Battery and current collector applied thereto, and battery pack and automobile including same

Abstract

According to one embodiment of the present invention, there is provided a battery comprising: an electrode assembly in which a first electrode, a second electrode, and a separator interposed therebetween are wound around a winding shaft to define a core and an outer circumferential surface; the first electrode includes a first uncoated portion that is not coated with an active material layer along the winding direction, and at least a portion of the first uncoated portion is used as an electrode tab; a housing having an opening on one side and configured to receive the electrode assembly through the opening; a first current collector including a peripheral portion disposed on an upper portion of the electrode assembly, a first uncoated portion coupling portion extending inward from the peripheral portion and coupled to the first uncoated portion, and a terminal coupling portion positioned spaced apart from the first uncoated portion coupling portion; and a terminal coupled to the terminal coupling portion.

Description

[Technical field]

[0001] The present invention relates to a battery, a current collector applied thereto, and a battery pack and an automobile including the same, and more particularly to a battery having a structure in which force is not concentrated at welded portions between parts even when external impact or vibration is applied during use of a secondary battery, a current collector applied thereto, and a battery pack and an automobile including the same.

[0002] This application is a continuation of Korean Patent Application No. 10-2021-0007278 filed on January 19, 2021, Korean Patent Application No. 10-2021-0022897 filed on February 19, 2021, Korean Patent Application No. 10-2021-0022894 filed on February 19, 2021, Korean Patent Application No. 10-2021-0022891 filed on February 19, 2021, Korean Patent Application No. 10-2021-0022881 filed on February 23, 2021, Korean Patent Application No. 10-2021-0024424 filed on March 8, 2021. Patent Application No. 10-2021-0030300, Korean Patent Application No. 10-2021-0030291 filed on March 8, 2021, Korean Patent Application No. 10-2021-0046798 filed on April 9, 2021, Korean Patent Application No. 10-2021-0058183 filed on May 4, 2021, Korean Patent Application No. 10-2021-0077046 filed on June 14, 2021, Korean Patent Application No. 10-2021-0084326 filed on June 28, 2021, Korean Patent Application No. 10-2021-0131225 filed on October 1, 2021, Korean Patent Application No. 10-2021-0131215 filed on October 1, 2021, Korean Patent Application No. 10-2021-0131205 filed on October 1, 2021, Korean Patent Application No. 10-2021-0131208 filed on October 1, 2021, Korean Patent Application No. 10-2021-0131207 filed on October 14, 2021, Korean Patent Application No. 10-2021-0137001 filed on October 15, 2021, Korean Patent Application No. 10-2021-0137856 filed on October 22, 2021 10-2021-0142196, Korean Patent Application No. 10-2021-0153472 filed on November 9, 2021, Korean Patent Application No. 10-2021-0160823 filed on November 19, 2021, Korean Patent Application No. 10-2021-0163809 filed on November 24, 2021, Korean Patent Application No. 10-2021-0165866 filed on November 26, 2021, Korean Patent Application No. 10-2021-0172446 filed on December 3, 2021, Korean Patent Application No. 10-2021-0177091 filed on December 10, 2021,Priority is claimed based on Korean Patent Application No. 10-2021-0194593 filed on December 31, 2021, Korean Patent Application No. 10-2021-0194610 filed on December 31, 2021, Korean Patent Application No. 10-2021-0194572 filed on December 31, 2021, Korean Patent Application No. 10-2021-0194612 filed on December 31, 2021, Korean Patent Application No. 10-2021-0194611 filed on December 31, 2021, and Korean Patent Application No. 10-2022-0001802 filed on January 5, 2022, and the contents disclosed in the specification and drawings of said applications are incorporated herein in their entirety. [Background technology]

[0003] The application areas of secondary batteries are very diverse. For example, battery packs applied to devices such as electric vehicles are required to have large capacity and high output. In addition, such large capacity and high output battery packs may include, for example, cylindrical batteries as unit cells.

[0004] In the case of cylindrical batteries with large capacity and high output characteristics, electrode tabs are provided on both sides of the jelly roll to increase current collection efficiency, and current collectors can be attached to both sides of the jelly roll. By applying this structure, the contact area between the electrode tabs and the current collectors can be maximized, thereby minimizing the resistance that occurs at the connection points between the parts.

[0005] As described above, when a cylindrical battery is applied to a device such as an automobile, it may be frequently subjected to external shocks and vibrations during use, which may cause damage to the joints for electrical connection between the components. Such damage to the joints may result in product defects.

[0006] Even if the electrical connection is not completely cut off due to damage to the joint portion for electrical connection, if the welded portion is partially damaged and the joint area between the parts is reduced, problems such as excessive heat generation due to increased resistance and the resulting deformation of the parts, causing internal short circuits, may occur.

[0007] Therefore, there is a need to develop a cylindrical battery with a structure that does not concentrate force on the joints between parts even when external impact and / or vibration are applied during use.

[0008] Meanwhile, in the case of cylindrical batteries, a separator, which is an insulator, is placed between the positive and negative electrodes, which is then rolled up to form a jelly-roll shaped electrode assembly, which is then inserted into a battery can together with an electrolyte to form a battery. A strip-shaped electrode tab is connected to the uncoated portion of each of the positive and negative electrodes, and the electrode tab electrically connects the electrode assembly to the electrode terminal exposed to the outside. For reference, the positive electrode terminal is the cap plate of the sealed body that seals the opening of the battery can, and the negative electrode terminal is the battery can.

[0009] However, in conventional cylindrical batteries having such a structure, current is concentrated in the strip-shaped electrode tabs connected to the positive electrode uncoated portion and / or the negative electrode uncoated portion, resulting in high resistance, large heat generation, and poor current collection efficiency.

[0010] Resistance and heat generation are not a big problem for small cylindrical batteries with the form factor of 18650 or 21700. However, when the form factor of a cylindrical battery is increased to be used in an electric vehicle, a large amount of heat is generated around the electrode tabs during the fast charging process, which can cause the cylindrical battery to catch fire.

[0011] To solve these problems, a cylindrical battery (so-called tab-less cylindrical battery) has been proposed, which is designed so that positive and negative uncoated parts are located at the top and bottom of the jelly roll type electrode assembly, respectively, and current collecting plates are welded to these uncoated parts to improve current collection efficiency.

[0012] Figures 1 to 3 are diagrams showing the manufacturing process of a tabless cylindrical battery. Figure 1 shows the structure of an electrode plate, Figure 2 shows the winding process of the electrode plate, and Figure 3 shows the process of welding a current collecting plate to the bent surface of the non-coated part. Figure 4 is a cross-sectional view of a tabless cylindrical battery cut in the longitudinal direction (Z direction).

[0013] 1 to 4, the positive electrode plate 210 and the negative electrode plate 211 have a structure in which an active material 221 is coated on a sheet-shaped current collector 220, and include a non-coated portion 222 on one long side along the winding direction (X direction).

[0014] The electrode assembly A is fabricated by sequentially stacking a positive electrode plate 210 and a negative electrode plate 211 together with two separators 212 as shown in Fig. 2, and then winding them in one direction (X direction). At this time, the non-coated portion of the positive electrode plate 210 and the non-coated portion of the negative electrode plate 211 are arranged in opposite directions.

[0015] After the winding process, the non-coated portion 210a of the positive electrode plate 210 and the non-coated portion 211a of the negative electrode plate 211 are bent toward the core side, and then the current collecting plates 230 and 231 are welded and coupled to the non-coated portions 210a and 211a, respectively.

[0016] Since no separate electrode tabs are attached to the positive electrode uncoated portion 210a and the negative electrode uncoated portion 211a, and the current collecting plates 230, 231 are connected to external electrode terminals, and a current path is formed with a large cross-sectional area along the winding axis direction of the electrode assembly A (see arrow), there is an advantage in that the resistance of the battery can be reduced. This is because resistance is inversely proportional to the cross-sectional area of ​​the path through which the current flows.

[0017] However, as the form factor of cylindrical batteries increases and the magnitude of the charging current during fast charging increases, heat generation problems also occur in table-less cylindrical batteries.

[0018] Specifically, a conventional tabless cylindrical battery 240 includes a battery can 241 and a sealing body 242, as shown in Fig. 4. The sealing body 242 includes a cap plate 242a, a sealing gasket 242b, and a connection plate 242c. The sealing gasket 242b surrounds the edge of the cap plate 242a and is fixed by a crimping portion 243. Also, the electrode assembly A is fixed in the battery can 241 by a beading portion 244 to prevent vertical movement.

[0019] Typically, the positive terminal is the cap plate 242a of the sealed body 242, and the negative terminal is the battery can 241. Thus, the current collecting plate 230 coupled to the non-coated portion 210a of the positive plate 210 is electrically connected to a connection plate 242c attached to the cap plate 242a by a strip-shaped lead 245. Also, the current collecting plate 231 coupled to the non-coated portion 211a of the negative plate 211 is electrically connected to the bottom of the battery can 241. The insulator 246 covers the current collecting plate 230 to prevent the battery can 241 and the non-coated portion 210a of the positive plate 210, which have opposite polarities, from coming into contact with each other and causing a short circuit.

[0020] When the current collecting plate 230 is connected to the connection plate 242c, a strip-shaped lead 245 is used. The lead 245 is either attached separately to the current collecting plate 230 or is manufactured integrally with the current collecting plate 230. However, since the lead 245 is in the form of a thin strip and has a small cross-sectional area, a large amount of heat is generated when a fast charging current flows. In addition, the excessive heat generated in the lead 245 is transferred to the electrode assembly A side and causes the separator 212 to shrink, which may cause an internal short circuit, which is a major cause of thermal runaway.

[0021] Furthermore, the leads 245 occupy a considerable amount of installation space within the battery can 241. As a result, the cylindrical battery 240 including the leads 245 has low space efficiency and is limited in increasing the energy density.

[0022] Moreover, in order to connect conventional table-less cylindrical batteries 240 in series and / or parallel, bus bar parts must be connected to the cap plate 242a of the sealed body 242 and the bottom surface of the battery can 241, resulting in reduced space efficiency. A battery pack mounted on an electric vehicle includes hundreds of cylindrical batteries 240. This inefficiency of electrical wiring causes considerable complication in the assembly process of the electric vehicle and the maintenance of the battery pack.

[0023] Meanwhile, as cylindrical batteries are being applied to electric vehicles recently, the form factor of cylindrical batteries is increasing, i.e., the diameter and height of cylindrical batteries are larger than those of conventional cylindrical batteries with form factors such as 18650 and 21700. The increase in form factor brings about an increase in energy density, increased safety against thermal runaway, and improved cooling efficiency.

[0024] The energy density of cylindrical batteries can be further increased when the wasted space inside the battery can is minimized with an increase in form factor, and therefore the components used for electrical insulation between the electrode assembly and the battery can, and the components used for collecting current from the positive and negative plates, must also be designed to increase the capacity of the battery and reduce the overall resistance of the battery. Summary of the Invention [Problem to be solved by the invention]

[0025] The present invention has been made in consideration of the above problems, and aims to prevent damage to the joints between parts by dispersing external impact and / or vibration rather than concentrating it on a specific part when the secondary battery is used.

[0026] Another object of the present invention is to ensure the safety of using the secondary battery by enabling the current collector itself to perform a current interruption function without the need for an additional current interruption member, thereby quickly interrupting the current when an overcurrent occurs due to a short circuit or the like.

[0027] It is yet another object of the present invention to provide a battery having a structure in which a positive terminal and a negative terminal are applied in the same direction.

[0028] Another object of the present invention is to ensure a sufficient area for welding an electrical connection component, such as a bus bar for manufacturing a battery pack, to the electrode terminal of the battery by utilizing a wide surface of a closed part of a housing as an electrode terminal when electrically connecting multiple batteries in one direction.

[0029] Another object of the present invention is to minimize the resistance of a cylindrical battery by improving the structure of the non-coated portion of the electrode assembly to increase the contact area between the electrode assembly and the current collector (first current collector) and / or the contact area between the terminal and the current collector (first current collector).

[0030] However, the technical problems that the present invention aims to solve are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description of the invention below. [Means for solving the problem]

[0031] In order to solve the above problems, a battery according to one embodiment of the present invention provides an electrode assembly in which a first electrode and a second electrode and a separator interposed therebetween are wound around a winding shaft to define an outer circumferential surface of a core, the first electrode including an electrode assembly including a first non-coated portion that is not coated with an active material layer along a winding direction, a housing including an opening on one side and configured to receive the electrode assembly through the opening, a first current collector including a peripheral portion disposed on an upper portion of the electrode assembly, a first non-coated portion coupling portion extending inward from the peripheral portion to couple with the first non-coated portion, and a terminal coupling portion positioned spaced apart from the first non-coated portion coupling portion, and a terminal coupled to the terminal coupling portion.

[0032] The peripheral portion may be in the form of a rim having an open inner space.

[0033] The first uncoated portion coupling portion and the terminal coupling portion may be electrically connected by the peripheral portion.

[0034] The terminal coupling portion may be located at a center of the inner space of the peripheral portion.

[0035] The first current collector may further include a connection portion extending inward from the peripheral portion and connecting with the terminal coupling portion.

[0036] At least a portion of the connection portion may be formed to have a smaller cross-sectional area than the first non-coated portion joining portion.

[0037] At least a portion of the connection portion may be smaller than the first non-coated portion coupling portion in at least one of a width and a thickness.

[0038] The connection portion may include a tapered portion whose width narrows continuously or stepwise along a direction from the inner surface of the peripheral portion toward the terminal coupling portion.

[0039] The first non-coated portion joining portion may be provided in a plurality of portions.

[0040] The first non-coated portion joining portions may be regularly arranged along an extension direction of the peripheral portion.

[0041] The extension lengths of the first uncoated portion joining portions may be substantially the same as each other.

[0042] The cross-sectional area of ​​each of the plurality of first uncoated portion bonding portions may be substantially the same.

[0043] The width and thickness of each of the plurality of first uncoated portion joining portions may be substantially the same.

[0044] The terminal coupling portion may be arranged to be surrounded by a plurality of the first uncoated portion coupling portions.

[0045] The connection portion may be located between a pair of adjacent first uncoated portion joining portions.

[0046] A distance from the connection portion to one of the pair of adjacent first non-coated portion joining portions along an extension direction of the peripheral portion may be substantially the same as a distance to the remaining one.

[0047] The connection portion may be provided in a plurality of parts.

[0048] Each of the multiple connection portions may be disposed between a pair of first uncoated portion joining portions adjacent to each other.

[0049] The multiple connection portions may be regularly arranged along the extension direction of the periphery.

[0050] A distance from each of the plurality of connection portions to one of the pair of adjacent first non-coated portion coupling portions along an extension direction of the peripheral portion may be substantially the same as a distance to the remaining one.

[0051] The connection portion may include a current interrupting portion formed to reduce a cross-sectional area of ​​the connection portion.

[0052] The current blocking portion may be a region having at least one of a width and a thickness reduced from the remaining region of the connection portion.

[0053] The current interrupting portion may include at least one of a notch, a groove, and a through hole formed on at least one surface of the connection portion.

[0054] The terminal coupling portion may be disposed at a position corresponding to a hole formed in a winding center portion of the electrode assembly.

[0055] The terminal coupling portion may be configured to cover a hole formed in the winding center portion of the electrode assembly so that the hole formed in the winding center portion of the electrode assembly is not exposed to the outside of the terminal coupling portion.

[0056] The diameter of the terminal connection portion may be substantially the same as or larger than the diameter of the hole formed in the winding center of the electrode assembly.

[0057] The first uncoated portion may extend toward a closed portion opposite the open portion of the housing.

[0058] The first uncoated portion coupling portion may be coupled to a coupling surface formed by bending an end of the first uncoated portion in a direction parallel to the first current collector.

[0059] The battery may further include a cap configured to seal the opening of the housing.

[0060] The cap is not electrically connected to the electrode assembly and does not have polarity.

[0061] The housing may include a beading portion formed adjacent to the opening and pressed toward the inside of the housing, and a crimping portion formed below the beading portion and extending and bent to surround an edge of the cap plate.

[0062] The sealing gasket may further be disposed within the crimping portion and interposed between the housing and the cap.

[0063] The terminals may be configured to extend through a closed portion opposite the open portion of the housing.

[0064] The terminal may extend through a center of the closure.

[0065] The terminals may be insulated from the housing.

[0066] An insulating gasket may be interposed between the housing and the terminals.

[0067] The housing may further include an insulator interposed between a closed portion located opposite the open portion of the housing and the first current collector.

[0068] The insulator may have a thickness corresponding to the distance between an inner surface of the closure portion of the housing and the first current collector.

[0069] The terminal may be coupled to the terminal coupling portion of the first current collector through a hole formed in the insulator.

[0070] A lower end of the terminal coupled to the terminal coupling portion may be located at the same height as or higher than a lower surface of the insulator.

