Battery and battery pack and vehicle with it

Abstract

Battery (1) comprising: a coiled electrode assembly (A; 10) having a first electrode (210) and a second electrode (211) and a separator (212) arranged therebetween, wherein the first electrode (210) has a first uncoated region (11; 210a) and the second electrode (211) has a second uncoated region (12; 211a), wherein the first uncoated region (11; 210a) and the second uncoated region (12; 211a) are free of an active material, wherein the first uncoated region (11; 210a) and the second uncoated region (12; 211a) are adjacent to a respective edge of the first electrode (210) and the second electrode (211) extending along a winding direction of the coiled electrode assembly (A; 10), wherein the first uncoated region (210a) and the second uncoated area (211a) at the edge extends beyond the separator (212); a battery can (20; 241) receiving the electrode assembly (A; 10) and electrically connected to the second uncoated region (12; 211a), the battery can (20; 241) having a first end face, a second end face, and a cylindrical side wall extending between the first end face and the second end face, the second end face having an opening, and the battery can (20; 241) being made of steel, stainless steel, and / or nickel-plated steel; a terminal (40) electrically connected to the first uncoated region (11; 210a) and penetrating the first end face of the battery can (20; 241); a cap (30) covering and closing the opening of the second end face of the battery can (20; 241); a first current collector (60) coupled to an end face of the electrode assembly, the first current collector being coupled to the terminal (40) to electrically connect the first uncoated region of the electrode assembly and the terminal, wherein at least a part of a lower surface of the terminal is formed as a flat portion parallel to an inner surface of the first end surface of the battery can, wherein the first current collector is directly coupled to the flat portion of the terminal; wherein a thickness of the side wall of the battery can (20; 241) is smaller than a thickness of the first end surface of the battery can (20; 241).

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a battery and a battery pack, and a vehicle including the battery. More specifically, the present disclosure relates to a cylindrical battery in which both a positive electrode terminal and a negative electrode terminal are arranged adjacently on each side of the cylindrical battery without greatly deviating from the structure of a conventional cylindrical battery, and to a battery pack and a vehicle including the cylindrical battery. STATE OF THE ART

[0002] Secondary batteries, which are easily applicable to various product groups and have electrical properties such as high energy density, are universally used not only for portable devices but also for electric vehicles (EVs) or hybrid electric vehicles (HEVs) powered by an electric power source.

[0003] These secondary batteries are attracting attention as a new energy source to improve environmental friendliness and energy efficiency because they have the main advantage of drastically reducing the use of fossil fuels and the secondary advantage of not producing any by-products from the use of energy.

[0004] Secondary batteries currently widely used in technology include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, and the like. A unit secondary battery has an operating voltage of approximately 2.5V to 4.5V. Therefore, when a higher output voltage is required, a battery pack is configured by connecting a plurality of batteries in series. In addition, a plurality of batteries may be connected in parallel to form a battery pack according to the charge / discharge capacity required for the battery pack. Accordingly, the number of batteries included in the battery pack and the form of electrical connection can be variously set according to the required output voltage and / or charge / discharge capacity.

[0005] Meanwhile, cylindrical, rectangular, and pouch-shaped batteries are known as a type of secondary battery. In the case of a cylindrical battery, a separator serving as an insulator is interposed between a positive electrode and a negative electrode, and they are wound to form an electrode assembly in a jelly-roll structure, which is inserted into a battery can together with an electrolyte to configure a battery. In addition, a strip-shaped electrode tab may be connected to an uncoated portion of both the positive electrode and the negative electrode, and the electrode tab electrically connects the electrode assembly and an externally exposed electrode terminal. For example, the positive electrode terminal is a cap of a sealing body that seals the opening of the battery can, and the negative electrode terminal is the battery can.

[0006] However, in the conventional cylindrical battery having such a structure, since current is concentrated in the strip-shaped electrode tab coupled to the uncoated region of the positive electrode and / or the uncoated region of the negative electrode, the current collection efficiency is not good due to a large resistance and a large heat generation.

[0007] For small cylindrical batteries with a form factor of 18650 or 21700, resistance and heat are not a major problem. However, when the form factor is increased to use the cylindrical battery in an electric vehicle, the cylindrical battery can self-ignite if excessive heat is generated around the electrode tab during the fast charging process.

[0008] To solve this problem, a cylindrical battery (so-called 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 positioned at the top and bottom of the rolled electrode assembly, respectively, and the current collector is welded to the uncoated portion to improve the current collection efficiency. DESCRIPTION

[0009] The Fig. 1 to Fig. 3 schematically show a method for producing a tabless, cylindrical battery, Fig. 1 shows the structure of an electrode, Fig. 2 shows a method of winding the electrode, and Fig. 3 shows a method for welding a current collector to a curved surface of an uncoated area. Fig. 4 shows a sectional view of a tabless, cylindrical battery along the longitudinal direction Y.

[0010] With reference to the Fig. 1 to Fig. 4, a positive electrode plate 210 and a negative electrode plate 211 have a structure in which a plate-shaped current collector 220 is coated with an active material 221, and include an uncoated region 222 on one longitudinal side along the winding direction X.

[0011] An electrode assembly A is manufactured by stacking the positive electrode 210 and the negative electrode 211 one after another together with two separating sheets 212 as shown in Fig. 2, and then wound in a direction X. At this time, the uncoated portion of the positive electrode 210 and the uncoated portion of the negative electrode 211 are arranged in opposite directions.

[0012] After the winding process, the uncoated portion 210a of the positive electrode 210 and the uncoated portion 211a of the negative electrode 211 are bent toward the core. Current collectors 230, 231 are then welded and coupled to the uncoated portions 210a and 211a, respectively.

[0013] An electrode tab is not separately coupled to the uncoated region 210a of the positive electrode and the uncoated region 211a of the negative electrode. The current collectors 230, 231 are connected to external electrode terminals, and a current path with a large cross-sectional area along the winding axis direction of the electrode assembly A (see arrow) is formed, which has the advantage of reducing the battery's resistance. This is because the resistance is inversely proportional to the cross-sectional area of ​​the path through which the current flows.

[0014] However, as the form factor of the cylindrical battery increases and the magnitude of the charging current during fast charging increases, the thermal problem of the tabless cylindrical battery reappears.

[0015] In particular, the conventional tabless cylindrical battery 240 comprises a battery can 241 and a sealing body 242 as shown in Fig. 4. The sealing body 242 includes a plate-shaped cap 242a, a gasket 242b, and a connecting plate 242c. The gasket 242b surrounds the edge of the cap 242a and is secured by a crimp portion 243. Additionally, the electrode assembly A is fixed in the battery can 241 by a bead portion 244 to prevent vertical movement.

[0016] Typically, the positive electrode terminal is the cap 242a of the sealing body 242, and the negative electrode terminal is the battery can 241. Therefore, the current collector 230, which is coupled to the uncoated portion 210a of the positive electrode 210, is electrically connected to the connecting plate 242c, which is attached to the cap 242a in a strip shape by a lead 245. In addition, the current collector 231, which is coupled to the uncoated portion 211a of the negative electrode 211, is electrically connected to the bottom of the battery can 241. The insulator 246 covers the current collector 230 to prevent the battery can 241 and the uncoated portion 210a of the positive electrode 210, which have different polarities, from touching each other and causing a short circuit.

[0017] When the current collector 230 is connected to the connecting plate 242c, the lead 245 is used in a strip shape. The lead 245 is separately attached to the current collector 230 or formed integrally with the current collector 230. However, since the lead 245 is in the shape of a thin strip, its cross-sectional area is small, and thus, when a rapid charging current flows, a lot of heat is generated. In addition, excess heat generated by the lead 245 is transferred to the electrode assembly A to shrink the separator 212, which can cause an internal short circuit, which is a major cause of thermal runaway.

[0018] The conduit 245 also occupies significant space within the battery container 241. Therefore, the cylindrical battery 240 incorporating the conduit 245 has low space efficiency, which limits the increase in energy density.

[0019] Furthermore, to connect the conventional tabless cylindrical batteries 240 in series and / or parallel, it is necessary to connect a busbar component to the cap 242a of the battery can 241 and the bottom surface of the sealing body 242, which reduces space efficiency. A battery pack mounted on an electric vehicle includes hundreds of cylindrical batteries 240. Accordingly, the inefficiency of the electrical wiring causes significant disruption to the electric vehicle assembly process and battery pack maintenance.

[0020] Meanwhile, with the recent use of cylindrical batteries in electric vehicles, the form factor of the cylindrical battery has increased. That is, the diameter and height of the cylindrical battery have increased compared to conventional cylindrical batteries with a form factor of 18650, 21700, or the like. This increase in the form factor leads to increased energy density, increased resistance to thermal runaway, and improved cooling efficiency.

[0021] The energy density of the cylindrical battery can be further increased by minimizing the unnecessary space in the battery can as the form factor increases. Therefore, components used for electrical insulation between the electrode assembly and the battery can, or components used for current collection from the positive and negative electrodes, must be optimally designed to increase battery capacity and reduce overall battery resistance. TECHNICAL TASK

[0022] The present disclosure is designed with the above objects in mind, and therefore, the present disclosure is directed to providing a cylindrical battery having a structure in which a positive electrode terminal and a negative electrode terminal are attached in the same direction.

[0023] The present disclosure is directed to ensuring sufficient space for welding an electrical connection component, such as a bus bar, to an electrode terminal of a cylindrical battery during manufacture of a battery pack by using a wide area of ​​a closed portion of a battery can as an electrode terminal when a plurality of cylindrical batteries are to be electrically connected in one direction.

[0024] According to another aspect, the present disclosure is directed to design optimization such that the area occupied by the upper surface of the terminal (first electrode terminal) and the area occupied by the outer surface (second electrode terminal) of the closed portion may be sufficient for coupling to a busbar.

[0025] According to yet another aspect, the present disclosure is directed to minimizing the resistance of the cylindrical battery by increasing a contact area of ​​the electrode assembly and the current collector (first current collector) and / or a contact area of ​​the terminal and the current collector (first current collector) by improving the structure of the uncoated portion of the electrode assembly.

[0026] According to yet another aspect, the present disclosure is directed to improving the electrical connection structure between the current collector (second current collector) and the battery can for multiplexing a current path and to maximizing the contact area to minimize the resistance of the cylindrical battery.

[0027] According to yet another aspect, the present disclosure is directed to reducing the current path by improving the electrical connection structure of the current collector (second current collector) and the battery can, thereby minimizing the resistance of the cylindrical battery.

[0028] In yet another aspect, the present disclosure is directed to minimizing dead space by improving the structure of the uncoated area of ​​the electrode assembly and / or optimally designing the height of the terminal and / or optimally designing the thickness of the battery can, thereby maximizing energy density.

[0029] However, the technical problem to be solved by the present disclosure is not limited to the above, and other problems not mentioned here will become clear to those skilled in the art from the following disclosure. TECHNICAL SOLUTION

[0030] The present invention is defined by the subject matter of claim 1. Particular examples for implementing the present invention are defined by the features of the dependent claims. The claimed subject matter may include any of the features defined above with reference to Fig. 1 to Fig. 3, unless otherwise stated or inappropriate

[0031] A battery may include a rolled electrode assembly, a battery can, a terminal, and a cap. The rolled electrode assembly may include a first electrode and a second electrode. The first electrode may include a first uncoated region. The second electrode may include a second uncoated region. Any or both of the first and second uncoated regions may be free of (i.e., not coated with) an active material. Any or both of the first and second uncoated regions may be disposed adjacent to a respective edge (e.g., disposed at a long side end) of the first electrode and the second electrode, respectively. The edge of the first and / or second electrode may extend along a winding direction of the electrode assembly.Any or both the first and second uncoated regions may extend beyond and / or be exposed from the separator at the respective edge of the first electrode and the second electrode, respectively. The battery can may house the electrode assembly. The battery can be electrically connected to the second uncoated region. The battery can may include a first end face, a second end face, and a sidewall extending between the first end face and the second end face. The sidewall of the battery can may be a cylindrical sidewall. The second end face may have an opening. The terminal may be electrically connected to the first uncoated region. The terminal may penetrate the first end face of the battery can. The cap may cover and / or seal the opening of the second end face of the battery can.

[0032] In another example, a battery may include: a rolled-up electrode assembly having a first electrode and a second electrode and a separator disposed therebetween, each of the first electrode and the second electrode having a first uncoated region and a second uncoated region that are not coated with an active material and are exposed from the separator at their long side ends; a battery can that accommodates the electrode assembly through an opening at a lower end thereof and is electrically connected to the second uncoated region; a terminal that is electrically connected to the first uncoated region and is exposed from the battery can through a closed portion of the battery can that is opposite to the opening; and a cap that covers and seals the opening of the battery can.

[0033] The rolled electrode assembly may comprise a laminate structure in which the positive electrode, the separator, and the negative electrode are stacked on top of one another. The laminate structure may be wound around a wound core to form the rolled electrode assembly. The wound core may be empty, filled, or partially filled. The rolled electrode assembly may have a (generally) cylindrical geometry defining a radial direction, an axial direction, and a circumferential (tangential) direction according to the teachings of mathematical geometry. Thus, the sidewall of the battery may refer to a side surface of the battery can that extends in the circumferential and axial directions. The first end surface and the second end surface of the battery can may each extend in the circumferential and radial directions.

[0034] In an unrolled view (i.e., without wrapping or rolling) of the electrode assembly, optionally the first electrode, the second electrode, and / or the separator may extend between two respective long side ends in the axial direction of the rolled electrode assembly. Optionally, the first electrode, the second electrode, and / or the separator extend between two respective short side ends in the winding direction (approximately circumferential direction) of the rolled electrode assembly. In some examples, any one of the long side ends may be longer than the short side ends. Alternatively, the terms long and short may be merely denominations, and any one of the short side ends may be longer than the long side ends. Any one of the long side ends may be linear, curved, or patterned (e.g., segmented, as described below), or a combination thereof.

[0035] Additionally or alternatively, the long side end of any of the first and second electrodes and / or the separator may correspond to a longer or longest side end of any of the plate-shaped first and second electrodes and / or the separator. For example, for any of the first and second electrodes and / or the separator having a substantially rectangular shape before being rolled up to form the electrode assembly of the battery, an edge of the rectangle formed by any of the unrolled first and second electrodes and / or the separator corresponding to the longer side of the rectangle may correspond to a respective "long side end." The long side end of any of the first and second electrodes and / or the separator may therefore be perpendicular to a height direction of the battery.In the direction perpendicular to the height of the battery, the uncoated portion of the respective electrode may protrude from and / or extend beyond the separator.

[0036] The first electrode may comprise a plate, sheet, or foil coated with the first electrode active material, e.g., by depositing or spraying the active material onto the first electrode plate, sheet, or foil. The first electrode may be coated or covered with the active material except for the uncoated region, which may be referred to as the first uncoated region. The first uncoated region may be formed at (along) one of the long side ends of the first electrode. The first electrode may be a positive electrode. Alternatively, the first electrode may be a negative electrode. The first electrode plate, sheet, or foil may comprise a metal.

[0037] The second electrode may comprise a plate, sheet, or foil coated with the active material of the second electrode, e.g., by depositing or spraying the active material onto the plate, sheet, or foil of the first electrode. The first electrode may be coated or covered with the active material except for the uncoated region, which may be referred to as the second uncoated region. The second uncoated region may be formed at (along) one of the long side ends of the second electrode. The second electrode may be a positive electrode. Alternatively, the second electrode may be a negative electrode. If the first electrode is a positive electrode, the second electrode may be a negative electrode, and vice versa. The active material of the second electrode may be different from the active material of the second electrode.The plate, sheet, or foil of the second electrode may comprise a metal. The metal of the second electrode may be different from the metal of the first electrode.

[0038] The battery can may have a (generally or approximately) cylindrical shape. The battery can may have a hollow interior volume to accommodate the rolled electrode assembly. The battery can may be considered a housing or casing for the rolled electrode assembly. The battery can may have an (approximately) cylindrical geometry. According to the cylindrical geometry, the battery can may have an axial direction, a radial direction, and a (tangential) circumferential direction. The directions may be similar or identical to the respective direction of the (approximately) cylindrical geometry of the electrode assembly. The battery can may have any of the features of the battery can, as described below with reference to the drawings.

[0039] The first end face of the battery can may be partially or mostly closed. Here, the first end face of the battery can may refer to the geometric construct (in terms of mathematical geometry) and may not be completely solid. The first end face of the battery can may be referred to as a closed portion. The first end face may comprise an opening, for example, in a central part in a plan view (i.e., when viewed in the axial direction of the battery can). The opening in / the first end face of the battery can extend through a full thickness of the battery can at the first end face (i.e., be a through-hole). As described herein, the terminal of the battery may pass through the opening of / in the first end face of the battery can. The opening in the first end face may have a circular or a polygonal cross-section.The first end face of the battery can may include any of the features of the closed portion as described below with reference to the drawings.

[0040] The second end face of the battery can may be largely open (empty, hollow). Here, the second end face of the battery can may refer to the geometric construct (in terms of mathematical geometry) and may be solid only at one boundary (perimeter, edge), which may be implemented by a round region, as described below. The second end face of the battery can may have an opening or may itself (simply) be referred to as an opening of the battery can. The opening may form a central part or the main part of the second end face in a plan view (i.e., when viewed in the axial direction of the battery can). The opening of the second end face of the battery can may extend through a full thickness of the battery can at the second end face (i.e., be a through-opening).The opening in the second end face of the battery may be configured such that the electrode assembly may be inserted through the opening in the second end face of the battery can. The opening in the second end face may have a circular or polygonal cross-section. The second end face of the battery can may include any of the features of a battery can opening, as described below with reference to the drawings.

[0041] The sidewall of the battery can may be referred to as a cylindrical sidewall of the battery can. The sidewall may completely surround the electrode assembly housed within the battery can. The sidewall of the battery can may provide a cylindrical side surface of the battery can, which may also be referred to as an outer peripheral surface. A portion of the sidewall may be further deformed (e.g., press-fitted) to form a bead portion extending inwardly in a radial direction. The sidewall of the battery can may include any of the sidewall or outer peripheral surface features, as described below with reference to the drawings.

[0042] The cap may be sized and / or arranged to close the opening of the second end face of the battery can. As described below, the cap may include a vent portion for releasing gas when a predetermined pressure is reached within the battery can. The cap may also be referred to as a cap plate. The cap may include any of the cap features described below with reference to the drawings.

[0043] The cap may have no polarity (or be designed to have one). The polarity may indicate a chemical potential equal to a chemical potential at any one of the first electrode and the second electrode. For example, the cap may be electrically insulated from any one or both of the first electrode and the second electrode.

[0044] The terminal may penetrate (be configured to penetrate) a center of the closed portion. As mentioned above, the closed portion may refer to the first end face of the battery can. The terminal may penetrate the first end face of the battery can. The terminal may be arranged to extend through the first end face of the battery can. For example, the terminal may be arranged through the opening in the first end face of the battery can.

[0045] The battery may further include an insulating gasket. The insulating gasket may be disposed between the battery can and the terminal. The insulating gasket may be provided on the side of the closed portion of the battery can. The battery may further include a gasket. The gasket may be disposed between the battery can and the cap such that the cap seals the opening. The gasket may be disposed such that the cap seals the opening of the second end face of the battery can. The insulating gasket may include any of the features of the insulating gasket as described below with reference to the drawings. The gasket may include any of the features of the gasket as described below with reference to the drawings.

[0046] The battery may further comprise a first bus bar terminal and / or a second bus bar terminal. A surface of the terminal exposed from the battery can may serve as a first electrode terminal to which a first bus bar terminal is coupled. A region of an outer surface of the closed portion of the battery can that may be occupied by an exposed surface parallel to a top surface of the first electrode terminal may serve as a second electrode terminal to which a second bus bar terminal is coupled. The first or second bus bar terminal may include any of the features of the respective bus bar terminal, as described below with reference to the drawings.

