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

Abstract

According to one embodiment of the present invention, there is provided a battery comprising: an electrode assembly in which a core and an outer circumferential surface are defined by winding a first electrode, a second electrode, and a separator interposed therebetween around a winding shaft, the first electrode including an active material portion coated with an active material layer along the winding direction and a first uncoated portion not coated with the active material layer, at least a portion of the first uncoated portion being used as an electrode tab; a battery housing that receives the electrode assembly through an opening formed on one side; a current collector including a tab connecting portion that connects with the first uncoated portion and a housing connecting portion that extends from the tab connecting portion and is electrically connected to an inner surface of the battery housing; and a cap that covers the opening.

Description

[Technical Field]

[0001] The present invention relates to a battery and a current collector applied thereto, as well as a battery pack and an automobile including the battery.

[0002] This application is a 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 specifications and drawings of those applications are incorporated herein in their entirety. [Background technology]

[0003] Conventional batteries typically have a structure in which tabs connecting a jelly-roll type electrode assembly to an external terminal are welded to the foil of the electrode assembly, but this type of battery has a limited current path and the resistance of the electrode assembly itself is very high.

[0004] As a result, attempts have been made to reduce resistance by increasing the number of tabs connecting the electrode assembly and external terminals, but simply increasing the number of tabs has limitations in reducing resistance to the desired level and ensuring a sufficient current path.

[0005] Therefore, in order to reduce the resistance of the electrode assembly itself, it is necessary to develop a new electrode assembly structure and a current collector structure suitable for such an electrode assembly structure. In particular, the application of such new electrode assemblies and current collectors is particularly necessary in devices requiring high-output / high-capacity battery packs, such as electric vehicles.

[0006] In addition, there is a need to develop a battery having a structure that maintains an improved bonding strength between the current collector and the battery housing, and a current collector structure applicable to such a battery.

[0007] In addition, there is a growing need to develop batteries that improve the energy density by minimizing the dead space inside the battery housing when the current collector and battery housing are combined.

[0008] Recently, as batteries are applied to electric vehicles, the form factor of the battery is increasing, i.e., the diameter and height of the battery are larger than those of conventional batteries with form factors such as 1865 and 2170. The increase in form factor brings about an increase in energy density, increased safety against thermal runaway, and improved cooling efficiency.

[0009] The energy density of a battery can be further increased by minimizing wasted space inside the battery housing as the form factor increases. As a result, the current collector must also be designed with a low resistance structure throughout the battery to minimize heat generation during fast charging while increasing battery capacity. Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention has been made in view of the above problems, and an object of the present invention is to provide a current collector having a structure suitable for an electrode assembly with a low resistance structure, and a battery including the same.

[0011] Another object of the present invention is to provide a current collector having a structure capable of improving the bonding strength between the current collector and the battery housing, and a battery including the same.

[0012] Another object of the present invention is to provide a current collector having a structure capable of improving the energy density of a battery, and a battery including the same.

[0013] Another object of the present invention is to provide a current collector having a structure that can improve the convenience of a welding process for electrically connecting a battery housing and a current collector when manufacturing a battery, thereby improving productivity, and a battery including the same.

[0014] However, the technical problems that the present invention aims to solve are not limited to the above-mentioned problems, and other problems not mentioned will be clearly understood by those skilled in the art from the following description of the invention. [Means for solving the problem]

[0015] To solve the above problems, a battery according to one embodiment of the present invention includes 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 an active material portion coated with an active material layer along the winding direction and a first uncoated portion not coated with the active material layer, and at least a portion of the first uncoated portion is used as an electrode tab by itself; a battery housing that receives the electrode assembly through an opening formed on one side thereof; a current collector including a tab connecting portion that connects with the first uncoated portion and a housing connecting portion that extends from the tab connecting portion and electrically connects with an inner surface of the battery housing; and a cap for covering the opening.

[0016] Preferably, the battery housing may include a beading portion formed at an end adjacent to the opening and pressed inward.

[0017] Preferably, the battery housing may include a crimping portion formed on a side facing the opening relative to the beading portion, and extending and bending toward the opening.

[0018] In particular, the housing coupling portion can be pressed and fixed by the crimping portion.

[0019] In one aspect of the present invention, the housing coupling portion may include a contact portion coupled to the beading portion of the battery housing, and a coupling portion connecting the tab coupling portion and the contact portion.

[0020] Preferably, the connecting portion may have a structure that bulges upward based on an imaginary line that connects one end of the contact portion and one end of the tab coupling portion.

[0021] In another aspect of the present invention, the connecting portion may have a structure that protrudes upward from the beading portion after undergoing a sizing process.

[0022] Preferably, the connecting portion may include at least one bent portion.

[0023] Preferably, the bent portion may be located above an imaginary plane that passes through the center of an imaginary line connecting one end of the contact portion and one end of the tab coupling portion and is parallel to the bottom surface of the battery housing.

[0024] In another aspect of the invention, the at least one bent portion may be bent at an obtuse angle so that they do not overlap each other when viewed along the longitudinal axis of the battery housing.

[0025] In yet another aspect of the present invention, the boundary between the contact portion and the connecting portion may be bent at an obtuse angle.

[0026] In still another aspect of the present invention, the slope of the connecting portion may decrease stepwise or gradually as the connecting portion approaches the beading portion.

[0027] In still another aspect of the present invention, the angle formed between the tab coupling portion and the connecting portion may be 0 to 90 degrees.

[0028] In yet another aspect of the invention, the connector may support the cap.

[0029] In yet another aspect of the present invention, the tab coupling portion and the contact portion may be located at the same height.

[0030] In yet another aspect of the invention, the contact portion may include a flat surface that mates with an upper surface of the beading portion that faces the open portion.

[0031] In yet another aspect of the present invention, the beading portion may include an upper surface of the beading portion located above the innermost point recessed by the press-fitting, and a lower surface of the beading portion located below the innermost point recessed by the press-fitting.

[0032] Preferably, at least one of the tab coupling portions of the current collector may be located below a lower surface of the beading portion.

[0033] In still another aspect of the present invention, at least one of an upper surface of the beading portion and a lower surface of the beading portion may be inclined at a predetermined angle with respect to a lower surface of the battery housing.

[0034] Here, the contact portion may be provided on an inclined upper surface of the beading portion.

[0035] In still another aspect of the present invention, at least one of an upper surface of the beading portion and a lower surface of the beading portion may be parallel to a lower surface of the battery housing in at least a portion thereof.

[0036] In yet another aspect of the present invention, the upper surface and the lower surface of the beading portion may be asymmetric with respect to an imaginary reference plane that passes through the innermost point of the beading portion parallel to the bottom surface of the battery housing.

[0037] Preferably, the contact portion may be provided on a flat upper surface of the beading portion.

[0038] In still another aspect of the present invention, the press-fit depth of the beading portion is defined as PD, and the minimum value of the radius of curvature of the beading portion is defined as R 1,min The minimum weld bead width is W bead,min The minimum radius of curvature in the boundary region between the beading portion and the inner surface of the battery housing is R 2,min Then, the following relation can be satisfied: PD≧R 1,min +R 2,min +W bead,min

[0039] Preferably, the press-fit depth of the beading portion may be 0.2 to 10 mm.

[0040] In still another aspect of the present invention, the press-fit depth of the beading portion is defined as PD, and the maximum value of the press-fit depth is defined as PD max The overlap length, which is the shortest distance from the end of the contact portion to the vertical line passing through the innermost point of the beading portion, is defined as OV, and the minimum value of the radius of curvature of the beading portion is defined as R 1,min The minimum weld bead width is W bead,min The minimum radius of curvature in the boundary region between the beading portion and the inner surface of the battery housing is R 2,min Then, the following relation can be satisfied: (R 1,min +W bead,min ) / PD max ≦OV / PD≦(PD max -R 2,min ) / PD max

[0041] In yet another aspect of the present invention, the contact portion may be joined to the beading portion by welding.

[0042] Preferably, the contact portion may be joined to the flat upper surface of the beading portion by welding.

[0043] More preferably, the welding area between the contact portion and the beading portion may be formed narrower than the flat upper surface of the beading portion.

[0044] In still another aspect of the present invention, the press-fit depth of the beading portion is defined as PD, and the maximum value of the press-fit depth is defined as PD max The distance from the innermost point of the beading portion to the center point of the outermost weld bead in the radial direction is W, the overlap length, which is the shortest distance from the end of the contact portion to the vertical line passing through the innermost point of the beading portion, is OV, and the minimum value of OV is OV. min The maximum value of OV is OV max The minimum weld bead width is W bead,min Then, the following relation can be satisfied: (OV min -0.5×W bead,min ) / PD max ≦W / PD≦(OV max -0.5×W bead,min ) / PD max

[0045] In still another aspect of the present invention, there may be at least one weld bead formed between the beading portion and the contact portion.

[0046] Preferably, the weld bead formed between the beating portion and the contact portion may form a linear weld pattern extending along the circumferential direction.

[0047] In yet another aspect of the present invention, there may be at least one weld bead formed between the beading portion and the contact portion, and the at least one weld bead may form an arc-shaped weld pattern extending along the circumferential direction.

[0048] In yet another aspect of the present invention, the weld bead formed between the beading portion and the contact portion forms a weld pattern, and the weld pattern may be a line formed by connecting spot welds.

[0049] In yet another aspect of the present invention, a plurality of weld beads may be formed between the beading portion and the contact portion within the same contact portion.

[0050] In yet another aspect of the present invention, a width of a weld bead formed between the beading portion and the contact portion may be 0.1 mm or more.

[0051] In yet another aspect of the present invention, the first uncoated portion and the tab connecting portion may be connected by welding along a radial direction of the electrode assembly.

[0052] In yet another aspect of the present invention, the tab connection portion may be connected to the first uncoated portion by welding while being parallel to a lower surface of the battery housing.

[0053] In yet another aspect of the present invention, a plurality of weld beads formed between the first uncoated portion and the tab connecting portion may form a linear weld pattern extending along a radial direction of the electrode assembly.

[0054] In yet another aspect of the present invention, the weld bead formed between the first uncoated portion and the tab connecting portion forms a weld pattern, and the weld pattern may be a line formed by connecting spot welds.

[0055] In yet another aspect of the present invention, a width of a weld bead formed between the first uncoated portion and the tab connecting portion may be 0.1 mm or more.

[0056] In still another aspect of the present invention, at least a portion of the first uncoated portion may include a plurality of segmented pieces separated along the winding direction of the electrode assembly.

[0057] Preferably, the plurality of segment pieces may be bent along a radial direction of the electrode assembly to form a curved surface.

[0058] Preferably, the plurality of segment pieces may be overlapped in multiple layers along the radial direction of the electrode assembly to form the curved surface.

[0059] More preferably, the bending surface may include a lamination number increasing section in which the number of overlaps of the segment pieces gradually increases up to a maximum value as it progresses from the outer periphery side of the electrode assembly toward the core side, and a lamination number uniform section from the radius point where the number of overlaps reaches a maximum value to the radius point where the innermost segment piece is present.

[0060] Preferably, the tab connection portion may be connected to the bending surface so as to overlap the uniform stacking number section.

[0061] More preferably, the number of overlaps in the uniform stacking section may be 10 or more.

[0062] More preferably, the tab connection portion is welded to the bent surface, and the welded area of ​​the tab connection portion overlaps the uniform lamination number section by at least 50% along the radial direction of the electrode assembly.

[0063] In yet another aspect of the present invention, the current collector may have a circular current collector hole in the center of the current collector.

[0064] Preferably, the diameter of the current collector hole may be equal to or larger than the diameter of the winding center hole provided in the core of the electrode assembly.

[0065] In yet another aspect of the present invention, the battery may include a sealing gasket disposed between the battery housing and the cap.

[0066] Preferably, the contact portion may be interposed between the sealing gasket and the beading portion.

[0067] More preferably, the thickness of the sealing gasket may vary along the circumferential direction.

[0068] Preferably, the thickness of the sealing gasket may alternately increase and decrease along the circumferential direction.

[0069] In one aspect of the present invention, the sealing gasket may have the same compressibility in an area that contacts the contact portion and an area that does not contact the contact portion.

[0070] In another aspect of the invention, the sealing gasket may have a smaller compressibility in areas not in contact with the contact portion than in areas in contact with the contact portion.

[0071] Preferably, the sealing gasket may have a greater thickness in areas not in contact with the contact portions than in areas in contact with the contact portions.

[0072] In yet another aspect of the present invention, the current collector may have a leg structure extending in a radial direction with the tab connecting portion and the housing connecting portion connected to each other.

[0073] Preferably, a plurality of the leg structures may be provided.

[0074] Preferably, the leg structures may be arranged in a radial pattern, a cross pattern, or a combination thereof with respect to the center of the current collector.

[0075] In still another aspect of the present invention, a plurality of the housing coupling portions may be provided, and the plurality of housing coupling portions may be integrally formed by being connected to each other.

[0076] In still another aspect of the present invention, the connecting portion may include at least one bent portion where the extension direction is changed at least once.

[0077] Preferably, the outermost protruding point of the bent portion may be spaced apart from the innermost point of the beading portion by a predetermined distance.

[0078] In yet another aspect of the present invention, the angle formed between the contact portion and the connecting portion may be an acute angle due to the bent portion.

[0079] In yet another aspect of the present invention, the connecting portion may be elastically biased upward by the bent portion.

[0080] In yet another aspect of the present invention, the circumferential length of the contact portion may be the same as the circumferential length of the tab coupling portion.

[0081] In yet another aspect of the present invention, the circumferential length of the contact portion may be the same as the circumferential length of the connecting portion.

[0082] In yet another aspect of the present invention, a circumferential length of the contact portion may be relatively longer than a circumferential length of the tab coupling portion.

[0083] In yet another aspect of the present invention, a circumferential length of the contact portion may be relatively longer than a circumferential length of the connecting portion.

[0084] In yet another aspect of the present invention, the contact portion may be arc-shaped and extend circumferentially along the beading portion of the battery housing.

[0085] In yet another aspect of the present invention, the contact portion may have an arc shape extending in opposite directions along a circumferential direction from an intersection point of the connecting portion and the contact portion.

[0086] In yet another aspect of the invention, the sum of the lengths of the contact portions extending in the circumferential direction may correspond to the length of the inner circumference of the battery housing.

[0087] In yet another aspect of the present invention, the connecting portion may be arc-shaped and extend in a circumferential direction along the contact portion.

[0088] In yet another aspect of the present invention, a boundary region between the tab connection portion and the housing connection portion may be bent so that an end of the housing connection portion faces the beading portion.

[0089] In yet another aspect of the present invention, the connecting portion between the contact portion and the connecting portion may be bent.

[0090] In yet another aspect of the present invention, a connecting portion between the contact portion and the connecting portion may have a complementary shape corresponding to an inner surface of the beading portion.

[0091] In still another aspect of the present invention, a connecting portion between the contact portion and the connecting portion may have a shape corresponding to an inner surface of the beading portion and may be coupled to the beading portion without any gap.

[0092] In still another aspect of the present invention, a boundary region between the tab coupling portion and the housing coupling portion may be located inside an innermost point of a beading portion formed on the battery housing.

[0093] Desirably, the tab bond may not be overlapped by the beading when viewed along the longitudinal axis of the battery housing.

[0094] In yet another aspect of the present invention, the battery may include a second uncoated portion at an end of a long side of the second electrode that is not coated with an active material layer and is exposed to the outside of the separator, and at least a portion of the second uncoated portion may be used as an electrode tab, and may include a terminal provided on the opposite side of the opening and electrically connected to the second uncoated portion.

[0095] Preferably, the battery may further include a second current collector formed between the second uncoated portion and the terminal, the second current collector including a tab coupling portion coupled to the second uncoated portion and a terminal coupling portion coupled to the terminal.

[0096] Preferably, the terminal coupling portion covers a winding center hole of the electrode assembly.

[0097] Preferably, the longest radius from the center of the terminal coupling portion to the end of the tab coupling portion of the second current collector may be greater than the longest radius from the center of the current collector to the end of the tab coupling portion.

[0098] In yet another aspect of the present invention, the tab bonded portion of the second current collector may be bonded to a bent end of the second uncoated portion.

[0099] Preferably, a welding area is further formed to connect the tab connection portion of the second current collector and the bent end portion of the second uncoated portion, and the distance from the center of the terminal connection portion of the second current collector to the welding area may be the same as or have a distance deviation of 5% or less than the distance from the center of the current collector to the welding area of ​​the tab connection portion.

[0100] Preferably, the welded area of ​​the second current collector may have a length greater than the welded area of ​​the tab bond of the current collector.

[0101] In yet another aspect of the present invention, the tab connection portion may be formed with one or more holes for injecting an electrolyte.

[0102] In yet another aspect of the invention, the battery may have a form factor ratio of diameter divided by height greater than 0.4.

[0103] In yet another aspect of the present invention, the resistance measured between the positive and negative electrodes may be 4 mΩ or less.

[0104] A battery pack according to an embodiment of the present invention includes a plurality of batteries according to an embodiment of the present invention as described above.

[0105] Preferably, the plurality of batteries are arranged in a predetermined number of rows, and the terminals of each battery and the outer surface of the bottom of the battery housing can be arranged to face upward.

[0106] In one aspect of the present invention, the battery pack may include a plurality of bus bars connecting the plurality of batteries in series and in parallel, each bus bar being disposed between terminals of adjacent batteries, and each bus bar may include a body extending between the adjacent terminals, a plurality of first bus bar terminals extending to one side of the body and electrically coupled to electrode terminals of the batteries located on that side, and a plurality of second bus bar terminals extending to the other side of the body and electrically coupled to an outer surface of a bottom of the battery housing of the batteries located on the other side.

[0107] 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.

