width of the height-variable region (h) of the segments increases, the stacking number of segments increases while the width of the uniform stacking number region b1 decreases.On the outer side of the uniform stacking number region b1, the decreasing stacking number region b2 appears, in which the stacking number of segments decreases as the radius increases. The decreasing stacking number region b2 is a radial region where the stacking number of segments decreases as the radius of the electrode array increases. The uniform stacking number region b1 and the decreasing stacking number region b2 are adjacent in the radial direction and complementary to each other. That is, when the length of one region increases, the length of the other region decreases. Furthermore, in the decreasing stacking number region b2, the stacking number decreases in proportion to the distance from the uniform stacking number region b1. From the standpoint of the segment stacking number, in embodiments 1-1 to 1-7, the segment stacking number is 10 or more in the uniform stacking number region b1. An area where the segment stacking number is 10 or more can be established as a desirable target welding area. The target welding area is a region to which at least a portion of the current collector plate can be welded. In embodiments 1-1 to 1-7, the uniform region in stacking number b1 starts from the point where the height-variable region () of the segments begins. That is, the height-variable region () starts with a radius of 5 mm and extends towards the outer circumference. In embodiments 1-1 to 1-7 and comparative example 1, for the positive electrode, Table 4 below shows the results of calculating a ratio of the length of the segment jump region (c) to the radius (b - a) of the electrode assembly excluding the core, a ratio (e / f) of the length of the stacking-number uniform region b1 to the length (f) from the point of radius (5 mm) where the stacking-number uniform region begins to the outermost point (22 mm) of the electrode assembly, a ratio (d / f) of the length of the height-variable region (d) of the segment to the length (f) from the point of radius (5 mm) where the stacking-number uniform region begins to the outermost point (22 mm) of the electrode assembly, a ratio (h) of the length of the electrode area corresponding to the segment jump region to the total length of the electrode,a ratio (i) of the length of the electrode area corresponding to the height-variable region to the total length of the electrode, and a ratio (j) of the length of the electrode area corresponding to the height-uniform region to the total length of the electrode, and the like. Except that the negative electrode shows a difference of 0.1% to 1.2% for the parameter h, the other parameters are substantially the same as those of the positive electrode. The sum of the proportions h, i, and j is slightly different from 100%. The reason is that there is a region without any segment in the second portion B3 corresponding to the uncoated core-side portion of the electrode. For example, in embodiment 1-1, there is no segment in the second portion B3 corresponding to approximately 3% of the total electrode length. In Table 4, aaf are parameters based on the length in the radial direction, and yh and i, i, and j are parameters based on the length in the electrode winding direction. Likewise, the parameters corresponding to the ratio (%) are values ​​rounded to one decimal place. These points are substantially the same in Tables 5 and 6, explained later. Looking at embodiments 1-1 to 1-7 in Table 4, the number of segment stacks ranges from 11 to 27, and the ratio (d / f) of the height-variable region (d) to the radial region f containing segments ranges from 6% to 41%. Furthermore, the ratio (e / f) of the uniform stacking number region (e) to the radial region f containing segments ranges from 47% to 82%. Additionally, the ratio (c / (b - a)) of the segment jump region (c) to the radius (b - a) of the electrode array excluding the core is 15%. Furthermore, the ratio of the length of the electrode area corresponding to the segment jump region to the total length of the electrode is 6%, the ratio of the length of the electrode area corresponding to the height-variable region to the total length of the electrode is 3% to 32%, and the ratio of the length of the electrode area corresponding to the height-uniform region to the total length of the electrode is 59% to 87%.The stacking number (g) of the uniform stacking number region is 10 or more in all embodiments 1-1 to 1-7. The uniform stacking number region (e) decreases as the height-variable region (d) of the segments increases, but the stacking number (g) of the segments increases in the uniform stacking number region (e). Preferably, the uniform stacking number region (e) in which the stacking number (g) of segments is 10 or more can be established as a target welding area. In cylindrical batteries with a form factor of 1865 or 2170, the radius of the electrode assembly is approximately 9 to 10 mm. Therefore, for a conventional cylindrical battery, as in embodiments 1-1 to 1-7, the length of the segment region (f) in the radial direction cannot be guaranteed to be 17 mm, and the length of the uniform stacking number region (e) cannot be guaranteed to be 8 to 14 mm. This is because, in a conventional cylindrical battery, when the core radius is designed to be 2 mm, which is the same as in embodiments 1-1 to 1-7, the radial region in which the segments can be arranged is substantially only 7 to 8 mm. Furthermore, in the conventional cylindrical battery, the electrode length in the winding direction is approximately 600 to 980 mm.This short electrode length is only about 15% to 24% of the electrode length (positive electrode 3948 mm, negative electrode 4045 mm) used in embodiments 1-1 to 1-7. Therefore, the numerical ranges for the parameters h, iyj cannot be easily deduced from conventional cylindrical battery design specifications. Next, when the maximum height (hN) of the segments is the same in the height-variable region (in Figure 10) of the segments, it will be explained through specific realizations how the number of stacking of the segments varies along the radial direction of the bending surface region F according to the change in the minimum height (h1) of the segments. The electrode assemblies of embodiments 2-1 to 2-5 have a radius of 22 mm and a core diameter C of 4 mm. In the height-variable region (in Figure 10) of segments 61, the minimum height (h1) is equal to 4 mm, and the maximum height (hN) varies from 6 mm to 10 mm in increments of 1 mm. Therefore, in the electrode assemblies of embodiments 2-1 to 2-5, the height-variable region (in Figure 10) of the segments has a width of 2 mm, 3 mm, 4 mm, 5 mm, and 6 mm, respectively, and the segment jump region (in Figure 10) is a radial region with a radius of 2 mm to 6 mm. The electrode assemblies of embodiments 3-1 to 3-4 have a radius of 22 mm and a core diameter C of 4 mm. In the height-variable region (in Figure 10) of segments 61, the minimum height (h1) is 5 mm, and the maximum height (hN) varies from 7 mm to 10 mm in 1 mm increments. Therefore, in the electrode assemblies of embodiments 3-1 to 3-4, the height-variable region (in Figure 10) of the segments has a width of 2 mm, 3 mm, 4 mm, and 5 mm, respectively, and the segment jump region (in Figure 10) is a radial region with a radius of 2 mm to 7 mm. The electrode assemblies of embodiments 4-1 to 4-3 have a radius of 22 mm and a core diameter C of 4 mm. In the height-variable region (in Figure 10) of segments 61, the minimum height (h1) is 6 mm, and the maximum height (hN) varies from 8 mm to 10 mm in 1 mm increments. Therefore, in the electrode assemblies of embodiments 4-1 to 4-3, the width of the height-variable region (in Figure 10) of the segments is 2 mm, 3 mm, and 4 mm, respectively, and the segment jump region (in Figure 10) is a radial region with a radius of 2 mm to 8 mm. The electrode assemblies of embodiments 5-1 to 5-2 have a radius of 22 mm and a core diameter C of 4 mm. In the height-variable region (in Figure 10) of segments 61, the minimum height (h1) is 7 mm, and the maximum height (hN) varies from 9 mm to 10 mm in 1 mm increments. Therefore, in the electrode assemblies of embodiments 5-1 to 5-2, the width of the height-variable region (in Figure 10) of the segments is 2 mm and 3 mm, respectively, and the segment jump region (in Figure 10) is a radial region with a radius of 2 mm to 9 mm. Figure 11b shows graphs that illustrate the results of counting the number of stacked segments along the radial direction in the flexural surface region F of the positive electrode formed in the upper portion of the electrode assemblies according to embodiments 2-1 to 2-5, embodiments 3-1 to 3-4, embodiments 4-1 to 4-3, and embodiments 5-1 to 5-2. The flexural surface region of the negative electrode also shows substantially the same results. In Figure 11b, graph (a) shows the result of counting the number of stacking segments along the radial direction in the bending surface region F for embodiments 2-1 to 2-5, graph (b) is for embodiments 3-1 to 3-4, graph (c) is for embodiments 4-1 to 4-3, and graph (d) is for embodiments 5-1 to 5-2. Referring to Figure 11b, the uniform stacking number region b1 of the segments is common to all embodiments. This region is a radial area within the planar region of the graph. The length of this region increases as the maximum height (hN) of the segments decreases, while the minimum height (h1) of the segments remains constant. Similarly, the length of this region increases as the minimum height (h1) of the segments decreases, while the maximum height (hN) of the segments remains constant. Furthermore, within this region, the stacking number of segments increases as the maximum height (hN) of the segments increases. In all embodiments, the decreasing stacking number region b2 is located close to this region. In all embodiments, the number of segment stacking in the uniform region with a stacking number b1 is 10 or more. Preferably, an area where the number of segment stacking is 10 or more can be established as a desirable target welding area. In the embodiments, the uniform region in stacking number b1 begins at the radius point where the height-variable region (in Figure 10) of the segments begins. In embodiments 2-1 to 2-5, the height-variable region (in Figure 10) of the segments begins at 6 mm and extends to the outer circumference. In embodiments 3-1 to 3-4, the height-variable region (in Figure 10) of the segments begins at 7 mm and extends to the outer circumference. In embodiments 4-3 to 4-3, the height-variable region (in Figure 10) of the segments begins at 8 mm and extends to the outer circumference. In embodiments 5-1 to 5-2, the height-variable region (in Figure 10) of the segments begins at 9 mm and extends to the outer circumference. Table 5 below shows the results of the calculation of various parameters for embodiments 2-1 to 2-5, embodiments 3-1 to 3-4, embodiments 4-1 to 4-3 and embodiments 5-1 to 5-2, including a ratio (e / f) of the length of the uniform stacking number region to the length from the point of radius (6 mm, 7 mm, 8 mm, 9 mm) where the uniform stacking number region begins to the outermost point (22 mm) of the electrode assembly, a ratio (d / f) of the length of the height variable region () of the segments to the length from the point of radius (6 mm, 7 mm, 8 mm, 9 mm) where the uniform stacking number region begins to the outermost point (22 mm) of the electrode assembly, and the like. Referring to embodiments 2-5, 3-4, 4-3, and 5-2 in Table 5, along with Figures 10 and 11b, the maximum height (hN) of the segments in the height-variable region () of the segments is equal to 10 mm, but the minimum height (h1) of the segments increases to 4 mm, 5 mm, 6 mm, and 7 mm in 1 mm increments, and the length of the height-variable region () decreases to 6 mm, 5 mm, 4 mm, and 3 mm in 1 mm increments. In all four embodiments, the ratio (e / f) of the uniform stacking number region is highest in embodiment 2-5 (69%) and lowest in embodiment 5-1 (31%), and the stacking numbers of the uniform stacking number regions are all equal.Based on the results shown in Table 5, when the maximum height (hN) of the segments is the same, it can be understood that as the width of the height-variable region (λ) of the segment increases due to the decrease in the minimum height (h1) of the segments, the width of the uniform stacking number region also increases proportionally. This is because, since the minimum length (h1) of the segments is smaller, the radius point where the segment begins is closer to the core, and therefore the area where the segments are stacked expands towards the core. Looking at Table 5, it can be found that the stacking number of segments ranges from 16 to 27, the ratio (d / f) of the height-variable region of the segments ranges from 13% to 38%, and the ratio (e / f) of the uniform stacking number region ranges from 31% to 69%. Furthermore, the ratio (c / (b - a)) of the segment jump region (c) to the radius (b - a) of the electrode array excluding the core ranges from 20% to 35%. Additionally, the ratio of the length of the electrode area corresponding to the segment jump region to the total electrode length ranges from 10% to 20%, the ratio of the length of the electrode area corresponding to the height-variable region to the total electrode length ranges from 6% to 25%, and the ratio of the length of the electrode area corresponding to the height-uniform region to the total electrode length ranges from 62% to 81%. In cylindrical batteries with a form factor of 1865 or 2170, the electrode assembly has a radius of approximately 9 mm to 10 mm. Therefore, unlike in the embodiments, it is not possible to ensure the length of the segment region (f) in the radial direction at the level of 13 mm to 16 mm, nor is it possible to ensure the length of the uniform stacking number region (e) where the stacking number of segments is 10 or more at the level of 5 mm to 11 mm, while ensuring the length of the segment jump region (c) at the level of approximately 4 mm to 7 mm. This is because, in the conventional cylindrical battery, when the core radius is designed to be 2 mm, which is the same as in the embodiments, the radial region in which the segments can be arranged is substantially only 7 mm to 8 mm. Furthermore, in the conventional cylindrical battery, the length of the electrode in the winding direction is approximately 600 mm to 980 mm.This short electrode length is only approximately 15% to 24% of the electrode length (positive electrode 3948 mm, negative electrode 4045 mm) in the embodiments. Therefore, the numerical ranges for the parameters h, i, and j cannot be easily deduced from the design specifications of conventional cylindrical batteries. Next, when the minimum height (h1) and the maximum height (hN) of the segments are the same in the height-variable region (of Figure 10) of the segments, it will be explained through specific embodiments how the stacking number of the segments changes according to the core diameter C of the electrode assembly along the radial direction of the bending surface region F. The electrode assemblies of embodiments 6-1 to 6-6 have a radius of 22 mm, and the radius of the core C is 4 mm. In the height-variable region (of Figure 10) of segments 61, the minimum height (h1) of the segments is 3 mm, and the maximum height (hN) of the segments varies from 5 mm to 10 mm in increments of 1 mm. Therefore, in the electrode assemblies of embodiments 6-1 to 6-6, the width of the height-variable region (of Figure 10) of the segments is 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, and 7 mm, respectively, and the segment jump region (of Figure 10) is a radial region with a radius of 4 mm to 7 mm. The electrode assemblies of embodiments 7-1 to 7-6 have a radius of 22 mm, and the radius of the core C is 2 mm. In the height-variable region (in Figure 10) of the segments 61, the minimum height (h1) of the segments is 3 mm, and the maximum height (hN) of the segments varies from 5 mm to 10 mm in increments of 1 mm. Therefore, in the electrode assemblies of embodiments 7-1 to 7-6, the height-variable region (in Figure 10) of the segments has a width of 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, and 7 mm, respectively, and the segment jump region () is entirely a radial region with a radius of 2 mm to 5 mm. Figure 11c shows graphs that illustrate the results of counting the number of stacked segments measured along the radial direction in the flex surface region F of the positive electrode formed in the upper portion of the electrode assembly according to embodiments 6-1 to 6-6 and embodiments 7-1 to 7-6. Substantially the same results appear in the flex surface region of the negative electrode. In Figure 11c, graph (a) shows the result of counting the number of stacked segments measured along the radial direction in the bending surface region F for embodiments 6-1 to 6-6, and graph (b) is for embodiments 7-1 to 7-6. Referring to Figure 11c, the uniform stacking number region b1 of the segments is common to all embodiments. The uniform stacking number region b1 is a radial region of area lana in the graph. The length of the uniform stacking number region b1 in the radial direction increases as the maximum height (hN) of the segments decreases, while the minimum height (h1) of the segments remains the same. Conversely, within the uniform stacking number region b1, the stacking number of segments increases as the maximum height (hN) of the segments increases. In the embodiments, the decreasing stacking number region b2 is identified near the uniform stacking number region b1. In all embodiments, the stacking number of segments is 10 or more in the uniform stacking number region b1. Preferably, an area where