[0047] The first busbar terminal may overlap, lie on, or touch the first electrode terminal at a level to form a first overlap region. The second busbar terminal may overlap, lie on, or touch the second electrode terminal at a level to form a second overlap region.

[0048] A diameter of the first electrode terminal and a width of the second electrode terminal can satisfy the following formulas: W1≤E1≤D−2Rd−2G−2 W2 E2=0.5⋅(D−2Rd−2G−E1)

[0049] (E1: Diameter of the terminal exposed from the battery can (diameter of the first electrode terminal), E2: Width of the exposed surface of the outer surface of the closed portion of the battery can, for example, parallel to the upper surface of the terminal (width of the second electrode terminal), D: Outer diameter of the battery can, Rd: Width of a round area at an edge of the battery can in a plan view (measured on a plane), G: Exposure width of an insulating gasket exposed from an edge of the first electrode terminal on a plane, W1: Maximum value of distances between two arbitrarily selected points at an edge of the first overlapping area; W2: Maximum value of distances between two points where multiple straight lines passing through a center of the first electrode terminal meet an edge of the second overlapping area).

[0050] An area of ​​the first electrode terminal (occupied by the first electrode terminal) may be 2% to 30% compared to an area of ​​the second electrode terminal (occupied by the second electrode terminal). Each of these areas may refer to a plan view viewed parallel to the axial direction of the battery can.

[0051] A ratio obtained by dividing a battery's diameter by its height may be greater than 0.4. This ratio may be referred to as a form factor ratio. The diameter and height can be determined according to the cylindrical geometry of the battery can.

[0052] At least a portion of the first uncoated region may include a plurality of segments divided along a winding direction of the electrode assembly. The plurality of segments may be bent along a radial direction of the electrode assembly.

[0053] The segments may be separate or distinct parts of the first uncoated region of the first electrode (referred to as such). The first uncoated region may be repeatedly and differently notched in parts to form the segments. The first uncoated region may be repeatedly cut inwardly from its edge (i.e., from the long side edge of the first electrode) in the axial direction of the rolled electrode assembly to form the segments. The cutting or notching may be performed or provided in any manner as described below with reference to the drawings. The segments may have any of the features as described below with reference to the drawings.

[0054] The winding direction may be along an edge of the first electrode, the second electrode, and / or the separator that extends around the winding center of the rolled electrode assembly. Accordingly, the winding direction of the electrode assembly may be a spiral. Approximately, the winding direction of the electrode assembly may be considered to be substantially identical to the (tangential) circumferential direction of the electrode assembly.

[0055] The plurality of curved segments may overlap each other to form a plurality of overlapping layers extending along the radial direction. The plurality of curved segments may be overlapped in a plurality of layers along the radial direction.

[0056] The electrode assembly may include a welding target region in which the number of overlapping layers of the segments of the first uncoated region is (maintained) constant along the radial direction of the electrode assembly. The welding target region may be a region or a region to which a current collector (for example, any of the first and second current collectors described below) is or can be welded. The welding target region may be provided by bending the segments to provide a (substantially) planar or flat surface of adjacent segments of the first uncoated region. The planar surface may face (substantially) in the axial direction.

[0057] At least a part of the second uncoated region may include a plurality of segments divided along a winding direction of the electrode assembly, and the plurality of segments may be bent along a radial direction of the electrode assembly.

[0058] The plurality of curved segments may be overlapped in multiple layers along the radial direction.

[0059] The electrode assembly may comprise a welding target region in which the number of overlapping layers of the segments of the second uncoated region is (maintained) constant along the radial direction of the electrode assembly. The welding target region may be a region or a region to which a current collector (for example, optionally the first and / or second current collectors described below) is or can be welded. The welding target region may be provided by bending the segments to provide a (substantially) planar or flat surface of adjacent segments of the second uncoated region. The planar surface may face (substantially) in the axial direction.

[0060] The battery box can be made of steel, stainless steel and / or nickel-plated steel.

[0061] The battery can can be designed to have different thicknesses depending on the location. In other words, the battery can can have a thickness that varies locally. The thickness of the battery can can vary as described below.

[0062] A thickness of the side wall of the battery can may be smaller than a thickness of the first end surface of the battery can, which may be the closed portion.

[0063] The first end surface of the battery can, ie the closed section, can have a thickness of 0.4 mm to 1.2 mm.

[0064] The side wall of the battery can have a thickness of 0.3 mm to 0.8 mm.

[0065] A nickel-plated layer formed on the battery can.

[0066] The nickel-plated layer can have a thickness of 1.5 m to 6.0 m.

[0067] The battery can may include a rounded portion connecting between the side wall and the first end surface (the closed portion) of the battery can. The rounded portion may form an edge between the side wall of the battery can and the first end surface of the battery can. The rounded portion may surround the first end surface. The rounded portion may have a ring shape. The rounded portion may include any of the features described below with reference to the drawings.

[0068] The battery can may include a bead portion formed by press-fitting a periphery of the side wall, i.e., the outer peripheral surface, of the battery can to the second end surface of the battery can. Here, the second end surface may be located near or adjacent to the second end surface in the axial direction. The bead portion may form a circumferential recess, notch, or groove extending inward from the side wall of the battery in the radial direction.

[0069] The bead portion may include an upper bead portion and a lower bead portion located above and below an innermost portion, respectively, in the radial direction. The innermost portion may refer to a portion located on an innermost side along the press-fitting direction. The upper bead portion and the lower bead portion may be parts of the bead portion facing in the opposite axial direction. For example, the upper bead portion may be proximal to the first end face of the battery can. For example, the lower bead portion may be proximal to the second end face of the battery can.

[0070] The upper bead portion and the lower bead portion may be asymmetrical. In particular, the upper bead portion and the lower bead portion may be asymmetrical with respect to a plane perpendicular to the axial direction. The upper bead portion and the lower bead portion may be asymmetrical with respect to one another.

[0071] The lower bead portion may include a flat portion parallel to the first end surface, i.e., the closed portion, of the battery can.

[0072] The upper bead portion may be at least partially inclined in an axial direction from the side wall of the battery can to the innermost portion of the bead portion. For example, the upper bead portion may be inclined, bent, or curved toward the first end surface or the second end surface.

[0073] The upper bead portion may be configured to press and / or secure a lower portion of the electrode assembly. For example, the upper bead portion may be shaped, arranged, and / or dimensioned to press and / or secure an end surface of the rolled electrode assembly.

[0074] The battery can may include a crimping portion formed below the bead portion and having a shape extending from the bead portion and curved to surround an outer peripheral surface of the cap and a portion of a bottom surface of the cap. The crimping portion may include any of the features of the crimping portion, as described below with reference to the drawings.

[0075] The battery may include a seal located at the crimp portion between the battery can and the cap. The seal may include any of the seal features described below with reference to the drawings.

[0076] The cap may include a vent portion configured to rupture when an internal pressure of the battery can rises above a predetermined level to vent gas generated within the battery can. The vent portion may include any of the vent portion features described below with reference to the drawings.

[0077] The venting portion may be a region of the cap that has a smaller thickness than surrounding regions. The venting portion may be a region of the cap that has a reduced thickness compared to a remainder of the cap.

[0078] The vent portion may be formed by forming a notch on one or both surfaces of the cap to partially reduce a thickness of the battery can. The vent portion may be formed by locally reducing a thickness of the battery can by forming a notch on one or both surfaces of the cap.

[0079] The vent portion may be formed along a periphery of an edge portion of a central portion projecting downwardly below the entire portion of the cap. The vent portion may be formed around a central portion projecting from a remainder of the cap in a direction opposite to the first end face of the battery can.

[0080] The venting section may be continuous. The venting section may be discontinuous.

[0081] The vent portion may be formed in a central region projecting downwardly below the entire portion of the cap, and the central region projecting downwardly may be located higher than a lower end of the battery can. The vent portion may be formed in a central region of the cap and project from the cap in the axial direction opposite to the first end face of the battery can. The central region may be offset from the second end face of the battery can toward the first end face of the battery can.

[0082] The terminal may include a terminal exposure portion exposed from the battery can. The terminal may include a terminal insertion portion provided by the closed portion of the battery can and located within the battery can. The terminal insertion portion may extend through the first end face of the battery can into the battery can.

[0083] The terminal insert portion may include an electrical connection portion electrically connected to the first uncoated area; and a flange portion formed on a periphery of the electrical connection portion and having a shape bent toward an inner surface of the first end surface (the closed portion) of the battery can to be riveted to the inner surface.

[0084] The connector can be made of aluminum.

[0085] A step may be formed between a top surface of the terminal exposure portion and the first end surface (which may also be referred to as a top surface) of the battery can. The step may be (referred to as) an edge or a ridge. The step may surround the terminal exposure portion. The step may be a boundary between the terminal exposure portion and the top surface of the battery can. The step may be formed by a difference in the positions of the terminal exposure portion and the first end surface (the top surface) of the battery can in the axial direction.

[0086] The terminal exposure portion may protrude from the battery can through the first end surface of the battery can.

[0087] The height of the step may be 0.8 mm or more. The height of the step may be a dimension in the axial direction between the first end surface of the battery can and the terminal exposure portion.

[0088] An insulating gasket may be disposed between the terminal and the battery can, and the insulating gasket may include a seal exposure portion disposed between the terminal exposure portion and the battery can; and a seal insertion portion disposed between the terminal insertion portion and the battery can. The insulating gasket, the seal exposure portion, and the seal insertion portion may each include any of the respective features, as described below with reference to the drawings.

[0089] The seal exposure section may have a thickness of 0.3 mm to 1 mm.

[0090] The seal exposure portion may extend longer than the terminal exposure portion so that it is exposed from the terminal exposure portion.

[0091] The sealing insert portion may be deformed when the flange portion of the terminal insert portion is riveted to be fixed to and / or in close contact with, seal against, or adhere to an inner surface of the first end surface (closed portion) of the battery can.

[0092] An area of ​​the seal insert portion (seal exposure portion) exposed from the terminal exposure portion may extend (have a width) by 0.1 mm to 3.0 mm. This can be measured in the radial direction.

[0093] The battery may include a first current collector coupled to an end face (upper portion) of the electrode assembly and coupled to the terminal to establish an electrical connection between the first uncoated area of ​​the electrode assembly and the terminal. The end face of the electrode assembly may be proximal to the first end face of the battery can.

[0094] The terminal may include a flat portion. At least a portion of a bottom surface of the terminal may be formed as a flat portion parallel to an inner surface of the first end surface (the closed portion) of the battery can. The flat portion may be formed in at least a portion of a bottom surface of the terminal. The first current collector may be coupled to the flat portion of the terminal.

[0095] The first current collector may be coupled to a coupling surface formed by bending one end of the first uncoated portion.

[0096] The battery may include a first current collector coupled to an upper portion of the electrode assembly and coupled to the terminal to electrically connect the first uncoated region of the electrode assembly and the terminal. The first current collector may be coupled to the first uncoated region within the weld target area, as indicated above or described below with reference to the drawings.

[0097] The first current collector may include an edge portion disposed on the electrode assembly; a first coupling portion of the uncoated area configured to extend inwardly from the edge portion and be coupled to the first uncoated area; and a terminal coupling portion configured to extend inwardly from the edge portion and be coupled to the terminal. The edge portion, the first coupling portion of the uncoated area, and the terminal coupling portion may each include any of the respective features described below with reference to the drawings.

[0098] The first coupling portion of the uncoated region and the terminal coupling portion may be connected via (through) the edge portion. The first coupling portion of the uncoated region and the terminal coupling portion may not be connected directly, but rather indirectly through the edge portion. In other words, the edge portion may connect the first coupling portion of the uncoated region to the terminal coupling portion.

[0099] The terminal coupling portion may be provided at a location corresponding to an opening formed at a winding center of the electrode assembly. The winding center may result from winding the laminate structure of the electrode assembly as described above. The winding center may be at least partially hollow (empty, open), thereby forming the opening in the axial direction in a plan view. The winding center may be substantially (approximately) cylindrical. The opening may have a circular shape in plan view.

[0100] The terminal coupling portion may be sized and arranged to completely cover the opening. The terminal coupling portion may be configured to cover the opening formed at the winding center, so that the opening formed at the winding center of the electrode assembly is not exposed from the terminal coupling portion.

[0101] The terminal coupling portion may have a diameter substantially equal to or greater than a diameter of the flat portion as specified above and described below with reference to the drawings.

[0102] The first current collector may further include a bridge portion extending between the edge portion and the terminal coupling portion. The bridge portion may be connected between the edge portion and the terminal coupling portion. The bridge portion may extend in the radial direction.

[0103] The bridge portion may include a notch portion formed to locally reduce a cross-section of the bridge portion. The cross-section may refer to a plane in the axial and radial directions. The bridge portion may include any of the features of the bridge portion described below with reference to the drawings.

[0104] At least a part of the first uncoated region may include a plurality of segments divided along a winding direction of the electrode assembly, and the segments may be bent along a radial direction of the electrode assembly to form a plurality of overlapping layers. The notch portion may be provided in a region corresponding to a welding target region in which the number of overlapping layers of the segments of the first uncoated region is (maintained) constant. The segments may be as specified above and may include any features of the segments as described below with reference to the drawings. The welding target region may be as specified above and may include any features of the welding target region as described below with reference to the drawings.

[0105] The notch portion may be provided at a position corresponding to a center in the radial direction of the electrode assembly.

[0106] A weld pattern drawn by weld beads formed on a surface of the terminal coupling portion of the first current collector may surround (be drawn) a center of a bottom surface of the terminal. The weld pattern may include any of the features of the weld pattern, as described below with reference to the drawings.

[0107] The weld pattern can be continuous. The weld pattern can be discontinuous.

[0108] The terminal coupling portion of the first current collector and a bottom surface (e.g., the flat surface) of the terminal may be welded to have a tensile force of 2 kgf or more.

[0109] A welding pattern drawn by welding beads formed on a surface of the terminal coupling portion of the first current collector may have a converted diameter of 2 mm or more.

[0110] A flat portion formed on the bottom surface of the terminal may have a diameter of 3 mm to 14 mm. The flat portion may be as specified above.

[0111] A ratio of an area of ​​a welding pattern drawn by welding beads formed on a surface of the terminal coupling portion of the first current collector to an area of ​​a flat portion formed on the bottom surface of the terminal may be 2.04% to 44.4%.

[0112] The battery may include a second current collector coupled to another end surface (a lower portion) of the electrode assembly. The second current collector may be coupled to the battery can to electrically connect the second uncoated region of the electrode assembly to the battery can. The other end surface of the electrode assembly may be proximal to the second end surface of the battery can.

[0113] The second current collector may be coupled to a coupling surface formed by bending one end of the second uncoated region. The coupling surface may be a region or a surface where the second current collector and the second uncoated region are in contact.

[0114] The battery may include a second current collector coupled to a lower portion of the electrode assembly and coupled to the battery can to electrically connect the second uncoated region of the electrode assembly and the battery can. The second current collector may be coupled to the second uncoated region within the weld target area, as noted above.

[0115] The second current collector may include a support portion disposed beneath the electrode assembly; a second uncoated region coupling portion configured to extend from the support portion and be coupled to the second uncoated region; and a can coupling portion configured to extend from the support portion and be coupled to the battery can. The second current collector, the support portion, the second uncoated region coupling portion, and the can coupling portion may each include any of the respective features described below with reference to the drawings.

[0116] The second coupling portion of the uncoated area and the socket coupling portion may be connected via (through) the support portion. In other words, the support portion may physically connect between the second coupling portion of the uncoated area and the socket coupling portion.

[0117] The second current collector may include a second uncoated region coupling portion coupled to the second uncoated region; and a can coupling portion coupled to the battery can.

[0118] The second current collector may include a plurality of can coupling portions. The plurality of can coupling portions may each extend in the radial direction. The can coupling portion may be provided in multiples, and the plurality of can coupling portions may be configured to extend radially toward a side wall of the battery can.

[0119] The second current collector and the battery socket can be electrically connected at several points.

[0120] The battery can may include a bead portion formed by press-fitting the side wall (outer peripheral surface) of the battery can at the second end surface. The can coupling portion of the second current collector may be electrically coupled to a bottom surface of the bead portion. The bottom surface of the bead portion may be as specified above.

[0121] The battery can may include a crimping portion formed below the bead portion and having a shape extending from the bead portion and curved to surround an outer peripheral surface of the cap and a part of a bottom surface of the cap. The battery may include a gasket disposed at the crimping portion between the battery can and the cap. The can coupling portion may be disposed between the gasket and the bottom surface of the bead portion. The crimping portion and the gasket may each include any of the respective features as described below with reference to the drawings.

[0122] The bead portion may include a flat portion parallel to the first end surface (the closed portion) on the underside of the bead portion. The socket coupling portion may be electrically coupled to the flat portion.

[0123] The can coupling portion may include a contact portion coupled to an inner surface of the battery can; and a connecting portion connecting a center of the second current collector and the contact portion. The contact portion and the connecting portion may each have any of the features described below with reference to the drawings.

[0124] The battery can may include a bead portion formed by press-fitting the side wall (outer peripheral surface) of the battery can at the second end surface. The contact portion may have a shape extending along a circumferential direction of the battery can over a predetermined length on the bead portion. The bead portion may be as specified above.

[0125] The second current collector may have a current collector opening formed at a location corresponding to an opening formed at a winding center of the electrode assembly. The current collector opening may have any of the current collector opening features described below with reference to the drawings.

[0126] The current collector opening may have a diameter substantially equal to or larger than the opening formed at the winding center of the electrode assembly.

[0127] The battery can may include the bead portion as specified above. A maximum distance from a center of the second current collector to an end of the coupling portion of the second uncoated region along the radial direction of the electrode assembly may be substantially equal to or smaller than an inner diameter of the battery can in a region where the bead portion is formed.

[0128] The battery may further comprise an insulator disposed between the first current collector and an inner surface of the first end surface (closed portion) of the battery can.

[0129] The insulator may have a thickness corresponding to the distance between the inner surface of the first end surface (the closed portion) of the battery can and the first current collector.

[0130] The terminal may be coupled to the first current collector through an opening formed in the insulator.

[0131] The insulator may have a thickness substantially equal to or greater than the distance between the inner surface of the first end surface (the closed portion) of the battery can and a bottom surface of the terminal.

[0132] The insulator may be arranged between the first uncoated area and a side wall of the battery can.

[0133] A top surface of the insulator may be in contact with the inner surface of the closed portion of the battery can and a bottom surface of the insulator may be in contact with a top surface of the first current collector.

[0134] The resistance measured between a positive electrode and a negative electrode of the battery may be 4 mΩ or less, 3 mΩ or less, or 2 mΩ or less. The resistance may be 0.5 mΩ or more or 1.0 mΩ or more.

[0135] In another aspect of the present disclosure, a battery pack is also provided that includes a plurality of batteries according to the present disclosure.

[0136] In the battery pack of the present disclosure, the plurality of batteries may be arranged in a predetermined number of columns, and the terminal of each cylindrical battery and an outer surface of the closed portion of the battery can may be arranged to face upward.

[0137] The battery pack may include a plurality of bus bars configured to connect the batteries in series and / or parallel. The bus bars may be arranged on the batteries. Each of the bus bars may include a body portion configured to extend between terminals of adjacent batteries; a plurality of first bus bar terminals configured to extend in one lateral direction of the body portion and electrically coupled to a terminal of a battery arranged in the one lateral direction; and a plurality of second bus bar terminals configured to extend in the other lateral direction of the body portion and electrically coupled to an outer surface of the closed portion of the battery can of a battery arranged in the other lateral direction.

[0138] According to another aspect of the present disclosure, a vehicle is also provided that includes at least one battery pack according to the present disclosure. BENEFICIAL EFFECTS

[0139] According to one aspect of the present disclosure, by improving the electrode terminal structure of the cylindrical battery to increase the space efficiency in the battery can, it is possible to reduce the internal resistance of the cylindrical battery and increase the energy density.

[0140] According to another aspect of the present disclosure, by improving the structure of the electrode terminal of the cylindrical battery to increase the cross-sectional area of ​​the current path, it is possible to improve the problem of internal heat generated during rapid charging.