[0071] The insulator may be interposed between the first uncoated portion and a sidewall of the housing.

[0072] An upper surface of the insulator may contact an inner surface of a closed portion opposite the open portion of the housing, and a lower surface of the insulator may contact an upper surface of the first current collector.

[0073] The second electrode may further include a second uncoated portion that is not coated with an active material layer along the winding direction, and the second uncoated portion may extend in an opposite direction to the first uncoated portion and be exposed to an outside of the separator.

[0074] The housing may be electrically connected to the second uncoated portion.

[0075] The battery may further include a second current collector coupled to the second uncoated portion and the housing, respectively, to electrically connect the second uncoated portion and the housing.

[0076] The second current collector may include a second current collector hole formed in a region corresponding to a hole formed in the winding center of the electrode assembly.

[0077] The second current collector hole may have the same diameter as or a larger diameter than the hole formed in the winding center of the electrode assembly so as not to block the hole formed in the winding center of the electrode assembly.

[0078] The second current collector may include a second uncoated portion coupling portion coupled to the second uncoated portion, and a housing coupling portion coupled to the housing.

[0079] The second uncoated portion and the second uncoated portion joining portion may be joined to each other by welding.

[0080] The housing and the housing coupling portion may be coupled to each other by welding.

[0081] The housing may include a beading portion formed adjacent to the opening and having an inwardly pressed-fit configuration.

[0082] The housing coupling portion may be electrically coupled to a lower surface of the beading portion.

[0083] A distance from a center of the first current collector to an outermost portion of the peripheral portion may be longer than a distance from a center of the second current collector to an outermost portion of the second non-coated portion joining portion.

[0084] A distance from a center of the second current collector to an outermost portion of the second non-coated portion joining portion may be equal to or shorter than half the inner diameter of the housing in a region where the beading portion is formed.

[0085] At least a portion of the first uncoated portion may include a plurality of segment pieces divided along a winding direction of the electrode assembly, and the plurality of segment pieces may be bent along a radial direction of the electrode assembly.

[0086] The bent segments may be overlapped in multiples.

[0087] The electrode assembly may include a welding target area, which is an area where an overlapping number of the plurality of segment pieces of the first non-coated portion is maintained constant along a radial direction of the electrode assembly.

[0088] At least a portion of the second uncoated portion may include a plurality of segment pieces divided along a winding direction of the electrode assembly, and the plurality of segment pieces may be bent along a radial direction of the electrode assembly.

[0089] The bent segments may be overlapped in multiples.

[0090] The electrode assembly may include a welding target area, which is an area where an overlapping number of the plurality of segment pieces of the second non-coated portion is maintained constant along a radial direction of the electrode assembly.

[0091] The first current collector may further include a bridge portion connecting at least one of adjacent first non-coated portion coupling portions, adjacent first non-coated portion coupling portions and connection portions, and adjacent connection portions.

[0092] The bridge portion may be located inwardly of the peripheral edge portion.

[0093] The first current collector may include an impregnation hole formed between the peripheral portion and the bridge portion.

[0094] The impregnation hole may have a slit shape extending along an extension direction of the peripheral portion.

[0095] The ratio of an area of ​​the first current collector that is not in contact with the upper surface of the electrode assembly to an area of ​​a circle having a diameter equal to the outer diameter of the electrode assembly may be 20% or more and less than 100%.

[0096] The number of the connectors may be one or two.

[0097] The cross-sectional area of ​​the connection portion in the region where the current blocking portion is formed may be 0.6 to 0.9 relative to the cross-sectional area of ​​the connection portion in a region adjacent to the region where the current blocking portion is formed.

[0098] The cross-sectional area of ​​the connection portion may be 0.2 to 1.0 times the cross-sectional area of ​​the first non-coated portion joining portion.

[0099] The outer diameter of the first current collector may be in the range of 33% to 98.5% of the inner diameter of the housing.

[0100] The weld target area may be an area where a maximum overlap of the bent segments is maintained.

[0101] The first current collector may be welded to the first uncoated portion so as to overlap the weld target area by at least 50% or more.

[0102] The welding target area may be an area where the number of overlaps of the plurality of segmented pieces that have been bent is maintained at a maximum.

[0103] The second current collector may be welded to the second non-coated portion so that at least 50% or more thereof overlaps with the welding target area.

[0104] The resistance measured between the positive electrode and the negative electrode may be 4 mΩ or less.

[0105] The current cutoff portion may be formed at a location that is 40% to 90% away from the radius of the electrode assembly along the radial direction from the core of the electrode assembly.

[0106] At least a part of the first non-coated portion includes a plurality of segmented pieces that are divided along the winding direction of the electrode assembly, and the plurality of segmented pieces are bent along the radial direction of the electrode assembly and overlapped multiple times. The current cutoff portion may be provided in an area corresponding to a welding target area that is an area where the number of overlaps of the plurality of segmented pieces of the first non-coated portion is maintained constant along the radial direction of the electrode assembly.

[0107] A tape may be attached to the current cutoff portion.

[0108] The tape may be made of a polyimide material.

[0109] The tape may be configured to surround the connection portion in the area where the current cutoff portion is formed.

[0110] When the outer diameter of the first current collector is T, the outer diameter of the electrode assembly is JR, and the height of the segmented piece located at the outermost contour in the radial direction of the electrode assembly is F, the battery may be configured to satisfy JR - 2×F ≤ T < JR.

[0111] The welding pattern depicted by the welding beads formed on one surface of the terminal connection portion of the first current collector may be depicted in a form that surrounds the center portion of the bottom surface of the terminal.

[0112] The weld pattern may be formed continuously or discontinuously.

[0113] The tensile strength of the welded portion formed between the terminal joint portion of the first current collector and the bottom surface of the terminal is 2 kgf (19.6N) It could be more than that.

[0114] A weld pattern formed by a weld bead formed on one surface of the terminal coupling portion of the first current collector may have an equivalent diameter of 2 mm or more.

[0115] The diameter of the flat portion formed on the bottom surface of the terminal may be 3 mm to 14 mm.

[0116] The ratio of an area of ​​a weld pattern formed by weld beads on the 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%.

[0117] The second current collector hole may have a smaller diameter than a hole formed in a winding center of the electrode assembly.

[0118] When the diameter of the hole formed in the winding center portion is R3, the diameter of the hole in the second current collector may be equal to or greater than 0.5×R3 and less than R3.

[0119] When the diameter of the hole formed in the winding center portion is R3, the diameter of the hole in the second current collector may be equal to or greater than 0.7×R3 and less than R3.

[0120] The secondary battery may have a form factor ratio of diameter divided by height greater than 0.4.

[0121] The length of a welded portion connecting the first uncoated portion connecting portion and the first uncoated portion along a radial direction of the electrode assembly may be longer than the length of a welded portion connecting the second uncoated portion connecting portion and the second uncoated portion along a radial direction of the electrode assembly.

[0122] A distance from a core of the electrode assembly to a start point of a weld that connects the first non-coated portion joining portion and the first non-coated portion may be substantially the same as a distance from a core of the electrode assembly to a start point of a weld that connects the second non-coated portion joining portion and the second non-coated portion.

[0123] A plurality of the current interrupting parts may be provided along a longitudinal direction of the connection part.

[0124] No weld is formed at the connection portion between the peripheral edge and the terminal.

[0125] At least a portion of the bottom surface of the terminal may be provided with a flat portion.

[0126] The first non-coated portion coupling portions may be arranged in a radial pattern, a cross pattern, or a combination thereof with respect to a center of the terminal coupling portion.

[0127] The extending direction of the first non-coated portion coupling portion and the extending direction of the connection portion are not parallel to each other.

[0128] The first non-coated portion joining portions are arranged in a plurality of pieces along a circumferential direction of the peripheral portion, and in this case, the terminal joining portion can be connected to a portion of the peripheral portion provided between a pair of first non-coated portion joining portions adjacent to each other in a circumferential direction of the peripheral portion.

[0129] The first non-coating portion coupling portion may be provided in a plurality of pieces, and in this case, the first non-coating portion coupling portions may be spaced apart from each other in a radial direction from the terminal coupling portion and may be radially arranged around the terminal coupling portion.

[0130] The connection portion may extend radially from the center of the terminal coupling portion and be connected to the peripheral edge portion.

[0131] A battery pack according to an embodiment of the present invention may include a battery according to an embodiment of the present invention and a pack housing that houses a plurality of the batteries.

[0132] A plurality of the batteries may be arranged in a predetermined number of rows, and the terminals of each of the batteries and an outer surface of the closed portion of the housing located opposite the open portion of the housing may be disposed so as to face upward.

[0133] The battery pack may include a plurality of bus bars connecting the plurality of batteries in series and parallel, the plurality of bus bars being disposed on top of the plurality of batteries, and each of the plurality of bus bars may include a body portion extending between terminals of adjacent batteries, a plurality of first bus bar terminals extending in one direction of the body portion and electrically connecting to terminals of a battery positioned in the one direction, and a plurality of second bus bar terminals extending in the other direction of the body portion and electrically connecting to an outer surface of a housing closure portion of a battery positioned in the other direction.

[0134] A vehicle according to an embodiment of the present invention includes a battery pack according to an embodiment of the present invention as described above.

[0135] Meanwhile, a current collector according to one embodiment of the present invention is a current collector that electrically connects a first non-coated portion and a first electrode terminal of an electrode assembly, and includes a peripheral portion provided at an edge and extending in a circumferential direction, a first non-coated portion coupling portion that extends inward from the peripheral portion and couples with the first non-coated portion, and a terminal coupling portion that is positioned apart from the first non-coated portion coupling portion and couples with the first electrode terminal. Effect of the Invention

[0136] According to one aspect of the present invention, even if an external impact and / or vibration is applied during use of a secondary battery, the impact and / or vibration is dispersed rather than concentrated at a specific location, thereby preventing damage to the joints between components.

[0137] Meanwhile, according to another aspect of the present invention, the current collector itself can perform a current interrupting function without the need for an additional current interrupting member, thereby quickly interrupting the current when an overcurrent occurs due to a short circuit, etc., thereby ensuring the safety of the secondary battery.

[0138] According to yet another aspect of the present invention, the electrode terminal structure of the battery is improved to increase the cross-sectional area of ​​the current path, thereby improving the problem of internal heat generation that occurs during fast charging.

[0139] In accordance with yet another aspect of the present invention, electrical wiring for series and / or parallel connection of batteries can be performed on one of the batteries.

[0140] According to another aspect of the present invention, when multiple batteries are to be electrically connected in one direction, a large surface of the closed portion of the housing can be utilized for the electrode terminals, thereby ensuring a sufficient area for welding the electrode terminals of the batteries to electrical connection components such as bus bars for manufacturing a battery pack.

[0141] According to another aspect of the present invention, the contact area between the electrode assembly and the current collector (first current collector) and / or the contact area between the terminal and the current collector (first current collector) can be increased by improving the structure of the non-coated portion of the electrode assembly, thereby minimizing the resistance of the battery.

[0142] However, the technical effects obtained by the present invention are not limited to the effects described above, and other effects not mentioned will be clearly understood by those skilled in the art from the following description of the invention.

[0143] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention, serve to further understand the technical ideas of the present invention. Therefore, the present invention should not be interpreted as being limited to only the matters described in the drawings. [Brief description of the drawings]

[0144] [Figure 1] FIG. 1 is a plan view showing the structure of an electrode plate used in a conventional tabless cylindrical battery. [Diagram 2] 1A to 1C are diagrams showing a winding process of an electrode assembly included in a conventional tabless cylindrical battery. [Diagram 3] 3 is a diagram showing a process in which a current collecting plate is welded to a bent surface of an uncoated portion in the electrode assembly of FIG. 2. [Figure 4] FIG. 1 is a cross-sectional view of a conventional tabless cylindrical battery cut in the longitudinal direction (Z direction). [Diagram 5] 1 is a diagram showing the appearance of a cylindrical battery according to an embodiment of the present invention; [Figure 6] 1 is a cross-sectional view showing an internal structure of a cylindrical battery according to an embodiment of the present invention. [Figure 7] FIG. 2 is a partial cross-sectional view showing an upper structure of a cylindrical battery according to an embodiment of the present invention. [Figure 8] FIG. 2 is an enlarged view of an upper portion of the electrode assembly of the present invention. [Figure 9] FIG. 9 is an enlarged view of the upper portion of the non-coated portion in FIG. 8. [Figure 10] 8 is a plan view showing a joining portion of a first current collector terminal as viewed in the direction of an arrow in FIG. 7. FIG. [Figure 11] 8 is a plan view showing a joining portion of a first current collector terminal as viewed in the direction of an arrow in FIG. 7. FIG. [Figure 12] 2A to 2C are diagrams showing various shapes of a current collector (first current collector) according to an embodiment of the present invention. [Figure 13] 2A to 2C are diagrams showing various shapes of a current collector (first current collector) according to an embodiment of the present invention. [Figure 14]2A to 2C are diagrams showing various shapes of a current collector (first current collector) according to an embodiment of the present invention. [Figure 15] 2A to 2C are diagrams showing various shapes of a current collector (first current collector) according to an embodiment of the present invention. [Figure 16] 1A to 1C are diagrams showing various forms of a current collector (first current collector) according to another embodiment of the present invention (a structure having a current collector current interruption part). [Figure 17] 1A to 1C are diagrams showing various forms of a current collector (first current collector) according to another embodiment of the present invention (a structure having a current collector current interruption part). [Figure 18] 1A to 1C are diagrams showing various forms of a current collector (first current collector) according to another embodiment of the present invention (a structure having a current collector current interruption part). [Figure 19] 1A to 1C are diagrams showing various forms of a current collector (first current collector) according to another embodiment of the present invention (a structure having a current collector current interruption part). [Figure 20] 1A to 1C are diagrams showing various forms of a current collector (first current collector) according to another embodiment of the present invention (a structure having a current collector current interruption part). [Figure 21] 11A and 11B are diagrams illustrating various forms of a current collector (first current collector) according to still another embodiment of the present invention (a structure in which a cover member is applied to a current interruption portion); [Figure 22] FIG. 16 is a diagram showing a current collector (first current collector) having a structure different from the current collectors (first current collectors) shown in FIGS. 12 to 15 (a structure in which a bridge portion is further applied). [Figure 23] FIG. 2 is a partial cross-sectional view showing a lower structure of a cylindrical battery according to an embodiment of the present invention. [Figure 24] FIG. 2 is a diagram showing the bottom surface of a cylindrical battery according to an embodiment of the present invention. [Diagram 25] FIG. 2 is a diagram showing an exemplary form of a second current collector applied to the present invention. [Figure 26] 2 is a plan view illustrating an example of an electrode structure according to a preferred embodiment of the present invention; FIG. [Figure 27] 1 is a cross-sectional view taken along a longitudinal direction (Z direction) of an electrode assembly in which the segmented structure of a non-coated portion of a first electrode is also applied to a second electrode according to an embodiment of the present invention. [Figure 28] 4 is a cross-sectional view taken along a longitudinal direction (Z direction) of an electrode assembly in which a non-coated portion is bent according to an embodiment of the present invention. [Figure 29] 1 is a perspective view of an electrode assembly in which a non-coated portion is bent according to an embodiment of the present invention; [Diagram 30] FIG. 2 is a top view showing a state in which a plurality of cylindrical batteries are connected in series and in parallel using a bus bar according to an embodiment of the present invention. [Diagram 31] 1 is a diagram showing a schematic configuration of a battery pack including a cylindrical battery according to an embodiment of the present invention; [Diagram 32] 1 is a diagram showing a schematic configuration of a vehicle including a battery pack according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0145] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings. Prior to this, the terms and words used in the specification and claims are not to be construed as being limited to their ordinary or dictionary meanings, but are to be construed as having meanings and concepts according to the technical ideas of the present invention, in accordance with the principle that the inventors themselves can appropriately define the concepts of terms in order to best describe the invention.

[0146] Therefore, it should be understood that the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiment of the present invention and do not represent the entire technical idea of ​​the present invention, and therefore there may be various equivalents and modifications that can be substituted therefor at the time of this application.

[0147] In addition, in order to facilitate understanding of the present invention, the accompanying drawings may be drawn not to scale but with some components exaggerated. In addition, the same reference numerals may be used to refer to the same components in different embodiments.

[0148] The fact that two comparison objects are identical means that they are "substantially identical." Therefore, "substantially identical" may include a deviation that is considered to be a low level in the art, for example, a deviation within 5%. Furthermore, the uniformity of any parameter in a given region may mean that it is uniform on average.

[0149] Terms such as "first" and "second" are used to describe various components, but the components are not limited by these terms. These terms are used to distinguish only one component from another component, and unless otherwise specified, the first component may be the second component.

[0150] Throughout the specification, unless otherwise specified, each element may be singular or plural.