the stacking number of segments is 10 or more can be established as a desirable target welding area. In the embodiments, the uniform region in stacking number b1 starts from the radius point where the height-variable region (of Figure 10) of the segments begins. In embodiments 6-1 to 6-6, the radius where the height-variable region (of Figure 10) of the segment begins is 7 mm, and in embodiments 7-1 to 7-6, the radius where the height-variable region (of Figure 10) of the segments begins is 5 mm. Table 6 below shows the results of the calculation of various parameters for embodiments 6-1 to 6-6 and embodiments 7-1 to 7-6, including a ratio (e / f) of the length of the uniform stacking number region to the length from the point of radius (7 mm, 5 mm) where the uniform stacking number region begins to the outermost point (22 mm) of the electrode assembly, a ratio (d / f) of the length of the height variable region () of the segments to the length from the point of radius (7 mm, 5 mm) where the uniform stacking number region begins to the outermost point (22 mm) of the electrode assembly, and the like. Referring to Figure 10 and embodiments 6-6 and 7-6 in Table 6, the minimum height (h1) and maximum height (hN) of the segments in the height-variable region (e) are 3 mm and 10 mm, respectively. However, in embodiment 6-6, the core radius is 2 mm larger than in embodiment 7-6. Therefore, in embodiment 6-6, the stacking-number uniform region (e) and the segment region (f) are 2 mm smaller than those in embodiment 7-6, and the segment stacking number is the same in the stacking-number uniform region. This result stems from the difference in the core radius.Based on the results shown in Table 6, when the width of the height-variable region (δ) of the segments is the same, it can be understood that, as the core radius (a) is smaller, the ratio (d / f) of the height-variable region (δ) decreases, but the ratio (e / f) of the uniform stacking number region increases. Looking at Table 6, it can be found that the segment stacking number ranges from 13 to 27, the ratio (d / f) of the height-variable region (δ) of the segments ranges from 12% to 47%, and the ratio (e / f) of the length of the uniform stacking number region ranges from 40% to 76%. Furthermore, the ratio (c / (b - a)) of the segment jump region (c) to the radius (b - a) of the electrode array excluding the core ranges from 15% to 17%.Furthermore, the ratio of the length of the electrode area corresponding to the segment jump region to the total length of the electrode is 6%, the ratio of the length of the electrode area corresponding to the height-variable region to the total length of the electrode is 7% to 32%, and the ratio of the length of the electrode area corresponding to the height-uniform region to the total length of the electrode is 59% to 83%. For cylindrical batteries with a form factor of 1865 or 2170, the electrode array radius is approximately 9 to 10 mm. Therefore, unlike in the embodiments, the length of the segment region (f) in the radial direction is not guaranteed to be 15 to 17 mm, and at the same time, the length of the uniform stacking number region (e), where the segment stacking number is 10 or more, cannot be guaranteed to be 6 to 13 mm, while the length of the segment jump region (c) is guaranteed to be approximately 3 mm. This is because, in the conventional cylindrical battery, when the core radius is designed to be 2 to 4 mm, which is the same as in the embodiments, the radial region in which the segments can be arranged is substantially only 5 to 8 mm. Furthermore, in the conventional cylindrical battery, the length of the electrode in the winding direction is approximately 600 mm to 980 mm.This short electrode length is only approximately 15% to 24% of the electrode length (positive electrode 3948 mm, negative electrode 4045 mm) in the embodiments. Therefore, the numerical ranges for the parameters h, i, and j cannot be easily deduced from the design specifications of conventional cylindrical batteries. Considering the data in Tables 4 to 6 as a whole, the number of segment stacks can range from 11 to 27 in the uniform segment stacking region. Furthermore, the d / f ratio of the variable segment height can range from 6% to 47%. Similarly, the e / f ratio of the uniform stacking region can range from 31% to 82%. Additionally, the c / (b - a) ratio of the segment jump region length to the electrode array radius excluding the core can range from 15% to 35%. Finally, the ratio of the electrode area length corresponding to the segment jump region to the total electrode length (length in the winding direction) can range from 6% to 20%. Furthermore, the ratio of the length of the electrode area corresponding to the height-variable region of the segments to the total length of the electrode can be from 3% to 32%.Furthermore, the ratio of the length of the electrode area corresponding to the uniform height region of the segments to the total length of the electrode can be from 59% to 87%. On the other hand, the parameters described in Tables 4 to 6 may vary according to design factors including the radius (a) of the core; the radius of the electrode assembly (b); the minimum height (h1) and maximum height (hN) in the height-variable region of the segments; the width of height change (h) of the segments per 1 mm increment of the radius; the thickness of the positive electrode, the negative electrode and the separator, and the like. Therefore, in the uniform segment stacking region, the segment stacking number can range from 10 to 35. The d / f ratio of the segment height-variable region can range from 1% to 50%. Similarly, the e / f ratio of the uniform stacking region can range from 30% to 85%. Furthermore, the c / (b - a) ratio of the segment jump region length to the electrode array radius excluding the core can range from 10% to 40%. Additionally, the ratio of the electrode area length corresponding to the segment jump region to the total electrode length (length in the winding direction) can range from 1% to 30%. Similarly, the ratio of the electrode area length corresponding to the segment height-variable region to the total electrode length can range from 1% to 40%.Furthermore, the ratio of the length of the electrode area corresponding to the uniform height region of the segments to the total length of the electrode can be expanded from 50% to 90%. In the flex surface region F formed in the upper and lower portions of the electrode assembly, the uniform stacking number region can be used as the target welding area of ​​the current collector plate. Preferably, the welding region of the current collector plate overlaps the uniform stacking number region by at least 50% in the radial direction of the electrode assembly, and a higher overlap ratio is preferred. Preferably, the resting area of ​​the current collector plate's solder region that does not overlap with the uniform stacking number region can overlap with the stacking number decrease region adjacent to the uniform stacking number region in the radial direction. More preferably, the resting area of ​​the current collector plate solder region that does not overlap with the uniform stacking number region may overlap with the area of ​​the decreasing stacking number region in which the stacking number of segments is 10 or more. If the current collector plate is welded to an area where the segment stacking number is 10 or more, it is desirable in terms of weld strength and to avoid damage to the separator or the active material layer during welding. This is particularly useful when welding the current collector plate using a high-power laser with high transmission characteristics. If the stacking-number uniform region where 10 or more of the segments and the current collector plate are stacked is laser welded, even if the laser output is increased to improve weld quality, the stacking-number uniform region absorbs most of the laser energy to form a weld bead, so it is possible to prevent the laser from damaging the separator and the active material layer below the bending surface region F. Furthermore, because the segment stacking number is 10 or more in the laser-irradiated area, weld beads with sufficient volume and thickness are formed. Therefore, adequate weld strength can be ensured, and the interfacial weld strength can be reduced to a level suitable for rapid loading. When welding the current collector plate, the laser output can be determined by the desired welding resistance between the bending surface region F and the current collector plate. The welding resistance increases in proportion to the stacking number of segments. This is because the volume of the weld beads formed by the laser increases with the stacking number. The weld beads form as the current collector plate material and the segment material fuse together. Therefore, when the weld bead volume is large, the current collector plate and the bending surface region are more tightly coupled, and the contact resistance of the weld interfacial surface decreases. Preferably, the welding strength may be 2 kgf / cm² or more, more preferably 4 kgf / cm² or more. Alternatively, the welding strength may be set preferably at 8 kgf / cm² or less, more preferably 6 kgf / cm² or less. When the welding strength meets the above numerical range, even if severe vibration is applied to the electrode assembly along the winding axis direction and / or the radial direction, the properties of the weld interfacial surface are not deteriorated, and the weld interfacial surface strength may be reduced because the volume of the weld beads is sufficient. The laser power required to meet the welding strength requirement differs depending on the laser equipment, and can be appropriately adjusted in the range of 250W to 320W or in the range of 40% to 90% of the maximum laser output provided by the equipment. The weld strength can be defined as the tensile force (kgf / cm²) per unit area of ​​the current collector plate when the plate begins to separate from the flexural surface region F. Specifically, after the current collector plate has been fully welded, a tensile force can be applied to it while gradually increasing its magnitude. When the tensile force exceeds a threshold value, the segment begins to separate from the weld interfacial surface. At this point, the value obtained by dividing the tensile force applied to the current collector plate by the plate's area corresponds to the weld strength. In the bending surface region F, the segments are stacked in a plurality of layers, and according to the above embodiments, the number of stacked segments can increase from a minimum of 10 to a maximum of 35. The thickness of the positive electrode current collector can be selected from 10 µm to 25 µm, and the thickness of the negative electrode current collector can be selected from 5 µm to 20 µm. Therefore, the bending surface region F of the positive electrode can include an area where the total stacking thickness of the segments is from 100 µm to 875 µm. Furthermore, the bending surface region F of the negative electrode can include an area where the total stacking thickness of the segments is from 50 µm to 700 µm. Figure 12 is a top plan view of the electrode assembly showing the uniform stacking number region b1 and the decreasing stacking number region b2 in the bending surface region F formed by the segments 61 included in the alignment of segments 50 according to an embodiment of the present disclosure. Referring to Figure 12, the bending surface region F of segments 61 is formed by bending the segments 61 included in the alignment of segments 50 toward the core C of the JR electrode assembly. In Figure 12, the area between two circles indicated by the dashed line corresponds to the stacking-number uniform region b1 in which the stacking number of segments 61 is 10 or more, and the area outside the stacking-number uniform region b1 corresponds to the stacking-number decreasing region b2. In one example, when the current collector plate (Pc) is welded to the bending surface region F formed by bending segments 61 of the segment alignment 50, a weld pattern (Wp) is generated on the surface of the current collector plate (Pc). The weld pattern (Wp) can have an ordered arrangement of line patterns or dot patterns. The weld pattern (Wp) corresponds to the weld region and can overlap by 50% or more with the uniform stacking number region b1 of the segments along the radial direction. Therefore, part of the weld pattern (Wp) can be included in the uniform stacking number region b1, and the remainder of the weld pattern (Wp) can be included in the decreasing stacking number region b2 outside the uniform stacking number region b1. Of course, the entire weld pattern (Wp) can overlap with the uniform stacking number region b1. Preferably, the edge of the portion where the current-collecting plate (Pc) contacts the bending surface region F can cover the end of segment 61 bent toward the core C in the last winding turn. In this case, because the weld pattern (Wp) is formed in a state where the segments 61 are pressed by the current-collecting plate (Pc), the current-collecting plate (Pc) and the bending surface region F are tightly coupled. As a result, because the segments 61 stacked in the winding axis direction are in close contact with each other, the resistance at the weld interfacial surface can be lowered, and lifting of the segments 61 can be prevented. On the other hand, the bending direction of the segments can be opposite to that described above. That is, the segments can bend from the core toward the outer circumference. In this case, the pattern in which the heights of the segments 61 included in the group of segments 61g change along the winding direction (X-axis direction) can be opposite to that of the embodiments (modifications) described above. For example, the heights of the segments 61 can decrease gradually from the core toward the outer circumference. Likewise, the structure applied to the first portion B1 and the structure applied to the second portion B3 can be interchanged.Preferably, the height change pattern can be designed so that the heights of segments 61 are gradually decreased from the core towards the outer circumference, but when segment 61 closest to the outer circumference of the electrode assembly bends towards the outer circumference, the end of segment 61 does not protrude beyond the outer circumference of the electrode assembly. The electrode structure of the above embodiments (modifications) may be applied to at least one of the first and second electrodes having different polarities included in the gypsy-arm type electrode assembly. Furthermore, when the electrode structure of the above embodiments (modifications) is applied to any one of the first and second electrodes, the conventional electrode structure may be applied to the other. Additionally, the electrode structures applied to the first and second electrodes may not be identical but may differ from each other. For example, when the first electrode and the second electrode are a positive electrode and a negative electrode, respectively, any one of the above embodiments (modifications) can be applied to the first electrode and the conventional electrode structure (see Figure 1) can 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, any one of the above embodiments (modifications) can be selectively applied to the first electrode and any one of the above embodiments (modifications) can be selectively applied to the second electrode. In this disclosure, a coated positive electrode active material over the positive electrode and a coated negative electrode active material over the negative electrode may employ any active material known in the art without limitation. In one example, the active positive electrode material may include an alkali metal compound expressed by a general formula A (AxMy) O2+z (A includes at least one element from Li, Na and K; M includes at least one element selected from Ni, Co, Mn, Ca, Mg, Al, Ti, Si, Fe, Mo, V, Zr, Zn, Cu, Al, Mo, Sc, Zr, Ru and Cr; x 0, 1 x + y 2.