[0141] According to yet another aspect of the present disclosure, an electrical wiring operation for connecting the batteries in series and / or parallel may be performed on one side of the batteries.

[0142] According to yet another aspect of the present disclosure, in the case of electrically connecting a plurality of batteries in one direction, it is possible to use the wide surface of the closed portion of the battery can as an electrode terminal, thereby ensuring sufficient space for welding electrical connection components, such as bus bars, for manufacturing a battery pack to electrode terminals of the batteries.

[0143] According to yet another aspect of the present disclosure, it is possible to perform design optimization so that the area occupied by the upper surface of the terminal (first electrode terminal) and the area occupied by the outer surface (second electrode terminal) of the closed portion are sufficient for coupling to the bus bar.

[0144] According to yet another aspect of the present disclosure, by improving the structure of the uncoated portion of the electrode assembly, the contact area of ​​the electrode assembly and the current collector (first current collector) and / or the contact area of ​​the terminal and the current collector (first current collector) can be increased, thereby minimizing the resistance of the cylindrical battery.

[0145] According to yet another aspect of the present disclosure, the current path can be multiplexed by improving the electrical connection structure of the current collector (second current collector) and the battery can, and the contact area between these parts can be maximized to minimize the resistance of the cylindrical battery.

[0146] According to yet another aspect of the present disclosure, it is possible to reduce the current path by improving the electrical connection structure of the current collector (second current collector) and the battery can, thereby minimizing the resistance of the cylindrical battery.

[0147] According to yet another aspect of the present disclosure, it is possible to minimize the dead space by improving the structure of the uncoated area of ​​the electrode assembly and / or optimally designing the height of the terminal and / or optimally designing the thickness of the battery can, thereby maximizing the energy density.

[0148] According to yet another aspect of the present disclosure, it is possible to provide a battery pack manufactured using the cylindrical battery having an improved structure and a vehicle including the same. FIGURE DESCRIPTION

[0149] The accompanying drawings illustrate a preferred embodiment of the present disclosure and, together with the foregoing disclosure, serve to provide a further understanding of the technical features of the present disclosure, and therefore, the present disclosure should not be construed as limited to the drawings. Fig. 1 is a plan view showing a structure of an electrode used for a conventional tabless cylindrical battery. Fig. 2 is a diagram showing a method of winding an electrode assembly included in the conventional tabless cylindrical battery. Fig. 3 is a diagram illustrating a method of welding a current collector to a curved surface of an uncoated area in the electrode assembly of Fig. 2 shows. Fig. 4 is a sectional view of a conventional tabless cylindrical battery taken along a longitudinal direction Y. Fig. 5 is a diagram showing an appearance of a cylindrical battery according to an embodiment of the present disclosure. Fig. 6 is a diagram showing an internal structure of the cylindrical battery according to an embodiment of the present disclosure. Fig. 7 and Fig. 8 are partial sectional views showing an upper structure of the cylindrical battery according to an embodiment of the present disclosure. Fig. 9 and Fig. 10 are plan views showing a coupling portion of a first current collector and a terminal along the arrow directions of Fig. 7 and Fig. Show 8. Fig. 11 and Fig. 12 are diagrams showing the first current collector and an exemplary shape of the first current collector employed in the present disclosure. Fig. 13 is a partial sectional view showing a lower structure of the cylindrical battery according to an embodiment of the present disclosure. Fig. 14 is a diagram showing a bottom surface of the cylindrical battery according to an embodiment of the present disclosure. Fig. 15 is a diagram showing an exemplary shape of a second current collector used in the present disclosure. Fig. 16 is a plan view illustrating an exemplary electrode structure according to a preferred embodiment of the present disclosure. Fig. 17 is a sectional view of an electrode assembly in which a segmentation structure of an uncoated region of a first electrode according to an embodiment of the present disclosure is also applied to a second electrode, along the longitudinal direction Y. Fig. 18 is a sectional view of an electrode assembly in which the uncoated region is bent according to an embodiment of the present disclosure, taken along the longitudinal direction Y. Fig. 19 is a perspective view of an electrode assembly in which the uncoated region is bent according to an embodiment of the present disclosure. Fig. 20 is a top plan view showing that a plurality of cylindrical batteries according to the present disclosure are connected in series and parallel using a bus bar. Fig. 21 is a partially enlarged view of Fig. 20. Fig. 22 and Fig. 23 are diagrams illustrating exemplary parameters used to define a diameter of the electrode terminal and an exposure width of an outer surface of a bottom of the battery can according to an embodiment of the present disclosure. Fig. 24 is a diagram showing a schematic configuration of a battery pack including the cylindrical batteries according to an embodiment of the present disclosure. Fig. 25 is a diagram showing a schematic configuration of a vehicle including the battery pack according to an embodiment of the present disclosure. PREFERRED EMBODIMENT

[0150] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. At the outset of the description, it should be understood that the terms used in the specification and the appended claims should not be construed as being limited to generic and literal meanings, but should be interpreted based on the meanings and concepts corresponding to technical aspects of the present disclosure, based on the principle that the inventor is allowed to appropriately define terms for the best explanation. Therefore, the description proposed here is merely a preferred example for illustrative purposes only, which is not intended to limit the scope of the disclosure, and therefore it should be understood that other equivalents and modifications could be made thereto without departing from the scope of the disclosure.

[0151] Furthermore, to facilitate understanding of the present disclosure, the accompanying drawings are not drawn to scale; rather, the dimensions of some components may be exaggerated. Furthermore, the same components may be assigned the same reference numerals in different embodiments.

[0152] When two tasks are declared to be identical, this means that these tasks are "essentially identical." Accordingly, the essentially identical tasks may exhibit deviations that are considered small in engineering terms, for example, deviations within 5%. Furthermore, when certain parameters are declared to be uniform within a predetermined range, this may mean that the parameters are uniform with respect to an average.

[0153] With reference to the Fig. 5 to Fig. 7, a cylindrical battery 1 according to an embodiment of the present disclosure includes an electrode assembly 10, a battery can 20, a cap 30, and a penetrating terminal 40. In addition to the above components, the cylindrical battery 1 may further include an insulating gasket 50, a first current collector 60, an insulator 70, a second current collector 80, and / or a gasket 90.

[0154] The electrode assembly 10 includes a first electrode with a first polarity, a second electrode with a second polarity, and a separator disposed between the first electrode and the second electrode. The first electrode is a positive electrode or a negative electrode, and the second electrode corresponds to an electrode with a polarity opposite to that of the first electrode.

[0155] The electrode assembly 10 may, for example, have a jelly-roll structure. That is, the electrode assembly 10 may be manufactured by preparing a stack formed by stacking a first electrode and a second electrode having a sheet shape at least once with a separator interposed therebetween, and winding the stack based on a winding center C. In this case, an additional separator may be provided on an outer peripheral surface of the electrode assembly 10 for insulation from the battery can 20. The jelly-roll structure known in the art may be used without limitations for the present disclosure.

[0156] The first electrode includes a first electrode current collector and a first electrode active material coated on one or both surfaces of the first electrode current collector. At one end of the first electrode current collector in a width direction (parallel to the Z axis), there is an uncoated region not coated with the first electrode active material. Hereinafter, the uncoated region serving as the first electrode tab 11 is referred to as the first uncoated region 11. The first uncoated region 11 is provided at an upper portion of the electrode assembly 10 housed in the battery can 20 in a height direction (parallel to the Z axis).That is, the first electrode current collector includes a first uncoated region 11 that is not coated with an active material layer at its long side end and is exposed from the separator. A portion of the first uncoated region 11 is used as an electrode tab. The first uncoated region 11 may, for example, be a positive electrode tab.

[0157] Meanwhile, at least a part of the first uncoated region 11 may include a plurality of segments divided along a winding direction of the electrode assembly 10. In this case, the plurality of segments may be bent along a radial direction of the electrode assembly 10. The plurality of bent segments may be overlapped in multiple layers. In this case, a first uncoated region coupling portion 62 of the first current collector 60, which will be explained later, may be coupled to a region where the plurality of segments overlap in multiple layers. Meanwhile, the electrode assembly 10 may include a welding target region, which is a region where the number of overlapping layers of the segments of the first uncoated region 11 is kept constant along the radial direction of the electrode assembly 10.Since the number of overlapping layers is kept to a maximum in this region, it may be advantageous for the first current collector 60, which will be explained later, and the first uncoated region 11 in this region to be welded. This is useful, for example, in the case of laser welding, to prevent the laser beam from passing through the first uncoated region 11 and damaging the electrode assembly 10 when the laser output power is increased to improve welding quality. In addition, this effectively prevents foreign matter such as welding spatter from flowing into the electrode assembly 10.

[0158] The second electrode includes a second electrode current collector and a second electrode active material coated on one or both surfaces of the second electrode current collector. At the other end of the second electrode current collector in the width direction (parallel to the Z axis), there is an uncoated region not coated with the second electrode active material. Hereinafter, the uncoated region serving as the second electrode tab 12 is referred to as the second uncoated region 12. The second uncoated region 12 is provided at a lower portion of the electrode assembly 10 housed in the battery can 20 in the height direction (parallel to the Z axis).That is, the second electrode current collector includes a second uncoated region 12 that is not coated with an active material layer at its long side end and is exposed from the separator, and at least a part of the second uncoated region 12 is used per se as an electrode tab. The second uncoated region 12 may be, for example, a negative electrode tab. Meanwhile, at least a part of the second uncoated region 12 may include a plurality of segments divided along the winding direction of the electrode assembly 10. In this case, the plurality of segments may be bent along the radial direction of the electrode assembly 10. The plurality of bent segments may be overlapped in multiple layers.In this case, a second uncoated area coupling portion 82 of the second current collector 80, which will be explained later, may be coupled to an area where the plurality of segments overlap in multiple layers. Meanwhile, the electrode assembly 10 may include a welding target area corresponding to an area where the number of overlapping layers of the segments of the second uncoated area 12 is kept constant along the radial direction of the electrode assembly 10. Since the number of overlapping layers is kept to a maximum in this area, it may be advantageous for the second current collector 80, which will be explained later, and the second uncoated area 12 to be welded in this area.This is the case, for example, in the case of laser welding applications, to prevent the laser beam from passing through the second uncoated area 12 and damaging the electrode assembly 10 when the laser output power is increased to improve weld quality. In addition, this is intended to effectively prevent foreign matter such as weld spatter from flowing into the electrode assembly 10.

[0159] The first uncoated region 11 and the second uncoated region 12 extend in opposite directions along the height direction (parallel to the Z-axis) of the cylindrical battery 1. The first uncoated region 11 extends toward a closed portion located opposite to an opening formed at the lower end of the battery can 20, and the second uncoated region 12 extends toward the opening of the battery can 20.

[0160] In the present disclosure, a positive electrode active material coated on the positive electrode plate and a negative electrode active material coated on the negative electrode plate may be any active material known in the art without limitation.

[0161] In one example, the positive electrode active material may include an alkali metal compound represented by a general formula A[A x M y ]O 2+z (A includes at least one element selected 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, y and z are selected so that the compound maintains electrical neutrality).

[0162] In another example, the positive electrode active material may be an alkali metal compound xLiM 1 O2(1x)Li2M 2 O3, which is disclosed in US6,677,082, US6,680,143, et al., where M 1 contains at least one element with an average oxidation state of 3; M 2 contains at least one element with an average oxidation state of 4; and 0 ≤ x ≤ 1).

[0163] In yet another example, the positive electrode active material may be lithium metal phosphate represented by a general formula Li a M 1 x Fe 1x M 2 y P 1y M 3 z O 4z expressed (M 1 contains at least one element selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg and Al; M 2contains 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; M 3 includes a halogen element, optionally including F; oa ≤ 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).

[0164] Preferably, the positive electrode active material may include primary particles and / or secondary particles in which the primary particles are aggregated.

[0165] In one example, the negative electrode active material may use carbon material, lithium metal or a lithium metal compound, silicon or a silicon compound, tin or a tin compound, or the like. Metal oxides such as TiO2 and SnO2 with a potential of less than 2 V may also be used as the negative electrode active material. Low-crystalline carbon and / or high-crystalline carbon may be used as the carbon material.

[0166] The separator may use 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 the like, or laminates thereof. As another example, the separator may use a conventional porous nonwoven fabric, for example, a nonwoven fabric made of high-melting-point glass fiber, polyethylene terephthalate fiber, or the like.

[0167] A coating layer of inorganic particles can be incorporated into at least one surface of the separator. It is also possible for the separator itself to consist of a coating layer of inorganic particles. Particles in the coating layer can be coupled with a binder, creating an interstitial volume between adjacent particles.

[0168] The inorganic particles may be composed of an inorganic material having a dielectric constant of 5 or more. As a non-limiting example, the inorganic particles may include at least one material selected from the group consisting of Pb(Zr,Ti)O3 (PZT), Pb 1x La x Zr 1y Ti y O3 (PLZT), PB(Mg3Nb 2 / 3 )O3PbTiO3 (PMNPT), BaTiO3, hafnium oxide (HfO2), SrTiO3, TiO2, Al2O3, ZrO2, SnO2, CeO2, MgO, CaO, ZnO and Y2O3.

[0169] The electrolyte may be a salt with a structure such as A+B-. Here, 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)3PF - , (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 - consists.

[0170] The electrolyte can also be dissolved in an organic solvent. The organic solvent can be propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), dimethyl sulfoxide, acetonitrile, dimethoxyethane, diethoxyethane, tetrahydrofuran, N-methyl-2-pyrrolidone (NMP), ethyl methyl carbonate (EMC), γ-butyrolactone, or a mixture thereof.

[0171] With reference to the Fig. 5 to Fig. 8, the battery can 20 is a substantially cylindrical container having an opening at a bottom and is made of, for example, a material with conductivity, such as metal. The material of the battery can 20 can be, for example, steel, stainless steel, or nickel-plated steel. The bottom of the battery can 20 having the opening is called an open end. The top surface opposite to the opening (or open end) is called a closed portion or a closed end. A side surface (outer peripheral surface) and a top surface of the battery can 20 may be integrally formed. Alternatively, the side wall and the closed portion of the battery can 20 may be provided separately and coupled to each other by welding or the like.The top surface of the battery can 20 (a surface parallel to the XY plane), namely an outer surface 20a of the closed portion, has a roughly flat shape. The battery can 20 accommodates the electrode assembly 10 through the opening formed at the bottom and, together with it, also accommodates an electrolyte.

[0172] The battery can 20 is electrically connected to the electrode assembly 10. For example, the battery can 20 is electrically connected to the second uncoated area 12 of the electrode assembly 10. In this case, the battery can 20 has the same polarity as the second uncoated area 12.

[0173] With reference to the Fig. 6 and Fig. 13, the battery can 20 may have a bead portion 21 and a crimp portion 22 formed at a lower end thereof. The bead portion 21 is located below the electrode assembly 10. The bead portion 21 is formed by press-fitting a periphery of the outer peripheral surface of the battery can 20. The upper bead portion 21a and the lower bead portion 21b, which are located above and below, respectively, based on an innermost portion 21c of the bead portion 21 located on an innermost side along the press-fitting direction, may have an asymmetric shape. This asymmetric shape may be formed in the process of compressing the battery can 20 along the height direction (parallel to the Z axis) through a sizing process.The sizing process is a process of adjusting the height of the cylindrical battery 1 to a design form factor by pressing the battery can 20 along the winding axis direction of the electrode assembly 10.

[0174] The lower bead portion 21b may include a flat portion substantially parallel to the closed portion of the battery can 20. Meanwhile, due to the asymmetrical configuration, the upper bead portion 21a may have a shape that is at least partially inclined upward along a direction toward the innermost portion 21c. Accordingly, the upper bead portion 21a can compress and fix the lower portion of the electrode assembly 10. The bead portion 21a prevents the electrode assembly 10, which has a size approximately equal to the inner diameter of the battery can 20, from protruding through the opening formed at the lower end of the battery can 20 and may serve as a support portion on which the cap 30 is placed.The lower bead portion 21b may serve as a support portion for fixing the contact portion 83a of the second current collector 80, the gasket 90 and the like, and the cap 30 explained later.

[0175] The crimping portion 22 is formed below the bead portion 21. The crimping portion 22 extends from the lower bead portion 21. The crimping portion 22 has a shape that extends and is bent to surround the outer peripheral surface of the cap 30, which is located below the bead portion 21, and a part of the bottom of the cap 30. The crimping portion 22 can fix the gasket 90 in addition to the cap 30.

[0176] However, the present disclosure does not exclude the case where the battery can 20 does not include the bead portion 21 and / or the crimp portion 22. In the present disclosure, when the battery can 20 does not include the bead portion 21 and / or the crimp portion 22, it is possible to fix the electrode assembly 10 and / or fix the cap 30 and / or seal the battery can 20, for example, by additionally using a component that can serve as a stopper for the electrode assembly 10, and / or additionally using a structure on which the cap 30 can be placed, and / or by welding the battery can 20 and the cap 30 together.

[0177] Meanwhile, the battery can 20 can be designed to have different thicknesses depending on the location. In the battery can 20, the thickness of the side wall can be made smaller than the thickness of the closed portion. Since the electrode assembly 10 can be designed to have a larger diameter in this case, it can be advantageous in terms of energy density.

[0178] The closed portion of the battery can 20, namely, a region forming the upper surface, may have a thickness in the range of, for example, about 0.4 mm to 1.2 mm, more preferably in the range of about 0.6 mm to 1.0 mm. If the thickness of the closed portion of the battery can 20 is too large, the risk of deformation of the battery can 20 may increase when the internal pressure increases or welding is performed. Conversely, if the thickness of the closed portion of the battery can 20 is too small, it may be disadvantageous in terms of processing of the battery can 20, and a loss in energy density may increase. Therefore, it is necessary to maintain the thickness of the closed portion of the battery can 20 at an appropriate level.

[0179] Meanwhile, in the battery can 20, the side wall forming the outer peripheral surface may, for example, have a thickness in the range of about 0.3 mm to 0.8 mm, more preferably in the range of about 0.4 mm to 0.6 mm. If the thickness of the side wall of the battery can 20 is too small, the possibility of fire spreading to adjacent cylindrical batteries 1 increases when a fire and explosion occur at the cylindrical battery 1. For example, in a battery pack including a plurality of cylindrical batteries 1, in the case where an abnormality occurs in some cylindrical batteries 1 to cause a fire and explosion, if the thickness of the side wall of the battery can 20 is too small, a pin hole may be generated, thereby increasing the risk of chain ignition and explosion.Meanwhile, if the thickness of the sidewall of the battery can 20 is too small, it may be detrimental to the processing of the battery can 20, and a loss in energy density may increase. Therefore, it is necessary to maintain the thickness of the sidewall of the battery can 20 at an appropriate level. Meanwhile, a plating layer may be formed on the battery can 20. In this case, the plating layer may include nickel (Ni), for example. The thickness of the plating layer may range from approximately 1.5 μm to 6.0 μm.

[0180] With reference to the Fig. 6 and Fig. 13, the cap 30 may be made of a metal material, for example, to ensure rigidity. The cap 30 seals the opening (or open end) formed at a lower end of the battery can 20. That is, the cap 30 serves as the bottom surface of the cylindrical battery 1. In the cylindrical battery 1 of the present disclosure, the cap 30 may have no polarity even if it is made of a conductive metal material. The fact that the cap 30 has no polarity may mean that the cap 30 is not electrically connected to the electrode assembly 10. If the cap 30 is not electrically connected to the electrode assembly 10 as above, the cap 30 does not serve as a positive electrode terminal or a negative electrode terminal.That is, in the present disclosure, the cap 30 does not need to be electrically connected to the electrode assembly 10 and the battery can 20, and its material does not necessarily need to be a conductive metal.