[0151] When a structure is disposed "on (or under)" a component or "above (or below)" a component, it may mean that the structure is disposed directly on the upper (or lower) surface of the component, but also that other structures may be interposed between the component and the structure disposed above (or below) the component.

[0152] Additionally, when a component is described as being "coupled," "coupled," or "connected" to another component, it should be understood that the components may be directly coupled or connected to each other, but that there may be other components "intervening" between each component, or each component may be "coupled," "coupled," or "connected" by other components.

[0153] Throughout the specification, unless otherwise specified, a reference to "A and / or B" means "A," "B," or "A and B," and a reference to "C through D" means at least C and at most D, unless otherwise specified.

[0154] For ease of explanation, in this specification, the direction along the longitudinal direction of the winding shaft of the electrode assembly wound in a wound form is referred to as the axial direction Y. The direction surrounding the winding shaft is referred to as the circumferential direction or peripheral direction X. The direction approaching or moving away from the winding shaft is referred to as the radial direction. Of these, the direction particularly approaching the winding shaft is referred to as the centripetal direction, and the direction moving away from the winding shaft is referred to as the centrifugal direction.

[0155] 5 and 6, a battery 1 according to an embodiment of the present invention may be, for example, a cylindrical battery. The cylindrical battery 1 includes an electrode assembly 10, a housing 20, a cap 30, a current collector (first current collector) 40, and a terminal 50. In addition to the above-mentioned components, the cylindrical battery 1 may further include an airtight gasket G1 and / or an insulating gasket G2 and / or an insulator 60 and / or a second current collector 70. The present invention is not limited by the shape of the battery, and may be applied to batteries of other shapes, for example, prismatic batteries.

[0156] The electrode assembly 10 includes a first electrode having a first polarity, a second electrode having a second polarity, and a separator interposed between the first and second electrodes. The first electrode is a positive or negative electrode, and the second electrode is an electrode having a polarity opposite to that of the first electrode.

[0157] The electrode assembly 10 may have, for example, a jelly-roll structure. That is, the electrode assembly 10 may be manufactured by stacking a first electrode collector and a second electrode collector having a sheet shape at least once with a separator interposed therebetween, and winding the stack in one direction based on a winding center C. In this case, a separator may be further provided on an outer circumferential surface of the electrode assembly 10 for insulation from the housing 20. Any structure of a wound electrode assembly known in the art may be applied to the present invention without any limitations.

[0158] The first electrode includes a first electrode collector and a first electrode active material applied on one or both sides of the first electrode collector. An uncoated portion where the first electrode active material is not applied is present at one end of the first electrode collector in the width direction (direction parallel to the Z axis). Hereinafter, the uncoated portion functioning as a first electrode tab is referred to as a first uncoated portion 11. The first uncoated portion 11 is provided at an upper portion in the height direction (direction parallel to the Z axis) of the electrode assembly 10 accommodated in the housing 20. That is, the first electrode collector includes the first uncoated portion 11 at a long side end where an active material layer is not coated and exposed to the outside of the separator, and a part of the first uncoated portion 11 is used as an electrode tab by itself. The first uncoated portion 11 may be, for example, a positive electrode tab.

[0159] Meanwhile, at least a portion of the first non-coated portion 11 may include a plurality of segment pieces divided along the winding direction of the electrode assembly 10. In this case, the plurality of segment pieces may be bent along the radial direction of the electrode assembly 10. The bent plurality of segment pieces may be overlapped in multiple layers. In this case, a first non-coated portion coupling portion 32, which will be described later, may be coupled to a region where the plurality of segment pieces are overlapped in multiple layers.

[0160] The second electrode includes a second electrode collector and a second electrode active material applied to one or both sides of the second electrode collector. An uncoated portion where the second electrode active material is not applied is present at the other end of the second electrode collector in the width direction (direction parallel to the Z axis). Hereinafter, the uncoated portion functioning as a second electrode tab is referred to as a second uncoated portion 12. The second uncoated portion 12 is provided at a lower portion in the height direction (direction parallel to the Z axis) of the electrode assembly 10 accommodated in the housing 20. That is, the second electrode collector includes the second uncoated portion 12 where the active material layer is not coated at the end of the long side and is exposed to the outside of the separator, and at least a portion of the second uncoated portion 12 is used as an electrode tab by itself. The second uncoated portion 12 may be, for example, a positive electrode tab. At least a portion of the second uncoated portion 12 may include a plurality of segment pieces divided along the winding direction of the electrode assembly 10. In this case, the plurality of segment pieces may be bent along the radial direction of the electrode assembly 10. The bent plurality of segment pieces may be overlapped in multiple layers. In this case, the second current collector 70, which will be described later, may be bonded to a region where the plurality of segment pieces are overlapped in multiple layers.

[0161] The first uncoated portion 11 and the second uncoated portion 12 extend in opposite directions along the height direction (parallel to the Z-axis) of the cylindrical battery 1. The first uncoated portion 11 extends toward the closed portion of the housing 20, and the second uncoated portion 12 extends toward the open portion of the housing 20.

[0162] In the present invention, the positive electrode active material coated on the positive electrode plate and the negative electrode active material coated on the negative electrode plate may be any active material known in the art without any limitations.

[0163] In one example, the positive electrode active material is represented by the general chemical formula A[A x M y ]O 2+z(A contains at least one or more elements of Li, Na, and K; M contains at least one or more elements 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; the stoichiometric coefficients x, y, and z are selected so that the compound maintains electrical neutrality.) may contain an alkali metal compound represented by

[0164] In other examples, the positive electrode active material is an alkali metal compound xLiM disclosed in US6,677,082, US6,680,143, etc. 1 O2-(1 - x)Li2M 2 O3(M 1 (M contains at least one or more elements having an average oxidation state of 3; M 2 (M contains at least one or more elements having an average oxidation state of 4; 0 ≦ x ≦ 1).

[0165] In still other examples, the positive electrode active material has the general chemical formula Li a M 1 x Fe 1-x M 2 y P 1-y M 3 z O 4-z (M 1 (M contains at least one or more elements selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg, and Al; M 2 (M contains at least one or more elements selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg, Al, As, Sb, Si, Ge, V, and S; M 3 (M contains a halogen group element selectively containing F; 0 < a ≦ 2, 0 ≦ x ≦ 1, 0 ≦ y < 1, 0 ≦ z < 1; the stoichiometric coefficients a, x, y, and z are selected so that the compound maintains electrical neutrality.), or it may be a lithium metal phosphate represented by Li3M2(PO4)3 [M contains at least one element selected from Ti, Si, Mn, Fe, Co, V, Cr, Mo, Ni, Al, Mg, and Al.].

[0166] Desirably, the positive electrode active material may include primary particles and / or secondary particles formed by agglomeration of the primary particles.

[0167] For example, the negative electrode active material may be a carbon material, lithium metal or a lithium metal compound, silicon or a silicon compound, tin or a tin compound, etc. Metal oxides such as TiO2 and SnO2 having a potential of less than 2 V may also be used as the negative electrode active material. As the carbon material, either low crystalline carbon or high crystalline carbon may be used.

[0168] The separation membrane may be a porous polymer film, for example, a porous polymer film made of a polyolefin polymer such as an ethylene homopolymer, a propylene homopolymer, an ethylene / butene copolymer, an ethylene / hexene copolymer, an ethylene / methacrylate copolymer, etc., either alone or in combination. In another example, the separation membrane may be a conventional porous nonwoven fabric, for example, a nonwoven fabric made of a high melting point glass fiber, a polyethylene terephthalate fiber, etc.

[0169] At least one surface of the separation membrane may include a coating layer of inorganic particles. The separation membrane itself may also be made of a coating layer of inorganic particles. The particles constituting the coating layer may have a structure in which they are bound to a binder such that there is an interstitial volume between adjacent particles.

[0170] The inorganic particles may be made of an inorganic material having a dielectric constant of 5 or more. Non-limiting examples of the inorganic particles include Pb(Zr,Ti)O3 (PZT), Pb 1-x La x Zr 1-y Ti y O3(PLZT), PB(Mg3Nb 2 / 3)O3-PbTiO3 (PMN-PT), BaTiO3, hafnia (HfO2), SrTiO3, TiO2, Al2O3, ZrO2, SnO2, CeO2, MgO, CaO, ZnO, and Y2O3.

[0171] The electrolyte is A + B - In this case, the salt may have the structure: + Li + , Na + , K + and combinations of these cations. - F - , Cl - , Br - , I - , NO3 - , N(CN)2 - , BF4 - , ClO4 - , AlO4 - , AlCl4 - , PF6 - , SbF6 - , AsF6 - , BF2C2O4 - , BC4O8 - , (CF3)2PF4 - , (CF3)3PF3 - , (CF3)4PF2 - , (CF3)5PF - , (CF3)6P - , CF3SO3 - , C4F9SO3 - , CF3CF2SO3 - , (CF3SO2)2N - , (FSO2)2N - , CF3CF2(CF3)2CO - , (CF3SO2)2CH - , (SF5)3C - , (CF3SO2)3C - , CF3(CF2)7SO3 - , CF3CO2 - , CH3CO2 - , SCN -and (CF3CF2SO2)2N - The anion includes one or more anions selected from the group consisting of:

[0172] The electrolyte may be dissolved in an organic solvent. Examples of the organic solvent include 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, and mixtures thereof.

[0173] 6, 7 and 23, the housing 20 is a substantially cylindrical container having an opening formed at the bottom, and is made of a conductive material such as metal. The material of the housing 20 may be, for example, steel, stainless steel, or nickel-plated iron. The upper surface opposite the opening is called a closed portion. The side wall and the closed portion of the housing 20 may be integrally formed. Alternatively, the side wall and the closed portion of the housing 20 may be provided separately and connected to each other by welding or the like. The upper surface of the housing 20 (a surface parallel to the XY plane), i.e., the outer surface 20a of the closed portion, may have a substantially flat shape. The housing 20 accommodates the electrode assembly 10 through an opening formed at the bottom, and also accommodates an electrolyte.

[0174] The housing 20 is electrically connected to the electrode assembly 10. The housing 20 is electrically connected to, for example, the second non-coated portion 12 of the electrode assembly 10. In this case, the housing 20 has the same polarity as the second non-coated portion 12.

[0175] 6 and 23, the housing 20 may include a beading portion 21 and a crimping portion 22 formed at its lower end. The beading portion 21 is located at the lower portion of the electrode assembly 10. The beading portion 21 is formed by pressing the outer circumferential surface of the housing 20. The upper beading portion 21a and the lower beading portion 21b, which are located at the upper and lower portions, respectively, based on the innermost portion 21c of the beading portion 21 located at the innermost portion along the pressing direction, may have asymmetric shapes. Such an asymmetric shape may be formed during a process in which the housing 20 is compressed along a height direction (a direction parallel to the Z axis) through a sizing process. The sizing process is a process in which the housing 20 is compressed along the winding axis direction of the electrode assembly 10 to match the height of the cylindrical battery 1 to a design form factor.

[0176] The lower beading portion 21b may have a flat portion approximately parallel to the closed portion of the housing 20. Meanwhile, due to the asymmetrical formation, the upper beading portion 21a may have a shape of at least a partial upward inclination along a direction toward the innermost portion 21c. As a result, the upper beading portion 21a may press and fix the lower portion of the electrode assembly 10. The beading portion 21 prevents the electrode assembly 10, which has a size approximately corresponding to the inner diameter of the housing 20, from slipping out of an opening formed at the lower end of the housing 20, and may function as a support portion on which the cap 30 is provided. The lower beading portion 21b may function as a support portion for fixing not only the cap 30 described below, but also a contact portion 73a of a current collector (second current collector 70), a sealing gasket G1, and the like.

[0177] The crimping portion 22 is formed below the beading portion 21. The crimping portion 22 extends from the lower beading portion 21. The crimping portion 22 is bent and extends to surround the outer circumferential surface of the cap 30 disposed below the beading portion 21 and a part of the lower surface of the cap 30. The crimping portion 22 may fix a sealing gasket G1 in addition to the cap 30.

[0178] However, the present invention does not exclude the case where the housing 20 does not include such a beading portion 21 and / or crimping portion 22. In the present invention, when the housing 20 does not include the beading portion 21 and / or the crimping portion 22, the fixing of the electrode assembly 10 and / or the fixing of the cap 30 and / or the sealing of the housing 20 may be achieved, for example, by adding a part that can function as a stopper for the electrode assembly 10 and / or adding a structure on which the cap 30 can be provided and / or welding the housing 20 and the cap 30 together, etc.

[0179] Meanwhile, the housing 20 may be configured to have different thicknesses depending on the position. The thickness of the side wall of the housing 20 may be thinner than the thickness of the closed portion. In this case, the diameter of the electrode assembly 10 may be made larger, which may be advantageous in terms of energy density.

[0180] The housing 20 may have a thickness of, for example, about 0.4 mm to 1.2 mm in its closed portion, i.e., the region forming the upper surface. More preferably, the thickness may be about 0.6 mm to 1.0 mm. If the thickness of the closed portion of the housing 20 is too thin, the housing 20 may be more likely to be distorted when the internal pressure increases or when welding. Conversely, if the thickness of the closed portion of the housing 20 is too thick, it may be disadvantageous in terms of processing the housing 20, and there may be a large loss in terms of energy density. For this reason, it is necessary to control the thickness of the closed portion of the housing 20 to an appropriate level.

[0181] Meanwhile, the side wall portion of the housing 20 forming the outer circumferential surface thereof may have a thickness of, for example, about 0.3 mm to 0.8 mm. More preferably, the side wall portion of the housing 20 may have a thickness of about 0.4 mm to 0.6 mm. If the thickness of the side wall portion of the housing 20 is too thin, when a cylindrical battery 1 ignites or explodes, the possibility of the fire spreading to the adjacent cylindrical batteries 1 increases. For example, in a battery pack including a plurality of cylindrical batteries 1, when an abnormality occurs in some cylindrical batteries 1 and ignites or explodes, if the thickness of the side wall portion of the housing 20 is too thin, a pinhole may be generated, which may increase the risk of a chain reaction of ignition and explosion. Meanwhile, if the thickness of the side wall portion of the housing 20 is too thick, it may be disadvantageous in terms of processing the housing 20, and a loss in terms of energy density may be large. Therefore, it is necessary to manage the thickness of the side wall portion of the housing 20 to an appropriate level. Meanwhile, a plating layer may be formed on the housing 20. In this case, the plating layer may include, for example, nickel (Ni). The thickness of the plating layer may range from about 1.5 μm to 6.0 μm.

[0182] 6 and 23, the cap 30 may be made of, for example, a metal material to ensure rigidity. The cap 30 seals an opening formed at the lower end of the housing 20. That is, the cap 30 forms the lower surface of the cylindrical battery 1. In the cylindrical battery 1 of the present invention, the cap 30 may not have polarity even if it is made of a conductive metal material. Not having polarity means that the cap 30 is not electrically connected to the electrode assembly 10. When the cap 30 is not electrically connected to the electrode assembly 10, the cap 30 does not function as a positive terminal or a negative terminal. That is, in the present invention, the cap 30 does not need to be electrically connected to the electrode assembly 10 and the housing 20, and the material thereof does not necessarily need to be a conductive metal.

[0183] When the housing 20 of the present invention includes a beading portion 21, the cap 30 may be supported by a lower surface of the beading portion 21 formed on the housing 20. When the housing 20 of the present invention includes a crimping portion 22, the cap 30 may be fixed by the crimping portion 22. That is, the upper surface of the cap 30 may be supported by the beading portion 21, and the outer circumferential surface and the lower surface may be supported by the crimping portion 22. A sealing gasket G1 may be interposed between the cap 30 and the crimping portion 22 of the housing 20 to ensure airtightness of the housing 20. Meanwhile, as described above, the housing 20 of the present invention may not include the beading portion 21 and / or the crimping portion 22, and in this case, the sealing gasket G1 may be interposed between the cap 30 and a fixing structure provided on the open side of the housing 20 to ensure airtightness of the housing 20.

[0184] 23 and 24, the cap 30 may further include a vent portion 31 formed to prevent the internal pressure from increasing beyond a preset value due to gas generated inside the housing 20. The preset internal pressure value is about 15 to 35 kgf / cm. 2 (1.47~3.43MPa) The vent portion 31 is a region of the cap 30 that is thinner than the surrounding region. The vent portion 31 is structurally weaker than the surrounding region. As a result, when an abnormality occurs in the cylindrical battery 1 and the internal pressure of the housing 20 increases above a certain level, the vent portion 31 breaks to release gas generated inside the housing 20. The vent portion 31 may be formed, for example, by notching one or both sides of the cap 30 to partially reduce the thickness of the housing 20.