- 0, 1 z 2; and the stoichiometric coefficients x, yyz are selected such that the compound maintains electrical neutrality). In another example, the active positive electrode material may be an alkali metal compound xLiM1O2- (1-x) Li2M2O3 disclosed in documents US6,677,082, US6,680,143, and others, wherein M1 includes at least one element having an average oxidation state of 3; M2 includes at least one element having an average oxidation state of 4; and 0 x 1). In yet another example, the active positive electrode material may be lithium metal phosphate expressed by a general formula LiaM1xFe1-xM2yP1-yM3zO4-z (M1 includes at least one element selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg, and Al; M2 includes at least one element selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg, Al, As, Sb, Si, Ge, V, and S; M3 includes a halogen element optionally including F; 0 < a 2, 0 x 1, 0 y < 1, 0 z < 1; the stoichiometric coefficients a, x, y, and z are selected such that the compound maintains electrical neutrality), or Li3M2 (PO4) 3 (M includes at least one element selected from Ti, Si, Mn, Fe, Co, V, Cr, Mo, Ni, Al, Mg and Al) . Preferably, the active material of the positive electrode may include primary particles and / or secondary particles in which the primary particles are aggregated. In one example, the active material of the negative electrode can be carbon, lithium metal or lithium metal compound, silicon or silicon compound, tin or tin compound, or similar materials. Metal oxides such as TiO2 and SnO2 with a potential of less than 2 V can also be used as the active material of the negative electrode. For the carbon material, low-crystallization carbon, high-crystallization carbon, or similar materials can be used. The separator may employ a porous polymer film, for example, a porous polymer film made of a polyolefin-based polymer such as ethylene homopolymer, propylene homopolymer, ethylene / butene copolymer, ethylene / hexene copolymer, ethylene / methacrylate copolymer, or similar materials, or laminates thereof. Alternatively, the separator may employ a common porous nonwoven fabric, for example, a nonwoven fabric made of high-melting-point fiberglass, polyethylene terephthalate fiber, or similar materials. At least one surface of the separator may include a coating layer of inorganic particles. It is also possible that the separator itself may be made of an inorganic coating layer. The particles that make up the coating layer may have a structure bonded with a binder such that interstitial volumes exist between adjacent particles. Inorganic particles can be made from an inorganic material having a dielectric constant of 5 or more. Inorganic particles can include at least one material selected from the group consisting of Pb(Zr,Ti)O3(PZT), Pb1-xLaxZr1-yTiyO3(PLZT), PB(Mg3Nb2 / 3)O3, PbTiO3(PMN-PT), BaTiO3, hafnia(HfO2), SrTiO3, TiO2, Al2O3, ZrO2, SnO2, CeO2, MgO, CaO, ZnO, and Y2O3. Hereafter in this document, the structure of the electrode assembly will be described in detail according to an embodiment of this disclosure. Figure 13 is a cross-sectional view of a gypsy arm type electrode assembly 100 in which the electrode 60 according to one embodiment is applied to a first electrode (positive electrode) and a second electrode (negative electrode), taken along the Y-axis direction (the winding axis direction) to pass through the segment alignment 50. Referring to Figure 13, the uncoated portion 43a of the first electrode includes a first portion B1 adjacent to the core of the electrode assembly 100, a second portion B3 adjacent to the surface of the outer circumference of the electrode assembly 100, and a third portion B2 interposed between the first portion B1 and the second portion B3. The height of the uncoated portion of the first portion B1 is relatively less than the height of segments 61. Furthermore, in the third portion B2, the bending length of the innermost segment 61 is equal to or less than the radial length R of the first portion B1. The bending length H corresponds to the distance from the point where the innermost segment 61 is bent to the top of segment 61. In a modification, the bending length H may be less than the sum of the radial length R of the winding turn formed by the first portion B1 and 10% of the radius of the core 102. Therefore, even if the segments 61 included in the segment alignment 50 are bent, 90% or more of the diameter of the core 102 of the electrode assembly 100 is exposed. The core 102 is a cavity in the center of the electrode assembly 100. If the core 102 is not blocked, there is no difficulty in the electrolyte injection process, and the electrolyte injection efficiency is improved. Furthermore, by inserting a welding template through the core 102, a welding process between the current collector plate of the negative (or positive) electrode and the battery housing (or rivet terminal) can be easily performed. The height of the uncoated portion of the second portion B3 is relatively less than the height of segment 61. Therefore, while the flange portion of the battery housing is pressed close to the winding turn of the second portion B3, it is possible to prevent an internal short circuit from occurring when the flange portion and the upper edge of the electrode assembly 100 come into contact with each other. In one modification, the second portion B3 may include segments 61 that form the alignment of segments 50, and the heights of the segments 61 in the second portion B3 may decrease gradually or in a stepped fashion, unlike what is shown in Figure 13. Furthermore, in Figure 13, the heights of the segments 61 in the alignment of segments 50 are the same along a portion of the outer circumference. However, the heights of the segments 61 in the alignment of segments 50 may increase gradually or in a stepped fashion from the boundary between the first portion B1 and the third portion B2 to the boundary between the third portion B2 and the second portion B3. In the alignment of segments 50, the region where the heights of the segments 61 change corresponds to the height-variable region (in Figure 10) of the segment. The second uncoated portion 43b has the same structure as the first uncoated portion 43a. In a modification, the second uncoated portion 43b may have a conventional electrode structure or an electrode structure of other embodiments (modifications). The end 101 of the segments 61 included in the segment alignment 50 can be bent in the radial direction of the electrode assembly 100, for example, from the outer circumference toward the core. At this point, the uncoated portions of the first segment B1 and the second segment B3 are not substantially bent. Because the alignment of segments 50 includes a plurality of segments 61 aligned in the radial direction, the bending stress is relieved to prevent tearing or abnormal deformation of the uncoated portions 43a, 43b near the bending point. Furthermore, when the width and / or height and / or spacing of the segments 61 are adjusted according to the numerical range of the aforementioned embodiment, the segments 61 bend toward the core and overlap in several layers sufficiently to ensure adequate weld strength, and no void (hole) is formed in the bending surface region F. Figure 14 is a cross-sectional view of an electrode assembly 110 according to yet another embodiment of the present disclosure, taken along the Y-axis direction (the winding axis direction) to pass through the segment alignment 50. Referring to Figure 14, the electrode assembly 110 has substantially the same configuration as the electrode assembly 100 in Figure 13, except that the segments 61 forming the segment alignment 50 are also included in the second portion B3 and the height of segment 61 of the second portion B3 is substantially identical to the height of the outermost segment 61 of the third portion B2. In electrode assembly 110, the height of the uncoated portion of the first segment B1 is relatively less than the height of the segments 61 included in segment alignment 50. Furthermore, in segment alignment 50, the bending length H of the innermost segment 61 is equal to or less than the radial length R of the winding turns formed by the first segment B1. Preferably, the winding turns formed by the first segment B1 can be the segment-skipping region (in Figure 10) without segments. In a modification, the bending length H can be less than the sum of the radial length R of the winding turns formed by the first segment B1 and 10% of the core radius 112. Therefore, even if the segments 61 included in the segment alignment 50 are bent, 90% or more of the diameter of the core 112 of the electrode assembly 110 is exposed. If the core 112 is not blocked, there is no difficulty in the electrolyte injection process, and the electrolyte injection efficiency is improved. Furthermore, the welding process between the current collector plate of the negative electrode (or positive electrode) and the battery housing (or rivet terminal) can be easily performed by inserting a welding template through the core 112. In one modification, the structure in which the heights of the segments 61 included in the alignment of segments 50 increase gradually or in steps from the core towards the outer circumference can be extended to the winding turns formed by the second portion B3. In this case, the heights of the segments 61 included in the alignment of segments 50 can increase gradually or in steps from the boundary between the first portion B1 and the third portion B2 to the outermost surface of the electrode assembly 110. The second uncoated portion 43b has the same structure as the first uncoated portion 43a. In a modification, the second uncoated portion 43b may have a conventional electrode structure or an electrode structure of other embodiments (modifications). The end 111 of the segments 61 included in the segment alignment 50 can be bent in the radial direction of the electrode assembly 110, for example, from the outer circumference toward the core. At this point, the uncoated portion of the first segment B1 is not substantially bent. Because the alignment of segments 50 includes a plurality of segments 61 arranged in the radial direction, the bending stress is relieved, making it possible to avoid tearing or abnormal deformation of the uncoated portions 43a, 43b near the bending point. Furthermore, when the width and / or height and / or spacing of the segments 61 are adjusted according to the numerical intervals of the preceding embodiment, the segments 61 bend toward the core and overlap in several layers sufficiently to ensure adequate weld strength, and no void (gap) is formed in the bending surface region. Figure 15 is a cross-sectional view showing the electrode assembly 120 according to yet another embodiment of the present disclosure, taken along the Y-axis direction (the winding axis direction) through the alignment of segments 50. Referring to Figure 15, the electrode assembly 120 is substantially identical to the electrode assembly 100 in Figure 13, except that the heights of the segments 61 included in the alignment of segments 50 have a pattern of gradually increasing or stepping up and then decreasing. The radial region in which the heights of the segments 61 change can be considered as the height-variable region (in Figure 10) of the segments. Even in this case, the height-variable region of the segments 61 can be designed such that the uniform stacking-number region in which the stacking number of the segments 61 is 10 or more occurs within the desirable numerical range described above in the flexural surface region F formed by bending the segments 61. In the electrode assembly 120, the height of the uncoated portion of the first segment B1 is relatively less than the height of the segments 61. Furthermore, the bending length H of the segment 61 closest to the core 122 is equal to or less than the radial length R of the winding turns formed by the first segment B1. The region corresponding to the winding turns formed by the first segment B1 corresponds to the segment skip region (in Figure 10) without any segments. In a modification, the bending length H can be less than the sum of the radial length R of the winding turns formed by the first segment B1 and 10% of the radius of the core 122. Therefore, even if the segments 61 included in the segment alignment 50 are bent toward the core, 90% or more of the core diameter 122 of the electrode assembly 120 is exposed. If the core 122 is not blocked, there is no difficulty in the electrolyte injection process, and the electrolyte injection efficiency is improved. Furthermore, by inserting a welding template through the core 122, the welding process can be easily performed between the current collector plate of the negative electrode (or positive electrode) and the battery housing (or rivet terminal). Furthermore, the height of the uncoated portion of the second portion B3 is relatively less than the heights of segments 61, and preferably, segment 61 may not be formed in the second portion B3. Therefore, it is possible to avoid the phenomenon of the flange portion and the edge of the electrode assembly 120 coming into contact with each other and causing an internal short circuit when the flange portion of the battery housing is pressed close to the winding turns formed by the second portion B3. In one modification, the second portion B3 may include segments that form the segment alignment 50, and the height of the segments of the second portion B3 may decrease gradually or in steps toward the outer circumference. The second uncoated portion 43b has the same structure as the first uncoated portion 43a. In a modification, the second uncoated portion 43b may have a conventional electrode structure or an electrode structure of other embodiments (modifications). The ends 121 of the segments 61 included in the segment alignment 50 can be bent from the outer circumference of the electrode assembly 120 toward the core. At this time, the uncoated portions of the first portion B1 and the second portion B3 are not substantially bent. Because the alignment of segments 50 includes a plurality of segments 61 arranged in the radial direction, the bending stress is relieved to prevent the uncoated portions 43a, 43b from tearing or abnormally deforming. Furthermore, when the width and / or height and / or spacing of the segments 61 are adjusted according to the numerical range of the preceding embodiment, the segments 61 bend toward the core and overlap in several layers sufficiently to ensure adequate weld strength, and no void (hole) is formed in the bending surface region F. Figure 16 is a cross-sectional view showing the electrode assembly 130 according to yet another embodiment of the present disclosure, taken along the Y-axis direction (the winding axis direction) to pass through the segment alignment 50. Referring to Figure 16, the electrode assembly 130 is substantially identical to the electrode assembly 120 of Figure 15, except that the second portion B3 includes the segments 61 that form the alignment of segments 50 and the height of segments 61 has a gradual or stepped decrease pattern from the boundary point of the second portion B3 and the third portion B2 towards the outermost surface of the electrode assembly 130. In the electrode assembly 130, the height of the uncoated portion of the first segment B1 is relatively less than the height of the segments 61. Furthermore, the bending length H of the segment 61 closest to the core 132 is equal to or less than the radial length R of the winding turns formed by the first segment B1. The winding turns formed by the first segment B1 correspond to the segment-skipping region (in Figure 10) without any segments. In a modification, the bending length H can be less than the sum of the radial length R of the winding turns formed by the first segment B1 and 10% of the radius of the core 132. Therefore, even if the segments 61 included in the segment alignment 50 are bent toward the core, 90% or more of the core diameter 132 of the electrode assembly 130 is exposed. If the core 132 is not blocked, there is no difficulty in the electrolyte injection process, and the electrolyte injection efficiency is improved. Furthermore, by inserting a welding template through the core 132, the welding process can be easily performed between the current collector plate of the negative electrode (or positive electrode) and the battery housing (or rivet terminal). The second uncoated portion 43b has the same structure as the first uncoated portion 43a. In a modification, the second uncoated portion 43b may have a conventional electrode structure or the electrode structure of other embodiments (modifications). The ends 131 of the segments 61 included in the segment alignment 50 can be bent from the outer circumference of the electrode assembly 130 toward the core. At this point, the uncoated portion of the first segment B1 is not substantially bent. Because the alignment of segments 50 includes a plurality of segments 61 arranged in the radial direction, the bending stress is relieved to prevent the uncoated portions 43a, 43b near the bending point from tearing or abnormally deforming. Furthermore, when the width and / or height and / or spacing of the segments 61 are adjusted according to the numerical range of the preceding embodiment, the segments 61 bend toward the core and overlap in several layers sufficiently to ensure adequate weld strength, and no void (hole) is formed in the bending surface region F. On the other hand, in the previous embodiments (modifications), the ends of the segments 61 included in the segment alignment 50 can be bent from the core toward the outer circumference. In this case, it is preferable that the winding turns formed by the second portion B3 be designed as the segment jump region (in Figure 10) without any segment and without being bent toward the outer circumference. Furthermore, the radial width of the winding turns formed by the second portion B3 can be equal to or greater than the bending length of the segment on the outermost side. In this case, when the outermost segment is bent toward the outer circumference, the end of the bent portion does not protrude onto the inner surface of the battery housing beyond the outer circumference of the electrode assembly.Furthermore, the structural change pattern of the segments included in the 50-segment alignment can be the opposite of the previous embodiments (modifications). For example, the segment heights can increase in a stepped or gradual manner from the outer circumference toward the core. That is, by sequentially arranging the segment jump region (in Figure 10), the height-variable region (in Figure 10), and the height-uniform region (in Figure 10) from the outer circumference of the electrode array toward the core, in the bending surface region F, the stacking-number-uniform region, where the segment stacking number is 10 or more, can appear within a desirable numerical range. Various electrode array structures according to an embodiment of the present disclosure can be applied to a cylindrical gypsy arm type battery. Preferably, the cylindrical battery can be, for example, a cylindrical battery whose form factor ratio (defined as a value obtained by dividing the diameter of the cylindrical battery by the height, in particular, a diameter () to height (H) ratio) is greater than approximately 0.4. In the present case, the form factor means a value that indicates the diameter and height of a cylindrical battery. Preferably, the cylindrical battery may have a diameter of 35 mm or more, preferably from 40 mm to 50 mm. The cylindrical battery may