[0108] The current collector according to an embodiment of the present invention includes at least one tab coupling portion coupled to the first non-coated portion of the electrode assembly;

[0109] and at least one housing connection portion extending from the tab connection portion and electrically connecting to a beading portion of the battery housing.

[0110] Meanwhile, a battery according to another embodiment of the present invention provides an electrode assembly having a structure in which sheet-like first and second electrodes and a separator interposed therebetween are wound in one direction, the first electrode including a first uncoated portion at an end of a long side thereof that is not coated with an active material layer and is exposed to the outside of the separator, at least a portion of the first uncoated portion being used as an electrode tab by itself; a battery housing that receives the electrode assembly through an opening formed on one side; a current collector electrically connected to the first uncoated portion and an inner surface of the battery housing; and a sealing gasket interposed between the opening of the battery housing and the current collector, wherein a portion of the current collector that contacts the inner surface of the battery housing is interposed between the inner surface of the battery housing and the sealing gasket.

[0111] Preferably, the battery housing may include a beading portion formed at an end adjacent to the opening and pressed inward.

[0112] In another aspect of the present invention, an extension direction of a weld pattern formed between the first uncoated portion and the tab coupling portion and an extension direction of a weld pattern formed between the beading portion and the contact portion may be perpendicular to each other.

[0113] In yet another aspect of the invention, the innermost point of the beading portion may be located radially more inward than the terminal point of the crimping portion.

[0114] In yet another aspect of the present invention, the sealing gasket may surround the cap, and the radial length of the portion of the sealing gasket that covers the lower surface of the cap may be smaller than the radial length of the portion of the sealing gasket that covers the upper surface of the cap.

[0115] In yet another aspect of the present invention, when the total radial length of the tab coupling portion is T, the outer diameter of the electrode assembly is JR, and the height of the segment piece arranged at the outermost periphery of the electrode assembly is F, the following relationship may be satisfied: JR-2×F≦T <JR

[0116] In yet another aspect of the present invention, when the minimum distance from the innermost point of the beading portion to the center point of the weld bead located on the outermost side in the radial direction is defined as W1, and the distance from the innermost point of the beading portion to the center point of the weld bead located on the outermost side in the radial direction when the overlap length is OV is defined as W, the following relationship can be satisfied. W1=R1+0.5×W bead,min W=OV-0.5×W bead,min

[0117] In yet another aspect of the present invention, the beading portion may have a flat section parallel to the bottom surface of the battery housing in at least a portion thereof, and the length of the flat section of the beading portion that contacts the current collector may be OV-R1.

[0118] Preferably, when the overlap length is OV, the radial width of the weld pattern formed between the beading portion and the contact portion is W bead,min It can be greater than or equal to OV-R1.

[0119] In still another aspect of the present invention, the ratio of the width length in the radial direction of the welding pattern to the length of the flat section may be in the range of 10 to 40%.

[0120] In yet another aspect of the present invention, the ratio of an area of ​​the 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 30% or more and less than 100%.

[0121] More preferably, the ratio of the area of ​​the current collector that is not in contact with the electrode assembly to the area of ​​a circle having the outer diameter of the electrode assembly as its diameter may be 60% or more and less than 100%.

[0122] In yet another aspect of the present invention, the diameter of the current collector hole may be smaller than the diameter of a winding center hole provided in the core of the electrode assembly.

[0123] Preferably, when the diameter of the winding center hole is R3, the diameter of the current collector hole may be 0.5×R3 or more but less than R3.

[0124] More preferably, when the diameter of the winding center hole is R3, the diameter of the current collector hole may be 0.7×R3 or more but less than R3.

[0125] In yet another aspect of the invention, the connecting portion may extend radially and in the winding axis direction.

[0126] In yet another aspect of the present invention, the tab coupling portion, the connecting portion, and the contact portion may have the same width along the extension direction.

[0127] Alternatively, the contact portion may have a width greater than that of the connecting portion.

[0128] In yet another aspect of the invention, the connecting portion may have a width smaller than the tab connection portion.

[0129] Additionally, the connecting portion may have a width greater than that of the tab connecting portion. [Effects of the Invention]

[0130] According to the present invention, the resistance in electrically connecting the electrode assembly and the battery housing can be significantly reduced.

[0131] Furthermore, according to the present invention, the bonding strength at the bonding site between the current collector and the battery housing can be improved.

[0132] Additionally, the present invention can improve the energy density of the battery.

[0133] Furthermore, according to the present invention, in manufacturing a battery, the convenience of the welding process for electrically connecting the battery housing and the current collector can be improved, thereby improving productivity.

[0134] 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.

[0135] 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 concept of the present invention, so the present invention should not be interpreted as being limited to the matters described in the drawings. [Brief explanation of the drawings]

[0136] [Figure 1a] 1 is a diagram showing a portion of a longitudinal cross section of a battery according to an embodiment of the present invention. [Figure 1b] FIG. 10 is a partial longitudinal cross-sectional view of a battery according to another embodiment of the present invention. [Figure 1c] FIG. 1b is an enlarged view of the upper part of the electrode assembly. [Figure 1d] FIG. 1b is an enlarged view of the upper part of the first uncoated portion of FIG. 1c. [Figure 2] FIG. 10 is a partial longitudinal cross-sectional view of a battery according to yet another embodiment of the present invention. [Figure 3] FIG. 10 is a partial longitudinal cross-sectional view of a battery according to yet another embodiment of the present invention. [Figure 4a] 4 is a diagram illustrating a current collector included in the battery of FIG. 3. FIG. [Figure 4b] 4b is a diagram illustrating an embodiment in which the bent portion is omitted from the current collector of FIG. 4a. FIG. [Figure 5] FIG. 10 is a diagram illustrating a current collector according to another embodiment of the present invention. [Figure 6] FIG. 10 is a diagram illustrating a current collector according to still another embodiment of the present invention. [Figure 7] FIG. 4 is a diagram illustrating the relationship between a current collector hole and a winding center hole. [Figure 8a] 4b is a diagram for explaining a welding area between the current collector and the first non-coated portion and a welding area between the current collector and the beading portion in FIG. 4a. FIG. [Figure 8b] 4b is a diagram illustrating a welding area between the current collector and the first non-coated portion and a welding area between the current collector and the beading portion. FIG. [Figure 9] 6 is a diagram for explaining a welding area between the current collector and the first non-coated portion and a welding area between the current collector and the beading portion in FIG. 5. FIG. [Figure 10] 7 is a diagram for explaining a welding area between the current collector and the first non-coated portion and a welding area between the current collector and the beading portion in FIG. 6. FIG. [Figure 11]10A and 10B are diagrams for explaining the position, length, width, etc. of a weld bead formed in a welding region between a contact portion and a beading portion. [Figure 12] FIG. 2 is a diagram for explaining the relationship between the diameter of the inner surface of the battery housing and the total diameter of the current collectors. [Figure 13a] FIG. 10 is a diagram illustrating a welding process of the current collector. [Figure 13b] 10A and 10B are diagrams for explaining a beading process for a battery housing. [Figure 13c] 10A and 10B are diagrams illustrating the crimping process of the battery housing. [Figure 13d] 10A and 10B are diagrams for explaining the sizing process of the battery housing. [Figure 13e] FIG. 10 is a diagram for explaining the change in the current collector before and after a sizing process that follows the shape of the current collector. [Figure 13f] 10A and 10B are diagrams for explaining the shape of a current collector in which a welded region is maintained even after a sizing process. [Figure 13g] 10A and 10B are diagrams for explaining the shape of a current collector in which a welded region is maintained even after a sizing process. [Figure 14] 1 is a plan view showing the structure of an electrode plate according to a preferred embodiment of the present invention; [Figure 15] 1 is a cross-sectional view taken along the longitudinal direction (Y direction) of an electrode assembly in which a segmented structure of an uncoated portion of an electrode plate according to an embodiment of the present invention is applied to a first electrode plate and a second electrode plate. [Figure 16a] 3 is a cross-sectional view of an electrode assembly in which a non-coated portion is bent in accordance with an embodiment of the present invention, taken along the longitudinal direction (Y direction). [Figure 16b] 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; [Figure 17] 1 is a top view showing a state in which a plurality of batteries are connected in series and in parallel using bus bars according to an embodiment of the present invention. FIG. [Figure 18a] FIG. 4 is a view illustrating a second current collector according to an embodiment of the present invention. [Figure 18b]FIG. 6 is a view illustrating a second current collector according to another embodiment of the present invention. [Figure 19] 1 is a diagram illustrating a battery pack including a battery according to an embodiment of the present invention; [Figure 20] FIG. 20 is a diagram illustrating a vehicle including the battery pack of FIG. 19. DETAILED DESCRIPTION OF THE INVENTION

[0137] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms and words used in the specification and claims should not be construed as being limited to their ordinary or dictionary meanings, but should be construed as having meanings and concepts corresponding 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 explain the invention.

[0138] 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 that there may be various equivalents and modifications that can be substituted for them at the time of this application.

[0139] In addition, in order to facilitate understanding of the invention, the accompanying drawings may be drawn not to scale but with some components exaggerated. The same reference numerals may be used to refer to the same components in different embodiments.

[0140] When two comparison objects are identical, it means that they are "substantially identical." Therefore, "substantially identical" may include deviations that are considered low in the art, for example, deviations within 5%. Furthermore, when any parameter is uniform in a given region, it may mean uniformity on average.

[0141] Terms such as "first" and "second" are used to describe various components, but these terms do not limit the components. These terms are used to distinguish only one component from another, and unless otherwise specified, the first component may be the second component.

[0142] Throughout the specification, unless otherwise specified, each element may be singular or plural.

[0143] When any structure is placed "on top (or bottom)" of a component or "above (or below)" a component, it can mean that the structure is placed directly on the top (or bottom) surface of the component, but also that other structures may be interposed between the component and any structure placed above (or below) the component.

[0144] Furthermore, 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 other components may be "intervening" between the components, or that each component may be "coupled," "coupled," or "connected" by other components.

[0145] Throughout the specification, unless otherwise specified, "A and / or B" means "A," "B," or "A and B," and "C through D" means at least C and at most D, unless otherwise specified.

[0146] 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.

[0147] 1a, a battery 1 according to an embodiment of the present invention includes an electrode assembly 10, a battery housing 20, a current collector (first current collector) 30, and a cap 40. The battery 1 may further include a terminal 50 and / or a sealing gasket G1 and / or an insulating gasket G2 and / or a current collector (second current collector) P and / or an insulator S. The terminal 50 may be provided on the opposite side of the open portion and may be electrically connected to the second uncoated portion 12.

[0148] The electrode assembly 10 includes a first uncoated portion 11 and a second uncoated portion 12. More specifically, the electrode assembly 10 may be manufactured by sequentially stacking a first electrode, a separator, a second electrode, and a separator at least once, and then winding the stack. That is, the electrode assembly 10 according to the present invention may be a winding-type electrode assembly. In this case, a separator may be further provided on the outer periphery of the electrode assembly 10 for insulation from the battery housing 20. The electrode assembly 10 may adopt any winding structure known in the related art without limitation.

[0149] The electrode assembly 10 may be 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. Here, the first electrode may include an active material portion coated with an active material layer along the winding direction, and a first uncoated portion 11 not coated with an active material layer.

[0150] More specifically, the electrode assembly 10 may be a winding-type electrode assembly having a structure in which sheet-like first and second electrodes and a separator interposed therebetween are wound in one direction. The first electrode may include a first uncoated portion 11 at an end of a long side where an active material layer is not coated and exposed to the outside of the separator. The second electrode may include a second uncoated portion 12 at an end of a long side where an active material layer is not coated and exposed to the outside of the separator. At least a portion of the first uncoated portion 11 may be used as an electrode tab by itself. At least a portion of the second uncoated portion 12 may be used as an electrode tab by itself.

[0151] Specifically, the first electrode includes a first electrode collector and a first electrode active material coated on one or both sides of the first electrode collector. An uncoated portion, where the first electrode active material is not coated, exists at one end of the first electrode collector in the width direction (parallel to the height direction of the battery 1 shown in FIG. 1a). The uncoated portion functions as a first electrode tab. The first uncoated portion 11 is provided at the upper portion in the height direction (parallel to the height direction of the battery 1 shown in FIG. 1a) of the electrode assembly 10 housed in the battery housing 20. The first uncoated portion 11 may be, for example, a negative electrode tab.

[0152] The second electrode includes a second electrode current collector and a second electrode active material coated on one or both sides of the second electrode current collector. An uncoated portion, where the second electrode active material is not coated, exists at the other end of the second electrode current collector in the width direction (a direction parallel to the height direction of the battery 1 shown in FIG. 1a). The uncoated portion functions as a second electrode tab. The second uncoated portion 12 is provided at the lower portion in the height direction of the electrode assembly 10 housed in the battery housing 20. The second uncoated portion 12 may be, for example, a positive electrode tab.

[0153] 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 limitation.

[0154] In one example, the positive electrode active material has the general chemical formula A[A x M y ]O 2+z (A includes at least one element selected from Li, Na, and K; M includes at least one element selected from Ni, Co, Mn, Ca, Mg, Al, Ti, Si, Fe, Mo, V, Zr, Zn, Cu, Al, Mo, Sc, Zr, Ru, and Cr; x≧0, 1≦x+y≦2, −0.1≦z≦2; the stoichiometric coefficients x, y, and z are selected to maintain electroneutrality of the compound.)

[0155] In another example, the positive electrode active material is an alkali metal compound xLiM disclosed in US Pat. No. 6,677,082, US Pat. No. 6,680,143, etc. 1 O2‐(1‐x)Li2M 2 O3(M 1 contains at least one element having an average oxidation state of 3; M 2 may contain at least one element having an average oxidation state of 4; 0≦x≦1).

[0156] In yet another example, 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 contains at least one element selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg, and Al; M 2 contains at least one element selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg, Al, As, Sb, Si, Ge, V, and S; M 3contains 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 can 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.].

[0157] Desirably, the positive electrode active material may contain primary particles and / or secondary particles formed by aggregation of primary particles.

[0158] In one example, the negative electrode active material can use a carbon material, a 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 with a potential of less than 2V can also be used as the negative electrode active material. As the carbon material, both low-crystalline carbon and high-crystalline carbon can be used.

[0159] The separation membrane can be used alone or in a laminated form a porous polymer film, for example, a porous polymer film made from polyolefin-based polymers such as ethylene homopolymer, propylene homopolymer, ethylene / butene copolymer, ethylene / hexene copolymer, ethylene / methacrylate copolymer, etc. In another example, the separation membrane can use a normal porous non-woven fabric, for example, a non-woven fabric made of high-melting-point glass fibers, polyethylene terephthalate fibers, etc.

[0160] [[ID=1**]]At least one surface of the separation membrane may include a coating layer of inorganic particles. Also, the separation membrane itself can consist of a coating layer of inorganic particles. The particles constituting the coating layer can have a structure in which they are combined with a binder so that an interstitial volume exists between adjacent particles.

[0161] The inorganic particles can be made of an inorganic substance with a dielectric constant of 5 or more. As this non-limiting example, the inorganic particles are Pb(Zr,Ti)O3 (PZT), Pb1-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.

[0162] The electrolyte is A + B - The salt may have the structure: + Li + , Na + , K. + and alkali metal cations such as B - is 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 comprises one or more anions selected from the group consisting of:

[0163] Alternatively, the electrolyte may be dissolved in an organic solvent, such as propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), dimethyl sulfoxide, acetonitrile, dimethoxyethane, diethoxyethane, tetrahydrofuran, N-methyl-2-pyrrolidone (NMP), ethyl methyl carbonate (EMC), γ-butyrolactone, or a mixture thereof.

[0164] The battery housing 20 is a generally cylindrical container having an opening on one side and is made of a conductive metal material. The side surface and the bottom surface (the lower surface in FIG. 1a) of the battery housing 20 opposite the opening are generally formed integrally. That is, the battery housing 20 generally has an open upper end in its height direction and a closed lower end except for the center. The bottom surface of the battery housing 20 may be generally flat. The battery housing 20 receives the electrode assembly 10 through an opening formed on one side in its height direction. The battery housing 20 may also receive an electrolyte through the opening.

[0165] The battery housing 20 may include a beading portion 21 formed at an end adjacent to the opening and pressed inward. The battery housing 20 may include a crimping portion 22 formed closer to the opening than the beading portion 21 and bent to extend toward the opening.

[0166] Specifically, the battery housing 20 may include a beading portion 21 formed at an upper end thereof. The battery housing 20 may further include a crimping portion 22 formed above the beading portion 21. The beading portion 21 has a shape in which the outer periphery of the battery housing 20 is press-fitted to a predetermined depth. The beading portion 21 is formed on the upper portion of the electrode assembly 10. The inner diameter of the battery housing 20 in the region where the beading portion 21 is formed is smaller than the diameter of the electrode assembly 10.

[0167] The beading portion 21 provides a support surface on which the cap 40 is provided. The beading portion 21 may also provide a support surface on which at least a portion of the periphery of the current collector 30 (described later) can be placed and coupled. That is, at least a portion of the periphery of the current collector 30 of the present invention and / or the periphery of the cap 40 of the present invention may be placed on the upper surface of the beading portion 21. As shown in FIGS. 2 and 3 , in order to stably support at least a portion of the periphery of the current collector 30 and / or the periphery of the cap 40, at least a portion of the upper surface of the beading portion 21 may extend in a direction substantially parallel to the lower surface of the battery housing 20, i.e., in a direction substantially perpendicular to the sidewall of the battery housing 20.

[0168] Meanwhile, the beading portion 21 may include an upper surface of the beading portion 21 located above the innermost point recessed by the press-fitting, and a lower surface of the beading portion 21 located below the innermost point recessed by the press-fitting.