[0185] As described below, the cylindrical battery 1 according to an embodiment of the present invention has a structure in which both the positive and negative terminals are present at the upper portion, and therefore the structure of the upper portion is more complicated than that of the lower portion. Therefore, in order to smoothly discharge gas generated inside the housing 20, a vent portion 31 may be formed in the cap 30 forming the lower surface of the cylindrical battery 1. As shown in FIG. 23, it is preferable that the lower end of the cap 30 is located higher than the lower end of the housing 20. In this case, even if the lower end of the housing 20 contacts the ground or the bottom surface of the housing for forming a module or pack, the cap 30 does not contact the ground or the bottom surface of the housing for forming a module or pack. This can prevent a phenomenon in which the pressure required to break the vent portion 31 differs from the design value due to the weight of the cylindrical battery 1, and therefore the smooth breaking of the vent portion 31 can be ensured.

[0186] Meanwhile, the vent portion 31 may have a shape that extends continuously or discontinuously so as to surround the central region of the cap 30. In this case, in terms of the ease of breaking of the vent portion 31 due to an increase in internal pressure, the greater the distance from the center of the cap 30 to the vent portion 31, the greater the force acting on the vent portion 31 becomes, making it easier to break, when the same internal pressure is applied. Also, in terms of the smoothness of discharging the vent gas, the greater the distance from the center of the cap 30 to the vent portion 31, the greater the area opened by venting becomes, which is advantageous. From this perspective, it may be advantageous for the vent portion 31 to be formed along the periphery of a central region that protrudes downward (in a direction toward the bottom with reference to FIG. 23) and has a substantially flat shape in the entire region of the cap 30.

[0187] 23 and 24 of the present invention, the vent portion 31 is formed continuously in a substantially circular shape in the cap 30, but the present invention is not limited thereto. The vent portion 31 may have a substantially elliptical shape formed to include the center point of the cap 30 inside, or other geometric shapes. The vent portion 31 may also be formed discontinuously instead of continuously.

[0188] 7, the current collector (first current collector) 40 is coupled to the upper portion of the electrode assembly 10. The current collector 40 is made of a conductive metal material and is connected to the first non-coated portion 11.

[0189] 7 and 8, the current collector 40 may be coupled to a coupling surface (bent surface) 102 formed by bending an end of the first non-coated portion 11 in a direction parallel to the current collector 40. The bending direction of the first non-coated portion 11 may be a radial direction of the electrode assembly 10. The bending direction of the first non-coated portion 11 may be, for example, a direction toward a winding center C of the electrode assembly 10. When the first non-coated portion 11 has such a bent shape, the space occupied by the first non-coated portion 11 is reduced, thereby improving the energy density. In addition, the increase in the coupling area between the first non-coated portion 11 and the current collector 40 may have the effect of improving the coupling force and reducing the contact resistance.

[0190] 7 to 9, at least a portion of the first uncoated portion 11 and / or the second uncoated portion 12 may include a plurality of segment pieces (see reference numeral 11a in FIGS. 26 and 29) divided along the winding direction of the electrode assembly 10. In this case, the plurality of segment pieces may be bent along the radial direction of the electrode assembly 10. The plurality of bent segment pieces may be overlapped in multiple layers. In this case, a first uncoated portion coupling portion 42 (see FIGS. 12 to 15) of a current collector (first current collector) 40 and / or a second uncoated portion coupling portion 72 (see FIG. 25) of a current collector (second current collector) 70, which will be described later, may be coupled to a region where the plurality of segment pieces are overlapped in multiple layers.

[0191] Referring to Figures 7 to 9, the first uncoated portion 11 and / or the second uncoated portion 12 are bent from the outer periphery side of the electrode assembly 10 toward the electrode core side, showing a section in which 10 or more segmented pieces are stacked.

[0192] When the segments of the first non-coated portion 11 and / or the second non-coated portion 12 are bent from the outer periphery side toward the core side of the electrode assembly 10 so that a plurality of segments are overlapped, the number of overlapped segments gradually increases from the outer periphery side toward the core side. The gradually increased number of overlapped segments is maintained constant until a certain section is reached.

[0193] The section where the overlap number of the segment pieces is approximately at a maximum and is maintained approximately constant is defined as a welding target area. The overlap number in the welding target area may be, for example, about 10 or more. The first current collector 40 and / or the second current collector 70 described below may be joined to the first non-coated portion 11 and / or the second non-coated portion 12 by welding so as to overlap the welding target area by at least 50% or more. When the first current collector 40 and / or the second current collector 70 are welded to the approximately flat joining surface 102 formed by bending the first non-coated portion 11 and / or the second non-coated portion 12, it is preferable to increase the output of the laser in order to ensure sufficient welding strength. When the output of the laser is increased, the laser may penetrate into the inside of the electrode assembly 10 through the overlapping area of ​​the first non-coated portion 11 and / or the second non-coated portion 12, causing damage to the separator, the active material layer, etc. Therefore, in order to prevent penetration of the laser, it is preferable to increase the number of overlaps of the first non-coated portion 11 and / or the second non-coated portion 12 to a certain level or more. In order to increase the number of overlaps of the first non-coated portion 11 and / or the second non-coated portion 12, the height of the segment pieces can be increased. However, if the height of the segment pieces is increased, undulations may occur in the first non-coated portion 11 and / or the second non-coated portion 12 during the manufacturing process of the electrode plate. Therefore, it is preferable to adjust the height of the segment pieces to an appropriate level.

[0194] As described above, when the radial length of the section in which the number of overlaps of the segment pieces of the first uncoated portion 11 and / or the second uncoated portion 12 is 10 or more is designed to be about 25% or more of the radius of the electrode assembly 10 and welding is performed within the welding target area, even if the laser output is increased, the overlapping portions of the first uncoated portion 11 and / or the second uncoated portion 12 can sufficiently mask the laser, thereby preventing damage to the separator, active material layer, etc. by the laser.

[0195] 6 and 7, the current collector (first current collector) 40 is coupled to an upper portion of the electrode assembly 10. In addition, the current collector 40 is coupled to a terminal 50. That is, the current collector 40 electrically connects the first non-coated portion 11 of the electrode assembly 10 to the terminal 50. The first current collector 40 is made of a conductive metal material.

[0196] 8 and 9 together with FIGS. 6 and 7, the current collector 40 may be coupled to a coupling surface (bent surface) 102 formed by bending an end of the first non-coated portion 11 in a direction parallel to the current collector 40. The bending direction of the first non-coated portion 11 may be, for example, toward the winding center C of the electrode assembly 10, i.e., toward the core. When the first non-coated portion 11 has such a bent shape, the space occupied by the first non-coated portion 11 is reduced, thereby improving the energy density. In addition, when the first non-coated portion 11 has such a bent shape, the coupling area between the first non-coated portion 11 and the current collector 40 is increased, thereby improving the coupling force and reducing resistance.

[0197] 12 to 15 together with FIGS. 6 and 7, the current collector 40 includes a peripheral portion 41, a non-coated portion coupling portion (first non-coated portion coupling portion) 42, and a terminal coupling portion 43. The peripheral portion 41 is disposed on the upper portion of the electrode assembly 10 and may have an approximately rim shape with a space S formed therein. In the drawings of the present invention, the peripheral portion 41 is shown only to have an approximately circular rim shape, but the present invention is not limited thereto. The peripheral portion 41 may have an approximately square rim shape, a hexagonal rim shape, an octagonal rim shape, or other rim shapes, unlike those shown in the drawings.

[0198] The non-coated portion joining portion (first non-coated portion joining portion) 42 extends inward from the peripheral portion 41 and is joined to the first non-coated portion 11. As described above, it is preferable that the current collector 40 and the first non-coated portion 11 are joined to each other such that at least about 50% of the current collector 40 overlaps with the welding target area, which is a section where the overlapping number of the segment pieces is approximately at its maximum and remains approximately constant. That is, the non-coated portion joining portion 42 of the current collector 40 may be joined to the first non-coated portion 11 to overlap with the welding target area by at least about 50%.

[0199] The terminal coupling portion 43 is located inside the peripheral portion 41, separated from the non-coated portion coupling portion 42. The terminal coupling portion 43 may be coupled to the terminal 50 by welding, which will be described later. The terminal coupling portion 43 may have a diameter substantially equal to or larger than the diameter of the flat portion formed on the bottom surface of the terminal 50, in order to secure a welding area for coupling with the flat portion formed on the bottom surface of the terminal 50. The terminal coupling portion 43 may be located, for example, at approximately the center of the inner space surrounded by the peripheral portion 41. The terminal coupling portion 43 may be disposed at a position corresponding to a hole formed in the winding center C of the electrode assembly 10. The terminal coupling portion 43 may be configured to cover the hole formed in the winding center C of the electrode assembly 10 so that the hole formed in the winding center C of the electrode assembly 10 is not exposed to the outside of the terminal coupling portion 43. In this way, when the hole formed in the winding center C of the electrode assembly 10 is blocked, a separator located inside the hole is damaged due to the flow speed of the electrolyte passing through the hole, thereby preventing the electrode from being exposed. For this purpose, the terminal coupling portion 43 may have a diameter or width larger than that of the hole formed in the winding center portion C of the electrode assembly 10 .

[0200] The non-coated portion coupling portion 42 and the terminal coupling portion 43 are not directly connected to each other, but are arranged to be spaced apart from each other, and are electrically connected by the periphery 41. As described above, the current collector 40 according to an embodiment of the present invention has a structure in which the non-coated portion coupling portion 42 and the terminal coupling portion 43 are not directly connected to each other, but are connected by the periphery 41. Therefore, when an impact and / or vibration occurs to the cylindrical battery 1, the impact applied to the coupling portion between the non-coated portion coupling portion 42 and the first non-coated portion 11 and the coupling portion between the terminal coupling portion 43 and the terminal 50 can be dispersed. As a result, the current collector 40 of the present invention can minimize or prevent damage to the welded portion due to an external impact. The current collector 40 of the present invention has a structure in which stress is concentrated at the connection portion between the periphery 41 and the terminal coupling portion 43 when an external impact is transmitted to the inside of the battery 1 through the terminal 50. However, this connection portion is not a portion where a welded portion is formed for joining the parts. Therefore, in the present invention, it is possible to effectively prevent the occurrence of product defects due to damage to the welded portion due to an external impact.

[0201] The current collector 40 may further include a connecting portion 44 extending inward from the peripheral portion 41 and connected to the terminal connecting portion 43. In the current collector 40, the first non-coated portion connecting portion 42 and the terminal connecting portion 43 may not be directly connected to each other but may be indirectly connected to each other via the connecting portion 44. The extending direction of the first non-coated portion connecting portion 42 and the extending direction of the connecting portion 44 may not be parallel. The connecting portion 44 may extend approximately in a radial direction from approximately the center of the terminal connecting portion 43 to be connected to the peripheral portion 41.

[0202] The connection portion 44 may have a tapered portion 44a whose width narrows along a direction from the inner surface of the peripheral portion 41 toward the terminal coupling portion 43. That is, the tapered portion 44a may have a shape whose width widens along a direction from a connection portion of the terminal coupling portion 43 and the peripheral portion 41 toward the peripheral portion 41. The change in width of the tapered portion 44a may include both a continuous change and a stepwise change. When the tapered portion 44a is provided, the rigidity of the parts at the connection portion of the connection portion 44 and the peripheral portion 41 may be improved. When the tapered portion 44a is provided, in a manufacturing process of the cylindrical battery 1, for example, a transport device and / or a worker may hold the tapered portion 44a, so that the current collector 40 and / or the combination of the current collector 40 and the electrode assembly 10 can be easily and safely transported. In other words, when the tapered portion 44a is provided, it is possible to prevent defects in the product that may occur when gripping a part that is to be welded to another part, such as the non-coated part connecting portion 42 or the terminal connecting portion 43.

[0203] Meanwhile, the first non-coating portion coupling portion 42 may be provided in a plurality. When the first non-coating portion coupling portion 42 is provided in a plurality, the plurality of non-coating portion coupling portions 42 may be arranged, for example, in a radial shape, a cross shape, or a combination thereof with respect to a center of the terminal coupling portion 43. The plurality of non-coating portion coupling portions 42 may be arranged along a circumferential direction of the peripheral portion 41. In this case, the terminal coupling portion 43 may be connected to a portion of the peripheral portion provided between a pair of non-coating portion coupling portions 42 adjacent to each other in a circumferential direction of the peripheral portion 41. The plurality of non-coating portion coupling portions 42 may be spaced apart from each other in a radial direction from the terminal coupling portion 43 and arranged approximately radially with the terminal coupling portion 43 as a center.

[0204] Although the drawings of the present invention only show the case where the number of the first non-coating portion coupling parts 42 is three and four, the present invention is not limited thereto. The number of the first non-coating portion coupling parts 42 may be determined in various ways in consideration of a resistance level required for the cylindrical battery 1, an aperture ratio of the first current collector 40, and the like. The first non-coating portion coupling parts 42 may be regularly arranged along the extension direction of the peripheral portion 41. For example, the first non-coating portion coupling parts 42 may be arranged at substantially equal intervals along the extension direction of the peripheral portion 41. The extension lengths of the first non-coating portion coupling parts 42 may be substantially the same as each other. The first non-coating portion coupling parts 42 may be coupled to the first non-coating portion 11 by welding.

[0205] The terminal coupling portion 43 may be disposed to be surrounded by the plurality of first non-coating portion coupling portions 42. The terminal coupling portion 43 may be coupled to the terminal 50 by welding. The connection portion 44 may be located between a pair of adjacent first non-coating portion coupling portions 42. In this case, a distance from the connection portion 44 to any one of the pair of first non-coating portion coupling portions 42 along the extension direction of the peripheral portion 41 may be substantially the same as a distance from the connection portion 44 to the remaining one of the pair of first non-coating portion coupling portions 42 along the extension direction of the peripheral portion 41. The cross-sectional areas of the plurality of first non-coating portion coupling portions 42 may be substantially the same. The widths and thicknesses of the plurality of first non-coating portion coupling portions 42 may be substantially the same.

[0206] The number of the connection parts 44 may be multiple. The number of the connection parts 44 may be determined in consideration of a resistance level required for the cylindrical battery 1, an aperture ratio of the first current collector 40, and the like. Each of the multiple connection parts 44 may be disposed between a pair of adjacent first non-coating portion coupling parts 42. The multiple connection parts 44 may be regularly disposed along the extension direction of the peripheral portion 41. For example, the multiple connection parts 44 may be disposed at substantially equal intervals along the extension direction of the peripheral portion 41. Meanwhile, a distance from each of the multiple connection parts 44 to one of the pair of adjacent first non-coating portion coupling parts 42 along the extension direction of the peripheral portion 41 may be substantially the same as a distance to the remaining one of the first non-coating portion coupling parts 42.

[0207] As described above, when a plurality of first non-coating portion joining portions 42 and / or connection portions 44 are provided, if the distance between the first non-coating portion joining portions 42 and / or the distance between the connection portions 44 and / or the distance between the first non-coating portion joining portions 42 and the connection portions 44 is formed to be approximately constant, a smooth flow of current can be formed from the first non-coating portion joining portions 42 to the connection portions 44 or from the connection portions 44 to the first non-coating portion joining portions 42.

[0208] The current collector 40 and the first non-coated portion 11 may be bonded to each other by welding, for example, laser welding, ultrasonic welding, or spot welding.

[0209] 16 to 20, the connection portion 44 may include current blocking portions N, G, and T formed to partially reduce the cross-sectional area of ​​the connection portion 44. The reduction in the cross-sectional area of ​​the connection portion 44 in the region where the current blocking portion is formed may be achieved by, for example, partially reducing the width and / or thickness of the connection portion 44. When the current blocking portion is provided, electrical resistance increases in the region where the current blocking portion is formed, and thus, when an overcurrent occurs, the current blocking portion breaks, enabling rapid current blocking. A plurality of the current blocking portions may be provided along the longitudinal direction of the connection portion. When a plurality of the connection portions 44 are provided, the current blocking portion may be provided in at least one of the plurality of connection portions 44. The current blocking portion may include, for example, at least one of a notch, a groove, and a through hole.

[0210] When the connection portion 44 includes the tapered portion 44a, the current interrupting portion may be located closer to the tapered portion 44a than to the terminal coupling portion 43. A relatively large amount of heat is generated at the narrowest portion of the tapered portion 44a, which allows the current interrupting portion adjacent to the tapered portion 44a to quickly interrupt an overcurrent.

[0211] Meanwhile, the current interrupting part is preferably provided in a region corresponding to the above-mentioned welding target region of the electrode assembly 10 in order to prevent foreign matter such as welding spatters generated during breakage from flowing into the electrode assembly 10. This is because the number of overlaps of the segments of the first non-coated portion 11 is maximized in this region, and thus the overlapped segments can function as a mask. The current interrupting part may be formed, for example, at a location that is about 40% to 90% away from the core of the electrode assembly 10 in the radial direction based on the radius of the electrode assembly. Preferably, the current interrupting part may be located approximately in the center between the core and the outermost periphery of the electrode assembly 10.