[0181] When the battery can 20 of the present disclosure includes the bead portion 21, the cap 30 can be supported by the bottom surface of the bead portion 21 formed on the battery can 20. When the battery can 20 of the present disclosure additionally includes the crimp portion 22, the cap 30 is fixed by the crimp portion 22. That is, the top surface of the cap 30 can be supported by the bead portion 21, and the outer peripheral surface and the bottom surface of the cap 30 can be supported by the bead portion 21. The gasket 90 can be arranged between the cap 30 and the crimp portion 22 of the battery can 20 to ensure the airtightness of the battery can 20.Meanwhile, as described above, the battery can 20 of the present disclosure may not include the bead portion 21 and / or the crimp portion 22, and in this case, the gasket 90 may be disposed between a fixing structure provided on one side of the battery can 20 having the opening and the cap 30 to ensure the airtightness of the battery can 20.

[0182] With reference to the Fig. 13 and Fig. 14, the cap 30 may further include a vent portion 31 configured to prevent an internal pressure due to a gas generated in the battery can 20 from rising above a preset value. The preset internal pressure value may be approximately 15 kgf / cm 2 up to 35 kgf / cm 2The vent portion 31 corresponds to a region having a smaller thickness than the peripheral region of the cap 30. The vent portion 31 is structurally weak compared to the peripheral region. Accordingly, when an abnormal situation occurs in the cylindrical battery 1 such that the internal pressure of the battery can 20 rises above a certain level, the vent portion 31 is cracked, so that the gas generated in the battery can 20 is discharged. The vent portion 31 can be formed by partially reducing the thickness of the battery can 20, for example, by notching any one surface or both surfaces of the cap 30.

[0183] The cylindrical battery 1 according to an embodiment of the present disclosure has a structure in which both a positive electrode terminal and a negative electrode terminal are provided at an upper portion thereof, as described later, and thus the upper structure is more complicated than the lower structure. Accordingly, the vent portion 31 may be formed on the cap 30 serving as a bottom surface of the cylindrical battery 1 to evenly discharge the gas generated in the battery can 20. As shown in Fig. As shown in Figure 7, the lower end of the cap 30 is preferably located higher than the lower end of the battery can 20. In this case, even if the lower end of the battery can 20 contacts the ground or the bottom of the case for a module or pack configuration, the cap 30 does not contact the ground or the bottom of the case for the module or pack configuration. Accordingly, the pressure required to rupture the vent portion 31 due to the weight of the cylindrical battery 1 can be prevented from differing from a design value, thereby ensuring smooth rupture of the vent portion 31.

[0184] Meanwhile, the vent portion 31 may have a shape extending continuously or discontinuously to surround the central region of the cap 30, as shown in Fig. 13 and Fig. 14. In this case, a longer distance from the center of the cap 30 to the vent portion 31 is advantageous in terms of the ease of rupture of the vent portion 31 due to the increase in internal pressure. This is because, when the same internal pressure is applied, as the distance from the center of the cap 30 to the vent portion 31 is greater, the force acting on the vent portion 31 further increases to ensure uniform rupture. In addition, a longer distance from the center of the cap 30 to the vent portion 31 is also advantageous in terms of uniform discharge of the vent gas because the area opened by the vent is increased.From this point of view, the vent portion 31 may advantageously be formed along a peripheral edge of the central portion having an approximately flat shape and extending downward (in a lower direction based on . Fig. 13).

[0185] Fig. 13 and Fig. 14 illustrate a case where the vent portion 31 is continuously formed in an approximately circular shape on the cap 30, but the present disclosure is not limited thereto. The vent portion 31 may have an approximately elliptical shape or another geometric shape formed to include the center of the cap 30 therein. Additionally, the vent portion 31 may be formed discontinuously rather than continuously.

[0186] With reference to the Fig. 5 to Fig. 7, the terminal 40 is made of a metal material with conductivity. The material of the terminal 40 may be aluminum (Al). When the material of the terminal 40 is aluminum, the riveting process explained later can be easily performed, and 10 series aluminum with a relatively low electrical resistance can be used. The terminal 40 penetrates a top surface of the battery can 20, namely, a surface (parallel to the XY plane) located on a side of the battery can 20 opposite the opening. The terminal 40 is electrically connected, for example, to the first uncoated region 11 of the electrode assembly 10. In this case, the terminal 40 has a first polarity. Accordingly, the terminal 40 may serve as a first electrode terminal in the cylindrical battery 1 of the present disclosure.When the terminal 40 has the first polarity like this, the terminal 40 is electrically insulated from the battery can 20 having the second polarity. The electrical insulation between the terminal 40 and the battery can 20 can be realized in various ways. For example, the insulation can be realized by disposing an insulating gasket 50, which will be explained later, between the terminal 40 and the battery can 20. Alternatively, the insulation can be realized by forming an insulating coating layer on a portion of the terminal 40. Alternatively, any method for structurally securely fixing the terminal 40 so that the terminal 40 and the battery can 20 cannot touch each other can be adopted. Alternatively, some of the above methods can be adopted together.

[0187] The terminal 40 includes a terminal exposure portion 41 and a terminal insertion portion 42. The terminal insertion portion 42 may include an electrical connection portion 42a and a flange portion 42b. The terminal exposure portion 41 is exposed from the battery can 20. The terminal exposure portion 41 may be located approximately at the center of the closed portion of the battery can 20. The maximum width of the terminal exposure portion 41 may be larger than the maximum width of the opening formed for inserting the terminal 40 in the battery can 20. The terminal insertion portion 42 may pass approximately through the center of the closed portion of the battery can 20, and the electrical connection portion 42a of the terminal insertion portion 42 may be electrically connected to the first uncoated area 11.The flange portion 42b of the terminal insert portion 42 is formed on the periphery of the electrical connection portion 42a and may be riveted to the inner surface of the closed portion of the battery can 20. That is, the flange portion 42b of the terminal insert portion 42 may have a shape curved toward the inner surface of the closed portion of the battery can 20. Therefore, the maximum width of the terminal insert portion 42 after the riveting process for securing the terminal 40 is performed may be larger than the maximum width of the opening formed in the battery can 20, allowing the terminal insert portion 42 to pass therethrough.

[0188] Meanwhile, when the cylindrical battery 1 of the present disclosure includes the first current collector 60, the electrical connection portion 42a of the terminal insertion portion 42 may be coupled to the first current collector 60. The electrical connection portion 42a of the terminal insertion portion 42 may, for example, have a substantially cylindrical shape. Of course, the shape of the electrical connection portion 42a of the terminal insertion portion 42 is not limited thereto. The electrical connection portion 42a of the terminal insertion portion 42 may have various shapes, such as a cylindrical shape with an elliptical cross section, a square columnar shape, a hexagonal columnar shape, an octagonal columnar shape, or the like. The bottom surface of the electrical connection portion 42a of the terminal insertion portion 42 may be formed to be at least partially substantially flat.

[0189] With reference to the Fig. 9 and Fig. 10 together with the Fig. 7 and Fig. 8, the bottom surface of the central region of the terminal insert portion 42 and the first current collector 60 may be coupled by, for example, laser welding, spot welding, or ultrasonic welding.

[0190] Welding can be performed by irradiating a laser through an opening formed at the coil center C of the electrode assembly 10, or by using a tool for ultrasonic welding or spot welding to form a weld bead W on a surface of the first current collector 60 (a surface facing the opening formed at the coil center C of the electrode assembly 10). A guide tube (not shown) for welding can be inserted into the opening formed at the coil center C. When welding is performed in a state where the guide tube is inserted, the risk of damage to the separator forming the inner wall of the opening formed at the coil center C can be reduced.

[0191] The welding pattern drawn by the welding bead W formed on a surface of the terminal coupling portion 63 of the first current collector 60 may be drawn so as to surround the center P of the bottom surface of the electrical connection portion 42a of the terminal insertion portion 42. The welding pattern may, for example, be approximately circular, and alternatively, the welding pattern may have an approximately elliptical shape or a polygonal shape, such as approximately square, hexagonal, and octagonal shapes. The welding pattern formed by the welding bead W may be continuous (see Fig. 9) or discontinuously (see Fig. 10). The circular, elliptical, and polygonal shapes, which are examples of the shape of the weld pattern formed by the weld bead W, do not mean geometrically perfect circles, ovals, and polygons.

[0192] Meanwhile, the diameter of the flat portion formed on the bottom surface of the electrical connection portion 42a of the terminal insert portion 42 can be determined taking into account the welding strength with the first current collector 60. The tensile force of the welded portion between the flat portion and the first current collector 60 can be at least about 2 kgf or more, 3 kgf or more, 4 kgf or more, 5 kgf or more, 6 kgf or more, 7 kgf or more, 8 kgf or more, 9 kgf or more, or 10 kgf or more. It is preferable to increase the tensile force of the welded portion as much as possible within an allowable range by optimally selecting a welding method.

[0193] The diameter (or maximum width) of the weld pattern formed on the flat portion to satisfy the tensile force requirement of the weld portion may be at least about 2 mm. The diameter of the weld pattern may be expressed as a converted diameter (2*(S / π) 0,5 ) of a circle when the area (S) of the weld bead W, indicated on the surface of the weld section, is divided into an area (πr 2 ) of the corresponding circle.

[0194] The flat portion formed on the bottom surface of the electrical connection portion 42a of the terminal insert portion 42 corresponds to a weldable area. The diameter of the weldable area can be approximately 3 mm to 14 mm. If the diameter of the weldable area is less than approximately 3 mm, it is difficult to secure a weld pattern with a diameter (converted diameter) of 2 mm or more. In particular, in the case of forming a weld pattern using laser welding, it is difficult to secure a weld pattern with a diameter of 2 mm or more due to laser beam interference.When the diameter of the weldable area exceeds about 14 mm, the diameter of the terminal exposure portion 41 of the terminal 40 is inevitably increased beyond that, and therefore it is difficult to ensure that the area of ​​the outer surface 20a of the battery can 20 is sufficiently usable as an electrode terminal having an opposite polarity to the terminal 40.

[0195] Taking into account the diameter condition of the weld pattern and the diameter condition of the weldable area, the ratio of the area of ​​the weld pattern to the area of ​​the weldable area required to ensure a weld portion tensile force of at least about 5 kgf or more is preferably about 2.04% (π1 2 / π7 2 ) to 44.4% (π12 / π1.5 2 )·

[0196] For example, when the flat portion formed on the bottom surface of the electrical connection portion 42a of the terminal insert portion 42 and the first current collector 60 are laser welded while the weld bead W forms a continuous or discontinuous line in the form of an approximate arc pattern, the diameter of the arc weld pattern is about 2 mm or more, preferably about 4 mm or more. When the diameter of the arc weld pattern satisfies the corresponding condition, it is possible to ensure sufficient welding strength by increasing the weld portion tensile force to about 5 kgf or more.

[0197] For example, when the flat portion formed on the bottom surface of the electrical connection portion 42a of the terminal insert portion 42 and the first current collector 60 are welded in a circular pattern by ultrasonic waves, the diameter of the circular weld pattern is preferably about 2 mm or more. When the diameter of the circular weld pattern satisfies the corresponding condition, it is possible to ensure sufficient welding strength by increasing the weld portion tensile force to about 5 kgf or more.

[0198] The diameter of the flat portion formed on the bottom surface of the terminal 40, which corresponds to the weldable area, can be set in the range of about 3 mm to 14 mm. If the radius of the flat portion is smaller than about 3 mm, it is difficult to form a weld pattern with a diameter of about 2 mm or more using a laser welding tool, an ultrasonic welding tool, or the like.

[0199] In another aspect, the distance from the center of the top surface of the terminal 40 to the outermost side, namely the radius R1 of the terminal exposure portion 41, may be approximately 10% to 70% of the radius (R2, 1 / 2 of the outer diameter of the battery can) of the top surface of the battery can 20. As R1 decreases, the welding space becomes insufficient when welding components (bus bars) are used for electrical connection of the terminal 40. Furthermore, as R1 increases, the welding space decreases when welding components (bus bars) are used for electrical connection in a remaining area on the top surface of the battery can 20 excluding the terminal 40.

[0200] When the ratio R1 / R2 is set between approximately 10% and 70%, the welding space for the terminal 40 and the welding space for the outer surface 20a of the closed portion of the battery can 20 can be properly secured.

[0201] In addition, the radius R3 of the bottom surface of the electrical connection portion 42a of the terminal insert portion 42 may be about 4% to 30% compared to R2.

[0202] As R3 decreases, the welding space becomes insufficient when welding the first current collector 60 to the flat portion formed on the bottom surface of the electrical connection portion 42a of the terminal insert portion 42, and the contact resistance may increase because the welding area of ​​the terminal 40 decreases. Moreover, R3 should be smaller than R1, and as R3 increases, the thickness of the flange portion 42b of the terminal insert portion 42 inevitably decreases, which weakens the force of the flange portion 42b to compress the insulating gasket 50, thereby deteriorating the sealing ability of the insulating gasket 50.

[0203] When R3 / R2 is set between about 4% and 30%, the welding process can be easily performed by sufficiently securing the welding surface between the bottom surface of the electrical connection portion 42a of the terminal insert portion 42 and the first current collector 60, and it is also possible to reduce the contact resistance of the welding surface and prevent the sealing ability of the insulating gasket 50 from deteriorating.

[0204] Meanwhile, the cylindrical battery 1 according to an embodiment of the present disclosure has a structure in which the bottom surface of the electrical connection portion 42a of the terminal insertion portion 42 is welded to the first current collector 60 as described above, thereby maximizing the bonding area between the first current collector 60 and the terminal 40. That is, at least a part of the bottom surface of the electrical connection portion 42a is formed flat, and thus the coupling area between the terminal 40 and the first current collector 60 can be maximized.Therefore, the cylindrical battery 1 according to an embodiment of the present disclosure can ensure a smooth current flow at the coupling portion of the first current collector 60 and the terminal 40 in the case where a large amount of current flows due to rapid charging, thereby obtaining the effects of shortening the charging time and reducing the amount of heat generated.

[0205] In the present disclosure, the top surface of the battery can 20, namely the outer surface 20a of the closed portion of the battery can 20, and the top surface of the terminal exposure portion 41 of the terminal 40 exposed from the battery can 20, have opposite polarities and face in the same direction. In addition, a step may be formed between the top surface of the terminal exposure portion 41 and the top surface of the battery can 20. That is, as shown in FIGS. Fig. 7 and Fig. As shown in Figure 8, the terminal exposure portion 41 may protrude toward the outside of the battery can 20 by a predetermined height through the top surface of the battery can 20. In this case, the height of the step may be in the range of about 0.08 mm to 4 mm. If the height of the step is formed too low beyond this range, there is a possibility that the bus bar coupled to the top surface of the terminal exposure portion 41 may come into contact with the top surface of the battery can 20, which has a polarity opposite to the terminal exposure portion 41, and / or the possibility that the terminal exposure portion 41 is deformed when the terminal 40 is riveted increases. The thickness of the seal exposure portion 51, which will be explained later, may be formed in the range of about 0.3 mm to 1 mm in consideration of insulation and sealing properties.If, considering the thickness of the seal exposure portion 51, the height of the terminal exposure portion 41 protruding toward the top surface 20a of the battery can 20 is less than about 0.08 mm, it becomes difficult to ensure the mechanical rigidity of the terminal exposure portion 41. In particular, this is more serious when the terminal 40 is made of aluminum. Meanwhile, if the height of the step is formed to be too high beyond the above range, the size of the cylindrical battery 1 increases in the height direction, which may increase the loss in energy density.

[0206] Meanwhile, in the drawings of the present disclosure, only the case where the terminal 40 protrudes higher than the top of the battery can 20 serving as the electrode terminal 20a having an opposite polarity to the terminal 40 is shown, but the present disclosure is not necessarily limited thereto.

[0207] For example, when the top surface of the battery can 20 has a shape that is concavely notched from the center downward, namely, toward the electrode assembly 10, the top surface of the battery can 20 may be higher than the terminal exposure portion 41 of the electrode terminal 40.

[0208] Meanwhile, in the case where the top surface of the battery can 20 has a shape that is concavely notched from the center downward, namely, toward the electrode assembly 10, the top surface of the battery can 20 and the top surface of the terminal exposure portion 41 may form the same plane according to the notched depth and the thickness of the terminal exposure portion 41 of the electrode terminal 40. In this case, no step may be formed between the top surface of the battery can 20 and the top surface of the terminal exposure portion 41.

[0209] The insulating gasket 50 is disposed between the battery can 20 and the terminal 40 to prevent the battery can 20 and the terminal 40, which have opposite polarities, from contacting each other. Accordingly, the top surface of the battery can 20, which has a roughly flat shape, can serve as the second electrode terminal of the cylindrical battery 1.

[0210] The insulating gasket 50 includes a gasket exposure portion 51 and a gasket insert portion 52. The gasket exposure portion 51 is disposed between the terminal exposure portion 41 of the terminal 40 and the battery can 20. The gasket exposure portion 51 may extend longer than the terminal exposure portion 41 and thus may be exposed from the terminal exposure portion 41 when the cylindrical battery 51 is viewed from above. The gasket insert portion 52 is disposed between the terminal insert portion 42 of the terminal 40 and the battery can 20. When the flange portion 42b of the terminal insert portion 42 is riveted, the gasket insert portion 52 can be deformed together to come into close contact with the inner surface of the closed portion of the battery can 20. The insulating gasket 50 may be made of, for example, a resin material having insulation and elasticity.

[0211] With reference to Fig. 8, the seal exposure portion 51 of the insulating gasket 50 may have an expanded shape to cover the outer peripheral surface of the terminal exposure portion 41 of the terminal 40. When the insulating gasket 50 covers the outer peripheral surface of the terminal 40 in this way, it is possible to prevent a short circuit from occurring during the process of coupling an electrical connection component, such as a bus bar, to the upper surface of the battery can 20 and / or the terminal 40. Although not shown in the drawings, the seal exposure portion 51 of the insulating gasket 50 may also have an expanded shape to cover not only the outer peripheral surface of the terminal exposure portion 41 but also a portion of the upper surface thereof.

[0212] In the case where the insulating gasket 50 is made of a resin material, the insulating gasket 50 may be coupled to the battery can 20 and the terminal 40 by thermal fusion. In this case, the airtightness can be enhanced at the coupling interface between the insulating gasket 50 and the terminal 40 and at the coupling interface between the insulating gasket 50 and the battery can 20. Meanwhile, in the case where the seal exposure portion 51 of the insulating gasket 50 extends to the upper surface of the terminal exposure portion 41, the terminal 40 may be coupled to the insulating gasket 50 by insert molding.

[0213] Meanwhile, with reference to the Fig. 7 and Fig. 8, the height H3 of the flange portion 42a of the terminal insert portion 42, which protrudes toward the inside of the battery can 20, is preferably about 0.5 mm to 3.0 mm. If the protrusion height H3 of the terminal insert portion 42 is less than about 0.5 mm, it is difficult to ensure sufficient sealing properties. In addition, if the protrusion height H3 of the terminal insert portion 42 exceeds 3 mm, the internal space of the battery can 20 that can be occupied by the electrode assembly 10 is reduced.

[0214] Preferably, the total height of the terminal 40 may be approximately 1.5 mm to 7 mm. The total height of the terminal 40 means the distance from the top surface of the terminal exposure portion 41 to the bottom surface of the terminal insertion portion 42. If the total height of the terminal 40 is less than approximately 1.5 mm, it is difficult to sufficiently increase the thickness of the seal insertion portion 52 to ensure sealing properties due to the thickness of the closed portion of the battery can 20. For example, the thickness of the closed portion of the battery can 20 may be formed in the range of approximately 0.4 mm to 1.2 mm. In addition, if the total height of the terminal 40 exceeds approximately 7 mm, the internal space of the battery can 20 that can be occupied by the electrode assembly 10 is excessively reduced, and the total height of the cylindrical battery 1 is increased, so that the energy density per unit area is correspondingly reduced.