[0169] For example, the press-fit depth PD of the beading portion 21 may be about 0.2 to 10 mm. The minimum value of the press-fit depth PD of the beading portion 21 is determined by the curvature radius R1 of the beading portion 21 and the weld bead width W bead and the radius of curvature R2 at the boundary region between the beading portion 21 and the inner surface of the battery housing 20 must all be taken into consideration. For example, referring to Figure 11, in order to enable welding, in addition to the radius of curvature R1 of the beading portion 21 and the radius of curvature R2 at the boundary region between the beading portion 21 and the inner surface of the battery housing 20, additional space is required. If the press-in depth PD is R1 + R2, this is because there is no flat section F in the beading portion. Furthermore, in order to enable welding, the additional space required is the minimum width W of the weld bead BD. bead,min As a result, the minimum value of the press-fit depth PD satisfies the following relational expression: PD≧R 1,min +R 2,min +W bead,min

[0170] For example, R 1,min and R 2,min The minimum value of each is approximately 0.05 mm, and W bead,min In this case, the minimum value of the indentation depth PD may be equal to or greater than about 0.2 mm.

[0171] The maximum press-fit depth PD of the beading portion 21 may vary depending on the material and thickness of the battery housing 20. For example, when the material of the battery housing 20 is steel and the maximum thickness of the battery housing 20 is approximately 1 mm, the maximum press-fit depth PD of the beading portion 21 may be approximately 10 mm. Thus, for example, the press-fit depth PD of the beading portion 21 may have a value of approximately 0.2 to 10 mm.

[0172] 1a, at least one of the upper surface and the lower surface of the beading portion 21 may be inclined at a predetermined angle with respect to the lower surface of the battery housing 20. Alternatively, as shown in FIGS. 2 and 3, at least one of the upper surface and the lower surface of the beading portion 21 may include a section that is parallel to the lower surface of the battery housing 20 in at least a portion thereof. That is, at least a portion of the upper surface of the beading portion 21 and the lower surface of the beading portion 21 may include a flat section (F in FIG. 3).

[0173] The crimping portion 22 is formed on the upper portion of the beading portion 21. The crimping portion 22 is bent and extends to surround the periphery of the cap 40 placed on the upper portion of the beading portion 21. The cap 40 is fixed to the beading portion 21 due to the bent shape of the crimping portion 22.

[0174] The innermost point of the beading portion 21 may be located radially inward relative to the terminal point of the crimping portion 22. For example, referring to FIG. 2, the terminal point of the crimping portion 22 may be located radially outward relative to the innermost point of the beading portion 21. This structure allows the beading portion 21 to remain flat even after the sizing process. For example, if the innermost point of the beading portion 21 is located radially outward relative to the terminal point of the crimping portion 22, the radial length of the upper surface of the crimping portion 22 will be longer than the radial length of the beading portion 21. In this case, the area of ​​the upper surface of the crimping portion 22 that is subjected to pressure during the sizing process will be larger, which may prevent the beading portion 21 from remaining flat after the sizing process. Therefore, in the present invention, it is preferable that the innermost point of the beading portion 21 be located radially inward relative to the terminal point of the crimping portion 22.

[0175] Of course, it is also possible to omit the crimping portion 22 and use another fixing structure to fix the cap 40 while covering the opening of the battery housing 20. For example, Korean Patent Publication No. 2019-0030016 by the present applicant discloses a cylindrical battery in which a beading portion is omitted, and this structure can be adopted in the present invention.

[0176] Hereinafter, the current collector (first current collector) 30 according to an embodiment of the present invention will be described in detail with reference to FIGS. 3 and 4a.

[0177] 3 , a current collector 30 according to an embodiment of the present invention is accommodated inside a battery housing 20 and is electrically connected to the electrode assembly 10 and the battery housing 20. That is, the current collector 30 electrically connects the electrode assembly 10 and the battery housing 20. Preferably, the current collector 30 may be electrically connected to the first uncoated portion 11 and the beading portion 21 of the battery housing 20. At least one tab coupling portion 32 of the current collector 30 may be located below the lower surface of the beading portion 21.

[0178] The current collector 30 includes a tab connecting portion 32 connected to the first non-coated portion 11, and a housing connecting portion 33 extending from the tab connecting portion 32 and electrically connected to the beading portion 21 on the inner surface of the battery housing 20. The boundary region between the tab connecting portion 32 and the housing connecting portion 33 may be bent such that an end of the housing connecting portion 33 faces the beading portion 21. That is, referring to FIG. 2 , the boundary region between the tab connecting portion 32 and the housing connecting portion 33 may have an upwardly bent shape. The housing connecting portion 33 may be pressed and fixed by the crimping portion 22.

[0179] Optionally, the current collector 30 may further include a central portion 31 in a core region of the current collector 30. The central portion 31 may have a substantially circular shape. For example, the central portion 31 may be a loop-shaped portion that surrounds the winding shaft of the electrode assembly 10. Preferably, the loop-shaped portion may have one or more cutouts along the circumferential direction. Meanwhile, the central portion 31 may be selectively coupled to the first non-coated portion 11.

[0180] Optionally, the current collector 30 may further include a cover portion extending from the loop-shaped portion and disposed to surround a portion of the first uncoated portion 11. The cover portion may increase the contact area between the first uncoated portion 11 and the current collector 30, thereby further reducing the internal resistance of the battery.

[0181] In another aspect of the present invention, the current collector 30 may have at least one leg structure extending radially with the tab coupling portion 32 and the housing coupling portion 33 connected to each other. Preferably, the current collector 30 may have a plurality of leg structures. For example, referring to FIGS. 4a to 6, the current collector 30 may have four leg structures. When the current collector 30 has a plurality of leg structures, the current collector 30 may also have a plurality of housing coupling portions 33. In this case, although not shown, the plurality of housing coupling portions 33 may be connected to each other and formed integrally. The leg structures may be arranged in a radial pattern, a cross pattern, or a combination thereof, based on the center portion 31 of the current collector 30.

[0182] The center portion 31 and the at least one tab coupling portion 32 are disposed on the upper portion of the electrode assembly 10, and may be located below the beading portion 21 when the beading portion 21 is formed on the battery housing 20. One or more holes for injecting an electrolyte may be formed on the tab coupling portion 32.

[0183] Meanwhile, when the total radial length of the tab connection portion 32 is T, the outer diameter of the electrode assembly 10 is JR, and the height of the segment piece 11a arranged at the outermost periphery of the electrode assembly is F, the following relational expression is satisfied. JR-2×F≦T <JR

[0184] Preferably, the total radial length T of the tab connector 32 is greater than or equal to the outer diameter JR of the electrode assembly 10 minus twice the height of the outermost segment 11a. When this relationship is satisfied, the tab connector 32 covers the end of the outermost segment 11a. That is, the current collector 30 may have an outer diameter that covers the end of the segment 11a bent at the last winding turn of the first electrode. In this case, the segment 11a forming the bent surface 102 that couples with the tab connector 32 can be welded while being uniformly pressed by the current collector 30, and the dense stacking of the segments 11a can be well maintained even after welding. A dense stacking state refers to a state in which there are substantially no gaps between the segments, as shown in FIG. 1c. A dense stacking state contributes to reducing the resistance of the battery 1 to a level suitable for fast charging (e.g., 0.5 mΩ to 4 mΩ, preferably 1.0 mΩ to 4 mΩ).

[0185] In another aspect of the present invention, the total radial length T of the tab coupling portion 32 may be smaller than the outer diameter JR of the electrode assembly 10. If the total radial length T of the tab coupling portion 32 is larger than the outer diameter JR of the electrode assembly 10, dead space inside the battery housing 20 increases, which may adversely affect the energy density of the battery 1. Therefore, it is preferable that the total radial length T be smaller than the outer diameter JR of the electrode assembly 10.

[0186] The center portion 31 has a circular current collector hole H2 formed at a position corresponding to a winding center hole H1 formed in the center of the electrode assembly 10. The winding center hole H1 and the current collector hole H2, which are connected to each other, can function as a passage for inserting a welding rod for welding a terminal 50 and a current collector (second current collector) P, which will be described later, or for welding the terminal 50 and a lead tab (not shown), or for irradiating a laser welding beam.

[0187] FIG. 7 is a diagram illustrating the relationship between the current collector holes and the winding center hole.

[0188] 7, the diameter of the current collector hole H2 may be equal to or larger than the diameter of the winding center hole H1 formed in the core of the electrode assembly 10. For example, the reason why the diameter of the current collector hole H2 is set larger than the diameter of the winding center hole H1 formed in the core of the electrode assembly 10 is because a space needs to be secured for inserting a welding rod for welding the terminal 50 to the current collector (second current collector) P or the terminal 50 to a lead tab (not shown) or for inserting a welding guide when irradiating a laser welding beam. If the diameter of the current collector hole H2 is too small compared to the diameter of the winding center hole H1, the winding center hole H1 may be blocked, causing an interference factor during continuous resistance welding (CRW).

[0189] Unlike the above embodiment, according to another embodiment of the present invention, the diameter of the current collector hole H2 may be smaller than the diameter of the winding center hole H1 formed in the core of the electrode assembly 10. For example, when the diameter of the winding center hole H1 is R3, the diameter of the current collector hole H2 may be 0.5×R3 or more and less than R3, and preferably 0.7×R3 or more and less than R3.

[0190] Typically, when venting occurs, gas is discharged from the winding center, and strong pressure can cause the separator and uncoated portion near the winding center to escape from the top of the electrode assembly 10. In this case, if the diameter of the current collector hole H2 is smaller than the diameter of the winding center hole H1 provided in the core of the electrode assembly 10, it is possible to prevent the separator and uncoated portion near the winding center from detaching from the top of the electrode assembly 10. However, if the diameter of the current collector hole H2 is too small, the injection of electrolyte may be impaired. Since it is necessary to secure space for welding the second current collector P to the terminal 50, the diameter of the current collector hole H2 is preferably 0.5×R3 or more, and more preferably 0.7×R3 or more.

[0191] In an aspect of the present invention, the central portion 31 may be a substantially circular plate. For example, referring to Fig. 4a, the central portion 31 may be a ring-shaped plate having a current collector hole H2 formed in its center.

[0192] The at least one tab coupling portion 32 may extend radially from the center portion 31 of the current collector 30 toward the sidewall of the battery housing 20. For example, a plurality of tab coupling portions 32 may be provided. For example, referring to FIG. 4a, the plurality of tab coupling portions 32 may be spaced apart from one another around the center portion 31. As such, the battery 1 of the present invention includes a plurality of tab coupling portions 32, which increases the coupling area with the first uncoated portion 11. This ensures a strong coupling force between the first uncoated portion 11 and the tab coupling portions 32, and reduces electrical resistance.

[0193] The tab coupling portion 32 may be coupled to the first uncoated portion 11 by welding. Examples of welding methods include, but are not limited to, laser welding, resistance welding, and ultrasonic welding. The tab coupling portion 32 may be coupled to the first uncoated portion 11 by welding in a state parallel to the lower surface of the battery housing 20. The first uncoated portion 11 and the tab coupling portion 32 may be coupled to each other by welding along the radial direction of the electrode assembly 10.

[0194] Fig. 1b is a partial longitudinal cross-sectional view of a battery according to another embodiment of the present invention, Fig. 1c is an enlarged view of an upper portion of the electrode assembly 10 in Fig. 1b, and Fig. 1d is an enlarged view of an upper portion of the first uncoated portion 11 in Fig. 1c.

[0195] Referring to FIG. 1b, welding may be performed on a certain region with the tab coupling portion 32 provided at the end of the first uncoated portion 11. Alternatively, at least a portion of the first uncoated portion 11 may include a plurality of segmented pieces 11a along the winding direction of the electrode assembly 10. The plurality of segmented pieces 11a may be bent along the radial direction of the electrode assembly 10 to form a bent surface 102. The radial direction of the electrode assembly refers to the direction toward the core or outer periphery. For example, as shown in FIG. 1b, at least a portion of the first uncoated portion 11 may include a plurality of segmented pieces 11a separated along the winding direction of the electrode assembly 10. The plurality of segmented pieces 11a may be bent toward the core side of the electrode assembly 10. Referring to FIGS. 1c and 1d, the plurality of segmented pieces 11a may be overlapped in multiple layers along the radial direction of the electrode assembly 10. The bending surface 102 may include a lamination number increasing section in which the number of overlaps of the segment pieces 11a gradually increases up to a maximum value as it progresses from the outer periphery side of the electrode assembly 10 toward the core side, and a lamination number uniform section from the radius point where the number of overlaps reaches a maximum value to the radius point where the innermost segment piece is located.

[0196] In this case, welding may be performed on a certain region while the tab coupling portion 32 is provided on the bent surface 102 of the first non-coated portion 11. That is, the tab coupling portion 32 may be coupled to a region where a plurality of segment pieces 11a are overlapped. For example, the tab coupling portion 32 may be coupled to the bent surface so as to overlap a section where the number of layers is uniform. Referring to FIG. 1d, welding of the tab coupling portion 32 to the first non-coated portion 11 may be performed on the bent surface 102 of the first non-coated portion 11 in a region where the number of layers of the first non-coated portion 11 is 10 or more. The radial proportion of the section where the number of layers is 10 or more may be designed to be 25% or more based on the radius of the electrode assembly excluding the core by adjusting the length of the first non-coated portion 11.

[0197] When welding the current collector 30 to the bent surface 102 of the first non-coated portion 11, it is preferable to increase the laser output to ensure sufficient welding strength. Increasing the laser output may cause the laser to penetrate the overlapping area of ​​the first non-coated portion 11 and penetrate into the interior of the electrode assembly 10, potentially damaging the separator, active material, etc. Therefore, to prevent penetration by the laser, it is preferable to increase the number of overlaps of the first non-coated portion 11 above a certain level. Increasing the number of overlaps of the first non-coated portion 11 can be achieved by increasing the height of the segment pieces 11a. However, increasing the height of the segment pieces 11a may cause waviness in the first non-coated portion 11 during the manufacturing process of the first electrode current collector. Therefore, it is preferable to adjust the height of the segment pieces 11a to an appropriate level.

[0198] As described above, when the proportion of the radial length where the number of overlapping non-coated segment pieces is 10 or more is designed to be 25% or more based on the radius of the electrode assembly, and the area where 10 or more non-coated segment pieces are overlapped is laser-welded to the current collector 30, the overlapping non-coated portion sufficiently masks the laser even when the laser output is increased, thereby preventing damage to the separator, active material, etc. by the laser.

[0199] Preferably, the laser output can be appropriately adjusted in the range of about 250W to 320W, or in the range of about 40% to 90% of the maximum laser output specification, but the present invention is not limited thereto. When the laser output satisfies the above numerical range, the welding strength can be sufficiently increased. For example, the welding strength is 2 kgf / cm. 2 (0.20 MPa) More preferably, 4kgf / cm 2 (0.39 MPa) The welding strength can be increased to more than 8 kgf / cm. 2 (0.78MPa) Less than 6kgf / cm, more preferably 2 (0.59 MPa) The weld strength can be set as follows: The tensile force per unit area (kgf / cm) of the current collector 30 when the current collecting plate begins to separate from the surface area of ​​the bending surface. 2) is defined as the welding strength. Specifically, after welding of the current collecting plate is completed, a tensile force is applied to the current collecting plate, and the strength of the force is gradually increased. As the tensile force increases, the uncoated portion begins to separate from the weld interface. At this time, the tensile force applied to the current collector divided by the area of ​​the current collecting plate is the weld strength.

[0200] FIG. 1d is a partial cross-sectional view showing the surface area of ​​the bent portion of the first electrode current collector, which is divided into multiple segments and bent from the outer periphery toward the core, resulting in ten or more overlapping segments in an electrode assembly with a 22 mm radius and a 4 mm core radius included in a 4680 form factor battery. The core area and areas of the electrode assembly where no segments exist are not shown separately. The segment heights start at 3 mm and increase by 1 mm for each 1 mm increase in the radius of the electrode assembly. After reaching the lengths of 6 mm, 7 mm, or 8 mm shown in the drawings, the segment heights remain substantially constant.

[0201] Referring to FIG. 1d, it can be seen that the number of overlaps of the first non-coated portion 11 gradually increases from the outer periphery toward the core, and the maximum value of the number of overlaps increases as the length of the first non-coated portion 11 increases.

[0202] For example, when the length of the first non-coated portion 11 is 8 mm, the number of overlaps of the first non-coated portion 11, divided into multiple segments, increases to 18 from the outer peripheral surface of the electrode assembly to a 7 mm section. The number of overlaps of the first non-coated portion 11 remains at a maximum of 18 in the 8 mm section toward the core, and decreases by 1 to 2 in the radial section adjacent to the core. The height of the segments increases stepwise from 3 mm to 8 mm in the 7 mm to 12 mm radius section. In the present invention, the uniform stacking number section is defined as the radial section from the radial point where the maximum number of overlaps is reached to the point where the innermost segment is located, as shown in FIG. 1D. Therefore, the percentage of the uniform stacking number section, where 10 or more segments 11a of the first non-coated portion 11 are overlapped, is 44.4% (8 / 18) of the radius of the electrode assembly excluding the core (4 mm).

[0203] In another example, when the length of the first non-coated portion 11 is 7 mm, the number of overlapping segments of the first non-coated portion 11 increases to 15 from the outer peripheral surface of the electrode assembly to a 6 mm section, and then remains constant at a maximum of 15 in the 9 mm section toward the core, decreasing by 1 to 2 in the radius section adjacent to the core. The height of the segments increases stepwise from 3 mm to 7 mm in the 7 mm to 11 mm radius section. As a result, the proportion of uniformly stacked segments, where 10 or more segments 11a of the first non-coated portion 11 are overlapped, is 50% (9 / 18) of the radius of the electrode assembly excluding the core (4 mm).