[0212] 16 and 17, the current interrupting portion may include a notch N formed on at least one surface of the connection portion 44. The notch N may have a shape in which its width gradually decreases from the surface of the connection portion 44 toward the inside. The notch N may be formed on the side surface and / or the top surface and / or the bottom surface of the connection portion 44. As shown in FIG. 17, when a plurality of connection portions 44 are provided, the notch N may be formed in at least one of the plurality of connection portions 44.

[0213] 18 and 19, the current interrupting portion may include a groove G formed on at least one surface of the connection portion 44. The groove G may be formed on a side surface and / or an upper surface and / or a lower surface of the connection portion 44. Although not shown, when there are a plurality of connection portions 44, the groove G may be formed in at least one of the plurality of connection portions 44.

[0214] 20, the current interruption portion may include a through hole T formed on at least one surface of the connection portion 44. The through hole T may have a shape that penetrates between an upper surface and a lower surface of the connection portion 44 and / or a shape that penetrates a side surface of the connection portion 44. Although not shown, when there are a plurality of connection portions 44, the through hole T may be formed in at least one of the plurality of connection portions 44.

[0215] Although not shown, when there are a plurality of connection portions 44 and two or more of the connection portions 44 are provided with current interrupting portions, the plurality of current interrupting portions may all have substantially the same shape or may have different shapes. For example, the plurality of current interrupting portions may include at least two of a notch N, a groove G, and a through hole T.

[0216] 21, a tape 46 may be attached to the current blocking portion. The tape 46 may be configured to surround the connection portion 44 in the area where the current blocking portion is formed. The tape 46 may be made of various materials, for example, polyimide (PI), which is difficult to deform due to heat. However, the material of the tape 46 of the present invention is not limited thereto.

[0217] When the tape 46 is applied, if heat is generated in the current interrupting part, the heat is less likely to be released. This allows the temperature to rise quickly in the current interrupting part, which allows the current interrupting part to break quickly and interrupt overcurrent. In addition, when the tape 46 is applied, it is possible to prevent foreign matter such as molten metal generated when the current interrupting part breaks down from flying to other parts.

[0218] The cross-sectional area of ​​the connection part 44 in the region where the current interrupting part is formed may be in the range of about 0.6 to 0.9 with respect to the cross-sectional area of ​​the connection part 44 in the region where the current interrupting part is not formed. For example, when the current interrupting part is provided in a form in which the width is narrowed while maintaining the thickness of the connection part 44, the width of the connection part 44 in the portion where the current interrupting part is formed may be in the range of about 0.6 to 0.9 with respect to the width of the connection part 44 in the region where the current interrupting part is not formed. This is also true when the current interrupting part is provided in a form in which the thickness is reduced while maintaining the width of the connection part 44. If the reduction in the cross-sectional area due to the current interrupting part is too large, the resistance of the cylindrical battery 1 becomes too large, and if the reduction in the cross-sectional area is insignificant, it becomes difficult to achieve the purpose of interrupting overcurrent.

[0219] In another aspect of the present invention, the number of the connection parts 44 may be one or two. This is for quickly interrupting overcurrent. If the number of the connection parts 44 is too large, the current flow may be dispersed, making it difficult for the fuse function to operate normally. In consideration of securing the rigidity of the current collector 40, the number of the connection parts 44 may be two. In yet another aspect of the present invention, the cross-sectional area of ​​the connection part 44 may be in the range of about 0.2 to 1.0 with respect to the cross-sectional area of ​​the non-coated portion coupling part 42. For example, when the thickness of the connection part 44 and the non-coated portion coupling part 42 are substantially the same, the width of the connection part 44 may be in the range of about 0.2 to 1.0 with respect to the width of the non-coated portion coupling part 42. If the cross-sectional area of ​​the connection part 44 is too large, it is difficult to achieve the purpose of interrupting overcurrent, and if the cross-sectional area of ​​the connection part 44 is too small, the overall resistance value of the cylindrical battery 1 may be too large.

[0220] In still another aspect of the present invention, the ratio of an area of ​​the current collector 40 that is not in contact with the upper surface of the electrode assembly 10 to an area of ​​a circle having a diameter equal to the outer diameter of the electrode assembly 10 may be defined as an aperture ratio of the current collector 40. The aperture ratio can be calculated by the following formula:

[0221] Opening ratio (%) = 1 - (area where the current collector is in contact with the top surface of the electrode assembly) / (area of ​​a circle whose diameter is the outer diameter of the electrode assembly) = (area where the current collector is not in contact with the top surface of the electrode assembly) / (area of ​​a circle whose diameter is the outer diameter of the electrode assembly)

[0222] The aperture ratio of the current collector 40 may be, for example, about 20% to less than 100%, and preferably about 30% to less than 100%. Taking the case where the current collector 40 shown in FIG. 12 is placed on and coupled to the electrode assembly 10 as an example, the area where the current collector 40 contacts the electrode assembly 10 may be the periphery 41, the non-coated part coupling part 42, and the coupling part 44. That is, the ratio of the area where the current collector 40 contacts the electrode assembly 10 to the area of ​​a circle having a diameter the same length as the outer diameter of the electrode assembly 10 may be about 80% or less, and preferably about 70% or less. When the aperture ratio of the current collector 40 is within the above range, the impregnation of the electrolyte can be smoothly performed. That is, there is a gap around the terminal coupling part 43 located at the center of the current collector 40, and the electrolyte spreads radially through the gap and moves to the open space, and then seeps into the electrode assembly 10.

[0223] 22, the current collector (first current collector) 40 includes, in addition to the embodiments shown in FIGS. 5 to 10, a bridge portion 45 connecting at least one of adjacent first non-coating portion coupling portions 42, adjacent first non-coating portion coupling portions 42 and connecting portions 44, and adjacent connecting portions 44. The bridge portion 45 is located inside the peripheral portion 41. The current collector 40 may have an impregnation hole 40a formed between the peripheral portion 41 and the bridge portion 45. The impregnation hole 40a may have a substantially slit shape extending along the extension direction of the peripheral portion 41, for example. The impregnation hole 40a increases the proportion of the space S formed inside the peripheral portion 41, facilitating the circulation of the electrolyte injected into the housing 20, thereby improving the impregnation.

[0224] 5 to 7, the terminal 50 is made of a conductive metal material. For example, aluminum (Al) may be used as the material of the terminal 50. When the terminal 50 is made of aluminum, 10-series aluminum having a relatively low electrical resistance and easy processing during riveting as described below may be used. The terminal 50 passes through the upper surface of the housing 20, that is, the surface (parallel to the XY plane) located opposite the open portion of the housing 20. The terminal 50 is electrically connected to, for example, the first non-coated portion 11 of the electrode assembly 10. In this case, the terminal 50 has a first polarity. Thus, the terminal 50 can function as a first electrode terminal in the cylindrical battery 1 of the present invention. When the terminal 50 has the first polarity as described above, the terminal 50 is electrically insulated from the housing 20 having the second polarity. The electrical insulation between the terminal 50 and the housing 20 can be achieved in various ways. For example, the insulation can be achieved by interposing an insulating gasket G2 between the terminal 50 and the housing 20. Alternatively, insulation may be achieved by forming an insulating coating layer on a portion of the terminal 50. Alternatively, a method may be applied in which the terminal 50 is structurally and firmly fixed so that the terminal 50 does not come into contact with the housing 20. Alternatively, a combination of the above methods may be used.

[0225] The terminal 50 includes a terminal exposing portion 51 and a terminal inserting portion 52. The terminal inserting portion 52 may include an electrical connection portion 52a and a flange portion 52b. The terminal exposing portion 51 is exposed to the outside of the housing 20. The terminal exposing portion 51 may be located at approximately the center of the closed portion of the housing 20. The maximum width of the terminal exposing portion 51 may be greater than the maximum width of a hole formed in the housing 20 for inserting the terminal 50. The terminal inserting portion 52 may pass through approximately the center of the closed portion of the housing 20, and the electrical connection portion 52a of the terminal inserting portion 52 may be electrically connected to the first non-coated portion 11. When the cylindrical battery 1 of the present invention includes an insulator 60, the terminal inserting portion 52 may have a shape surrounded by the insulator 60 so that a side surface of the terminal inserting portion 52 is not exposed. The flange portion 52b of the terminal inserting portion 52 may be formed around the electrical connection portion 52a and may be coupled to an inner surface of the closed portion of the housing 20 by a rivet. That is, the flange portion 52b of the terminal insertion portion 52 may be bent toward the inner surface of the closing portion of the housing 20. As a result, the maximum width of the terminal insertion portion 52 after a riveting process for fixing the terminal 50 is performed may be greater than the maximum width of a hole formed in the housing 20 through which the terminal insertion portion 52 passes.

[0226] 10 to 12 together with FIGS. 5 to 7, the electrical connection portion 52a of the terminal insertion portion 52 may be coupled to the terminal coupling portion 43 of the current collector (first current collector) 40. The electrical connection portion 52a of the terminal insertion portion 52 may have, for example, a substantially cylindrical shape. Of course, the shape of the electrical connection portion 52a of the terminal insertion portion 52 is not limited thereto. The electrical connection portion 52a of the terminal insertion portion 52 may have various shapes, for example, a cylindrical shape having an elliptical cross section, a rectangular prism shape, a hexagonal prism shape, or an octagonal prism shape. The bottom surface of the electrical connection portion 52a of the terminal insertion portion 52 may be formed to be at least partially substantially flat.

[0227] 9 and 10 together with FIG. 7, the connection between the bottom surface of the central region of the terminal insertion portion 52 and the current collector (first current collector) 40 may be performed by, for example, laser welding, spot welding, or ultrasonic welding.

[0228] The welding may be performed by irradiating a laser through a hole formed in the winding center C of the electrode assembly 10 or by inserting a tool for ultrasonic welding or spot welding to form a weld bead W on one side of the current collector 40 (the side facing the hole formed in the winding center C of the electrode assembly 10). A guide pipe (not shown) for the welding operation may be inserted into the hole formed in the winding center C. When the welding operation is performed with the guide pipe inserted, the risk of damage to the separator forming the inner surface of the hole formed in the winding center C can be reduced.

[0229] The weld pattern formed by the weld bead W formed on one side of the terminal coupling portion 43 of the current collector 40 may be drawn to surround the center P of the bottom surface of the electrical connection portion 52a of the terminal insertion portion 52. The weld pattern may be, for example, substantially circular, or may be substantially elliptical or polygonal, such as rectangular, hexagonal, or octagonal. The weld pattern formed by the weld bead W may be formed continuously (see FIG. 10) or discontinuously (see FIG. 11). The circle, ellipse, polygon, etc., exemplified as the shape of the weld pattern formed by the weld bead W, does not mean a geometrically perfect circle, ellipse, polygon, etc.

[0230] Meanwhile, the diameter of the flat portion formed on the bottom surface of the electrical connection portion 52a of the terminal insertion portion 52 may be determined in consideration of the welding strength with the current collector 40. The tensile strength of the weld between the flat portion and the current collector (first current collector) 40 is at least about 2 kgf. (19.6N) or more, or 3kgf (29.4N) or more, or 4kgf (39.2N) or more, or 5kgf (49.0N) or more, or 6kgf (58.8N) or more, or 7kgf (68.6N) or more, or 8kgf (78.5N) or more, or 9kgf(88.3N) or more, or 10kgf (98.1N) It is desirable to increase the tensile strength of the weld as much as possible while still allowing the best possible welding method.

[0231] The diameter (or maximum width) of the weld pattern formed on the flat portion to satisfy the tensile strength condition of the weld may be a minimum of about 2 mm. The diameter of the weld pattern is calculated by multiplying the area S of the weld bead W that appears on the surface of the welded portion by the area of ​​a circle (πr 2 ) is the equivalent diameter of the circle (2×(S / π) 0.5 )

[0232] The flat portion formed on the bottom surface of the electrical connection portion 52a of the terminal insertion portion 52 is a weldable region. The diameter of the weldable region may be about 3 mm to 14 mm. If the diameter of the weldable region is smaller than about 3 mm, it is difficult to secure a weld pattern having a diameter (equivalent diameter) of 2 mm or more. In particular, when forming a weld pattern using laser welding, it is difficult to secure a weld pattern having a diameter of 2 mm or more due to interference of the laser beam. If the diameter of the weldable region exceeds about 14 mm, the diameter of the terminal exposed portion 51 of the terminal 50 must also be larger than that, which makes it difficult to secure a sufficient area of ​​the outer surface 20a of the housing 20 to be used as an electrode terminal having the opposite polarity to the terminal 50.

[0233] Considering the diameter conditions of the welding pattern and the diameter conditions of the weldable area, at least about 5 kgf (49.0N) The ratio of the area of ​​the weld pattern to the area of ​​the weldable area required to ensure the above tensile strength of the weld is approximately 2.04% (π1 2 / π7 2 )~44.4%(π1 2 / π1.5 2 ) is preferable.

[0234] As an example, when the flat portion formed on the bottom surface of the electrical connection portion 52a of the terminal insertion portion 52 and the current collector 40 are welded by a laser, and the weld bead W is welded while drawing a continuous or discontinuous line in the form of an approximately arc pattern, the diameter of the arc weld pattern is preferably about 2 mm or more, and more preferably about 4 mm or more. When the diameter of the arc weld pattern satisfies this condition, the tensile force of the weld is about 5 kgf. (49.0N) By increasing the amount of welded material to the above level, sufficient weld strength can be ensured.

[0235] In another example, when the flat portion formed on the bottom surface of the electrical connection portion 52a of the terminal insertion portion 52 and the current collector 40 are ultrasonically welded in a circular pattern, the diameter of the circular weld pattern is preferably about 2 mm or more. When the diameter of the circular weld pattern satisfies this condition, the tensile force of the weld is about 2 kgf. (19.6N) By increasing the amount of welded material to the above level, sufficient weld strength can be ensured.

[0236] The diameter of the flat portion formed on the bottom surface of the terminal 50, which is the weldable area, can be adjusted within a range of about 3 mm to 14 mm. If the radius of the flat portion is less than about 3 mm, it is difficult to form a welding pattern having a diameter of about 2 mm or more using a laser welding tool, an ultrasonic welding tool, or the like.

[0237] Meanwhile, the cylindrical battery 1 according to an embodiment of the present invention has a structure in which the bottom surface of the electrical connection portion 52a of the terminal insertion portion 52 is welded and coupled onto the current collector 40 as described above, thereby maximizing the coupling area between the current collector 40 and the terminal 50. That is, at least a portion of the bottom surface of the electrical connection portion 52a is formed flat, thereby maximizing the coupling area between the terminal 50 and the current collector 40. Therefore, the cylindrical battery 1 according to an embodiment of the present invention can ensure smooth current flow at the coupling portion between the current collector 40 and the terminal 50 when a large amount of current flows due to quick charging, thereby achieving effects such as shortening the charging time and reducing the amount of heat generation.

[0238] The insulating gasket G2 includes a gasket exposing portion GA and a gasket inserting portion GB. The gasket exposing portion GA is interposed between the terminal exposing portion 51 of the terminal 50 and the housing 20. The gasket exposing portion GA extends longer than the terminal exposing portion 51, and thus may be exposed to the outside of the terminal exposing portion 51 in a top view of the cylindrical battery 1. The gasket inserting portion GB is interposed between the terminal inserting portion 52 of the terminal 50 and the housing 20. The gasket inserting portion GB may be deformed during riveting of the flange portion 52b of the terminal inserting portion 52, and may be in close contact with the inner surface of the closing portion of the housing 20. The insulating gasket G2 may be made of, for example, a resin material having insulating properties and elasticity.

[0239] 6, 7 and 12, the insulator 60 may be provided between the current collector (first current collector) 40 and the inner surface of the housing 20. The insulator 60 prevents contact between the current collector 40 and the housing 20. The insulator 60 may also be interposed between an upper end of the outer circumferential surface of the electrode assembly 10 and the inner surface of the housing 20. That is, the insulator 60 may also be interposed between the first non-coated portion 11 and the inner surface of the side wall of the housing 20. This is to prevent contact between the first non-coated portion 11 extending toward the closing portion of the housing 20 and the inner circumferential surface of the housing 20.

[0240] When the cylindrical battery 1 of the present invention includes an insulator 60, the terminal 50 is coupled to the current collector 40 by passing through the insulator 60. The insulator 60 may have a hole formed in approximately its center so that the terminal 50 can pass through. The hole formed in the insulator 60 may be formed at a position corresponding to the terminal coupling portion 43 of the current collector 40. The hole formed in the insulator 60 may be formed at a position corresponding to a hole formed in the winding center portion C of the electrode assembly 10. The hole formed in the insulator 60 may be formed at a position corresponding to the electrical connection portion 52a of the terminal insertion portion 52 provided in the terminal 50. Thus, the electrical connection portion 52a of the terminal insertion portion 52 may be coupled to the terminal coupling portion 43 of the current collector 40 through the hole formed in the insulator 60.