have a height of 70 mm or more, preferably from 75 mm to 90 mm. The cylindrical battery according to an embodiment of this disclosure may be, for example, a 46110 battery, a 4875 battery, a 48110 battery, a 4880 battery, or a 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. When an electrode assembly with a flangeless structure is applied to a cylindrical battery with a form factor ratio greater than 0.4, the radial stress applied when the uncoated portion is bent is large, such that the uncoated portion can easily tear. Furthermore, when welding the current collector plate to the bending surface region of the uncoated portion, it is necessary to sufficiently increase the number of stacked layers of the uncoated portion in the bending surface region to ensure adequate weld strength and reduce resistance. This requirement can be achieved by the electrode and electrode assembly according to the embodiments (modifications) of this disclosure. A battery according to an embodiment of the present disclosure may be an approximately cylindrical battery, the diameter of which is approximately 46 mm, the height of which is approximately 110 mm, and the form factor ratio of which is 0.418. A battery according to another embodiment can be an approximately cylindrical battery, whose diameter is approximately 48 mm, the height is approximately 75 mm and the form factor ratio is 0.640. A battery according to another embodiment may be an approximately cylindrical battery with a diameter of approximately 48 mm, a height of approximately 110 mm, and a form factor ratio of 0.436. A battery according to another embodiment may be an approximately cylindrical battery with a diameter of approximately 48 mm, a height of approximately 80 mm, and a form factor ratio of 0.600. A battery according to yet another embodiment may be an approximately cylindrical battery with a diameter of approximately 46 mm, a height of approximately 80 mm, and a form factor ratio of 0.575. Conventionally, batteries having a form factor ratio of approximately 0.4 or less have been used. That is, conventionally, for example, 1865 batteries, 2170 batteries, etc., were used.The 1865 battery has a diameter of approximately 18 mm, a height of approximately 65 mm, and a form factor ratio of 0.277. The 2170 battery has a diameter of approximately 21 mm, a height of approximately 70 mm, and a form factor ratio of 0.300. Hereafter in this document, the cylindrical battery will be described in detail according to an embodiment of this disclosure. Figure 17 is a cross-sectional view showing a cylindrical battery 190 according to an embodiment of the present disclosure, taken along the Y-axis direction to pass through the bending surface region F (Figure 6a) of the segments included in the segment alignment 50 (Figure 6a). Referring to Figure 17, the cylindrical battery 190 according to an embodiment of the present disclosure includes an electrode assembly 110 having a first electrode, a separator, and a second electrode, a battery housing 142 for housing the electrode assembly 110, and a sealing body 143 for sealing an open end of the battery housing 142. The battery housing 142 is a cylindrical container with an opening at the top. The battery housing 142 is made of a conductive metal material such as aluminum, steel, or stainless steel. A nickel coating may be formed on the surface of the battery housing 142. The battery housing 142 houses the electrode assembly 110 in the interior space through the opening at the top and also contains the electrolyte. The electrolyte can be a salt that has a structure like A+B-. In the present case, A+ includes an alkali metal cation such as Li+, Na+ or K+, or a combination thereof, and B- includes at least one anion selected from the group consisting of F-, Cl-, Br-, I-, NO3-, N(CN)2-, BF4-, ClO4-, AlO4-, AlCl4-, PF6-, SbF6-, AsF6-, BF2C2O4-, BC4O8-, (CF3)2PF4-, (CF3)3PF3-, (CF3)4PF2-, (CF3)5PF-, (CF3)6P-, CF3SO3-, C4F9SO3-, CF3CF2SO3-, (CF3SO2)2N-, (FSO2)2N-, CF3CF2(CF3)2CO-, (CF3SO2)2CH-, (SF5) 3C-, (CF3SO2) 3C-, CF3 (CF2) 7SO3-, CF3CO2-, CH3CO2-, SCN- and (CF3CF2SO2) 2N-. The electrolyte can also be dissolved in an organic solvent. The organic solvent may employ propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), dimethyl sulfoxide, acetonitrile, dimethoxyethane, dietoxyethane, tetrahydrofuran, N-methyl-2-pyrrolidone (NMP), ethyl methyl carbonate (EMC), β-butyrolactone, or a mixture thereof. The electrode assembly 110 can be in a jelly-roll form. The electrode assembly 110 can be manufactured by rolling a laminate formed by sequentially rolling a lower separator, a first electrode, an upper separator, and a second electrode at least once, based on the winding center C, as shown in Figure 2. The first and second electrodes have opposite polarities. That is, if one has a positive polarity, the other has a negative polarity. At least one of the first and second electrodes may have an electrode structure according to the above embodiments (modifications). Furthermore, the other of the first and second electrodes may have a conventional electrode structure or an electrode structure according to the embodiments (modifications). The electrode pair included in electrode assembly 110 is not limited to one pair; two or more pairs of electrodes may be included. In the upper and lower portions of the electrode assembly 110, as shown in Figures 6a and 7a, the alignment of segments 50 (see Figures 6a and 7a) is formed by the segments included in the first uncoated portion 146a of the first electrode and the second uncoated portion 146b of the second electrode, respectively. The segments included in the segment alignment 50 are bent in the radial direction of the electrode assembly 110, for example, from the outer circumference towards the core, to form a bending surface region F. The first portion B1 has a lower height than the other portion and corresponds to the segment jump region a1 without any segments, so it does not bend towards the core. Preferably, the flexing surface region F can include the segment jump region a1, the height-variable region a2 of the segments, and the height-uniform region a3 of the segments from the core to the outer circumference. As shown in Figures 11a, 11b, and 11c, the bending surface region F includes a stacking number uniform region b1 that has a stacking number of 10 or more adjacent to the segment jump region a1. The flexural surface region F may also include a stacking number decrease region b2 adjacent to the outer circumference of the electrode assembly 110, where the stacking number of segments decreases toward the outer circumference. Preferably, the stacking number uniform region b1 may be established as a target welding area. In the bending surface region F, the preferred numerical intervals of the ratio (a2 / c) of the height-variable region a2 of the segments to the radial region c containing segments, the ratio (b1 / c) of the stacking-number uniform region b1 of the segments, and the ratio of the area of ​​the stacking-number uniform region b1 to the area of ​​the bending surface region F have already been described above and will therefore not be described again. The first current collector plate 144 can be laser welded to the bending surface region F of the first uncoated portion 146a, and the second current collector plate 145 can be laser welded to the bending surface region F of the second uncoated portion 146b. The welding method can be substituted by ultrasonic welding, resistance welding, spot welding, and the like. Preferably, an area of ​​50% or more of the weld regions W of the first current collector plate 144 and the second current collector plate 145 may overlap with the uniform stacking number region b1 of the bending surface region F. Optionally, the remaining area of ​​the weld region W may overlap with the decreasing stacking number region b2 of the bending surface region F. In terms of high weld strength, low weld interfacial surface strength, and avoidance of damage to the separator or the active material layer, it is preferable for the entire weld region W to overlap with the uniform stacking number region b1. Preferably, in the uniform stacking number region b1 and, optionally, the decreasing stacking number region b2 that overlaps with the welding region W, the segment stacking number can be from 10 to 35. Optionally, when the stacking number of segments in the stacking number decrease region b2 overlapping the welding region W is less than 10, the laser output for the stacking number decrease region b2 can be lower than the laser output for the stacking number uniform region b1. That is, when the welding region W overlaps both the stacking number uniform region b1 and the stacking number decrease region b2, the laser output can be varied according to the stacking number of segments. In this case, the welding strength of the stacking number uniform region b1 can be higher than the welding strength of the stacking number decrease region b2. In the flex surface region F formed over the upper and lower portions of the electrode assembly 110, the radial length of the jump region of segment a1 and / or the variable height region of segment a2 and / or the uniform height region of segment a3 may be the same or different. Furthermore, the bending surface region F formed on the upper and lower portions of electrode array 110 can form a symmetrical structure with respect to a plane. Therefore, when the bending surface region F on the upper portion is projected onto the bending surface region F on the lower portion, they can substantially overlap. In the electrode assembly 110, the height of the uncoated portion of the first segment B1 is relatively less than the height of the other segments. Furthermore, as shown in Figure 14, the bending length H of the segment closest to the core is less than the sum of the radial length R of the winding turns formed by the first segment B1 and 10% of the core radius 112. Therefore, even if the segments included in the segment alignment 50 are bent towards the core, 90% or more of the core diameter 112 of the electrode assembly 110 can be exposed. If the core 112 is not blocked, there is no difficulty in the electrolyte injection process, and the electrolyte injection efficiency is improved. Furthermore, the welding process between the second current collector plate 145 and the battery housing 142 can be easily performed by inserting a welding template through the core 112. If the width and / or height and / or separation pitch of the segments are adjusted to satisfy the numerical range of the previous embodiment, when the segments are bent, the segments overlap in several layers sufficient to ensure sufficient weld strength, and no empty hole (void) is formed in the bending surface region F. Preferably, the first current-collecting plate 144 and the second current-collecting plate 145 can have outer diameters that cover the end of the segment 61 (Figure 12) bent into the last winding turn of the first and second electrodes. In this case, welding is possible in a state where the segments forming the bending surface region F are pressed uniformly by the current-collecting plate, and the tightly stacked state of the segments can be well maintained even after welding. The tightly stacked state means a state where there is substantially no gap between the segments, as shown in Figure 10. The tightly stacked state helps to lower the resistance of the cylindrical battery 190 to a level suitable for fast charging (e.g., 4 milliohms) or less. The sealing body 143 may include a cover plate 143a, a first gasket 143b to provide airtightness between the cover plate 143a and the battery housing 142 and having insulation, and a connection plate 143c electrically and mechanically coupled to the cover plate 143a. The cap plate 143a is a component made of a conductive metal material and covers the opening at the top of the battery housing 142. The cap plate 143a is electrically connected to the flex surface region F of the first electrode and is electrically insulated from the battery housing 142 by means of the first gasket 143b. Consequently, the cap plate 143a can function as the first electrode (e.g., positive electrode) of the cylindrical battery 190. The cover plate 143a is placed over the flanged portion 147 formed on the battery housing 142 and secured by a crimp portion 148. Between the cover plate 143a and the crimp portion 148, the first gasket 143b may be interposed to ensure airtightness of the battery housing 142 and electrical insulation between the battery housing 142 and the cover plate 143a. The cover plate 143a may have a projection 143d extending upwards from its center. Battery housing 142 is electrically connected to the flex surface region F of the second electrode. Therefore, battery housing 142 has the same polarity as the second electrode. If the second electrode has negative polarity, battery housing 142 also has negative polarity. The battery housing 142 includes the flange portion 147 and the crimp portion 148 on its upper part. The flange portion 147 is formed by press-fitting the periphery of the outer circumferential surface of the battery housing 142. The flange portion 147 prevents the electrode assembly 110 housed inside the battery housing 142 from escaping through the opening at the top of the battery housing 142, and can function as a support portion on which the sealing body 143 is placed. The second portion B3 of the first electrode may not include a segment, but it may be notched into the same structure as the first portion B1. Preferably, the inner circumference of the flange portion 147 may be separated by a predetermined interval from the winding turns formed by the second portion B3 of the first electrode. This is because the second portion B3 is notched like the first portion B1. More specifically, the lower end of the inner circumference of the flange portion 147 is separated by a predetermined interval from the winding turns formed by the second portion B3 of the first electrode. Furthermore, because the uncoated portion of the second portion B3 has a low height, the winding turns of the second portion B3 are not substantially affected even when the battery housing 142 is press-fitted to the outside to form the flange portion 147.Therefore, the winding turns of the second portion B3 are not pressed by other components such as the flange portion 147 and thus partial deformation of the electrode assembly 110 is avoided, thereby preventing a short circuit inside the cylindrical battery 190. Preferably, when the press-fit depth of the flange portion 147 is defined as D1 and the radial length from the inner circumference of the battery housing 142 to the boundary point between the second portion B3 and the third portion B2 is defined as D2, the relational expression D1 D2 can be satisfied. In this case, when the battery housing 142 is press-fitted to form the flange portion 147, it is possible to substantially prevent damage to the winding turns formed by the second portion B3. The crimp portion 148 is formed over the flange portion 147. The crimp portion 148 has an extended and folded shape to cover the outer circumference of the cap plate 143a disposed over the flange portion 147 and a portion of the top surface of the cap plate 143a. The cylindrical battery 190 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-collecting plate 144 is attached to the upper portion of the electrode assembly 110. The first current-collecting plate 144 is made of a conductive metal material such as aluminum, copper, steel, nickel, etc., and is electrically connected to the bending surface region F of the first electrode. The electrical connection can be made by welding. A conductor 149 can be connected to the first current-collecting plate 144. The conductor 149 can extend upward above the electrode assembly 110 and be attached to the connecting plate 143c or directly to the lower surface of the cover plate 143a. The conductor 149 can be connected to other components by welding. Preferably, the first current-collecting plate 144 can be formed in one piece with the conductor 149. In this case, the conductor 149 can have an elongated plate shape extending outwards from near the center of the first current-collecting plate 144. The first current-collecting plate 144 and the bending surface region F of the first electrode can be joined, for example, by laser welding. Laser welding can be performed by partially melting a base material of the current-collecting plate. In one modification, the first current-collecting plate 144 and the bending surface region F can be welded with an interposed weld between them. In this case, the weld can have a lower melting point compared to the first current-collecting plate 144 and the first uncoated portion 146a. Laser welding can be replaced by resistance welding, ultrasonic welding, spot welding, or similar methods. The second current-collecting plate 145 can be coupled to the lower surface of the electrode assembly 110. One side of the second current-collecting plate 145 can be welded to the bending surface region F of the second electrode, and the other side can be welded to the inner underside surface of the battery housing 142. The coupling structure between the second current-collecting plate 145 and the bending surface region F of the second electrode can be substantially the same as the coupling structure between the first current-collecting plate 144 and the bending surface region F of the first electrode. The insulator 146 can cover the first current collector plate 144. The insulator 146 can cover the first current collector plate 144 on the upper surface of the first current collector plate 144, thereby preventing direct contact between the first current collector plate 144 and the inner circumference of the battery housing 142. The insulator 146 has a conductor hole 151 such that the