[0204] In another example, when the length of the first non-coated portion 11 is 6 mm, the number of overlapping segments of the first non-coated portion 11 increases to 12 from the outer peripheral surface of the electrode assembly to a 5 mm section. In the 10 mm section toward the core, the number of overlapping segments of the first non-coated portion 11 remains constant at a maximum of 12, and decreases by 1 to 2 in the radius section adjacent to the core. The height of the segments increases from 3 mm to 6 mm in the radius section from 7 mm to 10 mm. As a result, the percentage of uniformly stacked segments, where 10 or more segments 11a of the first non-coated portion 11 are overlapped, is 55.6% (10 / 18) of the radius of the electrode assembly excluding the core (4 mm).

[0205] According to the embodiment, the length of the section where the number of overlaps increases gradually increases from 5 mm to 7 mm as the length of the first non-coating portion 11 increases, and in particular, it can be seen that the ratio of the uniform stack number section where the number of stacks is 10 or more is 25% or more based on the radius of the electrode assembly excluding the core.

[0206] In the present invention, the uniform lamination count section can be increased or decreased depending on the core radius, the minimum and maximum segment heights in the segment height variable section, and the increase in segment height in the radial direction of the electrode assembly. Therefore, it would be obvious to one skilled in the art to adjust factors affecting the proportion of the uniform lamination count section to design this proportion to be 25% or more. For example, if both the minimum and maximum segment heights in the segment height variable section are increased, the number of laminations increases, and the proportion of the uniform lamination count section can be reduced to the 25% level.

[0207] The uniform layer count section is the area where the current collector can be welded. Therefore, if the proportion of the uniform layer count section is adjusted to 25% or more, the welding strength of the current collector can be secured within a desirable range, which is also advantageous in terms of resistance at the weld interface.

[0208] In another aspect of the present invention, when the first uncoated portion 11 has such a curved shape, the space occupied by the first uncoated portion 11 is reduced, thereby improving energy density. Also, the bonding area between the first uncoated portion 11 and the current collector 30 is increased, thereby improving bonding strength and reducing resistance.

[0209] 8a to 10 are diagrams illustrating the welding area between the current collector 30 and the first uncoated portion 11. FIG.

[0210] 8a to 10, a weld bead BD may be formed in the welded region between the first non-coated portion 11 and the tab coupling portion 32. The weld bead BD refers to a substantially circular weld formed when spot welding is performed at a specific point. For example, FIG. 11 shows a substantially circular weld bead BD formed as a result of spot welding. When a plurality of the weld beads BD are connected, a specific weld pattern may be formed. For example, referring to FIG. 8a, a plurality of weld beads BD may gather together to form a substantially linear weld pattern. In one embodiment, a plurality of weld beads BD formed between the first non-coated portion 11 and the tab coupling portion 32 may form a weld pattern extending along the radial direction of the electrode assembly 10. Preferably, the weld bead BD formed between the first non-coated portion 11 and the tab coupling portion 32 may form a linear weld pattern extending along the radial direction of the electrode assembly 10. For example, the weld pattern formed between the first non-coated portion 11 and the tab coupling portion 32 may be a line formed by connecting spot welds. The width of the weld bead BD formed between the first non-coated portion 11 and the tab connecting portion 32 may be about 0.1 mm or more because the minimum width of the weld bead BD is about 0.1 mm or more when considering laser technology.

[0211] A longitudinal end of the tab coupling portion 32 may be located more inward than the innermost point of the beading portion 21 formed on the battery housing 20. More specifically, a boundary region between the tab coupling portion 32 and the housing coupling portion 33 may be located more inward in a direction toward the winding center hole H1 than the innermost point of the beading portion 21 formed on the battery housing 20. This structure prevents damage to the coupling portion between components that may occur when the current collector 30 is excessively bent to position the end of the housing coupling portion 33 on the beading portion 21. In other words, when viewed along the longitudinal axis of the battery housing 20, the at least one tab coupling portion 32 may have a shape that is not overlapped by the beading portion 21.

[0212] Meanwhile, in order to secure a bonding strength and reduce electrical resistance by increasing the bonding area between the current collector 30 and the electrode assembly 10, not only the tab coupling portion 32 but also the center portion 31 may be coupled to the first non-coated portion 11. The end of the first non-coated portion 11 may be bent parallel to the tab coupling portion 32. When the end of the first non-coated portion 11 is bent and coupled to the tab coupling portion 32 in this manner while being parallel to the tab coupling portion 32, the bonding area increases, thereby improving the bonding strength and reducing the electrical resistance, and also minimizing the overall height of the electrode assembly 10, thereby improving the energy density.

[0213] The at least one housing coupling portion 33 may extend from an end of the tab coupling portion 32 and be coupled to the beading portion 21 on the inner surface of the battery housing 20. For example, the at least one housing coupling portion 33 may extend from an end of the tab coupling portion 32 toward a sidewall of the battery housing 20. For example, a plurality of housing coupling portions 33 may be provided. For example, referring to FIG. 4a, the plurality of housing coupling portions 33 may be spaced apart from one another around the center portion 31. Referring to FIG. 1a, the plurality of housing coupling portions 33 may be coupled to the beading portion 21 on the inner surface of the battery housing 20. As shown in FIGS. 2 and 3, the upper surface of the beading portion 21 may extend in a direction substantially parallel to the lower surface of the battery housing 20, i.e., in a direction substantially perpendicular to the sidewall of the battery housing 20, and the housing coupling portion 33 may also extend in the same direction, thereby allowing the housing coupling portion 33 to stably contact the beading portion 21. In addition, since the housing coupling portion 33 is in stable contact with the beading portion 21, welding between the two parts is performed smoothly, thereby improving the coupling strength between the two parts and minimizing the increase in resistance at the coupling portion. Also, since the current collector 30 is coupled to the beading portion 21 of the battery housing 20 instead of to the inner surface of the cylindrical portion of the battery housing 20, the distance between the current collector 30 and the beading portion 21 can be reduced. As a result, dead space inside the battery housing 20 is minimized, and the energy density of the battery 1 can be improved.

[0214] 3 and 4a, the housing coupling portion 33 includes a contact portion 33a coupled to the beading portion 21 on the inner surface of the battery housing 20, and a connecting portion 33b connecting the tab coupling portion 32 and the contact portion 33a.

[0215] The contact portion 33a is coupled to the inner surface of the battery housing 20. When the beading portion 21 is formed on the battery housing 20, the contact portion 33a may be coupled to the beading portion 21 as described above. In this case, for stable contact and coupling, both the beading portion 21 and the contact portion 33a may have a shape extending in a direction substantially parallel to the bottom surface of the battery housing 20, i.e., a direction substantially perpendicular to the side wall of the battery housing 20, as described above. The contact portion 33a may have a flat surface that couples with the top surface of the beading portion 21 facing the opening. That is, the contact portion 33a includes at least a partial flat portion that is substantially parallel to the bottom surface of the battery housing 20.

[0216] In one embodiment of the present invention, the connecting portion 33b may extend in both the radial direction and the winding axis direction. Meanwhile, referring to FIG. 13f, the connecting portion 33b may have an upwardly bulging structure. For example, the connecting portion 33b may have a curved shape bulging upward. Alternatively, as shown in FIG. 13f, the connecting portion 33b may include at least one bent portion C. Preferably, the at least one bent portion C may be bent at an obtuse angle so that the connecting portions do not overlap each other when viewed along the longitudinal axis of the battery housing. More preferably, the boundary between the contact portion 33a and the connecting portion 33b may be bent at an obtuse angle. That is, as shown in FIG. 13f, the inclination of the connecting portion 33b may gradually or stepwise decrease as the connecting portion 33b approaches the beading portion.

[0217] Referring to FIG. 4a, in another embodiment of the present invention, the connecting portion 33b may have at least one bent portion B, where the extension direction of the connecting portion 33b is changed at least once between the center portion 31 and the contact portion 33a. That is, the connecting portion 33b may have, for example, a spring-like or bellows-like structure that can contract and expand within a certain range. Meanwhile, the connecting portion 33b may be elastically biased upward by the bent portion B. This structure of the connecting portion 33b allows the contact portion 33a to closely contact the beading portion 21 during the process of inserting the electrode assembly 10, to which the current collector 30 is connected, into the battery housing 20, even if there is a certain range of variation in the height of the electrode assembly 10. In addition, this structure of the connecting portion 33b may allow the shape to be more stably realized during a sizing process.

[0218] In another embodiment of the present invention, the connecting portion between the contact portion 33a and the connecting portion 33b may be curved as shown in Figures 2 and 3. Alternatively, as shown in Figure 1a, the connecting portion between the contact portion 33a and the connecting portion 33b may have a complementary shape corresponding to the inner surface of the beading portion 21. In particular, the connecting portion between the contact portion 33a and the connecting portion 33b may be coupled to the beading portion 21 without any gaps while having a shape that matches the inner surface of the beading portion 21. This structure allows the beading portion 21 to effectively support the current collector 30. Furthermore, this structure prevents interference between the beading portion 21 and the connecting portion 33b. Therefore, stable coupling between the contact portion 33a and the beading portion 21 can be effectively maintained.

[0219] According to another aspect of the present invention, the protruding outermost point of the bent portion B may be spaced a predetermined distance from the innermost point of the beading portion 21. For example, referring to FIG. 3, the bent portion B may not contact the beading portion 21. This structure can prevent interference between the beading portion 21 and the connecting portion 33b. Therefore, stable connection between the contact portion 33a and the beading portion 21 can be effectively maintained.

[0220] According to another aspect of the present invention, the bent portion B may form an acute angle between the contact portion 33a and the connecting portion 33b. For example, referring to FIGS. 2, 4b, and 8b, the connecting portion 33b does not include a bent portion. Therefore, the angle between the contact portion 33a and the connecting portion 33b may be an obtuse angle. On the other hand, referring to FIGS. 3 and 4a, the connecting portion 33b includes a bent portion. Therefore, the angle between the contact portion 33a and the connecting portion 33b may be an acute angle. With this structure, the angle between the contact portion 33a and the connecting portion 33b is an acute angle, which prevents interference between the beading portion 21 and the connecting portion 33b. Therefore, stable connection between the contact portion 33a and the beading portion 21 can be maintained. Although the drawings of the present invention show only one bent portion B, the present invention is not limited thereto and may include a plurality of bent portions B.

[0221] Preferably, the vertical distance between the contact portion 33a and the center portion 31 when no external force is applied to the current collector 30 and no deformation is present is the same as the vertical distance between the upper surface of the beading portion 21 and the center portion 31 when the electrode assembly 10, to which the current collector 30 is coupled, is installed in the battery housing 20, or is smaller within the extensible range of the connecting portion 33b. If the connecting portion 33b is configured to satisfy this condition, the contact portion 33a can naturally adhere to the beading portion 21 when the electrode assembly 10, to which the current collector 30 is coupled, is installed in the battery housing 20.

[0222] In addition, the contractible and expandable structure of the connecting portion 33b reduces the impact caused by the movement of the electrode assembly 10 within a certain range, even if vibrations and / or impacts occur during use of the battery 1 and cause the electrode assembly 10 to move up and down.

[0223] In another aspect of the present invention, the connecting portion 33b may have a curved shape that bulges upward. For example, the connecting portion 33b may protrude toward the winding center of the electrode assembly 10. This shape of the connecting portion 33b is intended to prevent damage to the bonding portion between the current collector (first current collector) 30 and the electrode assembly 10 and / or the bonding portion between the current collector (first current collector) 30 and the battery housing 20 during the sizing process.

[0224] 13a to 13d are diagrams illustrating the steps of manufacturing the battery 1 of the present invention.

[0225] 13a is a view illustrating the welding process of the current collector 30. This shows a process of placing the current collector 30 on the electrode assembly 10 housed inside the battery housing 20, and then welding the current collector 30 to the first non-coated portion 11 protruding upward from the electrode assembly 10. In this case, the tab coupling portion 32 of the current collector 30 is welded to the bent surface of the plurality of segment pieces 11a of the first non-coated portion 11.

[0226] 13b is a view illustrating the beading process of the battery housing 20. With the current collector 30 welded onto the electrode assembly 10, a beading knife is advanced toward the inside of the battery housing 20. As a result, a beading portion 21 is formed on the side of the battery housing 20, where a portion of the battery housing 20 is press-fitted into the inside of the battery housing 20. The beading portion 21 is positioned below the contact portion 33a of the current collector 30, so the contact portion 33a and the inner surface of the beading portion 21 are positioned so that they can be welded to each other.

[0227] 13c illustrates the crimping process of the battery housing 20. The contact portion 33a of the current collector 30 may be placed on the upper surface of the beading portion 21. A cap 40, the edge of which is surrounded by a sealing gasket G1, may be placed on the upper surface of the contact portion 33a. The battery housing 20 is then bent to surround the periphery of the cap 40, thereby fixing the cap 40 and the current collector 30. The cap 40 and the current collector 30 are fixed to the beading portion 21 due to the shape of the bent crimping portion 22.

[0228] Next, FIG. 13d is a diagram illustrating the sizing process of the battery housing 20. The sizing process is a compression process for reducing the height of the beading portion 21 of the battery housing 20 in order to reduce the overall height of the battery 1 during manufacturing. During the sizing process, the battery housing 20 is compressed in the longitudinal direction, so the electrode assembly 10 may be pressed by the beading portion 21 and have a partially compressed shape. Furthermore, during the sizing process, the battery housing 20 is compressed in the longitudinal direction (vertical direction), so the current collector 30 may be warped due to vertical pressure. That is, the tab coupling portion 32 may be warped upward, increasing the possibility of damage to the weld between the tab coupling portion 32 and the first non-coated portion 11. Therefore, a shape of the current collector 30 is required that will not damage the welded region between the tab coupling portion 32 and the first non-coated portion 11 even after the sizing process.

[0229] For example, when the connecting portion 33b is bulged upward as shown in Figure 13f, the phenomenon of the tab coupling portion 32 lifting upward as shown in Figure 13d can be minimized. That is, when the battery housing 20 shown in Figure 13c is compressed in the vertical direction, the current collector 30 of the present invention is subjected to stress in the vertical direction. However, because the connecting portion 33b of the current collector 30 of the present invention is bulged upward, the stress applied to the tab coupling portion 32 can be minimized. Therefore, the tab coupling portion 32 can maintain a good welded connection with the first non-coated portion 11 without warping upward.

[0230] 13f and 13g, the connecting portion 33b before the sizing process may have a shape that bulges upward with respect to an imaginary line connecting one end of the contact portion 33a and one end of the tab coupling portion 32. For example, the connecting portion 33b may have at least one bent portion C forming an obtuse angle. The bent portion C may be located above an imaginary plane that passes through the center of the imaginary line connecting one end of the contact portion 33a and one end of the tab coupling portion 32 and is parallel to the bottom surface of the battery housing 20. Preferably, the length of the connecting portion 33b adjacent to the tab coupling portion 32 with respect to the bent portion C may be longer than the length of the connecting portion 33b adjacent to the contact portion 33a with respect to the bent portion C.

[0231] With this structure, during the sizing process, which is subjected to vertical pressure, the contact portion 33a descends downward as shown by the arrow, and the connecting portion 33b protrudes upward as shown by the arrow (see dotted line). More specifically, the connecting portion 33b protrudes higher than the beading portion 21. That is, the profile of the housing connecting portion 33 changes before and after the sizing process, as shown in FIG. 13f. The degree of protrusion varies depending on the change in height of the battery housing 20 during the sizing process. Unlike the illustration, the position of the bent portion C may only protrude to the height level of the contact portion 33a. This upward protrusion of the connecting portion 33b allows the connecting portion 33b to absorb a large amount of stress, thereby reducing the stress applied to the welded region between the tab connecting portion 32 and the first non-coated portion 11. Therefore, according to the present invention, the tab connecting portion 32 does not lift upward. In addition, with the above-described structure, the length of the connecting portion 33b adjacent to the tab coupling portion 32 based on the bent portion C is longer than the length of the connecting portion 33b adjacent to the contact portion 33a based on the bent portion C, which makes it easier to insert the current collector 30 into the battery housing 20 and effectively distributes stress.

[0232] As another embodiment of the present invention, referring to Figure 13g, the profile of current collector 30 after the sizing process may be deformed differently from that of Figure 13f. For example, in Figure 13f, connecting portion 33b may be deformed into a curved, protruding structure after the sizing process, whereas in Figure 13g, connecting portion 33b may be deformed into a straight line bent around bend C after the sizing process. More specifically, in Figure 13g, after the sizing process, connecting portion 33b may be deformed to bulge upward while maintaining a straight line with respect to bend C, with respect to bend C, and with respect to bend C, with respect to bend C, and connecting portion 33b may be deformed to bulge upward.

[0233] The inventors have thoroughly investigated the shape of the current collector 30 that can prevent twisting and / or lifting of the current collector 30, and have found that when the connecting portion 33b has a structure in which it bulges upward, damage to the weld between the tab coupling portion 32 and the first non-coated portion 11 is significantly reduced.

[0234] FIG. 13e is a diagram for comparing the degree of damage to the welded region of the current collector 30 after the sizing process depending on the shape of the current collector 30 before the sizing process.