[0241] Meanwhile, if the welded joint portion between the terminal 50 and the first current collector 40 is located inside a hole formed in the winding center C of the electrode assembly 10, the electrode assembly 10 may be damaged. To prevent this, the lower end of the terminal 50 coupled to the terminal coupling portion 43 may be located at substantially the same height as the lower surface of the insulator 60 or may be located higher. In this case, the welded joint portion between the terminal 50 and the first current collector 40 is located outside a hole formed in the winding center C of the electrode assembly 10.

[0242] In consideration of this, the thickness of the insulator 60 may be substantially equal to or greater than the distance from the inner surface of the closed portion of the housing 20 to the flat portion provided at the lower end of the terminal 50. Meanwhile, the insulator 60 may have a thickness corresponding to the distance between the inner surface of the closed portion of the housing 20 and the current collector 40 so as to fill the space between the inner surface of the closed portion of the housing 20 and the current collector 40 along the height direction (direction parallel to the Z-axis) and prevent the electrode assembly 10 from moving up and down. In another aspect of the present invention, the upper surface of the insulator 60 may contact the inner surface of the closed portion of the housing 20, and the lower surface of the insulator 60 may contact the upper surface of the current collector 40.

[0243] 23 and 25, the current collector (second current collector) 70 is coupled to the lower part of the electrode assembly 10. The current collector 70 is made of a conductive metal material and is coupled to the second non-coated part 12. The current collector 70 is also electrically connected to the housing 20. The current collector 70 electrically connects the second non-coated part 12 and the housing 20. At least a part of the peripheral region of the current collector 70 may be interposed and fixed between a lower surface (mounting surface) of the beading part 21 of the housing 20 and a sealing gasket G1. In this case, the current collector 70 may be welded to the mounting surface formed by the beading part 21 of the housing 20. The sealing gasket G1 is disposed in the crimping part 22 and interposed between the housing 20 and the cap 30.

[0244] The current collector 70 may have a second current collector hole 70a formed in a region corresponding to a hole formed in the winding center C of the electrode assembly 10. The winding center hole of the electrode assembly 10 and the second current collector hole 70a, which are connected to each other, may function as a passage for inserting a welding rod or irradiating a laser beam to weld the terminal 50 and the terminal coupling portion 43 of the first current collector 40. The second current collector hole 70a may be configured to have a diameter larger than the diameter of the hole formed in the winding center C of the electrode assembly 10 so as not to block the hole formed in the winding center C of the electrode assembly 10. If the diameter of the second current collector hole 70a is too small compared to the diameter of the hole formed in the winding center C, the hole formed in the winding center C may be blocked, reducing the injection property, and it may be difficult to secure a sufficient space for inserting a welding device or irradiating a laser.

[0245] Unlike the above embodiment, according to another embodiment of the present invention, the diameter of the second current collector hole 70a may be smaller than the diameter of a hole formed in a winding center C provided in the core of the electrode assembly 10. For example, when the diameter of the hole formed in the winding center C is R3, the diameter of the second current collector hole 70a may be 0.5×R3 or more and less than R3, and preferably 0.7×R3 or more and less than R3.

[0246] Typically, when venting, gas is discharged from the winding center, and strong pressure may cause the separator and non-coated portion at the winding center to come out from the bottom surface of the electrode assembly 10. In this case, if the diameter of the second current collector hole 70a is smaller than the diameter of the hole provided in the core of the electrode assembly 10, it is possible to prevent the separator and non-coated portion at the winding center from coming out from the bottom surface of the electrode assembly 10. However, if the diameter of the second current collector hole 70a is too small, the injection property of the electrolyte may be reduced, and a space must be secured for the welding operation of the second current collector 70 and the terminal 50. Therefore, the diameter of the second current collector hole 70a is preferably 0.5×R3 or more, and more preferably 0.7×R3 or more.

[0247] The second current collector 70 may include a second uncoated portion connecting portion 72 connected to the second uncoated portion 12 and a housing connecting portion 73 connected to the housing 20. The second current collector 70 may further include a support portion 71. The second uncoated portion 12 and the second uncoated portion connecting portion 72 may be connected to each other by welding. The housing 20 and the housing connecting portion 73 may be connected to each other by welding. The housing connecting portion 73 may be electrically connected to a lower surface of the beading portion 21.

[0248] The support part 71 is disposed under the electrode assembly 10. When the support part 71 is provided, the second non-coated part coupling part 72 may extend from the support part 71 substantially along the radial direction of the electrode assembly 10 to be coupled to the second non-coated part 12. Also, the housing coupling part 73 may extend from the support part 71 substantially along the radial direction of the electrode assembly 10 to be coupled to the inner surface of the housing 20. The second non-coated part coupling part 72 and the housing coupling part 73 may not be directly connected to each other, but may be indirectly connected to each other through the support part 71. In this case, when an external impact is applied to the cylindrical battery 1, the possibility of damage occurring to the coupling part between the second current collector 70 and the electrode assembly 10 and the coupling part between the second current collector 70 and the housing 20 can be minimized. However, the second current collector 70 of the present invention is not limited to the structure in which the second non-coated part coupling part 72 and the housing coupling part 73 are indirectly connected to each other. For example, the second current collector 70 may have a structure that does not include a support portion 71 that indirectly connects the second non-coated portion connecting portion 72 and the housing connecting portion 73 and / or a structure in which the second non-coated portion connecting portion 72 and the housing connecting portion 73 are directly connected to each other.

[0249] Meanwhile, not only the second non-coating portion connecting portion 72 but also the supporting portion 71 may be connected to the second non-coating portion 12. When the beading portion 21 is formed on the housing 20, the supporting portion 71 and the second non-coating portion connecting portion 72 are located above the beading portion 21.

[0250] There may be a plurality of second non-coating portion coupling parts 72. When a plurality of second non-coating portion coupling parts 72 are provided, the plurality of second non-coating portion coupling parts 72 may extend radially from the support part 71 of the second current collector 70 toward the side wall of the housing 20. The plurality of second non-coating portion coupling parts 72 may be positioned around the support part 71 at intervals from each other.

[0251] The housing coupling parts 73 may be provided in a plurality. In this case, the plurality of housing coupling parts 73 may extend radially from the center of the second current collector 70 toward the side wall of the housing 20. Thus, the electrical connection between the second current collector 70 and the housing 20 may be performed at a plurality of points. By performing coupling for electrical connection at a plurality of points, the coupling area may be maximized and electrical resistance may be minimized. The plurality of housing coupling parts 73 may be located apart from each other along the circumference of the support part 71. At least one housing coupling part 73 may be located between adjacent second non-coated part coupling parts 72. The plurality of housing coupling parts 73 may be coupled to the inner surface of the housing 20, for example, to the beading part 21. The housing coupling part 73 may be coupled to the lower surface of the beading part 21 in particular.

[0252] The housing coupling portion 73 may include a contact portion 73a that couples with the inner surface of the housing 20, and an extension portion 73b that connects the support portion 71 and the contact portion 73a.

[0253] The contact portion 73a is coupled to the inner surface of the housing 20. In the case where the beading portion 21 is formed on the housing 20, the contact portion 73a may be coupled onto the beading portion 21 as described above. More specifically, the contact portion 73a may be electrically coupled to a flat portion formed on the lower surface of the beading portion 21 formed on the housing 20, and may be interposed between the lower surface of the beading portion 21 and the sealing gasket G1. In this case, for stable contact and coupling, the contact portion 73a may have a shape extending a predetermined length from the beading portion 21 along the circumferential direction of the housing 20.

[0254] 8 and 9 together with FIGS. 23 and 25, the current collector 70 may be bonded to a bonding surface formed by bending an end of the second non-coated portion 12 in a direction parallel to the current collector 70. The bending direction of the second non-coated portion 12 may be a radial direction of the electrode assembly 10. For example, it may be a direction toward the winding center C of the electrode assembly 10. When the second non-coated portion 12 has such a bent shape, the space occupied by the second non-coated portion 12 may be reduced, thereby improving the energy density. In addition, the bonding force between the second non-coated portion 12 and the current collector 70 may be improved and the contact resistance may be reduced. As in the case of the first non-coated portion bonding portion 42 of the first current collector 40 described above, the second non-coated portion bonding portion 72 of the second current collector 70 may also be bonded to the second non-coated portion 12 so as to overlap at least about 50% with the welding target region, which is a section in which the overlap number formed by bending the segments of the second non-coated portion 12 is maintained substantially constant.

[0255] 7, 23 and 25, the distance from the center of the first current collector 40 to the outermost part of the peripheral portion 41 (the outer diameter of the first current collector 40) may be longer than the distance from the center of the second current collector 70 to the outermost part of the second non-coated portion coupling portion 72 (the outer diameter of the second current collector 70). The first current collector 40 may have a diameter close to the inner diameter of the housing 20. The first current collector 40 may have an outer diameter in a range of about 33% to 98.5% of the inner diameter of the housing 20. The minimum value of the outer diameter of the first current collector 40 is a value for preventing an excessive increase in resistance. The maximum value of the outer diameter of the first current collector 40 takes into consideration, for example, the outer diameter tolerance of the first current collector 40 that may occur during manufacturing of the current collector 40, the assembly tolerance that may occur during combination of the electrode assembly 10 and the first current collector 40, the inner diameter tolerance of the housing 20 that may occur during manufacturing of the housing 20, and the positional tolerance that may occur when the combination of the electrode assembly 10 and the first current collector 40 is inserted into the housing 20. In the present invention, when the insulator 60 is used and has a structure in which the insulator 60 covers the outer circumferential surface of the electrode assembly 10 up to the upper end thereof, it is necessary to further consider the space for inserting the insulator 60, and therefore the ratio of the outer diameter of the first current collector 40 to the inner diameter of the housing 20 is smaller than the maximum value. However, the outer diameter of the first current collector 40 is limited to a level that is formed precisely smaller than the inner diameter of the housing 20 in consideration of such tolerance, while the diameter of the second current collector 70 may be further limited to avoid interference that may occur during a sizing process. In order to avoid such interference, the distance from the center of the second current collector 70 to the outermost part of the second non-coated part joining part 72 may be equal to or shorter than half the inner diameter of the region of the housing 20 where the beading part 21 is formed.

[0256] Meanwhile, the length L1 of the welded portion connecting the first non-coated portion connecting portion 42 of the first current collector 40 to the first non-coated portion 11 in the radial direction of the electrode assembly 10 may be longer than the length L2 of the welded portion connecting the second non-coated portion connecting portion 72 of the second current collector 70 to the second non-coated portion 12 in the radial direction of the electrode assembly 10. For example, when the first current collector 40 is a positive current collector made of aluminum and the second current collector 70 is a negative current collector made of the same material, if the length L1 is longer than the length L2, the area of ​​the welded portion of the positive current collector having a relatively lower electrical conductivity can be made larger, and the current flow in each of the positive current collector and the negative current collector can be balanced. Here, the extension length of the welded portion connecting the current collectors 40, 70 to the non-coated portions 11, 12 means the extension length of the weld bead formed by welding.

[0257] A distance from the core of the electrode assembly 10 to a start point of a weld that connects the first non-coated portion connecting portion 42 of the first current collector 40 to the first non-coated portion 11 may be substantially the same as a distance to a start point of a weld that connects the second non-coated portion connecting portion 72 to the second non-coated portion 12. Here, being substantially the same may mean that the two distances are the same as each other or have a deviation of, for example, about 5% or less.

[0258] In still another aspect of the present invention, the ratio of an area of ​​the current collector (second current collector) 70 that is not in contact with the lower surface of the electrode assembly 10 to an area of ​​a circle having a diameter equal to the outer diameter of the electrode assembly 10 may be defined as an aperture ratio of the current collector 70. The aperture ratio can be calculated by the following formula:

[0259] Opening ratio (%) = 1 - (area where the current collector is in contact with the bottom surface of the electrode assembly) / (area of ​​a circle whose diameter is the outer diameter of the electrode assembly) = (area where the current collector is not in contact with the bottom surface of the electrode assembly) / (area of ​​a circle whose diameter is the outer diameter of the electrode assembly)

[0260] The aperture ratio of the current collector 70 may be, for example, about 30% to less than 100%, and preferably about 60% to less than 100%. Taking the case where the current collector 40 shown in FIG. 25 is placed on and coupled to the electrode assembly 10 as an example, the area where the current collector 40 contacts the electrode assembly 10 may be a support part 71 and a non-coated part coupling part (second non-coated part coupling part) 72. That is, the ratio of the area where the current collector 70 contacts the electrode assembly 10 to the area of ​​a circle having a diameter the same length as the outer diameter of the electrode assembly 10 may be about 70% or less, and preferably about 40% or less. When the aperture ratio of the current collector 70 is within the above range, the electrolyte can smoothly permeate into the electrode assembly 10 through the area not blocked by the current collector 70 when the electrolyte is injected. That is, when the aperture ratio of the current collector 70 is within the above range, the electrolyte can seep into the electrode assembly 10 through the holes formed in the winding center C of the electrode assembly 10. In particular, since there are minute gaps between the overlapping surfaces of the segment pieces 11a and between the spacing pitches, the electrolyte can smoothly seep into the electrode assembly 10 through the gaps by capillary action.

[0261] 26 to 29, the structure of the electrode assembly 10 will be described in more detail. In the following description, of the first and second electrodes described above, the first electrode will be taken as an example, but the structure of the first electrode can be similarly applied to the second electrode.

[0262] 26 to 29, the first electrode 110 includes a sheet-shaped first electrode collector 111 made of a conductive foil, a first active material layer 112 formed on at least one surface of the first electrode collector 111, and a first non-coated portion 11 formed by not coating the active material on an end portion of a long side of the first electrode collector 111.

[0263] Preferably, the first non-coated portion 11 may include a plurality of segment pieces 11a that are cut. The plurality of segment pieces 11a may be arranged in a plurality of groups, and the segment pieces 11a belonging to each group may have substantially the same height (length in the Z direction) and / or width (length in the X direction) and / or spacing pitch. The number of segment pieces 11a belonging to each group may be greater or less than that shown in the figure. The segment pieces 11a have a geometric shape in which at least one straight line and / or at least one curved line are combined. Preferably, the segment pieces 11a may be trapezoidal, but may be modified into a rectangle, parallelogram, semicircle, inverse ellipse, or the like.

[0264] Preferably, the height of the segment piece 11a may increase stepwise along one direction parallel to the winding direction of the electrode assembly 10, for example, from the core side to the outer periphery side. Also, the core-side non-coated portion 11-1 adjacent to the core side of the electrode assembly 10 may not include segment piece 11a, and the height of the core-side non-coated portion 11-1 may be lower than the non-coated portions of other regions. Also, the outer-periphery-side non-coated portion 11-2 adjacent to the outer periphery side of the electrode assembly 10 may not include segment piece 11a, and the height of the outer-periphery-side non-coated portion 11-2 may be lower than the other non-coated portions.

[0265] Optionally, the first electrode 110 may include an insulating coating layer E covering the boundary between the active material layer 112 and the first non-coated portion 11. The insulating coating layer E may include an insulating polymer resin and may optionally further include an inorganic filler. The insulating coating layer E may prevent an end of the active material layer 112 from contacting an active material layer of the opposite polarity facing the active material layer 112 via a separator and may structurally support bending of the segment pieces 11a. For this reason, when the first electrode 110 is wound to form the electrode assembly 10, it is preferable that at least a portion of the insulating coating layer E is exposed to the outside through the separator.

[0266] 26 and 27, the electrode assembly 10 may be manufactured by the winding method described in FIG 2. For ease of explanation, the protruding structure of the non-coated portions 11 and 12 extending outward from the separator is shown in detail, and the winding structure of the first electrode, second electrode, and separator is omitted. The first non-coated portion 11 protruding upward extends from the first electrode, and the second non-coated portion 12 protruding downward extends from the second electrode.

[0267] The pattern in which the height of the non-coated portions 11, 12 varies is shown diagrammatically. That is, the height of the non-coated portions 11, 12 may vary irregularly depending on where the cross section is cut. For example, when a side portion of a trapezoidal segment 11a is cut, the height of the non-coated portion in the cross section will be lower than the height of segment 11a. Therefore, it can be understood that the height of the non-coated portions 11, 12 shown in the drawing showing the cross section of the electrode assembly 10 corresponds to the average height of the non-coated portions included in each winding turn.