conductor 149 extending upward from the first current-collecting plate 144 can be withdrawn through it. The conductor 149 is drawn upward through the conductor hole 151 and coupled to the lower surface of the connection plate 143c or to the lower surface of the cover plate 143a. A peripheral region of the edge of the insulator 146 can be interposed between the first current-collecting plate 144 and the flange portion 147 to fix the coupled body of the electrode assembly 110 and the first current-collecting plate 144. Consequently, the movement of the coupled body of the electrode assembly 110 and the first current-collecting plate 144 can be restricted in the height direction of the battery 140, thereby improving the assembly stability of the battery 140. The 146 insulator can be made from an insulating polymer resin. For example, the 146 insulator can be made from polyethylene, polypropylene, polyimide, or polybutylene terephthalate. The battery housing 142 may also include a vent portion 152 formed on its lower surface. The vent portion 152 is a thinner region compared to the surrounding area of ​​the lower surface of the battery housing 142. The vent portion 152 is structurally weak compared to the surrounding area. Consequently, when an anomaly occurs in the cylindrical battery 190 and the internal pressure rises to a predetermined level or higher, the vent portion 152 may rupture, allowing the gas generated inside the battery housing 142 to be discharged to the outside. The internal pressure at which the vent portion 152 ruptures can range from approximately 15 kgf / cm² to 35 kgf / cm². The vent portion 152 can be formed continuously or discontinuously while drawing a circle on the lower surface of the battery housing 142. In a modification, the vent portion 152 can be formed in a straight pattern or other patterns. Figure 18 is a cross-sectional view showing a cylindrical battery 200 according to an embodiment of the present disclosure, taken along the Y-axis direction to pass through the bending surface region F (Figure 6a) of the segments included in the segment alignment 50 (Figure 6a). With reference to Figure 18, the electrode assembly structure of the cylindrical battery 200 is substantially the same as that of the cylindrical battery 190 of Figure 17, with the other structure being changed except for the electrode assembly. Specifically, the cylindrical battery 200 includes a battery housing 171 through which a rivet terminal 172 is installed. The rivet terminal 172 is installed through a drilled hole formed in the closed surface (the top surface in the drawing) of the battery housing 171. The rivet terminal 172 is riveted to the drilled hole of the battery housing 171 in a state where a second gasket 173 made of an insulating material is interposed between them. The rivet terminal 172 is exposed to the outside in a direction opposite to the direction of gravity. The rivet terminal 172 includes a terminal exposure portion 172a and a terminal insertion portion 172b. The terminal exposure portion 172a is exposed to the outside of the enclosed surface of the battery housing 171. The terminal exposure portion 172a may be located approximately in the center portion of the enclosed surface of the battery housing 171. The maximum diameter of the terminal exposure portion 172a may be larger than the maximum diameter of the drilled hole formed in the battery housing 171. The terminal insertion portion 172b may be electrically connected to the uncoated portion 146a of the first electrode through approximately the center portion of the enclosed surface of the battery housing 171. The lower edge of the terminal insertion portion 172b may be riveted to the inside surface of the battery housing 171.That is, the lower edge of the terminal insert portion 172b may be curved towards the inner surface of the battery housing 171. A flat portion 172c is included on the inner side of the lower edge of the terminal insert portion 172b. The maximum diameter of the lower portion of the riveted terminal insert portion 172b may be larger than the maximum diameter of the drilled hole in the battery housing 171. The flat portion 172c of the terminal insertion portion 172b can be welded to the central portion of the first current collector plate 144 connected to the bending surface region F of the first electrode. Laser welding can be adopted as a preferred welding method, but laser welding can be substituted with other welding methods such as ultrasonic welding. An insulator 174 made of an insulating material can be interposed between the first current-collecting plate 144 and the inner surface of the battery housing 171. The insulator 174 covers the upper portion of the first current-collecting plate 144 and the upper edge of the electrode assembly 110. Consequently, it is possible to prevent the second portion B3 of the electrode assembly 110 from coming into contact with the inner surface of the battery housing 171, which has a different polarity, and causing a short circuit. The thickness of the insulator 174 corresponds to or is slightly greater than the distance between the upper surface of the first current collector plate 144 and the inner surface of the closed portion of the battery housing 171. Consequently, the insulator 174 can come into contact with the upper surface of the first current collector plate 144 and the inner surface of the closed portion of the battery housing 171. The terminal insert portion 172b of the rivet terminal 172 can be soldered to the first current collector plate 144 through the drilled hole in the insulator 174. The diameter of the drilled hole formed in the insulator 174 can be larger than the diameter of the riveting portion at the lower end of the terminal insert portion 172b. Preferably, the drilled hole can expose the lower portion of the terminal insert portion 172b and the second gasket 173. The second gasket 173 is interposed between the battery housing 171 and the rivet terminal 172 to prevent the battery housing 171 and the rivet terminal 172, which have opposite polarities, from making electrical contact with each other. Consequently, the approximately flat upper surface of the battery housing 171 can function as the second electrode (e.g., negative electrode) of the cylindrical battery 200. The second gasket 173 includes a gasket exposure portion 173a and a gasket insert portion 173b. The gasket exposure portion 173a is interposed between the terminal exposure portion 172a of the rivet terminal 172 and the battery housing 171. The gasket insert portion 173b is interposed between the terminal insert portion 172b of the rivet terminal 172 and the battery housing 171. The gasket insert portion 173b can be deformed together when the terminal insert portion 172b is riveted, to be in close contact with the inner surface of the battery housing 171. The second gasket 173 can be made, for example, of a polymer resin having insulating properties. The gasket exposure portion 173a of the second gasket 173 may have an extended shape to cover the outer circumference of the terminal exposure portion 172a of the rivet terminal 172. When the second gasket 173 covers the outer circumference of the rivet terminal 172, a short circuit can be prevented while an electrical connection part, such as a busbar, is mated to the top surface of the battery housing 171 and / or the rivet terminal 172. Although not shown in the drawings, the gasket exposure portion 173a may have an extended shape to cover not only the outer circumference surface of the terminal exposure portion 172a but also a portion of its top surface. When the second gasket 173 is made of a polymer resin, it can be attached to the battery housing 171 and the rivet terminal 172 by thermal fusion. In this case, airtightness can be enhanced at the mating interface between the second gasket 173 and the rivet terminal 172, and at the mating interface between the second gasket 173 and the battery housing 171. Alternatively, when the exposed portion of gasket 173a of the second gasket 173 extends to the upper surface of the exposed portion of terminal 172a, the rivet terminal 172 can be attached as a single piece to the second gasket 173 by insert injection molding. On the upper surface of the battery housing 171, a remaining area 175 distinct from the area occupied by the rivet terminal 172 and the second gasket 173 corresponds to the second electrode terminal having a polarity opposite to that of the rivet terminal 172. The second current-collecting plate 176 is coupled to the lower portion of the electrode assembly 141. The second current-collecting plate 176 is made of a conductive metal material such as aluminum, steel, copper, or nickel, and is electrically connected to the bending surface region F of the second electrode. Preferably, the second current collector plate 176 is electrically connected to the battery housing 171. For this purpose, at least a portion of the edge of the second current collector plate 176 can be interposed and fixed between the inner surface of the battery housing 171 and a first gasket 178b. In one example, at least a portion of the edge of the second current collector plate 176 can be fixed to the flange portion 180 by welding it in a supported state to the lower surface of the flange portion 180 formed on the underside of the battery housing 171. In an amendment, at least a portion of the edge of the second current collector plate 176 can be welded directly to the inner wall surface of the battery housing 171. Preferably, the second current-collecting plate 176 and the bending surface region F of the second electrode can be joined by welding, for example, laser welding. Furthermore, the welded portion of the second current-collecting plate 176 and the bending surface region F can be separated by a predetermined interval toward the core C based on the inner circumference of the flange portion 180. A sealing body 178 for sealing the lower open end of the battery housing 171 includes a cap plate 178a and a first gasket 178b. The first gasket 178b electrically isolates the cap plate 178a from the battery housing 171. A crimp portion 181 secures the edge of the cap plate 178a and the first gasket 178b together. The cap plate 178a has a vent portion 179. The configuration of the vent portion 179 is substantially the same as in the prior embodiment (modification). The lower surface of the cap plate 178a can be positioned above the lower end of the crimp portion 181. In this case, a space is formed beneath the cap plate 178a to smoothly effect venting. In particular, it is useful when the cylindrical battery 200 is installed in such a way that the crimp portion 181 is oriented in the direction of gravity. Preferably, the cover plate 178a is made of a conductive metal material. However, because the first gasket 178b is interposed between the cover plate 178a and the battery housing 171, the cover plate 178a does not have electrical polarity. The sealing body 178 seals the open end of the lower portion of the battery housing 171 and functions primarily to discharge gas when the internal pressure of the battery 200 rises above a critical value. A threshold pressure value is between 15 kgf / cm² and 35 kgf / cm². Preferably, the rivet terminal 172, electrically connected to the flex surface region F of the first electrode, is used as the first electrode terminal. Furthermore, on the upper surface of the battery housing 171, electrically connected to the flex surface region F of the second electrode via the second current collector plate 176, a portion 175, except for the rivet terminal 172, is used as the second electrode terminal, which has a different polarity than the first electrode terminal. If two electrode terminals are located on the upper portion of the cylindrical battery 200 as described above, electrical connection components such as busbars can be arranged on only one side of the cylindrical battery 200. This can lead to a simplified battery pack structure and improved energy density.Furthermore, because the portion 175 used as the second electrode terminal is approximately flat, a sufficient bonding area can be ensured for joining electrical connection components such as bus bars. Consequently, the cylindrical battery 200 can reduce the resistance in the bonding portion of the electrical connection components to a desirable level. Figure 19 is a cross-sectional view showing a cylindrical battery 210 according to yet another embodiment of the present disclosure, taken along the Y-axis direction to pass through the bending surface region F (Figure 6a) of the segments included in the segment alignment 50 (Figure 6a). Referring to Figure 19, the cylindrical battery 210 includes the electrode assembly 100 shown in Figure 13, and other configurations, except for the electrode assembly 100, are substantially the same as those of the cylindrical battery 190 shown in Figure 17. Consequently, the configuration described with reference to Figures 13 and 17 can be applied substantially the same to this embodiment. Preferably, the first and second uncoated portions 146a, 146b of the electrode assembly 100 include a plurality of segment groups 61g. The plurality of segment groups 61g forms a segment alignment 50 (Figure 6a) in the upper and lower portions of the electrode assembly 100. The segments 61 included in the segment alignment 50 are bent in the radial direction of the electrode assembly 100, for example, from the outer circumference toward the core. Because the first portion B1 of the first uncoated portion 146a and the uncoated portions of the second portion B3 are shorter than other portions and do not include segments, they are not substantially bent. The same applies to the second uncoated portion 146b. Also in this embodiment, the bending surface region F formed by the segments 61 included in the alignment of segments 50 may include a jump region of segment a1, a height-variable region of segment a2, and a height-uniform region of segment a3 extending from the core to the outer circumference. However, because the uncoated portion of the second segment B3 is not bent, the radial length of the bending surface region F may be shorter than in the previous embodiment. As shown in Figures 11a, 11b, and 11c, the bending surface region F includes a stacking number uniform region b1 that has a stacking number of 10 or more adjacent to the segment jump region a1. The flex surface region F may also include a decreasing stacking number region b2 adjacent to the winding turns of the second portion B3 of the electrode assembly 100, where the stacking number of segments decreases toward the outer circumference. Preferably, the uniform stacking number region b1 may be established as a target welding area. In the bending surface region F, the preferred numerical intervals of the ratio (a2 / c) of the height-variable region a2 of the segments to the radial region c containing segments, the ratio (b1 / c) of the stacking-number uniform region b1 of the segments, and the ratio of the area of ​​the stacking-number uniform region b1 to the area of ​​the bending surface region F have already been described above and will therefore not be described again. The first current collector plate 144 can be welded to the bending surface region F of the first uncoated portion 146a, and the second current collector plate 145 can be welded to the bending surface region F of the second uncoated portion 146b. The overlap relationship between the uniform stacking number region b1 and the decreasing stacking number region b2 and the welding region W, the outer diameters of the first current-collecting plate 144 and the second current-collecting plate 145, and the configuration in which the first portion B1 does not block the core are substantially the same as those described above. On the other hand, the second portion B3 does not include any segments, and the height of the uncoated portion is less than that of the segments in the third portion B2. Therefore, when the segments of the third portion B2 are bent, the second portion B3 is not substantially bent. Furthermore, because the winding turns of the second portion B3 are sufficiently separated from the flanged portion 147, the problem of damage to the winding turns of the second portion B3 can be solved while press-fitting the flanged portion 147. Figure 20 is a cross-sectional view showing a cylindrical battery 220 according to yet another embodiment of the present disclosure, taken along the Y-axis direction to pass through the bending surface region F (Figure 6a) of the segments included in the segment alignment 50 (Figure 6a). Referring to Figure 20, the cylindrical battery 220 includes the electrode assembly 100 shown in Figure 13, and other configurations, except for the electrode assembly 100, are substantially the same as those of the cylindrical battery 200 shown in Figure 18. Consequently, the configuration described with reference to Figures 13 and 18 can be applied substantially the same to this embodiment. Preferably, the first and second uncoated portions 146a, 146b of the electrode assembly 100 include a plurality of segment groups 61g, and the plurality of segment groups 61g are arranged in the radial direction to form a segment alignment 50 (Figure 6a). Furthermore, the segments included in the segment alignment 50 are bent from the outer circumference toward the core of the electrode assembly 100 to form a bending surface region F. Currently, because in the first portion B1 of the first uncoated portion 146a and the second portion B3, the uncoated portion is lower in height than the other portions and does not include segments, it is not substantially bent toward the core. This is also the case for the second uncoated portion 146b. Consequently, in this embodiment as well, the bending surface region F may include a jump region of segment a1, a height-variable region of segment a2, and