[0235] Referring to Figure 13e, Experimental Example 1 is an experimental example in which the connecting portion 33b before sizing was straight, Experimental Example 2 is an experimental example in which the connecting portion 33b before sizing was bulged downward, and Experimental Example 3 is an experimental example in which the connecting portion 33b before sizing was bulged upward. A 1 mm sizing process was performed on Experimental Examples 1 to 3. Experimental Example 1, in which the connecting portion 33b was straight, experienced a phenomenon in which the welded area with the tab connecting portion 32 rose by approximately 0.72 mm. Experimental Example 2, in which the connecting portion 33b was bulged downward, experienced a phenomenon in which the welded area with the tab connecting portion 32 rose by approximately 0.99 mm. That is, it was confirmed that when the connecting portion 33b bulged downward, the lifting phenomenon was more severe than when the connecting portion 33b was straight. Meanwhile, Experimental Example 3, in which the connecting portion 33b was bulged upward, experienced a phenomenon in which the welded area with the tab connecting portion 32 rose by approximately 0.02 mm. This means that the lifting phenomenon was significantly reduced compared to Experimental Examples 1 and 2. That is, in Experimental Example 3, in which the connecting portion 33b was shaped to bulge upward, it was confirmed that damage to the welded region between the tab coupling portion and the first non-coated portion was minimized. This is because the degree of lifting of the current collector 30 is affected by the stress that the current collector 30 applies to the electrode assembly 10. That is, in Experimental Example 1, in which the connecting portion 33b was straight, and Experimental Example 2, in which the connecting portion 33b was shaped to bulge downward, it was confirmed that the stress applied to the welded portion of the current collector 30 and the electrode assembly 10 during the sizing process was very large, at approximately 4.5 MPa and 3.7 MPa, respectively, and therefore the lifting phenomenon of the current collector 30 was severe. On the other hand, in Experimental Example 3, in which the connecting portion 33b is bulged upward, the stress applied to the portion where the current collector 30 and the electrode assembly 10 are welded during the sizing process was approximately 2.0 MPa, which is relatively lower than in Experimental Examples 1 and 2, and therefore, the lifting phenomenon of the current collector 30 occurred relatively less frequently.

[0236] Therefore, as shown in FIG. 13f, the inclination of the connecting portion 33b may be inconstant, and the inclination of the upper portion may be smaller than the inclination of the lower portion based on a predetermined point (e.g., bent portion C). The predetermined point may be located above the midpoint of the connecting portion 33b. Alternatively, the connecting portion 33b may have a shape that bulges upward based on an imaginary line connecting the tab coupling portion 32 and the contact portion 33a. The bulging shape may be a combination of two straight lines, a curved line, or a combination thereof. For example, as shown in FIG. 13f, the connecting portion 33b may have at least one bent portion C based on the predetermined point. Preferably, the at least one bent portion C may be bent at an obtuse angle so that they do not overlap each other when viewed along the longitudinal axis of the battery housing 20. In yet another variation, the inclination of the connecting portion 33b may gradually or stepwise decrease as the connecting portion 33b approaches the beading portion 21.

[0237] In yet another aspect of the present invention, referring to FIG. 13d, the angle θ formed between the tab connecting portion 32 and the connecting portion 33b may be, for example, 0 to 90 degrees. For example, if the height of the upper end of the electrode assembly 10 is raised to a level corresponding to the height of the beading portion 21 during the sizing process, the tab connecting portion 32 and the contact portion 33a may be positioned at the same height. That is, in this case, the angle θ formed between the tab connecting portion 32 and the connecting portion 33b is 0 degrees. Even after the sizing process, it is undesirable for the contact portion 33a to be positioned lower than the tab connecting portion 32. This is because the first non-coated portion 11 may be excessively pressed by the beading portion 21 and damaged. Therefore, it is preferable that the angle θ formed between the tab connecting portion 32 and the connecting portion 33b be greater than 0 degrees. However, the angle θ formed between the tab connecting portion 32 and the connecting portion 33b may increase up to 90 degrees depending on whether the length, thickness, or slope of the connecting portion 33b changes stepwise or gradually. However, to avoid contact with the cap 40, it is desirable that the angle θ not exceed 90°.

[0238] In yet another aspect of the present invention, the connecting portion 33b may support the cap 40. For example, the connecting portion 33b may be bent upward through a sizing process. In this case, the bent connecting portion 33b may come into contact with the cap 40. In this case, the connecting portion 33b may serve to support the cap 40 upward. Therefore, the current collector 30 may be securely fixed in the vertical direction through the sizing process. As a result, even if vibrations and / or impacts occur during use of the battery 1, the current collector 30 fixes the electrode assembly 10 in the vertical direction, preventing the electrode assembly 10 from moving up and down inside the battery housing 20.

[0239] In yet another aspect of the present invention, the upper surface and the lower surface of the beading portion 21 may be asymmetric with respect to an imaginary reference plane that passes through the innermost point of the beading portion 21 and is parallel to the bottom surface of the battery housing. For example, referring to Fig. 13d, since the battery housing 20 is compressed in the vertical direction during the sizing process, the beading portion 21 is also compressed in the vertical direction. As a result, the upper surface and the lower surface of the beading portion 21 may have an asymmetric shape with respect to an imaginary reference plane that passes through the innermost point of the beading portion 21.

[0240] In yet another aspect of the present invention, the press-fit depth of the beading portion 21 may be defined as PD. For example, referring to FIG. 11, the press-fit depth PD may be defined as the vertical distance from the inner surface of the battery housing 20 to the innermost point of the beading portion 21. Alternatively, the overlap length OV may be defined as the shortest distance from the end of the contact portion 33a to a vertical line passing through the innermost point of the beading portion 21. That is, referring to FIG. 11, the overlap length OV refers to the radial length of the area where the beading portion 21 overlaps with the current collector 30 when orthogonally projected in the vertical direction. In this case, the battery 1 of the present invention satisfies the following relationship: (R 1,min +W bead,min ) / PD max ≦OV / PD≦(PDmax -R 2,min ) / PD max

[0241] In order for the contact portion 33a of the current collector 30 to be placed on the beading portion 21 so as to be weldable, the ratio (R 1,min +W bead,min ) / PD max 11, in order for the contact portion 33a of the current collector 30 to be weldably placed on the beading portion 21, an overlapping area beyond the radius of curvature R1 of the beading portion 21 is required. For example, if the contact portion 33a overlaps the beading portion 21 by the radius of curvature R1, the flat section F does not exist, and the contact portion 33a can only contact the beading portion 21 at one point. In other words, the contact portion 33a cannot be stably placed on the beading portion 21. Therefore, the contact portion 33a needs an overlapping area in addition to the radius of curvature R1 of the beading portion 21, and in this case, the length of the overlapping area must be at least equal to the weld bead width W. bead That is, in the further overlapped region, the contact portion 33a is substantially overlapped with the beading portion 21, and welding can be performed in this region. Therefore, it is desirable that the length of the further overlapped region is at least the weld bead width W bead Only when the overlapping length is greater than the above, stable welding can be performed without straying from the overlapping area. That is, the minimum overlap length for the contact portion 33a to be placed on the beading portion 21 so as to be weldable is R 1,min +W bead,min becomes.

[0242] In order for the contact portion 33a of the current collector 30 to be placed so as to be weldable to the beading portion 21, the ratio (PD max -R 2,min ) / PD max11, there is a radius of curvature R2 in the boundary area between the beading portion 21 and the inner surface of the battery housing 20. As a result, when the contact portion 33a of the current collector 30 enters the boundary area between the beading portion 21, which has the radius of curvature R2, and the inner surface of the battery housing 20, the radius of curvature R2 prevents the contact portion 33a from adhering to the beading portion 21 and causes it to float up. As a result, the maximum overlap length for the contact portion 33a to be placed so as to adhering to the beading portion 21 is PD. max -R 2,min becomes.

[0243] For example, the maximum value PD of the press-fit depth PD of the beading portion 21 is max is about 10 mm, and R 1,min and R 2,min The minimum value of each is approximately 0.05 mm, and W bead,min The ratio of the overlap length OV to the press-fit depth PD of the beading portion 21 may be in the range of about 1.5 to 99.5%. In order for the contact portion 33a of the current collector 30 to be weldably placed on the beading portion 21, it is desirable that the ratio be about 1.5% or more. The lower limit of the OV / PD ratio is the maximum press-fit depth PD of the beading portion 21. max , the minimum value of the radius of curvature R1 1,min and the minimum width of the contact portion 33a that comes into contact with the upper surface of the beading portion 21 for welding of the contact portion 33a, i.e., the minimum width W of the weld bead BD. bead,min Specifically, in one example, the maximum value of the press-fit depth PD max is 10 mm, and the minimum contact width of the contact portion 33a required for welding the contact portion 33a, i.e., the minimum width W of the weld bead BD, bead,min The length of the curvature radius R1 is 0.1 mm, and the minimum value R 1,min can be 0.05 mm. Under this condition, the minimum value of the overlap length OV is 0.15 mm (= 0.1 mm + 0.05 mm), and PD maxSince the contact depth is 10 mm, the lower limit of the OV / PD ratio is 1.5%. Meanwhile, the point where the contact portion 33a of the current collector 30 can contact the flat portion of the upper surface of the beading portion 21 at the widest width is a point spaced apart from the inner surface of the battery housing by the radius of curvature R2. Therefore, when the end of the contact portion 33a is located at this point, the overlap length OV becomes maximum. The upper limit of the OV / PD ratio is determined by the ratio of the maximum press-fit depth to the minimum value R of the radius of curvature R2. 2,min Specifically, the maximum value of the press-fit depth is 10 mm, and the minimum value of the curvature radius R2 is 0.05 mm. Under these conditions, the maximum value of the overlap length OV is 9.95 mm (= 10 mm - 0.05 mm), and PD max Since the difference is 10 mm, the upper limit of the OV / PD ratio is 99.5%.

[0244] In yet another aspect of the present invention, the welding position where the beading portion 21 and the contact portion 33a are welded may be defined as W. More specifically, the welding position W may refer to the distance from the innermost point of the beading portion 21 to the center point of the weld bead BD located at the outermost radial position. In this case, the welding position W and the press-fit depth PD may satisfy the following relationship: (OV min -0.5×W bead,min ) / PD max ≦W / PD≦(OV max -0.5×W bead,min ) / PD max

[0245] The welding position W of the beading portion 21 and the contact portion 33a is determined by the overlap length between the contact portion 33a and the beading portion 21 and the minimum width W of the weld bead BD. bead,min The weld position W is the center point of the weld bead BD.

[0246] Explaining with reference to FIG. 11, the welding position when the contact portion 33a is minimally overlapped with the beading portion 21 can be defined as W1. The overlap length at this time is determined by the OV minOn the other hand, since stable welding is possible only when the weld bead BD is formed within the overlapping area, the weld bead BD must be completely contained within the overlapping area. Therefore, the welding position W1 is OV min from at least 0.5 × W bead,min The distance W1 must be a point spaced inward from the beading portion 21 by a distance of 1 / 2 mm. Therefore, W1 can satisfy the following relational expression. W1=OV min -0.5×W bead,min =R 1,min +W bead,min -0.5×W bead,min =R 1,min +0.5×W bead,min

[0247] On the other hand, in order for the value of W1 / PD to be minimum, the value of PD must be maximum, so the minimum value of W / PD is (OV min -0.5×W bead,min ) / PD max becomes.

[0248] On the other hand, referring to Fig. 11, the welding position when the contact portion 33a is fully inserted into the beading portion 21 can be defined as W2. The overlap length at this time is determined by the OV max On the other hand, since stable welding is possible only when the weld bead BD is formed within the overlapping area, the weld bead BD must be completely contained within the overlapping area. Therefore, the welding position W2 is OV. max from at least 0.5 × W bead,min The distance W2 must be a point spaced apart toward the inside of the beading portion 21 by a distance of 1 / 2 .mu.m. W2=OV max -0.5×W bead,min =PD max -R 2,min -0.5×W bead,min

[0249] On the other hand, in order to maximize the value of W2 / PD, PD max -R 2,min -0.5×W bead,min is divided by PD, which is 1-(R 2,min +0.5×W bead,min ) / PD must be maximized. That is, when the PD value is maximized, the W2 / PD value is also maximized. Therefore, the maximum value of W / PD is (OV min -0.5×W bead,min ) / PD max becomes.

[0250] For example, the minimum width required to weld the contact portion 33a to the beading portion 21 may be 0.1 mm. That is, the width of 0.1 mm is the minimum width of the weld bead BD that can be formed by laser welding. Therefore, the welding position W1 when the contact portion 33a contacts the top surface of the beading portion 21 with the minimum width is R 1,min +0.5 × 0.1 mm. 1,min is the minimum value of the radius of curvature R1, e.g., 0.05 mm. When a laser is irradiated to this point, a weld bead BD having a width of 0.1 mm is formed on the contact surface between contact portion 33a and beading portion 21. The width of weld bead BD also corresponds to the minimum contact width of contact portion 33a. Based on the press-fit depth PD of beading portion 21, welding position W1 is a point 0.1 mm away from the innermost point of beading portion 21.

[0251] On the other hand, when the contact portion 33a contacts the upper surface of the beading portion 21 at the maximum width, the end of the contact portion 33a is spaced apart from the inner surface of the battery housing by a radius of curvature R 2,min where R 2,minis the minimum value of the radius of curvature R2, and is, for example, 0.05 mm. In this case, the welding position W2 that can be closest to the end of the contact portion 33a is a point 0.05 mm away from the end of the contact portion 33a. When a laser is irradiated to this point, a weld bead having a minimum width of 0.1 mm can be formed so as to abut against the end of the contact portion 33a. The welding position W2 when the contact portion 33a contacts the top surface of the beading portion 21 at its widest width is determined by the PD-R, based on the innermost point of the beading portion 21. 2,min -0.05mm apart. For example, R 2,min When the distance W2 is 0.05 mm, the maximum value of the welding position W2 is a point spaced apart by PD-0.1 mm from the innermost point of the beading portion 21.

[0252] According to the above, R 1,min and R 2,min When the distance W is 0.05 mm, the welding position W of the contact portion 33a based on the press-fit depth PD can be set in the range of 0.1 mm to PD-0.1 mm based on the innermost point of the beading portion 21. The ratio of the welding position W1 based on the press-fit depth PD is when the press-fit depth PD is at its maximum value, so the minimum value (%) of W1 / PD is 1% (= 100 × 0.1 mm / 10 mm). The maximum value of the ratio W1 / PD of the welding position W2 based on the press-fit depth PD is when PD is at its maximum value, so the maximum value (%) of W2 / PD is 99% (= 100 × (10 mm - 0.1 mm) / 10 mm). In other words, the welding position range based on the press-fit depth PD can be a range of 1% to 99% based on the press-fit depth PD.

[0253] 11, when the overlap length is OV, the distance from the innermost point of the beading portion 21 to the center point of the outermost weld bead BD in the radial direction may be defined as W. In this case, the battery 1 of the present invention may satisfy the following relational expression: W=OV-0.5×W bead,min

[0254] Meanwhile, the beading portion 21 has a flat section F that is parallel to the lower surface of the battery housing 20 in at least a portion thereof, and the length of the flat section F of the beading portion 21 that contacts the current collector 30 may be OV-R1. That is, referring to FIG. 11, the flat section F is the length obtained by subtracting the radius of curvature R1 of the beading portion 21 from the overlap length OV.

[0255] In still another aspect of the present invention, when the overlap length is OV, the radial width of the welding pattern, which is a set of weld beads BD formed between the beading portion 21 and the contact portion 33a, is W bead,min It can be greater than or equal to OV-R1.

[0256] Referring to FIG. 11, the minimum width of the weld bead BD is W bead,min Therefore, the minimum value of the width length in the radial direction of the welding pattern formed between the beading portion 21 and the contact portion 33a is at least W bead,min Meanwhile, a plurality of weld beads BD may be formed over the entire area of ​​flat section F of beading portion 21. In this case, the plurality of weld beads BD may form a uniform weld pattern. Referring to FIG. 11, the maximum value of the radial width length of the weld pattern formed between beading portion 21 and contact portion 33a may satisfy the following relational expression: The maximum value of the width in the radial direction of the weld pattern formed between the beading portion 21 and the contact portion 33a = W-W1 + Minimum width of weld bead BD =[(OV-0.5×W bead,min )-(R1+0.5×W bead,min )]+W bead,min =OV-R1

[0257] In yet another aspect of the present invention, the ratio of the radial width of the welding pattern to the length of the flat section F may be in the range of approximately 10 to 40%. Preferably, the ratio is approximately 20 to 30%. When the ratio is in this range, the welding area increases, thereby increasing the welding strength. As a result, the battery 1 according to the present invention can ensure high impact resistance.

[0258] In yet another aspect of the present invention, the ratio of the area of ​​the current collector 30 that is not in contact with the upper surface of the electrode assembly 10 to the area of ​​a circle having a diameter equal to the outer diameter of the electrode assembly 10 may be defined as the aperture ratio of the current collector 30. The aperture ratio can be calculated by the following equation: Opening ratio (%) = 1 - (area where the current collector contacts 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 does not come into contact with the top surface of the electrode assembly) / (area of ​​a circle whose diameter is the outer diameter of the electrode assembly)

[0259] The aperture ratio of the current collector 30 may be, for example, about 30% to less than 100%, and preferably about 60% to less than 100%. Taking the example of the current collector 30 shown in FIG. 8a as being placed on and coupled to the electrode assembly 10, the area of ​​the current collector 30 that contacts the electrode assembly 10 may be the center portion 31 and the tab coupling portion 32. In other words, the ratio of the area of ​​the current collector 30 that contacts the electrode assembly 10 to the area of ​​a circle having the outer diameter of the electrode assembly 10 as its diameter may be about 70% or less, and preferably about 40% or less. When the aperture ratio of the current collector 30 is within this range, the electrolyte may smoothly permeate into the electrode assembly 10 through the open areas of the current collector 30, including the current collector holes H2, during injection of the electrolyte. That is, when the aperture ratio of the current collector 30 is within the above range, the electrolyte permeates into the electrode assembly 10 through the winding center hole H1 provided in the electrode assembly 10 and the open areas of the current collector 30. In particular, since minute gaps exist between the overlapping surfaces of the segment pieces 11a and between adjacent segment pieces 11a, the electrolyte can smoothly permeate into the electrode assembly 10 due to capillary action caused by the gaps.

[0260] Referring now to Figure 5, a current collector 30 according to another embodiment of the present invention is shown. The current collector 30 according to this embodiment of the present invention differs from the current collector 30 of Figure 4a described above only in the shape of the contact portion 33a, but otherwise the structure of the current collector 30 described above can be substantially the same.