[0268] 26 to 29, the non-coated portions 11 and 12 may be bent in the radial direction of the electrode assembly 10, for example, from the outer periphery side to the core side. The portion of the non-coated portions 11 and 12 where bending occurs is indicated by a dotted box in FIG. 27. When the non-coated portions 11 and 12 are bent, adjacent segments in the radial direction are overlapped to form bent surfaces 102 at the upper and lower parts of the electrode assembly 10. In this case, the non-coated portion on the core side (11-1 in FIG. 26) is too low to be bent, and the height h of the segment 11a bent at the innermost side is approximately equal to or smaller than the sum of the radial length r of the winding region formed by the non-coated portion 11-1 on the core side where no segment structure exists and 10% of the diameter of the winding center hole. As a result, the hole formed in the core C of the electrode assembly 10 is not closed. If the hole is not blocked, the electrolyte injection process is easy and the electrolyte injection efficiency can be improved. Also, a welding tool can be inserted through the hole to easily weld the terminal 50 and the first current collector 40 (see FIG. 7).

[0269] Meanwhile, when the outer diameter of the first current collector 40 and / or the second current collector 70 is T, the outer diameter of the electrode assembly 10 is JR, and the height of the outermost segment of the first non-coated portion 11 and / or the second non-coated portion 12 is F, the following relational expressions may be satisfied. Here, the outer diameter of the first current collector 40 means twice the distance from the center of the first current collector 40 to the end of the first non-coated portion connecting portion 42, and the outer diameter of the second current collector 70 means twice the distance from the center of the second current collector 70 to the end of the second non-coated portion connecting portion 72.

[0270] JR-2×F≦T <JR

[0271] Preferably, the outer diameter T of the first current collector 40 and / or the second current collector 70 may be greater than or equal to the outer diameter JR of the electrode assembly 10 minus twice the height F of the segment piece 11a of the first non-coated portion 11 and / or the segment piece of the second non-coated portion 12. If this relational expression is satisfied, the first non-coated portion joining portion 42 and / or the second non-coated portion joining portion 72 cover the end of the outermost segment piece 11a. That is, the first current collector 40 and / or the second current collector 70 may have an outer diameter that covers the end of the segment piece bent at the last winding turn of the first electrode. In this case, welding can be performed in a state where the entire segment piece 11a forming the bent surface 102 to which the first non-coated portion joining portion 42 and / or the second non-coated portion joining portion 72 are joined is uniformly pressed by the current collector 40, and the dense stacking state of the segment pieces 11a can be easily maintained even after welding. A densely stacked state means that there are substantially no gaps between the segments as shown in Fig. 8. The densely stacked state contributes to lowering the resistance of the cylindrical battery 1 to a level suitable for fast charging (e.g., 4 mΩ) or less.

[0272] In another aspect of the present invention, the outer diameter T of the first current collector 40 and / or the second current collector 70 may be smaller than the outer diameter JR of the electrode assembly 10. If the outer diameter T of the first current collector 40 and / or the second current collector 70 is larger than the outer diameter JR of the electrode assembly 10, the dead space inside the housing 20 increases, which may adversely affect the energy density of the cylindrical battery 1. Therefore, it is preferable that the outer diameter T of the first current collector 40 and / or the second current collector 70 is smaller than the outer diameter JR of the electrode assembly 10.

[0273] Meanwhile, referring to Fig. 30, a plurality of cylindrical batteries 1 may be connected in series and parallel at the top of the cylindrical batteries 1 using a bus bar 150. The number of cylindrical batteries 1 may be increased or decreased depending on the capacity of the battery pack.

[0274] In each cylindrical battery 1, the terminal 50 may have a positive polarity and the outer surface 20a of the closed part of the housing 20 may have a negative polarity. Of course, the opposite is also possible. The terminal 50 of the cylindrical battery 1 and the outer surface 20a of the closed part located opposite the open part of the housing 20 may all be arranged to face upward.

[0275] Preferably, the cylindrical batteries 1 may be arranged in a plurality of rows and columns. The rows are in a vertical direction with respect to the ground, and the rows are in a horizontal direction with respect to the ground. In order to maximize space efficiency, the cylindrical batteries 1 may be arranged in a closest packing structure. The closest packing structure is formed when the centers of the terminal exposed portions 51 of the terminals 50 exposed to the outside of the housing 20 are connected to each other to form an equilateral triangle. Preferably, the bus bar 150 may be arranged on top of the cylindrical batteries 1, more preferably between adjacent columns. Alternatively, the bus bar 150 may be arranged between adjacent rows.

[0276] Preferably, the bus bars 150 connect the batteries 1 arranged in the same row in parallel to each other, and connect the cylindrical batteries 1 arranged in two adjacent rows in series to each other.

[0277] 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 series and parallel connection. The body portion 151 may extend between the terminals 50 of adjacent cylindrical batteries 1, preferably between rows of cylindrical batteries 1. Alternatively, the body portion 151 may extend along the rows of cylindrical batteries 1 but be regularly folded, such as in a zigzag shape.

[0278] The plurality of first bus bar terminals 152 may protrude and extend from one side of the body portion 151 toward the terminals 50 of each cylindrical battery 1 and may be electrically coupled to the terminals 50. The electrical coupling between the first bus bar terminals 152 and the terminals 50 may be performed by laser welding, ultrasonic welding, etc. In addition, 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 coupling between the second bus bar terminals 153 and the outer surface 20a may be performed by laser welding, ultrasonic welding, etc.

[0279] Preferably, the body 151, the plurality of first busbar terminals 152, and the plurality of second busbar terminals 153 may be formed of one conductive metal plate. The metal plate may be, for example, an aluminum plate or a copper plate, but the present invention is not limited thereto. In a modified example, the body 151, the plurality of first busbar terminals 152, and the second busbar terminals 153 may be formed by manufacturing them as individual units and then bonding them to each other by welding or the like.

[0280] In the cylindrical battery 1 according to the present invention, the terminal 50 having a positive polarity and the outer surface 20a of the closed part of the housing 20 having a negative polarity are positioned in the same direction, so that electrical connection of the cylindrical battery 1 can be easily implemented using the bus bar 150.

[0281] In addition, since the terminal 50 of the cylindrical battery 1 and the outer surface 20a of the closed portion of the housing 20 have a large area, the connection area of ​​the bus bar 150 can be sufficiently secured, thereby sufficiently lowering the resistance of the battery pack including the cylindrical battery 1.

[0282] Desirably, the cylindrical battery may be, for example, a cylindrical battery having a form factor ratio (defined as the diameter divided by the height of the cylindrical battery, i.e., the ratio of the diameter Φ to the height H) of greater than about 0.4, where form factor refers to a value indicating the diameter and height of the cylindrical battery.

[0283] Preferably, the cylindrical battery has a diameter of about 40 mm to 50 mm and a height of about 60 mm to 130 mm. The cylindrical battery according to an embodiment of the present invention may be, for example, a 46110 battery, a 4875 battery, a 48110 battery, a 4880 battery, or a 4680 battery. In the form factor number, the first two digits indicate the diameter of the battery, the next two digits indicate the height of the battery, and the last digit 0 indicates that the cross section of the cell is circular. If the height of the cylindrical battery is 100 mm or more, the last digit can be omitted since three digits are required to indicate the height of the cylindrical battery.

[0284] When an electrode assembly having a tabless structure is applied to a cylindrical battery with a form factor ratio exceeding about 0.4, the non-coated portion is easily broken due to the large radial stress applied when bending the non-coated portion. Also, when welding a current collector to the surface of the bent surface of the non-coated portion, in order to ensure sufficient welding strength and reduce resistance, the number of layers of the non-coated portion must be sufficiently increased in the surface area of ​​the bent surface. These requirements can be achieved by the electrode and electrode assembly according to the embodiment (variant) of the present invention.

[0285] A cylindrical battery according to one embodiment of the present invention may be a substantially cylindrical battery having a diameter of about 46 mm, a height of about 110 mm, and a form factor ratio of about 0.418.

[0286] Another embodiment of the cylindrical battery may be a generally cylindrical battery having a diameter of about 48 mm, a height of about 75 mm, and a form factor ratio of about 0.640.

[0287] In yet another embodiment, the battery may be a generally cylindrical battery having a diameter of about 48 mm, a height of about 110 mm, and a form factor ratio of about 0.418.

[0288] In yet another embodiment, the battery may be a generally cylindrical battery having a diameter of about 48 mm, a height of about 80 mm, and a form factor ratio of about 0.600.

[0289] In yet another embodiment, the battery may be a generally cylindrical battery having a diameter of about 46 mm, a height of about 80 mm, and a form factor ratio of about 0.575.

[0290] Conventionally, batteries with a form factor ratio of about 0.4 or less have been used. That is, conventionally, for example, 1865 batteries, 2170 batteries, etc. have been used. In the case of an 1865 battery, its diameter is about 18 mm, its height is about 65 mm, and its form factor ratio is about 0.277. In the case of a 2170 battery, its diameter is about 21 mm, its height is about 70 mm, and its form factor ratio is about 0.300.

[0291] As described above, the cylindrical battery 1 of the present invention has a structure in which resistance is minimized by increasing the contact area between components, multiplying the current paths, minimizing the length of the current paths, etc. The AC resistance of the cylindrical battery 1 measured by a resistance meter between the positive and negative electrodes after the product is completed, i.e., between the top surface of the terminal 40 and the outer surface 20a of the closed part of the housing 20, may be about 4 mΩ (miliohm) or less. The AC resistance of the cylindrical battery 1 may be about 0.5 mΩ or more, preferably about 1.0 mΩ or more.

[0292] 31, a battery pack 3 according to an embodiment of the present invention includes a secondary battery assembly in which a plurality of cylindrical batteries 1 according to an embodiment of the present invention are electrically connected as described above, and a pack housing 2 that accommodates the secondary battery assembly. For convenience of illustration, components such as bus bars for electrical connection, a cooling unit, and power terminals are omitted from the drawings of the present invention. The electrical connection structure of a plurality of batteries 1 for manufacturing the battery pack 3 has been exemplarily described with reference to FIG.

[0293] 32, an automobile 5 according to an embodiment of the present invention may be, for example, an electric automobile, a hybrid automobile, or a plug-in hybrid automobile, and includes a battery pack 3 according to an embodiment of the present invention. The automobile 5 includes a four-wheeled automobile and a two-wheeled automobile. The automobile 5 operates by receiving power from the battery pack 3 according to an embodiment of the present invention.

[0294] Although the present invention has been described above with reference to limited embodiments and drawings, it goes without saying that the present invention is not limited thereto, and various modifications and variations can be made by those having ordinary skill in the art to which the present invention pertains within the scope of the technical spirit of the present invention and the scope of the claims.

Claims

1. An electrode assembly in which a first electrode, a second electrode and a separator interposed therebetween are wound around a winding shaft to define a core and an outer circumferential surface, the first electrode including a first non-coated portion that is not coated with an active material layer along a winding direction; a housing including an opening on one side thereof and configured to receive the electrode assembly through the opening; a first current collector including a peripheral portion disposed on an upper portion of the electrode assembly, a first non-coated portion coupling portion extending inward from the peripheral portion and coupling with the first non-coated portion, and a terminal coupling portion spaced apart from the first non-coated portion coupling portion; a terminal coupled to the terminal coupling portion; The terminal coupling portion is Located at the center of the inner space of the peripheral portion, the first non-coated portion joining portion and the terminal joining portion are positioned on an extension line aligned in a radial direction between the center portion and the peripheral portion of the first current collector; A battery, wherein the first uncoated portion coupling portion and the terminal coupling portion are not directly connected along a radial direction, but are spaced apart from each other and indirectly connected through the peripheral portion.

2. The peripheral portion is 2. The battery of claim 1, wherein the interior space is in the form of an open rim.

3. The first non-coated portion coupling portion and the terminal coupling portion are 3. The battery of claim 1 or 2, electrically connected by said periphery.

4. The first current collector is The battery according to claim 1 , further comprising a connection portion extending inwardly from the peripheral portion and connecting with the terminal coupling portion.

5. The connection portion is The battery according to claim 4 , wherein at least a portion of the first non-coated portion is formed to have a smaller cross-sectional area than the first non-coated portion joining portion.

6. The connection portion is The battery according to claim 5 , wherein at least a portion of the first non-coated portion joining portion is formed to be smaller in at least one of its width and thickness than the first non-coated portion joining portion.

7. The connection portion is The battery according to claim 4 , further comprising a tapered portion whose width narrows continuously or stepwise along a direction from the inner surface of the peripheral portion toward the terminal coupling portion.

8. The first non-coated portion joining portion is The battery of claim 4 provided in a plurality.

9. The first non-coating portion bonding portions include: The battery according to claim 8 , wherein the peripheral portion is regularly arranged along an extension direction of the peripheral portion.

10. The extension length of each of the first non-coating portion joining portions is 10. The battery of claim 8, wherein the batteries are substantially identical to one another.

11. The battery of claim 8 , wherein the cross-sectional area of ​​each of the first uncoated portion bonding portions is substantially the same.

12. The battery of claim 8 , wherein the width and thickness of each of the plurality of first uncoated portion joints are substantially the same.

13. The terminal coupling portion is The battery according to claim 8 , disposed so as to be surrounded by a plurality of the first uncoated portion joint portions.

14. The battery according to claim 8 , wherein the connection portion is located between a pair of adjacent first uncoated portion joining portions.

15. 15. The battery according to claim 14, wherein a distance from the connection portion to one of the pair of adjacent first uncoated portion joining portions along an extension direction of the peripheral portion is substantially the same as a distance to the remaining one of the pair of first uncoated portion joining portions.

16. The connection portion is The battery of claim 4 provided in a plurality.

17. The first non-coated portion joining portion is provided in a plurality of portions, Each of the plurality of connection portions includes The battery according to claim 16 , disposed between a pair of adjacent first uncoated portion joint portions.

18. The plurality of connection portions are The battery according to claim 16, wherein the peripheral portion is regularly arranged along an extension direction of the peripheral portion.

19. 18. The battery of claim 17, wherein a distance from each of the plurality of connection portions to one of the pair of adjacent first uncoated portion joining portions along an extension direction of the peripheral portion is substantially the same as a distance to the remaining one of the plurality of connection portions.

20. The connection portion is The battery of claim 4 , further comprising a current interrupting portion formed to reduce a cross-sectional area of ​​the connection portion.

21. The current interruption unit is The battery according to claim 20 , wherein the connecting portion is a region having a shape in which at least one of a width and a thickness is reduced compared to the remaining region of the connecting portion.

22. The current interruption unit is The battery of claim 20 , comprising at least one of a notch, a groove, and a through hole formed on at least one surface of the connection portion.

23. The battery according to claim 1 , wherein the terminal coupling portion is disposed at a position corresponding to a hole formed in a winding center portion of the electrode assembly.

24. The terminal coupling portion is The battery according to claim 23, which is configured to cover a hole formed in the winding center of the electrode assembly so that the hole is not exposed to an outside of the terminal coupling portion.

25. The diameter of the terminal connection portion is The battery according to claim 23 , wherein the diameter of the hole formed in the winding center of the electrode assembly is the same as or larger than the diameter of the hole formed in the winding center of the electrode assembly.

26. 26. The battery of claim 1, wherein the first uncoated portion extends toward a closed portion opposite the open portion of the housing.

27. The first non-coated portion joining portion is The battery according to claim 26, wherein an end of the first uncoated portion is bent along a direction parallel to the first current collector to be bonded to a bonding surface formed thereon.

28. 28. The battery of any one of claims 1 to 27, further comprising a cap configured to seal the opening of the housing.

29. The cap is 30. The battery of claim 28, which is not electrically connected to the electrode assembly and has no polarity.

30. The housing includes: a beading portion formed adjacent to the opening and pressed toward the inside of the housing; 30. The battery of claim 28, further comprising: a crimping portion formed below the beading portion and extending and bent to surround a periphery of the cap.

31. 31. The battery of claim 30, further comprising a sealing gasket disposed within the crimping portion and interposed between the housing and the cap.

32. The terminal is 32. The battery of claim 1 , wherein the battery extends through a closed portion opposite the open portion of the housing.

33. The terminal is 33. The battery of claim 32, wherein the closure passes through a center thereof.

34. The terminal is 33. The battery of claim 32, insulated from the housing.

35. 35. The battery of claim 34, wherein an insulating gasket is interposed between the housing and the terminals.

36. 36. The battery of claim 1, further comprising an insulator interposed between a closed portion opposite the open portion of the housing and the first current collector.

37. The insulator is 37. The battery of claim 36, having a thickness corresponding to a distance between an inner surface of the housing closure and the first current collector.

38. The terminal is 38. The battery of claim 37, wherein the insulator is coupled to the terminal coupling portion of the first current collector through a hole formed in the insulator.

39. The lower end of the terminal that is coupled to the terminal coupling portion is 40. The battery of claim 38, wherein the insulator is flush with or above a lower surface of the insulator.