a height-uniform region of segment a3 from the core to the outer circumference, similar to the embodiment in Figure 19. However, because the uncoated portion of the second portion B3 is not bent, the radial length of the bending surface region F may be shorter than in the case of the previous embodiment. As shown in Figures 11a, 11b, and 11c, the bending surface region F includes a stacking number uniform region b1 that has a stacking number of 10 or more adjacent to the segment jump region a1. The flex surface region F may also include a decreasing stacking number region b2 adjacent to the winding turns of the second portion B3 of the electrode assembly 100, where the stacking number of segments decreases toward the outer circumference. Preferably, the uniform stacking number region b1 may be established as a target welding area. In the bending surface region F, the preferred numerical intervals of the ratio (a2 / c) of the height-variable region a2 of the segments to the radial region c containing segments, the ratio (b1 / c) of the stacking-number uniform region b1 of the segments, and the ratio of the area of ​​the stacking-number uniform region b1 to the area of ​​the bending surface region F have already been described above and will therefore not be described again. The first current collector plate 144 can be welded to the bending surface region F of the first uncoated portion 146a, and the second current collector plate 176 can be welded to the bending surface region F of the second uncoated portion 146b. The overlap relationship between the uniform stacking number region b1 and the decreasing stacking number region b2 and the welding region W, the outer diameters of the first current-collecting plate 144 and the second current-collecting plate 176, and the configuration in which the first portion B1 does not block the core are substantially the same as those described above. In the embodiments (modifications), the first current collector plate 144 and the second current collector plate 176 included in the cylindrical batteries 200, 220 that include the rivet terminal 172 may have an improved structure as shown in Figures 21 and 22. The improved structure of the first current collector plate 144 and the second current collector plate 176 can contribute to lowering the resistance of the cylindrical battery, improving vibration resistance, and enhancing energy density. In particular, the first current collector plate 144 and the second current collector plate 176 are more effective when used in a large cylindrical battery with a diameter-to-height ratio greater than 0.4. Figure 21 is a top plan view showing the structure of the first current collector plate 144 e according to an embodiment of the present disclosure. Referring to Figures 20 and 21 together, the first current-collecting plate 144 may include a rim portion 144a, a first uncoated portion coupling portion 144b, and a terminal coupling portion 144c. The rim portion 144a is disposed over the electrode assembly 100. The rim portion 144a may have a substantially flanged shape having a void (open) formed therein. In the drawings in this disclosure, only one instance is illustrated in which the rim portion 144a has a substantially circular flanged shape, but this disclosure is not limited to this instance. The rim portion 144a may have a substantially rectangular flanged shape, a hexagonal flanged shape, an octagonal flanged shape, or other flanged shapes, as different from the one illustrated. The number of rim portions 144a may be increased to two or more.In this case, another rim portion can be included inside rim portion 144a. The mating portion of terminal 144c may have a diameter equal to or greater than the diameter of the flat portion 172c formed on the underside surface of the rivet terminal 172 to ensure a weld region for mating with the flat portion 172c formed on the underside surface of the rivet terminal 172. The first uncoated portion coupling portion 144b extends inward from the edge portion 144a and is welded to the bending surface region F of the uncoated portion 146a. The terminal coupling portion 144c separates from the first uncoated portion coupling portion 144b and is positioned inside the edge portion 144a. The terminal coupling portion 144c can be welded to the rivet terminal 172. The terminal coupling portion 144c can be located, for example, approximately in the center of the inner space (Sabierto) surrounded by the edge portion 144a. The terminal coupling portion 144c can be provided in a position corresponding to the hole formed in the core C of the electrode assembly 100.The terminal coupling portion 144c can be configured to cover the hole formed in the core C of the electrode assembly 100 such that the hole formed in the core C of the electrode assembly 100 is not exposed outside the terminal coupling portion 144c. To this end, the terminal coupling portion 144c can have a larger diameter or width than the hole formed in the core C of the electrode assembly 100. The first uncoated portion coupling portion 144b and the terminal coupling portion 144c may not be directly connected, but may be arranged to be separated from each other and connected indirectly by the rim portion 144a. Because the first current collector plate 144 has a structure in which the first uncoated portion coupling portion 144b and the terminal coupling portion 144c are not directly connected to each other, but are connected through the rim portion 144c as above, when a shock and / or vibration occurs in the cylindrical battery 220, it is possible to disperse the shock applied to the coupling portion between the first uncoated portion coupling portion 144b and the first uncoated portion 146a and the coupling portion between the terminal coupling portion 144c and the rivet terminal 172.The drawings in this disclosure illustrate only one instance where four first uncoated portion coupling portions 144b are provided, but this disclosure is not limited to that instance. The number of first uncoated portion coupling portions 144b can be determined in various ways, taking into account the manufacturing difficulty based on the complexity of the shape, electrical resistance, the internal space (Sabierto) within the edge portion 144a considering electrolyte impregnation, and similar factors. The first current-collecting plate 144 may further include a bridge portion 144d extending inward from the edge portion 144a and connected to the terminal coupling portion 144c. At least part of the bridge portion 144d may have a smaller cross-sectional area compared to the first uncoated coupling portion 144b and the edge portion 144a. For example, at least part of the bridge portion 144d may be shaped to have a smaller width and / or thickness compared to the first uncoated coupling portion 144b. In this case, the electrical resistance increases in the bridge portion 144d. Therefore, when a current flows through the bridge portion 144d, the relatively high resistance causes a portion of the bridge portion 144d to melt due to overcurrent heating. Consequently, the overcurrent is irreversibly blocked.The cross-sectional area of ​​the 144d bridge portion can be adjusted to an appropriate level taking into account the overcurrent blocking function. The bridge portion 144d may include a tapered portion 144e whose width gradually decreases from the inner surface of the rim portion 144a toward the terminal coupling portion 144c. When the tapered portion 144e is provided, the rigidity of the component can be improved in the connecting portion between the bridge portion 144d and the rim portion 144a. When the tapered portion 144e is provided, in the process for manufacturing the cylindrical battery 220, for example, a transfer device and / or a worker can easily and safely transport the first current-collecting plate 144 and / or a coupled body of the first current-collecting plate 144 and the electrode assembly 100 by grasping the tapered portion 144e.In other words, when the tapered portion 144e is provided, it is possible to avoid product defects that may occur when gripping a portion where welding is performed with other components such as the first uncoated portion coupling portion 144b and the terminal coupling portion 144c. The first uncoated portion coupling portion 144b may be provided in a plurality. The plurality of first uncoated portion coupling portions 144b may be arranged at substantially regular intervals from each other in the extension direction of the edge portion 144a. The extension length of each of the plurality of first uncoated portion coupling portions 144b may be substantially equal to each other. The first uncoated portion coupling portion 144b may be coupled to the bending surface region F of the uncoated portion 146a by laser welding. The welding may be substituted by ultrasonic welding, spot welding, or similar methods. A weld pattern 144f formed by welding between the first mating portion of the uncoated portion 144b and the bending surface region F may have a structure that extends along the radial direction of the electrode assembly 100. The weld pattern 144f may be an orderly arrangement of line patterns or dot patterns. The weld pattern 144f corresponds to the weld region. Therefore, it is desirable that the weld pattern 144f overlap with the uniform stacking number region b1 of the bending surface region F by 50% or more. The portion of the weld pattern 144f that does not overlap with the uniform stacking number region b1 may overlap with the decreasing stacking number region b2. More preferably, the entire weld pattern 144f may overlap with the uniform stacking number region b1 of the bending surface region F. In the bending surface region F below the point where the weld pattern 144f is formed, the uniform stacking number region b1 and, optionally, the decreasing stacking number region b2 preferably have a stacking number of 10 or more.The terminal coupling portion 144c can be arranged to be surrounded by a plurality of first uncoated portion coupling portions 144b. The terminal coupling portion 144c can be coupled to the flat portion 172c of the rivet terminal 172 by welding. The bridge portion 144d can be positioned between a pair of adjacent first uncoated portion coupling portions 144b. In this case, the distance from the bridge portion 144d to any one of the pair of first uncoated portion coupling portions 144b along the extension direction of the edge portion 144a can be substantially equal to the distance from the bridge portion 144d to the other of the pair of first uncoated portion coupling portions 144b along the extension direction of the edge portion 144a.The plurality of first uncoated coupling portions 144b may be formed to have substantially the same cross-sectional area. The plurality of first uncoated coupling portions 144b may be formed to have substantially the same width and thickness. Although not shown in the drawings, the bridging portion 144d may be provided in a plural number. Each of the plurality of bridging portions 144d may be arranged between a pair of adjacent first uncoated coupling portions 144b. The plurality of bridging portions 144d may be arranged at substantially regular intervals from each other in the extension direction of the edge portion 144a.A distance from each of the plurality of bridge portions 144d to one of the pair of first uncoated portion coupling portions 144b adjacent to each other along the extension direction of the edge portion 144a may be substantially equal to a distance from each of the plurality of bridge portion 144d to the other first uncoated portion coupling portion 144b. In the case where the first uncoated portion coupling portion 144b and / or the bridge portion 144d are provided in a plural number as described above, if the distance between the first uncoated portion coupling portions 144b and / or the distance between the bridge portions 144d and / or the distance between the first uncoated portion coupling portion 144b and the bridge portion 144d is formed uniformly, a current flowing from the first uncoated portion coupling portion 144b to the bridge portion 144d or a current flowing from the bridge portion 144d to the first uncoated portion coupling portion 144b can be formed smoothly. The bridge portion 144d may include a notched portion N formed to partially reduce the cross-sectional area of ​​the bridge portion 144d. The cross-sectional area of ​​the notched portion N may be adjusted, for example, by partially reducing the width and / or thickness of the bridge portion 144d. When the notched portion N is provided, the electrical resistance is increased in the region where the notched portion N is formed, thereby enabling rapid current interruption in the event of an overcurrent. The notched portion N is preferably provided in a region corresponding to the uniform stacking number region of the electrode assembly 100 to prevent foreign substances generated during breakage from flowing into the electrode assembly 100. This is because, in this region, the number of overlapping layers of the uncoated portion 146a segments is kept to a maximum, and therefore the overlapping segments can act as a mask. The notched portion N can be wrapped with insulating tape. Then, because the heat generated in the notched portion N is not dissipated to the outside, the notched portion N can break down more quickly when an overcurrent flows through the bridge portion 144d. Figure 22 is a top plan view showing the structure of the second current collector plate 176 according to an embodiment of the present disclosure. Referring to Figures 20 and 22 together, the second current-collecting plate 176 is disposed below the electrode assembly 100. Furthermore, the second current-collecting plate 176 can be configured to electrically connect the uncoated portion 146b of the electrode assembly 100 and the battery housing 171. The second current-collecting plate 176 is made of a conductive metal material and is electrically connected to the flexural surface region F of the uncoated portion 146b. Additionally, the second current-collecting plate 176 is electrically connected to the battery housing 171. The edge portion of the second current-collecting plate 176 can be interposed and secured between the inner surface of the battery housing 171 and the first gasket 178b.Specifically, the edge portion of the second current collector plate 176 may be interposed between the lower surface of the flange portion 180 of the battery housing 171 and the first gasket 178b. However, this disclosure is not limited to this, and the edge portion of the second current collector plate 176 may be welded to the inner wall surface of the battery housing 171 in a region where the flange portion 180 is not formed. The second current-collecting plate 176 may include a support portion 176a disposed below the electrode assembly 100, a second uncoated portion coupling portion 176b extending from the support portion 176a approximately along the radial direction of the electrode assembly 100 and coupled to the flex surface region F of the uncoated portion 176b, and a housing coupling portion 176c extending from the support portion 176a into the inner surface of the battery housing 171 approximately along an inclined direction based on the radial direction of the electrode assembly 100 and coupled to the inner surface of the battery housing 171. The second uncoated portion coupling portion 176b and the housing coupling portion 176c are connected indirectly through the support portion 176a and are not directly connected to each other.Therefore, when an external shock is applied to the cylindrical battery 220 of this disclosure, it is possible to minimize the possibility of damaging the coupling portion of the second current collector plate 176 and the electrode assembly 100 and the coupling portion of the second current collector plate 176 and the battery housing 171. However, the second current collector plate 176 of this disclosure is not limited to the structure where the second coupling portion of the uncoated portion 176b and the coupling portion of the housing 176c are only indirectly connected.For example, the second current collector plate 176 may have a structure that does not include the support portion 176a to indirectly connect the second uncoated portion coupling portion 176b and the housing coupling portion 176c and / or a structure in which the uncoated portion 176b and the housing coupling portion 176c are directly connected to each other. The support portion 176a and the second uncoated portion coupling portion 176b are positioned below the electrode assembly 100. The second uncoated portion coupling portion 176b engages with the flex surface region F of the uncoated portion 146b. In addition to the second uncoated portion coupling portion 176b, the support portion 176a can also engage with the uncoated portion 146b. The second uncoated portion coupling portion 176b and the flex surface region F of the uncoated portion 146b can be joined by welding. Welding can be replaced with ultrasonic welding or spot welding. The support portion 176a and the second uncoated portion coupling portion 176b are positioned higher than the flange portion 180 when the flange portion 180 is formed over the battery housing 171. The support portion 176a has a current collector plate hole 176d formed in a location corresponding to the hole formed in the core C of the electrode assembly 100. The core C of the electrode assembly 100 and the current collector plate hole 176d, which communicate with each other, can function as a step for inserting a welding rod for welding between the rivet terminal 172 and the terminal coupling portion 144c of the first current collector plate 144 or for irradiating a laser beam. The hole in the current collector plate 176d can have a radius of 0.5 rc or more compared to the radius (rc) of the hole formed in the