[0261] 5, in one embodiment, the contact portion 33a may have a width greater than that of the connecting portion 33b. For example, at least a portion of the contact portion 33a may extend along the inner circumferential surface of the battery housing 20. Preferably, the contact portion 33a may have an arc shape extending along the beading portion of the battery housing 20. Also, although not shown, to maximize the contact area, the current collector 30 may be configured such that the sum of the extension lengths of the contact portions 33a of at least one housing connecting portion 33 is approximately equal to the inner circumferential surface of the battery housing 20. In this embodiment, the maximization of the connecting area may result in improved connecting strength and reduced electrical resistance.

[0262] Referring now to Figure 6, a current collector 30 according to yet another embodiment of the present invention is shown. The current collector 30 according to this embodiment of the present invention differs from the current collector 30 of Figure 5 only in the shapes of the contact portion 33a and the connecting portion 33b. Otherwise, the structure of the current collector 30 described above may be substantially the same. That is, the connecting portion 33b may have a width greater than the tab connecting portion 32. Alternatively, in another embodiment, the connecting portion 33b may have a width smaller than the tab connecting portion 32.

[0263] 6, the connecting portion 33b may have a shape in which at least a portion thereof extends along the inner circumferential surface of the battery housing 20. Specifically, the contact portion 33a may have an arc shape extending along the beading portion of the battery housing 20, and the connecting portion 33b may have an arc shape extending along the contact portion 33a. With this structure, the area of ​​the current collector 30 is further increased compared to the current collector 30 shown in FIG. 5, thereby maximizing the effect of reducing electrical resistance.

[0264] 6, the current collector 30 may not have a bent portion B, unlike the current collector 30 shown in FIG. 4A or 5. When the bent portion B is not provided, the amount of raw material required to manufacture the current collector 30 can be reduced, thereby reducing the manufacturing cost of the current collector 30.

[0265] Referring to FIG. 1a, the cap 40 covers the opening formed on one side of the battery housing 20. The cap 40 may be fixed by a crimping portion 22 formed on the upper end of the battery housing 20. In this case, a sealing gasket G1 may be interposed between the battery housing 20 and the cap 40 to improve fixing strength and sealability of the battery housing 20. However, in the present invention, the cap 40 is not a part that needs to function as a current passage. Therefore, if other structures known in the related art can be applied to firmly fix the battery housing 20 and the cap 40 and ensure sealability of the opening of the battery housing 20, the application of such a sealing gasket G1 is not essential.

[0266] Meanwhile, taking the case where the sealing gasket G1 is applied as an example, the sealing gasket G1 may be interposed between the open portion of the battery housing 20 and the current collector 30, and the portion of the current collector 30 that contacts the beading portion 21 may be configured to be located between the beading portion 21 and the sealing gasket G1. The sealing gasket G1 may be substantially ring-shaped and surround the cap 40. The sealing gasket G1 may cover the top, bottom, and side surfaces of the cap 40. The radial length of the portion of the sealing gasket G1 that covers the bottom surface of the cap 40 may be smaller than or equal to the radial length of the portion of the sealing gasket G1 that covers the top surface of the cap 40. If the radial length of the portion of the sealing gasket G1 covering the underside of the cap 40 is too long, the sealing gasket G1 may pressurize the current collector 30 during the process of vertically compressing the battery housing 20 during the sizing process, potentially damaging the current collector 30 or the battery housing 20. In particular, if the radial length of the portion of the sealing gasket G1 covering the underside of the cap 40 is too long, the sealing gasket G1 may pressurize the connecting portion 33b excessively during the process of vertically compressing the battery housing 20 during the sizing process, potentially deforming the shape of the connecting portion 33b or damaging a portion of the connecting portion 33b. For this reason, it is necessary to maintain the radial length of the portion of the sealing gasket G1 covering the underside of the cap 40 at a small, consistent level.

[0267] In contrast, the portion of the sealing gasket G1 that covers the top surface of the cap 40 is structurally and positionally unlikely to interfere with the current collector 30. Meanwhile, the battery housing 20 and the cap 40 do not necessarily need to be insulated from each other. That is, the portion of the sealing gasket G1 that covers the top surface of the cap 40 only needs to fulfill a sealing function, and does not need to fulfill other functions such as insulation, so there are relatively few restrictions on its length.

[0268] 1a, the radial length of the portion of the sealing gasket G1 that covers the lower surface of the cap 40 may be the same as the radial length of the portion of the sealing gasket G1 that covers the upper surface of the cap 40. Alternatively, as shown in FIGS. 2 and 3, the radial length of the portion of the sealing gasket G1 that covers the lower surface of the cap 40 may be smaller than the radial length of the portion of the sealing gasket G1 that covers the upper surface of the cap 40.

[0269] Meanwhile, the contact portion 33a may be interposed and fixed between the beading portion 21 of the battery housing 20 and the sealing gasket G1. That is, the contact portion 33a may be fixed by the crimping force of the crimping portion 22 while being interposed between the beading portion 21 of the battery housing 20 and the sealing gasket G1.

[0270] In this case, the thickness of the sealing gasket G1 may be varied along the circumferential direction, for example, the thickness of the sealing gasket G1 may be alternately increased and decreased along the circumferential direction.

[0271] For example, the sealing gasket G1 may have the same compressibility in the area in contact with the contact portion 33 a and the area not in contact with the contact portion 33 a. That is, the thickness of the sealing gasket G1 may be configured to vary along the circumferential direction in advance in an uncompressed state.

[0272] In another example, the sealing gasket G1 may have a smaller compressibility in the area not in contact with the contact portion 33 a than in the area in contact with the contact portion 33 a. That is, the sealing gasket G1 may be configured to have a constant thickness along the circumferential direction in an uncompressed state, and may be configured to change in thickness only in a certain area when compressed by a crimping force.

[0273] In yet another example, the sealing gasket G1 may have a greater thickness in the area not in contact with the contact portion 33a than in the area in contact with the contact portion 33a. That is, although not shown, the sealing gasket G1 may have a relatively large compressibility in the area in contact with the contact portion 33a.

[0274] Furthermore, a weld may be formed between the beading portion 21 of the battery housing 20 and the contact portion 33a of the current collector. For example, the contact portion 33a may not be securely fixed by crimping force alone. Furthermore, if the sealing gasket G1 shrinks due to heat or the crimping portion 22 is deformed due to an external impact, the bonding strength between the current collector and the battery housing 20 may be weakened. As a result, the current collector 30 may be fixed to the battery housing 20 by welding with the contact portion 33a placed on the beading portion 21 of the battery housing 20. Then, a cap 40 surrounded by the sealing gasket G1 is placed on the upper end of the contact portion 33a to form the crimping portion 22, thereby completing the manufacturing process of the battery 1. In this case, the welding method may be, for example, laser welding, resistance welding, ultrasonic welding, or the like, but is not limited to these. In this way, the contact portion 33a is interposed between the beading portion 21 and the sealing gasket G1 and is welded to the beading portion 21. This increases the bonding strength of the welded portion and ensures surface adhesion even over long-term battery life, thereby minimizing safety issues such as cycle fading.

[0275] 8a to 10 are diagrams illustrating the welding area between the contact portion 33a and the beading portion 21. FIG.

[0276] 8a to 10, a weld bead BD may be formed in a welding region between the contact portion 33a and the beading portion 21. For example, as shown in FIG. 1a, if the upper surface and the lower surface of the beading portion 21 are each inclined at a predetermined angle with the lower surface of the battery housing 20, the contact portion 33a may be provided on the inclined upper surface of the beading portion 21. Alternatively, as shown in FIGS. 2 and 3, if the upper surface and the lower surface of the beading portion 21 each include a flat section F that is parallel to the lower surface of the battery housing 20 in at least a portion thereof, the contact portion 33a may be provided on the flat upper surface of the beading portion 21. Then, the contact portion 33a may be joined to the beading portion 21 by welding.

[0277] FIG. 11 is a diagram for explaining the position, length, width, etc. of weld bead BD formed in the welding region between contact portion 33a and beading portion 21. As shown in FIG.

[0278] Referring to FIG. 11, the contact portion 33a may be joined to the flat upper surface of the beading portion 21 by welding.

[0279] 8a to 10, when a plurality of weld beads BD are gathered together, a certain weld pattern may be formed. For example, referring to FIG. 8a, a plurality of weld beads BD may be gathered together to form a substantially linear weld pattern. For example, the weld pattern formed between the beading portion 21 and the contact portion 33a may have a line shape formed by connecting spot welds. The width of the weld bead BD formed between the beading portion 21 and the contact portion 33a may be approximately 0.1 mm or more. This is because, considering laser technology, the minimum width of the weld bead BD is approximately 0.1 mm or more.

[0280] At least one weld bead BD may be formed between the beading portion 21 and the contact portion 33a. For example, a plurality of weld beads BD may be formed between the beading portion 21 and the contact portion 33a along the circumferential direction. In particular, a plurality of weld beads BD may be formed within the same contact portion 33a. For example, the plurality of weld beads BD formed within the same contact portion 33a may be formed symmetrically within the same contact portion 33a. The plurality of weld beads BD formed within the same contact portion 33a may be spaced apart from one another by a predetermined angle, for example, 30°. Specifically, the plurality of weld beads BD formed within the same contact portion 33a may be positioned within a circumferential angle of 30° or less based on the center of the circle formed by the beading portion 21 within the same contact portion 33a.

[0281] The weld bead BD formed between the beading portion 21 and the contact portion 33a may form a linear weld pattern extending in the circumferential direction. Alternatively, the weld bead BD formed between the beading portion 21 and the contact portion 33a may form an arc-shaped weld pattern extending in the circumferential direction. According to an embodiment of the present invention, the circumferential length of the contact portion 33a may be the same as the circumferential length of the tab coupling portion 32. Furthermore, the circumferential length of the contact portion 33a may be the same as the circumferential length of the connecting portion 33b. For example, as shown in FIG. 4a, the tab coupling portion 32, the connecting portion 33b, and the contact portion 33a may extend with the same width. Preferably, the tab coupling portion 32, the connecting portion 33b, and the contact portion 33a may have the same width along the extension direction.

[0282] In another aspect, the extension direction of the weld pattern formed between the first uncoated portion 11 and the tab coupling portion 32 may be different from the extension direction of the weld pattern formed between the beading portion 21 and the contact portion 33a. Preferably, the extension direction of the weld pattern formed between the first uncoated portion 11 and the tab coupling portion 32 and the extension direction of the weld pattern formed between the beading portion 21 and the contact portion 33a may be approximately perpendicular to each other. Referring to FIGS. 8a and 8b, the weld pattern formed between the first uncoated portion 11 and the tab coupling portion 32 may be formed along the radial direction. Meanwhile, the weld pattern formed between the beading portion 21 and the contact portion 33a may be formed along the circumferential direction of the battery housing 20. That is, the extension direction of the weld pattern formed between the first uncoated portion 11 and the tab coupling portion 32 and the extension direction of the weld pattern formed between the beading portion 21 and the contact portion 33a may be approximately perpendicular to each other. This structure can increase the bonding strength between the current collector 30 and the electrode assembly 10. That is, this structure allows the current collector 30 to be fixed by welding in various directions, so that the current collector 30 can maintain a firmly fixed state even if it is subjected to vibration or impact in a specific direction.

[0283] According to another embodiment of the present invention, the circumferential length of the contact portion 33a may be relatively longer than the circumferential length of the tab coupling portion 32. Preferably, the circumferential length of the contact portion 33a may be relatively longer than the circumferential length of the connecting portion 33b. For example, referring to FIGS. 5 and 6, it can be seen that the circumferential length of the contact portion 33a is relatively longer than the circumferential length of the tab coupling portion 32. Also, referring to FIG. 5, it can be seen that the circumferential length of the contact portion 33a is relatively longer than the circumferential length of the connecting portion 33b. By increasing the circumferential length of the contact portion 33a, the bonding strength with the beading portion 21 of the current collector 30 can be improved. Consequently, by increasing the circumferential length of the contact portion 33a and / or the connecting portion 33b, the internal resistance of the battery can be reduced.

[0284] 5 and 6, the contact portion 33a may be arc-shaped and extend in a circumferential direction along the beading portion 21 of the battery housing. More specifically, the contact portion 33a may be arc-shaped and extend in opposite directions along the circumferential direction from the intersection of the connecting portion 33b and the contact portion 33a.

[0285] 6, the connecting portion 33b may also have an arc shape extending in the circumferential direction along the contact portion 33a. Since the contact portion 33a has an arc shape extending in the circumferential direction along the beading portion 21 of the battery housing, the bonding strength between the beading portion 21 and the current collector can be improved. More preferably, the sum of the lengths of the contact portions 33a extending in the circumferential direction can be configured to correspond to the length of the inner circumference of the battery housing. That is, although not shown, the current collector 30 may have a ring shape in which the contact portions 33a are interconnected. This shape can further improve the bonding strength between the beading portion 21 and the current collector 30.

[0286] FIG. 12 is a diagram for explaining the relationship between the diameter of the inner surface of the battery housing and the total diameter of the current collectors.

[0287] Referring to FIG. 12, when the diameter of the outer surface of the battery housing is De, the diameter of the inner surface of the battery housing 20 is Di, and the total diameter of the current collector 30 is d, the relationship De>Di>d can be satisfied.

[0288] Meanwhile, the cap 40 may include a vent portion 41 formed to prevent an increase in internal pressure due to gas generated inside the battery housing 20. The vent portion 41 is formed in a part of the cap 40 and is a region structurally weaker than the surrounding region so as to be easily broken when internal pressure is applied. The vent portion 41 may be, for example, a region thinner than the surrounding region.

[0289] The terminal 50 penetrates the battery housing 20 from the opposite side of the open portion thereof to be electrically connected to the second uncoated portion 12 of the electrode assembly 10. The terminal 50 may penetrate approximately the center of the bottom surface of the battery housing 20. The terminal 50 may be electrically connected to the electrode assembly 10 by, for example, connecting to a current collector (second current collector) P connected to the second uncoated portion 12 or connecting to a lead tab (not shown) connected to the second uncoated portion 12. As a result, the terminal 50 has the same polarity as the second electrode of the electrode assembly 10 and may function as a second electrode terminal T2. If the second uncoated portion 12 is a positive electrode tab, the terminal 50 may function as a positive electrode terminal. Preferably, the terminal 50 has a riveting structure. A battery employing the riveting structure of the terminal 50 can perform electrical wiring in one direction. Furthermore, the terminal 50 having a riveting structure has a large cross-sectional area and low resistance, making it highly suitable for fast charging.

[0290] 18a and 18b are diagrams illustrating a second current collector P according to an embodiment of the present invention.

[0291] 2 and 3, the second current collector P may be interposed between the second uncoated portion 12 and the terminal 50. Meanwhile, referring to FIGS. 18a and 18b, the second current collector P includes a tab coupling portion P1 coupled to the second uncoated portion 12 and a terminal coupling portion P2 coupled to the terminal 50. The second current collector P may further include a connecting portion P3 and / or an edge portion P4.

[0292] In one aspect of the present invention, a plurality of tab coupling portions P1 may be provided. Preferably, the plurality of tab coupling portions P1 may be arranged at equal intervals from one another. The extension lengths of the plurality of tab coupling portions P1 may be the same. The terminal coupling portion P2 may be arranged to be surrounded by the plurality of tab coupling portions P1.

[0293] Preferably, the terminal coupling portion P2 may be disposed at a position corresponding to a winding center hole H1 formed at the winding center of the electrode assembly 10. More preferably, the terminal coupling portion P2 may cover the winding center hole H1 of the electrode assembly 10. With this structure, the terminal 50 located above the winding center hole H1 of the electrode assembly 10 and the terminal coupling portion P2 may be coupled by welding.

[0294] The tab coupling portion P1 and the terminal coupling portion P2 may be spaced apart from each other without being directly connected. For example, the tab coupling portion P1 and the terminal coupling portion P2 may be indirectly connected by an edge portion P4. In this manner, the second current collector P according to an embodiment of the present invention has a structure in which the tab coupling portion P1 and the terminal coupling portion P2 are connected by the edge portion P4 rather than directly connected to each other. This can disperse impacts applied to the coupling portion between the tab coupling portion P1 and the second uncoated portion 12 and the coupling portion between the terminal coupling portion P2 and the terminal 50 when an impact and / or vibration occurs to the battery 1. This minimizes or prevents damage to welded portions due to external impacts. The second current collector P according to the present invention has a structure in which stress is concentrated at the coupling portion between the edge portion P4 and the terminal coupling portion P2 when an external impact is applied. However, because this coupling portion is not a portion where a weld is formed for connecting components, product defects due to damage to the weld due to external impacts can be prevented.

[0295] The second current collector P may further include a connecting portion P3 connected to the terminal connecting portion P2. At least a portion of the connecting portion P3 may be formed with a width smaller than that of the tab connecting portion P1. In this case, the electrical resistance of the connecting portion P3 increases, and when current flows through the connecting portion P3, a greater resistance occurs than in other portions. As a result, when an overcurrent occurs, a portion of the connecting portion P3 breaks, thereby interrupting the overcurrent. The width of the connecting portion P3 may be adjusted to an appropriate level in consideration of this overcurrent interruption function.

[0296] The second current collector P may further include an edge P4 having a generally rim-like shape with a space formed inside. In this case, the tab coupling portion P1 may extend inward from the edge P4 and couple with the second uncoated portion 12. While the drawings of the present invention only show the edge P4 having a generally circular rim shape, the present invention is not limited thereto. The edge P4 may have a generally square rim shape or other shapes, different from those shown in the drawings.