[0215] Meanwhile, the terminal 40 may have a riveted structure such that the terminal insert portion 42 is substantially parallel to the inner surface of the closed portion of the battery can 20. Accordingly, the angle formed by the inner surface of the closed portion and the surface of the terminal insert portion 42 relative to the inner surface of the closed portion of the battery can 20 may be substantially close to zero. In addition, the height H3 of the flange portion 42b of the terminal insert portion 42 protruding toward the inner side of the battery can 20 with respect to the inner surface of the closed portion of the battery can 20 may be equal to or greater than the height H2 of the seal insert portion 52 protruding toward the inner side of the battery can 20.In addition, the height H1 of the electrical connection portion 42a protruding toward the inside of the battery can 20 with respect to the inner surface of the closed portion of the battery can 20 may be equal to or greater than the protrusion height H3 of the flange portion 42b. In addition, the inner edge portion of the opening of the battery can 20 for the passage of the terminal 40 and the insulating gasket 50 has an arc shape with a predetermined curvature. In addition, the electrical connection portion 42a of the terminal insertion portion 42 of the terminal 40 may have a shape that gradually narrows toward its bottom surface.

[0216] Preferably, the thickness of the insulating gasket 50 may gradually decrease downward from an intermediate region where the seal exposure portion 51 and the seal insertion portion 52 are connected, and then slightly increase at the distal end of the seal insertion portion 52. The compression structure of the insulating gasket 50 may further improve the sealing properties for the space between the terminal 40 and the battery can 20.

[0217] Preferably, the rivet structure of the terminal 40 according to an embodiment of the present disclosure, as described above, can be used in a cylindrical battery having a form factor of greater than 21700.

[0218] With the recent use of cylindrical batteries in electric vehicles, the form factor of the cylindrical battery has increased compared to the conventional 18650, 21700, and the like. This increase in form factor results in increased energy density, increased thermal runaway resistance, and improved cooling efficiency.

[0219] Furthermore, as explained later, the cylindrical battery 1 using the riveted structure of the terminal 40 can conduct all electrical wiring for the positive electrode / negative electrode in one direction. In addition, the terminal 40 with the riveted structure, as described above, has a large cross-sectional area and low electrical resistance, which is very advantageous for fast charging.

[0220] According to one embodiment of the present disclosure, the insulating gasket 50, the insulator 70, and the gasket 90 may be made of the same material. However, this is not essential. The insulating gasket 50 and the insulator 70 may have substantially the same thickness. However, this is not essential. If they have different thicknesses, the insulator 70 may be thinner than the insulating gasket 50, and vice versa.

[0221] In the entire area of ​​the upper surface of the battery can 20, viewed from a position above the cylindrical battery 1, the entire area except the area occupied by the terminal 40 and the insulating gasket 50 corresponds to the second electrode terminal having the opposite polarity to the terminal 40.

[0222] The cylindrical side wall of the battery can 20 may be formed integrally with the second electrode terminal so that there is no discontinuous portion therebetween. The connecting portion from the side wall of the battery can 20 to the second electrode terminal may have a smooth curvature. That is, a rounded portion may be provided on the edge periphery of the upper surface 20a of the battery can 20. However, the present disclosure is not limited to this, and the connecting portion may include at least one corner having a predetermined angle.When the round portion is formed at the edge of the top surface 20a of the battery can 20, among the entire surface of the top surface of the battery can 20 as viewed from a position above the cylindrical battery 1, a portion occupied by the terminal 40 and the insulating gasket 50 and the entire portion except the round portion can serve as a second electrode terminal having an opposite polarity to the terminal 40.

[0223] With reference to the Fig. 7 and Fig. 8, the first current collector 60 is coupled to an upper portion of the electrode assembly 10. In addition, the first current collector 60 is coupled to the terminal 40. That is, the first current collector 60 electrically connects the first uncoated region 11 of the electrode assembly 10 and the terminal 40. The first current collector 60 is made of a metal material having conductivity and is connected to the first uncoated region 11. Although not shown in the drawings, the first current collector 60 may include a plurality of protrusions radially formed on a lower surface thereof. Once the protrusion is formed, the protrusion may be pressed into the first uncoated region 11 by pressing the first current collector 60.

[0224] A flat portion approximately parallel to the inner surface of the closed portion of the battery can 20 may be formed in at least a part of the bottom surface of the terminal 40, namely, the bottom surface of the electrical connection portion 42a of the terminal insert portion 42, and the first current collector 60 is coupled to the flat portion.

[0225] The first current collector 60 is coupled to one end of the first uncoated region 11. The coupling between the first uncoated region 11 and the first current collector 60 can be performed, for example, by laser welding. The laser welding can be performed by partially melting a base material of the first current collector 60 or can be performed in a state where a solder for welding is arranged between the first current collector 60 and the first uncoated region 11. In this case, the solder preferably has a lower melting point than the first current collector 60 and the first uncoated region 11.

[0226] The first current collector 60 may be coupled to a coupling surface of the first uncoated portion 11, which is formed by bending one end of the first uncoated portion 11 in a direction parallel to the first current collector 60. The bending direction of the first uncoated portion 11 may be, for example, a direction toward the winding center C, namely, the core, of the electrode assembly 10. When the first uncoated portion 11 has a curved shape as above, the space occupied by the first uncoated portion 11 can be reduced, thereby improving the energy density. In addition, as the coupling area between the first uncoated portion 11 and the first current collector 60 increases, the coupling force can be improved and the resistance can be reduced.

[0227] An exemplary form of the first current collector 60 of the present disclosure is described with reference to Fig. 11 together with Fig. 7 and Fig. 8. With reference to Fig. 11 together with Fig. 7 and Fig. 8, the first current collector 60 applied to the present disclosure may include an edge portion 61, a first uncoated area coupling portion 62, and a terminal coupling portion 63. The edge portion 61 is disposed on the electrode assembly 10. The edge portion 61 may have a substantially edge shape in which an empty space S is formed. In the drawings of the present disclosure, only a case where the edge portion 61 has a substantially circular edge shape is illustrated, but the present disclosure is not limited thereto. The edge portion 61 may have a substantially rectangular edge shape, a hexagonal edge shape, an octagonal edge shape, or other edge shapes other than the illustrated one.

[0228] The terminal coupling portion 63 may have a diameter substantially equal to or larger than the diameter of the flat portion formed on the bottom surface of the terminal 40 to secure a welding area for coupling with the flat portion formed on the bottom surface of the terminal 40.

[0229] The first coupling portion of the uncoated region 62 extends inward from the edge portion 61 and is coupled to the first uncoated region 11. The terminal coupling portion 63 is spaced from the first coupling portion of the uncoated region 62 and is located within the edge portion 61. The terminal coupling portion 63 may be coupled to the terminal 40 by welding. The terminal coupling portion 63 may be located approximately in the center of the interior space surrounded, for example, by the edge portion 61. The terminal coupling portion 63 may be provided at a location corresponding to the opening formed at the winding center C of the electrode assembly 10.The terminal coupling portion 63 may be configured to cover the opening formed at the coil center C of the electrode assembly 10 so that the opening formed at the coil center C of the electrode assembly 10 is not exposed from the terminal coupling portion 63. When the opening formed at the coil center C of the electrode assembly 10 is covered as above, the separator positioned within the opening can be prevented from being damaged due to the flow rate of the electrolyte passing through the opening, thus preventing the electrode from leaking. For this purpose, the terminal coupling portion 63 may have a larger diameter or width than the opening formed at the coil center C of the electrode assembly 10.

[0230] The first coupling portion of the uncoated portion 62 and the terminal coupling portion 63 may not be directly connected, but may be arranged to be spaced apart from each other and indirectly connected through the edge portion 61. Since the first current collector 60 has a structure in which the first coupling portion of the uncoated portion 62 and the terminal coupling portion 63 are not directly connected to each other, but are connected through the edge portion 61 as above, when an impact and / or vibration occurs on the cylindrical battery 1, the impact applied to the coupling portion between the first coupling portion of the uncoated portion 62 and the first uncoated portion 11 and the coupling portion between the terminal coupling portion 63 and the terminal 40 can be dispersed.In the drawings of the present disclosure, only a case where four first coupling portions of the uncoated region 62 are provided is illustrated, but the present disclosure is not limited to this. The number of first coupling portions of the uncoated region 62 can be variously determined in consideration of the manufacturing difficulty according to the complexity of the shape, the electrical resistance, the space within the edge portion 61, the electrolyte impregnation, and the like.

[0231] The first current collector 60 may further include a bridge portion 64 extending inward from the edge portion 61 and connected to the terminal coupling portion 63. At least a portion of the bridge portion 64 may have a smaller cross-sectional area compared to the first coupling portion of the uncoated region 62 and the edge portion 61. For example, at least a portion of the bridge portion 64 may be formed to have a smaller width and / or thickness compared to the first coupling portion of the uncoated region 62. In this case, the electrical resistance in the bridge portion 64 increases, and thus, when a current flows through the bridge portion 64, the relatively large resistance causes a portion of the bridge portion 64 to melt due to overcurrent heating, irreversibly blocking the overcurrent.The cross-sectional area of ​​the bridge section 64 can be set to an appropriate level taking into account the overcurrent blocking function.

[0232] The bridge portion 64 may include a tapered portion 64a whose width gradually decreases from the inner surface of the edge portion 61 toward the terminal coupling portion 63. When the tapered portion 64a is provided, the rigidity of the component can be improved at the connecting portion between the bridge portion 64 and the edge portion 61. When the tapered portion 64a is provided, in the method for manufacturing the cylindrical battery 1, for example, a transfer device and / or a worker can easily and safely transport the first current collector 60 and / or a coupled body of the first current collector 60 and the electrode assembly 10 by gripping the tapered portion 64a.That is, when the tapered portion 64a is provided, it is possible to prevent product defects that may occur by gripping a portion where welding is performed with other components such as the coupling portion 62 of the first uncoated area and the terminal coupling portion 63.

[0233] The coupling portion 62 of the first uncoated region may be provided in multiple portions. The plurality of coupling portions 62 of the first uncoated region may be arranged at substantially regular intervals from one another in the extension direction of the edge portion 61. An extension length of each of the plurality of coupling portions 62 of the first uncoated region may be substantially equal to one another. The coupling portion 62 of the first uncoated region may be coupled to the first uncoated region 11 by welding.

[0234] The terminal coupling portion 63 may be arranged to be surrounded by the plurality of coupling portions 62 of the first uncoated region. The terminal coupling portion 63 may be coupled to the terminal 40 by welding. The bridge portion 64 may be positioned between a pair of adjacent coupling portions 62 of the first uncoated region. In this case, the distance from the bridge portion 64 to any one of the pair of coupling portions 62 of the first uncoated region along the extending direction of the edge portion 61 may be substantially equal to the distance from the bridge portion 64 to the other of the pair of coupling portions 62 of the first uncoated region along the extending direction of the edge portion 61.The plurality of coupling sections 62 of the first uncoated region may be such that they have substantially the same cross-sectional area. The plurality of coupling sections 62 of the first uncoated region may be such that they have substantially the same width and thickness.

[0235] Although not shown in the drawings, the bridge portion 64 may be provided in multiples. Each bridge portion of the plurality of bridge portions 64 may be arranged between a pair of adjacent coupling portions 62 of the first uncoated region. The plurality of bridge portions 64 may be arranged at substantially regular intervals from each other in the extending direction of the edge portion 61. A distance from each bridge portion of the plurality of bridge portions 64 to a coupling portion of the pair of adjacent coupling portions 62 of the first uncoated region along the extending direction of the edge portion 61 may be substantially equal to a distance from each bridge portion of the plurality of bridge portions 64 to the other coupling portion 62 of the first uncoated region.

[0236] In the case where the coupling portion 62 of the first uncoated region and / or the bridge portion 64 is provided in plural numbers as described above, if the distance between the coupling portions 62 of the first uncoated region and / or the distance between the bridge portions 64 and / or the distance between the coupling portion 62 of the first uncoated region and the bridge portion 64 is uniformly formed, a current flowing from the coupling portion 62 of the first uncoated region to the bridge portion 64 or a current flowing from the bridge portion 64 to the coupling portion 62 of the first uncoated region can be uniformly formed.

[0237] Meanwhile, the first current collector 60 and the first uncoated area 11 may be coupled by welding. In this case, for example, laser welding, ultrasonic welding, spot welding, or the like may be applied. Another exemplary form of the first current collector 60 of the present disclosure will be described with reference to Fig. 12 together with Fig. 7 and Fig. 8. With reference to Fig. 12 together with Fig. 7 and Fig. 8, the bridge portion 64 may include a notch portion N formed to partially reduce a cross-sectional area of ​​the bridge portion 64. The cross-sectional area of ​​the notch portion N may be adjusted, for example, by partially reducing the width and / or thickness of the bridge portion 64. When the notch portion N is provided, the electrical resistance in the region where the notch portion N is formed is increased, thereby enabling rapid current interruption when an overcurrent occurs.

[0238] In the case where the bridge portion 64 includes the taper portion 64a, the notch portion N may be located closer to the taper portion 64a than the terminal coupling portion 63. Relatively more heat is generated in the narrowest part of the taper portion 64a, so that the notch portion N adjacent to the taper portion 64a can quickly cut off the overcurrent.

[0239] Meanwhile, the notch portion N is preferably provided in a region corresponding to the above-described welding target region of the electrode assembly 10 to prevent foreign matter such as welding spatter generated during cracking from flowing into the electrode assembly 10. This is because in this region, the first uncoated area 11 maintains the maximum number of overlapping layers of segments, and thus the overlapped segments can serve as a mask. For example, the notch portion N may be provided approximately at the center in the radial direction of the electrode assembly 10.

[0240] With reference to the Fig. 6 to Fig. 8, the insulator 70 is provided between an upper end of the electrode assembly 10 and the inner surface of the battery can 20, or between the first current collector 60 coupled to the upper portion of the electrode assembly 10 and the inner surface of the closed portion of the battery can 20. The insulator 70 prevents contact between the first uncoated area 11 and the battery can 20 and / or contact between the first current collector 60 and the battery can 20. The insulator 70 may also be disposed between an upper end of the outer peripheral surface of the electrode assembly 10 and the side wall of the battery can 20. That is, the insulator 70 may also be disposed between the uncoated area 11 and the side wall of the battery can 20. The first current collector 60 may be a plate that extends entirely over the upper surface of the outer peripheral surface of the electrode assembly 10.However, the present disclosure is not limited thereto, and the first current collector 60 may be formed to extend only partially over the top of the outer peripheral surface of the electrode assembly 10.

[0241] When the cylindrical battery 1 according to an embodiment of the present disclosure includes the insulator 70, the terminal insertion portion 42 of the terminal 40 is coupled to the first current collector 60 or the first uncoated area 11 through the insulator 70. The opening formed in the insulator 70 may be formed at a location corresponding to the opening formed at the winding center C of the electrode assembly 10. In addition, the opening formed in the insulator 70 may be formed at a location corresponding to the terminal coupling portion 63 of the first current collector 60.

[0242] Meanwhile, if the welding portion between the terminal 40 and the terminal coupling portion 63 of the first current collector 60 is located within the opening formed at the winding center C of the electrode assembly 10, the electrode assembly 10 may be damaged. To prevent this, the flat portion formed at the lower end of the terminal 40 coupled to the terminal coupling portion 43 may be located substantially at the same height as the bottom surface of the insulator 70 or higher. In this case, the welding portion between the terminal 40 and the first current collector 60 is located outside the opening formed at the winding center C of the electrode assembly 10.

[0243] Taking this into account, the thickness of the insulator 70 may have a thickness substantially equal to or greater than the distance from the inner surface of the closed portion of the battery can 20 to the flat portion provided at the lower end of the terminal 40. Meanwhile, the insulator 70 may have a thickness corresponding to the distance between the inner surface of the closed portion of the battery can 20 and the first current collector 60 by filling the space between the inner surface of the closed portion of the battery can 20 and the first current collector 60 along the height direction, so that no space is created in which the electrode assembly 10 can move.

[0244] In another aspect, the top surface of the insulator 70 may be in contact with the inner surface of the closed portion of the battery can 20 and the bottom surface of the insulator 70 may be in contact with the top surface of the first current collector 60.

[0245] With reference to Fig. 13, the second current collector 80 is arranged below the electrode assembly 10. In addition, the second current collector 80 may be configured to electrically connect the second uncoated region 12 of the electrode assembly 10 and the battery can 20. The second current collector 80 is made of a metal material having conductivity and is connected to the second uncoated region 12. In addition, the second current collector 80 is electrically connected to the battery can 20. The second current collector 80 may be arranged and fixed between the inner surface of the battery can 20 and the gasket 90. In particular, the second current collector 80 may be arranged between the underside of the bead portion 21 of the battery can 20 and the gasket 90. However, the present disclosure is not limited thereto.Alternatively, the second current collector 80 may be welded to the inner wall surface of the battery can 20 in a region in which the bead portion 21 is not formed.

[0246] Although not shown in the drawings, the second current collector 80 may include a plurality of asperities radially formed on a surface thereof. Once the asperity is formed, the asperity may be pressed into the second uncoated area 12 by pressing the second current collector 80.

[0247] The second current collector 80 is coupled to one end of the second uncoated region 12. The coupling between the second uncoated region 12 and the second current collector 80 can be performed, for example, by laser welding. The laser welding can be performed by partially melting a base material of the second current collector 80 or can be performed in a state where a solder for welding is arranged between the second current collector 80 and the second uncoated region 12. In this case, the solder preferably has a lower melting point than the second current collector 80 and the second uncoated region 12.

[0248] The second current collector 80 may be coupled to a coupling surface of the second uncoated portion 12, which is formed by bending one end of the second uncoated portion 12 in a direction parallel to the second current collector 80. The bending direction of the second uncoated portion 12 may be, for example, a direction toward the winding center C, namely, the core, of the electrode assembly 10. When the second uncoated portion 12 has a curved shape as above, the space occupied by the second uncoated portion 12 can be reduced, thereby improving the energy density. In addition, as the coupling area between the second uncoated portion 12 and the second current collector 80 increases, the coupling force can be improved and the resistance can be reduced.

[0249] With reference to Fig. 15, an exemplary form of the second current collector 80 of the present disclosure is shown. Referring to Fig. 15 together with Fig. 13, the second current collector 80 electrically connects the electrode assembly 10 and the battery can 20.

[0250] The second current collector 80 may include a support portion 81 disposed below the electrode assembly 10, a second uncoated region coupling portion 82 extending from the support portion 81 approximately along the radial direction of the electrode assembly 10 and coupled to the second uncoated region 12, and a can coupling portion 83 extending from the support portion 81 approximately along the radial direction of the electrode assembly 10 and coupled to the inner surface of the battery can 20. The second uncoated region coupling portion 82 and the can coupling portion 83 are indirectly connected through the support portion 81 and are not directly connected to each other.Therefore, when an external impact is applied to the cylindrical battery 1 of the present disclosure, it is possible to minimize the risk of damage to the coupling portion of the second current collector 80 and the electrode assembly 10, as well as the coupling portion of the second current collector 80 and the battery can 20. However, the second current collector 80 of the present disclosure is not limited to the structure in which the second coupling portion of the uncoated region 82 and the can coupling portion 83 are only indirectly connected. For example, the second current collector 80 may have a structure that does not include the support portion 81 for indirectly connecting the second coupling portion of the uncoated region 82 and the can coupling portion 83, and / or a structure in which the second uncoated region 12 and the can coupling portion 83 are directly connected to each other.

[0251] The support portion 81 and the second coupling portion of the uncoated region 82 are arranged below the electrode assembly 10. The second coupling portion of the uncoated region 82 is coupled to the second uncoated region 12 of the electrode assembly 10. In addition to the second coupling portion of the uncoated region 82, the support portion 81 may also be coupled to the second uncoated region 12. The second coupling portion of the uncoated region 82 and the second uncoated region 12 may be coupled by welding. The support portion 81 and the second coupling portion of the uncoated region 82 are located higher than the bead portion 21 when the bead portion 21 is formed on the battery can 20.