40. The insulator is 37. The battery of claim 36, interposed between the first uncoated portion and a sidewall of the housing.

41. 37. The battery of claim 36, wherein an upper surface of the insulator contacts an inner surface of a closed portion opposite the open portion of the housing, and a lower surface of the insulator contacts an upper surface of the first current collector.

42. 42. The battery of claim 1, wherein the second electrode further includes a second uncoated portion that is not coated with an active material layer along the winding direction, the second uncoated portion extending in an opposite direction to the first uncoated portion and exposed to an outside of the separator.

43. The housing comprises:

43. The battery of claim 42 in electrical communication with the second uncoated portion.

44. 43. The battery of claim 42, further comprising a second current collector coupled to the second uncoated portion and the housing, respectively, electrically connecting the second uncoated portion and the housing.

45. The second current collector is 45. The battery of claim 44, further comprising a second current collector hole formed in an area corresponding to the hole formed in the winding center of the electrode assembly.

46. The second current collector hole is 46. ​​The battery of claim 45, having a diameter equal to or larger than a hole formed in the winding center of the electrode assembly so as not to obstruct the hole formed in the winding center of the electrode assembly.

47. The second current collector is a second non-coated portion coupling portion coupled to the second non-coated portion; 45. The battery of claim 44, further comprising a housing mating portion mating with the housing.

48. 48. The battery of claim 47, wherein the second uncoated portion and the second uncoated portion joining portion are joined to one another by welding.

49. 48. The battery of claim 47, wherein the housing and the housing mating portion are joined to one another by welding.

50. The housing includes:

48. The battery of claim 47, further comprising a beading portion formed adjacent the opening and having an inwardly pressed-fit configuration.

51. The housing coupling portion is 51. The battery of claim 50 electrically coupled to the underside of the beading.

52. 48. The battery of claim 47, wherein a distance from a center of the first current collector to an outermost portion of the peripheral portion is greater than a distance from a center of the second current collector to an outermost portion of the second uncoated portion joint portion.

53. 53. The battery of claim 52, wherein the distance from the center of the second current collector to the outermost portion of the second uncoated portion joint is equal to or shorter than half the inner diameter of the housing in the region where the beading portion is formed.

54. At least a portion of the first non-coated portion includes a plurality of segment pieces separated along a winding direction of the electrode assembly, The battery of claim 1 , wherein the plurality of segments are bent along a radial direction of the electrode assembly.

55. 55. The battery of claim 54, wherein the bent segments are overlapped in multiples.

56. The electrode assembly includes:

56. The battery of claim 55, further comprising a weld target area, the area being an area where a number of overlaps of the plurality of segments of the first uncoated portion remains constant along a radial direction of the electrode assembly.

57. At least a portion of the second non-coated portion includes a plurality of segment pieces separated along a winding direction of the electrode assembly, 48. The battery of claim 47, wherein the plurality of segment pieces are bent along a radial direction of the electrode assembly.

58. The bent segments are 58. The battery of claim 57, which is stacked in multiples.

59. The electrode assembly includes:

60. The battery of claim 58, further comprising a weld target area, the weld target area being an area where a number of overlaps of the plurality of segments of the second uncoated portion remains constant along a radial direction of the electrode assembly.

60. The first current collector is 5. The battery of claim 4, further comprising a bridge portion connecting at least one of adjacent first uncoated portion joining portions, adjacent first uncoated portion joining portions and the connection portions, and adjacent connection portions.

61. The bridge portion is 61. The battery of claim 60, located inward from the periphery.

62. The first current collector is 62. The battery of claim 61, comprising an impregnation hole formed between the peripheral portion and the bridge portion.

63. The impregnation hole is 63. The battery of claim 62, having a slit shape extending along the extension direction of the peripheral edge.

64. 64. The battery of claim 1, wherein a ratio of an area of ​​the first current collector that is not in contact with the upper surface of the electrode assembly to an area of ​​a circle having an outer diameter of the electrode assembly as a diameter is 20% or more and less than 100%.

65. 21. The battery of claim 20, wherein the number of connections is one or two.

66. The battery according to claim 20, wherein a cross-sectional area of ​​the connection portion in a region where the current interruption portion is formed is 0.6 to 0.9 relative to a cross-sectional area of ​​the connection portion in a region adjacent to the region where the current interruption portion is formed.

67. The cross-sectional area of ​​the connection portion is The battery of claim 20, wherein the thickness of the first non-coated portion is 0.2 to 1.0 relative to a cross-sectional area of ​​the joint portion.

68. The outer diameter of the first current collector is 68. The battery of any one of claims 1 to 67, wherein the inner diameter of the housing is in the range of 33% to 98.5%.

69. The weld target area is 57. The battery of claim 56, wherein the overlap of the bent segments is maintained at a maximum in the region.

70. The first current collector is The battery of claim 56, wherein the first uncoated portion is welded to the weld target area such that the first uncoated portion overlaps the weld target area by at least 50% or more.

71. The weld target area is 60. The battery of claim 59, wherein the bent segments are in an area where a maximum number of overlaps are maintained.

72. The second current collector is The battery of claim 71, wherein the second uncoated portion is welded to the weld target area such that the second uncoated portion overlaps the weld target area by at least 50% or more.

73. 73. The battery of any one of claims 1 to 72, wherein the resistance measured between the positive and negative electrodes is 4 mΩ or less.

74. The current interruption unit is The battery according to claim 20, wherein the electrode assembly is formed at a location 40% to 90% away from the core in a radial direction based on a radius of the electrode assembly.

75. At least a portion of the first non-coated portion includes a plurality of segment pieces divided along a winding direction of the electrode assembly, and the plurality of segment pieces are bent along a radial direction of the electrode assembly and overlapped in multiple layers, 21. The battery of claim 20, wherein the current interrupting portion is provided in a region corresponding to a welding target region, which is a region where an overlapping number of the plurality of segment pieces of the first non-coated portion is maintained constant along a radial direction of the electrode assembly.

76. 21. The battery of claim 20, wherein the current interrupt portion has tape attached thereto.

77. 77. The battery of claim 76, wherein the tape is a polyimide material.

78. The tape is 77. The battery of claim 76, wherein the current interrupting portion is configured to surround the connection portion in a region where the current interrupting portion is formed.

79. The outer diameter of the first current collector is T, The outer diameter of the electrode assembly is defined as JR. If the height of the segment located at the outermost radial portion of the electrode assembly is F, JR-2×F≦T<JR 55. The battery of claim 54,

80. 80. The battery of claim 1, wherein a weld pattern formed by a weld bead on one surface of the terminal connection portion of the first current collector is formed in a shape that surrounds a center of a bottom surface of the terminal.

81. The weld pattern is 81. The battery of claim 80, which is continuously or discontinuously formed.

82. 82. The battery of claim 1, wherein a tensile strength of a weld formed between the terminal connection portion of the first current collector and the bottom surface of the terminal is 2 kgf (19.6 N) or more.

83. 83. The battery of claim 82, wherein a converted diameter of a weld pattern formed by a weld bead formed on one surface of the terminal connection portion of the first current collector is 2 mm or more.

84. The battery of claim 83, wherein the diameter of the flat portion formed on the bottom surface of the terminal is 3 mm to 14 mm.

85. The battery of claim 82, wherein a ratio of an area of ​​a weld pattern formed by a weld bead formed on a surface of the terminal connecting portion of the first current collector to an area of ​​a flat portion formed on a bottom surface of the terminal is 2.04% to 44.4%.

86. The second current collector hole is 46. ​​The battery of claim 45, wherein the electrode assembly has a diameter smaller than a hole formed in the winding center.

87. When the diameter of the hole formed in the winding center portion is R3, 87. The battery of claim 86, wherein the diameter of the second current collector hole is greater than or equal to 0.5×R3 and less than R3.

88. When the diameter of the hole formed in the winding center portion is R3, 87. The battery of claim 86, wherein the diameter of the second current collector hole is greater than or equal to 0.7×R3 and less than R3.

89. 89. The battery of any one of claims 1 to 88, wherein the form factor ratio of the diameter divided by the height of the battery is greater than 0.

4.

90. 48. The battery of claim 47, wherein a length of a welded portion connecting the first uncoated portion bonding portion and the first uncoated portion along a radial direction of the electrode assembly is longer than a length of a welded portion connecting the second uncoated portion bonding portion and the second uncoated portion along a radial direction of the electrode assembly.

91. 48. The battery of claim 47, wherein a distance to a start point of a weld that connects the first uncoated portion joint portion and the first uncoated portion and a distance to a start point of a weld that connects the second uncoated portion joint portion and the second uncoated portion, based on a core of the electrode assembly, are substantially the same.

92. The current interruption unit is The battery according to claim 20 , wherein a plurality of said connection portions are provided along a longitudinal direction of said connection portion.

93. 93. The battery of claim 1, wherein no weld is formed at the connection between the peripheral portion and the terminal.

94. 94. The battery of any one of claims 1 to 93, wherein at least a portion of a bottom surface of the terminal is provided with a flat portion.

95. The first non-coating portion bonding portions include: The battery according to claim 1 , wherein the terminal coupling portions are arranged in a radial, cross or combination thereof with respect to a center of the terminal coupling portions.

96. The battery according to claim 4 , wherein an extension direction of the first non-coated portion coupling portion and an extension direction of the connection portion are not parallel to each other.

97. The first non-coated portion coupling portion is arranged in a plurality of portions along a circumferential direction of the peripheral portion, The battery according to claim 1 , wherein the terminal connecting portion connects to a portion of the peripheral edge portion provided between a pair of the first uncoated portion connecting portions adjacent to each other in a circumferential direction of the peripheral edge.

98. The first non-coated portion coupling portion is provided in a plurality of pieces, 98. The battery of any one of claims 1 to 97, wherein the first non-coated portion connection portions are spaced apart from one another along a radial direction from the terminal connection portion and are radially arranged around the terminal connection portion.

99. The connection portion is 5. The battery of claim 4, wherein said terminal mating portions extend radially from a center thereof to connect to said peripheral edge.

100. 100. A battery according to any one of claims 1 to 99; and a pack housing that houses a plurality of the batteries.

101. A plurality of the batteries are arranged in a predetermined number of rows; 101. The battery pack of claim 100, wherein the terminals of each of the batteries and an outer surface of the housing closure opposite the housing open portion are arranged facing upward.

102. The battery pack includes a plurality of bus bars connecting the plurality of batteries in series and in parallel, the bus bars are disposed on top of the batteries; Each of the plurality of bus bars comprises: a body portion extending between the terminals of adjacent batteries; a plurality of first bus bar terminals extending in one direction of the body portion and electrically coupled to the terminals of the battery positioned in the one direction; and a plurality of second bus bar terminals extending in the other direction of the body and electrically coupling to an outer surface of the housing closure of the battery located in the other direction.

103. 103. A motor vehicle comprising a battery pack according to any one of claims 100 to 102.

104. a current collector electrically connecting the first non-coated portion of the electrode assembly to the first electrode terminal, a peripheral portion provided on the edge portion and extending in a circumferential direction; and a first non-coating portion connecting portion extending inward from the peripheral portion and connecting to the first non-coating portion; a terminal coupling portion spaced apart from the first non-coating portion coupling portion and coupled to the first electrode terminal, The terminal coupling portion is Located at the center of the inner space of the peripheral portion, the first non-coated portion joining portion and the terminal joining portion are positioned on an extension line aligned in a radial direction between the center portion and the peripheral portion of the current collector; A current collector, wherein the first uncoated portion coupling portion and the terminal coupling portion are not directly connected along a radial direction but are spaced apart from each other and are indirectly connected through the peripheral portion.

105. The peripheral portion is 105. The current collector of claim 104, wherein the interior space is in the form of an open rim.

106. The first non-coated portion coupling portion and the terminal coupling portion are 106. The current collector of claim 104 or 105, electrically connected by said periphery.

107. 107. The current collector of any one of claims 104 to 106, further comprising a connection portion extending inwardly from the peripheral edge portion and connected to the terminal coupling portion.

108. The connection portion is 108. The current collector of claim 107, wherein at least a portion of the current collector is formed to have a smaller cross-sectional area than the first uncoated portion bonding portion.

109. The connection portion is The current collector according to claim 108, wherein at least a portion of the current collector is formed to be smaller in at least one of its width and thickness than the first uncoated portion bonding portion.

110. The connection portion is 108. The current collector according to claim 107, comprising a tapered portion whose width narrows continuously or stepwise along a direction from the inner surface of the peripheral edge portion toward the terminal coupling portion.

111. The first non-coated portion joining portion is 108. The current collector of claim 107, wherein a plurality is provided.

112. The first non-coating portion bonding portions include: The current collector according to claim 111, wherein the current collector is regularly arranged along the extension direction of the peripheral edge.

113. The extension length of each of the first non-coating portion joining portions is 112. The current collectors of claim 111, which are substantially identical to one another.

114. 112. The current collector of claim 111, wherein a cross-sectional area of ​​each of the plurality of first uncoated portion bonds is substantially the same.

115. 112. The current collector of claim 111, wherein the width and thickness of each of the plurality of first uncoated portion bonds are substantially the same.

116. The terminal coupling portion is 112. The current collector of claim 111, wherein the current collector is disposed so as to be surrounded by a plurality of the first uncoated portion bonding portions.

117. The connection portion is located between a pair of adjacent first non-coated portion joining portions, 112. The current collector of claim 111, wherein a distance from the connection portion to one of the pair of first non-coated portion joining portions along an extension direction of the peripheral portion is substantially the same as a distance to the remaining one.

118. The connection portion is 112. The current collector of claim 111 , wherein a plurality is provided.

119. Each of the plurality of connection portions includes The current collector of claim 118, disposed between a pair of adjacent first uncoated portion joint portions.

120. The plurality of connection portions include The current collector according to claim 118, wherein the current collector is regularly arranged along the extension direction of the peripheral edge.

121. The current collector of claim 119, wherein the distance from each of the plurality of connection portions to one of the pair of adjacent first non-coated portion joining portions along the extension direction of the peripheral portion is substantially the same as the distance to the remaining one.

122. The connection portion is 108. The current collector of claim 107, comprising a current interrupting portion formed to reduce a cross-sectional area of ​​the connection portion.

123. The current interruption unit is The current collector of claim 122, wherein the region has a shape in which at least one of the width and the thickness is reduced compared to the remaining region of the connection portion.

124. The current interruption unit is The current collector of claim 122, comprising at least one of a notch, a groove, and a through hole formed on at least one surface of the connection portion.

125. 108. The current collector of claim 107, further comprising a bridge portion connecting at least one of adjacent first uncoated portion joining portions, adjacent first uncoated portion joining portions and connection portions, and adjacent connection portions.

126. The bridge portion is The current collector of claim 125, located inside the periphery.

127. 127. The current collector of claim 126, comprising an impregnation hole formed between the peripheral portion and the bridge portion.

128. The impregnation hole is The current collector according to claim 127, which is in the form of a slit extending along the extension direction of the peripheral edge portion.

129. The current collector of claim 122, wherein the number of the connections is one or two.

130. The cross-sectional area of ​​the connection portion in the region where the current interruption portion is formed is 0.6 to 0.9 relative to the cross-sectional area of ​​the connection portion in a region adjacent to the region where the current interruption portion is formed.

131. The cross-sectional area of ​​the connection portion is The current collector of claim 122, wherein the ratio of the cross-sectional area of ​​the first uncoated portion bonding portion to the cross-sectional area of ​​the first uncoated portion bonding portion is 0.2 to 1.

0.

132. 123. The current collector of claim 122, wherein the current interrupting portion has a tape attached thereto.

133. The tape is 133. The current collector of claim 132, which is made of a polyimide material.

134. The tape is 133. The current collector of claim 132, configured to surround the connection portion in an area where the current interrupting portion is formed.

135. The first non-coating portion bonding portions include: The current collector according to claim 104, wherein the current collectors are arranged in a radial, cross or combination thereof with respect to the center of the terminal connection portion.

136. The current collector according to claim 107 , wherein an extension direction of the first uncoated portion joining portion and an extension direction of the connection portion are not parallel to each other.

137. The first non-coated portion coupling portion is arranged in a plurality of portions along a circumferential direction of the peripheral portion, 105. The current collector of claim 104, wherein the terminal connection portion connects to a portion of the peripheral edge portion provided between a pair of the first uncoated portion connection portions adjacent to each other in a circumferential direction of the peripheral edge portion.

138. The first non-coated portion coupling portion is provided in a plurality of pieces, 105. The current collector of claim 104, wherein the first non-coated portion joining portions are spaced apart from one another along a radial direction from the terminal joining portion and are radially arranged around the terminal joining portion.

139. The connection portion is 108. The current collector of claim 107, extending radially from a center of the terminal coupling portion and connecting to the periphery.

Images