core C of the electrode assembly 100. If the radius of the hole in the current collector plate 176d is from 0.5 rc to 1.0 rc, when venting occurs in the cylindrical battery 220, the phenomenon of the separator or electrode winding structure near the core C of the electrode assembly 100 being pushed out of the core C due to venting pressure is avoided. When the radius of the hole in the current collector plate 176d is larger than 1.0 rc, the opening of the core C is maximized, so the electrolyte can be easily injected during the electrolyte injection process. When the second uncoated portion coupling portion 176b is provided in a plural number, the plurality of second uncoated portion coupling portions 176b may have a shape extending approximately radially from the support portion 176a of the second current collector plate 176 towards the side wall of the battery housing 171. The plurality of second uncoated portion coupling portions 176b may be positioned to be spaced apart from each other along the periphery of the support portion 176a. The housing coupling portion 176c may be provided in a plurality. In this case, the plurality of housing coupling portions 176c may be shaped to extend approximately radially from the center of the second current collector plate 176 toward the side wall of the battery housing 171. Consequently, the electrical connection between the second current collector plate 176 and the battery housing 171 may be made at a plurality of points. Because the coupling for the electrical connection is made at a plurality of points, the coupling area may be maximized, thereby minimizing electrical resistance. The plurality of housing coupling portions 176c may be positioned to be spaced apart from each other along the periphery of the support portion 176a.At least one housing coupling portion 176c may be placed between adjacent uncoated portion coupling portions 176b. The plurality of housing coupling portions 176c may be coupled, for example, to the flange portion 180 on the inner surface of the battery housing 171. The housing coupling portions 176c may be coupled, in particular, to the lower surface of the flange portion 180 by laser welding. Welding may be replaced, for example, by ultrasonic welding, spot welding, or similar methods. By coupled to the flange portion 180 by welding in this manner, the current path may be distributed radially such that the resistance level of the cylindrical battery 220 is limited to approximately 4 milliohms or less.Furthermore, because the lower surface of flange portion 180 is shaped to extend approximately parallel to the upper surface of battery housing 171, specifically approximately perpendicular to the side wall of battery housing 171, and the housing coupling portion 176c is also shaped to extend in the same direction, specifically radially and circumferentially, the housing coupling portion 176c can be stably in contact with flange portion 180. Moreover, because the housing coupling portion 176c is stably in contact with the flat portion of flange portion 180, the two components can be smoothly welded, thereby improving the coupling strength between the two components and minimizing the increase in resistance in the coupling portion. The housing coupling portion 176c may include a contact portion 176e coupled onto the inner surface of the battery housing 171 and a connection portion 176f for connecting the support portion 176a and the contact portion 176e. The contact portion 176e engages on the inner surface of the battery housing 171. If the flange portion 180 is formed on the battery housing 171, the contact portion 176e can be engaged on the flange portion 180 as described above. More specifically, the contact portion 176e can be electrically engaged with the flat portion formed on the lower surface of the flange portion 180 formed on the battery housing 171, and can be interposed between the lower surface of the flange portion 180 and the first gasket 178b. In this case, for stable contact and engagement, the contact portion 176e can be shaped to extend over the flange portion 180 by a predetermined length along the circumferential direction of the battery housing 171. The connecting portion 176f can be bent at an obtuse angle. The bending point can be higher than the midpoint of the connecting portion 176f. When the connecting portion 176f is bent, the contact portion 176e can be stably supported on the flat surface of the flange portion 180. The connecting portion 176f is divided into a lower and an upper portion based on the bending point, and the lower portion can be longer than the upper portion. Furthermore, the lower portion at the bending point can have a greater angle of inclination relative to the surface of the support portion 176a than the upper portion. When the connecting portion 176f is bent, it can dampen pressure (force) applied in the vertical direction to the battery housing 171.For example, in the process of sizing the battery housing 171, when pressure is transmitted to the contact portion 176e such that the contact portion 176e moves vertically towards the support portion 176b, the bending point of the connecting portion 176f moves upwards, such that the shape of the connecting portion 176 deforms to dampen the stress. On the other hand, the maximum distance from the center of the second current collector plate 176 to the end of the second uncoated coupling portion 176b along the radial direction of the electrode assembly 100 is preferably equal to or less than the inside diameter of the battery housing 171 in a region where the flange portion 180 is formed, specifically, the minimum inside diameter of the battery housing 171. This is to prevent the end of the second uncoated coupling portion 176b from pressing against the edge of the electrode assembly 100 during the dimensioning process, thus preventing compression of the battery housing 171 along the height direction. The second uncoated coupling portion 176b includes an orifice 176g. The orifice 176g can be used as a passage through which the electrolyte can move. The weld pattern 176h formed by welding between the second uncoated coupling portion 176b and the bending surface region F can have a structure extending along the radial direction of the electrode assembly 100. The weld pattern 176h can be a line pattern or an orderly arrangement of dots. The weld pattern 176h corresponds to the weld region. Therefore, it is preferable that the weld pattern 176h overlap by 50% or more with the uniform stacking number region b1 of the bending surface region F located in the lower portion of electrode assembly 100. The portion of the weld pattern 176h that does not overlap with the uniform stacking number region b1 may overlap with the decreasing stacking number region b2. More preferably, the entire weld pattern 176h may overlap with the uniform stacking number region b1 of the bending surface region F. In the bending surface region F in the upper portion of the point where the weld pattern 176h is formed, the uniform stacking number region b1 and, optionally, the decreasing stacking number region b2 preferably have a stacking number of 10 or more. The outside diameters of the first current-collecting plate 144 and the second current-collecting plate 176 described above are different. The outside diameter is the outer diameter of the contact area between the bending surface region F and the current-collecting plate. It is defined as the maximum distance between two points where a straight line passing through the center of the core C of the electrode assembly intersects the edge of the contact area. Because the second current-collecting plate 176 is located inside the flange portion, its outside diameter is smaller than that of the first current-collecting plate 144. Furthermore, the length of the weld pattern 144f of the first current-collecting plate 144 is longer than the length of the weld pattern 176h of the second current-collecting plate 176.Preferably, the 144f weld pattern and the 176h weld pattern can be extended towards the outer circumference from substantially the same point based on the center of the C core. The cylindrical battery 200, 220 according to an embodiment of the present disclosure has the advantage that the electrical connection can be made in the upper portion thereof. Figure 23 is a top plan view illustrating a state in which a plurality of cylindrical batteries 200 are electrically connected, and Figure 24 is a partially enlarged view of Figure 23. The cylindrical battery 200 can be replaced with a cylindrical battery 220 having a different structure. Referring to Figures 23 and 24, a plurality of cylindrical batteries 200 can be connected in series and in parallel in an upper portion of the cylindrical batteries 200 using a bus bar 210. The number of cylindrical batteries 200 can be increased or decreased depending on the capacity of the battery pack. In each cylindrical battery 200, the rivet terminal 172 can have a positive polarity, and the flat surface 171a around the rivet terminal 172 of the battery housing 171 can have a negative polarity, or vice versa. Preferably, the plurality of cylindrical batteries 200 can be arranged in a plurality of columns and rows. The columns are provided in a vertical direction based on the drawing, and the rows are provided in a left-right direction based on the drawing. Furthermore, to maximize space efficiency, the cylindrical batteries 200 can be arranged in a close-packed structure. The close-packed structure is formed by connecting the centers of the exposed rivet terminals 172 outside the battery housing 171 to each other to form an equilateral triangle. Preferably, the bus bar 210 connects the cylindrical batteries 200 arranged in the same column in parallel with each other, and connects the cylindrical batteries 200 arranged in two adjacent columns in series with each other. Preferably, the bus bar 210 may include a body portion 211, a plurality of first bus bar terminals 212 and a plurality of second bus bar terminals 213 for series and parallel connection. The body portion 211 can extend along the column of cylindrical batteries 200 between neighboring rivet terminals 172. Alternatively, the body portion 211 can extend along the column of cylindrical batteries 200 and can be regularly bent in a zigzag shape. The plurality of first busbar terminals 212 can extend laterally from the body portion 211 and can be electrically coupled to the rivet terminal 172 of the cylindrical battery 200 located laterally. The electrical connection between the first busbar terminal 212 and the rivet terminal 172 can be achieved by laser welding, ultrasonic welding, or similar means. The plurality of second busbar terminals 213 can extend in the other lateral direction of the body portion 211 and can be electrically coupled to the flat surface 171a around the rivet terminal 172 located in the other lateral direction. The electrical coupling between the second busbar terminal 213 and the flat surface 171a can be achieved by laser welding, ultrasonic welding, or similar means. Preferably, the body portion 211, the plurality of first busbar terminals 212, and the plurality of second busbar terminals 213 can be made of a conductive metal plate. The metal plate may be, for example, an aluminum plate or a copper plate, but this disclosure is not limited to these. In a modified example, the body portion 211, the plurality of first busbar terminals 212, and the second busbar terminals 213 can be manufactured as separate pieces and then joined together by welding or similar means. The cylindrical battery 200 of this disclosure, as described above, has a structure in which resistance is minimized by widening the weld region by means of the flex surface region F, multiplexing current paths by means of the second current collector plate 176, minimizing current path length, or similarly. The AC resistance of the cylindrical battery 200, measured through a resistance meter between the positive and negative electrodes, specifically between the rivet terminal 172 and the flat surface 171a around the rivet terminal 172, can be approximately 4 milliohms or less, suitable for rapid charging. In the cylindrical battery 200 according to the present disclosure, because the rivet terminal 172 having a positive polarity and the flat surface 171a having a negative polarity are located in the same direction, it is easy to electrically connect the cylindrical batteries 200 using the bus bar 210. Furthermore, because the rivet terminal 172 of the cylindrical battery 200 and the flat surface 171a around the rivet terminal 172 have a large area, the coupling area of ​​the bus bar 210 can be sufficiently secured to adequately reduce the resistance of the battery pack, including the cylindrical battery 200. Furthermore, because electrical wiring can be performed on the upper portion of the cylindrical 200 battery, there is an advantage in maximizing the energy density per unit volume of the battery module / battery pack. The cylindrical battery according to the above embodiments (modifications) can be used to manufacture a battery pack. Figure 25 is a diagram schematically showing a battery pack according to an embodiment of the present disclosure. Referring to Figure 25, a battery pack 300 according to one embodiment of this disclosure includes an assembly to which the cylindrical batteries 301 are electrically connected, and a pack housing 302 for housing the assembly. The cylindrical battery 301 can be any one of the batteries according to the preceding embodiments (modifications). In the drawing, components such as a bus bar for the electrical connection of the cylindrical batteries 301, a cooling unit, and an external terminal are not shown for illustrative purposes. The 300 battery pack can be installed in a vehicle. The vehicle can be, for example, an electric vehicle, a hybrid electric vehicle, or a plug-in hybrid vehicle. The vehicle includes both four-wheeled and two-wheeled vehicles. Figure 26 is a diagram that schematically shows a vehicle that includes the 300 battery pack from Figure 25. Referring to Figure 26, a vehicle V according to an embodiment of this disclosure includes the battery pack 300 according to an embodiment of this disclosure. The vehicle V is powered by the battery pack 300 according to an embodiment of this disclosure. According to this disclosure, the internal resistance of the battery can be reduced and the energy density increased by using the uncoated portion protruding from the upper and lower portions of the electrode assembly as an electrode tab. According to another aspect of this disclosure, by improving the structure of the uncoated portion of the electrode assembly so that the electrode assembly and the inner circumference of the battery housing do not interfere with the process of forming the flange portion of the battery housing, it is possible to prevent a short circuit from occurring inside the cylindrical battery due to partial deformation of the electrode assembly. According to another aspect of this disclosure, by improving the structure of the uncoated portion of the electrode assembly, it is possible to prevent the uncoated portion from tearing when it is bent, and it is possible to improve the welding strength of the current collector plate by sufficiently increasing the number of overlapping layers of the uncoated portion. According to another aspect of the present disclosure, it is possible to improve (the speed and uniformity of) electrolyte impregnation by applying a plurality of segments to the uncoated portion of the electrode, arranging the plurality of segments in a predetermined direction when the electrode is wound, and exposing the end of the active material layer formed on the electrode between the winding turn of the separator in a region where the segments are not arranged. According to another aspect of this disclosure, by applying a segmented structure to the uncoated portion of the electrode and optimizing the dimensions (width, height, separation pitch) of the segments to sufficiently increase the number of segment stacks in the area used as the target welding zone, it is possible to improve the properties of the area where the current collector plate is welded. According to another aspect of the present disclosure, an electrode assembly having improved energy density and reduced resistance can be provided by applying a structure in which a current-collecting plate is welded to a wide area of ​​the bending surface region formed by bending the segments. According to another aspect of this disclosure, a cylindrical battery may be provided which has an improved design such that electrical wiring can be carried out on the upper portion thereof. According to another aspect of this disclosure, by improving the structure of the uncoated portion adjacent to the core of the electrode assembly, the cavity in the core of the electrode assembly is prevented from being blocked when the uncoated portion is bent, so that the electrolyte injection process and the process for welding the battery housing (or rivet terminal) and the current collector plate can be easily performed. According to another aspect of this disclosure, it is possible to provide a cylindrical battery having a structure in which the internal resistance is low, an internal short circuit is avoided, and the solder resistance between the current collector plate and the uncoated portion is improved, and a battery pack and vehicle including the cylindrical battery. In particular, this disclosure may provide a cylindrical battery having a diameter-to-height ratio of 0.4 or more and a resistance of 4 milliohms or less, and a battery pack and vehicle including the cylindrical battery. The present disclosure has been described in detail. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the disclosure, are given for illustrative purposes only.