[0252] The support portion 81 has a current collector opening 80a formed at a location corresponding to the opening formed at the winding center C of the electrode assembly 10. The opening of the electrode assembly 10 and the current collector opening 80a, which communicate with each other, can serve as a passage for inserting a welding rod for welding between the terminal 40 and the terminal coupling portion 63 of the first current collector 60 or for irradiating a laser beam. The current collector opening 80a can have a diameter substantially equal to or larger than the opening formed at the winding center C of the electrode assembly 10.When the second uncoated portion coupling portion 82 is provided in plural, the plurality of second uncoated portion coupling portions 82 may have a shape extending approximately radially from the support portion 81 of the second current collector 80 toward the side wall of the battery can 20. Each of the plurality of second uncoated portion coupling portions 82 may be positioned to be spaced apart from each other along the circumference of the support portion 81. Meanwhile, to ensure the coupling force and reduce the electrical resistance by increasing the coupling area between the second current collector 80 and the electrode assembly 10, not only the second uncoated portion coupling portion 82 but also the support portion 81 may be coupled to the second uncoated portion 12.At least a part of the second uncoated region 12 may be formed in a curved shape such that one end thereof is substantially parallel to the coupling portion 82 of the second uncoated region. In this case, the second uncoated region 12 may be curved toward the winding center C of the electrode assembly 10, for example. When the end of the second uncoated region 12 is formed as above and coupled to the coupling portion 82 of the second uncoated region in a state where it is parallel to the coupling portion 82 of the second uncoated region, the coupling area is increased, thereby improving the coupling force and reducing the electrical resistance. In addition, by minimizing the overall height of the electrode assembly 10, the energy density can be improved. Meanwhile, the curved end of the second uncoated region 12 may be overlapped in multiple layers.When the second uncoated region 12 can be overlapped in multiple layers, the coupling portion 82 of the second current collector 80 of the second uncoated region can be coupled to a region in which the second uncoated region 12 is bent and overlapped in multiple layers.

[0253] The can coupling portion 83 may be provided in multiples. In this case, the plurality of can coupling portions 83 may have a shape that extends approximately radially from the center of the second current collector 80 toward the side wall of the battery can 20. Accordingly, the electrical connection between the second current collector 80 and the battery can 20 can be established at a plurality of locations. Since the coupling for electrical connection is established at a plurality of locations, the coupling area can be maximized, thereby minimizing the electrical resistance. The plurality of can coupling portions 83 may be positioned so that they are spaced apart from each other along the circumference of the support portion 81. At least one can coupling portion 83 may be positioned between adjacent coupling portions 82 of the second uncoated area.The plurality of can coupling portions 83 may, for example, be coupled to the bead portion 21 on the inner surface of the battery can 20. Specifically, the can coupling portions 83 may be coupled to the bottom surface of the bead portion 21. When this structure is applied to the cylindrical battery 1 of the present disclosure, the can coupling portion 83 can naturally be placed on the bottom surface of the bead portion 21 by the method of accommodating the electrode assembly 10 coupled to the second current collector 80 in the battery can 20. Therefore, the battery can 20 and the second current collector 80 can be easily welded. The welding for connecting the battery can 20 and the current collector 80 may use, for example, laser welding, ultrasonic welding, or spot welding.By coupling the can coupling portion 83 to the bead portion 21 by welding in this way, the resistance level can be limited to about 4 milliohms or less. The resistance can be at least 0.5 mΩ or 1.0 mΩ or more. Since the bottom of the bead portion 21 has a shape extending in a direction approximately parallel to the top of the battery can 20, namely, in a direction approximately perpendicular to the side wall of the battery can 20, and the can coupling portion 83 also has a shape extending in the same direction, namely, in the radial direction and the circumferential direction, the can coupling portion 83 can stably contact the bead portion 21.Since the can coupling portion 83 is stably in contact with the flat portion of the bead portion 21, the two components can be welded evenly, thereby improving the coupling force between the two components and minimizing the increase in resistance at the coupling portion.

[0254] The can coupling portion 83 may include a contact portion 83a coupled to the inner surface of the battery can 20 and a connecting portion 83b for connecting the support portion 81 and the contact portion 83a.

[0255] The contact portion 83a is coupled to the inner surface of the battery can 20. In the case where the bead portion 21 is formed on the battery can 20, the contact portion 83a may be coupled to the bead portion 21 as described above. Specifically, the contact portion 83a may be electrically coupled to the flat portion formed on the bottom surface of the bead portion 21 formed on the battery can 20 and may be disposed between the bottom surface of the bead portion 21 and the gasket 90. In this case, for stable contact and coupling, the contact portion 83a may have a shape extending from the bead portion 21 along the circumferential direction of the battery can 20 over a predetermined length.

[0256] Meanwhile, the maximum distance from the center of the second current collector 80 to the end of the coupling portion 82 of the second uncoated region along the radial direction of the electrode assembly 10 is preferably substantially equal to or smaller than the inner diameter of the battery can 20 in a region where the bead portion 21 is formed, namely the minimum inner diameter of the battery can 20. This is to prevent collision between the second current collectors 80 by the bead portion 21 during the sizing process for compressing the battery can 20 along the height direction, and thus prevent the electrode assembly 10 from being pressed by the second current collector.

[0257] With reference to the Fig. 16 to Fig. 19, the structure of the electrode assembly 10 is described in more detail. In the following description, the first electrode is described as an example among the first and second electrodes described above, but the structure of the first electrode can be equally applied to the second electrode.

[0258] With reference to the Fig. 16 and Fig. 17, the first electrode 110 includes a first electrode current collector 111 having a sheet shape made of a conductive foil, a first active material layer 112 formed on at least one surface of the first electrode current collector 111, and a first uncoated region 113 formed by not coating an active material on a long side end of the first electrode current collector 111.

[0259] Preferably, the first uncoated area 11 may include a plurality of notched segments 11a. The plurality of segments 11a form a plurality of groups, and the segments 11a included in each group may be identical in height (length in the Y-axis direction) and / or width (length in the X-axis direction) and / or separation pitch. The number of segments 11a belonging to each group may be larger or smaller than shown in the drawings. The segment 11a has a geometric shape in which at least one straight line and / or at least one curvature are combined. Preferably, the segment 11a may have a trapezoidal shape and may be deformed into a rectangular, parallelogram, semicircular, or semi-elliptical shape.

[0260] Preferably, the height of the segment 11a can be gradually increased along a direction parallel to the winding direction of the electrode assembly 10, for example, from the core to the outer periphery. Furthermore, a core-side uncoated region 11-1 adjacent to the core of the electrode assembly 10 may not include the segment 11a, and the core-side uncoated region 11-1 may have a lower height than the uncoated region of other regions. Additionally, an outer periphery region 11-2 adjacent to the outer periphery of the electrode assembly 10 may not include the segment 11a, and the outer periphery region 11-2 may have a lower height than other uncoated regions.

[0261] Optionally, the first electrode 110 may include an insulating coating layer E covering a boundary between the active material layer 112 and the first uncoated region 11. The insulating coating layer E includes a polymer resin having an insulating property and may optionally further include an inorganic filler. The insulating coating layer E may serve to prevent the end of the active material layer 112 from contacting an active material layer of opposite polarity exposed through the separator and to structurally support the bending of the segment 11a. For this purpose, when the first electrode 110 is wound to form the electrode assembly 10, at least a portion of the insulating coating layer E is preferably exposed to the outside of the separator.

[0262] With reference to the Fig. 16 and Fig. 17, the electrode assembly 10 can be formed by the method described above with reference to Fig. 2. For simplicity of explanation, the protruding structures of the uncoated regions 11, 12 extending from the separator are shown in detail, and the winding structures of the first electrode, the second electrode, and the separator are not shown. The first uncoated region 11, which protrudes upward, extends from the first electrode, and the second uncoated region 12, which protrudes downward, extends from the second electrode.

[0263] The pattern in which the heights of the uncoated regions 11, 12 change is shown schematically. That is, the heights of the uncoated regions 11, 12 may vary irregularly depending on the location where the cross section is cut. For example, when a side portion of the trapezoidal segment 11a is cut, the height of the uncoated region in the cross section is lower than the height of the segment 11a. Therefore, it should be understood that the heights of the uncoated regions 11, 12 shown in the drawings showing the cross section of the electrode assembly 10 correspond to the average of the heights of the uncoated regions included in each winding turn.

[0264] With reference to the Fig. 16 to Fig. 19, the uncoated areas 11, 12 may be bent along the radial direction of the electrode assembly 10, for example, from the outer circumference to the core. In the uncoated areas 11, 12, the area where the bending occurs is Fig. 17 is indicated by a dotted line box. When the uncoated areas 11, 12 are bent, curved surfaces 102 are formed at the upper and lower portions of the electrode assembly 10 because segments adjacent in the radial direction overlap in multiple layers. At this time, the core-side uncoated area 11-1 ( Fig. 16) is not bent due to its small height, and the height h of the segment 11a bent at the innermost side is equal to or less than the radial length R of the winding area formed by the core-side uncoated region 11-1 without a segment structure. Therefore, the opening formed at the core C of the electrode assembly 10 is not closed. The opening is not closed, there is no difficulty in the electrolyte injection process, and the electrolyte injection efficiency can be improved. In addition, by inserting a welding tool through the opening, it is possible to easily weld the terminal 40 and the first current collector 60 (see Fig. 7).

[0265] Meanwhile, the cylindrical battery 1 according to an embodiment of the present disclosure has a structure in which the cap 30 does not necessarily have a polarity, as described above. When the cap 30 has no polarity, the second current collector 80 is connected to the side wall of the battery can 20, and thus the outer surface 20a of the closed portion of the battery can 20 has a polarity opposite to the terminal 40. Therefore, when a plurality of cylindrical batteries 1 are to be connected in series and / or parallel, wiring work such as connecting a bus bar can be formed at the upper portion of the cylindrical battery 1 using the terminal 40 and the outer surface 20a of the closed portion of the battery can 20.As a result, energy density can be improved by increasing the number of cylindrical batteries 1 that can be mounted in the same space, and electrical wiring can be easily performed. That is, in the cylindrical battery 1 according to the present disclosure, the terminal 40 exposed from the battery can 20 can serve as the first electrode terminal, and the area of ​​the outer surface 20a of the closed portion of the battery can 20 occupied by the exposed surface approximately parallel to the upper surface of the first electrode terminal can serve as the second electrode terminal.Accordingly, when the plurality of cylindrical batteries 1 are to be electrically connected, a first bus bar may be coupled to the upper surface of the terminal 40 exposed from the battery can 20, and a second bus bar may be coupled to the area of ​​the outer surface 20a of the closed portion of the battery can 20 occupied by the exposed surface approximately parallel to the upper surface of the first electrode terminal.

[0266] With reference to Fig. 20, a plurality of cylindrical batteries 1 can be connected in series and parallel on top of the cylindrical batteries 1 using a bus bar 150. The number of cylindrical batteries 1 can be larger or smaller depending on the capacity of the battery pack.

[0267] In each cylindrical battery 1, the terminal 40 may have a positive polarity and the outer surface 20a of the closed portion of the battery can 20 may have a negative polarity, or vice versa.

[0268] Preferably, the plurality of cylindrical batteries 1 may be arranged in a plurality of columns and rows. Columns are provided in a vertical direction with respect to the ground, and rows are provided in a left and right direction with respect to the ground. In addition, to maximize space efficiency, the cylindrical batteries 1 may be arranged in a closest packing structure. The closest packing structure is formed when an equilateral triangle is formed by connecting the centers of the terminal exposure portions 41 of the terminal 40 exposed from the battery can 20. Preferably, the bus bar 150 may be arranged on the plurality of cylindrical batteries 1, more preferably between adjacent rows. Alternatively, the bus bar 150 may be arranged between adjacent rows.

[0269] Preferably, the bus bar 150 connects the cylindrical batteries 1 arranged in parallel to each other in the same column and connects the cylindrical batteries 1 arranged in two adjacent columns in series.

[0270] Preferably, the busbar 150 may include a body portion 151, a plurality of first busbar terminals 152, and a plurality of second busbar terminals 153 for serial and parallel connection.

[0271] The body portion 151 may extend between terminals 40 of adjacent cylindrical batteries 70, preferably between rows of the cylindrical batteries 1. Alternatively, the body portion 151 may extend along the row of cylindrical batteries 1 and may be regularly curved, such as a zigzag shape.

[0272] The plurality of first bus bar terminals 152 may protrude from one side of the body portion 151 toward the terminal 40 of each cylindrical battery 1 and may be electrically coupled to the terminal 40. The electrical connection between the first bus bar terminal 152 and the terminal 40 may be achieved by laser welding, ultrasonic welding, or the like. Furthermore, the plurality of second bus bar terminals 153 may be electrically coupled to the outer surface 20a of each cylindrical battery 1 from the other side of the body portion 151. The electrical connection between the second bus bar terminal 153 and the outer surface 20a may be achieved by laser welding, ultrasonic welding, or the like.

[0273] Preferably, the body portion 151, the plurality of first bus terminals 152, and the plurality of second bus terminals 153 may be made of a conductive metal plate. The metal plate may be, for example, an aluminum plate or a copper plate, but the present disclosure is not limited thereto. In a modified example, the body portion 151, the plurality of first bus terminals 152, and the second bus terminals 153 may be manufactured as separate parts and then coupled together by welding or the like.

[0274] Since, in the cylindrical battery 1 according to the present disclosure, the terminal 40 having a positive polarity and the outer surface 20a of the closed portion of the battery can 20 having a negative polarity are located in the same direction, the cylindrical batteries 1 can be easily electrically connected using the bus bar 150.

[0275] In addition, since the terminal 40 of the cylindrical battery 1 and the outer surface 20a of the closed portion of the battery can 20 have large areas, the coupling surface of the bus bar 150 can be sufficiently secured to sufficiently reduce the resistance of the battery pack including the cylindrical battery 1.

[0276] With reference to the Fig. 21 to Fig. 23, in the cylindrical battery 1, the diameter (E1) of the electrode terminal 40 and the width (E2) of the outer surface 20a can be adaptively adjusted with a ring shape taking into account the dimensions of the contact surfaces of the busbar terminals 152, 153.

[0277] Here, the width (E2) of the outer surface 20a of the closed portion of the battery can 20 is the width of the exposed surface parallel to the surface of the electrode terminal 40. Specifically, the width (E2) of the outer surface 20a is defined as the width of a line segment connecting two points where the straight line (L1) drawn in the radial direction from the center C of the electrode terminal 40 intersects the inner and outer boundaries of the outer surface 20. The width (E2) of the outer surface 20a is the width of the flat exposed surface in the entire upper surface of the battery can 20, excluding the rounded area R present at the edge of the closed portion of the battery can 20 and the seal exposure portion 51 of the insulating gasket 50.

[0278] The closed portion of the battery can 20 may be divided into the terminal 40, the seal exposure portion 51 of the insulating seal 50, and the round portion R formed at the edge of the outer surface 20a of the closed portion when viewed from above. The round portion R is a processing portion (see Fig. 7 and Fig. 8) for uniformly connecting the closed portion of the battery can 20 and the side wall of the battery can 20 and has a predetermined width (R d ) on one level.

[0279] The first bus bar terminal 152 of the bus bar 150 branches to a side different from the moving direction of the body portion 151 and is electrically coupled to the terminal exposure portion 41 of the terminal 40. At this time, the electrode terminal 40 and the first bus bar terminal 152 form a first overlap region (indicated by hatching) on ​​a plane, and the first overlap region has a first width (W1). Here, the first overlap region is a region where the electrode terminal 40 and the first bus bar terminal 152 overlap on a plane.

[0280] The first width (W1) is defined as a maximum value among the distances between any two points selected at the edge of the first overlap region. The definition of the first width (W1) is equally applied to the case where the first overlap region includes the center of the connector 40 ( Fig. 22), and in the case where the first overlap area does not include the center of the terminal 40 ( Fig. 23). With reference to the Fig. 22 and Fig. 23, the distance specified by W1 corresponds to a maximum value among the distances between any two points selected at the edge of the first overlap region.

[0281] The second bus bar terminal 153 of the bus bar 150 extends in a direction opposite to the first bus bar terminal 152 based on the movement direction of the body portion 151 and is electrically coupled to the outer surface 20a of the closed portion of the battery can 20. At this time, the second bus bar terminal 153 and the outer surface 20a form a second overlap region (indicated by hatching) on ​​a plane, and the second overlap region has a second width (W2). Here, the second overlap region is a region where the outer surface 20a and the second bus bar terminal 153 overlap on a plane.

[0282] The second width (W2) is defined as a maximum value among the distances between two points where each straight line meets an edge of the second overlap region when a plurality of straight lines (L2) are drawn from the center C of the terminal exposure portion 41 of the terminal 40 to pass through the second overlap region.

[0283] Preferably, the diameter (E1) of the terminal exposure portion 41 of the terminal 40 must be at least equal to or greater than the first width (W1) of the first busbar terminal 152. This is because the first overlap area of ​​the first busbar terminal 152 and the terminal exposure portion 41 must not deviate to the outside of the terminal exposure portion 41 on a plane. In addition, the diameter (E1) of the terminal 40 can be increased to the maximum until the distance between the boundary of the electrode terminal 40 and the second busbar terminal 153 corresponds to the width (G) of the seal exposure portion 51 of the insulating gasket 50. Therefore, the maximum value of the diameter (E1) of the terminal exposure portion 41 of the terminal 40 is "D-2*R d -2*G-2*W2”.

[0284] Preferably, the width (E2) of the outer surface 20a is a factor that depends on the diameter (E1) of the terminal exposure portion 41, and must be at least equal to or greater than the second width (W2) of the second busbar terminal 153. Only in this case can an overlap region of the second busbar terminal 153 and the outer surface 20a be formed. In addition, the width (E2) of the outer surface 20a can be set to up to 50% of "D-2*R d -2*G- E1", which is a value obtained by subtracting the diameter (E1) of the terminal exposure portion 41, the width (2*G) occupied by the seal exposure portion 51, and the width of the round area (2*R d ) from the outer diameter (D) of the battery box 20.

[0285] In summary, in the cylindrical battery 1 according to the present disclosure, the diameter (E1) of the terminal exposure portion 41 of the terminal 40 and the width (E2) of the outer surface 20a are preferably designed to satisfy the following formulas. W1≤E1≤D−2Rd−2G−2 W2 E2=0.5*(D−2Rd−2G−E1)

[0286] (E1: Diameter of the terminal 40 exposed from the battery can 20, E2: Width of the exposed surface of the outer surface 20a of the closed portion of the battery can 20 approximately parallel to the upper surface of the terminal 40, D: Outer diameter of the battery can 20, Rd: Width of the round area R measured on a plane, G: Exposure width of the insulating gasket 50 exposed from the terminal 40 located outside the battery can 20, W1: Width of the first busbar terminal 152, W2: Width of the second busbar terminal 153)

[0287] In a specific example, if D is 46 mm, W1 and W2 are 6 mm, G is 0.5 mm and R d 1 mm, the diameter (E1) of the terminal exposure portion 41 is 6 mm to 31 mm, and the width (E2) of the outer surface 20a is 6 mm and 18.5 mm.

[0288] As another example, if D is 46 mm, W1 and W2 are 6 mm, G is 0.5 mm and R d 1.5 mm, the diameter (E1) of the terminal exposure portion 41 is 6 mm to 30 mm, and the width (E2) of the outer surface 20a is 6 mm and 18 mm.

[0289] Meanwhile, the area occupied by the terminal exposure portion 41 (the area occupied by the first electrode terminal) is preferably about 2% to 30% of the area of ​​the exposed surface of the outer surface 20a of the closed portion of the battery can 20 approximately parallel to the upper surface of the terminal 40 (the area occupied by the second electrode terminal). This is due to the width of the bus bar, which is adopted considering that a current of about 300 A flows. If the ratio of the area occupied by the terminal exposure portion 41 to the area occupied by the outer surface 20a exceeds the upper limit of the above range, the area may be insufficient to connect the second bus bar terminal 153 to the outer surface 20a.Conversely, if the ratio of the area occupied by the terminal exposure portion 41 to the area occupied by the outer surface 20a does not reach the lower limit of the above range, the area when connecting the first bus bar terminal 153 to the terminal exposure portion 41 may be insufficient.