[0297] In another aspect of the present invention, referring to FIG. 18b, the connecting portion P3 may include a notch N formed to partially reduce the width of the connecting portion P3. When the notch N is provided, electrical resistance increases in the region where the notch N is formed, thereby enabling rapid current interruption when an overcurrent occurs. Preferably, the position of the notch N may be included in the uniform lamination number section (FIG. 1d). More preferably, the position of the notch N may be included in the section where the maximum number of laminations is maintained within the uniform lamination number section. This reliably prevents by-products generated when the notch N is broken from penetrating into the electrode assembly.

[0298] 18a and 18b, referring to FIGS. 2 and 3, in one aspect of the present invention, the longest radius from the center of the terminal coupling portion P2 of the second current collector P to the end of the tab coupling portion P1 may be larger than the longest radius from the center of the current collector 30 to the end of the tab coupling portion 32. For example, the radius of the edge portion P4, which is approximately rim-shaped, may be larger than the longest radius from the center of the current collector 30 to the end of the tab coupling portion 32. This is because the welding area between the tab coupling portion 32 of the current collector 30 and the first uncoated portion 11 is limited by the beading portion 21 being press-fitted into the battery housing 20.

[0299] In another aspect of the present invention, the tab connection portion P1 of the second current collector P may be connected to the bent end of the second uncoated portion 12. That is, the tab connection portion P1 of the second current collector P may be connected to the bent surface of the bent segments of the second uncoated portion 12 by welding. Preferably, the welded region overlaps the uniform lamination number section (FIG. 1d) by at least 50% along the radial direction, with the larger the overlap ratio, the more desirable. More preferably, the welded region overlaps the section with the largest overlap number in the uniform lamination number section along the radial direction by at least 50% along the radial direction, with the larger the overlap ratio, the more desirable. These welding conditions are substantially similarly applicable to the current collector 30.

[0300] In yet another aspect of the present invention, a welding region is further formed to connect the tab coupling portion P1 of the second current collector P and the bent end portion of the second uncoated portion 12, and the distance from the center of the terminal coupling portion P2 of the second current collector P to the welding region may be the same as the distance from the center of the current collector 30 to the welding region of the tab coupling portion 32, or may have a distance deviation of about 5% or less. In yet another aspect of the present invention, the welding region of the second current collector P may have a length longer than the welding region of the tab coupling portion 32 of the current collector 30.

[0301] In one example, when the flat portion of the terminal 50 (see FIG. 1a) and the second current collector P are welded by laser in a continuous or discontinuous line in the form of an arc pattern, the diameter of the arc weld pattern is 2 mm or more, preferably 4 mm or more. When the diameter of the arc weld pattern satisfies this condition, the tensile force of the weld is 2 kgf. (20N) By increasing the above, sufficient welding strength can be ensured.

[0302] In another example, when the flat portion of the terminal 50 and the second current collector P are ultrasonically welded to form a circular pattern, the diameter of the circular weld pattern is preferably 2 mm or more. If the diameter of the circular weld pattern satisfies this condition, the tensile force of the welded portion is 2 kgf. (20N) By increasing the above, sufficient welding strength can be ensured.

[0303] The diameter of the flat portion of the terminal 50, which is the weldable area, can be adjusted within a range of 3 mm to 14 mm. If the radius of the flat portion of the terminal 50 is smaller than 3 mm, it is difficult to form a welding pattern with a diameter of 2 mm or more using a laser welding tool, ultrasonic welding tool, etc. Also, if the radius of the flat portion of the terminal 50 exceeds 14 mm, the size of the terminal 50 is too large, reducing the area occupied by the outer surface of the bottom of the battery housing 20, making it difficult to connect an electrical connection component (bus bar) through the outer surface.

[0304] Preferably, the tensile strength of the weld is 2 kgf. (20N)The diameter of the welding pattern to ensure this is 2 mm or more, and the diameter of the weldable area is 3 mm to 14 mm. Therefore, the ratio of the area of ​​the welding pattern to the area of ​​the weldable area is 2.04 (100 × π1 2 / π7 2 )%~44.4(100×π1 2 / π1.5 2 )%.

[0305] Considering the polarity and function of the terminal 50, the terminal 50 must maintain an insulated state from the battery housing 20, which has the opposite polarity. For this purpose, an insulating gasket G2 may be applied between the terminal 50 and the battery housing 20. Alternatively, insulation may be achieved by coating part of the surface of the terminal 50 with an insulating material.

[0306] For the same reason, the second uncoated portion 12 and / or the current collector (second current collector) P must be insulated from the battery housing 20. For this reason, an insulator S may be interposed between the second uncoated portion 12 and the battery housing 20 and / or between the current collector (second current collector) P and the battery housing 20. When the insulator S is used, the terminal 50 may penetrate the insulator S for electrical connection with the second uncoated portion 12.

[0307] Preferably, the insulator S and the inner bottom surface of the battery housing 20 are in close contact with each other. Here, "close contact" means that there is no space (gap) that can be visually confirmed. To eliminate the space (gap), the distance from the inner bottom surface of the battery housing 20 to the flat portion of the terminal 50 may be the same as the thickness of the insulator S or slightly smaller than that.

[0308] Meanwhile, in the present invention, the entire surface of the battery housing 20 can function as the first electrode terminal T1. For example, if the first uncoated portion 11 is a negative electrode tab, the first electrode terminal T1 can be a negative electrode terminal. The battery 1 according to the present invention has a structure in which the terminal 50 exposed on the bottom surface opposite the opening of the battery housing 20 and the remaining area on the bottom surface of the battery housing 20 excluding the area occupied by the terminal 50 can be used as the second electrode terminal T2 and the first electrode terminal T1, respectively. As a result, the battery 1 according to the present invention can connect the positive and negative electrodes in one direction when electrically connecting multiple batteries 1, thereby simplifying the electrical connection structure. Furthermore, the battery 1 according to the present invention has a structure in which most of the bottom surface opposite the opening of the battery housing 20 can be used as an electrode terminal, which has the advantage of ensuring a sufficient area for welding components for electrical connection.

[0309] In yet another aspect, the electrodes constituting the electrode assembly 10 may have a segmented structure to facilitate bending of the uncoated portion 11 .

[0310] Referring to FIG. 14, the electrode plate includes a sheet-shaped first electrode collector made of a conductive foil, an active material layer formed on at least one surface of the first electrode collector, and a first uncoated portion 11 at the end of a long side of the first electrode where the active material is not coated.

[0311] Preferably, the first non-coating portion 11 may include a plurality of segment pieces 11a that have been cut. The segment pieces 11a are arranged in a plurality of groups, and the segment pieces 11a in each group may have the same height (length in the Y direction) and / or width (length in the X direction) and / or spacing pitch. The number of segment pieces 11a in each group may be greater or less than that shown in the figure. The segment pieces 11a have a geometric shape that combines at least one straight line and / or at least one curved line. Preferably, the segment pieces 11a may be trapezoidal, and may be modified into any shape, such as a rectangle, a balanced quadrilateral, a semicircle, or an inverse ellipse.

[0312] Preferably, the height of the segment pieces 11a may increase stepwise along a direction parallel to the winding direction of the electrode assembly, for example, from the core side to the outer periphery side. Furthermore, the core-side uncoated portion 11' adjacent to the core side may not include segment pieces 11a, and the height of the core-side uncoated portion 11' may be smaller than the other uncoated portions. Furthermore, the outer periphery-side uncoated portion 11" adjacent to the outer periphery may not include segment pieces 11a, and the height of the outer periphery-side uncoated portion 11" may be smaller than the other uncoated portions.

[0313] Optionally, the electrode plate may include an insulating coating layer 11b covering the boundary between the active material layer and the first non-coated portion 11. The insulating coating layer 11b includes an insulating polymer resin and may optionally further include an inorganic filler. The insulating coating layer 11b prevents the end of the active material layer from contacting the active material layer of the opposite polarity that faces the separator, and serves to structurally support the bending of the segment piece 11a. For this reason, it is preferable that at least a portion of the insulating coating layer 11b be exposed to the outside from the separator when the electrode plate is wound into the electrode assembly 10.

[0314] FIG. 15 is a cross-sectional view taken along the longitudinal direction Y of an electrode assembly 10 in which the segmented structure of the uncoated portion of the electrode plate according to an embodiment of the present invention is applied to the first electrode current collector and the second electrode current collector.

[0315] 15, the electrode assembly 10 may be manufactured by a winding method. The second uncoated portion 12 protruding from the bottom extends from the second electrode current collector, and the first uncoated portion 11 protruding from the top extends from the first electrode current collector.

[0316] The varying heights of the uncoated portions 11, 12 are shown schematically. That is, the heights of the uncoated portions 11, 12 may vary irregularly depending on where the cross section is cut. For example, if the side portions of the trapezoidal segment 11a are cut, the height of the uncoated portions in the cross section will be lower than the height of the segment 11a. Therefore, it should be understood that the height of the uncoated portions 11, 12 in the cross-sectional view of the electrode assembly 10 corresponds to the average height of the uncoated portions included in each winding turn.

[0317] The uncoated portions 11 and 12 can be bent along the radial direction of the electrode assembly 10, for example, from the outer periphery to the core, as shown in Figures 16a and 16b. In Figure 15, the bent portion 101 is indicated by a dotted box. When the uncoated portions 11 and 12 are bent, adjacent segments 11a in the radial direction overlap each other, forming bent surfaces 102 at the top and bottom of the electrode assembly 10. The uncoated portion on the core side (11' in Figure 14) is too short to bend, and the height h of the innermost bent segment 11a is equal to or smaller than the radial length r of the winding region formed by the uncoated portion 11' on the core side that does not have a segment 11a structure. This prevents the bent segment 11a from closing the winding center hole H1 in the core of the electrode assembly 10. If the winding center hole H1 is not blocked, the electrolyte injection process is easy and the efficiency of electrolyte injection is improved. Also, a welding tool can be inserted through the winding center hole H1 to easily weld the terminal 50 and the second current collector P.

[0318] FIG. 17 is a diagram showing a state in which the battery 1 according to the embodiment of the present invention is electrically connected using a bus bar 150.

[0319] 17, multiple batteries 1 can be connected in series and parallel at the top using bus bars 150. The number of batteries 1 can be increased or decreased depending on the capacity of the battery pack 3.

[0320] In each battery 1, the terminal 50 may have a positive polarity and the bottom exterior surface of the battery housing 20 may have a negative polarity, or vice versa.

[0321] Preferably, the batteries 1 may be arranged in a plurality of rows and columns. The columns are arranged vertically relative to the ground, and the rows are arranged horizontally relative to the ground. To maximize space efficiency, the batteries 1 may be arranged in the closest packing structure. The closest packing structure is formed when the centers of the terminals 50 are connected to each other to form an equilateral triangle.

[0322] Preferably, the bus bars 150 may be disposed on top of adjacent batteries 1, preferably between the terminals 50. In one example, the bus bars 150 may be disposed between adjacent columns. Alternatively, the bus bars 150 may be disposed between adjacent rows.

[0323] Preferably, the bus bars 150 connect the batteries arranged in the same row in parallel with each other, and connect the cylindrical batteries arranged in two adjacent rows in series with each other.

[0324] Desirably, bus bar 150 may include a body portion 151, a plurality of first bus bar terminals 152, and a plurality of second bus bar terminals 153 for series and parallel connections.

[0325] The main body portion 151 may extend along the row of batteries 1. Alternatively, the main body portion 151 may extend along the row of batteries 1 but be bent regularly, such as in a zigzag shape.

[0326] The plurality of first bus bar terminals 152 may protrude from one side of the body 151 toward the terminals 50 of each battery 1 and be electrically coupled to the terminals 50. The electrical coupling to the terminals 50 may be performed by laser welding, ultrasonic welding, etc. The plurality of second bus bar terminals 153 may protrude from the other side of the body 151 toward the outer surface of the bottom of the battery housing 20 of each battery 1 and be electrically coupled to the outer surface. The electrical coupling to the outer surface may be performed by laser welding, ultrasonic welding, etc.

[0327] Preferably, the main body 151, the plurality of first bus bar terminals 152, and the plurality of second bus bar terminals 153 may be formed from a single conductive metal plate. The metal plate may be an aluminum plate or a copper plate, but the present invention is not limited thereto. In a modified example, the main body 151, the plurality of first bus bar terminals 152, and the plurality of second bus bar terminals 153 may be manufactured as individual units and then joined together by welding or the like.

[0328] In the battery 1 according to the present invention, the terminal 50 having the positive polarity and the outer surface of the bottom of the battery housing 20 having the negative polarity are positioned in the same direction, so that electrical connection of the battery 1 can be easily realized using the bus bar 150.

[0329] Furthermore, since the terminal 50 and the outer surface of the battery 1 have a large area, the connection area of ​​the bus bar 150 can be sufficiently secured, and the resistance of the battery pack including the battery 1 can be sufficiently reduced.

[0330] Meanwhile, as described above, the battery 1 of the present invention has a structure in which resistance is minimized by increasing the contact area between components, multiplexing current paths, minimizing the length of the current paths, etc. After the product is completed, the AC resistance of the battery 1 measured with a resistance meter between the positive and negative electrodes, i.e., between the top surface of the terminal 50 and the outer surface of the closed portion of the battery housing 20, can be 0.5 mΩ to 4 mΩ, and preferably 1 mΩ to 4 mΩ, which is suitable for fast charging.

[0331] In the present invention, the battery may be, for example, a battery having a form factor ratio (defined as the value obtained by dividing the diameter of the battery by the height, i.e., the ratio of the diameter Φ to the height H) of greater than about 0.4. Here, the form factor refers to a value indicating the diameter and height of the battery.

[0332] Preferably, the cylindrical battery has a diameter of 40mm to 50mm and a height of 60mm to 130mm. According to one embodiment, the cylindrical battery 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, and the next two digits indicate the height of the battery.

[0333] Recently, as batteries are applied to electric vehicles, the form factor of the battery is increasing beyond the conventional 1865, 2170, etc. The increase in form factor brings about an increase in energy density, increased safety against thermal runaway, and improved cooling efficiency.

[0334] The energy density of a battery can be further increased by minimizing wasted space inside the battery housing as the form factor increases. The battery according to the present invention has an optimal structure that can improve the bonding strength between the current collector and the battery housing, and can reduce resistance while increasing the battery capacity.

[0335] A 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.

[0336] Another example 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.

[0337] 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 0.436.

[0338] 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.

[0339] 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.

[0340] Batteries with a form factor ratio of approximately 0.4 or less have been used in the past. For example, 1865 batteries and 2170 batteries have been used. The 1865 battery has a diameter of approximately 18 mm and a height of approximately 65 mm, resulting in a form factor ratio of approximately 0.277. The 2170 battery has a diameter of approximately 21 mm and a height of approximately 70 mm, resulting in a form factor ratio of approximately 0.300.

[0341] A battery according to an embodiment of the present invention may be included in a battery pack, and the battery pack may be mounted in a vehicle. Referring to Fig. 19, a battery pack 3 according to an embodiment of the present invention includes a secondary cell assembly in which a plurality of batteries 1 according to an embodiment of the present invention are electrically connected, and a pack housing 2 that accommodates the secondary cell assembly. For ease of illustration, components such as bus bars for electrical connections, a cooling unit, and power terminals are omitted from the drawings of the present invention.

[0342] 20, a vehicle 5 according to an embodiment of the present invention may be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle, and includes a battery pack 3 according to an embodiment of the present invention. The vehicle 5 operates by receiving power from the battery pack 3 according to an embodiment of the present invention.

[0343] 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 skilled in the art within the scope of the technical concept of the present invention and the scope of the claims. [Explanation of symbols]

[0344] 1 battery 2-pack housing 3 Battery Pack 5. Automobiles 10 Electrode assembly 11 First Uncoated Section 11a segmental piece 12 Second uncoated section 101 Bendable Part 102 Bending Surface H1 Winding center hole 20 Battery Housing 21 Beading section 22 Crimping section 30 Current collector (first current collector) H2 collector hole 31 Center 32 Tab joint 33 Housing joint 33a Contact part 33b Connection part 40 Cap 41 Vent G1 sealing gasket 50 terminals G2 Insulation Gasket T1 1st electrode terminal T2 2nd electrode terminal P current collector (second current collector) P1 tab joint P2 terminal connection part P3 connection part P4 Edge S insulator F Flat section BD Weld Bead PD Press-in depth OV Overlap length

Claims

1. an electrode assembly in which a core and an outer circumferential surface are defined by winding a first electrode, a second electrode, and a separator interposed therebetween around a winding shaft, wherein the first electrode includes an active material portion coated with an active material layer along the winding direction and a first uncoated portion not coated with the active material layer, at least a portion of the first uncoated portion being used as an electrode tab by itself; and the second electrode includes a second uncoated portion at an end of a long side of the electrode that is not coated with the active material layer and is exposed to the outside of the separator, at least a portion of the second uncoated portion being used as an electrode tab by itself; a battery housing that receives the electrode assembly through an opening formed on one side thereof, the battery housing being electrically connected to the first uncoated portion; a current collector including a tab connecting portion that connects with the first uncoated portion and a housing connecting portion that extends from the tab connecting portion and electrically connects with an inner surface of the battery housing; a cap for covering the opening; a terminal provided on the opposite side of the open portion and electrically connected to the second uncoated portion; Including, The battery housing includes: The battery comprises a beading portion formed at an end adjacent to the open portion and pressed inward.

2. The battery housing includes: The battery according to claim 1 , further comprising a crimping portion formed on a side closer to the opening than the beading portion, and extending and bending toward the opening.

3. The housing coupling portion is The battery according to claim 2 , wherein the battery is pressed and fixed by the crimping portion.

4. The housing coupling portion is a contact portion coupled to the beading portion of the battery housing; The battery of claim 1 , further comprising a connecting portion connecting the tab connecting portion and the contact portion.

5. The connecting portion is The battery according to claim 4 , wherein the battery has a structure that bulges upward from an imaginary line connecting one end of the contact portion and one end of the tab connecting portion.