Claims

1. An electrode assembly (JR) in which a first electrode, a second electrode, and a spacer interposed between them are wound about a winding axis defining a core (C) and an outer circumference, wherein the first electrode includes a first active material portion coated with a layer of active material (42) along a winding direction (X) and a first uncoated portion (146a) not coated with a layer of active material (42) and projecting outside the spacer (Se), the first uncoated portion (146a) includes a segment region (B2) divided into a plurality of independently bendable segments by a plurality of shear slots provided along the winding direction (X), the segment region (B2) includes a plurality of segment groups (61g) divided by a group separation step (PG) along the winding direction (X),one end of the electrode assembly (JR) includes a plurality of segment alignments (50) in which the plurality of segment groups (61g) are aligned to overlap along a radial direction, the segments included in each segment alignment (50) are bent along the radial direction to form a bending surface region (F), in which the bending surface region (F) partially covers a surface of one end of the electrode assembly (JR), and in winding turns corresponding to the plurality of segment alignments (50), the separation steps of segment groups arranged in the same winding turn are substantially identical, and the separation step (P) of the segment groups is greater in a winding turn of a region adjacent to the outer circumference than in a winding turn of a region adjacent to the core (C),wherein "substantially identical" with respect to the group separation pitch (PG) refers to a deviation of 10% or less.

2. The electrode assembly (JR) according to claim 1, wherein each segment alignment (50) includes a radial region in which the group separation pitch (PG) increases in a stepped or gradual manner from the winding turn of the region adjacent to the core (C) toward the winding turn of the region adjacent to the outer circumference.

3. The electrode assembly (JR) according to claim 1, wherein the bending surface region (F) has the shape of a geometric figure, and the width in the winding direction (X) of segment groups located within the geometric figure increases in a stepped or gradual manner along the radial direction of the electrode assembly (JR), wherein the geometric figure has a structure in which one or more straight lines are connected.one or more curved lines or combinations thereof.

4. The electrode assembly (JR) according to claim 3, wherein the geometric figure is fan-shaped.

5. The electrode assembly (JR) according to claim 3, wherein the geometric figure is rectangular or trapezoidal.

6. The electrode assembly (JR) according to claim 1, wherein, between adjacent bending surface regions (F) in a circumferential direction, an electrolyte impregnation portion (55) is provided, wherein one end of the first active material portion is recessed into the electrode assembly (JR) more than one end of the spacer and is exposed between the winding turns of the spacer.

7. The electrode assembly (JR) according to claim 1,wherein the plurality of segment alignments (50) extends radially from the center of the core (C).

8. The electrode assembly (JR) according to claim 6, wherein the electrolyte impregnation portion (55) is provided in a plural number, and the plurality of electrolyte impregnation portions (55) extends radially from the center of the core (C).

9. The electrode assembly (JR) according to claim 1, wherein the plurality of segment alignments (50) extends in a cross shape (+), a radial shape (X), or a linear shape from the center of the core (C), when viewed in the direction of the winding axis of the electrode assembly (JR).

10. The electrode assembly (JR) according to claim 1, wherein,When a line connecting the core center (C) and a geometric center of a figure corresponding to the bending surface region (F) is defined as an angle measurement line (L), the angles between angle measurement lines (L) of adjacent bending surface regions (F) in a circumferential direction are substantially identical, with deviations within 5%.

11. The electrode assembly (JR) according to claim 1, wherein, when a line connecting the center of the core (C) and a geometric center of a figure corresponding to the bending surface region (F) is defined as an angle measurement line (L), the angle between angle measurement lines (L) of adjacent bending surface regions (F) in a circumferential direction is 30° ± 10°, 40° ± 10°, 45° ± 10°, 60° ± 10°, 72° ± 10°, 90° ± 10°, 120° ± 10°, or 180° ± 10°.

12. The electrode assembly (JR) according to claim 1,wherein, when a line connecting the center of the core (C) and a geometric center of a figure corresponding to the bending surface region (F) is defined as an angle measurement line (L), the angle between angle measurement lines (L) of adjacent bending surface regions (F) in a circumferential direction is 90° ± 10°, and the group separation pitch (PG) between groups of segments arranged on the same winding turn is established within the range of 8 mm to 50 mm.

13. The electrode assembly (JR) according to claim 12, wherein the group separation pitch (PG) increases in a stepwise or gradual manner as the number of winding turns increases.

14. The electrode assembly (JR) according to claim 1, wherein,When a line connecting the center of the core (C) and a geometric center of a corresponding figure in the bending surface region (F) is defined as an angle measurement line (L), the angle between angle measurement lines (L) of adjacent bending surface regions (F) in a circumferential direction is 180° ± 10°, and the group separation pitch (PG) between groups of segments arranged in the same winding turn is set within the range of 30 mm to 90 mm.

15. The electrode assembly (JR) according to claim 14, wherein the group separation pitch (PG) increases in a stepwise or gradual manner as the number of winding turns increases.

16. The electrode assembly (JR) according to claim 1, wherein each of the segments has the shape of a geometric figure, wherein the geometric figure has a structure in which one or more straight lines are connected.one or more curved lines or combinations thereof.

17. The electrode assembly (JR) according to claim 16, wherein each segment has a greater width in a lower portion than in an upper portion.

18. The electrode assembly (JR) according to claim 16, wherein each segment has a tapered shape in which the width decreases gradually or continuously from a folded lower portion to an upper portion.

19. The electrode assembly (JR) according to claim 1, wherein the segment alignment (50) includes a height-variable region in which the segment heights increase in a stepped manner from a first height (h1) to an N-1st height (hN-1, N being a natural number of 3 or more) from the core (C) of the electrode assembly (JR) toward the outer circumference.and a height-uniform region in which the segment heights are maintained as a uniform Nth height (hN, greater than hN-1).

20. The electrode assembly (JR) according to claim 19, wherein, when an initial radius of a winding turn containing a segment with height hk (k being a natural number from 1 to N) is rk and the core radius (C) is rc, the segment height hk satisfies the following formula:

21. The electrode assembly (JR) according to claim 1, wherein, based on a cross-section along the winding axis direction, sequentially along the radial direction, the segment alignment (50) includes a segment-skipping region having no segments, a height-variable region in which the segment heights vary, and a height-uniform region in which the segment heights are uniform,and the plurality of segments is arranged in the height-variable region and the height-uniform region.

22. The electrode assembly (JR) according to claim 21, wherein, where the number of segments intersecting an imaginary line parallel to the winding axis direction at an arbitrary radius location of the bending surface region (F) based on the center of the core (C) of the electrode assembly (JR) is defined as a stacking number of the segments at the corresponding radius location, the bending surface region (F) includes, from the core (C) towards the outer circumference, a stacking number-uniform region (b1) wherein the stacking number of the segments is uniform and a decreasing stacking number region (b2) wherein the stacking number of the segments decreases towards the outer circumference,23. The electrode assembly (JR) according to claim 22, wherein, in the uniform stacking number region (b1), the stacking number of the segments is from 10 to 35.

24. The electrode assembly (JR) according to claim 22, wherein the first electrode is a positive electrode, and the stacking thickness of the segments in the uniform stacking number region (b1) is in the range of 100 µm to 875 µm.

25. The electrode assembly (JR) according to claim 22, wherein the first electrode is a negative electrode, and the stacking thickness of the segments in the uniform stacking number region (b1) is in the range of 50 µm to 700 µm.

26. The electrode assembly (JR) according to claim 1,wherein the second electrode includes a second active material portion coated with a layer of active material (42) along the winding direction (X) and a second uncoated portion (146b) not coated with a layer of active material (42), the second uncoated portion (146b) includes a segment region (B2) divided into a plurality of independently bendable segments by a plurality of shear slots provided along the winding direction (X), the segment region (B2) of the second uncoated portion (146b) includes a plurality of segment groups (61g) divided by a group separation step (PG) along the winding direction (X), the other end of the electrode assembly (JR) includes a plurality of segment alignments (50) wherein the plurality of segment groups (61g) of the second uncoated portion (146b) are aligned along the radial direction,The segments included in each segment alignment (50) of the second uncoated portion (146b) are bent along the radial direction to form a bending surface region (F), wherein the bending surface region (F) partially covers a surface of one end of the electrode assembly (JR), and in winding turns corresponding to the plurality of segment alignments (50) of the second uncoated portion (146b), the separation steps of groups of segments arranged in the same winding turn are substantially identical, and the separation step (P) of the groups of segments is greater in the winding turn of the region adjacent to the outer circumference than in the winding turn of the region adjacent to the core (C),wherein "substantially identical" with respect to the group separation step (PG) refers to a deviation of 10% or less.

27. The electrode assembly (JR) according to claim 26, wherein a plurality of segment alignments (50) included at one end of the electrode assembly (JR) and a plurality of segment alignments (50) included at the other end of the electrode assembly (JR) are arranged to be symmetrical with respect to a plane to each other.

28. The electrode assembly (JR) according to claim 1, wherein the total number of winding turns of the electrode assembly (JR) is from 20 to 55, and the electrode assembly (JR) has a diameter of 35 mm to 50 mm.

29. A battery, comprising: an electrode assembly (JR) wherein a first electrode,A second electrode and a spacer interposed thereon are wound about a winding axis to define a core (C) and an outer circumference, wherein the first electrode includes a first active material portion coated with a layer of active material (42) along a winding direction (X) and a first uncoated portion (146a) not coated with a layer of active material (42) and projecting outside the spacer (Se), the first uncoated portion (146a) includes a segment region (B2) divided into a plurality of independently bendable segments by a plurality of shear slots provided along the winding direction (X), the segment region (B2) includes a plurality of segment groups (61g) divided by a group separation step (PG) along the winding direction (X),one end of the electrode assembly (JR) includes a plurality of segment alignments (50) in which the plurality of segment groups (61g) are aligned to overlap along a radial direction, the segments included in each segment alignment (50) are bent along the radial direction to form a bending surface region (F) in which the bending surface region (F) partially covers a surface of one end of the electrode assembly (JR), and in winding turns corresponding to the plurality of segment alignments (50), the separation steps of segment groups arranged in the same winding turn are substantially identical, and the separation step (P) of the segment groups is greater in a winding turn of a region adjacent to the outer circumference than in a winding turn of a region adjacent to the core (C),wherein "substantially identical" with respect to the group separation step (PG) refers to a deviation of 10% or less; a battery housing (171) configured to house the electrode assembly (JR) and electrically connected to one of the first and second electrodes to have a first polarity; a sealing body (143) configured to seal an open end of the battery housing (171); and a terminal having an externally exposed surface and electrically connected to the other of the first and second electrodes to have a second polarity.

30. The battery according to claim 29,further comprising: a flange portion (147) formed by press-fitting an outer circumference of the open end of the battery housing (171) into the battery housing (171); a current-collecting plate (Pc) electrically coupled to the flex surface region (F); and an insulator (174) configured to cover the current-collecting plate (Pc) and having a flange interposed and fixed between an inner circumference of the flange portion (147) and the current-collecting plate (Pc).

31. The battery according to claim 29, wherein a cavity is provided in the core (C) of the electrode assembly (JR), and the cavity is not blocked by the flex surface region (F) and is open to the outside.

32. The battery according to claim 29, wherein the sealing body (143) includes a cap plate (143a) configured to seal the open end of the battery housing (171),and a gasket configured to surround an edge of the cap plate (143a) and crimped into an upper end of the battery housing (171), the terminal having the second polarity being the cap plate (143a).

33. The battery according to claim 29, further comprising: a current-collecting plate (Pc) electrically connected to the uncoated portion of the second electrode having the first polarity and having an edge at least partially coupled to a side wall of the battery housing (171), wherein the sealing body (143) includes a cap plate (143a) without any polarity and a gasket configured to surround an edge of the cap plate (143a) and crimped into the upper end of the battery housing (171),and the battery housing (171) includes a rivet terminal (172) installed to be insulated in a drilled hole formed in the center of a closed surface and electrically connected to the first electrode to have the second polarity.

34. A battery pack (300), comprising a plurality of batteries according to any one of claims 29 to 33.

35. A vehicle (V), comprising the battery pack (300) according to claim 34.

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