[0290] Meanwhile, the width (R d ) in the range of about 0.1 mm to 3.0 mm, preferably about 0.1 mm to 1.0 mm. If the width occupied by the seal exposure portion 51 (R d ) is too large, the connecting surface of the busbar terminals 152, 153 may not be sufficiently secured. Conversely, if the width occupied by the seal exposure section 51 (R d) is too small, for example when charging and discharging is carried out at a high C-rate of 300 A or more, the electrical insulation between the terminal 40 and the outer surface 20a of the battery can 20 may be interrupted in one plane.

[0291] Preferably, the cylindrical battery may, for example, be a cylindrical battery whose aspect ratio (defined as a value obtained by dividing the diameter of the cylindrical battery by the height, namely a ratio of height (H) to diameter (Φ)) is greater than about 0.4.

[0292] Here, the form factor refers to a value indicating the diameter and height of a cylindrical battery. The cylindrical battery according to an embodiment of the present disclosure may be, for example, a 46110 cell, a 48750 cell, a 48110 cell, a 48800 cell, or a 46800 cell. In the numerical value representing the form factor, the first two numbers indicate the diameter of the cell, the next two numbers indicate the height of the cell, and the last number "0" indicates that the cross-section of the cell is circular.

[0293] A battery according to an embodiment of the present disclosure may be a cylindrical battery having an approximately cylindrical shape, whose diameter is about 46 mm, whose height is about 110 mm, and whose aspect ratio is 0.418.

[0294] A battery according to another embodiment may be a cylindrical battery having a substantially cylindrical shape, the diameter of which is about 48 mm, the height of which is about 75 mm, and the aspect ratio of which is 0.640.

[0295] A battery according to yet another embodiment may be a cylindrical battery having an approximately cylindrical shape, whose diameter is about 48 mm, whose height is about 110 mm, and whose aspect ratio is 0.418.

[0296] A battery according to yet another embodiment may be a cylindrical battery having an approximately cylindrical shape, whose diameter is about 48 mm, whose height is about 80 mm, and whose aspect ratio is 0.600.

[0297] A battery according to yet another embodiment may be a cylindrical battery having an approximately cylindrical shape, whose diameter is about 46 mm, whose height is about 80 mm, and whose aspect ratio is 0.575.

[0298] Conventionally, batteries with a form factor ratio of about 0.4 or less were used. For example, 18650 cells, 21700 cells, etc. were conventionally used. The 18650 cell has a diameter of about 18 mm, a height of about 65 mm, and a form factor ratio of 0.277. The 21700 cell has a diameter of about 21 mm, a height of about 70 mm, and a form factor ratio of 0.300.

[0299] As described above, the cylindrical battery 1 of the present disclosure has a structure in which resistance is minimized by expanding a contact area between components, multiplexing the current path, minimizing a current path length, and the like. After the product is finally manufactured, the AC resistance of the cylindrical battery 1, measured using a resistance measuring instrument between the positive electrode and the negative electrode, namely, between the upper surface of the terminal 40 and the outer surface 20a of the closed portion of the battery can 20, can be about 4 milliohms (mΩ) or less. The resistance can be at least 0.5 mΩ or 1.0 mΩ or more.

[0300] With reference to Fig. 24, a battery pack 3 according to an embodiment of the present disclosure includes a secondary battery assembly in which a plurality of cylindrical batteries 1 according to an embodiment of the present disclosure are electrically connected as described above, and a pack case 2 for accommodating the secondary battery assembly. In Fig. 24 of the present disclosure, components for electrical connection, such as a bus bar, a cooling unit, and a power terminal, are not shown for the sake of simplicity. The electrical connection structure of the plurality of batteries 1 for manufacturing the battery pack 3 has been described above with reference to Fig. 20 and Fig. 21 described as an example.

[0301] With reference to Fig.25, a vehicle 5 according to an embodiment of the present disclosure may be, for example, an electric vehicle, a hybrid electric vehicle, or a plug-in vehicle, and includes the battery pack 3 according to an embodiment of the present disclosure. The vehicle 5 includes a four-wheel vehicle and a two-wheel vehicle. The vehicle 5 operates by receiving power from the battery pack 3 according to an embodiment of the present disclosure.

[0302] In view of the above, it is understood that the present invention also relates to the following unspecified embodiments: Item 1. Battery, including: a rolled electrode assembly having a first electrode and a second electrode and a separator disposed therebetween, wherein the first electrode and the second electrode each have a first uncoated region and a second uncoated region which are not coated with an active material at their long side end and are exposed from the separator; a battery can receiving the electrode assembly through an opening at its lower end and electrically connected to the second uncoated area; a terminal electrically connected to the first uncoated area and exposed from the battery can through a closed portion of the battery can opposite the opening; and a cap that covers and seals the opening of the battery can. Point 2. Battery according to point 1, but the cap has no polarity. Item 3. Battery according to item 1 or 2, with the terminal penetrating a center of the closed section. Item 4. The battery according to any one of items 1 to 3, wherein an insulating gasket disposed between the battery can and the terminal is provided on the closed portion side of the battery can, and wherein a gasket disposed between the battery can and the cap such that the cap seals the opening is provided on the opening side of the battery can. Point 5. Battery according to one of points 1 to 4, wherein a surface of the terminal exposed from the battery can serves as a first electrode terminal to which a first bus bar terminal is coupled, and wherein a region of an outer surface of the closed portion of the battery can occupied by an exposed surface parallel to an upper surface of the first electrode terminal serves as a second electrode terminal to which a second bus bar terminal is coupled. Item 6. The battery according to any one of items 1 to 5, wherein the first bus bar terminal overlaps with the first electrode terminal on a plane to form a first overlap region, wherein the second bus bar terminal overlaps with the second electrode terminal on a plane to form a second overlap region, and wherein a diameter of the first electrode terminal and a width of the second electrode terminal satisfy the following formulas: W1≤E1≤D−2Rd−2G−2 W2 E2=0.5*(D−2Rd−2G−E1) (E1: Diameter of the terminal exposed from the battery can (diameter of the first electrode terminal), E2: Width of the exposed surface of the outer surface of the closed portion of the battery can parallel to the upper surface of the terminal (width of the second electrode terminal), D: Outer diameter of the battery can, Rd: Width of a round area at an edge of the battery can measured on a plane, G: Exposure width of an insulating gasket exposed from an edge of the first electrode terminal on a plane, W1: Maximum value of distances between two arbitrarily selected points at an edge of the first overlapping area; W2: Maximum value of distances between two points where multiple straight lines passing through a center of the first electrode terminal meet an edge of the second overlapping area). Item 7. Battery according to one of items 1 to 6, wherein an area occupied by the first electrode terminal is 2% to 30% compared to an area occupied by the second electrode terminal. Item 8. The battery according to any one of items 1 to 7, wherein a form factor ratio obtained by dividing a diameter of the battery by a height thereof is greater than 0.4. Item 9. The battery according to any one of items 1 to 8, wherein at least a part of the first uncoated region comprises a plurality of segments divided along a winding direction of the electrode assembly, and wherein the plurality of segments are bent along a radial direction of the electrode assembly. Item 10. Battery according to any one of items 1 to 9, wherein the plurality of curved segments are overlapped in multiple layers along the radial direction. Item 11. The battery according to any one of items 1 to 10, wherein the electrode assembly comprises a welding target region in which the number of overlapping layers of the segments of the first uncoated region is kept constant along the radial direction of the electrode assembly. Item 12. The battery according to any one of items 1 to 11, wherein at least a part of the second uncoated region comprises a plurality of segments divided along a winding direction of the electrode assembly, and wherein the plurality of segments are bent along a radial direction of the electrode assembly. Item 13. The battery according to any one of items 1 to 12, wherein the plurality of curved segments are overlapped in multiple layers along the radial direction. Item 14. The battery according to any one of items 1 to 13, wherein the electrode assembly comprises a welding target region in which the number of overlapping layers of the segments of the second uncoated region is kept constant along the radial direction of the electrode assembly. Item 15. Battery according to any one of items 1 to 14, wherein the battery can is made of steel, stainless steel or nickel-plated steel. Item 16. Battery according to any one of items 1 to 15, wherein the battery can is designed to have different thicknesses depending on the location. Item 17. The battery according to any one of items 1 to 16, wherein the battery can is configured such that a thickness of a side wall thereof is smaller than a thickness of the closed portion. Item 18. Battery according to any one of items 1 to 17, wherein the closed portion has a thickness of 0.4 mm to 1.2 mm. Item 19. Battery according to one of items 1 to 18, wherein a side wall of the battery can has a thickness of 0.3 mm to 0.8 mm. Item 20. The battery according to any one of items 1 to 19, wherein the battery can has a nickel-plated layer formed on a surface thereof. Item 21. Battery according to any one of items 1 to 20, wherein the nickel-plated layer has a thickness of 1.5 µm to 6.0 µm. Item 22. A battery according to any one of items 1 to 21, wherein the battery can includes a circular portion for connecting a side wall thereof and the closed portion. Item 23. The battery according to any one of items 1 to 22, wherein the battery can includes a bead portion formed by press-fitting a periphery of an outer peripheral surface of the battery can at the opening side. Item 24. The battery according to any one of items 1 to 23, wherein the bead portion includes an upper bead portion and a lower bead portion located above and below based on an innermost portion located on an innermost side along the press-fitting direction. Item 25. Battery according to one of items 1 to 24, wherein the upper bead section and the lower bead section have asymmetric shapes. Item 26. A battery according to any one of items 1 to 25, wherein the lower bead portion includes a flat portion parallel to the closed portion. Item 27. Battery according to one of items 1 to 26, wherein the upper bead section is at least partially inclined upwards towards the innermost section. Item 28. Battery according to any one of items 1 to 27, wherein the upper bead portion is configured to press and fix a lower portion of the electrode assembly. Item 29. The battery according to any one of items 1 to 28, wherein the battery can has a crimping portion formed below the bead portion and having a shape extending from the bead portion and bent to surround an outer peripheral surface of the cap and a part of a bottom surface of the cap. Item 30. A battery according to any one of items 1 to 29, wherein the battery has a seal arranged at the crimping portion between the battery can and the cap. Item 31. The battery according to any one of items 1 to 30, wherein the cap has a vent portion configured to rupture when an internal pressure of the battery can rises above a predetermined level to discharge gas generated in the battery can. Item 32. A battery according to any one of items 1 to 31, wherein the vent portion is a region of the cap having a smaller thickness than surrounding regions. Item 33. The battery according to any one of items 1 to 32, wherein the vent portion is formed by forming a notch on one surface or both surfaces of the cap to partially reduce a thickness of the battery can. Item 34. The battery according to any one of items 1 to 33, wherein the vent portion is formed along a periphery of an edge portion of a central region projecting downward under the entire region of the cap. Item 35. Battery according to any one of items 1 to 34, wherein the venting section is formed continuously or discontinuously. Item 36. The battery according to any one of items 1 to 35, wherein the vent portion is formed in a central portion projecting downwardly below the entire portion of the cap, and wherein the central portion projecting downwardly is located higher than a lower end of the battery can. Item 37. The battery according to any one of items 1 to 36, wherein the terminal comprises: a terminal exposure portion exposed from the battery can; and a terminal insertion portion provided by the closed portion of the battery can and located within the battery can. Item 38. The battery according to any one of items 1 to 37, wherein the terminal insert portion comprises: an electrical connection portion electrically connected to the first uncoated area; and a flange portion formed on a periphery of the electrical connection portion and having a shape bent toward an inner surface of the closed portion of the battery can to be riveted to the inner surface. Item 39. Battery according to any one of items 1 to 38, wherein the terminal is made of aluminum. Item 40. The battery according to any one of items 1 to 39, wherein a step is formed between a top surface of the terminal exposure portion and a top surface of the battery can. Item 41. A battery according to any one of items 1 to 40, wherein the terminal exposure portion protrudes from the battery can through the top of the battery can. Item 42. Battery according to any of items 1 to 41, where the height of the step is 0.8 mm or more. Item 43. The battery according to any one of items 1 to 42, wherein an insulating gasket is disposed between the terminal and the battery can, and wherein the insulating gasket comprises: a gasket exposure portion disposed between the terminal exposure portion and the battery can; and a gasket insertion portion disposed between the terminal insertion portion and the battery can. Item 44. Battery according to any one of items 1 to 43, wherein the seal exposure portion has a thickness of 0.3 mm to 1 mm. Item 45. A battery according to any one of items 1 to 44, wherein the seal exposure portion extends longer than the terminal exposure portion so as to be exposed from the terminal exposure portion. Item 46. The battery according to any one of items 1 to 45, wherein the seal insert portion is deformed together when the flange portion of the terminal insert portion is riveted to be in close contact with the inner surface of the closed portion of the battery can. Item 47. The battery according to any one of items 1 to 46, wherein a region of the seal insert portion exposed from the terminal exposure portion has a width in the range of 0.1 mm to 3.0 mm. Item 48. The battery of any one of items 1 to 47, wherein the battery includes a first current collector coupled to an upper portion of the electrode assembly and coupled to the terminal to electrically connect the first uncoated region of the electrode assembly and the terminal. Item 49. The battery according to any one of items 1 to 48, wherein a flat portion parallel to an inner surface of the closed portion of the battery can is formed in at least a part of a bottom surface of the terminal, and the first current collector is coupled to the flat portion of the terminal. Item 50. The battery according to any one of items 1 to 49, wherein the first current collector is coupled to a coupling surface formed by bending one end of the first uncoated region. Item 51. The battery of any one of items 1 to 50, wherein the battery comprises a first current collector coupled to an upper portion of the electrode assembly and coupled to the terminal to electrically connect the first uncoated region of the electrode assembly and the terminal, and wherein the first current collector is coupled to the first uncoated region within the weld target area. Item 52. The battery according to any one of items 1 to 51, wherein the first current collector comprises: an edge portion disposed on the electrode assembly; a first uncoated region coupling portion configured to extend inwardly from the edge portion and to be coupled to the first uncoated region; and a terminal coupling portion configured to extend inwardly from the edge portion and to be coupled to the terminal. Item 53. Battery according to one of items 1 to 52, wherein the first coupling portion of the uncoated area and the terminal coupling portion are not directly connected but indirectly connected through the edge portion. Item 54. The battery according to any one of items 1 to 53, wherein the terminal coupling portion is provided at a position corresponding to an opening formed at a coil center of the electrode assembly. Item 55. The battery according to any one of items 1 to 54, wherein the terminal coupling portion is configured to cover the opening formed at the coil center so that the opening formed at the coil center of the electrode assembly is not exposed from the terminal coupling portion. Item 56. The battery according to any one of items 1 to 55, wherein the terminal coupling portion has a diameter substantially equal to or larger than a diameter of a flat portion formed on a bottom surface of the terminal. Item 57. The battery according to any one of items 1 to 56, wherein the first current collector further comprises a bridge portion configured to extend inwardly from the edge portion and to be connected to the terminal coupling portion. Item 58. The battery according to any one of items 1 to 57, wherein the bridge portion includes a notch portion formed to partially reduce a cross-sectional area of ​​the bridge portion. Item 59. The battery according to any one of items 1 to 58, wherein at least a part of the first uncoated region includes a plurality of segments divided along a winding direction of the electrode assembly, and the plurality of segments are bent along a radial direction of the electrode assembly to be overlapped in multiple layers, and wherein the notch portion is provided in a region corresponding to a welding target region in which the number of overlapping layers of the segments of the first uncoated region along the radial direction of the electrode assembly is kept constant. Item 60. The battery according to any one of items 1 to 59, wherein the notch portion is provided at a position corresponding to a center in the radial direction of the electrode assembly. Item 61. The battery according to any one of items 1 to 60, wherein a welding pattern drawn by welding beads formed on a surface of the terminal coupling portion of the first current collector is drawn so as to surround a center of a bottom surface of the terminal. Item 62. Battery according to any one of items 1 to 61, wherein the weld pattern is formed continuously or discontinuously. Item 63. The battery according to any one of items 1 to 62, wherein a welding portion formed between the terminal coupling portion of the first current collector and a bottom surface of the terminal has a tensile force of 2 kgf or more. Item 64. The battery according to any one of items 1 to 63, wherein a welding pattern drawn by welding beads formed on a surface of the terminal coupling portion of the first current collector has a converted diameter of 2 mm or more. Item 65. The battery according to any one of items 1 to 64, wherein a flat portion formed on the bottom surface of the terminal has a diameter of 3 mm to 14 mm. Item 66. The battery according to any one of items 1 to 65, wherein a ratio of an area of ​​a welding pattern drawn by welding beads formed on a surface of the terminal coupling portion of the first current collector to an area of ​​a flat portion formed on the bottom surface of the terminal is 2.04% to 44.4%. Item 67. Battery under any of items 1 to 66, wherein the battery comprises a second current collector coupled to a lower portion of the electrode assembly and coupled to the battery can to electrically connect the second uncoated region of the electrode assembly and the battery can. Item 68. The battery according to any one of items 1 to 67, wherein the second current collector is coupled to a coupling surface formed by bending one end of the first uncoated portion. Item 69. The battery of any one of items 1 to 68, wherein the battery comprises a second current collector coupled to a lower portion of the electrode assembly and coupled to the battery can to electrically connect the second uncoated region of the electrode assembly and the battery can, and wherein the second current collector is coupled to the second uncoated region within the weld target area. Item 70. The battery of any one of items 1 to 69, wherein the second current collector comprises: a support portion disposed below the electrode assembly; a second uncoated region coupling portion configured to extend from the support portion and be coupled to the second uncoated region; and a can coupling portion configured to extend from the support portion and be coupled to the battery can. Item 71. The battery according to any one of items 1 to 70, wherein the second coupling portion of the uncoated area and the can coupling portion are indirectly connected through the support portion. Item 72. The battery according to any one of items 1 to 71, wherein the second current collector comprises: a second uncoated region coupling portion coupled to the second uncoated region; and a can coupling portion coupled to the battery can. Item 73. The battery according to any one of items 1 to 72, wherein the can coupling portion is provided in plural numbers, and wherein the plurality of can coupling portions are configured to extend radially toward a side wall of the battery can. Item 74. A battery according to any one of items 1 to 73, wherein the second current collector and the battery can are electrically connected at a plurality of locations. Item 75. The battery according to any one of items 1 to 74, wherein the battery can includes a bead portion formed by press-fitting a periphery of an outer peripheral surface of the battery can at the opening side, and wherein the can coupling portion is electrically coupled to a bottom surface of the bead portion. Item 76. The battery according to any one of items 1 to 75, wherein the battery can has a crimping portion formed under the bead portion and has a shape extending from the bead portion and bent to surround an outer peripheral surface of the cap and a part of a bottom surface of the cap, the battery having a gasket disposed at the crimping portion between the battery can and the cap, and the can coupling portion is disposed between the gasket and the bottom surface of the bead portion. Item 77. The battery according to any one of items 1 to 76, wherein a flat portion is formed parallel to the closed portion on the underside of the bead portion, and wherein the can coupling portion is electrically coupled to the flat portion. Item 78. The battery according to any one of items 1 to 77, wherein the can coupling portion comprises: a contact portion coupled to an inner surface of the battery can; and a connecting portion configured to connect a center of the second current collector and the contact portion to each other. Item 79. The battery according to any one of items 1 to 78, wherein the battery can includes a bead portion formed by press-fitting a periphery of an outer peripheral surface of the battery can at the opening side, and wherein the contact portion has a shape extending along a circumferential direction of the battery can over a predetermined length on the bead portion. Item 80. The battery according to any one of items 1 to 79, wherein the second current collector has a current collector opening formed at a position corresponding to an opening formed at a winding center of the electrode assembly. Item 81. The battery according to any one of items 1 to 80, wherein the current collector opening has a diameter substantially equal to or larger than the opening formed at the winding center of the electrode assembly. Item 82. The battery according to any one of items 1 to 81, wherein the battery can includes a bead portion formed by press-fitting a periphery of an outer peripheral surface of the battery can at the opening side, and wherein a maximum distance from a center of the second current collector to an end of the coupling portion of the second uncoated region along the radial direction of the electrode assembly is substantially equal to or smaller than an inner diameter of the battery can in a region where the bead portion is formed. Item 83. A battery according to any one of items 1 to 82, wherein an insulator is arranged between the first current collector and an inner surface of the closed portion of the battery can. Item 84. A battery according to any one of items 1 to 83, wherein the insulator has a thickness corresponding to the distance between the inner surface of the closed portion of the battery can and the first current collector. Item 85. A battery according to any one of items 1 to 84, wherein the terminal is coupled to the first current collector through an opening formed in the insulator. Item 86. The battery according to any one of items 1 to 85, wherein the insulator has a thickness substantially equal to or greater than the distance between the inner surface of the closed portion of the battery can and a bottom surface of the terminal. Item 87. A battery according to any one of items 1 to 86, wherein the insulator is arranged between the first uncoated area and a side wall of the battery can. Item 88. A battery according to any one of items 1 to 87, wherein an upper surface of the insulator is in contact with the inner surface of the closed portion of the battery can and a lower surface of the insulator is in contact with an upper surface of the first current collector. Item 89. A battery according to any one of items 1 to 88, wherein the resistance measured between a positive electrode and a negative electrode of the battery is 4 mohm or less. Item 90. Battery pack comprising a plurality of batteries as defined in any one of items 1 to 89. Item 91. The battery pack of item 90, wherein the plurality of batteries are arranged in a predetermined number of columns, and wherein the terminal of each battery and an outer surface of the closed portion of the battery can are arranged to face upward. Item 92.The battery pack according to item 90 or 91, wherein the battery pack comprises a plurality of bus bars configured to connect the plurality of batteries in series and parallel, the plurality of bus bars being arranged on the plurality of batteries, and each of the bus bars comprising: a body portion configured to extend between terminals of adjacent batteries; a plurality of first bus bar terminals configured to extend in one side direction of the body portion and to be electrically coupled to a terminal of a battery arranged in the one side direction; and a plurality of second bus bar terminals configured to extend in the other side direction of the body portion and to be electrically coupled to an outer surface of the closed portion of the battery can of a battery arranged in the other side direction. Item 93. Vehicle comprising at least one battery pack as defined in any of items 90 to 92.