6. The connecting portion is The battery according to claim 4 or 5, having a structure that protrudes above the beading portion.

7. The connecting portion is The battery of claim 5 comprising at least one bend.

8. The bent portion is 8. The battery according to claim 7, wherein the contact portion is positioned above an imaginary plane that passes through the center of an imaginary line connecting one end of the contact portion and one end of the tab connecting portion and is parallel to the bottom surface of the battery housing.

9. The at least one bent portion is 8. The battery of claim 7, wherein the battery housing is bent at an obtuse angle to prevent stacking when viewed along the longitudinal axis of the battery housing.

10. The battery according to claim 7 , wherein a boundary point between the contact portion and the connecting portion is bent at an obtuse angle.

11. The connecting portion is The battery according to claim 9 , wherein the slope of the connecting portion decreases stepwise or gradually toward the beading portion.

12. The battery according to any one of claims 4 to 11, wherein an angle formed between the tab connection portion and the connecting portion is 0 to 90 degrees.

13. The battery of claim 4 , wherein the coupling portion supports the cap.

14. The battery of claim 4 , wherein the tab bond portion and the contact portion are located at the same height.

15. The contact portion is 15. The battery of claim 4, further comprising a flat surface that mates with an upper surface of the beading portion toward the opening.

16. The beading portion is an upper surface of the beading portion located above the innermost point recessed by press-fitting; The battery according to claim 4 , further comprising: a lower surface of the beading portion positioned below the innermost point recessed by the press fit.

17. At least one of the tab connections of the current collector is The battery of claim 16 , located below the lower surface of the beading portion.

18. At least one of the upper surface of the beading portion and the lower surface of the beading portion is 17. The battery of claim 16, wherein the battery is inclined at an angle to the underside of the battery housing.

19. The contact portion is 19. The battery of claim 18, wherein the beading portion is provided on an inclined upper surface.

20. At least one of the upper surface of the beading portion and the lower surface of the beading portion is 17. The battery of claim 16, wherein the battery is parallel to the bottom surface of the battery housing in at least some areas.

21. The upper surface of the beading portion and the lower surface of the beading portion are 17. The battery of claim 16, wherein the innermost point of the beading portion is asymmetric with respect to an imaginary reference plane passing through the innermost point of the beading portion parallel to the bottom surface of the battery housing.

22. The contact portion is 21. The battery of claim 20, wherein the beading is provided on a flat upper surface.

23. The press-fit depth of the beading portion is PD, The minimum value of the radius of curvature of the beading portion is R １，ｍｉｎ year, The minimum weld bead width is W ｂｅａｄ，ｍｉｎ year, The minimum value of the radius of curvature in the boundary region between the beading portion and the inner surface of the battery housing is R ２，ｍｉｎ When PD≧R １，ｍｉｎ +R ２，ｍｉｎ +W ｂｅａｄ，ｍｉｎ 23. The battery of claim 1, wherein

24. The battery according to any one of claims 1 to 23, wherein the press-fit depth of the beading portion is 0.2 to 10 mm.

25. The press-fit depth of the beading portion is defined as PD, and the maximum value of the press-fit depth is PD ｍａｘ year, An overlap length, which is the shortest distance from the end of the contact portion to a vertical line passing through the innermost point of the beading portion, is defined as OV, The minimum value of the radius of curvature of the beading portion is R １，ｍｉｎ year, The minimum weld bead width is W ｂｅａｄ，ｍｉｎ year, The minimum value of the radius of curvature in the boundary region between the beading portion and the inner surface of the battery housing is R ２，ｍｉｎ When (R １，ｍｉｎ +W ｂｅａｄ，ｍｉｎ ) / PD ｍａｘ ≦OV / PD≦(PD ｍａｘ -R ２，ｍｉｎ ) / PD ｍａｘ The battery of claim 4 , wherein

26. The battery of claim 4 , wherein the contact portion is coupled to the beading portion by welding.

27. 21. The battery of claim 20, wherein the contact portion is coupled to the flat upper surface of the beading portion by welding.

28. The welding area between the contact portion and the beading portion is 28. The battery of claim 27, wherein the beading portion is narrower than the flat upper surface.

29. The press-fit depth of the beading portion is defined as PD, and the maximum value of the press-fit depth is PD ｍａｘ year, The distance from the innermost point of the beading portion to the center point of the outermost weld bead in the radial direction is defined as W, The overlap length, which is the shortest distance from the end of the contact portion to the vertical line passing through the innermost point of the beading portion, is defined as OV, and the minimum value of OV is OV. ｍｉｎ The maximum value of OV is OV ｍａｘ year, The minimum weld bead width is W ｂｅａｄ，ｍｉｎ When (OV ｍｉｎ -0.5 x W ｂｅａｄ，ｍｉｎ ) / PD ｍａｘ ≦W / PD≦(OV ｍａｘ -0.5 x W ｂｅａｄ，ｍｉｎ ) / PD ｍａｘ The battery of claim 4 , wherein

30. At least one weld bead is formed between the beading portion and the contact portion, 28. The battery of claim 27, wherein the at least one weld bead forms a linear weld pattern extending along a circumferential direction.

31. At least one weld bead is formed between the beading portion and the contact portion, 28. The battery of claim 27, wherein the at least one weld bead forms an arcuate weld pattern extending along a circumferential direction.

32. a weld bead formed between the beading portion and the contact portion to form a weld pattern; 28. The battery of claim 27, wherein the weld pattern is a line of connected spot welds.

33. The battery according to claim 27 , wherein a plurality of weld beads are formed between the beading portion and the contact portion within the same contact portion.

34. 28. The battery of claim 27, wherein a width of a weld bead formed between the beading portion and the contact portion is 0.1 mm or more.

35. The battery according to claim 30 , wherein the first uncoated portion and the tab connecting portion are connected by welding along the radial direction of the electrode assembly.

36. The tab connection portion is 36. The battery of claim 1, wherein the first uncoated portion is connected by welding in a state parallel to the lower surface of the battery housing.

37. The plurality of weld beads formed between the first uncoated portion and the tab connecting portion include:

36. The battery of claim 35, wherein a linear weld pattern is formed extending along a radial direction of the electrode assembly.

38. a weld bead formed between the first uncoated portion and the tab connecting portion forms a weld pattern; 36. The battery of claim 35, wherein the weld pattern is characterized by a line of interlocking spot welds.

39. 36. The battery of claim 35, wherein a width of a weld bead formed between the first uncoated portion and the tab connection portion is 0.1 mm or more.

40. At least a portion of the first uncoated portion includes a plurality of segment pieces separated along a winding direction of the electrode assembly, 40. The battery of claim 1, wherein the plurality of segment pieces are bent along a radial direction of the electrode assembly to form a bent surface.

41. The plurality of segment pieces are The electrode assembly is overlapped in multiple layers along a radial direction to form the curved surface, 41. The battery of claim 40, wherein the curved surface includes: an increasing lamination number section in which the number of overlaps of the segment pieces gradually increases to a maximum value as the curved surface progresses from the outer periphery side of the electrode assembly toward the core side; and a uniform lamination number section from the radius point where the number of overlaps reaches the maximum value to the radius point where the innermost segment piece is present.

42. The tab connection portion is The battery of claim 41 , wherein the battery is bonded to the curved surface so as to overlap the uniform lamination section.

43. The battery according to claim 42, wherein the number of overlaps in the uniform stacking section is 10 or more.

44. 44. The battery of claim 43, wherein the tab joint is welded to the bent surface, and the welded area of ​​the tab joint overlaps the uniform stacking number section by at least 50% along the radial direction of the electrode assembly.

45. The current collector is 45. The battery of claim 1, wherein the current collector comprises a circular current collector hole in the center thereof.

46. The diameter of the current collector hole is 46. ​​The battery of claim 45, wherein the diameter is greater than or equal to the diameter of the winding center hole provided in the core of the electrode assembly.

47. The battery 5. The battery of claim 4, including a sealing gasket disposed between the battery housing and the cap.

48. The contact portion is 48. The battery of claim 47, interposed between the sealing gasket and the beading portion.

49. The thickness of the sealing gasket is:

48. The battery of claim 47, wherein the resistance is variable along the circumferential direction.

50. The thickness of the sealing gasket is:

48. The battery of claim 47, wherein the alternating increases and decreases occur along the circumferential direction.

51. The sealing gasket is 50. The battery of claim 49, wherein the compressibility is the same in the area in contact with the contact portion and in the area not in contact with the contact portion.

52. The sealing gasket is 50. The battery of claim 49, having a lower compressibility in areas not in contact with the contacts than in areas in contact with the contacts.

53. The sealing gasket is 48. The battery of claim 47, having a greater thickness in areas not in contact with the contacts than in areas in contact with the contacts.

54. The current collector is 54. The battery of claim 1, wherein the tab connection portion and the housing connection portion have a leg structure extending radially in a state where they are interconnected.

55. 55. The battery of claim 54, wherein the leg structures are provided in plurality.

56. The leg structure includes:

55. The battery of claim 54, wherein the current collectors are arranged in a radial, cross, or combination thereof pattern with respect to the center of the current collector.

57. A plurality of the housing coupling portions are provided, 56. The battery of claim 55, wherein a plurality of the housing joints are interconnected and integrally formed.

58. The connecting portion is The battery according to claim 4 , comprising at least one bent portion where the extension direction is changed at least once.

59. The outermost protruding point of the bent portion is 59. The battery of claim 58, spaced apart from the innermost point of the beading portion by a predetermined distance.

60. 59. The battery of claim 58, wherein the bent portion forms an acute angle between the contact portion and the connecting portion.

61. The connecting portion is 59. The battery of claim 58, wherein the battery is resiliently biased upward by the bent portion.

62. The circumferential length of the contact portion is The battery of claim 4 , wherein the length of the tab connection is the same as the circumferential length of the tab connection.

63. The circumferential length of the contact portion is The battery according to claim 4 , wherein the length of the connecting portion in the circumferential direction is the same as that of the connecting portion.

64. The circumferential length of the contact portion is The battery of claim 4 , wherein the length of the tab connection is relatively longer than the circumferential length of the tab connection.

65. The circumferential length of the contact portion is The battery according to claim 4 , wherein the length of the connecting portion is relatively longer than the circumferential length of the connecting portion.

66. The contact portion is 5. The battery of claim 4, wherein the beading portion of the battery housing has an arcuate shape extending circumferentially along the beading portion.

67. The contact portion is The battery according to claim 4 , wherein the connecting portion and the contact portion are arc-shaped and extend in opposite directions along the circumferential direction from an intersection point of the connecting portion and the contact portion.

68. The sum of the lengths of the contact portions extending in the circumferential direction is 67. The battery of claim 66, corresponding to the length of the inner circumference of the battery housing.

69. The connecting portion is 67. The battery of claim 66, wherein the contact is arcuate and extends circumferentially along the contact.

70. The boundary area between the tab connection portion and the housing connection portion is The battery according to claim 1 , wherein an end of the housing joint portion is bent toward the beading portion.

71. The battery according to claim 4 , wherein a connecting portion between the contact portion and the connecting portion is bent.

72. The connecting portion between the contact portion and the connecting portion is 5. The battery of claim 4, having a complementary shape that corresponds to the inner surface of the beading portion.

73. The connecting portion between the contact portion and the connecting portion is The battery according to claim 4 , wherein the beading portion is coupled to the beading portion in a shape corresponding to the inner surface of the beading portion.

74. The boundary area between the tab connection portion and the housing connection portion is 74. The battery of any one of claims 1 to 73, located inside the innermost point of a beading portion formed in the battery housing.

75. When viewed along the longitudinal axis of the battery housing: The battery of claim 1 , wherein the tab bond is not overlapped by the beading.

76. formed between the second uncoated portion and the terminal, a tab connecting portion connected to the second uncoated portion; 10. The battery of claim 1, further comprising a second current collector having a terminal mating portion mating with the terminal.

77. The terminal coupling portion is 77. The battery of claim 76, covering the winding center hole of the electrode assembly.

78. The longest radius from the center of the terminal coupling portion of the second current collector to the end of the tab coupling portion is 78. The battery of claim 77, wherein the diameter is greater than the longest radius from the center of the current collector to the end of the tab bond.

79. The tab connection portion of the second current collector is 77. The battery of claim 76, wherein the second uncoated portion is bonded to a bent end.

80. a welding region is further formed to connect the tab connection portion of the second current collector and the bent end portion of the second uncoated portion; 80. The battery of claim 79, wherein the distance from the center of the terminal bond of the second current collector to the welded area is the same as the distance from the center of the current collector to the welded area of ​​the tab bond or has a distance deviation of 5% or less.

81. The welding area of ​​the second current collector is 81. The battery of claim 80, wherein the current collector has a length greater than a welded area of ​​the tab bond.

82. 82. The battery of any one of claims 1 to 81, wherein the tab bond has one or more holes formed therein for injection of electrolyte.

83. 83. The battery of any one of claims 1 to 82, wherein the form factor ratio of the battery's diameter divided by its height is greater than 0.

4.

84. 84. The battery of any one of claims 1 to 83, wherein the resistance measured between the positive and negative electrodes is 4 mΩ or less.

85. an electrode assembly having a structure in which sheet-like first and second electrodes and a separator interposed therebetween are wound in one direction, wherein the first electrode includes a first uncoated portion at an end of a long side thereof that is not coated with an active material layer and is exposed to the outside of the separator, and at least a portion of the first uncoated portion is used as an electrode tab by itself; a battery housing that receives the electrode assembly through an opening formed on one side thereof; a current collector electrically coupled to the first uncoated portion and the inner surface of the battery housing; a sealing gasket interposed between the opening of the battery housing and the current collector; a portion of the current collector that contacts the inner surface of the battery housing is interposed between the inner surface of the battery housing and the sealing gasket.

86. The battery housing includes:

86. The battery of claim 85, further comprising a beading portion formed at an end adjacent the opening and pressed inward.

87. 38. The battery of claim 37, wherein an extension direction of a welding pattern formed between the first uncoated portion and the tab connecting portion and an extension direction of a welding pattern formed between the beading portion and the contact portion are perpendicular to each other.

88. The innermost point of the beading portion is The battery of claim 2 , wherein the crimping portion is located radially inward from an end point of the crimping portion.

89. the sealing gasket surrounds the cap; 48. The battery of claim 47, wherein the radial length of the portion of the sealing gasket that covers the lower surface of the cap is smaller than the radial length of the portion of the sealing gasket that covers the upper surface of the cap.

90. The total length of the tab connection portion in the radial direction is T, The outer diameter of the electrode assembly is defined as JR, When the height of the segment piece arranged at the outermost periphery of the electrode assembly is F, JR-2×F≦T<JR 41. The battery of claim 40, wherein

91. The minimum value of the distance from the innermost point of the beading portion to the center point of the outermost weld bead in the radial direction is defined as W1, When the overlap length is OV, the distance from the innermost point of the beading portion to the center point of the outermost weld bead in the radial direction is defined as W. W1=R1+0.5×W ｂｅａｄ，ｍｉｎ W=OV-0.5×W ｂｅａｄ，ｍｉｎ 30. The battery of claim 29, wherein

92. The beading portion has a flat section parallel to the lower surface of the battery housing in at least a partial area, The length of the flat section of the beading portion that contacts the current collector is The overlap length is OV, When the radius of curvature of the beading portion is R1, 30. The battery of claim 29, which is OV-R1.

93. The radial width of the weld pattern formed between the beading portion and the contact portion is W ｂｅａｄ，ｍｉｎ The battery of claim 92, wherein the OV-R1 is equal to or greater than OV-R1.

94. 94. The battery of claim 93, wherein a ratio of a width length in the radial direction of the welding pattern to a length of the flat section satisfies a range of 10 to 40%.

95. 95. The battery of claim 1, wherein the ratio of an area of ​​the 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 is 30% or more and less than 100%.

96. 95. The battery of claim 1, wherein the ratio of the area of ​​the current collector that is not in contact with the electrode assembly to the area of ​​a circle having the outer diameter of the electrode assembly as a diameter is 60% or more and less than 100%.

97. 47. The battery of claim 46, wherein the diameter of the current collector hole is smaller than the diameter of a winding center hole provided in the core of the electrode assembly.

98. When the diameter of the winding center hole is R3, 98. The battery of claim 97, wherein the diameter of the current collector hole is greater than or equal to 0.5 x R3 and less than R3.

99. When the diameter of the winding center hole is R3, 98. The battery of claim 97, wherein the diameter of the current collector hole is greater than or equal to 0.7 x R3 and less than R3.

100. The battery of claim 4 , wherein the connecting portion extends in the radial direction and in the winding axis direction.

101. The battery according to claim 4 , wherein the tab connection portion, the connecting portion, and the contact portion have the same width along the extension direction.

102. The battery of claim 4 , wherein the contact portion has a width greater than that of the coupling portion.

103. The battery of claim 4 , wherein the connecting portion has a width smaller than that of the tab bond portion.

104. The battery of claim 4 , wherein the connecting portion has a width greater than the tab bond portion.

105. 105. A battery pack comprising the battery of any one of claims 1 to 104.

106. The plurality of batteries are arranged in a predetermined number of rows; 106. The battery pack of claim 105, wherein the terminals of each battery and the outer surface of the bottom of the battery housing are arranged facing upward.

107. a plurality of bus bars connecting the plurality of batteries in series and in parallel; Each bus bar is positioned above the adjacent battery; Each of the bus bars is a body portion extending between adjacent terminals; a plurality of first bus bar terminals extending to one side of the body and electrically coupled to electrode terminals of the battery located on the one side; and a plurality of second bus bar terminals extending to the other side of the main body and electrically coupled to the outer surface of the bottom of the battery housing of the battery located on the other side.

108. 108. A motor vehicle comprising a battery pack according to any one of claims 105 to 107.

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