[0303] 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 intended for purposes of illustration only, since various changes and modifications within the scope of the disclosure will become apparent to those skilled in the art from this detailed description. REFERENCE SYMBOL 5 vehicle 3 battery packs 2 packing housings 1 cylindrical battery 10 Electrode assembly C Winding center 11 first uncoated area 12 second uncoated area 20 battery boxes 21 Bead section 22 Crimping section 30 cap 31 Ventilation section 40 connection 41 Connection clearance section 42 Connection insert section 50 insulating seal 60 first pantograph 61 marginal section 62 Coupling section of the first uncoated area 63 Connection coupling section 64 bridge section 70 Insulator 80 second pantograph 81 support section 82 Coupling section of the second uncoated area 83 Socket coupling section 90 Seal QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 6,677,082

[0162] US 6,680,143

[0162]

Claims

[1] Battery (1) comprising: a coiled electrode assembly (A; 10) having a first electrode (210) and a second electrode (211) and a separator (212) arranged therebetween, wherein the first electrode (210) has a first uncoated region (11; 210a) and the second electrode (211) has a second uncoated region (12; 211a), wherein the first uncoated region (11; 210a) and the second uncoated region (12; 211a) are free of an active material, wherein the first uncoated region (11; 210a) and the second uncoated region (12; 211a) are adjacent to a respective edge of the first electrode (210) and the second electrode (211) extending along a winding direction of the coiled electrode assembly (A; 10), wherein the first uncoated region (210a) and the second uncoated area (211a) at the edge extends beyond the separator (212); a battery can (20; 241) receiving the electrode assembly (A; 10) and electrically connected to the second uncoated region (12; 211a), the battery can (20; 241) having a first end face, a second end face, and a cylindrical side wall extending between the first end face and the second end face, the second end face having an opening, and the battery can (20; 241) being made of steel, stainless steel, and / or nickel-plated steel; a terminal (40) electrically connected to the first uncoated region (11; 210a) and penetrating the first end face of the battery can (20; 241); a cap (30) covering and closing the opening of the second end face of the battery can (20; 241); a first current collector (60) coupled to an end face of the electrode assembly, the first current collector being coupled to the terminal (40) to electrically connect the first uncoated region of the electrode assembly and the terminal, wherein at least a part of a lower surface of the terminal is formed as a flat portion parallel to an inner surface of the first end surface of the battery can, wherein the first current collector is directly coupled to the flat portion of the terminal; wherein a thickness of the side wall of the battery can (20; 241) is smaller than a thickness of the first end surface of the battery can (20; 241). [2] Battery (1) according to claim 1, wherein the terminal (40) penetrates a center (C) of the first end face of the battery can (20; 241). [3] Battery (1) according to one of the preceding claims, further comprising: an insulating seal (50) arranged between the battery can (20; 241) and the terminal (40); and a sealing seal (90) arranged between the battery can (20; 241) and the cap (30) so that the cap (30) closes the opening of the second end face of the battery can (20; 241). [4] Battery (1) according to one of the preceding claims, further comprising: a first bus bar terminal (152) coupled to a surface of the terminal exposed from the battery can (20; 241) serving as a first electrode terminal; a second bus bar terminal (153) coupled to an outer surface of the second end surface of the battery can (20; 241) serving as a second electrode terminal; and a round area connecting the side wall of the battery can (20; 241) and the first end surface of the battery can (20; 241), wherein the first busbar terminal (152) lies on the first electrode terminal to form a first overlap region, wherein the second busbar terminal (153) lies on the second electrode terminal to form a second overlap region, and where a diameter E1 of the first electrode terminal and a width E2 of the second electrode terminal satisfy the following formulas: W1≤E1≤D−2Rd−2G−2 W2 E2=0.5⋅(D−2Rd−2G−E1) where E1 is a diameter of the terminal exposed from the battery can (20; 241), E2 is a width of the exposed surface of the outer surface of the first end surface of the battery can (20; 241), D is an outer diameter of the battery can (20; 241), Rd is a width of the round portion at an edge of the battery can (20; 241) in a plan view, G is a width of an insulating gasket (50) exposed from an edge of the first electrode terminal on a plane, W1 is a maximum value among distances between any two points at an edge of the first overlapping portion, and W2 is a maximum value among distances between two points at which straight lines passing through a center (C) of the first electrode terminal meet an edge of the second overlapping portion. [5] The battery (1) according to claim 4, wherein an area of ​​the first electrode terminal is 2% to 30% compared to an area of ​​the second electrode terminal. [6] A battery (1) according to any one of the preceding claims, wherein a ratio obtained by dividing a diameter of the battery (1) by a height thereof is greater than 0.

4. [7] Battery (1) according to one of the preceding claims, wherein at least a part of the first uncoated region (11; 210a) and / or the second uncoated region (12; 211a) comprises a plurality of segments divided along a winding direction of the electrode arrangement (A; 10), and wherein the plurality of segments are bent along a radial direction of the electrode assembly (A; 10). [8] Battery (1) according to claim 7, wherein the plurality of curved segments overlap each other to form a plurality of overlapping layers extending along the radial direction, wherein the electrode assembly (A; 10) comprises a welding target region in which the number of overlapping layers of the segments of the first uncoated region (11; 210a) and / or the second uncoated region (12; 211a) is kept constant along the radial direction of the electrode assembly (A; 10). [9] Battery (1) according to one of the preceding claims, wherein the first end surface has a thickness of 0.4 mm to 1.2 mm; and / or wherein the side wall of the battery can (20; 241) has a thickness of 0.3 mm to 0.8 mm. [10] Battery (1) according to one of the preceding claims, wherein the battery can (20; 241) has a bead portion formed by press-fitting a periphery of the side wall of the battery can (20; 241) on the second end surface. [11] The battery (1) according to claim 10, wherein the bead portion comprises an upper bead portion and a lower bead portion located above and below an innermost portion in an axial direction. [12] Battery (1) according to claim 11, wherein the upper bead portion and the lower bead portion are asymmetrical. [13] Battery (1) according to one of claims 10 to 12, wherein: the lower bead portion comprises a flat portion parallel to the first end surface; and / or the upper bead portion is at least partially inclined in an axial direction from the side wall of the battery can (20; 241) to the innermost portion of the bead portion; and / or the upper bead portion is configured to press and / or fix a lower portion of the electrode assembly (A; 10). [14] The battery (1) according to any one of claims 10 to 13, wherein the battery can (20; 241) comprises a crimping portion formed below the bead portion and having a shape extending from the bead portion and bent to surround an outer peripheral surface of the cap (30) and a part of a lower surface of the cap (30). [15] Battery (1) according to claim 14, wherein the battery (1) comprises a sealing seal (90) arranged between the battery can (20; 241) and the cap (30) at the crimping portion. [16] A battery (1) according to any one of the preceding claims, wherein the cap (30) comprises a vent portion configured to be ruptured when an internal pressure of the battery can (20; 241) rises above a predetermined level to expel gas generated inside the battery can (20; 241). [17] Battery (1) according to claim 16, wherein the venting portion is a region of the cap (30) having a reduced thickness compared to a remainder of the cap (30); and / or wherein the vent portion is formed by locally reducing a thickness of the cap (30) by forming a notch on one surface or both surfaces of the cap (30). [18] Battery (1) according to claim 16 or 17, wherein the venting portion is formed around a central region projecting from a remainder of the cap (30) in a direction opposite to the first end face of the battery can (20; 241); and / or wherein the venting section is formed continuously or discontinuously; and / or wherein the central region is offset from the second end face of the battery can (20; 241) to the first end face of the battery can. [19] Battery (1) according to one of the preceding claims, wherein the terminal (40) comprises: a terminal exposure portion exposed from the battery box (20); and a terminal insert portion (42) extending through the first end face of the battery can (20; 241) into the battery can (20; 241). [20] Battery (1) according to claim 19, wherein the terminal insert portion (42) comprises: an electrical connection portion (42a) electrically connected to the first uncoated region (11; 210a); and a flange portion formed on a periphery of the electrical connection portion and having a shape bent toward an inner surface of the first end surface of the battery can (20; 241) to be riveted to the inner surface. [21] Battery (1) according to claim 19 or 20, wherein a step is formed between an upper surface of the terminal exposure portion and the first end surface of the battery can (20; 241); and / or wherein the terminal exposure portion protrudes from the battery can (20; 241) through the first end surface of the battery can (20; 241). [22] Battery (1) according to one of claims 19 to 21, wherein an insulating seal (50) is arranged between the terminal (40) and the battery box (20; 241), and wherein the insulating seal (50) comprises: - a seal exposed portion disposed between the terminal exposed portion and the battery can (20; 241); and - a sealing insert portion disposed between the terminal insert portion (42) and the battery can (20; 241). [23] The battery (1) according to claim 22, wherein the seal exposed portion extends longer than the terminal exposed portion so as to be exposed from the terminal exposed portion. [24] Battery (1) according to claim 22 or 23, wherein the sealing insert portion is deformed when the flange portion of the terminal insert portion (42) is riveted to be fixed to the inner surface of the first end surface of the battery can (20; 241); and / or wherein an area of ​​the seal insert portion exposed from the terminal exposed portion extends by 0.1 mm to 3.0 mm. [25] Battery (1) according to claim 1, wherein the first current collector (60) is coupled to a coupling surface formed by bending one end of the first uncoated region (11; 210a). [26] Battery (1) according to claim 8, wherein the first current collector (60) is coupled to the first uncoated area (11; 210a) within the welding target area. [27] Battery (1) according to one of claim 1 or claim 25 or 26, wherein the first current collector (60) comprises: an edge portion disposed on the electrode assembly (A; 10); a first uncoated area coupling portion (11; 210a) configured to extend inwardly from the edge portion and coupled to the first uncoated area (11; 210a); and a terminal coupling portion (40) configured to extend inwardly from the edge portion and coupled to the terminal (40). [28] Battery (1) according to claim 27, wherein: the first uncoated area coupling portion (11; 210a) and the terminal coupling portion are connected via the edge portion; and / or the terminal coupling portion is provided at a location corresponding to a hole formed at a winding center (C) of the electrode assembly (A; 10); and / or the terminal coupling portion is dimensioned and arranged to completely cover the hole; and / or the terminal coupling portion has a diameter substantially equal to or greater than a diameter of the flat portion of the terminal (40); and / or wherein the terminal coupling portion of the first current collector (60) and a lower surface of the terminal (40) are welded to have a tensile force of 19.6 N (2 kgf) or more. [29] The battery (1) according to claim 27 or 28, wherein the first current collector (60) further comprises a bridge portion extending between the edge portion and the terminal coupling portion. [30] The battery (1) according to claim 29, wherein the bridge portion comprises a notch portion formed to locally reduce a cross section of the bridge portion. [31] Battery (1) according to claim 30, wherein at least a part of the first uncoated region (11; 210a) comprises a plurality of segments divided along a winding direction of the electrode assembly (A; 10), and the plurality of segments are bent along a radial direction of the electrode assembly (A; 10) to form a plurality of overlapping layers, and wherein the notch portion is provided in a region corresponding to a welding target region in which the number of overlapping layers of the segments of the first uncoated region (11; 210a) is constant. [32] A battery (1) according to claim 30 or 31, wherein the notch portion is provided at a position corresponding to a center in the radial direction of the electrode assembly (A; 10). [33] Battery (1) according to one of claims 27 to 32, wherein: a welding pattern formed by welding beads formed on a surface of the terminal coupling portion of the first current collector (60) surrounds a center of a lower surface of the terminal (40); and / or a welding pattern formed by welding beads formed on a surface of the terminal coupling portion of the first current collector (60) has a converted diameter of 2 mm or more; and / or a ratio of an area of ​​a welding pattern marked by weld beads formed on a surface of the terminal coupling portion of the first current collector (60) to an area of ​​a flat portion formed on the lower surface of the terminal (40) is 2.04% to 44.4%. [34] Battery (1) according to one of claims 1 or claims 14 to 33, wherein the flat portion of the terminal (40) has a diameter of 3 mm to 14 mm. [35] Battery (1) according to one of the preceding claims, further comprising: a second current collector (80) coupled to another end face of the electrode assembly (A; 10), wherein the second current collector (80) is coupled to the battery can (20; 241) to electrically connect the second uncoated region (12; 211a) of the electrode assembly (A; 10) and the battery can (20; 241). [36] Battery (1) according to claim 35, wherein the second current collector (80) is coupled to a coupling surface formed by bending one end of the second uncoated region (12; 211a); and / or wherein the second current collector (80) is coupled to the second uncoated region (12; 211a) within a welding target region according to claim 8, claim 28 or claim 33. [37] Battery (1) according to claim 35 or 36, wherein the second current collector (80) comprises: a support portion disposed below the electrode assembly (A; 10); a second uncoated area coupling portion (12; 211a) configured to extend from the support portion and coupled to the second uncoated area (12; 211a); and a can coupling portion configured to extend from the support portion and coupled to the battery can (20; 241). [38] The battery (1) according to claim 37, wherein the second uncoated area coupling portion (12; 211a) and the can coupling portion are connected via the support portion. [39] Battery (1) according to one of claims 35 to 38, wherein the second current collector (80) comprises: a second uncoated area coupling portion (12; 211a) coupled to the second uncoated area (12; 211a); and a can coupling portion coupled to the battery can (20; 241). [40] Battery (1) according to claim 39, wherein the second current collector (80) has a plurality of socket coupling sections, and wherein the plurality of can coupling portions each extend in a radial direction of the battery can (20; 241). [41] Battery (1) according to claim 39 or 40, wherein the second current collector (80) and the battery can (20; 241) are electrically connected at a plurality of locations. [42] Battery (1) according to one of claims 39 to 41, further comprising: a bead portion formed by press-fitting the side wall of the battery can (20; 241) on the second end surface, wherein: the socket coupling portion is electrically coupled to a surface of the bead portion; and / or a maximum distance from a center of the second current collector (80) to an end of the second uncoated area coupling portion (12; 211a) along the radial direction of the electrode assembly (A; 10) is substantially equal to or smaller than an inner diameter of the battery can (20; 241) in a region in which the bead portion is formed. [43] Battery (1) according to claim 42, further comprising: a crimping portion between the bead portion and the second end surface of the battery can (20; 241), the crimping portion having a shape extending from the bead portion and bent to surround an outer peripheral surface of the cap (30) and a part of a lower surface of the cap (30), a sealing seal (90) between the battery can (20; 241) and the cap (30) at the crimping section, and wherein the can coupling portion is disposed between the closure seal (90) and the lower surface of the bead portion. [44] Battery (1) according to claim 42 or 43, wherein the bead portion has a flat portion formed parallel to the first end face on the lower surface of the bead portion, and wherein the can coupling portion is electrically coupled to the flat portion. [45] Battery (1) according to any one of claims 39 to 44, wherein the can coupling portion comprises: a contact portion coupled to an inner surface of the battery can (20; 241); and a connecting portion connecting a center of the second current collector (80) and the contact portion. [46] Battery (1) according to claim 45, further comprising: a bead portion formed by press-fitting the side wall of the battery can (20; 241) on the second end surface, and wherein the contact portion has a shape extending by a predetermined length along a circumferential direction of the battery can (20; 241) at the bead portion. [47] A battery (1) according to any one of claims 35 to 46, wherein the second current collector (80) has a current collector hole formed at a position corresponding to a hole formed at a winding center (C) of the electrode assembly (A; 10). [48] ​​A battery (1) according to claim 47, wherein the current collector hole has a diameter substantially equal to or larger than the hole formed at the winding center (C) of the electrode assembly (A; 10). [49] Battery (1) according to any one of claims 1 or 26 to 48, further comprising: an insulator between the first current collector (60) and an inner surface of the first end face of the battery can (20; 241). [50] Battery (1) according to claim 49, wherein: the insulator has a thickness corresponding to the distance between the inner surface of the first end face of the battery can (20; 241) and the first current collector (60); and / or the insulator has a thickness substantially equal to or greater than the distance between the inner surface of the first end face of the battery can (20; 241) and a lower surface of the terminal (40). [51] Battery (1) according to claim 49 or 50, wherein the terminal (40) is coupled to the first current collector (60) through a hole formed in the insulator. [52] Battery (1) according to one of claims 49 to 51, wherein: the insulator is arranged between the first uncoated area (11; 210a) and the side wall of the battery can (20; 241); and / or an upper surface of the insulator is in contact with the inner surface of the first end face of the battery can (20; 241) and a lower surface of the insulator is in contact with an upper surface of the first current collector (60). [53] Battery pack (3) comprising a plurality of batteries (1) according to one of the preceding claims. [54] Battery pack (3) according to claim 53, wherein the batteries are arranged in a predetermined number of columns, and wherein the terminal (40) of each battery (1) of the plurality of batteries and an outer surface of the first end surface of the battery can (20; 241) of each of the plurality of batteries are arranged to face upward. [55] Battery pack (3) according to claim 53 or 54, wherein the battery pack (3) has a plurality of busbars configured to connect the plurality of batteries in series and / or parallel, wherein the plurality of busbars are arranged on the plurality of batteries, and wherein each of the plurality of busbars comprises: - a body portion configured to extend between terminals (40) of adjacent batteries; - a plurality of first bus bar terminals (152) configured to extend in a lateral direction of the body portion and electrically coupled to a terminal (40) of a battery (1) located in the one lateral direction; and - a plurality of second bus bar terminals (153) configured to extend in the other side direction of the body portion and electrically coupled to an outer surface of the first end surface of the battery can (20; 241) of a battery (1) located in the other side direction. [56] Vehicle (5) comprising at least one battery pack (3) according to one of claims 53 to 55.

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